Mechanisms for plasma etching of HfO{sub 2} gate stacks with Si selectivity and photoresist trimming

Energy Technology Data Exchange (ETDEWEB)

Shoeb, Juline; Kushner, Mark J. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2009-11-15

To minimize leakage currents resulting from the thinning of the insulator in the gate stack of field effect transistors, high-dielectric constant (high-k) metal oxides, and HfO{sub 2} in particular, are being implemented as a replacement for SiO{sub 2}. To speed the rate of processing, it is desirable to etch the gate stack (e.g., metal gate, antireflection layers, and dielectric) in a single process while having selectivity to the underlying Si. Plasma etching using Ar/BCl{sub 3}/Cl{sub 2} mixtures effectively etches HfO{sub 2} while having good selectivity to Si. In this article, results from integrated reactor and feature scale modeling of gate-stack etching in Ar/BCl{sub 3}/Cl{sub 2} plasmas, preceded by photoresist trimming in Ar/O{sub 2} plasmas, are discussed. It was found that BCl{sub n} species react with HfO{sub 2}, which under ion impact, form volatile etch products such as B{sub m}OCl{sub n} and HfCl{sub n}. Selectivity to Si is achieved by creating Si-B bonding as a precursor to the deposition of a BCl{sub n} polymer which slows the etch rate relative to HfO{sub 2}. The low ion energies required to achieve this selectivity then challenge one to obtain highly anisotropic profiles in the metal gate portion of the stack. Validation was performed with data from literature. The effect of bias voltage and key reactant probabilities on etch rate, selectivity, and profile are discussed.

Characterization, integration and reliability of HfO{sub 2} and LaLuO{sub 3} high-κ/metal gate stacks for CMOS applications

Energy Technology Data Exchange (ETDEWEB)

Nichau, Alexander

2013-07-15

The continued downscaling of MOSFET dimensions requires an equivalent oxide thickness (EOT) of the gate stack below 1 nm. An EOT below 1.4 nm is hereby enabled by the use of high-κ/metal gate stacks. LaLuO{sub 3} and HfO{sub 2} are investigated as two different high-κ oxides on silicon in conjunction with TiN as the metal electrode. LaLuO{sub 3} and its temperature-dependent silicate formation are characterized by hard X-ray photoemission spectroscopy (HAXPES). The effective attenuation length of LaLuO{sub 3} is determined between 7 and 13 keV to enable future interface and diffusion studies. In a first investigation of LaLuO{sub 3} on germanium, germanate formation is shown. LaLuO{sub 3} is further integrated in a high-temperature MOSFET process flow with varying thermal treatment. The devices feature drive currents up to 70μA/μm at 1μm gate length. Several optimization steps are presented. The effective device mobility is related to silicate formation and thermal budget. At high temperature the silicate formation leads to mobility degradation due to La-rich silicate formation. The integration of LaLuO{sub 3} in high-T processes delicately connects with the optimization of the TiN metal electrode. Hereby, stoichiometric TiN yields the best results in terms of thermal stability with respect to Si-capping and high-κ oxide. Different approaches are presented for a further EOT reduction with LaLuO{sub 3} and HfO{sub 2}. Thereby the thermodynamic and kinetic predictions are employed to estimate the behavior on the nanoscale. Based on thermodynamics, excess oxygen in the gate stack, especially in oxidized metal electrodes, is identified to prevent EOT scaling below 1.2 nm. The equivalent oxide thickness of HfO{sub 2} gate stacks is scalable below 1 nm by the use of thinned interfacial SiO{sub 2}. The prevention of oxygen incorporation into the metal electrode by Si-capping maintains the EOT after high temperature annealing. Redox systems are employed within the

A Mid-Holocene Relative Sea-Level Stack, New Jersey, USA

Science.gov (United States)

Horton, B.; Walker, J. S.; Kemp, A.; Shaw, T. J.; Kopp, R. E.

2017-12-01

Most high resolution (decimeter- and decadal-scale) relative sea-level (RSL) records using salt-marsh microfossils as a proxy only extend through the Common Era, limiting our understanding of driving mechanisms of RSL change and how sea-level is influenced by changing climate. Records beyond the Common Era are limited by the depth of continuous sequences of salt-marsh peat suitable for high resolution reconstructions, as well as contamination by local processes such as sediment compaction. In contrast, sequences of basal peats have produced compaction-free RSL records through the Holocene, but at a low resolution (meter- and centennial-scale). We devise a new Multi-Proxy Presence/Absence Method (MP2AM) to develop a mid-Holocene RSL stack. We stack a series of 1 m basal peat cores that overlap along a uniform elevational gradient above an incompressible basal sand. We analyzed three sea-level indicators from 14 cores: foraminifera, testate amoebae, and stable carbon isotope geochemistry. To reconstruct RSL, this multi-proxy approach uses the timesaving presence/absence of forams and testates to determine the elevation of the highest occurrence of forams and the lowest occurrence of testates in each basal core. We use stable carbon isotope geochemistry to determine the C3/C4 vegetation boundary in each core. We develop age-depth models for each core using a series of radiocarbon dates. The RSL records from each 1 m basal core are combined to create a stack or, in effect, one long core of salt-marsh material. This method removes the issue of compaction to create a continuous RSL record to address temporal changes and periods of climate and sea-level variability. We reconstruct a southern NJ mid-Holocene RSL record from Edwin B. Forsythe National Wildlife Refuge, where Kemp et al. (2013) completed a 2500 yr RSL record using a foraminifera-based transfer function approach. Preliminary radiocarbon dates suggest the basal sequence is at least 4246-4408 cal yrs BP

Sea ice contribution to the air-sea CO{sub 2} exchange in the Arctic and Southern Oceans

Energy Technology Data Exchange (ETDEWEB)

Rysgaard, Soeren (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Centre for Earth Observation Science, CHR Faculty of Environment Earth and Resources, Univ. of Manitoba, Winnipeg (Canada)), e-mail: rysgaard@natur.gl; Bendtsen, Joergen (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Centre for Ice and Climate, Niels Bohr Inst., Univ. of Copenhagen, Copenhagen O (Denmark)); Delille, Bruno (Unit' e d' Oceanographie Chimique, Interfacultary Centre for Marine Research, Universite de Liege, Liege (Belgium)); Dieckmann, Gerhard S. (Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany)); Glud, Ronnie N. (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Scottish Association of Marine Sciences, Scotland UK, Southern Danish Univ. and NordCee, Odense M (Denmark)); Kennedy, Hilary; Papadimitriou, Stathys (School of Ocean Sciences, Bangor Univ., Menai Bridge, Anglesey, Wales (United Kingdom)); Mortensen, John (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark)); Thomas, David N. (School of Ocean Sciences, Bangor Univ., Menai Bridge, Anglesey, Wales (United Kingdom); Finnish Environment Inst. (SYKE), Marine Research Centre, Helsinki (Finland)); Tison, Jean-Louis (Glaciology Unit, Dept. of Earth and Environmental Sciences, Universite Libre de Bruxelles, Bruxelles, (Belgium))

2011-11-15

Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO{sub 2} and the subsequent effect on air-sea CO{sub 2} exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air-sea CO{sub 2} exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO{sub 2} uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO{sub 2} uptake in ice-free polar seas. This sea-ice driven CO{sub 2} uptake has not been considered so far in estimates of global oceanic CO{sub 2} uptake. Net CO{sub 2} uptake in sea-ice-covered oceans can be driven by; (1) rejection during sea-ice formation and sinking of CO{sub 2}-rich brine into intermediate and abyssal oceanic water masses, (2) blocking of air-sea CO{sub 2} exchange during winter, and (3) release of CO{sub 2}-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO{sub 2} drawdown during primary production in sea ice and surface oceanic waters

Co-Development of Supply Chain in the BOP Markets

Directory of Open Access Journals (Sweden)

Tsai Chi Kuo

2018-03-01

Full Text Available The challenge for enterprises to enter the market in the bottom of the pyramid (BOP segment is to revise their supply chain design. This article compiles the cases that demonstrate how enterprises can successfully enter BOP markets. Factors are extracted and analyzed according to the stages of the value chain and the supply chain. Furthermore, the Importance—Performance Analysis (IPA is used to explore the gap and the opportunities for improvement. Also, the multinational enterprises (MNEs in Taiwan and local manufacturers in Indonesia are compared for their suitability to the different business strategies. Results of these analyses could serve as a gap analysis tool for decision-making and business strategies entering the BOP market.

Voltage linearity modulation and polarity dependent conduction in metal-insulator-metal capacitors with atomic-layer-deposited Al{sub 2}O{sub 3}/ZrO{sub 2}/SiO{sub 2} nano-stacks

Energy Technology Data Exchange (ETDEWEB)

Zhu, Bao; Liu, Wen-Jun; Wei, Lei; Zhang, David Wei; Jiang, Anquan; Ding, Shi-Jin, E-mail: sjding@fudan.edu.cn [State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433 (China)

2015-07-07

Excellent voltage linearity of metal-insulator-metal (MIM) capacitors is highly required for next generation radio frequency integration circuits. In this work, employing atomic layer deposition technique, we demonstrated how the voltage linearity of MIM capacitors was modulated by adding different thickness of SiO{sub 2} layer to the nano-stack of Al{sub 2}O{sub 3}/ZrO{sub 2}. It was found that the quadratic voltage coefficient of capacitance (α) can be effectively reduced from 1279 to −75 ppm/V{sup 2} with increasing the thickness of SiO{sub 2} from zero to 4 nm, which is more powerful than increasing the thickness of ZrO{sub 2} in the Al{sub 2}O{sub 3}/ZrO{sub 2} stack. This is attributed to counteraction between the positive α for Al{sub 2}O{sub 3}/ZrO{sub 2} and the negative one for SiO{sub 2} in the MIM capacitors with Al{sub 2}O{sub 3}/ZrO{sub 2}/SiO{sub 2} stacks. Interestingly, voltage-polarity dependent conduction behaviors in the MIM capacitors were observed. For electron bottom-injection, the addition of SiO{sub 2} obviously suppressed the leakage current; however, it abnormally increased the leakage current for electron top-injection. These are ascribed to the co-existence of shallow and deep traps in ZrO{sub 2}, and the former is in favor of the field-assisted tunnelling conduction and the latter contributes to the trap-assisted tunnelling process. The above findings will be beneficial to device design and process optimization for high performance MIM capacitors.

Hexagonal perovskites with cationic vacancies. 14. The rhombohedral 12 L-stacking polytypes Ba/sub 2/La/sub 2/Bsup(II)(W/sub 2/sup(VI)vacantO/sub 12/)

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-02-01

Rhombohedral 12 L-stacking polytypes with cationic vacancies of type Ba/sub 2/La/sub 2/Bsup(II)(W/sub 2/sup(VI)vacantO/sub 12/) are reported for Bsup(II) = Mg, Zn (white), Ni (light brown) and Co (brown). For Bsup(II) = Cu, as a consequence of the Jahn Teller effect, a triclinic distorted lattice is observed.

Self-aligned top-gate InGaZnO thin film transistors using SiO{sub 2}/Al{sub 2}O{sub 3} stack gate dielectric

Energy Technology Data Exchange (ETDEWEB)

Chen, Rongsheng; Zhou, Wei; Zhang, Meng; Wong, Man; Kwok, Hoi Sing

2013-12-02

Self-aligned top-gate amorphous indium–gallium–zinc oxide (a-IGZO) thin film transistors (TFTs) utilizing SiO{sub 2}/Al{sub 2}O{sub 3} stack thin films as gate dielectric are developed in this paper. Due to high quality of the high-k Al{sub 2}O{sub 3} and good interface between active layer and gate dielectric, the resulting a-IGZO TFT exhibits good electrical performance including field-effect mobility of 9 cm{sup 2}/Vs, threshold voltage of 2.2 V, subthreshold swing of 0.2 V/decade, and on/off current ratio of 1 × 10{sup 7}. With scaling down of the channel length, good characteristics are also obtained with a small shift of the threshold voltage and no degradation of subthreshold swing. - Highlights: • Self-aligned top-gate indium–gallium–zinc oxide thin-film transistor is proposed. • SiO{sub 2}/Al{sub 2}O{sub 3} stack gate dielectric is proposed. • The source/drain areas are hydrogen-doped by CHF{sub 3} plasma. • The devices show good electrical performance and scaling down behavior.

L1{sub 0} stacked binaries as candidates for hard-magnets. FePt, MnAl and MnGa

Energy Technology Data Exchange (ETDEWEB)

Matsushita, Yu-ichiro [Max-Planck Institut fuer Microstrukture Physics, Halle (Germany); Department of Applied Physics, The University of Tokyo (Japan); Madjarova, Galia [Max-Planck Institut fuer Microstrukture Physics, Halle (Germany); Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University (Bulgaria); Flores-Livas, Jose A. [Department of Physics, Universitaet Basel (Switzerland); Dewhurst, J.K.; Gross, E.K.U. [Max-Planck Institut fuer Microstrukture Physics, Halle (Germany); Felser, C. [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Sharma, S. [Max-Planck Institut fuer Microstrukture Physics, Halle (Germany); Department of Physics, Indian Institute of Technology, Roorkee, Uttarkhand (India)

2017-08-15

We present a novel approach for designing new hard magnets by forming stacks of existing binary magnets to enhance the magneto crystalline anisotropy. This is followed by an attempt at reducing the amount of expensive metal in these stacks by replacing it with cheaper metal with similar ionic radius. This strategy is explored using examples of FePt, MnAl and MnGa. In this study a few promising materials are suggested as good candidates for hard magnets: stacked binary FePt{sub 2}MnGa{sub 2} in structure where each magnetic layer is separated by two non-magnetic layers, FePtMnGa and FePtMnAl in hexagonally distorted Heusler structures and FePt{sub 0.5}Ti{sub 0.5}MnAl. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Uranium chemistry in stack solutions and leachates of phosphogypsum disposed at a coastal area in Cyprus.

Science.gov (United States)

Lysandrou, M; Pashalidis, I

2008-02-01

The effect of the matrix composition (main constituents) on the concentration and chemical behavior of uranium in phosphogypsum stack solutions and leachates has been investigated. Solid and aqueous samples were taken from three different sub-areas of a phosphogypsum stack at a coastal area in Vasilikos (Cyprus). The sub-areas are characterized whether by their acidity (e.g. "aged" and "non-aged" phosphogypsum) or by their salt content, originating from pulping water during wet stacking or (after deposition) from the adjacent sea. Measurements in stack solutions and leachates showed that phosphogypsum characteristics affect both, the concentration and the chemical behavior of uranium in solution. Uranium concentration in solutions of increased salinity is up to three orders of magnitude higher than in solutions of low salinity and this is attributed to the effect of ionic strength on the solubility of phosphogypsum. Modelling showed that uranium in stack solutions is predominantly present in the form of uranium(VI) phosphate complexes (e.g. UO(2)(H(2)PO(4))(2), UO(2)HPO(4)), whereas in leachates uranium(VI) fluoro complexes (e.g. UO(2)F(2), UO(2)F(3)(-)) are predominant in solution. The latter indicates that elution of uranium from phosphogypsum takes places most probably in the form of fluoro complexes. Both, effective elution by saline water and direct migration of uranium to the sea, where it forms very stable uranium(VI) carbonato complexes, indicate that the adjacent sea will be the final receptor of uranium released from Vasilikos phosphogypsum.

Hexagonal perovskites with cationic vacancies. 4. Ba/sub 8/Re/sub 3/Msup(V)Wvacant/sub 3/O/sub 24/ with Msup(V) = Nb, Ta - perovskite stacking polytypes of 24 L type

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

1978-11-01

The yellow perovskite stacking polytypes Ba/sub 8/Re/sub 3/NbWvacant/sub 3/O/sub 24/ and Ba/sub 8/Re/sub 3/TaWvacant/sub 3/O/sub 24/ have a rhombohedral layer structure of 24 L type with 3 formula units in the trigonal setting (Ba/sub 8/Re/sub 3/NbWvacant/sub 3/O/sub 24/: a = 5,82 A; c = 55.6 A; Ba/sub 8/Re/sub 3/TaWvacant/sub 3/O/sub 24/; a = 5,81 A; c = 55.6 A).

Performance evaluation of a stack cooling system using CO{sub 2} air conditioner in fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Chul; Won, Jong Phil [Thermal Management Research Center, Korea Automotive Technology Institute, Chungnam 330-912 (Korea); Park, Yong Sun; Lim, Tae Won [Corporate Research and Development Division, Hyundai-Kia Motors, Gyeonggi 449-912 (Korea); Kim, Min Soo [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea)

2009-01-15

A relation between the heat release from a fuel cell stack and an air conditioning system's performance was investigated. The air conditioning system installed in a fuel cell vehicle can be used for stack cooling when additional stack heat release is required over a fixed radiator capacity during high vehicle power generation. This study investigated the performance of a stack cooling system using CO{sub 2} air conditioner at various operating conditions. Also, the heat releasing effectiveness and mutual interference were analyzed and compared with those for the conventional radiator cooling system with/without cabin cooling. When the radiator coolant inlet temperature and flow rate were 65 C and 80 L/min, respectively, for the outdoor air inlet speed of 5 m/s, the heat release of the stack cooling system with the aid of CO{sub 2} air conditioner increased up to 36% more than that of the conventional radiator cooling system with cabin cooling. Furthermore, this increased by 7% versus the case without cabin cooling. (author)

Hexagonal perovskites with cationic vacancies. 22. Polymorphism of the rhombohedral 12 L stacking polytypes in the system Sr/sub 4-x/Ba/sub x/NiRe/sub 2/vacantO/sub 12/

Energy Technology Data Exchange (ETDEWEB)

Herrmann, M; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-10-01

In the system Sr/sub 4-x/Ba/sub x/NiRe/sub 2/vacantO/sub 12/ two different stacking polytypes of the rhombohedral 12 L type are present. Both crystallize in the space group R-3m with the same sequence of the close packed AO/sub 3/ sheets: (3)(1) = (hhcc)/sub 3/. Accordingly the octahedral net consists of groups of three face connected octahedra which are linked by another through single corner sharing octahedra. In the strontium compound, Sr/sub 4/NiRe/sub 2/vacantO/sub 12/, the occupation of the octahedral holes is the same as in other rhombohedral 12 L perovskites of type A/sub 4/(B, M)/sub 3/vacantO/sub 12/ (The two outer octahedra are occupied by rhenium, the center is vacant and the nickel is located in the single octahedron). In the barium stacking polytype, Ba/sub 4/NiRe/sub 2/vacantO/sub 12/, the distribution is completely altered: The rhenium atoms occupy the central position in the block of three face connected octahedra and the single octahedron, the nickel atom and the vacancy are distributed statistically over the two outer positions in the block of three octahedra. Intensity calculations on powder data gave the intensity related R' value of 7.2% for Sr/sub 4/NiRe/sub 2/vacantO/sub 12/ and 6.2% for Ba/sub 4/NiRe/sub 2/vacantO/sub 12/.

Improved adhesive properties of recombinant bifidobacteria expressing the Bifidobacterium bifidum-specific lipoprotein BopA

Directory of Open Access Journals (Sweden)

Gleinser Marita

2012-06-01

Full Text Available Abstract Background Bifidobacteria belong to one of the predominant bacterial groups in the intestinal microbiota of infants and adults. Several beneficial effects on the health status of their human hosts have been demonstrated making bifidobacteria interesting candidates for probiotic applications. Adhesion of probiotics to the intestinal epithelium is discussed as a prerequisite for colonisation of and persistence in the gastrointestinal tract. Results In the present study, 15 different strains of bifidobacteria were tested for adhesion. B. bifidum was identified as the species showing highest adhesion to all tested intestinal epithelial cell (IEC lines. Adhesion of B. bifidum S17 to IECs was strongly reduced after treatment of bacteria with pronase. These results strongly indicate that a proteinaceous cell surface component mediates adhesion of B. bifidum S17 to IECs. In silico analysis of the currently accessible Bifidobacterium genomes identified bopA encoding a lipoprotein as a B. bifidum-specific gene previously shown to function as an adhesin of B. bifidum MIMBb75. The in silico results were confirmed by Southern Blot analysis. Furthermore, Northern Blot analysis demonstrated that bopA is expressed in all B. bifidum strains tested under conditions used to cultivate bacteria for adhesion assays. The BopA gene was successfully expressed in E. coli and purified by Ni-NTA affinity chromatography as a C-terminal His6-fusion. Purified BopA had an inhibitory effect on adhesion of B. bifidum S17 to IECs. Moreover, bopA was successfully expressed in B. bifidum S17 and B. longum/infantis E18. Strains overexpressing bopA showed enhanced adhesion to IECs, clearly demonstrating a role of BopA in adhesion of B. bifidum strains. Conclusions BopA was identified as a B. bifidum-specific protein involved in adhesion to IECs. Bifidobacterium strains expressing bopA show enhanced adhesion. Our results represent the first report on recombinant

Effect of the post-deposition annealing on electrical characteristics of MIS structures with HfO{sub 2}/SiO{sub 2} gate dielectric stacks

Energy Technology Data Exchange (ETDEWEB)

Taube, Andrzej [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Mroczynski, Robert, E-mail: rmroczyn@elka.pw.edu.pl [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Korwin-Mikke, Katarzyna [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Gieraltowska, Sylwia [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Szmidt, Jan [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Piotrowska, Anna [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-09-01

In this work, we report on effects of post-deposition annealing on electrical characteristics of metal-insulator-semiconductor (MIS) structures with HfO{sub 2}/SiO{sub 2} double gate dielectric stacks. Obtained results have shown the deterioration of electro-physical properties of MIS structures, e.g. higher interface traps density in the middle of silicon forbidden band (D{sub itmb}), as well as non-uniform distribution and decrease of breakdown voltage (U{sub br}) values, after annealing above 400 Degree-Sign C. Two potential hypothesis of such behavior were proposed: the formation of interfacial layer between hafnia and silicon dioxide and the increase of crystallinity of HfO{sub 2} due to the high temperature treatment. Furthermore, the analysis of conduction mechanisms in investigated stacks revealed Poole-Frenkel (P-F) tunneling at broad range of electric field intensity.

Fabrication and electrical properties of metal-oxide semiconductor capacitors based on polycrystalline p-Cu{sub x}O and HfO{sub 2}/SiO{sub 2} high-{kappa} stack gate dielectrics

Energy Technology Data Exchange (ETDEWEB)

Zou Xiao [Department of Electronic Science and Technology, School of Physical Science and Technology, Wuhan University, Wuhan, 430074 (China); Department of Electromachine Engineering, Jianghan University, Wuhan, 430056 (China); Fang Guojia, E-mail: gjfang@whu.edu.c [Department of Electronic Science and Technology, School of Physical Science and Technology, Wuhan University, Wuhan, 430074 (China); Yuan Longyan; Liu Nishuang; Long Hao; Zhao Xingzhong [Department of Electronic Science and Technology, School of Physical Science and Technology, Wuhan University, Wuhan, 430074 (China)

2010-05-31

Polycrystalline p-type Cu{sub x}O films were deposited after the growth of HfO{sub 2} dielectric on Si substrate by pulsed laser deposition, and Cu{sub x}O metal-oxide-semiconductor (MOS) capacitors with HfO{sub 2}/SiO{sub 2} stack gate dielectric were primarily fabricated and investigated. X-ray diffraction and X-ray photoelectron spectroscopy were applied to analyze crystalline structure and Cu{sup +}/Cu{sup 2+} ratios of Cu{sub x}O films respectively. SiO{sub 2} interlayer formed between the high-{kappa} dielectric and substrate was estimated by the transmission electron microscope. Results of electrical characteristic measurement indicate that the permittivity of HfO{sub 2} is about 22, and the gate leakage current density of MOS capacitor with 11.3 nm HfO{sub 2}/SiO{sub 2} stack dielectrics is {approx} 10{sup -4} A/cm{sup 2}. Results also show that the annealing in N{sub 2} can improve the quality of Cu{sub x}O/HfO{sub 2} interface and thus reduce the gate leakage density.

State analysis of BOP using statistical and heuristic methods

International Nuclear Information System (INIS)

Heo, Gyun Young; Chang, Soon Heung

2003-01-01

Under the deregulation environment, the performance enhancement of BOP in nuclear power plants is being highlighted. To analyze performance level of BOP, we use the performance test procedures provided from an authorized institution such as ASME. However, through plant investigation, it was proved that the requirements of the performance test procedures about the reliability and quantity of sensors was difficult to be satisfied. As a solution of this, state analysis method that are the expanded concept of signal validation, was proposed on the basis of the statistical and heuristic approaches. Authors recommended the statistical linear regression model by analyzing correlation among BOP parameters as a reference state analysis method. Its advantage is that its derivation is not heuristic, it is possible to calculate model uncertainty, and it is easy to apply to an actual plant. The error of the statistical linear regression model is below 3% under normal as well as abnormal system states. Additionally a neural network model was recommended since the statistical model is impossible to apply to the validation of all of the sensors and is sensitive to the outlier that is the signal located out of a statistical distribution. Because there are a lot of sensors need to be validated in BOP, wavelet analysis (WA) were applied as a pre-processor for the reduction of input dimension and for the enhancement of training accuracy. The outlier localization capability of WA enhanced the robustness of the neural network. The trained neural network restored the degraded signals to the values within ±3% of the true signals

Hexagonal perovskites with cationic vacancies. 8. Vibrational spectroscopic investigations on rhombohedral 18 L-stacking polytypes Ba/sub 6/B/sub 2/sup(III)vacantW/sub 3/sup(VI)O/sub 18/

Energy Technology Data Exchange (ETDEWEB)

Schittenhelm, H J; Fadini, A; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.)

1979-10-01

The vibrational spectra of the 18 L stacking polytypes Ba/sub 6/B/sub 2/sup(III)vacant W/sub 3/O/sub 18/ (space group R3m; sequence (hhcccc)/sub 3/) with Bsup(III) = Lu, Y are reported. The octahedral net consists of W/sub 2/vacantO/sub 12/ and WO/sub 6/ groups, which are isolated from each other by the Ba and B ions. An assignment of the vibrational frequencies has been made with the aid of factor group analysis. For the W/sub 2/vacantO/sub 12/ block a complete force constant calculation is reported.

Eosin Y-sensitized nanosheet-stacked hollow-sphere TiO{sub 2} for efficient photocatalytic H{sub 2} production under visible-light irradiation

Energy Technology Data Exchange (ETDEWEB)

Shi, Jinwen, E-mail: jinwen-shi@mail.xjtu.edu.cn; Guan, Xiangjiu; Zhou, Zhaohui; Liu, Haipei; Guo, Liejin [Xi’an Jiaotong University (XJTU), State Key Laboratory of Multiphase Flow in Power Engineering (MFPE), International Research Center for Renewable Energy IRCRE (China)

2015-06-15

Nanosheet (with around 20 nm in thickness)-stacked hollow-sphere TiO{sub 2} was synthesized via a modified solvothermal reaction for different times followed by calcination treatment at different temperatures. After surface modification by different cations (H{sup +} or Fe{sup 3+}) and further sensitization by Eosin Y, the obtained photocatalysts achieved remarkably enhanced H{sub 2}-production activity (about 4.2 times of that for Eosin Y-sensitized P25) and stability under visible-light irradiation. The improved photocatalytic performance was synergistically caused by the enhanced Eosin Y sensitization (due to the enlarged surface area and electropositively modified surface), the optimized crystal structure (well-crystallized anatase phase), and the unique micro/nanostructure (nanosheet-stacked hollow spheres). This work presented an effective route to explore new visible-light-driven H{sub 2}-production photocatalysts by coupling nanomaterials with special morphologies and metal-free dyes with visible-light absorption.

BOP2: Bayesian optimal design for phase II clinical trials with simple and complex endpoints.

Science.gov (United States)

Zhou, Heng; Lee, J Jack; Yuan, Ying

2017-09-20

We propose a flexible Bayesian optimal phase II (BOP2) design that is capable of handling simple (e.g., binary) and complicated (e.g., ordinal, nested, and co-primary) endpoints under a unified framework. We use a Dirichlet-multinomial model to accommodate different types of endpoints. At each interim, the go/no-go decision is made by evaluating a set of posterior probabilities of the events of interest, which is optimized to maximize power or minimize the number of patients under the null hypothesis. Unlike other existing Bayesian designs, the BOP2 design explicitly controls the type I error rate, thereby bridging the gap between Bayesian designs and frequentist designs. In addition, the stopping boundary of the BOP2 design can be enumerated prior to the onset of the trial. These features make the BOP2 design accessible to a wide range of users and regulatory agencies and particularly easy to implement in practice. Simulation studies show that the BOP2 design has favorable operating characteristics with higher power and lower risk of incorrectly terminating the trial than some existing Bayesian phase II designs. The software to implement the BOP2 design is freely available at www.trialdesign.org. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Design and experimental characterization of a 350 W High Temperature PEM fuel cell stack

Directory of Open Access Journals (Sweden)

Nicola Zuliani

2011-01-01

Full Text Available High Temperature Proton Exchange Membrane (HT PEM fuel cell based on polybenzimidazole (PBI polymer and phosphoric acid, can be operated at temperature between 120 °C and 180 °C. Reactants humidification is not required and CO content up to 2% in the fuel can be tolerated, affecting only marginally performance. This is what makes HT PEM very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. Till nowadays, from experimental point of view, only few studies relate to the development and characterization of high temperature stacks. The aim of this work is to present the main design features and the performance curves of a 25 cells HT PEM stack based on PBI and phosphoric acid membranes. Performance curves refer to the stack operating with two type of fuels: pure hydrogen and a gas mixture simulating a typical steam reformer output. The stack voltage distribution analysis and the stack temperature distribution analysis suggest that cathode air could be used as coolant leading to a better thermal management. This could simplify stack design and system BOP, thus increasing system performance.

Insights into thermal diffusion of germanium and oxygen atoms in HfO{sub 2}/GeO{sub 2}/Ge gate stacks and their suppressed reaction with atomically thin AlO{sub x} interlayers

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Shingo, E-mail: Shingo-Ogawa@trc.toray.co.jp [Toray Research Center, Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan); Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Asahara, Ryohei; Minoura, Yuya; Hosoi, Takuji, E-mail: hosoi@mls.eng.osaka-u.ac.jp; Shimura, Takayoshi; Watanabe, Heiji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Sako, Hideki; Kawasaki, Naohiko; Yamada, Ichiko; Miyamoto, Takashi [Toray Research Center, Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan)

2015-12-21

The thermal diffusion of germanium and oxygen atoms in HfO{sub 2}/GeO{sub 2}/Ge gate stacks was comprehensively evaluated by x-ray photoelectron spectroscopy and secondary ion mass spectrometry combined with an isotopic labeling technique. It was found that {sup 18}O-tracers composing the GeO{sub 2} underlayers diffuse within the HfO{sub 2} overlayers based on Fick's law with the low activation energy of about 0.5 eV. Although out-diffusion of the germanium atoms through HfO{sub 2} also proceeded at the low temperatures of around 200 °C, the diffusing germanium atoms preferentially segregated on the HfO{sub 2} surfaces, and the reaction was further enhanced at high temperatures with the assistance of GeO desorption. A technique to insert atomically thin AlO{sub x} interlayers between the HfO{sub 2} and GeO{sub 2} layers was proven to effectively suppress both of these independent germanium and oxygen intermixing reactions in the gate stacks.

Dimensional crossover of electron weak localization in ZnO/TiO{sub x} stacked layers grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Bhartiya, S. [Laser Materials Development & Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Gupta, M. [UGC-DAE Consortium for Scientific Research, Indore 452 017 (India)

2016-01-25

We report on the dimensional crossover of electron weak localization in ZnO/TiO{sub x} stacked layers having well-defined and spatially-localized Ti dopant profiles along film thickness. These films were grown by in situ incorporation of sub-monolayer TiO{sub x} on the growing ZnO film surface and subsequent overgrowth of thin conducting ZnO spacer layer using atomic layer deposition. Film thickness was varied in the range of ∼6–65 nm by vertically stacking different numbers (n = 1–7) of ZnO/TiO{sub x} layers of nearly identical dopant-profiles. The evolution of zero-field sheet resistance (R{sub ◻}) versus temperature with decreasing film thickness showed a metal to insulator transition. On the metallic side of the metal-insulator transition, R{sub ◻}(T) and magnetoresistance data were found to be well corroborated with the theoretical framework of electron weak localization in the diffusive transport regime. The temperature dependence of both R{sub ◻} and inelastic scattering length provided strong evidence for a smooth crossover from 2D to 3D weak localization behaviour. Results of this study provide deeper insight into the electron transport in low-dimensional n-type ZnO/TiO{sub x} stacked layers which have potential applications in the field of transparent oxide electronics.

Fermi level pinning in metal/Al{sub 2}O{sub 3}/InGaAs gate stack after post metallization annealing

Energy Technology Data Exchange (ETDEWEB)

Winter, R.; Krylov, I.; Cytermann, C.; Eizenberg, M. [Department of Materials Science and Engineering, Technion—Israel Institute of Technology, Haifa 32000 (Israel); Tang, K.; Ahn, J.; McIntyre, P. C. [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)

2015-08-07

The effect of post metal deposition annealing on the effective work function in metal/Al{sub 2}O{sub 3}/InGaAs gate stacks was investigated. The effective work functions of different metal gates (Al, Au, and Pt) were measured. Flat band voltage shifts for these and other metals studied suggest that their Fermi levels become pinned after the post-metallization vacuum annealing. Moreover, there is a difference between the measured effective work functions of Al and Pt, and the reported vacuum work function of these metals after annealing. We propose that this phenomenon is caused by charging of indium and gallium induced traps at the annealed metal/Al{sub 2}O{sub 3} interface.

Rapid extraction of uranium from sea water using Fe{sub 3}O{sub 4} and humic acid coated Fe{sub 3}O{sub 4} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Singhal, Pallavi, E-mail: psinghal@barc.gov.in [Homi Bhabha National Institute, Mumbai 400094 (India); Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Jha, Sanjay K. [Homi Bhabha National Institute, Mumbai 400094 (India); Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pandey, Shailaja P. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Neogy, Suman [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2017-08-05

Highlights: • Uranium extraction using Fe{sub 3}O{sub 4} and HA coated Fe{sub 3}O{sub 4} NPs has been demonstrated. • Result indicates uranium extraction from both water and sea water matrix. • With increase in HA coating uranium extraction increases. • Fe{sub 3}O{sub 4}/HA 1 is the best material among synthesized one for uranium extraction. - Abstract: Uranium is one of the most toxic elements present in the environment and a number of methods have been developed for its extraction. Herein we have demonstrated a new method using magnetic nanoparticles (NPs) that can be used for uranium extraction from water and sea water matrix. Fe{sub 3}O{sub 4} and humic acid (HA) coated Fe{sub 3}O{sub 4} NPs with different amount of HA coating were synthesized and uranium sorption from water and sea water matrix was demonstrated. It was observed that sorption increases with increase in amount of HA coating. NPs settlement in presence of magnetic field was monitored where only bare Fe{sub 3}O{sub 4} and Fe{sub 3}O{sub 4}/HA 1 NPs settles while no settlement was observed for Fe{sub 3}O{sub 4}/HA 2 and Fe{sub 3}O{sub 4}/HA 3 NPs. Considering both sorption and particle separation from the matrix Fe{sub 3}O{sub 4}/HA 1 NPs are the best among synthesized ones with maximum sorption capacity of 10.5 mg of U/g of NPs. The results presented here reveal the exceptional potential of magnetic NPs and functionalized magnetic NPs for environmental remediation of uranium and to extract uranium from sea water on which to the best of our knowledge no report is available till now.

Observation of dopant-profile independent electron transport in sub-monolayer TiO{sub x} stacked ZnO thin films grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Das, Gangadhar [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2016-01-18

Dopant-profile independent electron transport has been observed through a combined study of temperature dependent electrical resistivity and magnetoresistance measurements on a series of Ti incorporated ZnO thin films with varying degree of static-disorder. These films were grown by atomic layer deposition through in-situ vertical stacking of multiple sub-monolayers of TiO{sub x} in ZnO. Upon decreasing ZnO spacer layer thickness, electron transport smoothly evolved from a good metallic to an incipient non-metallic regime due to the intricate interplay of screening of spatial potential fluctuations and strength of static-disorder in the films. Temperature dependent phase-coherence length as extracted from the magnetotransport measurement revealed insignificant role of inter sub-monolayer scattering as an additional channel for electron dephasing, indicating that films were homogeneously disordered three-dimensional electronic systems irrespective of their dopant-profiles. Results of this study are worthy enough for both fundamental physics perspective and efficient applications of multi-stacked ZnO/TiO{sub x} structures in the emerging field of transparent oxide electronics.

Complementary and bipolar regimes of resistive switching in TiN/HfO{sub 2}/TiN stacks grown by atomic-layer deposition

Energy Technology Data Exchange (ETDEWEB)

Egorov, K.V.; Kirtaev, R.V.; Markeev, A.M.; Zablotskiy, A.V. [Moscow Institute of Physics and Technology, Institutskii per. 9, 141700, Dolgoprudny (Russian Federation); Lebedinskii, Yu.Yu.; Matveyev, Yu.A.; Zenkevich, A.V. [Moscow Institute of Physics and Technology, Institutskii per. 9, 141700, Dolgoprudny (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoye shosse 31, 115409, Moscow (Russian Federation); Orlov, O.M. [Scientific Research Institute of Molecular Electronics and Plant ' ' Micron' ' , 124462, Zelenograd (Russian Federation)

2015-04-01

Atomic-layer deposition (ALD) technique in combination with in vacuo X-ray photoelectron spectroscopy (XPS) analysis has been successfully employed to obtain fully ALD-grown planar TiN/HfO{sub 2}/TiN metal-insulator-metal structures for resistive random access memory (ReRAM) memory elements. In vacuo XPS analysis of ALD-grown TiN/HfO{sub 2}/TiN stacks reveals the presence of the ultrathin oxidized layers consisting of TiON (∝0.5 nm) and TiO{sub 2} (∝0.6 nm) at the bottom TiN/HfO{sub 2} interface (i); the nonoxidized TiN at the top HfO{sub 2}/TiN interface (ii); the oxygen deficiency in the HfO{sub 2} layer does not exceed the XPS detection limit (iii). Electroformed ALD TiN/HfO{sub 2}/TiN stacks reveal both conventional bipolar and complementary types of resistive switching. In the complementary resistive switching regime, each programming sequence is terminated by a reset operation, leaving the TiN/HfO{sub 2}/TiN stack in a high-resistance state. The observed feature can avoid detrimental leaky paths during successive reading operation, which is useful in the passive ReRAM arrays without a selector element. The bipolar regime of resistive switching is found to reveal the gradual character of the SET and RESET switching processes. Long-term potentiation and depression tests performed on ALD-grown TiN/HfO{sub 2}/TiN stacks indicate that they can be used as electronic synapse devices for the implementation of emerging neuromorphic computation systems. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Conceptual Design for BOP of the Sodium-Cooled Fast Reactor

International Nuclear Information System (INIS)

Yoo, Tae Geun; Kim, Seong O; Kim, Eui Kwang; Seong, Seung Hwan

2010-01-01

The heavy dependence on nuclear power eventually raise the issues of an efficient utilization of uranium resources, which Korea presently imports from abroad, end of a spent fuel storage. From the viewpoint that sodium-cooled fast Reactors (SFR s ) have the potential of an enhanced safety by utilizing inherent safety characteristics, trans-uranics (TRU) reduction and resolving the spent fuel storage problems through a proliferation-resistant actinide recycling. SFR s are sure to be most promising nuclear power operation. The Korea Atomic Energy Research Institute (KAERI) has been developing SFR design technologies since 1997. And nowadays, the preliminary heat balance of the demonstration SFR is calculated. However, in order to verify design condition of the NSSS, it is necessary to set the heat balance and the conceptual design for BOP of the SFR as a part of the SFR design technique development business. Moreover, in order to confirm whether the heat balance can actually appropriate via the turbine characteristic, it is required to carry out the performance analysis of the turbine cycle. For that, the main purposes of this study are; 1) to derivate the conceptual design for BOP, 2) to analyze the performance of the turbine cycle, 3) to derivate the main consideration for BOP design

Instant noodles as an antifriction device: making the BOP with PPP in PNG.

Science.gov (United States)

Errington, Frederick; Fujikura, Tatsuro; Gewertz, Deborah

2012-01-01

Focusing primarily, but not exclusively, on urban and periurban Papua New Guinea (PNG), we discuss the significance of instant ramen noodles to those now known as the “bottom of the pyramid” (BOP). Although instant noodles are remarkable in that they are eaten by virtually everyone in the world, albeit in different amounts and for different reasons, they are marketed in PNG specifically as a “popularly positioned product” (PPP) for the BOP. Cheap, convenient, tasty, filling, and shelf stable, they are a modern addition to Sidney Mintz's classic “proletarian hunger killers” of sugar, tea, and coffee. But, we argue, instant noodles have a distinctive contemporary role: they do more than sustain the poor; they transform them into the aspiring consumers of the BOP. As such, instant noodles can be viewed as an antifriction device, greasing the skids of capitalism as it extends its reach.

Sub-10 nm low current resistive switching behavior in hafnium oxide stack

Energy Technology Data Exchange (ETDEWEB)

Hou, Y., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn [Institute of Microelectronics, Peking University, 100871 Beijing (China); IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Celano, U.; Xu, Z.; Vandervorst, W. [IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Goux, L.; Fantini, A.; Degraeve, R.; Youssef, A.; Jurczak, M. [IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Liu, L., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn; Cheng, Y.; Kang, J. [Institute of Microelectronics, Peking University, 100871 Beijing (China)

2016-03-21

In this letter, a tip-induced cell relying on the conductive atomic force microscope is proposed. It is verified as a referable replica of an integrated resistive random access memory (RRAM) device. On the basis of this cell, the functionality of sub-10 nm resistive switching is confirmed in hafnium oxide stack. Moreover, the low current switching behavior in the sub-10 nm dimension is found to be more pronounced than that of a 50 × 50 nm{sup 2} device. It shows better ON/OFF ratio and low leakage current. The enhanced memory performance is ascribed to a change in the shape of the conductive filament as the device dimensions are reduced to sub-10 nm. Therefore, device downscaling provides a promising approach for the resistance optimization that benefits the RRAM array design.

Hexagonal perovskites with cationic vacancies. 7. Vibrational spectroscopic investigations on the rhombohedral 12 L-stacking polytypes Ba/sub 4/Bsup(II)(Re/sub 2/vacantO/sub 12/) and Ba/sub 4/Bsub(2/3)sup(III)vacantsub(1/3)(Re/sub 2/vacantO/sub 12/)

Energy Technology Data Exchange (ETDEWEB)

Fadini, A; Kemmler-Sack, S; Schittenhelm, H J; Rother, H J; Treiber, U [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1979-07-01

For the rhombohedral 12 L stacking polytypes Ba/sub 4/Bsup(II)(Re/sub 2/vacantO/sub 12/) and Ba/sub 4/Bsub(2/3)sup(III)vacantsub(1/3)(Re/sub 2/vacantO/sub 12/), space group R3m, sequence (3)(1), the lattice consists of groups of three face sharing octahedra with the composition Re/sub 2/vacantO/sub 12/. They are isolated from each other by the Ba and B ions. The vibrational spectra are interpreted according to the factor group analysis. For the Re/sub 2/vacantO/sub 12/ unit (symmetry Dsub(3d) the results of a complete vibrational analysis and the calculation of the force constants are reported.

Photoluminescence of trivalent rare earths in perovskite stacking polytypes Ba/sub 2/Lasub(2-x)REsub(x)/sup 3 +/MgW/sub 2/vacantO/sub 12/, Ba/sub 6/Ysub(2-x)REsub(x)/sup 3 +/W/sub 3/vacantO/sub 18/, and Sr/sub 8/SrGdsub(2-x)REsub(x)/sup 3 +/W/sub 4/vacantO/sub 24/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-12-01

Rhombohedral 12 L staking polytypes Ba/sub 2/Lasub(2-x)REsub(x)/sup 3 +/MgW/sub 2/vacantO/sub 12/ show with RE/sup 3 +/ = Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm; the 18 L stacking polytypes Ba/sub 6/Ysub(2-x)REsub(x)/sup 3 +/W/sub 3/vacantO/sub 18/ and the polymorphic perovskites Sr/sub 8/SrGdsub(2-x)REsub(x)/sup 3 +/W/sub 4/vacantO/sub 24/ with RE/sup 3 +/ = Sm, Eu, Dy, Ho, Er visible photoluminescence. The concentration dependence and the influence of the coordination number of the rare earth are reported.

A high fidelity model and code generator for the simulation of BOP systems

International Nuclear Information System (INIS)

Galen, S.; Vinay, M.

1993-01-01

TOPMERET represents a significant advance in the modelling fidelity of Balance of Plant systems (BOP). It is extremely flexible and can accommodate a variety of systems, including main steam, feedwater, turbine, condenser, offgas, large volumes, such as the containment, and water systems such as service water. It handles both normal and abnormal operating scenarios, including pipe break accidents. It was tested successfully on various simulators, and meets the fidelity required of BOP system models so as to successfully integrate with the high level of control automation of European designs. (Z.S.) 1 ref

Hexagonal perovskites with cationic vacancies. 5. Structure determination on H-Ba/sub 2/Lusub(2/3)vacantsub(1/3)WO/sub 6/ - a novel rhombohedral stacking polytype with 18 layers

Energy Technology Data Exchange (ETDEWEB)

Wischert, W; Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

1979-01-01

Compounds of type Ba/sub 2/Bsub(2/3)sup(III)vacantsub(1/3)Wsup(VI)O/sub 6/ with Bsup(III) = Gd-Lu, Y are polymorphic. They crystallize in a cubic 1:1 ordered perovskite structure and in a new rhombohedral perovskite stacking polytype of 18 L respectively. By intensity calculations out of the three possible stacking sequences (4)(2), (5)(1) and (3)1(1)1 (all space group R3m) the sequence (5)(1) can be selected. For H-Ba/sub 2/Lusub(2/3)vacant sub(1/3)WO/sub 6/ the refined R' factor is 14.1%. The structure contains groups of three octahedra connected with another by common faces which are linked with each other by three corner sharing octahedra. In the block of three face sharing octahedra the central octahedral lattice site is vacant, the two outer positions are occupied by tungsten atoms. According to this distribution a direct contact of occupied face sharing octahedra is absent.

Evolution of interfacial Fermi level in In{sub 0.53}Ga{sub 0.47}As/high-κ/TiN gate stacks

Energy Technology Data Exchange (ETDEWEB)

Carr, Adra; Rozen, John; Frank, Martin M.; Ando, Takashi; Cartier, Eduard A.; Kerber, Pranita; Narayanan, Vijay; Haight, Richard [IBM T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (United States)

2015-07-06

The net charge state was probed of metal-oxide-semiconductor gate stacks consisting of In{sub 0.53}Ga{sub 0.47}As /high-κ dielectric/5 nm TiN, for both Al{sub 2}O{sub 3} and HfO{sub 2} dielectrics, via investigation of band bending at the InGaAs/high-κ interface. Using pump-probe photoelectron spectroscopy, changes to band bending were studied for each sequential layer deposited onto the InGaAs substrate and subsequent annealing up to 600 °C. Two behavioral regions were observed in annealing studies: (1) a lower temperature (<350 °C) region, attributed to changes at the high-κ/TiN interface, and (2) a higher temperature region (> 350 °C), associated with a net positive charge increase within the oxide. These band bending measurements delineate the impact of processing steps inherently inaccessible via capacitance-voltage electrical characterization.

CoBOP: Microbial Biofilms: A Parameter Altering the Apparent Optical Properties of Sediments, Seagrasses and Surfaces

Science.gov (United States)

2002-09-30

CoBOP: Microbial Biofilms: A Parameter Altering the Apparent Optical Properties of Sediments, Seagrasses and Surfaces Alan W. Decho Department...TITLE AND SUBTITLE CoBOP: Microbial Biofilms: A Parameter Altering the Apparent Optical Properties of Sediments, Seagrasses and Surfaces 5a. CONTRACT...structures produced by bacteria. Their growth appears to depend on biofilm processes and light distributions ( photosynthesis ). Therefore, the data acquired

Enhanced photocatalytic activity over Cd{sub 0.5}Zn{sub 0.5}S with stacking fault structure combined with Cu{sup 2+} modified carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Gong, Beini; Lu, Yonghong [School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Wu, Pingxiao, E-mail: pppxwu@scut.edu.cn [School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Guangdong Provincial Engineering and Technology Research Centre for Environment Risk Prevention and Emergency Disposal, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); Huang, Zhujian; Zhu, Yajie; Dang, Zhi [School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Zhu, Nengwu [School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Guangdong Provincial Engineering and Technology Research Centre for Environment Risk Prevention and Emergency Disposal, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); Lu, Guining; Huang, Junyi [School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China)

2016-03-01

Graphical abstract: - Highlights: • CdZnS with stacking faults was combined with Cu{sup 2+} modified carbon nanotubes. • Stacking faults and carbon nanotubes (Cu) synergized to promote charge separation. • The composite exhibited enhanced photocatalytic performance. - Abstract: For enhanced photocatalytic performance of visible light responsive CdZnS, a series of Cd{sub 0.5}Zn{sub 0.5}S solid solutions were fabricated by different methods. It was found that the semiconductor obtained through the precipitation-hydrothermal method (CZS-PH) exhibited the highest photocatalytic hydrogen production rate of 2154 μmol h{sup −1} g{sup −1}. The enhanced photocatalytic hydrogen production of CZS-PH was probably due to stacking fault formation as well as narrow bandgap, a large surface area and a small crystallite size. Based on this, carbon nanotubes modified with Cu{sup 2+} (CNTs (Cu)) were used as a cocatalyst for CZS-PH. The addition of CNTs (Cu) enhanced notably the absorption of the composites for visible light. The highest photocatalytic hydrogen production rate of the Cd{sub 0.5}Zn{sub 0.5}S-CNTs (Cu) composite was 2995 μmol h{sup −1} g{sup −1} with 1.0 wt.% of CNTs (Cu). The improvement of the photocatalytic activity by loading of CNTs (Cu) was not due to alteration of bandgap energy or surface area, and was probably attributed to suppression of the electron-hole recombination by the CNTs, with Cu{sup 2+} anchored in the interface optimizing the photogenerated electron transfer pathway between the semiconductor and CNTs. We report here the successful combination of homojunction and heterojunction in CdZnS semiconductor, which resulted in promotion of charge separation and enhanced photocatalytic activity.

Interdependence of Pes1, Bop1, and WDR12 controls nucleolar localization and assembly of the PeBoW complex required for maturation of the 60S ribosomal subunit.

