Mechanically Strong Lightweight Materials for Aerospace Applications (x-aerogels)

Science.gov (United States)

Leventis, Nicholas

2005-01-01

The X-Aerogel is a new NASA-developed strong lightweight material made by reacting the mesoporous surfaces of 3-D networks of inorganic nanoparticles with polymeric crosslinkers. Since the relative amount of the crosslinker and the backbone are comparable, X-Aerogels can be viewed either as aerogels modified by templated accumulation of polymer on the skeletal nanoparticles, or as nanoporous polymers made by templated casting of polymeric precursors on a nanostructured framework. The most striking feature of X-Aerogels is that for a nominal 3-fold increase in density (still a ultralightweight material), the mechanical strength can be up to 300 times higher than the strength of the underlying native aerogel. Thus, X-Aerogels combine a multiple of the specific compressive strength of steel, with the thermal conductivity of styrofoam. XAerogels have been demonstrated with several polymers such as polyurethanes/polyureas, epoxies and polyolefins, while crosslinking of approximately 35 different oxide aerogels yields a wide variety of dimensionally stable, porous lightweight materials with interesting structural, magnetic and optical properties. X-Aerogels are evaluated for cryogenic rocket fuel storage tanks and for Advanced EVA suits, where they will play the dual role of the thermal insulator/structural material. Along the same lines, major impact is also expected by the use of X-Aerogels in structural components/thermal protection for small satellites, spacecrafts, planetary vehicles and habitats.

PREFACE: Strongly correlated electron systems Strongly correlated electron systems

Science.gov (United States)

Saxena, Siddharth S.; Littlewood, P. B.

2012-07-01

This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

Science.gov (United States)

Wang, Hailiang; Dai, Hongjie

2013-04-07

The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC

Magnetic properties of FeNi-based thin film materials with different additives

KAUST Repository

Liang, C.; Gooneratne, C.P.; Wang, Q.X.; Liu, Y.; Gianchandani, Y.; Kosel, Jü rgen

2014-01-01

This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials

Low-temperature fabrication of mesoporous solid strong bases by using multifunction of a carbon interlayer.

Science.gov (United States)

Liu, Xiao-Yan; Sun, Lin-Bing; Liu, Xiao-Dan; Li, Ai-Guo; Lu, Feng; Liu, Xiao-Qin

2013-10-09

Mesoporous solid strong bases are highly promising for applications as environmentally benign catalysts in various reactions. Their preparation attracts increasing attention for the demand of sustainable chemistry. In the present study, a new strategy was designed to fabricate strong basicity on mesoporous silica by using multifunction of a carbon interlayer. A typical mesoporous silica, SBA-15, was precoated with a layer of carbon prior to the introduction of base precursor LiNO3. The carbon interlayer performs two functions by promoting the conversion of LiNO3 at low temperatures and by improving the alkali-resistant ability of siliceous host. Only a tiny amount of LiNO3 was decomposed on pristine SBA-15 at 400 °C; for the samples containing >8 wt % of carbon, however, LiNO3 can be entirely converted to strongly basic sites Li2O under the same conditions. The guest-host redox reaction was proven to be the answer for the conversion of LiNO3, which breaks the tradition of thermally induced decomposition. More importantly, the residual carbon layer can prevent the siliceous frameworks from corroding by the newly formed strongly basic species, which is different from the complete destruction of mesostructure in the absence of carbon. Therefore, materials possessing both ordered mesostructure and strong basicity were successfully fabricated, which is extremely desirable for catalysis and impossible to realize by conventional methods. We also demonstrated that the resultant mesoporous basic materials are active in heterogeneous synthesis of dimethyl carbonate (DMC) and the yield of DMC can reach 32.4%, which is apparently higher than that over the catalysts without a carbon interlayer (<12.9%) despite the same lithium content. The strong basicity, in combination with the uniform mesopores, is believed to be responsible for such a high activity.

Nonlinear phononics and structural control of strongly correlated materials

Energy Technology Data Exchange (ETDEWEB)

Mankowsky, Roman

2016-01-20

Mid-infrared light pulses can be used to resonantly excite infrared-active vibrational modes for the phase control of strongly correlated materials on subpicosecond timescales. As the energy is transferred directly into atomic motions, dissipation into the electronic system is reduced, allowing for the emergence of unusual low energy collective properties. Light-induced superconductivity, insulator-metal transitions and melting of magnetic order demonstrate the potential of this method. An understanding of the mechanism, by which these transitions are driven, is however missing. The aim of this work is to uncover this process by investigating the nonlinear lattice dynamics induced by the excitation and to elucidate their contribution to the modulation of collective properties of strongly correlated materials. The first signature of nonlinear lattice dynamics was reported in the observation of coherent phonon oscillations, resonant with the excitation of an infrared-active phonon mode in a manganite. This nonlinear phononic coupling can be described within a model, which predicts not only oscillatory coherent phonons dynamics but also directional atomic displacements along the coupled modes on average, which could cause the previously observed transitions. We verified this directional response and quantified the anharmonic coupling constant by tracing the atomic motions in a time-resolved hard X-ray diffraction experiment with sub-picometer spatial and femtosecond temporal resolution. In a subsequent study, we investigated the role of nonlinear lattice dynamics in the emergence of superconductivity far above the equilibrium transition temperature, an intriguing effect found to follow lattice excitation of YBa{sub 2}Cu{sub 3}O{sub 6+x}. By combining density functional theory (DFT) calculations of the anharmonic coupling constants with time-resolved X-ray diffraction experiments, we identified a structural rearrangement, which appears and decays with the same temporal

Laser based imaging of time depending microscopic scenes with strong light emission

Science.gov (United States)

Hahlweg, Cornelius; Wilhelm, Eugen; Rothe, Hendrik

2011-10-01

Investigating volume scatterometry methods based on short range LIDAR devices for non-static objects we achieved interesting results aside the intended micro-LIDAR: the high speed camera recording of the illuminated scene of an exploding wire -intended for Doppler LIDAR tests - delivered a very effective method of observing details of objects with extremely strong light emission. As a side effect a schlieren movie is gathered without any special effort. The fact that microscopic features of short time processes with high emission and material flow might be imaged without endangering valuable equipment makes this technique at least as interesting as the intended one. So we decided to present our results - including latest video and photo material - instead of a more theoretical paper on our progress concerning the primary goal.

Solid-state dewetting and island morphologies in strongly anisotropic materials

International Nuclear Information System (INIS)

Jiang, Wei; Wang, Yan; Zhao, Quan; Srolovitz, David J.; Bao, Weizhu

2016-01-01

We propose a sharp-interface continuum model based on a thermodynamic variational approach to investigate the strong anisotropic effect on solid-state dewetting including contact line dynamics. For sufficiently strong surface energy anisotropy, we show that multiple equilibrium shapes may appear that cannot be described by the widely employed Winterbottom construction, i.e., the modified Wulff construction for an island on a substrate. We repair the Winterbottom construction to include multiple equilibrium shapes and employ our evolution model to demonstrate that all such shapes are dynamically accessible.

Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

OpenAIRE

Musa Ahmad; T.W. Tan

2017-01-01

An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to ...

Binary-collision-approximation-based simulation of noble gas irradiation to tungsten materials

International Nuclear Information System (INIS)

Saito, Seiki; Takayama, Arimichi; Ito, Atsushi M.; Nakamura, Hiroaki

2013-01-01

To reveal the possibility of fuzz formation of tungsten material under noble gas irradiation, helium, neon, and argon atom injections into tungsten materials are performed by binary-collision-approximation-based simulation. The penetration depth is strongly depends on the structure of the target material. Therefore, the penetration depth for amorphous and bcc crystalline structure is carefully investigated in this paper

Computational time-resolved and resonant x-ray scattering of strongly correlated materials

Energy Technology Data Exchange (ETDEWEB)

Bansil, Arun [Northeastern Univ., Boston, MA (United States)

2016-11-09

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source, literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspects of this grand challenge of x-ray science. In particular, our Collaborative Research Team (CRT) focused on developing viable computational schemes for modeling x-ray scattering and photoemission spectra of strongly correlated materials in the time-domain. The vast arsenal of formal/numerical techniques and approaches encompassed by the members of our CRT were brought to bear through appropriate generalizations and extensions to model the pumped state and the dynamics of this non-equilibrium state, and how it can be probed via x-ray absorption (XAS), emission (XES), resonant and non-resonant x-ray scattering, and photoemission processes. We explored the conceptual connections between the time-domain problems and other second-order spectroscopies, such as resonant inelastic x-ray scattering (RIXS) because RIXS may be effectively thought of as a pump-probe experiment in which the incoming photon acts as the pump, and the fluorescent decay is the probe. Alternatively, when the core-valence interactions are strong, one can view K-edge RIXS for example, as the dynamic response of the material to the transient presence of a strong core-hole potential. Unlike an actual pump-probe experiment, here there is no mechanism for adjusting the time-delay between the pump and the probe. However, the core hole

Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

Directory of Open Access Journals (Sweden)

Musa Ahmad

2017-11-01

Full Text Available An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to any pH changes and could be used to determine the end-point of the acid-base titration.

Strong Sporadic E Occurrence Detected by Ground-Based GNSS

Science.gov (United States)

Sun, Wenjie; Ning, Baiqi; Yue, Xinan; Li, Guozhu; Hu, Lianhuan; Chang, Shoumin; Lan, Jiaping; Zhu, Zhengping; Zhao, Biqiang; Lin, Jian

2018-04-01

The ionospheric sporadic E (Es) layer has significant impact on radio wave propagation. The traditional techniques employed for Es layer observation, for example, ionosondes, are not dense enough to resolve the morphology and dynamics of Es layer in spatial distribution. The ground-based Global Navigation Satellite Systems (GNSS) technique is expected to shed light on the understanding of regional strong Es occurrence, owing to the facts that the critical frequency (foEs) of strong Es structure is usually high enough to cause pulse-like disturbances in GNSS total electron content (TEC), and a large number of GNSS receivers have been deployed all over the world. Based on the Chinese ground-based GNSS networks, including the Crustal Movement Observation Network of China and the Beidou Ionospheric Observation Network, a large-scale strong Es event was observed in the middle latitude of China. The strong Es shown as a band-like structure in the southwest-northeast direction extended more than 1,000 km. By making a comparative analysis of Es occurrences identified from the simultaneous observations by ionosondes and GNSS TEC receivers over China middle latitude statistically, we found that GNSS TEC can be well employed to observe strong Es occurrence with a threshold value of foEs, 14 MHz.

3D printable highly conductive and mechanically strong thermoplastic-based nanocomposites

Science.gov (United States)

Tabiai, Ilyass; Therriault, Daniel

Highly conductive 3D printable inks can be used to design electrical devices with various functionalities and geometries. We use the solvent evaporation assisted 3D-printing method to create high resolution structures made of poly(lactid) acid (PLA) reinforced with multi-walled carbon nanotube (MWCNTs). We characterize fibers with diameters ranging between 100 μm to 330 μm and reinforced with MWCNTs from 0.5 up to 40wt% here. Tensile test, shrinkage ratio, density and electrical conductivity measurements of the printed nanocomposite are presented. The material's electrical conductivity is strongly improved by adding MWCNTs (up to 3000S/m), this value was found to be higher than any 3D-printable carbon based material available in the literature. It is observed that MWCNTs significantly increase the material's strength and stiffness while reducing its ductility. The ink's density was also higher while still being in the range of polymers' densities. The presented nanocomposite is light weight, highly conductive, has good mechanical properties and can be printed in a freeform fashion at the micro scale. A myriad of low power consumption with less resistive heating sensors and devices can potentially be designed using it and integrated into other 3D printable products.

Exceptionally strong, stiff and hard hybrid material based on an elastomer and isotropically shaped ceramic nanoparticles.

Science.gov (United States)

Georgopanos, Prokopios; Schneider, Gerold A; Dreyer, Axel; Handge, Ulrich A; Filiz, Volkan; Feld, Artur; Yilmaz, Ezgi D; Krekeler, Tobias; Ritter, Martin; Weller, Horst; Abetz, Volker

2017-08-04

In this work the fabrication of hard, stiff and strong nanocomposites based on polybutadiene and iron oxide nanoparticles is presented. The nanocomposites are fabricated via a general concept for mechanically superior nanocomposites not based on the brick and mortar structure, thus on globular nanoparticles with nanosized organic shells. For the fabrication of the composites oleic acid functionalized iron oxide nanoparticles are decorated via ligand exchange with an α,ω-polybutadiene dicarboxylic acid. The functionalized particles were processed at 145 °C. Since polybutadiene contains double bonds the nanocomposites obtained a crosslinked structure which was enhanced by the presence of oxygen or sulfur. It was found that the crosslinking and filler percolation yields high elastic moduli of approximately 12-20 GPa and hardness of 15-18 GPa, although the polymer volume fraction is up to 40%. We attribute our results to a catalytically enhanced crosslinking reaction of the polymer chains induced by oxygen or sulfur and to the microstructure of the nanocomposite.

