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Sample records for bl-3050 highly stable

  1. France: High and stable fertility

    Directory of Open Access Journals (Sweden)

    Clémentine Rossier

    2008-07-01

    Full Text Available The current total fertility rate in France is around 1.9 children per woman. This is a relatively high level by current European standards and makes France an outlier, despite the fact that its other demographic trends, especially conjugal behaviour, and social and economic trends are not very different from other Western European countries. France can serve as a counterfactual test case for some of the hypotheses advanced to explain the current low level of fertility in most European countries (delay in fertility, decline in marriage, increased birth control, greater economic uncertainty. France's fertility level can be partly explained by its active family policy introduced after the Second World War, and adapted in the 1980s to accommodate women's entry into the labour force. This policy is the result of a battle, fuelled by pro-natalism, between the conservative supporters of family values and the promoters of state-supported individual equality. French family policy thus encompasses a wide range of measures based on varying ideological backgrounds, and it is difficult to classify in comparison to the more precisely focused family policies of other European welfare states. The active family policy seems to have created especially positive attitudes towards two- or three child families in France.

  2. Stable magnesium peroxide at high pressure.

    Science.gov (United States)

    Lobanov, Sergey S; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B; Oganov, Artem R; Goncharov, Alexander F

    2015-01-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth's lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O2(2-)) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions. PMID:26323635

  3. Stable Vanadium Isotope Fractionation at High Temperatures

    Science.gov (United States)

    Prytulak, J.; Parkinson, I. J.; Savage, P. S.; Nielsen, S. G.; Halliday, A. N.

    2011-12-01

    Vanadium is a redox sensitive transition metal existing in multiple valence states at terrestrial conditions. Stable vanadium isotopes (reported as δ51V in % relative to an Alfa Aesar standard [1]) are a potentially powerful tracer of oxidation-reduction processes. However, the determination of δ51V is analytically challenging, primarily due to the extreme abundance ratio between the only two stable isotopes (51V/50V ~ 400) and, also, significant isobaric interferences of 50Ti and 50Cr on the minor 50V isotope. We have developed the first method able to determine δ51V to a precision (2 s.d. ~ 0.15%, [1,2]) that enables application of this isotope system to geological processes. To usefully investigate high temperature processes using vanadium isotopes, knowledge of the isotope composition and range of values present in the ambient mantle is required. Here we discuss the first δ51V measured in igneous materials encompassing peridotites, MORB, and primitive mantle-derived melts such as picrites. This first dataset provides a preliminary reconnaissance of the magnitude of natural fractionation. We find little isotope fractionation in suites of peridotites and MORB (vanadium isotope fractionation that may be expected at high temperatures. The presence of significant isotope variation outside of analytical precision in these materials bodes well for the use of δ51V to address a variety of broad scale questions in high temperature planetary processes. [1] Nielsen, S.G., Prytulak, J., Halliday, A.N. 2011. Geost. Geoanal. Res., in press. [2] Prytulak, J., Nielsen, S.G., Halliday, A.N. 2011. Geost. Geoanal. Res., in press. [3] Parkinson and Pearce, 1998. Journal of Petrology, 39, 1577-1618. [4] Lee et al., 2005. Journal of Petrology, 46, 2313-2336. [5] Cottrell and Kelley, 2011. Earth and Planetary Sciences Letters, 305, 270-282.

  4. Highly stable platinum nanoparticles on diamond

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: Platinum nanoparticles electrodeposited on diamond substrate show poor stability. Their electrochemical activities vary with different substrates and deposition methods. In this study Pt nanoparticles were prepared using a two-step deposition method. The stability and electrochemical activities of Pt nanoparticles on diamond were investigated in detail. The deposition method includes a wet-chemical seeding process and an electrochemical overgrowth of the seeds. The wet-chemical seeding process can be applied as well for other kinds of metal particles on diamond. H-terminated diamond surface is more favorable for seeding than O-terminated surface. Rapid thermal annealing process was applied to enhance the stability of Pt particles on diamond. Electrochemical activation and further overgrowth of annealed Pt nanoparticles were applied to improve the hydrogen adsorption/desorption activities of Pt nanoparticles on diamond with cyclic voltammetry in 0.1 M sulfuric acid solution. As confirmed by ultrasound removal and atomic force microscope (AFM) removal experiments as well as electrochemical tests, highly stable and active Pt nanoparticles on diamond were achieved after thermal annealing and electrochemical activation/overgrowth processes

  5. Compact, Highly Stable Ion Atomic Clock

    Science.gov (United States)

    Prestage, John

    2008-01-01

    A mercury-ion clock now at the breadboard stage of development (see figure) has a stability comparable to that of a hydrogen-maser clock: In tests, the clock exhibited an Allan deviation of between 2 x 10(exp -13) and 3 x 10(exp -13) at a measurement time of 1 second, averaging to about 10(exp -15) at 1 day. However, the clock occupies a volume of only about 2 liters . about a hundredth of the volume of a hydrogen-maser clock. The ion-handling parts of the apparatus are housed in a sealed vacuum tube, wherein only a getter pump is used to maintain the vacuum. Hence, this apparatus is a prototype of a generation of small, potentially portable high-precision clocks for diverse ground- and space-based navigation and radio science applications. Furthermore, this new ion-clock technology is about 100 times more stable and precise than the rubidium atomic clocks currently in use in the NAV STAR GPS Earth-orbiting satellites. In this clock, mercury ions are shuttled between a quadrupole and a 16-pole linear radio-frequency trap. In the quadrupole trap, the ions are tightly confined and optical state selection from a Hg-202 radio-frequency-discharge ultraviolet lamp is carried out. In the 16-pole trap, the ions are more loosely confined and atomic transitions resonant at frequency of about 40.507 GHz are interrogated by use of a microwave beam at that frequency. The trapping of ions effectively eliminates the frequency pulling caused by wall collisions inherent to gas-cell clocks. The shuttling of the ions between the two traps enables separation of the state-selection process from the clock microwave- resonance process, so that each of these processes can be optimized independently of the other. The basic ion-shuttling, two-trap scheme as described thus far is not new: it has been the basis of designs of prior larger clocks. The novelty of the present development lies in major redesigns of its physics package (the ion traps and the vacuum and optical subsystems) to effect

  6. MHD stable high beta spheromak equilibrium

    International Nuclear Information System (INIS)

    Recent observations of a pressure driven mode in CTX indicate that its performance is being limited by the low beta stability requirements typical of conventional spheromak designs. Improved designs with higher beat limits therefore have the potential to dramatically increase the temperature and lifetime of CTX and other spheromak experiments. This paper describes the results of an optimization study examining radically different geometries, but all with minimum energy current profiles which can easily be created experimentally and should be automatically stable to all ideal and resistive current drive modes. 2 refs., 3 figs

  7. Super Stable Ferroelectrics with High Curie Point

    Science.gov (United States)

    Gao, Zhipeng; Lu, Chengjia; Wang, Yuhang; Yang, Sinuo; Yu, Yuying; He, Hongliang

    2016-04-01

    Ferroelectric materials are of great importance in the sensing technology due to the piezoelectric properties. Thermal depoling behavior of ferroelectrics determines the upper temperature limit of their application. So far, there is no piezoelectric material working above 800 °C available. Here, we show Nd2Ti2O7 with a perovskite-like layered structure has good resistance to thermal depoling up to 1400 °C. Its stable behavior is because the material has only 180° ferroelectric domains, complex structure change at Curie point (Tc) and their sintering temperature is below their Tc, which avoided the internal stresses produced by the unit cell volume change at Tc. The phase transition at Tc shows a first order behavior which involving the tilting and rotation of the octahedron. The Curie – Weiss temperature is calculated, which might explain why the thermal depoling starts at about 1400 °C.

  8. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  9. Stable and unstable thermo -current states of high temperature superconductors

    International Nuclear Information System (INIS)

    Formation peculiarities of the stable and unstable states of high-Tc superconductors are discussed. To understand the basic physical trends, which are characteristic for the current penetration mechanism in high temperature superconductors, the operating states of Bi2212 slab without stabilizing matrix placed in DC external magnetic fields at low coolant temperature are theoretically investigated. It is proved that the temperature of a high-Tc superconductor is not equals to the coolant temperature before instability onset. Therefore, the voltage-current characteristic of a high-Tc superconductor has only a positive slope during continuous current charging. As a result, it does not allow one to find the boundary between stable and unstable thermo - current states. This peculiarity has to be considered during experiments at which the critical current of high-Tc superconductors is defined

  10. Stable Calcium Nitrides at Ambient and High Pressures.

    Science.gov (United States)

    Zhu, Shuangshuang; Peng, Feng; Liu, Hanyu; Majumdar, Arnab; Gao, Tao; Yao, Yansun

    2016-08-01

    The knowledge of stoichiometries of alkaline-earth metal nitrides, where nitrogen can exist in polynitrogen forms, is of significant interest for understanding nitrogen bonding and its applications in energy storage. For calcium nitrides, there were three known crystalline forms, CaN2, Ca2N, and Ca3N2, at ambient conditions. In the present study, we demonstrated that there are more stable forms of calcium nitrides than what is already known to exist at ambient and high pressures. Using a global structure searching method, we theoretically explored the phase diagram of CaNx and discovered a series of new compounds in this family. In particular, we found a new CaN phase that is thermodynamically stable at ambient conditions, which may be synthesized using CaN2 and Ca2N. Four other stoichiometries, namely, Ca2N3, CaN3, CaN4, and CaN5, were shown to be stable under high pressure. The predicted CaNx compounds contain a rich variety of polynitrogen forms ranging from small molecules (N2, N4, N5, and N6) to extended chains (N∞). Because of the large energy difference between the single and triple nitrogen bonds, dissociation of the CaNx crystals with polynitrogens is expected to be highly exothermic, making them as potential high-energy-density materials. PMID:27428707

  11. Boron Clusters as Highly Stable Magnesium-Battery Electrolytes**

    OpenAIRE

    Carter, Tyler J; Mohtadi, Rana; Arthur, Timothy S; Mizuno, Fuminori; Zhang, Ruigang; Shirai, Soichi; Kampf, Jeff W.

    2014-01-01

    Boron clusters are proposed as a new concept for the design of magnesium-battery electrolytes that are magnesium-battery-compatible, highly stable, and noncorrosive. A novel carborane-based electrolyte incorporating an unprecedented magnesium-centered complex anion is reported and shown to perform well as a magnesium-battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium-battery electro...

  12. High permeability-high frequency stable MnZn ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Kalarus, J. [Ferroxcube Polska, 96-100 Skierniewice (Poland); Kogias, G., E-mail: kogias@cperi.certh.gr [Centre for Research and Technology-Hellas, Chemical Process Engineering Research Institute, Laboratory of Inorganic Materials, 57001 Thessaloniki (Greece); Aristotle University of Thessaloniki, Department of Chemical Engineering, Laboratory of Materials Technology, 54124 Thessaloniki (Greece); Holz, D. [Ferroxcube Polska, 96-100 Skierniewice (Poland); Zaspalis, V.T. [Centre for Research and Technology-Hellas, Chemical Process Engineering Research Institute, Laboratory of Inorganic Materials, 57001 Thessaloniki (Greece); Aristotle University of Thessaloniki, Department of Chemical Engineering, Laboratory of Materials Technology, 54124 Thessaloniki (Greece)

    2012-09-15

    Modern MnZn ferrite applications require high magnetic initial permeability and exceptional frequency stability; the former implies large grains, while the latter high grain boundary resistivity. In this article the optimization of the final firing process is described for achieving both. The optimization is based on the homogeneous dissolution of dopants under oxidative conditions and their subsequent precipitation along grain boundaries. This was accomplished by integrating isothermal plateaus at the upper stadia of the cooling stage of the final firing process. MnZn ferrites of the basic composition [Mn{sub 0.47}Zn{sub 0.47}Fe{sub 0.06}{sup 2+}]Fe{sub 2}{sup 3+}O{sub 4} were synthesized with initial permeability (measured at f=10 kHz, B<0.1 mT, T=25 Degree-Sign C) 12,600 and losses, expressed as tan({delta})/{mu}{sub i}, of 3.1 Multiplication-Sign 10{sup -6} at 10 kHz and 20.5 Multiplication-Sign 10{sup -6} at 100 kHz (B<0.1 mT, T=25 Degree-Sign C), that reflect good frequency stability. These results could be reproduced in pilot production scale. - Highlights: Black-Right-Pointing-Pointer Optimization of sintering is described for achieving high initial permeability. Black-Right-Pointing-Pointer Optimization of sintering is described for receiving frequency stability. Black-Right-Pointing-Pointer For high permeability, high densities and large grain sizes are required. Black-Right-Pointing-Pointer The achieved initial permeability is higher than 12,500. Black-Right-Pointing-Pointer The losses, tan({delta})/{mu}{sub i}, are 3.1 Multiplication-Sign 10{sup -6} at 10 kHz and 20.5 Multiplication-Sign 10{sup -6} at 100 kHz.

  13. Highly stable organic fluorescent nanorods for living- cell imaging

    Institute of Scientific and Technical Information of China (English)

    Minhuan Lan[1,3; Jinfeng Zhang[1,3; Xiaoyue Zhu[1; Pengfei Wang[2; Xianfeng Chen[1; Chun-Sing Lee[1; Wenjun Zhang[1

    2015-01-01

    Metal-free, organic-dye-based fluorescent nanorods were fabricated through a simple solvent-exchange procedure. The as-prepared nanorods exhibit low toxicity to living cells and excellent photostability. Furthermore, they are stable in solutions of various pHs and high ionic strength and in solutions with interfering metal ions. Compared with the free DPP-Br molecules in THF, these nanorods exhibit larger Stokes shift, broader absorption spectra, and greatly improved photostability. We successfully demonstrated the application of the nanorods, including their aforementioned beneficial characteristics, as a good fluorescence probe for bio-imaging.

  14. Highly Photoluminescent and Stable Aqueous ZnS Quantum Dots

    OpenAIRE

    Li, Hui; Shih, Wan Y.; Shih, Wei-Heng

    2010-01-01

    We report an all-aqueous synthesis of highly photoluminescent and stable ZnS quantum dots (QDs) with water as the medium, i.e. first synthesizing ZnS QDs with 3-mercaptopropionic acid (MPA) as the capping molecule, followed by replacing some of MPA with (3-mercaptopropyl) trimethoxysilane (MPS). The resultant MPS-replaced ZnS QDs were about 5 nm in size with a cubic zinc blende crystalline structure, and had both MPA and MPS on the surface as confirmed by the Fourier Transform Infrared (FTIR)...

  15. Stable solid state reference electrodes for high temperature water chemistry

    International Nuclear Information System (INIS)

    A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

  16. Lasso peptide, a highly stable structure and designable multifunctional backbone.

    Science.gov (United States)

    Zhao, Ning; Pan, Yongxu; Cheng, Zhen; Liu, Hongguang

    2016-06-01

    Lasso peptide belongs to a new class of natural product with highly compact and stable structure. It has varieties of biological activities, among which the most important one is its antibacterial efficacy. Novel lasso peptides have been constantly discovered and analyzed by advanced techniques, and the biosynthesis or even chemical synthesis of lasso peptide has been studied after learning its constituent amino acids and maturation process. Structural identification of lasso peptide provides information for elucidating the mechanisms of its antibacterial activity and basis for further modifications. Ring of lasso peptide is the key to both its highly compact and stable structure and its intrinsic antibacterial property. The loop has been considered as suitable modification region of lasso peptide, such as V11-S18 of MccJ25 being modifiable without disrupting the lasso structure in biosynthesis. The tail is the immunity protein that can export lasso peptide out of its produced strain and serve as a self-protection mechanism at the same time. Most of currently known lasso peptides are non-pathogenic, which implies that the modified lasso peptides are promising candidates for medical applications. Arginine, glycine, and aspartic acid as a ligands of cancer-specific receptor have been grafted to the loop of lasso peptide without losing its bioactivity, and many other targets are expected to be used for lasso peptide modification. Multi-molecular modification and large-scale production need to be studied and solved in future for designing and using multifunctional lasso peptide based on its extraordinary stable structure. PMID:27074719

  17. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.

    2015-03-09

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured at room temperature and at 60°C. A tremendous improvement in gate-bias stress stability was obtained in case of the TFT with multiple layers of ZnO embedded between HfO2 layers compared to the TFT with a single layer of ZnO as the semiconductor. The ultra-thin HfO2 layers act as passivation layers, which prevent the adsorption of oxygen and water molecules in the ZnO layer and hence significantly improve the gate-bias stress stability of ZnO TFTs.

  18. High- and low-temperature-stable thermite composition for producing high-pressure, high-velocity gases

    Science.gov (United States)

    Halcomb, Danny L.; Mohler, Jonathan H.

    1990-10-16

    A high- and low-temperature-stable thermite composition for producing high-pressure and high-velocity gases comprises an oxidizable metal, an oxidizing reagent, and a high-temperature-stable gas-producing additive selected from the group consisting of metal carbides and metal nitrides.

  19. Preparation of highly active and hydrothermally stable nickel catalysts.

    Science.gov (United States)

    Li, Shaozhong; Chen, Hui; Shen, Jianyi

    2015-06-01

    The 60%Ni/AlSiO catalysts were prepared by the co-precipitation method, in which AlSiO were the composite supports with different mass ratios of Al2O3 and SiO2. It was found that the catalyst 60%Ni/AlSiO-4 with the Al2O3/SiO2 mass ratio of 4 in the support exhibited the high hydrothermal stability. The addition of proper amount of SiO2 inhibited the hydration of Al2O3 and prevented the growth of supported nickel particles during the hydrothermal treatment. The structure of the composite support in the 60%Ni/AlSiO-4 was stable and the supported nickel particles were highly dispersed. Accordingly, the hydrothermally treated catalyst maintained the high heats and uptakes for the adsorption of H2 and CO, and thus the high activity and stability for the hydrogenation of glucose to sorbitol in aqueous solution. PMID:25700212

  20. Highly Stable Mesoporous Zirconium Porphyrinic Frameworks with Distinct Flexibility.

    Science.gov (United States)

    Xu, Lei; Luo, Yan-Ping; Sun, Lin; Xu, Yan; Cai, Zhong-Sheng; Fang, Min; Yuan, Rong-Xin; Du, Hong-Bin

    2016-04-25

    The construction of highly stable metal-porphyrinic frameworks (MPFs) is appealing as these materials offer great opportunities for applications in artificial light-harvesting systems, gas storage, heterogeneous catalysis, etc. Herein, we report the synthesis of a novel mesoporous metal-porphyrinic framework (denoted as NUPF-1) and its catalytic properties. NUPF-1 is constructed from a new porphyrin linker and a Zr6 O8 structural building unit, possessing an unprecedented doubly interpenetrating scu net. The structure exhibits not only remarkable chemical and thermal stabilities, but also a distinct structural flexibility, which is seldom seen in metal-organic framework (MOF) materials. By the merit of high chemical stability, NUPF-1 could be easily post-metallized with [Ru3 (CO)12 ], and the resulting {NUPF-1-RuCO} is catalytically active as a heterogeneous catalyst for intermolecular C(sp(3) )-H amination. Excellent yields and good recyclability for amination of small substrates with various organic azides have been achieved. PMID:26960623

  1. Catalytic combustion over high temperature stable metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1996-12-31

    This thesis presents a study of the catalytic effects of two interesting high temperature stable metal oxides - magnesium oxide and manganese substituted barium hexa-aluminate (BMA) - both of which can be used in the development of new monolithic catalysts for such applications. In the first part of the thesis, the development of catalytic combustion for gas turbine applications is reviewed, with special attention to alternative fuels such as low-BTU gas, e.g. produced in an air blown gasifier. When catalytic combustion is applied for such a fuel, the primary advantage is the possibility of decreasing the conversion of fuel nitrogen to NO{sub x}, and achieving flame stability. In the experimental work, MgO was shown to have a significant activity for the catalytic combustion of methane, lowering the temperature needed to achieve 10 percent conversion by 270 deg C compared with homogeneous combustion.The reaction kinetics for methane combustion over MgO was also studied. It was shown that the heterogeneous catalytic reactions were dominant but that the catalytically initiated homogeneous gas phase reactions were also important, specially at high temperatures. MgO and BMA were compared. The latter showed a higher catalytic activity, even when the differences in activity decreased with increasing calcination temperature. For BMA, CO{sub 2} was the only product detected, but for MgO significant amounts of CO and C{sub 2}-hydrocarbons were formed. BMA needed a much lower temperature to achieve total conversion of other fuels, e.g. CO and hydrogen, compared to the temperature for total conversion of methane. This shows that BMA-like catalysts are interesting for combustion of fuel mixtures with high CO and H{sub 2} content, e.g. gas produced from gasification of biomass. 74 refs

  2. Progress Toward a Compact, Highly Stable Ion Clock

    Science.gov (United States)

    Prestage, John; Chung, Sang

    2009-01-01

    There was an update on the subject of two previous NASA Tech Briefs articles: Compact, Highly Stable Ion Clock (NPO-43075), Vol. 32, No. 5 (May 2008), page 63; and Neon as a Buffer Gas for a Mercury-Ion Clock (NPO-42919), Vol. 32, No. 7 (July 2008), page 62. To recapitulate: A developmental miniature mercury-ion clock has stability comparable to that of a hydrogen-maser clock. The ion-handling components are housed in a sealed vacuum tube, wherein a getter pump maintains the partial vacuum, and the evacuated tube is backfilled with mercury vapor in a neon buffer gas. There was progress in the development of the clock, with emphasis on the design, fabrication, pump-down, and bake-out of the vacuum tube (based on established practice in the travelingwave- tube-amplifier industry) and the ability of the tube to retain a vacuum after a year of operation. Other developments include some aspects of the operation of mercury-vapor source (a small appendage oven containing HgO) so as to maintain the optimum low concentration of mercury vapor, and further efforts to miniaturize the vacuum and optical subsystems to fit within a volume of 2 L.

  3. Thermally-Stable High Strain Deployable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is for the development of a thermally-stable composite made of carbon fibers and elastomeric resin. This combination of materials will allow...

  4. Quasi-stable Slope-Failure Dams in High Asia

    Science.gov (United States)

    Shroder, J. F.

    2010-12-01

    Collapses of steep mountain slopes in the Himalaya, Karakoram, Pamir, Hindu Kush, and Tibetan Plateau are well known as a result of:(1) generally high seismicity in active tectonic areas; (2) prior deglaciation leaving undercut, unstable cliffs; (3) present-day debuttressing of rock cliffs by glacial down-wasting in conditions of global warming; and (4) degradation of permafrost cohesion and water-ice cementation in high mountain slopes. Landslide dams across mountain rivers are also well known worldwide and generally do not endure for long because of the common landslide-lake outburst floods (LLOF) whose discharge is commonly sufficiently large to remove much of the dam in a short time. A number of massive slope-failure dams in south High Asia, however, have endured for centuries and require explanations for the length of duration, whereas recent examples require robust assessment for better predictive hazard analysis. Three main factors contribute to longevity of slope-failure dams: (1) mega-rocks >15-30 m that inhibit dam failure in overflow breaches; (2) mega-porosity wherein incoming discharge to the landslide lake is balanced by subterranean water through-flow within the landslide dam; (3) impermeable clay fills caused by remobilization of prior lacustrine-dammed sediment that impart dam strength to allow lasting integrity for a time, and (4) climate-change induced lake-level lowering. Several examples of long-lived or unusually stable, slope-failure dams associated with pronounced structural/tectonic associations include: (1) Pangong Tso, Ladakh and Tibet; (2) Lake Shewa, Afghanistan; (3) Sarez Lake, Tajikistan; and (4) Lake Hunza, Pakistan. Pangong Tso and Lake Shewa were emplaced thousands of years ago and only Lake Shewa shows some instability of the dam front where percolating water maintains lake level but may be causing new slumping. Sarez Lake behind the Usoi landslide dam was emplaced by an earthquake in 1911 and maintains its level by seepage. Lake

  5. Highly Potent, Chemically Stable Quorum Sensing Agonists for Vibrio Cholerae

    OpenAIRE

    Perez, Lark J; Karagounis, Theodora K.; Hurley, Amanda; Bassler, Bonnie L.; Semmelhack, Martin F.

    2013-01-01

    In the Vibrio cholerae pathogen, initiation of bacterial quorum sensing pathways serves to suppress virulence. We describe herein a potent and chemically stable small molecule agonist of V. cholerae quorum sensing, which was identified through rational drug design based on the native quorum sensing signal. This novel agonist may serve as a useful lead compound for the control of virulence in V. cholerae.

  6. Recent developments in high productivity stable isotope analysis

    International Nuclear Information System (INIS)

    The roots of today's high productivity stable isotope analyzers go back to the early 1980s. Development has since led to several 'continuous flow' methods. By 1984, three groups had interfaced an automated nitrogen analyzer (ANA) to an isotope ratio mass spectrometer (IRMS) for bulk analysis of 15N in solid and liquid samples. Continuous flow combustion converted sample N to a pulse of N2 gas, taken to the mass spectrometer by an He carrier. Carbon-13 analysis followed and the technique became automated nitrogen and carbon analysis-mass spectrometry (ANCA-MS). Also in 1984, a gas chromatograph (GC) was first used on-line with an IRMS for 13C analysis in individual compounds separated from a mixture (GC-IRMS). In 1987, a software controlled ANCA-MS was developed. Software control reduced running costs, allowed measurement of submicrogram quantities of N and also a 'turbo' mode to double 15N throughput. In 1990, a 'dual isotope' mode was added to analyse 13C and 15N in the same sample. Changes in research directions raised new analytical requirements: different gases and smaller samples. In 1992, a novel 120 deg. C mass analyzer was designed to meet these needs. Its precision of 13C and 15N for >50 μg N allows ANCA-MS to be used for 'natural abundance' applications. In 1989, a packed column GC-IRMS method was developed for 13CO2 in human breath. By 1993, it could analyze isotopes in other gases: 13CO2, 15N2, 15N2O and 13CH4 in 12 mL air samples; 18O from water equilibrated with CO2; and 15NO from NO-3 in KC1 extracts. A thermal desorption module allows GC-IRMS to measure denitrification rates down to 40 μg·ha-1·h-1, i.e. 1000 fold lower than conventional methods. Sulphur-34 analysis is actively being developed and there is the potential to measure D (or 2H) from water using H2 equilibration if the mass spectrometric interference between HD+ and the tail from 3He+ can be resolved. A capillary GC-IRMS approach has potential for measuring organic compounds for

  7. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    OpenAIRE

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, ...

  8. The design of high-voltage and stable power based on PWM technology

    International Nuclear Information System (INIS)

    A high-voltage and stable power based on PWM technology was introduced in this paper, which is principally used as the detector's high-voltage power. The high-voltage power adopts integrated circuit, which is integrated controller TL494, producing square wave control signal. The power supply adopts transformer-isolated forward converter topology. Since the performance of high-voltage power is stable and reliable in the experiment, it could be used as the detector's high-voltage power. (authors)

  9. High-Order Entropy Stable Finite Difference Schemes for Nonlinear Conservation Laws: Finite Domains

    Science.gov (United States)

    Fisher, Travis C.; Carpenter, Mark H.

    2013-01-01

    Developing stable and robust high-order finite difference schemes requires mathematical formalism and appropriate methods of analysis. In this work, nonlinear entropy stability is used to derive provably stable high-order finite difference methods with formal boundary closures for conservation laws. Particular emphasis is placed on the entropy stability of the compressible Navier-Stokes equations. A newly derived entropy stable weighted essentially non-oscillatory finite difference method is used to simulate problems with shocks and a conservative, entropy stable, narrow-stencil finite difference approach is used to approximate viscous terms.

  10. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    Science.gov (United States)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-10-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

  11. Dimensionally Stable Membrane for High Pressure Electrolyzers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilizing high strength polymers with controlled pore dimensions as a support, a customized membrane electrode assembly (MEA) can be generated for NASA's...

  12. Highly hydrothermally stable microporous silica membranes for hydrogen separation.

    Science.gov (United States)

    Wei, Qi; Wang, Fei; Nie, Zuo-Ren; Song, Chun-Lin; Wang, Yan-Li; Li, Qun-Yan

    2008-08-01

    Fluorocarbon-modified silica membranes were deposited on gamma-Al2O3/alpha-Al2O3 supports by the sol-gel technique for hydrogen separation. The hydrophobic property, pore structure, gas transport and separation performance, and hydrothermal stability of the modified membranes were investigated. It is observed that the water contact angle increases from 27.2+/-1.5 degrees for the pure silica membranes to 115.0+/-1.2 degrees for the modified ones with a (trifluoropropyl)triethoxysilane (TFPTES)/tetraethyl orthosilicate (TEOS) molar ratio of 0.6. The modified membranes preserve a microporous structure with a micropore volume of 0.14 cm3/g and a pore size of approximately 0.5 nm. A single gas permeation of H2 and CO2 through the modified membranes presents small positive apparent thermal activation energies, indicating a dominant microporous membrane transport. At 200 degrees C, a single H2 permeance of 3.1x10(-6) mol m(-2) s(-1) Pa(-1) and a H2/CO2 permselectivity of 15.2 were obtained after proper correction for the support resistance and the contribution from the defects. In the gas mixture measurement, the H2 permeance and the H2/CO2 separation factor almost remain constant at 200 degrees C with a water vapor pressure of 1.2x10(4) Pa for at least 220 h, indicating that the modified membranes are hydrothermally stable, benefiting from the integrity of the microporous structure due to the fluorocarbon modification. PMID:18613718

  13. High Rate and Stable Cycling of Lithium Metal Anode

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Jiangfeng; Henderson, Wesley A.; Xu, Wu; Bhattacharya, Priyanka; Engelhard, Mark H.; Borodin, Oleg; Zhang, Jiguang

    2015-02-20

    Lithium (Li) metal is an ideal anode material for rechargeable batteries. However, dendritic Li growth and limited Coulombic efficiency (CE) during repeated Li deposition/stripping processes have prevented the application of this anode in rechargeable Li metal batteries, especially for use at high current densities. Herein, we report that the use of highly concentrated electrolytes composed of ether solvents and the lithium bis(fluorosulfonyl)imide (LiFSI) salt enables the high rate cycling of a Li metal anode at high CE (up to 99.1 %) without dendrite growth. With 4 M LiFSI in 1,2-dimethoxyethane (DME) as the electrolyte, a Li|Li cell can be cycled at high rates (10 mA cm-2) for more than 6000 cycles with no increase in the cell impedance, and a Cu|Li cell can be cycled at 4 mA cm-2 for more than 1000 cycles with an average CE of 98.4%. These excellent high rate performances can be attributed to the increased solvent coordination and increased availability of Li+ concentration in the electrolyte. Further development of this electrolyte may lead to practical applications for Li metal anode in rechargeable batteries. The fundamental mechanisms behind the high rate ion exchange and stability of the electrolytes also shine light on the stability of other electrochemical systems.

  14. High stable power control of a laser diode

    Institute of Scientific and Technical Information of China (English)

    YANG Jiu-ru; LI Cheng; YE Hong-an; L(U) Guo-hui; JIA Shi-lou

    2006-01-01

    In this paper,the low and the high frequency noises of a laser diode have been analyzed. Based on the analysis a novel scheme that adapts analog and digital hybrid techniques is proposed to stabilize the output power of a laser diode. With the hybrid controller,the low and the high frequency noises of a laser diode are conspicuously reduced.By accurate calculation,the short-term stability of the output power of laser diode reaches ±0.55‰, and the long-term stability is ±0.7‰.

  15. Fractionation of Moderately and Highly Stable Organic Phosphorus in Acid Soil

    Institute of Scientific and Technical Information of China (English)

    FANYEKUAN; LISHIJUN

    1998-01-01

    The fractionation of moderately and highly organic phosphorus(Po) in acid soil was studied by two methods .By the first method,after incubation for 40 d; the mineralization rates of eight constituents of stable Po in the soil were determined.By the second method ,five constituents of peecipitates of stable Po in the soil were separated,then the five precipiates were put back into the original soils and incubated for 40 d and 60 d .Then,mineralization rates of the five precipitates were determined.The same results were obtained by the two methods.When the pH of the alkali solution containing stable Po was adjusted from 3.00 to 3.10,the mineralization rate of moderately stable Po Was rapidly raised.Therefore,the pH 3.00 is the critical point between moderately and highly stable Po.

  16. Synthesis of High-Thermal Stable Titanium Dioxide Nanoparticles

    OpenAIRE

    Rashidzadeh, M.

    2008-01-01

    Nanosized crystals of anatase phase T i O 2 with high-thermal stability was synthesized in the range of 15–17 nm via sol-gel method using titanium n-butoxide precursor. Synthesize was done at two different temperatures, that is, 200 and 3 0 0 ∘ C and the final products were calcined at 4 0 0 ∘ C . The final products were characterized by N 2 adsorption, X-ray diffraction, FT-IR, and TEM and tested in a photoreactor using fluorescien as model molecule. For thermal stability investigation, the ...

  17. Development of Thermally Stable and Highly Fluorescent IR Dyes

    Science.gov (United States)

    Bu, Xiu R.

    2004-01-01

    Fluorophores are the core component in various optical applications such as sensors and probes. Fluorphores with low-energy or long wavelength emission, in particular, in NIR region, possess advantages of low interference and high sensitivity. In this study, we has explored several classes of imidazole-based compounds for NIR fluorescent properties and concluded: (1) thiazole-based imidazole compounds are fluorescent; (2) emission energy is tunable by additional donor groups; (3) they also possess impressive two- photon absorption properties; and (4) fluorescence emission can be induced by two- photon input. This report summarizes (1) synthesis of new series of fluorophore; (2) impact of electron-withdrawing groups on fluorescent property; (3) unique property of two-photon absorption; and (4) on-going development.

  18. Highly stable digital holographic microscope using Sagnac interferometer.

    Science.gov (United States)

    Mahajan, Swapnil; Trivedi, Vismay; Vora, Priyanka; Chhaniwal, Vani; Javidi, Bahram; Anand, Arun

    2015-08-15

    Interferometric microscopy has grown into a very potent tool for quantitative phase imaging of biological samples. Among the interfermetric methods, microscopy by digital holography is one of the most effective techniques, especially for studying dynamics of cells. Imaging of cell fluctuations requires digital holographic setups with high temporal stability. Common path setups in which the object and the reference beams encounter the same set of optical elements provide better temporal stability compared to two-beam setups. Here, we present a compact, easy-to-implement, common path digital holographic microscope based on Sagnac interferometer geometry. The microscope is implemented using a diode laser module employing a CCD array or a webcam sensor to record holograms. The system was tested for three-dimensional imaging capability, numerical focusing ability, and temporal stability. Sub-nanometer temporal stability without external vibration isolation components was obtained in both cases. The higher temporal stability makes the microscope compatible to image cell fluctuations, which is demonstrated by imaging the oscillation of the cell membrane of human red blood cells. PMID:26274649

  19. A highly stable quartz crystal microbalance sensor and its application to water vapor measurements

    International Nuclear Information System (INIS)

    A highly stable quartz crystal microbalance (QCM) sensor showing frequency stability and a very low noise level has been developed for measurements of water vapor. The long-term drift was v. 2280 - 2329 Dr. Moon

  20. Operation regimes, gain dynamics and highly stable operation points of Ho:YLF regenerative amplifiers

    CERN Document Server

    Kroetz, Peter; Calendron, Anne-Laure; Chatterjee, Gourab; Cankaya, Huseyin; Murari, Krishna; Kaertner, Franz X; Hartl, Ingmar; Miller, R J Dwayne

    2016-01-01

    We present a comprehensive study of laser pulse amplification with respect to operation regimes, gain dynamics, and highly stable operation points of Ho:YLF regenerative amplifiers (RAs). The findings are expected to be more generic than for this specific case. Operation regimes are distinguished with respect to pulse energy and the appearance of pulse instability as a function of the repetition rate, seed energy, and pump intensity. The corresponding gain dynamics are presented, identifying highly stable operation points related to high gain build -up during pumping and high gain depletion during pulse amplification. These operation points are studied numerically and experimentally as a function of several parameters, thereby achieving, for our Ho:YLF RA, highly stable output pulses with measured fluctuations of only 0.19% (standard deviation).

  1. A stable high-speed rotational transmission system based on nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Kun, E-mail: caikun1978@163.com [College of Water Resources and Architectural Engineering, Northwest A and F University, Yangling 712100 (China); State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024 (China); Yin, Hang; Wei, Ning [College of Water Resources and Architectural Engineering, Northwest A and F University, Yangling 712100 (China); Chen, Zhen [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024 (China); Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211-2200 (United States); Shi, Jiao [Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211-2200 (United States)

    2015-01-12

    A stable rotational transmission system is designed with a single-walled carbon nanotube (SWCNT)-based motor and double-walled carbon nanotubes (DWCNTs)-based bearing. The system response is investigated using molecular dynamics (MD) simulation. It is found that the rotating motor can actuate the rotation of the inner tube in bearing because of the attraction between the two adjacent coaxial ends of motor and rotor (the inner tube in bearing). To have a stable nanostructure, each carbon atom on the adjacent ends of motor and rotor is bonded with a hydrogen atom. To obtain a stable high-speed rotational transmission system, both an armchair and a zigzag model are used in MD simulation. In each model, the motor with different diameters and rotational speeds is employed to examine the rotational transmission of corresponding DWCNTs. It is demonstrated that the long range van der Waals interaction between the adjacent ends of motor and rotor leads to a stable configuration of the adjacent ends, and further leads to a stable rotation of rotor when driven by a high-speed motor. As compared with the armchair model, the rotor in the zigzag model could reach a stable rotation mode much easier.

  2. Highly stable and sensitive glucose biosensor based on covalently assembled high density Au nanostructures.

    Science.gov (United States)

    Si, Peng; Kannan, Palanisamy; Guo, Longhua; Son, Hungsun; Kim, Dong-Hwan

    2011-05-15

    We describe the development of a highly stable and sensitive glucose biosensor based on the nanohybrid materials derived from gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNT). The biosensing platform was developed by using layer-by-layer (LBL) self-assembly of the nanohybrid materials and the enzyme glucose oxidase (GOx). A high density of AuNPs and MWCNT nanocomposite materials were constructed by alternate self assembly of thiol functionalized MWCNTs and AuNPs, followed by chemisoption of GOx. The surface morphology of multilayered AuNPs/MWCNT structure was characterized by field emission-scanning electron microscope (FE-SEM), and the surface coverage of AuNPs was investigated by cyclic voltammetry (CV), showing that 5 layers of assembly achieves the maximum particle density on electrode. The immobilization of GOx was monitored by electrochemical impedance spectroscopy (EIS). CV and amperometry methods were used to study the electrochemical oxidation of glucose at physiological pH 7.4. The Au electrode modified with five layers of AuNPs/MWCNT composites and GOx exhibited an excellent electrocatalytic activity towards oxidation of glucose, which presents a wide liner range from 20 μM to 10 mM, with a sensitivity of 19.27 μA mM(-1) cm(-2). The detection limit of present modified electrode was found to be 2.3 μM (S/N=3). In addition, the resulting biosensor showed a faster amperometric current response (within 3 s) and low apparent Michaelis-Menten constant (K(m)(app)). Our present study shows that the high density of AuNPs decorated MWCNT is a promising nanohybrid material for the construction of enzyme based electrochemical biosensors. PMID:21454070

  3. Stable level and phase control circuits for high power VHF transmitters for RIB applications

    International Nuclear Information System (INIS)

    For most applications it is required that the output power level and insertion phase of a high power transmitter remain unchanged against ambient temperature variation and power supply fluctuations. Design schemes for a stable level controller and a phase controller for use in a VHF transmitter that has been indigenously developed for RIB application at VECC is presented in this paper. (author)

  4. Highly Stable Surface-Enhanced Raman Spectroscopy Substrates Using Few-Layer Graphene on Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Jaehong Lee

    2015-01-01

    Full Text Available Graphene can be effectively applied as an ultrathin barrier for fluids, gases, and atoms based on its excellent impermeability. In this work, few-layer graphene was encapsulated on silver (Ag nanoparticles for the fabrication of highly stable surface-enhanced Raman scattering (SERS substrates, which has strong resistance to oxidation of the Ag nanoparticles. The few-layer graphene can be successfully grown on the surface of the Ag nanoparticles through a simple heating process. To prevent the agglomeration of the Ag nanoparticles in the fabrication process, poly(methyl methacrylate (PMMA layers were used as a solid carbon source instead of methane (CH4 gas generally used as a carbon source for the synthesis of graphene. X-ray diffraction (XRD spectra of the few-layer graphene-encapsulated Ag nanoparticles indicate that the few-layer graphene can protect the Ag nanoparticles from surface oxidation after intensive annealing processes in ambient conditions, giving the highly stable SERS substrates. The Raman spectra of Rhodamine 6G (R6G deposited on the stable SERS substrates exhibit maintenance of the Raman signal intensity despite the annealing process in air. The facile approach to fabricate the few-layer graphene-encapsulated Ag nanoparticles can be effectively useful for various applications in chemical and biological sensors by providing the highly stable SERS substrates.

  5. A highly stable and versatile heterobifunctional fluoroalkylation reagent for preparation of fluorinated organic compounds.

    Science.gov (United States)

    Dai, Jingwen; Li, Zili; Wang, Taisheng; Bai, Ruke

    2016-05-11

    A highly stable heterobifunctional fluoroalkylation reagent, 1-azido-2-chloro-1,1,2-trifluoro-2-iodoethane (ACTI) has been prepared in high yield for the first time by a new method. Moreover, the reactivity of both the azido group and the iodine atom of the reagent was systematically investigated and the results demonstrate that this compound is a very versatile and useful new fluoroalkylation reagent for preparation of fluorinated organic compounds. PMID:27109187

  6. Stable and high order accurate difference methods for the elastic wave equation in discontinuous media

    KAUST Repository

    Duru, Kenneth

    2014-12-01

    © 2014 Elsevier Inc. In this paper, we develop a stable and systematic procedure for numerical treatment of elastic waves in discontinuous and layered media. We consider both planar and curved interfaces where media parameters are allowed to be discontinuous. The key feature is the highly accurate and provably stable treatment of interfaces where media discontinuities arise. We discretize in space using high order accurate finite difference schemes that satisfy the summation by parts rule. Conditions at layer interfaces are imposed weakly using penalties. By deriving lower bounds of the penalty strength and constructing discrete energy estimates we prove time stability. We present numerical experiments in two space dimensions to illustrate the usefulness of the proposed method for simulations involving typical interface phenomena in elastic materials. The numerical experiments verify high order accuracy and time stability.

  7. Stable isotope and high precision concentration measurements confirm that all humans produce and exhale methane.

    Science.gov (United States)

    Keppler, Frank; Schiller, Amanda; Ehehalt, Robert; Greule, Markus; Hartmann, Jan; Polag, Daniela

    2016-03-01

    Mammalian formation of methane (methanogenesis) is widely considered to occur exclusively by anaerobic microbial activity in the gastrointestinal tract. Approximately one third of humans, depending on colonization of the gut by methanogenic archaea, are considered methane producers based on the classification terminology of high and low emitters. In this study laser absorption spectroscopy was used to precisely measure concentrations and stable carbon isotope signatures of exhaled methane in breath samples from 112 volunteers with an age range from 1 to 80 years. Here we provide analytical evidence that volunteers exhaled methane levels were significantly above background (inhaled) air. Furthermore, stable carbon isotope values of the exhaled methane unambiguously confirmed that this gas was produced by all of the human subjects studied. Based on the emission and stable carbon isotope patterns of various age groups we hypothesize that next to microbial sources in the gastrointestinal tracts there might be other, as yet unidentified, processes involved in methane formation supporting the idea that humans might also produce methane endogenously in cells. Finally we suggest that stable isotope measurements of volatile organic compounds such as methane might become a useful tool in future medical research diagnostic programs. PMID:26824393

  8. Theoretical design and preparation of high thermal-stable jet fuel

    Institute of Scientific and Technical Information of China (English)

    LIU GuoZhu; QU HaiJie; SHEN HuiMing; ZHANG XiangWen; MI ZhenTao

    2008-01-01

    A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel.Tannery diagrams were provided to visualize relationships among three main components (n-paraffins,iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta-bility.An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%.The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.

  9. Theoretical design and preparation of high thermal-stable jet fuel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel. Tannery diagrams were provided to visualize relationships among three main components (n-paraffins, iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta- bility. An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%. The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.

  10. 18-Months Operation of Lunar-based Ultraviolet Telescope: A Highly Stable Photometric Performance

    CERN Document Server

    Wang, J; Han, X H; Cai, H B; Cao, L; Deng, J S; Qiu, Y L; Wang, S; Wei, J Y; Hu, J Y

    2015-01-01

    We here report the photometric performance of Lunar-based Ultraviolet telescope (LUT), the first robotic telescope working on the Moon, for its 18-months operation. In total, 17 IUE standards have been observed in 51 runs until June 2015, which returns a highly stable photometric performance during the past 18 months (i.e., no evolution of photometric performance with time). The magnitude zero point is determined to be $17.53\\pm0.05$ mag, which is not only highly consistent with the results based on its first 6-months operation, but also independent on the spectral type of the standard from which the magnitude zero point is determined. The implications of this stable performance is discussed, and is useful for next generation lunar-based astronomical observations.

  11. Highly stable, luminescent core-shell type methylammonium-octylammonium lead bromide layered perovskite nanoparticles.

    Science.gov (United States)

    Bhaumik, Saikat; Veldhuis, Sjoerd A; Ng, Yan Fong; Li, Mingjie; Muduli, Subas Kumar; Sum, Tze Chien; Damodaran, Bahulayan; Mhaisalkar, Subodh; Mathews, Nripan

    2016-06-01

    A new protocol for the synthesis of a highly stable (over 2 months under ambient conditions) solution-processed core-shell type structure of mixed methylammonium-octylammonium lead bromide perovskite nanoparticles (5-12 nm), having spherical shape, color tunability in the blue to green spectral region (438-521 nm) and a high photoluminescence quantum yield (PLQY) of up to 92% is described. The color tunability, high PLQY and stability are due to the quantum confinement imparted by the crystal engineering associated with core-shell nanoparticle formation during growth. PMID:27165565

  12. Synthesis of highly thermally stable lanthanum-doped ordered mesoporous alumina

    International Nuclear Information System (INIS)

    Highly thermally stable lanthanum-doped ordered mesoporous alumina has been prepared in a sol-gel system with salicylic acid and citric acid as interfacial protectors. When the molar ratio of alumina to lanthanum is 25.5, most La3+ ions in the resulting alumina structure showed tetracoordination. Moreover, the as-obtained sample exhibits a surface area of 305 m2 g-1 when calcined at 400 oC and can maintain an ordered mesostructure with a high surface area of 205 m2 g-1 even when treated at 1000 oC, demonstrating its high thermal stability.

  13. Highly Stable Surface-Enhanced Raman Spectroscopy Substrates Using Few-Layer Graphene on Silver Nanoparticles

    OpenAIRE

    Jaehong Lee; Sera Shin; Subin Kang; Sanggeun Lee; Jungmok Seo; Taeyoon Lee

    2015-01-01

    Graphene can be effectively applied as an ultrathin barrier for fluids, gases, and atoms based on its excellent impermeability. In this work, few-layer graphene was encapsulated on silver (Ag) nanoparticles for the fabrication of highly stable surface-enhanced Raman scattering (SERS) substrates, which has strong resistance to oxidation of the Ag nanoparticles. The few-layer graphene can be successfully grown on the surface of the Ag nanoparticles through a simple heating process. To prevent t...

  14. Nitrogen stable isotopes of ammonium and nitrate in high mountain lakes of the Pyrenees

    OpenAIRE

    Bartrons, M.; Camarero, L.; Catalan, J

    2009-01-01

    Nitrogen stable isotopes (δ15N) are increasingly used to trace food web relationships and the flow of matter in lakes. However, there is high variability in δ15N among primary producers and other primary energy resources that can eventually propagate throughout the lake food web. To increase our understanding of the origin of this variability, we measured ammonium and nitrate δ15N in atmospheric...

  15. Highly stable trypsin-aggregate coatings on polymer nanofibers for repeated protein digestion

    OpenAIRE

    Kim, Byoung Chan; Lopez-Ferrer, Daniel; Lee, Sang-Mok; Ahn, Hye-Kyung; Nair, Sujith; Kim, Seong H; Kim, Beom Soo; Petritis, Konstantinos; Camp, David G.; Grate, Jay W.; Smith, Richard D.; Koo, Yoon-Mo; Gu, Man Bock; Kim, Jungbae

    2009-01-01

    A stable and robust trypsin-based biocatalytic system was developed and demonstrated for proteomic applications. The system utilizes polymer nanofibers coated with trypsin aggregates for immobilized protease digestions. After covalently attaching an initial layer of trypsin to the polymer nanofibers, highly concentrated trypsin molecules are crosslinked to the layered trypsin by way of a glutaraldehyde treatment. This process produced a 300-fold increase in trypsin activity compared with a co...

  16. Establishment of Stable High Expression Cell Line with Green Fluorescent Protein and Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shengtao; LIU Wenli; HE Peigen; GONG Feili; YANG Dongliang

    2006-01-01

    In order to establish stable high expression cell lines, the eukaryotic expression vector pIRES2EGFP and recombinant plasmid pIRES2EGFP-TIM-3 were transfected into mammalian cells CHO by Lipofectamine. The transfected cells were cultivated under selective growth medium including G418 and green fluorescent protein (GFP) positive cells were sorted by FACS. Simultaneously, growing transfectants were selected only by G418 in the medium. The GFP expression in stably transfected cells was detected by FACS. Under selective growth conditions with G418, the percentage of GFP positive cells was reduced rapidly and GFP induction was low. In contrast, the percentages of GFP positive cells were increased gradually after FACS. By 3 rounds of GFP selection, the stable high expression cell lines were established. Furthermore, using FACS analysis GFP and the target protein TIM-3 co-expression in the stable transfectants cultured in nonselective medium was detected. Theses results demonstrated that the stably transfected cell lines that express high titer of recombinant protein can be simply and fleetly obtained by using GFP and selective growth medium.

  17. Highly stable, protein capped gold nanoparticles as effective drug delivery vehicles for amino-glycosidic antibiotics

    International Nuclear Information System (INIS)

    A method for the production of highly stable gold nanoparticles (Au NP) was optimized using sodium borohydride as reducing agent and bovine serum albumin as capping agent. The synthesized nanoparticles were characterized using UV–visible spectroscopy, transmission electron microscopy, X‐ray diffraction (XRD) and dynamic light scattering techniques. The formation of gold nanoparticles was confirmed from the appearance of pink colour and an absorption maximum at 532 nm. These protein capped nanoparticles exhibited excellent stability towards pH modification and electrolyte addition. The produced nanoparticles were found to be spherical in shape, nearly monodispersed and with an average particle size of 7.8 ± 1.7 nm. Crystalline nature of the nanoparticles in face centered cubic structure is confirmed from the selected‐area electron diffraction and XRD patterns. The nanoparticles were functionalized with various amino-glycosidic antibiotics for utilizing them as drug delivery vehicles. Using Fourier transform infrared spectroscopy, the possible functional groups of antibiotics bound to the nanoparticle surface have been examined. These drug loaded nanoparticle solutions were tested for their antibacterial activity against Gram-negative and Gram-positive bacterial strains, by well diffusion assay. The antibiotic conjugated Au NP exhibited enhanced antibacterial activity, compared to pure antibiotic at the same concentration. Being protein capped and highly stable, these gold nanoparticles can act as effective carriers for drugs and might have considerable applications in the field of infection prevention and therapeutics. - Highlights: ► Method for NaBH4 reduced and BSA capped gold nanoparticle was standardized. ► Nanoparticles were spherical and nearly monodispersed with a size of 7.8 nm. ► Nanoparticles are extremely stable towards pH modification and electrolyte addition. ► Antibiotic conjugated nanoparticles exhibited enhanced antibacterial activity

  18. Novel Stable Compounds in the C-H-O Ternary System at High Pressure.

    Science.gov (United States)

    Saleh, Gabriele; Oganov, Artem R

    2016-01-01

    The chemistry of the elements is heavily altered by high pressure, with stabilization of many new and often unexpected compounds, the emergence of which can profoundly change models of planetary interiors, where high pressure reigns. The C-H-O system is one of the most important planet-forming systems, but its high-pressure chemistry is not well known. Here, using state-of-the-art variable-composition evolutionary searches combined with quantum-mechanical calculations, we explore the C-H-O system at pressures up to 400 GPa. Besides uncovering new stable polymorphs of high-pressure elements and known molecules, we predicted the formation of new compounds. A 2CH4:3H2 inclusion compound forms at low pressure and remains stable up to 215 GPa. Carbonic acid (H2CO3), highly unstable at ambient conditions, was predicted to form exothermically at mild pressure (about 1 GPa). As pressure rises, it polymerizes and, above 314 GPa, reacts with water to form orthocarbonic acid (H4CO4). This unexpected high-pressure chemistry is rationalized by analyzing charge density and electron localization function distributions, and implications for general chemistry and planetary science are also discussed. PMID:27580525

  19. A Novel High-Order, Entropy Stable, 3D AMR MHD Solver with Guaranteed Positive Pressure

    CERN Document Server

    Derigs, Dominik; Gassner, Gregor J; Walch, Stefanie

    2016-01-01

    We describe a high-order numerical magnetohydrodynamics (MHD) solver built upon a novel non-linear entropy stable numerical flux function that supports eight travelling wave solutions. By construction the solver conserves mass, momentum, and energy and is entropy stable. The method is designed to treat the divergence-free constraint on the magnetic field in a similar fashion to a hyperbolic divergence cleaning technique. The solver described herein is especially well-suited for flows involving strong discontinuities. Furthermore, we present a new formulation to guarantee positivity of the pressure. We present the underlying theory and implementation of the new solver into the multi-physics, multi-scale adaptive mesh refinement (AMR) simulation code $\\texttt{FLASH}$ (http://flash.uchicago.edu). The accuracy, robustness and computational efficiency is demonstrated with a number of tests, including comparisons to available MHD implementations in $\\texttt{FLASH}$.

  20. A novel high-order, entropy stable, 3D AMR MHD solver with guaranteed positive pressure

    Science.gov (United States)

    Derigs, Dominik; Winters, Andrew R.; Gassner, Gregor J.; Walch, Stefanie

    2016-07-01

    We describe a high-order numerical magnetohydrodynamics (MHD) solver built upon a novel non-linear entropy stable numerical flux function that supports eight travelling wave solutions. By construction the solver conserves mass, momentum, and energy and is entropy stable. The method is designed to treat the divergence-free constraint on the magnetic field in a similar fashion to a hyperbolic divergence cleaning technique. The solver described herein is especially well-suited for flows involving strong discontinuities. Furthermore, we present a new formulation to guarantee positivity of the pressure. We present the underlying theory and implementation of the new solver into the multi-physics, multi-scale adaptive mesh refinement (AMR) simulation code FLASH (http://flash.uchicago.edu)

  1. Production of highly concentrated, heat-stable hepatitis B surface antigen in maize.

    Science.gov (United States)

    Hayden, Celine A; Egelkrout, Erin M; Moscoso, Alessa M; Enrique, Cristina; Keener, Todd K; Jimenez-Flores, Rafael; Wong, Jeffrey C; Howard, John A

    2012-10-01

    Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat-stable, oral alternative to parenterally administered commercial vaccines. Here, we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than fourfold higher than any previously reported lines. HBsAg expressed in maize seeds was extremely heat stable, tolerating temperatures up to 55 °C for 1 month without degradation. Optimal heat stability was achieved after oil extraction of ground maize material, either by supercritical fluid extraction or hexane treatment. The contributions of this material towards the development of a practical oral vaccine delivery system are discussed. PMID:22816734

  2. A novel high-order, entropy stable, 3D AMR MHD solver with guaranteed positive pressure

    Science.gov (United States)

    Derigs, Dominik; Winters, Andrew R.; Gassner, Gregor J.; Walch, Stefanie

    2016-07-01

    We describe a high-order numerical magnetohydrodynamics (MHD) solver built upon a novel non-linear entropy stable numerical flux function that supports eight travelling wave solutions. By construction the solver conserves mass, momentum, and energy and is entropy stable. The method is designed to treat the divergence-free constraint on the magnetic field in a similar fashion to a hyperbolic divergence cleaning technique. The solver described herein is especially well-suited for flows involving strong discontinuities. Furthermore, we present a new formulation to guarantee positivity of the pressure. We present the underlying theory and implementation of the new solver into the multi-physics, multi-scale adaptive mesh refinement (AMR) simulation code FLASH (http://flash.uchicago.edu).

  3. Stable Peptides Instead of Stapled Peptides: Highly Potent αvβ6-Selective Integrin Ligands.

    Science.gov (United States)

    Maltsev, Oleg V; Marelli, Udaya Kiran; Kapp, Tobias G; Di Leva, Francesco Saverio; Di Maro, Salvatore; Nieberler, Markus; Reuning, Ute; Schwaiger, Markus; Novellino, Ettore; Marinelli, Luciana; Kessler, Horst

    2016-01-22

    The αvβ6 integrin binds the RGD-containing peptide of the foot and mouth disease virus with high selectivity. In this study, the long binding helix of this ligand was downsized to an enzymatically stable cyclic peptide endowed with sub-nanomolar binding affinity toward the αvβ6 receptor and remarkable selectivity against other integrins. Computational studies were performed to disclose the molecular bases underlying the high binding affinity and receptor subtype selectivity of this peptide. Finally, the utility of the ligand for use in biomedical studies was also demonstrated here. PMID:26663660

  4. Serial measurements of high-sensitivity cardiac troponin T after exercise stress test in stable coronary artery disease

    DEFF Research Database (Denmark)

    Axelsson, Anna; Ruwald, Martin Huth; Dalsgaard, Morten; Rossing, Kasper; Steffensen, Rolf; Iversen, Kasper

    2013-01-01

    The aim was to assess serial measurements of high-sensitivity cardiac troponin T (hs-cTNT) post-exercise in patients with stable coronary artery disease (CAD).......The aim was to assess serial measurements of high-sensitivity cardiac troponin T (hs-cTNT) post-exercise in patients with stable coronary artery disease (CAD)....

  5. Method of making highly porous, stable aluminum oxides doped with silicon

    Energy Technology Data Exchange (ETDEWEB)

    Khosravi-Mardkhe, Maryam; Woodfield, Brian F.; Bartholomew, Calvin H.; Huang, Baiyu

    2016-03-22

    The present invention relates to a method for making high surface area and large pore volume thermally stable silica-doped alumina (aluminum oxide) catalyst support and ceramic materials. The ability of the silica-alumina to withstand high temperatures in presence or absence of water and prevent sintering allows it to maintain good activity over a long period of time in catalytic reactions. The method of preparing such materials includes adding organic silicon reagents to an organic aluminum salt such as an alkoxide in a controlled quantity as a doping agent in a solid state, solvent deficient reaction followed by calcination. Alternatively, the organic silicon compound may be added after calcination of the alumina, followed by another calcination step. This method is inexpensive and simple. The alumina catalyst support material prepared by the subject method maintains high pore volumes, pore diameters and surface areas at very high temperatures and in the presence of steam.

  6. Stable type chromosome aberrations in the residents of the high background radiation area in China

    International Nuclear Information System (INIS)

    Chromosome translocations were analyzed by chromosome painting techniques using No.1, 2 and 4 whole chromosome painting probes to examine the effect of high-level natural radiation on the frequencies of chromosome translocations in human peripheral lymphocytes. The subjects were 5 children and 13 old men from the high background radiation area and 6 children and 11 old men from the control area. Children had lesser translocations and smaller variation compared with the old men. The frequency of translocations among the old subjects varied widely from person to person. There is no difference of the frequency of chromosome translocations between high background radiation area and control area. No effect of high-level natural background radiation on the frequencies of stable chromosome translocation was detected

  7. Identification, Attribution, and Quantification of Highly Heterogeneous Methane Sources Using a Mobile Stable Isotope Analyzer

    Science.gov (United States)

    Crosson, E.; Rella, C.; Cunningham, K.

    2012-04-01

    Despite methane's importance as a potent greenhouse gas second only to carbon dioxide in the magnitude of its contribution to global warming, natural contributions to the overall methane budget are only poorly understood. A big contributor to this gap in knowledge is the highly spatially and temporally heterogeneous nature of most natural (and for that matter anthropogenic) methane sources. This high degree of heterogeneity, where the methane emission rates can vary over many orders of magnitude on a spatial scale of meters or even centimeters, and over a temporal scale of minutes or even seconds, means that traditional methods of emissions flux estimation, such as flux chambers or eddy-covariance, are difficult or impossible to apply. In this paper we present new measurement methods that are capable of detecting, attributing, and quantifying emissions from highly heterogeneous sources. These methods take full advantage of the new class of methane concentration and stable isotope analyzers that are capable of laboratory-quality analysis from a mobile field platform in real time. In this paper we present field measurements demonstrating the real-time detection of methane 'hot spots,' attribution of the methane to a source process via real-time stable isotope analysis, and quantification of the emissions flux using mobile concentration measurements of the horizontal and vertical atmospheric dispersion, combined with atmospheric transport calculations. Although these techniques are applicable to both anthropogenic and natural methane sources, in this initial work we focus primarily on landfills and fugitive emissions from natural gas distribution, as these sources are better characterized, and because they provide a more reliable and stable source of methane for quantifying the measurement uncertainty inherent in the different methods. Implications of these new technologies and techniques are explored for the quantification of natural methane sources in a variety of

  8. Five roads towards increased optical absorption and high stable efficiency for thin film silicon solar cells

    Czech Academy of Sciences Publication Activity Database

    Vaněček, Milan; Poruba, Aleš; Remeš, Zdeněk; Holovský, Jakub; Purkrt, Adam; Babchenko, Oleg; Hruška, Karel; Meier, J.; Kroll, U.

    Munich: WIP- Renewable Energies, 2009 - (Sinke, W.; Ossenbrink, H.; Helm, P.), 2286-2289 ISBN 3-936338-25-6. [European Photovoltaic Solar Energy Conference /24./. Hamburg (DE), 21.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) 7E09057 EU Projects: European Commission(XE) 214134 - N2P; European Commission(XE) 19670 - ATHLET Institutional research plan: CEZ:AV0Z10100521 Keywords : thin film silicon solar cells * amorphous silicon * nanostructure * high stable efficiency Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Pt5Gd as a Highly Active and Stable Catalyst for Oxygen Electroreduction

    DEFF Research Database (Denmark)

    Escribano, Maria Escudero; Verdaguer-Casadevall, Arnau; Verdaguer Casadevall, Arnau;

    2012-01-01

    -fold increase in ORR activity, relative to pure Pt at 0.9 V, approaching the most active in the literature for catalysts prepared in this way. AR-XPS profiles after electrochemical measurements in 0.1 M HClO4 show the formation of a thick Pt overlayer on the bulk Pt5Gd, and the enhanced ORR activity...... can be explained by means of compressive strain effects. Furthermore, these novel bimetallic electrocatalysts are highly stable, which, in combination with their enhanced activity, makes them very promising for the development of new cathode catalysts for fuel cells....

  10. Prospects of building highly stable microwave oscillators with a narrow inherent line width

    Energy Technology Data Exchange (ETDEWEB)

    Braginskiy, V.B.; Minakova, I.I.; Panov, V.I.

    1976-01-01

    Highly stable narrow-line oscillators are required for the development of sensitive detectors of weak oscillations, doppler radar systems, secondary frequency standards, etc. one way to build microwave oscillators having a stability that is comparable to the stability of quantum standards and having a much higher output power is to use superconducting resonators (SCR's) in circuits with active solid-state elements. An analysis is given of the prospects of building a tunnel diode oscillator, operating at low temperatures (T = 2K), and a stabilized SCR with better frequency stability in a three-circuit scheme.

  11. Production of highly concentrated, heat stable hepatitis B surface antigen in maize

    OpenAIRE

    Hayden, Celine A; Egelkrout, Erin M.; Moscoso, Alessa M.; Enrique, Cristina; Keener, Todd K.; Jimenez-Flores, Rafael; Wong, Jeffrey C.; Howard, John A.

    2012-01-01

    Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat stable, oral alternative to parenterally administered commercial vaccines. Here we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than four-fold higher than any previously reported lines. HBs...

  12. Stable, high-efficiency amorphous-silicon solar cells with low hydrogen content

    Science.gov (United States)

    Hegedus, S. S.; Phillips, J. E.

    1993-08-01

    This report describes a 21-month project to demonstrate amorphous-silicon (a-Si) solar cells with high stabilized conversion efficiency. The objective was to develop a research program spanning material issues (more stable a-Si and better a-SiGe alloys) and device issues (more stable a-Si-based solar cells) with the goal of high stabilized solar cell efficiency. The Institute of Energy Conversion (IEC) produced and analyzed the stability of a-Si films and solar cells with reduced hydrogen content (2-6%). A thermodynamic model of defect formation was developed that describes the high-temperature degraded state of a solar cell. An analysis of bi-facial current voltage and quantum efficiency results for a-SiGe p-i-n devices with transparent front and back contacts provided information about the influence of alloying and band-gap grading on hole and electron collection. IEC also studied the stability of graded and ungraded a-SiGe solar cells using bifacial devices to learn about the relative degradation of hole and electron collection, and concludes that degradation of the photoconductivity of a-SiGe materials does not agree with degradation observed in solar cells.

  13. Soluble and meltable hyperbranched polyborosilazanes toward high-temperature stable SiBCN ceramics.

    Science.gov (United States)

    Kong, Jie; Wang, Minjun; Zou, Jianhua; An, Linan

    2015-04-01

    High-temperature stable siliconborocarbonitride (SiBCN) ceramics produced from single-source preceramic polymers have received increased attention in the last two decades. In this contribution, soluble and meltable polyborosilazanes with hyperbranched topology (hb-PBSZ) were synthesized via a convenient solvent-free, catalyst-free and one-pot A2 + B6 strategy, an aminolysis reaction of the A2 monomer of dichloromethylsilane and the B6 monomer of tris(dichloromethylsilylethyl)borane in the presence of hexamethyldisilazane. The amine transition reaction between the intermediates of dichlorotetramethyldisilazane and tri(trimethylsilylmethylchlorosilylethyl)borane led to the formation of dendritic units of aminedialkylborons rather than trialkylborons. The cross-linked hb-PBSZ precursors exhibited a ceramic yield higher 80%. The resultant SiBCN ceramics with a boron atomic composition of 6.0-8.5% and a representative formula of Si1B(0.19)C(1.21)N(0.39)O(0.08) showed high-temperature stability and retained their amorphous structure up to 1600 °C. These hyperbranched polyborosilazanes with soluble and meltable characteristics provide a new perspective for the design of preceramic polymers possessing advantages for high-temperature stable polymer-derived ceramics with complex structures/shapes. PMID:25775397

  14. Metal organic framework-mediated synthesis of highly active and stable Fischer-Tropsch catalysts.

    Science.gov (United States)

    Santos, Vera P; Wezendonk, Tim A; Jaén, Juan José Delgado; Dugulan, A Iulian; Nasalevich, Maxim A; Islam, Husn-Ubayda; Chojecki, Adam; Sartipi, Sina; Sun, Xiaohui; Hakeem, Abrar A; Koeken, Ard C J; Ruitenbeek, Matthijs; Davidian, Thomas; Meima, Garry R; Sankar, Gopinathan; Kapteijn, Freek; Makkee, Michiel; Gascon, Jorge

    2015-01-01

    Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging. Here we present a strategy to produce highly dispersed iron carbides embedded in a matrix of porous carbon. Very high iron loadings (>40 wt %) are achieved while maintaining an optimal dispersion of the active iron carbide phase when a metal organic framework is used as catalyst precursor. The unique iron spatial confinement and the absence of large iron particles in the obtained solids minimize catalyst deactivation, resulting in high active and stable operation. PMID:25740709

  15. A Stable, Extreme Temperature, High Radiation, Compact. Low Power Clock Oscillator for Space, Geothermal, Down-Hole & other High Reliability Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient and stable clock signal generation requirements at extreme temperatures and high radiation are not met with the current solutions. Chronos Technology...