Science.gov (United States)

Rohrmoser, Michaela; Hölzel, Michael; Grimm, Thomas; Malamoussi, Anastassia; Harasim, Thomas; Orban, Mathias; Pfisterer, Iris; Gruber-Eber, Anita; Kremmer, Elisabeth; Eick, Dirk

2007-05-01

The PeBoW complex is essential for cell proliferation and maturation of the large ribosomal subunit in mammalian cells. Here we examined the role of PeBoW-specific proteins Pes1, Bop1, and WDR12 in complex assembly and stability, nucleolar transport, and pre-ribosome association. Recombinant expression of the three subunits is sufficient for complex formation. The stability of all three subunits strongly increases upon incorporation into the complex. Only overexpression of Bop1 inhibits cell proliferation and rRNA processing, and its negative effects could be rescued by coexpression of WDR12, but not Pes1. Elevated levels of Bop1 induce Bop1/WDR12 and Bop1/Pes1 subcomplexes. Knockdown of Bop1 abolishes the copurification of Pes1 with WDR12, demonstrating Bop1 as the integral component of the complex. Overexpressed Bop1 substitutes for endogenous Bop1 in PeBoW complex assembly, leading to the instability of endogenous Bop1. Finally, indirect immunofluorescence, cell fractionation, and sucrose gradient centrifugation experiments indicate that transport of Bop1 from the cytoplasm to the nucleolus is Pes1 dependent, while Pes1 can migrate to the nucleolus and bind to preribosomal particles independently of Bop1. We conclude that the assembly and integrity of the PeBoW complex are highly sensitive to changes in Bop1 protein levels.

A preliminary analysis of the BOP design management in nuclear power plant

International Nuclear Information System (INIS)

Tian Bin

2014-01-01

BOP project is an important part of nuclear power plant to maintain the normal operation and maintenance of the plant. The level of the design management has the important influences on the quality of the whole project, Design management includes the choice of the design standards, design evaluation, document control, the management of the design interface, design modification management and the management of the design service. The paper will start from various design issues in the construction of the Fuqing BOP project, analyse the causes of the problems on the design schedule management, interface, evaluation and the modification management. And then the paper also provides suggestions for improvement about all of this. (author)

Accumulation of fossil CO/sub 2/ in the atmosphere and the sea

Energy Technology Data Exchange (ETDEWEB)

Fairhall, A W

1973-09-07

A model is presented which accounts quantitatively for the buildup of fossil CO/sub 2/ in the atmosphere. The model also predicts something not previously recognized: a significant uptake of fossil CO/sub 2/ by the sea. The sea is presently supersaturated with respect to aragonite and calcite, which calcareous organisms form in building their shells. Should the sea become unsaturated in CaCO/sub 3/ the shells of these organisms would tend to dissolve, as would the ocean's coral reefs. One test of the model would be afforded by careful monitoring of total CO/sub 2/ levels in the mixed layer over the next few years. The model predicts an increase in the mixed layer of about 1.4 per cent in the next decade. Because this is about double the accuracy of the present methods for measuring total CO/sub 2/ in seawater, this trend, if present, should be detectable within 3 to 5 years. (MFB)

Enhancement of stack ventilation in hot and humid climate using a combination of roof solar collector and vertical stack

Energy Technology Data Exchange (ETDEWEB)

Yusoff, Wardah Fatimah Mohammad; Salleh, Elias [Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Adam, Nor Mariah [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapian, Abdul Razak [Department of Architecture, Kulliyyah of Architecture and Environmental Design, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur (Malaysia); Yusof Sulaiman, Mohamad [Solar Energy Research Institute, 3rd Floor, Tun Sri Lanang Library Building, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2010-10-15

In the hot and humid climate, stack ventilation is inefficient due to small temperature difference between the inside and outside of naturally ventilated buildings. Hence, solar induced ventilation is a feasible alternative in enhancing the stack ventilation. This paper aims to investigate the effectiveness of a proposed solar induced ventilation strategy, which combines a roof solar collector and a vertical stack, in enhancing the stack ventilation performance in the hot and humid climate. The methodology selected for the investigation is physical experimental modelling which was carried out in the actual environment. The results are presented and discussed in terms of two performance variables: air temperature and air velocity. The findings indicate that the proposed strategy is able to enhance the stack ventilation, both in semi-clear sky and overcast sky conditions. The highest air temperature difference between the air inside the stack and the ambient air (T{sub i}-T{sub o}) is achieved in the semi-clear sky condition, which is about 9.9 C (45.8 C-35.9 C). Meanwhile, in the overcast sky condition, the highest air temperature difference (T{sub i}-T{sub o}) is 6.2 C (39.3 C-33.1 C). The experimental results also indicate good agreement with the theoretical results for the glass temperature, the air temperature in the roof solar collector's channel and the absorber temperature. The findings also show that wind has significant effect to the induced air velocity by the proposed strategy. (author)

Developing Blue Ocean Strategy of Sustainable Product Design and Development for Business Opportunities of BOP Groups in Taiwan

Directory of Open Access Journals (Sweden)

Jui-Che Tu

2014-01-01

Full Text Available This study expands the definition of the poor group and attempts to delve into and make known the phenomenon of poverty in Taiwan and aims to explore the goals and possibilities of the BOP consumer market. Through a questionnaire survey and expert interviews, this research adopts the concept of sustainability to discuss the lifestyle and consumption characteristics of the BOP group and establishes a design strategic norm of the sustainable products. The findings show that the BOP group in Taiwan is new poverty or working poor and high quality and common prices are the main requirements; these should be introduced into the development model of sustainable design.

Solvothermal synthesis and high optical performance of three-dimensional sea-urchin-like TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yi, E-mail: zhouyihn@163.com; Wang, Yutang; Li, Mengyao; Li, Xuzhi; Yi, Qin; Deng, Pan; Wu, Hongyan

2015-06-15

Graphical abstract: I–V characteristics of different TiO{sub 2} microspheres based DSSCs (a) 3D sphere-like, (b) 3D flower-like, (c) 3D sea-urchin-like. - Highlights: • 3D sea-urchin-like TiO{sub 2} was synthesized by solvothermal method. • The effects of preparation parameters on the microstructure of the microspheres were investigated. • The photoelectric properties of 3D sea-urchin-like TiO{sub 2} were studied upon DSSCs. • The PCE of the 3D sea-urchin-like TiO{sub 2} was higher than that of other morphologies. - Abstract: Three-dimensional (3D) sea-urchin-like TiO{sub 2} microspheres were successfully synthesised by solvothermal method. The effects of preparation parameters including reaction temperature, concentration and mass fraction of precursor, and solvent volume on the microstructure of the microspheres were investigated. Results of scanning electron microscopy showed that the preparation parameters played a critical role in the morphology of 3D sea-urchin-like TiO{sub 2}. In addition, when the sea-urchin-like TiO{sub 2} nanostructures were used as the dye-sensitized solar cells (DSSCs) anode, the power-conversion efficiency was higher than that of other morphologies, which was due to the special 3D hierarchical nanostructure, large specific surface area, and enhanced absorption of UV–vis of the TiO{sub 2} nanostructures.

Hexagonal perovskites with cationic vacancies. 17. Structure determination on Ba/sub 9/Nb/sub 6/Wvacant/sub 2/O/sub 27/ - the first stacking polytype of a rhombohedral 27 L-type

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Treiber, U [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-03-01

The hexagonal stacking polytype of rhombohedral 27 L-type, Ba/sub 9/Nb/sub 6/Wvacant/sub 2/O/sub 27/, crystallizes in the space group R3m with the sequence (4)1(3)1 = (hhccchhcc)/sub 3/ and three formula units for the trigonal setting. The refined, intensity, related, R'-value is 9.7%. The octahedral net consists of blocks of three face connected octahedra which are linked to each other alternately through one or two octahedra connected exclusively by common vertices. The cationic vacancies are located in the centers of the groups of three octahedra. With this distribution direct contact between occupied face-sharing octahedra is avoided. The niobium and tungsten atoms are distributed statistically between the remaining octahedral holes. In the blocks of three octahedra they are displaced by approximately 0.29 A from their ideal positions in the direction of the central void. The Ba atoms neighbouring a vacancy (all in hexagonal packed BaO/sub 3/ sheets) are dislocated in the direction of the void, while the cubic packed BaO/sub 3/ sheets maintain nearly regular form.

Routes to a commercially viable PEM fuel cell stack

Energy Technology Data Exchange (ETDEWEB)

Newton, J.; Foster, S.E.; Hodgson, D.; Marrett, A.

2002-07-01

This report describes the results of a project to design and build a 10 kW{sub e} proton exchange membrane fuel cell (PEMFC) stack, including membrane electrode assemblies (MEAs), bipolar plates and stack hardware. The aim was to prove the design concept and to demonstrate functionality by operating the stack at >1 kW{sub e}/L and 500 W/kg for 200 hours operation. The project was extended to include the assembly and testing of two additional 1 kW{sub e} PEMFC stacks based on coated metal components. Low equivalent weight perfluorinated ionomer ion exchange membranes were prepared and were found to give a superior electrochemical performance to commercial materials. A technique to etch various stainless steel grades and control processes was successfully developed and optimised. Coatings for stainless steel and titanium were successfully developed and met the required performance criteria. All PEMFC stack components were selected and designed to enable subsequent commercial manufacture.

Intrinsic Rashba-like splitting in asymmetric Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} heterogeneous topological insulator films

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaofei; Guo, Wanlin, E-mail: wlguo@nuaa.edu.cn [State Key Laboratory of Mechanics and Control for Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices (MOE), Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

2014-08-25

We show by density functional theory calculations that asymmetric hetero-stacking of Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} films can modulate the topological surface states. Due to the structure inversion asymmetry, an intrinsic Rashba-like splitting of the conical surface bands is aroused. While such splitting in homogeneous Bi{sub 2}Te{sub 3}-class topological insulators can be realized in films with more than three quintuple layers under external electric fields, the hetero-stacking breaks the limit of thickness for preserving the topological nature into the thinnest two quintuple layers. These results indicate that the hetero-stacking can serve as an efficient strategy for spin-resolved band engineering of topological insulators.

Insurer Provide Rating Software and Competitive Advantage: An Evaluation Based on BOP Insurance Applications at Wisconsin Agencies

OpenAIRE

Thomas A. Aiuppa; William E. Wehrs

1993-01-01

This research examines whether a competitive advantage exists for insurers which provide independent agencies with rating software to generate price quotes. Data relative to the Business Owners line of insurance were collected from several Wisconsin agencies which represent several BOP insurers, some of which provide software for rating BOP applications. The results indicate that providing rating software did not increase insurers’ business volumes, but may decrease their underwriting costs. ...

Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

Energy Technology Data Exchange (ETDEWEB)

Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

2012-07-15

Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

Hexagonal perovskites with cationic vacancies. 29. Structure of Ba/sub 4/ScReWvacantO/sub 12/ - on the function of octahedral cationic vacancies in perovskite stacking polytypes

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Herrmann, M [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-09-01

The hexagonal perovskite stacking polytype Ba/sub 4/ScReWvacantO/sub 12/ crystallizes in a rhombohedral 12 L structure (space group R-3m; sequence (hhcc)/sub 3/). The refined, intensity related R' value is 6.6%. The octahedral net consists of blocks of three face connected octahedra with a central vacancy, in the two outer positions the rhenium and tungsten atoms are located; these units are linked via common corners by single octahedra, occupied with scandium. The construction principles of hexagonal oxygen perovskites with octahedral, cationic vacancies are reported.

Dual stacked partial least squares for analysis of near-infrared spectra

Energy Technology Data Exchange (ETDEWEB)

Bi, Yiming [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Xie, Qiong, E-mail: yimbi@163.com [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Zhao, Yuhui [School of Economics and Business, Northeastern University at Qinhuangdao, 066000 Qinhuangdao City (China); Li, Changwen [Food Research Institute of Tianjin Tasly Group, 300410 Tianjin (China)

2013-08-20

Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications.

Dual stacked partial least squares for analysis of near-infrared spectra

International Nuclear Information System (INIS)

Bi, Yiming; Xie, Qiong; Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie; Zhao, Yuhui; Li, Changwen

2013-01-01

Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications

Analysis and prediction of stacking sequences in intercalated lamellar vanadium phosphates

Energy Technology Data Exchange (ETDEWEB)

Gautier, Romain [Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS - Ecole Nationale Superieure de Chimie de Rennes (France); Centre Nationale de la Recherche Scientifique (CNRS), Institut des Materiaux Jean Rouxel (IMN), Universite de Nantes (France); Fourre, Yoann; Furet, Eric; Gautier, Regis; Le Fur, Eric [Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS - Ecole Nationale Superieure de Chimie de Rennes (France)

2015-04-15

An approach is presented that enables the analysis and prediction of stacking sequences in intercalated lamellar vanadium phosphates. A comparison of previously reported vanadium phosphates reveals two modes of intercalation: (i) 3d transition metal ions intercalated between VOPO{sub 4} layers and (ii) alkali/alkaline earth metal ions between VOPO{sub 4}.H{sub 2}O layers. Both intercalations were investigated using DFT calculations in order to understand the relative shifts of the vanadium phosphate layers. These calculations in addition to an analysis of the stacking sequences in previously reported materials enable the prediction of the crystal structures of M{sub x}(VOPO{sub 4}).yH{sub 2}O (M = Cs{sup +}, Cd{sup 2+} and Sn{sup 2+}). Experimental realization and structural determination of Cd(VOPO{sub 4}){sub 2}.4H{sub 2}O by single-crystal X-ray diffraction confirmed the predicted stacking sequences. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Stacking order dependent mechanical properties of graphene/MoS{sub 2} bilayer and trilayer heterostructures

Energy Technology Data Exchange (ETDEWEB)

Elder, Robert M., E-mail: robert.elder26.ctr@mail.mil, E-mail: mahesh.neupane.ctr@mail.mil; Neupane, Mahesh R., E-mail: robert.elder26.ctr@mail.mil, E-mail: mahesh.neupane.ctr@mail.mil; Chantawansri, Tanya L. [U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

2015-08-17

Transition metal dichalcogenides (TMDC) such as molybdenum disulfide (MoS{sub 2}) are two-dimensional materials that show promise for flexible electronics and piezoelectric applications, but their weak mechanical strength is a barrier to practical use. In this work, we perform nanoindentation simulations using atomistic molecular dynamics to study the mechanical properties of heterostructures formed by combining MoS{sub 2} with graphene. We consider both bi- and tri-layer heterostructures formed with MoS{sub 2} either supported or encapsulated by graphene. Mechanical properties, such as Young's modulus, bending modulus, ultimate tensile strength, and fracture strain, are extracted from nanoindentation simulations and compared to the monolayer and homogeneous bilayer systems. We observed that the heterostructures, regardless of the stacking order, are mechanically more robust than the mono- and bi-layer MoS{sub 2}, mainly due to the mechanical reinforcement provided by the graphene layer. The magnitudes of ultimate strength and fracture strain are similar for both the bi- and tri-layer heterostructures, but substantially larger than either the mono- and bi-layer MoS{sub 2}. Our results demonstrate the potential of graphene-based heterostructures to improve the mechanical properties of TMDC materials.

Synthesis, crystal structure and photoluminescence of a new Eu-doped Sr containing sialon (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}

Energy Technology Data Exchange (ETDEWEB)

Yamane, Hisanori, E-mail: yamane@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Shimooka, Satoshi; Uheda, Kyota [Mitsubishi Chemical Group, Science and Technology Research Center, Inc. 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-8502 (Japan)

2012-06-15

Colorless transparent platelet single crystals of a novel Eu{sup 2+}-doped strontium silicon aluminum oxynitride, (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}, were prepared at 1800 Degree-Sign C and 0.92 MPa of N{sub 2}. Fundamental reflections of electron and X-ray diffraction of the crystals were indexed with a face-centered orthorhombic unit cell (a=5.8061(5) A, b=37.762(3) A, c=9.5936(9) A). Diffuse streaks elongated in the b-axis direction were observed around the fundamental reflections hkl with h=2n+1 of the electron and X-ray diffraction, indicating stacking faults of (0 1 0)[1 0 0]/2. A crystal structure model without the stacking faults was obtained using the X-ray diffraction data of the fundamental reflections with the space group Fdd2. A SiN{sub 4}-tetrahedron double layer of [SiN{sub 2}]{sub 2} and a Sr/Eu double layer of [(Sr{sub 0.94}Eu{sub 0.06})Al{sub 1.2}Si{sub 0.8}N{sub 0.8} O{sub 1.2}]{sub 2} are stacked alternately along the b-axis direction. The title compound showed an emission with a peak wavelength of 490 nm under 334 nm excitation at room temperature. - Graphical abstract: Single crystals of a novel Eu{sup 2+}-doped strontium silicon aluminum oxynitride, (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6}, having stacking faults on the (0 1 0) plane of an orthorhombic cell, were prepared at 1800 Degree-Sign C and 0.92 MPa of N{sub 2}. The compound showed emission with a peak wavelength of 490 nm under 334 nm excitation at room temperature. Highlights: Black-Right-Pointing-Pointer A new compound Eu{sup 2+}-doped (Sr{sub 0.94}Eu{sub 0.06})(Al{sub 0.3}Si{sub 0.7}){sub 4}(N{sub 0.8}O{sub 0.2}){sub 6} was prepared. Black-Right-Pointing-Pointer Stacking faults in the compound were clarified by electron and X-ray diffraction. Black-Right-Pointing-Pointer A basic crystal structure model was obtained based on the X-ray diffraction data. Black-Right-Pointing-Pointer An

Yttrium scandate thin film as alternative high-permittivity dielectric for germanium gate stack formation

Energy Technology Data Exchange (ETDEWEB)

Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Lee, Choong Hyun; Nishimura, Tomonori; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan); JST, CREST, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

2015-08-17

We investigated yttrium scandate (YScO{sub 3}) as an alternative high-permittivity (k) dielectric thin film for Ge gate stack formation. Significant enhancement of k-value is reported in YScO{sub 3} comparing to both of its binary compounds, Y{sub 2}O{sub 3} and Sc{sub 2}O{sub 3}, without any cost of interface properties. It suggests a feasible approach to a design of promising high-k dielectrics for Ge gate stack, namely, the formation of high-k ternary oxide out of two medium-k binary oxides. Aggressive scaling of equivalent oxide thickness (EOT) with promising interface properties is presented by using YScO{sub 3} as high-k dielectric and yttrium-doped GeO{sub 2} (Y-GeO{sub 2}) as interfacial layer, for a demonstration of high-k gate stack on Ge. In addition, we demonstrate Ge n-MOSFET performance showing the peak electron mobility over 1000 cm{sup 2}/V s in sub-nm EOT region by YScO{sub 3}/Y-GeO{sub 2}/Ge gate stack.

Coherent emission of terahertz radiation from intrinsic Josephson junctions in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}

Energy Technology Data Exchange (ETDEWEB)

Rudau, Fabian; Wieland, Raphael; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Quantum Science (CQ) in LISA+, Universitaet Tuebingen (Germany); Zhou, Xianjing; Ji, Min; Hao, Luyao; Huang, Ya; Wang, Huabing [Research Institute of Superconductor Electronics, Nanjing University (China); National Institute for Materials Science, Tsukuba (Japan); Kinev, Nickolay; Koshelets, Valery [Kotel' nikov Institute of Radio Engineering and Electronics, Moscow (Russian Federation); Li, Jun; Wu, Peiheng [Research Institute of Superconductor Electronics, Nanjing University (China); Hatano, Takeshi [National Institute for Materials Science, Tsukuba (Japan)

2016-07-01

Stacks of intrinsic Josephson junctions, made of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}, can be used as emitters of electromagnetic waves at terahertz frequencies. Coherent emission from 0.3 to 2.4 THz was detected from large, rectangular or disc-shaped mesa structures. Having a linewidth of only a few MHz, emission powers of several tens of microwatt can be produced for single stacks and up to 0.61 mW for an array of mesas. Since the mechanisms of synchronizing all the junctions in the stack is still not fully understood, we investigated the temperature distribution and electromagnetic standing waves in such stacks, as well as the generation of terahertz radiation, using a combination of electric transport measurements, direct radiation detection and low temperature scanning laser microscopy. Recent experimental results from our collaboration will be presented and compared to numerical simulations.

Fluxons in long and annular intrinsic Josephson junction stacks

CERN Document Server

Clauss, T; Moessle, M; Müller, A; Weber, A; Kölle, D; Kleiner, R

2002-01-01

A promising approach towards a THz oscillator based on intrinsic Josephson junctions in high-temperature superconductors is based on the collective motion of Josephson fluxons, which are predicted to form various configurations ranging from a triangular to a quadratic lattice. Not only for this reason, but certainly also for the sake of basic physics, several experimental and theoretical investigations have been done on the subject of collective fluxon dynamics in stacked intrinsic Josephson junctions. In this paper we will present some experimental results on the fluxon dynamics of long intrinsic Josephson junction stacks made of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8. The stacks were formed either in an open or in an annular geometry, and clear resonant fluxon modes were observed. Experiments discussed include measurements of current-voltage characteristics in external magnetic fields and in external microwave fields.

Evaluation and application of PEMFC fuel cell's technologies developed at IPEN applied to a 500 W{sub e} fuel cell stack; Avaliacao e aplicacao de tecnologias de celulas a combustivel tipo PEMFC desenvolvida no IPEN em um modulo de 500 W{sub e} de potencia nominal

Energy Technology Data Exchange (ETDEWEB)

Cunha, Edgar Ferrari da

2009-07-01

This work is part of a research project on PEMFC technologies carried out in IPEN to develop and optimize a 500 W{sub e} fuel cell stack. The MEAs scaling up from 25 cm{sup 2} to 144 cm{sup 2} produced by the method of sieve printing; computational fluid dynamics by computer simulation of gas flow channels in bipolar plates using COMSOL{sup R} program and the use of Pt/C electrodes developed by alcohol reduction method in single cells were used to build a stack of 500 W{sub e} nominal power for possible commercial applications, produced with national technology and industrial support. A 100 hours fuel cell's test was carried out in a 144 cm{sup 2} single cell to study the stability of the MEA fabricated by sieve printing method. This single cell showed good stability within this period of time. The developed stack has reached the maximum power of 574 W{sub e} at 100 A (694.4 mA cm{sup -2}). The operating power of 500 W{sub e} was obtained at 77.7 A (540.1 mA cm{sup -2}) and potential of 6.43 V, with efficiency of 43.3%. In terms of cogeneration, the thermal power or generated heat by the stack was 652 W{sub t}. The initial estimated cost for the 500 W{sub e} stack was about R$ 4,500.00, considering only the used materials for its construction. (author)

Lowering Investment Risk at the Bop Using Network Innovation Fundación pro Vivienda Social (Fpvs Case

Directory of Open Access Journals (Sweden)

Marìa Griselda Lassaga

2012-06-01

Full Text Available More than 2 million people from the outskirts of the Buenos Aires Metropolitan Region live in neighborhoods with restricted access to education, credit, healthcare, and basic services (Goytia and Lanfranchi, 2009. With nearly 4 billion people now living in poverty world wide, this situation is not unique to Buenos Aires. The size of this “Base of the Pyramid” (BOP economic market makes it impossible to ignore in the 21st century (Prahalad and Hart, 2002. Unfortunately however, most private businesses have overlooked this population and thereby denied it the opportunity to participate in the global economy. This article describes how Fundación Pro Vivienda Social (FPVS seeks to rectify this situation by facilitating economic engagement with the BOP. This case study, based on the testimony and experiences of participants, details the effort to create financially sustainable business opportunities for both the BOP and private sector. Specifically, this study deals with FPVS‟s role as a facilitator between businesses and poor communities in doing business with the Base of the Pyramid, (BOP. Testimony from this real case study in addition to the experience of the researchers and current business literature was the chosen path. As a longitudinal study, the case looks at how perceptions and relationships change over time. Based on the Developing Business Network Model, this article looked at the co-creation of value for all the parties within a sustainable framework. Specifically, the FPVS case deals with the foundation‟s leverage function in developing mutually beneficial infrastructure solutions. Since 1995, FPVS has focused on housing improvements and infrastructure development. Through its projects, FPVS has demonstrated that working with low-income communities is not high-risk, but rather good business. The foundation believes that by organizing communities around mobilizing events related to standard of living improvements, it can create

Analysis of chemical bond states and electrical properties of stacked AlON/HfO{sub 2} gate oxides formed by using a layer-by-layer technique

Energy Technology Data Exchange (ETDEWEB)

Choi, Wonjoon; Lee, Jonghyun; Yang, Jungyup; Kim, Chaeok; Hong, Jinpyo; Nahm, Tschanguh; Byun, Byungsub; Kim, Moseok [Hanyang University, Seoul (Korea, Republic of)

2006-06-15

Stacked AlON/HfO{sub 2} thin films for gate oxides in metal-oxide-semiconductor devices are successfully prepared on Si substrates by utilizing a layer-by-layer technique integrated with an off-axis RF remote plasma sputtering process at room temperature. This off-axis structure is designed to improve the uniformity and the quality of gate oxide films. Also, a layer-by-layer technique is used to control the interface layer between the gate oxide and the Si substrate. The electrical properties of our stacked films are characterized by using capacitance versus voltage and leakage current versus voltage measurements. The stacked AlON/HfO{sub 2} gate oxide exhibits a low leakage current of about 10{sup -6} A/cm{sup 2} and a high dielectric constant value of 14.26 by effectively suppressing the interface layer between gate oxide and Si substrate. In addition, the chemical bond states and the optimum thickness of each AlON and HfO{sub 2} thin film are analyzed using X-ray photoemission spectroscopy and transmission electron microscopy measurement.

Transverse peltier effect in Pb-Bi{sub 2}Te{sub 3} multilayer structures

Energy Technology Data Exchange (ETDEWEB)

Reitmaier, Christina; Walther, Franziska; Kyarad, Amir; Lengfellner, Hans [University of Regensburg (Germany)

2009-07-01

Metal-semiconductor multilayer structures show, according to model calculations, large anisotropy in their electrical and thermal transport properties. Multilayer stacks consisting of alternating layers of Pb and n-type Bi{sub 2}Te{sub 3} and prepared by a heating procedure displayed large thermoelectric anisotropy up to {delta}S{approx}200 {mu} V/K, depending on the thickness ratio p=d{sub BiTe}/d{sub Pb}, where d{sub BiTe} and d{sub Pb} are the thicknesses of Bi{sub 2}Te{sub 3} and Pb layers, respectively. From multilayer stacks, tilted samples with layers inclined with respect to the sample surface where obtained by cutting stacks obliquely to the stack axis. Non-zero off-diagonal elements in the Seebeck-tensor describing the thermopower of tilted samples allow for the occurance of a transverse Peltier effect. Experimental results demonstrate cooling by the transverse Peltier effect and are compared to model calculations.

Two superstructures of Ce{sub 3}Rh{sub 4}Ge{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Vosswinkel, Daniel; Hoffmann, Rolf-Dieter [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Svitlyk, Volodymyr [European Synchrotron Radiation Facility, Grenoble (France); and others

2018-04-01

Two different samples of Ce{sub 3}Rh{sub 4}Ge{sub 4} were synthesized from different starting compositions by melting of the elements in an arc-melting furnace followed by annealing sequences in a sealed tantalum ampoule in a muffle furnace. The structures of two different stacking variants were refined on the basis of temperature dependent single-crystal X-ray diffractometer data. At high temperature Ce{sub 3}Rh{sub 4}Ge{sub 4} adopts the U{sub 3}Ni{sub 4}Si{sub 4} type structure with strongly enhanced anisotropic displacement parameters for the Rh1 atoms. For the two different crystals, additional reflections start to appear at different temperatures. The first crystal showed additional reflections already at room temperature (stacking variant I) and the second one showed additional reflections emerging below 270 K (stacking variant II). Stacking variant I could be described with the (3+1)D superspace group I2/m(α0γ)00; α=1/2a*, γ=1/2c*; (Z=2), 1252 F{sup 2} values, 48 variables, wR=0.0306 for the main and wR=0.0527 for 440 1{sup st} order satellite reflections, similar to Pr{sub 3}Rh{sub 4}Ge{sub 4}. For stacking variant II the (3+1)D superspace group is Immm(α00)00s; α=1/2a*; (Z=2). The structure could be refined with 1261 F{sup 2} values, 53 variables and residuals of wR=0.0331 for the main reflections and wR=0.1755 (R1{sub obs}=0.0788) for the 1{sup st} order satellite reflections, [a=406.2(1), b=423.7(1) and c=2497.1(1) pm]. The commensurate description could be transformed to a three-dimensional (3D) supercell with space group Pnma and Z=4: a=812.5(1), b=423.7(1), c=2497.1(2) pm, 1261 F{sup 2} values, 69 variables and wR=0.0525. The relation of the U{sub 3}Ni{sub 4}Si{sub 4} type structure, the (3+1)D modulated and the 3D supercells are discussed on the basis of group-subgroup schemes. Ab initio electronic structure calculations are in line with the diffraction experiments, revealing the lowest total energy for the Pnma phase.

Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}

Energy Technology Data Exchange (ETDEWEB)

Oehmichen, V.

2007-09-29

Goal of this thesis was to extend the knowledge of fluxon dynamics in intrinsic Josephson junctions out of BSCCO and to manipulate this dynamics in a purposeful way. New approaches to create ThZ-radiation were investigated. Step stacks out of BSCCO have been prepared with dimensions of 1-3 {mu}m (width) and 3-10 {mu}m (length). The necessary fabrication process was established based on Wang's double-sided technique. Transport measurements without and with magnetic field were realised on the so produced samples. The magnetic field of some Tesla was oriented parallel to the CuO{sub 2}-double layers. Collective plasma resonances were observed. Those were more stable than the resonances in mesa-structures. The resonances in the low current range can be assigned to an out-of-phase configuration, whereas in the high current range there are some possible configurations. Flux-flow-oscillations measured at these step stacks support the arrangement of the fluxons in an out-of-phase configuration. The in-phase configuration couldn't be observed clearly, so two approaches were followed to manipulate aimingly the fluxon dynamics to create THz-radiation: * control current * geometric manipulation: width-modulated stack For electronic manipulation an additional current line (control current line) was prepared along the stack's bottom. During transport measurements in zero field a current of 0-30 {mu}A was sent through this control current line. The so created inhomogeneity should have provoked fluxons without the help of a magnetic field. A visible effect couldn't be measured. Geometric manipulation of fluxon dynamics to reach in-phase configuration relys on modulation of the stack's width: it has periodic necks (comb structure). First measurements on comb structures prepared in double-side technique show promising hints, that manipulation on purpose of fluxon dynamics is possible using width-modulation. Simulations were performed for different depths of

Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}

Energy Technology Data Exchange (ETDEWEB)

Oehmichen, V

2007-09-29

Goal of this thesis was to extend the knowledge of fluxon dynamics in intrinsic Josephson junctions out of BSCCO and to manipulate this dynamics in a purposeful way. New approaches to create ThZ-radiation were investigated. Step stacks out of BSCCO have been prepared with dimensions of 1-3 {mu}m (width) and 3-10 {mu}m (length). The necessary fabrication process was established based on Wang's double-sided technique. Transport measurements without and with magnetic field were realised on the so produced samples. The magnetic field of some Tesla was oriented parallel to the CuO{sub 2}-double layers. Collective plasma resonances were observed. Those were more stable than the resonances in mesa-structures. The resonances in the low current range can be assigned to an out-of-phase configuration, whereas in the high current range there are some possible configurations. Flux-flow-oscillations measured at these step stacks support the arrangement of the fluxons in an out-of-phase configuration. The in-phase configuration couldn't be observed clearly, so two approaches were followed to manipulate aimingly the fluxon dynamics to create THz-radiation: * control current * geometric manipulation: width-modulated stack For electronic manipulation an additional current line (control current line) was prepared along the stack's bottom. During transport measurements in zero field a current of 0-30 {mu}A was sent through this control current line. The so created inhomogeneity should have provoked fluxons without the help of a magnetic field. A visible effect couldn't be measured. Geometric manipulation of fluxon dynamics to reach in-phase configuration relys on modulation of the stack's width: it has periodic necks (comb structure). First measurements on comb structures prepared in double-side technique show promising hints, that manipulation on purpose of fluxon dynamics is possible using width-modulation. Simulations were performed for different depths of modulation, small and

A comparative study of charge trapping in HfO{sub 2}/Al{sub 2}O{sub 3} and ZrO{sub 2}/Al{sub 2}O{sub 3} based multilayered metal/high-k/oxide/Si structures

Energy Technology Data Exchange (ETDEWEB)

Spassov, D., E-mail: d_spassov@abv.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, Sofia 1784 (Bulgaria); Skeparovski, A. [Institute of Physics, Faculty of Natural Sciences and Mathematics, University “Ss. Cyril and Methodius”, Arhimedova 3, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Paskaleva, A. [Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, Sofia 1784 (Bulgaria); Novkovski, N. [Institute of Physics, Faculty of Natural Sciences and Mathematics, University “Ss. Cyril and Methodius”, Arhimedova 3, 1000 Skopje (Macedonia, The Former Yugoslav Republic of)

2016-09-01

The electrical properties of multilayered HfO{sub 2}/Al{sub 2}O{sub 3}/HfO{sub 2}/SiO{sub 2} and ZrO{sub 2}/Al{sub 2}O{sub 3}/ZrO{sub 2}/SiO{sub 2} metal-oxide semiconductor capacitors were investigated in order to evaluate the possibility of their application in charge-trapping non-volatile memory devices. The stacks were deposited by reactive radiofrequency magnetron sputtering on Si substrates with thermal SiO{sub 2} with a thickness ranging from 2 to 5 nm. Both types of stacks show negative initial oxide charge and its density is higher for HfO{sub 2}-based structures. Memory window up to 6V at sweeping voltage range of ± 16V was obtained for HfO{sub 2}-based stacks. The hysteresis in these structures is mainly due to a trapping of electrons injected from the Si substrate. The charge-trapping properties of ZrO{sub 2}-based samples are compromised by the high leakage currents and the dielectric breakdown. The conduction through the capacitors at low applied voltages results from hopping of thermally excited electrons from one isolated state to another. The energy depth of the traps participating in the hopping conduction was determined as ~ 0.7 eV for the HfO{sub 2}-based layers and ~ 0.6 eV for ZrO{sub 2}-based ones, originating from negatively charged oxygen vacancies. At high electric fields, the current voltage characteristics were interpreted in terms of space charge limited currents, Fowler–Nordheim tunneling, Schottky emission, and Poole–Frenkel mechanism. The charge retention characteristics do not depend on the thickness of the tunnel SiO{sub 2}. - Highlights: • Sputtered HfO{sub 2}/Al{sub 2}O{sub 3}/HfO{sub 2} and ZrO{sub 2}/Al{sub 2}O{sub 3}/ZrO{sub 2} charge-trapping layers were studied. • HfO{sub 2}/Al{sub 2}O{sub 3}/HfO{sub 2} stacks show memory window up to 6 V and good retention times. • Negatively charged oxygen vacancies were identified as main defects in the stacks. • Electrical breakdown compromise the charge-trapping properties

Electrical and materials properties of AlN/ HfO{sub 2} high-k stack with a metal gate

Energy Technology Data Exchange (ETDEWEB)

Reid, Kimberly G. [Tokyo Electron U.S., 14338 FM 1826, Austin, TX 78737 (United States)], E-mail: kim@ireid.com; Dip, Anthony [Tokyo Electron U.S., 2400 Grove Blvd., Austin, TX 78747 (United States)], E-mail: anthony.dip@us.tel.com; Sasaki, Sadao [Tokyo Electron U.S. (United States)], E-mail: Sadao.sasaki@us.tel.com; Triyoso, Dina [Freescale Semiconductor Inc., 3501 Ed Bluestein Blvd, Austin, TX 78721 (United States)], E-mail: Dina.Triyoso@freescale.com; Samavedam, Sri [Freescale Semiconductor Inc., 3501 Ed Bluestein Blvd, Austin, TX 78721 (United States)], E-mail: Sri.Samavedam@freescale.com; Gilmer, David [SEMATECH 2706 Montopolis Drive, Austin, TX 78741 (United States)], E-mail: David.Gilmer@sematech.org; Gondran, Carolyn F.H. [Process Characterization Laboratory, ATDF/SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741 (United States)], E-mail: Carolyn.Gondran@atdf.com

2009-02-27

In this study, aluminum nitride (AlN) was grown by molecular layer deposition on HfO{sub 2} that had been deposited on 200 mm Si (100) substrates. The AlN was grown on HfO{sub 2} using sequential exposures of trimethyl-aluminum and ammonia (NH{sub 3}) in a batch vertical furnace. Excellent thickness uniformity on test wafers from the top of the furnace to the bottom of the furnace (across the furnace load) was obtained. The equivalent oxide thickness was 16.5-18.8 A for the AlN/HfO{sub 2} stack on patterned device wafers with a molybdenum oxynitride metal gate with leakage current densities from low 10{sup -5} to mid 10{sup -6} A/cm{sup 2} at threshold voltage minus one volt. There was no change in the work function with the AlN cap on HfO{sub 2} with the MoN metal gate, even with a 1000 deg. C anneal.

Storing CO{sub 2} under the North Sea Basin - A key solution for combating climate change

Energy Technology Data Exchange (ETDEWEB)

Skogen, T; Morris, B; Agerup, M; Svenningsen, S Oe; Kropelien, K F; Solheim, M; Northmore, B; Dixon, T; O' Carroll, K; Greaves, A; Golder, J; Selmer-Olsen, S; Sjoeveit, A; Kaarstad, O; Riley, N; Wright, I; Mansfield, C

2007-06-15

This report represents the first deliverable of the North Sea Basin Task Force, which Norway and the UK established in November 2005 to work together on issues surrounding the transport and storage of CO{sub 2} beneath the North Sea. The North Sea represents the best geological opportunity for storing our CO{sub 2} emissions away from the atmosphere for both the UK and Norway

Evaluation and application of PEMFC fuel cell's technologies developed at IPEN applied to a 500 W{sub e} fuel cell stack; Avaliacao e aplicacao de tecnologias de celulas a combustivel tipo PEMFC desenvolvida no IPEN em um modulo de 500 W{sub e} de potencia nominal

Energy Technology Data Exchange (ETDEWEB)

Cunha, Edgar Ferrari da

2009-07-01

This work is part of a research project on PEMFC technologies carried out in IPEN to develop and optimize a 500 W{sub e} fuel cell stack. The MEAs scaling up from 25 cm{sup 2} to 144 cm{sup 2} produced by the method of sieve printing; computational fluid dynamics by computer simulation of gas flow channels in bipolar plates using COMSOL{sup R} program and the use of Pt/C electrodes developed by alcohol reduction method in single cells were used to build a stack of 500 W{sub e} nominal power for possible commercial applications, produced with national technology and industrial support. A 100 hours fuel cell's test was carried out in a 144 cm{sup 2} single cell to study the stability of the MEA fabricated by sieve printing method. This single cell showed good stability within this period of time. The developed stack has reached the maximum power of 574 W{sub e} at 100 A (694.4 mA cm{sup -2}). The operating power of 500 W{sub e} was obtained at 77.7 A (540.1 mA cm{sup -2}) and potential of 6.43 V, with efficiency of 43.3%. In terms of cogeneration, the thermal power or generated heat by the stack was 652 W{sub t}. The initial estimated cost for the 500 W{sub e} stack was about R$ 4,500.00, considering only the used materials for its construction. (author)

Converter fed sub sea motor drives

Energy Technology Data Exchange (ETDEWEB)

Raad, R O

1995-09-01

Minor offshore gas and oil resources located 20-50 km from existing installations may often be commercially exploited only by use of complete sub sea solutions. This thesis deals with analyses of a sub sea adjustable speed electric motor which is fed by a frequency converter via a long cable (up to 50 km) between the converter and the motor. The author develops a general model for analysing such motor drive systems with the objective of verifying the feasibility of specific applications and of specifying the requirements on the system components. The simulation model is used to identify the critical frequency ranges in which the converter must not generate significant harmonics, to verify the start-up strategy chosen, and to verify the stability with potential disturbances applied to the system. Simulation models are developed for both transient and steady state analyses. They are accurate up to 5 kHz and can incorporate the frequency dependency of the motor and cable parameters. Ideal thyristors and diodes are used. The models are implemented in existing simulation tools. Most of the results relate to a base case with a 670 kW squirrel cage motor fed from a 30 km long cable, but cases with 3 MW rating or with 50 km cable have also been analyzed and found to be feasible. Each specific application must be separately studied. Results of simulation calculations are presented and conclusions given. 53 refs., 124 figs., 23 tabs.

Inter-layered clay stacks in Jurassic shales

Science.gov (United States)

Pye, K.; Krinsley, D. H.

1983-01-01

Scanning electron microscopy in the backscattered electron mode is used together with energy-dispersive X-ray microanalysis to show that Lower Jurassic shales from the North Sea Basin contain large numbers of clay mineral stacks up to 150 microns in size. Polished shale sections are examined to determine the size, shape orientation, textural relationships, and internal compositional variations of the clays. Preliminary evidence that the clay stacks are authigenic, and may have formed at shallow burial depths during early diagenesis, is presented.

Optimal Stack Layout in a Sea Container Terminal with Automated Lifting Vehicles

OpenAIRE

Roy, D.; Gupta, A.; Parhi, S.; de Koster, M.B.M.

2014-01-01

textabstractContainer terminal performance is largely determined by its design decisions, which include the number and type of quay cranes (QCs), stack cranes (SCs), transport vehicles, vehicle travel path, and stack layout. The terminal design process is complex because it is affected by factors such as topological constraints, stochastic interactions among the quayside, vehicle transport and stackside operations. Further, the orientation of the stack layout (parallel or perpendicular to the...

Effects of sub-domain structure on initial magnetization curve and domain size distribution of stacked media

International Nuclear Information System (INIS)

Sato, S.; Kumagai, S.; Sugita, R.

2015-01-01

In this paper, in order to confirm the sub-domain structure in stacked media demagnetized with in-plane field, initial magnetization curves and magnetic domain size distribution were investigated. Both experimental and simulation results showed that an initial magnetization curve for the medium demagnetized with in-plane field (MDI) initially rose faster than that for the medium demagnetized with perpendicular field (MDP). It is inferred that this is because the MDI has a larger number of domain walls than the MDP due to the existence of the sub-domains, resulting in an increase in the probability of domain wall motion. Dispersion of domain size for the MDI was larger than that for the MDP. This is because sub-domains are formed not only inside the domain but also at the domain boundary region, and they change the position of the domain boundary to affect the domain size. - Highlights: • An initial magnetization curve for MDI initially rose faster than that for MDP. • Dispersion of domain size for the MDI was larger than that for the MDP. • Experimental and simulation results can be explained by existence of sub-domains

Structure and microwave dielectric characteristics of (Sr{sub 1−x}Ca{sub x})Nd{sub 2}Al{sub 2}O{sub 7} ceramics

Energy Technology Data Exchange (ETDEWEB)

Yi, Lei; Liu, Xiao Qiang; Li, Lei; Chen, Xiang Ming, E-mail: xmchen59@zju.edu.cn

2014-09-15

(Sr{sub 1−x}Ca{sub x})Nd{sub 2}Al{sub 2}O{sub 7} (x = 0, 0.1, 0.3, 0.5) ceramics were synthesized by a standard solid state reaction method. Their microwave dielectric properties were investigated together with the structural evolution. X-ray diffraction analysis indicated that Ruddlesden–Popper solid solutions with n = 2 were obtained for all the compositions investigated here. Ca-substitution significantly improved the densification behavior which was associated with the variation of ε{sub r}. More importantly, with increasing the content of Ca, τ{sub f} value was generally improved towards near-zero, and the significantly improved Qf value was obtained at x = 0.5. The stacking fault and distorted lattice fringe in the ceramics were confirmed by TEM observation, and these defects were deeply concerned with the microwave dielectric loss. The best combination of microwave dielectric characteristics was achieved for the composition of x = 0.5: ε{sub r} = 21.1, Qf = 68,200 GHz and τ{sub f} = −0.5 ppm/°C. - Highlights: • The formation of solid solutions with partial Ca substitution for Sr improved the sintering behavior of SrNd{sub 2}Al{sub 2}O{sub 7} ceramics. • Stacking fault and distorted lattice fringe were confirmed by transmission electron microscopy. • The variation of Qf value was associated with the stacking fault and distorted lattice fringe.

The Role of Relative Sea Level Changes in Diagenetic Processes and Stacking Pattern of Kangan Formation Sediments in one of the Persian Gulf Fields

Directory of Open Access Journals (Sweden)

حسن اشراقی

2016-01-01

Full Text Available The Lower to Middle Triassic aged Kangan Formation is one of the most significant carbonate gas reservoirs in Iranian territory. In this study, thin sections data were used to recognize microfacies, sedimentary environments and the interaction between diagenetic processes and facies stacking pattern in a sequence stratigraphic framework. Petrographic studies leaded to recognition of eight microfacies related to three facies belts including tidal flat, lagoon and shoal. Moreover, the observed microfacies patterns indicate a ramp carbonate platform as depositional environment for this carbonate succession. The main diagenetic processes of Kangan Formation include micritization, isopachous and fibrous cements (primary marine diagenesis, dissolution and moldic porosity (meteoric diagenesis, compaction and stylolitization (secondary diagenesis. Based on facies changes, two third-order sequences were specified, each of which could be divided into two systems tracts including transgressive systems tract (TST and highstand systems tract (HST. In addition, sequence boundaries were identified with bedded, massive and nodular anhydrite. These facies, that are indicative of maximum sea level fall, were deposited in hypersaline lagoons. There is a close association between diagenetic processes and relative sea level changes of Kangan Formation, so that diagenetic processes of studied succession have been controlled by sediments stacking patterns during transgression and regression of sea level. During the transgression, the main diagenetic processes in shoal facies are marine cementation and dolomitization in lagoon and tidal flat facies. However, during the sea level fall, these processes include dissolution in shoal facies and dolomitization, anhydrite nodule formation and cementation in lagoon and tidal flat settings.

Omnidirectional mirror based on Bragg stacks with a periodic gain-loss modulation

Energy Technology Data Exchange (ETDEWEB)

Manzanares-Martinez, Jesus; Ham-Rodriguez, Carlos Ivan [Departamento de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83000 (Mexico); Moctezuma-Enriquez, Damian, E-mail: foxonicos@gmail.com [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua 31109 (Mexico); Manzanares-Martinez, Betsabe [Departamento de Fisica, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora 83000 (Mexico)

2014-01-15

In this work we demonstrate that a Bragg Stack with a periodic gain-loss modulation can function as an Omnidirectional Mirror (OM) with complete reflection at any angle of incidence irrespective of the light polarization. The Bragg Stack is composed by the periodic variation of two layers with the same value of the real part of the refractive index (n{sub r}) and a periodic modulation in the imaginary part (n{sub i}). The origin of the band gaps is due to the interference of complex waves with propagating and evanescent fields in each layer. It is found that the band gaps are wider as the contrast n{sub i}/n{sub r} increases. We have found the ambient conditions to obtain an OM considering an auxiliary medium n{sup ′} external to the Bragg Stack.

The value of C sub(e) for the Arabian Sea during summer monsoon

Digital Repository Service at National Institute of Oceanography (India)

Rao, A.S.; Sadhuram, Y.; Krishna, V.V.G.

We estimate, from the moisture budget the bulk aerodynamic coefficient for latent heat flux (C sub(e)) during the monsoon season over the central Arabian Sea. The average value of C sub(e) under active monsoon conditions was found to be 2.25 x 10...

Photovoltaic sub-cell interconnects

Energy Technology Data Exchange (ETDEWEB)

van Hest, Marinus Franciscus Antonius Maria; Swinger Platt, Heather Anne

2017-05-09

Photovoltaic sub-cell interconnect systems and methods are provided. In one embodiment, a photovoltaic device comprises a thin film stack of layers deposited upon a substrate, wherein the thin film stack layers are subdivided into a plurality of sub-cells interconnected in series by a plurality of electrical interconnection structures; and wherein the plurality of electrical interconnection structures each comprise no more than two scribes that penetrate into the thin film stack layers.

Facile Template-Free Fabrication of the hollow sea cucumber-like TbF{sub 3} and luminescent properties

Energy Technology Data Exchange (ETDEWEB)

Gao, Yu, E-mail: gaoy777@126.com [College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang, 100142 (China); Shi, Shan; Fang, Qinghong; Yang, Feng [College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang, 100142 (China); Xu, Zhenhe [College of Applied Chemistry, Shenyang University of Chemical Technology, Shenyang, 100142 (China)

2014-12-15

Graphical abstract: Hollow sea cucumber-like TbF{sub 3} has been prepared via a facile hydrothermal route. The possible growth mechanism and the luminescent properties of the as-prepared sample have been discussed. - Highlights: • TbF3 particles were prepared by a facile hydrothermal route. • TbF3 product show strong green emission. • This method may be more widely applicable in the design of other rare-earth compounds. - Abstract: Hollow sea cucumber-like TbF{sub 3} was successfully fabricated by a self-assembled hydrothermal method. The crystal structure, morphology and photoluminescence properties of the as-prepared TbF{sub 3} crystals were investigated. The results revealed that the as-prepared TbF{sub 3} sample has orthorhombic structure and composed of monodispersed 3D hollow sea cucumber-like particles. The possible formation mechanism for sea cucumber-like TbF{sub 3} is presented in detail. Additionally, the as-prepared sample possesses property of down-conversion photoluminescence. The excitation spectrum of TbF{sub 3} sample was obtained by monitoring the emission of Tb{sup 3+} at 545 nm was composed of the characteristics f–f transition lines within the Tb{sup 3+} 4f{sup 8} configuration. Under the UV light irradiation, the emission spectrum exhibited four obvious lines centered at 491, 545, 588, and 620 nm, which was corresponding to the {sup 5}D{sub 4} → {sup 7}F{sub J} (J = 6, 5, 4, 3) transitions of the Tb{sup 3+} ions in the TbF{sub 3} nanoparticles.

Experimental 1 kW 20 cell PEFC stack

Energy Technology Data Exchange (ETDEWEB)

Buechi, F N; Marmy, C A; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

1999-08-01

A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

Optimal Stack Layout in a Sea Container Terminal with Automated Lifting Vehicles

NARCIS (Netherlands)

D. Roy (Debjit); A. Gupta (Akash); S. Parhi (Sampanna); M.B.M. de Koster (René)

2014-01-01

textabstractContainer terminal performance is largely determined by its design decisions, which include the number and type of quay cranes (QCs), stack cranes (SCs), transport vehicles, vehicle travel path, and stack layout. The terminal design process is complex because it is affected by factors

First-principles study on lithium removal from Li{sub 2}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Koyama, Yukinori; Tanaka, Isao [Department of Materials Science and Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Nagao, Miki; Kanno, Ryoji [Department of Electronic Chemistry, Tokyo Institute of Technology, Nagatsuda, Midori, Yokohama 226-8502 (Japan)

2009-04-01

A systematic first-principles calculation based on density functional theory is carried out to discuss the redox mechanism of Li{sub 2}MnO{sub 3}. The lattices of structural models having C2/m- and C2/c-type stacking sequences can be regarded as hexagonal, while their symmetry is monoclinic. Different stacking sequences of [Mn{sub 2/3}Li{sub 1/3}] layers do not cause differences in the energy or crystallographic structure, suggesting a disordered stacking sequence. A calculation for Li{sub 2-x}MnO{sub 3} assuming topotactic lithium removal indicates that lithium removal can occur at a potential of about 4.6 V with a wide potential plateau. The electronic structure of Li{sub 2-x}MnO{sub 3} shows that the manganese ions remain in the charge state of Mn{sup 4+} and the charge of the removed lithium ions is compensated by the oxidation of oxygen. (author)

Centers of sustainable co-created products by BoP: Development inspired by social entrepreneurs.