Ultra-thin and strong formvar-based membranes with controlled porosity for micro- and nano-scale systems

Science.gov (United States)

Auchter, Eric; Marquez, Justin; Stevens, Garrison; Silva, Rebecca; Mcculloch, Quinn; Guengerich, Quintessa; Blair, Andrew; Litchfield, Sebastian; Li, Nan; Sheehan, Chris; Chamberlin, Rebecca; Yarbro, Stephen L.; Dervishi, Enkeleda

2018-05-01

We present a methodology for developing ultra-thin and strong formvar-based membranes with controlled morphologies. Formvar is a thin hydrophilic and oleophilic polymer inert to most chemicals and resistant to radiation. The formvar-based membranes are viable materials as support structures in micro- and macro-scale systems depending on thinness and porosity control. Tunable sub-micron thick porous membranes with 20%–65% porosity were synthesized by controlling the ratios of formvar, glycerol, and chloroform. This synthesis process does not require complex separation or handling methods and allows for the production of strong, thin, and porous formvar-based membranes. An expansive array of these membrane characterizations including chemical compatibility, mechanical responses, wettability, as well as the mathematical simulations as a function of porosity has been presented. The wide range of chemical compatibility allows for membrane applications in various environments, where other polymers would not be suitable. Our formvar-based membranes were found to have an elastic modulus of 7.8 GPa, a surface free energy of 50 mN m‑1 and an average thickness of 125 nm. Stochastic model simulations indicate that formvar with the porosity of ∼50% is the optimal membrane formulation, allowing the most material transfer across the membrane while also withstanding the highest simulated pressure loadings before tearing. Development of novel, resilient and versatile membranes with controlled porosity offers a wide range of exciting applications in the fields of nanoscience, microfluidics, and MEMS.

Advanced Materials for Health Monitoring with Skin-Based Wearable Devices.

Science.gov (United States)

Jin, Han; Abu-Raya, Yasmin Shibli; Haick, Hossam

2017-06-01

Skin-based wearable devices have a great potential that could result in a revolutionary approach to health monitoring and diagnosing disease. With continued innovation and intensive attention to the materials and fabrication technologies, development of these healthcare devices is progressively encouraged. This article gives a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to recent advances and developments in the scope of skin-based wearable devices (e.g. temperature, strain, biomarker-analysis werable devices, etc.), with an emphasis on emerging materials and fabrication techniques in the relevant fields. To give a comprehensive statement, part of the review presents and discusses different aspects of these advanced materials, such as the sensitivity, biocompatibility and durability as well as the major approaches proposed for enhancing their chemical and physical properties. A complementary section of the review linking these advanced materials with wearable device technologies is particularly specified. Some of the strong and weak points in development of each wearable material/device are highlighted and criticized. Several ideas regarding further improvement of skin-based wearable devices are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiation-induced structural transitions in composite materials with strong interaction of polymer components

International Nuclear Information System (INIS)

Zaikin, Yu.A.; Koztaeva, U.P.

2002-01-01

In earlier papers the internal friction (IF) method was applied to studies of structural relaxation in different types of polymer-based composite materials (glass-cloth, paper-based and foiled laminates impregnated by epoxy and phenolic resins) irradiated by 2 MeV electrons in the dose range of 0.1-50.0 MGy. Selectivity and high sensibility of the internal friction method allowed to distinguish glassy transitions in different structural components of the composites. The relaxation processes observed were identified and attributed to structural alterations in the polymer filler, the binder and the boundary layers. It was shown that changes in the parameters of relaxation maximums during irradiation can be considered as quantitative characteristics for the degree of radiation-induced degradation or cross-linking of polymer molecules. This paper deals with specific features of IF spectra in paper-based laminates where both the filler fibers and the binder are strongly interacting polymers. Anisotropy of viscous and elastic properties is very weak for this kind of materials, so that IF measurements give nearly the same result independently on the filler fiber orientation in the sample. The main reasons for it are the rigid chain structure of fillers (polyethylene-terephthalate and cellulose) and the good adhesion strengthened by diffusion of the epoxy or phenolic binder to defect regions of the filler.The IF temperature dependence observed in paper-based laminates is represented by superposition of two very broad relaxation maximums associated with transitions from glassy to high-elastic state in structural components, each based on one of the polymers. The inflection points characteristic for IF temperature dependence in paper-based laminates give a reason to treat them as a superposition of α-peaks associated with transitions from glassy to high-elastic state in structural components of a composite based on the binder and the filler, respectively. Another

LDEF materials data bases

Science.gov (United States)

Funk, Joan G.; Strickland, John W.; Davis, John M.

1993-01-01

The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

Characterization of weak, fair and strong neutron absorbing materials by means of neutron transmission: Beam hardening effect

Science.gov (United States)

Kharfi, F.; Bastuerk, M.; Boucenna, A.

2006-09-01

The characterization of neutron absorbing materials as well as quantification of neutron attenuation through matter is very essential in various fields, namely in shielding calculation. The objective of this work is to describe an experimental procedure to be used for the determination of neutron transmission through different materials. The proposed method is based on the relation between the gray value measured on neutron radiography image and the corresponding inducing neutron beam. For such a purpose, three kinds of materials (in shape of plate) were investigated using thermal neutrons: (1) boron-alloyed stainless steel as strong absorber; (2) copper and steel as fair absorbers and (3) aluminum as weak absorber. This work is not limited to the determination of neutron transmission through matters; it is also spread out to the measure of the surface density of the neutron absorbing elements (ρs) as a function of thickness of neutron absorbing material such as boron-alloyed stainless steel. The beam hardening effect depending on material thickness was also studied using the neutron transmission measurements. A theoretical approach was used to interpret the experimental results. The neutron transmission measurements were performed at the Neutron Radiography and Tomography facility of the Atomic Institute of the Austrian Universities in Vienna. Finally, a Maxwellian neutron distribution of incident neutron beam was used in the theoretical calculations of neutron energy shift in order to compare with experiments results. The obtained experimental results are in a good agreement with the developed theoretical approach.

Strong industrial base vital for economic revival

CERN Multimedia

2001-01-01

At the inauguration of a 2-day conference on nuclear technology in Islamabad, the chairman of PAEC said that Pakistan needs to develop a strong industrial base and capability to export equipment to improve the economic condition of the country. He descibed how Pakistan has already had a breakthrough with the export of equipment to CERN, Geneva (1 page).

Membrane materials based on polyheteroarylenes and their application for pervaporation

International Nuclear Information System (INIS)

Pulyalina, A Yu; Polotskaya, G A; Toikka, A M

2016-01-01

Studies on the transport properties of membrane materials are topical in connection with the need to solve the fundamental problems and to analyze the applied aspects of the theory of membrane separation processes including, in particular, the development of the energy- and resource-saving, environmentally safe technologies. The aim of the review is to generalize the experimental data on the separation of practically valuable mixtures using membranes based on polyheteroarylenes (thermally stable and mechanically strong polymers). First of all, our analysis covers publications that give a detailed description of the physicochemical properties of the membranes and an interpretation of the specific features of mass transfer during pervaporation of liquid mixtures using membrane materials based on polyheteroarylenes. The dependences of the transport parameters of pervaporation on the process conditions and on the methods for production of membrane materials are discussed. The data presented may be useful for the development of the theory of membrane processes taking into account the chemical nature and physicochemical features of polymeric membrane materials. The bibliography includes 151 references

Tough hybrid ceramic-based material with high strength

International Nuclear Information System (INIS)

Guo, Shuqi; Kagawa, Yutaka; Nishimura, Toshiyuki

2012-01-01

This study describes a tough and strong hybrid ceramic material consisting of platelet-like zirconium compounds and metal. A mixture of boron carbide and excess zirconium powder was heated to 1900 °C using a liquid-phase reaction sintering technique to produce a platelet-like ZrB 2 -based hybrid ceramic bonded by a thin zirconium layer. The platelet-like ZrB 2 grains were randomly present in the as-sintered hybrid ceramic. Relative to non-hybrid ceramics, the fracture toughness and flexural strength of the hybrid ceramic increased by approximately 2-fold.

Adler Award Lecture: Fermi-Liquid Instabilities in Strongly Correlated f-Electron Materials.^*

Science.gov (United States)

Maple, M. Brian

1996-03-01

Strongly correlated f-electron materials are replete with novel electronic states and phenomena ; e. g. , a metallic ``heavy electron'' state with a quasiparticle effective mass of several hundred times the free electron mass, anisotropic superconductivity with an energy gap that may vanish at points or along lines on the Fermi surface, the coexistence of superconductivity and antiferromagnetism over different parts of the Fermi surface, multiple superconducting phases in the hyperspace of chemical composition, temperature, pressure, and magnetic field, and an insulating phase, in so-called ``hybridization gap semiconductors'' or ``Kondo insulators'', with a small energy gap of only a few meV. During the last several years, a new low temperature non-Fermi-liquid (NFL) state has been observed in a new class of strongly correlated f-electron materials which currently consists of certain Ce and U intermetallics into which a nonmagnetic element has been substituted.(M. B. Maple et al./) , J. Low Temp. Phys. 99 , 223 (1995). The Ce and U ions have partially-filled f-electron shells and carry magnetic dipole or electric quadrupole moments which interact with the spins and charges of the conduction electrons and can participate in magnetic or quadrupolar ordering at low temperatures. The physical properties of these materials exhibit weak power law or logarithmic divergences in temperature and suggest the existence of a critical point at T=0 K. Possible origins of the 0 K critical point include an unconventional moment compensation process, such as a multichannel Kondo effect, and fluctuations of the order parameter in the vicinity of a 0 K second order phase transition. In some systems, such as Y_1-xU_xPd 3 and U_1-xTh_xPd _2Al 3 , the NFL characteristics appear to be single ion effects since they persist to low concentrations of f-moments, whereas in other systems, such as CeCu _5.9Au _0.1 , the NFL behavior seems to be associated with interactions between the f

Basicities of Strong Bases in Water: A Computational Study

OpenAIRE

Kaupmees, Karl; Trummal, Aleksander; Leito, Ivo

2014-01-01

Aqueous pKa values of strong organic bases – DBU, TBD, MTBD, different phosphazene bases, etc – were computed with CPCM, SMD and COSMO-RS approaches. Explicit solvent molecules were not used. Direct computations and computations with reference pKa values were used. The latter were of two types: (1) reliable experimental aqueous pKa value of a reference base with structure similar to the investigated base or (2) reliable experimental pKa value in acetonitrile of the investigated base itself. ...

Vanadium based materials as electrode materials for high performance supercapacitors

Science.gov (United States)

Yan, Yan; Li, Bing; Guo, Wei; Pang, Huan; Xue, Huaiguo

2016-10-01

As a kind of supercapacitors, pseudocapacitors have attracted wide attention in recent years. The capacitance of the electrochemical capacitors based on pseudocapacitance arises mainly from redox reactions between electrolytes and active materials. These materials usually have several oxidation states for oxidation and reduction. Many research teams have focused on the development of an alternative material for electrochemical capacitors. Many transition metal oxides have been shown to be suitable as electrode materials of electrochemical capacitors. Among them, vanadium based materials are being developed for this purpose. Vanadium based materials are known as one of the best active materials for high power/energy density electrochemical capacitors due to its outstanding specific capacitance and long cycle life, high conductivity and good electrochemical reversibility. There are different kinds of synthetic methods such as sol-gel hydrothermal/solvothermal method, template method, electrospinning method, atomic layer deposition, and electrodeposition method that have been successfully applied to prepare vanadium based electrode materials. In our review, we give an overall summary and evaluation of the recent progress in the research of vanadium based materials for electrochemical capacitors that include synthesis methods, the electrochemical performances of the electrode materials and the devices.

Novel high-strength Fe-based composite materials with large plasticity

Energy Technology Data Exchange (ETDEWEB)

Werniewicz, Katarzna; Kuehn, Uta; Mattern, Norbert; Eckert, Juergen; Siegel, Uwe; Bartusch, Birgit; Schultz, Ludwig [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Kulik, Tadeusz [Warsaw University of Technology, Faculty of Materials Science and Engineering (Poland)

2007-07-01

Among glass-forming alloy systems reported so far, Fe-based bulk metallic glasses play a special role. Compared to other amorphous alloys e.g. Zr-, Ti-based, such glasses show superior mechanical strength. However, due to the general brittleness their wider application as structural materials is strongly restricted. The alternative approach to overcome this defect is to design BMG composites. In this work we present a series of new Fe-Cr-Mo-Ga-(Si,C) composite materials derived from an Fe-Cr-Mo-Ga-C-P-B glassy alloy, with the aim to improve the ductility of this high-strength material. The effect of the composition and the phase formation on the resulting mechanical properties was investigated. It has been found that the formation of a complex microstructure, which essentially consists of soft Ga-rich dendrites embedded in a hard Cr- and Mo-rich matrix, leads to a material with excellent compressive mechanical properties. While the obtained values of true strength are comparable with data reported for Fe-Cr-Mo-Ga-C-P-B BMG, the values of true strain are greatly improved for investigated composites.

Biopolymer-based hydrogels as injectable materials for tissue repair scaffolds

International Nuclear Information System (INIS)

Fiejdasz, Sylwia; Szczubiałka, Krzysztof; Lewandowska-Łańcucka, Joanna; Nowakowska, Maria; Osyczka, Anna M

2013-01-01

The progress in tissue regeneration is strongly dependent on the development of biocompatible materials with properties resembling those of a native tissue. Also, the application of noninvasive methods of delivering the scaffold into the tissue defect is of great importance. In this study we present a group of biopolymer-based materials as potential injectable scaffolds. In contrast to other studies involving collagen neutralization or additional incubation of gel in genipin solution, we propose collagen and collagen–chitosan gels crosslinked in situ with genipin. Since some parameters of the cells should be considered in the microscale, the steady-state fluorescence anisotropy was applied to study the microenvironment of the gels. To our knowledge we are the first to report on microrheological properties, such as gel time and microviscosity, for this group of hydrogels. Rapid gelation at physiological temperatures found makes these materials of special interest in applications requiring gel injectability. Physico-chemical investigation showed the influence of the crosslinking agent concentration and chitosan addition on the crosslinking degree, swelling ratio, gel microviscosity, and the degradation rate. Strong correlation was revealed between the surface wettability and the viability of cultured mesenchymal stem cells. Cytotoxicity studies indicated that the collagen–chitosan hydrogels showed the best biocompatibility. (paper)

Modelling decreased food chain accumulation of HOCs due to strong sorption to carbonaceous materials and metabolic transformation

NARCIS (Netherlands)

Moermond, C.T.A.; Traas, T.P.; Roessink, I.; Veltman, K.; Hendriks, A.J.; Koelmans, A.A.