  16. Construction of a highly stable artificial glutathione peroxidase on a protein nanoring.

    Science.gov (United States)

    Miao, Lu; Zhang, Xiyu; Si, Chengye; Gao, Yuzhou; Zhao, Linlu; Hou, Chunxi; Shoseyov, Oded; Luo, Quan; Liu, Junqiu

    2014-01-14

    Stable Protein One (SP1) is a boiling-stable oligomeric protein. The unique characteristics of SP1 offer a scaffold to design artificial enzymes against extreme temperature. Here, an efficient antioxidase is successfully constructed on the ring-shaped SP1 homododecamer. By means of computational design and genetic engineering, the active center of glutathione peroxidase (GPx), selenocysteine (Sec), is introduced to the SP1 monomer surface, and the self-assembly properties of the protein monomer lead to a ring-shaped SP1 with homododecamer catalytic selenium centers. This artificial selenoenzyme exhibits high GPx catalytic activity and shows a typical ping-pong kinetic mechanism. Moreover, it has a significantly broader temperature range and high thermostability. Owing to having multi-GPx active centers on a SP1 oligomer, this selenium-containing biomacromolecule exerts an excellent capability to protect cells from oxidative damage at the mitochondrial level. This strategy represents a new way to develop thermostable artificial nanoenzymes for some specific applications. PMID:24264596

  17. Hydrogen-incorporated ZnO nanowire films: stable and high electrical conductivity

    International Nuclear Information System (INIS)

    Post-growth hydrogen annealing treatment of highly oriented ZnO nanowire (NW) films (ZnO : H) results in high electrical conductivity (3.7 × 103 S m−1) and fully suppressed defect emission at room temperature. The formation of hydrogen-related vacancy complexes is responsible for the suppression of vacancies ( Vo+ and Vo2+), leading to a reduction in defect-based emission. ZnO : H NW films show five orders larger stable electrical conductance with a four-fold increment in carrier mobility (7–28 cm2 V−1 s−1). As compared with pristine NWs, the carrier concentration in ZnO : H NW films increases from 1015 to 1019 cm−3, which is in the range of commercial transparent conducting oxides. X-ray photoelectron spectroscopy and secondary ion mass spectrometry analyses reveal stable OH bond formation, which strongly supports the prediction of H doping. These films offer a promising conducting oxide platform for photovoltaic applications. (paper)

  18. Stable isotopes in lakes of the High Tatra mountains, Western Carpathians, Slovakia

    International Nuclear Information System (INIS)

    Data of oxygen, hydrogen and sulphate sulphur stable isotopes from the lakes of the Vysoke Tatry Mts., acquired in the framework of IAEA No. 8675/RB project ''Stable isotopes in lakes of High Tatra mountains, Western Carpathians, Slovakia'' represent the first set of this kind information on the territory of Slovakia. Moreover a complete set of chemical composition of waters was taken and compared to preceding results and contemporary state of acidification was evaluated. Values of studied chemical compounds respond to their source - initial precipitation waters and bedrock character with influence of biochemical processes. Acidification is due to inactive geological background (granites), high contribution of SOx and NOx from atmospheric deposition and low buffering ability of soil. Acidification of lakes is lowered from 1980 and is approaching to level before acidification, probably as consequence of industry crisis in Eastern Europe after 1989. Water samples from the Furkotska dolina valley water system follow the MWL with natural trend of increasing content of heavy isotopes with lowering altitude. In depth profiles of single lakes' isotope composition does not change - due to natural conditions during sampling campaigns (spring and fall homothermy?), all waters are meteoric in origin without signs of evaporation. Water of the Strbske pleso lake is enriched to heavy isotopes, all samples fit an evaporation line. This could be explained by longer residence time of water, or by the recharging from the last phases of the snowmelt. Sulphate sulphur isotope ratios from lakes are the same and they are identical with these of snow packs. (author)

  19. “A novel highly stable and injectable hydrogel based on a conformationally restricted ultrashort peptide”

    Science.gov (United States)

    Thota, Chaitanya Kumar; Yadav, Nitin; Chauhan, Virander Singh

    2016-01-01

    Nanostructures including hydrogels based on peptides containing non protein amino acids are being considered as platform for drug delivery because of their inherent biocompatibility and additional proteolytic stability. Here we describe instantaneous self-assembly of a conformationally restricted dipeptide, LeuΔPhe, containing an α,β-dehydrophenylalanine residue into a highly stable and mechanically strong hydrogel, under mild physiological aqueous conditions. The gel successfully entrapped several hydrophobic and hydrophilic drug molecules and released them in a controlled manner. LeuΔPhe was highly biocompatible and easily injectable. Administration of an antineoplastic drug entrapped in the gel in tumor bearing mice significantly controlled growth of tumors. These characteristics make LeuΔPhe an attractive candidate for further development as a delivery platform for various biomedical applications. PMID:27507432

  20. Highly Efficient, Selective, and Stable CO2 Electroreduction on a Hexagonal Zn Catalyst.

    Science.gov (United States)

    Won, Da Hye; Shin, Hyeyoung; Koh, Jaekang; Chung, Jaehoon; Lee, Hee Sang; Kim, Hyungjun; Woo, Seong Ihl

    2016-08-01

    Electrocatalytic CO2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H2 evolution during CO2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO2 to CO by more effectively stabilizing a (.) COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst. PMID:27352078

  1. Ladder polymers for use as high temperature stable resins or coatings

    Science.gov (United States)

    Meador, Mary Ann (Inventor)

    1990-01-01

    An object of the invention is to synthesize a new class of ladder and partial ladder polymers. In accordance with the invention, the new class of ladder and partial ladder polymers are synthesized by polymerizing a bis-dienophile with a bis-diene. Another object of the invention is to provide a fabricated, electrically conducting, void free composite comprising the new class of the ladder and partial ladder polymers described above. The novelty of the invention relates to a new class of ladder and partial ladder polymers and a process for synthesizing these polymers. These polymers are soluble in common organic solvents and are characterized with a unique dehydration property at temperatures of 300 to 400 C to provide thermo-oxidatively stable pentiptycene units along the polymeric backbone. These polymers are further characterized with high softening points and good thermo-oxidative stability properties. Thus these polymers have potential as processable, matrix resins for high temperature composite applications.

  2. Deformation-Induced Highly Oriented and Stable Mesomorphic Phase in Quenched Isotactic Polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Qiu,J.; Wang, Z.; Yang, L.; Zhao, J.; Niu, Y.; Hsiao, B.

    2007-01-01

    Changes of structure and morphology of quenched isotactic polypropylene (i-PP) film during tensile deformation at room temperature have been investigated by applying in situ synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques. SAXS patterns show that the isotropic diffuse scattering peak in the initial quenched i-PP film disappears after the film experiences necking and a strong streak, which accompanies obvious film stress-whitening, appears when strain reaches 600% and above. Explanation to the former is the dropping of density contrast between amorphous and mesomorphic phases due to deformation and that to the latter is the formation of microfibrils and/or microvoids in the film. WAXD patterns indicate that i-PP chains in the mesomorphic phase become highly oriented along the drawing direction with the strain value more than 5% and the three-fold helical chain conformation keeps in the deformed mesomorphic phase. The mesomorphic structure in the initial quenched i-PP film does not transform into crystal phase although high orientation appears during tensile deformation and the highly oriented mesomorphic phase is considered to be quite stable. Thermal behaviors of the initial quenched i-PP and deformed i-PP with the strain value of 650% are examined by modulated differential scanning calorimetry (MDSC). MDSC results show that the highly oriented i-PP chains in deformed mesomorphic phase are stable, which brings about restriction to chain mobility and prohibits from phase transformation of mesophase to crystal phase in the temperature range normally measurable for the initial quenched i-PP. A model about tensile deformation of the quenched i-PP is outlined to distinctly illuminate the changes of structure and morphology in both the amorphous and mesomorphic phases.

  3. Deformation-Induced Highly Oriented and Stable Mesomorphic Phase in Quenched Isotactic Polypropylene

    International Nuclear Information System (INIS)

    Changes of structure and morphology of quenched isotactic polypropylene (i-PP) film during tensile deformation at room temperature have been investigated by applying in situ synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques. SAXS patterns show that the isotropic diffuse scattering peak in the initial quenched i-PP film disappears after the film experiences necking and a strong streak, which accompanies obvious film stress-whitening, appears when strain reaches 600% and above. Explanation to the former is the dropping of density contrast between amorphous and mesomorphic phases due to deformation and that to the latter is the formation of microfibrils and/or microvoids in the film. WAXD patterns indicate that i-PP chains in the mesomorphic phase become highly oriented along the drawing direction with the strain value more than 5% and the three-fold helical chain conformation keeps in the deformed mesomorphic phase. The mesomorphic structure in the initial quenched i-PP film does not transform into crystal phase although high orientation appears during tensile deformation and the highly oriented mesomorphic phase is considered to be quite stable. Thermal behaviors of the initial quenched i-PP and deformed i-PP with the strain value of 650% are examined by modulated differential scanning calorimetry (MDSC). MDSC results show that the highly oriented i-PP chains in deformed mesomorphic phase are stable, which brings about restriction to chain mobility and prohibits from phase transformation of mesophase to crystal phase in the temperature range normally measurable for the initial quenched i-PP. A model about tensile deformation of the quenched i-PP is outlined to distinctly illuminate the changes of structure and morphology in both the amorphous and mesomorphic phases.

  4. A wearable, highly stable, strain and bending sensor based on high aspect ratio graphite nanobelts

    Science.gov (United States)

    Alaferdov, A. V.; Savu, R.; Rackauskas, T. A.; Rackauskas, S.; Canesqui, M. A.; de Lara, D. S.; Setti, G. O.; Joanni, E.; de Trindade, G. M.; Lima, U. B.; de Souza, A. S.; Moshkalev, S. A.

    2016-09-01

    A simple and scalable method was developed for the fabrication of wearable strain and bending sensors, based on high aspect ratio (length/thickness ∼103) graphite nanobelt thin films deposited by a modified Langmuir–Blodgett technique onto flexible polymer substrates. The sensing mechanism is based on the changes in contact resistance between individual nanobelts upon substrate deformation. Very high sensor response stability for more than 5000 strain–release cycles and a device power consumption as low as 1 nW were achieved. The device maximum stretchability is limited by the metal electrodes and the polymer substrate; the maximum strain that could be applied to the polymer used in this work was 40%. Bending tests carried out for various radii of curvature demonstrated distinct sensor responses for positive and negative curvatures. The graphite nanobelt thin flexible films were successfully tested for acoustic vibration and heartbeat sensing.

  5. Single step surface modification of highly stable magnetic nanoparticles for purification of His-tag proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Sumanta Kumar [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Chakrabarty, Arindam [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Bhattacharya, Dipsikha [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Ghosh, Sudip K. [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Pramanik, Panchanan, E-mail: chandrasourov@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

    2011-06-15

    The aim of this study was to develop a simple, cheap, and rapid method for purification of His-tag recombinant proteins with high yields. The new immobilized metal ion affinity adsorbent containing superparamagnetic nanoparticles and hydrophilic resins are proposed here to improve the purification of His-tagged recombinant proteins. In this report, we have described the preparation of nanosized superparamagnetic nanoparticles (Fe{sub 3}O{sub 4}) which were prepared by chemical precipitation method followed by surface modification using phosphonomethyl iminodiacetic acid. The stable surface functionalized nanoparticles were further linked with Ni{sup 2+} for purification of 6 Multiplication-Sign His-tagged proteins. The phosphonate group of the N-phosphonomethyl iminodiacetic acid ligand acts as a surface anchoring agent on magnetite nanoparticles and the remaining free -COOH groups outside for binding with Ni{sup 2+} ions. The nanoparticles were approximately 6-8 nm in size and were stable and had negligible non-specific binding for protein. The proteins were purified within 1 h and observed on sodium dodecyl sulfate-polyacrylamide electrophoresis gel.

  6. High-coercivity, thermally stable and low unblocking temperature magnetic phase: Implications for Archeomagnetic studies

    Science.gov (United States)

    Hartmann, G. A.; Gallet, Y.; Trindade, R. I.; Genevey, A.; Berquo, T. S.; Neumann, R.; Le Goff, M.

    2013-05-01

    The thermoremanent magnetization in baked clay archeological materials provide very useful information on the time evolution of the Earth's magnetic field over the past few millennia. In these materials, a thermally stable magnetic phase characterized by high coercivities (>400 mT) and low unblocking temperatures (~200 degrees Celsius) has recently been recognized in European bricks, tiles, kilns and hearth samples. Both the identification and the origin of this phase remain, however, poorly constrained. The very same high-coercivity, thermally stable, low unblocking temperature (HCSLT) magnetic phase has been identified in Brazilian bricks fragments dated of the past five centuries. We report here a large set of measurements on a selected collection of samples showing variable contributions of the HCSLT phase. These measurements include low-field magnetic susceptibility vs. temperature curves, hysteresis loops, isothermal remanent magnetization (IRM) acquisition, thermal demagnetization of the three-axis IRM, first order reversal curves (FORC), low-temperature magnetization experiments (remanent magnetization curves and alternating current susceptibility), Mössbauer spectroscopy and X-ray diffraction. Results show the coexistence of low-coercivity magnetic minerals (magnetite and titanomagnetite) and high-coercivity minerals (hematite, HCSLT phase and, in some cases, goethite). We note that the HCSLT magnetic phase is always found in association with hematite. We further observe that the Mössbauer spectroscopy, X-ray diffraction spectra, and the FORC diagrams are also very similar to results previously obtained from annealed clays in which nontronite or iron-rich montmorillonite was transformed into Al-substituted hematite by heating. The HCSLT magnetic phase is thus confidently identified as being hematite with Al substitution. Moreover, considering the abundance of montmorillonite in clay mining settings, we suggest that the widespread occurrence of HCSLT in

  7. Immobilization of actinides in stable mineral type and ceramic materials (high temperature synthesis)

    Energy Technology Data Exchange (ETDEWEB)

    Starkov, O.; Konovalov, E.

    1996-05-01

    Alternative vitrification technologies are being developed in the world for the immobilization of high radioactive waste in materials with improved thermodynamic stability, as well as improved chemical and thermal stability and stability to radiation. Oxides, synthesized in the form of analogs to rock-forming minerals and ceramics, are among those materials that have highly stable properties and are compatible with the environment. In choosing the appropriate material, we need to be guided by its geometric stability, the minimal number of cations in the structure of the material and the presence of structural elements in the mineral that are isomorphs of uranium and thorium, actinoids found in nature. Rare earth elements, yttrium, zirconium and calcium are therefore suitable. The minerals listed in the table (with the exception of the zircon) are pegatites by origin, i.e. they are formed towards the end of the magma crystallization of silicates form the residual melt, enriched with Ta, Nb, Ti, Zr, Ce, Y, U and Th. Uranium and thorium in the form of isomorphic admixtures form part of the lattice of the mineral. These minerals, which are rather simple in composition and structure and are formed under high temperatures, may be viewed as natural physio-chemical systems that are stable and long-lived in natural environments. The similarity of the properties of actinoids and lanthanoids plays an important role in the geochemistry of uranium and thorium; however, uranium (IV) is closer to the {open_quotes}heavy{close_quotes} group of lanthanoids (the yttrium group) while thorium (IV) is closer to the {open_quotes}light{close_quotes} group (the cerium group). That is why rare earth minerals contain uranium and thorium in the form of isomorphic admixtures.

  8. Flexible, Highly Durable, and Thermally Stable SWCNT/Polyimide Transparent Electrodes.

    Science.gov (United States)

    Kim, Seong-Ku; Liu, Tao; Wang, Xiaogong

    2015-09-23

    Flexible, transparent, and electrically conducting electrode materials are highly desired for flexible electronic applications. With a highly transparent polyimide (PI) as a substrate, a comprehensive and comparative study was performed to investigate four different fabrication schemes in producing transparent and electrically conducting SWCNT/PI electrodes. A very promising method that involves an in situ imidization process and nitric acid doping treatment was identified, which led to the fabrication of highly durable and thermally stable SWCNT/PI electrodes. The best performed electrode has a transmission of 77.6% at 550 nm and a sheet resistance (Rs) of 1169 ± 172 Ω/□, which appeared no changes after repeating tests of bending, folding-unfolding, adhesive-tape-peeling-off, and wet tissue-paper scratching/wiping. The excellent thermal stability of such fabricated SWCNT/PI electrode is manifested by the very high glass transition temperature of 290.1 °C and low coefficient of thermal expansion (CTE) of 28.5 ppm °C(-1) in the temperature range from 75 to 200 °C. The new method expects to be able to pave the way in facile production of high-performance flexible, transparent, and conducting electrodes. PMID:26323087

  9. Thermally Stable Nanocatalyst for High Temperature Reactions: Pt-Mesoporous Silica Core-Shell Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Sang Hoon; Park, J.Y.; Tsung, C.-K.; Yamada, Y.; Yang, P.; Somorjai, G.A.

    2008-10-25

    Recent advances in colloidal synthesis enabled the precise control of size, shape and composition of catalytic metal nanoparticles, allowing their use as model catalysts for systematic investigations of the atomic-scale properties affecting catalytic activity and selectivity. The organic capping agents stabilizing colloidal nanoparticles, however, often limit their application in high-temperature catalytic reactions. Here we report the design of a high-temperature stable model catalytic system that consists of Pt metal core coated with a mesoporous silica shell (Pt{at}mSiO{sub 2}). While inorganic silica shells encaged the Pt cores up to 750 C in air, the mesopores directly accessible to Pt cores made the Pt{at}mSiO{sub 2} nanoparticles as catalytically active as bare Pt metal for ethylene hydrogenation and CO oxidation. The high thermal stability of Pt{at}mSiO{sub 2} nanoparticles permitted high-temperature CO oxidation studies, including ignition behavior, which was not possible for bare Pt nanoparticles because of their deformation or aggregation. The results suggest that the Pt{at}mSiO{sub 2} nanoparticles are excellent nanocatalytic systems for high-temperature catalytic reactions or surface chemical processes, and the design concept employed in the Pt{at}mSiO{sub 2} core-shell catalyst can be extended to other metal-metal oxide compositions.

  10. Five roads towards increased optical absorption and high stable efficiency for thin film silicon solar cells

    Czech Academy of Sciences Publication Activity Database

    Vaněček, Milan; Poruba, Aleš; Remeš, Zdeněk; Holovský, Jakub; Purkrt, Adam; Babchenko, Oleg; Hruška, Karel; Meier, J.; Kroll, U.

    Munich: WIP- Renewable Energies, 2009 - (Sinke, W.; Ossenbrink, H.; Helm, P.), s. 2286-2289 ISBN 3-936338-25-6. [European Photovoltaic Solar Energy Conference /24./. Hamburg (DE), 21.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) 7E09057 EU Projects: European Commission(XE) 214134 - N2P; European Commission(XE) 19670 - ATHLET Institutional research plan: CEZ:AV0Z10100521 Keywords : high stable efficiency * amorphous silicon * thin film solar cell * 3-dimensional nanostructuring * transparent conductive oxides Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.4229/24thEUPVSEC2009-3BO.9.1

  11. High voltage threshold for stable operation in a dc electron gun

    Science.gov (United States)

    Yamamoto, Masahiro; Nishimori, Nobuyuki

    2016-07-01

    We report clear observation of a high voltage (HV) threshold for stable operation in a dc electron gun. The HV hold-off time without any discharge is longer than many hours for operation below the threshold, while it is roughly 10 min above the threshold. The HV threshold corresponds to the minimum voltage where discharge ceases. The threshold increases with the number of discharges during HV conditioning of the gun. Above the threshold, the amount of gas desorption per discharge increases linearly with the voltage difference from the threshold. The present experimental observations can be explained by an avalanche discharge model based on the interplay between electron stimulated desorption (ESD) from the anode surface and subsequent secondary electron emission from the cathode by the impact of ionic components of the ESD molecules or atoms.

  12. Stable amorphous georgeite as a precursor to a high-activity catalyst

    DEFF Research Database (Denmark)

    Kondrat, Simon A.; Smith, Paul J.; Wells, Peter P.;

    2016-01-01

    Copper and zinc form an important group of hydroxycarbonate minerals that include zincian malachite, aurichalcite, rosasite and the exceptionally rare and unstable-and hence little known and largely ignored-georgeite. The first three of these minerals are widely used as catalyst precursors for the...... and solvation power of supercritical carbon dioxide to rapidly expand and supersaturate solutions, can be used to prepare copper/zinc hydroxycarbonate precursors with low sodium content. These include stable georgeite, which we find to be a precursor to highly active methanol-synthesis and superior...... LTS catalysts. Our findings highlight the value of advanced synthesis methods in accessing unusual mineral phases, and show that there is room for exploring improvements to established industrial catalysts....

  13. Highly stable tandem solar cell monolithically integrating dye-sensitized and CIGS solar cells

    Science.gov (United States)

    Chae, Sang Youn; Park, Se Jin; Joo, Oh-Shim; Jun, Yongseok; Min, Byoung Koun; Hwang, Yun Jeong

    2016-01-01

    A highly stable monolithic tandem solar cell was developed by combining the heterogeneous photovoltaic technologies of dye-sensitized solar cell (DSSC) and solution-processed CuInxGa1-xSeyS1-y (CIGS) thin film solar cells. The durability of the tandem cell was dramatically enhanced by replacing the redox couple from to [Co(bpy)3]2+ /[Co(bpy)3]3+), accompanied by a well-matched counter electrode (PEDOT:PSS) and sensitizer (Y123). A 1000 h durability test of the DSSC/CIGS tandem solar cell in ambient conditions resulted in only a 5% decrease in solar cell efficiency. Based on electrochemical impedance spectroscopy and photoelectrochemical cell measurement, the enhanced stability of the tandem cell is attributed to minimal corrosion by the cobalt-based polypyridine complex redox couple. PMID:27489138

  14. High-order Composite Likelihood Inference for Max-Stable Distributions and Processes

    KAUST Repository

    Castruccio, Stefano

    2015-09-29

    In multivariate or spatial extremes, inference for max-stable processes observed at a large collection of locations is a very challenging problem in computational statistics, and current approaches typically rely on less expensive composite likelihoods constructed from small subsets of data. In this work, we explore the limits of modern state-of-the-art computational facilities to perform full likelihood inference and to efficiently evaluate high-order composite likelihoods. With extensive simulations, we assess the loss of information of composite likelihood estimators with respect to a full likelihood approach for some widely-used multivariate or spatial extreme models, we discuss how to choose composite likelihood truncation to improve the efficiency, and we also provide recommendations for practitioners. This article has supplementary material online.

  15. Sensitive and selective detection of copper ions with highly stable polyethyleneimine-protected silver nanoclusters.

    Science.gov (United States)

    Yuan, Zhiqin; Cai, Na; Du, Yi; He, Yan; Yeung, Edward S

    2014-01-01

    Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive Cu(2+) detection is very important to prevent over-ingestion, and visual detection using unaugmented vision is preferred for practical applications. In this study, hyperbranched polyethyleneimine-protected silver nanoclusters (hPEI-AgNCs) were successfully synthesized using a facile, one-pot reaction under mild conditions. The hPEI-AgNCs were very stable against extreme pH, ionic strength, temperature, and photoillumination and could act as sensitive and selective Cu(2+) sensing nanoprobes in aqueous solutions with a 10 nM limit of detection. In addition, hPEI-AgNCs-doped agarose hydrogels were developed as an instrument-free and regenerable platform for visual Cu(2+) and water quality monitoring. PMID:24274096

  16. Pt Monolayer Shell on Nitrided Alloy Core—A Path to Highly Stable Oxygen Reduction Catalyst

    Directory of Open Access Journals (Sweden)

    Jue Hu

    2015-07-01

    Full Text Available The inadequate activity and stability of Pt as a cathode catalyst under the severe operation conditions are the critical problems facing the application of the proton exchange membrane fuel cell (PEMFC. Here we report on a novel route to synthesize highly active and stable oxygen reduction catalysts by depositing Pt monolayer on a nitrided alloy core. The prepared PtMLPdNiN/C catalyst retains 89% of the initial electrochemical surface area after 50,000 cycles between potentials 0.6 and 1.0 V. By correlating electron energy-loss spectroscopy and X-ray absorption spectroscopy analyses with electrochemical measurements, we found that the significant improvement of stability of the PtMLPdNiN/C catalyst is caused by nitrogen doping while reducing the total precious metal loading.

  17. Monolithic Highly Stable Yb-Doped Femtosecond Fiber Lasers for Applications in Practical Biophotonics

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2012-01-01

    Operational and environmental stability of ultrafast laser systems is critical for their applications in practical biophotonics. Mode-locked fiber lasers show great promise in applications such as supercontinuum sources or multiphoton microscopy systems. Recently, substantial progress has been made...... in the development of all-fiber nonlinear-optical laser control schemes, which resulted in the demonstration of highly stable monolithic, i.e., not containing any free-space elements, lasers with direct fiber-end delivery of femtosecond pulses. This paper provides an overview of the progress in the...... development of such all-fiber mode-locked lasers based on Yb-fiber as gain medium, operating at the wavelength around 1 $\\mu$m, and delivering femtosecond pulses reaching tens of nanojoules of energy....

  18. Highly stable gelatin layer-protected gold nanoparticles as surface-enhanced Raman scattering substrates.

    Science.gov (United States)

    Lee, Changwon; Zhang, Peng

    2014-06-01

    Amine and carboxylic groups rich gelatin was used as reducing and stabilizing agent to form highly stable gold nanoparticles for surface-enhanced Raman scattering (SERS) applications. The size of the particle was determined to be 13 nm by TEM with mono-dispersity. The size of the gold nanoparticles was little affected by the initial gelatin concentration. The gelatin-gold nanoparticles show strong SERS activity with Rhodamine 6G and Ruthenium bipyridine as reporter molecules. Both carboxylic acid groups and amine groups were identified by FT-IR to be present on the gelatin-gold nanoparticle surface, providing the possibility of further conjugation with other molecules. The gelatin-protected gold nanoparticles prepared by this simple, green, method displayed very good solubility and stability in many solvents, and good monodispersity, all desirable features as good SERS substrates. PMID:24738391

  19. A 66 fs highly stable single wall carbon nanotube mode locked fiber laser

    International Nuclear Information System (INIS)

    We demonstrate a highly stable mode locked fiber laser based on single wall carbon nanotubes. The mode locking is achieved by the evanescent field interaction of the propagating light with a single wall carbon nanotube saturable absorber in a microfiber. The pulse width is 66 fs, which, to the best of our knowledge, is the shortest pulse achieved in a carbon nanotube mode locked fiber laser. The maximum average output power is 26 mW, which is about 20 times larger than that of a typical carbon nanotube mode locked fiber laser. The center of the wavelength is 1555 nm, with 54 nm spectral width. The repetition rate is 146 MHz. To investigate the laser’s stability, the output pulses are monitored for 120 h and there is no significant degradation of the laser spectral width or shape. (paper)

  20. High-Temperature-Stable and Regenerable Catalysts: Platinum Nanoparticles in Aligned Mesoporous Silica Wells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Chaoxian [Ames Laboratory; Maligal-Ganesh, Raghu V. [Ames Laboratory; Li, Tao [Argonne Laboratory; Wi, Zhiyuan [Ames Laboratory; Guo, Zhiyong [Ames Laboratory; Brashler, Kyle T. [Ames Laboratory; Goes, Shannon [Ames Laboratory; Li, Xinle [Ames Laboratory; Goh, Tian Wei [Ames Laboratory; Winans, Randall E. [Argonne Laboratory; Huang, Wenyu [Ames Laboratory

    2013-08-22

    We report the synthesis, structural characterization, thermal stability study, and regeneration of nanostructured catalysts made of 2.9 nm Pt nanoparticles sandwiched between a 180 nm SiO2 core and a mesoporous SiO2 shell. The SiO2 shell consists of 2.5 nm channels that are aligned perpendicular to the surface of the SiO2 core. The nanostructure mimics Pt nanoparticles that sit in mesoporous SiO2 wells (Pt@MSWs). By using synchrotron-based small-angle X-ray scattering, we were able to prove the ordered structure of the aligned mesoporous shell. By using high-temperature cyclohexane dehydrogenation as a model reaction, we found that the Pt@MSWs of different well depths showed stable activity at 500 °C after the induction period. Conversely, a control catalyst, SiO2-sphere-supported Pt nanoparticles without a mesoporous SiO2 shell (Pt/SiO2), was deactivated. We deliberately deactivated the Pt@MSWs catalyst with a 50 nm deep well by using carbon deposition induced by a low H2/cyclohexane ratio. The deactivated Pt@MSWs catalyst was regenerated by calcination at 500 °C with 20 % O2 balanced with He. After the regeneration treatments, the activity of the Pt@MSWs catalyst was fully restored. Our results suggest that the nanostructured catalysts—Pt nanoparticles confined inside mesoporous SiO2 wells—are stable and regenerable for treatments and reactions that require high temperatures.

  1. Highly stable high power fiber laser system for optical trapping of ultracold atoms

    International Nuclear Information System (INIS)

    Full text: For our quantum gas experiments we simultaneously confine ultracold Rb and Cs atoms in an optical dipole trap. For that purpose the light of a commercially available, narrow-band, single mode 1064-nm solid-state laser is amplified in a home-built fiber amplifier using a Yb-doped large mode area (LMA) fiber. The fiber is pumped by a high-power 980-nm diode laser and yields an (amplified) narrow-band optical output of more than 30 W for an input seed power of about 1 W at 1064 nm. The performance of this fiber amplifier is presented in terms of slope efficiency, relative intensity noise (RIN), and long term stability. The light of the fiber laser is used for optical trapping of the quantum gas mixture in running wave and standing wave dipole traps. We present our progress towards the realization of a 3D optical lattice for the realization of strongly correlated quantum gas mixtures and for the study of quantum gas mixtures in low-dimensional geometry. (author)

  2. Research of high power and stable laser in portable Raman spectrometer based on SHINERS technology

    Science.gov (United States)

    Cui, Yongsheng; Yin, Yu; Wu, Yulin; Ni, Xuxiang; Zhang, Xiuda; Yan, Huimin

    2013-08-01

    The intensity of Raman light is very weak, which is only from 10-12 to 10-6 of the incident light. In order to obtain the required sensitivity, the traditional Raman spectrometer tends to be heavy weight and large volume, so it is often used as indoor test device. Based on the Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) method, Raman optical spectrum signal can be enhanced significantly and the portable Raman spectrometer combined with SHINERS method will be widely used in various fields. The laser source must be stable enough and able to output monochromatic narrow band laser with stable power in the portable Raman spectrometer based on the SHINERS method. When the laser is working, the change of temperature can induce wavelength drift, thus the power stability of excitation light will be affected, so we need to strictly control the working temperature of the laser, In order to ensure the stability of laser power and output current, this paper adopts the WLD3343 laser constant current driver chip of Wavelength Electronics company and MCU P89LPC935 to drive LML - 785.0 BF - XX laser diode(LD). Using this scheme, the Raman spectrometer can be small in size and the drive current can be constant. At the same time, we can achieve functions such as slow start, over-current protection, over-voltage protection, etc. Continuous adjustable output can be realized under control, and the requirement of high power output can be satisfied. Max1968 chip is adopted to realize the accurate control of the laser's temperature. In this way, it can meet the demand of miniaturization. In term of temperature control, integral truncation effect of traditional PID algorithm is big, which is easy to cause static difference. Each output of incremental PID algorithm has nothing to do with the current position, and we can control the output coefficients to avoid full dose output and immoderate adjustment, then the speed of balance will be improved observably. Variable

  3. Sub-0.5 V Highly Stable Aqueous Salt Gated Metal Oxide Electronics

    Science.gov (United States)

    Park, Sungjun; Lee, Seyeong; Kim, Chang-Hyun; Lee, Ilseop; Lee, Won-June; Kim, Sohee; Lee, Byung-Geun; Jang, Jae-Hyung; Yoon, Myung-Han

    2015-08-01

    Recently, growing interest in implantable bionics and biochemical sensors spurred the research for developing non-conventional electronics with excellent device characteristics at low operation voltages and prolonged device stability under physiological conditions. Herein, we report high-performance aqueous electrolyte-gated thin-film transistors using a sol-gel amorphous metal oxide semiconductor and aqueous electrolyte dielectrics based on small ionic salts. The proper selection of channel material (i.e., indium-gallium-zinc-oxide) and precautious passivation of non-channel areas enabled the development of simple but highly stable metal oxide transistors manifested by low operation voltages within 0.5 V, high transconductance of ~1.0 mS, large current on-off ratios over 107, and fast inverter responses up to several hundred hertz without device degradation even in physiologically-relevant ionic solutions. In conjunction with excellent transistor characteristics, investigation of the electrochemical nature of the metal oxide-electrolyte interface may contribute to the development of a viable bio-electronic platform directly interfacing with biological entities in vivo.

  4. Synthesis of highly stable, water-dispersible copper nanoparticles as catalysts for nitrobenzene reduction.

    Science.gov (United States)

    Kaur, Ravneet; Giordano, Cristina; Gradzielski, Michael; Mehta, Surinder K

    2014-01-01

    We report an aqueous-phase synthetic route to copper nanoparticles (CuNPs) using a copper-surfactant complex and tests of their catalytic efficiency for a simple nitrophenol reduction reaction under atmospheric conditions. Highly stable, water-dispersed CuNPs were obtained with the aid of polyacrylic acid (PAA), but not with other dispersants like surfactants or polymethacrylic acid (PMAA). The diameter of the CuNPs could be controlled in the range of approximately 30-85 nm by modifying the ratio of the metal precursor to PAA. The catalytic reduction of p-nitrophenol to p-aminophenol takes place at the surface of CuNPs at room temperature and was accurately monitored by UV/Vis spectroscopy. The catalytic efficiency was found to be remarkably high for these PAA-capped CuNPs, given the fact that at the same time PAA is efficiently preventing their oxidation as well. The activity was found to increase as the size of the CuNPs decreased. It can therefore be concluded that the synthesized CuNPs are catalytically highly efficient in spite of the presence of a protective PAA coating, which provides them with a long shelf life and thereby enhances the application potential of these CuNPs. PMID:24124135

  5. A simple and highly stable free-flow electrophoresis device with thermoelectric cooling system.

    Science.gov (United States)

    Yan, Jian; Guo, Cheng-Gang; Liu, Xiao-Ping; Kong, Fan-Zhi; Shen, Qiao-Yi; Yang, Cheng-Zhang; Li, Jun; Cao, Cheng-Xi; Jin, Xin-Qiao

    2013-12-20

    Complex assembly, inconvenient operations, poor control of Joule heating and leakage of solution are still fundamental issues greatly hindering application of free-flow electrophoresis (FFE) for preparative purpose in bio-separation. To address these issues, a novel FFE device was developed based on our previous work. Firstly, a new mechanical structure was designed for compact assembly of separation chamber, fast removal of air bubble, and good anti-leakage performance. Secondly, a highly efficient thermoelectric cooling system was used for dispersing Joule heating for the first time. The systemic experiments revealed the three merits: (i) 3min assembly without any liquid leakage, 80 times faster than pervious FFE device designed by us or commercial device (4h); (ii) 5s removing of air bubble in chamber, 1000-fold faster than a normal one (2h or more) and (iii) good control of Joule heating by the cooling system. These merits endowed the device high stable thermo- and hydro-dynamic flow for long-term separation even under high electric field of 63V/cm. Finally, the developed device was used for up to 8h continuous separation of 5mg/mL fuchsin acid and purification of three model proteins of phycocyanin, myoglobin and cytochrome C, demonstrating the applicability of FFE. The developed FFE device has evident significance to the studies on stem cell, cell or organelle proteomics, and protein complex as well as micro- or nano-particles. PMID:24246174

  6. Purification and characterization of a highly stable tyrosinase from Thermomicrobium roseum.

    Science.gov (United States)

    Kong, K H; Hong, M P; Choi, S S; Kim, Y T; Cho, S H

    2000-04-01

    Tyrosinase, with an isoelectric point at pH 4.9, was purified to electrophoretic homogeneity from an extremely thermophilic bacterium, Thermomicrobium roseum. Gel filtration, N-terminal amino acid sequencing and SDS/PAGE analysis indicate that T. roseum tyrosinase is composed of two identical subunits, each with a molecular mass of 43000 Da. The enzyme exhibited high substrate specificity towards catechol, chlorogenic acid, L-3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) and pyrogallol. The K(m) value of the enzyme for L-DOPA was 0.18 mM. beta-Mercaptoethanol and sodium diethyldithiocarbamate notably inhibited the enzymic activity. The activity of the enzyme was optimal at pH 9.5 and 70 degrees C, and was increased by addition of 1 mM Mg(2+), K(+) or Cu(2+). The enzyme was highly stable against high temperature and guanidine hydrochloride. The N-terminal amino acid sequence of the enzyme was determined to be Asp-Ile-Asn-Gly-Gly-Gly-Ala-Thr-Leu-Pro-Gln-Lys-Leu-Tyr. These facts indicate that T. roseum tyrosinase appears to be distinct from the tyrosinases so far purified from other sources. PMID:10744956

  7. Sub-0.5 V Highly Stable Aqueous Salt Gated Metal Oxide Electronics.

    Science.gov (United States)

    Park, Sungjun; Lee, SeYeong; Kim, Chang-Hyun; Lee, Ilseop; Lee, Won-June; Kim, Sohee; Lee, Byung-Geun; Jang, Jae-Hyung; Yoon, Myung-Han

    2015-01-01

    Recently, growing interest in implantable bionics and biochemical sensors spurred the research for developing non-conventional electronics with excellent device characteristics at low operation voltages and prolonged device stability under physiological conditions. Herein, we report high-performance aqueous electrolyte-gated thin-film transistors using a sol-gel amorphous metal oxide semiconductor and aqueous electrolyte dielectrics based on small ionic salts. The proper selection of channel material (i.e., indium-gallium-zinc-oxide) and precautious passivation of non-channel areas enabled the development of simple but highly stable metal oxide transistors manifested by low operation voltages within 0.5 V, high transconductance of ~1.0 mS, large current on-off ratios over 10(7), and fast inverter responses up to several hundred hertz without device degradation even in physiologically-relevant ionic solutions. In conjunction with excellent transistor characteristics, investigation of the electrochemical nature of the metal oxide-electrolyte interface may contribute to the development of a viable bio-electronic platform directly interfacing with biological entities in vivo. PMID:26271456

  8. Highly stable supercapacitors with conducting polymer core-shell electrodes for energy storage applications

    KAUST Repository

    Xia, Chuan

    2015-01-14

    Conducting polymers such as polyaniline (PAni) show a great potential as pseudocapacitor materials for electrochemical energy storage applications. Yet, the cycling instability of PAni resulting from structural alteration is a major hurdle to its commercial application. Here, the development of nanostructured PAni-RuO2 core-shell arrays as electrodes for highly stable pseudocapacitors with excellent energy storage performance is reported. A thin layer of RuO2 grown by atomic layer deposition (ALD) on PAni nanofibers plays a crucial role in stabilizing the PAni pseudocapacitors and improving their energy density. The pseudocapacitors, which are based on optimized PAni-RuO2 core-shell nanostructured electrodes, exhibit very high specific capacitance (710 F g-1 at 5 mV s-1) and power density (42.2 kW kg-1) at an energy density of 10 Wh kg-1. Furthermore, they exhibit remarkable capacitance retention of ≈88% after 10 000 cycles at very high current density of 20 A g-1, superior to that of pristine PAni-based pseudocapacitors. This prominently enhanced electrochemical stability successfully demonstrates the buffering effect of ALD coating on PAni, which provides a new approach for the preparation of metal-oxide/conducting polymer hybrid electrodes with excellent electrochemical performance.

  9. A scalable synthesis of highly stable and water dispersible Ag 44(SR)30 nanoclusters

    KAUST Repository

    AbdulHalim, Lina G.

    2013-01-01

    We report the synthesis of atomically monodisperse thiol-protected silver nanoclusters [Ag44(SR)30] m, (SR = 5-mercapto-2-nitrobenzoic acid) in which the product nanocluster is highly stable in contrast to previous preparation methods. The method is one-pot, scalable, and produces nanoclusters that are stable in aqueous solution for at least 9 months at room temperature under ambient conditions, with very little degradation to their unique UV-Vis optical absorption spectrum. The composition, size, and monodispersity were determined by electrospray ionization mass spectrometry and analytical ultracentrifugation. The produced nanoclusters are likely to be in a superatom charge-state of m = 4-, due to the fact that their optical absorption spectrum shares most of the unique features of the intense and broadly absorbing nanoparticles identified as [Ag44(SR) 30]4- by Harkness et al. (Nanoscale, 2012, 4, 4269). A protocol to transfer the nanoclusters to organic solvents is also described. Using the disperse nanoclusters in organic media, we fabricated solid-state films of [Ag44(SR)30]m that retained all the distinct features of the optical absorption spectrum of the nanoclusters in solution. The films were studied by X-ray diffraction and photoelectron spectroscopy in order to investigate their crystallinity, atomic composition and valence band structure. The stability, scalability, and the film fabrication method demonstrated in this work pave the way towards the crystallization of [Ag44(SR)30]m and its full structural determination by single crystal X-ray diffraction. Moreover, due to their unique and attractive optical properties with multiple optical transitions, we anticipate these clusters to find practical applications in light-harvesting, such as photovoltaics and photocatalysis, which have been hindered so far by the instability of previous generations of the cluster. © 2013 The Royal Society of Chemistry.

  10. A Highly Stable D-Amino Acid Oxidase of the Thermophilic Bacterium Rubrobacter xylanophilus.

    Science.gov (United States)

    Takahashi, Shouji; Furukawara, Makoto; Omae, Keishi; Tadokoro, Namiho; Saito, Yayoi; Abe, Katsumasa; Kera, Yoshio

    2014-12-01

    d-Amino acid oxidase (DAO) is a biotechnologically attractive enzyme that can be used in a variety of applications, but its utility is limited by its relatively poor stability. A search of a bacterial genome database revealed a gene encoding a protein homologous to DAO in the thermophilic bacterium Rubrobacter xylanophilus (RxDAO). The recombinant protein expressed in Escherichia coli was a monomeric protein containing noncovalently bound flavin adenine dinucleotide as a cofactor. This protein exhibited oxidase activity against neutral and basic d-amino acids and was significantly inhibited by a DAO inhibitor, benzoate, but not by any of the tested d-aspartate oxidase (DDO) inhibitors, thus indicating that the protein is DAO. RxDAO exhibited higher activities and affinities toward branched-chain d-amino acids, with the highest specific activity toward d-valine and catalytic efficiency (kcat/Km) toward d-leucine. Substrate inhibition was observed in the case of d-tyrosine. The enzyme had an optimum pH range and temperature of pH 7.5 to 10 and 65°C, respectively, and was stable between pH 5.0 and pH 8.0, with a T50 (the temperature at which 50% of the initial enzymatic activity is lost) of 64°C. No loss of enzyme activity was observed after a 1-week incubation period at 30°C. This enzyme was markedly inactivated by phenylmethylsulfonyl fluoride but not by thiol-modifying reagents and diethyl pyrocarbonate, which are known to inhibit certain DAOs. These results demonstrated that RxDAO is a highly stable DAO and suggested that this enzyme may be valuable for practical applications, such as the determination and quantification of branched-chain d-amino acids, and as a scaffold to generate a novel DAO via protein engineering. PMID:25217016

  11. Determination of stable and long-lived radioactive halides using high resolution ICP-MS

    International Nuclear Information System (INIS)

    Routine control of radioactive waste demands efficient techniques which allow many samples to be analyzed per day with high precision and accuracy. ICP-MS is well established as a trace analytical method and permits the extremely sensitive and fast detection of stable and long-lived radioactive nuclides. Though ICP-MS is rarely used for the determination of halides, the author's investigation shows that a sufficient low detection limit can be achieved (e.g., for the declaration of 129I in radioactive waste samples.). In this work, a double focusing mass spectrometer with an ICP ion source (open-quotes ELEMENTclose quotes, Finnigan MAT) is used for the determination of halides (Cl, Br and I) in biological standard reference materials as well as 129I in low-activity radioactive waste samples. A method was developed for the determination of halides in the μg/mL-range for bromine and chlorine and the ng/mL-range for iodine including isotopic analysis of stable and radioactive halides. Possible interferences of atomic ions with other ions (e.g., 129I+ with 129Xe+) were investigated and possibilities for correction of these interferences will be discussed. To achieve a lower detection limit a new method for iodine sample introduction was developed. The iodide ion in an aqueous sample is oxidized to elemental iodine and introduced directly into the ICP by a special introduction system. Iodine (127I or 129I) can be measured by this new method even in the lower ng/mL-range. The studies were extended to include the determination of bromine and chlorine

  12. An effective method for the preparation of high temperature stable anatase TiO2 photocatalysts

    Science.gov (United States)

    Fagan, Rachel; Synnott, Damian W.; McCormack, Declan E.; Pillai, Suresh C.

    2016-05-01

    An efficient, rapid and straightforward method for the preparation of nitrogen and fluorine (N, F) codoped high temperature stable anatase using a microwave pre-treatment is reported. Using a single source, ammonium fluoride (NH4F) for both nitrogen and fluorine, effective doping of the precursor titanium isopropoxide (TTIP) was possible. These samples were characterised for their structural and optical properties using X-ray diffraction (XRD), Fourier Transform IR (FTIR), Raman spectroscopy and UV-vis spectroscopy. In terms of the anatase to rutile transition enhancement using a novel microwave assisted technique, the sample prepared in a composition of 1:8 TiO2: NH4F at 1200 °C was seen to be most effective, having stable anatase present at 57.1% compared to undoped TiO2 being 100% rutile from 900 °C. This method involves the production of ammonium oxofluorotitanates (NH4TiOF3) at low temperatures. The inclusion of these intermediates greatly reduces the particle size growth and delays the anatase to rutile transition. The photocatalytic activity of these materials was studied by analysing the degradation of an organic dye, rhodamine 6G as a model system and the rate constant was calculated by pseudo-first-order kinetics. These results showed that the doped sample (0.0225 min-1) was three times more active than the undoped sample (0.0076 min-1) and over seven times faster than the commercial TiO2 photocatalyst standard Degussa P-25 calcined at 1200 °C (0.0030 min-1). The formation of intermediate compounds, oxofluorotitanates, was identified as the major reason for a delay in the anatase to rutile transition.

  13. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    International Nuclear Information System (INIS)

    Highlights: ► A series of mesoporous CuxMnyOz/SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn2O3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO3/SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe2Ox/MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn2O3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  14. STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Eric D. Wachsman

    2000-10-01

    Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible CO, HC, or NOx and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at lower temperatures tremendous benefits may be accrued, not the least of which is reduced cost. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research is to develop a stable high conductivity (>0.05 S cm{sup -1} at 550 C) electrolyte for lower temperature SOFCs. This objective is specifically directed toward meeting the lowest (and most difficult) temperature criteria for the 21st Century Fuel Cell Program. Meeting this objective provides a potential for future transportation applications of SOFCs, where their ability to directly use hydrocarbon fuels could permit refueling within the existing transportation infrastructure. In order to meet this objective we are developing a functionally gradient bilayer electrolyte comprised of bismuth oxide on the air side and ceria on the fuel side. Bismuth oxide and doped ceria are among the highest ionic conducting electrolytes and in fact bismuth oxide based

  15. Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications

    Science.gov (United States)

    Abu El Hawa, Hani W.

    In this thesis, the inert gas leak evolution problem in electroless-plated palladium-based composite membranes has been revisited. Palladium was doped with a higher melting point element such as ruthenium or platinum and the rate of increase of the nitrogen leak in the temperature range of 500-600 ºC was determined. The results showed that doping Pd with Pt or Ru significantly reduces the leak growth rate compared to a pure Pd membrane by almost one order of magnitude. The addition of Ru to Pd was sufficient to lower the leak growth rate, though the hydrogen permeance stability was not improved. The Pd-Pt alloy membrane, despite having a lower hydrogen permeance, had a stable hydrogen flux at higher temperatures. The influence of high temperature annealing (> 640 ºC) on the thermal stability of pure Pd composite membranes was also investigated in order to correlate between thermal stability and microstructural evolution. Pure Pd composite membranes were subjected to different high temperature annealing processes. It was found that employing such heat treatments improved the thermal stability of the membranes when operated at lower temperatures; evidenced by a suppression of the rate at which hydrogen selectivity towards nitrogen declined over time. SEM images of the microstructural evolution as a function of temperature revealed that porosity, which is typically present in as-deposited electroless plated films, is significantly reduced after heat treatment. Thermal stability was also evaluated in actual steam methane reforming (SMR) environments. Thin film (˜5.0 microm thick) Pd-Ru and Pd-Au composite membranes were fabricated and used to carry out SMR over commercial Ni or Ru based catalysts at temperatures > 480 °C and pressures up to 2.9 MPa. The conversions obtained (≥ 80%) were significantly higher than the thermodynamic equilibrium predicted ( 500 hours) revealed the potential suitability of these Pd-alloys to be candidates for use in SMR membrane

  16. Miniaturizable Ion-Selective Arrays Based on Highly Stable Polymer Membranes for Biomedical Applications

    Science.gov (United States)

    Mir, Mònica; Lugo, Roberto; Tahirbegi, Islam Bogachan; Samitier, Josep

    2014-01-01

    Poly(vinylchloride) (PVC) is the most common polymer matrix used in the fabrication of ion-selective electrodes (ISEs). However, the surfaces of PVC-based sensors have been reported to show membrane instability. In an attempt to overcome this limitation, here we developed two alternative methods for the preparation of highly stable and robust ion-selective sensors. These platforms are based on the selective electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT), where the sulfur atoms contained in the polymer covalently interact with the gold electrode, also permitting controlled selective attachment on a miniaturized electrode in an array format. This platform sensor was improved with the crosslinking of the membrane compounds with poly(ethyleneglycol) diglycidyl ether (PEG), thus also increasing the biocompatibility of the sensor. The resulting ISE membranes showed faster signal stabilization of the sensor response compared with that of the PVC matrix and also better reproducibility and stability, thus making these platforms highly suitable candidates for the manufacture of robust implantable sensors. PMID:24999717

  17. Ultra-small, highly stable, and membrane-impermeable fluorescent nanosensors for oxygen

    International Nuclear Information System (INIS)

    We report on the preparation of ultra-small fluorescent nanosensors for oxygen via a one-pot approach. The nanoparticles have a hydrophobic core capable of firmly hosting hydrophobic luminescent oxygen probes. Their surface is composed of a dense and long-chain poly(ethylene glycol) shell, which renders them cell-membrane impermeable but yet highly sensitive to oxygen, and also highly stable in aqueous solutions and cell culture media. These features make them potentially suitable for sensing oxygen in extracellular fluids such as blood, interstitial and brain fluid, in (micro) bioreactors and micro- or nanoscale fluidic devices. Four kinds of nanosensors are presented, whose excitation spectra cover a wide spectral range (395–630 nm), thus matching many common laser lines, and with emission maxima ranging from 565 to 800 nm, thereby minimizing interference from background luminescence of biomatter. The unquenched lifetimes are on the order of 5.8–234 μs, which—in turn—enables lifetime imaging and additional background separation via time-gated methods. (paper)

  18. Improvement Design of Biochip Towards High Stable Bioparticle Detection Utilizing Dielectrophoresis Impedance Measurement

    Institute of Scientific and Technical Information of China (English)

    Huang Haibo; Qian Cheng; Li Xiangpeng; Chen Liguo; Xu Wenkui; Zheng Liang; Sun Lining

    2015-01-01

    Dielectrophoresis impedance measurement (DEPIM ) is a powerful tool for bioparticle detection due to its advantages of high efficiency ,label-free and low costs .However ,the strong electric field may decrease the viabili-ty of the bioparticle ,thus leading to instability of impedance measurement .A new design of biochip is presented with high stable bioparticle detection capabilities by using both negative dielectrophoresis (nDEP) and traveling wave dielectrophoresis (twDEP) .In the biochip ,a spiral electrode is arranged on the top of channel ,while a detec-tor is arranged on the bottom of the channel .The influence factors on the DEP force and twDEP force are investi-gated by using the basic principle of DEP ,based on which ,the relationship between Clausius-Mossotti (CM) fac-tor and the frequency of electric field is obtained .The two-dimensional model of the biochip is built by using Com-sol Multiphysics .Electric potential distribution ,force distribution and particle trajectory in the channel are then obtained by using the simulation model .Finally ,both the simulations and experiments are performed to demon-strate that the new biochip can enhance the detection efficiency and reduce the negative effects of electric field on the bioparticles .

  19. Stable amorphous georgeite as a precursor to a high-activity catalyst

    Science.gov (United States)

    Kondrat, Simon A.; Smith, Paul J.; Wells, Peter P.; Chater, Philip A.; Carter, James H.; Morgan, David J.; Fiordaliso, Elisabetta M.; Wagner, Jakob B.; Davies, Thomas E.; Lu, Li; Bartley, Jonathan K.; Taylor, Stuart H.; Spencer, Michael S.; Kiely, Christopher J.; Kelly, Gordon J.; Park, Colin W.; Rosseinsky, Matthew J.; Hutchings, Graham J.

    2016-03-01

    Copper and zinc form an important group of hydroxycarbonate minerals that include zincian malachite, aurichalcite, rosasite and the exceptionally rare and unstable—and hence little known and largely ignored—georgeite. The first three of these minerals are widely used as catalyst precursors for the industrially important methanol-synthesis and low-temperature water-gas shift (LTS) reactions, with the choice of precursor phase strongly influencing the activity of the final catalyst. The preferred phase is usually zincian malachite. This is prepared by a co-precipitation method that involves the transient formation of georgeite; with few exceptions it uses sodium carbonate as the carbonate source, but this also introduces sodium ions—a potential catalyst poison. Here we show that supercritical antisolvent (SAS) precipitation using carbon dioxide (refs 13, 14), a process that exploits the high diffusion rates and solvation power of supercritical carbon dioxide to rapidly expand and supersaturate solutions, can be used to prepare copper/zinc hydroxycarbonate precursors with low sodium content. These include stable georgeite, which we find to be a precursor to highly active methanol-synthesis and superior LTS catalysts. Our findings highlight the value of advanced synthesis methods in accessing unusual mineral phases, and show that there is room for exploring improvements to established industrial catalysts.

  20. Stable amorphous georgeite as a precursor to a high-activity catalyst.

    Science.gov (United States)

    Kondrat, Simon A; Smith, Paul J; Wells, Peter P; Chater, Philip A; Carter, James H; Morgan, David J; Fiordaliso, Elisabetta M; Wagner, Jakob B; Davies, Thomas E; Lu, Li; Bartley, Jonathan K; Taylor, Stuart H; Spencer, Michael S; Kiely, Christopher J; Kelly, Gordon J; Park, Colin W; Rosseinsky, Matthew J; Hutchings, Graham J

    2016-03-01

    Copper and zinc form an important group of hydroxycarbonate minerals that include zincian malachite, aurichalcite, rosasite and the exceptionally rare and unstable--and hence little known and largely ignored--georgeite. The first three of these minerals are widely used as catalyst precursors for the industrially important methanol-synthesis and low-temperature water-gas shift (LTS) reactions, with the choice of precursor phase strongly influencing the activity of the final catalyst. The preferred phase is usually zincian malachite. This is prepared by a co-precipitation method that involves the transient formation of georgeite; with few exceptions it uses sodium carbonate as the carbonate source, but this also introduces sodium ions--a potential catalyst poison. Here we show that supercritical antisolvent (SAS) precipitation using carbon dioxide (refs 13, 14), a process that exploits the high diffusion rates and solvation power of supercritical carbon dioxide to rapidly expand and supersaturate solutions, can be used to prepare copper/zinc hydroxycarbonate precursors with low sodium content. These include stable georgeite, which we find to be a precursor to highly active methanol-synthesis and superior LTS catalysts. Our findings highlight the value of advanced synthesis methods in accessing unusual mineral phases, and show that there is room for exploring improvements to established industrial catalysts. PMID:26878237

  1. Structural and spectroscopic evidence for stable chemical bonds and the correlation with high Tc superconductivity

    International Nuclear Information System (INIS)

    It is discovered that in the high-Tc superconducting YBa2−xLaxCu3Oz system, by structural analysis and Raman spectroscopy, a stable ‘fixed triangle’ structure exists in the CuO2 planes. All chemical bonds and angles constituting the O(3)–Cu(2)–O(2) triangle are almost constant with doping. The frequencies and linewidths of the out-of-phase c-axis O(2)–O(3) buckling modes around 337 cm−1 and the in-plane Cu(2)–O(2) bond stretching modes around 534 cm−1 are both independent of the doping level, providing direct evidence for the stability of this fixed triangle. It was previously revealed that just these two phonons couple strongly with the antinodal and nodal electronic states, respectively, resulting in an anisotropic electron–phonon interaction in the cuprates. This work implies that the stability of the CuO2 subunit and phonons related to it might be quite important in inducing the d-wave high-Tc superconductivity and should be paid more attention. (paper)

  2. Generation of highly stable DC current by using a superconducting transformer

    International Nuclear Information System (INIS)

    The purpose of this study is to generate a highly stable DC current by using a superconducting transformer. For the first trial stage, a 100 A class superconducting transformer was designed and fabricated for operation at the temperature of liquid nitrogen. The secondary coil of the transformer was wound with a superconducting Bi-2223 tape, and the turn ratio of the primary and secondary windings was about 11:1, which brought an output current of about 80 A by a small varying control current. The control system was constructed with a PC, an AD/DA conversion PCI board and a small current supply. The primary input current was controlled by a normal PID control program. The secondary output current was evaluated by measuring the voltage on a low resistivity shunt. As the result of this study, it was suggested that in the case of small impedance in secondary winding circuit, the DC output current with high stability can be obtained by applying an easy control algorithm to the program running on the controlling PC

  3. Assessment of sulfate sources in high-elevation Asian precipitation using stable sulfur isotopes.

    Science.gov (United States)

    Pruett, Lee E; Kreutz, Karl J; Wadleigh, Moire; Aizen, Vladimir

    2004-09-15

    Stable sulfur isotope measurements (delta34S) made on samples collected from a 2 m snowpit on the Inilchek Glacier, Tien Shan Mountains (42.16 degrees N, 80.25 degrees E, 5100 m) are used to estimate sources of sulfate (SO4(2-)) in high-elevation Central Asian precipitation. Comparison of snowpit oxygen isotope (delta18O) data with previous work constrains the age of the snowpit samples to the summer season during which they were retrieved (1999). Delta34S measurements were made at 10 cm resolution (20 samples total), with delta34S values ranging from 0.4/1000 during background ([SO4(2-)] Tien Shan snowpit provide the first unambiguous identification of evaporite and anthropogenic SO4(2-) in high-elevation Asian precipitation, and future ice core studies using improved analysis techniques and source delta34S values can provide detailed information on sulfur biogeochemistry and anthropogenic impacts in Asian alpine regions. PMID:15487779

  4. A highly stable and sensitive chemically modified screen-printed electrode for sulfide analysis

    International Nuclear Information System (INIS)

    We report here a highly stable and sensitive chemically modified screen-printed carbon electrode (CMSPE) for sulfide analysis. The CMSPE was prepared by first ion-exchanging ferricyanide into a Tosflex anion-exchange polymer and then sealing with a tetraethyl orthosilicate sol-gel layer. The sol-gel overlayer coating was crucial to stabilize the electron mediator (i.e., Fe(China)63-) from leaching. The strong interaction between the oxy-hydroxy functional group of sol-gel and the hydrophilic sites of Tosflex makes the composite highly rigid to trap the ferricyanide mediator. An obvious electrocatalytic sulfide oxidation current signal at ∼0.20 V versus Ag/AgCl in pH 7 phosphate buffer solution was observed at the CMSPE. A linear calibration plot over a wide range of 0.1 μM to 1 mM with a slope of 5.6 nA/μM was obtained by flow injection analysis. The detection limit (S/N = 3) was 8.9 nM (i.e., 25.6 ppt). Practical utility of the system was applied to the determination of sulfide trapped from cigarette smoke and sulfide content in hot spring water

  5. Highly stable concentrated nanoemulsions by the phase inversion composition method at elevated temperature.

    Science.gov (United States)

    Yu, Lijie; Li, Chao; Xu, Jian; Hao, Jingcheng; Sun, Dejun

    2012-10-16

    Oil-in-water nanoemulsions were produced in the system water/Span 80-Tween 80/paraffin oil via the phase inversion composition (PIC) method at elevated temperature. With the increase of preparation temperature from 20 to 70 °C, we found that the emulsion droplet diameter decreases from 10.3 μm to 51 nm, proving the formation of nanoemulsions. The viscosity of nanoemulsions clearly increases with droplet volume fraction, φ, but the droplet size changes less. Significantly, at φ ≤ 0.5, the size distribution of nanoemulsions can be kept unchangeable more than 5 months. These results proved that the highly viscous paraffin oil can hardly be dispersed by the PIC method at 25 °C, but the increase in preparation temperature makes it possible for producing monodisperse nanoemulsions. Once the nanoemulsion is produced, the stability against Ostwald ripening is outstanding due to the extremely low solubility of the paraffin oil in the continuous phase. The highly stable nanoemulsions are of great importance in practical applications. PMID:22985401

  6. Highly stable and sensitive LnMOF ratiometric thermometers constructed with mixed ligands.

    Science.gov (United States)

    Wei, Yongqin; Sa, Rongjian; Li, Qiaohong; Wu, Kechen

    2015-02-21

    The mixed-lanthanide metal-organic frameworks (M'LnMOFs) applied for accurate, non-invasive and self-reference temperature measurements have been only recently recognized. It is a great challenge for chemists to fulfil the requirements of a thermostable structure, intense luminescence and high temperature sensitivity on one LnMOF ratiometric thermometer for thermometric applications. By choosing 2,4-(2,2':6',2''-terpyridin-4'-yl)-benzenedisulfonic acid (H2DSTP) as the first ligand and changing the ancillary ligand to oxalic acid (OA) or 1,4-benzene dicarboxylic acid (BDC), we have successfully developed two types of highly stable and sensitive thermometers [Tb1-xEux(OA)0.5(DSTP)]·3H2O and [Tb1-xEux(BDC)0.5(DSTP)]·2H2O (x = 0.01, 0.02) that in addition exhibit brilliant luminescence over a wide temperature range, providing a new strategy to explore luminescence-based M'LnMOF thermometers. PMID:25566973

  7. High-resolution profiling of the stable isotopes of water in unsaturated coal waste rock

    Science.gov (United States)

    Barbour, S. Lee; Hendry, M. Jim; Carey, Sean K.

    2016-03-01

    Characterization of the rate of water migration through unsaturated mine waste rock dumps is an essential element in assessing the chemical loading from these landforms; yet our understanding of how water moves into, through and out of waste rock is incomplete. To further understand the rates and magnitude of percolation through waste rock, deep high-resolution (every 0.1-4.5 m) depth profiles of the stable isotopes of water (δ2H and δ18O) at two coal waste rock dumps and a natural alluvial deposit down-gradient of one of the dumps were collected in the Elk Valley, British Columbia, Canada. The profiles were generated using vapor equilibrium techniques applied to continuous core samples collected using dry sonic drilling methods. Elevated core temperatures (up to 80 °C) were measured during sonic coring. The isotopic values of pore waters measured in the core samples were corrected for water loss to the atmosphere attributed to the elevated core temperatures. The average isotopic composition of the core samples were compared to water collected from rock drains discharging from the base of the dumps. The results indicate that high-resolution profiles of δ2H and δ18O can be measured to depths of 86 m in coal waste rock dumps and, based on the seasonal cycles in the isotopic composition of recharging water, can be used to characterize the migration of recharge water within these dumps. These profiles also suggest that recharge into these dumps occurs from both rain as well as snow melt and may be as high as 400-600 mm/yr (60-75% of annual precipitation). Combined with the relatively low volumetric water contents of these dumps (5-10%) the rates of water migration through the dumps are tens of meters each year.

  8. Highly Stable Operation of Lithium Metal Batteries Enabled by the Formation of a Transient High Concentration Electrolyte Layer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Mei, Donghai; Engelhard, Mark H.; Cartmell, Samuel S.; Polzin, Bryant; Wang, Chong M.; Zhang, Jiguang; Xu, Wu

    2016-02-08

    Lithium (Li) metal has been extensively investigated as an anode for rechargeable battery applications due to its ultrahigh specific capacity and the lowest redox potential. However, significant challenges including dendrite growth and low Coulombic efficiency are still hindering the practical applications of rechargeable Li metal batteries. Here, we demonstrate that long-term cycling of Li metal batteries can be realized by the formation of a transient high concentration electrolyte layer near the surface of Li metal anode during high rate discharge process. The highly concentrated Li+ ions in this transient layer will immediately solvate with the available solvent molecules and facilitate the formation of a stable and flexible SEI layer composed of a poly(ethylene carbonate) framework integrated with other organic/inorganic lithium salts. This SEI layer largely suppresses the corrosion of Li metal anode by free organic solvents and enables the long-term operation of Li metal batteries. The fundamental findings in this work provide a new direction for the development and operation of Li metal batteries that could be operated at high current densities for a wide range of applications.

  9. Unpredictably Stable

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2014-01-01

    Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications for...

  10. A highly active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide.

    Science.gov (United States)

    Liu, Wen; Hu, Enyuan; Jiang, Hong; Xiang, Yingjie; Weng, Zhe; Li, Min; Fan, Qi; Yu, Xiqian; Altman, Eric I; Wang, Hailiang

    2016-01-01

    Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superior activity for hydrogen evolution, achieving current densities of 10 mA cm(-2) and 100 mA cm(-2) at overpotentials of 48 mV and 109 mV, respectively. Phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation. PMID:26892437

  11. Globally stable structures of LixZn (x = 1-4) compounds at high pressures.

    Science.gov (United States)

    Bi, Haixin; Zhang, Shoutao; Wei, Shubo; Wang, Jianyun; Zhou, Dan; Li, Quan; Ma, Yanming

    2016-02-01

    Pressure can change the properties of atoms and bonding patterns, leading to the synthesis of novel compounds with interesting properties. The intermetallic lithium-zinc (Li-Zn) compounds have attracted increasing attention because of their fascinating mechanical properties and widespread applications in rechargeable Li-ion batteries. Using the effective CALYPSO searching method in combination with first-principles calculations, we theoretically investigated the LixZn (x = 1-4) compounds at pressures of 0 to 100 GPa. We found several stable structures with a variety of stoichiometries and the phase diagram on the Li-rich side under high pressure. The electronic structures of these compounds reveal transferred charges from lithium to zinc mainly fill Zn 4p states and compounds with negatively charged Zn atoms are dramatic. We also calculated the elastic constants to discuss their mechanical properties. Our results enrich the crystal structures of the Li-Zn system and provide a further understanding of structural features and their properties. PMID:26791574

  12. Highly enhanced and temporally stable field emission from MWCNTs grown on aluminum coated silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sreekanth, M.; Ghosh, S., E-mail: santanu1@physics.iitd.ernet.in; Patra, R.; Srivastava, P. [Nanostech Laboratory, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016 (India)

    2015-06-15

    In this work, a detailed field emission study of multi-walled carbon nanotubes (MWCNTs) grown on Si and Al coated Si substrates is reported. Morphological and microstructural studies of the films show higher entanglement of CNTs in the case of CNT/Si film as compared to CNT/Al/Si film. Raman studies show that the defect mediated peak (D) is substantially suppressed as compared to graphitic peak (G) resulting in significant reduction in I{sub D}/I{sub G} value in CNT/Al/Si film. Field emission (FE) current density of CNT/Al/Si film (∼25 mA/cm{sup 2}) is significantly higher as compared to that of CNT/Si film (∼1.6 mA/cm{sup 2}). A substantial improvement in temporal stability is also observed in CNT/Al/Si film. This enhancement in field emission current is attributed to strong adhesion between substrate and CNTs, low work function, high local field enhancement factor at the CNT tips and less entanglement of CNTs grown on Al/Si. The temporally stable CNT/Al/Si cold cathode can be a potential candidate to replace conventional electron sources in prototype devices.

  13. Highly enhanced and temporally stable field emission from MWCNTs grown on aluminum coated silicon substrate

    International Nuclear Information System (INIS)

    In this work, a detailed field emission study of multi-walled carbon nanotubes (MWCNTs) grown on Si and Al coated Si substrates is reported. Morphological and microstructural studies of the films show higher entanglement of CNTs in the case of CNT/Si film as compared to CNT/Al/Si film. Raman studies show that the defect mediated peak (D) is substantially suppressed as compared to graphitic peak (G) resulting in significant reduction in ID/IG value in CNT/Al/Si film. Field emission (FE) current density of CNT/Al/Si film (∼25 mA/cm2) is significantly higher as compared to that of CNT/Si film (∼1.6 mA/cm2). A substantial improvement in temporal stability is also observed in CNT/Al/Si film. This enhancement in field emission current is attributed to strong adhesion between substrate and CNTs, low work function, high local field enhancement factor at the CNT tips and less entanglement of CNTs grown on Al/Si. The temporally stable CNT/Al/Si cold cathode can be a potential candidate to replace conventional electron sources in prototype devices

  14. Synthesis of Highly Stable Cobalt Nanomaterial Using Gallic Acid and Its Application in Catalysis

    Directory of Open Access Journals (Sweden)

    Saba Naz

    2014-01-01

    Full Text Available We report the room temperature (25–30°C green synthesis of cobalt nanomaterial (CoNM in an aqueous medium using gallic acid as a reducing and stabilizing agent. pH 9.5 was found to favour the formation of well dispersed flower shaped CoNM. The optimization of various parameters in preparation of nanoscale was studied. The AFM, SEM, EDX, and XRD characterization studies provide detailed information about synthesized CoNM which were of 4–9 nm in dimensions. The highly stable CoNM were used to study their catalytic activity for removal of azo dyes by selecting methyl orange as a model compound. The results revealed that 0.4 mg of CoNM has shown 100% removal of dye from 50 μM aqueous solution of methyl orange. The synthesized CoNM can be easily recovered and recycled several times without decrease in their efficiency.

  15. Highly sensitive and stable electrochemical sulfite biosensor incorporating a bacterial sulfite dehydrogenase.

    Science.gov (United States)

    Kalimuthu, Palraj; Tkac, Jan; Kappler, Ulrike; Davis, Jason J; Bernhardt, Paul V

    2010-09-01

    This paper describes a highly sensitive electrochemical (voltammetric) determination of sulfite using a combination of Starkeya novella sulfite dehydrogenase (SDH), horse heart cytochrome c (cyt c), and a self-assembled monolayer of 11-mercaptoundecanol (MU) cast on a gold electrode. The biosensor was optimized in terms of pH and the ratio of cyt c/SDH. The electrocatalytic oxidation current of sulfite increased linearly from 1 to 6 microM at the enzyme-modified electrode with a correlation coefficient of 0.9995 and an apparent Michaelis constant (K(M,app)) of 43 microM. Using an amperometric method, the low detection limit for sulfite at the enzyme-modified electrode was 44 pM (signal-to-noise ratio = 3). The modified electrode retained a stable response for 3 days while losing only ca. 4% of its initial sensitivity during a 2 week storage period in 50 mM Tris buffer solution at 4 degrees C. The enzyme electrode was successfully used for the determination of sulfite in beer and white wine samples. The results of these electrochemical analyses agreed well with an independent spectrophotometric method using Ellman's reagent, but the detection limit was far superior using the electrochemical method. PMID:20698497

  16. Surface engineered gold nanoparticles through highly stable metal-surfactant complexes.

    Science.gov (United States)

    Kim, Sunghwan; Jang, Youngjin; Yoon, Ki Youl; Park, Jongnam

    2016-02-15

    Monodispersed Au nanoparticles were synthesized by the reduction of Au-decyltrimethylammonium bromide (Au-DTAB), which was easily prepared via the reaction of HAuCl4 and DTAB. This Au-DTAB complex is highly stable in air and moisture, and suitable for large-scale synthesis of uniform-sized Au nanoparticles. The nanoparticles were characterized by transmission electron microscopy, optical absorption spectrometry, X-ray diffraction, and Fourier Transform infrared spectroscopy. The size of Au nanoparticles was controlled in the range of 5-10nm by changing the concentrations of reducing agent and Au precursor. The resulting Au nanoparticles were transferred to the aqueous phase after surface engineering using multidentate polymeric ligands with multiple imidazole functional groups. Polymeric imidazole ligands (PILs) demonstrated enhanced binding stability with the Au surface, and overcame the disadvantage of multidentate thiol ligand systems which have oxidative cross-linking and the formation of disulfide bonding. The colloidal stability of surface engineered Au nanoparticles with PILs was investigated by dynamic light scattering (DLS) characterization. PMID:26609930

  17. A highly active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide

    Science.gov (United States)

    Liu, Wen; Hu, Enyuan; Jiang, Hong; Xiang, Yingjie; Weng, Zhe; Li, Min; Fan, Qi; Yu, Xiqian; Altman, Eric I.; Wang, Hailiang

    2016-02-01

    Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superior activity for hydrogen evolution, achieving current densities of 10 mA cm-2 and 100 mA cm-2 at overpotentials of 48 mV and 109 mV, respectively. Phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation.