NARCIS (Netherlands)

Jauregui Becker, Juan Manuel; Franco Garcia, Maria Maria; Groen, Arend J.

2012-01-01

This paper frames the main components required to set-up Product Co-Creation Centers (PC3) within (rural or urban) BoP environments as a method to (1) identify creative and entrepreneur individuals; (2) aid the process of generating new ideas; (3) support the co-creation of products and services as

In situ observation of transformation in alpha-Fe sub 2 O sub 3 under hydrogen implantation

CERN Document Server

Watanabe, Y; Ishikawa, N; Furuya, K; Kato, M

2002-01-01

An in situ observation of the alpha-Fe sub 2 O sub 3 -to-Fe sub 3 O sub 4 transformation has been performed using a dual-ion-beam accelerator interfaced with a transmission electron microscope (TEM). During the hydrogen-ion implantation of alpha-Fe sub 2 O sub 3 , transformation into the new phase (gamma-Fe sub 2 O sub 3 or Fe sub 3 O sub 4) was observed. It was also found that the orientation relationship between alpha-Fe sub 2 O sub 3 and the new phase (gamma-Fe sub 2 O sub 3 or Fe sub 3 O sub 4) satisfies the Shoji-Nishiyama relationship, in agreement with previous experiments. It was also found that the nearest interatomic distance does not vary by the implantation until the re-stacked phase appears, although when the re-stacked phase is formed, the lattice expansion is observed in the transformed (re-stacked) phase. Judging from these results, we have concluded that the alpha-Fe sub 2 O sub 3 to Fe sub 3 O sub 4 transformation is induced during the hydrogen ion implantation of alpha-Fe sub 2 O sub 3.

Solid State Energy Conversion Energy Alliance (SECA)

Energy Technology Data Exchange (ETDEWEB)

Hennessy, Daniel [Delphi Automotive Systems, LLC, Troy, MI (United States); Sibisan, Rodica [Delphi Automotive Systems, LLC, Troy, MI (United States); Rasmussen, Mike [Delphi Automotive Systems, LLC, Troy, MI (United States)

2011-09-12

The overall objective is to develop a solid oxide fuel cell (SOFC) stack that can be economically produced in high volumes and mass customized for different applications in transportation, stationary power generation, and military market sectors. In Phase I, work will be conducted on system design and integration, stack development, and development of reformers for natural gas and gasoline. Specifically, Delphi-Battelle will fabricate and test a 5 kW stationary power generation system consisting of a SOFC stack, a steam reformer for natural gas, and balance-of-plant (BOP) components, having an expected efficiency of 35 percent (AC/LHV). In Phase II and Phase III, the emphasis will be to improve the SOFC stack, reduce start-up time, improve thermal cyclability, demonstrate operation on diesel fuel, and substantially reduce materials and manufacturing cost by integrating several functions into one component and thus reducing the number of components in the system. In Phase II, Delphi-Battelle will fabricate and demonstrate two SOFC systems: an improved stationary power generation system consisting of an improved SOFC stack with integrated reformation of natural gas, and the BOP components, with an expected efficiency of ≥40 percent (AC/LHV), and a mobile 5 kW system for heavy-duty trucks and military power applications consisting of an SOFC stack, reformer utilizing anode tailgate recycle for diesel fuel, and BOP components, with an expected efficiency of ≥30 percent (DC/LHV). Finally, in Phase III, Delphi-Battelle will fabricate and test a 5 kW Auxiliary Power Unit (APU) for mass-market automotive application consisting of an optimized SOFC stack, an optimized catalytic partial oxidation (CPO) reformer for gasoline, and BOP components, having an expected efficiency of 30 percent (DC/LHV) and a factory cost of ≤$400/kW.

Solid State Energy Conversion Energy Alliance (SECA)

Energy Technology Data Exchange (ETDEWEB)

Hennessy, Daniel [Delphi Automotive Systems, LLC, Troy, MI (United States); Sibisan, Rodica [Delphi Automotive Systems, LLC, Troy, MI (United States); Rasmussen, Mike [Delphi Automotive Systems, LLC, Troy, MI (United States)

2011-09-12

The overall objective is to develop a Solid Oxide Fuel Cell (SOFC) stack that can be economically produced in high volumes and mass customized for different applications in transportation, stationary power generation, and military market sectors. In Phase I, work will be conducted on system design and integration, stack development, and development of reformers for natural gas and gasoline. Specifically, Delphi-Battelle will fabricate and test a 5 kW stationary power generation system consisting of a SOFC stack, a steam reformer for natural gas, and balance-of-plant (BOP) components, having an expected efficiency of ≥ 35 percent (AC/LHV). In Phase II and Phase III, the emphasis will be to improve the SOFC stack, reduce start-up time, improve thermal cyclability, demonstrate operation on diesel fuel, and substantially reduce materials and manufacturing cost by integrating several functions into one component and thus reducing the number of components in the system. In Phase II, Delphi-Battelle will fabricate and demonstrate two SOFC systems: an improved stationary power generation system consisting of an improved SOFC stack with integrated reformation of natural gas, and the BOP components, with an expected efficiency of ≥ 40 percent (AC/LHV), and a mobile 5 kW system for heavy-duty trucks and military power applications consisting of an SOFC stack, reformer utilizing anode tailgate recycle for diesel fuel, and BOP components, with an expected efficiency of ≥ 30 percent (DC/LHV). Finally, in Phase III, Delphi-Battelle will fabricate and test a 5 kW Auxiliary Power Unit (APU) for mass-market automotive application consisting of an optimized SOFC stack, an optimized catalytic partial oxidation (CPO) reformer for gasoline, and BOP components, having an expected efficiency of ≥ 30 percent (DC/LHV) and a factory cost of ≤ $400/kW.

Study on the polarity, solubility, and stacking characteristics of asphaltenes

KAUST Repository

Zhang, Long-li

2014-07-01

The structure and transformation of fused aromatic ring system in asphaltenes play an important role in the character of asphaltenes, and in step affect the properties of heavy oils. Polarity, solubility and structural characteristics of asphaltenes derived from Tahe atmospheric residue (THAR) and Tuo-826 heavy crude oil (Tuo-826) were analyzed for study of their internal relationship. A fractionation method was used to separate the asphaltenes into four sub-fractions, based on their solubility in the mixed solvent, for the study of different structural and physical-chemical properties, such as polarity, solubility, morphology, stacking characteristics, and mean structural parameters. Transmission electron microscope (TEM) observation can present the intuitive morphology of asphaltene molecules, and shows that the structure of asphaltenes is in local order as well as long range disorder. The analysis results showed that n-heptane asphaltenes of THAR and Tuo-826 had larger dipole moment values, larger fused aromatic ring systems, larger mean number of stacking layers, and less interlayer spacing between stacking layers than the corresponding n-pentane asphaltenes. The sub-fractions that were inclined to precipitate from the mixture of n-heptane and tetrahydrofuran had larger polarity and less solubility. From the first sub-fraction to the fourth sub-fraction, polarity, mean stacking numbers, and average layer size from the TEM images follow a gradual decrease. The structural parameters derived from TEM images could reflect the largest fused aromatic ring system in asphaltene molecule, yet the parameters derived from 1H NMR data reflected the mean message of poly-aromatic ring systems. The structural parameters derived from TEM images were more consistent with the polarity variation of sub-fractions than those derived from 1H NMR data, which indicates that the largest fused aromatic ring system will play a more important role in the stacking characteristics of

Glycosides from the sea cucumber Cucumaria frondosa. IV. Structure of frondosides A{sub 2}-4, A{sub 2}-7, and A{sub 2}-8, three new minor monosulfated triterpene glycosides

Energy Technology Data Exchange (ETDEWEB)

Silchenko, A.S.; Avilov, S.A.; Antonov, A.S.; Kalinovsky, A.I.; Dmitrenok, P.S.; Kalinin, V.I. [Pacific Inst. of Bioorganic Chemistry, Far East Div. of the Russian Academy of Sciences, Vladivostok (Russian Federation)], E-mail: kalininv@piboc.dvo.ru; Woodward, C.; Collin, P.D. [Coastside Bio Resources Inc., Stonington, Maine (United States)

2005-12-15

Frondosides A{sub 2}-4, A{sub 2}-7, and A{sub 2}-8 are new monosulfated triterpene glycosides isolated from the sea cucumber Cucumaria frondosa. Their structures have been elucidated on the basis of spectral data (2D NMR and MS). Frondosides A{sub 2}-7 and A{sub 2}-8 are isomers and differ from each other only by the position of a double bond in their non-holostane-type aglycones. (author)

Investigation of stacked elemental layers for Cu(In,Ga)Se{sub 2} thin film preparation by rapid thermal selenization

Energy Technology Data Exchange (ETDEWEB)

Stroth, Christiane; Ohland, Joerg; Mikolajczak, Ulf; Madena, Thomas; Keller, Jan; Parisi, Juergen; Hammer, Maria; Riedel, Ingo [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg, 26111 Oldenburg (Germany)

2013-07-01

Rapid thermal selenization of pure metallic (Cu-In-Ga) or selenium-containing (Cu-In-Ga-Se) precursors is a favorable method to fabricate Cu(In,Ga)Se{sub 2} absorber films for application in thin film solar cells. Because of its upscaling potential and the short process time it is a promising approach for the fabrication of CIGSe photovoltaic modules on industrial scale. As a preliminary work for prospective plasma-enhanced selenization of stacked elemental layers (SEL) the elements copper, indium and gallium were sequentially deposited on molybdenum coated soda-lime glass by thermal evaporation. The stacking order was varied and the precursors were annealed with different heating rates. Morphology, elemental depth distribution and phases of the layers were investigated before and after annealing using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. Furthermore the influence of different heating rates on phase transitions during annealing was studied by in-situ X-ray diffraction.

Enhanced dielectric properties of thin Ta{sub 2}O{sub 5} films grown on 65 nm SiO{sub 2}/Si

Energy Technology Data Exchange (ETDEWEB)

Kolkovsky, Vl.; Kurth, E.; Kunath, C. [IPMS Fraunhofer, Dresden, Maria-Reiche Str. 2, 01109 Dresden (Germany)

2016-12-15

The structural and electrical properties of Ta{sub 2}O{sub 5}/65 nm SiO{sub 2} structures with different thicknesses of Ta{sub 2}O{sub 5} varying in the range of 0-260 nm are investigated. We find that the stack structures grown by the magnetron sputtering technique and annealed at 1220 K in O and Ar atmosphere show one of the highest dielectric constant of Ta{sub 2}O{sub 5}(about 64) among those previously reported in the literature. The structure of the annealed polycrystalline Ta{sub 2}O{sub 5} films is orthorhombic, as obtained from X-ray diffraction measurements and we do not observe any preferential orientation of the annealed films. The Ta{sub 2}O{sub 5} films contain positively charged defects which become mobile at around 400 K and they are tentatively correlated with the oxygen vacancies. The leakage current in the stack structures is a factor of 20 higher compared to that in thin layers with 65 nm SiO{sub 2}. The conduction mechanism in the stack structures can be described by the Fowler-Nordheim model with a barrier height that decreases slightly (<10%) as a function of the thickness of the films. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Syntheses, crystal structures, and properties of the isotypic pair [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O and [In(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Van, Nguyen-Duc; Kleeberg, Fabian M.; Schleid, Thomas [Institut fuer Anorganische Chemie, Universitaet Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany)

2015-11-15

Single crystals of [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O and [In(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O were obtained by reactions of aqueous solutions of the acid (H{sub 3}O){sub 2}[B{sub 12}H{sub 12}] with chromium(III) hydroxide and indium metal shot, respectively. The title compounds crystallize isotypically in the trigonal system with space group R anti 3c (a = 1157.62(3), c = 6730.48(9) pm for the chromium, a = 1171.71(3), c = 6740.04(9) pm for the indium compound, Z = 6). The arrangement of the quasi-icosahedral [B{sub 12}H{sub 12}]{sup 2-} dianions can be considered as stacking of two times nine layers with the sequence..ABCCABBCA.. and the metal trications arrange in a cubic closest packed..abc.. stacking sequence. The metal trications are octahedrally coordinated by six water molecules of hydration, while another fifteen H{sub 2}O molecules fill up the structures as zeolitic crystal water or second-sphere hydrating species. Between these free and the metal-bonded water molecules, bridging hydrogen bonds are found. Furthermore, there is also evidence of hydrogen bonding between the anionic [B{sub 12}H{sub 12}]{sup 2-} clusters and the free zeolitic water molecules according to B-H{sup δ-}..{sup δ+}H-O interactions. Vibrational spectroscopy studies prove the presence of these hydrogen bonds and also show slight distortions of the dodecahydro-closo-dodecaborate anions from their ideal icosahedral symmetry (I{sub h}). Thermal decomposition studies for the example of [Cr(H{sub 2}O){sub 6}]{sub 2}[B{sub 12}H{sub 12}]{sub 3}.15H{sub 2}O gave no hints for just a simple multi-stepwise dehydration process. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Electrically programmable-erasable In-Ga-Zn-O thin-film transistor memory with atomic-layer-deposited Al{sub 2}O{sub 3}/Pt nanocrystals/Al{sub 2}O{sub 3} gate stack

Energy Technology Data Exchange (ETDEWEB)

Qian, Shi-Bing; Zhang, Wen-Peng; Liu, Wen-Jun; Ding, Shi-Jin, E-mail: sjding@fudan.edu.cn [State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433 (China)

2015-12-15

Amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) memory is very promising for transparent and flexible system-on-panel displays; however, electrical erasability has always been a severe challenge for this memory. In this article, we demonstrated successfully an electrically programmable-erasable memory with atomic-layer-deposited Al{sub 2}O{sub 3}/Pt nanocrystals/Al{sub 2}O{sub 3} gate stack under a maximal processing temperature of 300 {sup o}C. As the programming voltage was enhanced from 14 to 19 V for a constant pulse of 0.2 ms, the threshold voltage shift increased significantly from 0.89 to 4.67 V. When the programmed device was subjected to an appropriate pulse under negative gate bias, it could return to the original state with a superior erasing efficiency. The above phenomena could be attributed to Fowler-Nordheim tunnelling of electrons from the IGZO channel to the Pt nanocrystals during programming, and inverse tunnelling of the trapped electrons during erasing. In terms of 0.2-ms programming at 16 V and 350-ms erasing at −17 V, a large memory window of 3.03 V was achieved successfully. Furthermore, the memory exhibited stable repeated programming/erasing (P/E) characteristics and good data retention, i.e., for 2-ms programming at 14 V and 250-ms erasing at −14 V, a memory window of 2.08 V was still maintained after 10{sup 3} P/E cycles, and a memory window of 1.1 V was retained after 10{sup 5} s retention time.

Modeling sub-sea permafrost in the East Siberian Arctic Shelf: the Dmitry Laptev Strait

International Nuclear Information System (INIS)

Nicolsky, D; Shakhova, N

2010-01-01

The present state of sub-sea permafrost modeling does not agree with certain observational data on the permafrost state within the East Siberian Arctic Shelf. This suggests a need to consider other mechanisms of permafrost destabilization after the recent ocean transgression. We propose development of open taliks wherever thaw lakes and river paleo-valleys were submerged shelf-wide as a possible mechanism for the degradation of sub-sea permafrost. To test the hypothesis we performed numerical modeling of permafrost dynamics in the Dmitry Laptev Strait area. We achieved sufficient agreement with the observed distribution of thawed and frozen layers to suggest that the proposed mechanism of permafrost destabilization is plausible.

Nanocomposites of manganese oxides and carbon nanotubes for aqueous supercapacitor stacks

Energy Technology Data Exchange (ETDEWEB)

Zhang Shengwen; Peng Chuang; Ng, Kok C. [Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Chen, George Z., E-mail: george.chen@nottingham.ac.u [Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

2010-10-30

Symmetrical supercapacitors and their serially connected two-cell stacks via a bipolar electrode were constructed with nanocomposites of manganese oxides and carbon nanotubes (MnO{sub x}/CNTs) as the electrode materials. Nanocomposites with different contents of MnO{sub x} were synthesised through the redox reaction between KMnO{sub 4} and CNTs in aqueous solutions. The nanocomposites were characterised by scanning and transmission electron microscopy, BET nitrogen adsorption and X-ray diffraction before being examined in a three-electrode cell with a novel trenched graphite disc electrode by electrochemical means, including cyclic voltammetry, galvanostatic charging-discharging, and electrochemical impedance spectroscopy. The nanocomposites demonstrated capacitive behaviour in the potential range of 0-0.85 V (vs Ag/AgCl) in aqueous KCl electrolytes with less than 9% capacitance decrease after 9000 charging-discharging cycles. Symmetrical supercapacitors of identical positive and negative MnO{sub x}/CNTs electrodes showed capacitive performance in good agreement with the individual electrodes (e.g. 0.90 V, 0.53 F, 1.3 cm{sup 2}). The bipolarly connected two-cell stacks of the symmetrical cells exhibited characteristics in accordance with expectation, including a doubled stack voltage and reduced internal resistance per cell.

Installation of deep water sub-sea equipment

Energy Technology Data Exchange (ETDEWEB)

Pollack, Jack; Demian, Nabil [SBM-IMODCO Inc., Houston, TX (UNited States)

2004-07-01

Offshore oil developments are being planned in water depths exceeding 2000 m. Lowering and positioning large, heavy sub sea hardware, using conventional methods, presents new technical challenges in these ultra deep waters. In 3000 m a safe lift using conventional steel cables will require more capacity to support the cable self weight than the static payload. Adding dynamic loads caused by the motions of the surface vessel can quickly cause the safe capacity of the wire to be exceeded. Synthetic ropes now exist to greatly reduce the lowering line weight. The lower stiffness of these synthetic ropes aggravate the dynamic line tensions due to vessel motions and relatively little is known about the interaction of these ropes on the winches and sheaves required for pay-out and haul-in of these lines under dynamic load. Usage of conventional winches would damage the synthetic rope and risk the hardware being deployed. Reliable and economic installation systems that can operate from existing installation vessels are considered vital for ultra deep-water oil development. The paper describes a Deep Water Sub-Sea Hardware Deployment system consisting of a buoy with variable, pressure-balanced buoyancy, which is used to offset most of the payload weight as it is lowered. The buoyant capacity is controlled by air pumped into the tank from the surface vessel through a reinforced hose. The buoy and payload motion are isolated from the deployment line surface dynamics using a simple passive heave compensator mounted between the buoy and the bottom of the deployment rope. The system components, functionality and dynamic behavior are presented in the paper. (author)

Lotus japonicus NOOT-BOP-COCH-LIKE1 is essential for nodule, nectary, leaf and flower development

DEFF Research Database (Denmark)

Magne, Kévin; George, Jeoffrey; Berbel Tornero, Ana

2018-01-01

The NOOT-BOP-COCH-LIKE (NBCL) genes are orthologs of Arabidopsis thaliana BLADE-ON-PETIOLE1/2. NBCLs are developmental regulators essential for plant shaping mainly through the regulation of organ boundaries, the promotion of lateral organ differentiation and the acquisition of organ identity. In...

Terahertz emission and electromagnetic waves in single crystal Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} structures

Energy Technology Data Exchange (ETDEWEB)

Wieland, Raphael; Rudau, Fabian; Gross, Boris; Judd, Thomas; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA" +, Universitaet Tuebingen, Tuebingen (Germany); Kinev, Nickolay; Koshelets, Valery [Kotel' nikov Institute of Radio Engineering and Electronics, Moscow (Russian Federation); Tsujimoto, Manabu [Kyoto University, Kyoto (Japan); Ji, Min; Huang, Ya; Zhou, Xianjing; An, Deyue; Wang, Huabing [National Institute for Materials Science, Tsukuba (Japan); Research Institute of Superconductor Electronics, Nanjing University, Nanjing (China); Wu, Peihang [Research Institute of Superconductor Electronics, Nanjing University, Nanjing (China); Hatano, Takeshi [National Institute for Materials Science, Tsukuba (Japan)

2015-07-01

Josephson Junctions (JJs) offer a natural way to convert a dc voltage into high-frequency electromagnetic radiation. In the high-Tc superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (BSCCO), JJs form intrinsically, allowing to fabricate stacks of hundreds of junctions easily. Emission can occur at relatively low bias currents but also at larger input power with frequencies from 0.4 to 1 THz. At high bias, a hot spot forms, affecting both the intensity and the linewidth of the radiation. BSCCO mesas are believed to work as a cavity for electromagnetic standing waves, synchronizing all the junctions in the stack. We investigated THz emission and hotspot formation using a combination of transport measurements, electromagnetic wave detection via a superconducting receiver and low temperature scanning laser microscopy.

Iridium Interfacial Stack (IRIS)

Science.gov (United States)

Spry, David James (Inventor)

2015-01-01

An iridium interfacial stack ("IrIS") and a method for producing the same are provided. The IrIS may include ordered layers of TaSi.sub.2, platinum, iridium, and platinum, and may be placed on top of a titanium layer and a silicon carbide layer. The IrIS may prevent, reduce, or mitigate against diffusion of elements such as oxygen, platinum, and gold through at least some of its layers.

Rotating preventers

International Nuclear Information System (INIS)

Tangedahl, M.J.; Stone, C.R.

1992-01-01

This paper reports that recent changes in the oil and gas industry and ongoing developments in horizontal and underbalanced drilling necessitated development of a better rotating head. A new device called the rotating blowout preventer (RBOP) was developed by Seal-Tech. It is designed to replace the conventional rotating control head on top of BOP stacks and allows drilling operations to continue even on live (underbalanced) wells. Its low wear characteristics and high working pressure (1,500 psi) allow drilling rig crews to drill safely in slightly underbalanced conditions or handle severe well control problems during the time required to actuate other BOPs in the stack. Drilling with a RBOP allows wellbores to be completely closed in tat the drill floor rather than open as with conventional BOPs

Single crystal Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} structures as THz-emitters

Energy Technology Data Exchange (ETDEWEB)

Wieland, Raphael; Rudau, Fabian; Langer, Julian; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, Universitaet Tuebingen, Tuebingen (Germany); Kinev, Nickolay; Koshelets, Valery [Kotel' nikov Institute of Radio Engineering and Electronics, Moscow (Russian Federation); Yuan, Jie; Ishii, Akira; Hatano, Takeshi [National Institute for Materials Science, Tsukuba (Japan); Huang, Ya; Ji, Min; Zhou, Xianjing; Wang, Huabing [National Institute for Materials Science, Tsukuba (Japan); Research Institute of Superconductor Electronics, Nanjing University, Nanjing (China); Wu, Peiheng [Research Institute of Superconductor Electronics, Nanjing University, Nanjing (China)

2016-07-01

By means of Josephson Junctions (JJs) one can easily convert a dc voltage into high-frequency electromagnetic radiation. The high-Tc superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (BSCCO) has a layered crystal structure in such a way that JJs form intrinsically. This allows to fabricate hundreds of stacked junctions with reasonable effort. Terahertz emission can be observed at relatively low bias currents but also at higher input power. Emission frequencies from 0.4 to 2.4 THz have been measured. A hot spot forms at high bias currents with effect on both intensity and linewidth of the THz emission.BSCCO mesas probably act as a cavity for electromagnetic standing waves that synchronize all junctions in the stack. We investigated hotspot formation and THz emission using a combination of transport measurements, low temperature scanning laser microscopy and electromagnetic wave detection via a superconducting receiver.

Comprehensive study and design of scaled metal/high-k/Ge gate stacks with ultrathin aluminum oxide interlayers

Energy Technology Data Exchange (ETDEWEB)

Asahara, Ryohei; Hideshima, Iori; Oka, Hiroshi; Minoura, Yuya; Hosoi, Takuji, E-mail: hosoi@mls.eng.osaka-u.ac.jp; Shimura, Takayoshi; Watanabe, Heiji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ogawa, Shingo [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Toray Research Center Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan); Yoshigoe, Akitaka; Teraoka, Yuden [Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2015-06-08

Advanced metal/high-k/Ge gate stacks with a sub-nm equivalent oxide thickness (EOT) and improved interface properties were demonstrated by controlling interface reactions using ultrathin aluminum oxide (AlO{sub x}) interlayers. A step-by-step in situ procedure by deposition of AlO{sub x} and hafnium oxide (HfO{sub x}) layers on Ge and subsequent plasma oxidation was conducted to fabricate Pt/HfO{sub 2}/AlO{sub x}/GeO{sub x}/Ge stacked structures. Comprehensive study by means of physical and electrical characterizations revealed distinct impacts of AlO{sub x} interlayers, plasma oxidation, and metal electrodes serving as capping layers on EOT scaling, improved interface quality, and thermal stability of the stacks. Aggressive EOT scaling down to 0.56 nm and very low interface state density of 2.4 × 10{sup 11 }cm{sup −2}eV{sup −1} with a sub-nm EOT and sufficient thermal stability were achieved by systematic process optimization.

Evidence from the Baltic Sea for an enhanced CO{sub 2} air-sea transfer velocity

Energy Technology Data Exchange (ETDEWEB)

Kuss, Joachim; Nagel, Klaus; Schneider, Bernd [Baltic Sea Research Institute, Warnemuende (Germany). Dept. of Marine Chemistry

2004-04-01

Surface water total CO{sub 2} concentrations (CT) and the CO{sub 2} partial pressure of the surface water and in the atmosphere were measured in the eastern Gotland Sea at approximately monthly intervals during five cruises in the winter of 1999/2000. Taking into account vertical/lateral exchange processes and the decomposition of organic matter, the monthly changes in CT were used to determine CO{sub 2} evasion fluxes. In addition, the CO{sub 2} fluxes were calculated on the basis of the CO{sub 2} partial pressure differences using local wind speed (u) records and different currently applied parametrizations of the gas exchange transfer velocity (k). The latter resulted in substantially lower monthly fluxes that indicated a considerable underestimation of k from the k(u) functions used. To achieve an optimal agreement between the flux calculations and the balance-derived CO{sub 2} fluxes, the coefficients of both a simple quadratic and cubic function k(u) were iterated using a least-squares fitting procedure. The resulting equations, which refer to short-term wind data and to the CO{sub 2} exchange at 20 deg C, were k= (0.45 {+-} 0.10)u{sup 2} and k(0.037 {+-} 0.008)u{sup 3} (k, cm/h; u, m/s) . These yielded higher k values than most of the previously proposed parametrizations. Unfortunately, our data did not allow us to decide whether the quadratic or cubic function is more appropriate to describe the gas exchange dynamics.

Progress of MCFC stack technology at Toshiba

Energy Technology Data Exchange (ETDEWEB)

Hori, M.; Hayashi, T.; Shimizu, Y. [Toshiba Corp., Tokyo (Japan)

1996-12-31

Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

Geochemical nature of sub-ridge mantle and opening dynamics of the South China Sea

Science.gov (United States)

Zhang, Guo-Liang; Luo, Qing; Zhao, Jian; Jackson, Matthew G.; Guo, Li-Shuang; Zhong, Li-Feng

2018-05-01

The Indian-type mantle (i.e., above the north hemisphere reference line on the plot of 208Pb/204Pb vs. 206Pb/204Pb) has been considered as a "Southern Hemisphere" geochemical signature, whose origin remains enigmatic. The South China Sea is an extensional basin formed after rifting of the Euro-Asia continent in the Northern Hemisphere, however, the geochemical nature of the igneous crust remains unexplored. For the first time, IODP Expedition 349 has recovered seafloor basalts covered by the thick sediments in the Southwest sub-basin (Sites U1433 and U1434) and the East sub-basin (Site U1431). The Southwest sub-basin consists of enriched (E)-MORB type basalts, and the East sub-basin consists of both normal (N)-MORB-type and E-MORB-type basalts based on trace element compositions. The basalts of the two sub-basins are Indian-type MORBs based on Sr-Nd-Pb-Hf isotope compositions, and the Southwest sub-basin basalts show isotopic compositions (i.e., 206Pb/204Pb of 17.59-17.89) distinctly different from the East sub-basin (i.e., 206Pb/204Pb of 18.38-18.57), suggesting a sub-basin scale mantle compositional heterogeneity and different histories of mantle compositional evolution. Two different enriched mantle end-members (EM1 and EM2) are responsible for the genesis of the Indian-type mantle in the South China Sea. We have modeled the influences of Hainan mantle plume and lower continental crust based on Sr-Nd-Pb-Hf isotope compositions. The results indicate that the influence of Hainan plume can explain the elevated 206Pb/204Pb of the East sub-basin basalts, and the recycling of lower continental crust can explain the low 206Pb/204Pb of the Southwest sub-basin basalts. Based on the strong geochemical imprints of Hainan plume in the ridge magmatism, we propose that the Hainan plume might have promoted the opening of the South China Sea, during which the Hainan plume contributed enriched component to the sub-ridge mantle and caused thermal erosion and return of lower

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

Science.gov (United States)

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer

Fundamental BOP I and C systems structure in nuclear power plants

International Nuclear Information System (INIS)

Ishii, K.; Harada, H.; Yamamori, T.; Igarashi, K.; Arakida, T.

2008-01-01

Digital instrumentation and control (I and C) systems using distributed control systems (DCS) are essential elements for nuclear power plants (NPPs) seeking higher reliability, availability and maintainability. Hitachi can boast its broad new build and refurbishment project experience in Japan and other markets since the 1970s. Throughout its continuous involvement in NPP design, fabrication, construction and maintenance over 30 years, Hitachi has increasingly integrated digital I and C system with its own DCS suite. This paper focuses on the fundamental characteristics of Hitachi's Balance of Plant (BOP) I and C systems structure for new build nuclear projects. (author)

Orthogonal stack of global tide gauge sea level data

Science.gov (United States)

Trupin, A.; Wahr, J.

1990-01-01

Yearly and monthly tide gauge sea level data from around the globe are fitted to numerically generated equilibrium tidal data to search for the 18.6 year lunar tide and 14 month pole tide. Both tides are clearly evident in the results, and their amplitudes and phases are found to be consistent with a global equilibrium response. Global, monthly sea level data from outside the Baltic sea and Gulf of Bothnia are fitted to global atmospheric pressure data to study the response of the ocean to pressure fluctuations. The response is found to be inverted barometer at periods greater than two months. Global averages of tide gauge data, after correcting for the effects of post glacial rebound on individual station records, reveal an increase in sea level over the last 80 years of between 1.1 mm/yr and 1.9 mm/yr.

The Sea Stacks Project: Enhancing the Use of Regional Literature in Atlantic Canadian Schools

Directory of Open Access Journals (Sweden)

Vivian Howard

2012-06-01

Full Text Available Research over the past two decades has amply demonstrated the importance of literature to the formation of both regional and national cultural identity, particularly in the face of mass market globalization of children’s book publishing in the 21st century as well as the predominance of non-Canadian content from television, movies, books, magazines and internet media. However, Canadian children appear to have only very limited exposure to Canadian authors and illustrators. In Atlantic Canada, regional Atlantic Canadian authors and illustrators for children receive very limited critical attention, and resources for the study and teaching of Atlantic Canadian children’s literature are few. Print and digital information sources on regional children’s books, publishing, authors and illustrators are scattered and inconsistent in quality and currency. This research project directly addresses these key concerns by summarizing the findings of a survey of Atlantic Canadian teachers on their use of regional books. In response to survey findings, the paper concludes by describing the creation of the Sea Stacks Project an authoritative web-delivered information resource devoted to contemporary Atlantic Canadian literature for children and teens.

Sea-ice dynamics strongly promote Snowball Earth initiation and destabilize tropical sea-ice margins

Directory of Open Access Journals (Sweden)

A. Voigt

2012-12-01

Full Text Available The Snowball Earth bifurcation, or runaway ice-albedo feedback, is defined for particular boundary conditions by a critical CO<sub>2sub> and a critical sea-ice cover (SI, both of which are essential for evaluating hypotheses related to Neoproterozoic glaciations. Previous work has shown that the Snowball Earth bifurcation, denoted as (CO<sub>2sub>, SI^*, differs greatly among climate models. Here, we study the effect of bare sea-ice albedo, sea-ice dynamics and ocean heat transport on (CO<sub>2sub>, SI^* in the atmosphere–ocean general circulation model ECHAM5/MPI-OM with Marinoan (~ 635 Ma continents and solar insolation (94% of modern. In its standard setup, ECHAM5/MPI-OM initiates a~Snowball Earth much more easily than other climate models at (CO<sub>2sub>, SI^* ≈ (500 ppm, 55%. Replacing the model's standard bare sea-ice albedo of 0.75 by a much lower value of 0.45, we find (CO<sub>2sub>, SI^* ≈ (204 ppm, 70%. This is consistent with previous work and results from net evaporation and local melting near the sea-ice margin. When we additionally disable sea-ice dynamics, we find that the Snowball Earth bifurcation can be pushed even closer to the equator and occurs at a hundred times lower CO<sub>2sub>: (CO<sub>2sub>, SI^* ≈ (2 ppm, 85%. Therefore, the simulation of sea-ice dynamics in ECHAM5/MPI-OM is a dominant determinant of its high critical CO<sub>2sub> for Snowball initiation relative to other models. Ocean heat transport has no effect on the critical sea-ice cover and only slightly decreases the critical CO<sub>2sub>. For disabled sea-ice dynamics, the state with 85% sea-ice cover is stabilized by the Jormungand mechanism and shares characteristics with the Jormungand climate states. However, there is no indication of the Jormungand bifurcation and hysteresis in ECHAM5/MPI-OM. The state with 85% sea-ice cover therefore is a soft Snowball state rather than a true

Separation of arsenic species by capillary electrophoresis with sample-stacking techniques

Energy Technology Data Exchange (ETDEWEB)

Chen, Zu Liang; Naidu, Ravendra [Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064, Glen Osmond, SA (Australia); Lin, Jin-Ming [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 100085, Beijing (China)

2003-03-01

A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO{sub 2}{sup 2-}, AsO{sub 4}{sup 2-}, and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L{sup -1} sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 {mu}mol L{sup -1} of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water. (orig.)

The Burkholderia pseudomallei Proteins BapA and BapC Are Secreted TTSS3 Effectors and BapB Levels Modulate Expression of BopE.

Directory of Open Access Journals (Sweden)

Puthayalai Treerat

Full Text Available Many Gram-negative pathogens use a type III secretion system (TTSS for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC-FlAsH™ labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.

Atomic layer-deposited Al–HfO{sub 2}/SiO{sub 2} bi-layers towards 3D charge trapping non-volatile memory

Energy Technology Data Exchange (ETDEWEB)

Congedo, Gabriele, E-mail: gabriele.congedo@mdm.imm.cnr.it; Wiemer, Claudia; Lamperti, Alessio; Cianci, Elena; Molle, Alessandro; Volpe, Flavio G.; Spiga, Sabina, E-mail: sabina.spiga@mdm.imm.cnr

2013-04-30

A metal/oxide/high-κ dielectric/oxide/silicon (MOHOS) planar charge trapping memory capacitor including SiO{sub 2} as tunnel oxide, Al–HfO{sub 2} as charge trapping layer, SiO{sub 2} as blocking oxide and TaN metal gate was fabricated and characterized as test vehicle in the view of integration into 3D cells. The thin charge trapping layer and blocking oxide were grown by atomic layer deposition, the technique of choice for the implementation of these stacks into 3D structures. The oxide stack shows a good thermal stability for annealing temperature of 900 °C in N{sub 2}, as required for standard complementary metal–oxide–semiconductor processes. MOHOS capacitors can be efficiently programmed and erased under the applied voltages of ± 20 V to ± 12 V. When compared to a benchmark structure including thin Si{sub 3}N{sub 4} as charge trapping layer, the MOHOS cell shows comparable program characteristics, with the further advantage of the equivalent oxide thickness scalability due to the high dielectric constant (κ) value of 32, and an excellent retention even for strong testing conditions. Our results proved that high-κ based oxide structures grown by atomic layer deposition can be of interest for the integration into three dimensionally stacked charge trapping devices. - Highlights: ► Charge trapping device with Al–HfO{sub 2} storage layer is fabricated and characterized. ► Al–HfO{sub 2} and SiO{sub 2} blocking oxides are deposited by atomic layer deposition. ► The oxide stack shows a good thermal stability after annealing at 900 °C. ► The device can be efficiently programmed/erased and retention is excellent. ► The oxide stack could be used for 3D-stacked Flash non-volatile memories.

Relative role of transfer zones in controlling sequence stacking patterns and facies distribution: insights from the Fushan Depression, South China Sea

Science.gov (United States)

Liu, Entao; Wang, Hua; Li, Yuan; Huang, Chuanyan

2015-04-01

In sedimentary basins, a transfer zone can be defined as a coordinated system of deformational features which has good prospects for hydrocarbon exploration. Although the term 'transfer zone' has been widely applied to the study of extensional basins, little attention has been paid to its controlling effect on sequence tracking pattern and depositional facies distribution. Fushan Depression is a half-graben rift sub-basin, located in the southeast of the Beibuwan Basin, South China Sea. In this study, comparative analysis of seismic reflection, palaeogeomorphology, fault activity and depositional facies distribution in the southern slope indicates that three different types of sequence stacking patterns (i.e. multi-level step-fault belt in the western area, flexure slope belt in the central area, gentle slope belt in the eastern area) were developed along the southern slope, together with a large-scale transfer zone in the central area, at the intersection of the western and eastern fault systems. Further analysis shows that the transfer zone played an important role in the diversity of sequence stacking patterns in the southern slope by dividing the Fushan Depression into two non-interfering tectonic systems forming different sequence patterns, and leading to the formation of the flexure slope belt in the central area. The transfer zone had an important controlling effect on not only the diversity of sequence tracking patterns, but also the facies distribution on the relay ramp. During the high-stand stage, under the controlling effect of the transfer zone, the sediments contain a significant proportion of coarser material accumulated and distributed along the ramp axis. By contrast, during the low-stand stage, the transfer zone did not seem to contribute significantly to the low-stand fan distribution which was mainly controlled by the slope gradient (palaeogeomorphology). Therefore, analysis of the transfer zone can provide a new perspective for basin analysis

Edge functionalised & Li-intercalated 555-777 defective bilayer graphene for the adsorption of CO{sub 2} and H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Lalitha, Murugan [School of Chemical Engineering, The University of Queensland, Brisbane 4072, QLD (Australia); Department of Physics, Bharathiar University, Coimbatore 641046, Tamil Nadu (India); Lakshmipathi, Senthilkumar, E-mail: lsenthilkumar@buc.edu.in [School of Chemical Engineering, The University of Queensland, Brisbane 4072, QLD (Australia); Department of Physics, Bharathiar University, Coimbatore 641046, Tamil Nadu (India); Bhatia, Suresh K., E-mail: s.bhatia@uq.edu.au [School of Chemical Engineering, The University of Queensland, Brisbane 4072, QLD (Australia)

2017-04-01

Highlights: • DV defect in fluorinated graphene sheet enhances hydrophobicity. • Intercalation of Li atom decreases the separation in bilayer graphene sheets. • Bernal stacking increases hydrophobicity of the bilayer graphene sheets. - Abstract: The adsorption of CO{sub 2} and H{sub 2}O on divacanacy (DV) defected graphene cluster, and its bilayer counterpart is investigated using first-principles calculations. Both single and bilayer DV graphene cluster, are functionalised with H and F atoms. On these sheets the gas molecules are physisorbed, and the divacancy defect effectively improves the adsorption of CO{sub 2}, while fluorination enhances the hydrophobicity of the graphene cluster. Among the convex and concave curvature regions induced due to the DV defect, the adsorption of the gas molecules on the concave meniscus is more favourable. Fluorine termination induces 73% reduction in Henry law constants for H{sub 2}O, while for the CO{sub 2} molecule it increases by 8%, which indicates the DV defective sheet is a better candidate for CO{sub 2} capture compared to the STW defective sheet. Besides, both AA and AB divacant defect bilayer sheets are equally stable, wherein AA stacking results in a cavity between the sheets, while in AB stacking, the layers slide one over the other. Nevertheless, both these bilayer sheets are comparatively stabler than the monolayer. However, intercalation of lithium decreases the interlayer separation, particularly in AA stacking, which enhances the CO{sub 2} adsorption, but in the Bernal stacking enhances it hydrophobicity.

Study of the La-related dipole in TiN/LaO{sub x}/HfSiON/SiON/Si gate stacks using hard X-ray photoelectron spectroscopy and backside medium energy ion scattering

Energy Technology Data Exchange (ETDEWEB)

Boujamaa, R. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); CEA-LETI, MINATEC Campus, F38054 Grenoble (France); Laboratoire des Matériaux et du Génie Physique, CNRS, Grenoble INP, 3 parvis L. Néel, BP 257, 38016 Grenoble (France); Martinez, E.; Pierre, F.; Renault, O. [CEA-LETI, MINATEC Campus, F38054 Grenoble (France); Detlefs, B.; Zegenhagen, J. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38000 Grenoble (France); Baudot, S. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Gros-Jean, M., E-mail: Mickael.Gros-Jean@st.com [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Bertin, F. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Dubourdieu, C., E-mail: Catherine.Dubourdieu@ec-lyon.fr [Institut des Nanotechnologies de Lyon, CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully (France)

2015-04-30

Highlights: • Precise La depth distribution in gate stacks before and after annealing by MEIS. • Analysis by HAXPES of the buried high K/SiO{sub 2} interface without removing TiN gate. • Formation of La-silicate at the HfSiON/SiON interface. • Internal electrical field induced at the HfSiON/SiON interface by the La diffusion. • Increase of electric field strength with initial LaO{sub x} thickness. - Abstract: In this paper, we report the effect of high temperature annealing on the chemical and electronic structure of technologically relevant TiN/LaO{sub x}/HfSiON/SiON/Si gate stacks. Using medium energy ion scattering from the backside of the samples, a non-destructive compositional depth profile of La has been obtained, revealing the lanthanum diffusion in the SiON interface layer upon annealing. To complement this analysis, hard X-ray photoelectron spectroscopy with synchrotron radiation has been performed to investigate the chemical and electronic structure of the gate stacks. The results show clear changes in the Hf and Ti core level energy positions with respect to Si bulk, with changes in the thickness of the LaO{sub x} capping layer. We infer that La diffusion generates an internal electrical field at the La-silicate interface between HfSiON and SiON, and that its strength increases with the increase of LaO{sub x} thickness. These findings support the band alignment model based on a La-induced interfacial dipole.

Effect of Additional Structure on Effective Stack Height of Gas Dispersion in Atmosphere

OpenAIRE

Takenobu Michioka; Koichi Sada; Kazuki Okabayashi

2016-01-01

Wind-tunnel experiments were conducted to evaluate the effect of additional structure (building, sea wall and banking) on the effective stack height, which is usually used in safety analyses of nuclear power facilities in Japan. The effective stack heights were estimated with and without the additional structure in addition to the reactor building while varying several conditions such as the source height, the height of additional structure and the distance between the source position and the...

Online estimation of wax deposition thickness in single-phase sub-sea pipelines based on acoustic chemometrics: A feasibility study

OpenAIRE

Halstensen, Maths; Arvoh, Benjamin Kaku; Amundsen, Lene; Hoffmann, Rainer

2012-01-01

Wax deposition in sub-sea oil producing pipelines is a concern to the oil producing companies. The deposition of wax in pipelines can cause serious economic implications if not monitored and controlled. Several researchers have developed models and investigated the deposition of wax in crude oil pipelines. As of today, there is no off the shelf instrument available for reliable online estimation of the wax depo- sition thickness in sub-sea pipelines. Acoustic chemometrics was applied to inves...

The research of electrical tracing system construction management and related questions of BOP project

International Nuclear Information System (INIS)

Wang Lining; Li Jingmin; Ma Ding; Tu Haitao

2015-01-01

Based on Hongyanhe nuclear power plant in Liaoning province, the paper studies the anti-freeze and heat tracing work of BOP project. It compares several different heat tracing solutions in terms of technicality and applicability, and gave the most suitable scheme by using electrical tracing. It also presents the construction details of the electrical tracing system, analyzes the key points of the construction management from quantity, safety and schedule aspects, and gave the improvement suggestions. (authors)

Recognition of depositional sequences and stacking patterns, Late Devonian (Frasnian) carbonate platforms, Alberta basin

Energy Technology Data Exchange (ETDEWEB)

Anderson, J.H.; Reeckmann, S.A.; Sarg, J.F.; Greenlee, S.M.

1987-05-01

Six depositional sequences bounded by regional unconformities or their correlative equivalents (sequence boundaries) have been recognized in Late Devonian (Frasnian) carbonate platforms in the Alberta basin. These sequences consist of a predictable vertical succession of smaller scale shoaling-upward cycles (parasequences). Parasequences are arranged in retrogradational, aggradational, and progradational stacking patterns that can be modeled as a sediment response to relative changes in sea level. Sequence boundaries are recognized by onlap onto underlying shelf or shelf margin strata. This onlap includes shelf margin wedges and deep marine onlap. In outcrop sections shelf margin wedges exhibit an abrupt juxtaposition of shallow water facies over deeper water deposits with no gradational facies changes at the boundaries. High on the platform, subaerial exposure fabrics may be present. The shelf margin wedges are interpreted to have formed during lowstands in sea level and typically exhibit an aggradational stacking pattern. On the platform, two types of sequences are recognized. A type 1 cycle occurs where the sequence boundary is overlain by a flooding surface and subsequent parasequences exhibit retrogradational stacking. In a type 2 cycle the sequence boundary is overlain by an aggradational package of shallow water parasequences, followed by a retrogradational package. These two types of sequences can be modeled using a sinusoidal eustatic sea level curve superimposed on thermo-tectonic subsidence.

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

Science.gov (United States)

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective

The Influence of deep-sea bed CO<sub>2sub> sequestration on small metazoan (meiofaunal) community structure and function

Energy Technology Data Exchange (ETDEWEB)

Carman, Kevin R. [Louisiana State Univ., Baton Rouge, LA (United States); Fleeger, John W. [Louisiana State Univ., Baton Rouge, LA (United States); Thistle, David [Florida State Univ., Tallahassee, FL (United States)

2013-02-17

reduction in pH to about 7.0 after 30 days were as great as an extreme pH reduction (5.4), suggesting that moderate CO<sub>2sub exposure, compared to the range of exposures possible following CO<sub>2sub release, causes high mortality rates in the two most abundant sediment-dwelling metazoans (nematodes and copepods). While we found evidence for negative impacts on deep-sea benthos, we also observed that small-scale experiments with CO<sub>2sub releases were difficult to replicate in the deep sea. Specifically, in one CO<sub>2sub-release experiment in the Monterey Canyon we did not detect an adverse impacts on benthic meiofauan. In laboratory experiments, we manipulated seawater acidity by addition of HCl and by increasing CO<sub>2sub concentration and observed that two coastal harpacticoid copepod species were both more sensitive to increased acidity when generated by CO<sub>2sub. Copepods living in environments more prone to hypercapnia, such as mudflats, may be less sensitive to future acidification. Ocean acidification is also expected to alter the toxicity of waterborne metals by influencing their speciation in seawater. CO<sub>2sub enrichment did not affect the free-ion concentration of Cd but did increase the free-ion concentration of Cu. Antagonistic toxicities were observed between CO<sub>2sub with Cd, Cu and Cu free-ion. This interaction could be due to a competition for H+ and metals for binding sites.

Mastery of innovation risk in deep sea developments (part 1) - Drilling and well - round table no.4; Maitrise du risque de l'innovation dans le developpement en grand fond (1. partie) - le forage et le puits - table ronde no.4

Energy Technology Data Exchange (ETDEWEB)

Charlez, Ph.A.; Lassus Dessus, J.; Gazaniol, D. [TotalFinaElf, La Defense, 92 - Courbevoie (France); Guesnon, J. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Hudson, W. [DORIS Engineering, 75 - Paris (France); Chauvin, H. [Geoservices S.A., 93 - Le Blanc Mesnil (France)

2003-02-01

This round table comprises 5 articles dealing with: 1) - the specific problems and drilling risks in very deep waters: risers (diameter, length, volume and weight), sea bottom conditions (high pressure and low temperature), and management of drilling mud weight (pore and fracturing pressures window, mud hydrates formation); 2) - the implementation of risers in very deep waters: risers mechanical properties (tension, weight), stresses on connected and non-connected risers, possible improvements (reduction of mud and riser weights), steel/composite technology for safety lines, lack of knowledge in the implementation of risers (vibrations, fatigue sources, simulation codes, optimization), instrumentation system for risers; 3) - drilling with surface BOP (blow out preventers): advantages and domains of use, risk management; 4) - safety using gas measurement in very deep drilling: detection of gas events (H{sub 2}S, alkanes, CO{sub 2}, benzene, toluene, xylene) during well drilling, improvement of detectors, implementation, reliability; 5) - Girassol field drillings and completions: contractual strategy, wells design, productivity, drilling and completion, underwater systems. (J.S.)

Geological characterization of CO{sub 2} storage sites: lessons from Sleipner, Northern North Sea

Energy Technology Data Exchange (ETDEWEB)

R.A. Chadwick; P. Zweigel; U. Gregersen; G.A. Kirby; S. Holloway; P.N. Johannessen [British Geological Survey, Keyworth (United Kingdom). Kingsley Dunham Centre

2003-07-01

The paper aims to draw some generic conclusions on reservoir characterization based on the Sleipner operation in the North Sea where CO{sub 2} is being injected into the Utsira Sand, a saline aquifer. Regional mapping and petrophysical characterization of the reservoir, based on 2D seismic and well data, enable gross storage potential to be evaluated. Site specific injection studies, however, require precision depth mapping based on 3D seismic data and detailed knowledge of reservoir stratigraphy. Stratigraphical and structural permeability barriers, difficult to detect prior to CO{sub 2} injection, can radically affect CO{sub 2} migration within the aquifer. 5 refs., 5 figs.