2007-01-01

The predictive power of bioaccumulation models may be limited when they do not account for strong sorption of organic contaminants to carbonaceous materials (CM) such as black carbon, and when they do not include metabolic transformation. We tested a food web accumulation model, including sorption

Electrical switching of antiferromagnets via strongly spin-orbit coupled materials

Science.gov (United States)

Li, Xi-Lai; Duan, Xiaopeng; Semenov, Yuriy G.; Kim, Ki Wook

2017-01-01

Electrically controlled ultra-fast switching of an antiferromagnet (AFM) is shown to be realizable by interfacing it with a material of strong spin-orbit coupling. The proximity interaction between the sublattice magnetic moments of a layered AFM and the spin-polarized free electrons at the interface offers an efficient way to manipulate antiferromagnetic states. A quantitative analysis, using the combination with a topological insulator as an example, demonstrates highly reliable 90° and 180° rotations of AFM magnetic states under two different mechanisms of effective torque generation at the interface. The estimated switching speed and energy requirement are in the ps and aJ ranges, respectively, which are about two-three orders of magnitude better than the ferromagnetic counterparts. The observed differences in the magnetization dynamics may explain the disparate characteristic responses. Unlike the usual precessional/chiral motions in the ferromagnets, those of the AFMs can essentially be described as a damped oscillator with a more direct path. The impact of random thermal fluctuations is also examined.

Materials And Processes Technical Information System (MAPTIS) LDEF materials data base

Science.gov (United States)

Funk, Joan G.; Strickland, John W.; Davis, John M.

1993-01-01

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated from LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux) and author(s) or principal investigator(s). Tne LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which has been computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. The LDEF Materials Data Base is described and step-by-step example searches using the data base are included. Information on how to become an authorized user of the system is included.

Pakistan strong industrial base urged for economic progress

CERN Multimedia

2001-01-01

A conference organized by Pakistan Nuclear Society urged that Pakistan should develop a strong industrial base and capability to export equipment for economic progress. The chairmen of PAEC pointed out that Pakistan is already showing remarkable progress in export of science-related equipment to CERN. He also asked scientists to wage a war against Pakistans inability to acquire indigenous technology (1 page).

Precious-metal-base advanced materials

International Nuclear Information System (INIS)

Nowicki, T.; Carbonnaux, C.

1993-01-01

Precious metals constitute also the base of several advanced materials used in the industry in hundreds of metric tons. Platinum alloys have been used as structural materials for equipments in the glass industry. The essential reason for this is the excellent resistance of platinum alloys to oxidation and electrolytical corrosion in molten glasses at temperatures as high as 1200-1500 C. The major drawback is a weak creep resistance. The unique way for significant improvement of platinum base materials creep resistance is a strengthening by an oxide dispersion (ODS). In the case of CLAL's patented ''Plativer'' materials, 0.05 wt% of Y 2 O 3 is incorporated within the alloy matrix by the flame spraying process. Further improvement of platinum base materials is related, in the authors opinion, to the development of precious metals base intermetallics. Another interesting applications of precious metals are silver base electrical contacts. They are in fact silver matrix composites containing varying amounts of well-dispersed particles of constituents such as CdO, SnO 2 , Ni, WC or C. In the case of such materials, particular properties are required and tested : resistance to arc erosion, resistance to welding and contact resistance. Many other technically fascinating precious metals base materials exist: brazing alloys for assembling metals, superconductors and ceramics; dental materials including magnetic biocompatible alloys; silver composites for superconductor wire jackets. The observation of current evolution indicates very clearly that precious metals cannot be replaced by common metals because of their unique characteristics due to their atomic level properties

Ultrathin nanosheets of Mn3O4: A new two-dimensional ferromagnetic material with strong magnetocrystalline anisotropy

Science.gov (United States)

Wu, Jun-Chi; Peng, Xu; Guo, Yu-Qiao; Zhou, Hao-Dong; Zhao, Ji-Yin; Ruan, Ke-Qin; Chu, Wang-Sheng; Wu, Changzheng

2018-06-01

Two-dimensional (2D) materials with robust ferromagnetism have played a key role in realizing nextgeneration spin-electronic devices, but many challenges remain, especially the lack of intrinsic ferromagnetic behavior in almost all 2D materials. Here, we highlight ultrathin Mn3O4 nanosheets as a new 2D ferromagnetic material with strong magnetocrystalline anisotropy. Magnetic measurements along the in-plane and out-of-plane directions confirm that the out-of-plane direction is the easy axis. The 2D-confined environment and Rashba-type spin-orbit coupling are thought to be responsible for the magnetocrystalline anisotropy. The robust ferromagnetism in 2D Mn3O4 nanosheets with magnetocrystalline anisotropy not only paves a new way for realizing the intrinsic ferromagnetic behavior in 2D materials but also provides a novel candidate for building next-generation spin-electronic devices.

Numerical simulation of strong evaporation and condensation for plasma-facing materials

International Nuclear Information System (INIS)

Kunugi, T.; Yasuda, H.

1994-01-01

The thermal response of the divertor plate to the hard plasma disruptions had been analyzed numerically by the two dimensional transient heat transfer code. There are several studies of the vapor shielding effects on the thermal response to the plasma disruption. However, it was pointed out some discrepancies among the numerical results calculated by U.S., EC and Japan for the same disruption conditions by van der Laan. One of the authors studied the sensitivity of some parameters (i.e., the temperature dependency of the thermal properties, an evaporation coefficient and a saturated condensation ratio) of disruption erosion analysis. Though the authors expected that the variations in evaporation models lead to the large variety of the erosion, they gave no significant effects on the surface temperature, the evaporation and melt-layer thickness. In this paper, the authors will describe the development of the numerical simulation codes for the strong evaporation and condensation from the plasma facing materials (PFMs) such as carbon, tungsten and beryllium

EPR-based material modelling of soils

Science.gov (United States)

Faramarzi, Asaad; Alani, Amir M.

2013-04-01

In the past few decades, as a result of the rapid developments in computational software and hardware, alternative computer aided pattern recognition approaches have been introduced to modelling many engineering problems, including constitutive modelling of materials. The main idea behind pattern recognition systems is that they learn adaptively from experience and extract various discriminants, each appropriate for its purpose. In this work an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR). EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial tests are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well-known conventional material models and it is shown that EPR-based models can provide a better prediction for the behaviour of soils. The main benefits of using EPR-based material models are that it provides a unified approach to constitutive modelling of all materials (i.e., all aspects of material behaviour can be implemented within a unified environment of an EPR model); it does not require any arbitrary choice of constitutive (mathematical) models. In EPR-based material models there are no material parameters to be identified. As the model is trained directly from experimental data therefore, EPR-based material models are the shortest route from experimental research (data) to numerical modelling. Another advantage of EPR-based constitutive model is that as more experimental data become available, the quality of the EPR prediction can be improved by learning from the additional data, and therefore, the EPR model can become more effective and robust. The developed EPR-based material models can be incorporated in finite element (FE) analysis.

Casting fine grained, fully dense, strong inorganic materials

Science.gov (United States)

Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

2015-11-24

Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

Strong Coupling between Plasmons and Organic Semiconductors

Directory of Open Access Journals (Sweden)

Joel Bellessa

2014-05-01

Full Text Available In this paper we describe the properties of organic material in strong coupling with plasmon, mainly based on our work in this field of research. The strong coupling modifies the optical transitions of the structure, and occurs when the interaction between molecules and plasmon prevails on the damping of the system. We describe the dispersion relation of different plasmonic systems, delocalized and localized plasmon, coupled to aggregated dyes and the typical properties of these systems in strong coupling. The modification of the dye emission is also studied. In the second part, the effect of the microscopic structure of the organics, which can be seen as a disordered film, is described. As the different molecules couple to the same plasmon mode, an extended coherent state on several microns is observed.

Femtosecond laser ablation of single-wall carbon nanotube-based material

International Nuclear Information System (INIS)

Danilov, Pavel A; Ionin, Andrey A; Kudryashov, Sergey I; Makarov, Sergey V; Mel’nik, Nikolay N; Rudenko, Andrey A; Yurovskikh, Vladislav I; Zayarny, Dmitry V; Lednev, Vasily N; Obraztsova, Elena D; Pershin, Sergey M; Bunkin, Alexey F

2014-01-01

Single- and multi-shot femtosecond laser surface ablation of a single-wall carbon nanotube-based substrate at 515- and 1030 nm wavelengths was studied by scanning electron microscopy and micro-Raman spectroscopy. The laser ablation proceeds in two ways: as the low-fluence mesoscopic shallow disintegration of the surface nanotube packing, preserving the individual integrity and the semiconducting character of the nanotubes or as the high-fluence deep material removal apparently triggered by the strong intrinsic or impurity-mediated ablation of the individual carbon nanotubes on the substrate surface. (letter)

Electron dynamics in metals and semiconductors in strong THz fields

DEFF Research Database (Denmark)

Jepsen, Peter Uhd

2017-01-01

Semiconductors and metals respond to strong electric fields in a highly nonlinear fashion. Using single-cycle THz field transients it is possible to investigate this response in regimes not accessible by transport-based measurements. Extremely high fields can be applied without material damage...

Feasibility of coal fly ash based bricks and roof tiles as construction materials: a review

Directory of Open Access Journals (Sweden)

Akhtar M.N.

2017-01-01

Full Text Available The aim of present study is to investigate about the potential use of coal fly ash along with other natural and solid wastes for the production of coal fly ash based bricks and roof tiles. The study is based on the comprehensive reviews available from the previous experimental data on coal fly ash based bricks and roof tiles. The study intendeds to provide the essential technical information and data for the use of fly ash mix with other solid wastes and reveal their suitability as construction materials. It has been found that samples were non-hazardous in nature and vigorously used as an additional construction materials and their compositions are perfectly fit to make the strong composite material for bricks and tiles. The three past studies have been demonstrated that, fly ash based bricks and roof tiles provides a sustainable supplement to the traditional clay bricks and roof tiles, that not only increases the efficiency of traditional bricks and roof tiles but also helps significantly to reduce the environmental issues associated with the disposal of these waste materials. In addition to this study highlights the potential use of fly ash for producing sustainable construction materials.

Use of Synergistic Interactions to Fabricate Strong, Tough, and Conductive Artificial Nacre Based on Graphene Oxide and Chitosan.

Science.gov (United States)

Wan, Sijie; Peng, Jingsong; Li, Yuchen; Hu, Han; Jiang, Lei; Cheng, Qunfeng

2015-10-27

Graphene is the strongest and stiffest material, leading to the development of promising applications in many fields. However, the assembly of graphene nanosheets into macrosized nanocomposites for practical applications remains a challenge. Nacre in its natural form sets the "gold standard" for toughness and strength, which serves as a guide to the assembly of graphene nanosheets into high-performance nanocomposites. Here we show the strong, tough, conductive artificial nacre based on graphene oxide through synergistic interactions of hydrogen and covalent bonding. Tensile strength and toughness was 4 and 10 times higher, respectively, than that of natural nacre. The exceptional integrated strong and tough artificial nacre has promising applications in aerospace, artificial muscle, and tissue engineering, especially for flexible supercapacitor electrodes due to its high electrical conductivity. The use of synergistic interactions is a strategy for the development of high-performance nanocomposites.

Response of base isolated structure during strong ground motions beyond design earthquakes

International Nuclear Information System (INIS)

Yabana, Shuichi; Ishida, Katsuhiko; Shiojiri, Hiroo

1991-01-01

In Japan, some base isolated structures for fast breeder reactors (FBR) are tried to design. When a base isolated structure are designed, the relative displacement of isolators are generally limited so sa to be remain in linear state of those during design earthquakes. But to estimate safety margin of a base isolated structure, the response of that until the failure must be obtained experimentally to analytically during strong ground motions of beyond design earthquake. The aim of this paper is to investigate the response of a base isolated structure when the stiffness of the isolators hardens and to simulate the response during strong ground motions of beyond design earthquakes. The optimum characteristics of isolators, with which the margin of the structure are increased, are discussed. (author)

Dissolution performance of plutonium nitride based fuel materials

Energy Technology Data Exchange (ETDEWEB)

Aneheim, E.; Hedberg, M. [Nuclear Chemistry, Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivaegen 4, Gothenburg, SE41296 (Sweden)

2016-07-01

Nitride fuels have been regarded as one viable fuel option for Generation IV reactors due to their positive features compared to oxides. To be able to close the fuel cycle and follow the Generation IV concept, nitrides must, however, demonstrate their ability to be reprocessed. This means that the dissolution performance of actinide based nitrides has to be thoroughly investigated and assessed. As the zirconium stabilized nitrides show even better potential as fuel material than does the pure actinide containing nitrides, investigations on the dissolution behavior of both PuN and (Pu,Zr)N has been undertaken. If possible it is desirable to perform the fuel dissolutions using nitric acid. This, as most reprocessing strategies using solvent-solvent extraction are based on a nitride containing aqueous matrix. (Pu,Zr)N/C microspheres were produced using internal gelation. The spheres dissolution performance was investigated using nitric acid with and without additions of HF and Ag(II). In addition PuN fuel pellets were produced from powder and their dissolution performance were also assessed in a nitric acid based setting. It appears that both PuN and (Pu,Zr)N/C fuel material can be completely dissolved in nitric acid of high concentration with the use of catalytic amounts of HF. The amount of HF added strongly affects dissolution kinetics of (Pu, Zr)N and the presence of HF affects the 2 solutes differently, possibly due to inhomogeneity o the initial material. Large additions of Ag(II) can also be used to facilitate the dissolution of (Pu,Zr)N in nitric acid. PuN can be dissolved by pure nitric acid of high concentration at room temperature while (Pu, Zr)N is unaffected under similar conditions. At elevated temperature (reflux), (Pu,Zr)N can, however, also be dissolved by concentrated pure nitric acid.