  18. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, F.M. [Department of Chemistry, Tianjin University, Tianjin 300072 (China); Liu, B.S., E-mail: bingsiliu@tju.edu.cn [Department of Chemistry, Tianjin University, Tianjin 300072 (China); Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle [Department of Chemistry, Tianjin University, Tianjin 300072 (China)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer A series of mesoporous Cu{sub x}Mn{sub y}O{sub z}/SBA-15 sorbents were fabricated for hot coal gas desulfurization. Black-Right-Pointing-Pointer 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. Black-Right-Pointing-Pointer Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700-850 Degree-Sign C. The successive nine desulfurization-regeneration cycles at 800 Degree-Sign C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn{sub 2}O{sub 3} particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 Degree-Sign C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO{sub 3}/SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe{sub 2}O{sub x}/MCM-41 (5.58 g S/100 g sorbents) used only at 500-550 Degree-Sign C. This suggested that the loading of Mn{sub 2}O{sub 3} active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  19. The research of the high precision universal stable reconnaissance platform in near space

    Science.gov (United States)

    Yang, Hong-tao; Cao, Jian-zhong; Fan, Zhe-yuan; Chen, Wei-ning

    2011-08-01

    The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20μrad and burden heavy load to the best of one's abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

  20. STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Eric D. Wachsman; Keith L. Duncan

    2001-09-30

    Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible hydrocarbons, CO, or NO{sub x} and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at low to intermediate1 temperatures tremendous benefits may be accrued. At low temperatures, in particular, it becomes feasible to use ferritic steel for interconnects instead of expensive and brittle ceramic materials such as those based on LaCrO{sub 3}. In addition, sealing the fuel cell becomes easier and more reliable; rapid start-up is facilitated; thermal stresses (e.g., those caused by thermal expansion mismatches) are reduced; radiative losses ({approx}T{sup 4}) become minimal; electrode sintering becomes negligible and (due to a smaller thermodynamic penalty) the SOFC operating cycle (heating from ambient) would be more efficient. Combined, all these improvements further result in reduced initial and operating costs. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research are to develop a stable high conductivity (> 0.05 S cm{sup -1} at {le} 550 C) electrolyte for lower

  1. Topology-guided design and syntheses of highly stable mesoporous porphyrinic zirconium metal-organic frameworks with high surface area

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tian -Fu [Texas A & M Univ., College Station, TX (United States); Feng, Dawei [Texas A & M Univ., College Station, TX (United States); Chen, Ying -Pin [Texas A & M Univ., College Station, TX (United States); Zou, Lanfang [Texas A & M Univ., College Station, TX (United States); Bosch, Mathieu [Texas A & M Univ., College Station, TX (United States); Yuan, Shuai [Texas A & M Univ., College Station, TX (United States); Wei, Zhangwen [Texas A & M Univ., College Station, TX (United States); Fordham, Stephen [Texas A & M Univ., College Station, TX (United States); Wang, Kecheng [Texas A & M Univ., College Station, TX (United States); Zhou, Hong -Cai [Texas A & M Univ., College Station, TX (United States)

    2015-01-14

    Through a topology-guided strategy, a series of Zr₆-containing isoreticular porphyrinic metal–organic frameworks (MOFs), PCN-228, PCN-229, and PCN-230, with ftw-a topology were synthesized using the extended porphyrinic linkers. The bulky porphyrin ring ligand effectively prevents the network interpenetration which often appears in MOFs with increased linker length. The pore apertures of the structures range from 2.5 to 3.8 nm, and PCN-229 demonstrates the highest porosity and BET surface area among the previously reported Zr-MOFs. Additionally, by changing the relative direction of the terminal phenyl rings, this series replaces a Zr₈ cluster with a smaller Zr₆ cluster in a topologically identical framework. The high connectivity of the Zr₆ cluster yields frameworks with enhanced stability despite high porosity and ultralarge linker. As a representative example, PCN-230, constructed with the most extended porphyrinic linker, shows excellent stability in aqueous solutions with pH values ranging from 0 to 12 and demonstrates one of the highest pH tolerances among all porphyrinic MOFs. This work not only presents a successful example of rational design of MOFs with desired topology, but also provides a strategy for construction of stable mesoporous MOFs.

  2. Topology-Guided Design and Syntheses of Highly Stable Mesoporous Porphyrinic Zirconium Metal-Organic Frameworks with High Surface Area

    Energy Technology Data Exchange (ETDEWEB)

    Liu, TF; Feng, DW; Chen, YP; Zou, LF; Bosch, M; Yuan, S; Wei, ZW; Fordham, S; Wang, KC; Zhou, HC

    2015-01-14

    Through a topology-guided strategy, a series of Zr-6-containing isoreticular porphyrinic metalorganic frameworks (MOFs), PCN-228, PCN-229, and PCN-230, with ftw-a topology were synthesized using the extended porphyrinic linkers. The bulky porphyrin ring ligand effectively prevents the network interpenetration which often appears in MOFs with increased linker length. The pore apertures of the structures range from 2.5 to 3.8 nm, and PCN-229 demonstrates the highest porosity and BET surface area among the previously reported Zr-MOFs. Additionally, by changing the relative direction of the terminal phenyl rings, this series replaces a Zr-8 cluster with a smaller Zr-6 cluster in a topologically identical framework. The high connectivity of the Zr-6 cluster yields frameworks with enhanced stability despite high porosity and ultralarge linker. As a representative example, PCN-230, constructed with the most extended porphyrinic linker, shows excellent stability in aqueous solutions with pH values ranging from 0 to 12 and demonstrates one of the highest pH tolerances among all porphyrinic MOFs. This work not only presents a successful example of rational design of MOFs with desired topology, but also provides a strategy for construction of stable mesoporous MOFs.

  3. Highly Sensitive and Long Term Stable Electrochemical Microelectrodes for Implantable Glucose Monitoring Devices

    Science.gov (United States)

    Qiang, Liangliang

    A miniature wireless implantable electrochemical glucose system for continuous glucose monitoring with good selectivity, sensitivity, linearity and long term stability was developed. First, highly sensitive, long-term stable and reusable planar H2O2 microelectrodes have been fabricated by microlithography. These electrodes composed of a 300 nm Pt black layer situated on a 5 um thick Au layer, provide effective protection to the underlying chromium adhesion layer. Using repeated cyclic voltammetric sweeps in flowing buffer solution, highly sensitive Pt black working electrodes were realized with five-decade linear dynamic range and low detection limit (10 nM) for H2O2 at low oxidation potentials. Second, a highly sensitive, low cost and flexible microwire biosensor was described using 25-mum thick gold wire as working electrode together with 125-mum thick Pt/Ir and Ag wires as counter and reference electrode, embedded within a PDMS-filled polyethylene tube. Surface area and activity of sensor was enhanced by converting gold electrode to nanoporous configuration followed by electrodeposition of platinum black. Glucose oxidase based biosensors by electrodeposition of poly(o-phenylenediamine) and glucose oxidase on the working electrode, displayed a higher glucose sensitivity (1.2 mA mM-1 cm-2) than highest literature reported. In addition it exhibits wide detection range (up to 20 mM) and selectivity (>95%). Third, novel miniaturized and flexible microelectrode arrays with 8 of 25 mum electrodes displayed the much needed 3D diffusion profiles similar to a single 25 mum microelectrode, but with one order increase in current levels. These microelectrode arrays displayed a H2O2 sensitivity of 13 mA mM-1 cm-2, a wide dynamic range of 100 nM to 10 mM, limit of detection of 10 nM. These microwire based edge plane microsensors incorporated flexibility, miniaturization and low operation potential are an promising approach for continuous in vivo metabolic monitoring. Fourth

  4. Nitrogen stable isotopes of ammonium and nitrate in high mountain lakes of the Pyrenees

    Directory of Open Access Journals (Sweden)

    M. Bartrons

    2009-12-01

    Full Text Available Nitrogen stable isotopes (δ15N are increasingly used to trace food web relationships and the flow of matter in lakes. However, there is high variability in δ15N among primary producers and other primary energy resources that can eventually propagate throughout the lake food web. To increase our understanding of the origin of this variability, we measured ammonium and nitrate δ15N in atmospheric deposition (AD, epilimnetic water (EW, deep chlorophyll maximum water (DCMW, and sediment porewater (SPW in eight mountain lakes. A general δ15N (−3.4‰ for AD was estimated as the signature for AD ammonium and nitrate did not differ. All lakes showed similar high δ15N-NH4+ values for SPW (ca. 2.2‰. In contrast, the variability among lakes in water column values was high, although differences between EW and DCMW within a lake were low. δ15N-NO3- correlated with the altitude of the lakes, and its variability was interpreted as the influence of catchment nitrification, which is higher in talus landscapes. δ15N-NH4+ distribution had two modes, positive values (ca. 3‰ were associated to DCMW of shallow lakes, and probably reflect the SPW influence. Lower values (ca. −3‰ occur in EW and DCMW of deep lakes, and its variability was related to the degree that NO3- was up taken by primary producers and recycled within the food-web when NH4+ availability was low compared to demand. Overall, altitude, lake depth and seasonal cumulative primary production largely explain the patterns of δ15N variability observed in nitrogen dissolved compounds.

  5. A Stable Flexible Silicon Nanowire Array as Anode for High-Performance Lithium-ion Batteries

    International Nuclear Information System (INIS)

    Highlights: • A flexible SiNW array in PDMS structure is designed and fabricated as Li-ion battery anode material. • The aggregation and fracture of SiNWs are alleviated by the flexible PDMS skeleton during the process of charge and discharge. • The loose SiO2 shells coating on the SiNWscould form the protective layer in charge/discharge. • The as-obtain flexible SiNW array/PDMS composite exhibits a much better cycling stability. - Abstract: A Silicon nanowire (SiNW) array inserted into flexible poly-dimethylsiloxane (SiNW array/PDMS) composite structure as anode with high capacity and long-term cycling stability is synthesized by a cost-effective and scalable method. In this structure, the aggregation and fracture of SiNWs are alleviated by the flexible PDMS skeleton. Act as the main active component, the SiNWs are coated by loose SiO2 shells. These loose SiO2 shells not only provide space for the large volume changes of SiNW, but also react with the electrolyte and form the stable protective layer during the processes of the lithiation and delithiation. These two functions could improve the cycling stability and columbic efficiency of the SiNWs. The as-obtain flexible SiNW array/PDMS composite structure exhibits excellent long-term cycling stability with a specific capacity of 887.2 mA·h·g−1 and capacity retention of ∼83.4% over 350 cycles at 0.5 C rate compared with the fifteenth cycle. The design of this new structure provides a potential way for developing other functional composite materials

  6. Highly Active and Stable Large Catalase Isolated from a Hydrocarbon Degrading Aspergillus terreus MTCC 6324.

    Science.gov (United States)

    Vatsyayan, Preety; Goswami, Pranab

    2016-01-01

    A hydrocarbon degrading Aspergillus terreus MTCC 6324 produces a high level of extremely active and stable cellular large catalase (CAT) during growth on n-hexadecane to combat the oxidative stress caused by the hydrocarbon degrading metabolic machinery inside the cell. A 160-fold purification with specific activity of around 66 × 10(5) U mg(-1) protein was achieved. The native protein molecular mass was 368 ± 5 kDa with subunit molecular mass of nearly 90 kDa, which indicates that the native CAT protein is a homotetramer. The isoelectric pH (pI) of the purified CAT was 4.2. BLAST aligned peptide mass fragments of CAT protein showed its highest similarity with the catalase B protein from other fungal sources. CAT was active in a broad range of pH 4 to 12 and temperature 25°C to 90°C. The catalytic efficiency (K cat/K m ) of 4.7 × 10(8) M(-1) s(-1) within the studied substrate range and alkaline pH stability (half-life, t 1/2 at pH 12~15 months) of CAT are considerably higher than most of the extensively studied catalases from different sources. The storage stability (t 1/2) of CAT at physiological pH 7.5 and 4°C was nearly 30 months. The haem was identified as haem b by electrospray ionization tandem mass spectroscopy (ESI-MS/MS). PMID:27057351

  7. HIGH ORDER ONE-STEP A-STABLE EXPONENTIALLY FITTED METHODS

    Institute of Scientific and Technical Information of China (English)

    YangFengiian; ChenXinming; LuoYiping

    1999-01-01

    In this paper,the necessary and sutlicient conditions for general one-step methoos to be exponentially fitted at q0∈C are given, A class of multtderivative hybrid one-step methods of order at least s+1 is constructed with s+1 parameters,where s is the order of derivative. The necessary and sufficient conditions for these methods to be A-stable and exponentially fitted is proved, Furthermore,a class of A-stable 2 parameters hybrid one-step methods of order at least 8 are constructed,which use 4th order derivative,These methods are exponentially fitted at q0 if and only its fitted function f(q) satisfies f(q0)= 0, Finally,an A-stable exponentlally fitted method of order 8 is obtained.

  8. Restrictions of stable bundles

    CERN Document Server

    Balaji, V

    2011-01-01

    The Mehta-Ramanathan theorem ensures that the restriction of a stable vector bundle to a sufficiently high degree complete intersection curve is again stable. We improve the bounds for the "sufficiently high degree" and propose a possibly optimal conjecture.

  9. Potassium Stable Isotopic Compositions Measured by High-Resolution MC-ICP-MS

    Science.gov (United States)

    Morgan, Leah E.; Lloyd, Nicholas S.; Ellam, Robert M.; Simon, Justin I.

    2012-01-01

    Potassium isotopic (K-41/K-39) compositions are notoriously difficult to measure. TIMS measurements are hindered by variable fractionation patterns throughout individual runs and too few isotopes to apply an internal spike method for instrumental mass fractionation corrections. Internal fractionation corrections via the K-40/K-39 ratio can provide precise values but assume identical K-40/K-39 ratios (e.g. 0.05% (1sigma) in [1]); this is appropriate in some cases (e.g. identifying excess K-41) but not others (e.g., determining mass fractionation effects and metrologically traceable isotopic abundances). SIMS analyses have yielded measurements with 0.25% precisions (1sigma) [2]. ICP-MS analyses are significantly affected by interferences from molecular species such as Ar-38H(+) and Ar-40H(+) and instrument mass bias. Single collector ICP-MS instruments in "cold plasma" mode have yielded uncertainties as low as 2% (1sigma, e.g. [3]). Although these precisions may be acceptable for some concentration determinations, they do not resolve isotopic variation in terrestrial materials. Here we present data from a series of measurements made on the Thermo Scientific NEPTUNE Plus multi-collector ICP-MS that demonstrate the ability to make K-41/K-39 ratio measurements with 0.07% precisions (1sigma). These data, collected on NIST K standards, indicate the potential for MC-ICP-MS measurements to look for K isotopic variations at the sub-permil level. The NEPTUNE Plus can sufficiently resolve 39K and 41K from the interfering 38ArH+ and 40ArH+ peaks in wet cold plasma and high-resolution mode. Measurements were made on small but flat, interference-free, plateaus (ca. 50 ppm by mass width for K-41). Although ICP-MS does not yield accurate K-41/K-39 values due to significant instrumental mass fractionation (ca. 6%), this bias can be sufficiently stable over the time required for several measurements so that relative K-41/K-39 values can be precisely determined via sample

  10. Development of thermally stable and mechanically strong polymer composite materials for high impact applications

    International Nuclear Information System (INIS)

    The focus of this work was to develop thermally stable and mechanically strong polymer blend / composite systems for certain high impact applications. Two different commercially available polymers Polyamide (Nylon 6) and Polycarbonate (PC) were selected for this purpose. In order to improve the thermal and mechanical properties of Nylon, organically Modified clay was incorporated in the thermo-plastic matrix material. The uniform distribution and dispersion of clay was achieved by optimizing various parameters like temperature, time of mixing, torque during flush and cycle mode of operation of the co- rotating conical twin screw mini-extrusion machine. Duration of ten minutes under cycle mode at 250 degree C was found to be optimum for uniform exfoliation and distribution of organically modified clay platelets in the matrix. For the development of polycarbonate (PC) based nanocomposites with improved thermal and mechanical properties, Polymethylmethacrylate (PMMA) was blended in 5, 10 and 15 wt. % ratios with PC. Good miscibility in PC/PMMA blends was observed by melt blending them at 260 degree C for 20 minutes. The properties of the blends were further enhanced by incorporating 0.1, 0.2 and 0.3 wt. % of both pristine and carboxylic group (-COOH) functionalized carbon nanotubes (CNTs). While maintaining PC/PMMA blending ratios as 95/5 and 90/10, shear mixing of CNTs in the blend was carried out in the co-rotating conical twin screw extruder at 260 degree C for 20 minutes. Characterization of these composites was performed using FTIR, XRD, Dynamic thermo-mechanical analysis (DTMA) and mechanical testing using universal testing machine. The TMA and XRD results exhibited formation of miscible blends of PC/PMMA when melt blending is performed at 260 degree C for 20 minutes. Although miscible blends were achieved by incorporating up to 15 wt.% PMMA in PC, however, only the combination in 90/10 ratio of PC/PMMA and their composites were found to have high thermal

  11. Stable isotopes and Digital Elevation Models to study nutrient inputs in high-Arctic lakes

    Science.gov (United States)

    Calizza, Edoardo; Rossi, David; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

    2016-04-01

    Ice cover, run-off from the watershed, aquatic and terrestrial primary productivity, guano deposition from birds are key factors controlling nutrient and organic matter inputs in high-Arctic lakes. All these factors are expected to be significantly affected by climate change. Quantifying these controls is a key baseline step to understand what combination of factors subtends the biological productivity in Arctic lakes and will drive their ecological response to environmental change. Basing on Digital Elevation Models, drainage maps, and C and N elemental content and stable isotope analysis in sediments, aquatic vegetation and a dominant macroinvertebrate species (Lepidurus arcticus Pallas 1973) belonging to Tvillingvatnet, Storvatnet and Kolhamna, three lakes located in North Spitsbergen (Svalbard), we propose an integrated approach for the analysis of (i) nutrient and organic matter inputs in lakes; (ii) the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments; (iii) effects of diverse nutrient inputs on the isotopic niche of Lepidurus arcticus. Given its high run-off and large catchment, organic deposits in Tvillingvatnet where dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake with low potential run-off. In Kolhamna, organic deposits seem to be dominated by inputs from birds, which actually colonise the area. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The isotopic niche of L. aricticus reflected differences in sediments between lakes, suggesting a bottom-up effect of hydro-geomorphology characterizing each lake on nutrients assimilated by this species. The presented approach proven to be an effective research pathway for the identification of factors subtending to nutrient and organic matter inputs and transfer

  12. Variation in High-Sensitivity C-Reactive Protein Levels over 24 Hours in Patients with Stable Coronary Artery Disease

    OpenAIRE

    Koc, Mevlut; KARAARSLAN, OSMAN; Abali, Gulcan; Batur, Mustafa Kemal

    2010-01-01

    Limited, controversial data exist regarding changes in high-sensitivity C-reactive protein (hs-CRP) levels over short times and the importance of detecting these changes in patients who have coronary artery disease (CAD). We investigated the variation of hs-CRP levels and their association with the severity of CAD in patients with stable CAD.

  13. Combining UHPLC-High Resolution MS and Feeding of Stable Isotope Labeled Polyketide Intermediates for Linking Precursors to End Products

    DEFF Research Database (Denmark)

    Klitgaard, Andreas; Frandsen, Rasmus John Normand; Holm, Dorte Koefoed; Knudsen, Peter Boldsen; Frisvad, Jens Christian; Nielsen, Kristian Fog

    2015-01-01

    We present the results from stable isotope labeled precursor feeding studies combined with ultrahigh performance liquid chromatography-high resolution mass spectrometry for the identification of labeled polyketide (PK) end-products. Feeding experiments were performed with 13C8-6-methylsalicylic...

  14. Interannual climate variability in the Miocene: high resolution trace element and stable isotope ratios in giant clams

    NARCIS (Netherlands)

    Batenburg, S.J.; Reichart, G.-J.; Jilbert, T.; Janse, Max; Wesselingh, F.P.; Renema, Willem

    2011-01-01

    High resolution stable isotope and trace elemental ratios of a recent Tridacna squamosa from Vietnam and a Middle to Late Miocene (10–13 Ma) Tridacna gigas from Indonesia are presented. The seasonal pattern of modern sea surface temperature (SST) variability offshore Vietnam is faithfully recorded i

  15. Stable Field Emission from Layered MoS2 Nanosheets in High Vacuum and Observation of 1/f Noise

    OpenAIRE

    Ranjit V. Kashid; Joag, Pracheetee D.; Thripuranthaka, M.; Rout, Chandra S.; Late, Dattatray J.; More, Mahendra A.

    2015-01-01

    Field emission and current noise of hydrothermally synthesized MoS2 nanosheets are investigated in ultra- high-vacuum and industrially suited high-vacuum conditions. The study reveals that the emission turn-on field is pressure dependent. Moreover, the MoS2 nano‐ sheets exhibit more stable field-electron emission in high- vacuum than in ultra-high-vacuum conditions. The investigations on field-emission current fluctuations show features of 1/f-type noise in ultra-high-vacuum and high- vacuum ...

  16. Stable Amplification and High Current Drop Bistable Switching in Supercritical GaAs Tills

    DEFF Research Database (Denmark)

    Izadpanah, S.H; Jeppsson, B; Jeppesen, Palle;

    1974-01-01

    Bistable switching with current drops of 40% and switching times of 100 ps are obtained in pulsed operation of 10¿m supercritically doped n+ nn+ GaAs Transferred Electron Devices (TEDs). When CW-operated the same devices exhibit a 5-17 GHz bandwidth for the stable negative resistance....

  17. Shelf-stable egg-based products processed by high pressure thermal sterilization

    Science.gov (United States)

    Producing a thermally sterilized egg-based product with increased shelf life without losing the sensory and nutritional properties of the freshly prepared product is challenging. Until recently, all commercial shelf-stable egg-based products were sterilized using conventional thermal processing; how...

  18. High-order provably stable overset grid methods for hyperbolic problems, with application to the Euler equations

    Science.gov (United States)

    Sharan, Nek; Pantano, Carlos; Bodony, Daniel

    2015-11-01

    Overset grids provide an efficient and flexible framework to implement high-order finite difference methods for simulations of compressible viscous flows over complex geometries. However, prior overset methods were not provably stable and were applied with artificial dissipation in the interface regions. We will discuss new, provably time-stable methods for solving hyperbolic problems on overlapping grids. The proposed methods use the summation-by-parts (SBP) derivative approximations coupled with the simultaneous-approximation-term (SAT) methodology for applying boundary conditions and interface treatments. The performance of the methods will be assessed against the commonly-used approach of injecting the interpolated data onto each grid. Numerical results will be presented to confirm the stability and the accuracy of the methods for solving the Euler equations. The extension of these methods to solve the Navier-Stokes equations on overset grids in a time-stable manner will be briefly discussed.

  19. H4octapa: highly stable complexation of lanthanide(III) ions and copper(II).

    Science.gov (United States)

    Kálmán, Ferenc Krisztián; Végh, Andrea; Regueiro-Figueroa, Martín; Tóth, Éva; Platas-Iglesias, Carlos; Tircsó, Gyula

    2015-03-01

    The acyclic ligand octapa(4-) (H4octapa = 6,6'-((ethane-1,2-diylbis((carboxymethyl)azanediyl))bis(methylene))dipicolinic acid) forms stable complexes with the Ln(3+) ions in aqueous solution. The stability constants determined for the complexes with La(3+), Gd(3+), and Lu(3+) using relaxometric methods are log KLaL = 20.13(7), log KGdL = 20.23(4), and log KLuL = 20.49(5) (I = 0.15 M NaCl). High stability constants were also determined for the complexes formed with divalent metal ions such as Zn(2+) and Cu(2+) (log KZnL = 18.91(3) and log KCuL = 22.08(2)). UV-visible and NMR spectroscopic studies and density functional theory (DFT) calculations point to hexadentate binding of the ligand to Zn(2+) and Cu(2+), the donor atoms of the acetate groups of the ligand remaining uncoordinated. The complexes formed with the Ln(3+) ions are nine-coordinated thanks to the octadentate binding of the ligand and the presence of a coordinated water molecule. The stability constants of the complexes formed with the Ln(3+) ions do not change significantly across the lanthanide series. A DFT investigation shows that this is the result of a subtle balance between the increased binding energies across the 4f period, which contribute to an increasing complex stability, and the parallel increase of the absolute values of the hydration free energies of the Ln(3+) ions. In the case of the [Ln(octapa)(H2O)](-) complexes the interaction between the amine nitrogen atoms of the ligand and the Ln(3+) ions is weakened along the lanthanide series, and therefore the increased electrostatic interaction does not overcome the increasing hydration energies. A detailed kinetic study of the dissociation of the [Gd(octapa)(H2O)](-) complex in the presence of Cu(2+) shows that the metal-assisted pathway is the main responsible for complex dissociation at pH 7.4 and physiological [Cu(2+)] concentration (1 μM). PMID:25692564

  20. Stable and high-performance multiwavelength erbium-doped fiber laser based on fiber delay interferometer

    Institute of Scientific and Technical Information of China (English)

    Shuang LIU; Junqiang SUN; Ping SHUM

    2009-01-01

    In this paper, we proposed a novel scheme to realize the multiwavelength erbium-doped fiber lasers. By adding a length of dispersion shifted fiber (DSF) in the ring cavity, we can suppress the cavity mode competition resulting from homogeneous line broadening (HLB) effect. In addition, a comb filter based on fiber delay inter-ferometer (DI) is used for frequency selecting. To enhance the extinction ratio while maintaining the free space range (FSR), the proposed isolator-assisted double-pass DI is utilized into the laser cavity, and a stable 7-wavelength simultaneous lasing spaced at 21.5GHz is accordingly achieved with an extinction ratio of higher than 40 dB. The lasers are stable with a maximum power fluctuation per channel of less than 0.6 dB during an hour test.

  1. System for High Throughput Water Extraction from Soil Material for Stable Isotope Analysis of Water

    OpenAIRE

    Timothy S. Goebel; Lascano, Robert J.

    2012-01-01

    A major limitation in the use of stable isotope of water in ecological studies is the time that is required to extract water from soil and plant samples. Using vacuum distillation the extraction time can be less than one hour per sample. Therefore, assembling a distillation system that can process multiple samples simultaneously is advantageous and necessary for ecological or hydrological investigations. Presented here is a vacuum distillat...

  2. High resolution measurements of isotope shifts and hyperfine structure in stable and radioactive lead isotopes

    International Nuclear Information System (INIS)

    We present new measurements of isotopic shifts and hyperfine structure in the lead resonance line for a total of 15 isotopes. The experimental accuracy is of order 4 MHz. Using independent measurements of the nuclear parameter lambda for the stable isotopes we have derived lambda for all measured isotopes. The derived lambda values are compared with various theoretical predictions for the lead nuclei. We also give values for the nuclear magnetic dipole and electric quadrupole moments deduced from our measurements. (orig.)

  3. High magnetic shear gain in a liquid sodium stable couette flow experiment A prelude to an alpha - omega dynamo

    Energy Technology Data Exchange (ETDEWEB)

    Colgate, Stirling [Los Alamos National Laboratory; Li, Jui [Los Alamos National Laboratory; Finn, John [Los Alamos National Laboratory; Pariev, Vladimir [Los Alamos National Laboratory; Beckley, Howard [NM INSTIT. OF MINING AND TECH; Si, Jiahe [NM INSTIT. OF MINING AND TECH.; Martinic, Joe [NM INSTIT. OF MINING AND TECH.; Westpfahl, David [NM INSTIT. OF TECH.; Slutz, James [NM INSTIT. OF MINING AND TECH.; Westrom, Zeb [NM INSTIT. OF TECH.; Klein, Brianna [NM INSTIT. OF MINING AND TECH.

    2010-11-08

    The {Omega}-phase of the liquid sodium {alpha}-{Omega} dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, B{sub {phi}} {approx_equal} 8 x B{sub r} from the radial component of an applied poloidal magnetic field, B{sub r}. This enhanced toroidal field is produced by rotational shear in stable Couette Row within liquid sodium at Rm {approx_equal} 120. The small turbulence in stable Taylor-Couette Row is caused by Ekman Row where ({delta}v/v){sup 2} {approx} 10{sup -3}. This high {Omega}-gain in low turbulence flow contrasts with a smaller {Omega}-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays a diffusive role that enables magnetic flux linkage.

  4. Preconditioning methods for high-order strongly stable time integration methods with an application for a DAE problem

    OpenAIRE

    Axelsson, O.; Blaheta, R. (Radim); Kohut, R. (Roman)

    2015-01-01

    High-order strongly stable time integration method enables use of large time steps and is applicable also for differential–algebraic problems, without any order reduction. At each time step, frequently a large-scale linear algebraic system must be solved. To solve the arising block matrix systems, an efficient preconditioning method is presented and analysed. The method is applied for the solution of a consolidation problem arising in poroelasticity.

  5. High-throughput DNA sequence analysis reveals stable engraftment of gut microbiota following transplantation of previously frozen fecal bacteria

    OpenAIRE

    Hamilton, Matthew J; Weingarden, Alexa R.; Unno, Tatsuya; Khoruts, Alexander; Sadowsky, Michael J.

    2013-01-01

    Fecal microbiota transplantation (FMT) is becoming a more widely used technology for treatment of recurrent Clostridum difficile infection (CDI). While previous treatments used fresh fecal slurries as a source of microbiota for FMT, we recently reported the successful use of standardized, partially purified and frozen fecal microbiota to treat CDI. Here we report that high-throughput 16S rRNA gene sequencing showed stable engraftment of gut microbiota following FMT using frozen fecal bacteria...

  6. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to gamma-valerolactone

    OpenAIRE

    Luo, Wenhao; Meenakshisundaram, Sankar; Beale, Andrew M; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into gamma-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on...

  7. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone

    OpenAIRE

    W. Luo; Sankar, M.; Beale, A.M.; Q. He; Kiely, C. J.; Bruijnincx, P. C.; Weckhuysen, B. M.

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on tit...

  8. [Establishment of stable subline of K562 cells overexpressing high mobility group B1 protein].

    Science.gov (United States)

    Yan, Fan-Zhi; Yan, Jin-Song; Zhao, Jia; Li, Wei-Ping; Chen, Xue-Yu; Yang, Yan; Rao, Shu-Mei; Jin, Jing

    2011-02-01

    This study was aimed to establish a stable subline of K562 cells (K562-HMGB1) overexpressing HMGB1 protein and K562-HMGB1 sublines served as control, so as to provide a basis for exploring the role of hmgb1 gene in occurrence and development of leukemia and their mechanism. Protein-coding gene of hmgb1 was amplified by PCR with cDNA as template, which was synthesized by reverse transcription from total RNA extracted from U937 cells. The PCR-amplified hmgb1 gene was ligated into PMD18-T vector (PMD18-T-HMGB1 vector), and then transformed into E. coli strain DH5α. DH5α containing PMD18-T-HMGB1 vector were grown on LB agar plate supplemented with 100 µg/ml ampicillin overnight. The single ampicillin-selected DH5α clone was picked for culturing overnight and then harvested for plasmid extraction. The extracted plasmid was characterized to contain hmgb1 gene digested with the desired restriction enzymes of KpnI/XhoI. The correctness of hmgb1 sequence was confirmed with DNA sequencing. The insert of hmgb1 gene contained in PMD18-T-HMGB1 vector was cut out with restriction enzymes of KpnI/XhoI and then ligated into eukaryotic expression vector pcDNA3.1 to form pcDNA3.1-HMGB1 vector. 10µg of pcDNA3.1-HMGB1 or pcDNA3.1 plasmid was separately electroporated into K562 cells. At 48 hours after electroporation the cells were cultured with G418 at a final concentration of 800 µg/ml for over 2 weeks. Finally stably transfected sublines of K562 cells containing hmgb1 gene (K562-HMGB1), and of K562 containing pcDNA3.1 vector (K562-pcDNA3.1) served as a control, were obtained. The transcriptional or translational expression of hmgb1 gene was detected with RT-PCR or Western blot, respectively, to testify transfected efficiency and validity of stable subline of K562-HMGB1. The results indicated that the eukaryotic expression vector pcDNA3.1-HMGB1 plasmid was successfully constructed and was electroporated into K562 cells. The transcriptional or translational expression of hmgb1

  9. Stable Field Emission from Layered MoS2 Nanosheets in High Vacuum and Observation of 1/f Noise

    Directory of Open Access Journals (Sweden)

    Ranjit V. Kashid

    2015-04-01

    Full Text Available Field emission and current noise of hydrothermally synthesized MoS2 nanosheets are investigated in ultra- high-vacuum and industrially suited high-vacuum conditions. The study reveals that the emission turn-on field is pressure dependent. Moreover, the MoS2 nano‐ sheets exhibit more stable field-electron emission in high- vacuum than in ultra-high-vacuum conditions. The investigations on field-emission current fluctuations show features of 1/f-type noise in ultra-high-vacuum and high- vacuum conditions, attributed to adsorption and desorp‐ tion processes. The post-field-emission results indicate the MoS2 nanosheets are a robust field emitter in high- vacuum conditions.

  10. Stable isotopes on seasonal to millennial time scales as recorded in low-latitude, high-altitude ice cores

    International Nuclear Information System (INIS)

    Full text: This paper examines the stable isotopic ratios, 18O/16O (δ18Oice) and 2H/1H (δDice), preserved in mid to low-latitude glaciers as tools for paleoclimate reconstruction. Ice cores are particularly valuable as they contain additional data (such as dust concentrations, aerosol chemistry, and accumulation rates) that can be combined with the isotopic information to assist with inferences about the regional climate conditions prevailing at the time of deposition. We use a collection of multi-proxy ice core histories to explore the stable isotopic climate relationship on seasonal, decadal, centennial, and millennial timescales. The paper looks closely at the relationship between temperature-precipitation and stable isotopes over these diverse time perspectives. Stable isotopic variations in ice cores from the tropics are highly correlated with sea surface temperatures (SSTs) across the equatorial Pacific Ocean, which are closely linked to ENSO variability. Therefore, a network of ice cores from selected locations offers the prospect of reconstructing low-latitude circulation. Decadally-averaged stable isotopes records from three Andean and three Tibetan ice cores are combined in a composite in order to present a low-latitude stable isotope history for the last two millennium. Comparisons of this composite over the last millennium are made with the Northern Hemisphere proxy record (1000-2000 A.D.) reconstructed by Mann et al. (1999) and measured temperatures (1856-2000 A.D.) reported by Jones et al. (1999). The ice cores evidently have captured a great deal of the decadal-scale variability in the global temperature trends. The ice core record shows a 20th century isotopic enrichment that suggests that a large scale warming is underway at low latitudes. The rate of this isotopically-inferred warming is amplified at higher elevations over the Tibetan Plateau, while amplification in the Andes is latitude-dependent with enrichment (warming) increasing equator

  11. Stable, high-efficiency amorphous silicon solar cells with low hydrogen content

    Science.gov (United States)

    Fortmann, C. M.; Hegedus, S. S.

    1992-12-01

    Results and conclusions obtained during the investigation of amorphous silicon, amorphous silicon based alloy materials, and solar cells fabricated by photo-chemical vapor and glow discharge depositions are reported. Investigation of the effects of the hydrogen content in a-Si:H i-layers in amorphous silicon solar cells show that cells with lowered hydrogen content i-layers are more stable. A classical thermodynamic formulation of the Staebler-Wronski effect has been developed for standard solar cell operating temperatures and illuminations. Methods have been developed to extract a lumped equivalent circuit from the current voltage characteristic of a single junction solar cell in order to predict its behavior in a multijunction device.

  12. Unusually stable abnormal karyotype in a highly aggressive melanoma negative for telomerase activity

    Directory of Open Access Journals (Sweden)

    Irminger-Finger Irmgard

    2008-08-01

    Full Text Available Abstract Malignant melanomas are characterized by increased karyotypic complexity, extended aneuploidy and heteroploidy. We report a melanoma metastasis to the peritoneal cavity with an exceptionally stable, abnormal pseudodiploid karyotype as verified by G-Banding, subtelomeric, centromeric and quantitative Fluorescence in Situ Hybridization (FISH. Interestingly this tumor had no detectable telomerase activity as indicated by the Telomere Repeat Amplification Protocol. Telomeric Flow-FISH and quantitative telomeric FISH on mitotic preparations showed that malignant cells had relatively short telomeres. Microsatellite instability was ruled out by the allelic pattern of two major mononucleotide repeats. Our data suggest that a combination of melanoma specific genomic imbalances were sufficient and enough for this fatal tumor progression, that was not accompanied by genomic instability, telomerase activity, or the engagement of the alternative recombinatorial telomere lengthening pathway.

  13. Structural Characteristics in a Stable Metallic ET Salt with Unusually High Oxidation State (ET: Bis(ethylenedithio)tetrathiafulvalene)

    OpenAIRE

    Minemawari, Hiromi; Jose, Judy Fe F.; Takahashi, Yukihiro; Naito, Toshio; Inabe, Tamotsu

    2012-01-01

    Electrolysis of ET in a mixed solvent of methanol/CHCl3 with bromide yielded (ET)3(Br3)5, in which an unusually high formal charge of ET^[5/3+] is achieved. ET forms a two-dimensional conducting sheet incorporating Br3-[-]. Despite the high formal charge of the ET cations, the strong electrostatic attractions between the ET cations and Br3^[-] support aggregation of the ET cations, allowing sufficient π-π overlap for delocalization of the π-electrons. The crystal shows stable metallic behavio...

  14. High-yield production of a stable Vero cell-based vaccine candidate against the highly pathogenic avian influenza virus H5N1

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Fangye; Zhou, Jian; Ma, Lei; Song, Shaohui; Zhang, Xinwen; Li, Weidong; Jiang, Shude [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People' s Republic of China (China); Wang, Yue, E-mail: euy-tokyo@umin.ac.jp [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Yingxin Lane 100, Xicheng District, Beijing 100052, People' s Republic of China (China); Liao, Guoyang, E-mail: liaogy@21cn.com [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People' s Republic of China (China)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Vero cell-based HPAI H5N1 vaccine with stable high yield. Black-Right-Pointing-Pointer Stable high yield derived from the YNVa H3N2 backbone. Black-Right-Pointing-Pointer H5N1/YNVa has a similar safety and immunogenicity to H5N1delta. -- Abstract: Highly pathogenic avian influenza (HPAI) viruses pose a global pandemic threat, for which rapid large-scale vaccine production technology is critical for prevention and control. Because chickens are highly susceptible to HPAI viruses, the supply of chicken embryos for vaccine production might be depleted during a virus outbreak. Therefore, developing HPAI virus vaccines using other technologies is critical. Meeting vaccine demand using the Vero cell-based fermentation process has been hindered by low stability and yield. In this study, a Vero cell-based HPAI H5N1 vaccine candidate (H5N1/YNVa) with stable high yield was achieved by reassortment of the Vero-adapted (Va) high growth A/Yunnan/1/2005(H3N2) (YNVa) virus with the A/Anhui/1/2005(H5N1) attenuated influenza vaccine strain (H5N1delta) using the 6/2 method. The reassorted H5N1/YNVa vaccine maintained a high hemagglutination (HA) titer of 1024. Furthermore, H5N1/YNVa displayed low pathogenicity and uniform immunogenicity compared to that of the parent virus.

  15. High-yield production of a stable Vero cell-based vaccine candidate against the highly pathogenic avian influenza virus H5N1

    International Nuclear Information System (INIS)

    Highlights: ► Vero cell-based HPAI H5N1 vaccine with stable high yield. ► Stable high yield derived from the YNVa H3N2 backbone. ► H5N1/YNVa has a similar safety and immunogenicity to H5N1delta. -- Abstract: Highly pathogenic avian influenza (HPAI) viruses pose a global pandemic threat, for which rapid large-scale vaccine production technology is critical for prevention and control. Because chickens are highly susceptible to HPAI viruses, the supply of chicken embryos for vaccine production might be depleted during a virus outbreak. Therefore, developing HPAI virus vaccines using other technologies is critical. Meeting vaccine demand using the Vero cell-based fermentation process has been hindered by low stability and yield. In this study, a Vero cell-based HPAI H5N1 vaccine candidate (H5N1/YNVa) with stable high yield was achieved by reassortment of the Vero-adapted (Va) high growth A/Yunnan/1/2005(H3N2) (YNVa) virus with the A/Anhui/1/2005(H5N1) attenuated influenza vaccine strain (H5N1delta) using the 6/2 method. The reassorted H5N1/YNVa vaccine maintained a high hemagglutination (HA) titer of 1024. Furthermore, H5N1/YNVa displayed low pathogenicity and uniform immunogenicity compared to that of the parent virus.

  16. A highly phase-stable differential detector amplifier for magnetic induction tomography

    International Nuclear Information System (INIS)

    Magnetic induction tomography (MIT) has been proposed for the detection of cerebral oedema and haemorrhagic stroke. Achieving the required phase measurement precision for these applications is however a major technical challenge. A critical component within an MIT system is the detector amplifier and for this role an ultra-phase-stable, low noise instrumentation amplifier has been developed. The design of the amplifier is described and (i) the results of simulations and measurements of the amplifiers phase stability versus temperature and (ii) measurements of the phase noise and drift performance of the amplifier within a single-channel magnetic induction spectroscopy system are provided and discussed. For a 10 MHz signal the amplifier, with a gain of 21, displayed an average change in the measured phase of its output of just −0.1 ± 0.6 m° °C–1 as the ambient temperature was varied between 35 and 50 °C, demonstrating a level of phase stability approaching that required for potential biomedical applications such as the detection of cerebral haemorrhage

  17. A high-density ternary barcode detection system employing a stable fixed-period delay method

    Science.gov (United States)

    Wakaumi, Hiroo

    2011-09-01

    A fixed-period delay method is proposed to increase the detection range and detection stability of a ternary barcode detection system. The system combines an envelope differential detection technique containing nonlinear filtering and a fixed-period delay to detect the barcode over a longer range and at higher scanning speeds while being simple and capable of handling a large amount of information. The system was demonstrated with its miniaturized circuit, and it was established that the detection range of the system for a minimum bar width W = 0.25 mm was 1.8 times that of the conventional count-latch envelope differential technique because of the stable delay achieved by a shift register and the noise suppression by a nonlinear filter. In addition, the system operated at a maximum scanning speed of 8.3 times that of conventional charge-coupled device cameras under the practical detection range for W = 0.3 mm. This system is expected to facilitate the real-time identification of goods on production lines and in automated warehouses.

  18. Fully discrete energy stable high order finite difference methods for hyperbolic problems in deforming domains

    Science.gov (United States)

    Nikkar, Samira; Nordström, Jan

    2015-06-01

    A time-dependent coordinate transformation of a constant coefficient hyperbolic system of equations which results in a variable coefficient system of equations is considered. By applying the energy method, well-posed boundary conditions for the continuous problem are derived. Summation-by-Parts (SBP) operators for the space and time discretization, together with a weak imposition of boundary and initial conditions using Simultaneously Approximation Terms (SATs) lead to a provable fully-discrete energy-stable conservative finite difference scheme. We show how to construct a time-dependent SAT formulation that automatically imposes boundary conditions, when and where they are required. We also prove that a uniform flow field is preserved, i.e. the Numerical Geometric Conservation Law (NGCL) holds automatically by using SBP-SAT in time and space. The developed technique is illustrated by considering an application using the linearized Euler equations: the sound generated by moving boundaries. Numerical calculations corroborate the stability and accuracy of the new fully discrete approximations.

  19. Optofluidic laser array based on stable high-Q Fabry-Pérot microcavities.

    Science.gov (United States)

    Wang, Wenjie; Zhou, Chunhua; Zhang, Tingting; Chen, Jingdong; Liu, Shaoding; Fan, Xudong

    2015-10-01

    We report the development of an optofluidic laser array fabricated on a chip using stable plano-concave Fabry-Pérot (FP) microcavities, which are far less susceptible to optical misalignment during device assembly than the commonly used plano-plano FP microcavities. The concave mirrors in our FP microcavities were created by first generating an array of microwells of a few micrometers in depth and a few tens of micrometers in diameter on a fused silica chip using a CO2 laser, followed by coating of distributed Bragg reflection (DBR) layers. The plano-concave FP microcavity had a Q-factor of 5.6 × 10(5) and finesse of 4 × 10(3), over 100 times higher than those for the FP microcavities in existing optofluidic lasers. 1 mM R6G dye in ethanol was used to test the plano-concave FP microcavities, showing an ultralow lasing threshold of only 90 nJ mm(-2), over 10 times lower than that in the corresponding unstable plano-plano FP microcavities formed by the same DBR coatings on the same chip. Simultaneous laser emission from the optofluidic laser array on the chip and single-mode lasing operation were also demonstrated. Our work will lead to the development of optofluidic laser-based biochemical sensors and novel on-chip photonic devices with extremely low lasing thresholds (nJ mm(-2)) and mode volumes (fL). PMID:26304622

  20. High stable suspension of magnetite nanoparticles in ethanol by using sono-synthesized nanomagnetite in polyol medium

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The sonochemical synthesis of magnetite nanoparticles was carried out in EG without any surfactant. • The nanoparticles with sizes ∼24 nm were composed of small building blocks with sizes ∼2 nm. • The hydrophilic magnetite nanoparticles were stable in ethanol even after 8 months. • Ultrasonic intensity showed a crucial role on the obtained high stable magnetite nanoparticles in ethanol. - Abstract: The sonochemical synthesis of magnetite nanoparticles was carried out at relatively low temperature (80 °C) in ethylene glycol (EG) as a polyol solvent. The particle size was determined by transmission electron microscopy (TEM). The magnetite nanoparticles with an average size of 24 nm were composed of small building blocks with an average size of 2–3 nm and the particles exhibited nearly spherical shape. The surface characterization was investigated by using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The stability of magnetite nanoparticles was studied in ethanol as a polar solvent. The nanoparticles showed an enhanced stability in ethanol which is due to the hydrophilic surface of the particles. The colloidal stability of magnetite nanoparticles in ethanol was monitored by UV–visible spectrophotometer. According to the results, the nanoparticles synthesized in 30 min of sonication with intensity of 35 W/cm2 (50%) led to a maximum stability in ethanol as a polar solvent with respect to the other applied intensities. The obtained magnetite nanoparticles were stable for more than12 months

  1. High stable suspension of magnetite nanoparticles in ethanol by using sono-synthesized nanomagnetite in polyol medium

    Energy Technology Data Exchange (ETDEWEB)

    Bastami, Tahereh Rohani; Entezari, Mohammad H., E-mail: moh_entezari@yahoo.com

    2013-09-01

    Graphical abstract: - Highlights: • The sonochemical synthesis of magnetite nanoparticles was carried out in EG without any surfactant. • The nanoparticles with sizes ∼24 nm were composed of small building blocks with sizes ∼2 nm. • The hydrophilic magnetite nanoparticles were stable in ethanol even after 8 months. • Ultrasonic intensity showed a crucial role on the obtained high stable magnetite nanoparticles in ethanol. - Abstract: The sonochemical synthesis of magnetite nanoparticles was carried out at relatively low temperature (80 °C) in ethylene glycol (EG) as a polyol solvent. The particle size was determined by transmission electron microscopy (TEM). The magnetite nanoparticles with an average size of 24 nm were composed of small building blocks with an average size of 2–3 nm and the particles exhibited nearly spherical shape. The surface characterization was investigated by using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The stability of magnetite nanoparticles was studied in ethanol as a polar solvent. The nanoparticles showed an enhanced stability in ethanol which is due to the hydrophilic surface of the particles. The colloidal stability of magnetite nanoparticles in ethanol was monitored by UV–visible spectrophotometer. According to the results, the nanoparticles synthesized in 30 min of sonication with intensity of 35 W/cm{sup 2} (50%) led to a maximum stability in ethanol as a polar solvent with respect to the other applied intensities. The obtained magnetite nanoparticles were stable for more than12 months.

  2. Highly efficient synthesis of endomorphin-2 under thermodynamic control catalyzed by organic solvent stable proteases with in situ product removal.

    Science.gov (United States)

    Xu, Jiaxing; Sun, Honglin; He, Xuejun; Bai, Zhongzhong; He, Bingfang

    2013-02-01

    An efficient enzymatic synthesis of endomorphin-2 (EM-2) was achieved using organic solvent stable proteases in nonaqeous media, based on thermodynamic control and an in situ product removal methodology. The high stability of biocatalysts in organic solvents enabled the aleatoric modulation of the nonaqueous reaction media to shift thermodynamic equilibrium toward synthesis. Peptide Boc-Phe-Phe-NH2 was synthesized with a high yield of 96% by the solvent stable protease WQ9-2 in monophase medium with an economical molar ratio of the substrate of 1:1. The tetrapeptide Boc-Tyr-Pro-Phe-Phe-NH2 was synthesized with a yield of 88% by another organic solvent tolerant protease PT121 from Boc-Tyr-Pro-OH and Phe-Phe-NH2 in an organic-aqueous biphasic system. The reaction-separation coupling in both enzymatic processes provides "driving forces" for the synthetic reactions and gives a high yield and high productivity without purification of the intermediate, thereby making the synthesis more amenable to scale-up. PMID:23305895

  3. Modeling and Simulation of High Power Ultrasonic Process in Preparation of Stable Oil-in-Water Emulsion

    OpenAIRE

    Attieh Hassani; Mohamad Taghi Hamed Mosavian; Javad Sargolzaei

    2011-01-01

    The aims of this research are to study application of high power ultrasound in preparation of stable oil-in-water emulsion. The effect of pH, ionic strength, pectin, Guar gum, lecithin, egg yolk, and xanthan gum as well as the time of sonication, temperature and viscosity of oil-water mixture on the specific surface area and size of droplets, and creaming index of the emulsion samples was investigated. The experimental data were analyzed with Taguchi method and optimum conditions were determi...

  4. Graphene controlled H- and J-stacking of perylene dyes into highly stable supramolecular nanostructures for enhanced photocurrent generation

    DEFF Research Database (Denmark)

    Gan, Shiyu; Zhong, Lijie; Engelbrekt, Christian;

    2014-01-01

    We report a new method for controlling H- and J-stacking in supramolecular self-assembly. Graphene nanosheets act as structure inducers to direct the self-assembly of a versatile organic dye, perylene into two distinct types of functional nanostructures, i.e. one-dimensional nanotubes via J......-stacking and two-dimensional branched nanobuds through H-stacking. Graphene integrated supramolecular nanocomposites are highly stable and show significant enhancement of photocurrent generation in these two configurations of photosensing devices, i.e. solid-state optoelectronic constructs and liquid...

  5. Level of high-sensitivity C-reactive protein in saudi patients with chronic stable coronary artery disease

    International Nuclear Information System (INIS)

    Inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) is an independent predictor of future cardiovascular events and it predicts risk of incident hypertension and diabetes. The aim of this study was to determine the serum levels of the circulating acute-phase reactant high-sensitivity C-reactive protein (hsCRP) in Saudi patients with chronic stable Coronary Artery Disease (CAD). This cross sectional study was conducted in the Department of Physiology and Department of Cardiology, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh between August 2006 and December 2007. One hundred and seven individuals with chronic stable CAD and 33 healthy, age and BMI-matched individuals were studied. Overnight fasting blood samples were collected, and analyzed for total cholesterol (TC), Triglycerides (TG), Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL) and hsCRP in patients with chronic stable CAD. TC (Control 4.41+-0.57 vs CAD 4.28+-1.40, p=0.8394) and LDL levels (Control 2.70+-0.52 vs CAD 2.71+-1.20, p=0.7963) did not differ significantly between the two groups. While there were significant differences in TG (Control 1.13+-0.47 vs CAD 1.84+-1.10, p=0.0135) and HDL levels (Control 1.06+-0.30 vs CAD 0.71+-0.25, p=0.0000). hsCRP levels were significantly higher in patients with CAD (5.0+-4.4) compared to healthy individuals (2.7+-2.7, p=0.0166). Frequency of low risk levels was significantly higher in Controls than CAD patients (24.2% vs 8.4%, p=0.0332) and vice versa for high risk levels (24.2% vs 51.4%, p=0.0110). At average risk levels frequency did not differ significantly (51.5% vs 40.1%, p=0.3429) between control and CAD groups. Saudi patients with stable chronic CAD have higher hsCRP levels compared to healthy individuals. Moreover the prevalence of undesirable risk levels of hsCRP is also higher in CAD patients. (author)

  6. High-resolution stable isotope analysis of tree rings: implications of 'microdendroclimatology' for palaeoenvironmental research

    International Nuclear Information System (INIS)

    High-resolution stable isotope analyses were carried out on a sample of oak (Quercus petraea) from Cultra, Co Down, UK. A sampling strategy of unparalleled resolution was adopted in an attempt to reconstruct short-term climatic changes during the growing season. The results display a surprising clarity of signal and suggest a significant relationship between delta(13)C and relative humidity and, to a lesser extent,temperature. This preliminary study proposes possible reasons for the isotopic profile observed and highlights the perceived future value of intra-ring isotope studies ('microdendroclimatology')

  7. Pilot scale production of highly efficacious and stable enterovirus 71 vaccine candidates.

    Directory of Open Access Journals (Sweden)

    Ai-Hsiang Chou

    Full Text Available BACKGROUND: Enterovirus 71 (EV71 has caused several epidemics of hand, foot and mouth diseases (HFMD in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial. PRINCIPAL FINDING: In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration, a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7-10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30-43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37 °C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4 °C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice

  8. Thermally Stable Catalytic Combustors for Very High Altitude Airbreathing Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerospace vehicles operating at high altitudes have the potential to be less expensive and more versatile alternatives to space based systems for earth/space...

  9. Stable, highly nonlinear amorphous silicon nanowires with very low nonlinear absorption

    CERN Document Server

    Carletti, Luca; Grossec, Phillipe; Ben-Bakir, Badhise; Menezoc, Sylvie; Fedelic, Jean-Marc; Moss, David J; Monat, Christelle

    2014-01-01

    The nonlinear characteristics of hydrogenated amorphous silicon nanowires are experimentally demonstrated. A high nonlinear refractive index, n2=1.19 x 10-17 m2/W, combined with a low two-photon absorption, 0.14 x 10-11 m/W, resulted in a high nonlinear FOM of 5.5. Furthermore, systematic studies over hours of operational time under 2.2W of pulse peak power revealed no degradation of the optical response.

  10. Stable propagation of a high-current electron beam: experimental observations and computational modeling

    International Nuclear Information System (INIS)

    Experimental studies of self-focused, high-current electron-beam propagation phenomena are compared with the results of computational modeling. The model includes the radial structure of the beam-plasma system, a full electromagnetic field description, primary and secondary gas ionization processes, and a linear theory of the hose-like distortions. Good agreement between the experimental results and the computations strengthens the premise that hose instability is the principal limitation to propagation at high pressure

  11. Thermally stable yttrium-scandium oxide high-k dielectrics deposited by a solution process

    Science.gov (United States)

    Hu, Wenbing; Frost, Bradley; Peterson, Rebecca L.

    2016-03-01

    We investigated the thermal stability of electrical properties in ternary alloy (Y x Sc1-x )2O3 high-k oxides as a function of yttrium fraction, x. The yttrium-scandium oxide dielectric films are deposited using a facile ink-based process. The oxides have a stoichiometry-dependent relative dielectric constant of 26.0 to 7.7 at 100 kHz, low leakage current density of 10-8 A·cm-2, high breakdown field of 4 MVṡcm-1, and interface trap density of 1012 cm-2·eV-1 with silicon. Compared with binary oxides, ternary alloys exhibit less frequency dispersion of the dielectric constant and a higher crystallization temperature. After crystallization is induced through a 900 °C anneal, ternary (Y0.6Sc0.4)2O3 films maintain their low leakage current and high breakdown field. In contrast, the electrical performance of the binary oxides significantly degrades following the same treatment. The solution-processed ternary oxide dielectrics demonstrated here may be used as high-k gate insulators in complementary metal-oxide semiconductor (CMOS) technologies, in novel electronic material systems and devices, and in printed, flexible thin film electronics, and as passivation layers for high power devices. These oxides may also be used as insulators in fabrication process flows that require a high thermal budget.

  12. High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum

    Directory of Open Access Journals (Sweden)

    Diogo Vieira Carvalho

    2015-10-01

    Full Text Available A novel membrane based on silicon dioxide (SiO2 and hydroxypropyl guar gum (HPG as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO2 and guar gum microstructure towards organic liquid electrolytes. Additionally, the separator shows high thermal stability and no dimensional-shrinkage at high temperatures due to the use of the ceramic filler and the thermally stable natural polymer. The electrochemical tests show the good electrochemical stability of the separator in a wide range of potential, as well as its outstanding cycle performance.

  13. A stable route to high-{beta}{sub p} plasmas with non-monotonic q-profiles

    Energy Technology Data Exchange (ETDEWEB)

    Soeldner, F.X.; Baranov, Y.; Bhatnagar, V.P.; Bickley, A.J.; Challis, C.D.; Fischer, B.; Gormezano, C.; Huysmans, G.T.A.; Kerner, W.; Rimini, F.; Sips, A.C.C.; Springmann, R.; Taroni, A. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Goedbloed, J.P.; Holties, H.A. [Institute for Plasmas Physics, Nieuwegein (Netherlands); Parail, V.V.; Pereverzev, G.V. [Kurchatov Institute of Atomic Energy, Moscow (Russian Federation)

    1994-07-01

    Steady-state operation of tokamak reactors seems feasible in so-called Advanced Scenarios with high bootstrap current in high-beta{sub p} operation. The stabilization of such discharges with noninductive profile control will be attempted on JET in pursuit of previous high bootstrap current studies. Results of modelling studies of full noninductive current drive scenarios in JET and ITER are presented. Fast Waves (FW), Lower Hybrid (LH) Waves and Neutral Beam Injection (NBI) are used for heating and current drive, alternatively or in combination. A stable route to nonmonotonic q-profiles has been found with a specific ramp-up scenario which combines LH-current drive (LHCD) and a fast Ohmic ramp-up. A hollow current profile with deep shear reversal over the whole central region is thereby formed in an early low-beta phase and frozen in by additional heating. (authors). 5 refs., 4 figs.

  14. Very stable 188Re-S4 chelates for labelling biomolecules. Preparation with highly concentrated perrhenate eluates

    International Nuclear Information System (INIS)

    Aim: The preparation and stability of a new 188Re-S4-complex [S4 (1-aza-18-crown-6)(O)C-C(SH)-C(SH)-C(O)NH-(CH2)3-NH-(CH2)3-NHC(O)- = C(SH)- C(SH )-C(O)(1-aza-18-crown-6)] was studied at therapeutic relevant radioactive concentrations. The results were compared with 188Re-MAG3 (MAG3: mercaptoacetyltriglycine) and 188Re-DMSA preparations (DMSA: dimercaptosuccinic acid) performed with the same highly concentrated [188Re]perrhenate solution (12-15 GBq/ml). Methods: The 188Re complexes were prepared by direct reduction of perrhenate (188Re-S4-complex) as well as via the 188Re-EDTA precursor complex (188Re-MAG3, 188Re-DMSA). The preparations were stabilised with 15 mg of ascorbic acid and analysed after 1, 2, and 24 hours by TLC and HPLC. Additionally, in vitro and in vivo stability studies were performed with the purified complexes. Results: After stabilisation with 15 mg of ascorbic acid, all of the complexes were nearly stable under nitrogen for hours, and only 2-8% of perrhenate was observed after 24 h. In contrast, only the 188Re-S4 complex was completely stable in vitro and in all investigated in vivo samples after separation of ligand excess and reducing agent by HPLC. Conclusion: The bridging amine group or free carboxylic groups of the S4-ligand framework make available reactive positions for coupling biomolecules to the chelate. Thus it appears that the new 188Re-S4 complexes offer the possibility of stable and high specific activity labelling of biomolecules for therapeutic application. (orig.)

  15. Development of highly active and stable hybrid cathode catalyst for PEMFCs

    Science.gov (United States)

    Jung, Won Suk

    Polymer electrolyte membrane fuel cells (PEMFCs) are attractive power sources of the future for a variety of applications including portable electronics, stationary power, and automobile application. However, sluggish cathode kinetics, high Pt cost, and durability issues inhibit the commercialization of PEMFCs. To overcome these drawbacks, research has been focused on alloying Pt with transition metals since alloy catalysts show significantly improved catalytic properties like high activity, selectivity, and durability. However, Pt-alloy catalysts synthesized using the conventional impregnation method exhibit uneven particle size and poor particle distribution resulting in poor performance and/or durability in PEMFCs. In this dissertation, a novel catalyst synthesis methodology is developed and compared with catalysts prepared using impregnation method and commercial catalysts. Two approaches are investigated for the catalyst development. The catalyst durability was studied under U. S. DRIVE Fuel Cell Tech Team suggested protocols. In the first approach, the carbon composite catalyst (CCC) having active sites for oxygen reduction reaction (ORR) is employed as a support for the synthesis of Pt/CCC catalyst. The structural and electrochemical properties of Pt/CCC catalyst are investigated using high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, while RDE and fuel cell testing are carried out to study the electrochemical properties. The synergistic effect of CCC and Pt is confirmed by the observed high activity towards ORR for the Pt/CCC catalyst. The second approach is the synthesis of Co-doped hybrid cathode catalysts (Co-doped Pt/CCC) by diffusing the Co metal present within the CCC support into the Pt nanoparticles during heat-treatment. The optimized Co-doped Pt/CCC catalyst performed better than the commercial catalysts and the catalyst prepared using the impregnation method in PEMFCs and showed high

  16. Highly transparent and thermally stable superhydrophobic coatings from the deposition of silica aerogels

    International Nuclear Information System (INIS)

    Transparent superhydrophobic coatings, having high water contact angle (>160°) and low sliding angle (29Si CP MAS NMR, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The optimum performance coating exhibits superhydrophobicity (CA, 164.7° and SA, 2.7°), a high transparency (transmittance closes to 90%) and a good thermal stability (up to 400 °C). Note that the optimum coating directly from sol–gel process exhibits poor moisture resistance. The low surface energy and high volume-fraction porosity structure are responsible for the superhydrophobicity, transparency and thermal stability of the as-prepared coating, while the poor moisture is attributed to the untreated hydroxyl groups on the surface of coating. The moisture resistance of coating can be improved by further treated by cetyltrimethoxylsilane (CTMS), and the coating could switch from superhydrophobic (164.7°) to superhydrophilic (0°) after heat-treating at 600 °C.

  17. Multicatalytic colloids with highly scalable, adjustable, and stable functionalities in organic and aqueous media

    Science.gov (United States)

    Kim, Donghee; Cheong, Sanghyuk; Ahn, Yun Gyong; Ryu, Sook Won; Kim, Jai-Kyeong; Cho, Jinhan

    2016-03-01

    Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent media. Here, we report on layer-by-layer (LbL) assembled multicatalysts with high catalytic performance, showing high dispersion and recycling stability in organic and aqueous media. The remarkable advantages of our approach are as follows. (i) Various metal or metal oxide NPs with desired catalytic performance can be easily incorporated into multilayered shells, forming densely packed arrays that allow one colloid to be used as a multicatalyst with highly integrated and controllable catalytic properties. (ii) Additionally, the dispersion stability of catalytic colloids in a desired solvent can be determined by the type of ultrathin outermost layer coating each colloid. (iii) Lastly, the covalent bonding between inorganic NPs and dendrimers within multilayer shells enhances the recycling stability of multicatalytic colloids. The resulting core-shell colloids including OA-Fe3O4 NPs, TOABr-Pd NPs, and OA-TiO2 NPs exhibited excellent performance in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and photocatalysis in aqueous media and in the Sonogashira coupling reaction (99% yield) in organic media. Given that the catalytic properties of recyclable colloids reported to date have entirely depended on the functionality of a single catalytic NP layer deposited onto colloids in selective solvent media, our approach provides a basis for the design and exploitation of high-performance recyclable colloids with integrated multicatalytic properties and high dispersion stability in a variety of solvents.Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent

  18. Multicatalytic colloids with highly scalable, adjustable, and stable functionalities in organic and aqueous media.

    Science.gov (United States)

    Kim, Donghee; Cheong, Sanghyuk; Ahn, Yun Gyong; Ryu, Sook Won; Kim, Jai-Kyeong; Cho, Jinhan

    2016-03-24

    Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent media. Here, we report on layer-by-layer (LbL) assembled multicatalysts with high catalytic performance, showing high dispersion and recycling stability in organic and aqueous media. The remarkable advantages of our approach are as follows. (i) Various metal or metal oxide NPs with desired catalytic performance can be easily incorporated into multilayered shells, forming densely packed arrays that allow one colloid to be used as a multicatalyst with highly integrated and controllable catalytic properties. (ii) Additionally, the dispersion stability of catalytic colloids in a desired solvent can be determined by the type of ultrathin outermost layer coating each colloid. (iii) Lastly, the covalent bonding between inorganic NPs and dendrimers within multilayer shells enhances the recycling stability of multicatalytic colloids. The resulting core-shell colloids including OA-Fe3O4 NPs, TOABr-Pd NPs, and OA-TiO2 NPs exhibited excellent performance in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and photocatalysis in aqueous media and in the Sonogashira coupling reaction (99% yield) in organic media. Given that the catalytic properties of recyclable colloids reported to date have entirely depended on the functionality of a single catalytic NP layer deposited onto colloids in selective solvent media, our approach provides a basis for the design and exploitation of high-performance recyclable colloids with integrated multicatalytic properties and high dispersion stability in a variety of solvents. PMID:26524289

  19. A ZnO nanowire array film with stable highly water-repellent properties

    International Nuclear Information System (INIS)

    Highly water-repellent surfaces have been prepared from arrayed nanowires of zinc oxide (ZnO) by a treatment with stearic acid. The layers are electrochemically deposited on a nanocrystalline seed layer from an oxygenated aqueous zinc chloride solution. An advancing contact angle (CA) as high as 1760 is obtained with a very small hysteresis ∼10. These results, supplemented by infrared spectroscopy, show that the stearic acid forms a very well-packed self-assembled monolayer. The CA measurements show a very good stability of the treated surface even when exposed to harsh conditions or long-term ambient illumination

  20. Evolution from spherical single-particle structure to stable triaxiality at high spins in 140Nd

    International Nuclear Information System (INIS)

    The level structure of 60140Nd80 has been established up to spin 48 by in-beam γ-ray spectroscopy by use of the 96Zr(48Ca, 4n) reaction. High-fold γ-ray coincidences were measured with the EUROBALL spectrometer. Twelve new rotational bands have been discovered at high spins. They are interpreted as being formed in a deep triaxial minimum at ε2≅0.25 and γ≅35 deg. Possible configurations are assigned to the observed bands on the basis of configuration-dependent cranked Nilsson-Strutinsky calculations

  1. Immobilization of molecular cobalt electrocatalyst by hydrophobic interaction with hematite photoanode for highly stable oxygen evolution

    KAUST Repository

    Joya, Khurram

    2015-07-15

    A unique modification of a hematite photoanode with perfluorinated Co-phthalocyanine (CoFPc) by strong binding associated with hydrophobic interaction is demonstrated. The resultant molecular electrocatalyst – hematite photoanode hybrid material showed significant onset shift and high stability for photoelectrochemical oxidation evolution reaction (OER).

  2. Stable, fertile, high polyhydroxyalkanoate producing plants and methods of producing them

    Energy Technology Data Exchange (ETDEWEB)

    Bohmert-Tatarev, Karen; McAvoy, Susan; Peoples, Oliver P.; Snell, Kristi D.

    2015-08-04

    Transgenic plants that produce high levels of polyhydroxybutyrate and methods of producing them are provided. In a preferred embodiment the transgenic plants are produced using plastid transformation technologies and utilize genes which are codon optimized. Stably transformed plants able to produce greater than 10% dwt PHS in tissues are also provided.

  3. Powerful highly stable laser diodes for pumping of solid-state lasers

    International Nuclear Information System (INIS)

    Powerful laser diodes, representing partly phase-locked laser arrays based on quantum-well heterostructures, were developed. The high temporal and spatial stability, and the long service life of such laser diodes make them suitable for optical pumping of solid-state lasers. (lasers, active media)

  4. Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS)

    Science.gov (United States)

    Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate into silver ion using 2 % trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were ...

  5. Highly Stable Transparent Electrodes Made from Copper Nanotrough Coated with AZO/Al2O3.

    Science.gov (United States)

    Li, Peng; Yan, Xingzhen; Ma, Jiangang; Xu, Haiyang; Liu, Yichun

    2016-04-01

    Due to their high flexibility, high conductivity and high transparency in a wide spectrum range, metal nanowires and meshes are considered to be two of the most promising candidates to replace the traditional transparent conducting films, such as tin doped indium oxide. In this paper, transparent conducting films made from copper nanotroughs are prepared by the electrospinning of polymer fibers and subsequent thermal evaporation of copper. The advantages of the technique include low junction resistance, low cost and low preparation temperature. Although the copper nanotrough transparent conducting films exhibited a low sheet resistance (19.2 Ω/sq), with a high transmittance (88% at 550 nm), the instability of copper in harsh environments seriously hinders its applications. In order to improve the stability of the metal transparent conducting films, copper nanotroughs were coated with 39 nm thick aluminum-doped zinc oxide and 1 nm thick aluminum oxide films by atomic layer deposition. The optical and electrical measurements show that coating copper nanotrough with oxides barely reduces the transparency of the films. It is worth noting that conductive oxide coating can effectively protect copper nanotroughs from thermal oxidation or acidic corrosion, whilst maintaining the same flexibility as copper nanotroughs on its own. PMID:27451715

  6. Highly thermostable and pH-stable cellulases from Aspergillus niger NS-2: properties and application for cellulose hydrolysis.