Improvements in the reliability of a-InGaZnO thin-film transistors with triple stacked gate insulator in flexible electronics applications

Energy Technology Data Exchange (ETDEWEB)

Chen, Hua-Mao [Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang3708@gmail.com [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Tai, Ya-Hsiang [Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Chen, Kuan-Fu [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Chiang, Hsiao-Cheng [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Liu, Kuan-Hsien [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China); Lee, Chao-Kuei [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Lin, Wei-Ting; Cheng, Chun-Cheng; Tu, Chun-Hao; Liu, Chu-Yu [Advanced Technology Research Center, AU Optronics Corp, Hsinchu, Taiwan (China)

2015-11-30

This study examined the impact of the low-temperature stacking gate insulator on the gate bias instability of a-InGaZnO thin film transistors in flexible electronics applications. Although the quality of SiN{sub x} at low process/deposition temperature is better than that of SiO{sub x} at similarly low process/deposition temperature, there is still a very large positive threshold voltage (V{sub th}) shift of 9.4 V for devices with a single low-temperature SiN{sub x} gate insulator under positive gate bias stress. However, a suitable oxide–nitride–oxide-stacked gate insulator exhibits a V{sub th} shift of only 0.23 V. This improvement results from the larger band offset and suitable gate insulator thickness that can effectively suppress carrier trapping behavior. - Highlights: • The cause of the bias instability for a low-temperature gate insulator is verified. • A triple-stacked gate insulator was fabricated. • A suitable triple stacked gate insulator shows only 0.23 V threshold voltage shift.

Community metabolism and air-sea CO[sub 2] fluxes in a coral reef ecosystem (Moorea, French Polynesia)

Energy Technology Data Exchange (ETDEWEB)

Gattuso, J P; Pichon, M; Delesalle, B; Frankignoulle, M [Observatory of European Oceanology (Monaco)

1993-06-01

Community metabolism (primary production, respiration and calcification) and air-sea CO[sub 2] fluxes of the 'Tiahura barrier reef' (Moorea, French Polynesia) were investigated in November and December 1991. Gross production and respiration were respectively 640.2 to 753 and 590.4 to 641.5 mmol (O[sub 2] or CO[sub 2]) m[sup 2] d[sup -1] (7.7 to 9.0 and 7.1 to 7.7 g C m)[sup 2] d[sup -1] and the reef displayed a slightly negative excess (net) production. The contribution of planktonic primary production to reef metabolism was negligible (0.15% of total gross production). Net calcification was positive both during the day and at night; its daily value was 243 mmol CaCO[sub 3] m[sup 2] d[sup -1] (24.3 g CaCO)[sub 3] m[sup -2] d[sup -1]. Reef metabolism decreased seawater total CO[sub 2] by 433.3 mmol m[sup 2] d[sup -1]. The air-sea CO[sub 2] fluxes were close to zero in the ocean but displayed a strong daily pattern at the reef front and the back reef. Fluxes were positive (CO[sub 2] evasion) at night, decreased as irradiance increased and were negative during the day (CO[sub 2] invasion). Integration of the fluxes measured during a 24 h experiment at the back reef showed that the reef was a source of CO[sub 2] to the atmosphere (1.5 mmol m[sup 2] d[sup -1]).

A search for the coherently radiating fluxon state in stacks of long intrinsic Josephson junctions

CERN Document Server

Lee, H J; Bae, M H; Wang, H; Yamashita, T

2002-01-01

We studied the motion of fluxons in a stack of intrinsic Josephson junctions (IJJs) of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8 sub + subdelta single crystals in a long junction limit. Driven by the tunnelling bias, current Josephson fluxons excite plasma oscillations and move in resonance with the plasma propagation modes. We examined two types of samples in this study; mesa structure (UD1) and a stack of junctions sandwiched between normal-metallic electrodes (DSC1). In a high magnetic field, the hysteresis in the I-V characteristics of both-types of samples vanished. The resulting single I-V curve exhibited a cusp structure at characteristic bias voltages which were believed to be boundaries of different moving fluxon configurations. We studied the sample-geometry dependence of the cusp characteristics by comparing the results from the two types of samples.

Effect of Additional Structure on Effective Stack Height of Gas Dispersion in Atmosphere

Directory of Open Access Journals (Sweden)

Takenobu Michioka

2016-03-01

Full Text Available Wind-tunnel experiments were conducted to evaluate the effect of additional structure (building, sea wall and banking on the effective stack height, which is usually used in safety analyses of nuclear power facilities in Japan. The effective stack heights were estimated with and without the additional structure in addition to the reactor building while varying several conditions such as the source height, the height of additional structure and the distance between the source position and the additional structure. When the source height is equivalent to the reactor building height, the additional structure enhances both the vertical and horizontal gas dispersion widths and decreases the ground gas concentration, and it means that the additional structure does not decrease the effective stack height. When the source height is larger than the reactor height, the additional structures might affect the effective stack height. As the distance between the source and the additional structure decreases, or as the height of the additional structure increases, the structure has a larger effect on the effective stack height.

Physical characterization of Cu{sub 2}ZnGeSe{sub 4} thin films from annealing of Cu-Zn-Ge precursor layers

Energy Technology Data Exchange (ETDEWEB)

Buffière, M., E-mail: buffiere@imec.be [Imec—Partner in Solliance, Leuven (Belgium); Department of Electrical Engineering (ESAT), KU Leuven, Heverlee (Belgium); ElAnzeery, H. [Imec—Partner in Solliance, Leuven (Belgium); KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Microelectronics System Design department, Nile University, Cairo (Egypt); Oueslati, S.; Ben Messaoud, K. [Imec—Partner in Solliance, Leuven (Belgium); KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Department of Physics, Faculty of Sciences of Tunis, El Manar (Tunisia); Brammertz, G.; Meuris, M. [Imec Division IMOMEC — Partner in Solliance, Diepenbeek (Belgium); Institute for Material Research (IMO) Hasselt University, Diepenbeek (Belgium); Poortmans, J. [Imec—Partner in Solliance, Leuven (Belgium); Department of Electrical Engineering (ESAT), KU Leuven, Heverlee (Belgium)

2015-05-01

Cu{sub 2}ZnGeSe{sub 4} (CZGeSe) can be considered as a potential alternative for wide band gap thin film devices. In this work, CZGeSe thin films were deposited on Mo-coated soda lime glass substrates by sequential deposition of sputtered Cu, Zn and e-beam evaporated Ge layers from elemental targets followed by annealing at high temperature using H{sub 2}Se gas. We report on the effect of the precursor stack order and composition and the impact of the annealing temperature on the physical properties of CZGeSe thin films. The optimal layer morphology was obtained when using a Mo/Cu/Zn/Ge precursor stack annealed at 460 °C. We have observed that the formation of secondary phases such as ZnSe can be prevented by tuning the initial composition of the stack, the stack order and the annealing conditions. This synthesis process allows synthesizing CZGeSe absorber with an optical band gap of 1.5 eV. - Highlights: • Cu{sub 2}ZnGeSe{sub 4} (CZGeSe) thin films were deposited using a two-step process. • CZGeSe dense layers were obtained using a Mo/Cu/Zn/Ge precursor annealed at 460 °C. • Formation of ZnSe can be avoided by tuning the composition and order of the initial stack. • P-type CZGeSe absorber with an optical band gap of 1.5 eV was obtained.

Hexagonal perovskites with cationic vacancies. 12. Structure determination on Ba/sub 6/W/sub 4/vacant/sub 2/O/sub 18/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Treiber, U [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1979-08-01

The stacking polytype Ba/sub 6/W/sub 4/vacant/sub 2/O/sub 18/ is the first oxide variant of the Cs/sub 3/Tl/sub 2/Cl/sub 9/-type. The structure determination gave for the space group R3c with the sequence (h)/sub 6/, Z = 3, the refined, intensity related R' value of 6.8%. The octahedral net consists of groups of two face sharing WO/sub 6/ octahedra (W/sub 2/ Osub(6/2)O/sub 6/), which are in the (110) plane displaced against each other. In the double octahedra the tungsten atoms are shifted away from their ideal central position (W-W:2.32/sub 7/ A) with the result, that the W-W distance has increased to 2.90/sub 5/ A.

Correlated lateral phase separations in stacks of lipid membranes

Energy Technology Data Exchange (ETDEWEB)

Hoshino, Takuma, E-mail: hoshino-takuma@ed.tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Komura, Shigeyuki, E-mail: komura@tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Andelman, David, E-mail: andelman@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)

2015-12-28

Motivated by the experimental study of Tayebi et al. [Nat. Mater. 11, 1074 (2012)] on phase separation of stacked multi-component lipid bilayers, we propose a model composed of stacked two-dimensional Ising spins. We study both its static and dynamical features using Monte Carlo simulations with Kawasaki spin exchange dynamics that conserves the order parameter. We show that at thermodynamical equilibrium, due to strong inter-layer correlations, the system forms a continuous columnar structure for any finite interaction across adjacent layers. Furthermore, the phase separation shows a faster dynamics as the inter-layer interaction is increased. This temporal behavior is mainly due to an effective deeper temperature quench because of the larger value of the critical temperature, T{sub c}, for larger inter-layer interaction. When the temperature ratio, T/T{sub c}, is kept fixed, the temporal growth exponent does not increase and even slightly decreases as a function of the increased inter-layer interaction.

Hexagonal perovskites with cationic vacancies. 32. Photoluminescence of trivalent rare earth in the systems Ba/sub 2-y/Sr/sub y/La/sub 2-x/RE/sub x/MgW/sub 2/vacantO/sub 12/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1982-06-01

In the series Ba/sub 2-y/Sr/sub y/La/sub 2-x/RE/sub x/MgW/sub 2/vacantO/sub 12/ the Ba/sup 2 +/ can be completely substituted by Sr/sup 2 +/. All compounds crystallize in the rhombohedral 12 L-type (space group R-3m; sequence (hhcc)/sub 3/). By doping the stacking polytypes with some of the trivalent rare earths efficient visible photoluminescence is obtained. The simultaneous incorporation of two different rare earth ions leads to two-color-phosphors, which, according to the excitation energy used, emit either mainly the typical spectrum from one or the other activator; the corresponding luminescence mechanism are discussed.

Probing Temperature Inside Planar SOFC Short Stack, Modules, and Stack Series

Science.gov (United States)

Yu, Rong; Guan, Wanbing; Zhou, Xiao-Dong

2017-02-01

Probing temperature inside a solid oxide fuel cell (SOFC) stack lies at the heart of the development of high-performance and stable SOFC systems. In this article, we report our recent work on the direct measurements of the temperature in three types of SOFC systems: a 5-cell short stack, a 30-cell stack module, and a stack series consisting of two 30-cell stack modules. The dependence of temperature on the gas flow rate and current density was studied under a current sweep or steady-state operation. During the current sweep, the temperature inside the 5-cell stack decreased with increasing current, while it increased significantly at the bottom and top of the 30-cell stack. During a steady-state operation, the temperature of the 5-cell stack was stable while it was increased in the 30-cell stack. In the stack series, the maximum temperature gradient reached 190°C when the gas was not preheated. If the gas was preheated and the temperature gradient was reduced to 23°C in the stack series with the presence of a preheating gas and segmented temperature control, this resulted in a low degradation rate.

How reversible is sea ice loss?

Directory of Open Access Journals (Sweden)

J. K. Ridley

2012-02-01

Full Text Available It is well accepted that increasing atmospheric CO<sub>2sub> results in global warming, leading to a decline in polar sea ice area. Here, the specific question of whether there is a tipping point in the sea ice cover is investigated. The global climate model HadCM3 is used to map the trajectory of sea ice area under idealised scenarios. The atmospheric CO<sub>2sub> is first ramped up to four times pre-industrial levels (4 × CO<sub>2sub>, then ramped down to pre-industrial levels. We also examine the impact of stabilising climate at 4 × CO<sub>2sub> prior to ramping CO<sub>2sub> down to pre-industrial levels. Against global mean temperature, Arctic sea ice area is reversible, while the Antarctic sea ice shows some asymmetric behaviour – its rate of change slower, with falling temperatures, than its rate of change with rising temperatures. However, we show that the asymmetric behaviour is driven by hemispherical differences in temperature change between transient and stabilisation periods. We find no irreversible behaviour in the sea ice cover.

Indium and gallium diffusion through zirconia in the TiN/ZrO{sub 2}/InGaAs stack

Energy Technology Data Exchange (ETDEWEB)

Ceballos-Sanchez, O. [CINVESTAV-Unidad Queretaro, Queretaro, Qro. 76230 (Mexico); Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Martinez, E.; Guedj, C.; Veillerot, M. [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Herrera-Gomez, A. [CINVESTAV-Unidad Queretaro, Queretaro, Qro. 76230 (Mexico)

2015-06-01

Angle-resolved X-ray Photoelectron Spectroscopy (ARXPS) was applied to the TiN/ZrO{sub 2}/InGaAs stack to assess its thermal stability. Through a robust ARXPS analysis, it was possible to observe subtle effects such as the thermally induced diffusion of substrate atomic species (In and Ga) through the dielectric layer. The detailed characterization of the film structure allowed for assessing the depth profiles of the diffused atomic species by means of the scenarios-method. Since the quantification for the amount of diffused material was done at different temperatures, it was possible to obtain an approximate value of the activation energy for the diffusion of indium through zirconia. The result is very similar to the previously reported values for indium diffusion through alumina and through hafnia.

Growth and characterization of thin oriented Co{sub 3}O{sub 4} (111) films obtained by decomposition of layered cobaltates Na{sub x}CoO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Buršík, Josef, E-mail: bursik@iic.cas.cz [Institute of Inorganic Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., 250 68, Husinec-Řež 1001 (Czech Republic); Soroka, Miroslav, E-mail: soroka@iic.cas.cz [Institute of Inorganic Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., 250 68, Husinec-Řež 1001 (Czech Republic); Kužel, Radomír, E-mail: kuzel@karlov.mff.cuni.cz [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Mika, Filip, E-mail: filip.mika@isibrno.cz [Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 147, 612 64 Brno (Czech Republic)

2015-07-15

The formation and structural characterization of highly (111)-oriented Co{sub 3}O{sub 4} films prepared by a novel procedure from weakly (001)-oriented Na{sub x}CoO{sub 2} is reported. The Na{sub x}CoO{sub 2} films were deposited on both single crystal and amorphous substrates by chemical solution deposition (CSD) method and crystallized at 700 °C. Subsequently they were transformed into (111)-oriented Co{sub 3}O{sub 4} phase during post-growth annealing at 900 °C. The degree of preferred orientation in Co{sub 3}O{sub 4}, which was determined by phi-scan and pole figure measurements, depends on the content of Na in the starting Na{sub x}CoO{sub 2} phase. Surface morphology of the films was investigated using electron microscopy and atomic force microscopy. - Graphical abstract: Structure of growth twins and possible O{sup 2−} stacking sequences in (111)-oriented Co{sub 3}O{sub 4} thin films on α-Al{sub 2}O{sub 3}(001) prepared by chemical solution deposition through the transformation of (001)-oriented Na{sub x}CoO{sub 2} thin film. - Highlights: • Single phase Co{sub 3}O{sub 4} thin films was prepared by means of chemical solution deposition. • Conditions for γ-Na{sub x}CoO{sub 2} to Co{sub 3}O{sub 4} transformation were optimized. • Growth twinning of Co{sub 3}O{sub 4} films due to two possible O{sup 2−} stacking sequences. • Growth with (pseudo)epitaxial relation Co{sub 3}O{sub 4} (111)[−121]//α-Al{sub 2}O{sub 3} (001)[10−10].

Behavioral responses of Arctica islandica (Bivalvia: Arcticidae) to simulated leakages of carbon dioxide from sub-sea geological storage

Energy Technology Data Exchange (ETDEWEB)

Bamber, Shaw D., E-mail: shaw.bamber@iris.no; Westerlund, Stig, E-mail: sw@iris.no

2016-11-15

Highlights: • Valve pumping activity in A. islandica significantly increased at pH 6.2 seawater. • Changes in valve movements were not related to attempted burrowing activities. • Valve activity returned to control levels after 5 days of continuous exposure. • A. islandica tolerate pH reductions likely to follow leakage of sub-sea stored CO{sub 2}. - Abstract: Sub-sea geological storage of carbon dioxide (CO{sub 2}) provides a viable option for the Carbon Capture and Storage (CCS) approach for reducing atmospheric emissions of this greenhouse gas. Although generally considered to offer a low risk of major leakage, it remains relevant to establish the possible consequences for marine organisms that live in or on sediments overlying these storage areas if such an event may occur. The present study has used a series of laboratory exposures and behavioral bioassays to establish the sensitivity of Arctica islandica to simulated leakages of CO{sub 2}. This long-lived bivalve mollusc is widely distributed throughout the North Sea, an area where geological storage is currently taking place and where there are plans to expand this operation significantly. A recently published model has predicted a maximum drop of 1.9 pH units in seawater at the point source of a substantial escape of CO{sub 2} from sub-sea geological storage in this region. Valve movements of A. islandica exposed to reduced pH seawater were recorded continuously using Hall effect proximity sensors. Valve movement regulation is important for optimising the flow of water over the gills, which supplies food and facilitates respiration. A stepwise reduction in seawater pH showed an initial increase in both the rate and extent of valve movements in the majority of individuals tested when pH fell to 6.2 units. Exposing A. islandica to pH 6.2 seawater continuously for seven days resulted in a clear increase in valve movements during the first 40 h of exposure, followed by a gradual reduction in activity

Strontium titanate/silicon-based terahertz photonic crystal multilayer stack

Energy Technology Data Exchange (ETDEWEB)

Xin, J.Z.; Jim, K.L.; Tsang, Y.H.; Chan, H.L.W.; Leung, C.W. [Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Centre, Kowloon, Hong Kong (China); Yang, J.; Gong, X.J.; Chen, L.Q.; Gao, F. [Chinese Academy of Sciences, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Shenzhen (China)

2012-04-15

A one-dimensional photonic crystal working in the terahertz (THz) range was designed and implemented. To facilitate the design, the transmission properties of strontium titanate crystals were characterized by THz-time-domain spectroscopy. Relatively high refractive index ({proportional_to}18.5) and transmission ratio (0.08) were observed between 0.2 to 1 THz. A stacked structure of (Si d{sub Si}/STO d{sub STO}){sub N} /Si d{sub Si} was then designed, with transmission spectra calculated by the transfer matrix method. The effects of the filling ratio (d{sub STO}/(d{sub Si}+d{sub STO})), periodicity (d{sub Si}+d{sub STO}) and the number of repeats N on the transmission of PC were investigated. The effect of introducing a defect layer was also studied. Based on these, Si/STO multilayers with STO defect thickness of 125 {mu}m and 200 {mu}m were measured. The shift of the defect mode was observed and compared with the calculations. (orig.)

Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation

Energy Technology Data Exchange (ETDEWEB)

Ke, M., E-mail: kiramn@mosfet.t.u-tokyo.ac.jp; Yu, X.; Chang, C.; Takenaka, M.; Takagi, S. [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan and JST-CREST, K' s Gobancho 6F, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)

2016-07-18

The realization of Ge gate stacks with a small amount of slow trap density as well as thin equivalent oxide thickness and low interface state density (D{sub it}) is a crucial issue for Ge CMOS. In this study, we examine the properties of slow traps, particularly the location of slow traps, of Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge and HfO{sub 2}/Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge MOS interfaces with changing the process and structural parameters, formed by atomic layer deposition (ALD) of Al{sub 2}O{sub 3} and HfO{sub 2}/Al{sub 2}O{sub 3} combined with plasma post oxidation. It is found that the slow traps can locate in the GeO{sub x} interfacial layer, not in the ALD Al{sub 2}O{sub 3} layer. Furthermore, we study the time dependence of channel currents in the Ge n-MOSFETs with 5-nm-thick Al{sub 2}O{sub 3}/GeO{sub x}/Ge gate stacks, with changing the thickness of GeO{sub x}, in order to further clarify the position of slow traps. The time dependence of the current drift and the effective time constant of slow traps do not change among the MOSFETs with the different thickness GeO{sub x}, demonstrating that the slow traps mainly exist near the interfaces between Ge and GeO{sub x}.

Improvement of Ohmic contacts on Ga<sub>2sub>O>3sub> through use of ITO-interlayers

Energy Technology Data Exchange (ETDEWEB)

Carey, Patrick H. [Univ. of Florida, Gainesville, FL (United States). Department of Chemical Engineering; Yang, Jiancheng [Univ. of Florida, Gainesville, FL (United States). Department of Chemical Engineering; Ren, Fan [Univ. of Florida, Gainesville, FL (United States). Department of Chemical Engineering; Hays, David C. [Univ. of Florida, Gainesville, FL (United States). Department of Materials Science and Engineering; Pearton, Stephen J. [Univ. of Florida, Gainesville, FL (United States). Department of Materials Science and Engineering; Kuramata, Akito [Tamura Corporation, Sayama (Japan). Japan and Novel Crystal Technology, Inc.; Kravchenko, Ivan I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)

2017-10-03

In this work, the use of ITO interlayers between Ga<sub>2sub>O>3sub> and Ti/Au metallization is shown to produce Ohmic contacts after annealing in the range of 500–600 °C. Without the ITO, similar anneals do not lead to linear current–voltage characteristics. Transmission line measurements were used to extract the specific contact resistance of the Au/Ti/ITO/Ga<sub>2sub>O>3sub> stacks as a function of annealing temperature. Sheet, specific contact, and transfer resistances all decreased sharply from as-deposited values with annealing. The minimum transfer resistance and specific contact resistance of 0.60 Ω mm and 6.3 × 10^-5 Ω cm² were achieved after 600 °C annealing, respectively. Lastly, the conduction band offset between ITO and Ga<sub>2sub>O>3sub> is 0.32 eV and is consistent with the improved electron transport across the heterointerface.

Anisotropic electrical, thermal and magnetic properties of Al{sub 13}Ru{sub 4} decagonal quasicrystalline approximant

Energy Technology Data Exchange (ETDEWEB)

Wencka, Magdalena [Polish Academy of Sciences, Poznan (Poland). Inst. of Molecular Physics; Vrtnik, Stanislav; Kozelj, Primoz; Dolinsek, Janez [Ljubljana Univ. (Slovenia). Faculty of Mathematics and Physics; Jozef Stefan Institute, Ljubljana (Slovenia); Jaglicic, Zvonko [Ljubljana Univ. (Slovenia). Inst. of Mathematics, Physics and Mechanics; Gille, Peter [Muenchen Univ. (Germany). Crystallography Section

2017-09-01

We present measurements of the anisotropic electrical and thermal transport coefficients (the electrical resistivity, the thermoelectric power, the thermal conductivity), the magnetization and the specific heat of the Al{sub 13}Ru{sub 4} monoclinic approximant to the decagonal quasicrystal, in comparison to the isostructural Al{sub 13}Fe{sub 4}. The electrical and thermal transport parameters of Al{sub 13}Ru{sub 4} were found to exhibit significant anisotropy, qualitatively similar to that found previously in the Al{sub 13}Fe{sub 4} (P. Popcevic, et al., Phys. Rev. B 2010, 81, 184203). The crystallographic b direction, corresponding to the stacking direction of the (a,c) atomic planes, is the most conducting direction for the electricity and heat. The thermopower is strongly anisotropic with a complicated temperature dependence, exhibiting maxima, minima, crossovers and sign change. The electronic density of states (DOS) at the Fermi energy is reduced to 35% of the DOS of Al metal. The magnetic susceptibility is diamagnetic and the diamagnetism is by a factor of 2 stronger for the magnetic field along the stacking b direction.

Structure and mechanical properties of as-cast (ZrTi){sub 100−x}B{sub x} alloys

Energy Technology Data Exchange (ETDEWEB)

Xia, C.Q.; Jiang, X.J.; Wang, X.Y.; Zhou, Y.K.; Feng, Z.H. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Tan, C.L. [Beijing Institute of Spacecraft System Engineering, Beijing 100094 (China); Ma, M.Z. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, R.P., E-mail: riping@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2015-07-15

Highlights: • Trace boron additions result in significant grain refinement. • Large numbers of stacking faults are observed in ZrB{sub 2} and TiB intermetallics. • The tensile strength is enhanced by increasing the amount of B. • Intermetallics microcracking causes the failure of the alloys. - Abstract: The microstructure, mechanical properties, and fracture characteristics of (Zr{sub 50}Ti{sub 50}){sub 100−x}B{sub x} alloys (x = 0, 0.5, 1, 2 at.%) obtained by casting were investigated. Trace additions of boron (B) to the Zr{sub 50}Ti{sub 50} alloys induced significant microstructural changes. Changes included the promotion of dendritic growth and refinement in prior-β grain and α′-lath size. Large numbers of stacking faults were also observed in ZrB{sub 2} and TiB intermetallics. The location of B atoms and the lattice mismatch energy between intermetallics and matrix were responsible for the stacking faults. (ZrTi)B alloys demonstrated higher tensile strength than matrix material. Both the intermetallics with high strength and modulus and the grain refinement played important roles in improving the mechanical properties of alloys. This result could be explained in terms of a shear-lag model based on the load transfer concept and Hall–Petch mechanism. The elongation-to-failure of (ZrTi)B alloys decreased with increased B concentration. The reduction in elongation-to-failure of (ZrTi)B alloys could be attributed to the presence of ZrB{sub 2} and TiB intermetallics and refinement of α′-laths.

Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

Science.gov (United States)

Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

2015-02-07

Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

Direct fuel cell power plants: the final steps to commercialization

Science.gov (United States)

Glenn, Donald R.

Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each

Metal ion displacements in noncentrosymmetric chalcogenides La{sub 3}Ga{sub 1.67}S{sub 7}, La{sub 3}Ag{sub 0.6}GaCh{sub 7} (Ch=S, Se), and La{sub 3}MGaSe{sub 7} (M=Zn, Cd)

Energy Technology Data Exchange (ETDEWEB)

Iyer, Abishek K. [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G2G2 (Canada); Yin, Wenlong [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G2G2 (Canada); Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900 (China); Rudyk, Brent W. [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G2G2 (Canada); Lin, Xinsong [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G2G2 (Canada); Centre for Oil Sands Sustainability, Northern Alberta Institute of Technology, Edmonton, Alberta, Canada T6N1E5 (Canada); Nilges, Tom [Department of Chemistry, Technical University of Munich, 85748 Garching b. München (Germany); Mar, Arthur, E-mail: arthur.mar@ualberta.ca [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G2G2 (Canada)

2016-11-15

The quaternary Ga-containing chalcogenides La{sub 3}Ag{sub 0.6}GaS{sub 7}, La{sub 3}Ag{sub 0.6}GaSe{sub 7}, La{sub 3}ZnGaSe{sub 7}, and La{sub 3}CdGaSe{sub 7}, as well as the related ternary chalcogenide La{sub 3}Ga{sub 1.67}S{sub 7}, were prepared by reactions of the elements at 950 °C. They adopt noncentrosymmetric hexagonal structures (space group P6{sub 3}, Z=2) with cell parameters (a=10.2 Å, c=6.1 Å for the sulfides; a=10.6 Å, c=6.4 Å for the selenides) that are largely controlled by the geometrical requirements of one-dimensional stacks of Ga-centered tetrahedra separated by the La atoms. Among these compounds, which share the common formulation La{sub 3}M{sub 1–x}GaCh{sub 7} (M=Ga, Ag, Zn, Cd; Ch=S, Se), the M atoms occupy sites within a stacking of trigonal antiprisms formed by Ch atoms. The location of the M site varies between extremes with trigonal antiprismatic (CN6) and trigonal planar (CN3) geometry. Partial occupation of these sites and intermediate ones accounts for the considerable versatility of these structures and the occurrence of large metal displacement parameters. The site occupations can be understood in a simple way as being driven by the need to satisfy appropriate bond valence sums for both the M and Ch atoms. Band structure calculations rationalize the substoichiometry observed in the Ag-containing compounds (La{sub 3}Ag{sub 0.6}GaS{sub 7}, La{sub 3}Ag{sub 0.6}GaSe{sub 7}) as a response to overbonding. X-ray photoelectron spectroscopy supports the presence of monovalent Ag atoms in these compounds, which are not charge-balanced. - Graphical abstract: Partial occupation of metal atoms in multiple sites accounts for versatility in Ga-containing chalcogenides La{sub 3}M{sub 1–x}GaCh{sub 7} with noncentrosymmetric hexagonal structures. - Highlights: • La{sub 3}M{sub 1–x}GaCh{sub 7} (M =Ga, Ag, Zn, Cd; Ch =S, Se) adopt related hexagonal structures. • Large displacements of M atoms originate from partial occupation of multiple

Air-sea interaction regimes in the sub-Antarctic Southern Ocean and Antarctic marginal ice zone revealed by icebreaker measurements

Science.gov (United States)

Yu, Lisan; Jin, Xiangze; Schulz, Eric W.; Josey, Simon A.

2017-08-01

This study analyzed shipboard air-sea measurements acquired by the icebreaker Aurora Australis during its off-winter operation in December 2010 to May 2012. Mean conditions over 7 months (October-April) were compiled from a total of 22 ship tracks. The icebreaker traversed the water between Hobart, Tasmania, and the Antarctic continent, providing valuable in situ insight into two dynamically important, yet poorly sampled, regimes: the sub-Antarctic Southern Ocean and the Antarctic marginal ice zone (MIZ) in the Indian Ocean sector. The transition from the open water to the ice-covered surface creates sharp changes in albedo, surface roughness, and air temperature, leading to consequential effects on air-sea variables and fluxes. Major effort was made to estimate the air-sea fluxes in the MIZ using the bulk flux algorithms that are tuned specifically for the sea-ice effects, while computing the fluxes over the sub-Antarctic section using the COARE3.0 algorithm. The study evidenced strong sea-ice modulations on winds, with the southerly airflow showing deceleration (convergence) in the MIZ and acceleration (divergence) when moving away from the MIZ. Marked seasonal variations in heat exchanges between the atmosphere and the ice margin were noted. The monotonic increase in turbulent latent and sensible heat fluxes after summer turned the MIZ quickly into a heat loss regime, while at the same time the sub-Antarctic surface water continued to receive heat from the atmosphere. The drastic increase in turbulent heat loss in the MIZ contrasted sharply to the nonsignificant and seasonally invariant turbulent heat loss over the sub-Antarctic open water.Plain Language SummaryThe icebreaker Aurora Australis is a research and supply vessel that is regularly chartered by the Australian Antarctic Division during the southern summer to operate in waters between Hobart, Tasmania, and Antarctica. The vessel serves as the main lifeline to three permanent research stations on the

BUILDING A BILLION SPATIO-TEMPORAL OBJECT SEARCH AND VISUALIZATION PLATFORM

Directory of Open Access Journals (Sweden)

D. Kakkar

2017-10-01

Full Text Available With funding from the Sloan Foundation and Harvard Dataverse, the Harvard Center for Geographic Analysis (CGA has developed a prototype spatio-temporal visualization platform called the Billion Object Platform or BOP. The goal of the project is to lower barriers for scholars who wish to access large, streaming, spatio-temporal datasets. The BOP is now loaded with the latest billion geo-tweets, and is fed a real-time stream of about 1 million tweets per day. The geo-tweets are enriched with sentiment and census/admin boundary codes when they enter the system. The system is open source and is currently hosted on Massachusetts Open Cloud (MOC, an OpenStack environment with all components deployed in Docker orchestrated by Kontena. This paper will provide an overview of the BOP architecture, which is built on an open source stack consisting of Apache Lucene, Solr, Kafka, Zookeeper, Swagger, scikit-learn, OpenLayers, and AngularJS. The paper will further discuss the approach used for harvesting, enriching, streaming, storing, indexing, visualizing and querying a billion streaming geo-tweets.

Building a Billion Spatio-Temporal Object Search and Visualization Platform

Science.gov (United States)

Kakkar, D.; Lewis, B.

2017-10-01

With funding from the Sloan Foundation and Harvard Dataverse, the Harvard Center for Geographic Analysis (CGA) has developed a prototype spatio-temporal visualization platform called the Billion Object Platform or BOP. The goal of the project is to lower barriers for scholars who wish to access large, streaming, spatio-temporal datasets. The BOP is now loaded with the latest billion geo-tweets, and is fed a real-time stream of about 1 million tweets per day. The geo-tweets are enriched with sentiment and census/admin boundary codes when they enter the system. The system is open source and is currently hosted on Massachusetts Open Cloud (MOC), an OpenStack environment with all components deployed in Docker orchestrated by Kontena. This paper will provide an overview of the BOP architecture, which is built on an open source stack consisting of Apache Lucene, Solr, Kafka, Zookeeper, Swagger, scikit-learn, OpenLayers, and AngularJS. The paper will further discuss the approach used for harvesting, enriching, streaming, storing, indexing, visualizing and querying a billion streaming geo-tweets.

Optical and photoelectrochemical studies on Ag{sub 2}O/TiO{sub 2} double-layer thin films

Energy Technology Data Exchange (ETDEWEB)

Li, Chuan, E-mail: cli10@yahoo.com [Department of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan 11221 (China); Department of Mechanical Engineering, National Central University, Jhongli, Taoyuan, Taiwan 32001 (China); Hsieh, J.H. [Department of Materials Engineering, Ming Chi University of Technology, Taishan, Taipei, Taiwan 24301 (China); Cheng, J.C. [Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan 10608 (China); Huang, C.C. [Department of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan 11221 (China)

2014-11-03

When two different oxides films stacked together, if the absorption (upper) layer has both its conduction and valence bands more negatively lower than that of the layer underneath, then the photo-excited electrons can be forwarded to the underneath layer to become an effect of energy storage. Recent studies discovered that the double-layers of Cu{sub 2}O/TiO{sub 2} films possess such capacity. In order to investigate this specific phenomenon, we use a DC magnetron reactive sputtering to deposit a double-layer of Ag{sub 2}O/TiO{sub 2} films on glass substrate. The film thicknesses of the double-layer are 300 nm and 200 nm respectively. X-Ray diffraction (XRD), scanning electron microscope (SEM) and UV–VIS–NIR photospectrometer and photoluminance tests were used to study the structure, morphology, optical absorption and band gaps of the stacked films. From XRD and SEM, we can confirm the microstructures of each layer. The UV–VIS–NIR spectrum revealed that the optical absorption of Ag{sub 2}O/TiO{sub 2} fell in between the single film of Ag{sub 2}O and TiO{sub 2}. Further, two band gaps were estimated for Ag{sub 2}O/TiO{sub 2} films based on the Beer-Lambert law and Tauc plot. Photoluminance and photoelectrochemical tests indicated that delayed emission by electron-hole recombination and photoelectrical current was effectively support the mechanism of electrons transfer from Ag{sub 2}O to TiO{sub 2} at Ag{sub 2}O/TiO{sub 2} interface in the double-layer films. - Highlights: • A double-layer of Ag{sub 2}O/TiO{sub 2} films was deposited on glass substrate by sputtering. • XRD confirms the nanocrystalline structures of the stack deposited films. • UV–VIS–NIR spectroscopy shows the enhanced of optical absorption in Ag{sub 2}O/TiO{sub 2}. • Photoluminance and photoelectrochemical tests show electron-hole separation effect.

Effects of neutron irradiation of Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} in the 121–1085 °C temperature range

Energy Technology Data Exchange (ETDEWEB)

Tallman, Darin J. [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States); He, Lingfeng; Gan, Jian [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Caspi, El' ad N. [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States); Physics Department, Nuclear Research Centre – Negev, 84190 Israel (Israel); Hoffman, Elizabeth N. [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Barsoum, Michel W., E-mail: barsoumw@drexel.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States)

2017-02-15

Herein we report on the formation of defects in response to neutron irradiation of polycrystalline Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} samples exposed to total fluences of ≈6 × 10{sup 20} n/m{sup 2}, 5 × 10{sup 21} n/m{sup 2} and 1.7 × 10{sup 22} n/m{sup 2} at irradiation temperatures of 121(12), 735(6) and 1085(68)°C. These fluences correspond to 0.14, 1.6 and 3.4 dpa, respectively. After irradiation to 0.14 dpa at 121 °C and 735 °C, black spots are observed via transmission electron microscopy in both Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2}. After irradiation to 1.6 and 3.4 dpa at 735 °C, basal dislocation loops, with a Burgers vector of b = ½ [0001] are observed in Ti{sub 3}SiC{sub 2}, with loop diameters of 21(6) and 30(8) nm after 1.6 dpa and 3.4 dpa, respectively. In Ti{sub 3}AlC{sub 2}, larger dislocation loops, 75(34) nm in diameter are observed after 3.4 dpa at 735 °C, in addition to stacking faults. Impurity particles of TiC, as well as stacking fault TiC platelets in the MAX phases, are seen to form extensive dislocation loops under all conditions. Cavities were observed at grain boundaries and within stacking faults after 3.4 dpa irradiation, with extensive cavity formation in the TiC regions at 1085 °C. Remarkably, denuded zones on the order of 1 μm are observed in Ti{sub 3}SiC{sub 2} after irradiation to 3.4 dpa at 735 °C. Small grains, 3–5 μm in diameter, are damage free after irradiation at 1085 °C at this dose. The results shown herein confirm once again that the presence of the A-layers in the MAX phases considerably enhance their irradiation tolerance. Based on these results, and up to 3.4 dpa, Ti{sub 3}SiC{sub 2} remains a promising candidate for high temperature nuclear applications as long as the temperature remains >700 °C.

Perpendicular magnetic anisotropy in Co{sub X}Pd{sub 100−X} alloys for magnetic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Clark, B.D.; Natarajarathinam, A.; Tadisina, Z.R. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, AL 35487 (United States); Chen, P.J.; Shull, R.D. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Gupta, S., E-mail: Sgupta@eng.ua.edu [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, AL 35487 (United States)

2017-08-15

Highlights: • CoPd alloy perpendicular anisotropy dependent on composition and thickness. • CIPT results show that TMR tracks with PMA of CoPd. • Potential replacement for Co/Pd multilayers. - Abstract: CoFeB/MgO-based perpendicular magnetic tunnel junctions (p-MTJ’s) with high anisotropy and low damping are critical for spin-torque transfer random access memory (STT-RAM). Most schemes of making the pinned CoFeB fully perpendicular require ferrimagnets with high damping constants, a high temperature-grown L1{sub 0} alloy, or an overly complex multilayered synthetic antiferromagnet (SyAF). We report a compositional study of perpendicular Co{sub x}Pd alloy-pinned Co{sub 20}Fe{sub 60}B{sub 20}/MgO based MTJ stacks, grown at moderate temperatures in a planetary deposition system. The perpendicular anisotropy of the Co{sub x}Pd alloy films can be tuned based on the layer thickness and composition. The films were characterized by alternating gradient magnetometry (AGM), energy-dispersive X-rays (EDX), and X-ray diffraction (XRD). Current-in-plane tunneling (CIPT) measurements have also been performed on the compositionally varied Co{sub x}Pd MTJ stacks. The Co{sub x}Pd alloy becomes fully perpendicular at approximately x = 30% (atomic fraction) Co. Full-film MTJ stacks of Si/SiO{sub 2}/MgO (13)/Co{sub X}Pd{sub 100−x} (50)/Ta (0.3)/CoFeB (1)/MgO (1.6)/CoFeB (1)/Ta (5)/Ru (10), with the numbers enclosed in parentheses being the layer thicknesses in nm, were sputtered onto thermally oxidized silicon substrates and in-situ lamp annealed at 400 °C for 5 min. CIPT measurements indicate that the highest TMR is observed for the CoPd composition with the highest perpendicular magnetic anisotropy.

Investigations of the R<sub>5sub>(Si_xGe>1-xsub>)>4sub> Intermetallic Compounds by X-Ray Resonant Magnetic Scattering

Energy Technology Data Exchange (ETDEWEB)

Tan, Lizhi [Iowa State Univ., Ames, IA (United States)

2008-08-18

The XRMS experiment on the Gd<sub>5sub>Ge>4sub> system has shown that, below the Neel temperature, T<sub>N> = 127 K, the magnetic unit cells is the same as the chemical unit cell. From azimuth scans and the Q dependence of the magnetic scattering, all three Gd sites in the structure were determined to be in the same magnetic space group Pnma. The magnetic moments are aligned along the c-axis and the c-components of the magnetic moments at the three different sites are equal. The ferromagnetic slabs are stacked antiferromagnetically along the b-direction. They found an unusual order parameter curve in Gd<sub>5sub>Ge>4sub>. A spin-reorientation transition is a possibility in Gd<sub>5sub>Ge>4sub>, which is similar to the Tb<sub>5sub>Ge>4sub> case. Tb<sub>5sub>Ge>4sub> possesses the same Sm<sub>5sub>Ge>4sub>-type crystallographic structure and the same magnetic space group as Gd<sub>5sub>Ge>4sub> does. The difference in magnetic structure is that Tb<sub>5sub>Ge>4sub> has a canted one but Gd<sub>5sub>Ge>4sub> has nearly a collinear one in the low temperature antiferromagnetic phase. The competition between the magneto-crystalline anisotropy and the nearest-neighbor magnetic exchange interactions may allow a 3-dimensional canted antiferromagnetic structure in Tb<sub>5sub>Ge>4sub>. The spin-reorientation transition in both Gd<sub>5sub>Ge>4sub> and Tb<sub>5sub>Ge>4sub> may arise from the competition between the magnetic anisotropy from the spin-orbit coupling of the conduction electrons and the dipolar interactions anisotropy.

Hexagonal perovskites with cationic vacancies. 24. Rhombohedral 9 L stacking polytypes in the systems Ba/sub 3/Wsub(2-x)sup(VI)Msub(x)sup(V)vacantOsub(9-x/2)vacantsub(x/2) with Msup(V) = Nb, Ta

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-12-01

In the system Ba/sub 3/Wsub(2-x)sup(VI)Nbsub(x)sup(V)vacantOsub(9-x/2)vacantsub(x/2) stacking polytypes of rhombohedral 9 L type (sequence (hhc)/sub 3/; space group R-3m) can be prepared with approximately 1/3 <= x <= 2. For x = 2(Ba/sub 3/Nb/sub 2/vacantO/sub 8/vacant) two modifications are formed. In the corresponding Ta system the phase width is reduced to a smaller region with x approximately 1/3.

Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

DEFF Research Database (Denmark)

Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Raja Abid

2013-01-01

A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell...... stack and BOP has been investigated in this study. The results show that humidification of the inlet air is of great importance. By decreasing the relative humidity of inlet air from 95% to 25%, the voltage can drop by 29%. In addition, elevated stack temperature can lead to a higher average cell...... voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water-ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32-33% in the inner loop and 60-65% in the outer loop for all ranges of current...

Comparison of SeaWiFS and MODIS time series of inherent optical properties for the Adriatic Sea

Directory of Open Access Journals (Sweden)

F. Mélin

2011-05-01

Full Text Available Time series of inherent optical properties (IOPs derived from SeaWiFS and MODIS are compared for the Adriatic Sea. The IOPs are outputs of the Quasi-Analytical Algorithm and include total absorption a, phytoplankton absorption a<sub>ph>, absorption associated with colored detrital material (CDM a<sub>cdm>, and particle backscattering coefficient b<sub>bp>. The average root-mean square difference Δ computed for log-transformed distributions decreases for $a$ from 0.084 at 412 nm to 0.052 at 490 nm, is higher for a<sub>ph>(443 (0.149 than for a<sub>cdm>(443 (0.071, and is approximately 0.165 for b<sub>bp> at various wavelengths. The SeaWiFS a at 443 and 490 nm, a<sub>ph> at 443 nm and b<sub>bp> are on average higher than the MODIS counterparts. Statistics show significant variations in space and time. There is an overall increasing gradient for Δ associated with the absorption terms from the open southern and central Adriatic to the northwest part of the basin, and a reversed gradient for the particulate backscattering coefficient. For time series analysis, only a(412 and a<sub>cdm>(443 currently present an unbiased continuity bridging the SeaWiFS and MODIS periods for the Adriatic Sea.

Synthesis, structural approach and electronic properties of V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6}: a new organically templated vanadium oxide exhibiting V{sub 2}O{sub 5} layer topology

Energy Technology Data Exchange (ETDEWEB)

Sicard, M.; Maignan, A. [Laboratoire Crismat-ISMRa UMR 6508, 14 - Caen (France); Riou, D. [Universite de Versailles St Quentin, Institut Lavoisier UMR CNRS 8637, 78 - Versailles (France)

2002-02-01

V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6} was hydrothermally synthesized in the form of thin platelets. Its structural approach was investigated by single crystal X-ray diffraction (non-centrosymmetric P2{sub 1} (No 4) monoclinic space group with a 10.7713(3) Angstrom, b = 11.2697(3) Angstrom, c = 29.7630(9) Angstrom, {beta} = 93.924(1) deg., V = 3604.4(2) Angstrom{sup 3}, Z = 2). V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6} exhibits a lamellar structure built up from the stacking of vanadium oxide slabs between which the di-protonated 1,4-di-aza-bi-cyclo[2.2.2]octane organic cations are intercalated. The oxide layers are topologically similar to those encountered in the parent vanadium penta-oxide V{sub 2}O{sub 5} but exhibiting here a mixed valence V{sup IV}/V{sup V} with a ratio equal to 2. The electronic conductivity measurements performed on the crystals show that the resistivity curves are described by an Arrhenius law with an activation energy of 0.16 eV. (authors)

Innovative sub sea pipeline maintenance in line with emerging offshore trends and maintenance safety standards

Energy Technology Data Exchange (ETDEWEB)

Lim, George [T.D. Williamson, Inc., Tulsa, OK (United States)

2012-07-01

Sub sea hot tapping of pipelines is performed for a variety of reasons, including tie-ins, pipeline repair, insertion of instrumentation, facilitating chemical injection or providing access for temporary isolation tools. The full hot tap process - that is, installing the hot tap assembly, performing the tap and recovering the hot tap machine - is normally conducted with diver assistance. After bolting the assembly of the machine, isolation valve and fitting to the pipeline (or machine and isolation valve to a pre-installed flanged membrane on the pipeline), the divers then operate the machine to perform the tap, under instructions from - and supervision by - hot tap technicians located on deck of the diving support vessel (DSV). Subsequent unbolting and removal of the hot tap machine is also carried out by the divers. The demands of deep water have necessitated development of a totally diver-less, remote-controlled system. Diver operations are limited to a maximum of 300 meters of water depth, whereas a significant portion of existing sub sea field infrastructure, as well as projected future developments, are in deeper waters in depths up to 3,000 meters. In addition, diver safety concerns in shallow water, as well as impaired diver efficiency in difficult environmental conditions such as wave breaking zones, prompts the call for a reduction of diver exposure or complete elimination of diver assistance. The recent completion of a remote-controlled hot tap machine (the Sub sea 1200RC Tapping Machine) is a first step toward developing a totally diver-less system. The installation of the hot tap assembly and subsequent removal of the machine still require diver assistance, but the performance of the tap itself is remotely controlled by a hot tap technician from the deck of the DSV. The concept is a topside-driven hot tap machine with 'passive Remote Operating Vehicle (ROV) interface', which means a stationary ROV with its hydraulics and control system

Design and development of major balance of plant components in solid oxide fuel cell system

Energy Technology Data Exchange (ETDEWEB)

Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

2013-07-01

The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

Parameters Comparsion of Leads Detection in Arctic Sea Ice Using CRYOSAT-2 Waveform Data

Science.gov (United States)

Li, J.; Zhang, S.; Xiao, F.; Zhu, C.; Zhang, Y.; Zhu, T.; Yuan, L.

2018-04-01

Leads are only a small part of the polar sea ice structure, but they play a dominant role on the turbulence exchange between the ocean and the atmosphere, they are also important factors about sea ice thickness inversion. Since the early 2000s, Satellite altimetry has been applied to monitor the Arctic sea ice thickness, Satellite altimetry data can be used to distinguish leads and sea ice. In this paper, four parameters including Pulse peakiness (PP), stack standard deviation (SSD), stack kurtosis (SKU) and stack skewness (SSK) are extracted from CryoSat-2 satellite altimetry waveform data. The four parameters are combined into five combinations (PP, PP&SSD, PP&SSD&SKU, PP&SSD&SSK, PP&SSD&SSK&SKU) with constrain conditions to detect the leads. The results of the five methods are compared with MODIS (moderate-resolution imagining spectroradiometer) images and show that, the combination of PP&SSD is better than the single PP, the rest of combinations are the same as the combination of PP&SSD. It turns out, there is no promotion when we add SSK and SKU, successively or simultaneously.

Assessment of the seismic resistance of a ventilation stack on a reactor building

International Nuclear Information System (INIS)

Makovicka, Daniel; Makovicka, Daniel

2005-01-01

The paper analyzes the seismic resistance of a ventilation stack on a reactor building, including the possible reserves of increasing the resistance. Structures of this type are highly sensitive to seismic loads, as the tuning of the stack (the spectrum of its lowest natural frequencies) corresponds with the frequency spectrum of excitation due to seismic effects. The purpose of the paper is to present an example of an actual structure to show the character of the response of the structure, and the participation of the individual frequency components of the response in the overall stress and strain state of a structure of this type. The methodology for a numerical analysis of the structure is also given. The load of the stack proper is modified by the transfer characteristics of the building. In engineering practice, the system is usually divided into two subsystems: the building with the sub-base, and the stack proper. The level of justification for the application of this simplification depends on the distance of the natural frequencies of the stack from the natural frequencies of the building. Finally, the paper deals with possible errors in determining the actual seismic resistance of the stack structure

High Temperature Co-electrolysis of Steam and CO<sub>2sub> in an SOC stack: Performance and Durability

DEFF Research Database (Denmark)

Chen, Ming; Høgh, Jens Valdemar Thorvald; Nielsen, Jens Ulrik

2012-01-01

C and -0.5 A/cm2 with no long term degradation, as long as the inlet gases to the Ni/YSZ electrode were cleaned [3]. In this work, co-electrolysis of steam and carbon dioxide was studied in a TOFC® 10-cell stack, containing 3 different types ofNi/YSZ electrode supported cells with a footprint of 12X12 cm2....... The stack was operated at 800 oC and -0.75 A/cm2 with 60% conversion for a period of 1000 hours. One type of the cells showed no long term degradation but actually activation during the entire electrolysis period, while the other two types degraded. The performance and durability of the different cell types...... is discussed with respect to cell material composition and microstructure. The results of this study show that long term electrolysis is feasible without notable degradation also at lower temperature (800 oC) and higher current density (-0.75 A/cm2)....