Development of starch-based materials

NARCIS (Netherlands)

Habeych Narvaez, E.A.

2009-01-01

Starch-based materials show potential as fully degradable plastics. However, the current
applicability of these materials is limited due to their poor moisture tolerance and
mechanical properties. Starch is therefore frequently blended with other polymers to make
the material more

Tunable elastic parity-time symmetric structure based on the shunted piezoelectric materials

Science.gov (United States)

Hou, Zhilin; Assouar, Badreddine

2018-02-01

We theoretically and numerically report on the tunable elastic Parity-Time (PT) symmetric structure based on shunted piezoelectric units. We show that the elastic loss and gain can be archived in piezoelectric materials when they are shunted by external circuits containing positive and negative resistances. We present and discuss, as an example, the strongly dependent relationship between the exceptional points of a three-layered system and the impedance of their external shunted circuit. The achieved results evidence that the PT symmetric structures based on this proposed concept can actively be tuned without any change of their geometric configurations.

Materials data base for fusion reactors-I

International Nuclear Information System (INIS)

Iwata, S.; Nogami, A.; Ishino, S.; Mishima, Y.; Takao, Y.; Aruga, T.; Shiraishi, K.

1982-01-01

The materials data base is a set of experimental and/or calculated data being compiled to meet the broad needs for materials data by taking advantage of the data base management systems. In this paper the objective of such computerized data base is described and the characteristics of fusion reactor materials are discussed from the viewpoint of the data base development. The near-term emphasis of the development has been put on the irradiation data for 316 type stainless steels. Through the test of this small data base, it can be concluded that this approach is promising for materials data base management and for the establishment of the interface between fusion reactor designer and materials investigator. (orig.)

Polyphosphazine-based polymer materials

Science.gov (United States)

Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

2010-05-25

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

Ensemble-based Kalman Filters in Strongly Nonlinear Dynamics

Institute of Scientific and Technical Information of China (English)

Zhaoxia PU; Joshua HACKER

2009-01-01

This study examines the effectiveness of ensemble Kalman filters in data assimilation with the strongly nonlinear dynamics of the Lorenz-63 model, and in particular their use in predicting the regime transition that occurs when the model jumps from one basin of attraction to the other. Four configurations of the ensemble-based Kalman filtering data assimilation techniques, including the ensemble Kalman filter, ensemble adjustment Kalman filter, ensemble square root filter and ensemble transform Kalman filter, are evaluated with their ability in predicting the regime transition (also called phase transition) and also are compared in terms of their sensitivity to both observational and sampling errors. The sensitivity of each ensemble-based filter to the size of the ensemble is also examined.

Some functional properties of composite material based on scrap tires

Science.gov (United States)

Plesuma, Renate; Malers, Laimonis

2013-09-01

The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

Sustainable bio-based materials: opportunities and challenges

NARCIS (Netherlands)

van der Meer, Yvonne

2017-01-01

Research in the area of bio-based materials aims to achieve breakthroughs in bio-based materials development. A novel way is presented to organise bio-based materials research with a value chain approach in which sustainability research is integrated in the research program. This research approach

Future perspectives of resin-based dental materials.

Science.gov (United States)

Jandt, Klaus D; Sigusch, Bernd W

2009-08-01

This concise review and outlook paper gives a view of selected potential future developments in the area of resin-based biomaterials with an emphasis on dental composites. A selection of key publications (1 book, 35 scientific original publications and 1 website source) covering the areas nanotechnology, antimicrobial materials, stimuli responsive materials, self-repairing materials and materials for tissue engineering with direct or indirect relations and/or implications to resin-based dental materials is critically reviewed and discussed. Connections between these fields and their potential for resin-based dental materials are highlighted and put in perspective. The need to improve shrinkage properties and wear resistance is obvious for dental composites, and a vast number of attempts have been made to accomplish these aims. Future resin-based materials may be further improved in this respect if, for example nanotechnology is applied. Dental composites may, however, reach a completely new quality by utilizing new trends from materials science, such as introducing nanostructures, antimicrobial properties, stimuli responsive capabilities, the ability to promote tissue regeneration or repair of dental tissues if the composites were able to repair themselves. This paper shows selected potential future developments in the area of resin-based dental materials, gives basic and industrial researchers in dental materials science, and dental practitioners a glance into the potential future of these materials, and should stimulate discussion about needs and future developments in the area.

Investigations on field-effect transistors based on two-dimensional materials

Energy Technology Data Exchange (ETDEWEB)

Finge, T.; Riederer, F.; Grap, T.; Knoch, J. [Institute of Semiconductor Electronics, RWTH Aachen University (Germany); Mueller, M.R. [Institute of Semiconductor Electronics, RWTH Aachen University (Germany); Infineon Technologies, Villach (Austria); Kallis, K. [Intelligent Microsystems Chair, TU Dortmund University (Germany)

2017-11-15

In the present article, experimental and theoretical investigations regarding field-effect transistors based on two-dimensional (2D) materials are presented. First, the properties of contacts between a metal and 2D material are discussed. To this end, metal-to-graphene contacts as well to transition metal dichalcogenides (TMD) are studied. Whereas metal-graphene contacts can be tuned with an appropriate back-gate, metal-TMD contacts exhibit strong Fermi level pinning showing substantially limited maximum possible drive current. Next, tungsten diselenide (WSe{sub 2}) field-effect transistors are presented. Employing buried-triple-gate substrates allows tuning source, channel and drain by applying appropriate gate voltages so that the device can be reconfigured to work as n-type, p-type and as so-called band-to-band tunnel field-effect transistor on the same WSe{sub 2} flake. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

New Cork-Based Materials and Applications

Directory of Open Access Journals (Sweden)

Luís Gil

2015-02-01

Full Text Available This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders, and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before.

New Cork-Based Materials and Applications

Science.gov (United States)

Gil, Luís

2015-01-01

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before. PMID:28787962

New Cork-Based Materials and Applications.

Science.gov (United States)

Gil, Luís

2015-02-10

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before.

Sensor-based material tagging system

International Nuclear Information System (INIS)

Vercellotti, L.C.; Cox, R.W.; Ravas, R.J.; Schlotterer, J.C.

1991-01-01

Electronic identification tags are being developed for tracking material and personnel. In applying electronic identification tags to radioactive materials safeguards, it is important to measure attributes of the material to ensure that the tag remains with the material. The addition of a microcontroller with an on-board analog-to-digital converter to an electronic identification tag application-specific integrated-circuit has been demonstrated as means to provide the tag with sensor data. Each tag is assembled into a housing, which serves as a scale for measuring the weight of a paint-can-sized container and its contents. Temperature rise of the can above ambient is also measured, and a piezoelectric detector detects disturbances and immediately puts the tag into its alarm and beacon mode. Radiation measurement was also considered, but the background from nearby containers was found to be excessive. The sensor-based tagging system allows tracking of the material in cans as it is stored in vaults or is moved through the manufacturing process. The paper presents details of the sensor-based material tagging system and describes a demonstration system

Tungsten - Yttrium Based Nuclear Structural Materials

Science.gov (United States)

Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

2013-04-01

The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

Time-domain modeling for shielding effectiveness of materials against electromagnetic pulse based on system identification

International Nuclear Information System (INIS)

Chen, Xiang; Chen, Yong Guang; Wei, Ming; Hu, Xiao Feng

2013-01-01

Shielding effectiveness (SE) of materials against electromagnetic pulse (EMP) cannot be well estimated by traditional test method of SE of materials which only consider the amplitude-frequency characteristic of materials, but ignore the phase-frequency ones. In order to solve this problem, the model of SE of materials against EMP was established based on system identification (SI) method with time-domain linear cosine frequency sweep signal. The feasibility of the method in this paper was examined depending on infinite planar material and the simulation research of coaxial test method and windowed semi-anechoic box of materials. The results show that the amplitude-frequency and phase-frequency information of each frequency can be fully extracted with this method. SE of materials against strong EMP can be evaluated with time-domain low field strength (voltage) of cosine frequency sweep signal. And SE of materials against a variety EMP will be predicted by the model.

Nanocellulose based polymer composite for acoustical materials

Science.gov (United States)

Farid, Mohammad; Purniawan, Agung; Susanti, Diah; Priyono, Slamet; Ardhyananta, Hosta; Rahmasita, Mutia E.

2018-04-01

Natural fibers are biodegradable materials that are innovatively and widely used for composite reinforcement in automotive components. Nanocellulose derived from natural fibers oil palm empty bunches have properties that are remarkable for use as a composite reinforcement. However, there have not been many investigations related to the use of nanocellulose-based composites for wideband sound absorption materials. The specimens of nanocellulose-based polyester composite were prepared using a spray method. An impedance tube method was used to measure the sound absorption coefficient of this composite material. To reveal the characteristics of the nanocellulose-based polyester composite material, SEM (scanning electron microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infra Red), TGA (Thermogravimetric Analysis), and density tests were performed. Sound absorption test results showed the average value of sound absorption coefficient of 0.36 to 0,46 for frequency between 500 and 4000 Hz indicating that this nanocellulose-based polyester composite materials had a tendency to wideband sound absorption materials and potentially used as automotive interior materials.

Using bio-based polymers for curing cement-based materials

NARCIS (Netherlands)

Zlopasa, J.; Koenders, E.A.B.; Picken, S.J.

2014-01-01

Curing is the process of controlling the rate and extent of moisture loss from the surface of cement based materials. It is the final stage in the production of cement-based materials and it is the essential part for achieving continuous hydration of cement, while avoiding cracking due to drying

Graphene nanomesh-based devices exhibiting a strong negative differential conductance effect

International Nuclear Information System (INIS)

Hung Nguyen, V; Mazzamuto, F; Saint-Martin, J; Bournel, A; Dollfus, P

2012-01-01

Using atomistic quantum simulation based on a tight binding model, we have investigated the transport characteristics of graphene nanomesh-based devices and evaluated the possibilities of observing negative differential conductance. It is shown that by taking advantage of bandgap opening in the graphene nanomesh lattice, a strong negative differential conductance effect can be achieved at room temperature in pn junctions and n-doped structures. Remarkably, the effect is improved very significantly (with a peak-to-valley current ratio of a few hundred) and appears to be weakly sensitive to the transition length in graphene nanomesh pn hetero-junctions when inserting a pristine (gapless) graphene section in the transition region between n and p zones. The study therefore suggests new design strategies for graphene electronic devices which may offer strong advantages in terms of performance and processing over the devices studied previously. (paper)

Finite Elements Based on Strong and Weak Formulations for Structural Mechanics: Stability, Accuracy and Reliability

Directory of Open Access Journals (Sweden)

Francesco Tornabene

2017-07-01

Full Text Available The authors are presenting a novel formulation based on the Differential Quadrature (DQ method which is used to approximate derivatives and integrals. The resulting scheme has been termed strong and weak form finite elements (SFEM or WFEM, according to the numerical scheme employed in the computation. Such numerical methods are applied to solve some structural problems related to the mechanical behavior of plates and shells, made of isotropic or composite materials. The main differences between these two approaches rely on the initial formulation – which is strong or weak (variational – and the implementation of the boundary conditions, that for the former include the continuity of stresses and displacements, whereas in the latter can consider the continuity of the displacements or both. The two methodologies consider also a mapping technique to transform an element of general shape described in Cartesian coordinates into the same element in the computational space. Such technique can be implemented by employing the classic Lagrangian-shaped elements with a fixed number of nodes along the element edges or blending functions which allow an “exact mapping” of the element. In particular, the authors are employing NURBS (Not-Uniform Rational B-Splines for such nonlinear mapping in order to use the “exact” shape of CAD designs.

Pulsed Neutron Scattering Studies of Strongly Fluctuating solids, Final Report

Energy Technology Data Exchange (ETDEWEB)

Collin Broholm

2006-06-22

The conventional description of a solid is based on a static atomic structure with small amplitude so-called harmonic fluctuations about it. This is a final technical report for a project that has explored materials where fluctuations are sufficiently strong to severely challenge this approach and lead to unexpected and potentially useful materials properties. Fluctuations are enhanced when a large number of configurations share the same energy. We used pulsed spallation source neutron scattering to obtain detailed microscopic information about structure and fluctuations in such materials. The results enhance our understanding of strongly fluctuating solids and their potential for technical applications. Because new materials require new experimental techniques, the project has also developed new techniques for probing strongly fluctuating solids. Examples of material that were studied are ZrW2O8 with large amplitude molecular motion that leads to negative thermal expansion, NiGa2S4 where competing interactions lead to an anomalous short range ordered magnet, Pr1- xBixRu2O7 where a partially filled electron shell (Pr) in a weakly disordered environment produces anomalous metallic properties, and TbMnO3 where competing interactions lead to a magneto-electric phase. The experiments on TbMnO3 exemplify the relationship between research funded by this project and future applications. Magneto-electric materials may produce a magnetic field when an electric field is applied or vise versa. Our experiments have clarified the reason why electric and magnetic polarization is coupled in TbMnO3. While this knowledge does not render TbMnO3 useful for applications it will focus the search for a practical room temperature magneto-electric for applications.