    Science.gov (United States)

    Bansal, Namita; Janveja, Chetna; Tewari, Rupinder; Soni, Raman; Soni, Sanjeev Kumar

    2014-01-01

    Optimization of cultural conditions for enhanced cellulase production by Aspergillus niger NS-2 were studied under solid-state fermentation. Significant increase in yields (CMCase 463.9 ± 20.1 U/g, FPase 101.1 ± 3.5 U/g and β-glucosidase 99 ± 4.0 U/g) were obtained under optimized conditions. Effect of different nutritional parameters was studied to induce the maximum production of cellulase complex. Scale-up studies for enzyme production process were carried out. Characterization studies showed that enzymes produced by A. niger NS-2 were highly temperature- and pH stable. At 50 °C, the half life for CMCase, FPase, β-glucosidase were approximately 240 h. Cellulases from A. niger NS-2 were stable at 35 °C for 24 h over a broader pH range of 3.0-9.0. We examined the feasibility of using steam pretreatment to increase the saccharification yields from various lignocellulosic residues for sugar release which can potentially be used in bioethanol production. Saccharification of pretreated dry potato peels, carrot peels, composite waste mixture, orange peels, onion peels, banana peels, pineapple peels by crude enzyme extract from A. niger NS-2, resulted in very high cellulose conversion efficiencies of 92-98 %. PMID:24052336

  7. Comparison of the ENIGMA code with experimental data on thermal performance, stable fission gas and iodine release at high burnup

    International Nuclear Information System (INIS)

    The predictions of the ENIGMA code have been compared with data from high burn-up fuel experiments from the Halden and RISO reactors. The experiments modelled were IFA-504 and IFA-558 from Halden and the test II-5 from the RISO power burnup test series. The code has well modelled the fuel thermal performance and has provided a good measure of iodine release from pre-interlinked fuel. After interlinkage the iodine predictions remain a good fit for one experiment, but there is significant overprediction for a second experiment (IFA-558). Stable fission gas release is also well modelled and the predictions are within the expected uncertainly band throughout the burn-up range. This report presents code predictions for stable fission gas release to 40GWd/tU, iodine release measurements to 50GWd/tU and thermal performance (fuel centre temperature) to 55GWd/tU. Fuel ratings of up to 38kW/m were modelled at the high burn-up levels. The code is shown to accurately or conservatively predict all these parameters. (author). 1 ref., 6 figs

  8. Broadband, stable and highly coherent supercontinuum generation at telecommunication wavelengths in an hydrogenated amorphous silicon waveguide

    CERN Document Server

    Leo, F; Kuyken, B; Roelkens, G; Gorza, S -P

    2014-01-01

    Hydrogenated amorphous silicon (a:Si-H) has recently been recognized as a highly nonlinear CMOS compatible photonic platform. We experimentally demonstrate the generation of a supercontinuum (SC) spanning over 500 nm in a-Si:H photonic wire waveguide at telecommunication wavelengths using femtosecond input pulse with energy lower than 5 pJ. Numerical modeling of pulse propagation in the waveguide, based on the experimentally characterized dispersion profile, shows that the supercontinuum is the result of soliton fission and dispersive wave generation. It is demonstrated that the SC is highly coherent and that the waveguides do not suffer from material degradation under femtosecond pulse illumination. Finally, a direct comparison of SC generation in c-Si and a-Si:H waveguides confirms the higher performances of a-Si:H over c-Si for broadband low power SC generation at telecommunication wavelengths.

  9. Stable ultrathin partially oxidized copper film electrode for highly efficient flexible solar cells

    OpenAIRE

    ZHAO Guoqing; Wang, Wei; Bae, Tae-Sung; Lee, Sang-Geul; Mun, ChaeWon; Lee, Sunghun; Yu, Huashun; Lee, Gun-Hwan; Song, Myungkwan; Yun, Jungheum

    2015-01-01

    Advances in flexible optoelectronic devices have led to an increasing need for developing highly efficient, low-cost, flexible transparent conducting electrodes. Copper-based electrodes have been unattainable due to the relatively low optical transmission and poor oxidation resistance of copper. Here, we report the synthesis of a completely continuous, smooth copper ultra-thin film via limited copper oxidation with a trace amount of oxygen. The weakly oxidized copper thin film sandwiched betw...

  10. Sub-0.5 V Highly Stable Aqueous Salt Gated Metal Oxide Electronics

    OpenAIRE

    Sungjun Park; SeYeong Lee; Chang-Hyun Kim; Ilseop Lee; Won-June Lee; Sohee Kim; Byung-Geun Lee; Jae-Hyung Jang; Myung-Han Yoon

    2015-01-01

    Recently, growing interest in implantable bionics and biochemical sensors spurred the research for developing non-conventional electronics with excellent device characteristics at low operation voltages and prolonged device stability under physiological conditions. Herein, we report high-performance aqueous electrolyte-gated thin-film transistors using a sol-gel amorphous metal oxide semiconductor and aqueous electrolyte dielectrics based on small ionic salts. The proper selection of channel ...

  11. Rad-Tolerant, Thermally Stable, High-Speed Fiber-Optic Network for Harsh Environments

    Science.gov (United States)

    Leftwich, Matt; Hull, Tony; Leary, Michael; Leftwich, Marcus

    2013-01-01

    Future NASA destinations will be challenging to get to, have extreme environmental conditions, and may present difficulty in retrieving a spacecraft or its data. Space Photonics is developing a radiation-tolerant (rad-tolerant), high-speed, multi-channel fiber-optic transceiver, associated reconfigurable intelligent node communications architecture, and supporting hardware for intravehicular and ground-based optical networking applications. Data rates approaching 3.2 Gbps per channel will be achieved.

  12. Hydrophobic and Metallophobic Surfaces: Highly Stable Non-wetting Inorganic Surfaces Based on Lanthanum Phosphate Nanorods

    OpenAIRE

    Sasidharan Sankar; Nair, Balagopal N.; Takehiro Suzuki; Gopinathan M. Anilkumar; Moothetty Padmanabhan; Unnikrishnan Nair S. Hareesh; Warrier, Krishna G.

    2016-01-01

    Metal oxides, in general, are known to exhibit significant wettability towards water molecules because of the high feasibility of synergetic hydrogen-bonding interactions possible at the solid-water interface. Here we show that the nano sized phosphates of rare earth materials (Rare Earth Phosphates, REPs), LaPO4 in particular, exhibit without any chemical modification, unique combination of intrinsic properties including remarkable hydrophobicity that could be retained even after exposure to...

  13. Stable Isolation of Phycocyanin from Spirulina platensis Associated with High-Pressure Extraction Process

    OpenAIRE

    Kyung-Hwan Jung; Jin Oh Park; Jong Ho Park; Woo Seok Choi; Yong Chang Seo; Hyeon Yong Lee

    2013-01-01

    A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%–5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also show...

  14. Stable Plastid Transformation for High-Level Recombinant Protein Expression: Promises and Challenges

    Directory of Open Access Journals (Sweden)

    Meili Gao

    2012-01-01

    Full Text Available Plants are a promising expression system for the production of recombinant proteins. However, low protein productivity remains a major obstacle that limits extensive commercialization of whole plant and plant cell bioproduction platform. Plastid genetic engineering offers several advantages, including high levels of transgenic expression, transgenic containment via maternal inheritance, and multigene expression in a single transformation event. In recent years, the development of optimized expression strategies has given a huge boost to the exploitation of plastids in molecular farming. The driving forces behind the high expression level of plastid bioreactors include codon optimization, promoters and UTRs, genotypic modifications, endogenous enhancer and regulatory elements, posttranslational modification, and proteolysis. Exciting progress of the high expression level has been made with the plastid-based production of two particularly important classes of pharmaceuticals: vaccine antigens, therapeutic proteins, and antibiotics and enzymes. Approaches to overcome and solve the associated challenges of this culture system that include low transformation frequencies, the formation of inclusion bodies, and purification of recombinant proteins will also be discussed.

  15. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti3+:Al2O3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10-2 to 67 x 103 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti3+:Al2O3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  16. In situ Poly(methyl methacrylate)/Graphene Composite Gel Electrolytes for Highly Stable Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Kang, Yu-il; Moon, Jun Hyuk

    2015-11-01

    Dye-sensitized solar cells (DSCs) with long-term stability are produced using polymer-gel electrolytes (PGEs). In this study, we introduce the formation of PGEs using in situ gelation with poly(methyl methacrylate) (PMMA) particles and graphene fillers that are pre-deposited on the counter electrodes. We obtain a high concentration PMMA-based PGEs (i.e., over 10 wt%). A DSC composed of a PMMA/graphene composite PGEs exhibits an 8.49% photon-to-electric conversion efficiency, which is comparable to conventional liquid electrolyte DSCs. This finding is attributed to increased ion diffusivity and conductivity of the PMMA-based PGEs resulting from the incorporation of graphene nanofillers. The PMMA-based PGE DSCs exhibit highly stable long-term efficiencies, maintaining up to 90% of their initial efficiency during thermal soaking, whereas the efficiencies of liquid electrolyte cells decrease significantly, by up to 60%. PMID:26471468

  17. Toward site-specific, homogeneous and highly stable fluorescent silver nanoclusters fabrication on triplex DNA scaffolds

    OpenAIRE

    Feng, Lingyan; Huang, Zhenzhen; Ren, Jinsong; Qu, Xiaogang

    2012-01-01

    A new strategy to create site-specific, homogeneous, and bright silver nanoclusters (AgNCs) with high-stability was demonstrated by triplex DNA as template. By reasonable design of DNA sequence, homogeneous Ag2 cluster was obtained in the predefined position of CG.C+ site of triplex DNA. This strategy was also explored for controlled alignment of AgNCs on the DNA nanoscaffold. To the best of our knowledge, this was the first example to simultaneously answer the challenges of excellent site-sp...

  18. Atomic force microscope studies of fullerene films - Highly stable C60 fcc (311) free surfaces

    Science.gov (United States)

    Snyder, Eric J.; Tong, William M.; Williams, R. S.; Anz, Samir J.; Anderson, Mark S.

    1991-01-01

    Atomic force microscopy and X-ray diffractometry were used to study 1500 A-thick films of pure C60 grown by sublimation in ultrahigh vacuum onto a CaF2 (111) substrte. Topographs of the films did not reveal the expected close-packed structures, but they showed instead large regions that correspond to a face-centered cubic (311) surface and distortions of this surface. The open (311) structure may have a relatively low free energy because the low packing density contributes to a high entropy of the exposed surface.

  19. High-performance CaMKI: A highly active and stable form of CaMKIδ produced by high-level soluble expression in Escherichia coli.

    Science.gov (United States)

    Senga, Yukako; Akizuki, Kazutoshi; Katayama, Syouichi; Shigeri, Yasushi; Kameshita, Isamu; Ishida, Atsuhiko; Sueyoshi, Noriyuki

    2016-07-01

    We describe here the expression and characterization of a constitutively active fragment of zebrafish Ca(2+)/calmodulin-dependent protein kinase (CaMK) Iδ designated zCaMKIδ(1-299) that lacks an autoinhibitory domain. We used a simple one-step purification method to isolate the recombinant enzyme at high yield (220 mg/l of the culture medium) from the soluble fraction of lysates prepared from Escherichia coli. Unlike the corresponding fragment of CaMKIα (CaMKΙα(1-294)), the kinase activity of zCaMKIδ(1-299), without activation procedures, was comparable to that of wild-type zCaMKIδ activated by CaMK kinase. zCaMKIδ(1-299) exhibited broad substrate specificity highly similar to that of wild-type zCaMKIδ, and complementary to that of the cAMP-dependent protein kinase catalytic subunit (PKAc). The protein kinase activity of zCaMKIδ(1-299) was higher compared with that of PKAc as well as CX-30K-CaMKII that comprises a constitutively active fragment of CaMKII fused to the N-terminal region of Xenopus CaMKI. Furthermore, kinase activity was highly stable against thermal inactivation and repeated freezing-thawing. Thus, zCaMKIδ(1-299) represents a readily available alternative that can be used as a "High-performance phosphorylating reagent" alone or in combination with PKAc in diverse experiments on protein phosphorylation and dephosphorylation. PMID:27207832

  20. Highly stable and finely tuned magnetic fields generated by permanent magnet assemblies.

    Science.gov (United States)

    Danieli, E; Perlo, J; Blümich, B; Casanova, F

    2013-05-01

    Permanent magnetic materials are the only magnetic source that can be used to generate magnetic fields without power consumption or maintenance. Such stand-alone magnets are very attractive for many scientific and engineering areas, but they suffer from poor temporal field stability, which arises from the strong sensitivity of the magnetic materials and mechanical support to temperature variation. In this work, we describe a highly efficient method useful to cancel the temperature coefficient of permanent magnet assemblies in a passive and accurate way. It is based on the combination of at least two units made of magnetic materials with different temperature coefficients arranged in such a way that the ratio of the fields generated by each unit matches the ratio of their effective temperature coefficients defined by both the magnetic and mechanical contributions. Although typically available magnetic materials have negative temperature coefficients, the cancellation is achieved by aligning the fields generated by each unit in the opposite direction. We demonstrate the performance of this approach by stabilizing the field generated by a dipolar Halbach magnet, recently proposed to achieve high field homogeneity. Both the field drift and the homogeneity are monitored via nuclear magnetic resonance spectroscopy experiments. The results demonstrate the compatibility of the thermal compensation approach with existing strategies useful to fine-tune the spatial dependence of the field generated by permanent magnet arrays. PMID:23683185

  1. Highly stable and flexible silver nanowire-graphene hybrid transparent conducting electrodes for emerging optoelectronic devices

    Science.gov (United States)

    Lee, Donghwa; Lee, Hyungjin; Ahn, Yumi; Jeong, Youngjun; Lee, Dae-Young; Lee, Youngu

    2013-08-01

    A new AgNW-graphene hybrid transparent conducting electrode (TCE) was prepared by dry-transferring a chemical vapor deposition (CVD)-grown monolayer graphene onto a pristine AgNW TCE. The AgNW-graphene hybrid TCE exhibited excellent optical and electrical properties as well as mechanical flexibility. The AgNW-graphene hybrid TCE showed highly enhanced thermal oxidation and chemical stabilities because of the superior gas-barrier property of the graphene protection layer. Furthermore, the organic solar cells with the AgNW-graphene hybrid TCE showed excellent photovoltaic performance as well as superior long-term stability under ambient conditions.A new AgNW-graphene hybrid transparent conducting electrode (TCE) was prepared by dry-transferring a chemical vapor deposition (CVD)-grown monolayer graphene onto a pristine AgNW TCE. The AgNW-graphene hybrid TCE exhibited excellent optical and electrical properties as well as mechanical flexibility. The AgNW-graphene hybrid TCE showed highly enhanced thermal oxidation and chemical stabilities because of the superior gas-barrier property of the graphene protection layer. Furthermore, the organic solar cells with the AgNW-graphene hybrid TCE showed excellent photovoltaic performance as well as superior long-term stability under ambient conditions. Electronic supplementary information (ESI) available: Detailed electrical connection, mechanical flexibility, and chemical stability tests of the AgNW and AgNW-graphene hybrid TCEs are included. See DOI: 10.1039/c3nr02320f

  2. The 2-micron plasmid as a nonselectable, stable, high copy number yeast vector

    Science.gov (United States)

    Ludwig, D. L.; Bruschi, C. V.

    1991-01-01

    The endogenous 2-microns plasmid of Saccharomyces cerevisiae has been used extensively for the construction of yeast cloning and expression plasmids because it is a native yeast plasmid that is able to be maintained stably in cells at high copy number. Almost invariably, these plasmid constructs, containing some or all 2-microns sequences, exhibit copy number levels lower than 2-microns and are maintained stably only under selective conditions. We were interested in determining if there was a means by which 2-microns could be utilized for vector construction, without forfeiting either copy number or nonselective stability. We identified sites in the 2-microns plasmid that could be used for the insertion of genetic sequences without disrupting 2-microns coding elements and then assessed subsequent plasmid constructs for stability and copy number in vivo. We demonstrate the utility of a previously described 2-microns recombination chimera, pBH-2L, for the manipulation and transformation of 2-microns as a pure yeast plasmid vector. We show that the HpaI site near the STB element in the 2-microns plasmid can be utilized to clone yeast DNA of at least 3.9 kb with no loss of plasmid stability. Additionally, the copy number of these constructs is as high as levels reported for the endogenous 2-microns.

  3. Highly Stable and Finely Tuned Magnetic Fields Generated by Permanent Magnet Assemblies

    Science.gov (United States)

    Danieli, E.; Perlo, J.; Blümich, B.; Casanova, F.

    2013-05-01

    Permanent magnetic materials are the only magnetic source that can be used to generate magnetic fields without power consumption or maintenance. Such stand-alone magnets are very attractive for many scientific and engineering areas, but they suffer from poor temporal field stability, which arises from the strong sensitivity of the magnetic materials and mechanical support to temperature variation. In this work, we describe a highly efficient method useful to cancel the temperature coefficient of permanent magnet assemblies in a passive and accurate way. It is based on the combination of at least two units made of magnetic materials with different temperature coefficients arranged in such a way that the ratio of the fields generated by each unit matches the ratio of their effective temperature coefficients defined by both the magnetic and mechanical contributions. Although typically available magnetic materials have negative temperature coefficients, the cancellation is achieved by aligning the fields generated by each unit in the opposite direction. We demonstrate the performance of this approach by stabilizing the field generated by a dipolar Halbach magnet, recently proposed to achieve high field homogeneity. Both the field drift and the homogeneity are monitored via nuclear magnetic resonance spectroscopy experiments. The results demonstrate the compatibility of the thermal compensation approach with existing strategies useful to fine-tune the spatial dependence of the field generated by permanent magnet arrays.

  4. Layered bismuth selenide utilized as hole transporting layer for highly stable organic photovoltaics

    KAUST Repository

    Yuan, Zhongcheng

    2015-11-01

    Abstract Layered bismuth selenide (L-Bi2Se3) nanoplates were implemented as hole transporting layers (HTLs) for inverted organic solar cells. Device based on L-Bi2Se3 showed increasing power conversion efficiency (PCE) during ambient condition storage process. A PCE of 4.37% was finally obtained after 5 days storage, which outperformed the ones with evaporated-MoO3 using poly(3-hexylthiophene) (P3HT) as donor material and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as acceptor. The improved device efficiency can be attributed to the high conductivity and increasing work function of L-Bi2Se3. The work function of L-Bi2Se3 increased with the storage time in ambient condition due to the oxygen atom doping. Ultraviolet photoelectron spectroscopy and high resolution X-ray photoelectron spectroscopy were conducted to verify the increased work function, which originated from the p-type doping process. The device based on L-Bi2Se3 exhibited excellent stability in ambient condition up to 4 months, which was much improved compared to the device based on traditional HTLs. © 2015 Elsevier B.V.

  5. Air-stable magnesium nanocomposites provide rapid and high-capacity hydrogen storage without using heavy-metal catalysts.

    Science.gov (United States)

    Jeon, Ki-Joon; Moon, Hoi Ri; Ruminski, Anne M; Jiang, Bin; Kisielowski, Christian; Bardhan, Rizia; Urban, Jeffrey J

    2011-04-01

    Hydrogen is a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density (142 MJ kg(-1); ref. 1), great variety of potential sources (for example water, biomass, organic matter), light weight, and low environmental impact (water is the sole combustion product). However, there remains a challenge to produce a material capable of simultaneously optimizing two conflicting criteria--absorbing hydrogen strongly enough to form a stable thermodynamic state, but weakly enough to release it on-demand with a small temperature rise. Many materials under development, including metal-organic frameworks, nanoporous polymers, and other carbon-based materials, physisorb only a small amount of hydrogen (typically 1-2 wt%) at room temperature. Metal hydrides were traditionally thought to be unsuitable materials because of their high bond formation enthalpies (for example MgH(2) has a ΔHf~75 kJ mol(-1)), thus requiring unacceptably high release temperatures resulting in low energy efficiency. However, recent theoretical calculations and metal-catalysed thin-film studies have shown that microstructuring of these materials can enhance the kinetics by decreasing diffusion path lengths for hydrogen and decreasing the required thickness of the poorly permeable hydride layer that forms during absorption. Here, we report the synthesis of an air-stable composite material that consists of metallic Mg nanocrystals (NCs) in a gas-barrier polymer matrix that enables both the storage of a high density of hydrogen (up to 6 wt% of Mg, 4 wt% for the composite) and rapid kinetics (loading in storage kinetics without using expensive heavy-metal catalysts. PMID:21399630

  6. Chemically stable Dy–Y double substituted barium zirconate with high proton conductivity and improved sinterability

    International Nuclear Information System (INIS)

    Highlights: • BaZr(0.8−x)DyxY0.2O3−δ (0 ⩽ x ⩽ 0.2) powders were synthesized by a wet chemical route. • The ability of the synthesized powders in uptaking water was determined. • Chemical stability of the synthesized powders was evaluated under in wet and CO2 atmosphere. • The conductivity of the sintered pellets was measured by AC impedance spectroscopy. • It was shown that Dy-doped BZY20 ceramic has excellent proton conductivity. • It was proved that Dy-doped BZY20 ceramic has good chemical stability. • It was concluded that Dy-doped BZY20 electrolyte can be considered as a promising electrolyte for solid oxide fuel cell applications. - Abstract: Novel proton conductors BaZr(0.8−x)DyxY0.2O3−δ (BZ0.8−xDxY20, 0 ⩽ x ⩽ 0.2) with high proton conductivity, chemical stability and improved sinterability are developed by partially substituting the Zr site of the 20 mol% Y-doped barium zirconate (BZY20) with Dy. A modified Pechini method was applied to synthesize the BZ0.8−xDxY20 powders. The X-ray diffraction patterns of the well-calcined powders indicated that the specimens with 0 ⩽ x ⩽ 0.2 possessed a single-phase of cubic perovskite-type oxides. Stability tests under both CO2 and moist air atmospheres demonstrated that the excellent chemical stability of the base BZY20 material was not influenced by the introduction of Dy. High density pellets with larger grain sizes were obtained at temperatures lower than those commonly employed for the base Y-doped barium zirconate compound. The proton conductivities, measured in different oxidizing and reducing, dry and humidified atmospheres by impedance spectroscopy, were significantly influenced by the Dy amount. In overall, BaZr(0.8−x)DyxY0.2O3−δ solid solutions having Dy ∼ 5–10% showed excellent chemical stability and high conductivity (above 10−2 S cm−1 at 600 °C, PH2O = 0.023), which was influenced by the moisture content of the applied atmosphere

  7. Chemically stable Dy–Y double substituted barium zirconate with high proton conductivity and improved sinterability

    Energy Technology Data Exchange (ETDEWEB)

    Paydar, M.H., E-mail: paaydar@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Nishimura, Ch. [Hydrogen Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, Tsukuba, Ibaraki (Japan); Kobayashi, K. [Advanced Ceramics Group, Materials Processing Unit, Advanced Key Technologies Division, National Institute for Materials Science, Tsukuba, Ibaraki (Japan)

    2015-10-05

    Highlights: • BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} (0 ⩽ x ⩽ 0.2) powders were synthesized by a wet chemical route. • The ability of the synthesized powders in uptaking water was determined. • Chemical stability of the synthesized powders was evaluated under in wet and CO{sub 2} atmosphere. • The conductivity of the sintered pellets was measured by AC impedance spectroscopy. • It was shown that Dy-doped BZY20 ceramic has excellent proton conductivity. • It was proved that Dy-doped BZY20 ceramic has good chemical stability. • It was concluded that Dy-doped BZY20 electrolyte can be considered as a promising electrolyte for solid oxide fuel cell applications. - Abstract: Novel proton conductors BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} (BZ{sub 0.8−x}D{sub x}Y20, 0 ⩽ x ⩽ 0.2) with high proton conductivity, chemical stability and improved sinterability are developed by partially substituting the Zr site of the 20 mol% Y-doped barium zirconate (BZY20) with Dy. A modified Pechini method was applied to synthesize the BZ{sub 0.8−x}D{sub x}Y20 powders. The X-ray diffraction patterns of the well-calcined powders indicated that the specimens with 0 ⩽ x ⩽ 0.2 possessed a single-phase of cubic perovskite-type oxides. Stability tests under both CO{sub 2} and moist air atmospheres demonstrated that the excellent chemical stability of the base BZY20 material was not influenced by the introduction of Dy. High density pellets with larger grain sizes were obtained at temperatures lower than those commonly employed for the base Y-doped barium zirconate compound. The proton conductivities, measured in different oxidizing and reducing, dry and humidified atmospheres by impedance spectroscopy, were significantly influenced by the Dy amount. In overall, BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} solid solutions having Dy ∼ 5–10% showed excellent chemical stability and high conductivity (above 10{sup −2} S cm{sup −1} at

  8. Highly stable evolution of Earth's future orbit despite chaotic behavior of the Solar System

    CERN Document Server

    Zeebe, Richard E

    2015-01-01

    Due to the chaotic nature of the Solar System, the question of its dynamic long-term stability can only be answered in a statistical sense, e.g. based on numerical ensemble integrations of nearby orbits. Destabilization, including catastrophic encounters and/or collisions involving the Earth, has been suggested to be initiated through a large increase in Mercury's eccentricity (eM), with an estimated probability of ~1%. However, it has recently been shown that the statistics of numerical Solar System integrations are sensitive to the accuracy and type of numerical algorithm. Here I report results from computationally demanding ensemble integrations (N=1,600 with slightly different initial conditions) at unprecedented accuracy based on the full equations of motion of the eight planets and Pluto over 5Gyr, including contributions from general relativity. The standard symplectic algorithm produced spurious results for highly eccentric orbits and during close encounters, which were hence integrated with a suitabl...

  9. High Molecular Weight Thermally Stable Poly (Sodium Methacrylate / Magnetites Nanocomposites Via Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Rasha A. El-Ghazawya,

    2014-04-01

    Full Text Available Core/shell type magnetite nanocomposites (MN were synthesized using sodium methacrylate (NMA monomer. Functionalized and bare magnetite nanoparticles were prepared by conventional co-precipitation method giving particles with 3-10 nm in diameter. Microemulsion polymerization was used for constructing core/shell structure with magnetite nanoparticles as core and poly (sodium methacrylate as shell. Chemical structure and morphology of the synthesized PNMA/magnetite nanocomposites were investigated using FTIR and TEM, respectively. The synthesized nanocomposites show effective encapsulation of different treated magnetite nanoparticles in the polymer matrix and exhibited good thermal stability. Such magnetite nanocomposites with high molecular weight and thermal stability have potential application in enhanced oil recovery application.

  10. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin

    2014-08-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, bIm and 2-mbIm in DMF solution at 180 °C. Topological analysis indicated that JUC-160 has a zeolite GIS (gismondine) topology. Study of the gas adsorption and thermal and chemical stability of JUC-160 demonstrated its selective adsorption property for carbon dioxide, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvent for up to one week. © 2014 Elsevier B.V.

  11. Study of Stable Cathodes and Electrolytes for High Specific Density Lithium-Air Battery

    Science.gov (United States)

    Hernandez-Lugo, Dionne M.; Wu, James; Bennett, William; Ming, Yu; Zhu, Yu

    2015-01-01

    Future NASA missions require high specific energy battery technologies, greater than 400 Wh/kg. Current NASA missions are using "state-of-the-art" (SOA) Li-ion batteries (LIB), which consist of a metal oxide cathode, a graphite anode and an organic electrolyte. NASA Glenn Research Center is currently studying the physical and electrochemical properties of the anode-electrolyte interface for ionic liquid based Li-air batteries. The voltage-time profiles for Pyr13FSI and Pyr14TFSI ionic liquids electrolytes studies on symmetric cells show low over-potentials and no dendritic lithium morphology. Cyclic voltammetry measurements indicate that these ionic liquids have a wide electrochemical window. As a continuation of this work, sp2 carbon cathode and these low flammability electrolytes were paired and the physical and electrochemical properties were studied in a Li-air battery system under an oxygen environment.

  12. Near field magnetostatics and Neel Brownian interactions mediated magnetorheological characteristics of highly stable nano ferrocolloids

    CERN Document Server

    Katiyar, Ajay; Das, Sarit K; Nandi, Tandra

    2015-01-01

    Magnetic nanocolloids with synthesized super paramagnetic Fe3O4 nanoparticles (SPION) (5 to 15 nm) dispersed in insitu developed Polyethylene Glycol (PEG 400) and nano silica complex have been synthesized. The PEG nano Silica complex physically encapsulates the SPIONs, ensuring no phase separation under high magnetic fields (1.2 T). Exhaustive magnetorheological investigations have been performed to comprehend the structural behavior and response of the ferrocolloids. Remarkable stability and reversibility have been observed under magnetic field for concentrated systems. The results exhibit the impact of particle concentration, size and encapsulation efficiency on parameters such as shear viscosity, yield stress, viscoelastic moduli, magnetoviscous hysteresis etc. Analytical models to reveal the system mechanism and mathematically predict the magnetoviscosity and magneto yield stress has been theorized. The mechanistic approach based on near field magnetostatics and Neel Brownian interactivities can predict t...

  13. Thermally Stable Ohmic Contacts on Silicon Carbide Developed for High- Temperature Sensors and Electronics

    Science.gov (United States)

    Okojie, Robert S.

    2001-01-01

    The NASA aerospace program, in particular, requires breakthrough instrumentation inside the combustion chambers of engines for the purpose of, among other things, improving computational fluid dynamics code validation and active engine behavioral control (combustion, flow, stall, and noise). This environment can be as high as 600 degrees Celsius, which is beyond the capability of silicon and gallium arsenide devices. Silicon-carbide- (SiC-) based devices appear to be the most technologically mature among wide-bandgap semiconductors with the proven capability to function at temperatures above 500 degrees Celsius. However, the contact metalization of SiC degrades severely beyond this temperature because of factors such as the interdiffusion between layers, oxidation of the contact, and compositional and microstructural changes at the metal/semiconductor interface. These mechanisms have been proven to be device killers. Very costly and weight-adding packaging schemes that include vacuum sealing are sometimes adopted as a solution.

  14. Note: Thermally stable thin-film filters for high-power extreme-ultraviolet applications.

    Science.gov (United States)

    Tarrio, C; Berg, R F; Lucatorto, T B; Lairson, B; Lopez, H; Ayers, T

    2015-11-01

    We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm(-2), Ni-mesh-backed Zr filters have a typical lifetime of 20 h, at which point they suffer from pinholes and a 50% loss of transmission. Initial trials with Si filters on Ni meshes resulted in rupture of the filters in less than an hour. A simple thermal calculation showed that the temperature rise in those filters to be about 634 K. A similar calculation indicated that using a finer mesh with thicker wires and made of Cu reduces the temperature increase to about 60 K. We have exposed a Si filter backed by such a mesh for more than 60 h with little loss of transmission and no leaks. PMID:26628184

  15. Highly stable glycosylated serine protease from the medicinal plant Euphorbia milii.

    Science.gov (United States)

    Yadav, Subhash C; Pande, Monu; Jagannadham, M V

    2006-07-01

    A serine protease, named as "Milin" was purified to homogeneity from the latex of Euphorbia milii, a medicinal plant of Euphorbiaceae family. The molecular mass (SDS-PAGE), optimum pH and temperature of the enzyme were 51kDa, pH 8.0 and 60 degrees C, respectively. Milin retains full proteolytic activity over a wide range of pH (5.5-12) and temperature (up to 65 degrees C) with casein and azoalbumin as substrates. The activity of milin is inhibited by serine proteases inhibitors like PMSF, APMSF and DFP, but not by any other protease inhibitors such as E-64 and PCMB. Like the other serine proteases from the genus Euphorbia, the activity of milin was not inhibited by the proteinaceous inhibitor soyabean trypsin inhibitor (SBTI) even at very high concentrations that is naturally present in plants. The specific extinction coefficient (epsilon(280 nm)(1%)), molar extinction coefficient (a(m)) and isoelectric point of the enzyme were found to be 29, 152,500 M(-1) cm(-1) and pH 7.2, respectively. The enzyme is a glycoprotein with detectable carbohydrate moiety (7-8%) in its constitution, which is essential for the activity. The numbers of tryptophan, tyrosine and cysteine residues in the sequence of milin were estimated chemically and are 23, 14 and 14, respectively. Of the 14-cysteine residues, 12 constituted 6-disulfide linkages while two are free cysteines. The N-terminal sequence (first 12 amino acid residues) was determined and does not match with any sequence of known plant serine proteases. Perturbation studies by temperature, pH and chaotropes of the enzyme also reveal its high stability as seen by CD, fluorescence and proteolytic activity. Thus, this serine protease may have potential applications in food industry. PMID:16839575

  16. High-radiance LDP source: clean, reliable, and stable EUV source for mask inspection

    Science.gov (United States)

    Teramoto, Yusuke; Santos, Bárbara; Mertens, Guido; Kops, Ralf; Kops, Margarete; von Wezyk, Alexander; Bergmann, Klaus; Yabuta, Hironobu; Nagano, Akihisa; Ashizawa, Noritaka; Taniguchi, Yuta; Shirai, Takahiro; Nakamura, Kiyotada; Aoki, Kazuya; Kasama, Kunihiko

    2016-03-01

    High-throughput and -resolution actinic mask inspection tools are needed as EUVL begins to enter into volume production phase. To realize such inspection tools, a high-radiance EUV source is necessary. Ushio's laser-assisted discharge-produced plasma (LDP) source is able to meet industry's requirements in radiance, cleanliness, stability and reliability. Ushio's LDP source has shown the peak radiance at plasma of 180 W/mm2/sr and the area-averaged radiance in a 200-μm-diameter circle behind the debris mitigation system of 120 W/mm2/sr. A new version of the debris mitigation system is in testing phase. Its optical transmission was confirmed to be 73 %, which is 4 % lower than that of the previous version and therefore will be improved. Cleanliness of the system is evaluated by exposing Ru mirrors placed behind the debris mitigation system. Ru sputter rate was proven to be sufficiently low as 3~5 nm/Gpulse at 7 kHz, whereas frequency-dependent sputter rate was 1~3 nm/Gpulse at 5~9 kHz as previously reported. Sn deposition remained very low (energy stability was approximately 10 %. Dose energy stability dropped from approximately 2 % to 0.1 % when feedback control was activated. EUV emission position stability was studied at 3 kHz. Deviation of the plasma center of gravity was 6 μm, which is 3 % of plasma diameter and therefore considered to be negligible. Reliability tests were performed on both R and D and prototype machines and up to 200 hours of non-interrupted operation was demonstrated.

  17. Stable Isolation of Phycocyanin from Spirulina platensis Associated with High-Pressure Extraction Process

    Directory of Open Access Journals (Sweden)

    Kyung-Hwan Jung

    2013-01-01

    Full Text Available A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%–5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also showed the highest purity of 0.909 based on absorbance of 2.104 at 280 nm and 1.912 at 620 nm. Two subunits of phycocyanin namely α-phycocyanin (18.4 kDa and β-phycocyanin (21.3 kDa were found to remain from the original mixtures after being extracted, based on SDS-PAGE analysis, clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent, temperature, etc. The stability of the extracted phycocyanin was also confirmed by comparing its DPPH (α,α-diphenyl-β-picrylhydrazyl scavenging activity, showing 83% removal of oxygen free radicals. This activity was about 15% higher than that of commercially available standard phycocyanin, which implies that the combined extraction method can yield relatively intact chromoprotein through absence of degradation. The results were achieved because the low temperature and high pressure extraction effectively disrupted the cell membrane of Spirulina platensis and degraded less the polypeptide subunits of phycocyanin (which is a temperature/pH-sensitive chromoprotein as well as increasing the extraction yield.

  18. High-radiance LDP source: clean, reliable, and stable EUV source for mask inspection

    Science.gov (United States)

    Teramoto, Yusuke; Santos, Bárbara; Mertens, Guido; Kops, Ralf; Kops, Margarete; von Wezyk, Alexander; Bergmann, Klaus; Yabuta, Hironobu; Nagano, Akihisa; Ashizawa, Noritaka; Taniguchi, Yuta; Shirai, Takahiro; Nakamura, Kiyotada; Aoki, Kazuya; Kasama, Kunihiko

    2016-03-01

    High-throughput and -resolution actinic mask inspection tools are needed as EUVL begins to enter into volume production phase. To realize such inspection tools, a high-radiance EUV source is necessary. Ushio's laser-assisted discharge-produced plasma (LDP) source is able to meet industry's requirements in radiance, cleanliness, stability and reliability. Ushio's LDP source has shown the peak radiance at plasma of 180 W/mm2/sr and the area-averaged radiance in a 200-μm-diameter circle behind the debris mitigation system of 120 W/mm2/sr. A new version of the debris mitigation system is in testing phase. Its optical transmission was confirmed to be 73 %, which is 4 % lower than that of the previous version and therefore will be improved. Cleanliness of the system is evaluated by exposing Ru mirrors placed behind the debris mitigation system. Ru sputter rate was proven to be sufficiently low as 3~5 nm/Gpulse at 7 kHz, whereas frequency-dependent sputter rate was 1~3 nm/Gpulse at 5~9 kHz as previously reported. Sn deposition remained very low (discharge frequencies. Pulse energy stability was approximately 10 %. Dose energy stability dropped from approximately 2 % to 0.1 % when feedback control was activated. EUV emission position stability was studied at 3 kHz. Deviation of the plasma center of gravity was 6 μm, which is 3 % of plasma diameter and therefore considered to be negligible. Reliability tests were performed on both R and D and prototype machines and up to 200 hours of non-interrupted operation was demonstrated.

  19. Mount Aragats as a stable electron accelerator for atmospheric high-energy physics research

    Science.gov (United States)

    Chilingarian, Ashot; Hovsepyan, Gagik; Mnatsakanyan, Eduard

    2016-03-01

    Observation of the numerous thunderstorm ground enhancements (TGEs), i.e., enhanced fluxes of electrons, gamma rays, and neutrons detected by particle detectors located on the Earth's surface and related to the strong thunderstorms above it, helped to establish a new scientific topic—high-energy physics in the atmosphere. Relativistic runaway electron avalanches (RREAs) are believed to be a central engine initiating high-energy processes in thunderstorm atmospheres. RREAs observed on Mount Aragats in Armenia during the strongest thunderstorms and simultaneous measurements of TGE electron and gamma-ray energy spectra proved that RREAs are a robust and realistic mechanism for electron acceleration. TGE research facilitates investigations of the long-standing lightning initiation problem. For the last 5 years we were experimenting with the "beams" of "electron accelerators" operating in the thunderclouds above the Aragats research station. Thunderstorms are very frequent above Aragats, peaking in May-June, and almost all of them are accompanied with enhanced particle fluxes. The station is located on a plateau at an altitude 3200 asl near a large lake. Numerous particle detectors and field meters are located in three experimental halls as well as outdoors; the facilities are operated all year round. All relevant information is being gathered, including data on particle fluxes, fields, lightning occurrences, and meteorological conditions. By the example of the huge thunderstorm that took place at Mount Aragats on August 28, 2015, we show that simultaneous detection of all the relevant data allowed us to reveal the temporal pattern of the storm development and to investigate the atmospheric discharges and particle fluxes.

  20. Long Term and High Frequency Non-Destructive Monitoring of Soil Water Stable Isotope Compositions in the Laboratory

    Science.gov (United States)

    Rothfuss, Y.; Merz, S.; Pohlmeier, A. J.; Vereecken, H.; Brueggemann, N.

    2014-12-01

    The fate and dynamics of water stable isotopologues (1H2H16O and 1H218O) are currently well implemented into physically based Soil-Vegetation-Atmosphere Transfer (SVAT) models (e.g. Hydrus 1D, SiSPAT-I, Soil-Litter iso, TOUGHREACT). However, contrary to other state variables (e.g., water content and tension) that can be monitored over long periods (e.g., by time-domain reflectometry, capacitive sensing, tensiometry or micro-psychrometry), water stable isotope compositions (δ2H and δ18O) are analyzed following destructive sampling, and thus are available only at a given time. Thus, there are important discrepancies in time resolution between soil water and stable isotope information which greatly limit the insight potential of the latter. Recently however, a technique based on direct infrared laser absorption spectroscopy was developed that allows simultaneous and direct measurements of δ2H and δ18O in water vapor. Here, we present a non-destructive method for monitoring soil liquid δ2H and δ18O by sampling and measuring water vapor equilibrated with soil water using gas-permeable polypropylene tubing and a Cavity Ring-Down laser Spectrometer (CRDS). An acrylic glass column (d=11 cm, h=60 cm) was (i) equipped with temperature and soil water probes in addition to gas-permeable tubing sections at eight different depths, (ii) filled with pure quartz sand, (iii) saturated from the bottom, and (iv) installed on weighing balances and let dry for 250 days. Each day, soil vapor δ2H and δ18O were measured for each depth by purging the soil water vapor sampled in the tubing sections with dry air and analyzing it with a CRDS. Soil liquid water δ2H and δ18O were then inferred from the values measured in the vapor. The experimental setup allowed following the evolution of the soil water δ2H and δ18O profile, which developed as a result of isotope convective capillary rise and back-diffusion of the stable isotope excess at the soil surface due to fractionating soil

  1. Highly Stable Nanocontainer of APTES-Anchored Layered Titanate Nanosheet for Reliable Protection/Recovery of Nucleic Acid.

    Science.gov (United States)

    Kim, Tae Woo; Kim, In Young; Park, Dae-Hwan; Choy, Jin-Ho; Hwang, Seong-Ju

    2016-01-01

    A universal technology for the encapsulative protection of unstable anionic species by highly stable layered metal oxide has been developed via the surface modification of a metal oxide nanosheet. The surface anchoring of (3-aminopropyl)triethoxysilane (APTES) on exfoliated titanate nanosheet yields a novel cationic metal oxide nanosheet, which can be universally used for the hybridization with various biological and inorganic anions. The encapsulation of deoxyribonucleic acid (DNA) in the cationic APTES-anchored titanate lattice makes possible the reliable long-term protection of DNA against enzymatic, chemical, and UV-vis light corrosions. The encapsulated DNA can be easily released from the titanate lattice via sonication, underscoring the functionality of the cationic APTES-anchored titanate nanosheet as a stable nanocontainer for DNA. The APTES-anchored titanate nanosheet can be also used as an efficient CO2 adsorbent and a versatile host material for various inorganic anions like polyoxometalates, leading to the synthesis of novel intercalative nanohybrids with unexplored properties and useful functionalities. PMID:26906340

  2. Highly Stable Nanocontainer of APTES-Anchored Layered Titanate Nanosheet for Reliable Protection/Recovery of Nucleic Acid

    Science.gov (United States)

    Kim, Tae Woo; Kim, In Young; Park, Dae-Hwan; Choy, Jin-Ho; Hwang, Seong-Ju

    2016-02-01

    A universal technology for the encapsulative protection of unstable anionic species by highly stable layered metal oxide has been developed via the surface modification of a metal oxide nanosheet. The surface anchoring of (3-aminopropyl)triethoxysilane (APTES) on exfoliated titanate nanosheet yields a novel cationic metal oxide nanosheet, which can be universally used for the hybridization with various biological and inorganic anions. The encapsulation of deoxyribonucleic acid (DNA) in the cationic APTES-anchored titanate lattice makes possible the reliable long-term protection of DNA against enzymatic, chemical, and UV-vis light corrosions. The encapsulated DNA can be easily released from the titanate lattice via sonication, underscoring the functionality of the cationic APTES-anchored titanate nanosheet as a stable nanocontainer for DNA. The APTES-anchored titanate nanosheet can be also used as an efficient CO2 adsorbent and a versatile host material for various inorganic anions like polyoxometalates, leading to the synthesis of novel intercalative nanohybrids with unexplored properties and useful functionalities.

  3. Synthesis, characterization, and in vitro biological evaluation of highly stable diversely functionalized superparamagnetic iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Dipsikha; Sahu, Sumanta K. [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Banerjee, Indranil [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Das, Manasmita [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Mishra, Debashish; Maiti, Tapas K. [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Pramanik, Panchanan, E-mail: dipsikha.chem@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

    2011-09-15

    In this article, we report the design and synthesis of a series of well-dispersed superparamagnetic iron oxide nanoparticles (SPIONs) using chitosan as a surface modifying agent to develop a potential T{sub 2} contrast probe for magnetic resonance imaging (MRI). The amine, carboxyl, hydroxyl, and thiol functionalities were introduced on chitosan-coated magnetic probe via simple reactions with small reactive organic molecules to afford a series of biofunctionalized nanoparticles. Physico-chemical characterizations of these functionalized nanoparticles were performed by TEM, XRD, DLS, FTIR, and VSM. The colloidal stability of these functionalized iron oxide nanoparticles was investigated in presence of phosphate buffer saline, high salt concentrations and different cell media for 1 week. MRI analysis of human cervical carcinoma (HeLa) cell lines treated with nanoparticles elucidated that the amine-functionalized nanoparticles exhibited higher amount of signal darkening and lower T{sub 2} relaxation in comparison to the others. The cellular internalization efficacy of these functionalized SPIONs was also investigated with HeLa cancer cell line by magnetically activated cell sorting (MACS) and fluorescence microscopy and results established selectively higher internalization efficacy of amine-functionalized nanoparticles to cancer cells. These positive attributes demonstrated that these nanoconjugates can be used as a promising platform for further in vitro and in vivo biological evaluations.

  4. Synthesis, characterization, and in vitro biological evaluation of highly stable diversely functionalized superparamagnetic iron oxide nanoparticles

    International Nuclear Information System (INIS)

    In this article, we report the design and synthesis of a series of well-dispersed superparamagnetic iron oxide nanoparticles (SPIONs) using chitosan as a surface modifying agent to develop a potential T2 contrast probe for magnetic resonance imaging (MRI). The amine, carboxyl, hydroxyl, and thiol functionalities were introduced on chitosan-coated magnetic probe via simple reactions with small reactive organic molecules to afford a series of biofunctionalized nanoparticles. Physico-chemical characterizations of these functionalized nanoparticles were performed by TEM, XRD, DLS, FTIR, and VSM. The colloidal stability of these functionalized iron oxide nanoparticles was investigated in presence of phosphate buffer saline, high salt concentrations and different cell media for 1 week. MRI analysis of human cervical carcinoma (HeLa) cell lines treated with nanoparticles elucidated that the amine-functionalized nanoparticles exhibited higher amount of signal darkening and lower T2 relaxation in comparison to the others. The cellular internalization efficacy of these functionalized SPIONs was also investigated with HeLa cancer cell line by magnetically activated cell sorting (MACS) and fluorescence microscopy and results established selectively higher internalization efficacy of amine-functionalized nanoparticles to cancer cells. These positive attributes demonstrated that these nanoconjugates can be used as a promising platform for further in vitro and in vivo biological evaluations.

  5. Stable hole doping of graphene for low electrical resistance and high optical transparency

    International Nuclear Information System (INIS)

    We report on the p doping of graphene with the polymer TFSA ((CF3SO2)2NH). Modification of graphene with TFSA decreases the graphene sheet resistance by 70%. Through such modification, we report sheet resistance values as low as 129 Ω, thus attaining values comparable to those of indium-tin oxide (ITO), while displaying superior environmental stability and preserving electrical properties over extended time scales. Electrical transport measurements reveal that, after doping, the carrier density of holes increases, consistent with the acceptor nature of TFSA, and the mobility decreases due to enhanced short-range scattering. The Drude formula predicts that competition between these two effects yields an overall increase in conductivity. We confirm changes in the carrier density and Fermi level of graphene through changes in the Raman G and 2D peak positions. Doped graphene samples display high transmittance in the visible and near-infrared spectrum, preserving graphene's optical properties without any significant reduction in transparency, and are therefore superior to ITO films in the near infrared. The presented results allow integration of doped graphene sheets into optoelectronics, solar cells, and thermoelectric solar cells as well as engineering of the electrical characteristics of various devices by tuning the Fermi level of graphene.

  6. Stable hole doping of graphene for low electrical resistance and high optical transparency.

    Science.gov (United States)

    Tongay, S; Berke, K; Lemaitre, M; Nasrollahi, Z; Tanner, D B; Hebard, A F; Appleton, B R

    2011-10-21

    We report on the p doping of graphene with the polymer TFSA ((CF(3)SO(2))(2)NH). Modification of graphene with TFSA decreases the graphene sheet resistance by 70%. Through such modification, we report sheet resistance values as low as 129 Ω, thus attaining values comparable to those of indium-tin oxide (ITO), while displaying superior environmental stability and preserving electrical properties over extended time scales. Electrical transport measurements reveal that, after doping, the carrier density of holes increases, consistent with the acceptor nature of TFSA, and the mobility decreases due to enhanced short-range scattering. The Drude formula predicts that competition between these two effects yields an overall increase in conductivity. We confirm changes in the carrier density and Fermi level of graphene through changes in the Raman G and 2D peak positions. Doped graphene samples display high transmittance in the visible and near-infrared spectrum, preserving graphene's optical properties without any significant reduction in transparency, and are therefore superior to ITO films in the near infrared. The presented results allow integration of doped graphene sheets into optoelectronics, solar cells, and thermoelectric solar cells as well as engineering of the electrical characteristics of various devices by tuning the Fermi level of graphene. PMID:21934196

  7. Plasma graft-polymerization for synthesis of highly stable hydroxide exchange membrane

    Science.gov (United States)

    Hu, Jue; Zhang, Chengxu; Jiang, Lin; Fang, Shidong; Zhang, Xiaodong; Wang, Xiangke; Meng, Yuedong

    2014-02-01

    A novel plasma graft-polymerization approach is adopted to prepare hydroxide exchange membranes (HEMs) using cardo polyetherketone powders (PEK-C) and vinylbenzyl chloride. The benzylic chloromethyl groups can be successfully introduced into the PEK-C polymer matrix via plasma graft-polymerization. This approach enables a well preservation in the structure of functional groups and formation of a highly cross-linked structure in the membrane, leading to an improvement on the stability and performance of HEMs. The chemical stabilities, including alkaline and oxidative stability, are evaluated under severe conditions by measuring hydroxide conductivity and weight changes during aging. The obtained PGP-NOH membrane retains 86% of the initial hydroxide conductivity in 6 mol L-1 KOH solution at 60 °C for 120 h, and 94% of the initial weight in 3 wt% H2O2 solution at 60 °C for 262 h. The PGP-NOH membrane also possesses excellent thermal stability (safely used below 120 °C), alcohol resistance (ethanol permeability of 6.6 × 10-11 m2 s-1 and diffusion coefficient of 3.7 × 10-13 m2 s-1), and an acceptable hydroxide conductivity (8.3 mS cm-1 at 20 °C in deionized water), suggesting a good candidate of PGP-NOH membrane for HEMFC applications.

  8. Hydrophobic and Metallophobic Surfaces: Highly Stable Non-wetting Inorganic Surfaces Based on Lanthanum Phosphate Nanorods.

    Science.gov (United States)

    Sankar, Sasidharan; Nair, Balagopal N; Suzuki, Takehiro; Anilkumar, Gopinathan M; Padmanabhan, Moothetty; Hareesh, Unnikrishnan Nair S; Warrier, Krishna G

    2016-01-01

    Metal oxides, in general, are known to exhibit significant wettability towards water molecules because of the high feasibility of synergetic hydrogen-bonding interactions possible at the solid-water interface. Here we show that the nano sized phosphates of rare earth materials (Rare Earth Phosphates, REPs), LaPO4 in particular, exhibit without any chemical modification, unique combination of intrinsic properties including remarkable hydrophobicity that could be retained even after exposure to extreme temperatures and harsh hydrothermal conditions. Transparent nanocoatings of LaPO4 as well as mixture of other REPs on glass surfaces are shown to display notable hydrophobicity with water contact angle (WCA) value of 120° while sintered and polished monoliths manifested WCA greater than 105°. Significantly, these materials in the form of coatings and monoliths also exhibit complete non-wettability and inertness towards molten metals like Ag, Zn, and Al well above their melting points. These properties, coupled with their excellent chemical and thermal stability, ease of processing, machinability and their versatile photo-physical and emission properties, render LaPO4 and other REP ceramics utility in diverse applications. PMID:26955962

  9. Stable and High Ajmalicine or Serpentine Production of Gamma Radiation Induction Mutant Catharantus Roseus

    International Nuclear Information System (INIS)

    Catharantus roseus Mutant have been selected by gamma irradiation with 20 krad doses of radiation and characterized as biochemical mutant with anti-feed back inhibition mechanism of tritophan decarboxylase (TDR) enzyme in biosynthetic path way of indole alkaloid. Production of indole alkaloid mainly ajmalicine with high economical values as a pharmaceutical drug for heart attack have been studied by using cell suspension cultures with several variation of medium, elicitors and stress osmosis. This treatment produced variation of indole alkaloid ajmalicine and serpentine. Several induction methods using Murashige and Skoog (MS) medium and polyethylene glycol PEG (6000) 1 to 7%, with hormones concentration of 2,4-D and kinetin as (10 : 1), showed optimal results of ajmalicine range between 20 and 50 nmol/gFW, and serpentine 10 to 60 nmol/gFW. This production increases ten time in mutant (20 Krad) by stress osmotic condition and performed long term stability in culture without subculture. In this paper explanation in detail about the selection methods, stability of mutant and the production of indole alkaloid ajmalicine and serpentine during growth phase, such as adaptation, log, and stationar in suspention culture of mutan cells. (author)

  10. Hydrophobic and Metallophobic Surfaces: Highly Stable Non-wetting Inorganic Surfaces Based on Lanthanum Phosphate Nanorods

    Science.gov (United States)

    Sankar, Sasidharan; Nair, Balagopal N.; Suzuki, Takehiro; Anilkumar, Gopinathan M.; Padmanabhan, Moothetty; Hareesh, Unnikrishnan Nair S.; Warrier, Krishna G.

    2016-03-01

    Metal oxides, in general, are known to exhibit significant wettability towards water molecules because of the high feasibility of synergetic hydrogen-bonding interactions possible at the solid-water interface. Here we show that the nano sized phosphates of rare earth materials (Rare Earth Phosphates, REPs), LaPO4 in particular, exhibit without any chemical modification, unique combination of intrinsic properties including remarkable hydrophobicity that could be retained even after exposure to extreme temperatures and harsh hydrothermal conditions. Transparent nanocoatings of LaPO4 as well as mixture of other REPs on glass surfaces are shown to display notable hydrophobicity with water contact angle (WCA) value of 120° while sintered and polished monoliths manifested WCA greater than 105°. Significantly, these materials in the form of coatings and monoliths also exhibit complete non-wettability and inertness towards molten metals like Ag, Zn, and Al well above their melting points. These properties, coupled with their excellent chemical and thermal stability, ease of processing, machinability and their versatile photo-physical and emission properties, render LaPO4 and other REP ceramics utility in diverse applications.

  11. High-capacity graphene/sulfur/polyaniline ternary composite cathodes with stable cycling performance

    International Nuclear Information System (INIS)

    Highlights: • Graphene/S/PANI composites have been synthesized by a facile two-step method. • Graphene/S/PANI delivers considerably higher specific capacity than graphene/S. • Improved cycling stability combined with superior Coulombic efficiency is attained. • Graphene and PANI can prevent polysulfide species diffusion. - Abstract: Ternary graphene/sulfur/polyaniline (graphene/S/PANI) composites have been successfully prepared via a facile two-step synthesis method. S nanoparticle is uniformly decorated on the graphene surface, and PANI nanowires cover the graphene/S surface. When used as cathode material for lithium-sulfur batteries, the specific ternary composite achieves excellent electrochemical performance with high capacity and improved cycling stability. The graphene/S/PANI sample delivers a specific capacity of up to 837 mAh g−1 after a few cycles at 0.1C, which is considerably higher than that delivered by the graphene/S sample. In addition, the graphene/S/PANI sample and the graphene/S sample show improved cycling stability with improved Coulombic efficiency compared with pure S sample. This observation indicates the successful prevention of the polysulfide species diffusion owing to graphene introduction. Furthermore, the activation mechanism of graphene/S is studied through morphology change during cycling, which demonstrates that activation is ascribed to the gradual spread of S on the graphene surface during cycling

  12. Highly Stable Liquid Metal-Based Pressure Sensor Integrated with a Microfluidic Channel

    Directory of Open Access Journals (Sweden)

    Taekeon Jung

    2015-05-01

    Full Text Available Pressure measurement is considered one of the key parameters in microfluidic systems. It has been widely used in various fields, such as in biology and biomedical fields. The electrical measurement method is the most widely investigated; however, it is unsuitable for microfluidic systems because of a complicated fabrication process and difficult integration. Moreover, it is generally damaged by large deflection. This paper proposes a thin-film-based pressure sensor that is free from these limitations, using a liquid metal called galinstan. The proposed pressure sensor is easily integrated into a microfluidic system using soft lithography because galinstan exists in a liquid phase at room temperature. We investigated the characteristics of the proposed pressure sensor by calibrating for a pressure range from 0 to 230 kPa (R2 > 0.98 using deionized water. Furthermore, the viscosity of various fluid samples was measured for a shear-rate range of 30–1000 s−1. The results of Newtonian and non-Newtonian fluids were evaluated using a commercial viscometer and normalized difference was found to be less than 5.1% and 7.0%, respectively. The galinstan-based pressure sensor can be used in various microfluidic systems for long-term monitoring with high linearity, repeatability, and long-term stability.

  13. Cold Flow as Versatile Approach for Stable and Highly Luminescent Quantum Dot-Salt Composites.

    Science.gov (United States)

    Benad, Albrecht; Guhrenz, Chris; Bauer, Christoph; Eichler, Franziska; Adam, Marcus; Ziegler, Christoph; Gaponik, Nikolai; Eychmüller, Alexander

    2016-08-24

    Since the beginning of the 1980s, colloidally synthesized quantum dots (QDs) have been in the focus of interest due to their possible implementation for color conversion, luminescent light concentrators, and lasing. For all these applications, the QDs benefit from being embedded into a host matrix to ensure stability and usability. Many different host materials used for this purpose still have their individual shortcomings. Here, we present a universal, fast, and flexible approach for the direct incorporation of a wide range of QDs into inorganic ionic crystals using cold flow. The QD solution is mixed with a finely milled salt, followed by the removal of the solvent under vacuum. Under high pressure (GPa), the salt powder loaded with QDs transforms into transparent pellets. This effect is well-known for many inorganic salts (e.g., KCl, KBr, KI, NaCl, CsI, AgCl) from, e.g., sample preparation for IR spectroscopy. With this approach, we are able to obtain strongly luminescent QD-salt composites, have precise control over the loading, and provide a chemically robust matrix ensuring long-term stability of the embedded QDs. Furthermore, we show the photo-, chemical, and thermal stability of the composite materials and their use as color conversion layers for a white light-emitting diode (w-LED). The method presented can potentially be used for all kinds of nanoparticles synthesized in organic as well as in aqueous media. PMID:27482755

  14. STUDIES ON HIGH SOLID CONTENT AND STABLE EMULSIFIER—FREE EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    TangGuangliang; HaoGuangjie; 等

    1998-01-01

    In this article,AHPS(3-allyloxy-2-hydroxy-1-propanesulfonate salt) was synthesized to use in emulsifier-free emulsion polymerization of BA/BMA/MMA system for high solid content latexes.Storage stability,flow behavior of the latexes,morphology of the obtained latex particles,dynamic viscoelastic behavior,tensile strength and water resistance properties of the resulted copolymers were investigated.The experimental results show that with the addition of AHPS,stability of the emulsion is greatly improved that there appears no apparent precipitation during the polymerization and storage at room temperature for 6 months and at -10℃ for four months.Flow of the latexes follows the Bingham body laws,diameter of the latex particles is about 0.6μm,of which is larger than that of by conventional emulsion polymerization(0.12μm).In addition,not only water resistance of the copolymers obtained by emulsifier-free emulstion polymerization is greatly improved,but also tensile strength is obviously enhanced.

  15. Correction: Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: Preparation of highly active and stable supported Pt catalysts in microemulsions

    OpenAIRE

    Parapat, R.; Wijaya, M.; M. Schwarze; Selve, .; Willinger, M.; Schomäcker, R.

    2016-01-01

    Correction for ‘Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: preparation of highly active and stable supported Pt catalysts in microemulsions’ by Riny Y. Parapat et al., Nanoscale, 2013, 5, 796–805.

  16. Correction: Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: preparation of highly active and stable supported Pt catalysts in microemulsions

    Science.gov (United States)

    Parapat, Riny Y.; Wijaya, Muliany; Schwarze, Michael; Selve, Sören; Willinger, Marc; Schomäcker, Reinhard

    2016-03-01

    Correction for `Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: preparation of highly active and stable supported Pt catalysts in microemulsions' by Riny Y. Parapat et al., Nanoscale, 2013, 5, 796-805.

  17. High-temperature stable absorber coatings for linear concentrating solar thermal power plants; Hochtemperaturstabile Absorberschichten fuer linear konzentrierende solarthermische Kraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Christina

    2009-03-23

    This work describes the development of new absorber coatings for different applications - para-bolic trough and linear Fresnel collectors - and operating conditions - absorber in vacuum or in air. The demand for higher efficiencies of solar thermal power plants using parabolic trough technology results in higher temperatures in the collectors and on the absorber tubes. As heat losses increase strongly with increasing temperatures, the need for a lower emissivity of the absorber coating at constant absorptivity arises. The linear Fresnel application envisions ab-sorber tubes stable in air at high temperatures of about 450 C, which are to date commercially not available. This work comprises the theoretical background, the modeling and the fabrication of absorber tubes including the technology transfer to a production-size inline sputter coater. In annealing tests and accompanying optical measurements, degradation processes have been observed and specified more precisely by material characterization techniques. The simulations provided the capability of different materials used as potential IR-reflector. The highest selectivity can be achieved by applying silver which consequently has been chosen for the application in absorber coatings of the parabolic trough technology. Thin silver films how-ever need to be stabilized when used at high temperatures. Appropriate barrier layers as well as process and layer parameters were identified. A high selectivity was achieved and stability of the absorber coating for 1200 h at 500 C in vacuum has been demonstrated. For the application in air, silver was also analyzed as a potential IR-reflector. Even though the stability could be increased considerably, it nevertheless proved to be insufficient. The main factors influencing stability in a positive way are the use of higher quality polishing, additional barrier layers and adequate process parameters. This knowledge was applied for developing coatings which are stable in air at

  18. Highly stable and self-repairing membrane-mimetic 2D nanomaterials assembled from lipid-like peptoids

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Haibao; Jiao, Fang; Daily, Michael D.; Chen, Yulin; Yan, Feng; Ding, Yanhuai; Zhang, Xin; Robertson, Ellen J.; Baer, Marcel D.; Chen, Chunlong

    2016-07-12

    Two-dimensional (2D) materials with molecular-scale thickness have attracted increasing interest for separation, electronic, catalytic, optical, energy and biomedical applications.1-4 Although extensive research on 2D materials, such as graphene and graphene oxide, has been performed in recent years, progress is limited on self-assembly of 2D materials from sequence-specific macromolecules,5-7 especially from synthetic sequences that could exhibit lipid-like self-assembly of bilayer sheets and mimic membrane proteins for functions. The creation of such new class of materials could enable development of highly stable biomimetic membranes that exhibit cell-membrane-like molecular transport with exceptional selectively and high transport rates.8,9 Here we demonstrate self-assembly of lipid-like 12-mer peptoids into extremely stable, crystalline, flexible and free-standing 2D membrane materials. As with cell membranes, upon exposure to external stimuli, these materials exhibit changes in thickness,10 varying from 3.5 nm to 5.6 nm. We find that self-assembly occurs through a facile crystallization process, in which inter-peptoid hydrogen bonds and enhanced hydrophobic interactions drive the formation of a highly-ordered structure. Molecular simulation confirms this is the energetically favored structure. Displaying functional groups at arbitrary locations of membrane-forming peptoids produces membranes with similar structures. This research further shows that single-layer membranes can be coated onto substrate surfaces. Moreover, membranes with mechanically-induced defects can self-repair. Given that peptoids are sequence-specific and exhibit protein-like molecular recognition with enhanced stability,11 we anticipate our membranes to be a robust platform tailored to specific applications.

  19. Highly stable copper oxide composite as an effective photocathode for water splitting via a facile electrochemical synthesis strategy

    KAUST Repository

    Zhang, Zhonghai

    2012-01-01

    Hydrogen generation through photoelectrochemical (PEC) water splitting using solar light as an energy resource is believed to be a clean and efficient way to overcome the global energy and environmental problems. Extensive research effort has been focused on n-type metal oxide semiconductors as photoanodes, whereas studies of p-type metal oxide semiconductors as photocathodes where hydrogen is generated are scarce. In this paper, highly efficient and stable copper oxide composite photocathode materials were successfully fabricated by a facile two-step electrochemical strategy, which consists of electrodeposition of a Cu film on an ITO glass substrate followed by anodization of the Cu film under a suitable current density and then calcination to form a Cu 2O/CuO composite. The synthesized Cu 2O/CuO composite was composed of a thin layer of Cu 2O with a thin film of CuO on its top as a protecting coating. The rational control of chemical composition and crystalline orientation of the composite materials was easily achieved by varying the electrochemical parameters, including electrodeposition potential and anodization current density, to achieve an enhanced PEC performance. The best photocathode material among all materials prepared was the Cu 2O/CuO composite with Cu 2O in (220) orientation, which showed a highly stable photocurrent of -1.54 mA cm -2 at a potential of 0 V vs reversible hydrogen electrode at a mild pH under illumination of AM 1.5G. This photocurrent density was more than 2 times that generated by the bare Cu 2O electrode (-0.65 mAcm -2) and the stability was considerably enhanced to 74.4% from 30.1% on the bare Cu 2O electrode. The results of this study showed that the top layer of CuO in the Cu 2O/CuO composite not only minimized the Cu 2O photocorrosion but also served as a recombination inhibitor for the photogenerated electrons and holes from Cu 2O, which collectively explained much enhanced stability and PEC activity of the Cu 2O/CuO composite

  20. Highly active and stable platinum catalyst supported on porous carbon nanofibers for improved performance of PEMFC

    International Nuclear Information System (INIS)

    Porous carbon nanofibers (PCNFs) were used as the support to prepare platinum (Pt) catalyst (Pt/PCNFs) for proton exchange membrane fuel cell (PEMFC) applications. As a comparison, Pt supported on carbon black (Vulcan XC-72) (Pt/Vulcan) was also synthesized by the same ethylene glycol reduction method. Platinum was more uniformly deposited on PCNFs than that on the Vulcan XC-72. The electrocatalytic activity and stability of the resultant catalysts along with the commercial one (JM20) were investigated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) with a rotating disk electrode (RDE). The Pt/PCNFs exhibited much-enhanced electrocatalytic activity and stability compared with the Pt/Vulcan and JM20. The mass activity (at 0.80 V) of Pt/PCNFs is 2.6 times higher and 20% higher than that of Pt/Vulcan and JM20, respectively; the Pt/PCNFs retained about 50% of ECSA whereas JM20 and Pt/Vulcan kept only 25% and 5% of ECSA, respectively, even after 1000 cycles. Furthermore, the single cell performance of Pt/PCNFs was superior to that of Pt/Vulcan and even better than JM20 during high current densities. The cross-section of the membrane electrode assembly (MEA) showed that the Pt/PCNFs construct a loose three-dimensionally connected catalyst layer that is totally different from the tightly stacking catalyst layer composed of carbon black support. Thus, the mass transfer resistance is reduced and water drainage becomes easy when Pt/PCNFs were used as cathode catalyst. These results indicate PCNFs a promising candidate as catalyst supports for the enhancement of PEMFC performance

  1. Production of shelf-stable ranch dressing using high-pressure processing.

    Science.gov (United States)

    Waite, J G; Jones, J M; Turek, E J; Dunne, C P; Wright, A O; Yang, T C S; Beckwitt, R; Yousef, A E

    2009-03-01

    High-pressure processing (HPP) can reduce or eliminate microorganisms of concern in food without deteriorating product quality; however, quality benefits must justify the substantial capital investment for the utilization of this technology. HPP is particularly a beneficial preservation technology for products damaged by thermal treatments or when product quality could be improved by reformulation to raise pH or eliminate chemical preservatives. The primary objectives of this study were to determine the efficacy of HPP to protect premium ranch dressing (pH 4.4) from microbial spoilage and to assess changes in physical, chemical, and sensory attributes throughout the product's shelf life. In inoculated-packages studies, the efficacy of HPP was measured against ranch dressing spoilage organisms: Pediococcus acidilactici, Lactobacillus brevis, and Torulaspora delbrueckii. HPP treatment (600 MPa, 3 min) decreased population of P. acidilactici, the most pressure-resistant spoilage organism tested, by >or= 6.4 log CFU/g. During a shelf-life study of edible product, treating ranch dressing at 600 MPa for 5 min effectively prevented microbial spoilage throughout the storage period (26 wk at 4 and 26 degrees C). The pH and emulsion stability of ranch dressing were not adversely influenced by HPP. Extended storage of HPP product for 16 to 26 wk at 26 degrees C resulted in a decrease in consumer acceptance and significant changes in color and organic acid profile (specifically, increased pyroglutamic acid). These changes were consistent with those expected during extended storage of commercially available products. HPP may be used to produce premium ranch dressing, with defined shelf-life and storage conditions, without significantly changing product attributes. PMID:19323763

  2. Furazans with Azo Linkages: Stable CHNO Energetic Materials with High Densities, Highly Energetic Performance, and Low Impact and Friction Sensitivities.