CZTS absorber layer for thin film solar cells from electrodeposited metallic stacked precursors (Zn/Cu-Sn)

Energy Technology Data Exchange (ETDEWEB)

Khalil, M.I., E-mail: mdibrahim.khalil@polimi.it [Dipartimento di Chimica, Materiali e Ing. Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milano (Italy); Atici, O. [Dipartimento di Chimica, Materiali e Ing. Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milano (Italy); Lucotti, A. [Dipartimento di Chimica, Materiali e Ing. Chimica “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Binetti, S.; Le Donne, A. [Department of Materials Science and Solar Energy Research Centre (MIB-SOLAR), University of Milano- Bicocca, Via Cozzi 53, 20125 Milano (Italy); Magagnin, L., E-mail: luca.magagnin@polimi.it [Dipartimento di Chimica, Materiali e Ing. Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milano (Italy)

2016-08-30

Highlights: • CZTS absorber layer was fabricated by electrodeposition—annealing route from stacked bilayer precursor (Zn/Cu-Sn). • Different characterization techniques have ensured the well formed Kesterite CZTS along the film thickness also. • Two different excitation wavelengths of laser lines (514.5 and 785 nm) have been used for the Raman characterization of the films. • No significant Sn loss is observed in CZTS films after the sulfurization of the stacked bilayer precursors. • Photoluminescence spectroscopy reveals the PL peak of CZTS at 1.15 eV at low temperature (15 K). - Abstract: In the present work, Kesterite-Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films were successfully synthesized from stacked bilayer precursor (Zn/Cu-Sn) through electrodeposition-annealing route. Adherent and homogeneous Cu-poor, Zn-rich stacked metal Cu-Zn-Sn precursors with different compositions were sequentially electrodeposited, in the order of Zn/Cu-Sn onto Mo foil substrates. Subsequently, stacked layers were soft annealed at 350 °C for 20 min in flowing N{sub 2} atmosphere in order to improve intermixing of the elements. Then, sulfurization was completed at 585 °C for 15 min in elemental sulfur environment in a quartz tube furnace with N{sub 2} atmosphere. Morphological, compositional and structural properties of the films were investigated using SEM, EDS and XRD methods. Raman spectroscopy with two different excitation lines (514.5 and 785 nm), has been carried out on the sulfurized films in order to fully characterize the CZTS phase. Higher excitation wavelength showed more secondary phases, but with low intensities. Glow discharge optical emission spectroscopy (GDOES) has also been performed on films showing well formed Kesterite CZTS along the film thickness as compositions of the elements do not change along the thickness. In order to investigate the electronic structure of the CZTS, Photoluminescence (PL) spectroscopy has been carried out on the films, whose

BOP theory in an emerging market economy: India under the microscope

Directory of Open Access Journals (Sweden)

Gouher Ahmed

2015-07-01

Full Text Available Poverty is a universal phenomenon which does not go well with the progressive 21st century and hence the worldwide efforts to overcome the problem. At the beginning of the 21st century (2002, the late professor C.K. Prahalad had propounded a path breaking theory of poverty alleviation called the bottom of the pyramid business theory, which is not only making MNCs investments (FDI in underdeveloped countries and promoting their growth and employment generation and increase in incomes and thereby consumption and expenditure but also producing goods and services needed by the poor households at the bottom of the economic and business pyramid. The paper is devoted to the consideration of the theory in the emerging market economy of India where poverty is a biggest problem and the situation is not found significant for the BOP business. Can there be a market solution to it?

The Irminger Sea and the Iceland Sea time series measurements of sea water carbon and nutrient chemistry 1983–2008

Directory of Open Access Journals (Sweden)

J. Olafsson

2010-03-01

Full Text Available This paper describes the ways and means of assembling and quality controling the Irminger Sea and Iceland Sea time-series biogeochemical data which are included in the CARINA data set. The Irminger Sea and the Iceland Sea are hydrographically different regions where measurements of sea water carbon and nutrient chemistry were started in 1983. The sampling is seasonal, four times a year. The carbon chemistry is studied with measurements of the partial pressure of carbon dioxide in seawater, pCO<sub>2sub>, and total dissolved inorganic carbon, TCO<sub>2sub>. The carbon chemistry data are for surface waters only until 1991 when water column sampling was initiated. Other measured parameters are salinity, dissolved oxygen and the inorganic nutrients nitrate, phosphate and silicate. Because of the CARINA criteria for secondary quality control, depth >1500 m, the IRM-TS could not be included in the routine QC and the IS-TS only in a limited way. However, with the information provided here, the quality of the data can be assessed, e.g. on the basis of the results obtained with the use of reference materials.

Fabrication of a Cu/Ni stack in supercritical carbon dioxide at low-temperature

Energy Technology Data Exchange (ETDEWEB)

Rasadujjaman, Md, E-mail: rasadphy@duet.ac.bd [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Department of Physics, Dhaka University of Engineering & Technology, Gazipur 1700 (Bangladesh); Watanabe, Mitsuhiro [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Sudoh, Hiroshi; Machida, Hideaki [Gas-Phase Growth Ltd., 2-24-16 Naka, Koganei, Tokyo 184-0012 (Japan); Kondoh, Eiichi [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan)

2015-09-30

We report the low-temperature deposition of Cu on a Ni-lined substrate in supercritical carbon dioxide. A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. From the temperature dependence of the growth rate, the activation energy for Cu growth on the Ni film was determined to be 0.19 eV. The films and interfaces were characterized by Auger electron spectroscopy. At low temperature (140 °C), we successfully deposited a Cu/Ni stack with a sharp Cu/Ni interface. The stack had a high adhesion strength (> 1000 mN) according to microscratch testing. The high adhesion strength originated from strong interfacial bonding between the Cu and the Ni. However, at a higher temperature (240 °C), significant interdiffusion was observed and the adhesion became weak. - Highlights: • Cu/Ni stack fabricated in supercritical CO{sub 2} at low temperature. • A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. • Adhesion strength of Cu/Ni stack improved dramatically. • Fabricated Cu/Ni stack is suitable for Cu interconnections in microelectronics.

Screening of prospective sites for geological storage of CO{sub 2} in the Southern Baltic Sea

Energy Technology Data Exchange (ETDEWEB)

Vernon, R.; O' Neil, N.; Pasquali, R. [SLR Consulting, Dublin (Ireland); Nieminen, M.

2013-05-15

The BASTOR project focuses on identifying and characterising potential sites for CO{sub 2} storage in the southern Baltic Sea region. A compilation of available digital data from well logs, seismic line data interpretations, mapped structure outlines and published material from existing hydrocarbon fields and identified and mapped structures from Sweden, Poland, Latvia, Lithuania and Kaliningrad have been incorporated into a regional GIS for the Baltic Sea region. A detailed screening of regional sedimentary basins identified the Slupsk Border Zone as having suitable structures for storage of CO{sub 2} in depleted oil and gas fields or saline aquifers. Cambrian sandstone saline aquifers below 900 m have been identified as the principal regional potential storage target with the Dalders Monocline as the most promising area. Eight individual structures were identified as having greatest potential. Detailed 3D geological static models were developed for three of these structures located in offshore Latvia (E6 and E7) and one cross-border structure (Dalders Structure). A theoretical regional CO{sub 2} storage capacity calculation based on the GeoCapacity methodology was undertaken. A regional storage capacity for Cambrian sandstones below 900 m was estimated at a total of 16 Gt, with 2 Gt for the Dalders Monocline. Theoretical storage estimates for individual structures for the Baltic Sea regions includes 760 Mt for the Latvian structures and the Dalders Structure, 9.1 Mt for the structures located in Poland, 31 Mt in Lithuania and 170 Mt in Kaliningrad. These estimates are based on the best available data at the time of writing. However these estimates will be improved upon as new data becomes available from other sources. (orig.)

Continuous sea-level reconstructions beyond the Pleistocene: improving the Mediterranean sea-level method

Science.gov (United States)

Grant, K.; Rohling, E. J.; Amies, J.

2017-12-01

Sea-level (SL) reconstructions over glacial-interglacial timeframes are critical for understanding the equilibrium response of ice sheets to sustained warming. In particular, continuous and high-resolution SL records are essential for accurately quantifying `natural' rates of SL rise. Global SL changes are well-constrained since the last glacial maximum ( 20,000 years ago, ky) by radiometrically-dated corals and paleoshoreline data, and fairly well-constrained over the last glacial cycle ( 150 ky). Prior to that, however, studies of ice-volume:SL relationships tend to rely on benthic δ18O, as geomorphological evidence is far more sparse and less reliably dated. An alternative SL reconstruction method (the `marginal basin' approach) was developed for the Red Sea over 500 ky, and recently attempted for the Mediterranean over 5 My (Rohling et al., 2014, Nature). This method exploits the strong sensitivity of seawater δ18O in these basins to SL changes in the relatively narrow and shallow straits which connect the basins with the open ocean. However, the initial Mediterranean SL method did not resolve sea-level highstands during Northern Hemisphere insolation maxima, when African monsoon run-off - strongly depleted in δ18O - reached the Mediterranean. Here, we present improvements to the `marginal basin' sea-level reconstruction method. These include a new `Med-Red SL stack', which combines new probabilistic Mediterranean and Red Sea sea-level stacks spanning the last 500 ky. We also show how a box model-data comparison of water-column δ18O changes over a monsoon interval allows us to quantify the monsoon versus SL δ18O imprint on Mediterranean foraminiferal carbonate δ18O records. This paves the way for a more accurate and fully continuous SL reconstruction extending back through the Pliocene.

Structure and strain relaxation effects of defects in In{sub x}Ga{sub 1–x}N epilayers

Energy Technology Data Exchange (ETDEWEB)

Rhode, S. L., E-mail: sr583@cam.ac.uk; Fu, W. Y.; Massabuau, F. C.-P.; Kappers, M. J.; McAleese, C.; Oehler, F.; Humphreys, C. J.; Sahonta, S.-L. [Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Moram, M. A. [Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Dusane, R. O. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India)

2014-09-14

The formation of trench defects is observed in 160 nm-thick In{sub x}Ga{sub 1–x}N epilayers with x≤0.20, grown on GaN on (0001) sapphire substrates using metalorganic vapour phase epitaxy. The trench defect density increases with increasing indium content, and high resolution transmission electron microscopy shows an identical structure to those observed previously in InGaN quantum wells, comprising meandering stacking mismatch boundaries connected to an I₁-type basal plane stacking fault. These defects do not appear to relieve in-plane compressive strain. Other horizontal sub-interface defects are also observed within the GaN pseudosubstrate layer of these samples and are found to be pre-existing threading dislocations which form half-loops by bending into the basal plane, and not basal plane stacking faults, as previously reported by other groups. The origins of these defects are discussed and are likely to originate from a combination of the small in-plane misorientation of the sapphire substrate and the thermal mismatch strain between the GaN and InGaN layers grown at different temperatures.

Synthesis, crystal structure, and ionic conductivity of a new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung-Chul; Kwak, Hyun-Jung [Department of Energy Systems Research, Ajou University, Suwon 16499 (Korea, Republic of); Yoo, Chung-Yul [Advanced Materials & Devices Laboratory, Korea Institute of Energy Research, Daejeon 34129 (Korea, Republic of); Yun, Hoseop [Department of Energy Systems Research, Ajou University, Suwon 16499 (Korea, Republic of); Kim, Seung-Joo, E-mail: sjookim@ajou.ac.kr [Department of Energy Systems Research, Ajou University, Suwon 16499 (Korea, Republic of)

2016-11-15

A new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}, was synthesized in the form of either a single-crystal or polycrystalline powder using the molten hydroxide flux method or a solid-state reaction, respectively. Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} crystallizes to the P2{sub 1}/n (Z=4) monoclinic space group with lattice parameters a≈4.95 Å, b≈22.06 Å, c≈8.63 Å, and β≈91.5°. The structure is composed of stacked [LiSrAl(PO{sub 4}){sub 2}] layers alternating regularly with [LiSrPO{sub 4}] layers. In the [LiSrAl(PO{sub 4}){sub 2}] sublattice, the AlO{sub 6} octahedra and PO{sub 4} tetrahedra are tilted cooperatively to form an anionic, corrugated, two-dimensional [Al(PO{sub 4}){sub 2}]{sup 3−} framework that can be regarded as a “distorted-glaserite” structure. The [LiSrPO{sub 4}] sublattice is that of a layered block containing a six-membered ring formed from alternating linkages of LiO{sub 4} and PO{sub 4} tetrahedra. The six-membered rings show a boat-type arrangement with the up(U) or down(D) pointing sequence, UUDUUD. The interspace between the two sublattices generates a two-dimensional pathway for Li{sup +} ion conduction. The impedance measurement indicated that Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} had a moderate ion conductivity (σ≈1.30×10{sup −4} S cm{sup −1} at 667 K), with an activation energy E{sub a}≈1.02 eV. - Graphical abstract: Polyhedral view of Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}. Li{sup +} ions are represented by green spheres, Sr atoms by white spheres, AlO{sub 6} groups by octahedra, and PO{sub 4} groups by tetrahedra. - Highlights: • New compound Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} is reported. • The crystal structure is investigated by single-crystal XRD analysis. • The structure is formed by the alternate stacking of two different sublattices. • Correlation between the crystal structure and ionic conductivity is discussed.

Stacking with stochastic cooling

Energy Technology Data Exchange (ETDEWEB)

Caspers, Fritz E-mail: Fritz.Caspers@cern.ch; Moehl, Dieter

2004-10-11

Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles 'seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly 'protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently 'shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 10{sup 5} the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the 'old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the 'radial' separation schemes and also gives some

Elucidating structural order and disorder phenomena in mullite-type Al{sub 4}B{sub 2}O{sub 9} by automated electron diffraction tomography

Energy Technology Data Exchange (ETDEWEB)

Zhao, Haishuang; Krysiak, Yaşar [Institute of Inorganic Chemistry and Analytical Chemistry, Jakob-Welder-Weg 11, Johannes Gutenberg-University Mainz, 55128 Mainz (Germany); Hoffmann, Kristin [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); Institute of Inorganic Chemistry and Crystallography, Leobener Str. NW2, University of Bremen, 28359 Bremen (Germany); Barton, Bastian [Institute of Inorganic Chemistry and Analytical Chemistry, Jakob-Welder-Weg 11, Johannes Gutenberg-University Mainz, 55128 Mainz (Germany); Molina-Luna, Leopoldo [Department of Materials and Geoscience, Technische Universität Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany); Neder, Reinhard B. [Department of Physics, Lehrstuhl für Kristallographie und Strukturphysik, Friedrich-Alexander University Erlangen-Nürnberg, Staudtstr.3, 91058 Erlangen (Germany); Kleebe, Hans-Joachim [Department of Materials and Geoscience, Technische Universität Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany); Gesing, Thorsten M. [Institute of Inorganic Chemistry and Crystallography, Leobener Str. NW2, University of Bremen, 28359 Bremen (Germany); MAPEX Center for Materials and Processes, Bibliothekstr.1, University of Bremen, 28359 Bremen (Germany); Schneider, Hartmut [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); Fischer, Reinhard X. [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); MAPEX Center for Materials and Processes, Bibliothekstr.1, University of Bremen, 28359 Bremen (Germany); and others

2017-05-15

The crystal structure and disorder phenomena of Al{sub 4}B{sub 2}O{sub 9}, an aluminum borate from the mullite-type family, were studied using automated diffraction tomography (ADT), a recently established method for collection and analysis of electron diffraction data. Al{sub 4}B{sub 2}O{sub 9}, prepared by sol-gel approach, crystallizes in the monoclinic space group C2/m. The ab initio structure determination based on three-dimensional electron diffraction data from single ordered crystals reveals that edge-connected AlO{sub 6} octahedra expanding along the b axis constitute the backbone. The ordered structure (A) was confirmed by TEM and HAADF-STEM images. Furthermore, disordered crystals with diffuse scattering along the b axis are observed. Analysis of the modulation pattern implies a mean superstructure (AAB) with a threefold b axis, where B corresponds to an A layer shifted by ½a and ½c. Diffraction patterns simulated for the AAB sequence including additional stacking disorder are in good agreement with experimental electron diffraction patterns. - Graphical abstract: Crystal structure and disorder phenomena of B-rich Al{sub 4}B{sub 2}O{sub 9} studied by automated electron diffraction tomography (ADT) and described by diffraction simulation using DISCUS. - Highlights: • Ab-initio structure solution by electron diffraction from single nanocrystals. • Detected modulation corresponding mainly to three-fold superstructure. • Diffuse diffraction streaks caused by stacking faults in disordered crystals. • Observed streaks explained by simulated electron diffraction patterns.

EmuStack: An OpenStack-Based DTN Network Emulation Platform (Extended Version

Directory of Open Access Journals (Sweden)

Haifeng Li

2016-01-01

Full Text Available With the advancement of computing and network virtualization technology, the networking research community shows great interest in network emulation. Compared with network simulation, network emulation can provide more relevant and comprehensive details. In this paper, EmuStack, a large-scale real-time emulation platform for Delay Tolerant Network (DTN, is proposed. EmuStack aims at empowering network emulation to become as simple as network simulation. Based on OpenStack, distributed synchronous emulation modules are developed to enable EmuStack to implement synchronous and dynamic, precise, and real-time network emulation. Meanwhile, the lightweight approach of using Docker container technology and network namespaces allows EmuStack to support a (up to hundreds of nodes large-scale topology with only several physical nodes. In addition, EmuStack integrates the Linux Traffic Control (TC tools with OpenStack for managing and emulating the virtual link characteristics which include variable bandwidth, delay, loss, jitter, reordering, and duplication. Finally, experiences with our initial implementation suggest the ability to run and debug experimental network protocol in real time. EmuStack environment would bring qualitative change in network research works.

Electron spin resonance in Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles synthesized with the thermal decomposition method

Energy Technology Data Exchange (ETDEWEB)

Edelman, I.S., E-mail: ise@iph.krasn.ru [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Zharkov, S.M.; Pankrats, A.I. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk 660041 (Russian Federation); Vorotynov, A.M.; Tugarinov, V.I.; Ivantsov, R.D.; Petrov, D.A. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Velikanov, D.A. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk 660041 (Russian Federation); Lin, Chun-Rong; Chen, Chin-Chang; Tseng, Yaw-Teng; Hsu, Hua-Shu [National Pingtung University, Pingtung City, Pingtung County 90003, Taiwan (China)

2017-08-15

Highlights: • Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles were synthesized as (1 1 1) nanocrystalline plates. • Nanoparticles tend to form stacks consisting of plates attached “face to face”. • ESR parameters demonstrate unusual temperature dependences with a kink at 120–130 K. - Abstract: In this paper, we present a study of the electron spin resonance (ESR) of nanoparticles (NPs) of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} chalcogenides with x = 0, 0.2, and 0.4. NPs were synthesized via the thermal decomposition of metal chloride salts and selenium powder in a high-temperature organic solvent. According to the XRD and HRTEM data, the NPs were single crystalline nearly hexagonal plates with the structure close to CuCr{sub 2}Se{sub 4} (Fd-3m, a = 10.337 Å). For x = 0 and 0.2, the NPs tend to form long stacks consisting of the plates “face to face” attached to each other due to the magnetostatic interparticle interaction. Only separate NPs were observed in the case of x = 0.4. Peculiarities were revealed in the ESR temperature behavior for the NPs with x = 0 and 0.2 consistent with the features in the temperature dependences of the NPs magnetization. The non-monotonous dependence of the resonance field H{sub res} on the temperature with a kink near 130 K and the energy gap in the resonance spectrum depending on the type of nanoparticle compacting are the distinct peculiarities. One of the main factors is discussed in order to explain the peculiarities: the coexistence of two types of anisotropy in the Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} NPs, in-plain shape anisotropy and magnetocrystalline anisotropy with four easy axes, which increases strongly with the temperature decrease.

Pre-stack estimation of time-lapse seismic velocity changes : an example from the Sleipner CO2-sequestration project

International Nuclear Information System (INIS)

Ghaderi, A.; Landro, M.; Ghaderi, A.

2005-01-01

Carbon dioxide (CO 2 ) is being injected into a shallow sand formation at around a 1,000 metre depth at the Sleipner Field located in the North Sea. It is expected that the CO 2 injected in the bottom of the formation, will form a plume consisting of CO 2 accumulating in thin lenses during migration up through the reservoir. Several studies have been published using stacked seismic data from 1994, 1999, 2001 and 2002. A thorough analysis of post-stack seismic data from the Sleipner CO2-Sequestration Pilot Project was conducted. Interpretation of seismic data is usually done on post-stack data. For a given subsurface reflection point, seismic data are acquired for various incidence angles, typically 40 angles. These 40 seismic signals are stacked together in order to reduce noise. The term pre-stack refers to seismic data prior to this step. For hydrocarbon-related 4-dimensional seismic studies, travel time shift estimations have been used. This paper compared pre-stack and post-stack estimation of average velocity changes based on measured 4-dimensional travel time shifts. It is more practical to compare estimated velocity changes than the actual travel time changes, since the time shifts vary with offset for pre-stack time-lapse seismic analysis. It was concluded that the pre-stack method gives smaller velocity changes when estimated between two key horizons. Therefore, pre-stack travel time analysis in addition to conventional post-stack analysis is recommended. 6 refs., 12 figs

Basal-plane stacking faults in non-polar GaN studied by off-axis electron holography

Energy Technology Data Exchange (ETDEWEB)

Liu, Lewis Z-Y; Rao, D V Sridhara; Kappers, M J; Humphreys, C J [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Geiger, D, E-mail: ZL249@cam.ac.u [Triebenberg Laboratory, Institute for Structure Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany)

2010-02-01

We have studied basal-plane stacking faults in a non-polar (11-20) GaN epilayer using high-resolution electron microscopy and off-axis electron holography. The microstructure of the basal-plane stacking faults (BSFs) has been determined to be I{sub 1} type from high-resolution TEM images. High-resolution holograms along the [11-20] zone axis were obtained by off-axis electron holography on a Cs-corrected TEM, providing {approx}2 A spatial resolution in the reconstructed amplitude and phase images. Phase fluctuations across the stacking faults were detected, suggesting the presence of a built-in electric field. The uncertainties in the experiments and their interpretation are discussed.

Algebraic stacks

Indian Academy of Sciences (India)

Deligne, Mumford and Artin [DM, Ar2]) and consider algebraic stacks, then we can cons- truct the 'moduli ... the moduli scheme and the moduli stack of vector bundles. First I will give ... 1–31. © Printed in India. 1 ...... Cultura, Spain. References.

Survey Data of Community-Based Environmental and Species Observations from the Bering Sea Sub-Network, 2008-2009, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The Bering Sea Sub-Network (BSSN) is comprised of a set of coastal communities representing six indigenous cultures: three in the Russian Federation and three in the...

Summary Report of Community-Based Environmental and Species Observations from the Bering Sea Sub-Network, 2008-2009, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The Bering Sea Sub-Network (BSSN) is comprised of a set of coastal communities representing six indigenous cultures: three in the Russian Federation and three in the...

StackGAN++: Realistic Image Synthesis with Stacked Generative Adversarial Networks

OpenAIRE

Zhang, Han; Xu, Tao; Li, Hongsheng; Zhang, Shaoting; Wang, Xiaogang; Huang, Xiaolei; Metaxas, Dimitris

2017-01-01

Although Generative Adversarial Networks (GANs) have shown remarkable success in various tasks, they still face challenges in generating high quality images. In this paper, we propose Stacked Generative Adversarial Networks (StackGAN) aiming at generating high-resolution photo-realistic images. First, we propose a two-stage generative adversarial network architecture, StackGAN-v1, for text-to-image synthesis. The Stage-I GAN sketches the primitive shape and colors of the object based on given...

Effect of annealing temperature on the magnetoelectric properties of CoFe{sub 2}O{sub 4}/Pt/Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} multilayer films

Energy Technology Data Exchange (ETDEWEB)

Eum, You Jeong; Hwang, Sung Ok; Koo, Chang Young; Lee, Jai Yeoul; Lee, Hee Young [Yeungnam University, Gyeongsan (Korea, Republic of); Ryu, Jung Ho [Korea Institute of Materials Science, Changwon (Korea, Republic of); Park, Jung Min [Osaka University, Osaka (Japan)

2014-08-15

CoFe{sub 2}O{sub 4}(CoFO)/Pt/Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PZT) multilayer films were grown on Pt/Ti/SiO{sub 2}/Si substrates. A thin Pt layer was inserted between the ferrimagnetic and the ferroelectric layers in order to suppress diffusion at high temperatures and thereby to prevent possible interfacial reactions. The effect of annealing on the film's microstructure and multiferroic properties was then investigated using thin film stacks heat-treated at temperatures ranging from 550 to 650 .deg. C. The magnetoelectric coefficients were calculated from the magnetoelectric voltages measured using a magnetoelectric measurement system. The effect of annealing temperature on the magnetoelectric coupling in the CoFO/Pt/PZT multilayer thin film is discussed in detail.

PARAMETERS COMPARSION OF LEADS DETECTION IN ARCTIC SEA ICE USING CRYOSAT-2 WAVEFORM DATA

Directory of Open Access Journals (Sweden)

J. Li

2018-04-01

Full Text Available Leads are only a small part of the polar sea ice structure, but they play a dominant role on the turbulence exchange between the ocean and the atmosphere, they are also important factors about sea ice thickness inversion. Since the early 2000s, Satellite altimetry has been applied to monitor the Arctic sea ice thickness, Satellite altimetry data can be used to distinguish leads and sea ice. In this paper, four parameters including Pulse peakiness (PP, stack standard deviation (SSD, stack kurtosis (SKU and stack skewness (SSK are extracted from CryoSat-2 satellite altimetry waveform data. The four parameters are combined into five combinations (PP, PP&SSD, PP&SSD&SKU, PP&SSD&SSK, PP&SSD&SSK&SKU with constrain conditions to detect the leads. The results of the five methods are compared with MODIS (moderate-resolution imagining spectroradiometer images and show that, the combination of PP&SSD is better than the single PP, the rest of combinations are the same as the combination of PP&SSD. It turns out, there is no promotion when we add SSK and SKU, successively or simultaneously.

Polarization-insensitive optical gain characteristics of highly stacked InAs/GaAs quantum dots

International Nuclear Information System (INIS)

Kita, Takashi; Suwa, Masaya; Kaizu, Toshiyuki; Harada, Yukihiro

2014-01-01

The polarized optical gain characteristics of highly stacked InAs/GaAs quantum dots (QDs) with a thin spacer layer fabricated on an n + -GaAs (001) substrate were studied in the sub-threshold gain region. Using a 4.0-nm-thick spacer layer, we realized an electronically coupled QD superlattice structure along the stacking direction, which enabled the enhancement of the optical gain of the [001] transverse-magnetic (TM) polarization component. We systematically studied the polarized electroluminescence properties of laser devices containing 30 and 40 stacked InAs/GaAs QDs. The net modal gain was analyzed using the Hakki-Paoli method. Owing to the in-plane shape anisotropy of QDs, the polarization sensitivity of the gain depends on the waveguide direction. The gain showing polarization isotropy between the TM and transverse-electric polarization components is high for the [110] waveguide structure, which occurs for higher amounts of stacked QDs. Conversely, the isotropy of the [−110] waveguide is easily achieved even if the stacking is relatively low, although the gain is small.

Effect of stacking faults on the magnetocrystalline anisotropy of hcp Co-based nanowires

Energy Technology Data Exchange (ETDEWEB)

Kha, Tuan Mai; Schoenstein, Frédéric; Zighem, Fatih [Laboratoire des Sciences des Procédés et des Matériaux (LSPM-UPR3407), CNRS-Université Paris XIII, Sorbonne Paris Cité, Villetaneuse (France); Nowak, Sophie [Université Paris Diderot, Sorbonne Paris Cité, ITODYS, CNRS UMR 7086, 15 rue J.-A. de Baïf, 75205 Paris Cedex 13 (France); Leridon, Brigitte [LPEM, ESPCI Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, F-75005 Paris (France); Jouini, Noureddine [Laboratoire des Sciences des Procédés et des Matériaux (LSPM-UPR3407), CNRS-Université Paris XIII, Sorbonne Paris Cité, Villetaneuse (France); Mercone, Silvana, E-mail: silvana.mercone@univ-paris13.fr [Laboratoire des Sciences des Procédés et des Matériaux (LSPM-UPR3407), CNRS-Université Paris XIII, Sorbonne Paris Cité, Villetaneuse (France)

2017-01-15

Replacing materials based on rare-earth elements in current permanent magnets is a real scientific, economic and environmental challenge. Ferromagnetic 3d transition metals seem an apt direction to go in this field, due to their high residual magnetization and thermal stability. In order to improve their coercive behavior, nanostructured magnets based on the assembly of high-aspect-ratio nanoparticles (i.e. cobalt based nanorods and nanowires) have recently been proposed. In these, the nanoparticle morphology itself drives the magnetization reversal mechanism. This purely geometrical effect seems to obscure the effects of structural defects, although it is clear that high magnetocrystalline energy is required to maintain a stable orientation of the magnetic moment inside the nanoparticles. We present here an experimental study whose aim is to distinguish the role of the stacking faults from the effects of shape and morphology on the magnetization reversal mechanism in cobalt-based nanowires. Coercive field results have been obtained on Co{sub 80}Ni{sub 20} nanowires synthesized by a polyol process. Through accurate control of shape and morphology, it was possible to discard the effects of shape and thus to highlight the influence of crystal defects on the magnetism of Co{sub 80}Ni{sub 20} nanowires. A micromagnetic study, consistent with the experimental analyses, is also presented. The results discussed in this work clearly show that even if the morphological characteristics are conducive to a high coercive field, the presence of numerous stacking faults has the opposite effect and leads to materials with a significantly lower coercive field than expected, which is not suitable for permanent magnet applications. - Highlights: • Optimization of the nanowires magnetic properties for permanent magnet applications. • Magnetization reversal mechanism study as function of the shape, structural and chemical homogeneity. • Effect of stacking faults on the coercive

Crystal structure of vanuralite, Al[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}](OH) . 8.5H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Plasil, Jakub [Czech Academy of Sciences, Praha (Czech Republic). Inst. of Physics

2017-07-01

Vanuralite, Al[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}](OH) . 8.5H{sub 2}O, is a rare supergene uranyl vanadate that forms during hydration-oxidation weathering of uraninite in oxide zones of U deposits. On the basis of single-crystal X-ray diffraction data it is monoclinic, space group P2{sub 1}/n, with a = 10.4637(10), b = 8.4700(5), c = 20.527(2) Aa, β = 102.821(9) , V=1773.9(3) Aa{sup 3} and Z = 4, D{sub calc.} = 3.561 g cm{sup -3}. The structure of vanuralite (R = 0.058 for 2638 unique observed reflections) contains uranyl vanadate sheets of francevillite topology of the composition [(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}]{sup 2-}. Sheets are stacked perpendicular to c, and an interstitial complex {sup [6]}Al(OH)(H{sub 2}O){sub 4}(H{sub 2}O){sub 4.5}; adjacent structural sheets are linked through an extensive network of hydrogen bonds. Vanuralite is the most complex mineral among uranyl vanadates, with 961 bits/cell. The scarcity of occurrences is probably caused by the less common combination of elements present in the structure, as well as the relatively high complexity of the structure (compared to related minerals), arising namely from the complicated network of H-bonds.

Intermittent sea-level acceleration

Science.gov (United States)

Olivieri, M.; Spada, G.

2013-10-01

Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

n-TiO{sub 2} and CdCl{sub 2} co-exposure to titanium dioxide nanoparticles and cadmium: Genomic, DNA and chromosomal damage evaluation in the marine fish European sea bass (Dicentrarchus labrax)

Energy Technology Data Exchange (ETDEWEB)

Nigro, M.; Bernardeschi, M. [Department of Clinical and Experimental Medicine, Pisa University, Pisa (Italy); Costagliola, D. [Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta (Italy); Della Torre, C. [Department of Physical, Earth and Environmental Sciences, University of Siena, Siena (Italy); Frenzilli, G., E-mail: giada@biomed.unipi.it [Department of Clinical and Experimental Medicine, Pisa University, Pisa (Italy); Guidi, P.; Lucchesi, P. [Department of Clinical and Experimental Medicine, Pisa University, Pisa (Italy); Mottola, F.; Santonastaso, M. [Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta (Italy); Scarcelli, V. [Department of Clinical and Experimental Medicine, Pisa University, Pisa (Italy); Monaci, F.; Corsi, I. [Department of Physical, Earth and Environmental Sciences, University of Siena, Siena (Italy); Stingo, V.; Rocco, L. [Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta (Italy)

2015-11-15

Highlights: • European sea bass was exposed to CdCl{sub 2} and n-TiO{sub 2} alone and in combination. • Genotoxicity was evaluated by RAPD-assay, comet assay and cytome assay. • CdCl{sub 2} induced DNA primary damage but not chromosomal damage. • n-TiO{sub 2} induced chromosomal damage but not DNA primary damage. • Co-exposure effects depend on the biomarker used. - Abstract: Due to the large production and growing use of titanium dioxide nanoparticles (n-TiO{sub 2}), their release in the marine environment and their potential interaction with existing toxic contaminants represent a growing concern for biota. Different end-points of genotoxicity were investigated in the European sea bass Dicentrarchus labrax exposed to n-TiO{sub 2} (1 mg L{sup −1}) either alone and combined with CdCl{sub 2} (0.1 mg L{sup −1}) for 7 days. DNA primary damage (comet assay), apoptotic cells (diffusion assay), occurrence of micronuclei and nuclear abnormalities (cytome assay) were assessed in peripheral erythrocytes and genomic stability (random amplified polymorphism DNA-PCR, RAPD assay) in muscle tissue. Results showed that genome template stability was reduced after CdCl{sub 2} and n-TiO{sub 2} exposure. Exposure to n-TiO{sub 2} alone was responsible for chromosomal alteration but ineffective in terms of DNA damage; while the opposite was observed in CdCl{sub 2} exposed specimens. Co-exposure apparently prevents the chromosomal damage and leads to a partial recovery of the genome template stability.

OpenStack cloud security

CERN Document Server

Locati, Fabio Alessandro

2015-01-01

If you are an OpenStack administrator or developer, or wish to build solutions to protect your OpenStack environment, then this book is for you. Experience of Linux administration and familiarity with different OpenStack components is assumed.

Development and testing of a hybrid system with a sub-kW open-cathode type PEM (proton exchange membrane) fuel cell stack

International Nuclear Information System (INIS)

Huang, Zhen-Ming; Su, Ay; Liu, Ying-Chieh

2014-01-01

In this study, the performance of a polymer electrolyte membrane fuel cell stack has been evaluated for a hybrid power system test platform. To simulate vehicle acceleration, the stack was operated under dynamic-loading, and to demonstrate the exchange of power flow between two power sources the hybrid power system was tested under three different modes. A unit cell was fabricated for high stack performance and the stack was constructed with 18 open-cathode type fuel cells. Air which acts as a coolant as well as an oxidant for electrochemical reactions is provided by a pair of fans. The capabilities of the stack for hybrid power system test platform were validated by successful dynamic-loading tests. The performance of the stack for various air fan voltage was evaluated and an optimal value was concluded. The conditions like inlet temperature of H 2 and the stack current were established for maximum power. It was also found that humidification of hydrogen at anode inlet degrades the stack performance and stability due to flooding. Evidence shows that for the higher overall performance, the fuel cell acts continuously on constant current output. The study contributes to the design of mobility hybrid system to get better performance and reliability. - Highlights: • An open-cathode type PEMFC (polymer electrolyte membrane fuel cell) stack (rated output 300 W) was fabricated. • The open-cathode configuration simplifies the design of a stack system. • Assess the feasibility of combining a fuel cell stack in a hybrid system. • The study contributes to the design of mobility hybrid system to get better performance and reliability

Atomic layer deposition of W{sub x}N/TiN and WN{sub x}C{sub y}/TiN nanolaminates

Energy Technology Data Exchange (ETDEWEB)

Elers, K.-E.; Saanila, V.; Li, W.-M.; Soininen, P.J.; Kostamo, J.T.; Haukka, S.; Juhanoja, J.; Besling, W.F.A

2003-06-23

Diffusion barrier materials, such as TiN, W{sub x}N, WN{sub x}C{sub y} and their nanolaminates were deposited by atomic layer deposition method. TiN film exhibited excellent properties, but W{sub x}N film exhibited high resistivity despite the low residue concentration. Both TiN and W{sub x}N films suffered from serious incompatibility with the copper metal. WN{sub x}C{sub y} film was deposited by introducing triethylboron as a reducing agent for tungsten. Excellent film properties were obtained, including very good compatibility with the copper metal, evident as strong adhesion and no pitting on the copper surface. Nanolaminate barrier stacks of W{sub x}N/TiN and WN{sub x}C{sub y}/TiN were successfully deposited. TiN deposition did not cause copper pitting when thin WN{sub x}C{sub y} film was deposited underneath.

Crystal and molecular structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H{sub 2}L)(NO{sub 3}){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Egorova, O. A. [People’s Friendship University of Russia (Russian Federation); Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Sergienko, V. S. [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation); Davydov, V. V. [People’s Friendship University of Russia (Russian Federation)

2016-07-15

The crystal structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H{sub 2}L)(NO{sub 3}){sub 2} is studied by X-ray diffraction (T = 150 K, R1 = 0.0467). The H{sub 2}L{sup 2+} cation is located on the twofold rotation axis and connected with two NO{sub 3}{sup −} anions by strong N–H···O hydrogen bonds. Planar quinoxaline fragments of cations form stacks with the interplanar spacing of 3.308 Å. The structure of the diprotonated H{sub 2}L{sup 2+} cation is compared with those of the monoprotonated H{sub 2}L{sup 2+} cation and neutral L molecule.

Electrical power from sea and river water by reverse electrodialysis: a first step from the laboratory to a real power plant.

Science.gov (United States)

Veerman, Joost; Saakes, Michel; Metz, Sybrand J; Harmsen, G Jan

2010-12-01

Electricity can be produced directly with reverse electrodialysis (RED) from the reversible mixing of two solutions of different salinity, for example, sea and river water. The literature published so far on RED was based on experiments with relatively small stacks with cell dimensions less than 10 × 10 cm(2). For the implementation of the RED technique, it is necessary to know the challenges associated with a larger system. In the present study we show the performance of a scaled-up RED stack, equipped with 50 cells, each measuring 25 × 75 cm(2). A single cell consists of an AEM (anion exchange membrane) and a CEM (cation exchange membrane) and therefore, the total active membrane area in the stack is 18.75 m(2). This is the largest dimension of a reverse electrodialysis stack published so far. By comparing the performance of this stack with a small stack (10 × 10 cm(2), 50 cells) it was found that the key performance parameter to maximal power density is the hydrodynamic design of the stack. The power densities of the different stacks depend on the residence time of the fluids in the stack. For the large stack this was negatively affected by the increased hydrodynamic losses due to the longer flow path. It was also found that the large stack generated more power when the sea and river water were flowing in co-current operation. Co-current flow has other advantages, the local pressure differences between sea and river water compartments are low, hence preventing leakage around the internal manifolds and through pinholes in the membranes. Low pressure differences also enable the use of very thin membranes (with low electrical resistance) as well as very open spacers (with low hydrodynamic losses) in the future. Moreover, we showed that the use of segmented electrodes increase the power output by 11%.

Characterization of the Structural Modulations in n-type Bi{sub 2} (Te{sub 0}.95Se{sub 0}.05){sub 3} Thermoelectric Compound

Energy Technology Data Exchange (ETDEWEB)

Yoon, Sung Ho; Lee, Kap Ho [Chungnam National University, Daejeon (Korea, Republic of); Hong, Soon Jik [Kongju National University, Cheonan (Korea, Republic of)

2015-02-15

An n-type Bi{sub 2}Te{sub 3} thermoelectric compound was analyzed by using a high resolution transmission electron microscopy, and was further analyzed by using an image processing unit. A sinusoidal strain contrast of the structural modulations appeared in a multi-beam image and the fringes showed a wavelength of 12 nm with a wave vector parallel to the {101‾ 10} planes. A numerous dislocations were found to glide on to the (0001) plane with a Burgers vector of 1/3<21‾1‾0>-type on the strain field. In order for the elastic strain energy to be relieved, the resultant 1/3<21‾ 1‾0>-type dislocation was thought to be dissociated into two partial dislocations gliding on the {1‾015} planes. The variation in stacking periodicity of the 5-layers lamellar structure with respect to the basal plane of Bi{sub 2}Te{sub 3} was also observed locally. However, this stacking variation is not responsible for the formation of structural modulations. The displacement of the sinusoidal strain field on the structural modulations seems to be generated by dislocation, with presence of dipoles that are about a few nanometers apart. It is understandable that phonons should be scattered throughout the strain field of the structural modulation. Hence, the lattice thermal conductivity is expected to be decreased due to the phonon scattering on sinusoidal strain field of the structural modulations.

Oil release from Macondo well MC252 following the Deepwater Horizon accident.

Science.gov (United States)

Griffiths, Stewart K

2012-05-15

Oil flow rates and cumulative discharge from the BP Macondo Prospect well in the Gulf of Mexico are calculated using a physically based model along with wellhead pressures measured at the blowout preventer (BOP) over the 86-day period following the Deepwater Horizon accident. Parameters appearing in the model are determined empirically from pressures measured during well shut-in and from pressures and flow rates measured the preceding day. This methodology rigorously accounts for ill-characterized evolution of the marine riser, installation and removal of collection caps, and any erosion at the wellhead. The calculated initial flow rate is 67,100 stock-tank barrels per day (stbd), which decays to 54,400 stbd just prior to installation of the capping stack and subsequent shut-in. The calculated cumulative discharge is 5.4 million stock-tank barrels, of which 4.6 million barrels entered the Gulf. Quantifiable uncertainties in these values are -9.3% and +7.5%, yielding a likely total discharge in the range from 4.9 to 5.8 million barrels. Minimum and maximum credible values of this discharge are 4.6 and 6.2 million barrels. Alternative calculations using the reservoir and sea-floor pressures indicate that any erosion within the BOP had little affect on cumulative discharge.

Hexagonal perovskites with cationic vacancies. 21. Structure of Ba/sub 4/Nb/sub 2/WvacantO/sub 12/ and Ba/sub 3/LaNb/sub 3/vacantO/sub 12/

Energy Technology Data Exchange (ETDEWEB)

Rother, H J; Kemmler-Sack, S; Treiber, U; Cyris, W R [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-07-01

Compounds of type Ba/sub 4/M/sub 2/sup(V)WvacantO/sub 12/ and Ba/sub 3/LaM/sub 3/sup(V)vacantO/sub 12/ with Msup(V) = Nb, Ta belong to the group of rhombohedral 12 L stacking polytypes (space group R-3m, sequence (hhcc)/sub 3/). The structure determinations on powder patterns for the Nb compounds gave a refined, intensity related R' value of 6.3% (Ba/sub 4/Nb/sub 2/WvacantO/sub 12/) and 6.6% (Ba/sub 3/LaNb/sub 3/vacantO/sub 12/). The octahedral net consists of blocks of three face connected octahedra with a central void (M/sub 2/vacantO/sub 12/ unit), which are linked to each other through single corner sharing octahedra. In both compounds the M atoms in the M/sub 2/vacantO/sub 12/ groups are displaced in the direction of the central void. The A atoms move in the same direction but the dislocation for A in the hexagonal packed sheets (neighbouring the vacancies) is stronger than in the cubic packed AO/sub 3/ sheets. The results of the vibrational spectroscopic investigations are reported for Ba/sub 4/Nb/sub 2/WvacantO/sub 12/, Ba/sub 4/Ta/sub 2/WvacantO/sub 12/, Ba/sub 3/LaNb/sub 3/vacantO/sub 12/ and Ba/sub 4/CeW/sub 2/vacantO/sub 12/; they are discussed in connection with the factor group analysis.

Evaluation of the alkalinity in sea water by means of gran calculation. A procedure for titration in order to quantify the acidification of the seas by CO{sub 2} absorption; Bestimmung der Alkalinitaet in Meerwasser durch Granberechnung. Ein Titrationsverfahren zur Quantifizierung der Versauerung der Meere durch CO{sub 2}-Aufnahme

Energy Technology Data Exchange (ETDEWEB)

Peters, Juergen [SI Analytics GmbH, Mainz (Germany)

2012-04-15

In the last 200 years, the content of carbon dioxide in the air has risen from about 280 ppm to more than 380 ppm. Here, the increase of the concentration of CO{sub 2} is discussed as a reason for 'global warming'. While in the atmosphere about 800 billion tons of carbon dioxide (calculated as carbon) are located, 38,000 billion tons of carbon dioxide are dissolved in seawater, ie 50 times of the amount of CO{sub 2} in the atmosphere. The increase in the amount of CO{sub 2} in the atmosphere also results in an almost 50-fold increase in the total dissolved carbon dioxide in the sea. This results in a lowering of the pH value, and in an influencing of the equilibrium of aragonite and calcite. Many sea creatures are hampered in their growth.

A novel ternary uranium-based intermetallic U{sub 34}Fe{sub 4−x}Ge{sub 33}: Structure and physical properties

Energy Technology Data Exchange (ETDEWEB)

Henriques, M.S., E-mail: mish@itn.pt [Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, CFMC-UL, Estrada Nacional 10, 2695-066 Bobadela (Portugal); Berthebaud, D. [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, Université Rennes 1, UMR CNRS 6226, 263 Avenue du Général Leclerc, 35042 Rennes (France); CRISMAT, UMR CNRS 6508, 6 bd. Maréchal Juin, 14050 Caen (France); Waerenborgh, J.C.; Lopes, E.B. [Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, CFMC-UL, Estrada Nacional 10, 2695-066 Bobadela (Portugal); Pasturel, M.; Tougait, O. [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, Université Rennes 1, UMR CNRS 6226, 263 Avenue du Général Leclerc, 35042 Rennes (France); Gonçalves, A.P. [Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, CFMC-UL, Estrada Nacional 10, 2695-066 Bobadela (Portugal)

2014-09-01

Highlights: • A new uranium intermetallic compound U{sub 34}Fe{sub 4−x}ge{sub 33} was prepared and characterized. • It crystallizes in the tetragonal system with an original structure-type. • U lattice stacking is made of cupolae, orthobicupola and irregular cubes. • U{sub 34}Fe{sub 4−x}Ge{sub 33} orders magnetically at T{sub C} = 28 K, with pure U magnetism. • T{sub C} and electrical resistivity increase with applied magnetic field. - Abstract: The new ternary phase U{sub 34}Fe{sub 4−x}Ge{sub 33} has been synthesized and characterized by means of single crystal X-ray diffraction, magnetization, Mössbauer spectroscopy, specific heat, electrical resistivity, magnetoresistivity and thermopower measurements. It crystallizes in its own tetragonal structure type which can be described as derived from the one of the binary USi (U{sub 34}Si{sub 34.5} structure-type, space group I4/mmm), with lattice parameters at room temperature, a = 10.873(5) Å and c = 25.274(3) Å. Structure refinement confirmed six inequivalent U atoms, occupying sites with dissimilar coordination, the Ge atoms staying on seven positions and Fe on two positions, one of the Fe sites with a partial occupancy. The U sub-lattice is composed by the stacking of a square cupola, two distorted cubes and a square orthobicupola. U{sub 34}Fe{sub 4−x}Ge{sub 33} with x = 0.68 undergoes a ferromagnetic-type transition below 28 K. Mössbauer spectroscopy shows that the magnetism is ruled by the U sub-lattice, as Fe atoms have no ordered moments. The Sommerfeld coefficient of the electronic specific heat is γ = 131 mJ/(mol{sub U} K{sup 2}), whereas the estimated magnetic entropy at T{sub C} is 0.22Rln2. A residual resistivity of 314 μΩ cm and a resistivity ratio of 1.1 were found in the electrical resistivity curve, which also exhibits an upturn below T{sub C} that shifts towards higher temperatures with the applied magnetic field. This behavior may be related to some disorder in the non

Modeling electrochemical performance in large scale proton exchange membrane fuel cell stacks

Energy Technology Data Exchange (ETDEWEB)

Lee, J H [Los Alamos National Lab., NM (United States); Lalk, T R [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering; Appleby, A J [Center for Electrochemical Studies and Hydrogen Research, Texas Engineering Experimentation Station, Texas A and M Univ., College Station, TX (United States)

1998-02-01

The processes, losses, and electrical characteristics of a Membrane-Electrode Assembly (MEA) of a Proton Exchange Membrane Fuel Cell (PEMFC) are described. In addition, a technique for numerically modeling the electrochemical performance of a MEA, developed specifically to be implemented as part of a numerical model of a complete fuel cell stack, is presented. The technique of calculating electrochemical performance was demonstrated by modeling the MEA of a 350 cm{sup 2}, 125 cell PEMFC and combining it with a dynamic fuel cell stack model developed by the authors. Results from the demonstration that pertain to the MEA sub-model are given and described. These include plots of the temperature, pressure, humidity, and oxygen partial pressure distributions for the middle MEA of the modeled stack as well as the corresponding current produced by that MEA. The demonstration showed that models developed using this technique produce results that are reasonable when compared to established performance expectations and experimental results. (orig.)

The impact of stack geometry and mean pressure on cold end temperature of stack in thermoacoustic refrigeration systems

Science.gov (United States)

Wantha, Channarong

2018-02-01

This paper reports on the experimental and simulation studies of the influence of stack geometries and different mean pressures on the cold end temperature of the stack in the thermoacoustic refrigeration system. The stack geometry was tested, including spiral stack, circular pore stack and pin array stack. The results of this study show that the mean pressure of the gas in the system has a significant impact on the cold end temperature of the stack. The mean pressure of the gas in the system corresponds to thermal penetration depth, which results in a better cold end temperature of the stack. The results also show that the cold end temperature of the pin array stack decreases more than that of the spiral stack and circular pore stack geometry by approximately 63% and 70%, respectively. In addition, the thermal area and viscous area of the stack are analyzed to explain the results of such temperatures of thermoacoustic stacks.

OpenStack essentials

CERN Document Server

Radez, Dan

2015-01-01

If you need to get started with OpenStack or want to learn more, then this book is your perfect companion. If you're comfortable with the Linux command line, you'll gain confidence in using OpenStack.

First Simultaneous Visualization of SO{sub 2} and NO{sub 2} Plume Dispersions using Imaging Differential Optical Absorption Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Lee, Hanlim; Hong, Hyunkee; Han, Kyungsoo [Pukyong National Univ., Busan (Korea, Republic of); Noh, Youngmin [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Kwon, Soonchul [Georgia Institute of Technology, Atlanta (United States)

2014-04-15

Imaging Differential Optical Absorption Spectroscopy (Imaging-DOAS) has been utilized in recent years to provide slant column density (SCD) distributions of several trace gas species in the plume. The present study introduces a new method using Imaging-DOAS data to determine two-dimensional plume structure from the plume emissions of power plant in conditions of negligible aerosol effects on radiative transfer within the plume. We demonstrates for the first time that two-dimensional distributions of sulfur dioxide (SO{sub 2}) and nitrogen dioxide (NO{sub 2}) in power plant emissions can be determined simultaneously in terms of SCD distribution. The SO{sub 2} SCD values generally decreased with increasing distance from the stack and with distance from the center of the plume. Meanwhile, high NO{sub 2} SCD was observed at locations several hundred meters away from the first stack due to the ratio change of NO to NO{sub 2} in NOx concentration, attributed to the NO oxidation by O{sub 3}. The results of this study show the capability of the Imaging-DOAS technique as a tool to estimate plume dimensions in power plant emissions.