LDEF materials special investigation group's data bases

Science.gov (United States)

Strickland, John W.; Funk, Joan G.; Davis, John M.

1993-01-01

The Long Duration Exposure Facility (LDEF) was composed of and contained a wide array of materials, representing the largest collection of materials flown for space exposure and returned for ground-based analyses to date. The results and implications of the data from these materials are the foundation on which future space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been tasked with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the space user community in an easily accessed, user-friendly form. The format and content of the data bases developed or being developed to accomplish this task are discussed. The hardware and software requirements for each of the three data bases are discussed along with current availability of the data bases.

Nanomagnets with high shape anisotropy and strong crystalline anisotropy: perspectives on magnetic force microscopy

International Nuclear Information System (INIS)

Campanella, H; Llobet, J; Esteve, J; Plaza, J A; Jaafar, M; Vázquez, M; Asenjo, A; Del Real, R P

2011-01-01

We report on a new approach for magnetic imaging, highly sensitive even in the presence of external, strong magnetic fields. Based on FIB-assisted fabricated high-aspect-ratio rare-earth nanomagnets, we produce groundbreaking magnetic force tips with hard magnetic character where we combine a high aspect ratio (shape anisotropy) together with strong crystalline anisotropy (rare-earth-based alloys). Rare-earth hard nanomagnets are then FIB-integrated to silicon microcantilevers as highly sharpened tips for high-field magnetic imaging applications. Force resolution and domain reversing and recovery capabilities are at least one order of magnitude better than for conventional magnetic tips. This work opens new, pioneering research fields on the surface magnetization process of nanostructures based either on relatively hard magnetic materials—used in magnetic storage media—or on materials like superparamagnetic particles, ferro/antiferromagnetic structures or paramagnetic materials.

Strong ion difference in urine: new perspectives in acid-base assessment.

OpenAIRE

Gattinoni, L.; Carlesso, E.; Cadringher, P.; Caironi, P.

2006-01-01

The plasmatic strong ion difference (SID) is the difference between positively and negatively charged strong ions. At pH 7.4, temperature 37°C and partial carbon dioxide tension 40 mmHg, the ideal value of SID is 42 mEq/l. The buffer base is the sum of negatively charged weak acids ([HCO3 -], [A-], [H2PO4 -]) and its normal value is 42 mEq/l. According to the law of electroneutrality, the amount of positive and negative charges must be equal, and therefore the SID value is equal to the buffer...

EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

Science.gov (United States)

Ronning, Filip; Batista, Cristian

2011-03-01

during SCES 2010. As we learned, past dogmas about strongly correlated materials and phenomena must be re-examined with an open and inquisitive mind. Invited speakers and respected leaders in the field were invited to contribute to this special issue and we have insisted that they present new data, ideas, or perspectives, as opposed to simply an overview of their past work. As with the conference, this special issue touches upon recent developments of strongly correlated electron systems in d-electron materials, such as Sr3Ru2O7, graphene, and the new Fe-based superconductors, but it is dominated by topics in f-electron compounds. Contributions reflect the growing appreciation for the influence of disorder and frustration, the need for organizing principles, as well as detailed investigations on particular materials of interest and, of course, new materials. As this special issue could not possibly capture the full breadth and depth that the conference had to offer, it is being published simultaneously with an issue of Journal of Physics: Conference Series containing 157 manuscripts in which all poster presenters at SCES 2010 were invited to contribute. Since this special issue grew out of the 2010 SCES conference, we take this opportunity to give thanks. This conference would not have been possible without the hard work of the SCES 2010 Program Committee, International and National Advisory Committees, Local Committee, and conference organizers, the New Mexico Consortium. We thank them as well as those organizations that generously provided financial support: ICAM-I2CAM, Quantum Design, Lakeshore, the National High Magnetic Field Laboratory and the Department of Energy National Laboratories at Argonne, Berkeley, Brookhaven, Los Alamos and Oak Ridge. Of course, we especially thank the participants for bringing new ideas and new results, without which SCES 2010 would not have been possible. Strongly correlated electron systems contents Spin-orbit coupling and k

Densified ultra-light cement-based materials

DEFF Research Database (Denmark)

Esteves, Luis Pedro

2015-01-01

be used as a “clean technology” in the production of cement-based materials for structural applications with a low carbon footprint. This paper describes the principles of this concept coupled with experimental results on the basic properties of this enhanced type of cement-based materials with combined...

Materials data base as an interface between fusion reactor designs and materials development

International Nuclear Information System (INIS)

Ishino, S.; Iwata, S.

1983-01-01

The materials data base is an integrated information system of experimental and/or calculated data of materials being compiled to meet the broad needs for materials data by taking advantage of the data base management systems. In this paper the objective of such computerized data base is described from the viewpoint of materials engineers and fusion system designers. Materials data spread themselves widely from the field that relates fundamental understanding of the behaviors of electrons, atoms, vacancies, dislocations and so on to the performance of components, devices, machines and systems. In our approach this information is described as ''relations'' by a set of tables which comprise related variables, for example, a set of values about essential properties for materials selection. This approach based on the relational model enables relational operations, i.e. SELECTION, PROJECTION, JOIN and so on, to select suitable materials, to set trade-off parameters for system designers and to establish design criteria. Stored data comprise (i) fundamental properties for all elements and potential structural materials, (ii) low cycle fatigue, irradiation creep and swelling data for type 316 stainless steels. These data have been selected and evaluated from critical reviews of existing data base of about 2 mega bytes data, some examples of materials selections and extraction of trade-off parameters are shown as a subject of critical issue concerning how to bridge the large gap between materials developments and system designs. (author)

NTERACTION BETWEEN SURFACE CHARGE PHENOMENA AND MULTI-SPECIES DIFFUSION IN CEMENT BASED MATERIALS

DEFF Research Database (Denmark)

Johannesson, Björn

2008-01-01

Measurements strongly indicate that the ‘inner’ surface of the microscopic structure of cement based materials has a fixed negative charge. This charge contributes to the formation of so-called electrical double layers. In the case of cement based materials the ionic species located in such layers...... are typically potassium -, sodium - and calcium ions. Due to the high specific surface area of hydrated cement, a large amount of ions can be located in theses double layers even if the surface charge is relatively low. The attraction force, caused by the fixed surface charge on ions located close to surfaces......, is one possible explanation for the observed low global diffusion rates in the pore system of positively charged ions compared to the negatively charged ones. Here it is of interest to simulate the multi ionic diffusion behavior when assigning positively charged ions a comparably lower diffusion constant...

A data base for aging of structural materials

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.; Jerath, S.

1993-01-01

USNRC initiated a Structural Aging (SAG) Program ORNL. The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One main part focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented

Learning material recommendation based on case-based reasoning similarity scores

Science.gov (United States)

Masood, Mona; Mokmin, Nur Azlina Mohamed

2017-10-01

A personalized learning material recommendation is important in any Intelligent Tutoring System (ITS). Case-based Reasoning (CBR) is an Artificial Intelligent Algorithm that has been widely used in the development of ITS applications. This study has developed an ITS application that applied the CBR algorithm in the development process. The application has the ability to recommend the most suitable learning material to the specific student based on information in the student profile. In order to test the ability of the application in recommending learning material, two versions of the application were created. The first version displayed the most suitable learning material and the second version displayed the least preferable learning material. The results show the application has successfully assigned the students to the most suitable learning material.

Strong piezoelectricity in bioinspired peptide nanotubes.

Science.gov (United States)

Kholkin, Andrei; Amdursky, Nadav; Bdikin, Igor; Gazit, Ehud; Rosenman, Gil

2010-02-23

We show anomalously strong shear piezoelectric activity in self-assembled diphenylalanine peptide nanotubes (PNTs), indicating electric polarization directed along the tube axis. Comparison with well-known piezoelectric LiNbO(3) and lateral signal calibration yields sufficiently high effective piezoelectric coefficient values of at least 60 pm/V (shear response for tubes of approximately 200 nm in diameter). PNTs demonstrate linear deformation without irreversible degradation in a broad range of driving voltages. The results open up a wide avenue for developing new generations of "green" piezoelectric materials and piezonanodevices based on bioactive tubular nanostructures potentially compatible with human tissue.

Electron holography of Fe-based nanocrystalline magnetic materials (invited)

International Nuclear Information System (INIS)

Shindo, Daisuke; Park, Young-Gil; Gao, Youhui; Park, Hyun Soon

2004-01-01

Magnetic domain structures of nanocrystalline magnetic materials were extensively investigated by electron holography with a change in temperature or magnetic field applied. In both soft and hard magnetic materials, the distribution of lines of magnetic flux clarified in situ by electron holography was found to correspond well to their magnetic properties. An attempt to produce a strong magnetic field using a sharp needle made of a permanent magnet, whose movement is controlled by piezo drives has been presented. This article demonstrates that the attempt is promising to investigate the magnetization process of hard magnetic materials by electron holography

A data base for aging of structural materials

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.; Jerath, S.

1993-01-01

The U.S. Nuclear Regulatory Commission (USNRC) initiated a Structural Aging (SAG) Program at the Oak Ridge National Laboratory (ORNL). The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One of the main parts of the program focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented. (author)

Simulation-based marginal likelihood for cluster strong lensing cosmology

Science.gov (United States)

Killedar, M.; Borgani, S.; Fabjan, D.; Dolag, K.; Granato, G.; Meneghetti, M.; Planelles, S.; Ragone-Figueroa, C.

2018-01-01

Comparisons between observed and predicted strong lensing properties of galaxy clusters have been routinely used to claim either tension or consistency with Λ cold dark matter cosmology. However, standard approaches to such cosmological tests are unable to quantify the preference for one cosmology over another. We advocate approximating the relevant Bayes factor using a marginal likelihood that is based on the following summary statistic: the posterior probability distribution function for the parameters of the scaling relation between Einstein radii and cluster mass, α and β. We demonstrate, for the first time, a method of estimating the marginal likelihood using the X-ray selected z > 0.5 Massive Cluster Survey clusters as a case in point and employing both N-body and hydrodynamic simulations of clusters. We investigate the uncertainty in this estimate and consequential ability to compare competing cosmologies, which arises from incomplete descriptions of baryonic processes, discrepancies in cluster selection criteria, redshift distribution and dynamical state. The relation between triaxial cluster masses at various overdensities provides a promising alternative to the strong lensing test.

Text Based Analogy in Overcoming Student Misconception on Simple Electricity Circuit Material

Science.gov (United States)

Hesti, R.; Maknun, J.; Feranie, S.

2017-09-01

Some researcher have found that the use of analogy in learning and teaching physics was effective enough in giving comprehension in a complicated physics concept such as electrical circuits. Meanwhile, misconception become main cause that makes students failed when learning physics. To provide teaching physics effectively, the misconception should be resolved. Using Text Based Analogy is one of the way to identifying misconceptions and it is enough to assist teachers in conveying scientific truths in order to overcome misconceptions. The purpose of the study to investigate the use of text based analogy in overcoming students misconception on simple electrical circuit material. The samples of this research were 28 of junior high school students taken purposively from one high school in South Jakarta. The method use in this research is pre-experimental and design in one shot case study. Students who are the participants of sample have been identified misconception on the electrical circuit material by using the Diagnostic Test of Simple Electricity Circuit. The results of this study found that TBA can replace the misconceptions of the concept possessed by students with scientific truths conveyed in the text in a way that is easily understood so that TBA is strongly recommended to use in other physics materials.

Chaotic secure communication based on strong tracking filtering

International Nuclear Information System (INIS)

Li Xiongjie; Xu Zhengguo; Zhou Donghua

2008-01-01

A scheme for implementing secure communication based on chaotic maps and strong tracking filter (STF) is presented, and a modified STF algorithm with message estimation is developed for the special requirement of chaotic secure communication. At the emitter, the message symbol is modulated by chaotic mapping and is output through a nonlinear function. At the receiver, the driving signal is received and the message symbol is recovered dynamically by the STF with estimation of message symbol. Simulation results of Holmes map demonstrate that when message symbols are binary codes, STF can effectively recover the codes of the message from the noisy chaotic signals. Compared with the extended Kalman filter (EKF), STF has a lower bit error rate

Membrane-based biomolecular smart materials

International Nuclear Information System (INIS)

Sarles, Stephen A; Leo, Donald J

2011-01-01

Membrane-based biomolecular materials are a new class of smart material that feature networks of artificial lipid bilayers contained within durable synthetic substrates. Bilayers contained within this modular material platform provide an environment that can be tailored to host an enormous diversity of functional biomolecules, where the functionality of the global material system depends on the type(s) and organization(s) of the biomolecules that are chosen. In this paper, we review a series of biomolecular material platforms developed recently within the Leo Group at Virginia Tech and we discuss several novel coupling mechanisms provided by these hybrid material systems. The platforms developed demonstrate that the functions of biomolecules and the properties of synthetic materials can be combined to operate in concert, and the examples provided demonstrate how the formation and properties of a lipid bilayer can respond to a variety of stimuli including mechanical forces and electric fields

Standard test methods for the strong-base resins used in the recovery of uranium

International Nuclear Information System (INIS)

Ford, M.A.; Lombaard, L.R.