    Science.gov (United States)

    Qu, Yanyang; Zeng, Qun; Wang, Jun; Ma, Qing; Li, Hongzhen; Li, Haibo; Yang, Guangcheng

    2016-08-22

    Various highly energetic azofurazan derivatives were synthesized by simple and efficient chemical routes. These nitrogen-rich materials were fully characterized by FTIR spectroscopy, elemental analysis, multinuclear NMR spectroscopy, and high-resolution mass spectrometry. Four of them were further confirmed structurally by single-crystal X-ray diffraction. These compounds exhibit high densities, ranging from 1.62 g cm(-3) up to a remarkably high 2.12 g cm(-3) for nitramine-substituted azofurazan DDAzF (2), which is the highest yet reported for an azofurazan-based CHNO energetic compound and is a consequence of the formation of strong intermolecular hydrogen-bonding networks. From the heats of formation, calculated with Gaussian 09, and the experimentally determined densities, the energetic performances (detonation pressure and velocities) of the materials were ascertained with EXPLO5 v6.02. The results suggest that azofurazan derivatives exhibit excellent detonation properties (detonation pressures of 21.8-46.1 GPa and detonation velocities of 6602-10 114 m s(-1) ) and relatively low impact and friction sensitivities (6.0-80 J and 80-360 N, respectively). In particular, they have low electrostatic spark sensitivities (0.13-1.05 J). These properties, together with their high nitrogen contents, make them potential candidates as mechanically insensitive energetic materials with high-explosive performance. PMID:27439332

  3. Cu-Au alloy nanostructures coated with aptamers: a simple, stable and highly effective platform for in vivo cancer theranostics

    Science.gov (United States)

    Ye, Xiaosheng; Shi, Hui; He, Xiaoxiao; Yu, Yanru; He, Dinggeng; Tang, Jinlu; Lei, Yanli; Wang, Kemin

    2016-01-01

    As a star material in cancer theranostics, photoresponsive gold (Au) nanostructures may still have drawbacks, such as low thermal conductivity, irradiation-induced melting effect and high cost. To solve the problem, copper (Cu) with a much higher thermal conductivity and lower cost was introduced to generate a novel Cu-Au alloy nanostructure produced by a simple, gentle and one-pot synthetic method. Having the good qualities of both Cu and Au, the irregularly-shaped Cu-Au alloy nanostructures showed several advantages over traditional Au nanorods, including a broad and intense near-infrared (NIR) absorption band from 400 to 1100 nm, an excellent heating performance under laser irradiation at different wavelengths and even a notable photostability against melting. Then, via a simple conjugation of fluorophore-labeled aptamers on the Cu-Au alloy nanostructures, active targeting and signal output were simultaneously introduced, thus constructing a theranostic platform based on fluorophore-labeled, aptamer-coated Cu-Au alloy nanostructures. By using human leukemia CCRF-CEM cancer and Cy5-labeled aptamer Sgc8c (Cy5-Sgc8c) as the model, a selective fluorescence imaging and NIR photothermal therapy was successfully realized for both in vitro cancer cells and in vivo tumor tissues. It was revealed that Cy5-Sgc8c-coated Cu-Au alloy nanostructures were not only capable of robust target recognition and stable signal output for molecular imaging in complex biological systems, but also killed target cancer cells in mice with only five minutes of 980 nm irradiation. The platform was found to be simple, stable, biocompatible and highly effective, and shows great potential as a versatile tool for cancer theranostics.As a star material in cancer theranostics, photoresponsive gold (Au) nanostructures may still have drawbacks, such as low thermal conductivity, irradiation-induced melting effect and high cost. To solve the problem, copper (Cu) with a much higher thermal conductivity

  4. Highly stable and re-dispersible nano Cu hydrosols with sensitively size-dependent catalytic and antibacterial activities

    Science.gov (United States)

    Zhang, Yu; Zhu, Pengli; Li, Gang; Wang, Wenzhao; Chen, Liang; Lu, Daoqiang Daniel; Sun, Rong; Zhou, Feng; Wong, Chingping

    2015-08-01

    Highly stable monodispersed nano Cu hydrosols were facilely prepared by an aqueous chemical reduction method through selecting copper hydroxide (Cu(OH)2) as the copper precursor, poly(acrylic acid) (PAA) and ethanol amine (EA) as the complexing agents, and hydrazine hydrate as the reducing agent. The size of the obtained Cu colloidal nanoparticles was controlled from 0.96 to 26.26 nm by adjusting the dosage of the copper precursor. Moreover, the highly stable nano Cu hydrosols could be easily concentrated and re-dispersed in water meanwhile maintaining good dispersibility. A model catalytic reaction of reducing p-nitrophenol with NaBH4 in the presence of nano Cu hydrosols with different sizes was performed to set up the relationship between the apparent kinetic rate constant (kapp) and the particle size of Cu catalysts. The experimental results indicate that the corresponding kapp showed an obvious size-dependency. Calculations revealed that kapp was directly proportional to the surface area of Cu catalyst nanoparticles, and also proportional to the reciprocal of the particle size based on the same mass of Cu catalysts. This relationship might be a universal principle for predicting and assessing the catalytic efficiency of Cu nanoparticles. The activation energy (Ea) of this catalytic reaction when using 0.96 nm Cu hydrosol as a catalyst was calculated to be 9.37 kJ mol-1, which is considered an extremely low potential barrier. In addition, the synthesized nano Cu hydrosols showed size-dependent antibacterial activities against Pseudomonas aeruginosa (P. aeruginosa) and the minimal inhibitory concentration of the optimal sample was lower than 5.82 μg L-1.Highly stable monodispersed nano Cu hydrosols were facilely prepared by an aqueous chemical reduction method through selecting copper hydroxide (Cu(OH)2) as the copper precursor, poly(acrylic acid) (PAA) and ethanol amine (EA) as the complexing agents, and hydrazine hydrate as the reducing agent. The size of the

  5. Positively-charged reduced graphene oxide as an adhesion promoter for preparing a highly-stable silver nanowire film

    Science.gov (United States)

    Sun, Qijun; Lee, Seong Jun; Kang, Hyungseok; Gim, Yuseong; Park, Ho Seok; Cho, Jeong Ho

    2015-04-01

    An ultrathin conductive adhesion promoter using positively charged reduced graphene oxide (rGO-NH3+) has been demonstrated for preparing highly stable silver nanowire transparent conductive electrodes (AgNW TCEs). The adhesion promoter rGO-NH3+, spray coated between the substrate and AgNWs, significantly enhances the chemical and mechanical stabilities of the AgNW TCEs. Besides, the ultrathin thickness of the rGO-NH3+ ensures excellent optical transparency and mechanical flexibility for TCEs. The AgNW films prepared using the adhesion promoter are extremely stable under harsh conditions, including ultrasonication in a variety of solvents, 3M Scotch tape detachment test, mechanical bending up to 0.3% strain, or fatigue over 1000 cycles. The greatly enhanced adhesion force is attributed to the ionic interactions between the positively charged protonated amine groups in rGO-NH3+ and the negatively charged hydroxo- and oxo-groups on the AgNWs. The positively charged GO-NH3+ and commercial polycationic polymer (poly allylamine hydrochloride) are also prepared as adhesion promoters for comparison with rGO-NH3+. Notably, the closely packed hexagonal atomic structure of rGO offers better barrier properties to water permeation and demonstrates promising utility in durable waterproof electronics. This work offers a simple method to prepare high-quality TCEs and is believed to have great potential application in flexible waterproof electronics.An ultrathin conductive adhesion promoter using positively charged reduced graphene oxide (rGO-NH3+) has been demonstrated for preparing highly stable silver nanowire transparent conductive electrodes (AgNW TCEs). The adhesion promoter rGO-NH3+, spray coated between the substrate and AgNWs, significantly enhances the chemical and mechanical stabilities of the AgNW TCEs. Besides, the ultrathin thickness of the rGO-NH3+ ensures excellent optical transparency and mechanical flexibility for TCEs. The AgNW films prepared using the adhesion

  6. Generating high-current monoenergetic proton beams by a circularly polarized laser pulse in the phase-stable acceleration regime.

    Science.gov (United States)

    Yan, X Q; Lin, C; Sheng, Z M; Guo, Z Y; Liu, B C; Lu, Y R; Fang, J X; Chen, J E

    2008-04-01

    A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations. PMID:18517963

  7. Parametrizing soil-vegetation-atmosphere transfer models with non-destructive and high resolution stable isotope data

    Science.gov (United States)

    Rothfuss, Youri; Vereecken, Harry; Brüggemann, Nicolas

    2015-04-01

    For nearly 50 years, stable isotopologues of water (1H2H16O and 1H218O) have been used in a wide range of water research disciplines to identify the origin and to quantify proportions of water pools involved in processes of the terrestrial water cycle. In soils between rain events, the combined action of convective capillary rise of water depleted in 1H2H16O and 1H218O with back-diffusion of water enriched in 1H2H16O and 1H218O from the evaporation site (i.e., soil surface or evaporation front) downwards leads to the formation of - typically exponential - soil water stable isotopologue profiles. The first steady state and isothermal analytical solutions of these isotopologues profiles were proposed in the late 60ies. They were later extended to unsteady state and non-isothermal conditions. These analytical formulations link the shape of the isotopologue profiles to soil evaporation flux and regime, and to the soil physical properties associated with both diffusive and convective water transport (such as tortuosity length and dispersivity). More recently, the movement of 1H2H16O and 1H218O was implemented in physically-based numerical soil-vegetation-atmosphere transfer (SVAT) models (e.g., TOUGHREACT, SiSPAT-Isotope, Soil-Litter iso, Hydrus 1D). In these fully coupled models, the output of the heat transfer module, i.e., the temperature profile, is fed into the isotope module. Isotope and water transport are therefore inter-dependent as opposed to analytical solutions. In addition to thermodynamic (equilibrium) isotope effects, which are only temperature-dependent, kinetic isotope effects during soil evaporation greatly affect the stable isotopic composition of soil water and evaporation and can be highly variable. Thus, a better understanding of the implications of these kinetic effects in addition to the well characterized equilibrium effects as well as their implementation in SVAT models are required for improving the use of 1H2H16O and 1H218O as tracers of soil

  8. Formation of ultrasmooth and highly stable copper surfaces through annealing and self-assembly of organic monolayers.

    Science.gov (United States)

    Platzman, Ilia; Saguy, Cecile; Brener, Reuven; Tannenbaum, Rina; Haick, Hossam

    2010-01-01

    Copper (Cu) has been extensively used as an interconnect material for microelectronic devices because of its high electrical and thermal conductivity and excellent electromigration resistance. However, the formation of relatively rough Cu surfaces ( approximately 5 nm roughness) and Cu-oxide layers upon exposure to air still hinders their reliable application in a wide range of fields. In this article, we show the potential values of highly stable and ultrasmooth polycrystalline bare Cu obtained by simple annealing and chemical modification for a wide range of Cu-based electronic devices. The morphological properties and oxidation behavior of annealed Cu surfaces, before and after coating by self-assembled monolayers of terephthalic acid (TPA), were examined upon exposure to ambient air conditions ( approximately 110 days). Thin films of polycrystalline Cu, deposited on top of an adhesion layer of tantalum nitride (TaN) and annealed for 8 h at 580 degrees C under 2 x 10(-7) Torr, provided ultrasmooth Cu surfaces (R(rms) = 0.15-1.1 nm for fresh samples) and had a stable Cu-oxide layer after 65 days ( approximately 3.5 nm). These observations were perceived to be superior to nonannealed polycrystalline Cu samples. Coating fresh (oxide-free) samples of ultrasmooth Cu with TPA molecules created a closely packed monolayer with a standing-up phase configuration and molecular coverage of approximately 90%. The TPA-coated Cu surface has not shown any detectable oxidation during the first 2 weeks of exposure. The protection efficiency of this layer was found to be superior to those reported earlier on polycrystalline Cu surfaces. The oxidation mechanisms of both annealed and nonannealed Cu surfaces are presented and discussed. PMID:19715329

  9. Long-term and high frequency non-destructive monitoring of water stable isotope profiles in an evaporating soil column

    Science.gov (United States)

    Rothfuss, Y.; Merz, S.; Vanderborght, J.; Hermes, N.; Weuthen, A.; Pohlmeier, A.; Vereecken, H.; Brüggemann, N.

    2015-04-01

    The stable isotope compositions of soil water (δ2H and δ18O) carry important information about the prevailing soil hydrological conditions and for constraining ecosystem water budgets. However, they are highly dynamic, especially during and after precipitation events. The classical method of determining soil water δ2H and δ18O at different depths, i.e., soil sampling and cryogenic extraction of the soil water, followed by isotope-ratio mass spectrometer analysis is destructive and laborious with limited temporal resolution. In this study, we present a new non-destructive method based on gas-permeable tubing and isotope-specific infrared laser absorption spectroscopy. We conducted a laboratory experiment with an acrylic glass column filled with medium sand equipped with gas-permeable tubing at eight different soil depths. The soil column was initially saturated from the bottom, exposed to evaporation for a period of 290 days, and finally rewatered. Soil water vapor δ2H and δ18O were measured daily, sequentially for each depth. Soil liquid water δ2H and δ18O were inferred from the isotopic values of the vapor assuming thermodynamic equilibrium between liquid and vapor phases in the soil. The experimental setup allowed following the evolution of typical exponential-shaped soil water δ2H and δ18O profiles with unprecedentedly high temporal resolution. As the soil dried out, we could also show for the first time the increasing influence of the isotopically depleted ambient water vapor on the isotopically enriched liquid water close to the soil surface (i.e., atmospheric invasion). Rewatering at the end of the experiment led to instantaneous resetting of the stable isotope profiles, which could be closely followed with the new method.

  10. Synthesis of highly luminescent water stable ZnO quantum dots as photoluminescent sensor for picric acid

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Kulvinder; Chaudhary, G.R.; Singh, Sukhjinder; Mehta, S.K., E-mail: skmehta@pu.ac.in

    2014-10-15

    Highly luminescent, water stable (3-aminopropyl) triethoxysilane capped ZnO quantum dots (QDs) have been synthesized using a simple solution route. The synthesized ZnO QDs have been characterized using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Particle size analyzer (PSA), UV–visible (UV–vis), Photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The PL studies demonstrate that the particles synthesized are highly luminescent in nature emitting yellow color on exposure to UV radiation. Further, PL emission of ZnO QDs in the presence of picric acid (PA) shows their high sensitivity and selectivity for PA. The superior response of ZnO QDs in the presence of PA makes them very effective PL sensors. The limit of detection comes out to be 2.86 µM. - Highlights: • ZnO QDs act as photoluminiscent sensor for picric acid in aqueous medium. • Sensor shows high selectivity and sensitivity with a detection limit of 2.86 μM. • More the number of nitro groups, more is the quenching in PL emission of ZnO QDs.

  11. Synthesis of highly luminescent water stable ZnO quantum dots as photoluminescent sensor for picric acid

    International Nuclear Information System (INIS)

    Highly luminescent, water stable (3-aminopropyl) triethoxysilane capped ZnO quantum dots (QDs) have been synthesized using a simple solution route. The synthesized ZnO QDs have been characterized using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Particle size analyzer (PSA), UV–visible (UV–vis), Photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. The PL studies demonstrate that the particles synthesized are highly luminescent in nature emitting yellow color on exposure to UV radiation. Further, PL emission of ZnO QDs in the presence of picric acid (PA) shows their high sensitivity and selectivity for PA. The superior response of ZnO QDs in the presence of PA makes them very effective PL sensors. The limit of detection comes out to be 2.86 µM. - Highlights: • ZnO QDs act as photoluminiscent sensor for picric acid in aqueous medium. • Sensor shows high selectivity and sensitivity with a detection limit of 2.86 μM. • More the number of nitro groups, more is the quenching in PL emission of ZnO QDs

  12. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template. PMID:26289389

  13. Stable transduction of large DNA by high-capacity adeno-associated virus/adenovirus hybrid vectors

    International Nuclear Information System (INIS)

    Viral vectors with high cloning capacity and host chromosomal integration ability are in demand for the efficient and permanent genetic modification of target cells with large DNA molecules. We have generated a hybrid gene transfer vehicle consisting of recombinant adeno-associated virus (AAV) replicative intermediates packaged in adenovirus (Ad) capsids. This arrangement allows cell cycle-independent nuclear delivery of recombinant AAV genomes with lengths considerably above the maximum size (i.e., 4.7 kb) that can be accommodated within AAV capsids. Here we show that high-capacity AAV/Ad hybrid vector gene transfer mediates cellular genomic integration of large fragments of foreign DNA and accomplishes stable long-term transgene expression in rapidly proliferating cells. Southern blot and polymerase chain reaction analyses of chromosomal DNA extracted from clones of stably transduced cells revealed that most of them contained a single copy of the full-length hybrid vector genome with AAV inverted terminal repeat (ITR) sequences at both ends. The high-capacity AAV/Ad hybrid vector system can thus be used for the transfer and expression of transgenes that cannot be delivered by conventional integrating viral vectors

  14. Stable isotopes reflect the ecological stability of two high-elevation mammals from the late Quaternary of Colorado

    Science.gov (United States)

    McLean, Bryan S.; Emslie, Steven D.

    2012-05-01

    The vertebrate fossil record of Cement Creek Cave, Colorado, spans from > 45,000 yr ago to the present and represents the richest stratified series of high-elevation (> 2900 m) mammal remains known from the late Quaternary of North America. Stable carbon and oxygen isotope analyses of tooth enamel were used to assess potential ecological responses of two species found commonly throughout the cave, Yellow-bellied marmots (Marmota flaviventris) and Bushy-tailed woodrats (Neotoma cinerea), to late Quaternary climate and environmental changes of the Southern Rocky Mountains. Results indicate that despite such perturbations, the dietary ecologies of both species were maintained across this period. Neither taxon shifted to consuming C4 taxa or different C3 functional groups; similarly, no significant shifts in surface water use were detected. Variations in enamel δ13C were observed, however, that represent the physiological responses of high-elevation plants to changing levels of late Quaternary atmospheric CO2. While our findings extend both the geographic and elevational record of this plant CO2 response, they simultaneously highlight the ecological stability of high-elevation M. flaviventris and N. cinerea during climate changes of late Quaternary magnitude.

  15. The application of stable, high power, twin frequency, optically pumped far-infrared lasers to fusion plasma diagnostics

    International Nuclear Information System (INIS)

    There is presently considerable worldwide interest in the study of high temperature plasmas. Much of this interest is driven by the goal of achieving controlled thermonuclear fusion, which involves the release of net nuclear energy from the fusion of light nuclei such as deuteneum and tritium. In order to understand many of the issues and problems relating to the physics of magnetically confined plasmas, there is a need for accurate, high resolution and flexible diagnostic systems. The far-infrared spectral region (100-1000 μm) is ideally suited to a number of fusion plasma diagnostic techniques such as collective Thomson scattering, multichannel interferometry and polarimetry. The only practical radiation source currently available is the optically pumped far-infrared (FIR) laser. This paper describes the development of a high power, stable, twin frequency FIR laser for diagnosis of fusion plasmas. The use of buffer gases, temperature optimization and operation of the laser in both ring and linear cavities will be described. In addition, diagnostic measurements on the TEXT device will be presented to demonstrate the flexibility and importance of FIR diagnostics in the fusion program

  16. A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions.

    Science.gov (United States)

    Rosenberg, Yvonne J; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

    2015-01-01

    Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1-2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product. PMID:26268538

  17. Carboxymethylated lignins with low surface tension toward low viscosity and highly stable emulsions of crude bitumen and refined oils.

    Science.gov (United States)

    Li, Shuai; Ogunkoya, Dolanimi; Fang, Tiegang; Willoughby, Julie; Rojas, Orlando J

    2016-11-15

    Kraft and organosolv lignins were subjected to carboxymethylation to produce fractions that were soluble in water, displayed a minimum surface tension as low as 34mN/m (25°C) and a critical aggregation concentration of ∼1.5wt%. The carboxymethylated lignins (CML), which were characterized in terms of their degree of substitution ((31)P NMR), elemental composition, and molecular weight (GPC), were found suitable in the formulation of emulsions with bitumens of ultra-high viscosity, such as those from the Canadian oil sands. Remarkably, the interfacial features of the CML enabled fuel emulsions that were synthesized in a very broad range of internal phase content (30-70%). Cryo-replica transmission electron microscopy, which was used here the first time to assess the morphology of the lignin-based emulsions, revealed the droplets of the emulsion stabilized with the modified lignin. The observed drop size (diametersdistribution. Such characteristics led to stable emulsified systems that are amenable for a wide range of applications. Emulsification with CML afforded bitumen emulsions with very high colloidal stability (no change was noted for over one month) and with a strong shear thinning behavior. Both features indicate excellent prospects for storage, transport and spraying, which are relevant in operations for power generation, which also take advantage of the high heating value of the emulsion components. The ability of CML to stabilize emulsions and to contribute in their combustion was tested with light fuels (kerosene, diesel, and jet fuel) after formulation of high internal phase systems (70% oil) that enabled operation of a fuel engine. A significant finding is that under certain conditions and compared to the respective pure fuel, combustion of the O/W emulsions stabilized by CML presented lower NOx and CO emissions and maintained a relatively high combustion efficiency. The results highlight the possibilities in high volume application for lignin

  18. Fe-O stable isotope pairs elucidate a high-temperature origin of Chilean iron oxide-apatite deposits

    Science.gov (United States)

    Bilenker, Laura D.; Simon, Adam C.; Reich, Martin; Lundstrom, Craig C.; Gajos, Norbert; Bindeman, Ilya; Barra, Fernando; Munizaga, Rodrigo

    2016-03-01

    Iron oxide-apatite (IOA) ore deposits occur globally and can host millions to billions of tons of Fe in addition to economic reserves of other metals such as rare earth elements, which are critical for the expected growth of technology and renewable energy resources. In this study, we pair the stable Fe and O isotope compositions of magnetite samples from several IOA deposits to constrain the source reservoir of these elements in IOAs. Since magnetite constitutes up to 90 modal% of many IOAs, identifying the source of Fe and O within the magnetite may elucidate high-temperature and/or lower-temperature processes responsible for their formation. Here, we focus on the world-class Los Colorados IOA in the Chilean iron belt (CIB), and present data for magnetite from other Fe oxide deposits in the CIB (El Laco, Mariela). We also report Fe and O isotopic values for other IOA deposits, including Mineville, New York (USA) and the type locale, Kiruna (Sweden). The ranges of Fe isotopic composition (δ56Fe, 56Fe/54Fe relative to IRMM-14) of magnetite from the Chilean deposits are: Los Colorados, δ56Fe (±2σ) = 0.08 ± 0.03‰ to 0.24 ± 0.08‰; El Laco, δ56Fe = 0.20 ± 0.03‰ to 0.53 ± 0.03‰; Mariela, δ56Fe = 0.13 ± 0.03‰. The O isotopic composition (δ18O, 18O/16O relative to VSMOW) of the same Chilean magnetite samples are: Los Colorados, δ18O (±2σ) = 1.92 ± 0.08‰ to 3.17 ± 0.03‰; El Laco, δ18O = 4.00 ± 0.10‰ to 4.34 ± 0.10‰; Mariela, δ18O = (1.48 ± 0.04‰). The δ18O and δ56Fe values for Kiruna magnetite yield an average of 1.76 ± 0.25‰ and 0.16 ± 0.07‰, respectively. The Fe and O isotope data from the Chilean IOAs fit unequivocally within the range of magnetite formed by high-temperature magmatic or magmatic-hydrothermal processes (i.e., δ56Fe 0.06-0.49‰ and δ18O = 1.0-4.5‰), consistent with a high-temperature origin for Chilean IOA deposits. Additionally, minimum formation temperatures calculated by using the measured Δ18O

  19. Individual variation in contagious yawning susceptibility is highly stable and largely unexplained by empathy or other known factors.

    Science.gov (United States)

    Bartholomew, Alex J; Cirulli, Elizabeth T

    2014-01-01

    The contagious aspect of yawning is a well-known phenomenon that exhibits variation in the human population. Despite the observed variation, few studies have addressed its intra-individual reliability or the factors modulating differences in the susceptibility of healthy volunteers. Due to its obvious biological basis and impairment in diseases like autism and schizophrenia, a better understanding of this trait could lead to novel insights into these conditions and the general biological functioning of humans. We administered 328 participants a 3-minute yawning video stimulus, a cognitive battery, and a comprehensive questionnaire that included measures of empathy, emotional contagion, circadian energy rhythms, and sleepiness. Individual contagious yawning measurements were found to be highly stable across testing sessions, both in a lab setting and if administered remotely online, confirming that certain healthy individuals are less susceptible to contagious yawns than are others. Additionally, most individuals who failed to contagiously yawn in our study were not simply suppressing their reaction, as they reported not even feeling like yawning in response to the stimulus. In contrast to previous studies indicating that empathy, time of day, or intelligence may influence contagious yawning susceptibility, we found no influence of these variables once accounting for the age of the participant. Participants were less likely to show contagious yawning as their age increased, even when restricting to ages of less than 40 years. However, age was only able to explain 8% of the variability in the contagious yawn response. The vast majority of the variability in this extremely stable trait remained unexplained, suggesting that studies of its inheritance are warranted. PMID:24632594

  20. High-power, highly stable KrF laser with a 4-kHz pulse repetition rate

    Science.gov (United States)

    Borisov, V. M.; El'tsov, A. V.; Khristoforov, O. B.

    2015-08-01

    An electric-discharge KrF laser (248 nm) with an average output power of 300 W is developed and studied. A number of new design features are related to the use of a laser chamber based on an Al2O3 ceramic tube. A high power and pulse repetition rate are achieved by using a volume discharge with lateral preionisation by the UV radiation of a creeping discharge in the form of a homogeneous plasma sheet on the surface of a plane sapphire plate. Various generators for pumping the laser are studied. The maximum laser efficiency is 3.1%, the maximum laser energy is 160 mJ pulse-1, and the pulse duration at half maximum is 7.5 ns. In the case of long-term operation at a pulse repetition rate of 4 kHz and an output power of 300 W, high stability of laser output energy (σ <= 0.7%) is achieved using an all-solid-state pump system.

  1. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    Science.gov (United States)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  2. Volume 1, 1st Edition, Multiscale Tailoring of Highly Active and Stable Nanocomposite Catalysts, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Veser, Goetz

    2009-08-31

    Nanomaterials have gained much attention as catalysts since the discovery of exceptional CO oxidation activity of nanoscale gold by Haruta. However, many studies avoid testing nanomaterials at the high-temperatures relevant to reactions of interest for the production of clean energy (T > 700°C). The generally poor thermal stability of catalytically active noble metals has thus far prevented significant progress in this area. We have recently overcome the poor thermal stability of nanoparticles by synthesizing a platinum barium-hexaaluminate (Pt-BHA) nanocomposite which combines the high activity of noble metal nanoparticles with the thermal stability of hexaaluminates. This Pt-BHA nanocomposite demonstrates excellent activity, selectivity, and long-term stability in CPOM. Pt-BHA is anchored onto a variety of support structures in order to improve the accessibility, safety, and reactivity of the nanocatalyst. Silica felts prove to be particularly amenable to this supporting procedure, with the resulting supported nanocatalyst proving to be as active and stable for CPOM as its unsupported counterpart. Various pre-treatment conditions are evaluated to determine their effectiveness in removing residual surfactant from the active nanoscale platinum particles. The size of these particles is measured across a wide temperature range, and the resulting “plateau” of stability from 600-900°C can be linked to a particle caging effect due to the structure of the supporting ceramic framework. The nanocomposites are used to catalyze the combustion of a dilute methane stream, and the results indicate enhanced activity for both Pt-BHA as well as ceria-doped BHA, as well as an absence of internal mass transfer limitations at the conditions tested. In water-gas shift reaction, nanocomposite Pt-BHA shows stability during prolonged WGS reaction and no signs of deactivation during start-up/shut-down of the reactor. The chemical and thermal stability, low molecular weight, and

  3. Innermost stable circular orbit near dirty black holes in magnetic field and ultra-high-energy particle collisions

    International Nuclear Information System (INIS)

    We consider the behavior of the innermost stable circular orbit (ISCO) in the magnetic field near ''dirty'' (surrounded by matter) axially symmetric black holes. The cases of near-extremal, extremal, and nonextremal black holes are analyzed. For nonrotating black holes, in the strong magnetic field ISCO approaches the horizon (when backreaction of the field on the geometry is neglected). Rotation destroys this phenomenon. The angular momentum and radius of ISCO look model-independent in the main approximation. We also study the collisions between two particles that results in the ultra-high energy Ec.m. in the center-of-mass frame. Two scenarios are considered - when one particle moves on the near-horizon ISCO or when collision occurs on the horizon, one particle having the energy and angular momentum typical of ISCO. If the magnetic field is strong enough and a black hole is slowly rotating, Ec.m. can become arbitrarily large. The kinematics of the high-energy collision is discussed. As an example, we consider the magnetized Schwarzschild black hole for an arbitrary strength of the field (the Ernst solution). It is shown that backreaction of the magnetic field on the geometry can bound the growth of Ec.m. (orig.)

  4. Low-Temperature Photochemically Activated Amorphous Indium-Gallium-Zinc Oxide for Highly Stable Room-Temperature Gas Sensors.

    Science.gov (United States)

    Jaisutti, Rawat; Kim, Jaeyoung; Park, Sung Kyu; Kim, Yong-Hoon

    2016-08-10

    We report on highly stable amorphous indium-gallium-zinc oxide (IGZO) gas sensors for ultraviolet (UV)-activated room-temperature detection of volatile organic compounds (VOCs). The IGZO sensors fabricated by a low-temperature photochemical activation process and exhibiting two orders higher photocurrent compared to conventional zinc oxide sensors, allowed high gas sensitivity against various VOCs even at room temperature. From a systematic analysis, it was found that by increasing the UV intensity, the gas sensitivity, response time, and recovery behavior of an IGZO sensor were strongly enhanced. In particular, under an UV intensity of 30 mW cm(-2), the IGZO sensor exhibited gas sensitivity, response time and recovery time of 37%, 37 and 53 s, respectively, against 750 ppm concentration of acetone gas. Moreover, the IGZO gas sensor had an excellent long-term stability showing around 6% variation in gas sensitivity over 70 days. These results strongly support a conclusion that a low-temperature solution-processed amorphous IGZO film can serve as a good candidate for room-temperature VOCs sensors for emerging wearable electronics. PMID:27430635

  5. Highly stable and ultrasensitive chlorogenic acid sensor based on metal-organic frameworks/titanium dioxide nanocomposites.

    Science.gov (United States)

    Wang, Yang; Chen, Huanhuan; Hu, Xiaoya; Yu, Hai

    2016-08-01

    Metal-organic frameworks/titanium dioxide (UiO-66-NH2/TiO2) nanocomposites have been prepared by a simple hydrothermal reaction and they exhibit excellent electrocatalytic activity for chlorogenic acid oxidation due to the synergic effect of UiO-66-NH2 and TiO2. Under the optimal conditions, the sensor can be employed in the quantification of chlorogenic acid in the ranges of 0.01-1.0 μmol L(-1) and 1.0-15 μmol L(-1) with an ultralow detection limit of 7 nmol L(-1) (S/N = 3). Moreover, UiO-66-NH2/TiO2 nanocomposites demonstrate significant stability in acidic buffer solution and maintain their electrocatalytic activities at least up to 90 cycles. The potential utility was validated by the analysis of coffee and tea samples and good recoveries were obtained from different spiked values. The UiO-66-NH2/TiO2 based sensor with highly sensitive, selective and stable consecutive monitoring of chlorogenic acid is a promising candidate for the construction of highly active electrocatalyst in electrochemical biosensors. PMID:27241453

  6. High-temperature synthesis of highly hydrothermal stable mesoporous silica and Fe-SiO2 using ionic liquid as a template

    International Nuclear Information System (INIS)

    Mesoporous silicas and Fe-SiO2 with worm-like structures have been synthesized using a room temperature ionic liquid, 1-hexadecane-3-methylimidazolium bromide, as a template at a high aging temperature (150-190 oC) with the assistance of NaF. The hydrothermal stability of mesoporous silica was effectively improved by increasing the aging temperature and adding NaF to the synthesis gel. High hydrothermally stable mesoporous silica was obtained after being aged at 190 oC in the presence of NaF, which endured the hydrothermal treatment in boiling water at least for 10 d or steam treatment at 600 oC for 6 h. The ultra hydrothermal stability could be attributed to its high degree of polymerization of silicate. Furthermore, highly hydrothermal stable mesoporous Fe-SiO2 has been synthesized, which still remained its mesostructure after being hydrothermally treated at 100 oC for 12 d or steam-treated at 600 oC for 6 h. -- Graphical abstract: Worm-like mesoporous silica and Fe-SiO2 with high hydrothermal stability have been synthesized using ionic liquid 1-hexadecane-3-methylimidazolium bromide as a template under the assistance of NaF at high temperature. Display Omitted Research highlights: → Increasing aging temperature improved the hydrothermal stability of materials. →Addition of NaF enhanced the polymerization degree of silicates. → Mesoporous SiO2 and Fe-SiO2 obtained have remarkable hydrothermal stability.

  7. Strain-assisted control of high stable dielectric tunability in (1 0 0) oriented (Pb,Sr)TiO3 thin films

    International Nuclear Information System (INIS)

    Highlights: •The (1 0 0) (Pb,Sr)TiO3 thin films are strained by the Tb–PbTiO3 inducing layer. •The tunability is stable with the composition of the strained (Pb,Sr)TiO3 thin films. •The tunability of the strained (Pb,Sr)TiO3 thin films is stable from 20 °C to 200 °C. -- Abstract: The (1 0 0) oriented (Pb,Sr)TiO3 (PST) thin films were prepared using terbium-doped lead titanate as inducing layer. Misfit strain of the PST thin films changed gradually along direction of thickness and with different compositions. Controlled by the strain, the Curie temperature was independent of the composition of the PST and the width of the Curie peak was broadened. The as-prepared PST thin films exhibited stable high dielectric tunability which was almost independent of composition as well as applied temperature. With the composition of PST changing from PST35 (PbxSr1−xTiO3x = 0.35) to PST50, the room temperature tunability of the PST thin films maintains a stable value of about 40%. At a high applied temperature of 200 °C, the PST thin films still show a high tunability of about 35%. The strain-assisted control of the Curie temperature and the Curie peak width is attractive in designing high stable devices with high dielectric tunability

  8. Stable high-level expression of truncated human papillomavirus type 16 L1 protein in Drosophila Schneider-2 cells

    Institute of Scientific and Technical Information of China (English)

    Jin Zheng; Xiaofeng Yang; Ying Sun; Baochang Lai; Yili Wang

    2008-01-01

    To improve the existing human papillomavirus type 16 (HPV16) virus-like particle (VLP) preparation, the Drosophila inducible/secreted expression system, a highly efficient, economical method, was used to produce HPV16 VLPs. Drosophila Schneider-2 cells were cotransfected with pMT/BiP/V5-His expression vector containing the target gene encoding HPV16L1protein without nucleus localization sequence and the selection vector pCoHygro plasmids at the ratio of 4:1. The stabled hygromycin-resistant cell line was obtained 1 month later, and the protein expression was induced by copper sulfate. The molecular mass of expressed HPV16L1 protein was 66 kDa, as revealed by SDS-PAGE,and confirmed by Western blot analysis. The yield of HPV16L1 protein was 0.554 mg per lxl07 cells. The characteristics of HPV16L1 protein were further analyzed by mouse erythrocyte hemagglutination assay, hemagglutination inhibition assay, and transmission electron microscopy. Results showed that the truncated protein was as biologically active as natural HPVLI protein, inducing murine erythrocyte agglutination and VLP formation. These findings indicate that the Drosophila inducible/secreted expression system is promising as a convenient and economical method for the preparation of HPV 16 VLP vaccine.

  9. Highly Stable PEGylated Poly(lactic-co-glycolic acid) (PLGA) Nanoparticles for the Effective Delivery of Docetaxel in Prostate Cancers

    Science.gov (United States)

    Cao, Long-Bin; Zeng, Sha; Zhao, Wei

    2016-06-01

    In the present study, a highly stable luteinizing-hormone-releasing hormone (LHRH)-conjugated PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles were developed for the successful treatment of prostate cancers. We have demonstrated that a unique combination of targeted drug delivery and controlled drug release is effective against prostate cancer therapy. The docetaxel (DTX)/PLGA-LHRH micelles possessed a uniform spherical shape with an average diameter of ~170 nm. The micelles exhibited a controlled drug release for up to 96 h which can minimize the non-specific systemic spread of toxic drugs during circulation while maximizing the efficiency of tumor-targeted drug delivery. The LHRH-conjugated micelles showed enhanced cellular uptake and exhibited significantly higher cytotoxicity against LNCaP cancer cells. We have showed that PLGA-LHRH induced greater caspase-3 activity indicating its superior apoptosis potential. Consistently, LHRH-conjugated micelles induced threefold and twofold higher G2/M phase arrest than compared to free DTX or PLGA NP-treated groups. Overall, results indicate that use of LHRH-conjugated nanocarriers may potentially be an effective nanocarrier to effectively treat prostate cancer.

  10. In-situ synthesis of high stable CdS quantum dots and their application for photocatalytic degradation of dyes.

    Science.gov (United States)

    Samadi-Maybodi, Abdolraouf; Sadeghi-Maleki, Mohammad-Rasool

    2016-01-01

    Photocatalysis based on semiconductor quantum dots, which utilize the solar energy can be used for elimination of pollutants from aqueous media and applied for water purification. In this paper, high stable CdS quantum dots (QDs) with good optical properties were successfully synthesized in a facile in-situ method, using Na2S2O3 as precursor and thioglycolic acid (TGA) as a catalyst, as well as capping agent in aqueous media. The synthesis process was optimized with a 2IV(7-3) fractional factorial design method. Then, we studied the degradation of some industrial dyes including: alizarin, acid violet, mordant red and thymol blue as a tool to check the photocatalytic activity of synthesized CdS QDs. Results specified that the synthesized CdS QDs are capable for degradation of organic dyes under visible light irradiation with good recycling stability during photocatalytic experiments. Structural and spectroscopic properties of the synthesized CdS QDs were studied by TEM, XRD and absorption and fluorescence spectroscopy techniques. The synthesized TGA-capped CdS QDs have sizes in the range of 2.65-2.93nm with cubic crystalline structures. PMID:26208270

  11. COMPCOAL{trademark}: A profitable process for production of a stable high-Btu fuel from Powder River Basin coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-07-01

    This report describes the Western Research Institute (WRI) COMPCOAL{trademark} process which is designed to produce a stable, high-Btu fuel from Powder River Basin (PRB) and other low-rank coals. The process is designed to overcome the problems of oxidation and spontaneous combustion, readsorption of moisture, and dust formation from the friable coal. PRB coal is susceptible to low-temperature oxidation and self-heating, particularly after it has been dried. This report describes a method WRI has developed to prevent self-heating of dried PRB coal. The ``accelerated aging`` not only stabilizes the dried coal, but it also increases the heating value of the COMPCOAL product. The stabilized COMPCOAL product has a heating value of 12,000 to 12,700 Btu/lb, contains 35 to 40 wt % volatiles, and is comparable to unprocessed PRB coal in self-heating and low-temperature oxidation characteristics. Importantly, the self-heating tendency can be controlled by slightly adjusting the ``aging`` step in the process.

  12. In-situ synthesis of high stable CdS quantum dots and their application for photocatalytic degradation of dyes

    Science.gov (United States)

    Samadi-Maybodi, Abdolraouf; Sadeghi-Maleki, Mohammad-Rasool

    2016-01-01

    Photocatalysis based on semiconductor quantum dots, which utilize the solar energy can be used for elimination of pollutants from aqueous media and applied for water purification. In this paper, high stable CdS quantum dots (QDs) with good optical properties were successfully synthesized in a facile in-situ method, using Na2S2O3 as precursor and thioglycolic acid (TGA) as a catalyst, as well as capping agent in aqueous media. The synthesis process was optimized with a 2IV7-3 fractional factorial design method. Then, we studied the degradation of some industrial dyes including: alizarin, acid violet, mordant red and thymol blue as a tool to check the photocatalytic activity of synthesized CdS QDs. Results specified that the synthesized CdS QDs are capable for degradation of organic dyes under visible light irradiation with good recycling stability during photocatalytic experiments. Structural and spectroscopic properties of the synthesized CdS QDs were studied by TEM, XRD and absorption and fluorescence spectroscopy techniques. The synthesized TGA-capped CdS QDs have sizes in the range of 2.65-2.93 nm with cubic crystalline structures.

  13. An Acinetobacter trimeric autotransporter adhesin reaped from cells exhibits its nonspecific stickiness via a highly stable 3D structure.

    Science.gov (United States)

    Yoshimoto, Shogo; Nakatani, Hajime; Iwasaki, Keita; Hori, Katsutoshi

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific, high adhesiveness to abiotic material surfaces as well as to biotic surfaces. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced as a recombinant protein. In this study, we isolated AtaA's passenger domain (AtaA PSD), which is translocated to the cell surface through the C-terminal transmembrane domain and exhibits biological functions, using a new method. We introduced a protease recognition site and reaped AtaA nanofibers 225 nm in length from the cell surface through proteolytic cleavage with a specific protease. Biochemical and biophysical analyses of the purified native AtaA PSD revealed that it has a stable structure under alkaline and acidic conditions. Temperatures above 80 °C, which disrupted AtaA's higher-order structure but maintained the full-length AtaA polypeptide, inactivated AtaA's nonspecific adhesiveness, suggesting that the stickiness of AtaA requires its 3D structure. This finding refutes the widespread but vague speculation that large unfolded polypeptides readily stick to various surfaces. PMID:27305955

  14. Highly stable noble metal nanoparticles dispersible in biocompatible solvents: synthesis of cationic phosphonium gold nanoparticles in water and DMSO.

    Science.gov (United States)

    Ju-Nam, Yon; Abdussalam-Mohammed, Wanisa; Ojeda, Jesus J

    2016-04-12

    In this work, we report the synthesis of novel cationic phosphonium gold nanoparticles dispersible in water and dimethyl sulfoxide (DMSO) for their potential use in biomedical applications. All the cationic-functionalising ligands currently reported in the literature are ammonium-based species. Here, the synthesis and characterisation of an alternative system, based on phosphonioalkylthiosulfate zwitterions and phosphonioalkylthioacetate were carried out. We have also demonstrated that our phosphonioalkylthiosulfate zwitterions readily disproportionate into phosphonioalkylthiolates in situ during the synthesis of gold nanoparticles produced by the borohydride reduction of gold(iii) salts. The synthesis of the cationic gold nanoparticles using these phosphonium ligands was carried out in water and DMSO. UV-visible spectroscopic and TEM studies have shown that the phosphonioalkylthiolates bind to the surface of gold nanoparticles which are typically around 10 nm in diameter. The resulting cationic-functionalised gold nanoparticles are dispersible in aqueous media and in DMSO, which is the only organic solvent approved by the U.S. Food and Drug Administration (FDA) for drug carrier tests. This indicates their potential future use in biological applications. This work shows the synthesis of a new family of phosphonium-based ligands, which behave as cationic masked thiolate ligands in the functionalisation of gold nanoparticles. These highly stable colloidal cationic phosphonium gold nanoparticles dispersed in water and DMSO can offer a great opportunity for the design of novel biorecognition and drug delivery systems. PMID:26796782

  15. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone

    Science.gov (United States)

    Luo, Wenhao; Sankar, Meenakshisundaram; Beale, Andrew M.; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-03-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on titanium dioxide are prepared with a modified metal impregnation method. Gold-palladium/titanium dioxide shows a marked,~27-fold increase in activity (that is, turnover frequency of 0.1 s-1) compared with its monometallic counterparts. Although ruthenium-palladium/titanium dioxide is not only exceptionally active (that is, turnover frequency of 0.6 s-1), it shows excellent, sustained selectivity to γ-valerolactone (99%). The dilution and isolation of ruthenium by palladium is thought to be responsible for this superior catalytic performance. Alloying, furthermore, greatly improves the stability of both supported nano-alloy catalysts.

  16. Highly Stable PEGylated Poly(lactic-co-glycolic acid) (PLGA) Nanoparticles for the Effective Delivery of Docetaxel in Prostate Cancers.

    Science.gov (United States)

    Cao, Long-Bin; Zeng, Sha; Zhao, Wei

    2016-12-01

    In the present study, a highly stable luteinizing-hormone-releasing hormone (LHRH)-conjugated PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles were developed for the successful treatment of prostate cancers. We have demonstrated that a unique combination of targeted drug delivery and controlled drug release is effective against prostate cancer therapy. The docetaxel (DTX)/PLGA-LHRH micelles possessed a uniform spherical shape with an average diameter of ~170 nm. The micelles exhibited a controlled drug release for up to 96 h which can minimize the non-specific systemic spread of toxic drugs during circulation while maximizing the efficiency of tumor-targeted drug delivery. The LHRH-conjugated micelles showed enhanced cellular uptake and exhibited significantly higher cytotoxicity against LNCaP cancer cells. We have showed that PLGA-LHRH induced greater caspase-3 activity indicating its superior apoptosis potential. Consistently, LHRH-conjugated micelles induced threefold and twofold higher G2/M phase arrest than compared to free DTX or PLGA NP-treated groups. Overall, results indicate that use of LHRH-conjugated nanocarriers may potentially be an effective nanocarrier to effectively treat prostate cancer. PMID:27325521

  17. High-Performance Inkjet-Printed Indium-Gallium-Zinc-Oxide Transistors Enabled by Embedded, Chemically Stable Graphene Electrodes.

    Science.gov (United States)

    Secor, Ethan B; Smith, Jeremy; Marks, Tobin J; Hersam, Mark C

    2016-07-13

    Recent developments in solution-processed amorphous oxide semiconductors have established indium-gallium-zinc-oxide (IGZO) as a promising candidate for printed electronics. A key challenge for this vision is the integration of IGZO thin-film transistor (TFT) channels with compatible source/drain electrodes using low-temperature, solution-phase patterning methods. Here we demonstrate the suitability of inkjet-printed graphene electrodes for this purpose. In contrast to common inkjet-printed silver-based conductive inks, graphene provides a chemically stable electrode-channel interface. Furthermore, by embedding the graphene electrode between two consecutive IGZO printing passes, high-performance IGZO TFTs are achieved with an electron mobility of ∼6 cm(2)/V·s and current on/off ratio of ∼10(5). The resulting printed devices exhibit robust stability to aging in ambient as well as excellent resilience to thermal stress, thereby offering a promising platform for future printed electronics applications. PMID:27327555

  18. Finding the stable structures of N1-xWx with an ab initio high-throughput approach

    Science.gov (United States)

    Mehl, Michael J.; Finkenstadt, Daniel; Dane, Christian; Hart, Gus L. W.; Curtarolo, Stefano

    2015-05-01

    Using density functional theory calculations, many researchers have predicted that various tungsten nitride compounds N1-xWx (x large bulk and shear moduli, greater than approximately 200 GPa, and are elastically and vibrationally stable. Compounds with such desirable properties also must be energetically stable against decomposition into other compounds. This test for stability can only be found after the determination of the convex hull for N1-xWx , which connects the lowest enthalpy structures as a function of composition. Unfortunately, the experimental phase diagram of the N-W structure is uncertain, as it is difficult to break the N2 bond to form compounds with tungsten. Experiment also indicates that there are a large number of partially filled sites in most N-W structures. This introduces computational difficulties since we cannot easily model randomly placed vacancies. In addition, van der Waals forces play a significant role in determining the structure of solid N2 and the nitrogen-rich compounds. This makes it difficult to determine the relative energies of these compounds, as there is no universally accepted density functional incorporating van der Waals interactions. The exact shape and even composition of the convex hull is dependent upon the choice of density functional, even if we only chose between the local density approximation and a generalized gradient functional. Despite these difficulties, computations can determine much about the ground-state form of the convex hull. Here, we use high-throughput calculations to map out the hull and other low-energy structures for the N-W system. The lowest-energy structures all have vacancies, on the tungsten sites in hexagonal-based compounds, and on both the nitrogen and tungsten sites in cubic compounds. We find that most of the N-W structures proposed in the literature, both theoretical and experimental, are above the convex hull, in some cases by over 0.2 eV /atom . One of the ground-state phases, N

  19. [Research on the Highly Stable White LED with CdSe/ZnS Quantum Dot as Light Conversion Layer].

    Science.gov (United States)

    Cao, Jin; Zhou, Jie; Xie, Jing-weil; Chen, An-ping; Zhang, Xuel; Yin, Lu-qiao; Zhang, Jian-hua

    2016-02-01

    In accordance with the one-step synthesis, in this paper, we synthesized 510, 550 and 630 nm three emission peaks CdSe/ZnS core-shell quantum dots with high stability and high quantum yield whose quantum yield were 82%, 98% and 97%. We used the quantum dot material to replace the phosphor material, and mixed QDs with the silicone uniformly, then dispersed the QDs/silicone composites onto the blue InGaN LEDs to fabricate the QDs-WLEDs. By successively adding different colors of quantum dots for the preparation of quantum dot light converting layer, We investigated that how does the ratio of the three kind of quantum dots whose peaks were 510, 550 and 630 nm effect on the properties of the white LED devices. This paper also studied the mechanism of energy conversion between different colors of quantum dots. We also utilized the mechanism that the quantum dots effect on the white spectrum and color coordinates; we got the results of the optimization of the white device and the ratio of three-color quantum dots. The results show that when the quantum dot ratio is 24:7:10, white LED devices with high stability and high efficiency can be obtained, in the current range of 20-200 mA, the range of color temperature is from 4 607 to 5 920 K, the CIE-1931 coordinates is from (0.355 1,0.348 3) to (0.323 4, 0.336 1), the color rendering index is from 77. 6 to 84. 2, and the highest power efficiency of the devices achieves to 31.69 lm · W⁻¹ @ 20 mA. In addition, in order to further investigate the reason of stable device performance, We studied the effects of time, temperature, UV treatment on the stability of CdSe/ZnS QDs/silicone light conversion material, the results show that the excellent stability of the devices attributes to the stability of the one-step synthesis of core-shell structure of the quantum dot material, the final optimized device is a low-power high-quality white light source and the device has good application prospects in the field of standard white

  20. Highly Stable and Sensitive Paper-Based Bending Sensor Using Silver Nanowires/Layered Double Hydroxides Hybrids.

    Science.gov (United States)

    Wei, Yong; Chen, Shilong; Li, Fucheng; Lin, Yong; Zhang, Ying; Liu, Lan

    2015-07-01

    Highly sensitive flexible piezoresistive materials using silver nanowires (AgNWs) composites have been widely researched due to their excellent electrical, optical, and mechanical properties. Intrinsically, AgNWs tend to aggregate in polymer matrix because of the intense depletion-induced interactions, which seriously influence the percolation threshold of the composites. In this study, we report a highly stable and sensitive paper-based bending sensor using the AgNWs and layered double hydroxides (LDHs) to construct a hybrid conductive network in waterborne polyurethane that is easy to destruct and reconstruct under bending deformation. The nonconductive 2D LDH nanosheets are embedded into AgNWs network and assist dispersion of AgNWs, which depends on the hydrogen bonding between the two nanostructures. The percolation threshold of the composites decreases from 10.8 vol % (55 wt %) to 3.1 vol % (23.8 wt %), and the composites reaches a very low resistivity (10(-4) Ω·cm) with a small amount of AgNWs (8.3 vol %) due to the dispersion improvement of AgNWs with the effect of LDH nanosheets. The as-prepared conductive composites with low percolation threshold can be manufactured on paper via various methods such as rollerball pen writing, inkjet printing, or screen printing. The bending sensor prepared by manufacturing the composites on paper shows low-cost, excellent conductivity, flexibility (>3000 bending cycles), sensitivity (0.16 rad(-1)), fast response (120 ms) and relaxation time (105 ms), and nontoxicity. Therefore, a simple but efficient wearable sensor is developed to monitor the human motions (such as fingers and elbow joints movements) and presents good repeatability, stability, and responsiveness, making the bending sensor possibly able to meet the needs in numerous applications for robotic systems. PMID:26083146

  1. Color-stable, reduced efficiency roll-off hybrid white organic light emitting diodes with ultra high brightness

    International Nuclear Information System (INIS)

    High-brightness and color-stable two-wavelength hybrid white organic light emitting diodes (HWOLEDs) with the configuration of indium tin oxide (ITO)/ N, N, N', N'-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD): tetrafluoro-tetracyanoqino dimethane (F4-TCNQ)/N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB)/4,4-N,N-dicarbazolebiphenyl (CBP): iridium (III) diazine complexes (MPPZ)2Ir(acac)/NPB/2-methyl-9,10-di(2-naphthyl)anthracene (MADN): p-bis(p-N,N-di-phenyl-aminostyryl)benzene (DSA-ph)/ bis(10-hydroxybenzo[h] quinolinato)beryllium complex (Bebq2)/LiF/Al have been fabricated and characterized. The optimal brightness of the device is 69932 cd/m2 at a voltage of 13 V, and the Commission Internationale de l'Eclairage (CIE) chromaticity coordinates are almost constant during a large voltage change of 6–12 V. Furthermore, a current efficiency of 15.3 cd/A at an illumination-relevant brightness of 1000 cd/m2 is obtained, which rolls off slightly to 13.0 cd/A at an ultra high brightness of 50000 cd/m2 . We attribute this great performance to wisely selecting an appropriate spacer together with effectively utilizing the combinations of exciton-harvested orange-phosphorescence/ blue-fluorescence in the device. Undoubtedly, this is one of the most exciting results in two-wavelength HWOLEDs up to now

  2. Stable compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Accetta, F.S.; Gleiser, M.; Holman, R.; Kolb, E.W.

    1986-03-01

    We show that compactifications of theories with extra dimensions are unstable if due to monopole configurations of an antisymmetric tensor field balanced against one-loop Casimir corrections. In the case of ten dimensional supergravity, it is possible, at least for a portion of the phase space, to achieve a stable compactification without fine-tuning by including the contribution of fermionic condensates to the monopole configurations. 23 refs., 2 figs.

  3. Stable compactifications

    International Nuclear Information System (INIS)

    We show that compactifications of theories with extra dimensions are unstable if due to monopole configurations of an antisymmetric tensor field balanced against one-loop Casimir corrections. In the case of ten dimensional supergravity, it is possible, at least for a portion of the phase space, to achieve a stable compactification without fine-tuning by including the contribution of fermionic condensates to the monopole configurations. 23 refs., 2 figs

  4. Xanthine oxidoreductase activity assay in tissues using stable isotope-labeled substrate and liquid chromatography high-resolution mass spectrometry.

    Science.gov (United States)

    Murase, Takayo; Nampei, Mai; Oka, Mitsuru; Ashizawa, Naoki; Matsumoto, Koji; Miyachi, Atsushi; Nakamura, Takashi

    2016-01-01

    Studies of pathological mechanisms and XOR inhibitor characterization, such as allopurinol, febuxostat, and topiroxostat, require accurate and sensitive measurements of XOR activity. However, the established assays have some disadvantages such as susceptibility to endogenous substances such as uric acid (UA), xanthine, or hypoxanthine. Here, we aimed to develop a novel XOR activity assay utilizing a combination of high-performance liquid chromatography (LC) and high-resolution mass spectrometry (HRMS) for tissues such as the liver, kidney, and plasma. Stable isotope-labeled [(15)N2]-xanthine was utilized as substrate and the production of [(15)N2]-uric acid was determined. [(15)N2]-UA production by XOR was dependent on the amounts of [(15)N2]-xanthine and enzyme and the time of reaction. Because high concentrations of endogenous xanthine and hypoxanthine affect XOR activities, we employed a multi-component analysis using LC/HRMS to improve the accuracy of XOR activity assay. Quantification of [(15)N2]-UA was validated and showed good linearity, accuracy, and precision. We measured the XOR activities of retired ICR mice using [(15)N2]-xanthine and LC/MS. The XOR activities in plasma, kidney, and liver samples were 38.1±0.7, 158±5, 928±25pmol/min/mg of protein, respectively (mean±SD, n=5). Furthermore, we measured the XOR activities in the same samples using the LC/ultraviolet and LC/fluorescence (FL) methods. The level of [(15)N2]-xanthine oxidation by XOR was equal to that of xanthine oxidation and approximately 7.9-8.9 times higher than that of pterin oxidation. We found a good correlation between XOR activities examined using LC/MS assay with [(15)N2]-xanthine and those examined using LC/FL assay with pterin. This result suggested that although both the LC/MS assay with [(15)N2]-xanthine and the LC/FL assay with pterin were useful, the former provided information regarding XOR activities that more directly reflected the physiological condition than the latter

  5. COMPCOAL{trademark}: A profitable process for production of a stable high-Btu fuel from Powder River Basin coal

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.; Merriam, N.W.

    1994-10-01

    Western Research Institute (WRI) is developing a process to produce a stable, clean-burning, premium fuel from Powder River Basin (PRB) coal and other low-rank coals. This process is designed to overcome the problems of spontaneous combustion, dust formation, and readsorption of moisture that are experienced with PRB coal and with processed PRB coal. This process, called COMPCOAL{trademark}, results in high-Btu product that is intended for burning in boilers designed for midwestern coals or for blending with other coals. In the COMPCOAL process, sized coal is dried to zero moisture content and additional oxygen is removed from the coal by partial decarboxylation as the coal is contacted by a stream of hot fluidizing gas in the dryer. The hot, dried coal particles flow into the pyrolyzer where they are contacted by a very small flow of air. The oxygen in the air reacts with active sites on the surface of the coal particles causing the temperature of the coal to be raised to about 700{degrees}F (371{degrees}C) and oxidizing the most reactive sites on the particles. This ``instant aging`` contributes to the stability of the product while only reducing the heating value of the product by about 50 Btu/lb. Less than 1 scf of air per pound of dried coal is used to avoid removing any of the condensible liquid or vapors from the coal particles. The pyrolyzed coal particles are mixed with fines from the dryer cyclone and dust filter and the resulting mixture at about 600{degrees}F (316{degrees}C) is fed into a briquettor. Briquettes are cooled to about 250{degrees}F (121{degrees}C) by contact with a mist of water in a gas-tight mixing conveyor. The cooled briquettes are transferred to a storage bin where they are accumulated for shipment.

  6. Stable, high-efficiency, CuInSe2-based, polycrystalline, thin-film tandem solar cells

    Science.gov (United States)

    Birkmire, R. W.; Phillips, J. E.

    1987-10-01

    The long-term objective of this research was to obtain a stable, thin-film solar cell based on polycrystalline materials with an efficiency of 15 percent. The approach was to make a tandem cell based on CuInSe2/CdS as the bottom cell and CdTe/CdS as the top cell. An essential feature was to develop a CdTe cell with transport contacts. A suitable contacting system was developed using transparent conducting oxides (ITO and SnO2) in conjunction with a thin layer of copper. Cells were made with efficiencies over 8.5 percent. A reproducible fabrication process for CuInSe2/(CdZn)S cells was developed based on CuInSe2 films grown by vacuum evaporation using Knudsen-type effusion sources. These cells were made with efficiencies over 10 percent. The composition of the CuInSe2 films can be varied over a considerable range and still yield high-efficiency cells. Adding Zn to the CdS did not increase the V(sub oc) of the devices; analysis showed that the V(sub oc) is not controlled by interface recombination. The effect of oxidizing and reducing heat treatments on CuInSe2 cells is to change carrier concentration and thus V(sub oc). Analysis suggests that J(sub o) is controlled by band-to-band recombination. Monolithic tandem CuInSe2 CdTe cells have been made with efficiencies of approximately 3 percent, demonstrating the feasibility of this approach.

  7. High-speed highly temperature stable 980 nm VCSELs operating at 25 Gb/s at up to 85 °C for short reach optical interconnects

    Science.gov (United States)

    Mutig, Alex; Lott, James A.; Blokhin, Sergey A.; Moser, Philip; Wolf, Philip; Hofmann, Werner; Nadtochiy, Alexey M.; Bimberg, Dieter

    2011-03-01

    The progressive penetration of optical communication links into traditional copper interconnect markets greatly expands the applications of vertical cavity surface emitting lasers (VCSELs) for the next-generation of board-to-board, moduleto- module, chip-to-chip, and on-chip optical interconnects. Stability of the VCSEL parameters at high temperatures is indispensable for such applications, since these lasers typically reside directly on or near integrated circuit chips. Here we present 980 nm oxide-confined VCSELs operating error-free at bit rates up to 25 Gbit/s at temperatures as high as 85 °C without adjustment of the drive current and peak-to-peak modulation voltage. The driver design is therefore simplified and the power consumption of the driver electronics is lowered, reducing the production and operational costs. Small and large signal modulation experiments at various temperatures from 20 up to 85 °C for lasers with different oxide aperture diameters are presented in order to analyze the physical processes controlling the performance of the VCSELs. Temperature insensitive maximum -3 dB bandwidths of around 13-15 GHz for VCSELs with aperture diameters of 10 μm and corresponding parasitic cut-off frequencies exceeding 22 GHz are observed. Presented results demonstrate the suitability of our VCSELs for practical high speed and high temperature stable short-reach optical links.

  8. Insight Into Climate Variations Of The Early Middle Eocene: High-Resolution Benthic Stable Isotope Data From Site 1408, Newfoundland Ridge

    OpenAIRE

    Wu, Fei

    2015-01-01

    The middle Eocene is a transitional period from the greenhouse early Eocene to the ice-house Eocene-Oligocene Transition. Due to lack of high-resolution records, the details of this long-term cooling trend are not clear. Low-resolution atmospheric CO2 records suggest declining, but highly variable levels during the middle Eocene which might have driven transient climate variations. However, high-resolution stable isotope records are lacking to document the true climate patterns over this peri...

  9. Rational synthesis of an exceptionally stable Zn(ii) metal-organic framework for the highly selective and sensitive detection of picric acid.

    Science.gov (United States)

    Hu, Yingli; Ding, Meili; Liu, Xiao-Qin; Sun, Lin-Bing; Jiang, Hai-Long

    2016-04-14

    Based on an organic ligand involving both carboxylate and tetrazole groups, a chemically stable Zn(ii) metal-organic framework has been rationally synthesized and behaves as a fluorescence chemosensor for the highly selective and sensitive detection of picric acid, an extremely hazardous and strong explosive. PMID:27046028

  10. The influence of stable element inventory on the migration of radionuclides in the vicinity of a high level nuclear waste repository exemplified for 59Ni

    International Nuclear Information System (INIS)

    competition effects of stable isotopes present in a high-level waste repository on the migration of radioactive 59Ni(II). More detailed scenario calculations would be possible if a more detailed “geochemical inventory” of radionuclides and stable isotopes were to become available. Nevertheless, upper limits for the effects of sorption competition of bivalent stable isotopes on the migration of 59Ni in the vicinity of a high-level nuclear waste repository were assessed

  11. Breeding of high yield strain producing acid-stable α-amylase by N+ ion beam irradiation

    International Nuclear Information System (INIS)

    Bacillus subtilis BF7658, which produces medium-temperature α-amylase,was implanted with N+ ion beam to breed mutants. Under the optimal fluence of 1 x 1016 cm-2, a mutant TCCC 11525 producing the acid-stable and medium-temperature α-amylase was obtained. The activity of the mutagenised enzyme is 207 U/mL. (authors)

  12. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  13. Synthesis and characterization of highly stable optically passive CeO{sub 2}-ZrO{sub 2} counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bhosale, A.K. [Department of Physics, Raje Ramrao Mahavidhyalaya, Jath 416005 (India); Shinde, P.S.; Tarwal, N.L.; Pawar, R.C. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India); Kadam, P.M. [Department of Electronics, Kasturbai Walchand College, Sangli 416416 (India); Patil, P.S., E-mail: psp_phy@unishivaji.ac.i [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India)

    2010-02-15

    Transparent and adherent CeO{sub 2}-ZrO{sub 2} thin films having film thicknesses approx543-598 nm were spray deposited onto the conducting (fluorine doped tin oxide coated glass) substrates from a blend of equimolar concentrations of cerium nitrate hexahydrate and zirconium nitrate having different volumetric proportions (0-6 vol.% of Zr) in methanol. CeO{sub 2}-ZrO{sub 2} films were polycrystalline with cubic fluorite crystal structure and the crystallinity was improved with increasing ZrO{sub 2} content. Films were highly transparent (T approx 92%), showing decrease in band gap energy from 3.45 eV for pristine CeO{sub 2} to 3.08-3.14 eV for CeO{sub 2}-ZrO{sub 2} films. The different morphological features of the film obtained at various CeO{sub 2}-ZrO{sub 2} compositions had pronounced effect on the ion storage capacity and electrochemical stability. CeO{sub 2}-ZrO{sub 2} film prepared at 5 vol.% Zr concentration exhibited higher ion storage capacity of 24 mC cm{sup -2} and electrochemical stability of 10,000 cycles in 0.5 M LiClO{sub 4} + PC electrolyte due to its film thickness (584 nm) coupled with relatively larger porosity (8%). The optically passive behavior of such CeO{sub 2}-ZrO{sub 2} film (with 5 vol.% Zr) is affirmed by its negligible transmission modulation irrespective of repeated Li{sup +} and electron insertion/extraction. The coloration efficiency of spray deposited WO{sub 3} thin film is found to enhance from 47 to 107 cm{sup 2} C{sup -1} when CeO{sub 2}-ZrO{sub 2} is coupled as a counter electrode with WO{sub 3} in an electrochromic device (ECD). These films can be used as stable 'passive' counter electrodes in electrochromic smart windows as they retain full transparency in both the oxidized and reduced states and ever-reported longevity.

  14. High-Speed and Low-Energy Flip-Flop Operation of Asymmetric Active-Multimode Interferometer Bi-Stable Laser Diodes

    DEFF Research Database (Denmark)

    Jiang, Haisong; Chaen, Yutaka; Hagio, Takuma;

    2011-01-01

    High-speed (121/25 ps rise/fall time) and low-switching energy (7.1 and 3.4 fJ) alloptical flip-flop operation of single-wavelength high-mesa asymmetric active-MMI bi-stable laser diodes is demonstrated for the first time using 25 ps long switching pulses.......High-speed (121/25 ps rise/fall time) and low-switching energy (7.1 and 3.4 fJ) alloptical flip-flop operation of single-wavelength high-mesa asymmetric active-MMI bi-stable laser diodes is demonstrated for the first time using 25 ps long switching pulses....

  15. Graphite-coated ZnO nanosheets as high-capacity, highly stable, and binder-free anodes for lithium-ion batteries

    Science.gov (United States)

    Quartarone, Eliana; Dall'Asta, Valentina; Resmini, Alessandro; Tealdi, Cristina; Tredici, Ilenia Giuseppina; Tamburini, Umberto Anselmi; Mustarelli, Piercarlo

    2016-07-01

    ZnO is one of the materials of choice as anode for lithium batteries, due to its high theoretical capacity, natural abundance, low toxicity, and low cost. At present, however, its industrial exploitation is impeded by massive capacity fading, and by cycling instability due to the drastic volume expansions during the electrochemical lithiation/delithiation process. Herein, we present a novel graphite coated-ZnO anode for LiBs based on films of nanosheets, coated with graphite. The electrode is obtained by a simple and inexpensive solution hydrothermal synthesis, whereas the graphite is deposited by thermal evaporation, which is easier to perform than a wet chemistry technique. Our approach leads to a substantial increase of the permanent specific capacity, obtaining values of 600 mAhg-1 after 100 cycles at a high specific current of 1 Ag-1. This represents the best performance for long-cycled, ZnO-based anodes obtained so far. Such result derives from the peculiar porous structure of the nanosheets film (pore diameter < 1 nm), as well as by the graphite coating that works as a dimensional buffer and preserves its morphology during cycling. This appears a very promising strategy for designing more stable ZnO-based anodes for Li batteries and microbatteries.

  16. Characterization of a Large, Stable, High-Copy-Number Streptomyces Plasmid That Requires Stability and Transfer Functions for Heterologous Polyketide Overproduction▿

    OpenAIRE

    Fong, Ryan; Hu, Zhihao; Hutchinson, C. Richard; Huang, Jianqiang; Cohen, Stanley; Kao, Camilla

    2006-01-01

    A major limitation to improving small-molecule pharmaceutical production in streptomycetes is the inability of high-copy-number plasmids to tolerate large biosynthetic gene cluster inserts. A recent finding has overcome this barrier. In 2003, Hu et al. discovered a stable, high-copy-number, 81-kb plasmid that significantly elevated production of the polyketide precursor to the antibiotic erythromycin in a heterologous Streptomyces host (J. Ind. Microbiol. Biotechnol. 30:516-522, 2003). Here, ...

  17. Characterization of a large, stable, high-copy-number Streptomyces plasmid that requires stability and transfer functions for heterologous polyketide overproduction.

    Science.gov (United States)

    Fong, Ryan; Vroom, Jonathan A; Hu, Zhihao; Hutchinson, C Richard; Huang, Jianqiang; Cohen, Stanley N; Cohen, Stanley; Kao, Camilla M; Kao, Camilla

    2007-02-01

    A major limitation to improving small-molecule pharmaceutical production in streptomycetes is the inability of high-copy-number plasmids to tolerate large biosynthetic gene cluster inserts. A recent finding has overcome this barrier. In 2003, Hu et al. discovered a stable, high-copy-number, 81-kb plasmid that significantly elevated production of the polyketide precursor to the antibiotic erythromycin in a heterologous Streptomyces host (J. Ind. Microbiol. Biotechnol. 30:516-522, 2003). Here, we have identified mechanisms by which this SCP2*-derived plasmid achieves increased levels of metabolite production and examined how the 45-bp deletion mutation in the plasmid replication origin increased plasmid copy number. A plasmid intramycelial transfer gene, spd, and a partition gene, parAB, enhance metabolite production by increasing the stable inheritance of large plasmids containing biosynthetic genes. Additionally, high product titers required both activator (actII-ORF4) and biosynthetic genes (eryA) at high copy numbers. DNA gel shift experiments revealed that the 45-bp deletion abolished replication protein (RepI) binding to a plasmid site which, in part, supports an iteron model for plasmid replication and copy number control. Using the new information, we constructed a large high-copy-number plasmid capable of overproducing the polyketide 6-deoxyerythronolide B. However, this plasmid was unstable over multiple culture generations, suggesting that other SCP2* genes may be required for long-term, stable plasmid inheritance. PMID:17142363

  18. Neutron Halo Isomers in Stable Nuclei and their Possible Application for the Production of Low Energy, Pulsed, Polarized Neutron Beams of High Intensity and High Brilliance

    CERN Document Server

    Habs, D; Thirolf, P G; Böni, P

    2010-01-01

    We propose to search for neutron halo isomers populated via $\\gamma$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $\\gamma$-beams of high intensity and small band width ($\\le$ 0.1\\%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei \\cite{hansen95,tanihata96,aumann00}, the low neutron separation energy and short-range nuclear force allows the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half lives of the isomers for the $\\gamma$-decay back to the ground state in the 100 ps-$\\mu$s range. Similar to the treatment of photodisintegration ...