A new slip stacking RF system for a twofold power upgrade of Fermilab's Accelerator Complex

Energy Technology Data Exchange (ETDEWEB)

Madrak, Robyn [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2014-05-15

Fermilab's Accelerator Complex has been recently upgraded, in order to increase the 120 GeV proton beam power on target from about 400 kW to over 700 kW for NOvA and other future intensity frontier experiments. One of the key ingredients of the upgrade is the offloading of some Main Injector synchrotron operations - beam injection and RF manipulation called ''slip stacking'' - to the 8GeV Recycler Ring, which had until recently been used only for low-intensity antiproton storage and cooling. This required construction of two new 53 MHz RF systems for the slip-stacking manipulations. The cavities operate simultaneously at V<sub>peak> ≲150 kV, but at slightly different frequencies (Δf=1260 Hz). Their installation was completed in September 2013. This article describes the novel solutions used in the design of the new cavities, their tuning system, and the associated high power RF system. First results showing effective operation of the RF system, beam capture and successful slip-stacking in the Recycler Ring are presented.

Studies on solid solutions based on layered honeycomb-ordered phases P2-Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn)

Energy Technology Data Exchange (ETDEWEB)

Berthelot, Romain; Schmidt, Whitney; Sleight, A.W. [Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States); Subramanian, M.A., E-mail: mas.subramanian@oregonstate.edu [Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States)

2012-12-15

Three complete solid solutions between the layered phases P2-Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn) have been prepared by conventional solid state method and investigated through X-ray diffraction, magnetism and optical measurements. All compositions are characterized by a M{sup 2+}/X{sup 6+} honeycomb ordering within the slabs and crystallize in a hexagonal unit cell. However, a structural transition based on a different stacking is observed as nickel (space group P6{sub 3}/mcm) is substituted by zinc or cobalt (space group P6{sub 3}22). All compositions exhibit a paramagnetic Curie-Weiss behavior at high temperatures; and the magnetic moment values confirm the presence of Ni{sup 2+} and/or Co{sup 2+} cations. The low-temperature antiferromagnetic order of Na{sub 2}Ni{sub 2}TeO{sub 6} and Na{sub 2}Co{sub 2}TeO{sub 6} is suppressed by zinc substitution. The color of the obtained compositions varies from pink, to light green and white when M=Co, Ni, Zn, respectively. - Graphical abstract: The comparison between the structure of Na{sub 2}Ni{sub 2}TeO{sub 6} (left) and Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Zn) (right) evidences the stacking difference with distinct atom sequences along the hexagonal c-axis. Highlights: Black-Right-Pointing-Pointer Solid solutions between lamellar phases Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn) are investigated. Black-Right-Pointing-Pointer A M{sup 2+}/X{sup 6+} honeycomb ordering characterized all the compositions. Black-Right-Pointing-Pointer A structural transition is shown when Ni is replaced by Co or Zn. Black-Right-Pointing-Pointer The low-temperature AFM ordering of Na{sub 2}Ni{sub 2}TeO{sub 6} and Na{sub 2}Co{sub 2}TeO{sub 6} is suppressed by zinc substitution. Black-Right-Pointing-Pointer Color changes from pink to light green and white when M=Co, Ni, Zn, respectively.

Coherent stacking of picosecond laser pulses in a high-Q optical cavity for accelerator applications

International Nuclear Information System (INIS)

Androsov, V.P.; Karnaukhov, I.M.; Telegin, Yu.N.

2007-01-01

We have performed the harmonic analysis of the steady-state coherent pulse-stacking process in a high-Q Fabry-Perot cavity. The expression for the stacked pulse shape is obtained as a function of both the laser cavity and pulse-stacking cavity parameters. We have also estimated the pulse power gains attainable in the laser-optical system of NESTOR storage ring, which is under development at Kharkov Institute of Physics and Technology. It is shown that high power gains (∼10 4 ) can be, in principle, achieved in a cavity, formed with low-absorption, high reflectivity (R ∼ 0.9999) mirrors, if the laser cavity length will differ exactly by half wavelength from the pulse-stacking cavity length. It implies development of the sophisticated frequency stabilization loop for maintaining the cavity length constant within a sub-nanometer range. At the same time, power gains of ∼10 3 can be obtained with medium reflectivity mirrors (R ∼ 0.999) at considerably lower cost

Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations.

Science.gov (United States)

Michael, S A; Howe, L; Chilvers, B L; Morel, Pch; Roe, W D

2016-09-01

To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure. Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was >30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples. Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive. Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.

Preparative separation and structural identification of impurities of a new α{sub 2}-Adrenoceptor agonist using stacking injection, LC-MS{sup n} and LC-SPE-NMR

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Josiane O.; Thomasi, Sérgio S.; Venâncio, Tiago; Oliveira, Regina V., E-mail: oliveirarv@ufscar.br [Universidade Federal de São Carlos (UFSCar), SP (Brazil). Departamento de Química; Pitta, Ivan R.; Lima, Maria do Carmo A. de [Universidade Federal de Pernambuco (NUPIT/UFPE), Recife, PE (Brazil). Núcleo de Pesquisa em Inovação Tecnológica

2017-07-01

Identifying impurities in drug substances has become one of the most important issues in pharmaceutical analysis since it can have a significant impact on the efficacy of new pharmaceutical products. Due to the purity requirements, in this paper a new synthetic α{sub 2}-adrenoceptor agonist, called LPSF-PT-31, was purified and its impurities were characterized by liquid chromatography multistage mass spectrometry (LC-MS{sup n}) and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR). The purification step was conducted using a semi-preparative liquid chromatography and stacked injections as a new approach to drug purification. As a result, a total yield of 75% of the pure LPSF-PT-31 and 2.9 L day{sup -}'1 in solvent reduction was obtained. The combination of semi-preparative stacking injection, LC-MS{sup n}, and LC-SPE-NMR, demonstrated to be efficient to purify active drugs and unambiguously identify its impurities. In addition, isolation and identification of drug impurities in the early stages of development can improve the synthetic pathway, preventing the formation of impurities or minimizing this formation to minimum levels. (author)

Twinning in ZnO ceramics with Sb sub 2 O sub 3 additions

Energy Technology Data Exchange (ETDEWEB)

Senda, T. (Ministry of Transportation, Tokyo (Japan). Ship Research Inst.); Bradt, R.C. (Univ. of Nevada-Reno, Nevada (U.S.A.). Mackay School of Mines)

1991-09-01

A mechanism is proposed for the nucleation of ZnO growth twins which is based on the crystallography of the wurtzite and spinel structures. In this paper, possible twin origins from either phase transformation or a result of deformation are both rejected. It is concluded that the ZnO twins are growth twins which nucleate in the early stages of sintering and grain growth of the ceramic powder compacts. Consideration of the oxygen anion stacking layer sequences in the hexagonal ZnO wurtzite structure and the cubic Zn {sub 7} Sb {sub 2} O {sub 12} spinel structure suggests that the nuclei for the twins may form as embryos consisting of a faulted region of the spinel-oxygen anion layer stacking sequence. And then, the faulted layer sequence is created by the presence of the antimony oxide and its reaction with the ZnO. Further, the fact that the wurtzite structure is polar and the ZnO twins are inversion twins explains why there is only a single twin per grain, as multiple twins would result in the unfavorable structural configuration. 24 refs., 2 figs.

Live-cell imaging of dual-labeled Golgi stacks in tobacco BY-2 cells reveals similar behaviors for different cisternae during movement and brefeldin A treatment.

Science.gov (United States)

Madison, Stephanie L; Nebenführ, Andreas

2011-09-01

In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A (BFA)-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a remarkable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addition, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.

Modeling fuel cell stack systems

Energy Technology Data Exchange (ETDEWEB)

Lee, J H [Los Alamos National Lab., Los Alamos, NM (United States); Lalk, T R [Dept. of Mech. Eng., Texas A and M Univ., College Station, TX (United States)

1998-06-15

A technique for modeling fuel cell stacks is presented along with the results from an investigation designed to test the validity of the technique. The technique was specifically designed so that models developed using it can be used to determine the fundamental thermal-physical behavior of a fuel cell stack for any operating and design configuration. Such models would be useful tools for investigating fuel cell power system parameters. The modeling technique can be applied to any type of fuel cell stack for which performance data is available for a laboratory scale single cell. Use of the technique is demonstrated by generating sample results for a model of a Proton Exchange Membrane Fuel Cell (PEMFC) stack consisting of 125 cells each with an active area of 150 cm{sup 2}. A PEMFC stack was also used in the verification investigation. This stack consisted of four cells, each with an active area of 50 cm{sup 2}. Results from the verification investigation indicate that models developed using the technique are capable of accurately predicting fuel cell stack performance. (orig.)

Modelling the protocol stack in NCS with deterministic and stochastic petri net

Science.gov (United States)

Hui, Chen; Chunjie, Zhou; Weifeng, Zhu

2011-06-01

Protocol stack is the basis of the networked control systems (NCS). Full or partial reconfiguration of protocol stack offers both optimised communication service and system performance. Nowadays, field testing is unrealistic to determine the performance of reconfigurable protocol stack; and the Petri net formal description technique offers the best combination of intuitive representation, tool support and analytical capabilities. Traditionally, separation between the different layers of the OSI model has been a common practice. Nevertheless, such a layered modelling analysis framework of protocol stack leads to the lack of global optimisation for protocol reconfiguration. In this article, we proposed a general modelling analysis framework for NCS based on the cross-layer concept, which is to establish an efficiency system scheduling model through abstracting the time constraint, the task interrelation, the processor and the bus sub-models from upper and lower layers (application, data link and physical layer). Cross-layer design can help to overcome the inadequacy of global optimisation based on information sharing between protocol layers. To illustrate the framework, we take controller area network (CAN) as a case study. The simulation results of deterministic and stochastic Petri-net (DSPN) model can help us adjust the message scheduling scheme and obtain better system performance.

Ordered perovskites with cationic vacancies. 9. Compounds of the type Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ (Bsup(III) = La, Pr, Nd, Sm - Tm, Y)

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-08-01

The compounds Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) = 7:1). For the larger Bsup(III) ions (La, Pr, Nd, Sm-Dy) different ordering effects are observed. The perovskites with Bsup(III) = Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (Bsup(III) = Gd: a = 2 x 8.23/sub 4/ A); LT modification: hexagonal perovskite stacking polytype (Bsup(III) = Gd: a = 9.95/sub 4/ A; c = 19.0/sub 4/ A)). With the smaller Bsup(III) ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.

Triangular Zn{sub 3} and Ga{sub 3} units in Sr{sub 2}Au{sub 6}Zn{sub 3}, Eu{sub 2}Au{sub 6}Zn{sub 3}, Sr{sub 2}Au{sub 6}Ga{sub 3}, and Eu{sub 2}Au{sub 6}Ga{sub 3}. Structure, magnetism, {sup 151}Eu Moessbauer and {sup 69;71}Ga solid state NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Gerke, Birgit; Niehaus, Oliver; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Korthaus, Alexander; Haarmann, Frank [RWTH Aachen Univ. (Germany). Inst. fuer Anorganische Chemie

2016-08-01

The gold-rich intermetallic compounds Sr{sub 2}Au{sub 6}Zn{sub 3}, Eu{sub 2}Au{sub 6}Zn{sub 3}, Sr{sub 2}Au{sub 6}Ga{sub 3}, and Eu{sub 2}Au{sub 6}Ga{sub 3} were synthesized from the elements in sealed tantalum ampoules in induction or muffle furnaces. The europium compounds are reported for the first time and their structures were refined from single crystal X-ray diffractometer data: Sr{sub 2}Au{sub 6}Zn{sub 3} type, R anti 3c, a = 837.7(1), c = 2184.5(4) pm, wR2 = 0.0293, 572 F{sup 2} values for Eu{sub 2}Au{sub 6.04}Zn{sub 2.96} and a = 838.1(2), c = 2191.7(5) pm, wR2 = 0.0443, 513 F{sup 2} values for Eu{sub 2}Au{sub 6.07}Ga{sub 2.93} with 20 variables per refinement. The structures consist of a three-dimensional gold network with a 6R stacking sequence, similar to the respective diamond polytype. The cavities of the network are filled in a ratio of 2:1 by strontium (europium) atoms and Ga{sub 3} (Zn{sub 3}) triangles in an ordered manner. Sr{sub 2}Au{sub 6}Zn{sub 3} and Sr{sub 2}Au{sub 6}Ga{sub 3} are diamagnetic with room temperature susceptibilities of -3.5 x 10{sup -4} emu mol{sup -1}. Temperature dependent susceptibility and {sup 151}Eu Moessbauer spectroscopic measurements show a stable divalent ground state for both europium compounds. Eu{sub 2}Au{sub 6}Zn{sub 3} and Eu{sub 2}Au{sub 6}Ga{sub 3} order antiferromagnetically below Neel temperatures of 16.3 and 12.1 K, respectively. Anisotropic electrical conductivity of Sr{sub 2}Au{sub 6}Ga{sub 3} is proven by an alignment of the crystallites in the magnetic field. Orientation-dependent {sup 69;71}Ga NMR experiments combined with quantum mechanical calculations (QM) give evidence for a highly anisotropic charge distribution of the Ga atoms.

Characterization of mesoporous carbon prepared from date stems by H{sub 3}PO{sub 4} chemical activation

Energy Technology Data Exchange (ETDEWEB)

Hadoun, H., E-mail: hhadoun@hotmail.com [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria); Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Sadaoui, Z. [Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Souami, N.; Sahel, D.; Toumert, I. [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria)

2013-09-01

The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d{sub 200} and d{sub 100}), stack height (L{sub c}), stack width (L{sub a}) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, S{sub BET}, and total pore volume of 682, 1455, 1319 m{sup 2}/g and 0,343, 1,045 and 0.735 cm{sup 3}/g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

Linear and non-linear sea-level variations in the Adriatic Sea from tide gauge records (1872-2012

Directory of Open Access Journals (Sweden)

Gaia Galassi

2015-03-01

Full Text Available We have analyzed tide gauge data from the Adriatic Sea in order to assess the secular sea-level trend, its acceleration and the existence of possible cyclic variation. Analyzing the sea-level stack of all Adriatic tide gauges, we have obtained a trend of (1.25±0.04 mm yr-1, in agreement with that observed for the last century in the Mediterranean Sea, and an acceleration that is negligibile compared to the average global values. By means of the Ensemble Empirical Mode Decomposition technique, we have evidenced an energetic oscillation with a period of ∼20 years that we relate with the recurrence of opposite phases in the Atlantic Multi–decadal Oscillation and North Atlantic Oscillation indices. We suggest that anomalously high sea-level values observed at all the Adriatic tide gauges during 2010 and 2011 can be explained by the rising phase of this 20 years cycle.

Influence of the dissolution of increasing quantities of CO{sub 2} in the sea water; Influence de la dissolution de quantites croissantes de CO{sub 2} dans l'eau de mer

Energy Technology Data Exchange (ETDEWEB)

Poitou, J

2007-03-15

By the increase of carbon dioxide quantity in the atmosphere, the acidity of the ocean, which absorbs a part of this CO{sub 2}, will increase. This acidity level is going to modify the shells and calcareous bases formation of many sea species. The author details the principle of the acidity evolution by the CO{sub 2} increase, the consequences on the ocean fauna and the impacts for the humans. (A.L.B.)

Synthesis and characterisation of Cu{sub 2}ZnSnSe{sub 4} thin films prepared via a vacuum evaporation-based route

Energy Technology Data Exchange (ETDEWEB)

Volobujeva, O., E-mail: v.olga@staff.ttu.ee; Bereznev, S.; Raudoja, J.; Otto, K.; Pilvet, M.; Mellikov, E.

2013-05-01

Different sequentially stacked binary chalcogenide layers (CuSe, ZnSe, and SnSe) deposited by vacuum evaporation onto molybdenum covered soda-lime glass substrates were used as precursors to form Cu{sub 2}ZnSnSe{sub 4} films. The influence of the stacked binary layer sequence, substrate temperature, both the duration and speed of deposition and the post deposition treatment atmosphere on the structural and the morphological parameters of the Cu{sub 2}ZnSnSe{sub 4} thin films was studied. Our results indicate the possibility of replacing the Se{sub 2} selenisation with a thermal treatment in an SnSe{sub 2} atmosphere to avoid the selenisation of the Mo substrate and MoSe{sub 2} formation. This SnSe{sub 2} treatment forms p-type Cu{sub 2}ZnSnSe{sub 4} films with an optical band-gap of 1.14 eV and a solar cell structure with an efficiency of up to 3%. - Highlights: ► Cu{sub 2}ZnSnSe{sub 4} thin films were grown using binary precursors and selenisation. ► Composition and morphology were studied in dependence of selenisation atmosphere. ► The use of SnSe{sub 2} selenisation allows to avoid Mo substrate selenisation. ► The high quality of films is indicated by the value of their E{sub g} = 1.14 eV. ► Cu{sub 2}ZnSnSe{sub 4} thin films were in p-type conductivity and were realized as solar cells.

ChotuKool - Indian Godrej is creating a disruptive innovation - a low-cost refrigerator for the BOP market

DEFF Research Database (Denmark)

Hollensen, Svend; Raman, Anthony

2012-01-01

A disruptive innovation is a technology whose performance does not currently meet the requirements of the developed market. However, it does meet the requirements of a lower-end market, with customers that have lover performance requirements and are more sensitive to price. Indian Godrej followed...... these principles and developed a "simple" refrigerator, which is especially targeted for the Bottom-of Pyramid (BOP) market......A disruptive innovation is a technology whose performance does not currently meet the requirements of the developed market. However, it does meet the requirements of a lower-end market, with customers that have lover performance requirements and are more sensitive to price. Indian Godrej followed...

Superconductivity in the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n}

Energy Technology Data Exchange (ETDEWEB)

Grosse, Corinna; Chiatti, Olivio; Fischer, Saskia F. [Novel Materials Group, Humboldt-Universitaet Berlin (Germany); Alemayehu, Matti B.; Falmbigl, Matthias; Johnson, David C. [Department of Chemistry, University of Oregon, Eugene, OR (United States)

2016-07-01

The ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} are artificially layered materials consisting of n NbSe{sub 2} single-layers stacked alternately with atomic double layers of PbSe. NbSe{sub 2} is a transition metal dichalcogenide with interesting electrical properties such as superconductivity and charge density waves. The influence of turbostratic disorder, a random rotation between the NbSe{sub 2} and PbSe layers, on the superconducting transition temperature has been unknown so far. We investigate the structural and temperature-dependent electrical properties of the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} by means of scanning transmission electron microscopy, X-ray diffraction, in-plane resistivity and Hall measurements and compare them to those of analogous non-disordered misfit layer compound (MLC) polymorphs. We observe a superconducting transition in the resistivity of the ferecrystals. The transition temperatures are reduced by up to 55 % with respect to the analogous MLC polymorphs. This indicates that turbostratic disorder substantially weakens the electron-phonon coupling in (PbSe){sub 1.14}(NbSe{sub 2}){sub n}. We discuss the results of the structural and electrical properties of the ferecrystals with respect to their MLC analogues and also with respect to ultra-thin NbSe{sub 2} layers.

Manipulation of stored charge in anodic aluminium oxide/SiO{sub 2} dielectric stacks by the use of pulsed anodisation

Energy Technology Data Exchange (ETDEWEB)

Lu, Zhong, E-mail: z.lu@unsw.edu.au [School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Ouyang, Zi [School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Grant, Nicholas; Wan, Yimao; Yan, Di [Centre for Sustainable Energy Systems, Faculty of Engineering and Information Technology, The Australian National University, Canberra, ACT 0200 (Australia); Lennon, Alison [School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia)

2016-02-15

Graphical abstract: - Highlights: • Pulse anodisation was used to grow AAO layers with controllable stored charge. • Stored charge density ranging from −5.2 × 10{sup 11} to 2.5 × 10{sup 12} q/cm{sup 2} was demonstrated. • Enhancement in surface passivation was demonstrated with charge management. • Annealing significantly reduces the positive stored charge and the interface defect. - Abstract: A method of fabricating anodic aluminium oxide (AAO) with the capability of manipulating its stored charge is reported. This method involves the use of a pulsed current source to anodise aluminium layers instead of the typically used constant current/voltage source, with the test structures experiencing positive and negative cycles periodically. By tuning the positive cycle percentage, it is demonstrated that the effective stored charge density can be manipulated in a range from −5.2 × 10{sup 11} to 2.5 × 10{sup 12} q/cm{sup 2} when the AAO is formed over a 12 nm SiO{sub 2} layer. An investigation of the stored charge distribution in the dielectric stacks indicates a positive fixed charge at the SiO{sub 2}/Si interface, a negative fixed charge at the AAO/SiO{sub 2} interface and a positive bulk charge within the AAO layer. The effective stored charge density and interface states were found to be affected by annealing conditions and it is suggested that oxygen annealing can reduce the bulk positive charge while post-metallisation anneal is most effective in reducing silicon interface defects. Charge manipulation using pulsed anodisation is shown to reduce carrier recombination on boron-diffused silicon surfaces highlighting the potential of the process to be used to tune the electrical properties of dielectric layers so that they can reduce surface recombination on silicon surfaces having different dopant polarity and concentrations.

Development of sintering materials by sea sediments and TiO/sub 2/ for the cleaning teaching

International Nuclear Information System (INIS)

Rehman, M.A.; Alam, A.M.A.; Kaneco, S.; Katsumata, H.; Suzuki, T.

2007-01-01

A solar decontamination process for water was developed using photocatalysts supported on sea bottom sediments with sodium silicate. The supported catalysts were systematically optimized with respect to TiO/sub 2/ dosages, calcinations temperature and binder dosages. The Young's Modulus value (compressed strength) was found 12.5 kN/mm/sub 2/ of optimized supported catalyst which would not mixed with the water of real samples during the photocatalysis. The composition of the optimized catalyst was selected as sediments 82%, TiO /sub 2/ 15% and Na/sub 2/SiO/sub 3/ 3%, where the sintering temperature was 750degreeC. Humic acid as a model compound was used to evaluate the degradation efficiency of the developed sintering material. The complete mineralization of humic acid was achieved by 40 h sunlight irradiation. About 100 ml of (15 mg/L) of humic acid was successfully degraded with 15 g sintering materials under sunlight irradiation. The solar photocatalytical degradation treatment is simple, easy handling and cheap. Therefore, since the artificial lamp devices, for example Hg-Xe lamp, are particularly expensive in the local and nonexclusive areas, the optimized developed sintering material appears to be very suitable treatment method for humic acid in those area

High-fidelity stack and system modeling for tubular solid oxide fuel cell system design and thermal management

Science.gov (United States)

Kattke, K. J.; Braun, R. J.; Colclasure, A. M.; Goldin, G.

Effective thermal integration of system components is critical to the performance of small-scale (design and simulation tool for a highly-integrated tubular SOFC system. The SOFC is modeled using a high fidelity, one-dimensional tube model coupled to a three-dimensional computational fluid dynamics (CFD) model. Recuperative heat exchange between SOFC tail-gas and inlet cathode air and reformer air/fuel preheat processes are captured within the CFD model. Quasi one-dimensional thermal resistance models of the tail-gas combustor (TGC) and catalytic partial oxidation (CPOx) complete the balance of plant (BoP) and SOFC coupling. The simulation tool is demonstrated on a prototype 66-tube SOFC system with 650 W of nominal gross power. Stack cooling predominately occurs at the external surface of the tubes where radiation accounts for 66-92% of heat transfer. A strong relationship develops between the power output of a tube and its view factor to the relatively cold cylinder wall surrounding the bundle. The bundle geometry yields seven view factor groupings which correspond to seven power groupings with tube powers ranging from 7.6-10.8 W. Furthermore, the low effectiveness of the co-flow recuperator contributes to lower tube powers at the bundle outer periphery.

The Caribbean conundrum of Holocene sea level.

Science.gov (United States)

Jackson, Luke; Mound, Jon

2014-05-01

In the tropics, pre-historic sea-level curve reconstruction is often problematic because it relies upon sea-level indicators whose vertical relationship to the sea surface is poorly constrained. In the Caribbean, fossil corals, mangrove peats and shell material dominate the pre-historic indicator record. The common approach to reconstruction involves the use of modern analogues to these indicators to establish a fixed vertical habitable range. The aim of these reconstructions is to find spatial variability in the Holocene sea level in an area gradually subsiding (different depths. We use the first catalogue to calibrate 14C ages to give a probabilistic age range for each indicator. We use the second catalogue to define a depth probability distribution function (pdf) for mangroves and each coral species. The Holocene indicators are grouped into 12 sub-regions around the Caribbean. For each sub-region we apply our sea-level reconstruction, which involves stepping a fixed-length time window through time and calculating the position (and rate) of sea-level (change) using a thousand realisations of the time/depth pdfs to define an envelope of probable solutions. We find that the sub-regional relative sea-level curves display spatio-temporal variability including a south-east to north-west 1500 year lag in the arrival of Holocene sea level to that of the present day. We demonstrate that these variations are primarily due to glacial-isostatic-adjustment induced sea-level change and that sub-regional variations (where sufficient data exists) are due to local uplift variability.

Optimization of Nb{sub 2}O{sub 5}/Ag/Nb{sub 2}O{sub 5} multilayers as transparent composite electrode on flexible substrate with high figure of merit

Energy Technology Data Exchange (ETDEWEB)

Dhar, Aritra [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Alford, T. L. [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

2012-11-15

Different multilayer structures of Nb{sub 2}O{sub 5}/Ag/Nb{sub 2}O{sub 5} have been deposited onto flexible substrates by sputtering at room temperature to develop an indium free transparent composite electrode. The effect of Ag thickness on the electrical and optical properties of the multilayer stack has been studied in accordance with the Ag morphology. The critical thickness of Ag to form a continuous conducting layer is found to be 9.5 nm. A new conduction mechanism has been proposed to describe the conduction before and after the critical thickness. The effective Hall resistivity of the optimized films is as low as 6.44 Multiplication-Sign 10{sup -5} Ohm-Sign -cm with a carrier concentration and mobility of 7.4 Multiplication-Sign 10{sup 21} cm{sup -3} and 13.1 cm{sup 2} /V-s, respectively, at the critical Ag layer thickness. The multilayer stack has been optimized to obtain a sheet resistance of 7.2 Ohm-Sign /sq and an average optical transmittance of 86% at 550 nm without any substrate heating or post-annealing process. The Haacke figure of merit (FOM) has been calculated for the films, and the multilayer with a 9.5 nm thick Ag layer has the highest FOM at 31.5 Multiplication-Sign 10-3 {Omega}{sup -1}, which is one of the highest FOM values reported for TCE deposited at room temperature on a flexible substrate.

Alternating stacking of ferromagnetic nanosheet and nanoparticle films: heteroassembly and magneto-optical Kerr effect

Energy Technology Data Exchange (ETDEWEB)

Jia, Baoping, E-mail: baoping.jia@cczu.edu.cn [Changzhou University, School of Materials Science and Engineering (China); Zhang, Wei, E-mail: wei.zhang@unisa.edu.au [University of Tokyo, Department of Urban Engineering (Japan); Liu, Hui [Central South University, School of Metallurgy and Environment, National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (China); Lin, Bencai; Ding, Jianning [Changzhou University, School of Materials Science and Engineering (China)

2016-09-15

Heterostructured multilayer films of two different nanocrystals have been successfully fabricated by layer-by-layer stacking of Ti{sub 0.8}Co{sub 0.2}O{sub 2} nanosheet and Fe{sub 3}O{sub 4} nanoparticle films. UV–Vis spectroscopy and AFM observation confirmed the successful alternating deposition in the multilayer buildup process. The average thickness of both Ti{sub 0.8}Co{sub 0.2}O{sub 2} nanosheet and Fe{sub 3}O{sub 4} nanoparticle layers was determined to be about 1.4–1.7 and 5 nm, which was in good agreement with TEM results. Magneto-optical Kerr effect measurements demonstrated that the heteroassemblies exhibit gigantic magnetic circular dichroism (MCD) (2 × 10{sup 4} deg/cm) at 320–360 nm, deriving from strong interlayer [Co{sup 2+}]t{sub 2g}–[Fe{sup 3+}]e{sub g} d–d charge transfer which was further confirmed by X-ray photoelectron spectroscopy. Their structure-dependent MCD showed high potential in rational design and construction of high-efficiency magneto-optical devices.

The Carbon Dioxide System in the Baltic Sea Surface Waters

Energy Technology Data Exchange (ETDEWEB)

Wesslander, Karin

2011-05-15

The concentration of carbon dioxide (CO{sub 2}) in the atmosphere is steadily increasing because of human activities such as fossil fuel burning. To understand how this is affecting the planet, several pieces of knowledge of the CO{sub 2} system have to be investigated. One piece is how the coastal seas, which are used by people and influenced by industrialization, are functioning. In this thesis, the CO{sub 2} system in the Baltic Sea surface water has been investigated using observations from the last century to the present. The Baltic Sea is characterized of a restricted water exchange with the open ocean and a large inflow of river water. The CO{sub 2} system, including parameters such as pH and partial pressure of CO{sub 2} (pCO{sub 2}), has large seasonal and inter-annual variability in the Baltic Sea. These parameters are affected by several processes, such as air-sea gas exchange, physical mixing, and biological processes. Inorganic carbon is assimilated in the primary production and pCO{sub 2} declines to approx150 muatm in summer. In winter, pCO{sub 2} levels increase because of prevailing mineralization and mixing processes. The wind-mixed surface layer deepens to the halocline (approx60 m) and brings CO{sub 2}- enriched water to the surface. Winter pCO{sub 2} may be as high as 600 muatm in the surface water. The CO{sub 2} system is also exposed to short-term variations caused by the daily biological cycle and physical events such as upwelling. A cruise was made in the central Baltic Sea to make synoptic measurements of oceanographic, chemical, and meteorological parameters with high temporal resolution. Large short-term variations were found in pCO{sub 2} and oxygen (O{sub 2}), which were highly correlated. The diurnal variation of pCO{sub 2} was up to 40 muatm. The CO{sub 2} system in the Baltic Sea changed as the industrialization increased around 1950, which was demonstrated using a coupled physical-biogeochemical model of the CO{sub 2} system

Three-dimensional supercapacitors composed of Ba{sub 0.65}Sr{sub 0.35}TiO{sub 3} (BST)/NiSi{sub 2}/silicon microchannel plates

Energy Technology Data Exchange (ETDEWEB)

Liu Tao; Zhang Huayan; Wang Fei; Shi Jing; Ci Pengliang [Laboratory of Polar Materials and Devices, Ministry of Education, and Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241 (China); Wang Lianwei, E-mail: lwwang@ee.ecnu.edu.cn [Laboratory of Polar Materials and Devices, Ministry of Education, and Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241 (China); Ge Shuli; Wang Qingjiang [Department of Chemistry, East China Normal University, Shanghai 200241 (China); Chu, Paul K. [Department of Physics and Material Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2011-03-25

Three-dimensional (3D) supercapacitors consisting of Ba{sub 0.65}Sr{sub 0.35}TiO{sub 3} (BST)/NiSi{sub 2}/silicon microchannel plate (MCP) stacked structure have been fabricated. The silicon MCP produced by electrochemical etching is utilized as a backbone of the 3D structure on which a nickel silicide current collector layer and Ba{sub 0.65}Sr{sub 0.35}TiO{sub 3} dielectric layer are deposited successively by electroless plating and the sol-gel method, respectively. The morphology and structure of the 3D BST/NiSi{sub 2}/Si-MCP structure are characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) and the electrochemical properties are determined by cyclic voltammetry (CV) and chronopotentiometry. The structure exhibits excellent capacitive behavior with a maximum capacitance of 784 F g{sup -1}. After 700 charging/discharging cycles, the C{sub f} decreases slightly with only a 5.7% loss and is stable after more than 700 cycles. The BST/NiSi{sub 2}/Si-MCP 3D structure is a potential supercapacitor in industrial applications.

Environmental assessment of phosphogypsum stacks

International Nuclear Information System (INIS)

Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

2008-03-01

Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

Environmental assessment of phosphogypsum stacks

International Nuclear Information System (INIS)

Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

2009-01-01

Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

Behavioral responses of Arctica islandica (Bivalvia: Arcticidae) to simulated leakages of carbon dioxide from sub-sea geological storage

International Nuclear Information System (INIS)

Bamber, Shaw D.; Westerlund, Stig

2016-01-01

Highlights: • Valve pumping activity in A. islandica significantly increased at pH 6.2 seawater. • Changes in valve movements were not related to attempted burrowing activities. • Valve activity returned to control levels after 5 days of continuous exposure. • A. islandica tolerate pH reductions likely to follow leakage of sub-sea stored CO_2. - Abstract: Sub-sea geological storage of carbon dioxide (CO_2) provides a viable option for the Carbon Capture and Storage (CCS) approach for reducing atmospheric emissions of this greenhouse gas. Although generally considered to offer a low risk of major leakage, it remains relevant to establish the possible consequences for marine organisms that live in or on sediments overlying these storage areas if such an event may occur. The present study has used a series of laboratory exposures and behavioral bioassays to establish the sensitivity of Arctica islandica to simulated leakages of CO_2. This long-lived bivalve mollusc is widely distributed throughout the North Sea, an area where geological storage is currently taking place and where there are plans to expand this operation significantly. A recently published model has predicted a maximum drop of 1.9 pH units in seawater at the point source of a substantial escape of CO_2 from sub-sea geological storage in this region. Valve movements of A. islandica exposed to reduced pH seawater were recorded continuously using Hall effect proximity sensors. Valve movement regulation is important for optimising the flow of water over the gills, which supplies food and facilitates respiration. A stepwise reduction in seawater pH showed an initial increase in both the rate and extent of valve movements in the majority of individuals tested when pH fell to 6.2 units. Exposing A. islandica to pH 6.2 seawater continuously for seven days resulted in a clear increase in valve movements during the first 40 h of exposure, followed by a gradual reduction in activity intensity over the

Mastering OpenStack

CERN Document Server

Khedher, Omar

2015-01-01

This book is intended for system administrators, cloud engineers, and system architects who want to deploy a cloud based on OpenStack in a mid- to large-sized IT infrastructure. If you have a fundamental understanding of cloud computing and OpenStack and want to expand your knowledge, then this book is an excellent checkpoint to move forward.

Solid Oxide Fuel Cell Stack Diagnostics

DEFF Research Database (Denmark)

Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation....... An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

Cu(InGa)Se{sub 2} absorber formation by in-situ, low-temperature annealing of co-evaporated bilayer (InGa){sub 2}Se{sub 3}/CuSe precursors

Energy Technology Data Exchange (ETDEWEB)

Moon, Kyeongchan; Kim, Woo Kyoung, E-mail: wkim@ynu.ac.kr

2015-12-01

Chalcopyrite Cu(InGa)Se{sub 2} (CIGS) absorbers were fabricated by the formation of bilayer stacked glass/Mo/(InGa){sub 2}Se{sub 3}/CuSe precursors followed by in-situ thermal annealing at 450 °C for approximately 10 min in a vacuum evaporator. The material properties (e.g., crystal orientation, compositional depth profile, and overall composition) and device performance of the resulting CIGS absorbers were compared with those of the CIGS absorbers formed by conventional 1-stage and 3-stage CIGS formation processes at a similar temperature. X-ray diffraction confirmed that the 1-stage co-evaporation and in-situ annealing of the bilayer precursor produced a polycrystalline CIGS absorber without a specific texture, whereas the CIGS absorber formed by the 3-stage process showed a highly (220) preferred orientation. Secondary ion mass spectrometry revealed Ga accumulation at the bottom of CIGS formed by in-situ annealing of the bilayer precursors. The cell efficiency of the device with the CIGS absorber formed by the in-situ, low-temperature (450 °C) annealing of bilayer stacked glass/Mo/(InGa){sub 2}Se{sub 3}/CuSe precursors was comparable to that produced by the conventional 3-stage process at a similar temperature. - Highlights: • Annealing of (InGa){sub 2}Se{sub 3}/CuSe precursors was compared with coevaporation process. • In-situ annealing of (InGa){sub 2}Se{sub 3}/CuSe precursors at 450 °C produced about 9% solar cell. • Ga profile within Cu(InGa)Se{sub 2} depended on process profile during co-evaporation.

ooi: OpenStack OCCI interface

Directory of Open Access Journals (Sweden)

Álvaro López García

2016-01-01

Full Text Available In this document we present an implementation of the Open Grid Forum’s Open Cloud Computing Interface (OCCI for OpenStack, namely ooi (Openstack occi interface, 2015  [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

ooi: OpenStack OCCI interface

Science.gov (United States)

López García, Álvaro; Fernández del Castillo, Enol; Orviz Fernández, Pablo

In this document we present an implementation of the Open Grid Forum's Open Cloud Computing Interface (OCCI) for OpenStack, namely ooi (Openstack occi interface, 2015) [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

Structure and magnetic properties of La{sub 2/3}Sr{sub 1/3}MnO{sub 3}/CaMnO{sub 3} multilayers

Energy Technology Data Exchange (ETDEWEB)

Granada, Mara [Centro Atomico Bariloche and Instituto Balseiro, CNEA-UNC, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina)]. E-mail: granadam@cab.cnea.gov.ar; Sirena, Martin [Centro Atomico Bariloche and Instituto Balseiro, CNEA-UNC, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Steren, Laura B. [Centro Atomico Bariloche and Instituto Balseiro, CNEA-UNC, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Leyva, Gabriela [Depto. de Fisica, Centro Atomico Constituyentes, CNEA, Av. Gral. Paz y Constituyentes, 1650 San Martin (Argentina)

2004-12-31

Structural and magnetic properties of manganite-based multilayers, La{sub 2/3}Sr{sub 1/3}MnO{sub 3}/CaMnO{sub 3}, composed of ferromagnetic metals and antiferromagnetic insulator barriers are investigated in this work. Compounds of similar lattice parameters were used to build the samples, so we expect an excellent stacking of the different layers along the structure. To get a first insight of this system, the crystalline structure of a series of samples, grown on (1 0 0) SrTiO{sub 3} and (1 0 0) MgO single-crystalline substrates, has been studied. X-ray diffraction patterns show that the structure is strongly textured in the (1 0 0) direction when grown on SrTiO{sub 3}, regardless the composition of the bottom layer. A different result is found on the same system grown on MgO: when the buffer layer is CaMnO{sub 3}, the structure grows in the (1 1 0) orientation while it grows in the (1 0 0) direction when the bottom layer is La{sub 2/3}Sr{sub 1/3}MnO{sub 3}. Magnetic coupling of the ferromagnetic layers across the antiferromagnetic spacer has been studied with magnetization measurements.

UV light induced insulator-metal transition in ultra-thin ZnO/TiO{sub x} stacked layer grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2016-08-28

In the present study, atomic layer deposition has been used to grow a series of Ti incorporated ZnO thin films by vertically stacking different numbers (n = 1–7) of ZnO/TiO{sub x} layers on (0001) sapphire substrates. The effects of defect states mediated chemisorption of O{sub 2} and/OH groups on the electrical properties of these films have been investigated by illuminating the samples under UV light inside a high vacuum optical cryostat. The ultra-thin film having one stacked layer (n = 1) did not show any change in its electrical resistance upon UV light exposure. On the contrary, marginal drop in the electrical resistivity was measured for the samples with n ≥ 3. Most surprisingly, the sample with n = 2 (thickness ∼ 12 nm) showed an insulator to metal transition upon UV light exposure. The temperature dependent electrical resistivity measurement on the as grown film (n = 2) showed insulating behaviour, i.e., diverging resistivity on extrapolation to T→ 0 K. However, upon UV light exposure, it transformed to a metallic state, i.e., finite resistivity at T → 0 K. Such an insulator-metal transition plausibly arises due to the de-trapping of conduction electrons from the surface defect sites which resulted in an upward shift of the Fermi level above the mobility edge. The low-temperature electron transport properties on the insulating film (n = 2) were investigated by a combined study of zero field electrical resistivity ρ(T) and magnetoresistance (MR) measurements. The observed negative MR was found to be in good agreement with the magnetic field induced suppression of quantum interference between forward-going paths of tunnelling electrons. Both ρ(T) and MR measurements provided strong evidence for the Efros-Shklovskii type variable range hopping conduction in the low-temperature (≤40 K) regime. Such studies on electron transport in ultra-thin n-type doped ZnO films are crucial to achieve optimum functionality

Substrate type < 111 >-Cu{sub 2}O/<0001 >-ZnO photovoltaic device prepared by photo-assisted electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Zamzuri, Mohd, E-mail: zamzuri@tf.me.tut.ac.jp [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); School of Manufacturing Eng., Universiti Malaysia Perlis, Kampus Tetap Pauh Putra, Jln Arau-Changlun, 02600 Arau, Perlis (Malaysia); Sasano, Junji [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Mohamad, Fariza Binti [Faculty of Electrical & Electronic Eng., University Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor (Malaysia); Izaki, Masanobu [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)

2015-11-30

The substrate-type < 0001 > ZnO/<111 > Cu{sub 2}O photovoltaic (PV) device has been constructed by electrodeposition of a < 111 >-p-Cu{sub 2}O layer on an Au(111)/Si wafer substrate followed by stacking the n-ZnO layer by electrodeposition during light irradiation in aqueous solutions. The PV device was fabricated by stacking the Al:ZnO-window by sputtering and the top Al electrode by vacuum evaporation. The < 0001 >-ZnO layer was composed of aggregates of hexagonal columnar grains grown in the direction normal to the surface, and pores could be observed between the ZnO grains at the deposition time last 1800 s. The < 0001 >-ZnO/<111 >-Cu{sub 2}O PV device showed a photovoltaic performance under AM1.5 illumination, and showed the improved short-circuit current density of 5.87 mA cm{sup −2} by stacking the AZO-TCO due to the increase in the diffusion length of the carrier. - Highlights: • Substrate type ZnO/Cu{sub 2}O photovoltaic devices only by electrodeposition • ZnO layer was stacked on the Cu{sub 2}O layer by photo-assisted electrodeposition. • AZO/ZnO/Cu{sub 2}O photovoltaic devices with a short-circuit current density of 5.87 mA cm{sup −2}.

The effect of millennial-scale changes in Arabian Sea denitrification on atmospheric CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Altabet, M.A.; Higginson, M.J. [University of Massachusetts, New Bedford, MA (United States). School for Marine Science and Technology; Murray, D.W. [Brown University, Providence, RI (United States). Center for Environmental Studies

2002-07-01

Most global biogeochemical processes are known to respond to climate change, some of which have the capacity to produce feedbacks through the regulation of atmospheric greenhouse gases. Marine denitrification - the reduction of nitrate to gaseous nitrogen - is an important process in this regard, affecting greenhouse gas concentrations directly through the incidental production of nitrous oxide, and indirectly through modification of the marine nitrogen inventory and hence the biological pump for C0{sub 2}. Although denitrification has been shown to vary with glacial-interglacial cycles, its response to more rapid climate change has not yet been well characterized. Here we present nitrogen isotope ratio, nitrogen content and chlorin abundance data from sediment cores with high accumulation rates on the Oman continental margin that reveal substantial millennial-scale variability in Arabian Sea denitrification and productivity during the last glacial period. The detailed correspondence of these changes with Dansgaard-Oeschger events recorded in Greenland ice cores indicates rapid, century-scale reorganization of the Arabian Sea ecosystem in response to climate excursions, mediated through the intensity of summer monsoonal upwelling. Considering the several-thousand-year residence time of fixed nitrogen in the ocean, the response of global marine productivity to changes in denitrification would have occurred at lower frequency and appears to be related to climatic and atmospheric C0{sub 2} oscillations observed in Antarctic ice cores between 20 and A kyr ago. (author)

An investigation on groundwater recovery rate within sub sea floor tunnels at closed coal mines

International Nuclear Information System (INIS)

Nakata, Eiji; Suenaga, Hiroshi; Oyama, Takahiro; Nomura, Tokisada; Ichihara, Yoshihisa

2008-01-01

The groundwater recovery rate investigated at the closed coal mines extended within sub sea floor tunnels. The Ikeshima and the Taiheiyo coal mine companies exploited the deep coal-bearing strata beneath the ocean. Ikeshima coal mine, excavated S.L. -650m to 6km offshore from Ikeshima island, was closed at November 2002, and Taiheiyo coal mine, excavated S.L. -720m to 9km offshore from Hokkaido, was stopped to excavate from the deep area at January 2003. After closing and stopping of development, we began the investigation of the groundwater recovery rate at both coal mines. The groundwater level of Ikeshima coal mine raised +405m per 1.8 years at the main shaft. The permeability coefficient estimated between 10 - 8 m /s and 10 -6 m/s to use the water recovery rate at the shaft. Otherwise, at Taiheiyo coal mine, we measured the air pressure in tubes used by 3.5km 2.5km, and 1.5km length 2mm diameters tubes to estimate the groundwater recovery level at the 3.2km offshore plug site. Groundwater didn't reach 4.7km (1.5+3.2km) area until November 2004. There were breakdown of shotcleate and rock mass from the roof of tunnel at 5.3km from offshore line. In this paper, we try to show the groundwater recovery rate of these sub sea floor collieries. (author)

Stack gas treatment

Science.gov (United States)

Reeves, Adam A.

1977-04-12

Hot stack gases transfer contained heat to a gravity flow of pebbles treated with a catalyst, cooled stacked gases and a sulfuric acid mist is withdrawn from the unit, and heat picked up by the pebbles is transferred to air for combustion or other process. The sulfuric acid (or sulfur, depending on the catalyst) is withdrawn in a recovery unit.

Single-layer and double-layer microwave absorbers based on Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Wang, Min [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Wang, Zhongzhu, E-mail: wangzz@ahu.edu.cn [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Wang, Peihong; Liao, Yanlin [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Bi, Hong [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230601 (China)

2017-03-01

Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals were synthesized by hydrothermal method. The complex permeability and complex permittivity of the as-prepared powders dispersing in wax (60 wt% powder) were measured using a vector network analyzer in 2–18 GHz frequency range. The calculated microwave absorption of single-layer and double-layer absorbers based on Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals were analyzed in 2–18 GHz frequency range. The results show that the Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4}nanocrystals with the relatively low permittivity and Co{sub 67}Ni{sub 33} microspheres with the relatively high dielectric loss and magnetic loss can be used as proper matching layer and excellent absorption layer, respectively. The double-layer absorber with a coating thickness of 2.1 mm exhibits a maximum reflection loss of −43.8 dB as well as a bandwidth (reflection loss less than −10 dB) of 5 GHz. Moreover, their absorption peak and the absorption intensity can be adjusted easily through changing the stacking order and each layer thickness. - Highlights: • Ni-Zn ferrite nanocrystals can use as matching layer in double-layer absorbers. • Co{sub 67}Ni{sub 33} microspheres with high dielectric loss can use as absorption layer. • Double-layer absorbers exhibits an excellent microwave absorption in 2–18 GHz.

Tidal and sub-tidal sea level variability at the northern shelf of the Brazilian Northeast Region.

Science.gov (United States)

Frota, Felipe F; Truccolo, Eliane C; Schettini, Carlos A F

2016-09-01

A characterization of the sea level variability at tidal and sub-tidal frequencies at the northern shore of the Brazilian Northeast shelf for the period 2009-2011 is presented. The sea level data used was obtained from the Permanent Geodetic Tide Network from the Brazilian Institute of Geography and Statistics for the Fortaleza gauge station. Local wind data was also used to assess its effects on the low-frequency sea level variability. The variability of the sea level was investigated by classical harmonic analysis and by morphology assessment over the tidal signal. The low frequencies were obtained by low-pass filtering. The tidal range oscillated with the highest value of 3.3 m during the equinox and the lowest value of 0.7 m during the solstice. Differences between the spring and neap tides were as high as 1 m. A total of 59 tidal constituents were obtained from harmonic analysis, and the regional tide was classified as semi-diurnal pure with a form number of 0.11. An assessment of the monthly variability of the main tidal constituents (M2, S2, N2, O1, and K1) indicated that the main semi-diurnal solar S2 presented the highest variability, ranging from 0.21 to 0.41 m; it was the main element altering the form number through the years. The low frequency sea-level variability is negligible, although there is a persistent signal with an energy peak in the 10-15 day period, and it cannot be explained by the effects of local winds.

A Time-predictable Stack Cache

DEFF Research Database (Denmark)

Abbaspour, Sahar; Brandner, Florian; Schoeberl, Martin

2013-01-01

Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to le...... of a cache for stack allocated data. Our port of the LLVM C++ compiler supports the management of the stack cache. The combination of stack cache instructions and the hardware implementation of the stack cache is a further step towards timepredictable architectures.......Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to less...... precise results of the cache analysis part of the WCET analysis. Splitting the data cache for different data areas enables composable data cache analysis. The WCET analysis tool can analyze the accesses to these different data areas independently. In this paper we present the design and implementation...

Spin dynamics in the strongly magnetically frustrated compounds YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} probed by NMR and ESR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Iakovleva, Margarita [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); E. K. Zavoisky Physical-Technical Institute, Kazan (Russian Federation); Zeisner, Julian; Zimmermann, Stephan; Buechner, Bernd [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); Valldor, Martin [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Dresden (Germany); Vavilova, Evgeniia [E. K. Zavoisky Physical-Technical Institute, Kazan (Russian Federation); Grafe, Hans-Joachim; Alfonsov, Alexey; Kataev, Vladislav [IFW Dresden, Dresden (Germany)

2016-07-01

In the Swedenborgite type compounds YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} the magnetic lattice can be described as a stacking of kagome layers, where unconventional ground states such as a spin liquid state can be expected due to the strong geometrical frustration. We performed a combined experimental study of magnetic properties of single crystals of YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} with high field ESR and high field NMR spectroscopy. The experimental results show the occurrence of short-range quasi static electron spin correlations at T{sup *} ∼ 22 K for YBaCo{sub 3}AlO{sub 7} and T{sup *} ∼ 60K for YBaCo{sub 3}FeO{sub 7} but not a long-range antiferromagnetic order. We compare our results with AC and DC susceptibility measurements and discuss a possible competition between a spin glass-like state due to intrinsic structural disorder and a spin liquid state arising from strong magnetic frustration in this materials.

Development of all chemical solution derived Ce<sub>0.9sub>La>0.1sub>O>2 − ysub>/Gd>2sub>Zr>2sub>O>7sub> buffer layer stack for coated conductors: influence of the post-annealing process on surface crystallinity

DEFF Research Database (Denmark)

Yue, Zhao; Li, Xiaofen; Khoryushin, Alexey

2012-01-01

Preparation and characterization of a biaxially textured Gd2Zr2O7 and Ce0.9La0.1O2 − y (CLO, cap)/Gd2Zr2O7 (GZO, barrier) buffer layer stack by the metal–organic deposition route are reported. YBa2Cu3O7 − d (YBCO) superconductor films were deposited by the pulsed-laser deposition (PLD) technique ...