1986-01-01

There are no detailed specifications for the strong-base ion-exchange resins used in continuous ion-exchange plants, and it was considered that a very useful purpose would be served by the publication of a series of standard laboratory tests on which such specifications could be based. This report describes test methods that are relevant to the ion-exchange recovery of uranium. They include tests of the physical properties of strong-base resins (relative density, particle-size distribution, and moisture content) and of their chemical properties (theoretical capacity, equilibrium capacity, kinetics of loading and elution). Included are several supporting procedures that are used in conjunction with these methods

[Meeting point Stewart. Buffer bases, base excess and strong ions].

Science.gov (United States)

Lang, W

2007-04-01

Development of a two-buffer model which simulates the acid-base properties of blood and allows comparison of the different acidbase concepts according to Stewart and to Siggaard-Andersen. The two-buffer model consisted of different aqueous solutions of bicarbonate/CO(2) (pCO(2), sCO(2), pK(1)), HEPES buffer (A(tot), pK(a)) and electrolytes. These were used to calculate the pH from the independent variables according to Stewart - strong ion difference (SID), pCO(2) and total concentration of the weak acids (A(tot)) - from which all other dependent variables (cHCO(3)(-), cA(-), BB, BE) were obtained and compared with the measured values. The normal pH (7.408) was calculated from the normal values for SID (48 mmol/l), pCO(2) (40 mmHg) and A(tot) (45.2 mmol/l) and agreed perfectly with the measured value (7.409+/-0.001). This was also valid for all calculated and measured pH values when the SID was varied: non-respiratory alkalosis ( upward arrow) or acidosis ( downward arrow), pCO(2):respiratory acidosis ( upward arrow) or alkalosis ( downward arrow) and A(tot):hyperproteinemic acidosis ( upward arrow) or hypoproteinemic alkalosis ( downward arrow) were varied and the sum of the buffer bases (BB) was always equal to the SID. All changes and hence BE were also equal, providing that A(tot) was normal. This was not the case, however, if A(tot) was outside the normal range, when BE was then the difference from the normal BB at the respective reference point. Whereas the deviation of the measured pCO(2) was acceptable (1.74+/-0.86 mmHg), this was not the case for the SID (-6.18+/-3.58 mmol/l) calculated from the measured ion concentrations (Na, K, Ca, Cl). Despite controversial discussions, both concepts are much closer than might be expected. Whereas in the Stewart approach the focus of analysis is on plasma, with the Siggaard-Andersen approach it is on blood. Hence, a combined analysis of the blood gases (pH, pCO(2), pO(2), sO(2), cHb, BE) and of the strong ion gap (SIG

Emerging terahertz photodetectors based on two-dimensional materials

Science.gov (United States)

Yang, Jie; Qin, Hua; Zhang, Kai

2018-01-01

Inspired by the innovations in photonics and nanotechnology, the remarkable properties of two-dimensional (2D) materials have renewed interest for the development of terahertz (THz) photodetectors. The versatility of these materials enables ultrafast and ultrasensitive photodetection of THz radiation at room temperature. The atomically thin characteristic together with van der Waals interactions among the layers make it easy to scaling down and integrate with other 2D materials based devices, as well as silicon chips. Efforts have increased fast in the past decade in developing proof-of-concept and the further prospective THz photodetectors based on 2D materials. Here, the recent progress on the exploring of THz photodetectors based on 2D materials is reviewed. We summarized the THz photodetectors under different physical mechanism and introduced the state-of-the-art THz photodetectors based on various promising 2D materials, such as graphene, transition metal dichalcogenides (TMDCs), black phosphorus (BP) and topological insulators (TIs). A brief discussion on the remaining challenges and a perspective of the 2D materials based THz photodetectors are also given.

Leaching from denture base materials in vitro

Energy Technology Data Exchange (ETDEWEB)

Lygre, H.; Solheim, E.; Gjerdet, N.R. [School of Medicine, Univ. of Bergen (Norway)

1995-04-01

Specimens made from denture base materials were leached in Ringer Solution and in ethanol. The specimens comprised a heat-cured product processed in two different ways and two cold-cured materials. The organic compounds leaching from the specimens to the solutions were separated, identified, and quantified by a combined gas-chromatography and gas-chromatography/mass-spectrometry technique. Additives and degradation products, possibly made by free radical reactions, were released from the denture base materials. In Ringer solution only phthalates could be quantified. In ethanol solvent, biphenyl, dibutyl phthalate, dicyclohexyl phthalate, phenyl benzoate, and phenyl salicylate were quantified. In addition, copper was found in the ethanol solvent from one of the denture base materials. The amount of leachable organic compounds varies among different materials. Processing temperature influences the initial amount of leachable compounds. 36 refs., 7 figs., 1 tab.

Manganese oxide-based materials as electrochemical supercapacitor electrodes.

Science.gov (United States)

Wei, Weifeng; Cui, Xinwei; Chen, Weixing; Ivey, Douglas G

2011-03-01

Electrochemical supercapacitors (ECs), characteristic of high power and reasonably high energy densities, have become a versatile solution to various emerging energy applications. This critical review describes some materials science aspects on manganese oxide-based materials for these applications, primarily including the strategic design and fabrication of these electrode materials. Nanostructurization, chemical modification and incorporation with high surface area, conductive nanoarchitectures are the three major strategies in the development of high-performance manganese oxide-based electrodes for EC applications. Numerous works reviewed herein have shown enhanced electrochemical performance in the manganese oxide-based electrode materials. However, many fundamental questions remain unanswered, particularly with respect to characterization and understanding of electron transfer and atomic transport of the electrochemical interface processes within the manganese oxide-based electrodes. In order to fully exploit the potential of manganese oxide-based electrode materials, an unambiguous appreciation of these basic questions and optimization of synthesis parameters and material properties are critical for the further development of EC devices (233 references).

Resilient Modulus Characterization of Alaskan Granular Base Materials

Science.gov (United States)

2010-08-01

Resilient modulus (MR) of base course material is an important material input for : pavement design. In Alaska, due to distinctiveness of local climate, material source, : fines content and groundwater level, resilient properties of D-1 granular base...

Strong reflector-based beamforming in ultrasound medical imaging.

Science.gov (United States)

Szasz, Teodora; Basarab, Adrian; Kouamé, Denis

2016-03-01

This paper investigates the use of sparse priors in creating original two-dimensional beamforming methods for ultrasound imaging. The proposed approaches detect the strong reflectors from the scanned medium based on the well known Bayesian Information Criteria used in statistical modeling. Moreover, they allow a parametric selection of the level of speckle in the final beamformed image. These methods are applied on simulated data and on recorded experimental data. Their performance is evaluated considering the standard image quality metrics: contrast ratio (CR), contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). A comparison is made with the classical delay-and-sum and minimum variance beamforming methods to confirm the ability of the proposed methods to precisely detect the number and the position of the strong reflectors in a sparse medium and to accurately reduce the speckle and highly enhance the contrast in a non-sparse medium. We confirm that our methods improve the contrast of the final image for both simulated and experimental data. In all experiments, the proposed approaches tend to preserve the speckle, which can be of major interest in clinical examinations, as it can contain useful information. In sparse mediums we achieve a highly improvement in contrast compared with the classical methods. Copyright © 2015 Elsevier B.V. All rights reserved.

[Preface for special issue on bio-based materials (2016)].

Science.gov (United States)

Weng, Yunxuan

2016-06-25

Bio-based materials are new materials or chemicals with renewable biomass as raw materials such as grain, legume, straw, bamboo and wood powder. This class of materials includes bio-based polymer, biobased fiber, glycotechnology products, biobased rubber and plastics produced by biomass thermoplastic processing and basic biobased chemicals, for instance, bio-alcohols, organic acids, alkanes, and alkenes, obtained by bio-synthesis, bio-processing and bio-refinery. Owing to its environmental friendly and resource conservation, bio-based materials are becoming a new dominant industry taking the lead in the world scientific and technological innovation and economic development. An overview of bio-based materials development is reported in this special issue, and the industrial status and research progress of the following aspects, including biobased fiber, polyhydroxyalkanoates, biodegradable mulching film, bio-based polyamide, protein based biomedical materials, bio-based polyurethane, and modification and processing of poly(lactic acid), are introduced.

Protein-Based Drug-Delivery Materials

Directory of Open Access Journals (Sweden)

Dave Jao

2017-05-01

Full Text Available There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function—including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments—are summarized at the end of this review.

Materiality in a practice-based approach

DEFF Research Database (Denmark)

Svabo, Connie

2009-01-01

The paper provides an overview of the vocabulary for materiality which is used by practice-based approaches to organizational knowing. Common terms for materiality are 'artifact' and 'object'. The interaction between social and material realities is grasped as several processes: object......-oriented activity, symbolization, embodiment, performance, alignment and mediation. Material artifacts both stabilize and destabilize organizational action. They may ensure coordination, communication, and control, but they may also create disturbance and conflict....

Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives

Directory of Open Access Journals (Sweden)

Cai Liang

2014-07-01

Full Text Available This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B.

Magnetic properties of FeNi-based thin film materials with different additives

KAUST Repository

Liang, C.

2014-07-04

This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. 2014 by the authors.

Ion exchange behaviour of citrate and EDTA anions on strong and weak base organic ion exchangers

International Nuclear Information System (INIS)

Askarieh, M.M.; White, D.A.

1988-01-01

The exchange of citrate and EDTA ions with two strong base and two weak base exchangers is considered. Citrate and EDTA analysis for this work was performed using a colorimetric method developed here. The ions most selectively exchanged on the resins are H 2 cit - and H 2 EDTA 2- , though EDTA is generally less strongly sorbed on strong base resins. In contact with weak base resins, deprotonation of the resin occurs during ion exchange with a noticeable drop in solution pH. Although EDTA sorption can be reversed by nitric acid, citrate ions are significantly held on the resin at low pH. The exchange of citrate can be made reversible if bicarbonate is added to the initial solutions. Alkaline regeneration of exchangers loaded with EDTA proved to be very effective. (author)

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar; Thingbaijam, Kiran Kumar; Adhikari, M. D.; Nayak, Avinash; Devaraj, N.; Ghosh, Soumalya K.; Mahajan, Arun K.

2013-01-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar

2013-12-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Identification of strong promoters based on the transcriptome of Bacillus licheniformis.

Science.gov (United States)

Liu, Xin; Yang, Haiyan; Zheng, Junwei; Ye, Yanrui; Pan, Li

2017-06-01

To expand the repertoire of strong promoters for high level expression of proteins based on the transcriptome of Bacillus licheniformis. The transcriptome of B. licheniformis ATCC14580 grown to the early stationary phase was analyzed and the top 10 highly expressed genes/operons out of the 3959 genes and 1249 operons identified were chosen for study promoter activity. Using beta-galactosidase gene as a reporter, the candidate promoter pBL9 exhibited the strongest activity which was comparable to that of the widely used strong promoter p43. Furthermore, the pro-transglutaminase from Streptomyces mobaraensis (pro-MTG) was expressed under the control of promoter pBL9 and the activity of pro-MTG reached 82 U/ml after 36 h, which is 23% higher than that of promoter p43 (66.8 U/ml). In our analyses of the transcriptome of B. licheniformis, we have identified a strong promoter pBL9, which could be adapted for high level expression of proteins in the host Bacillus subtilis.

Molecular plasmonics: The role of rovibrational molecular states in exciton-plasmon materials under strong-coupling conditions

Science.gov (United States)

Sukharev, Maxim; Charron, Eric

2017-03-01

We extend the model of exciton-plasmon materials to include a rovibrational structure of molecules using wave-packet propagations on electronic potential energy surfaces. Our model replaces conventional two-level emitters with more complex molecules, allowing us to examine the influence of alignment and vibrational dynamics on strong coupling with surface plasmon-polaritons. We apply the model to a hybrid system comprising a thin layer of molecules placed on top of a periodic array of slits. Rigorous simulations are performed for two types of molecular systems described by vibrational bound-bound and bound-continuum electronic transitions. Calculations reveal new features in transmission, reflection, and absorption spectra, including the observation of significantly higher values of the Rabi splitting and vibrational patterns clearly seen in the corresponding spectra. We also examine the influence of anisotropic initial conditions on optical properties of hybrid materials, demonstrating that the optical response of the system is significantly affected by an initial prealignment of the molecules. Our work demonstrates that prealigned molecules could serve as an efficient probe for the subdiffraction characterization of the near-field near metal interfaces.

The constitutive compatibility method for identification of material parameters based on full-field measurements

KAUST Repository

Moussawi, Ali

2013-10-01

We revisit here the concept of the constitutive relation error for the identification of elastic material parameters based on image correlation. An additional concept, so called constitutive compatibility of stress, is introduced defining a subspace of the classical space of statically admissible stresses. The key idea is to define stresses as compatible with the observed deformation field through the chosen class of constitutive equation. This makes possible the uncoupling of the identification of stress from the identification of the material parameters. As a result, the global cost of the identification is strongly reduced. This uncoupling also leads to parametrized solutions in cases where the solution is non-unique as demonstrated on 2D numerical examples. © 2013 Elsevier B.V.