  19. Stable, Extreme Temperature, High Radiation, Compact. Low Power Clock Oscillator for Space, Geothermal, Down-Hole & other High Reliability Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient and stable clock signal generation requirements at extreme temperatures (-180C to +450C)and radiation (>250 Krad TID) are not met with the current...

  20. Stable Isotope Probing Analysis of the Diversity and Activity of Methanotrophic Bacteria in Soils from the Canadian High Arctic ▿

    OpenAIRE

    Martineau, Christine; Whyte, Lyle G.; Greer, Charles W.

    2010-01-01

    The melting of permafrost and its potential impact on CH4 emissions are major concerns in the context of global warming. Methanotrophic bacteria have the capacity to mitigate CH4 emissions from melting permafrost. Here, we used quantitative PCR (qPCR), stable isotope probing (SIP) of DNA, denaturing gradient gel electrophoresis (DGGE) fingerprinting, and sequencing of the 16S rRNA and pmoA genes to study the activity and diversity of methanotrophic bacteria in active-layer soils from Ellesmer...

  1. The preparation of high performance polymers for composites and blends : A) thermally stable ion containing polymers B) epoxy and hydroxy functional polyolefin macromers

    OpenAIRE

    Facinelli, John Victor

    1996-01-01

    In this dissertation, two approaches were taken to design aqueous dispersable or soluble high performance ion containing polymers to be used as composite system interfacial modifiers and processing aids. In the first approach, thermally stable pyridine containing poly(ary/ene ether)s were designed which could be ionized by protonation in acidic aqueous media. A novel pyridine containing bisphenol monomer, 2,6-(p-hydroxyphenoxy)pyridine, was synthesized and utilized as a mono...

  2. Combining electron-neutral building blocks with intramolecular "conformational locks" affords stable, high-mobility p- and n-channel polymer semiconductors.

    Science.gov (United States)

    Huang, Hui; Chen, Zhihua; Ponce Ortiz, Rocio; Newman, Christopher; Usta, Hakan; Lou, Sylvia; Youn, Jangdae; Noh, Yong-Young; Baeg, Kang-Jun; Chen, Lin X; Facchetti, Antonio; Marks, Tobin J; Marks, Tobin

    2012-07-01

    Understanding the relationship between molecular/macromolecular architecture and organic thin film transistor (TFT) performance is essential for realizing next-generation high-performance organic electronics. In this regard, planar π-conjugated, electron-neutral (i.e., neither highly electron-rich nor highly electron-deficient) building blocks represent a major goal for polymeric semiconductors, however their realization presents synthetic challenges. Here we report that an easily accessible (minimal synthetic steps), electron-neutral thienyl-vinylene (TVT)-based building block having weak intramolecular S···O "conformational locks" affords a new class of stable, structurally planar, solution-processable, high-mobility, molecular, and macromolecular semiconductors. The attraction of merging the weak TVT electron richness with supramolecular planarization is evident in the DFT-computed electronic structures, favorable MO energetics, X-ray diffraction-derived molecular structures, experimental lattice coehesion metrics, and excellent TFT performance. TVT-based polymer TFTs exhibit stable carrier mobilities in air as high as 0.5 and 0.05 cm(2)/V·s (n- and p-type, respectively). All-TVT polymer-based complementary inverter circuitry exhibiting high voltage gains (~50) and ring oscillator circuitry with high f(osc)(~1.25 kHz) is readily fabricated from these materials by simple inkjet printing. PMID:22679903

  3. Highly stable ECL active films formed by the electrografting of a diazotized ruthenium complex generated in situ from the amine.

    Science.gov (United States)

    Piper, David J E; Barbante, Gregory J; Brack, Narelle; Pigram, Paul J; Hogan, Conor F

    2011-01-01

    The electrodeposition of the electrochemiluminescent (ECL) ruthenium complex, bis(2,2'-bipyridyl)(4'-(4-aminophenyl)-2,2'-bipyridyl)ruthenium(II), [Ru(bpy)(2)(apb)](2+), via the in situ formation of a diazonium species from aqueous media is reported. Surface characterization undertaken using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) determined that the layer is bound to the substrate via azo bonding. The layer displays good ECL activity and is stable over a long period of time. The excellent potential of this system for ECL sensing applications is demonstrated using the well-known ECL coreactant 2-(dibutylamino)ethanol (DBAE) as a model analyte, which can be detected to a level of 10 nM with a linear range between 10(-8) and 10(-4) M. PMID:21117679

  4. Highly stable triple helix formation by homopyrimidine (l)-acyclic threoninol nucleic acids with single stranded DNA and RNA

    DEFF Research Database (Denmark)

    Kumar, Vipin; Kesavan, Venkitasamy; Gothelf, Kurt Vesterager

    2015-01-01

    Acyclic (l)-threoninol nucleic acid (aTNA) containing thymine, cytosine and adenine nucleobases were synthesized and shown to form surprisingly stable triplexes with complementary single stranded homopurine DNA or RNA targets. The triplex structures consist of two (l)-aTNA strands and one DNA or...... RNA, and these triplexes are significantly stronger than the corresponding DNA or RNA duplexes as shown in competition experiments. As a unique property the (l)-aTNAs exclusively form triplex structures with DNA and RNA and no duplex structures are observed by gel electrophoresis. The results were...... compared to the known enantiomer (d)-aTNA, which forms much weaker triplexes depending upon temperature and time. It was demonstrated that (l)-aTNA triplexes are able to stop primer extension on a DNA template, showing the potential of (l)-aTNA for antisense applications....

  5. Aligned spins: orbital elements, decaying orbits, and last stable circular orbit to high post-Newtonian orders

    International Nuclear Information System (INIS)

    In this paper, the quasi-Keplerian parameterization for the case that spins and orbital angular momentum in a compact binary system are aligned or anti-aligned with the orbital angular momentum vector is extended to 3PN point-mass, next-to-next-to-leading order spin–orbit, next-to-next-to-leading order spin(1)–spin(2) and next-to-leading order spin-squared dynamics in the conservative regime. In a further step, we use the expressions for the radiative multipole moments with spin to leading order linear and quadratic in both spins to compute radiation losses of the orbital binding energy and angular momentum. Orbital averaged expressions for the decay of energy and eccentricity are provided. An expression for the last stable circular orbit is given in terms of the angular velocity-type variable x. (paper)

  6. Aligned Spins: Orbital Elements, Decaying Orbits, and Last Stable Circular Orbit to high post-Newtonian Orders

    CERN Document Server

    Tessmer, Manuel; Schäfer, Gerhard

    2012-01-01

    In this article the quasi-Keplerian parameterisation for the case that spins and orbital angular momentum in a compact binary system are aligned or anti-aligned with the orbital angular momentum vector is extended to 3PN point-mass, next-to-next-to-leading order spin-orbit, next-to-next-to-leading order spin(1)-spin(2), and next-to-leading order spin-squared dynamics in the conservative regime. In a further step, we use the expressions for the radiative multipole moments with spin to leading order linear and quadratic in both spins to compute radiation losses of the orbital binding energy and angular momentum. Orbital averaged expressions for the decay of energy and eccentricity are provided. An expression for the last stable circular orbit is given in terms of the angular velocity type variable $x$.

  7. Form-stable paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: preparation and thermal properties

    International Nuclear Information System (INIS)

    This paper deals with the preparation of paraffin/high density polyethylene (HDPE) composites as form-stable, solid-liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of paraffins with melting temperatures of 42-44 deg. C (type P1) and 56-58 deg. C (type P2) and latent heats of 192.8 and 212.4 J g-1 were used. The maximum weight percentage for both paraffin types in the PCM composites without any seepage of the paraffin in the melted state were found as high as 77%. It is observed that the paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 deg. C, and 147.6 and 162.2 J g-1, respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance

  8. Ag-bridged Ag2O nanowire network/TiO2 nanotube array p–n heterojunction as a highly efficient and stable visible light photocatalyst

    International Nuclear Information System (INIS)

    Graphical abstract: A unique Ag-bridged Ag2O nanowire network/TiO2 nanotube array p–n heterojunction was fabricated by simple electrochemical method. The heterostructures exhibit high photocatalytic activity and excellent recycling performance. - Highlights: • Ag-bridged Ag2O nanowire network self-stability structure. • Ag2O nanowire network/TiO2 nanotube p–n heterojunction. • High visible light photocatalytic activity. • Highly stable recycling performance. - Abstract: A unique Ag-bridged Ag2O nanowire network/TiO2 nanotube array p–n heterojunction (Ag–Ag2O/TiO2 NT) was fabricated by simple electrochemical method. Ag nanoparticles were firstly electrochemically deposited onto the surface of TiO2 NT and then were partly oxidized to Ag2O nanowires while the rest of Ag mother nanoparticles were located at the junctions of Ag2O nanowire network. The Ag–Ag2O/TiO2 NT heterostructure exhibited strong visible-light response, effective separation of photogenerated carriers, and high adsorption capacity. The integration of Ag–Ag2O self-stability structure and p–n heterojunction permitted high and stable photocatalytic activity of Ag–Ag2O/TiO2 NT heterostructure photocatalyst. Under 140-min visible light irradiation, the photocatalytic removal efficiency of both dye acid orange 7 (AO7) and industrial chemical p-nitrophenol (PNP) over Ag–Ag2O/TiO2 NT reached nearly 100% much higher than 17% for AO7 or 13% for PNP over bare TiO2 NT. After 5 successive cycles under 600-min simulated solar light irradiation, Ag–Ag2O/TiO2 NT remained highly stable photocatalytic activity

  9. Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage.

    Science.gov (United States)

    Lee, Gwan-Hyoung; Cui, Xu; Kim, Young Duck; Arefe, Ghidewon; Zhang, Xian; Lee, Chul-Ho; Ye, Fan; Watanabe, Kenji; Taniguchi, Takashi; Kim, Philip; Hone, James

    2015-07-28

    Emerging two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. However, 2D materials are by nature sensitive to environmental influences, such as temperature, humidity, adsorbates, and trapped charges in neighboring dielectrics. Therefore, it is crucial to develop device architectures that provide both high performance and long-term stability. Here we report high performance of dual-gated van der Waals (vdW) heterostructure devices in which MoS2 layers are fully encapsulated by hexagonal boron nitride (hBN) and contacts are formed using graphene. The hBN-encapsulation provides excellent protection from environmental factors, resulting in highly stable device performance, even at elevated temperatures. Our measurements also reveal high-quality electrical contacts and reduced hysteresis, leading to high two-terminal carrier mobility (33-151 cm(2) V(-1) s(-1)) and low subthreshold swing (80 mV/dec) at room temperature. Furthermore, adjustment of graphene Fermi level and use of dual gates enable us to separately control contact resistance and threshold voltage. This novel vdW heterostructure device opens up a new way toward fabrication of stable, high-performance devices based on 2D materials. PMID:26083310

  10. Highly efficient and stable organic light-emitting diodes employing MoO{sub 3}-doped perylene-3, 4, 9, 10-tetracarboxylic dianhydride as hole injection layer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Linsen; Guan, Min [Chinese Academy of Sciences, Key Laboratory of Semiconductor Materials Science, Beijing (China); Cao, Guohua; Li, Yiyang; Zeng, Yiping [Chinese Academy of Sciences, Material Science Center, Institute of Semiconductors, Beijing (China)

    2010-04-15

    We report highly efficient and stable organic light-emitting diodes (OLEDs) with MoO{sub 3}-doped perylene-3, 4, 9, 10-tetracarboxylic dianhydride (PTCDA) as hole injection layer (HIL). A green OLED with structure of ITO/20 wt% MoO{sub 3}: PTCDA/NPB/Alq{sub 3}/LiF/Al shows a long lifetime of 1012 h at the initial luminance of 2000 cd/m{sup 2}, which is 1.3 times more stable than that of the device with MoO{sub 3} as HIL. The current efficiency of 4.7 cd/A and power efficiency of 3.7 lm/W at about 100 cd/m{sup 2} have been obtained. The charge transfer complex between PTCDA and MoO{sub 3} plays a decisive role in improving the performance of OLEDs. (orig.)

  11. ZnO/MoO 3 mixed oxide nanotube: A highly efficient and stable catalyst for degradation of dye by air under room conditions

    Science.gov (United States)

    Huang, Jiguo; Wang, Xiaohong; Li, Sen; Wang, Yu

    2010-10-01

    As a continuation of our work to develop catalysts with high activity for catalytic air wet oxidation process under mild conditions, degradation of wastewater containing 0.3 g/L Safranin-T (ST) by air oxidation over ZnO/MoO 3 nanotube catalyst was studied. It was found the decolorization efficiency and the chemical oxygen demand (COD) removal of ST reached above 98% and 95%, respectively, within 18 min at room temperature and atmospheric pressure. And the organic pollutants were totally mineralized to simple inorganic species such as HCO 3-, Cl - and NO 3-, while the total organic carbon (TOC) decreased 99.3%. The structure and morphology of the catalyst after ten cycling runs showed that the catalyst was stable under such operating condition and the leaching test showed negligible leaching effect. This ZnO/MoO 3 nanotube is proved to be an active and stable heterogeneous catalyst in CWAO of ST under extremely mild conditions.

  12. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  13. High-energy, phase-stable, ultrabroadband kHz OPCPA at 2.1 $\\propto$m pumped by a picosecond cryogenic Yb:YAG laser

    OpenAIRE

    Hong, K.-H.; Huang, S.-W.; Moses, J.; Fu, X; Lai, C.-J.; Cirmi, G.; Sell, A; Granados, E.; Keathley, P.; Kärtner, F. X.

    2011-01-01

    We report on a kHz, mJ-level, carrier-envelope phase (CEP)-stable ultrabroadband optical parametric chirped-pulse amplifier (OPCPA) at 2.1-μm wavelength, pumped by a high-energy, 14 ps, cryogenic Yb:YAG pump laser, and its application to high-order harmonic generation (HHG) with Xe. The pre-amplifier chain is pumped by a 12-ps Nd:YLF pump laser and both pump lasers are optically synchronized to the signal pulse of the OPCPA. An amplified pulse energy of 0.85 mJ was obtained at the final OPCPA...

  14. Stable-on-the-Table” Biosensors: Hemoglobin-Poly (Acrylic Acid Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity

    Directory of Open Access Journals (Sweden)

    Ananta Ghimire

    2015-09-01

    Full Text Available In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb is stabilized by wrapping it in high molecular weight poly(acrylic acid (PAA, MW 450k, and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17–20 psi without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at −0.279 and −0.334 V in cyclic voltammetry (CV and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications.

  15. "Stable-on-the-Table" Biosensors: Hemoglobin-Poly (Acrylic Acid) Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity.

    Science.gov (United States)

    Ghimire, Ananta; Zore, Omkar V; Thilakarathne, Vindya K; Briand, Victoria A; Lenehan, Patrick J; Lei, Yu; Kasi, Rajeswari M; Kumar, Challa V

    2015-01-01

    In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb) is stabilized by wrapping it in high molecular weight poly(acrylic acid) (PAA, M(W) 450k), and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17-20 psi) without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at -0.279 and -0.334 V in cyclic voltammetry (CV) and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications. PMID:26393601

  16. Production of Silver Nanoparticles with Strong and Stable Antimicrobial Activity against Highly Pathogenic and Multidrug Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Amr T. M. Saeb

    2014-01-01

    Full Text Available Aims. To synthesize, characterize, and analyze antimicrobial activity of AgNPs of Escherichia hermannii (SHE, Citrobacter sedlakii (S11P, and Pseudomonas putida (S5. Methods. The synthesized AgNPs were examined using ultraviolet-visible spectroscopy (UV-vis and, zeta potential, and the size and the morphology obtained from the three different isolates were also confirmed by TEM. Results. Among the three isolates tested, SHE showed the best antimicrobial activity due to the presence of small (4–12 nm and stable (−22 mV AgNPs. Stability of AgNPs was also investigated and found to be dependent on the nature of isolates. Conclusion. Produced AgNPs showed particle stability and antimicrobial efficacy up to 90 days of production. Our AgNPs exhibited greater antimicrobial activity compared with gentamicin against P. aeruginosa isolates and vancomycin against S. aureus and MRSA isolates at very low concentration (0.0002 mg per Microliters.

  17. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric

    Science.gov (United States)

    Fujii, Mami N.; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-12-01

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices.

  18. EFFICACY AND SAFETY OF METOPROLOL SUCCINATE IN HIGH DOSES IN PATIENTS WITH STABLE COURSE OF ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    S. N. Tolpygina

    2016-01-01

    Full Text Available Aim. To compare two initial doses (50 or 100mg/day ofmetoprolol succinate in control released presentation (Betaloc ZOK, AstraZeneca for achievement of target level of heart rate (HR in patients with stable course of ischemic heart disease (IHD.Material and methods. 50 patients (34 men and 16 women, aged 61,3 y.o., in average with IHD were involved into the open randomized comparative study. IHD duration was from 1 to 22 years (8,3 years in average. 47 patients completed study, 3 patients drop out because of side effects. Previous therapy with β-blockers or other HR reducing drugs was replaced on metoprolol. Patients were randomized in 2 groups (G1 and G2. The initial metoprolol dose was 50 mg in G1 patients and 100 mg - in G2 patients. The dose was enlarged twice if necessary. Study duration was 6 weeks. The change of HR, blood pressure, electrocardiogram parameters was evaluated. Patients filled in Seattle angina questionnaire initially and after 6 weeks treatment. Therapy tolerability was also estimated.Results. In 6 weeks of therapy 61% of G1 patients and 87,5% of G2 patients (p<0,01 reached HR target. Dependence of achievement of target HR and dose of metoprolol was observed (r=0,3; p=0,056. Improvement of the HR control was accompanied by reduction of frequency of angina attacks and increase of life quality.Conclusion. Metoprolol (Betaloc ZOK 200 mg/day provides more effective HR control in patients with IHD vs metoprolol 50-100 mg/day and has good tolerability.

  19. Highly Efficient C-SeCF3 Coupling of Aryl Iodides Enabled by an Air-Stable Dinuclear Pd(I) Catalyst.

    Science.gov (United States)

    Aufiero, Marialuisa; Sperger, Theresa; Tsang, Althea S-K; Schoenebeck, Franziska

    2015-08-24

    Building on our recent disclosure of catalysis at dinuclear Pd(I) sites, we herein report the application of this concept to the realization of the first catalytic method to convert aryl iodides into the corresponding ArSeCF3 compounds. Highly efficient C-SeCF3 coupling of a range of aryl iodides was achieved, enabled by an air-, moisture-, and thermally stable dinuclear Pd(I) catalyst. The novel SeCF3 -bridged dinuclear Pd(I) complex 3 was isolated, studied for its catalytic competence and shown to be recoverable. Experimental and computational data are presented in support of dinuclear Pd(I) catalysis. PMID:26118426

  20. A Novel Gene Expression Control System and Its Use in Stable, High-Titer 293 Cell-Based Adeno-Associated Virus Packaging Cell Lines

    OpenAIRE

    Qiao, Chunping; Bing WANG; Zhu, Xiaodong; Li, Juan; Xiao, Xiao

    2002-01-01

    Previous attempts to establish 293cell-based stable and high-titer adeno-associated virus (AAV) packaging cell lines were unsuccessful, primarily due to adenovirus E1-activated Rep gene expression, which exerts cytostatic and cytotoxic effects on the host cells. Control of the two large AAV Rep proteins (Rep78/68) was insufficient to eliminate the adverse effects, because of the leaky expression of the two small Rep proteins (Rep52/40). However, it was unsuccessful to control Rep52/40 gene ex...

  1. A Novel Route for Preparing Highly Stable Fe3O4 Fluid with Poly(Acrylic Acid) as Phase Transfer Ligand

    Science.gov (United States)

    Oanh, Vuong Thi Kim; Lam, Tran Dai; Thu, Vu Thi; Lu, Le Trong; Nam, Pham Hong; Tam, Le The; Manh, Do Hung; Phuc, Nguyen Xuan

    2016-08-01

    Highly stable Fe3O4 liquid was synthesized by thermal decomposition using poly(acrylic acid) (PAA) as a phase transfer ligand. The crystalline structure, morphology, and magnetic properties of the as-prepared samples were thoroughly characterized. Results demonstrated that the magnetic Fe3O4 nanomaterial was formed in liquid phase with a spinel single-phase structure, average size of 8-13 nm, and high saturation magnetization (up to 75 emu/g). The PAA-capped Fe3O4 nanoparticles displayed high stability over a wide pH range (from 4 to 7) in 300 mM salt solution. More importantly, the heat-generating capacity of the nanoparticle systems was quantified at a specific absorption rate (SAR) of 70.22 W/g, which is 35% higher than magnetic nanoparticles coated with sodium dodecyl sulfate (SDS). These findings suggest the potential application of PAA-coated magnetic nanoparticles in magnetic hyperthermia.

  2. Design and operation of a stable intense high-temperature arc-discharge source of hydrogen atoms and metastable trihydrogen molecules

    International Nuclear Information System (INIS)

    We report a design for a stable intense beam source of hyperthermal hydrogen atoms. The basis for the design is an arc heater used first by Knuth for the generation of high-translational energy He--Ar beams. In the case of hydrogen atom generation this source is very unstable due to the corresponding higher temperatures which are generated by the plasma discharge. We have substantially eliminated these difficulties by the insertion of discharge-localizing insulators and the use of a tungsten nozzle mounted in the center of a 1-kG electromagnet. This source generates exceptionally high hydrogen atom beam intensities of approx.1022 atoms s-1 sr-1 with translational energy distribution functions which extend to 18 eV and whose peak occurs at energies as high as 13 eV. In addition metastable H3 molecules having an intensity between 1020 and 1021 molecules s-1 sr-1 are formed

  3. A Novel Route for Preparing Highly Stable Fe3O4 Fluid with Poly(Acrylic Acid) as Phase Transfer Ligand

    Science.gov (United States)

    Oanh, Vuong Thi Kim; Lam, Tran Dai; Thu, Vu Thi; Lu, Le Trong; Nam, Pham Hong; Tam, Le The; Manh, Do Hung; Phuc, Nguyen Xuan

    2016-05-01

    Highly stable Fe3O4 liquid was synthesized by thermal decomposition using poly(acrylic acid) (PAA) as a phase transfer ligand. The crystalline structure, morphology, and magnetic properties of the as-prepared samples were thoroughly characterized. Results demonstrated that the magnetic Fe3O4 nanomaterial was formed in liquid phase with a spinel single-phase structure, average size of 8-13 nm, and high saturation magnetization (up to 75 emu/g). The PAA-capped Fe3O4 nanoparticles displayed high stability over a wide pH range (from 4 to 7) in 300 mM salt solution. More importantly, the heat-generating capacity of the nanoparticle systems was quantified at a specific absorption rate (SAR) of 70.22 W/g, which is 35% higher than magnetic nanoparticles coated with sodium dodecyl sulfate (SDS). These findings suggest the potential application of PAA-coated magnetic nanoparticles in magnetic hyperthermia.

  4. A Highly Stable Microporous Covalent Imine Network Adsorbent for Natural Gas Upgrading and Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan K.

    2016-06-06

    The feasible capture and separation of CO2 and N2 from CH4 is an important task for natural gas upgrading and the control of greenhouse gas emissions. Here, we studied the microporous covalent imine networks (CIN) material prepared through Schiff base condensation and exhibited superior chemical robustness under both acidic and basic conditions and high thermal stability. The material possesses a relatively uniform nanoparticle size of approximately 70 to 100 nm. This network featured permanent porosity with a high surface area (722 m2g-1) and micropores. A single-component gas adsorption study showed enhanced CO2 and CH4 uptakes of 3.32 mmol/g and 1.14 mmol/g, respectively, at 273 K and 1 bar, coupled with high separation selectivities for CO2/CH4, CH4/N2, and CO2/N2 of 23, 11.8 and 211, respectively. The enriched Lewis basicity in the porous skeletons favours the interaction of quadrupolar CO2 and polarizable CH4, resulting in enhanced CH4 and CO2 uptake and high CH4/N2, CO2/CH4 and CO2/N2 selectivities. Breakthrough experiments showed high CO2/CH4, CH4/N2 and CO2/N2 selectivities of 7.29, 40 and 125, respectively, at 298 K and 1 bar. High heats of adsorption for CH4 and CO2 (QstCH4; 32.61 kJ mol-1 and QstCO2; 42.42 kJ mol-1) provide the ultimate validation for the high selectivity. To the best of our knowledge, such a versatile adsorbent material that displays both enhanced uptake and selectivity for a variety of binary gas mixtures, including CO2/ CH4, CO2/N2 and CH4/N2, has not been extensively explored.

  5. Synthesis of stable and highly luminescent beryllium and magnesium doped ZnS quantum dots suitable for design of photonic and sensor material

    International Nuclear Information System (INIS)

    Highly luminescent ZnS quantum dots (QDs) and their Be2+ and Mg2+ derivatives having nominal compositions Zn1−xBexS and Zn1−xMgxS (where x=0.0–0.6 and Δx=0.1) have been synthesized using the co-precipitation technique. The synthesized QDs are stable for a period of up to 7 months. They have a cubic closed packed (zinc blende) structure and average particle size of 2–3 nm as measured by TEM, XRD and UV–vis spectral analysis. Incorporation of Be2+ and Mg2+ into the ZnS lattice has shown noteworthy effects on the intensity of defect-states emission that enhances the luminescence intensity of the QDs. The absorption bands in the visible spectral range for ions of Be and Mg elements are observed to overlap with the fluorescence transitions of ZnS QDs. These highly luminescent and stable QDs could be utilized for the development of new quantum dot-based sensors, light emitting diodes, phosphor and coating for long term applications. - Highlights: ► We have reported synthesis of luminescent ZnS quantum dots which are stable for a period of 7 months. ► The co-precipitation technique is used to synthesize the quantum dots. ► Spectral analysis by TEM, XRD and UV–vis shows average quantum dots size of 2–3 nm. ► Doping of ZnS with Be and Mg enhances the fluorescence. ► The doped ZnS quantum dots can be used as photonic and sensor materials.

  6. STEM–EELS analysis reveals stable high-density He in nanopores of amorphous silicon coatings deposited by magnetron sputtering

    International Nuclear Information System (INIS)

    A broad interest has been showed recently on the study of nanostructuring of thin films and surfaces obtained by low-energy He plasma treatments and He incorporation via magnetron sputtering. In this paper spatially resolved electron energy-loss spectroscopy in a scanning transmission electron microscope is used to locate and characterize the He state in nanoporous amorphous silicon coatings deposited by magnetron sputtering. A dedicated MATLAB program was developed to quantify the helium density inside individual pores based on the energy position shift or peak intensity of the He K-edge. A good agreement was observed between the high density (∼35–60 at nm−3) and pressure (0.3–1.0 GPa) values obtained in nanoscale analysis and the values derived from macroscopic measurements (the composition obtained by proton backscattering spectroscopy coupled to the macroscopic porosity estimated from ellipsometry). This work provides new insights into these novel porous coatings, providing evidence of high-density He located inside the pores and validating the methodology applied here to characterize the formation of pores filled with the helium process gas during deposition. A similar stabilization of condensed He bubbles has been previously demonstrated by high-energy He ion implantation in metals and is newly demonstrated here using a widely employed methodology, magnetron sputtering, for achieving coatings with a high density of homogeneously distributed pores and He storage capacities as high as 21 at%. (paper)

  7. STEM-EELS analysis reveals stable high-density He in nanopores of amorphous silicon coatings deposited by magnetron sputtering.

    Science.gov (United States)

    Schierholz, Roland; Lacroix, Bertrand; Godinho, Vanda; Caballero-Hernández, Jaime; Duchamp, Martial; Fernández, Asunción

    2015-02-20

    A broad interest has been showed recently on the study of nanostructuring of thin films and surfaces obtained by low-energy He plasma treatments and He incorporation via magnetron sputtering. In this paper spatially resolved electron energy-loss spectroscopy in a scanning transmission electron microscope is used to locate and characterize the He state in nanoporous amorphous silicon coatings deposited by magnetron sputtering. A dedicated MATLAB program was developed to quantify the helium density inside individual pores based on the energy position shift or peak intensity of the He K-edge. A good agreement was observed between the high density (∼35-60 at nm(-3)) and pressure (0.3-1.0 GPa) values obtained in nanoscale analysis and the values derived from macroscopic measurements (the composition obtained by proton backscattering spectroscopy coupled to the macroscopic porosity estimated from ellipsometry). This work provides new insights into these novel porous coatings, providing evidence of high-density He located inside the pores and validating the methodology applied here to characterize the formation of pores filled with the helium process gas during deposition. A similar stabilization of condensed He bubbles has been previously demonstrated by high-energy He ion implantation in metals and is newly demonstrated here using a widely employed methodology, magnetron sputtering, for achieving coatings with a high density of homogeneously distributed pores and He storage capacities as high as 21 at%. PMID:25627862

  8. A stable and high resolution optical waveguide biosensor based on dense TiO2/Ag multilayer film

    Science.gov (United States)

    Jin, Zhao; Guan, Weiming; Liu, Chang; Xue, Tianyu; Wang, Qiyu; Zheng, Weitao; Cui, Xiaoqiang

    2016-07-01

    Optical waveguide (OWG) biosensor has attracted much attention according to the high sensitivity and resolution compared with conventional surface plasmon resonance (SPR) biosensor. Nanoporous materials are usually used as the waveguide layer for absorbing analytes into the porous structure and enhancing the sensor signal. However, this kind of waveguide layer provides poor protection to the metal film and leads to the damage of the biosensor. Ag film can provide great sensitivity in SPR sensing comparing to other metal but was rarely used because of its poor chemical stability. Fabricating high stability Ag based SPR biosensor is still a challenge. In this work we produce an OWG biosensor using a dense TiO2 film as the waveguide layer which provides high resolution and remarkable protection to the metal film. This waveguide structure makes long time detection possible using Ag as the metal layer and is able to lead an enhancement of sensitivity comparing to the Au-based biosensor.

  9. Highly Stable Porous Covalent Triazine-Piperazine Linked Nanoflower as a Feasible Adsorbent for Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan K.

    2016-02-11

    Here, we report a porous covalent triazine-piperazine linked polymer (CTPP) featuring 3D nanoflower morphology and enhanced capture/removal of CO2, CH4 from air (N2), essential to control greenhouse gas emission and natural gas upgrading. 13C solid-state NMR and FTIR analyses and CHN and X-ray photoelectron spectroscopy (XPS) elemental analyses confirmed the integration of triazine and piperazine components in the network. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analyses revealed a relatively uniform particle size of approximately 400 to 500 nm with 3D nanoflower microstructure, which was formed by the self-assembly of interwoven and slight bent nanoflake components. The material exhibited outstanding chemical robustness under acidic and basic medium and high thermal stability up to 773 K. The CTPP possess high surface area (779 m2/g) and single-component gas adsorption study exhibited enhanced CO2 and CH4 uptake of 3.48 mmol/g, 1.09 mmol/g, respectively at 273 K, 1 bar; coupled with high sorption selectivities for CO2/N2 and CH4/N2 of 128 and 17, respectively. The enriched Lewis basicity of the CTPP favors the interaction with CO2, which results in an enhanced CO2 adsorption capacity and high CO2/N2 selectivity. The binary mixture breakthrough study for the flue gas composition at 298 K showed a high CO2/N2 selectivity of 82. CO2 heats of adsorption for the CTPP (34 kJ mol−1) were realized at the borderline between strong physisorption and weak chemisorption (QstCO2; 25−50 kJ mol−1) and low Qst value for N2 (22.09 kJ mol−1), providing the ultimate validation for the high selectivity of CO2 over N2.

  10. Evaluation of Pressure Stable Chip-to-Tube Fittings Enabling High-Speed Chip-HPLC with Mass Spectrometric Detection.

    Science.gov (United States)

    Lotter, Carsten; Heiland, Josef J; Stein, Volkmar; Klimkait, Michael; Queisser, Marco; Belder, Detlev

    2016-08-01

    Appropriate chip-to-tube interfacing is an enabling technology for high-pressure and high-speed liquid chromatography on chip. For this purpose, various approaches, to connect pressure resistant glass chips with HPLC pumps working at pressures of up to 500 bar, were examined. Three side-port and one top-port connection approach were evaluated with regard to pressure stability and extra column band broadening. A clamp-based top-port approach enabled chip-HPLC-MS analysis of herbicides at the highest pressure and speed. PMID:27397738

  11. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to gamma-valerolactone

    NARCIS (Netherlands)

    Luo, Wenhao; Meenakshisundaram, Sankar; Beale, Andrew M.; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into gamma-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, s

  12. Stable and solid pellets of functionalized multi-walled carbon nanotubes produced under high pressure and temperature

    International Nuclear Information System (INIS)

    High pressure/temperature was applied on samples of pristine multi-walled carbon nanotubes (MWCNT), functionalized nanotubes (f-MWCNT), and nanotubes doped with nitrogen (CNxMWNT). Cylindrical compact pellets of f-MWCNT with diameters of about 6 mm were obtained under pressure of 4.0 GPa at room temperature and at 400 °C, using graphite as pressure transmitting medium. The best pellet samples were produced using nitric and sulfuric acids for the functionalization of MWCNT. The effect of high pressure/temperature on CNT was investigated by several spectroscopy and characterization techniques, such as Raman spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, N2 adsorption/desorption isotherms, and transmission electron microscopy. It was found that MWCNT maintain their main features in the compacted pellets, such as integrity, original morphology, and structure, demonstrating that high-pressure/temperature compaction can indeed be used to fabricate novel CNT self-supported materials. Additionally, the specific surface area and porosity are unchanged, which is important when using bulk CNT in adsorption processes. Raman analysis of the G’-band showed a shift to lower wavenumbers when f-MWCNT were processed under high pressure, suggesting that CNT are under tensile stress

  13. Highly stable carbon nanotube field emitters on small metal tips against electrical arcing for miniature X-ray tubes

    International Nuclear Information System (INIS)

    If CNT emitters are operated at a high voltage or at a high electric field, electrical arcing (or vacuum breakdown) can occur. Arcing can be initiated by the removed CNTs, impurities on the CNTs or substrates, protrusion of CNTs, low operating vacuum, and a very high electric field. Since arcing is accompanied with a very high current flow and it can produce plasma channel near the emitter, CNTs are seriously damaged or sometimes CNTs are almost completely removed from the substrate by the arcing events. Detachment of CNTs from a substrate is an irreversible catastrophic phenomenon for a device operation. In addition to the detachment of CNTs, arcing induces a sudden voltage drop and thus device operation is stopped. The metal mixture strongly attached CNTs to the tip substrate. Due to the strong adhesion, CNT emitters could be pre-treated with electrical conditioning process without seriously damaging the CNTs even though many intense arcing events were induced at the small and sharp geometry of the tip substrate. Impurities that were loosely bound to the substrates were almost removed and CNTs heights became uniform after the electrical conditioning process

  14. A stable, reusable, and highly active photosynthetic bioreactor by bio-interfacing an individual cyanobacterium with a mesoporous bilayer nanoshell.

    Science.gov (United States)

    Jiang, Nan; Yang, Xiao-Yu; Deng, Zhao; Wang, Li; Hu, Zhi-Yi; Tian, Ge; Ying, Guo-Liang; Shen, Ling; Zhang, Ming-Xi; Su, Bao-Lian

    2015-05-01

    An individual cyanobacterium cell is interfaced with a nanoporous biohybrid layer within a mesoporous silica layer. The bio-interface acts as an egg membrane for cell protection and growth of outer shell. The resulting bilayer shell provides efficient functions to create a single cell photosynthetic bioreactor with high stability, reusability, and activity. PMID:25641812

  15. Highly stable carbon nanotube field emitters on small metal tips against electrical arcing for miniature X-ray tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jun Mok; Kim, Hyun Jin; Kim, Hyun Nam; Raza, Hamid Saeed; Cho, Sung Oh [Korea Advanced Institute of Science and Technology Daejeon (Korea, Republic of)

    2015-05-15

    If CNT emitters are operated at a high voltage or at a high electric field, electrical arcing (or vacuum breakdown) can occur. Arcing can be initiated by the removed CNTs, impurities on the CNTs or substrates, protrusion of CNTs, low operating vacuum, and a very high electric field. Since arcing is accompanied with a very high current flow and it can produce plasma channel near the emitter, CNTs are seriously damaged or sometimes CNTs are almost completely removed from the substrate by the arcing events. Detachment of CNTs from a substrate is an irreversible catastrophic phenomenon for a device operation. In addition to the detachment of CNTs, arcing induces a sudden voltage drop and thus device operation is stopped. The metal mixture strongly attached CNTs to the tip substrate. Due to the strong adhesion, CNT emitters could be pre-treated with electrical conditioning process without seriously damaging the CNTs even though many intense arcing events were induced at the small and sharp geometry of the tip substrate. Impurities that were loosely bound to the substrates were almost removed and CNTs heights became uniform after the electrical conditioning process.

  16. Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Deng, X.; Jones, S.J.; Liu, T.; Izu, M. [Energy Conversion Devices, Inc., Troy, MI (United States)

    1998-04-01

    This report summarizes Energy Conversion Devices, Inc.`s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasma-deposited i-layers. ECD conducted comprehensive research to develop a {mu}c-Si p{sup +} layer using VHF deposition process with the objectives of establishing a wider process window for the deposition of high-quality p{sup +} materials and further enhancing their performance of a-Si solar cells by improving its p-layers. ECD optimized the deposition of the intrinsic a-Si layer and the boron-doped {mu}c-Si p{sup +} layer to improve the V{sub oc}. Researchers deposited wide-bandgap a-Si films using high hydrogen dilution; investigated the deposition of the ZnO layer (for use in back-reflector) using a sputter deposition process involving metal Zn targets; and obtained a baseline fabrication for single-junction a-Si n-i-p devices with 10.6% initial efficiency and a baseline fabrication for triple-junction a-Si devices with 11.2% initial efficiency. ECD researchers also optimized the deposition parameters for a-SiGe with high Ge content; designed a novel structure for the p-n tunnel junction (recombination layer) in a multiple-junction solar cell; and demonstrated, in n-i-p solar cells, the improved stability of a-Si:H:F materials when deposited using a new fluorine precursor. Researchers investigated the use of c-Si(n{sup +})/a-Si alloy/Pd Schottky barrier device as a tool for the effective evaluation of photovoltaic performance on a-Si alloy materials. Through alterations in the deposition conditions and system hardware, researchers improved their understanding for the deposition of uniform and high-quality a-Si and a-SiGe films over large areas. ECD researchers also performed extensive research to optimize the deposition process of the newly constructed 5-MW back-reflector deposition machine.

  17. An easily sintered, chemically stable, barium zirconate-based proton conductor for high-performance proton-conducting solid oxide fuel cells

    KAUST Repository

    Sun, Wenping

    2014-07-25

    Yttrium and indium co-doped barium zirconate is investigated to develop a chemically stable and sintering active proton conductor for solid oxide fuel cells (SOFCs). BaZr0.8Y0.2-xInxO3- δ possesses a pure cubic perovskite structure. The sintering activity of BaZr0.8Y0.2-xInxO3- δ increases significantly with In concentration. BaZr0.8Y0.15In0.05O3- δ (BZYI5) exhibits the highest total electrical conductivity among the sintered oxides. BZYI5 also retains high chemical stability against CO2, vapor, and reduction of H2. The good sintering activity, high conductivity, and chemical stability of BZYI5 facilitate the fabrication of durable SOFCs based on a highly conductive BZYI5 electrolyte film by cost-effective ceramic processes. Fully dense BZYI5 electrolyte film is successfully prepared on the anode substrate by a facile drop-coating technique followed by co-firing at 1400 °C for 5 h in air. The BZYI5 film exhibits one of the highest conductivity among the BaZrO3-based electrolyte films with various sintering aids. BZYI5-based single cells output very encouraging and by far the highest peak power density for BaZrO3-based proton-conducting SOFCs, reaching as high as 379 mW cm-2 at 700 °C. The results demonstrate that Y and In co-doping is an effective strategy for exploring sintering active and chemically stable BaZrO3-based proton conductors for high performance proton-conducting SOFCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Stable 'floating' air diffusion biocathode based on direct electron transfer reactions between carbon particles and high redox potential laccase

    Energy Technology Data Exchange (ETDEWEB)

    Shleev, S. [Laboratory of Chemical Enzymology, A.N. Bach Institute of Biochemistry, Moscow (Russian Federation); Biomedical Laboratory Science, Health and Society, Malmoe University (Sweden); Shumakovich, G.; Morozova, O.; Yaropolov, A. [Laboratory of Chemical Enzymology, A.N. Bach Institute of Biochemistry, Moscow (Russian Federation)

    2010-08-15

    We report on the assembly and characterisation of a high potential, stable, mediator-less and cofactor free biocathode based on a fungal laccase (Lc), adsorbed on highly dispersed carbonaceous materials. First, the stability and activity of Trametes hirsuta Lc immobilised on different carbon particles were studied and compared to the solubilised enzyme. Based on the experimental results and a literature analysis, the carbonaceous material BM-4 was chosen to design efficient and stable biocatalysts for the production of a 'floating' air diffusion Lc-based biocathode. Voltammetric characteristics and operational stability of the biocathode were investigated. The current density of oxygen reduction at the motionless biocathode in a quiet, air saturated citrate buffer (100 mM, pH 4.5, 23 C) reached values as high as 0.3 mA cm{sup -2} already at 0.7 V versus NHE. The operational stability of the biocathode depended on the current density of the device. For example, at low current density (20 {mu}A cm{sup -2}), the biocathode lost only 5 x of its initial power after 1 month of continuous operation. However, when the device was polarised at 150 mV it lost more than 32 x of its initial power in just 10 min. We also found that co-immobilisation of Lc and peroxidase on highly dispersed carbon materials could protect the biocatalyst from rapid inactivation by hydrogen peroxide produced during electrocatalytic reactions at high-current densities. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  19. High-resolution vertical profiles of stable water isotopes from airborne measurements in the western Mediterranean during HyMeX in October 2012

    Science.gov (United States)

    Sodemann, Harald; Aemisegger, Franziska; Pfahl, Stephan; Corsmeier, Ulrich; Wieser, Andreas; Bitter, Mark; Feuerle, Thomas; Hankers, Rudolf; Schulz, Helmut; Hsiao, Gregor; Wernli, Heini

    2013-04-01

    Stable water isotopes are useful indicators of meteorological processes on a broad range of scales, reflecting for example evaporation, precipitation and airmass mixing processes. Scientific understanding of water isotope meteorology has long been impeded by the sparsity of observational data. Most measurements of precipitation and water vapour have been made at the surface. Both sampling and isotope measurements had been fairly intricate until recently, and required to transfer samples to a lab environment. With the recent advent of fast laser-based spectroscopic methods it has become possible to measure the isotopic composition of atmospheric water vapour in situ at high temporal resolution, enabling to tremendously extend the measurement data base in space and time. Here we present the first set of airborne spectroscopic stable water isotopes measurements in the Mediterranean. Measurements have been acquired by a customised Picarro L2130i instrument with enhanced data acquisition rate by a dual-laser system. The instrument was deployed in cooperation with the Karlsruhe Institute of Technology (KIT) onboard the Dornier 128-6 research aircraft D-IBUF of the Institute of Flight Guidance, TU Braunschweig together with a meteorological flux measurement package during HYMEX in Corsica, France. Taking into account memory effects of the pipe system, the typical time resolution of the measurements was about 30s, resulting in an average spatial resolution of about 2 km. Cross-calibration of the water vapour observations with other humidity sensors showed good agreement in most flight conditions but very turbulent ones. In total 23 successful stable isotope flights have been performed. We report on the measurement setup, calibration procedures and data quality, and a first interpretation of these new airborne observations. A climatological perspective of the vertical stable isotope composition in the vicinity of Corsica during the campaign reveals for the first time

  20. An Acinetobacter trimeric autotransporter adhesin reaped from cells exhibits its nonspecific stickiness via a highly stable 3D structure

    OpenAIRE

    Shogo Yoshimoto; Hajime Nakatani; Keita Iwasaki; Katsutoshi Hori

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific, high adhesiveness to abiotic material surfaces as well as to biotic surfaces. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced...

  1. High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum

    OpenAIRE

    Diogo Vieira Carvalho; Nicholas Loeffler; Guk-Tae Kim; Stefano Passerini

    2015-01-01

    A novel membrane based on silicon dioxide (SiO2) and hydroxypropyl guar gum (HPG) as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO2 and guar gum microstructure towards organic liquid electrolytes...

  2. Use of stable isotopes of N and C to explain unexpectedly high levels of PCBs and other organochlorines in walrus

    Energy Technology Data Exchange (ETDEWEB)

    Muir, D.; Segstro, M.; Stewart, R. [Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada); Hobson, K. [Canadian Wildlife Service, Saskatoon, Saskatchewan (Canada); Olpinski, S.

    1994-12-31

    Walrus (Odobenus rosmarus) blubber from Inukjuak and Akulivik (E. Hudson Bay), Foxe Basin and E. Baffin Is. was analyzed for PCB congeners and other persistent organochlorines (DDT, toxaphene, chlordanes) as part of studies documenting spatial trends in contaminants in Canadian arctic marine biota. Samples from 18 of 53 individuals had wet weight concentrations of {Sigma}PCBs ranging from 1 to 20 {mu}g//g; the remaining individuals had much lower concentrations. Highest concentrations were found in samples from Inukjuak where 11 of 13 animals (males and females) had high levels. {Sigma}PCB concentrations greater than 0.5 {mu}g/g were unexpected based on previous studies in Greenland and Alaska. Local contamination was ruled out because DDT, chlordanes and toxaphene were all elevated, and high levels were found in both males and females from 2 of 4 other locations. {sup 13}C and {sup 15}N isotope measurements using muscle samples from the jaws of walrus and seals, showed that walrus with high EPCB had higher {delta}{sup 15}N values than those with low PCBs. The results suggest that the walrus with elevated organochlorines are feeding at a higher trophic level than those with low levels and are probably utilizing ringed seals (Phoca hispida) for a significant proportion of their diet.

  3. Highly stable nanofluid based on polyhedral oligomeric silsesquioxane-decorated graphene oxide nanosheets and its enhanced electro-responsive behavior

    Science.gov (United States)

    Li, Yizhuo; Guan, Yanqing; Liu, Yang; Yin, Jianbo; Zhao, Xiaopeng

    2016-05-01

    Graphene oxide (GO) shows potential as an anisotropic nanofiller or a dispersed phase of electro-responsive electrorheological (ER) nanofluid due to its small size and high aspect ratio. But it is difficult to disperse GO in non-polar oil due to the hydrophilic nature of GO and thus the resulting fluid is often subject to dispersion instability and low ER effect. These disadvantages largely limit the real application of GO-based ER nanofluid. In this paper, we develop the polyhedral oligomeric silsesquioxane (POSS)-decorated GO (POSS-GO) nanosheets and demonstrate that decorating with POSS overcomes the dispersion instability of GO in silicone oil and enhances the ER effect. The morphology and structure of samples are characterized by atomic force microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and x-ray photoelectronic spectroscopy. The results show that the POSS-GO nanosheets are ultrathin with ∼3 nm thickness and have good compatibility with silicone oil and, as a result, the nanofluid of POSS-GO nanosheets in silicone oil shows high dispersion stability. After standing for one year at room temperature, no sedimentation occurs. Under an external electric field, the ER efficiency of the POSS-GO nanofluid is ten times as high as that of the pure GO fluid. This enhanced electro-responsive behavior is related to the fact that decorating with POSS partly reduces the GO and compresses the dielectrophoretic effect of the negatively charged pure GO fluid.

  4. Combined use of stable isotopes and hydrologic modeling to better understand nutrient sources and cycling in highly altered systems (Invited)

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Guerin, M.; Stringfellow, W. T.; Silva, S. R.; Harter, T.; Parker, A.

    2013-12-01

    The Sacramento and San Joaquin Rivers provide the majority of freshwater for the San Francisco Bay Delta. Both rivers are important sources of drinking and irrigation water for California, and play critical roles in the health of California fisheries. Understanding the factors controlling water quality and primary productivity in these rivers and the Delta is essential for making sound economic and environmental water management decisions. However, these highly altered surface water systems present many challenges for water quality monitoring studies due to factors such as multiple potential nutrient and contaminant inputs, dynamic source water inputs, and changing flow regimes controlled by both natural and engineered conditions. The watersheds for both rivers contain areas of intensive agriculture along with many other land uses, and the Sacramento River receives significant amounts of treated wastewater from the large population around the City of Sacramento. We have used a multi-isotope approach combined with mass balance and hydrodynamic modeling in order to better understand the dominant nutrient sources for each of these rivers, and to track nutrient sources and cycling within the complex Delta region around the confluence of the rivers. High nitrate concentrations within the San Joaquin River fuel summer algal blooms, contributing to low dissolved oxygen conditions. High δ15N-NO3 values combined with the high nitrate concentrations suggest that animal manure is a significant source of nitrate to the San Joaquin River. In contrast, the Sacramento River has lower nitrate concentrations but elevated ammonium concentrations from wastewater discharge. Downstream nitrification of the ammonium can be clearly traced using δ15N-NH4. Flow conditions for these rivers and the Delta have strong seasonal and inter-annual variations, resulting in significant changes in nutrient delivery and cycling. Isotopic measurements and estimates of source water contributions

  5. Sunlight based irradiation strategy for rapid green synthesis of highly stable silver nanoparticles using aqueous garlic (Allium sativum) extract and their antibacterial potential

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, Lori [National Center for Chemical Characterization of Materials, Bhabha Atomic Research Centre, ECIL-PO, Hyderabad 500 062 (India); Arunachalam, J., E-mail: aruncccm@rediffmail.com [National Center for Chemical Characterization of Materials, Bhabha Atomic Research Centre, ECIL-PO, Hyderabad 500 062 (India)

    2011-09-15

    Highlights: {yields} We report green synthetic route for the production crystalline silver nanoparticles using garlic as both reducing and stabilizing agent. {yields} Synthesis has been achieved by exposing the solution mixture of [Ag(NH{sub 3}){sub 2}]{sup +} and aqueous garlic extract under sunlight. {yields} Role of light in the synthesis process has been investigated and is discussed in detail. {yields} The antibacterial effect of the synthesized silver nanoparticles has been assessed against both Gram classes of bacteria. {yields} Synthesized silver colloidal solutions were found to be stable for a very long period and retained their bactericidal potential. - Abstract: A green synthetic route for the production of highly stable silver nanoparticles using aqueous garlic extract is being reported for the first time. The silver nanoparticles were synthesized by exposing a mixture of 0.1 M [Ag(NH{sub 3}){sub 2}]{sup +} and diluted aqueous garlic extract under bright sunlight for 15 min. The garlic extract components served as both reducing and capping agents in the synthesis of silver nanoparticles while the sunlight acted as catalyst in the synthesis process. The synthesized nanoparticles were characterized using UV-visible (UV-vis) spectrophotometer; transmission electron microscopy (TEM), glancing angle X-ray diffraction (GA-XRD) and Fourier transform infra red (FTIR) spectrometry. The nanoparticles were found to be poly-dispersed in nature, spherical in shape and of 7.3 {+-} 4.4 nm in size. The FTIR analysis was suggestive of proteins as capping agents around the nanoparticles. The yield of synthesized nanoparticles was calculated to be approximately 80% by dry weight and 85% ICP-AES method. The synthesized silver nanoparticles exhibited good antibacterial potential against both Gram positive and Gram negative bacterial strains, as measured using well diffusion assay. Most importantly, the silver colloidal solutions thus synthesized were found to be stable for

  6. Short term effects of rosuvastation on plasma concentration of high sensitivity c-reactive protein in patients with chronic stable angina

    International Nuclear Information System (INIS)

    Objective: To determine the short term effects of rosuvastatin on elevated base line high-sensitivity C-reactive protein (hs-CRP) in patients with chronic stable angina. Methodology: This Quasi-experimental comparative study was conducted in Cardiology department, Lady Reading Hospital Peshawar, between March 2010 and February, 2011. We selected 44 consecutive patients age 40 years or above, of any gender having hs-CRP levels = 1.2 mg/l with chronic stable angina. Base line levels of hs-CRP, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and creatine phosphokinase (CPK) were measured in fasting status. These patients were treated with rosuvastatin 20 mg once daily at night and followed up for one month. Using SPSS version 16 data was analyzed. Results: Mean age was 53 +- 7.2 and 50% were females. Following treatment with rosuvastatin 20 mg for one month the mean hs-CRP levels reduced from 4.08+-2.56 to 2.72 +- 2.40 (95 % CI, 0.41 to 2.29, p=0.006). Similarly mean total cholesterol levels decreased from 185.88 +- 37.62 to 147.45 +- 38.35, (p=0.0001). LDL cholesterol decreased from 118.34 +- 31.31 to 86.63 +-35.72 (p= 0.0001). But mean HDL cholesterol had no significant increase from baseline levels i.e. from 32.18+- 9.93 to 33.95 +-7.65 (p=0.174). TGs levels reduced from 240.11 +- 123.66 to 197.43 +- 88.24 (p=0.008). Mean CPK levels did not differ significantly from base line at follow up, from 101.43 +-58.63 to 96.22 +- 55.10 (p=0.646). Conclusion: Short term treatment with rosuvastatin significantly decreases elevated hs-CRP levels in patients with chronic stable angina. (author)

  7. Sunlight based irradiation strategy for rapid green synthesis of highly stable silver nanoparticles using aqueous garlic (Allium sativum) extract and their antibacterial potential

    International Nuclear Information System (INIS)

    Highlights: → We report green synthetic route for the production crystalline silver nanoparticles using garlic as both reducing and stabilizing agent. → Synthesis has been achieved by exposing the solution mixture of [Ag(NH3)2]+ and aqueous garlic extract under sunlight. → Role of light in the synthesis process has been investigated and is discussed in detail. → The antibacterial effect of the synthesized silver nanoparticles has been assessed against both Gram classes of bacteria. → Synthesized silver colloidal solutions were found to be stable for a very long period and retained their bactericidal potential. - Abstract: A green synthetic route for the production of highly stable silver nanoparticles using aqueous garlic extract is being reported for the first time. The silver nanoparticles were synthesized by exposing a mixture of 0.1 M [Ag(NH3)2]+ and diluted aqueous garlic extract under bright sunlight for 15 min. The garlic extract components served as both reducing and capping agents in the synthesis of silver nanoparticles while the sunlight acted as catalyst in the synthesis process. The synthesized nanoparticles were characterized using UV-visible (UV-vis) spectrophotometer; transmission electron microscopy (TEM), glancing angle X-ray diffraction (GA-XRD) and Fourier transform infra red (FTIR) spectrometry. The nanoparticles were found to be poly-dispersed in nature, spherical in shape and of 7.3 ± 4.4 nm in size. The FTIR analysis was suggestive of proteins as capping agents around the nanoparticles. The yield of synthesized nanoparticles was calculated to be approximately 80% by dry weight and 85% ICP-AES method. The synthesized silver nanoparticles exhibited good antibacterial potential against both Gram positive and Gram negative bacterial strains, as measured using well diffusion assay. Most importantly, the silver colloidal solutions thus synthesized were found to be stable for a very long period (more than a year) and retained their

  8. Highly stable SERS pH nanoprobes produced by co-solvent controlled AuNP aggregation.

    Science.gov (United States)

    Wei, Haoran; Willner, Marjorie R; Marr, Linsey C; Vikesland, Peter J

    2016-08-15

    Production of gold nanoparticle (AuNP) surface-enhanced Raman spectroscopy (SERS) nanoprobes requires replicable aggregation to produce multimers with high signal intensity. Herein, we illustrate a novel, yet simple, approach to produce SERS nanoprobes through control of co-solvent composition. AuNP multimers were produced by mixing AuNP monomers in water : ethanol co-solvent for variable periods of time. By varying the water : ethanol ratio and the amount of 4-mercaptobenzoic acid (4-MBA) present, the aggregation rate can be systematically controlled. Thiolated poly(ethylene glycol) was then added to halt the aggregation process and provide steric stability. This approach was used to produce pH nanoprobes with excellent colloidal stability in high ionic strength environments and in complex samples. The pH probe exhibits broad pH sensitivity over the range 6-11 and we calculate that a single AuNP dimer in a 35 fL volume is sufficient to generate a detectable SERS signal. As a proof-of-concept, the probes were used to detect the intracellular pH of human prostate cancer cells (PC-3). The internalized probes exhibit a strong 4-MBA signal without any interfering bands from either the cells or the culture media and produce exceptionally detailed pH maps. pH maps obtained from 19 xy surface scans and 14 yz depth scans exhibit highly consistent intracellular pH in the range of 5 to 7, thus indicating the greater reliability and reproducibility of our pH probes compared with other probes previously reported in the literature. Our water : ethanol co-solvent production process is fast, simple, and efficient. Adjustment of solvent composition may become a powerful way to produce SERS tags or nanoprobes in the future. PMID:27143623

  9. Highly fluorescence-stable blue CdZnS/ZnS quantum dots against degradable environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki-Heon; Lee, Jeong-Hoon; Kang, Hee-Don; Han, Chang-Yeol [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Bae, Seung Muk [Kunsan National University Center For Research Facilities, Kunsan National University, Gunsan, Jeonbuk 573-701 (Korea, Republic of); Lee, Yangjin; Hwang, Jun Yeon [Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905 (Korea, Republic of); Yang, Heesun, E-mail: hyang@hongik.ac.kr [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of)

    2014-10-15

    Graphical abstract: Blue-emitting CdZnS/ZnS alloy QDs exhibited the excellent fluorescent stability against a thorough purification cycle, long-term UV illumination, and hydrophobic-to-hydrophilic ligand exchange. - Highlights: • Highly efficient, color-pure blue CdZnS/ZnS QDs are synthesized. • Fluorescent properties of the QDs remain unchanged against various degradable conditions. • Closely-packed solid QD film is compared with QD solution in PL QY and emission decay dynamics. - Abstract: We report on synthesis of highly efficient, color-pure blue CdZnS/ZnS quantum dots (QDs) and their excellent fluorescent stability against degradable environmental conditions. The CdZnS/ZnS QDs finely emission-tunable in the range of 440–461 nm exhibit high photoluminescence (PL) quantum yields (QYs) of 81–92% along with an exceptionally narrow spectral bandwidth of 19 nm. These QDs are subjected to various post-treatments of a thorough purification cycle, long-term UV illumination, and hydrophobic-to-hydrophilic ligand exchange, each of which is usually detrimental to QD fluorescence. As a result, no noticeable deterioration in the fluorescent properties is observed, indicative of the insensitiveness of our CdZnS/ZnS QDs to the above degradable processes. Furthermore, PL properties of a solid film of multiple QD layers are assessed and compared with those of a diluted QD solution, showing an unprecedentedly small QY reduction of solid QD film versus QD solution. The above promising results are justified mainly by emphasizing the role of a thick ZnS shell present in CdZnS/ZnS QDs.

  10. Highly stable polyglutamate derivatives/siRNA polyplex efficiently down-relegate survivin expression and augment the efficacy of cisplatin.

    Science.gov (United States)

    Wang, Zhongjuan; Zou, Haijuan; Wang, Zirui; Wu, Jiamin; Xia, Zhongsheng; Feng, Min

    2016-05-30

    RNA interfere (RNAi)-based technology holds great promise in cancer treatment. The use of small interfering RNA (siRNA), however, is hampered by its low delivery efficiency in vivo when they are diluted in blood biofluids and in the presence of serum and salt. In this study, we developed the polyglutamate derivative polymer brush, poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (mPEG-b-PG-g-spermine, PPGS), which could efficiently deliver survivin-siRNA under ultra-high dilution and in the presence of salt (NaCl 150mM) and serum (10% FBS), most likely due to its PEG-shelled polymer brush structure. On the contrary, aggregation occurred when PEI/siRNA polyplex dispersed in saline and serum-containing media and PEI polyplex dissociated after making a 256-fold dilution. PPGS/si-survivin polyplex exhibited high cellular uptake efficiency and efficiently down-regulated the expression of survivin mRNA in the cisplatin-resistance of non-small cell human lung adenocarcinoma (A549/DDP) cells in the presence of serum. However, either PEI polyplex or Lipofectmine 2000 complex was unstable in serum and salt-containing media and at high dilution rates, which resulted in their dramatical decrease of cellular uptake and gene-silencing efficiency in these conditions. The PPGS/si-survivin polyplex also exhibited synergistic effects of killing the cancer cells by combination treatment with cisplatin. Therefore, the PPGS gene carrier showed great potential in systemic siRNA delivery, and its combination with chemotherapeutic drug is promising in treating drug resistant cancers. PMID:27039150

  11. Layer-by-layer assembly of polyelectrolyte and gold nanoparticle for highly reproducible and stable SERS substrate

    Science.gov (United States)

    Liu, Zhicheng; Yan, Zhaodong; Bai, Lu

    2016-01-01

    Building high-quality surface-enhanced Raman spectroscopy (SERS) substrates has attracted considerable attention from both fundamental and applied research. In this work, a simple layer-by-layer assembly of polyelectrolytes and gold nanoparticles was utilized to obtain multilayer thin films with tunable SERS performances. A relative uniform distribution of gold nanoparticles in the films was observed. Moreover, the SERS signals collected from the constructed substrates showed excellent reproducibility and stability. The obtained SERS substrates have a promising future in the field of sensing.

  12. CoSn5 Phase: Crystal Structure Resolving and Stable High Capacity as Anodes for Li Ion Batteries.

    Science.gov (United States)

    Wang, Xiao-Liang; Chen, Haiyan; Bai, Jianming; Han, Wei-Qiang

    2012-06-01

    Tin alloys form a class of interesting high-energy-density anode materials for Li ion batteries, but the improvement of their cycling stability is elusive. Here, we provide new insight on this fatal issue by synthesizing novel CoSn5-phase nanospheres via a conversion chemistry route and directly comparing their cell behavior with that of recently found FeSn5-phase nanospheres. The CoSn5 phase is absent in previous Co-Sn phase diagrams. Co0.83Sn5 nanospheres show a much longer cycle life, which partially is related to milder evolution of their cycling profiles over time. PMID:26285626

  13. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  14. Confined Porous Graphene/SnOx Frameworks within Polyaniline-Derived Carbon as Highly Stable Lithium-Ion Battery Anodes.

    Science.gov (United States)

    Zhou, Dan; Song, Wei-Li; Li, Xiaogang; Fan, Li-Zhen

    2016-06-01

    Tin oxides are promising anode materials for their high theoretical capacities in rechargeable lithium-ion batteries (LIBs). However, poor stability usually limits the practical application owing to the large volume variation during the cycling process. Herein, a novel carbon confined porous graphene/SnOx framework was designed using a silica template assisted nanocasting method followed by a polyaniline-derived carbon coating process. In this process, silica served as a template to anchor SnOx nanoparticles on porous framework and polyaniline was used as the carbon source for coating on the porous graphene/SnOx framework. The synthesized carbon confined porous graphene/SnOx frameworks demonstrate substantially improved rate capacities and enhanced cycling stability as the anode materials in LIBs, showing a high reversible capacity of 907 mAh g(-1) after 100 cycles at 100 mA g(-1) and 555 mAh g(-1) after 400 cycles at 1000 mA g(-1). The remarkably improved electrochemical performance could be assigned to the unique porous architecture, which effectively solves the drawbacks of SnOx including poor electrical conductivity and undesirable volume expansion during cycling process. Consequently, such design concept for promoting SnOx performance could provide a novel stage for improving anode stability in LIBs. PMID:27169479

  15. Virtual testing system for high-stable power supply%高稳定电源虚拟测试系统

    Institute of Scientific and Technical Information of China (English)

    袁水平; 董全林

    2013-01-01

    为了测试电子显微镜高稳定线圈恒流电源的稳定度,设计了一种基于虚拟仪器技术的在线测试系统。该系统硬件平台基于GPIB总线,以8位半数字多用表为高精度电压采集设备,软件系统以LabVIEW为开发平台,可以实时采集处理线圈电流反馈的电压信号。应用该系统测试了稳定度为2 ppm/min的物镜线圈电源。结果表明,该测试系统精度高,反应快,使用方便,满足自动测试高稳定电源的需求。%To test the stability of high-stable constant current power supply of electronic microscope,an online testing sys-tem based on the virtual instrument technology was designed. The hardware platform of the system is based on GPIB. 8 12 bit digi-tal multimeter is taken as the high-accuracy voltage acquisition instrument. The software system was developed with LabVIEW. This system can collect and analyze the voltage signal fed backed from coil current in real time. The objective coil power supply with 2 ppm/min stability was tested. The tested esults show that the system has high accuracy and fast response,is to use,and can satisfy the demand of measuring high-stable power supplies automatically.

  16. A step toward the development of high-temperature stable ionic liquid-in-oil microemulsions containing double-chain anionic surface active ionic liquid.

    Science.gov (United States)

    Rao, Vishal Govind; Banerjee, Chiranjib; Ghosh, Surajit; Mandal, Sarthak; Kuchlyan, Jagannath; Sarkar, Nilmoni

    2013-06-20

    Owing to their fascinating properties and wide range of potential applications, interest in nonaqueous microemulsions has escalated in the past decade. In the recent past, nonaqueous microemulsions containing ionic liquids (ILs) have been utilized in performing chemical reactions, preparation of nanomaterials, synthesis of nanostructured polymers, and drug delivery systems. The most promising fact about IL-in-oil microemulsions is their high thermal stability compared to that of aqueous microemulsions. Recently, surfactant-like properties of surface active ionic liquids (SAILs) have been used for preparation of microemulsions with high-temperature stability and temperature insensitivity. However, previously described methods present a limited possibility of developing IL-in-oil microemulsions with a wide range of thermal stability. With our previous work, we introduced a novel method of creating a huge number of IL-in-oil microemulsions (Rao, V. G.; Ghosh, S.; Ghatak, C.; Mandal, S.; Brahmachari, U.; Sarkar, N. J. Phys. Chem. B2012, 116, 2850-2855), composed of a SAIL as a surfactant, room-temperature ionic liquids as a polar phase, and benzene as a nonpolar phase. The use of benzene as a nonpolar solvent limits the application of the microemulsions to temperatures below 353 K. To overcome this limitation, we have synthesized N,N-dimethylethanolammonium 1,4-bis(2-ethylhexyl) sulfosuccinate (DAAOT), which was used as a surfactant. DAAOT in combination with isopropyl myristate (IPM, as an oil phase) and ILs (as a polar phase) produces a huge number of high-temperature stable IL-in-oil microemulsions. By far, this is the first report of a huge number of high-temperature stable IL-in-oil microemulsions. In particular, we demonstrate the wide range of thermal stability of [C6mim][TF2N]/DAAOT/IPM microemulsions by performing a phase behavior study, dynamic light scattering measurements, and (1)H NMR measurements and by using coumarin-480 (C-480) as a fluorescent probe

  17. High-Q energy trapping of temperature-stable shear waves with Lamé cross-sectional polarization in a single crystal silicon waveguide

    Science.gov (United States)

    Tabrizian, R.; Daruwalla, A.; Ayazi, F.

    2016-03-01

    A multi-port electrostatically driven silicon acoustic cavity is implemented that efficiently traps the energy of a temperature-stable eigen-mode with Lamé cross-sectional polarization. Dispersive behavior of propagating and evanescent guided waves in a ⟨100⟩-aligned single crystal silicon waveguide is used to engineer the acoustic energy distribution of a specific shear eigen-mode that is well known for its low temperature sensitivity when implemented in doped single crystal silicon. Such an acoustic energy trapping in the central region of the acoustic cavity geometry and far from substrate obviates the need for narrow tethers that are conventionally used for non-destructive and high quality factor (Q) energy suspension in MEMS resonators; therefore, the acoustically engineered waveguide can simultaneously serve as in-situ self-oven by passing large uniformly distributed DC currents through its body and without any concern about perturbing the mode shape or deforming narrow supports. Such a stable thermo-structural performance besides large turnover temperatures than can be realized in Lamé eigen-modes make this device suitable for implementation of ultra-stable oven-controlled oscillators. 78 MHz prototypes implemented in arsenic-doped single crystal silicon substrates with different resistivity are transduced by in- and out-of-plane narrow-gap capacitive ports, showing high Q of ˜43k. The low resistivity device shows an overall temperature-induced frequency drift of 200 ppm over the range of -20 °C to 80 °C, which is ˜15× smaller compared to overall frequency drift measured for the similar yet high resistivity device in the same temperature range. Furthermore, a frequency tuning of ˜2100 ppm is achieved in high resistivity device by passing 45 mA DC current through its body. Continuous operation of the device under such a self-ovenizing current over 10 days did not induce frequency instability or degradation in Q.

  18. High numbers of IL-2-producing CD8+ T cells during viral infection: correlation with stable memory development

    DEFF Research Database (Denmark)

    Kristensen, Nanna Ny; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    Using infections with lymphocytic choriomeningitis virus (LCMV) and vesicular stomatitis virus in mice as model systems, we have investigated the ability of antigen-primed CD8+ T cells generated in the context of viral infections to produce IL-2. Our results indicate that acute immunizing infection...... normally leads to generation of high numbers of IL-2-producing antigen-specific CD8+ T cells. By costaining for IL-2 and IFN-gamma intracellularly, we found that IL-2-producing cells predominantly constitute a subset of cells also producing IFN-gamma. Comparison of the kinetics of generation revealed that...... chronic LCMV infection. Furthermore, in MHC class II-deficient mice, which only transiently control LCMV infection, IL-2-producing CD8+ T cells are initially generated, but by 4 weeks after infection this subset has nearly disappeared. Eventually the capacity to produce IFN-gamma also becomes impaired...

  19. Ammonia intercalated flower-like MoS2 nanosheet film as electrocatalyst for high efficient and stable hydrogen evolution

    Science.gov (United States)

    Wang, F. Z.; Zheng, M. J.; Zhang, B.; Zhu, C. Q.; Li, Q.; Ma, L.; Shen, W. Z.