2D-2D stacking of graphene-like g-C{sub 3}N{sub 4}/Ultrathin Bi{sub 4}O{sub 5}Br{sub 2} with matched energy band structure towards antibiotic removal

Energy Technology Data Exchange (ETDEWEB)

Ji, Mengxia; Di, Jun; Ge, Yuping; Xia, Jiexiang, E-mail: xjx@ujs.edu.cn; Li, Huaming, E-mail: lhm@ujs.edu.cn

2017-08-15

Highlights: • 2D-2D graphene-like g-C{sub 3}N{sub 4}/ultrathin Bi{sub 4}O{sub 5}Br{sub 2} materials have been prepared. • With matched energy band structure, the effective charge separation can be achieved. • The holes and O{sub 2}{sup −} are determined to be the main active species. - Abstract: A novel visible-light-driven 2D-2D graphene-like g-C{sub 3}N{sub 4}/ultrathin Bi{sub 4}O{sub 5}Br{sub 2} photocatalyst was prepared via a facile solvothermal method in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C{sub 16}mim]Br) for the first time. FT-IR, XPS and TEM analysis results demonstrated the successful introduction of the 2D graphene-like g-C{sub 3}N{sub 4} material to the Bi{sub 4}O{sub 5}Br{sub 2} system. DRS and BET analysis results indicated the existence of the g-C{sub 3}N{sub 4} could lead to the broaden absorption edge and larger surface area of the ultrathin Bi{sub 4}O{sub 5}Br{sub 2} nanosheets. The electrochemical analysis implied a fast transfer of the interfacial electrons and low recombination rate of photogenerated charge carriers in g-C{sub 3}N{sub 4}/Bi{sub 4}O{sub 5}Br{sub 2}, which could be assigned to the sufficient and tight contact between ultrathin Bi{sub 4}O{sub 5}Br{sub 2} and graphene-like g-C{sub 3}N{sub 4}. The quinolone antibiotic ciprofloxacin (CIP) was chosen as the target pollutant to evaluate the photocatalytic performance of the as-prepared samples under visible light irradiation. 1 wt% g-C{sub 3}N{sub 4}/Bi{sub 4}O{sub 5}Br{sub 2} composite exhibited the highest photocatalytic degradation performance among all of the as-prepared photocatalysts. The enhancement of photocatalytic activity was attributed to the maximum contact between graphene-like g-C{sub 3}N{sub 4} and ultrathin Bi{sub 4}O{sub 5}Br{sub 2} material with matched energy band structure, which enable the efficient charge seperation. A possible photocatalytic mechanism also was proposed.

Stack Characterization in CryoSat Level1b SAR/SARin Baseline C

Science.gov (United States)

Scagliola, Michele; Fornari, Marco; Di Giacinto, Andrea; Bouffard, Jerome; Féménias, Pierre; Parrinello, Tommaso

2015-04-01

CryoSat was launched on the 8th April 2010 and is the first European ice mission dedicated to the monitoring of precise changes in the thickness of polar ice sheets and floating sea ice. CryoSat is the first altimetry mission operating in SAR mode and it carries an innovative radar altimeter called the Synthetic Aperture Interferometric Altimeter (SIRAL), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for azimuth processing. The current CryoSat IPF (Instrument Processing Facility), Baseline B, was released in operation in February 2012. After more than 2 years of development, the release in operations of the Baseline C is expected in the first half of 2015. It is worth recalling here that the CryoSat SAR/SARin IPF1 generates 20Hz waveforms in correspondence of an approximately equally spaced set of ground locations on the Earth surface, i.e. surface samples, and that a surface sample gathers a collection of single-look echoes coming from the processed bursts during the time of visibility. Thus, for a given surface sample, the stack can be defined as the collection of all the single-look echoes pointing to the current surface sample, after applying all the necessary range corrections. The L1B product contains the power average of all the single-look echoes in the stack: the multi-looked L1B waveform. This reduces the data volume, while removing some information contained in the single looks, useful for characterizing the surface and modelling the L1B waveform. To recover such information, a set of parameters has been added to the L1B product: the stack characterization or beam behaviour parameters. The stack characterization, already included in previous Baselines, has been reviewed and expanded in Baseline C. This poster describes all the stack characterization parameters, detailing what they represent and how they have been computed. In details, such parameters can be summarized in: - Stack

Wind-sea surface temperature-sea ice relationship in the Chukchi-Beaufort Seas during autumn

Science.gov (United States)

Zhang, Jing; Stegall, Steve T.; Zhang, Xiangdong

2018-03-01

Dramatic climate changes, especially the largest sea ice retreat during September and October, in the Chukchi-Beaufort Seas could be a consequence of, and further enhance, complex air-ice-sea interactions. To detect these interaction signals, statistical relationships between surface wind speed, sea surface temperature (SST), and sea ice concentration (SIC) were analyzed. The results show a negative correlation between wind speed and SIC. The relationships between wind speed and SST are complicated by the presence of sea ice, with a negative correlation over open water but a positive correlation in sea ice dominated areas. The examination of spatial structures indicates that wind speed tends to increase when approaching the ice edge from open water and the area fully covered by sea ice. The anomalous downward radiation and thermal advection, as well as their regional distribution, play important roles in shaping these relationships, though wind-driven sub-grid scale boundary layer processes may also have contributions. Considering the feedback loop involved in the wind-SST-SIC relationships, climate model experiments would be required to further untangle the underlying complex physical processes.

Extraction of lithium from sea water with metallic aluminum

International Nuclear Information System (INIS)

Takeuchi, Takeji

1980-01-01

Extraction of lithium from sea water was investigated. It was found that a corrosion product of metallic aluminum immersed in sea water extracts lithium from it selectively. Effects of the temperature and the pH of sea water, and of the initial concentration of lithium in it were examined. On the basis of the analysis of the surface deposit on aluminum, which is a corrosion product of aluminum, the selectivity coefficients were calculated. For the extraction of lithium from natural sea water, the values of K sub(Na)sup(Li), K sub(Mg)sup(Li), K sub(Ca)sup(Li) and K sub(K)sup(Li) were 9.9 x 10 2 , 1.1 x 10, 4.5 x 10 and 4.4 x 10 2 , respectively. (author)

The monoclinic superstructure of the M{sub 2}Pt{sub 6}Al{sub 15} series (M=Ca, Sc, Y, La, Lu)

Energy Technology Data Exchange (ETDEWEB)

Radzieowski, Mathis; Stegemann, Frank; Hoffmann, Rolf-Dieter [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Oldenburg Univ. (Germany). Inst. fuer Chemie

2017-07-01

The five ternary intermetallic compounds M{sub 2}Pt{sub 6}Al{sub 15} (M=Ca, Sc, Y, La, Lu) were prepared from the elements by arc-melting. The crystal structure was determined via single crystal X-ray diffraction. The title compounds crystallize in a superstructure of the RE{sub 0.67}Pt{sub 2}Al{sub 5} type structure (P6{sub 3}/mmc) in the monoclinic crystal system with space group P12{sub 1}/m1 (Sc{sub 2}Pt{sub 6}Al{sub 15}: a=734.19(2), b=1628.96(10), c=734.19(2) pm, β=119.999(3) ; wR=0.0356, 3034 F{sup 2} values, 68 variables). The superstructure can be derived by the superspace formalism using (3+2)D or (3+1)D interpretations of the diffraction data. The structural relation to the subcell structure is discussed on the basis of a group-subgroup scheme. In the crystal structure strongly bonded [Pt{sub 2}Al{sub 4}]{sup δ-} slabs are alternatingly stacked with ordered layers containing M atoms and Al{sub 3} triangles.

Effect of substitution of 1 at% Ni for Zn on the microstructure and mechanical properties of Mg{sub 94}Y{sub 4}Zn{sub 2} alloy

Energy Technology Data Exchange (ETDEWEB)

Liu, Huan, E-mail: liuhuanseu@hotmail.com [Jiangsu Key Lab of Advanced Metallic Materials, School of Material Science and Engineering, Southeast University, Nanjing 211189 (China); Xue, Feng, E-mail: xuefeng@seu.edu.cn [Jiangsu Key Lab of Advanced Metallic Materials, School of Material Science and Engineering, Southeast University, Nanjing 211189 (China); Bai, Jing; Zhou, Jian [Jiangsu Key Lab of Advanced Metallic Materials, School of Material Science and Engineering, Southeast University, Nanjing 211189 (China); Liu, Xiaodao [Nanjing Yunhai Special Metals Co., Ltd., Nanjing 211200 (China)

2013-11-15

The microstructure and mechanical properties of Mg{sub 94}Y{sub 4}Zn{sub 2} and Mg{sub 94}Y{sub 4}Zn{sub 1}Ni{sub 1} alloys have been systematically investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and an electronic universal testing machine. The as-cast WZ42 alloy is composed of α-Mg matrix, 18R LPSO (long period stacking ordered) phase and a small fraction of Mg{sub 24}(Y,Zn){sub 5} phases. With the replacement of 1 at% Ni atoms, the phase structures in WZN411 alloy remain unchanged, but their chemical compositions vary obviously. A great number of stacking faults exist in α-Mg grains of WZ42 alloy, while they are barely observed in WZN411 alloy. After annealing at 500 °C for 12 h, there are plenty of 14H LPSO lamellas formed in WZ42 alloy and many nano-scale α-Mg slices generated between 18R phases. In contrast, the 18R in WZN411 alloy is thermally stable, and both the formation of α-Mg slices and 14H lamellas are restricted for annealed WZN411 alloy. Tensile tests indicate that the as-extruded WZ42 alloy exhibits ultimate tensile strength of 390 MPa, tensile yield strength of 246 MPa and elongation of 2.8% at room temperature. With the replacement of 1 at% Ni, the UTS and TYS of WZN411 alloy increase by 20 MPa and the ductility improves as well. The improvement of comprehensive mechanical properties could be ascribed to the substitution of 1 at% Ni element, which could enhance the degree of solid-solution strengthening and stimulate the thermal stability of 18R phase during annealing and extrusion processes.

Lightweight Stacks of Direct Methanol Fuel Cells

Science.gov (United States)

Narayanan, Sekharipuram; Valdez, Thomas

2004-01-01

An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

Stacked white OLED having separate red, green and blue sub-elements

Energy Technology Data Exchange (ETDEWEB)

Forrest, Stephen; Qi, Xiangfei; Slootsky, Michael

2015-06-23

The present invention relates to efficient organic light emitting devices (OLEDs). More specifically, the present invention relates to white-emitting OLEDs, or WOLEDs. The devices of the present invention employ three emissive sub-elements, typically emitting red, green and blue, to sufficiently cover the visible spectrum. The sub-elements are separated by charge generating layers.

Stacked white OLED having separate red, green and blue sub-elements

Science.gov (United States)

Forrest, Stephen; Qi, Xiangfei; Slootsky, Michael

2016-06-28

The present invention relates to efficient organic light emitting devices (OLEDs). More specifically, the present invention relates to white-emitting OLEDs, or WOLEDs. The devices of the present invention employ three emissive sub-elements, typically emitting red, green and blue, to sufficiently cover the visible spectrum. The sub-elements are separated by charge generating layers.

Partition/Ion-Exclusion Chromatographic Ion Stacking for the Analysis of Trace Anions in Water and Salt Samples by Ion Chromatography.

Science.gov (United States)

Akter, Fouzia; Saito, Shingo; Tasaki-Handa, Yuiko; Shibukawa, Masami

2018-01-01

A new analytical methodology for a simple and efficient on-line preconcentration of trace inorganic anions in water and salt samples prior to ion chromatographic determination is proposed. The preconcentration method is based on partition/ion-exclusion chromatographic ion stacking (PIEC ion stacking) with a hydrophilic polymer gel column containing a small amount of fixed anionic charges. The developed on-line PIEC ion stacking-ion chromatography method was validated by recovery experiments for the determination of nitrate in tap water in terms of both accuracy and precision, and the results showed the reliability of the method. The method proposed was also successfully applied to the determination of trace impurity nitrite and nitrate in reagent-grade salts of sodium sulfate. A low background level can be achieved since pure water is used as the eluant for the PIEC ion stacking. It is possible to reach sensitive detection at sub-μg L -1 levels by on-line PIEC ion stacking-ion chromatography.

First-principle calculations on the structural and electronic properties of hard C{sub 11}N{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Li, Dongxu, E-mail: lidongxu@hqu.edu.cn [College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Shi, Jiancheng; Lai, Mengling; Li, Rongkai [College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Yu, Dongli [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2014-09-15

A graphite-like C{sub 11}N{sub 4} model was built by stacking graphene and a C{sub 3}N{sub 4} triazine layer and simulated by first principle calculations, which transfers to a diamond-like structure under high pressure. The structural, mechanical, and electronic properties of both materials were calculated. The elastic constants of both materials satisfy the Born-criterion. Furthermore, no imaginary frequencies were observed in phonon calculations. The diamond-like C{sub 11}N{sub 4} is semiconducting and consists of polyhedral and hollow C–N cages. The Vickers hardness of diamond-like C{sub 11}N{sub 4} was calculated to be 58 GPa. The phase transformation from graphite-like to diamond-like C{sub 11}N{sub 4} is proposed to occur at approximately 27.2 GPa based on the pressure-dependent enthalpy.

Carbon, nitrogen and phosphorus dynamics in nine sub-systems of the Sylt-Rømø Bight ecosystem, German Wadden Sea

Science.gov (United States)

Baird, Dan; Asmus, Harald; Asmus, Ragnhild

2011-01-01

Flow networks of nine sub-systems consisting of 59 components each of the Sylt-Rømø Bight, German Wadden Sea, were constructed depicting the standing stocks and flows of material and energy within and between the sub-systems. Carbon, nitrogen and phosphorous were used as currencies for each sub-system, thus resulting in 27 network models, which were analyzed by ecological network analytical protocols. Results show substantial variability in the dynamics of these elements within and between the nine sub-systems, which differ in habitat structure, species diversity and in the standing stocks of their constituent living and non-living components. The relationship between the biodiversity and selected information indices and ratios, derived from ecological network analysis, of individual sub-systems is variable and differ substantially between them. Ecosystem properties such as the structure and magnitude of the recycling of these elements, number of cycles, and total sub-system activity were calculated and discussed, highlighting the differences between and complexity of the flow of C, N and P in a coastal marine ecosystem. The average number of cycles increase from 179 for C, to 16,923 and 20,580 for N and P respectively, while the average amount of recycled material, as measured by the Finn Cycling Index (FCI), increase from 17% for C, to 52% for P and to 61% for N. The number of cycles and the FCI vary considerably between the sub-systems for the different elements. The largest number of cycles of all three elements was observed in the muddy sand flat sub-system, but the highest FCIs were computed for both C (32%) and N (85%) in the Arenicola Flats, and in sparse Zostera noltii sea grass beds for P (67%). Indices reflecting on the growth, organization and resilience of the sub-systems also showed considerable variability between and within the inter-tidal ecosystems in the Bight. Indices such as, for example, the relative ascendency ratios increase on average

REAuAl{sub 4}Ge{sub 2} and REAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (RE=rare earth element): Quaternary intermetallics grown in liquid aluminum

Energy Technology Data Exchange (ETDEWEB)

Xiuni, Wu [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States); Kanatzidis, Mercouri G [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)

2005-11-15

The two families of intermetallic phases REAuAl{sub 4}Ge{sub 2} (1) (RE=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm and Yb) and REAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (2) (x=0.4) (RE=Ce and Eu) were obtained by the reactive combination of RE, Au and Ge in liquid aluminum. The structure of (1) adopts the space group R-3m (CeAuAl{sub 4}Ge{sub 2}, a=4.2384(7)A, c=31.613(7)A; NdAuAl{sub 4}Ge{sub 2}, a=4.2258(4)A, c=31.359(5)A; GdAuAl{sub 4}Ge{sub 2}, a=4.2123(6)A, c=30.994(6)A; ErAuAl{sub 4}Ge{sub 2}, a=4.2074(4)A, c=30.717(5)A). The structure of (2) adopts the tetragonal space group P4/mmm with lattice parameters: a=4.3134(8)A, c=8.371(3)A for EuAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4). Both structure types present slabs of ''AuAl{sub 4}Ge{sub 2}'' or ''AuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2}'' stacking along the c-axis with layers of RE atoms in between. Magnetic susceptibility measurements indicate that the RE atoms (except for Ce and Eu) possess magnetic moments consistent with +3 species. The Ce atoms in CeAuAl{sub 4}Ge{sub 2} and CeAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4) appear to be in a mixed +3/+4 valence state; DyAuAl{sub 4}Ge{sub 2} undergoes an antiferromagnetic transition at 11K and below this temperature exhibits metamagnetic behavior. The Eu atoms in EuAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4) appear to be in a 2+ oxidation state.

Diversity and distribution of microbes in deep-sea sub-vent systems, using newly designed in situ growth chambers

Science.gov (United States)

Higashi, Y.; Sunamura, M.; Utsumi, M.; Urabe, T.; Maruyama, A.

2004-12-01

Subsurface of deep-sea hydrothermal vent environments is one of the most difficult fields on the Earth to approach and collect reliable samples for microbiological study. In our Archaean Park project, we developed in situ incubation instruments to directly collect microbes from sub-vent fields through a drilled borehole. After excavation using a portable submarine driller (BMS) around deep-sea hydrothermal vents in the Suiyo Seamount on the Izu-Bonin Arc (2001, 2002) and the South Mariana (2003), microbial diversity was examined in samples collected from the boreholes, as well as natural vents, using catheter- and column-type in situ growth chambers. In the catheter samples collected from the Suiyo Seamount, several novel phylotypes of microbial SSU rRNA genes were assigned within epsilon-Proteobacteria and hyperthermophile-related Euryarchaea groups. The former novel epsilon group (SSSV-BE1) was also detected in the South Mariana, but they only appeared in the catheter samples collected just below the venting seafloor. These suggest that the group must be significant in warm, shallow and microaerobic sub-vent layers over the sea, at least in the northwest Pacific Ocean. The column-type in situ growth chamber was specially designed for creating and maintaining physico-chemical gradients in a ca. 40-cm-long column situated on an active vent. In Suiyo Seamount samples (vent temp.: ca. 30-100 degree C), a unique vertical profile was found in the diversity of Archaea. At the column bottom, most of the clones were assigned to be members within the lithoautotrophic thermophilic Ignicoccus, while heterotrophic thermophilic Thermococcus were abundant at the column top. Similar vertical profile has also been appeared in the column samples from the South Mariana. Further quantitative population analysis is now under going using these samples. Our approach to the sub-vent biosphere by the combination of drilling and in situ incubation is almost sure to give us important clues

Effect of atomic-arrangement matching on La{sub 2}O{sub 3}/Ge heterostructures for epitaxial high-k-gate-stacks

Energy Technology Data Exchange (ETDEWEB)

Kanashima, T., E-mail: kanashima@ee.es.osaka-u.ac.jp; Zenitaka, M.; Kajihara, Y.; Yamada, S.; Hamaya, K. [Graduate School of Engineering Science, Osaka University, Machkaneyama 1-3, Toyonaka, Osaka 560-8531 (Japan); Nohira, H. [Tokyo City University, 1-28-1 Tamazutumi, Setagaya-ku, Tokyo 158-8557 (Japan)

2015-12-14

We demonstrate a high-quality La{sub 2}O{sub 3} layer on germanium (Ge) as an epitaxial high-k-gate-insulator, where there is an atomic-arrangement matching condition between La{sub 2}O{sub 3}(001) and Ge(111). Structural analyses reveal that (001)-oriented La{sub 2}O{sub 3} layers were grown epitaxially only when we used Ge(111) despite low growth temperatures less than 300 °C. The permittivity (k) of the La{sub 2}O{sub 3} layer is roughly estimated to be ∼19 from capacitance-voltage (C-V) analyses in Au/La{sub 2}O{sub 3}/Ge structures after post-metallization-annealing treatments, although the C-V curve indicates the presence of carrier traps near the interface. By using X-ray photoelectron spectroscopy analyses, we find that only Ge–O–La bonds are formed at the interface, and the thickness of the equivalent interfacial Ge oxide layer is much smaller than that of GeO{sub 2} monolayer. We discuss a model of the interfacial structure between La{sub 2}O{sub 3} and Ge(111) and comment on the C-V characteristics.

Measuring Energy Expenditure in Sub-Adult and Hatchling Sea Turtles via Accelerometry

Science.gov (United States)

Halsey, Lewis G.; Jones, T. Todd; Jones, David R.; Liebsch, Nikolai; Booth, David T.

2011-01-01

Measuring the metabolic of sea turtles is fundamental to understanding their ecology yet the presently available methods are limited. Accelerometry is a relatively new technique for estimating metabolic rate that has shown promise with a number of species but its utility with air-breathing divers is not yet established. The present study undertakes laboratory experiments to investigate whether rate of oxygen uptake ( o 2) at the surface in active sub-adult green turtles Chelonia mydas and hatchling loggerhead turtles Caretta caretta correlates with overall dynamic body acceleration (ODBA), a derivative of acceleration used as a proxy for metabolic rate. Six green turtles (25–44 kg) and two loggerhead turtles (20 g) were instrumented with tri-axial acceleration logging devices and placed singly into a respirometry chamber. The green turtles were able to submerge freely within a 1.5 m deep tank and the loggerhead turtles were tethered in water 16 cm deep so that they swam at the surface. A significant prediction equation for mean o 2 over an hour in a green turtle from measures of ODBA and mean flipper length (R2 = 0.56) returned a mean estimate error across turtles of 8.0%. The range of temperatures used in the green turtle experiments (22–30°C) had only a small effect on o 2. A o 2-ODBA equation for the loggerhead hatchling data was also significant (R2 = 0.67). Together these data indicate the potential of the accelerometry technique for estimating energy expenditure in sea turtles, which may have important applications in sea turtle diving ecology, and also in conservation such as assessing turtle survival times when trapped underwater in fishing nets. PMID:21829613

Band gaps of wurtzite Sc{sub x}Ga{sub 1−x}N alloys

Energy Technology Data Exchange (ETDEWEB)

Tsui, H. C. L.; Moram, M. A. [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Goff, L. E. [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Rhode, S. K. [Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Pereira, S. [CICECO and Dept. Physics, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Beere, H. E.; Farrer, I.; Nicoll, C. A.; Ritchie, D. A. [Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2015-03-30

Optical transmittance measurements on epitaxial, phase-pure, wurtzite-structure Sc{sub x}Ga{sub 1−x}N films with 0 ≤ x ≤ 0.26 showed that their direct optical band gaps increased from 3.33 eV to 3.89 eV with increasing x, in agreement with theory. These films contained I{sub 1}- and I{sub 2}-type stacking faults. However, the direct optical band gaps decreased from 3.37 eV to 3.26 eV for Sc{sub x}Ga{sub 1−x}N films, which additionally contained nanoscale lamellar inclusions of the zinc-blende phase, as revealed by aberration-corrected scanning transmission electron microscopy. Therefore, we conclude that the apparent reduction in Sc{sub x}Ga{sub 1−x}N band gaps with increasing x is an artefact resulting from the presence of nanoscale zinc-blende inclusions.

Influence of Rare Earth Elements on Microstructure and Mechanical Properties of Mg{sub 97}Zn{sub 1}Y{sub 1}RE{sub 1} Alloys

Energy Technology Data Exchange (ETDEWEB)

Kim, Jonghyun, E-mail: joindoc@kumamoto-u.ac.jp [Department of Material Science, Magnesium Research Center (MRC), Kumamoto University, Kumamoto, 860-8555 (Japan); Kawamura, Y. [Department of Material Science, Magnesium Research Center (MRC), Kumamoto University, Kumamoto, 860-8555 (Japan)

2013-06-20

Mg{sub 97}Zn{sub 1}Y{sub 1}RE{sub 1} (RE=La, Ce, Nd and Sm, at. %) alloys were prepared by high-frequency induction melting in an Ar atmosphere. Rods were extruded at 623 K and a ram speed of 2.5 mm·s{sup −1} using a circular die with an extrusion ratio of 10. The microstructure and mechanical properties of the extruded alloys were investigated. The Mg{sub 97}Zn{sub 1}Y{sub 1}Nd{sub 1} and Mg{sub 97}Zn{sub 1}Y{sub 1}Sm{sub 1} alloys consisted of only two phases: α-Mg and a Mg-RE intermetallic compound. The Mg{sub 97}Zn{sub 1}Y{sub 1}La{sub 1} and Mg{sub 97}Zn{sub 1}Y{sub 1}Ce{sub 1} alloys consisted of three phases: α-Mg, a Mg-RE intermetallic compound, and a Mg{sub 12}ZnY phase with a long-period stacking ordered (LPSO) phase. Additionally, after extrusion, the three-phase Mg{sub 97}Zn{sub 1}Y{sub 1}RE{sub 1} alloys, i.e., those with an LPSO phase, had a stratified microstructure and exhibited better mechanical properties than those without an LPSO. At room temperature, the yield strength and ultimate tensile strength of the three-phase Mg{sub 97}Zn{sub 1}Y{sub 1}La{sub 1} and Mg{sub 97}Zn{sub 1}Y{sub 1}Ce{sub 1} alloys were 381–384 MPa and 427–429 MPa, respectively, and yield strengths greater than 280 MPa were observed at the elevated temperature of 523 K.

Helping Students Design HyperCard Stacks.

Science.gov (United States)

Dunham, Ken

1995-01-01

Discusses how to teach students to design HyperCard stacks. Highlights include introducing HyperCard, developing storyboards, introducing design concepts and scripts, presenting stacks, evaluating storyboards, and continuing projects. A sidebar presents a HyperCard stack evaluation form. (AEF)

Hexagonal perovskites with cationic vacancies. 20. Ba/sub 6/Nb/sub 4/ZrvacantO/sub 18/ - a new stacking polytype with a rhombohedral 18 L structure

Energy Technology Data Exchange (ETDEWEB)

Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-06-01

The white Ba/sub 6/Nb/sub 4/ZrvacantO/sub 18/ crystallizes in a rhombohedral 18 L structure (a = 5.82/sub 1/ A; c = 42.6/sub 3/ A; space group R3m) with three formula units for the trigonal setting (rhosub(exp) = 6.0/sub 5/ g/cm/sup 3/; rhosub(calc) = 6.27/sub 1/ g/cm/sup 3/). The corresponding Tisup(IV) and Hfsup(IV) compounds, Ba/sub 6/Nb/sub 4/TivacantO/sub 18/ and Ba/sub 6/Nb/sub 4/HfvacantO/sub 18/, are isotypic.

A 500 kyr record of global sea-level oscillations in the Gulf of Lion, Mediterranean Sea: new insights into MIS 3 sea-level variability

Directory of Open Access Journals (Sweden)

J. Frigola

2012-06-01

Full Text Available Borehole PRGL1-4 drilled in the upper slope of the Gulf of Lion provides an exceptional record to investigate the impact of late Pleistocene orbitally-driven glacio-eustatic sea-level oscillations on the sedimentary outbuilding of a river fed continental margin. High-resolution grain-size and geochemical records supported by oxygen isotope chronostratigraphy allow reinterpreting the last 500 ka upper slope seismostratigraphy of the Gulf of Lion. Five main sequences, stacked during the sea-level lowering phases of the last five glacial-interglacial 100-kyr cycles, form the upper stratigraphic outbuilding of the continental margin. The high sensitivity of the grain-size record down the borehole to sea-level oscillations can be explained by the great width of the Gulf of Lion continental shelf. Sea level driven changes in accommodation space over the shelf cyclically modified the depositional mode of the entire margin. PRGL1-4 data also illustrate the imprint of sea-level oscillations at millennial time-scale, as shown for Marine Isotopic Stage 3, and provide unambiguous evidence of relative high sea-levels at the onset of each Dansgaard-Oeschger Greenland warm interstadial. The PRGL1-4 grain-size record represents the first evidence for a one-to-one coupling of millennial time-scale sea-level oscillations associated with each Dansgaard-Oeschger cycle.

Hydrate prevention in petroleum production sub sea system

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Paula L.F.; Rocha, Humberto A.R. [Universidade Estacio de Sa (UNESA), Rio de Janeiro, RJ (Brazil); Rodrigues, Antonio P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2012-07-01

In spite of the merits of the several hydrate prevention techniques used nowadays, such as: chemical product injection for inhibition and use of thick thermal insulate lines; hydrates per times happen and they are responsible for considerable production losses. Depressurization techniques can be used so much for prevention as in the remediation. Some hydrate removal techniques need a rig or vessel, resources not readily available and with high cost, reason that limits such techniques just for remediation and not for prevention. In the present work it is proposed and described an innovative depressurization system, remote and resident, for hydrate prevention and removal, applicable as for individual sub sea wells as for grouped wells by manifold. Based on low cost jet pumps, without movable parts and with a high reliability, this technique allows hydrate prevention or remediation in a fast and remote way, operated from the production unit. The power fluid line and fluid return line can be integrated in the same umbilical or annulus line structure, without significant increase in the construction costs and installation. It is not necessary to wait for expensive resource mobilization, sometimes not available quickly, such as: vessels or rigs. It still reduces the chemical product consumption and permits to depressurized stopped lines. Other additional advantage, depressurization procedure can be used in the well starting, removing fluid until riser emptying. (author)

Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1987, SDLS CD-ROM vol 13

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during the 1987 field season in the Ross Sea, Antarctica, by SEVMORGEOLOGIA, RUSSIA. The...

Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1980, SDLS CD-ROM vol 3

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from four lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1980, SDLS, CD-ROM vol 4

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from seven lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR - Ross Sea - 1989, SDLS CD-ROM vol 14

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1989 field season in the Ross Sea, Antarctica, by the SEVMORGEOLOGIA, RUSSIS. The...

Multichannel Seismic Reflection Data - SCAR - Ross Sea 1980, SDLS, CD-ROM vol 5

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from eleven lines recorded during 1980 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

Modular fuel-cell stack assembly

Science.gov (United States)

Patel, Pinakin

2010-07-13

A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

Guanine base stacking in G-quadruplex nucleic acids

Science.gov (United States)

Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

2013-01-01

G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study, we investigate how guanine base stacking influences the stability of G-quadruplexes and their stacked higher-order structures. A structural survey of the Protein Data Bank is conducted to characterize experimentally observed guanine base stacking geometries within the core of G-quadruplexes and at the interface between stacked G-quadruplex structures. We couple this survey with a systematic computational examination of stacked G-tetrad energy landscapes using quantum mechanical computations. Energy calculations of stacked G-tetrads reveal large energy differences of up to 12 kcal/mol between experimentally observed geometries at the interface of stacked G-quadruplexes. Energy landscapes are also computed using an AMBER molecular mechanics description of stacking energy and are shown to agree quite well with quantum mechanical calculated landscapes. Molecular dynamics simulations provide a structural explanation for the experimentally observed preference of parallel G-quadruplexes to stack in a 5′–5′ manner based on different accessible tetrad stacking modes at the stacking interfaces of 5′–5′ and 3′–3′ stacked G-quadruplexes. PMID:23268444

Mixed valent perovskites Ba/sub 3/B/sup 3 +/Ru/sub 2/sup(4. 5+)O/sub 9/. Catalytic activity of perovskite oxides with noble metals

Energy Technology Data Exchange (ETDEWEB)

Treiber, U; Kemmler-Sack, S; Ehmann, A; Schaller, H U; Duerrschmidt, E; Thumm, I; Bader, H [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-10-01

The black compounds Ba/sub 3/B/sup 3 +/Ru/sub 2/O/sub 9/ crystallize with B/sup 3 +/ = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Y in a hexagonal BaTiO/sub 3/ structure (6L, sequence (hcc)/sub 2/) with an ordered distribution (1:2 order) of B/sup 3 +/ and ruthenium (BO/sub 6/ single octahedra; Ru/sub 2/O/sub 9/ double groups). The mean oxidation state of ruthenium is about +4.5. The properties are compared with those of other isotypic stacking polytypes Ba/sub 3/B/sup 3 +/M/sub 2/sup(4.5)O/sub 9/ (M/sub 2/ = IrRu, Ir/sub 2/, PtRu) and Ba/sub 3/B/sup 2 +/M/sub 2//sup 5 +/O/sub 9/ (M = Ru, Ir). The results of activity tests concerning the efficiency of perovskite oxides with noble metals in respect of the oxidation of CO or CHsub(x) and the reduction of NOsub(x) are reported.

Structure and Magnetic Properties of Cu<sub>3sub>Ni>2sub>SbO>6sub> and Cu<sub>3sub>Co>2sub>SbO>6sub> Delafossites with Honeycomb Lattices

DEFF Research Database (Denmark)

Roudebush, J. H.; Andersen, Niels Hessel; Ramlau, R.

2013-01-01

-resolution electron microscopy confirms ordering, and selected-area electron diffraction patterns identify examples of the stacking polytypes. Low temperature synthetic treatments result in disordered stacking of the layers, but heating just below their melting points results in nearly fully ordered stacking variants......, approximately parallel to the stacking direction. Bulk magnetization properties are discussed in terms of their magnetic structures....

Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 19

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR, Ross Sea - 1982-1983, CD-ROM vol 9

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from fourteen lines recorded during 1982 in the Ross Sea and Wilkes Island, Antarctica, by the...

Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 18

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 17

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR - Ross Sea 1982, SDLS CD-ROM vol 12

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from seven lines recorded during 1982 in the Ross Sea, Antarctica, by the Institut Francais du...

Characteristics and Dynamics of a Large Sub-Tidal Sand Wave Field—Habitat for Pacific Sand Lance (Ammodytes personatus, Salish Sea, Washington, USA

Directory of Open Access Journals (Sweden)

H. Gary Greene

2017-10-01

Full Text Available Deep-water sand wave fields in the San Juan Archipelago of the Salish Sea and Pacific Northwest Washington, USA, have been found to harbor Pacific sand lance (PSL, Ammodytes personatus, a critical forage fish of the region. Little is known of the dynamics of these sand waves and the stability of the PSL sub-tidal habitats. Therefore, we have undertaken an initial investigation to determine the dynamic conditions of a well-known PSL habitat in the San Juan Channel within the Archipelago using bottom sediment sampling, an acoustical doppler current profiling (ADCP system, and multi-beam echo sounder (MBES bathymetry. Our study indicates that the San Juan Channel sand wave field maintained its shape and bedforms geometry throughout the years it has been studied. Based on bed phase diagrams for channelized bedforms, the sand waves appear to be in a dynamic equilibrium condition. Sea level rise may change the current regime within the Archipelago and may alter some of the deep-water or sub-tidal PSL habitats mapped there. Our findings have global significance in that these dynamic bedforms that harbor PSL and sand-eels elsewhere along the west coast of North America and in the North Sea may also be in a marginally dynamic equilibrium condition and may be prone to alteration by sea level rise, indicating an urgency in locating and investigating these habitats in order to sustain the forage fish.

Doping efficiency of single and randomly stacked bilayer graphene by iodine adsorption

Energy Technology Data Exchange (ETDEWEB)

Kim, HoKwon; Renault, Olivier; Rouchon, Denis; Mariolle, Denis; Chevalier, Nicolas [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Tyurnina, Anastasia; Simonato, Jean-Pierre; Dijon, Jean [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LITEN, Minatec Campus, F-38054 Grenoble (France)

2014-07-07

We report on the efficiency and thermal stability of p-doping by iodine on single and randomly stacked, weakly coupled bilayer polycrystalline graphene, as directly measured by photoelectron emission microscopy. The doping results in work function value increase of 0.4–0.5 eV, with a higher degree of iodine uptake by the bilayer (2%) as compared to the single layer (1%) suggesting iodine intercalation in the bilayer. The chemistry of iodine is identified accordingly as I{sub 3}{sup −} and I{sub 5}{sup −} poly iodide anionic complexes with slightly higher concentration of I{sub 5}{sup −} in bilayer than monolayer graphene, likely attributed to differences in doping mechanisms. Temperature dependent in-situ annealing of the doped films demonstrated that the doping remains efficient up to 200 °C.

Analysis of potentials and costs of CO{sub 2} storage in the Utsira aquifer in the North Sea

Energy Technology Data Exchange (ETDEWEB)

Fidje, Audun; Espegren, Kari; Wangen, Magnus; Seljom, Pernille; Ramirez, Andrea; Hoefnagels, Ric; Wu, Zhenxue; Broek, Machteld van den; Strachan, Neil; Blesl, Markus; Kober, Tom; Grohnheit, Poul Erik; Luethje, Mikael

2010-10-22

lower energy prices tend to favor CCS technologies or natural gas technologies. CCS and nuclear appear in the same cost range so, without further limitations impose by policy, these two technologies appear to compete with each other. Further, the deployment of CCS technologies is also influenced by the national electricity supply options and the opportunity for cross-boundary CO{sub 2} transport. For the CO{sub 2} transport to Utsira, three different network layouts have been analysed. The analysis showed that electricity generation structure of the neighboring countries of the North Sea is not influenced by the type of network but rather by climate policies. Different CO{sub 2} infrastructure layouts for the North Sea region primary affect the transported quantities of CO{sub 2} from the Netherlands (acting as a regional hub) to Utsira. However, the different infrastructures options have little impact on the CO{sub 2} storage from the other North Sea countries. (Author)

Electrically detected magnetic resonance study of the Ge dangling bonds at the Ge(1 1 1)/GeO{sub 2} interface after capping with Al{sub 2}O{sub 3} layer

Energy Technology Data Exchange (ETDEWEB)

Paleari, S., E-mail: s.paleari6@campus.unimib.it [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via Cozzi 53, I-20125 Milan (Italy); Molle, A. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, MB (Italy); Accetta, F. [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via Cozzi 53, I-20125 Milan (Italy); Lamperti, A.; Cianci, E. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, MB (Italy); Fanciulli, M., E-mail: marco.fanciulli@unimib.it [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via Cozzi 53, I-20125 Milan (Italy); Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, MB (Italy)

2014-02-01

The electrical activity of Ge dangling bonds is investigated at the interface between GeO{sub 2}-passivated Ge(1 1 1) substrate and Al{sub 2}O{sub 3} grown by atomic layer deposition, by means of electrically detected magnetic resonance spectroscopy (EDMR). The Al{sub 2}O{sub 3}/GeO{sub 2}/Ge stacked structure is promising as a mobility booster for the post-Si future electronic devices. EDMR proved to be useful in characterizing interface defects, even at the very low concentrations of state-of-the-art devices (<10{sup 10} cm{sup −2}). In particular, it is shown that capping the GeO{sub 2}-passivated Ge(1 1 1) with Al{sub 2}O{sub 3} has no impact on the microstructure of the Ge dangling bond.

Stack filter classifiers

Energy Technology Data Exchange (ETDEWEB)

Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

2009-01-01

Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

Arctic Sea Ice Thickness Estimation from CryoSat-2 Satellite Data Using Machine Learning-Based Lead Detection

Directory of Open Access Journals (Sweden)

Sanggyun Lee

2016-08-01

Full Text Available Satellite altimeters have been used to monitor Arctic sea ice thickness since the early 2000s. In order to estimate sea ice thickness from satellite altimeter data, leads (i.e., cracks between ice floes should first be identified for the calculation of sea ice freeboard. In this study, we proposed novel approaches for lead detection using two machine learning algorithms: decision trees and random forest. CryoSat-2 satellite data collected in March and April of 2011–2014 over the Arctic region were used to extract waveform parameters that show the characteristics of leads, ice floes and ocean, including stack standard deviation, stack skewness, stack kurtosis, pulse peakiness and backscatter sigma-0. The parameters were used to identify leads in the machine learning models. Results show that the proposed approaches, with overall accuracy >90%, produced much better performance than existing lead detection methods based on simple thresholding approaches. Sea ice thickness estimated based on the machine learning-detected leads was compared to the averaged Airborne Electromagnetic (AEM-bird data collected over two days during the CryoSat Validation experiment (CryoVex field campaign in April 2011. This comparison showed that the proposed machine learning methods had better performance (up to r = 0.83 and Root Mean Square Error (RMSE = 0.29 m compared to thickness estimation based on existing lead detection methods (RMSE = 0.86–0.93 m. Sea ice thickness based on the machine learning approaches showed a consistent decline from 2011–2013 and rebounded in 2014.

Existence of ternary hydrogenated phases of BeP/sub 2-x/H/sub y/

International Nuclear Information System (INIS)

Jean-Francois, B.; Gerardin, R.; El Maslout, A.; Zanne, M.; Courtois, A.; Aubry, J.

1975-01-01

The phosphidation of beryllium in the presence of traces of hydrogen leads to non stoichiometric ternary phases BeP/sub 2-x/H/sub y/. The stoichiometric diphosphide BeP 2 cannot be obtained. The hydrogenated phases are black and nonhygroscopic. The structural study with x-ray diffraction, neutrons diffraction, electronic microdiffraction, as well as the crystallographic data from single crystal, provide evidence for a quadratic cell with a = 7.08 A and c = 30.12 A. The stacking is diamond type when considering all the atoms: Be, P and H

Thermal management of a PEMFC stack by 3D nodal modeling

Energy Technology Data Exchange (ETDEWEB)

Dumercy, L.; Glises, R.; Kauffmann, J.M. [Laboratoire de Recherche en Electronique, Electrotechnique et Systemes (L2ES), UFC-UTBM EA 3898, Rue T. MIEG, 90010 Belfort cedex (France); Louahlia-Gualous, H. [FEMTO-ST, CNRS UMR6174, CREST, 2 av. Jean Moulin, 90000 Belfort (France)

2006-05-19

This paper describes a 3D thermal modeling by a nodes network model for two PEMFC of 150 and 500W (respectively, 3 and 20 cells). Modeling are realized for each case for one cell before to be integrated on all the stack. Absolute temperatures of H{sub 2}, air and water channels are used as Dirichlet conditions. Temperatures of external surfaces are obtained thanks to an infrared thermographic camera. Final external heat fluxes are deduced from the integrated model. (author)

Study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst

Energy Technology Data Exchange (ETDEWEB)

Hibbert, D B; Tseung, A C.C.

1979-12-01

A study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst a perovskite oxide, to determine the effects of oxygen and water on SO2 reduction showed that in the presence of 5 to 16% oxygen, the reaction between sulfur dioxide and carbon monoxide still occurred if there was sufficient carbon monoxide in the gas to react with all the oxygen. At 600C, all the sulfur dioxide was removed at 5 to 16% oxygen levels. Water vapor at 2% did not adversely affect the reaction. The unwanted by-products, hydrogen disulfide and carbonyl sulfide, were reduced at contact times below 0.25 sec. During the reaction, the catalyst itself reacted with sulfur to give metal sulfides. When reagent grade CO/sub 2/O/sub 3/ was substituted for perovskite oxide, the maximum conversion of 98% of sulfur dioxide was attained at 550C, but an unacceptably high concentration of carbonyl sulfide was formed; within 1 hr, the sulfur dioxide conversion fell to 60%. The perovskite oxide reaction may be useful in removing sulfur dioxide from fosill fuel stack gases.

Carbon dioxide and nitrous oxide in the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A; Sengupta, R.; DileepKumar, M.

This review concentrates on some aspects of biogeochemical cycling of carbon and nitrogen in the Arabian Sea with emphasis on the atmospheric fluxes of CO sub(2) and N sub(2)O. The Arabian Sea appears to serve as a net sink for combined nitrogen...

From the components to the stack. Developing and designing 5kW HT-PEFC stacks; Von der Komponente zum Stack. Entwicklung und Auslegung von HT-PEFC-Stacks der 5 kW-Klasse

Energy Technology Data Exchange (ETDEWEB)

Bendzulla, Anne

2010-12-22

The aim of the present project is to develop a stack design for a 5-kW HTPEFC system. First, the state of the art of potential materials and process designs will be discussed for each component. Then, using this as a basis, three potential stack designs with typical attributes will be developed and assessed in terms of practicality with the aid of a specially derived evaluation method. Two stack designs classified as promising will be discussed in detail, constructed and then characterized using short stack tests. Comparing the stack designs reveals that both designs are fundamentally suitable for application in a HT-PEFC system with on-board supply. However, some of the performance data differ significantly for the two stack designs. The preferred stack design for application in a HT-PEFC system is characterized by robust operating behaviour and reproducible high-level performance data. Moreover, in compact constructions (120 W/l at 60 W/kg), the stack design allows flexible cooling with thermal oil or air, which can be adapted to suit specific applications. Furthermore, a defined temperature gradient can be set during operation, allowing the CO tolerance to be increased by up to 10 mV. The short stack design developed within the scope of the present work therefore represents an ideal basis for developing a 5-kW HT-PEFC system. Topics for further research activities include improving the performance by reducing weight and/or volume, as well as optimizing the heat management. The results achieved within the framework of this work clearly show that HTPEFC stacks have the potential to play a decisive role in increasing efficiency in the future, particularly when combined with an on-board supply system. (orig.) [German] Ziel der vorliegenden Arbeit ist die Entwicklung eines Stackkonzeptes fuer ein 5 kW-HT-PEFC System. Dazu wird zunaechst fuer jede Komponente der Stand der Technik moeglicher Materialien und Prozesskonzepte diskutiert. Darauf aufbauend werden drei

Multichannel Seismic Reflection Data - SCAR - Ross Sea 1987-1988, SDLS CD-ROM vol 2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data from six lines recorded during 1988 in the Ross Sea, Antarctica, by the Bundesanstalt fur...

Multichannel Seismic Reflection Data - SCAR - Amundsen Sea - 1986-1987, SDLS CD-ROM vol 23

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1986-87 in the Amundsen Sea, Antarctica, by the Japan National Oil Corporation....

Text-Filled Stacked Area Graphs

DEFF Research Database (Denmark)

Kraus, Martin

2011-01-01

-filled stacked area graphs; i.e., graphs that feature stacked areas that are filled with small-typed text. Since these graphs allow for computing the text layout automatically, it is possible to include large amounts of textual detail with very little effort. We discuss the most important challenges and some...... solutions for the design of text-filled stacked area graphs with the help of an exemplary visualization of the genres, publication years, and titles of a database of several thousand PC games....

Sea-to-air and diapycnal nitrous oxide fluxes in the eastern tropical North Atlantic Ocean

Directory of Open Access Journals (Sweden)

A. Kock

2012-03-01

Full Text Available Sea-to-air and diapycnal fluxes of nitrous oxide (N<sub>2sub>O into the mixed layer were determined during three cruises to the upwelling region off Mauritania. Sea-to-air fluxes as well as diapycnal fluxes were elevated close to the shelf break, but elevated sea-to-air fluxes reached further offshore as a result of the offshore transport of upwelled water masses. To calculate a mixed layer budget for N<sub>2sub>O we compared the regionally averaged sea-to-air and diapycnal fluxes and estimated the potential contribution of other processes, such as vertical advection and biological N<sub>2sub>O production in the mixed layer. Using common parameterizations for the gas transfer velocity, the comparison of the average sea-to-air and diapycnal N<sub>2sub>O fluxes indicated that the mean sea-to-air flux is about three to four times larger than the diapycnal flux. Neither vertical and horizontal advection nor biological production were found sufficient to close the mixed layer budget. Instead, the sea-to-air flux, calculated using a parameterization that takes into account the attenuating effect of surfactants on gas exchange, is in the same range as the diapycnal flux. From our observations we conclude that common parameterizations for the gas transfer velocity likely overestimate the air-sea gas exchange within highly productive upwelling zones.

Do Productive Uses of ICT Connect to Income Benefits: A Case Study on Teleuse@BOP4 Survey in Indonesia

Directory of Open Access Journals (Sweden)

Ibrahim Kholilul Rohman

2013-03-01

Full Text Available The question whether the telecommunication sector has been really supporting poverty alleviation and increasing welfare at the household level, in terms of an additional income in Indonesia is still undisclosed. This paper aims at investigating whether the mobile phone access and the uses on productive features/content/services have brought many benefits to the households in terms of an additional income based on the BOP survey conducted by LIRNEAsia and the Institute for Economic and Social Research, University of Indonesia (LPEM FEUI in 2011. The paper found that the respondents with the productive use to their device have a higher likelihood for contributing to their household income.

High permittivity materials for oxide gate stack in Ge-based metal oxide semiconductor capacitors

Energy Technology Data Exchange (ETDEWEB)

Molle, Alessandro, E-mail: alessandro.molle@mdm.infm.i [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Baldovino, Silvia [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy); Spiga, Sabina [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Fanciulli, Marco [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy)

2010-01-01

In the effort to ultimately shrink the size of logic devices towards a post-Si era, the integration of Ge as alternative channel material for high-speed p-MOSFET devices and the concomitant coupling with high permittivity dielectrics (high-k) as gate oxides is currently a key-challenge in microelectronics. However, the Ge option still suffers from a number of unresolved drawbacks and open issues mainly related to the thermodynamic and electrical compatibility of Ge substrates with high-k gate stack. Strictly speaking, two main concerns can be emphasized. On one side is the dilemma on which chemical/physical passivation is more suitable to minimize the unavoidable presence of electrically active defects at the oxide/semiconductor interface. On the other side, overcoming the SiO{sub 2} gate stack opens the route to a number of potentially outperforming high-k oxides. Two deposition approaches were here separately adopted to investigate the high-k oxide growth on Ge substrates, the molecular beam deposition (MBD) of Gd{sub 2}O{sub 3} and the atomic layer deposition (ALD) of HfO{sub 2}. In the MBD framework epitaxial and amorphous Gd{sub 2}O{sub 3} films were grown onto GeO{sub 2}-passivated Ge substrates. In this case, Ge passivation was achieved by exploiting the Ge{sup 4+} bonding state in GeO{sub 2} ultra-thin interface layers intentionally deposited in between Ge and the high-k oxide by means of atomic oxygen exposure to Ge. The composition of the interface layer has been characterized as a function of the oxidation temperature and evidence of Ge dangling bonds at the GeO{sub 2}/Ge interface has been reported. Finally, the electrical response of MOS capacitors incorporating Gd{sub 2}O{sub 3} and GeO{sub 2}-passivated Ge substrates has been checked by capacitance-voltage measurements. On the other hand, the structural and electrical properties of HfO{sub 2} films grown by ALD on Ge by using different oxygen precursors, i.e. H{sub 2}O, Hf(O{sup t}Bu){sub 2}(mmp){sub

Study of substitution in the systems UNi5sub(-)sub(x)Msub(x) and ZrNi5sub(-)sub(x)Msub(x) (M = In, Sn, Zn)

International Nuclear Information System (INIS)

Blazina, Z.; Drasner, A.; Ban, Z.; Zagreb Univ.

1981-01-01

X-ray powder diffraction studies and metallographic examinations in the systems UNi 5 sub(-)sub(x)Msub(x) and ZrNi 5 sub(-)sub(x)Msub(x) (M = In, Sn, Zn) revealed the existence of single phase regions up to the composition 1 : 4 : 1, i.e. up to UNi 4 M and ZrNi 4 M, respectively. Comparison between calculated and observed intensity values showed that nickel atoms, in the crystallographic positions 4(c) of the isostructural binary compounds UNi 5 or ZrNi 5 (UNi 5 -type, S.G. F43m), are substituted by M atoms. Vegard's rule is obeyed in the single phase regions of all investigated systems. The crystal structures of UNi 4 M and ZrNi 4 M are superlattice structures of the MgSnCu 4 -type (S.G. F43m). Structural correlations of these phases with corresponding binary prototypes are made in terms of stacking sequences. (orig.)