Earthquake statistics and plastic events in soft-glassy materials

NARCIS (Netherlands)

Benzi, Roberto; Kumar, Pinaki; Toschi, Federico; Trampert, Jeannot

2016-01-01

We propose a new approach for generating synthetic earthquakes based on the physics of soft glasses. The continuum approach produces yield-stress materials based on Lattice–Boltzmann simulations. We show that if the material is stimulated below yield stress, plastic events occur, which have strong

Cement-based materials' characterization using ultrasonic attenuation

Science.gov (United States)

Punurai, Wonsiri

The quantitative nondestructive evaluation (NDE) of cement-based materials is a critical area of research that is leading to advances in the health monitoring and condition assessment of the civil infrastructure. Ultrasonic NDE has been implemented with varying levels of success to characterize cement-based materials with complex microstructure and damage. A major issue with the application of ultrasonic techniques to characterize cement-based materials is their inherent inhomogeneity at multiple length scales. Ultrasonic waves propagating in these materials exhibit a high degree of attenuation losses, making quantitative interpretations difficult. Physically, these attenuation losses are a combination of internal friction in a viscoelastic material (ultrasonic absorption), and the scattering losses due to the material heterogeneity. The objective of this research is to use ultrasonic attenuation to characterize the microstructure of heterogeneous cement-based materials. The study considers a real, but simplified cement-based material, cement paste---a common bonding matrix of all cement-based composites. Cement paste consists of Portland cement and water but does not include aggregates. First, this research presents the findings of a theoretical study that uses a set of existing acoustics models to quantify the scattered ultrasonic wavefield from a known distribution of entrained air voids. These attenuation results are then coupled with experimental measurements to develop an inversion procedure that directly predicts the size and volume fraction of entrained air voids in a cement paste specimen. Optical studies verify the accuracy of the proposed inversion scheme. These results demonstrate the effectiveness of using attenuation to measure the average size, volume fraction of entrained air voids and the existence of additional larger entrapped air voids in hardened cement paste. Finally, coherent and diffuse ultrasonic waves are used to develop a direct

Strong, tough and stiff bioinspired ceramics from brittle constituents

Science.gov (United States)

Bouville, Florian; Maire, Eric; Meille, Sylvain; van de Moortèle, Bertrand; Stevenson, Adam J.; Deville, Sylvain

2014-05-01

High strength and high toughness are usually mutually exclusive in engineering materials. In ceramics, improving toughness usually relies on the introduction of a metallic or polymeric ductile phase, but this decreases the material’s strength and stiffness as well as its high-temperature stability. Although natural materials that are both strong and tough rely on a combination of mechanisms operating at different length scales, the relevant structures have been extremely difficult to replicate. Here, we report a bioinspired approach based on widespread ceramic processing techniques for the fabrication of bulk ceramics without a ductile phase and with a unique combination of high strength (470 MPa), high toughness (22 MPa m1/2), and high stiffness (290 GPa). Because only mineral constituents are needed, these ceramics retain their mechanical properties at high temperatures (600 °C). Our bioinspired, material-independent approach should find uses in the design and processing of materials for structural, transportation and energy-related applications.

Sugar-Based Polyamides: Self-Organization in Strong Polar Organic Solvents.

Science.gov (United States)

Rosu, Cornelia; Russo, Paul S; Daly, William H; Cueto, Rafael; Pople, John A; Laine, Roger A; Negulescu, Ioan I

2015-09-14

Periodic patterns resembling spirals were observed to form spontaneously upon unassisted cooling of d-glucaric acid- and d-galactaric acid-based polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similar observations were made in d-galactaric acid-based polyamide/ionic liquid (IL) solutions. The morphologies were investigated by optical, polarized light and confocal microscopy assays to reveal pattern details. Differential scanning calorimetry was used to monitor solution thermal behavior. Small- and wide-angle X-ray scattering data reflected the complex and heterogeneous nature of the self-organized patterns. Factors such as concentration and temperature were found to influence spiral dimensions and geometry. The distance between rings followed a first-order exponential decay as a function of polymer concentration. Fourier-Transform Infrared Microspectroscopy analysis of spirals pointed to H-bonding between the solvent and the pendant hydroxyl groups of the glucose units from the polymer backbone. Tests on self-organization into spirals of ketal-protected d-galactaric acid polyamides in NMMO monohydrate confirmed the importance of the monosaccharide's pendant free hydroxyl groups on the formation of these patterns. Rheology performed on d-galactaric-based polyamides at high concentration in NMMO monohydrate solution revealed the optimum conditions necessary to process these materials as fibers by spinning. The self-organization of these sugar-based polyamides mimics certain biological materials.

Electrospun materials for affinity-based engineering and drug delivery

International Nuclear Information System (INIS)

Sill, T J; Von Recum, H A

2015-01-01

Electrospinning is a process which can quickly and cheaply create materials of high surface to volume and aspect ratios from many materials, however in application toward drug delivery this can be a strong disadvantage as well. Diffusion of drug is proportional to the thickness of that device. In moving from macro to micro to nano-sized electrospun materials drug release rates change to profiles that are too fast to be therapeutically beneficial. In this work we use molecular interactions to further control the rate of release beyond that capable of diffusion alone. To do this we create materials with molecular pockets, which can 'hold' therapeutic drugs through a reversible interaction such as a host/guest complexation. Through these complexes we show we are able to impact delivery of drug from electrospun materials, and also apply them in tissue engineering for the reversible presentation of biomolecules on a fiber surface. (paper)

Self-Assembling Multi-Component Nanofibers for Strong Bioinspired Underwater Adhesives

Science.gov (United States)

Zhong, Chao; Gurry, Thomas; Cheng, Allen A; Downey, Jordan; Deng, Zhengtao; Stultz, Collin M.; Lu, Timothy K

2014-01-01

Many natural underwater adhesives harness hierarchically assembled amyloid nanostructures to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Despite recent advances, our understanding of the molecular design, self-assembly, and structure-function relationship of those natural amyloid fibers remains limited. Thus, designing biomimetic amyloid-based adhesives remains challenging. Here, we report strong and multi-functional underwater adhesives obtained from fusing mussel foot proteins (Mfps) of Mytilus galloprovincialis with CsgA proteins, the major subunit of Escherichia coli amyloid curli fibers. These hybrid molecular materials hierarchically self-assemble into higher-order structures, in which, according to molecular dynamics simulations, disordered adhesive Mfp domains are exposed on the exterior of amyloid cores formed by CsgA. Our fibers have an underwater adhesion energy approaching 20.9 mJ/m2, which is 1.5 times greater than the maximum of bio-inspired and bio-derived protein-based underwater adhesives reported thus far. Moreover, they outperform Mfps or curli fibers taken on their own at all pHs and exhibit better tolerance to auto-oxidation than Mfps at pH ≥7.0. This work establishes a platform for engineering multi-component self-assembling materials inspired by nature. PMID:25240674

Strong Teens: A School-Based Small Group Experience for African American Males

Science.gov (United States)

White, Nathan J.; Rayle, Andrea Dixon

2007-01-01

This article describes the school-based, small group adaptation of the existing Strong Teens Curriculum (STC) for African American male adolescents in high schools. The STC was created to equip adolescents with skills that promote more effective social interaction and enhance personal emotional and psychological wellness. The authors present a…

Developing Novel Protein-based Materials using Ultrabithorax: Production, Characterization, and Functionalization

Science.gov (United States)

Huang, Zhao

2011-12-01

Compared to 'conventional' materials made from metal, glass, or ceramics, protein-based materials have unique mechanical properties. Furthermore, the morphology, mechanical properties, and functionality of protein-based materials may be optimized via sequence engineering for use in a variety of applications, including textile materials, biosensors, and tissue engineering scaffolds. The development of recombinant DNA technology has enabled the production and engineering of protein-based materials ex vivo. However, harsh production conditions can compromise the mechanical properties of protein-based materials and diminish their ability to incorporate functional proteins. Developing a new generation of protein-based materials is crucial to (i) improve materials assembly conditions, (ii) create novel mechanical properties, and (iii) expand the capacity to carry functional protein/peptide sequences. This thesis describes development of novel protein-based materials using Ultrabithorax, a member of the Hox family of proteins that regulate developmental pathways in Drosophila melanogaster. The experiments presented (i) establish the conditions required for the assembly of Ubx-based materials, (ii) generate a wide range of Ubx morphologies, (iii) examine the mechanical properties of Ubx fibers, (iv) incorporate protein functions to Ubx-based materials via gene fusion, (v) pattern protein functions within the Ubx materials, and (vi) examine the biocompatibility of Ubx materials in vitro. Ubx-based materials assemble at mild conditions compatible with protein folding and activity, which enables Ubx chimeric materials to retain the function of appended proteins in spatial patterns determined by materials assembly. Ubx-based materials also display mechanical properties comparable to existing protein-based materials and demonstrate good biocompatibility with living cells in vitro. Taken together, this research demonstrates the unique features and future potential of novel Ubx-based

Resolving glass transition in Te-based phase-change materials by modulated differential scanning calorimetry

Science.gov (United States)

Chen, Yimin; Mu, Sen; Wang, Guoxiang; Shen, Xiang; Wang, Junqiang; Dai, Shixun; Xu, Tiefeng; Nie, Qiuhua; Wang, Rongping

2017-10-01

Glass transitions of Te-based phase-change materials (PCMs) were studied by modulated differential scanning calorimetry. It was found that both Ge2Sb2Te5 and GeTe are marginal glass formers with ΔT (= T x - T g) less than 2.1 °C when the heating rate is below 3 °C min-1. The fragilities of Ge2Sb2Te5 and GeTe can be estimated as 46.0 and 39.7, respectively, around the glass transition temperature, implying that a fragile-to-strong transition would be presented in such Te-based PCMs. The above results provide direct experimental evidence to support the investigation of crystallization kinetics in supercooled liquid PCMs.

[Current status of bio-based materials industry in China].

Science.gov (United States)

Diao, Xiaoqian; Weng, Yunxuan; Huang, Zhigang; Yang, Nan; Wang, Xiyuan; Zhang, Min; Jin, Yujuan

2016-06-25

In recent years, bio-based materials are becoming a new dominant industry leading the scientific and technological innovation, and economic development of the world. We reviewed the new development of bio-based materials industry in China, analyzed the entire market of bio-based materials products comprehensively, and also stated the industry status of bio-based chemicals, such as lactic acid, 1,3-propanediol, and succinic acid; biodegradable bio-based polymers, such as co-polyester of diacid and diol, polylactic acid, carbon dioxide based copolymer, polyhydroxyalknoates, polycaprolactone, and thermoplastic bio-based plastics; non-biodegradable bio-based polymers, such as bio-based polyamide, polytrimethylene terephthalate, bio-based polyurethane, and bio-based fibers.

Carbon-Nanotube-Based Thermoelectric Materials and Devices

Energy Technology Data Exchange (ETDEWEB)

Blackburn, Jeffrey L. [Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden CO 80401-3305 USA; Ferguson, Andrew J. [Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden CO 80401-3305 USA; Cho, Chungyeon [Department of Mechanical Engineering, Texas A& M University, College Station TX 77843-3003 USA; Grunlan, Jaime C. [Department of Mechanical Engineering, Texas A& M University, College Station TX 77843-3003 USA

2018-01-22

Conversion of waste heat to voltage has the potential to significantly reduce the carbon footprint of a number of critical energy sectors, such as the transportation and electricity-generation sectors, and manufacturing processes. Thermal energy is also an abundant low-flux source that can be harnessed to power portable/wearable electronic devices and critical components in remote off-grid locations. As such, a number of different inorganic and organic materials are being explored for their potential in thermoelectric-energy-harvesting devices. Carbon-based thermoelectric materials are particularly attractive due to their use of nontoxic, abundant source-materials, their amenability to high-throughput solution-phase fabrication routes, and the high specific energy (i.e., W g-1) enabled by their low mass. Single-walled carbon nanotubes (SWCNTs) represent a unique 1D carbon allotrope with structural, electrical, and thermal properties that enable efficient thermoelectric-energy conversion. Here, the progress made toward understanding the fundamental thermoelectric properties of SWCNTs, nanotube-based composites, and thermoelectric devices prepared from these materials is reviewed in detail. This progress illuminates the tremendous potential that carbon-nanotube-based materials and composites have for producing high-performance next-generation devices for thermoelectric-energy harvesting.

Graphene-Based Carbon Materials for Electrochemical Energy Storage

Directory of Open Access Journals (Sweden)

Fei Liu

2013-01-01

Full Text Available Because of their unique 2D structure and numerous fascinating properties, graphene-based materials have attracted particular attention for their potential applications in energy storage devices. In this review paper, we focus on the latest work regarding the development of electrode materials for batteries and supercapacitors from graphene and graphene-based carbon materials. To begin, the advantages of graphene as an electrode material and the existing problems facing its use in this application will be discussed. The next several sections deal with three different methods for improving the energy storage performance of graphene: the restacking of the nanosheets, the doping of graphene with other elements, and the creation of defects on graphene planes. State-of-the-art work is reviewed. Finally, the prospects and further developments in the field of graphene-based materials for electrochemical energy storage are discussed.

Water vapor movement in freezing aggregate base materials.

Science.gov (United States)

2014-06-01

The objectives of this research were to 1) measure the extent to which water vapor movement results in : water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement : in freezing base materials;...

Materiality in a Practice-Based Approach

Science.gov (United States)

Svabo, Connie

2009-01-01

Purpose: The paper aims to provide an overview of the vocabulary for materiality which is used by practice-based approaches to organizational knowing. Design/methodology/approach: The overview is theoretically generated and is based on the anthology Knowing in Organizations: A Practice-based Approach edited by Nicolini, Gherardi and Yanow. The…

The preliminary Long Duration Exposure Facility (LDEF) materials data base

International Nuclear Information System (INIS)

Funk, J.G.; Strickland, J.W.; Davis, J.M.

1992-10-01

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and author(s) or principal investigator(s). The LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which was computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. This paper describes the LDEF Materials Data Base and includes step-by-step example searches using the data base. Information on how to become an authorized user of the system is included

The preliminary Long Duration Exposure Facility (LDEF) materials data base

Science.gov (United States)

Funk, Joan G.; Strickland, John W.; Davis, John M.