    2016-01-01

    Ammonia intercalated flower-like MoS2 electrocatalyst film assembled by vertical orientated ultrathin nanosheet on graphite sheethas been successfully synthesized using one-step hydrothermal method. In this strategy, ammonia can effectively insert into the parallel plane of the MoS2 nanosheets, leading to the expansion of lattice and phase transfer from 2H to 1T, generating more active unsaturated sulfur atoms. The flower-like ammoniated MoS2 electrocatalysts with more active sites and large surface area exhibited excellent HER activity with a small Tafel slope and low onset overpotential, resulting a great enhancement in hydrogen evolution. The high efficient activity and recyclable utilization, as well as large-scale, indicate that it is a very promising electrocatalyst to replace Pt in industry application. PMID:27538812

  20. Phase-sensitive optical coherence tomography-based vibrometry using a highly phase-stable akinetic swept laser source

    Energy Technology Data Exchange (ETDEWEB)

    Applegate, Brian E.; Park, Jesung; Carbajal, Esteban [Department of Biomedical Engineering, Texas A& M University, College Station, Texas (United States); Oghalai, John S. [Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, California (United States)

    2015-12-31

    Phase-sensitive Optical Coherence Tomography (PhOCT) is an emerging tool for in vivo investigation of the vibratory function of the intact middle and inner ear. PhOCT is able to resolve micron scale tissue morphology in three dimensions as well as measure picometer scale motion at each spatial position. Most PhOCT systems to date have relied upon the phase stability offered by spectrometer detection. On the other hand swept laser source based PhOCT offers a number of advantages including balanced detection, long imaging depths, and high imaging speeds. Unfortunately the inherent phase instability of traditional swept laser sources has necessitated complex user developed hardware/software solutions to restore phase sensitivity. Here we present recent results using a prototype swept laser that overcomes these issues. The akinetic swept laser is electronically tuned and precisely controls sweeps without any mechanical movement, which results in high phase stability. We have developed an optical fiber based PhOCT system around the akinetic laser source that had a 1550 nm center wavelength and a sweep rate of 140 kHz. The stability of the system was measured to be 4.4 pm with a calibrated reflector, thus demonstrating near shot noise limited performance. Using this PhOCT system, we have acquired structural and vibratory measurements of the middle ear in a mouse model, post mortem. The quality of the results suggest that the akinetic laser source is a superior laser source for PhOCT with many advantages that greatly reduces the required complexity of the imaging system.

  1. Phase-sensitive optical coherence tomography-based vibrometry using a highly phase-stable akinetic swept laser source

    International Nuclear Information System (INIS)

    Phase-sensitive Optical Coherence Tomography (PhOCT) is an emerging tool for in vivo investigation of the vibratory function of the intact middle and inner ear. PhOCT is able to resolve micron scale tissue morphology in three dimensions as well as measure picometer scale motion at each spatial position. Most PhOCT systems to date have relied upon the phase stability offered by spectrometer detection. On the other hand swept laser source based PhOCT offers a number of advantages including balanced detection, long imaging depths, and high imaging speeds. Unfortunately the inherent phase instability of traditional swept laser sources has necessitated complex user developed hardware/software solutions to restore phase sensitivity. Here we present recent results using a prototype swept laser that overcomes these issues. The akinetic swept laser is electronically tuned and precisely controls sweeps without any mechanical movement, which results in high phase stability. We have developed an optical fiber based PhOCT system around the akinetic laser source that had a 1550 nm center wavelength and a sweep rate of 140 kHz. The stability of the system was measured to be 4.4 pm with a calibrated reflector, thus demonstrating near shot noise limited performance. Using this PhOCT system, we have acquired structural and vibratory measurements of the middle ear in a mouse model, post mortem. The quality of the results suggest that the akinetic laser source is a superior laser source for PhOCT with many advantages that greatly reduces the required complexity of the imaging system

  2. Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF3-sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF3 and D-bisCF3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF3, D-CF3, D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF3, CF3, OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF3, D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF3 and -OH groups at the TiO2 surface, moderate dye loading on TiO2, and high charge collection efficiency. Moreover, the D-bisCF3 and D-CF3 based DSSCs exhibit good stability under 100 mW cm−2 light soaking at 60 °C for 400 h

  3. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Garofalo, A. M., E-mail: garofalo@fusion.gat.com; Burrell, K. H.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Turnbull, A. D. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Eldon, D.; Grierson, B. A.; Solomon, W. M. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Hanson, J. M. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Holland, C. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Huijsmans, G. T. A.; Liu, F.; Loarte, A. [ITER Organization, Route de Vinon sur Verdon, 13067 St Paul Lez Durance (France); Zeng, L. [University of California Los Angeles, P.O. Box 957099, Los Angeles, California 90095-7099 (United States)

    2015-05-15

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

  4. Phase-sensitive optical coherence tomography-based vibrometry using a highly phase-stable akinetic swept laser source

    Science.gov (United States)

    Applegate, Brian E.; Park, Jesung; Carbajal, Esteban; Oghalai, John S.

    2015-12-01

    Phase-sensitive Optical Coherence Tomography (PhOCT) is an emerging tool for in vivo investigation of the vibratory function of the intact middle and inner ear. PhOCT is able to resolve micron scale tissue morphology in three dimensions as well as measure picometer scale motion at each spatial position. Most PhOCT systems to date have relied upon the phase stability offered by spectrometer detection. On the other hand swept laser source based PhOCT offers a number of advantages including balanced detection, long imaging depths, and high imaging speeds. Unfortunately the inherent phase instability of traditional swept laser sources has necessitated complex user developed hardware/software solutions to restore phase sensitivity. Here we present recent results using a prototype swept laser that overcomes these issues. The akinetic swept laser is electronically tuned and precisely controls sweeps without any mechanical movement, which results in high phase stability. We have developed an optical fiber based PhOCT system around the akinetic laser source that had a 1550 nm center wavelength and a sweep rate of 140 kHz. The stability of the system was measured to be 4.4 pm with a calibrated reflector, thus demonstrating near shot noise limited performance. Using this PhOCT system, we have acquired structural and vibratory measurements of the middle ear in a mouse model, post mortem. The quality of the results suggest that the akinetic laser source is a superior laser source for PhOCT with many advantages that greatly reduces the required complexity of the imaging system.

  5. Origin and characteristics of high Shannon entropy at the pivot of locally stable rotors: insights from computational simulation.

    Directory of Open Access Journals (Sweden)

    Anand N Ganesan

    Full Text Available BACKGROUND: Rotors are postulated to maintain cardiac fibrillation. Despite the importance of bipolar electrograms in clinical electrophysiology, few data exist on the properties of bipolar electrograms at rotor sites. The pivot of a spiral wave is characterized by relative uncertainty of wavefront propagation direction compared to the periphery. The bipolar electrograms used in electrophysiology recording encode information on both direction and timing of approaching wavefronts. OBJECTIVE: To test the hypothesis that bipolar electrograms from the pivot of rotors have higher Shannon entropy (ShEn than electrograms recorded at the periphery due to the spatial dynamics of spiral waves. METHODS AND RESULTS: We studied spiral wave propagation in 2-dimensional sheets constructed using a simple cell automaton (FitzHugh-Nagumo, atrial (Courtemanche-Ramirez-Nattel and ventricular (Luo-Rudy myocyte cell models and in a geometric model spiral wave. In each system, bipolar electrogram recordings were simulated, and Shannon entropy maps constructed as a measure of electrogram information content. ShEn was consistently highest in the pivoting region associated with the phase singularity of the spiral wave. This property was consistently preserved across; (i variation of model system (ii alterations in bipolar electrode spacing, (iii alternative bipolar electrode orientation (iv bipolar electrogram filtering and (v in the presence of rotor meander. Directional activation plots demonstrated that the origin of high ShEn at the pivot was the directional diversity of wavefront propagation observed in this location. CONCLUSIONS: The pivot of the rotor is consistently associated with high Shannon entropy of bipolar electrograms despite differences in action potential model, bipolar electrode spacing, signal filtering and rotor meander. Maximum ShEn is co-located with the pivot for rotors observed in the bipolar electrogram recording mode, and may be an intrinsic

  6. Hydrogen Embrittlement Susceptibility of Fe-Mn Binary Alloys with High Mn Content: Effects of Stable and Metastable ɛ-Martensite, and Mn Concentration

    Science.gov (United States)

    Koyama, Motomichi; Okazaki, Shota; Sawaguchi, Takahiro; Tsuzaki, Kaneaki

    2016-03-01

    To obtain a basic understanding of hydrogen embrittlement associated with ɛ-martensite, we investigated the tensile behavior of binary Fe-Mn alloys with high Mn content under cathodic hydrogen charging. We used Fe-20Mn, Fe-28Mn, Fe-32Mn, and Fe-40Mn alloys. The correlation between the microstructure and crack morphology was clarified through electron backscatter diffraction measurements and electron channeling contrast imaging. ɛ-martensite in the Fe-20Mn alloy critically deteriorated the resistance to hydrogen embrittlement owing to transformation to α'-martensite. However, when ɛ-martensite is stable, hydrogen embrittlement susceptibility became low, particularly in the Fe-32Mn alloys, even though the formation of ɛ-martensite plates assisted boundary cracking. The Fe-40Mn alloys, in which no martensite forms even after fracture, showed higher hydrogen embrittlement susceptibility compared to the Fe-32Mn alloy. Namely, in Fe-Mn binary alloys, the Mn content has an optimal value for hydrogen embrittlement susceptibility because of the following two reasons: (1) The formation of stable ɛ-martensite seems to have a positive effect in suppressing hydrogen-enhanced localized plasticity, but causes boundary cracking, and (2) an increase in Mn content stabilizes austenite, suppressing martensite-related cracking, but probably decreases the cohesive energy of grain boundaries, causing intergranular cracking. As a consequence, the optimal Mn content was 32 wt pct in the present alloys.

  7. Imperceptible effect of radiation based on stable type chromosome aberrations accumulated in the lymphocytes of residents in the high background radiation area in China

    International Nuclear Information System (INIS)

    Cytogenetic investigation of stable type aberrations (translocations) was performed with our improved methods in 6 children and 15 elderly persons in a high background radiation area (HBRA) in China, and in 8 children and 11 elderly persons in a control area. The total numbers of cells analyzed in elderly persons were 68,297 in HBRA and 35,378 in controls and in children were 45,535 in HBRA and 56,198 in controls. On average 5138 cells per subject were analyzed. The variation in the frequencies of translocations per 1000 cells was small in children while it was large in elderly persons. No significant difference was found in the frequencies between HBRA and control (P>0.05, Mann-Whitney U test). On the other hand, correlation between age and translocation frequencies was significant at the 1% level (rs=0.658 with 37DF, Spearman rank correlation test). The contribution of an elevated level of natural radiation in HBRA in China to the induction of stable type chromosome aberrations does not have a significant effect compared with the contribution of chemical mutagens and/or metabolic factors. The present study suggests that the probability of the risk of causing malignant and/or congenital diseases by the increased amount of radiation is imperceptible in HBRA where the level of natural radiation is 3 to 5 times higher than that in the control area. (author)

  8. Simple, stable and sensitive electrogenerated chemiluminescence detector for high-performance liquid chromatography and its application in direct determination of multiple fluoroquinolone residues in milk.

    Science.gov (United States)

    Li, Yongbo; Zhang, Zhujun; Li, Jinsong; Li, Hongguang; Chen, Yan; Liu, Zhaohui

    2011-05-15

    A simple, stable and sensitive electrogenerated chemiluminescence (ECL) detector was developed. It was based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) immobilized on the surface of a Pt wire with Nepem-105D ion exchange solution. The detector was prepared by inserting a Pt wire with immobilized Ru(bpy)(3)(2+) (working electrode) into a capillary tube, followed by inserting another Pt wire (counter electrode) in this tube and sealing. ECL behavior was investigated using ofloxacin as an analyte. Under optimal conditions, stable ECL intensity was obtained. This detector has been used in HPLC-ECL for the determination of multiple target fluoroquinolone residues in milk. There is no post column reagent addition, which would dilute the analytes, potentially leading to chromatographic band-broadening. The system is very simple with low dead volume, low baseline and background noise, together with high sensitivity and stability. The as-prepared ECL detector, when was used for the determination of ofloxacin, pefloxacin, enrofloxacin and difloxacin in milk, demonstrated adequate sensitivity to allow quantification of trace FQ levels in commercial milk samples. One or more of the target FQ analytes were present at levels above the LOD of the new ECL detector in each and every one of the 22 milk samples analysed. PMID:21482269

  9. Subnanometer Molybdenum Sulfide on Carbon Nanotubes as a Highly Active and Stable Electrocatalyst for Hydrogen Evolution Reaction.

    Science.gov (United States)

    Li, Ping; Yang, Zhi; Shen, Juanxia; Nie, Huagui; Cai, Qiran; Li, Luhua; Ge, Mengzhan; Gu, Cancan; Chen, Xi'an; Yang, Keqin; Zhang, Lijie; Chen, Ying; Huang, Shaoming

    2016-02-10

    Electrochemically splitting water for hydrogen evolution reaction (HER) has been viewed as a promising approach to produce renewable and clean hydrogen energy. However, searching for cheap and efficient HER electrocatalysts to replace the currently used Pt-based catalysts remains an urgent task. Herein, we develop a one-step carbon nanotube (CNT) assisted synthesis strategy with CNTs' strong adsorbability to mediate the growth of subnanometer-sized MoS(x) on CNTs. The subnanometer MoS(x)-CNT hybrids achieve a low overpotential of 106 mV at 10 mA cm(-2), a small Tafel slope of 37 mV per decade, and an unprecedentedly high turnover frequency value of 18.84 s(-1) at η = 200 mV among all reported non-Pt catalysts in acidic conditions. The superior performance of the hybrid catalysts benefits from the presence of a higher number of active sites and the abundant exposure of unsaturated S atoms rooted in the subnanometer structure, demonstrating a new class of subnanometer-scale catalysts. PMID:26765150

  10. Highly Stable and Active Pt/Nb-TiO2 Carbon-Free Electrocatalyst for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Shuhui Sun

    2012-01-01

    Full Text Available The current materials used in proton exchange membrane fuel cells (PEMFCs are not sufficiently durable for commercial deployment. One of the major challenges lies in the development of an inexpensive, efficient, and highly durable and active electrocatalyst. Here a new type of carbon-free Pt/Nb-TiO2 electrocatalyst has been reported. Mesoporous Nb-TiO2 hollow spheres were synthesized by the sol-gel method using polystyrene (PS sphere templates. Pt nanoparticles (NPs were then deposited onto mesoporous Nb-TiO2 hollow spheres via a simple wet-chemical route in aqueous solution, without the need for surfactants or potentiostats. The growth densities of Pt NPs on Nb-TiO2 supports could be easily modulated by simply adjusting the experimental parameters. Electrochemical studies of Pt/Nb-TiO2 show much enhanced activity and stability than commercial E-TEK Pt/C catalyst. PtNP/Nb-TiO2 is a promising new cathode catalyst for PEMFC applications.

  11. VNARs: An Ancient and Unique Repertoire of Molecules That Deliver Small, Soluble, Stable and High Affinity Binders of Proteins

    Directory of Open Access Journals (Sweden)

    Caroline Barelle

    2015-09-01

    Full Text Available At 420 million years, the variable domain of New Antigen Receptors or VNARs are undoubtedly the oldest (and smallest antigen binding single domains identified in the vertebrate kingdom. Their role as an integral part of the adaptive immune system of sharks has been well established and has served to provide a greater understanding of the evolution of humoral immunity; their cellular components and processes as well as the underlying genetic organization and molecular control mechanisms. Intriguingly, unlike the variable domain of the camelid heavy chain antibodies or VHH, VNARs do not conform to all of the characteristic properties of classical antibodies with an ancestral origin that clearly distinguishes them from true immunoglobulin antibodies. However, this uniqueness of their origin only adds to their potential as next generation therapeutic biologics with their structural and functional attributes and commercial freedom all enhancing their profile and current success. In fact their small size, remarkable stability, molecular flexibility and solubility, together with their high affinity and selectivity for target, all reinforce the potential of these domains as drug candidates. The purpose of this review is to provide an overview of the existing basic biology of these unique domains, to highlight the drug-like properties of VNARs and describe current progress in their journey towards the clinic.

  12. High Order A-stable Continuous General Linear Methods for Solution of Systems of Initial Value Problems in ODEs

    Directory of Open Access Journals (Sweden)

    Dauda GuliburYAKUBU

    2012-12-01

    Full Text Available Accurate solutions to initial value systems of ordinary differential equations may be approximated efficiently by Runge-Kutta methods or linear multistep methods. Each of these has limitations of one sort or another. In this paper we consider, as a middle ground, the derivation of continuous general linear methods for solution of stiff systems of initial value problems in ordinary differential equations. These methods are designed to combine the advantages of both Runge-Kutta and linear multistep methods. Particularly, methods possessing the property of A-stability are identified as promising methods within this large class of general linear methods. We show that the continuous general linear methods are self-starting and have more ability to solve the stiff systems of ordinary differential equations, than the discrete ones. The initial value systems of ordinary differential equations are solved, for instance, without looking for any other method to start the integration process. This desirable feature of the proposed approach leads to obtaining very high accuracy of the solution of the given problem. Illustrative examples are given to demonstrate the novelty and reliability of the methods.

  13. Quadruple-junction solar cells and modules based on amorphous and microcrystalline silicon with high stable efficiencies

    Science.gov (United States)

    Kirner, Simon; Neubert, Sebastian; Schultz, Christof; Gabriel, Onno; Stannowski, Bernd; Rech, Bernd; Schlatmann, Rutger

    2015-08-01

    Quadruple junction solar cells and modules are presented, which consist of hydrogenated amorphous (a-Si:H) and microcrystalline silicon (µc-Si:H) in the a-Si:H/a-Si:H/µc-Si:H/µc-Si:H configuration. The highest measured conversion efficiency of a mini-module with an aperture area of 61.44 cm2 was 13.4% before and 12.0% after more than 1000 h of light soaking, respectively. In this paper, we discuss the advantages of the quadruple junction design over the common tandem design, which is ascribed mainly to the fact that the total absorber thickness can be increased while electronic properties and stability are maintained or even improved. The role of the µc-SiOx:H intermediate reflector is highlighted and an optimization of the doping concentration in this layer is presented. Furthermore, the advantage of the high maximum power voltage for the monolithic cell interconnection laser design of modules is shown.

  14. Highly stable polymer coated nano-clustered silver plates: a multimodal optical contrast agent for biomedical imaging

    Science.gov (United States)

    Ray, Aniruddha; Mukundan, Ananya; Xie, Zhixing; Karamchand, Leshern; Wang, Xueding; Kopelman, Raoul

    2014-11-01

    Here, we present a new optical contrast agent based on silver nanoplate clusters embedded inside of a polymer nano matrix. Unlike nanosphere clusters, which have been well studied, nanoplate clusters have unique properties due to the different possible orientations of interaction between the individual plates, resulting in a significant broadening of the absorption spectra. These nanoclusters were immobilized inside of a polymer cladding so as to maintain their stability and optical properties under in vivo conditions. The polymer-coated silver nanoplate clusters show a lower toxicity compared to the uncoated nanoparticles. At high nanoparticle concentrations, cell death occurs mostly due to apoptosis. These nanoparticles were used for targeted fluorescence imaging in a rat glioma cell line by incorporating a fluorescent dye into the matrix, followed by conjugation of a tumor targeting an F3 peptide. We further used these nanoparticles as photoacoustic contrast agents in vivo to enhance the contrast of the vasculature structures in a rat ear model. We observed a contrast enhancement of over 90% following the nanoparticle injection. It is also shown that these NPs can serve as efficient contrast agents, with specific targeting abilities for broadband multimodal imaging that are usable for diagnostic applications and that extend into use as therapeutic agents as well.

  15. Highly stable polymer coated nano-clustered silver plates: a multimodal optical contrast agent for biomedical imaging

    International Nuclear Information System (INIS)

    Here, we present a new optical contrast agent based on silver nanoplate clusters embedded inside of a polymer nano matrix. Unlike nanosphere clusters, which have been well studied, nanoplate clusters have unique properties due to the different possible orientations of interaction between the individual plates, resulting in a significant broadening of the absorption spectra. These nanoclusters were immobilized inside of a polymer cladding so as to maintain their stability and optical properties under in vivo conditions. The polymer-coated silver nanoplate clusters show a lower toxicity compared to the uncoated nanoparticles. At high nanoparticle concentrations, cell death occurs mostly due to apoptosis. These nanoparticles were used for targeted fluorescence imaging in a rat glioma cell line by incorporating a fluorescent dye into the matrix, followed by conjugation of a tumor targeting an F3 peptide. We further used these nanoparticles as photoacoustic contrast agents in vivo to enhance the contrast of the vasculature structures in a rat ear model. We observed a contrast enhancement of over 90% following the nanoparticle injection. It is also shown that these NPs can serve as efficient contrast agents, with specific targeting abilities for broadband multimodal imaging that are usable for diagnostic applications and that extend into use as therapeutic agents as well. (paper)

  16. MRI Monitoring of Tumor-Selective Anticancer Drug Delivery with Stable Thermosensitive Liposomes Triggered by High-Intensity Focused Ultrasound.

    Science.gov (United States)

    Kim, Hyun Ryoung; You, Dong Gil; Park, Sang-Jun; Choi, Kyu-Sil; Um, Wooram; Kim, Jae-Hun; Park, Jae Hyung; Kim, Young-Sun

    2016-05-01

    Monitoring of drug release from a heat-activated liposome carrier provides an opportunity for real-time control of drug delivery and allows prediction of the therapeutic effect. We have developed short-chain elastin-like polypeptide-incorporating thermosensitive liposomes (STLs). Here, we report the development of STL encapsulating gadobenate dimeglumine (Gd-BOPTA), a MRI contrast agent, and doxorubicin (Dox) (Gd-Dox-STL). The Dox release profile from Gd-Dox-STL was comparable to Gd-Dox-LTSL; however, the serum stability of Gd-Dox-STL was much higher than Gd-Dox-LTSL. MRI studies showed that the difference in T1 relaxation time between 37 and 42 °C for Gd-Dox-STL was larger than the difference for Gd-Dox-LTSL. Although relaxivity for both liposomes at 42 °C was similar, the relaxivity of Gd-Dox-STL at 37 °C was 2.5-fold lower than that of Gd-Dox-LTSL. This was likely due to Gd-BOPTA leakage from the LTSL because of low stability at 37 °C. Pharmacokinetic studies showed plasma half-lives of 4.85 and 1.95 h for Gd-Dox-STL and Gd-Dox-LTSL, respectively, consistent with in vitro stability data. In vivo MRI experiments demonstrated corelease of Dox and Gd-BOPTA from STL under mild hyperthermia induced by high-intensity focused ultrasound (HIFU), which suggests STL is a promising tumor selective formulation when coupled with MR-guided HIFU. PMID:26998616

  17. High yield production of influenza virus in Madin Darby canine kidney (MDCK cells with stable knockdown of IRF7.

    Directory of Open Access Journals (Sweden)

    Itsuki Hamamoto

    Full Text Available Influenza is a serious public health problem that causes a contagious respiratory disease. Vaccination is the most effective strategy to reduce transmission and prevent influenza. In recent years, cell-based vaccines have been developed with continuous cell lines such as Madin-Darby canine kidney (MDCK and Vero. However, wild-type influenza and egg-based vaccine seed viruses will not grow efficiently in these cell lines. Therefore, improvement of virus growth is strongly required for development of vaccine seed viruses and cell-based influenza vaccine production. The aim of our research is to develop novel MDCK cells supporting highly efficient propagation of influenza virus in order to expand the capacity of vaccine production. In this study, we screened a human siRNA library that involves 78 target molecules relating to three major type I interferon (IFN pathways to identify genes that when knocked down by siRNA lead to enhanced production of influenza virus A/Puerto Rico/8/1934 in A549 cells. The siRNAs targeting 23 candidate genes were selected to undergo a second screening pass in MDCK cells. We examined the effects of knockdown of target genes on the viral production using newly designed siRNAs based on sequence analyses. Knockdown of the expression of a canine gene corresponding to human IRF7 by siRNA increased the efficiency of viral production in MDCK cells through an unknown process that includes the mechanisms other than inhibition of IFN-α/β induction. Furthermore, the viral yield greatly increased in MDCK cells stably transduced with the lentiviral vector for expression of short hairpin RNA against IRF7 compared with that in control MDCK cells. Therefore, we propose that modified MDCK cells with lower expression level of IRF7 could be useful not only for increasing the capacity of vaccine production but also facilitating the process of seed virus isolation from clinical specimens for manufacturing of vaccines.

  18. Gradual crossover in molecular organization of stable liquid H2O at moderately high pressure and temperature

    Directory of Open Access Journals (Sweden)

    Yoshikata Koga

    2014-09-01

    Full Text Available Using the literature raw data of the speed of sound and the specific volume, the isothermal compressibility, κT, a second derivative thermodynamic quantity of G, was evaluated for liquid H2O in the pressure range up to 350 MPa and the temperature to 50 ºC. We then obtained its pressure derivative, dκT/dp, a third derivative numerically without using a fitting function to the κT data. On taking yet another p-derivative at a fixed T graphically without resorting to any fitting function, the resulting d2κT/dp2, a fourth derivative, showed a weak but clear step anomaly, with the onset of the step named point X and its end point Y. In analogy with another third and fourth derivative pair in binary aqueous solutions of glycerol, dαp/dxGly and d2αp/dxGly2, at 0.1 MPa (αp is the thermal expansivity and xGly the mole fraction of solute glycerol in our recent publication [J. Solution Chem. 43, 663-674 (2014; DOI:10.1007/s10953-013-0122-7], we argue that there is a gradual crossover in the molecular organization of pure H2O from a low to a high p-regions starting at point X and ending at Y at a fixed T. The crossover takes place gradually spanning for about 100 MPa at a fixed temperature. The extrapolated temperature to zero p seems to be about 70 – 80 °C for points X and 90 – 110 °C for Y. Furthermore, the mid-points of X and Y seem to extrapolate to the triple point of liquid, ice Ih and ice III. Recalling that the zero xGly extrapolation of point X and Y for binary aqueous glycerol at 0.1 MPa gives about the same T values respectively, we suggest that at zero pressure the region below about 70 °C the hydrogen bond network is bond-percolated, while above about 90 ºC there is no hydrogen bond network. Implication of these findings is discussed.

  19. Gradual crossover in molecular organization of stable liquid H2O at moderately high pressure and temperature

    International Nuclear Information System (INIS)

    Using the literature raw data of the speed of sound and the specific volume, the isothermal compressibility, κT, a second derivative thermodynamic quantity of G, was evaluated for liquid H2O in the pressure range up to 350 MPa and the temperature to 50 ºC. We then obtained its pressure derivative, dκT/dp, a third derivative numerically without using a fitting function to the κT data. On taking yet another p-derivative at a fixed T graphically without resorting to any fitting function, the resulting d2κT/dp2, a fourth derivative, showed a weak but clear step anomaly, with the onset of the step named point X and its end point Y. In analogy with another third and fourth derivative pair in binary aqueous solutions of glycerol, dαp/dxGly and d2αp/dxGly2, at 0.1 MPa (αp is the thermal expansivity and xGly the mole fraction of solute glycerol) in our recent publication [J. Solution Chem. 43, 663-674 (2014); DOI:10.1007/s10953-013-0122-7], we argue that there is a gradual crossover in the molecular organization of pure H2O from a low to a high p-regions starting at point X and ending at Y at a fixed T. The crossover takes place gradually spanning for about 100 MPa at a fixed temperature. The extrapolated temperature to zero p seems to be about 70 – 80 °C for points X and 90 – 110 °C for Y. Furthermore, the mid-points of X and Y seem to extrapolate to the triple point of liquid, ice Ih and ice III. Recalling that the zero xGly extrapolation of point X and Y for binary aqueous glycerol at 0.1 MPa gives about the same T values respectively, we suggest that at zero pressure the region below about 70 °C the hydrogen bond network is bond-percolated, while above about 90 ºC there is no hydrogen bond network. Implication of these findings is discussed

  20. Two high-field thermodynamically stable conductivity states in photoconductive CdS, one n-type and one p-type

    Energy Technology Data Exchange (ETDEWEB)

    Böer, Karl W. [Department of Physics and Astronomy, 217 Sharp Lab, University of Delaware, Newark, Delaware 19716 (United States)

    2015-08-28

    Photoconductive CdS is known to be n-type and develops high-field domains in the range of negative differential conductivities. These domains have been extensively discussed, and when remaining attached to the electrodes have been renamed Böer domains (a broader definition suggested earlier is misleading) [K. Thiessen, Phys. Status Solidi B 248, 2775 (2011)]. They are occurring at high applied voltage in a range at which the current becomes highly non-ohmic that is conventionally described as N-shaped when the conductance decreases with increasing bias or as S-shaped when the current starts to increase again. In this paper only such cases will be discussed in which the current stays below significant Joule heating (no current channel formation), and only for stationary electrode-attached high-field domains. These are the cathode-attached domains that are maintained by field-quenching and are thermodynamically stable. Their finding is summarized in the first segment of this paper. When the applied voltage is increased, an anode-attached hyper-high-field domain develops that is stabilized by a hole blocking anode and will be analyzed in more detail below. It will be shown that they are a thermodynamically stable p-type photoconductive state of CdS. These two new states can be used to determine the carrier densities and mobilities as function of the field and the effective work function in dependence of the spectral distribution of the optical excitation. In a thin slab adjacent to a blocking cathode, the quasi-Fermi levels are spread to a precise amount and are kept there in the entire high-field region. This opens the opportunity to analyze with small modulation of the excitation the trap transition coefficients near these quasi-Fermi levels separately, without broadening interference from other signals. This has already resulted in the discovery of an unusually sharp electron quenching level when the CdS was in a p-type state with an anode adjacent domain. It is

  1. Two high-field thermodynamically stable conductivity states in photoconductive CdS, one n-type and one p-type

    Science.gov (United States)

    Böer, Karl W.

    2015-08-01

    Photoconductive CdS is known to be n-type and develops high-field domains in the range of negative differential conductivities. These domains have been extensively discussed, and when remaining attached to the electrodes have been renamed Böer domains (a broader definition suggested earlier is misleading) [K. Thiessen, Phys. Status Solidi B 248, 2775 (2011)]. They are occurring at high applied voltage in a range at which the current becomes highly non-ohmic that is conventionally described as N-shaped when the conductance decreases with increasing bias or as S-shaped when the current starts to increase again. In this paper only such cases will be discussed in which the current stays below significant Joule heating (no current channel formation), and only for stationary electrode-attached high-field domains. These are the cathode-attached domains that are maintained by field-quenching and are thermodynamically stable. Their finding is summarized in the first segment of this paper. When the applied voltage is increased, an anode-attached hyper-high-field domain develops that is stabilized by a hole blocking anode and will be analyzed in more detail below. It will be shown that they are a thermodynamically stable p-type photoconductive state of CdS. These two new states can be used to determine the carrier densities and mobilities as function of the field and the effective work function in dependence of the spectral distribution of the optical excitation. In a thin slab adjacent to a blocking cathode, the quasi-Fermi levels are spread to a precise amount and are kept there in the entire high-field region. This opens the opportunity to analyze with small modulation of the excitation the trap transition coefficients near these quasi-Fermi levels separately, without broadening interference from other signals. This has already resulted in the discovery of an unusually sharp electron quenching level when the CdS was in a p-type state with an anode adjacent domain. It is

  2. Two high-field thermodynamically stable conductivity states in photoconductive CdS, one n-type and one p-type

    International Nuclear Information System (INIS)

    Photoconductive CdS is known to be n-type and develops high-field domains in the range of negative differential conductivities. These domains have been extensively discussed, and when remaining attached to the electrodes have been renamed Böer domains (a broader definition suggested earlier is misleading) [K. Thiessen, Phys. Status Solidi B 248, 2775 (2011)]. They are occurring at high applied voltage in a range at which the current becomes highly non-ohmic that is conventionally described as N-shaped when the conductance decreases with increasing bias or as S-shaped when the current starts to increase again. In this paper only such cases will be discussed in which the current stays below significant Joule heating (no current channel formation), and only for stationary electrode-attached high-field domains. These are the cathode-attached domains that are maintained by field-quenching and are thermodynamically stable. Their finding is summarized in the first segment of this paper. When the applied voltage is increased, an anode-attached hyper-high-field domain develops that is stabilized by a hole blocking anode and will be analyzed in more detail below. It will be shown that they are a thermodynamically stable p-type photoconductive state of CdS. These two new states can be used to determine the carrier densities and mobilities as function of the field and the effective work function in dependence of the spectral distribution of the optical excitation. In a thin slab adjacent to a blocking cathode, the quasi-Fermi levels are spread to a precise amount and are kept there in the entire high-field region. This opens the opportunity to analyze with small modulation of the excitation the trap transition coefficients near these quasi-Fermi levels separately, without broadening interference from other signals. This has already resulted in the discovery of an unusually sharp electron quenching level when the CdS was in a p-type state with an anode adjacent domain. It is

  3. Determination of the number of atoms present in nano contact based on shot noise measurements with highly stable nano-fabricated electrodes

    Science.gov (United States)

    Takahashi, Ryoji; Kaneko, Satoshi; Marqués-González, Santiago; Fujii, Shintaro; Nishino, Tomoaki; Tsukagoshi, Kazuhito; Kiguchi, Manabu

    2016-07-01

    A highly stable experimental setup was developed for the measurement of shot noise in atomic contacts and molecular junctions to determine the number of atoms or molecules present. The use of a nano-fabricated mechanically controllable break junction (MCBJ) electrode improved the overall stability of the experimental setup. The improved stability of the system and optimization of measurement system enabled us to comprehensively investigate the shot noise as well as charge transport properties in Au atomic contacts and molecular junctions. We present a solid proof that the number of atoms (cross sectional atom) in the Au atomic contacts was exactly one. In the atomic contacts, contribution from the additional channels was under the detection limit. Furthermore, the effect of molecular adsorption on the charge transport in the Au atomic contact was investigated. Additional transport channels were opened by exposing pyrazine molecules to the Au contacts, which gave rise to an increase in the Fano factor in the shot noise.

  4. Solution-processable, photo-stable, low-threshold, and broadly tunable thin film organic lasers based on novel high-performing laser dyes

    Science.gov (United States)

    Díaz-García, María. A.; Morales-Vidal, Marta; Ramírez, Manuel G.; Villalvilla, José M.; Boj, Pedro G.; Quintana, José A.; Retolaza, A.; Merino, S.

    2015-09-01

    Thin film organic lasers (TFOLs) represent a new generation of inexpensive, mechanically flexible devices with demonstrated applicability in numerous applications in the fields of spectroscopy, optical communications and sensing requiring an organic, efficient, stable, wavelength-tunable and solution-processable laser material. A distributed feedback (DFB) laser is a particularly attractive TFOL because it shows single mode emission, low pump energy, easy integration with other devices, mechanical flexibility and potentially low production cost. Here, amplified spontaneous emission (ASE) and DFB laser applications of novel high performing perylene dyes and p-phenylenevinylene (PV) oligomers, both dispersed in thermoplastic polymers, used as passive matrixes, are reported. Second-order DFB lasers based on these materials show single mode emission, wavelength tunability across the visible spectrum, operational lifetimes of >105 pump pulses, larger than previously reported PV oligomers or polymers, and thresholds close to pumping requirements with light-emitting diodes.

  5. Determination of the number of atoms present in nano contact based on shot noise measurements with highly stable nano-fabricated electrodes.

    Science.gov (United States)

    Takahashi, Ryoji; Kaneko, Satoshi; Marqués-González, Santiago; Fujii, Shintaro; Nishino, Tomoaki; Tsukagoshi, Kazuhito; Kiguchi, Manabu

    2016-07-22

    A highly stable experimental setup was developed for the measurement of shot noise in atomic contacts and molecular junctions to determine the number of atoms or molecules present. The use of a nano-fabricated mechanically controllable break junction (MCBJ) electrode improved the overall stability of the experimental setup. The improved stability of the system and optimization of measurement system enabled us to comprehensively investigate the shot noise as well as charge transport properties in Au atomic contacts and molecular junctions. We present a solid proof that the number of atoms (cross sectional atom) in the Au atomic contacts was exactly one. In the atomic contacts, contribution from the additional channels was under the detection limit. Furthermore, the effect of molecular adsorption on the charge transport in the Au atomic contact was investigated. Additional transport channels were opened by exposing pyrazine molecules to the Au contacts, which gave rise to an increase in the Fano factor in the shot noise. PMID:27291763

  6. Online stable carbon isotope ratio measurement in formic acid, acetic acid, methanol and ethanol in water by high performance liquid chromatography-isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    A suitable analysis condition was determined for high performance liquid chromatography-isotope ratio mass spectrometry (HPLC-IRMS) while making sequential measurements of stable carbon isotope ratios of δ13C in formic acid, acetic acid, methanol and ethanol dissolved in water. For this online column separation method, organic reagents are not applicable due to carbon contamination; thus, water and KH2PO4 at low concentrations were tested as mobile phase in combination with a HyPURITY AQUASTARTM column. Formic acid, acetic acid, methanol and ethanol were separated when 2 mM KH2PO4 aqueous solution was used. Under the determined analysis condition for HPLC-IRMS, carbon concentrations could be measured quantitatively as well as carbon isotope ratio when carbon concentration was higher than 0.4 mM L for each chemical

  7. Periodic nanostructures imprinted on high-temperature stable sol–gel films by ultraviolet-based nanoimprint lithography for photovoltaic and photonic applications

    International Nuclear Information System (INIS)

    Nanostructured sol–gel films with high-temperature stability are used in the area of electronics, photonics or biomimetic materials as light-trapping architectures in solar cells, displays, waveguides or as superhydrophobic surfaces with a lotus effect. In this work, high-temperature stable 2-μm nanostructured surfaces were prepared by ultraviolet-based nanoimprint lithography using an alkoxysilane binder incorporating modified silica nanoparticles. Material densification during thermal curing and microstructural evolution which are destined for a high structural fidelity of nanostructured films were investigated in relation to precursor chemistry, particle morphology and particle content of the imprint resist. The mechanism for densification and shrinkage of the films was clarified and correlated with the structural fidelity to explain the influence of the geometrical design on the optical properties. A high internal coherence of the microstructure of the nanostructured films results in a critical film thickness of > 5 μm. The structured glassy layers with high inorganic content show thermal stability up to 800 °C and have a high structural fidelity > 90% with an axial shrinkage of 16% and a horizontal shrinkage of 1%. This material allows the realization of highly effective light-trapping architectures for polycrystalline silicon thin-film solar cells on glass but also for the preparation of 2D photonic crystals for telecommunication wavelengths. - Highlights: • Fundamental research • Hybrid sol–gel material with high-temperature stability and contour accuracy • Ensuring of cost-efficient and industrially feasible processing • Application in photonic and photovoltaic

  8. Periodic nanostructures imprinted on high-temperature stable sol–gel films by ultraviolet-based nanoimprint lithography for photovoltaic and photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Back, Franziska [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany); Bockmeyer, Matthias; Rudigier-Voigt, Eveline [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Löbmann, Peer [Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany)

    2014-07-01

    Nanostructured sol–gel films with high-temperature stability are used in the area of electronics, photonics or biomimetic materials as light-trapping architectures in solar cells, displays, waveguides or as superhydrophobic surfaces with a lotus effect. In this work, high-temperature stable 2-μm nanostructured surfaces were prepared by ultraviolet-based nanoimprint lithography using an alkoxysilane binder incorporating modified silica nanoparticles. Material densification during thermal curing and microstructural evolution which are destined for a high structural fidelity of nanostructured films were investigated in relation to precursor chemistry, particle morphology and particle content of the imprint resist. The mechanism for densification and shrinkage of the films was clarified and correlated with the structural fidelity to explain the influence of the geometrical design on the optical properties. A high internal coherence of the microstructure of the nanostructured films results in a critical film thickness of > 5 μm. The structured glassy layers with high inorganic content show thermal stability up to 800 °C and have a high structural fidelity > 90% with an axial shrinkage of 16% and a horizontal shrinkage of 1%. This material allows the realization of highly effective light-trapping architectures for polycrystalline silicon thin-film solar cells on glass but also for the preparation of 2D photonic crystals for telecommunication wavelengths. - Highlights: • Fundamental research • Hybrid sol–gel material with high-temperature stability and contour accuracy • Ensuring of cost-efficient and industrially feasible processing • Application in photonic and photovoltaic.

  9. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  10. Phoenix dactylifera (date palm) pit aqueous extract mediated novel route for synthesis high stable silver nanoparticles with high antifungal and antibacterial activity.

    Science.gov (United States)

    Khatami, Mehrdad; Pourseyedi, Shahram

    2015-08-01

    The biological synthesis of silver nanoparticles (AgNPs) was conducted using date palm pit aqueous extract. The first visible sign of the synthesis of AgNPs was the change in colour of reaction mixtures from yellowish to reddish brown. The resulting synthesised AgNPs were characterised using UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The UV-visible spectra gave surface plasmon resonance at 428 nm. XRD confirmed that the silver particles formed in our experiments were in the form of nanocrystals. TEM images revealed the formation of AgNPs with spherical shape and sizes in the range between 1-40 nm. DLS showed nanoparticles with an average size of 27 nm. Fourier transform infrared spectroscopy indicated the role of different possible functional groups (carboxyl, amine, aromatic and hydroxyl) in the formation of AgNPs. AgNPs were stable at 28°C in vitro for over a year without any precipitation or decreased production of antimicrobial effect. Then, the antifungal and antibacterial activities of synthesised AgNPs were investigated. The synthesised AgNPs showed significant inhibitory effects on Rhizoctonia solani (AG2_2) cultures, so that the concentration of 25 µg/ml prevented approximately 83% of the mycelium growth of the fungus. Then, the broth macro-dilution method was used for examining antibacterial effect of AgNPs. The minimum inhibitory concentration and minimum bactericide concentration against Klebsiella pneumonia (PCI 602) and Acinetobacter baumannii (ATCC 19606) were recorded as 1.56 and 3.12 µg/ml AgNPs, respectively. PMID:26224347

  11. Moisture-Stable Zn(II) Metal-Organic Framework as a Multifunctional Platform for Highly Efficient CO2 Capture and Nitro Pollutant Vapor Detection.

    Science.gov (United States)

    Chen, Di-Ming; Tian, Jia-Yue; Chen, Min; Liu, Chun-Sen; Du, Miao

    2016-07-20

    A moisture-stable three-dimensional (3D) metal-organic framework (MOF), {(Me2NH2)[Zn2(bpydb)2(ATZ)](DMA)(NMF)2}n (1, where bpydb = 4,4'-(4,4'-bipyridine-2,6-diyl)dibenzoate, ATZ = deprotonated 5-aminotetrazole, DMA = N,N-dimethylacetamide, and NMF = N-methylformamide), with uncoordinated N-donor sites and charged framework skeleton was fabricated. This MOF exhibits interesting structural dynamic upon CO2 sorption at 195 K and high CO2/N2 (127) and CO2/CH4 (131) sorption selectivity at 298 K and 1 bar. Particularly, its CO2/CH4 selectivity is among the highest MOFs for selective CO2 separation. The results of Grand Canonical Monte Carlo (GCMC) simulation indicate that the polar framework contributes to the strong framework-CO2 binding at zero loading, and the tetrazole pillar contributes to the high CO2 uptake capacity at high loading. Furthermore, the solvent-responsive luminescent properties of 1 indicate that it could be utilized as a fluorescent sensor to detect trace amounts of nitrobenzene in both solvent and vapor systems. PMID:27340895

  12. Facile synthesis of high-temperature (1000 °C) phase-stable rice-like anatase TiO2 nanocrystals

    International Nuclear Information System (INIS)

    High-temperature phase-stable rice-like anatase TiO2 nanocrystals were synthesized by one-pot solvothermal method using soluble titania xerogel and isopropyl alcohol (IPA) as the precursor and the solvent, respectively. Sample characterization was carried out by powder X-ray diffraction, high-resolution transmission electron microscopy, field emission scanning electron microscope, X-ray photoelectron spectroscopy, and N2 adsorption–desorption isotherms. The results showed that TiO2 nanocrystals had rice-like shapes with an average size of 5 nm in width and 35 nm in length. The BET surface area was 153 m2/g. Unexpectedly, the rice-like TiO2 nanocrystals exhibited high-temperature phase stability, which could remain as pure anatase phase after calcinations at 1000 °C. Growth mechanism investigation revealed that the IPA solvent played a key role in nucleation and growth of rice-like anatase TiO2 nanocrystals. The photodegradation of rhodamine B demonstrated that rice-like anatase TiO2 nanocrystals exhibited enhanced photocatalytic activity under visible light irradiation

  13. Constructing heterostructure on highly roughened caterpillar-like gold nanotubes with cuprous oxide grains for ultrasensitive and stable nonenzymatic glucose sensor.

    Science.gov (United States)

    Chen, Anran; Ding, Yu; Yang, Zhimao; Yang, Shengchun

    2015-12-15

    In this study, a metal-metal oxide heterostructure was designed and constructed by growing cuprous oxide (Cu2O) grains on highly surface roughened caterpillar-like Au nanotubes (CLGNs) for ultrasensitive, selective and stable nonenzymatic glucose biosensors. The Cu2O grains are tightly anchored to the surface of CLGNs by the spines, resulting in a large increase in the contact area between Cu2O grains and the CLGNs, which facilitates the electron transport between metal and metal oxide and improves the sensitivity and stability of the sensors. The electron transfer coefficient (α) and electron transfer rate constant (ks) for redox reaction of Cu2O-CLGNs/GCE are found to be 0.50114 and 3.24±0.1 s(-1), respectively. The biosensor shows a linear response to glucose over a concentration range of 0.1-5mM and a high sensitivity of 1215.7 µA mM(-1) cm(-2) with a detection limit of 1.83 μM. Furthermore, the Cu2O-CLGNs biosensor exhibited strong anti-interference capability against uric acid (UA), ascorbic acid (AA), potassium chloride (KCl) and sodium ascorbate (SA), as well as a high stability and repeatability. Our current research indicates that the Cu2O-CLGNs hybrid electrode is a promising choice for constructing nonenzyme based electrochemical biosensors. PMID:26258877

  14. Morphology controlled synthesis of layered NH4V4O10 and the impact of binder on stable high rate electrochemical performance

    International Nuclear Information System (INIS)

    Highlights: • Present work focus on new synthesis process for development of NH4V4O10 cathode material for lithium storage application. Herein, we report for the first time improved and stable electrochemical performance of NH4V4O10 material without composite formation or insitu conductive coating at high rate with the use of interactive binder like sodium salt of carboxymethyl cellulose (CMC), and alginate (sodium salt of alginic acid). - Abstract: Rich electrochemistry of vanadium based compounds in terms of high lithium storage capability along with low cost prompted us to study NH4V4O10 as cathode material for lithium ion batteries. Herein, we report for the first time, a high rate and high energy density cathode based on intercalated ammonium vanadate. The present strategy of making such high rate cathode is mainly based on the use of interactive binder like carboxy methyl cellulose (CMC) or alginate binder instead of poly(vinylidene difluride) (PVDF) binder along with 2D morphology. A detailed study shows the dependency of morphology, reaction pH and binder selection on electrochemical performance. In brief, we have demonstrated NH4V4O10-CMC/alginate based cathode as superior candidate for next generation lithium-ion batteries. The as synthesized NH4V4O10 along with CMC/alginate binder delivers discharge capacity of 200 mAh g−1 at very high current rate of 1000 mA g−1 and completely retains its original discharge state at low current rate of 100 mA g−1 rate, whereas PVDF-based cathode delivers discharge capacity of 125 mAh g−1 at same current rate. Based on morphological and FT-IR studies, we have revealed interactions between active materials and binder particles (CMC and alginate) which play a crucial role in determining the electrochemical performance

  15. The high Andes, gene flow and a stable hybrid zone shape the genetic structure of a wide-ranging South American parrot

    Directory of Open Access Journals (Sweden)

    Schaefer H Martin

    2011-06-01

    Full Text Available Abstract Background While the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints. In southern South America, the Andes (here up to 6,900 m may constitute a formidable barrier to dispersal. In addition, this region was affected by cycles of intercalating arid/moist periods during the Upper/Late Pleistocene and Holocene. These factors may have been crucial in driving the phylogeographic structure of the vertebrate fauna of the region. Here we test these hypotheses in the burrowing parrot Cyanoliseus patagonus (Aves, Psittaciformes across its wide distributional range in Chile and Argentina. Results Our data show a Chilean origin for this species, with a single migration event across the Andes during the Upper/Late Pleistocene, which gave rise to all extant Argentinean mitochondrial lineages. Analyses suggest a complex population structure for burrowing parrots in Argentina, which includes a hybrid zone that has remained stable for several thousand years. Within this zone, introgression by expanding haplotypes has resulted in the evolution of an intermediate phenotype. Multivariate regressions show that present day climatic variables have a strong influence on the distribution of genetic heterogeneity, accounting for almost half of the variation in the data. Conclusions Here we show how huge barriers like the Andes and the regional environmental conditions imposed constraints on the ability of a parrot species to colonise new habitats, affecting the way in which populations diverged and thus, genetic structure. When contact between divergent populations was re-established, a stable hybrid zone was formed, functioning as a channel for genetic exchange between populations.

  16. Stable and high-quality Al-doped ZnO films with ICP-assisted facing targets sputtering at low temperature

    International Nuclear Information System (INIS)

    FTS (facing targets sputtering) has been studied intensively for high-quality TCO films in low-temperature processes. In this study, we designed ICP-assisted FTS process for high-quality Al-doped ZnO film synthesis in a low temperature process. A one-turn ICP coil was installed a few cm above the upper target edge through which hydrogen was introduced and fully dissociated to the atomic radicals. The increase of ICP power caused heating and rarefaction of Ar gas and generated abundant hydrogen atoms and hydrogenated molecules. In FESEM analysis, the films synthesized with high ICP power showed high crystallinity. XPS was used to analyze the film structure. In O1s spectra, the low binding energy component located at ∼530.3 ± 0.4 eV corresponding to O2− ions on the wurtzite structure of the hexagonal Zn2+ ion array increased with the ICP power, indicating good crystal quality. With increasing ICP power fixing while fixing the RF power at the cathode, the resistivity was observed to decrease to 5 × 10−4 Ω-cm. For thermal reliability tests, films were stored in an air-based chamber at 200 °C. The films synthesized without ICP showed rapid degradation in the electrical properties, while the films synthesized with high ICP power showed good stabilities with little change in the electrical properties after 30 h of storage in an oven. By adding hydrogen, the carrier concentration of the films increased, while the mobility did not change much. From these results, it is expected that hydrogen was incorporated into the film as a stable n-dopant by using an auxiliary ICP plasma source. (papers)

  17. Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers.

    Science.gov (United States)

    Kim, Sok; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-08-01

    Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28±13.15mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume. PMID:27045623

  18. A highly sensitive and stable electrochemical sensor for simultaneous detection towards ascorbic acid, dopamine, and uric acid based on the hierarchical nanoporous PtTi alloy.

    Science.gov (United States)

    Zhao, Dianyun; Yu, Guolong; Tian, Kunlong; Xu, Caixia

    2016-08-15

    In current work highly sensitive and stable electrochemical sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is constructed based on the hierarchical nanoporous (HNP) PtTi alloy. The HNP-PtTi alloy is simply fabricated by two-step dealloying process, characterized by the bimodal ligament/pore size distributions and interconnected hollow channels. The HNP structure with the advantages of large surface area, excellent structure stability, and rich pore channels is used for facilitating the electron conductivity and the mass transfer. Combined with the dual effects of the bimodal nanoporous architecture and the excellent electrocatalytic activity of PtTi alloy, the constructed sensor exhibits high electrochemical sensing activity with wide linear responses from 0.2 to 1mM, 0.004 to 0.5mM, and 0.1 to 1mM for simultaneous detection of AA, DA, and UA, respectively. In addition, HNP-PtTi alloy also shows long-term sensing stability towards the AA, DA, and UA detection and behaves as a good anti-interference towards NaCl, KCl, FeCl3, CuCl2, AlCl3, glucose, and H2O2. The HNP-PtTi alloy manifests intriguing application potential as the candidate for the application of the electrochemical sensor for simultaneous detection of AA, DA, and UA. PMID:27058442

  19. Highly stable rice-straw-derived charcoal in 3700-year-old ancient paddy soil: evidence for an effective pathway toward carbon sequestration.

    Science.gov (United States)

    Wu, Mengxiong; Yang, Min; Han, Xingguo; Zhong, Ting; Zheng, Yunfei; Ding, Pin; Wu, Weixiang

    2016-01-01

    Recalcitrant charcoal application is predicted to decelerate global warming through creating a long-term carbon sink in soil. Although many studies have showed high stability of charcoal derived from woody materials, few have focused on the dynamics of straw-derived charcoal in natural environment on a long timescale to evaluate its potential for agricultural carbon sequestration. Here, we examined straw-derived charcoal in an ancient paddy soil dated from ~3700 calendar year before present (cal. year BP). Analytical results showed that soil organic matter consisted of more than 25% of charcoal in charcoal-rich layer. Similarities in morphology and molecular structure between the ancient and the fresh rice-straw-derived charcoal indicated that ancient charcoal was derived from rice straw. The lower carbon content, higher oxygen content, and obvious carbonyl of the ancient charcoal compared with fresh rice straw charcoal implied that oxidation occurred in the scale of thousands years. However, the dominant aromatic C of ancient charcoal indicated that rice-straw-derived charcoal was highly stable in the buried paddy soil due to its intrinsic chemical structures and the physical protection of ancient paddy wetland. Therefore, it may suggest that straw charcoal application is a potential pathway for C sequestration considering its longevity. PMID:25850742

  20. Synergistic Na-storage reactions in Sn4P3 as a high-capacity, cycle-stable anode of Na-ion batteries.

    Science.gov (United States)

    Qian, Jiangfeng; Xiong, Ya; Cao, Yuliang; Ai, Xinping; Yang, Hanxi

    2014-01-01

    Room-temperature Na-ion batteries have attracted great interest as a low cost and environmentally benign technology for large scale electric energy storage, however their development is hindered by the lack of suitable anodic host materials. In this paper, we described a green approach for the synthesis of Sn4P3/C nanocomposite and demonstrated its excellent Na-storage performance as a novel anode of Na-ion batteries. This Sn4P3/C anode can deliver a very high reversible capacity of 850 mA h g(-1) with a remarkable rate capability with 50% capacity output at 500 mA g(-1) and can also be cycled with 86% capacity retention over 150 cycles due to a synergistic Na-storage mechanism in the Sn4P3 anode, where the Sn nanoparticles act as electronic channels to enable electrochemical activation of the P component, while the elemental P and its sodiated product Na3P serve as a host matrix to alleviate the aggregation of the Sn particles during Na insertion reaction. This mechanism may offer a new approach to create high capacity and cycle-stable alloy anodes for Na-ion batteries and other electrochemical energy storage applications. PMID:24611662

  1. The Use of an Edible Mushroom-Derived Renewable Carbon Material as a Highly Stable Electrocatalyst towards Four-Electron Oxygen Reduction

    Directory of Open Access Journals (Sweden)

    Chaozhong Guo

    2015-12-01

    Full Text Available The development of highly stable and efficient electrocatalysts for sluggish oxygen reduction reaction (ORR is exceedingly significant for the commercialization of fuel cells but remains a challenge. We here synthesize a new nitrogen-doped biocarbon composite material (N-BC@CNP-900 as a nitrogen-containing carbon-based electrocatalyst for the ORR via facile all-solid-state multi-step pyrolysis of bioprotein-enriched enoki mushroom as a starting material, and inexpensive carbon nanoparticles as the inserting matrix and conducting agent at controlled temperatures. Results show that the N-BC@CNP-900 catalyst exhibits the best ORR electrocatalytic activity with an onset potential of 0.94 V (versus reversible hydrogen electrode, RHE and high stability. Meanwhile, this catalyst significantly exhibits good selectivity of the four-electron reaction pathway in an alkaline electrolyte. It is notable that pyridinic- and graphtic-nitrogen groups that play a key role in the enhancement of the ORR activity may be the catalytically active structures for the ORR. We further propose that the pyridinic-nitrogen species can mainly stabilize the ORR activity and the graphitic-nitrogen species can largely enhance the ORR activity. Besides, the addition of carbon support also plays an important role in the pyrolysis process, promoting the ORR electrocatalytic activity.

  2. A Novel Gene Expression Control System and Its Use in Stable, High-Titer 293 Cell-Based Adeno-Associated Virus Packaging Cell Lines

    Science.gov (United States)

    Qiao, Chunping; Wang, Bing; Zhu, Xiaodong; Li, Juan; Xiao, Xiao

    2002-01-01

    Previous attempts to establish 293cell-based stable and high-titer adeno-associated virus (AAV) packaging cell lines were unsuccessful, primarily due to adenovirus E1-activated Rep gene expression, which exerts cytostatic and cytotoxic effects on the host cells. Control of the two large AAV Rep proteins (Rep78/68) was insufficient to eliminate the adverse effects, because of the leaky expression of the two small Rep proteins (Rep52/40). However, it was unsuccessful to control Rep52/40 gene expression since its promoter is located within the coding sequence of Rep78/68. To tightly regulate all four Rep proteins by using their own promoters, we have developed a novel gene control paradigm termed “dual splicing switch,” which disrupts all four Rep genes by inserting into their shared coding region an intron that harbors transcription termination sequences flanked the LoxP sites. As a result, the structure and activities of the Rep gene promoters, both p5 and p19, are not affected; however, all of the Rep transcripts are prematurely terminated and the genes were inactivated. Removal of the terminator by Cre protein reactivates the transcription of all four Rep proteins derived from their own promoters. This switch system was initially tested in the lacZ gene and a 600-fold induction of β-galactosidase activity was observed. Using the dual splicing switch strategy, we have subsequently established a number of AAV packaging cell lines from 293 cells, which showed a normal growth rate, high stability, and more importantly, high yields of AAV vectors. Such a gene control paradigm is also useful for other viruses, e.g., autonomous parvoviruses. Finally, the high-titer 293-based AAV packaging cell lines should greatly reduce the risk of wild-type adenovirus contamination and provide a scalable AAV vector production method for both preclinical and clinical studies. PMID:12438627

  3. Stable solid and aqueous H2CO3 from CO2 and H2O at high pressure and high temperature.

    Science.gov (United States)

    Wang, Hongbo; Zeuschner, Janek; Eremets, Mikhail; Troyan, Ivan; Willams, Jonathan

    2016-01-01

    Carbonic acid (H2CO3) forms in small amounts when CO2 dissolves in H2O, yet decomposes rapidly under ambient conditions of temperature and pressure. Despite its fleeting existence, H2CO3 plays an important role in the global carbon cycle and in biological carbonate-containing systems. The short lifetime in water and presumed low concentration under all terrestrial conditions has stifled study of this fundamental species. Here, we have examined CO2/H2O mixtures under conditions of high pressure and high temperature to explore the potential for reaction to H2CO3 inside celestial bodies. We present a novel method to prepare solid H2CO3 by heating CO2/H2O mixtures at high pressure with a CO2 laser. Furthermore, we found that, contrary to present understanding, neutral H2CO3 is a significant component in aqueous CO2 solutions above 2.4 GPa and 110 °C as identified by IR-absorption and Raman spectroscopy. This is highly significant for speciation of deep C-O-H fluids with potential consequences for fluid-carbonate-bearing rock interactions. As conditions inside subduction zones on Earth appear to be most favorable for production of aqueous H2CO3, a role in subduction related phenomena is inferred. PMID:26813580

  4. Highly Stable Zr(IV)-Based Metal-Organic Frameworks for the Detection and Removal of Antibiotics and Organic Explosives in Water.

    Science.gov (United States)

    Wang, Bin; Lv, Xiu-Liang; Feng, Dawei; Xie, Lin-Hua; Zhang, Jian; Li, Ming; Xie, Yabo; Li, Jian-Rong; Zhou, Hong-Cai

    2016-05-18

    Antibiotics and organic explosives are among the main organic pollutants in wastewater; their detection and removal are quite important but challenging. As a new class of porous materials, metal-organic frameworks (MOFs) are considered as a promising platform for the sensing and adsorption applications. In this work, guided by a topological design approach, two stable isostructural Zr(IV)-based MOFs, Zr6O4(OH)8(H2O)4(CTTA)8/3 (BUT-12, H3CTTA = 5'-(4-carboxyphenyl)-2',4',6'-trimethyl-[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid) and Zr6O4(OH)8(H2O)4(TTNA)8/3 (BUT-13, H3TTNA = 6,6',6″-(2,4,6-trimethylbenzene-1,3,5-triyl)tris(2-naphthoic acid)) with the the-a topological structure constructed by D4h 8-connected Zr6 clusters and D3h 3-connected linkers were designed and synthesized. The two MOFs are highly porous with the Brunauer-Emmett-Teller surface area of 3387 and 3948 m(2) g(-1), respectively. Particularly, BUT-13 features one of the most porous water-stable MOFs reported so far. Interestingly, these MOFs represent excellent fluorescent properties, which can be efficiently quenched by trace amounts of nitrofurazone (NZF) and nitrofurantoin (NFT) antibiotics as well as 2,4,6-trinitrophenol (TNP) and 4-nitrophenol (4-NP) organic explosives in water solution. They are responsive to NZF and TNP at parts per billion (ppb) levels, which are among the best performing luminescent MOF-based sensing materials. Simultaneously, both MOFs also display high adsorption abilities toward these organic molecules. It was demonstrated that the adsorption plays an important role in the preconcentration of analytes, which can further increase the fluorescent quenching efficiency. These results indicate that BUT-12 and -13 are favorable materials for the simultaneous selective detection and removal of specific antibiotics and organic explosives from water, being potentially useful in monitoring water quality and treating wastewater. PMID:27090616

  5. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  6. Development of a new highly conductive and thermomechanically stable complex membrane based on sulfonated polyimide/ionic liquid for high temperature anhydrous fuel cells

    Science.gov (United States)

    Deligöz, Hüseyin; Yılmazoğlu, Mesut

    The paper deals with the synthesis and characterization of a new type of acid doped highly conductive complex membrane based on sulfonated polyimide (sPI) and ionic liquid (IL) for high temperature anhydrous fuel cells. For this purpose, 2,4-diaminobenzene sulfonic acid (2,4-DABSA) is reacted with benzophenontetracarboxylic dianhydride (BTDA) to yield sulfonated poly(amic acid) (sPAA) intermediate. Subsequently, IL is added into sPAA to form an interaction between sulfonic acid and imidazolium group of IL followed by acid doping. The ionic conductivity of acid doped sPI/IL complex polymer membrane is higher than that of IL containing composite membranes reported in the literature (5.59 × 10 -2 S cm -1 at 180 °C). Furthermore, dynamic mechanical analysis (DMA) results of acid doped sPI/IL complex membrane show that the mechanical strength of the complex product is slightly changed until 350 °C due to the formation of ionic interactions between sulfonic acid groups of sPI and imidazolium groups of IL. Consequently, the ionic interaction not only provides high ionic conductivity with excellent thermomechanical properties (the storage module of 0.91 GPa at 300 °C) but also results in a positive effect in long term conductivity stability by blocking IL migration through the membrane.

  7. The effects of high intensity exercise during pulmonary rehabilitation on ventilatory parameters in people with moderate to severe stable COPD: a systematic review

    Directory of Open Access Journals (Sweden)

    Osterling K

    2014-10-01

    Full Text Available Kristin Osterling,1 Kimbly MacFadyen,1 Robert Gilbert,2 Gail Dechman1 1School of Physiotherapy, 2School of Health Sciences, Dalhousie University, Halifax, NS, Canada Objective: The objective of this systematic review was to determine whether people with moderate to severe COPD who are participating in pulmonary rehabilitation and exercising at high intensity demonstrate the changes in ventilatory parameters that are associated with decreased dyspnea. Data sources: The authors searched EMBASE, The Cochrane Library, and CINAHL databases up to December 2013 for relevant randomized control trials, systematic reviews, and observational studies. References of identified studies were also screened. Study selection: Studies conducted in a pulmonary rehabilitation setting that included education and exercise were included. Symptom-limited, graded exercise testing that measured tidal volume, respiratory rate, minute ventilation, and inspiratory capacity was required. The studies that contained these keywords in the title or the abstract were selected for further evaluation of the text. Disagreements between reviewers were resolved by consensus. Four studies met these inclusion criteria. Data extraction: Quality assessment and data extraction were performed independently by two reviewers. Risk of bias and quality was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. Data synthesis: Participants in three studies trained at high intensity (70%–80% maximum workload, demonstrating statistically significant changes in tidal volume and respiratory rate. One study did not demonstrate positive ventilatory benefits; however, participants may not have met the desired training intensity. Two studies reported improvement in dyspnea at submaximal exercise intensities. One study noted an increased maximum workload with no significant change in dyspnea at peak exercise. Conclusion: People with moderate to severe, stable COPD were able

  8. Beneficial metabolic actions of a stable GIP agonist following pre-treatment with a SGLT2 inhibitor in high fat fed diabetic mice.

    Science.gov (United States)

    Millar, P J B; Pathak, V; Moffett, R C; Pathak, N M; Bjourson, A J; O'Kane, M J; Flatt, P R; Gault, V A

    2016-01-15

    The purpose of the present study was to examine if a stable glucose-dependent insulinotropic polypeptide (GIP) agonist could exert beneficial metabolic control in diabetic mice which had been pre-treated with sodium-glucose-cotransporter-2 (SGLT2) inhibitor dapagliflozin (DAPA). High fat fed mice administered low dose streptozotocin (STZ) received vehicle, DAPA once-daily over 28 days, or DAPA once-daily for 14 days followed by (DAla(2))GIP once-daily for 14 days. Energy intake, body weight, glucose and insulin concentrations were measured at regular intervals. Glucose tolerance, insulin tolerance test, dual-energy X-ray absorptiometry (DEXA) and pancreatic histology were examined. Once-daily administration of (DAla(2))GIP for 14 days in high fat fed diabetic mice pre-treated with DAPA demonstrated significant decrease in body weight, blood glucose and increased insulin concentrations which were independent of changes in energy intake. Similarly, glucose tolerance, glucose-stimulated insulin secretion, insulin sensitivity and HOMA-β were significantly enhanced in (DAla(2))GIP-treated mice. DEXA analysis revealed sustained percentage body fat loss with no changes in lean mass, bone mineral content and density. Pancreatic immunohistochemical analysis revealed decreased islet number and increases in islet area, beta cell area and pancreatic insulin content. The DAPA-induced increase in alpha cell area was also reversed. Additional acute in vitro and in vivo experiments confirmed that the impaired action of (DAla(2))GIP under hyperglycaemic-induced conditions was significantly reversed by DAPA treatment. These data demonstrate that (DAla(2))GIP can exert beneficial metabolic control in high fat fed diabetic mice pre-treated with DAPA. The results highlight possibility of a targeted and personalized approach using a GIP agonist and SGLT2 inhibitor for the treatment of type 2 diabetes. PMID:26607806

  9. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  10. High-Quality Perovskite Films Grown with a Fast Solvent-Assisted Molecule Inserting Strategy for Highly Efficient and Stable Solar Cells.

    Science.gov (United States)

    Yuan, Shuai; Qiu, Zhiwen; Gao, Chaomin; Zhang, Hailiang; Jiang, Yanan; Li, Cuncheng; Yu, Jinghua; Cao, Bingqiang

    2016-08-31

    The performance of organolead halide perovskites based solar cells has been enhanced dramatically due to the morphology control of the perovskite films. In this paper, we present a fast solvent-assisted molecule inserting (S-AMI) strategy to grow high-quality perovskite film, in which the methylammonium iodide/2-propanol (MAI/IPA) solution is spin-coated onto a dimethylformamide (DMF) wetted mixed lead halide (PbX2) precursor film. The DMF can help the inserting of MAI molecules into the PbX2 precursor film and provide a solvent environment to help the grain growth of the perovskite film. The perovskite film grown by the S-AMI approach shows large and well-oriented grains and long carrier lifetime due to the reduced grain boundary. Solar cells constructed with these perovskite films yield an average efficiency over 17% along with a high average fill factor of 80%. Moreover, these unsealed solar cell devices exhibit good stability in an ambient atmosphere. PMID:27526617

  11. Microfluidic preparation of a highly active and stable catalyst by high performance of encapsulation of polyvinylpyrrolidone (PVP)-Pt nanoparticles in microcapsules.