Unprecedented connection mode of [V{sub 16}Sb{sub 4}O{sub 42}(H{sub 2}O)]{sup 8-} cluster anions by Mn{sup 2+} centered complexes. Solvothermal synthesis and properties of {[Mn(teta)]_4V_1_6Sb_4O_4_2(H_2O)}{sub n}.[(H{sub 2}O){sub 12}]{sub n}

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Maren; Naether, Christian; Bensch, Wolfgang [Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel (Germany); Leusen, Jan van; Koegerler, Paul [Institute of Inorganic Chemistry, RWTH Aachen University, Aachen (Germany)

2017-11-17

The new compound {[Mn(teta)]_4V_1_6Sb_4O_4_2}{sub n}.[(H{sub 2}O){sub 12}]{sub n} (teta = triethylenetetraamine) was synthesized under solvothermal conditions. The crystal structure features the high nuclearity [V{sub 16}{sup IV}Sb{sub 4}{sup III}O{sub 42}(H{sub 2}O)]{sup 8-} cluster anion, which consists of two rings composed of 8 edge-sharing VO{sub 5} polyhedra. The rings are perpendicular to each other generating four niches, which are occupied by two VO{sub 5} pyramids and two handle-like Sb{sub 2}O{sub 5} units. The two unique anions are each surrounded by eight Mn{sup 2+} centered complexes via Mn-O{sub term}-V bonds. Such an expansion has never been observed in heterometal polyoxovanadate chemistry. The connection mode between cluster anions and complex cations generates two individual layers stacked onto each other. Between the layers weak Sb..O contacts are observed. The crystal water molecules are mainly located in the empty space between the layers. Upon heating H{sub 2}O molecules are removed, while the crystal structure remains intact. The magnetic behavior is dominated by strong antiferromagnetic exchange interactions between the central V{sup 4+} ions, while the interaction between the cluster anion and central Mn{sup 2+} ions is significantly less pronounced. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Maturing of SOFC cell and stack production technology and preparation for demonstration of SOFC stacks. Part 2

Energy Technology Data Exchange (ETDEWEB)

2006-07-01

The TOFC/Riso pilot plant production facility for the manufacture of anode-supported cells has been further up-scaled with an automated continuous spraying process and an extra sintering capacity resulting in production capacity exceeding 15,000 standard cells (12x12 cm2) in 2006 with a success rate of about 85% in the cell production. All processing steps such as tape-casting, spraying, screen-printing and atmospheric air sintering in the cell production have been selected on condition that up-scaling and cost effective, flexible, industrial mass production are feasible. The standard cell size is currently being increased to 18x18 cm2, and 150 cells of this size have been produced in 2006 for our further stack development. To improve quality and lower production cost, a new screen printing line is under establishment. TOFC's stack design is an ultra compact multilayer assembly of cells (including contact layers), metallic interconnects, spacer frames and glass seals. The compactness ensures minimized material consumption and low cost. Standard stacks with cross flow configuration contains 75 cells (12x12cm2) delivering about 1.2 kW at optimal operation conditions with pre-reformed NG as fuel. Stable performance has been demonstrated for 500-1000 hours. Significantly improved materials, especially concerning the metallic interconnect and the coatings have been introduced during the last year. Small stacks (5-10 cells) exhibit no detectable stack degradation using our latest cells and stack materials during test periods of 500-1000 hours. Larger stacks (50-75 cells) suffer from mal-distribution of gas and air inside the stacks, gas leakage, gas cross-over, pressure drop, and a certain loss of internal electrical contact during operation cycles. Measures have been taken to find solutions during the following development work. The stack production facilities have been improved and up-scaled. In 2006, 5 standard stacks have been assembled and burned in based on

Sea Legs

Science.gov (United States)

Macdonald, Kenneth C.

Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

Variability of three-dimensional sea breeze structure in southern France: observations and evaluation of empirical scaling laws

Directory of Open Access Journals (Sweden)

P. Drobinski

2006-08-01

Full Text Available Sea-breeze dynamics in southern France is investigated using an airborne Doppler lidar, a meteorological surface station network and radiosoundings, in the framework of the ESCOMPTE experiment conducted during summer 2001 in order to evaluate the role of thermal circulations on pollutant transport and ventilation. The airborne Doppler lidar WIND contributed to three-dimensional (3-D mapping of the sea breeze circulation in an unprecedented way. The data allow access to the onshore and offshore sea breeze extents (x<sub>sb>, and to the sea breeze depth (z<sub>sb> and intensity (u<sub>sb>. They also show that the return flow of the sea breeze circulation is very seldom seen in this area due to (i the presence of a systematic non zero background wind, and (ii the 3-D structure of the sea breeze caused by the complex coastline shape and topography. A thorough analysis is conducted on the impact of the two main valleys (Rhône and Durance valleys affecting the sea breeze circulation in the area.

Finally, this dataset also allows an evaluation of the existing scaling laws used to derive the sea breeze intensity, depth and horizontal extent. The main results of this study are that (i latitude, cumulative heating and surface friction are key parameters of the sea breeze dynamics; (ii in presence of strong synoptic flow, all scaling laws fail in predicting the sea breeze characteristics (the sea breeze depth, however being the most accurately predicted; and (iii the ratio z<sub>sb/u_sb> is approximately constant in the sea breeze flow.

Features of a time domain simulation tool for rigid riser design

Energy Technology Data Exchange (ETDEWEB)

Morooka, Celso K.; Brandt, Dustin M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo; Matt, Cyntia G.C.; Franciss, Ricardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2008-07-01

This paper present a number of numerical implementations designed for the analysis of rigid riser's static and dynamic behavior that includes the effects of vortex induced vibrations (VIV) and marine hydrodynamic loads in time domain. Features include the ability to consider pipe with a free-span utilizing a soil/riser interaction model. An implementation of a numerical coupling scheme to couple the vertical riser and platform dynamics was developed to allow prediction of the sub sea Blow-Out Preventer (BOP) re-entry into a sub sea petroleum well when drilling different phases of deep and ultra-deep wells. The developments contains support for the consideration of the Self Standing Hybrid Riser (SSHR) configuration which has been shown to be a promising riser configuration in deep and ultra-deep waters. A graphical interface was also created to better grasp the results and aid in the modeling, processing and to help analyze the numerical simulations, contributing to enhance agility and quality of the riser design and analysis processes. (author)

Multilayer stacks obtained by ion assisted EB PVD aimed at thermal barrier coating

Energy Technology Data Exchange (ETDEWEB)

Roos, E.; Maile, K.; Lyutovich, A. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA)

2010-07-01

Thermal Barrier Coating (TBC) using Electron Beam Physical Vapour Deposition (EB PVD) is widely implemented, especially for aero-engine turbine blades. Generally, multilayer stacks are used for these aims. For the additional improvement of intermediate layers with graded transitions to the initial Ni-based alloy, the use of accelerated ions in the EBPVD-process is advantageous. The effect of the substrate bias potential, ion current density and deposition temperature on the structure and properties of Ti and Zr intermediate layers are investigated. The morphology of the films is studied using optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). It is found that the surface morphology becomes smoother with rising bias potential and decreasing ion current density. Measurements of Vicker's micro-hardness performed on these coatings have shown its increase with higher values of the bias and its reduction with the growing temperature. This effect is caused by the observed decrease in grain size and higher porosity of the films. A multilayer coating system Ni (based substrate)-Si-Si{sub x}Al{sub y}-Al with graded transitions between the layers is obtained using ion assisted EBPVD. Architecture of a multilayer stack for TBC with graded transitions is proposed. (orig.)

Three-dimensional sea-urchin-like hierarchical TiO{sub 2} microspheres synthesized by a one-pot hydrothermal method and their enhanced photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yi, E-mail: zhouyihn@163.com [Department of Chemical and Biological Engineering, Changsha University of Science and Technology, Hunan, 410114 (China); Huang, Yan; Li, Dang; He, Wenhong [Department of Chemical and Biological Engineering, Changsha University of Science and Technology, Hunan, 410114 (China)

2013-07-15

Graphical abstract: SEM images of the samples synthesized at different hydrothermal temperatures for 8 h: (a) 75; (b) 100; (c) 120; and (d) 140°C, followed by calcination at 450 °C for 2 h. Highlights: ► Effects of calcination temperature on the phase transformation were studied. ► Effects of hydrothermal temperature and time on the morphology growth were studied. ► A two-stage reaction mechanism for the formation was presented. ► The photocatalytic activity was evaluated under sunlight irradiation. ► Effects of calcination temperature on the photocatalytic activity were studied. - Abstract: Novel three-dimensional sea-urchin-like hierarchical TiO{sub 2} superstructures were synthesized on a Ti plate in a mixture of H{sub 2}O{sub 2} and NaOH aqueous solution by a facile one-pot hydrothermal method at a low temperature, followed by protonation and calcination. The results of series of electron microscopy characterizations suggested that the hierarchical TiO{sub 2} superstructures consisted of numerous one-dimensional nanostructures. The microspheres were approximately 2–4 μm in diameter, and the one-dimensional TiO{sub 2} nanostructures were up to 600–700 nm long. A two-stage reaction mechanism, i.e., initial growth and then assembly, was proposed for the formation of these architectures. The three-dimensional sea-urchin-like hierarchical TiO{sub 2} microstructures showed excellent photocatalytic activity for the degradation of Rhodamine B aqueous solution under sunlight irradiation, which was attributed to the special three-dimensional hierarchical superstructure, and increased number of surface active sites. This novel superstructure has promising use in practical aqueous purification.

Study on the influence of nickel and Al{sub 2}O{sub 3} support on MoS{sub 2} as hydrodenitrogenation catalysts

Energy Technology Data Exchange (ETDEWEB)

Hein, J.; Hrabar, A.; Gutierrez, O.Y.; Lercher, J.A. [Technische Univ. Muenchen, Garching (Germany). Catalysis Research Center

2012-07-01

Alumina-supported Mo and Ni-Mo catalysts as well as an unsupported NiMo catalyst were characterized and tested in the hydrodenitrogenation (HDN) of quinoline in the presence of dibenzothiophene (DBT). The supported catalysts had a well dispersed MoS{sub 2} phase with an average stacking degree around two and slabs length below 10 nm. The unsupported NiMo sulfide catalyst exhibited long, multistacked MoS{sub 2} slabs and contained segregated Ni{sub x}S{sub y} phases. The formation of the Ni-Mo-S phase in both Ni containing catalysts was verified by X-ray absorption spectroscopy, whereas the concentration of coordinatively unsaturated sites was higher for the supported Mo and Ni-Mo catalysts than for the unsupported one. All catalysts were active in the HDN of quinoline and hydrodesulfurization of DBT. The catalytic activity increased in the order Mo/Al{sub 2}O{sub 3} < NiMo/unsupported < Ni-Mo/Al{sub 2}O{sub 3}. Thus, the influence on the catalytic activity of the promoter metal Ni is more important than the presence of a support due to the formation of the Ni-Mo-S phase (more active than MoS{sub 2}). (orig.)

CO{sub 2} capture and utilization for enhanced oil recovery

Energy Technology Data Exchange (ETDEWEB)

Vilhelmsen, P.J.; Well, W. van; Nielsen, Charles [DONG Energy Generation, Fredericia (Denmark); Harrar, W.; Reffstrup, J. [DONG Energy Exploration and Production, Hoersholm (Denmark)

2007-05-15

CO{sub 2} is an international theme and the cap-and-trade systems under implementation will lead to significant alterations in the energy market and in the energy system altogether. A possible technical step to reduce atmospheric emissions is CO{sub 2} capture and the utilisation of the CO{sub 2} for Enhanced Oil Recovery (EOR). CO{sub 2} capture is to some extent a know technology but has not yet been optimised and commercialised for power plant utilisation. Correspondingly CO{sub 2} utilisation for EOR is a known method in other areas of the world where the reservoir conditions are different from those of the North Sea. For several years Elsam and Energi E2, part of DONG Energy, have worked on reducing CO{sub 2} emissions through increased efficiency at the coal-fired power plants, and this work has now been extended to also include capture and utilisation of CO{sub 2}. DONG E and P within DONG Energy has started work on the utilisation of CO{sub 2} for EOR at the company's fields in the North Sea. Based on DONG Energy's interest in working through the whole value chain from power plants to EOR utilisation in the North Sea, this paper describes our experience with CO{sub 2} capture at the trial plant CASTOR at Esbjerg power plant and the actual work of investigating and preparing the pilot test of CO{sub 2} for EOR in the North Sea. The paper also illustrates the perspectives of retrofitting the existing fleet of super critical coal-fired power plants close to the North Sea with CO{sub 2} capture and the utilisation of the CO{sub 2} for EOR in the North Sea. DONG Energy's perspective is that CO{sub 2} for EOR can contribute to materialising the vision that the central power plant can be developed into an energy refinery. The development work presented will be carried out in cooperation with leading international players and Danish universities and knowledge centres Technical University of Denmark (DTU), The Danish Geotechnical Institute (GEO) and Geological

Optical and vibrational properties of (ZnO){sub k} In{sub 2}O{sub 3} natural superlattice nanostructures

Energy Technology Data Exchange (ETDEWEB)

Margueron, Samuel [Laboratoire Matériaux Optiques, Photonique et Systèmes, Université de Lorraine et CentraleSupélec, 57070 Metz (France); John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Maryland 02138 (United States); Pokorny, Jan; Skiadopoulou, Stella; Kamba, Stanislav [Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Liang, Xin [School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu Province 213164 (China); Clarke, David R. [John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Maryland 02138 (United States)

2016-05-21

A thermodynamically stable series of superlattices, (ZnO){sub k}In{sub 2}O{sub 3}, form in the ZnO-In{sub 2}O{sub 3} binary oxide system for InO{sub 1.5} concentrations from about 13 up to about 33 mole percent (m/o). These natural superlattices, which consist of a periodic stacking of single, two-dimensional sheets of InO{sub 6} octahedra, are found to give rise to systematic changes in the optical and vibrational properties of the superlattices. Low-frequency Raman scattering provides the evidence for the activation of acoustic phonons due to the folding of Brillouin zone. New vibrational modes at 520 and 620 cm{sup −1}, not present in either ZnO or In{sub 2}O{sub 3}, become Raman active. These new modes are attributed to collective plasmon oscillations localized at the two-dimensional InO{sub 1.5} sheets. Infrared reflectivity experiments, and simulations taking into account a negative dielectric susceptibility due to electron carriers in ZnO and interface modes of the dielectric layer of InO{sub 2}, explain the occurrence of these new modes. We postulate that a localized electron gas forms at the ZnO/InO{sub 2} interface due to the electron band alignment and polarization effects. All our observations suggest that there are quantum contributions to the thermal and electrical conductivity in these natural superlattices.

Hexagonal perovskites with cationic vacancies. 13. Rhombohedral 12 L-stacking polytypes Ba/sub 4/M/sub 2/sup(V)WvacantO/sub 12/ with Msup(V) = Nb, Ta

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.)

1979-10-01

The white quaternary oxides Ba/sub 4/Nb/sub 2/WvacantO/sub 12/ and Ba/sub 4/Ta/sub 2/WvacantO/sub 12/ belong to the group of hexagonal perovskites with cationic vacancies. They crystallize in the rhombohedral 12 L-type: Sequence (3)(1) = (hhcc)/sub 3/; space group R/sup -/3m (Ba/sub 4/Nb/sub 2/WvacantO/sub 12/: a = 5.77/sub 6/ A; c = 28.0/sub 55/ A; Ba/sub 4/Ta/sub 2/WvacantO/sub 12/: a = 5.77/sub 3/ A; c = 28.0/sub 75/ A; Z = 3).

V-stack piezoelectric actuator

Science.gov (United States)

Ardelean, Emil V.; Clark, Robert L.

2001-07-01

Aeroelastic control of wings by means of a distributed, trailing-edge control surface is of interest with regards to maneuvers, gust alleviation, and flutter suppression. The use of high energy density, piezoelectric materials as motors provides an appealing solution to this problem. A comparative analysis of the state of the art actuators is currently being conducted. A new piezoelectric actuator design is presented. This actuator meets the requirements for trailing edge flap actuation in both stroke and force. It is compact, simple, sturdy, and leverages stroke geometrically with minimum force penalties while displaying linearity over a wide range of stroke. The V-Stack Piezoelectric Actuator, consists of a base, a lever, two piezoelectric stacks, and a pre-tensioning element. The work is performed alternately by the two stacks, placed on both sides of the lever. Pre-tensioning can be readily applied using a torque wrench, obviating the need for elastic elements and this is for the benefit of the stiffness of the actuator. The characteristics of the actuator are easily modified by changing the base or the stacks. A prototype was constructed and tested experimentally to validate the theoretical model.

Market orientated design studies for SOFC based systems

Energy Technology Data Exchange (ETDEWEB)

Nietsch, T.; Clark, J.

1999-07-01

This report examines the development status of Solid Oxide Fuel Cell (SOFC) technology, assesses its commercial potential for heat and power generation in the UK and identifies key development areas for both the SOFC stack and associated system components. A range of Distributed Generation (DG) and Combined Heat and Power (CHP) applications were considered in arriving at these recommendations. The project commenced with initial surveys of leading SOFC technology companies and centres world-wide. These surveys were conducted in parallel with consultations with key operator organisations in the UK which enabled the requirements of these organisations within the UK Energy Supply Industry to be identified. As a result of the initial survey, over 30 fuel cell based power plants, of size ranging from 1 kW{sub e} to 20 MW{sub e} for both DG and CHP applications, were identified. Outline designs of these applications were then set up and simulated. These candidate systems were then assessed against each other in terms of efficiency, cost of electricity, specific costs, technical risk and market potential for the UK industry. The final ranking obtained was then confirmed with the key operator organisations. On the basis of the ranking process noted above, nine SOFC based power generation/CHP applications were chosen for more detailed investigation in terms of their potential in both UK and overseas markets. Detailed simulations were conducted for each application to allow study of: the influence of efficiency on the economics of the different plants/stacks; the combination of stack and Balance of Plant (BoP) costs; and the cost and availability of key balance of plant devices. These systems were then again assessed in terms of the criteria noted for the outline stage. Finally key development areas for both SOFC stacks and associated Balance of Plant devices were identified. (author)

A multivariate analysis of Antarctic sea ice since 1979

Energy Technology Data Exchange (ETDEWEB)

Magalhaes Neto, Newton de; Evangelista, Heitor [Universidade do Estado do Rio de Janeiro (Uerj), LARAMG - Laboratorio de Radioecologia e Mudancas Globais, Maracana, Rio de Janeiro, RJ (Brazil); Tanizaki-Fonseca, Kenny [Universidade do Estado do Rio de Janeiro (Uerj), LARAMG - Laboratorio de Radioecologia e Mudancas Globais, Maracana, Rio de Janeiro, RJ (Brazil); Universidade Federal Fluminense (UFF), Dept. Analise Geoambiental, Inst. de Geociencias, Niteroi, RJ (Brazil); Penello Meirelles, Margareth Simoes [Universidade do Estado do Rio de Janeiro (UERJ)/Geomatica, Maracana, Rio de Janeiro, RJ (Brazil); Garcia, Carlos Eiras [Universidade Federal do Rio Grande (FURG), Laboratorio de Oceanografia Fisica, Rio Grande, RS (Brazil)

2012-03-15

Recent satellite observations have shown an increase in the total extent of Antarctic sea ice, during periods when the atmosphere and oceans tend to be warmer surrounding a significant part of the continent. Despite an increase in total sea ice, regional analyses depict negative trends in the Bellingshausen-Amundsen Sea and positive trends in the Ross Sea. Although several climate parameters are believed to drive the formation of Antarctic sea ice and the local atmosphere, a descriptive mechanism that could trigger such differences in trends are still unknown. In this study we employed a multivariate analysis in order to identify the response of the Antarctic sea ice with respect to commonly utilized climate forcings/parameters, as follows: (1) The global air surface temperature, (2) The global sea surface temperature, (3) The atmospheric CO{sub 2} concentration, (4) The South Annular Mode, (5) The Nino 3, (6) The Nino (3 + 4, 7) The Nino 4, (8) The Southern Oscillation Index, (9) The Multivariate ENSO Index, (10) the Total Solar Irradiance, (11) The maximum O{sub 3} depletion area, and (12) The minimum O{sub 3} concentration over Antarctica. Our results indicate that western Antarctic sea ice is simultaneously impacted by several parameters; and that the minimum, mean, and maximum sea ice extent may respond to a separate set of climatic/geochemical parameters. (orig.)

Reflector imaging by diffraction stacking with stacking velocity analysis; Jugo sokudo kaiseki wo tomonau sanran jugoho ni yoru hanshamen imaging

Energy Technology Data Exchange (ETDEWEB)

Matsushima, J; Rokugawa, S; Kato, Y [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yokota, T [Japan National Oil Corp., Tokyo (Japan); Miyazaki, T [Geological Survey of Japan, Tsukuba (Japan)

1997-10-22

Concerning seismic reflection survey for geometrical arrangement between pits, the scattering stacking method with stacking velocity analysis is compared with the CDP (common depth point horizontal stacking method). The advantages of the CDP supposedly include the following. Since it presumes an average velocity field, it can determine velocities having stacking effects. The method presumes stratification and, since such enables the division of huge quantities of observed data into smaller groups, more data can be calculated in a shorter time period. The method has disadvantages, attributable to its presuming an average velocity field, that accuracy in processing is lower when the velocity field contrast is higher, that accuracy in processing is low unless stratification is employed, and that velocities obtained from stacking velocity analysis are affected by dipped structures. Such shortcomings may be remedied in the scattering stacking method with stacking velocity analysis. Possibilities are that, as far as the horizontal reflection plane is concerned, it may yield stack records higher in S/N ratio than the CDP. Findings relative to dipped reflection planes will be introduced at the presentation. 6 refs., 12 figs.

Joint Polish–Finnish sampling of surface waters around the phosphogypsum waste stacks in Gdańsk and Police from 1 to 3 July 2013 – Results of the expedition

OpenAIRE

Räike, Antti; Koskela, Jarkko; Knuuttila, Seppo; Lehtoranta, Jouni; Pitkänen, Heikki; Risto, Maarit; Vuorinen, Jyrki

2015-01-01

The report describes the results of the joint Polish–Finnish sampling expedition aimed at estimating the possible effects of the two Polish phosphogypsum stacks located in Wislinka (Gdańsk) and Police on the loading of the Baltic Sea and the nearby watercourses. The joint expedition was based on the agreement between the Polish and Finnish Ministers of the Environment in June 2013. The results indicate a clear effect of the phosphogypsum stack on phosphate and total phosphorus concentratio...

Study of interfaces and band offsets in TiN/amorphous LaLuO3 gate stacks

KAUST Repository

Mitrovic, Ivona Z.; Simutis, G.; Davey, W. M.; Sedghi, Naser; Hall, Stephen D.; Dhanak, Vinod R.; Alexandrou, Ioannis; Wang, Qingxiao; Lopes, Joao Marcelo J.; Schubert, Jü rgen M.

2011-01-01

sub-peak which relates to Ti bond to interstitial oxygen have been identified for an ultra-thin 1.7 nm TiN/3 nm LLO gate stack. The angle-dependent XPS analysis of Si2s spectra as well as shifts of La4d, La3d and Lu4d core levels suggests a silicate-type

Electronic and magnetic properties of organic conductors (DMET) sub 2 MBr sub 4 (M=Fe, Ga)

CERN Document Server

Enomoto, K; Enoki, T; Yamaura, J I

2003-01-01

(DMET) sub 2 MBr sub 4 (M=Fe, Ga) are isostructural organic conductors whose crystal structure consists of an alternate stacking of quasi one-dimensional chain-based donor layers and anion square lattices. The resistivity, ESR, magnetic susceptibility, magnetization, and magnetoresistance of these salts were investigated in order to clarify the correlation between the electronic structure and the magnetism. The electronic structures of both salts are metallic down to T sub M sub I - 40 K, below which a Mott insulating state is stabilized, accompanied by an SDW transition at T sub S sub D sub W - 25 K. The FeBr sub 4 salt with Fe sup 3 sup + (S=5/2) localized spins undergoes an antiferromagnetic transition at T sub N = 3.7 K. In the FeBr sub 4 salt, the magnetization curves, which show field-direction-dependent anomalies in addition to a spin-flop transition, are demonstrated to have a participation of donor pi-electron spins in the magnetization processes. The field dependence of the magnetoresistances below ...

Intracomplex {pi}-{pi} stacking interaction between adjacent phenanthroline molecules in complexes with rare-earth nitrates: Crystal and molecular structures of bis(1,10-Phenanthroline)trinitratoytterbium and bis(1,10-Phenanthroline)trinitratolanthanum

Energy Technology Data Exchange (ETDEWEB)

Sadikov, G. G., E-mail: sadgg@igic.ras.ru; Antsyshkina, A. S.; Rodnikova, M. N.; Solonina, I. A. [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation)

2009-01-15

Crystals of the compounds Yb(NO{sub 3}){sub 3}(Phen){sub 2} and La(NO{sub 3}){sub 3}(Phen){sub 2} (Phen = 1,10-phenanthroline) are investigated using X-ray diffraction. It is established that there exist two different crystalline modifications: the main modification (phase 1) is characteristic of all members of the isostructural series, and the second modification (phase 2) is observed only for the Eu, Er, and Yb elements. It is assumed that the stability and universality of main phase 1 are associated with the occurrence of the nonbonded {pi}-{pi} stacking interactions between the adjacent phenanthroline ligands in the complexes. The indication of the interactions is a distortion of the planar shape of the Phen molecule (the folding of the metallocycle along the N-N line with a folding angle of 11{sup o}-13{sup o} and its 'boomerang' distortion). The assumption regarding the {pi}-{pi} stacking interaction is very consistent with the shape of the ellipsoids of atomic thermal vibrations, as well as with the data obtained from thermography and IR spectroscopy. An analysis of the structures of a number of rare-earth compounds has demonstrated that the intracomplex {pi}-{pi} stacking interactions directly contribute to the formation of supramolecular associates in the crystals, such as molecular dimers, supramolecules, chain and layered ensembles, and framework systems.

Hexagonal perovskites with cationic vacancies. 18. Structure of the rhombohedral 12 L-stacking polytypes Ba/sub 2/La/sub 2/Bsup(II)(W/sub 2/sup(VI)vacantO/sub 12/)

Energy Technology Data Exchange (ETDEWEB)

Rother, H J; Fadini, A; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-04-01

According to the intensity calcualtions for Ba/sub 2/La/sub 2/Zn(W/sub 2/vacantO/sub 12/) the compounds of this type crystallize in the space group R3m-Dsub(3d)/sup 5/ with the sequence (3)(1)equivalent (hhcc)/sub 3/. The refined, intensity related R' value is 5,8%. The octahedral net consists of blocks of three face connected octahedra which are linked to each other by corner sharing BO/sub 6/ octahedra. The cationic vacancies are located in the centers of the groups of three octahedra. The two tungsten atoms in the outer positions are displaces by about 0.13 A from their ideal positions in direction of the central void. The (Ba, La) atoms neighbouring a vacancy (all in hexagonal close packed (Ba, La)O/sub 3/ sheets) are also dislocated in direction of the void, while the (Ba, La) atoms in the cubic packed sheets maintain nearly their ideal positions. The vibrational spectra of the compounds Ba/sub 2/La/sub 2/ Bsup(II)(W/sub 2/vacantO/sub 12/) are discussed. The force constants for the W/sub 2/vacantO/sub 12/ groups (factor group and Ppoint Dsub(3d)) were calculated and compared with the correspoinding values of Re/sub 2/vacantO/sub 12/ and ReWvacantO/sub 12/ units.

Optics of the CuGaSe{sub 2} solar cell for highly efficient tandem concepts; Optik der CuGaSe{sub 2}-Solarzelle fuer hocheffiziente Tandemkonzepte

Energy Technology Data Exchange (ETDEWEB)

Schmid, Martina

2010-01-25

A principle aim of solar cell research lies in optimizing the exploitation of the incident solar light. Yet, for single junction solar cells there exists an efficiency limit as described by Shockley and Queisser. The only concept realized so far to overcome this threshold is - apart from concentration - the multijunction solar cell. However, any kind of multijunction design poses new challenges: The upper wide-gap solar cell (top cell) needs to show efficient light absorption in the short-wavelength region. At the same time sufficient transmission for long-wavelength light is required which then needs to be absorbed effectively by the low-gap bottom cell. In tandem solar cells a proper light management in top and bottom solar cell is of great importance. This work focuses on chalcopyrite-based tandem solar cells. For the wide-bandgap IR-transparent ZnO:Al/i-ZnO/CdS/CuGaSe{sub 2}/SnO{sub 2}:F/glass solar cell an optical model has been established. Starting from modeling each of the individual layers building the stack the optical behavior of the complete thin film system of the top cell could be described. Carefully selected layer combinations and comparison of experimental and calculated data allowed for the attribution of transmission losses to the distinct material properties. Defects in the absorber are of crucial importance but also free carrier absorption in the window and in the transparent back contact contribute significantly to optical losses. The quantification of the losses was achieved by calculating the effects of reduced top cell transmission on the photo current of a simplified bottom cell. An extension of the optical model allowed to calculate the effective absorption in the individual layers and to determine reflection losses at the interfaces. From these results an optimized top cell stack was derived which is characterized by A) simulation of the monolithic integration, B) reduced layer thicknesses wherever possible from the electrical point of

Towards stacked zone plates

International Nuclear Information System (INIS)

Werner, S; Rehbein, S; Guttman, P; Heim, S; Schneider, G

2009-01-01

Fresnel zone plates are the key optical elements for soft and hard x-ray microscopy. For short exposure times and minimum radiation load of the specimen the diffraction efficiency of the zone plate objectives has to be maximized. As the efficiency strongly depends on the height of the diffracting zone structures the achievable aspect ratio of the nanostructures determines these limits. To reach aspect ratios ≥ 20:1 for high efficient optics we propose to superimpose zone plates on top of each other. With this multiplication approach the final aspect ratio is only limited by the number of stacked zone plate layers. For the stack process several nanostructuring process steps have to be developed and/or improved. Our results show for the first time two layers of zone plates stacked on top of each other.

Releases of ¹⁴CO<sub>2sub> from nuclear facilities with gaseous effluents; Die Emission von 14C02 mit der Abluft kerntechnischer Anlagen

Energy Technology Data Exchange (ETDEWEB)

Schuettelkopf, H.

1977-06-01

Since only little information is available about the extent and type of the ¹⁴C emission from nuclear facilities, the Radiation Protection and Safety Department of the Karlsruhe Nuclear Research Center has measured the ¹⁴C stack vent emission from various facilities. The measurement was restricted to ¹⁴CO<sub>2sub> because it is only this coumpound which can lead to exposure doses as a result of ingestion and inhalation. Sampling was carried out with 200 ml of 5 M NaOH in a scrubber. The sample flow was 1 l/min. The sampling period was one week. The ¹⁴CO<sub>2sub> emission was measured in the stack vent air of the FR-2 research reactor, the Multi-purpose Research Reactor (MZFR), the combustion facility for burnable radioactive waste (FERAB), the Karlsruhe Reprocessing Plant (WAK), all of which are located on the premises of the Karlsruhe Nuclear Research Center, and in the exhaust air of the Obrigheim (KWO) and Biblis A Nuclear Power Stations.

Tunable electro-optic filter stack

Science.gov (United States)

Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

2017-09-05

A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

Sea level anomaly in the North Atlantic and seas around Europe: Long-term variability and response to North Atlantic teleconnection patterns.

Science.gov (United States)

Iglesias, Isabel; Lorenzo, M Nieves; Lázaro, Clara; Fernandes, M Joana; Bastos, Luísa

2017-12-31

Sea level anomaly (SLA), provided globally by satellite altimetry, is considered a valuable proxy for detecting long-term changes of the global ocean, as well as short-term and annual variations. In this manuscript, monthly sea level anomaly grids for the period 1993-2013 are used to characterise the North Atlantic Ocean variability at inter-annual timescales and its response to the North Atlantic main patterns of atmospheric circulation variability (North Atlantic Oscillation, Eastern Atlantic, Eastern Atlantic/Western Russia, Scandinavian and Polar/Eurasia) and main driven factors as sea level pressure, sea surface temperature and wind fields. SLA variability and long-term trends are analysed for the North Atlantic Ocean and several sub-regions (North, Baltic and Mediterranean and Black seas, Bay of Biscay extended to the west coast of the Iberian Peninsula, and the northern North Atlantic Ocean), depicting the SLA fluctuations at basin and sub-basin scales, aiming at representing the regions of maximum sea level variability. A significant correlation between SLA and the different phases of the teleconnection patterns due to the generated winds, sea level pressure and sea surface temperature anomalies, with a strong variability on temporal and spatial scales, has been identified. Long-term analysis reveals the existence of non-stationary inter-annual SLA fluctuations in terms of the temporal scale. Spectral density analysis has shown the existence of long-period signals in the SLA inter-annual component, with periods of ~10, 5, 4 and 2years, depending on the analysed sub-region. Also, a non-uniform increase in sea level since 1993 is identified for all sub-regions, with trend values between 2.05mm/year, for the Bay of Biscay region, and 3.98mm/year for the Baltic Sea (no GIA correction considered). The obtained results demonstrated a strong link between the atmospheric patterns and SLA, as well as strong long-period fluctuations of this variable in spatial and

Forced Air-Breathing PEMFC Stacks

Directory of Open Access Journals (Sweden)

K. S. Dhathathreyan

2012-01-01

Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

East Siberian Sea, an Arctic region of very high biogeochemical activity

Directory of Open Access Journals (Sweden)

L. G. Anderson

2011-06-01

Full Text Available Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biogeochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO<sub>2sub> that oversaturates all waters from the surface to bottom relative to atmospheric level, even when primary production, inferred from low surface water nutrients, has occurred. The eastern surface waters were under-saturated with respect to CO<sub>2sub> illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of ~0.8 ± 2 mol C m⁻², which when multiplied by half the area of the East Siberian Sea, ~500 000 km², results in an annual primary production of 0.4 (± 1 × 10¹² mol C or ~4 (± 10 × 10¹² gC. Microbial decay occurs through much of the water column, but dominates at the sediment interface where the majority of organic matter ends up, thus more of the decay products are recycled to the bottom water. High nutrient concentrations and fugacity of CO<sub>2sub> and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH<sub>4sub>, was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from

CO<sub>2sub> Problems and waste recycling. Research at the Institute of ferrous metallurgy

OpenAIRE

Gudenau, H. W.; Senk, D.; Babich, A.; Fröhling, C.; Kueon, O. S.; Wang, S.; Wieting, X.

2005-01-01

In a short introduction tests and calculations about CO<sub>2sub>-ice-blocs in the deep sea, use of CO<sub>2sub> for underground-coal-gasification and tertiary processes to increase oil-production by C02-flooding are shown. New activities are presented e.g. CO<sub>2sub>-injection into EAF combined with injection of coal, coke or directreduction-fines. After research of injection of coals, fine ores or dust into blast furnaces and other shaft furnaces ...

Method for monitoring stack gases for uranium activity

International Nuclear Information System (INIS)

Beverly, C.R.; Ernstberger, H.G.

1988-01-01

A method for sampling stack gases emanating from the purge cascade of a gaseous diffusion cascade system utilized to enrich uranium for determining the presence and extent of uranium in the stack gases in the form of gaseous uranium hexafluoride, is described comprising the steps of removing a side stream of gases from the stack gases, contacting the side stream of the stack gases with a stream of air sufficiently saturated with moisture for reacting with and converting any gaseous uranium hexafluroide contracted thereby in the side stream of stack gases to particulate uranyl fluoride. Thereafter contacting the side stream of stack gases containing the particulate uranyl fluoride with moving filter means for continuously intercepting and conveying the intercepted particulate uranyl fluoride away from the side stream of stack gases, and continually scanning the moving filter means with radiation monitoring means for sensing the presence and extent of particulate uranyl fluoride on the moving filter means which is indicative of the extent of particulate uranyl fluoride in the side stream of stack gases which in turn is indicative of the presence and extent of uranium hexafluoride in the stack gases

Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

Directory of Open Access Journals (Sweden)

Xuezhong Yu

2017-01-01

Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub

Flexural characteristics of a stack leg

International Nuclear Information System (INIS)

Cook, J.

1979-06-01

A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

Time-predictable Stack Caching

DEFF Research Database (Denmark)

Abbaspourseyedi, Sahar

completely. Thus, in systems with hard deadlines the worst-case execution time (WCET) of the real-time software running on them needs to be bounded. Modern architectures use features such as pipelining and caches for improving the average performance. These features, however, make the WCET analysis more...... addresses, provides an opportunity to predict and tighten the WCET of accesses to data in caches. In this thesis, we introduce the time-predictable stack cache design and implementation within a time-predictable processor. We introduce several optimizations to our design for tightening the WCET while...... keeping the timepredictability of the design intact. Moreover, we provide a solution for reducing the cost of context switching in a system using the stack cache. In design of these caches, we use custom hardware and compiler support for delivering time-predictable stack data accesses. Furthermore...

Multilayer As{sub 2}Se{sub 3}/GeS{sub 2} quarter wave structures for photonic applications

Energy Technology Data Exchange (ETDEWEB)

Todorov, R; Tasseva, J; Babeva, Tz; Petkov, K, E-mail: rossen@clf.bas.b [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl.109, 1113 Sofia (Bulgaria)

2010-12-22

The optical properties of single layers from As{sub 2}Se{sub 3} and GeS{sub 2}, double-layered stack and quarter-wave multilayer structure consisting of alternating layers from both materials are investigated. For modelling of multilayer coating the thickness dependence of the refractive index of single coatings from both materials is studied. The particularities and scope of application of different spectrophotometric methods for calculation of optical parameters of thin chalcogenide layers are discussed for film thickness, d, in the range {lambda}/25-1.5{lambda} ({lambda} being the operating wavelength). Having acquired the knowledge of optical parameters (refractive index, n, and extinction coefficient, k) of the single layers, we designed and produced a one-dimensional photonic crystal with fundamental reflection band at {lambda} = 850 nm. It was shown that the photoinduced changes of the refractive index of thin chalcogenide films can be used for enhancement of the optical contrast of both materials.

Hexagonal perovskites with cationic vacancies. 26. Ba/sub 12/Ba/sub 2//sub 2/3/M/sub 7//sup V//sub 1/3/vacant/sub 2/O/sub 33/vacant/sub 3/ (Msup(V) =Nb, Ta) - the first stacking polytypes of a rhombohedral 36 L-type

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-05-01

In the systems BaO-M/sub 2//sup V/O/sub 5/ (M/sup V/ = Nb, Ta) for a Ba:M/sup V/ ratio of 2:1 polymorphism is observed. Here the low temperature modifications are described. They crystallize in a rhombohedral 36 L structure with three formula units Ba/sub 12/Ba/sub 2//sub 2/3/M/sub 7//sup V//sub 1/3/vacant/sub 2/O/sub 33/vacant/sub 3/ for the trigonal setting (M/sup V/ = Nb: a = 5.92/sub 2/ A; c = 93./sub 25/ A; Ta: a = 5.92/sub 2/ A; c = 93.4 A).

Hexagonal perovskites with cationic vacancies. 19. The rhombohedral 12 L stacking polytypes Ba/sub 3/LaBsup(III) (W/sub 2/sup(VI)vacantO/sub 12/)

Energy Technology Data Exchange (ETDEWEB)

Rother, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-06-01

Hexagonal perovskites are described for the new type Ba/sub 3/LaBsup(III)(W/sub 2/sup(VI)vacantO/sub 12/) with Bsup(III) = Sc, In, Lu, Yb. According to the intensity calculations for Ba/sub 3/LaIn(W/sub 2/vacantO/sub 12/) they crystallize in a rhombohedral 12 L structure with the sequence (3)(1) respectively (hhcc)/sub 3/; space group R3m. The refined, intensity related R' value is 6.7%.

Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean

NARCIS (Netherlands)

Kleinherenbrink, M.; Riva, R.E.M.; Sun, Y.

2016-01-01

. In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and

Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Koley, Biplab [Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Chatterjee, S. [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Jana, Partha P., E-mail: ppj@chem.iitkgp.ernet.in [Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

2017-02-15

A new phase in the Rh-Cd binary system - Rh{sub 2}Cd{sub 5} has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh{sub 2}Cd{sub 5} crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh{sub 2}Cd{sub 5} can be described as a defect form of the In{sub 3}Pd{sub 5} structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (3{sup 5}) (3{sup 7})- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh{sub 2}Cd{sub 5}. - Graphical abstract: (3.6.3.6)-Kagomé nets of cadmium atoms (top) and (3{sup 5}) (3{sup 7})- nets of both cadmium and rhodium atoms (bottom) in the structure of Rh{sub 2}Cd{sub 5}.

Principles for Instructional Stack Development in HyperCard.

Science.gov (United States)

McEneaney, John E.

The purpose of this paper is to provide information about obtaining and using HyperCard stacks that introduce users to principles of stack development. The HyperCard stacks described are available for downloading free of charge from a server at Indiana University South Bend. Specific directions are given for stack use, with advice for beginners. A…

DBaaS with OpenStack Trove

CERN Document Server

Giardini, Andrea

2013-01-01

The purpose of the project was to evaluate the Trove component for OpenStack, understand if it can be used with the CERN infrastructure and report the benefits and disadvantages of this software. Currently, databases for CERN projects are provided by a DbaaS software developed inside the IT-DB group. This solution works well with the actual infrastructure but it is not easy to maintain. With the migration of the CERN infrastructure to OpenStack the Database group started to evaluate the Trove component. Instead of mantaining an own DbaaS service it can be interesting to migrate everything to OpenStack and replace the actual DbaaS software with Trove. This way both virtual machines and databases will be managed by OpenStack itself.

Nitrogen isotopic studies in the suboxic Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A; Yoshinari, T.; Brandes, J.A; Devol, A; Jayakumar, D.A; Narvekar, P.V.; Altabet, M.A; Codispoti, L.A.

sub(2) and oxygen (O sub(2)), respectively] have been made in water column at several locations in the Arabian Sea, a region with one of the thickest and most intense O sub(2) minima observed in the open ocean. Microbially-mediated reduction of NO sub...

Ultra-thin distributed Bragg reflectors via stacked single-crystal silicon nanomembranes

Energy Technology Data Exchange (ETDEWEB)

Cho, Minkyu; Seo, Jung-Hun; Lee, Jaeseong; Mi, Hongyi; Kim, Munho; Ma, Zhenqiang, E-mail: mazq@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Zhao, Deyin; Zhou, Weidong [Nanophotonics Lab, Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States); Yin, Xin; Wang, Xudong [Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2015-05-04

In this paper, we report ultra-thin distributed Bragg reflectors (DBRs) via stacked single-crystal silicon (Si) nanomembranes (NMs). Mesh hole-free single-crystal Si NMs were released from a Si-on-insulator substrate and transferred to quartz and Si substrates. Thermal oxidation was applied to the transferred Si NM to form high-quality SiO{sub 2} and thus a Si/SiO{sub 2} pair with uniform and precisely controlled thicknesses. The Si/SiO{sub 2} layers, as smooth as epitaxial grown layers, minimize scattering loss at the interface and in between the layers. As a result, a reflection of 99.8% at the wavelength range from 1350 nm to 1650 nm can be measured from a 2.5-pair DBR on a quartz substrate and 3-pair DBR on a Si substrate with thickness of 0.87 μm and 1.14 μm, respectively. The high reflection, ultra-thin DBRs developed here, which can be applied to almost any devices and materials, holds potential for application in high performance optoelectronic devices and photonics applications.

Uma análise das dimensões estratégicas críticas para a internacionalização das empresas brasileiras nos mercados de base da pirâmide (BOP globais

Directory of Open Access Journals (Sweden)

Renata Giovinazzo Spers

2013-01-01

Full Text Available Este trabalho apresenta as dimensões estratégicas c ríticas para atuar em mercados internacionais de Base-da-Pirâmide (BOP. As variáv eis estudadas são motivos para a internacionalização: preços, promoção, distribuição , produtos, inovação, ingresso em mercados e processos. Uma pesquisa descritiva, inve stigativa de vários casos foi desenvolvida com as empresas brasileiras Natura , O Boticário, AmBev, Embraco, Perdigão e Havaianas . Análises longitudinais e comparativas levaram à con clusão que o principal motivo para o ingresso nos mercados BOP internacionais são as mai ores vendas e receitas de longo prazo. Dimensões estratégicas críticas são gestão de marca s, mistura de produtos adequada, inovação do processo, relacionamentos com stakeholders e fortalecimento da cultura corporativa.

“Distributed hybrid” MH–CGH2 system for hydrogen storage and its supply to LT PEMFC power modules

Energy Technology Data Exchange (ETDEWEB)

Lototskyy, M., E-mail: mlototskyy@uwc.ac.za [HySA Systems Competence Centre, South African Institute for Advanced Materials Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Tolj, I.; Davids, M.W.; Bujlo, P. [HySA Systems Competence Centre, South African Institute for Advanced Materials Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Smith, F. [Impala Platinum Ltd, Springs (South Africa); Pollet, B.G. [HySA Systems Competence Centre, South African Institute for Advanced Materials Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa)

2015-10-05

Highlights: • Prototype hydrogen storage and supply system for LTPEMFC applications was developed. • Combination of MH and CGH2 tanks with common gas manifold was used. • Thermal coupling of fuel cell stack and MH tank was applied. • The system uses AB2-type MH; H2 equilibrium pressure ∼10 bar at room temperature. • Shorter H2 charge time and stable H2 supply at a fluctuating load were observed. - Abstract: This paper describes the layout and presents the results of the testing of a novel prototype “distributed hybrid” hydrogen storage and supply system that has the potential to be used for Low Temperature Proton Exchange Membrane Fuel Cell (LT-PEMFC) applications. The system consists of individual Metal Hydride (MH) and Compressed Gas (CGH2) tanks with common gas manifold, and a thermal management system where heat exchanger of the liquid heated-cooled MH tank is integrated with the cooling system of the LT-PEMFC BoP. The MH tank is filled with a medium-stability AB{sub 2}-type MH material (H{sub 2} equilibrium pressure of about 10 bar at room temperature). This innovative solution allows for (i) an increase in hydrogen storage capacity of the whole gas storage system and the reduction of H{sub 2} charge pressure; (ii) shorter charging times in the refuelling mode and smoother peaks of H{sub 2} consumption during its supply to the fuel cell stack; (iii) the use of standard parts with simple layout and lower costs; and (iv) adding flexibility in the layout and placement of the components of the hydrogen storage and supply system.

Stacking the Equiangular Spiral

OpenAIRE

Agrawal, A.; Azabi, Y. O.; Rahman, B. M.

2013-01-01

We present an algorithm that adapts the mature Stack and Draw (SaD) methodology for fabricating the exotic Equiangular Spiral Photonic Crystal Fiber. (ES-PCF) The principle of Steiner chains and circle packing is exploited to obtain a non-hexagonal design using a stacking procedure based on Hexagonal Close Packing. The optical properties of the proposed structure are promising for SuperContinuum Generation. This approach could make accessible not only the equiangular spiral but also other qua...

Stochastic stacking without filters

International Nuclear Information System (INIS)

Johnson, R.P.; Marriner, J.

1982-12-01

The rate of accumulation of antiprotons is a critical factor in the design of p anti p colliders. A design of a system to accumulate higher anti p fluxes is presented here which is an alternative to the schemes used at the CERN AA and in the Fermilab Tevatron I design. Contrary to these stacking schemes, which use a system of notch filters to protect the dense core of antiprotons from the high power of the stack tail stochastic cooling, an eddy current shutter is used to protect the core in the region of the stack tail cooling kicker. Without filters one can have larger cooling bandwidths, better mixing for stochastic cooling, and easier operational criteria for the power amplifiers. In the case considered here a flux of 1.4 x 10 8 per sec is achieved with a 4 to 8 GHz bandwidth

Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

Energy Technology Data Exchange (ETDEWEB)

Popovici, M., E-mail: Mihaela.Ioana.Popovici@imec.be; Swerts, J.; Redolfi, A.; Kaczer, B.; Aoulaiche, M.; Radu, I.; Clima, S.; Everaert, J.-L.; Van Elshocht, S.; Jurczak, M. [Imec, Leuven 3001 (Belgium)

2014-02-24

Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electrically active defects and is essential to achieve a low leakage current in the MIM capacitor.

Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

International Nuclear Information System (INIS)

Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Abid; Mortensen, Henrik Hilleke

2013-01-01

Highlights: ► Developing a general zero dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model for a forklift. ► System performance with different cooling fluids. ► Water and thermal management of fuel cell system. ► Effect of inlet temperature, outlet temperature and temperature gradient on system performance. - Abstract: A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell stack and BOP has been investigated in this study. The results show that humidification of the inlet air is of great importance. By decreasing the relative humidity of inlet air from 95% to 25%, the voltage can drop by 29%. In addition, elevated stack temperature can lead to a higher average cell voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water–ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32–33% in the inner loop and 60–65% in the outer loop for all ranges of current. The system can then be started up at about −25 °C with negligible change in the efficiency

A STACKED ANALYSIS OF 115 PULSARS OBSERVED BY THE FERMI LAT

Energy Technology Data Exchange (ETDEWEB)

McCann, A., E-mail: mccann@kicp.uchicago.edu [Kavli Institute for Cosmological Physics, University of Chicago 933 East 56th Street, Chicago, IL 60637 (United States)

2015-05-10

Due to the low gamma-ray fluxes from pulsars above 50 GeV and the small collecting area of space-based telescopes, the gamma-ray emission discovered by the Fermi Large Area Telescope (LAT) in ∼150 pulsars is largely unexplored at these energies. In this regime, the uncertainties on the spectral data points and/or the constraints from upper limits are not sufficient to provide robust tests of competing emission models in individual pulsars. The discovery of power-law-type emission from the Crab pulsar at energies exceeding 100 GeV provides a compelling justification for exploration of other pulsars at these energies. We applied the method of aperture photometry to measure pulsar emission spectra from Fermi-LAT data and present a stacked analysis of 115 pulsars selected from the Second Fermi-LAT catalog of gamma-ray pulsars. This analysis, which uses an average of ∼4.2 yr of data per pulsar, aggregates low-level emission which cannot be resolved in individual objects but can be detected in an ensemble. We find no significant stacked excess at energies above 50 GeV. An upper limit of 30% of the Crab pulsar level is found for the average flux from 115 pulsars in the 100–177 GeV energy range at the 95% confidence level. Stacked searches exclusive to the young pulsar sample, the millisecond pulsar sample, and several other promising sub-samples also return no significant excesses above 50 GeV.

Assessing Elementary Algebra with STACK

Science.gov (United States)

Sangwin, Christopher J.

2007-01-01

This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

Learning OpenStack networking (Neutron)