    Science.gov (United States)

    Nam, Jin-Oh; Kim, Jongmin; Jin, Si Hyung; Chung, Young-Min; Lee, Chang-Soo

    2016-02-15

    The encapsulation of active metals in microcapsules would be highly advantageous in maintaining or improving the reaction performance of an array of widely used chemical reactions. However, conventional methods suffer from low uniformity, complicated fabrication steps, sintering, leaching, decline of catalytic activity, and/or poor reusability. Here, we report an efficient microfluidic approach to encapsulate Pt nanoparticle stabilized by polyvinylpyrrolidone (PVP) in photocurable double-emulsion droplets with semipermeable thin shells. The encapsulated catalysts are prepared by the in situ photopolymerization of a double emulsion. The rapid and exquisite microfluidics-based fabrication process successfully generates monodisperse microcapsules without loss of the PVP-Pt nanoparticles, which is the first demonstration of the microfluidic encapsulation of active metal with promising catalytic activity. Specifically, compared to quasi-homogeneous catalysis of PVP-Pt nanoparticles for 4-nitrophenol hydrogenation, the encapsulated PVP-Pt nanoparticles demonstrate excellent catalytic activity, a leaching-proof nature, and high reusability under the same reaction conditions. We envision that the approach described here may be an example of elegant catalyst design to efficiently overcome difficult problems in active-metal encapsulation and to dramatically enhance catalytic activity by taking advantage of the unique aspects of microfluidic methods. PMID:26624530

  12. Search for magnetic monopoles and stable particles with high electric charges in 8 TeV $pp$ collisions with the ATLAS detector

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Bjergaard, David Martin; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blanco, Jacobo Ezequiel; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Bogaerts, Joannes Andreas; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozic, Ivan; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bruscino, Nello; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabrera Urbán, Susana; Caforio, Davide; Cairo, Valentina; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Cardillo, Fabio; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Shion; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choi, Kyungeon; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Colasurdo, Luca; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cúth, Jakub; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey Rogers; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Mora, Jennifer; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; do Vale, Maria Aline Barros; Dobos, Daniel; Dobre, Monica; Doglioni, Caterina; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Feremenga, Last; Fernandez Martinez, Patricia; Fernandez Perez, Sonia; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Fletcher, Rob Roy MacGregor; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; French, Sky; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geich-Gimbel, Christoph; Geisler, Manuel Patrice; Gemme, Claudia; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghasemi, Sara; Ghazlane, Hamid; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Guan, Liang; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Yicheng; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Hall, David; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Haney, Bijan; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harrington, Robert; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Hejbal, Jiri; Helary, Louis; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Hengler, Christopher; Henkelmann, Steffen; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hinman, Rachel Reisner; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohlfeld, Marc; Hohn, David; Holmes, Tova Ray; Homann, Michael; Hong, Tae Min; Hooft van Huysduynen, Loek; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Qipeng; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansky, Roland; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Yi; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kajomovitz, Enrique; Kalderon, Charles William; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karamaoun, Andrew; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katre, Akshay; Katzy, Judith; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharlamov, Alexey; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kim, Hee Yeun; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; King, Matthew; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Knapik, Joanna; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumnack, Nils; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; Kyriazopoulos, Dimitrios; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, J örn Christian; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Liblong, Aaron; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Hao; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loew, Kevin Michael; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Looper, Kristina Anne; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Lösel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeda, Junpei; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maier, Thomas; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany; Mann, Alexander; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mantoani, Matteo; Mapelli, Livio; March, Luis; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazza, Simone Michele; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer Zu Theenhausen, Hanno; Middleton, Robin; Miglioranzi, Silvia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milesi, Marco; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mistry, Khilesh; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Monden, Ryutaro; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Mori, Daniel; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Mortensen, Simon Stark; Morton, Alexander; Morvaj, Ljiljana; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Mueller, Thibaut; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nomachi, Masaharu; Nomidis, Ioannis; Nooney, Tamsin; Noordeh, Emil; Norberg, Scarlet; Nordberg, Markus; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Ochoa-Ricoux, Juan Pedro; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Oide, Hideyuki; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onogi, Kouta; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palma, Alberto; Pan, Yibin; Panagiotopoulou, Evgenia; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Pauly, Thilo; Pearce, James; Pearson, Benjamin; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrucci, Fabrizio; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Pickering, Mark Andrew; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinfold, James; Pingel, Almut; Pires, Sylvestre; Pirumov, Hayk; Pitt, Michael; Pizio, Caterina; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Pluth, Daniel; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Prell, Soeren; Price, Darren; Price, Lawrence; Primavera, Margherita; Prince, Sebastien; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Ptacek, Elizabeth; Puddu, Daniele; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quarrie, David; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Raddum, Silje; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Rangel-Smith, Camila; Rauscher, Felix; Rave, Stefan; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Huan; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Jonatan; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Saddique, Asif; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sahinsoy, Merve; Saimpert, Matthias; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Salazar Loyola, Javier Esteban; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sammel, Dirk; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sasaki, Yuichi; Sato, Koji; Sauvage, Gilles; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaeffer, Jan; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Schiavi, Carlo; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitt, Stefan; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Seliverstov, Dmitry; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyedruhollah; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidebo, Per Edvin; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silver, Yiftah; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simon, Dorian; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinner, Malcolm Bruce; Skottowe, Hugh Philip; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Sokhrannyi, Grygorii; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopczak, Andre; Sopko, Bruno; Sopko, Vit; Sorin, Veronica; Sosa, David; Sosebee, Mark; Sotiropoulou, Calliope Louisa; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spanò, Francesco; Spearman, William Robert; Sperlich, Dennis; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; Spreitzer, Teresa; St Denis, Richard Dante; Stabile, Alberto; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Shuji; Tannenwald, Benjamin Bordy; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Frank; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Temple, Darren; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorov, Theodore; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turra, Ruggero; Turvey, Andrew John; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valderanis, Chrysostomos; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloce, Laurelle Maria; Veloso, Filipe; Velz, Thomas; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Tingting; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Wasicki, Christoph; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; Wharton, Andrew Mark; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, Alan; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winter, Benedict Tobias; Wittgen, Matthias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wu, Mengqing; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamada, Miho; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yuen, Stephanie P; Yurkewicz, Adam; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zeng, Qi; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Chen; Zhou, Lei; Zhou, Li; Zhou, Mingliang; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Živković, Lidija; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zwalinski, Lukasz

    2016-01-01

    A search for highly ionizing particles produced in proton-proton collisions at 8 TeV center-of-mass energy is performed by the ATLAS collaboration at the CERN Large Hadron Collider. The dataset used corresponds to an integrated luminosity of 7.0 fb$^{-1}$. A customized trigger significantly increases the sensitivity, permitting a search for such particles with charges and energies beyond what was previously accessible. No event is found in the signal region, leading to production cross-section upper limits in the mass range 200--2500 GeV for magnetic monopoles with magnetic charge in the range $0.5g_{D}<|g|<2.0g_{D}$, where $g_{D}$ is the Dirac charge, and for stable particles with electric charge in the range $10<|z|<60$. Model-dependent limits are presented in given pair-production scenarios, and model-independent limits are presented in fiducial regions of particle energy and pseudorapidity.

  13. A high resolution record of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the glacial inception

    Directory of Open Access Journals (Sweden)

    R. Schneider

    2013-04-01

    Full Text Available The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (δ13Catm, as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a highly resolved record of δ13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 yr BP. The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC and the Talos Dome ice cores in East Antarctica. We find an 0.4‰ offset between the mean δ13Catm level in the Penultimate (~140 000 yr BP and Last Glacial Maximum (~22 000 yr BP, which can be explained by either (i changes in the isotopic composition or (ii intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 yr, but with different phasing and magnitudes. Furthermore, a 5000 yr lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS 5.5 (120 000 yr BP. Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

  14. Temperature variability at Dürres Maar, Germany during the Migration Period and at High Medieval Times, inferred from stable carbon isotopes of Sphagnum cellulose

    Science.gov (United States)

    Moschen, R.; Kühl, N.; Peters, S.; Vos, H.; Lücke, A.

    2011-09-01

    This paper presents a high resolution reconstruction of local growing season temperature (GST) anomalies at Dürres Maar, Germany, spanning the last two millennia. The GST anomalies were derived from a stable carbon isotope time series of cellulose chemically extracted from Sphagnum leaves (δ13Ccellulose) separated from a kettle-hole peat deposit of several metres thickness. The temperature reconstruction is based on the Sphagnum δ13Ccellulose/temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period, marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times, the amplitude in the reconstructed temperature variability is most likely overestimated; nevertheless, above-average temperatures are obvious during this time span, which are followed by a temperature decrease. On the contrary, a pronounced Late Roman Climate Optimum, often described as similarly warm or even warmer as medieval times, could not be detected. The temperature signal of the Little Ice Age (LIA) is not preserved in Dürres Maar due to considerable peat cutting that takes place in the first half of the 19th century. The local GST anomalies show a remarkable agreement to northern hemispheric temperature reconstructions based on tree-ring datasets and are also in accordance with climate reconstructions on the basis of lake sediments, glacier advances and retreats, and historical datasets. Most notably, e.g., during the Early Middle Ages and at High Medieval Times, temperatures were neither low nor high in general. Rather high frequency temperature variability with multiple narrow intervals of below- and above-average temperatures at maximum lasting a few decades are reconstructed. Especially the

  15. High-resolution stable carbon isotope monitoring indicates variable flow dynamic patterns in a deep saline aquifer at the Ketzin pilot site (Germany)

    International Nuclear Information System (INIS)

    Highlights: • Isotopically very distinct kinds of CO2 are injected at the Ketzin pilot site. • We used these isotope variances at the injection well as a tracer input signal. • We found none of these signals at a monitored observation well. • This indicates that CO2 is immobilised at this point in the reservoir. • After immobilization, the δ13CCO2 value was altered by fractionation processes. - Abstract: Stable isotopes of injected CO2 act as useful tracers in carbon capture and storage (CCS) because the CO2 itself is the carrier of the tracer signal and remains unaffected by sorption or partitioning effects. At the Ketzin pilot site (Germany), carbon stable isotope composition (δ13C) of injected CO2 at the injection well was analyzed over a time period of 4 months. Occurring isotope variances resulted from the injection of CO2 from two different sources (an oil refinery and a natural gas-reservoir). The two gases differed in their carbon isotope composition by more than 27‰. In order to find identifiable patterns of these variances in the reservoir, more than 250 CO2-samples were collected and analyzed for their carbon isotope ratios at an observation well 100 m distant from the injection well. An isotope ratio mass spectrometer connected to a modified Thermo Gasbench system allowed quick and cost effective isotope analyses of a high number of CO2 gas specimens. CO2 gas from the oil refinery (δ13C = −30.9‰, source A) was most frequently injected and dominated the reservoir δ13C values at the injection site. Sporadic injection of the CO2 from the natural gas-reservoir (δ13C = −3.5‰, source B) caused isotope shifts of up to +5‰ at the injection well. These variances provided a potential ideal tracer for CO2 migration behavior. Based on these findings, tracer input signals that were injected during the last 2 years of injection could be reconstructed with the aid of an isotope mixing model and CO2 delivery schedules. However, in contrast to

  16. Long-term and high-frequency non-destructive monitoring of water stable isotope profiles in an evaporating soil column

    Science.gov (United States)

    Rothfuss, Y.; Merz, S.; Vanderborght, J.; Hermes, N.; Weuthen, A.; Pohlmeier, A.; Vereecken, H.; Brüggemann, N.

    2015-10-01

    The stable isotope compositions of soil water (δ2H and δ18O) carry important information about the prevailing soil hydrological conditions and for constraining ecosystem water budgets. However, they are highly dynamic, especially during and after precipitation events. In this study, we present an application of a method based on gas-permeable tubing and isotope-specific infrared laser absorption spectroscopy for in situ determination of soil water δ2H and δ18O. We conducted a laboratory experiment where a sand column was initially saturated, exposed to evaporation for a period of 290 days, and finally rewatered. Soil water vapor δ2H and δ18O were measured daily at each of eight available depths. Soil liquid water δ2H and δ18O were inferred from those of the vapor considering thermodynamic equilibrium between liquid and vapor phases in the soil. The experimental setup allowed for following the evolution of soil water δ2H and δ18O profiles with a daily temporal resolution. As the soil dried, we could also show for the first time the increasing influence of the isotopically depleted ambient water vapor on the isotopically enriched liquid water close to the soil surface (i.e., atmospheric invasion). Rewatering at the end of the experiment led to instantaneous resetting of the stable isotope profiles, which could be closely followed with the new method. From simple soil δ2H and δ18O gradients calculations, we showed that the gathered data allowed one to determinate the depth of the evaporation front (EF) and how it receded into the soil over time. It was inferred that after 290 days under the prevailing experimental conditions, the EF had moved down to an approximate depth of -0.06 m. Finally, data were used to calculate the slopes of the evaporation lines and test the formulation for kinetic isotope effects. A very good agreement was found between measured and simulated values (Nash and Sutcliffe efficiency, NSE = 0.92) during the first half of the

  17. High intraspecific variability in the diet of a deep-sea nematode: Stable isotope and fatty acid analyses of Deontostoma tridentum on Chatham Rise, Southwest Pacific

    Science.gov (United States)

    Leduc, Daniel; Brown, Julie C. S.; Bury, Sarah J.; Lörz, Anne-Nina

    2015-03-01

    Small deep-sea organisms may exhibit a high degree of intraspecific variability in diet due to their ability to exploit a wide range of food sources and patchiness in food availability. Trophic interactions of small deep-sea benthic organisms, however, remain poorly understood. Here we describe spatial variation in diet/trophic level of the common deep-sea nematode Deontostoma tridentum on Chatham Rise, Southwest Pacific, using carbon and nitrogen stable isotope and fatty acid analyses. We also analysed sediment organic matter (SOM) and compared the isotopic composition of D. tridentum to other benthic and suprabenthic macrofaunal taxa with a variety of feeding modes. Variability in D. tridentum δ13C and δ15N signatures was high both among sites and within a single site on the southern flank of Chatham Rise. Among-site variation in SOM δ13C signatures was not sufficient to explain variation in nematode isotopic signatures. The presence of a positive correlation between δ13C and δ15N signatures of D. tridentum (both among and within sites) could suggest that differences in trophic level is the cause behind this variation. Nitrogen isotope data suggest the presence of 1-3 trophic levels in this species, which may reflect differences in prey availability, nematode body size, or habitat (benthic versus epizoic). Nematode δ15N values exceeded those of all other taxa we investigated, including other predators, but reasons for this enrichment remain unclear. The fatty acid composition of D. tridentum did not vary substantially between sites and was characterised by relatively high levels of 18:1n9 (15-20%) and polyunsaturated fatty acids (PUFAs; ~22%). Although limited inferences can be made based on fatty acid composition due to the potential impacts of non-dietary factors, high levels of PUFAs indicate that D. tridentum represents a good source of these essential nutrients to higher trophic levels. In conclusion, our results show that (1) some deep-sea organisms

  18. Identification of microbial populations assimilating nitrogen from RDX in munitions contaminated military training range soils by high sensitivity stable isotope probing.

    Science.gov (United States)

    Andeer, Peter; Stahl, David A; Lillis, Lorraine; Strand, Stuart E

    2013-09-17

    The leaching of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) from particulates deposited in live-fire military training range soils contributes to significant pollution of groundwater. In situ microbial degradation has been proposed as a viable method for onsite containment of RDX. However, there is only a single report of RDX degradation in training range soils and the soil microbial communities involved in RDX degradation were not identified. Here we demonstrate aerobic RDX degradation in soils taken from a target area of an Eglin Air Force Base bombing range, C52N Cat's Eye, (Eglin, Florida U.S.A.). RDX-degradation activity was spatially heterogeneous (found in less than 30% of initial target area field samples) and dependent upon the addition of exogenous carbon sources to the soils. Therefore, biostimulation (with exogenous carbon sources) and bioaugmentation may be necessary to sustain timely and effective in situ microbial biodegradation of RDX. High sensitivity stable isotope probing analysis of extracted soils incubated with fully labeled (15)N-RDX revealed several organisms with (15)N-labeled DNA during RDX-degradation, including xplA-bearing organisms. Rhodococcus was the most prominent genus in the RDX-degrading soil slurries and was completely labeled with (15)N-nitrogen from the RDX. Rhodococcus and Williamsia species isolated from these soils were capable of using RDX as a sole nitrogen source and possessed the genes xplB and xplA associated with RDX-degradation, indicating these genes may be suitable genetic biomarkers for assessing RDX degradation potential in soils. Other highly labeled species were primarily Proteobacteria, including: Mesorhizobium sp., Variovorax sp., and Rhizobium sp. PMID:23909596

  19. Highly stable, monolithic, single-mode mid-infrared supercontinuum source based on low-loss fusion spliced silica and fluoride fibers.

    Science.gov (United States)

    Yin, Ke; Zhang, Bin; Yao, Jinmei; Yang, Linyong; Chen, Shengping; Hou, Jing

    2016-03-01

    A 0.8 to 4.5 μm highly stable all-fiber spliced mid-infrared supercontinuum (SC) source was presented. The joint between the single-mode (SM) pump silica fiber and the ZBLAN fiber (ZrF4 - BaF2 - LaF3 - AlF3 - NaF, a type of fluoride fiber) was fusion spliced, which greatly improved the SC's stability. The low-loss splicing was guaranteed by the similar mode field areas of the fundamental mode LP(01) of the silica and ZBLAN fibers. At the splicing joint the ZBLAN fiber enveloped the silica fiber, thus increasing the robustness of the splice. A low splicing loss of less than 0.1 dB was calculated, which ensured that the whole SC source was very reliable. The SC had a maximal average power of 550.8 mW with a 1.5 dB spectral bandwidth ranging from 2642 to 4065 nm. In particular, the SC power for λ>3.8  μm was measured to be 116.1 mW with a power ratio of ∼21.1% of the total SC power. Perfect Gaussian beam profiles of the SC source demonstrated its SM operation. Over 12 h of continuous operation of this SC source showed its outstanding power stability with a root mean square variation of 0.59%, which also demonstrated the high quality of the fusion spliced joint. PMID:26974087

  20. Study on High Stable Measurement Techniques for Campbell Fission Chambers%坎贝尔裂变室的高稳定性测量技术研究

    Institute of Scientific and Technical Information of China (English)

    毕道伟

    2016-01-01

    由于负电性分子俘获等微观机理影响,坎贝尔裂变室的动态特性在运行期间将发生变化,甚至导致测量输出严重偏离堆芯真实功率。为防止上述因素对核电厂安全造成的不利影响,建立了裂变室时频冲击响应模型,研究了微观过程与频谱特性的映射关系,引入带通滤波方法对传统测量系统进行改进,将坎贝尔测量限制在电子漂移区,实现了复杂变化条件下的高稳定性测量。%Dynamic characteristics of Campbell fission chambers will change while in operation , due to the im-pacts of such microscopic mechanisms as capturing of electrically negative molecules , which could potentially result in measurement outputs significantly deviating from the true reactor power .To avoid the abovementioned negative impacts on reactor safety , time-frequency impulse response models are established for fission cham-bers, and the mapping relationship between microscopic processes and frequency characteristics are well stud -ied.The signal processing method of band -pass filtering is therefore introduced to improve performance of tra-dition measurement systems and limit the Campbell measurement within the range of electron drift zone , thus a-chieving highly stable measurement under complicated changing conditions .

  1. pH-induced photocurrent switching based on a highly stable drop-casting film of imidazole moiety-containing dinuclear Ru(II) Complex

    International Nuclear Information System (INIS)

    Graphical abstract: > Solvent-casting Ru(II) complex modified electrode. > Positive shifting of half-wave potentials of Ru(III)/Ru(II) by pH decreases. > Greatly enhanced cathodic photocurrents by pH decreases. - Highlights: • Solvent-casting Ru(II) complex modified electrode. • Positive shifting of half-wave potentials of Ru(III)/Ru(II) by pH decreases. • Greatly enhanced cathodic photocurrents by pH decreases. - Abstract: A new dinuclear Ru(II) complex of [(H2L1)Ru(H2L2)Ru(H2L1)](ClO4)4 {H2L1 = 2,6-bis(2-benzimidazolyl)pyridine; H2L2 = 2,6-bis(4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)-1,5- dihydrobenzo[1,2-d:4,5-d’]diimidazole} is synthesized and characterized. The Ru(II) complex modified indium-tin oxide electrode prepared using a drop-casting method, exhibited a couple of stable surface-confined Ru(III)/Ru(II)-based redox waves centered at +0.65 V vs saturated calomel electrode that were almost unchanged after 50 consecutive cyclic voltammetry scanning. The modified electrode showed pH-dependent redox behaviors with the formal potential being decreased by 430 mV due to the occurrance of the proton-coupled redox reactions. The cathodic photocurrent generation of the modified electrode was also found to be highly pH-dependent, switching from an “off” state at pH ∼11.0 to an “on” state at pH = 2.20 with an enhancement factor of 18. The modified electrode was shown to have promising applications as photoelectrochemical pH sensing and switching devices

  2. Novel electrodeposition media to synthesize CoNi-Pt Core@Shell stable mesoporous nanorods with very high active surface for methanol electro-oxidation

    International Nuclear Information System (INIS)

    Highlights: • Novel electrochemical strategies to synthesise mesoporous CoNi@Pt nanorods. • Electrocatalysts for methanol oxidation in fuel cells. • Electrosynthesis in W-in-IL microemulsion leads to greatly porous nanorods. • Mesoporous CoNi@Pt nanorods exhibit extraordinary electrocatalytic activity for MOR. • Pt shell over mesoporous nanorods enhances platinum activity. - Abstract: Three strategies have been tested to obtain stable mesoporous CoNi@Pt nanorods with a very high effective area and good performance for methanol electro-oxidation. They are based on, firstly, an electrochemical synthesis of the CoNi nanorods using three clearly different systems (micellar solution, water-in-ionic liquid microemulsion and suspension of polystyrene nanoparticles), and, secondly, a posterior platinum shell formation by interfacial replacement reaction. The obtained nanorods have been compared with pure platinum ones prepared following the three methods. The synthesized mesoporous platinum nanorods already show very good performance for methanol oxidation in comparison with compact ones or the usual Pt/C catalyzers, but the mesoporous CoNi@Pt nanorods have demonstrated much better performance for methanol oxidation, due to the more active platinum atoms in the shell of platinum than in the bulk, the higher good poison tolerance and the lower cost of the material -owing to the drastic saving in platinum in the nanostructures-. The mesoporous CoNi@Pt nanorods obtained from the water-in-ionic liquid microemulsion are the best candidates as electrocatalysers because they provide a significantly higher mass-normalized current density (1326 mA mg−1), a good stability in the sulfuric acidic medium and significant electrocatalytic stability under continuous operating conditions

  3. Stable Boundary Layer Education (STABLE) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The properties of, and the processes that occur in, the nocturnal stable boundary layer are not well understood, making it difficult to represent adequately in numerical models. The nocturnal boundary layer often is characterized by a temperature inversion and, in the Southern Great Plains region, a low-level jet. To advance our understanding of the nocturnal stable boundary layer, high temporal and vertical resolution data on the temperature and wind properties are needed, along with both large-eddy simulation and cloud-resolving modeling.

  4. 高温下非传统稳定同位素分馏%Non-traditional stable isotope fractionation at high temperatures

    Institute of Scientific and Technical Information of China (English)

    黄方

    2011-01-01

    The last ten years have seen big progress and wide applications of a novel field, non-traditional stable isotope (NTSI) geochemistry, to high temperature geo-science studies. Invention of multi-collector-inductively coupled plasma-mass spectrometry (MC-ICP-MS) led to the big breakthrough of analytical methods for heavy stable isotopes. This contribution summarizes Ii, Fe, and Mg isotope studies on igneous rocks and minerals, as representative of NTSI geochemistry. Ii isotopes have been widely applied to the studies of mantle geochemistry, recycling of subducted materials, and metamorphism to constrain the source of magma and kinetic diffusion process. Fe isotope fractionation is related to partitioning of multi-valent Fe between Fe-bearing phases, which can occur in the course of mantle metasomatism, partial melting, and fractional crystallization. Mg isotopic compositions of igneous rocks most likely reflect the source signatures. Variation of Mg isotopic ratios of mantle peridotites is trivial and this provides a homogenous background for Mg isotope fractionation in low temperature processes. Furthermore, Cl, Si, Cu, Ca, and U isotopes are also promising in the future geochemical studies. Experimental studies and theoretical simulation for the mechanisms of isotope fractionation provide important guidances for understanding the NTIS data. Experimental studies show that light and heavy isotopes have different migration velocity at high temperature processes such as chemical diffusion, evaporation, and desublimation, which could produce significant kinetic isotope fractionation. Equilibrium isotopic fractionation could occur among mineral, melt, and fluid when chemical environment of the isotopes are different between the phases. Recent thermal diffusion and migration experiments on silicate material reveal a " new" mechanism of magma differentiation and isotope fractionation. Along a temperature gradient in silicate magma, large elemental variation and isotopic

  5. Temperature variability at Dürres Maar, Germany during the Migration Period and at High Medieval Times, inferred from stable carbon isotopes of Sphagnum cellulose

    Directory of Open Access Journals (Sweden)

    A. Lücke

    2011-09-01

    Full Text Available This paper presents a high resolution reconstruction of local growing season temperature (GST anomalies at Dürres Maar, Germany, spanning the last two millennia. The GST anomalies were derived from a stable carbon isotope time series of cellulose chemically extracted from Sphagnum leaves (δ13Ccellulose separated from a kettle-hole peat deposit of several metres thickness. The temperature reconstruction is based on the Sphagnum δ13Ccellulose/temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period, marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times, the amplitude in the reconstructed temperature variability is most likely overestimated; nevertheless, above-average temperatures are obvious during this time span, which are followed by a temperature decrease. On the contrary, a pronounced Late Roman Climate Optimum, often described as similarly warm or even warmer as medieval times, could not be detected. The temperature signal of the Little Ice Age (LIA is not preserved in Dürres Maar due to considerable peat cutting that takes place in the first half of the 19th century. The local GST anomalies show a remarkable agreement to northern hemispheric temperature reconstructions based on tree-ring datasets and are also in accordance with climate reconstructions on the basis of lake sediments, glacier advances and retreats, and historical datasets. Most notably, e.g., during the Early Middle Ages and at High Medieval Times, temperatures were neither low nor high in general. Rather high frequency temperature variability with multiple narrow intervals of below- and above-average temperatures at maximum lasting a few decades are

  6. Temperature variability at Dürres Maar, Germany during the migration period and at high medieval times, inferred from stable carbon isotopes of Sphagnum cellulose

    Directory of Open Access Journals (Sweden)

    R. Moschen

    2011-02-01

    Full Text Available This paper presents a high resolution reconstruction of local growing season temperature (GST anomalies at Dürres Maar, Germany, spanning the last two millennia. The GST anomalies were derived from a stable carbon isotope time series of cellulose chemically extracted from Sphagnum leaves (δ13Ccellulose separated from a kettle-hole peat deposit of several metres thickness. The temperature reconstruction is based on the Sphagnum δ13Ccellulose /temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably also wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times above-average temperatures are obvious followed by a temperature decrease. On the contrary, a pronounced Late Roman Climate Optimum, often described as similar warm or even warmer as medieval times, could not be detected. The temperature signal of the Little Ice Age (LIA is not preserved in Dürres Maar due to considerable peat cutting that takes place in the first half of the 19th century. The local GST anomalies show a remarkable agreement to northern hemispheric temperature reconstructions based on tree-ring data sets and are also in accordance with climate reconstructions on the basis of lake sediments, glacier advances and retreats, and historical data sets. Most notably, e.g. during the Early Middle Ages and at High Medieval Times, temperatures were not low or high in general. Rather high frequency temperature variability with multiple narrow intervals of below- and above-average temperatures at maximum lasting a few decades are reconstructed. Especially the agreements between our estimated GST anomalies and the NH

  7. Highly Active and Stable MgAl2O4 Supported Rh and Ir Catalysts for Methane Steam Reforming: A Combined Experimental and Theoretical Study

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Donghai; Glezakou, Vassiliki Alexandra; Lebarbier, Vanessa MC; Kovarik, Libor; Wan, Haiying; Albrecht, Karl O.; Gerber, Mark A.; Rousseau, Roger J.; Dagle, Robert A.

    2014-07-01

    In this work we present a combined experimental and theoretical investigation of stable MgAl2O4 spinel-supported Rh and Ir catalysts for the steam methane reforming (SMR) reaction. Firstly, catalytic performance for a series of noble metal catalysts supported on MgAl2O4 spinel was evaluated for SMR at 600-850°C. Turnover rate at 850°C follows the order: Pd > Pt > Ir > Rh > Ru > Ni. However, Rh and Ir were found to have the best combination of activity and stability for methane steam reforming in the presence of simulated biomass-derived syngas. It was found that highly dispersed ~2 nm Rh and ~1 nm Ir clusters were formed on the MgAl2O4 spinel support. Scanning Transition Electron Microscopy (STEM) images show that excellent dispersion was maintained even under challenging high temperature conditions (e.g. at 850°C in the presence of steam) while Ir and Rh catalysts supported on Al2O3 were observed to sinter at increased rates under the same conditions. These observations were further confirmed by ab initio molecular dynamics (AIMD) simulations which find that ~1 nm Rh and Ir particles (50-atom cluster) bind strongly to the MgAl2O4 surfaces via a redox process leading to a strong metal-support interaction, thus helping anchor the metal clusters and reduce the tendency to sinter. Density functional theory (DFT) calculations suggest that these supported smaller Rh and Ir particles have a lower work function than larger more bulk-like ones, which enables them to activate both water and methane more effectively than larger particles, yet have a minimal influence on the relative stability of coke precursors. In addition, theoretical mechanistic studies were used to probe the relationship between structure and reactivity. Consistent with the experimental observations, our theoretical modeling results also suggest that the small spinel-supported Ir particle catalyst is more active than the counterpart of Rh catalyst for SMR. This work was financially supported by the

  8. High-sensitivity C-reactive protein and N-terminal pro-B-type natriuretic peptide in patients with stable coronary artery disease: a prognostic study within the CLARICOR Trial

    DEFF Research Database (Denmark)

    Harutyunyan, Marina J; Mathiasen, Anders B; Winkel, Per; Gøtze, Jens P; Hansen, Jørgen Fischer; Hildebrandt, Per; Jensen, Gorm Boje; Hilden, Jørgen; Jespersen, Christian M; Kjøller, Erik; Kolmos, Hans J; Gluud, Christian; Kastrup, Jens

    2011-01-01

    BACKGROUND: Patients with stable coronary artery disease (CAD) have a poor prognosis. The aim of the study was to evaluate the extent to which serum high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement alone or together could be...

  9. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  10. Measurement of Niacin in a Variety of Food Samples by High Performance Liquid Chromatography-Stable Isotope Dilution Mass Spectrometry (AOAC Annual Meeting, Minneapolis, MN, Sept. 2006)

    Science.gov (United States)

    The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectrometry (SIDMS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin, niacin, in food samples. We have developed a method based on AOAC Peer-Verif...

  11. A novel high-temperature combustion based system for stable isotope analysis of dissolved organic carbon in aqueous samples. : I development and validation

    NARCIS (Netherlands)

    Federherr, E.; Cerli, C.; Kirkels, F. M. S. A.; Kalbitz, K.; Kupka, H. J.; Dunsbach, R.; Lange, L.; Schmidt, T. C.

    2014-01-01

    RATIONALE: Traditionally, dissolved organic carbon (DOC) stable isotope analysis (SIA) is performed using either offline sample preparation followed by elemental analyzer/isotope ratiomass spectrometry (EA/IRMS) or a wet chemical oxidation (WCO)-based device coupled to an isotope ratio mass spectrom

  12. High-intensity versus low-intensity non-invasive ventilation in patients with stable hypercapnic COPD : a randomised crossover trial

    NARCIS (Netherlands)

    Dreher, Michael; Storre, Jan H.; Schmoor, Claudia; Windisch, Wolfram

    2010-01-01

    Rationale The conventional approach of low-intensity non-invasive positive pressure ventilation (NPPV) produces only minimal physiological and clinical benefits in patients with stable hypercapnic chronic obstructive pulmonary disease ( COPD). Objectives To determine whether the novel approach of hi

  13. Dynamic stable set

    OpenAIRE

    Hannu Vartiainen

    2008-01-01

    We study a dynamic vNM stable set in a compact metric space under the assumption of complete and continuous dominance relation. Internal and external stability are defined with respect to farsighted dominance. Stability of an outcome is conditioned on the history via which it is reached. A dynamic stable set always exists. Any covering set by Dutta (1988) coincides with the set of outcomes that are implementable via a dynamic stable set. The maximal implementable outcome set is a version of t...

  14. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process......This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...

  15. Stable Delaunay Graphs

    OpenAIRE

    Agarwal, Pankaj K.; Gao, Jie; Guibas, Leonidas J.; Kaplan, Haim; Rubin, Natan; Sharir, Micha

    2015-01-01

    Let $P$ be a set of $n$ points in $\\mathrm{R}^2$, and let $\\mathrm{DT}(P)$ denote its Euclidean Delaunay triangulation. We introduce the notion of an edge of $\\mathrm{DT}(P)$ being {\\it stable}. Defined in terms of a parameter $\\alpha>0$, a Delaunay edge $pq$ is called $\\alpha$-stable, if the (equal) angles at which $p$ and $q$ see the corresponding Voronoi edge $e_{pq}$ are at least $\\alpha$. A subgraph $G$ of $\\mathrm{DT}(P)$ is called {\\it $(c\\alpha, \\alpha)$-stable Delaunay graph} ($\\math...

  16. On Power Stable Ideals

    OpenAIRE

    Sharma, Pramod K.

    2007-01-01

    We define the notion of a power stable ideal in a polynomial ring $ R[X]$ over an integral domain $ R $. It is proved that a maximal ideal $\\chi$ $ M $ in $ R[X]$ is power stable if and only if $ P^t $ is $ P$- primary for all $ t\\geq 1 $ for the prime ideal $ P = M \\cap R $. Using this we prove that for a Hilbert domain $R$ any radical ideal in $R[X]$ which is a finite intersection G-ideals is power stable. Further, we prove that if $ R $ is a Noetherian integral domain of dimension 1 then a...

  17. Persistent angina: highly prevalent and associated with long-term anxiety, depression, low physical functioning, and quality of life in stable angina pectoris

    DEFF Research Database (Denmark)

    Jespersen, L.; Abildstrom, S. Z.; Hvelplund, Anders;

    2013-01-01

    To evaluate persistent angina in stable angina pectoris with no obstructive coronary artery disease (CAD) compared to obstructive CAD and its relation to long-term anxiety, depression, quality of life (QOL), and physical functioning. We invited 357 patients (men = 191; women = 166; response rate 83...... %) with no prior cardiovascular disease who had a first-time coronary angiography (CAG) in 2008-2009 due to suspected stable angina to participate in a questionnaire survey in 2011 with the Seattle Angina Questionnaire and the Hospital Anxiety and Depression Scale as key elements. Long-term persistent...... angina (i.e., symptoms at least once a month) was present in 64 % of patients with diffuse non-obstructive CAD (1-49 % stenosis), 49 % of patients with normal coronary arteries (0 % stenosis), and 41 % of patients with obstructive CAD (a parts per thousand yen50 % stenosis) (P = 0.01). Depression and...

  18. Lentiviral vectors containing an enhancer-less ubiquitously acting chromatin opening element (UCOE) provide highly reproducible and stable transgene expression in hematopoietic cells

    OpenAIRE

    Zhang, F.; Thornhill, S. I.; Howe, S. J.; Ulaganathan, M.; Scharnbach, A.; Sinclair, J; Kinnon, C.; Gaspar, H. B.; Antoniou, M; Thrasher, A. J.

    2007-01-01

    Ubiquitously acting chromatin opening elements (UCOEs) consist of methylation-free CpG islands encompassing dual divergently transcribed promoters of housekeeping genes that have been shown to confer resistance to transcriptional silencing and to produce consistent and stable transgene expression in tissue culture systems. To develop improved strategies for hematopoietic cell gene therapy, we have assessed the potential of the novel human HNRPA2B1-CBX3 UCOE (A2UCOE) within the context of a se...

  19. Stable Research Platform Workshop

    OpenAIRE

    Fisher, F H; Bishop, C B

    1988-01-01

    A workshop on stable oceanographic research platforms was held at the Marine Physical Laboratory June 29-30, 1987. Research needs of several scientific disciplines, including physical oceanography, air-sea interaction, biological oceanography (especially bio-optics), and acoustics were discussed in detail with respect to the advantages of various stable platforms. This workshop was stimulated by recent requests involving the use of FLIP in weather conditions beyond its original capab...

  20. Uses of stable isotopes

    International Nuclear Information System (INIS)

    The most important fields of stable isotope use with examples are presented. In isotope dilution analysis the stable isotopes are used in trace analysis, measurements of volumes and masses. In the field of stable isotope use as tracers the following applications are encountered: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic. In the domain of isotope equilibrium effects applications in the study of mechanism of drug action, study of natural processes, investigation of equilibrium conditions and water cycle as well as in temperature measurements are encountered. Stable isotopes are also used in advanced nuclear reactors, particularly, the uranium nitride with 15 N as nuclear fuel and 157 Gd for reactor control. In spite of some difficulties of stable isotope use, especially related to analytical techniques, which are slow and expensive, the number of papers reporting this subject is steadily growing as well the number of scientific meetings organized by International Isotope Society and IAEA, Gordon Conferences, and regional meetings in Germany, France, etc. Stable isotope application development on large scale is ensured by improving their production technologies, as well as by development of new labelled compounds and of analytical techniques. (author)

  1. Stable isotope applications

    International Nuclear Information System (INIS)

    The following domains of stable isotope applications are presented: - isotope dilution analyses as in trace analyses or volume and mass determinations; - stable isotopes as tracers as applied in environmental studies, agricultural research, products and objects authentification, transport phenomena, reaction mechanisms, determinations of structure and complex biological function, metabolism studies, diagnostic respiration tests, positron emission tomography; - equilibrium isotopic effects as investigated in measurements of effects, studies of equilibrium conditions, the mechanism of drug action, study of natural processes, water circuit, temperature measurements; - kinetic isotopic effects, as, for instance, reaction rates and mechanisms, solvent isotopic effects; - stable isotopes for advanced nuclear reactors as, for instance, uranium nitride with 15 N as nuclear fuel or 157 Gd for reactivity control. In spite of the difficulties regarding stable isotope use and first of all, of the difficult and costly analytical techniques, a continuous growth of the number of stable isotope applications in different fields is registered. The number of works and scientific meetings on the subject, as organized by the International Society of Isotopes and IAEA-Vienna, Gordon Conferences, regional meetings in Germany, France, etc. increase continuously. Development of the stable isotope application on a larger scale requires improving both their production technologies as well as those of labelled substances and, at the same time, the analytical methods

  2. Advanced Thermally Stable Jet Fuels

    Energy Technology Data Exchange (ETDEWEB)

    A. Boehman; C. Song; H. H. Schobert; M. M. Coleman; P. G. Hatcher; S. Eser

    1998-01-01

    The Penn State program in advanced thermally stable jet fuels has five components: 1) development of mechanisms of degradation and solids formation; 2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles during thermal stressing; 3) characterization of carbonaceous deposits by various instrumental and microscopic methods; 4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and 5) assessment of the potential of producing high yields of cycloalkanes and hydroaromatics from coal.

  3. Design and operation of a stable intense high-temperature arc-discharge source of hydrogen atoms and metastable trihydrogen molecules

    OpenAIRE

    Garvey, James F.; Kuppermann, Aron

    1986-01-01

    We report a design for a stable intense beam source of hyperthermal hydrogen atoms. The basis for the design is an arc heater used first by Knuth for the generation of high‐translational energy He–Ar beams. In the case of hydrogen atom generation this source is very unstable due to the corresponding higher temperatures which are generated by the plasma discharge. We have substantially eliminated these difficulties by the insertion of discharge‐localizing insulators and the use of a tungsten n...

  4. Stable isotope laser spectroscopy

    Science.gov (United States)

    Becker, J. F.; Yaldaei, Ramil; Mckay, Christopher P.

    1989-01-01

    Recent advances in semiconductor laser technology have produced a reliable lightweight device ideally suited for a spacecraft high resolution molecular spectrometer. Lead-salt tunable diode lasers (TDL) emit in several spectral modes, each with a very narrow linewidth of -0.0003/cm. This spectral resolution is much narrower than typical Doppler broadened molecular linewidths in the mid-IR range. Thus it is possible to detect individual rotational lines within the vibrational band and measure their intensity, which can be used to determine gas concentration. The narrow spectral lines of any impurity gas tend to lie between the narrow lines of the gas of interest. This represents a major advantage over the accepted gas chromatograph mass spectrometer (GCMS) technique for measuring gas concentrations and isotope ratios. The careful and extensive gas purification procedures required to remove impurities for reliable GCMS measurements will not be required for an IR laser gas analysis. The infrared laser gas analysis technique is being developed to measure stable isotopic ratios of gases such as CO2, CH4, N2O, and NH3. This will eventually lead to development of instruments capable of in situ istopic measurements on planets such as Mars. The carbon (C-12, C-13) isotope ratio is indicative of the type of carbon fixation mechanisms (e.g., photosynthesis, respiration) in operation on a planet, while the nitrogen (N-14, N-15) isotope ratio can probably be used to date nitrogen-bearing Martian samples. The absorbance ratio of two adjacent lines of CO2 in the 2300/cm (4.3 micron) region of the spectrum was measured. The precision of the measurement is presently better than 1 percent and significant improvement is anticipated as rapid sweep-integration techniques and computer controlled data acquistion capabilities are incorporated.

  5. Unique anisotropic optical properties of a highly stable metal-organic framework based on trinuclear iron(iii) secondary building units linked by tetracarboxylic linkers with an anthracene core.

    Science.gov (United States)

    Vinogradov, A V; Milichko, V A; Zaake-Hertling, H; Aleksovska, A; Gruschinski, S; Schmorl, S; Kersting, B; Zolnhofer, E M; Sutter, J; Meyer, K; Lönnecke, P; Hey-Hawkins, E

    2016-05-01

    A highly stable metal-organic framework, [{Fe3(ACTBA)2}X·6DEF]n (1; X = monoanion), based on trinuclear iron(iii) secondary building units connected by tetracarboxylates with an anthracene core, 2,6,9,10-tetrakis(p-carboxylatophenyl)anthracene (ACTBA), is reported. Depending on the direction of light polarisation, crystals of 1 exhibit anisotropic optical properties with birefringence Δn = 0.3 (λ = 590 nm). PMID:26906040

  6. Foraging ecology of ringed seals (Pusa hispida, beluga whales (Delphinapterus leucas and narwhals (Monodon monoceros in the Canadian High Arctic determined by stomach content and stable isotope analysis

    Directory of Open Access Journals (Sweden)

    Jordan K. Matley

    2015-05-01

    Full Text Available Stomach content and stable isotope analysis (δ13C and δ15N from liver and muscle were used to identify habitat and seasonal prey selection by ringed seals (Pusa hispida; n=21, beluga whales (Delphinapterus leucas; n=13 and narwhals (Monodon monoceros; n=3 in the eastern Canadian Arctic. Arctic cod (Boreogadus saida was the main prey item of all three species. Diet reconstruction from otoliths and stable isotope analysis revealed that while ringed seal size influenced prey selection patterns, it was variable. Prey-size selection and on-site observations found that ringed seals foraged on smaller, non-schooling cod whereas belugas and narwhals consumed larger individuals in schools. Further interspecific differences were demonstrated by δ13C and δ15N values and indicated that ringed seals consumed inshore Arctic cod compared to belugas and narwhals, which foraged to a greater extent offshore. This study investigated habitat variability and interseasonal variation in the diet of Arctic marine mammals at a local scale and adds to the sparse data sets available in the Arctic. Overall, these findings further demonstrate the critical importance of Arctic cod to Arctic food webs.

  7. Highly corrosion-resistant Cu70(Ni,Fe,Mn,Cr)30 cupronickel designed using a cluster model for stable solid solutions

    International Nuclear Information System (INIS)

    Minor M (M = Fe, Mn, Cr) additions are widely added to enhance the corrosion resistance of commercial cupronickel alloys. The present paper aims at optimizing the amounts of M in Cu70(Ni,Fe,Mn,Cr)30 (at.%) alloys using a cluster-plus-glue-atom model for stable solid solutions. By this model, it assumed that 1 M atom and 12 Ni atoms formed an M-centered and Ni-surrounded cube-octahedron cluster and the isolated M1Ni12 clusters are embedded in a Cu matrix, conforming to a cluster formula [M1Ni12]Cu30.3 = [M1/13Ni12/13]30Cu70. A structure of this kind satisfies ideally the nearest neighbor requirement, i.e. only M-Ni and Ni-Cu neighbors are allowed and the unfavorable Cu-M pairs are avoided, and hence it describes a stable solid solution structure with good thermal stability. Electrochemical corrosion measurements indicated that [(Fe0.6Mn0.25Cr0.15)1Ni12]Cu30.3 had the best corrosion resistance in 3.5% NaCl aqueous solution.

  8. Synthesis and characterization of water-soluble, stable and highly luminescent itaconic acid/methacrylic acid copolymer-coated CdSe/CdS quantum dots

    International Nuclear Information System (INIS)

    The itaconic acid/methacrylic acid (PIA-MAA) copolymer ligand (PIA-MAA) with carboxylate anchoring groups was found to efficiently convert CdSe/CdS core-shell quantum dots (QDs) in chloroform to water-soluble PIA-MAA-ligand stabilized nanocrystals (PIA-MAA-QDs). The quantum yield (QY) of the resulting PIA-MAA-QDs was 24%. In addition, the carboxylate-based PIA-MAA-QDs survived UV irradiation in air for at least 16 days. Upon UV irradiation, the PIA-MAA-QDs became about 2 times brighter than the original CdSe/CdS QDs in chloroform, and the UV-brightened photoluminescence (PL) can retain the brightness for at least several months. Experimental results further confirmed that the PIA-MAA-QDs were more stable than the original CdSe/CdS QDs against strong acid, strong oxidant, photochemical and thermal treatments. The PIA-MAA-QDs were soluble and stable in water, some polar solvents and buffer solutions. In addition to good performance of PIA-MAA-QDs, the synthesis of PIA-MAA ligands and the corresponding water-soluble QDs is relatively simple.

  9. Stable generalized complex structures

    CERN Document Server

    Cavalcanti, Gil R

    2015-01-01

    A stable generalized complex structure is one that is generically symplectic but degenerates along a real codimension two submanifold, where it defines a generalized Calabi-Yau structure. We introduce a Lie algebroid which allows us to view such structures as symplectic forms. This allows us to construct new examples of stable structures, and also to define period maps for their deformations in which the background three-form flux is either fixed or not, proving the unobstructedness of both deformation problems. We then use the same tools to establish local normal forms for the degeneracy locus and for Lagrangian branes. Applying our normal forms to the four-dimensional case, we prove that any compact stable generalized complex 4-manifold has a symplectic completion, in the sense that it can be modified near its degeneracy locus to produce a compact symplectic 4-manifold.

  10. Mercury stable isotope biogeochemistry

    International Nuclear Information System (INIS)

    Full text: Methods for high precision measurement of natural Hg isotope ratios by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) have been developed recently by our group and allow the use of Hg isotopes to trace the biogeochemistry of Hg. Mercury has seven stable isotopes ranging from 196 to 204 amu.We have found that the isotopic composition of Hg varies by both mass dependent fractionation (MDF) and mass independent fractionation (MIF). Even and odd isotopes of Hg are fractionated by mass-dependent processes, whereas odd isotopes are also fractionated in a mass-independent way by photochemical reactions. Isotope ratios are measured relative to the NIST 3133 Hg standard reference material. MDF is reported as δ202Hg (± 0.08 %o, 2 SD) which is the difference in 202Hg/198Hg between a sample and NIST 3133 in permil (%o). MIF is reported as Δ 201Hg (± 0.05 %o, 2 SD), which is the difference in 201Hg/198Hg ratio in permil from what the 201Hg/198Hg ratio would be if the fractionation were entirely mass dependent. In this presentation we summarize the range of Hg isotopic compositions of a variety of environmental and geological materials. In previous work we described biotic and abiotic laboratory fractionation experiments demonstrating the range of mass dependent and mass independent fractionation caused by mercury redox transformations in the surface environment. Thus far we have found that MIF occurs during photochemical reduction of methyl-Hg and Hg2+ following a Rayleigh-like fractionation. Bacterial reduction causes Rayleigh-like MDF but no MIF. Coastal-marine and freshwater fish from North America have positive Δ 201Hg values (0.2 to > 3 %o) reflecting transfer of methyl-Hg into the food web after partial reduction by photochemical reactions. Most coals and the organic horizons of soils from North America have negative Δ 201Hg values (-0.1 to -0.4 %o), possibly reflecting the influence of Hg that was photochemically reduced in

  11. An investigation into the accuracy, stability and parallel performance of a highly stable explicit technique for stiff reaction-transport PDEs

    Energy Technology Data Exchange (ETDEWEB)

    Franz, A., LLNL

    1998-02-17

    The numerical simulation of chemically reacting flows is a topic, that has attracted a great deal of current research At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear Partial Differential Equations (PDES). Due to the stiffness that is usually present, explicit time differencing schemes are not used despite their inherent simplicity and efficiency on parallel and vector machines, since these schemes require prohibitively small numerical stepsizes. Implicit time differencing schemes, although possessing good stability characteristics, introduce a great deal of computational overhead necessary to solve the simultaneous algebraic system at each timestep. This thesis examines an algorithm based on a preconditioned time differencing scheme. The algorithm is explicit and permits a large stable time step. An investigation of the algorithm`s accuracy, stability and performance on a parallel architecture is presented

  12. Ag-bridged Ag{sub 2}O nanowire network/TiO{sub 2} nanotube array p–n heterojunction as a highly efficient and stable visible light photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chengbin, E-mail: chem_cbliu@hnu.edu.cn [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Cao, Chenghao [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Luo, Xubiao [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Luo, Shenglian [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China)

    2015-03-21

    Graphical abstract: A unique Ag-bridged Ag{sub 2}O nanowire network/TiO{sub 2} nanotube array p–n heterojunction was fabricated by simple electrochemical method. The heterostructures exhibit high photocatalytic activity and excellent recycling performance. - Highlights: • Ag-bridged Ag{sub 2}O nanowire network self-stability structure. • Ag{sub 2}O nanowire network/TiO{sub 2} nanotube p–n heterojunction. • High visible light photocatalytic activity. • Highly stable recycling performance. - Abstract: A unique Ag-bridged Ag{sub 2}O nanowire network/TiO{sub 2} nanotube array p–n heterojunction (Ag–Ag{sub 2}O/TiO{sub 2} NT) was fabricated by simple electrochemical method. Ag nanoparticles were firstly electrochemically deposited onto the surface of TiO{sub 2} NT and then were partly oxidized to Ag{sub 2}O nanowires while the rest of Ag mother nanoparticles were located at the junctions of Ag{sub 2}O nanowire network. The Ag–Ag{sub 2}O/TiO{sub 2} NT heterostructure exhibited strong visible-light response, effective separation of photogenerated carriers, and high adsorption capacity. The integration of Ag–Ag{sub 2}O self-stability structure and p–n heterojunction permitted high and stable photocatalytic activity of Ag–Ag{sub 2}O/TiO{sub 2} NT heterostructure photocatalyst. Under 140-min visible light irradiation, the photocatalytic removal efficiency of both dye acid orange 7 (AO7) and industrial chemical p-nitrophenol (PNP) over Ag–Ag{sub 2}O/TiO{sub 2} NT reached nearly 100% much higher than 17% for AO7 or 13% for PNP over bare TiO{sub 2} NT. After 5 successive cycles under 600-min simulated solar light irradiation, Ag–Ag{sub 2}O/TiO{sub 2} NT remained highly stable photocatalytic activity.

  13. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  14. Thermodynamically Stable Pickering Emulsions

    NARCIS (Netherlands)

    Sacanna, S.; Kegel, W.K.; Philipse, A.P.

    2007-01-01

    We show that under appropriate conditions, mixtures of oil, water, and nanoparticles form thermodynamically stable oil-in-water emulsions with monodisperse droplet diameters in the range of 30–150 nm. This observation challenges current wisdom that so-called Pickering emulsions are at most metastabl

  15. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  16. Classified Stable Matching

    CERN Document Server

    Huang, Chien-Chung

    2009-01-01

    We introduce the {\\sc classified stable matching} problem, a problem motivated by academic hiring. Suppose that a number of institutes are hiring faculty members from a pool of applicants. Both institutes and applicants have preferences over the other side. An institute classifies the applicants based on their research areas (or any other criterion), and, for each class, it sets a lower bound and an upper bound on the number of applicants it would hire in that class. The objective is to find a stable matching from which no group of participants has reason to deviate. Moreover, the matching should respect the upper/lower bounds of the classes. In the first part of the paper, we study classified stable matching problems whose classifications belong to a fixed set of ``order types.'' We show that if the set consists entirely of downward forests, there is a polynomial-time algorithm; otherwise, it is NP-complete to decide the existence of a stable matching. In the second part, we investigate the problem using a p...

  17. 2005 Economy: Stable Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      2005 is the fifth year of China's Tenth Five-Year Plan, it is an important year to implement commitment for entering into WTO as well as a key year for deepening macro-control. With further deepening of macro control and development of regional economy, Chinese economy will operate in a more healthy and stable way.……

  18. 2005 Economy: Stable Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ 2005 is the fifth year of China's Tenth Five-Year Plan, it is an important year to implement commitment for entering into WTO as well as a key year for deepening macro-control. With further deepening of macro control and development of regional economy, Chinese economy will operate in a more healthy and stable way.

  19. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  20. Elliptic stable envelope

    CERN Document Server

    Aganagic, Mina

    2016-01-01

    We construct stable envelopes in equivariant elliptic cohomology of Nakajima quiver varieties. In particular, this gives an elliptic generalization of the results of arXiv:1211.1287. We apply them to the computation of the monodromy of $q$-difference equations arising the enumerative K-theory of rational curves in Nakajima varieties, including the quantum Knizhnik-Zamolodchikov equations.

  1. Stable continuous-time autoregressive process driven by stable subordinator

    Science.gov (United States)

    Wyłomańska, Agnieszka; Gajda, Janusz

    2016-02-01

    In this paper we examine the continuous-time autoregressive moving average process driven by α-stable Lévy motion delayed by inverse stable subordinator. This process can be applied to high-frequency data with visible jumps and so-called "trapping-events". Those properties are often visible in financial time series but also in amorphous semiconductors, technical data describing the rotational speed of a machine working under various load regimes or data related to indoor air quality. We concentrate on the main characteristics of the examined subordinated process expressed in the language of the measures of dependence which are main tools used in statistical investigation of real data. However, because the analyzed system is based on the α-stable distribution therefore we cannot consider here the correlation (or covariance) as a main measure which indicates at the dependence inside the process. In the paper we examine the codifference, the more general measure of dependence defined for wide class of processes. Moreover we present the simulation procedure of the considered system and indicate how to estimate its parameters. The theoretical results we illustrate by the simulated data analysis.

  2. Particle shape optimization by changing from an isotropic to an anisotropic nanostructure: preparation of highly active and stable supported Pt catalysts in microemulsions

    Science.gov (United States)

    Parapat, Riny Y.; Wijaya, Muliany; Schwarze, Michael; Selve, Sören; Willinger, Marc; Schomäcker, Reinhard

    2012-12-01

    We recently introduced a new method to synthesize an active and stable Pt catalyst, namely thermo-destabilization of microemulsions (see R. Y. Parapat, V. Parwoto, M. Schwarze, B. Zhang, D. S. Su and R. Schomäcker, J. Mater. Chem., 2012, 22 (23), 11605-11614). We are able to produce Pt nanocrystals with a small size (2.5 nm) of an isotropic structure i.e. truncated octahedral and deposit them well on support materials. Although we have obtained good results, the performance of the catalyst still needed to be improved and optimized. We followed the strategy to retain the small size but change the shape to an anisotropic structure of Pt nanocrystals which produces more active sites by means of a weaker reducing agent. We found that our catalysts are more active than those we reported before and even show the potential to be applied in a challenging reaction such as hydrogenation of levulinic acid.We recently introduced a new method to synthesize an active and stable Pt catalyst, namely thermo-destabilization of microemulsions (see R. Y. Parapat, V. Parwoto, M. Schwarze, B. Zhang, D. S. Su and R. Schomäcker, J. Mater. Chem., 2012, 22 (23), 11605-11614). We are able to produce Pt nanocrystals with a small size (2.5 nm) of an isotropic structure i.e. truncated octahedral and deposit them well on support materials. Although we have obtained good results, the performance of the catalyst still needed to be improved and optimized. We followed the strategy to retain the small size but change the shape to an anisotropic structure of Pt nanocrystals which produces more active sites by means of a weaker reducing agent. We found that our catalysts are more active than those we reported before and even show the potential to be applied in a challenging reaction such as hydrogenation of levulinic acid. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32122j

  3. Method for in-situ prevention of stable barium carbonate formation in high Tc ceramic superconductor including the use of iodine or an iodine c

    International Nuclear Information System (INIS)

    This patent describes a method of making a pre-ceramic resinous material capable of being converted into a ceramic semiconductor material substantially free from stable barium carbonate and having the general composition RR'2Cu3O7-x where R is a rare earth metal, R' is an alkaline earth metal, and x is from 0 to 0.5. It comprises: refluxing stoichiometric amounts of a first solution comprising a rare earth isopropoxide and an alkaline earth isopropoxide in isopropanol; adding to the first solution a stoichiometric amount of a second solution comprising copper ethylhexanoate in isopropanol; refluxing the first and second solutions to obtain a precipitate; hydrolyzing the precipitate in a quantity of a first solvent comprising water and isopropanol sufficient to substantially dissolve the precipitate into a precipitate solution; adding a third solution comprising an iodine compound in an alcohol to the precipitate solution to form a precursor solution having at least about 1 mole of iodine per mole of rare earth metal; concentrating the precursor solution by removing a sufficient amount of solvents to produce the pre-ceramic resinous material; and adding a second solvent comprising a nonpolar solvent to the pre-ceramic resinous material to obtain a desired viscosity

  4. MoO3–Au composite interfacial layer for high efficiency and air-stable organic solar cells

    DEFF Research Database (Denmark)

    Pan, Hongbin; Zuo, Lijian; Fu, Weifei;

    2013-01-01

    investigated by atomic force microscopy (AFM) and showed that the originally rough ITO substrate became smooth after depositing the composite film, with the root mean square roughness (RMS) decreased from 4.08nm to 1.81nm. The smooth surface reduced the bias-dependent carrier recombination, resulting in a......Efficient and stable polymer bulk-heterojunction solar cells based on regioregular poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) blend active layer have been fabricated with a MoO3–Au co-evaporation composite film as the anode interfacial layer (AIL). The optical...... large shunt resistance and thus improving the fill factor and efficiency of the devices. Additionally, the air stability of devices with different AILs (MoO3–Au composite, MoO3 and PEDOT:PSS) were studied and it was found that the MoO3–Au composite layer remarkably improved the stability of the solar...

  5. Stable Charged Cosmic Strings

    International Nuclear Information System (INIS)

    We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius ≅10-18 m. The vacuum remains stable in our model, because neutral strings are not energetically favored.

  6. Stable charged cosmic strings.

    Science.gov (United States)

    Weigel, H; Quandt, M; Graham, N

    2011-03-11

    We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius ≈10(-18)  m. The vacuum remains stable in our model, because neutral strings are not energetically favored. PMID:21469786

  7. Strategically Stable Technological Alliance

    OpenAIRE

    Nikolai V. Kolabutin; Zenkevich, Nikolay A. (Eds.)

    2011-01-01

    There are two conditions that are important to investigate the stability problem when considering the long-term cooperative agreements: the dynamic stability (time consistency), and strategic stability. This paper presents the results based on the profit distribution procedure (PRP), which implement a model of stable cooperation. The paper also shows the relationship between the dynamic and strategic stability of cooperative agreement and the numerical results showing the influence of paramet...

  8. Stable Allocations of Risk

    OpenAIRE

    Csóka, Péter; Herings, Jean-Jacques; Kóczy, László Á.

    2007-01-01

    The measurement and the allocation of risk are fundamental problems of portfolio management. Coherent measures of risk provide an axiomatic approach to the former problem. In an environment given by a coherent measure of risk and the various portfolios’ realization vectors, risk allocation games aim at solving the second problem: How to distribute the diversification benefits of the various portfolios? Understanding these cooperative games helps us to find stable, efficient, and fair allocati...

  9. Kinetic Stable Delaunay Graphs

    CERN Document Server

    Agarwal, Pankaj K; Guibas, Leonidas J; Kaplan, Haim; Koltun, Vladlen; Rubin, Natan; Sharir, Micha

    2011-01-01

    We consider the problem of maintaining the Euclidean Delaunay triangulation $\\DT$ of a set $P$ of $n$ moving points in the plane, along algebraic trajectories of constant description complexity. Since the best known upper bound on the number of topological changes in the full $\\DT$ is nearly cubic, we seek to maintain a suitable portion of it that is less volatile yet retains many useful properties. We introduce the notion of a stable Delaunay graph, which is a dynamic subgraph of the Delaunay triangulation. The stable Delaunay graph (a) is easy to define, (b) experiences only a nearly quadratic number of discrete changes, (c) is robust under small changes of the norm, and (d) possesses certain useful properties. The stable Delaunay graph ($\\SDG$ in short) is defined in terms of a parameter $\\alpha>0$, and consists of Delaunay edges $pq$ for which the angles at which $p$ and $q$ see their Voronoi edge $e_{pq}$ are at least $\\alpha$. We show that (i) $\\SDG$ always contains at least roughly one third of the Del...

  10. Stable Spirocyclic Meisenheimer Complexes

    Directory of Open Access Journals (Sweden)

    Gonzalo Guirado

    2008-06-01

    Full Text Available Meisenheimer complexes are important intermediates in Nucleophilic Aromatic Substitution Reactions (SNAr. They are formed by the addition of electron rich species to polynitro aromatic compounds or aromatic compounds with strong electron withdrawing groups. It is possible to distinguish two types of Meisenheimer or σ-complexes, the σHcomplex or σX-complex (also named ipso, depending on the aromatic ring position attacked by the nucleophile (a non-substituted or substituted one, respectively. Special examples of σX- or ipso-complexes are formed through intermediate spiro adducts, via intramolecular SNAr. Some of these spirocyclic Meisenheimer complexes, a type of σXcomplex, are exceptionally stable in solution and/or as solids. They can be isolated and characterized using X-ray, and various spectroscopic techniques such as NMR, UV-Vis, IR, and fluorescence. A few of these stable spirocyclic Meisenheimer complexes are zwitterionic and exhibit interesting photophysical and redox properties. We will review recent advances, synthesis and potential applications of these stable spirocyclic Meisenheimer complexes.

  11. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  12. High precision dual-inlet IRMS measurements of the stable isotopes of CO2 and the N2O/CO2 ratio from polar ice core samples

    Directory of Open Access Journals (Sweden)

    T. K. Bauska

    2014-07-01

    Full Text Available An important constraint on mechanisms of past carbon cycle variability is provided by the stable isotopic composition of carbon in atmospheric carbon dioxide (δ13C-CO2 trapped in polar ice cores, but obtaining very precise measurements has proven to be a significant analytical challenge. Here we describe a new technique to determine the δ13C of CO2 at exceptional precision, as well as measuring the CO2 and N2O mixing ratios. In this method, ancient air is extracted from relatively large ice samples (~ 400 grams with a dry-extraction "ice-grater" device. The liberated air is cryogenically purified to a CO2 and N2O mixture and analyzed with a micro-volume equipped dual-inlet IRMS (Thermo MAT 253. The reproducibility of the method, based on replicate analysis of ice core samples, is 0.02‰ for δ13C-CO2 and 2 ppm and 4 ppb for the CO2 and N2O mixing ratios, respectively (1-sigma pooled standard deviation. Our experiments show that minimizing water vapor pressure in the extraction vessel by housing the grating apparatus in a ultra-low temperature freezer (−60 °C improves the precision and decreases the experimental blank of the method. We describe techniques for accurate calibration of small samples and the application of a mass spectrometric method based on source fragmentation for reconstructing the N2O history of the atmosphere. The oxygen isotopic composition of CO2 is also investigated, confirming previous observations of oxygen exchange between gaseous CO2 and solid H2O within the ice archive. These data offer a possible constraint on oxygen isotopic fractionation during H2O and CO2 exchange below the H2O bulk melting temperature.

  13. Development of a Lower-SWaP, RAD-Tolerant, Thermally Stable High Speed Fiber Optics Network for Harsh Environment Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase I objectives and work plan, carried through to completion, will result in the development of a RAD-tolerant, high-speed, multi-channel fiber...

  14. Stable Complete Intersections

    CERN Document Server

    Robbiano, Lorenzo

    2011-01-01

    A complete intersection of n polynomials in n indeterminates has only a finite number of zeros. In this paper we address the following question: how do the zeros change when the coefficients of the polynomials are perturbed? In the first part we show how to construct semi-algebraic sets in the parameter space over which all the complete intersection ideals share the same number of isolated real zeros. In the second part we show how to modify the complete intersection and get a new one which generates the same ideal but whose real zeros are more stable with respect to perturbations of the coefficients.

  15. Highly Stable Etch Stopper Technology for 0.25 μm 1 Transistor 1 Capacitor (1T1C) 32 Mega-Bit Ferroelectric Random Access Memory (FRAM)

    Science.gov (United States)

    Jang, Nak-Won; Song, Yoon-Jong; Joo, Suk-Ho; Lee, Kyu-Mann; Kim, Hyun-Ho; Joo, Heung-Jin; Park, Jung-Hoon; Lee, Sang-Woo; Lee, Sung-Yung; Kim, Kinam

    2003-04-01

    Since current 32 Mb high-density ferroelectric random access memory (FRAM) shows very narrow sensing window, it is strongly desired to improve the sensing widow for generating a reliable high yield. In this paper, we propose a TiAlN oxygen stopping layer for enhancing the diffusion barrier layer, which makes it possible to reduce the bottom stack height from 180 nm to 90 nm, resulting in the increase of effective cell area and cell charge. In addition to the enhanced diffusion barrier, we developed a stable PE-SiN etch stopper for replacing Ir noble metal etch stopper that has strong stress variation and eventually deteriorates the cell charge distribution. By using TiAlN oxygen stopping layer and PE-SiN etch stopper, the 32 Mb FRAM device shows very wide sensing window of 100 fC, which guarantees a reliable high yield.

  16. Emergence of a few distinct structures from a single formal structure type during high-throughput screening for stable compounds: The case of RbCuS and RbCuSe

    Science.gov (United States)

    Trimarchi, Giancarlo; Zhang, Xiuwen; DeVries Vermeer, Michael J.; Cantwell, Jacqueline; Poeppelmeier, Kenneth R.; Zunger, Alex

    2015-10-01

    Theoretical sorting of stable and synthesizable "missing compounds" from those that are unstable is a crucial step in the discovery of previously unknown functional materials. This active research area often involves high-throughput (HT) examination of the total energy of a given compound in a list of candidate formal structure types (FSTs), searching for those with the lowest energy within that list. While it is well appreciated that local relaxation methods based on a fixed list of structure types can lead to inaccurate geometries, this approach is widely used in HT studies because it produces answers faster than global optimization methods (that vary lattice vectors and atomic positions without local restrictions). We find, however, a different failure mode of the HT protocol: specific crystallographic classes of formal structure types each correspond to a series of chemically distinct "daughter structure types" (DSTs) that have the same space group but possess totally different local bonding configurations, including coordination types. Failure to include such DSTs in the fixed list of examined candidate structures used in contemporary high-throughput approaches can lead to qualitative misidentification of the stable bonding pattern, not just quantitative inaccuracies. In this work, we (i) clarify the understanding of the general DST-FST relationship, thus improving current discovery HT approaches, (ii) illustrate this failure mode for RbCuS and RbCuSe (the latter being a yet unreported compound and is predicted here) by developing a synthesis method and accelerated crystal-structure determination, and (iii) apply the genetic-algorithm-based global space-group optimization (GSGO) approach which is not vulnerable to the failure mode of HT searches of fixed lists, demonstrating a correct identification of the stable DST. The broad impact of items (i)-(iii) lies in the demonstrated predictive ability of a more comprehensive search strategy than what is currently

  17. LC-quadrupole/Orbitrap high-resolution mass spectrometry enables stable isotope-resolved simultaneous quantification and ¹³C-isotopic labeling of acyl-coenzyme A thioesters.

    Science.gov (United States)

    Frey, Alexander J; Feldman, Daniel R; Trefely, Sophie; Worth, Andrew J; Basu, Sankha S; Snyder, Nathaniel W

    2016-05-01

    Acyl-coenzyme A (acyl-CoA) thioesters are evolutionarily conserved, compartmentalized, and energetically activated substrates for biochemical reactions. The ubiquitous involvement of acyl-CoA thioesters in metabolism, including the tricarboxylic acid cycle, fatty acid metabolism, amino acid degradation, and cholesterol metabolism highlights the broad applicability of applied measurements of acyl-CoA thioesters. However, quantitation of acyl-CoA levels provides only one dimension of metabolic information and a more complete description of metabolism requires the relative contribution of different precursors to individual substrates and pathways. Using two distinct stable isotope labeling approaches, acyl-CoA thioesters can be labeled with either a fixed [(13)C3(15)N1] label derived from pantothenate into the CoA moiety or via variable [(13)C] labeling into the acyl chain from metabolic precursors. Liquid chromatography-hybrid quadrupole/Orbitrap high-resolution mass spectrometry using parallel reaction monitoring, but not single ion monitoring, allowed the simultaneous quantitation of acyl-CoA thioesters by stable isotope dilution using the [(13)C3(15)N1] label and measurement of the incorporation of labeled carbon atoms derived from [(13)C6]-glucose, [(13)C5(15)N2]-glutamine, and [(13)C3]-propionate. As a proof of principle, we applied this method to human B cell lymphoma (WSU-DLCL2) cells in culture to precisely describe the relative pool size and enrichment of isotopic tracers into acetyl-, succinyl-, and propionyl-CoA. This method will allow highly precise, multiplexed, and stable isotope-resolved determination of metabolism to refine metabolic models, characterize novel metabolism, and test modulators of metabolic pathways involving acyl-CoA thioesters. PMID:26968563

  18. Air-stable π-conjugated amorphous copolymer field-effect transistors with high mobility of 0.3 cm2/Vs

    DEFF Research Database (Denmark)

    Georgakopoulos, S.; Gu, Y.; Nielsen, Martin Meedom; Shkunov, M.

    2012-01-01

    We have fabricated organic bottom-contact top-gate field-effect transistors with an indenofluorene-phenanthrene co-polymer semiconductor, exhibiting ON/OFF ratio of 10(7) and uncommonly high mobility for an amorphous conjugated polymer of up to 0.3 cm(2)/Vs. Lack of crystallinity in this material...... is indicated by atomic force microscopy, grazing incidence wide angle X-ray scattering, and differential scanning calorimetry data. Nevertheless, fitting transistor data to the Gaussian disorder model gives low energetic disorder of sigma = 48 meV and high prefactor mobility mu(0) = 0.67 cm(2)/Vs...

  19. A high-order and unconditionally stable scheme for the modified anomalous fractional sub-diffusion equation with a nonlinear source term

    Science.gov (United States)

    Mohebbi, Akbar; Abbaszadeh, Mostafa; Dehghan, Mehdi

    2013-05-01

    The aim of this paper is to study the high order difference scheme for the solution of modified anomalous fractional sub-diffusion equation. The time fractional derivative is described in the Riemann-Liouville sense. In the proposed scheme we discretize the space derivative with a fourth-order compact scheme and use the Grünwald-Letnikov discretization of the Riemann-Liouville derivative to obtain a fully discrete implicit scheme. We analyze the solvability, stability and convergence of the proposed scheme using the Fourier method. The convergence order of method is O(τ+h4). Numerical examples demonstrate the theoretical results and high accuracy of the proposed scheme.

  20. Stable Umbral Chromospheric Structures

    CERN Document Server

    Henriques, V M J; Mathioudakis, M; Kiselman, D; Gallagher, P T; Keenan, F P

    2014-01-01

    Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods. Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results. We find 0"15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing was moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 minutes. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5". Some of these structures have a correspondence in H-alpha but we ...