1992-01-01

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and author(s) or principal investigator(s). The LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which was computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. This paper describes the LDEF Materials Data Base and includes step-by-step example searches using the data base. Information on how to become an authorized user of the system is included.

Strongly Correlated Systems Theoretical Methods

CERN Document Server

Avella, Adolfo

2012-01-01

The volume presents, for the very first time, an exhaustive collection of those modern theoretical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciates consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as po...

Strongly correlated systems numerical methods

CERN Document Server

Mancini, Ferdinando

2013-01-01

This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possi...

Strongly correlated systems experimental techniques

CERN Document Server

Mancini, Ferdinando

2015-01-01

The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

Development of a materials data base for modeling

International Nuclear Information System (INIS)

Iwata, S.; Ashino, T.; Ishino, S.

1988-01-01

Materials selection for fusion reactors requires a materials data base and a set of methods to estimate material properties in a ''virtual'' fusion reactor. This estimation process, namely, modeling, is analyzed as compromising of design requirements, available data bases and methods of estimation, and a concept of an ideal computer system to support this modeling process is proposed. The limitations of a commercial DBMS (Data Base Management System) to handle sophisticated materials data are described in accordance with our experiences. Secondly, ways to manipulate analytical expressions are discussed as the next step for computer assisted modeling. Finally, an advanced method is presented which is able to manage models and data in the same manner without paying attention to annoying rules compelled by constraints of using computers. (orig.)

Unconventional superconductivity in cuprates, cobaltates and graphene. What is universal and what is material-dependent in strongly versus weakly correlated materials?

International Nuclear Information System (INIS)

Kiesel, Maximilian Ludwig

2013-01-01

A general theory for all classes of unconventional superconductors is still one of the unsolved key issues in condensed-matter physics. Actually, it is not yet fully settled if there is a common underlying pairing mechanism. Instead, it might be possible that several distinct sources for unconventional (not phonon-mediated) superconductivity have to be considered, or an electron-phonon interaction is not negligible. The focus of this thesis is on the most probable mechanism for the formation of Cooper pairs in unconventional superconductors, namely a strictly electronic one where spin fluctuations are the mediators. Studying different superconductors in this thesis, the emphasis is put on material-independent features of the pairing mechanism. In addition, the investigation of the phase diagrams enables a view on the vicinity of superconductivity. Thus, it is possible to clarify which competing quantum fluctuations enhance or weaken the propensity for a superconducting state. The broad range of superconducting materials requires the use of more than one numerical technique to study an appropriate microscopic description. This is not a problem but a big advantage because this facilitates the approach-independent description of common underlying physics. For this evaluation, the strongly correlated cuprates are simulated with the variational cluster approach. Especially the question of a pairing glue is taken into consideration. Furthermore, it is possible to distinguish between retarded and non-retarded contributions to the gap function. The cuprates are confronted with the cobaltate Na x CoO 2 and graphene. These weakly correlated materials are investigated with the functional renormalization group (fRG) and reveal a comprehensive phase diagram, including a d+id-wave superconductivity, which breaks time-reversal symmetry. The corresponding gap function is nodeless, but for NaCoO, it features a doping-dependent anisotropy. In addition, some general considerations on

Unconventional superconductivity in cuprates, cobaltates and graphene. What is universal and what is material-dependent in strongly versus weakly correlated materials?

Energy Technology Data Exchange (ETDEWEB)

Kiesel, Maximilian Ludwig

2013-02-08

A general theory for all classes of unconventional superconductors is still one of the unsolved key issues in condensed-matter physics. Actually, it is not yet fully settled if there is a common underlying pairing mechanism. Instead, it might be possible that several distinct sources for unconventional (not phonon-mediated) superconductivity have to be considered, or an electron-phonon interaction is not negligible. The focus of this thesis is on the most probable mechanism for the formation of Cooper pairs in unconventional superconductors, namely a strictly electronic one where spin fluctuations are the mediators. Studying different superconductors in this thesis, the emphasis is put on material-independent features of the pairing mechanism. In addition, the investigation of the phase diagrams enables a view on the vicinity of superconductivity. Thus, it is possible to clarify which competing quantum fluctuations enhance or weaken the propensity for a superconducting state. The broad range of superconducting materials requires the use of more than one numerical technique to study an appropriate microscopic description. This is not a problem but a big advantage because this facilitates the approach-independent description of common underlying physics. For this evaluation, the strongly correlated cuprates are simulated with the variational cluster approach. Especially the question of a pairing glue is taken into consideration. Furthermore, it is possible to distinguish between retarded and non-retarded contributions to the gap function. The cuprates are confronted with the cobaltate Na{sub x}CoO{sub 2} and graphene. These weakly correlated materials are investigated with the functional renormalization group (fRG) and reveal a comprehensive phase diagram, including a d+id-wave superconductivity, which breaks time-reversal symmetry. The corresponding gap function is nodeless, but for NaCoO, it features a doping-dependent anisotropy. In addition, some general

Fractal nature of humic materials

International Nuclear Information System (INIS)

Rice, J.A.

1992-01-01

Fractals are geometric representatives of strongly disordered systems whose structure is described by nonintegral dimensions. A fundamental tenet of fractal geometry is that disorder persists at any characterization scale-length used to describe the system. The nonintegral nature of these fractal dimensions is the result of the realization that a disordered system must possess more structural detail than an ordered system with classical dimensions of 1, 2, or 3 in order to accommodate this ''disorder within disorder.'' Thus from a fractal perspective, disorder is seen as an inherent characteristic of the system rather than as a perturbative phenomena forced upon it. Humic materials are organic substances that are formed by the profound alteration of organic matter in a natural environment. They can be operationally divided into 3 fractions; humic acid (soluble in base), fulvic acid (soluble in acid or base), and humin (insoluble in acid or base). Each of these fraction has been shown to be an extremely heterogeneous mixture. These mixtures have proven so intractable that they may represent the ultimate in molecular disorder. In fact, based on the characteristics that humic materials must possess in order to perform their functions in natural systems, it has been proposed that the fundamental chemical characteristic of a humic material is not a discrete chemical structure but a pronounced lack of order on a molecular level. If the fundamental chemical characteristic of a humic material is a strongly disordered nature, as has been proposed, then humic materials should be amenable to characterization by fractal geometry. The purpose of this paper is to test this hypothesis

RIM as the data base management system for a material properties data base

Science.gov (United States)

Karr, P. H.; Wilson, D. J.

1984-01-01

Relational Information Management (RIM) was selected as the data base management system for a prototype engineering materials data base. The data base provides a central repository for engineering material properties data, which facilitates their control. Numerous RIM capabilities are exploited to satisfy prototype data base requirements. Numerical, text, tabular, and graphical data and references are being stored for five material types. Data retrieval will be accomplished both interactively and through a FORTRAN interface. The experience gained in creating and exercising the prototype will be used in specifying requirements for a production system.

Materiales Maria Maya: community-based materials development.

Science.gov (United States)

Moran, B C

1982-01-01

Materials Maria Maya (MMM) is a Guatemalan organization which has dedicated itself to making health education more relevant to the rural Mayans who constitute the majority of Guatemala's population. The administration and direction of the project is in the hands of a team of qualified Mayan men and women. Funding is primarily through various charitable international organizations. The content of preexisting health education programs, strongly influenced by the dominant "ladino" Spanish speaking culture was found to be inappropriate to the goal of this program. MMM set about to formulate a new teaching format which would draw upon, rather than trample over, established cultural practices and life styles. By a process of trial and error, involving small scale field tests, a new program format was developed. By questioning local women about perceived priority areas, through the study of morbidity and mortality data, decisions were made as to topics to be covered. Investigators, authors, and artists worked together to form a "materials package" which was then subject to pretesting. Out of this effort, MMM has been able to come up with a method to encourage more effective participative teaching through the use of education materials.

Key parameters in testing biodegradation of bio-based materials in soil.

Science.gov (United States)

Briassoulis, D; Mistriotis, A

2018-05-05

Biodegradation of plastics in soil is currently tested by international standard testing methods (e.g. ISO 17556-12 or ASTM D5988-12). Although these testing methods have been developed for plastics, it has been shown in project KBBPPS that they can be extended also to lubricants with small modifications. Reproducibility is a critical issue regarding biodegradation tests in the laboratory. Among the main testing variables are the soil types and nutrients available (mainly nitrogen). For this reason, the effect of the soil type on the biodegradation rates of various bio-based materials (cellulose and lubricants) was tested for five different natural soil types (loam, loamy sand, clay, clay-loam, and silt-loam organic). It was shown that use of samples containing 1 g of C in a substrate of 300 g of soil with the addition of 0.1 g of N as nutrient strongly improves the reproducibility of the test making the results practically independent of the soil type with the exception of the organic soil. The sandy soil was found to need addition of higher amount of nutrients to exhibit similar biodegradation rates as those achieved with the other soil types. Therefore, natural soils can be used for Standard biodegradation tests of bio-based materials yielding reproducible results with the addition of appropriate nutrients. Copyright © 2018 Elsevier Ltd. All rights reserved.

Carbon-Nanotube-Based Thermoelectric Materials and Devices.

Science.gov (United States)

Blackburn, Jeffrey L; Ferguson, Andrew J; Cho, Chungyeon; Grunlan, Jaime C

2018-03-01

Conversion of waste heat to voltage has the potential to significantly reduce the carbon footprint of a number of critical energy sectors, such as the transportation and electricity-generation sectors, and manufacturing processes. Thermal energy is also an abundant low-flux source that can be harnessed to power portable/wearable electronic devices and critical components in remote off-grid locations. As such, a number of different inorganic and organic materials are being explored for their potential in thermoelectric-energy-harvesting devices. Carbon-based thermoelectric materials are particularly attractive due to their use of nontoxic, abundant source-materials, their amenability to high-throughput solution-phase fabrication routes, and the high specific energy (i.e., W g -1 ) enabled by their low mass. Single-walled carbon nanotubes (SWCNTs) represent a unique 1D carbon allotrope with structural, electrical, and thermal properties that enable efficient thermoelectric-energy conversion. Here, the progress made toward understanding the fundamental thermoelectric properties of SWCNTs, nanotube-based composites, and thermoelectric devices prepared from these materials is reviewed in detail. This progress illuminates the tremendous potential that carbon-nanotube-based materials and composites have for producing high-performance next-generation devices for thermoelectric-energy harvesting. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Material model of pelvic bone based on modal analysis: a study on the composite bone.

Science.gov (United States)

Henyš, Petr; Čapek, Lukáš

2017-02-01

Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74 % in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34 %. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

Self-shielding and burn-out effects in the irradiation of strongly-neutron-absorbing material

International Nuclear Information System (INIS)

Sekine, T.; Baba, H.

1978-01-01

Self-shielding and burn-out effects are discussed in the evaluation of radioisotopes formed by neutron irradiation of a strongly-neutron-absorbing material. A method of the evaluation of such effects is developed both for thermal and epithermal neutrons. Gadolinium oxide uniformly mixed with graphite powder was irradiated by reactor-neutrons together with pieces of a Co-Al alloy wire (the content of Co being 0.475%) as the neutron flux monitor. The configuration of the samples and flux monitors in each of two irradiations is illustrated. The yields of activities produced in the irradiated samples were determined by the γ-spectrometry with a Ge(Li) detector of a relative detection efficiency of 8%. Activities at the end of irradiation were estimated by corrections due to pile-up, self-absorption, detection efficiency, branching ratio, and decay of the activity. Results of the calculation are discussed in comparison with the observed yields of 153 Gd, 160 Tb, and 161 Tb for the case of neutron irradiation of disc-shaped targets of gadolinium oxide. (T.G.)

Reaproveitamento da areia de fundição como material de base e sub-base de pavimentos flexíveis

Directory of Open Access Journals (Sweden)

Luis Miguel Gutiérrez Klinsky

2010-04-01

Full Text Available O principal resíduo das indústrias de fundição é a areia de fundição de descarte que, no ano 2007, no Brasil, ultrapassou os três milhões de toneladas. Com o objetivo de preservar os recursos naturais e diminuir a degradação do meio ambiente, procuram-se alternativas para reutilizar a areia de fundição em grandes quantidades e a utilização na construção de rodovias fornece oportunidades. Assim, este trabalho avaliou a possibilidade de reutilizar a areia de fundição, misturada a solos argilosos, como material de base e subbase para rodovias de baixo volume de tráfego e vias urbanas para a região de Sertãozinho/SP, que é geradora de resíduo de areia de fundição, mas carece de jazidas de solos arenosos para a construção de rodovias. No estudo foi empregada a técnica de estabilização granulométrica para obter misturas solo-areia em diferentes proporções, nas quais foram realizados ensaios de classificação, propriedades mecânicas e ambientais. Os resultados dos ensaios mostraram que solos argilosos com 60% de areia de fundição adicionada poderiam ser utilizados como material de sub-base e base para pavimentos de tráfego leve, com baixo risco de poluir o meio ambiente.

<strong>Abstract>: The main residue of the foundry industries is the foundry sand that in 2007, in Brazil, exceeded three millions tons. The modern world searches the preservation of the natural resources and the reduction of the environment degeneration. Aiming at these objectives, new alternatives are researched to reuse the foundry sand in large amounts and the pavement construction provides opportunities. This paper evaluated the reuse of the foundry sand in pavement sub-bases and bases, through its incorporation to clay soils from Sertaozinho/SP. This region has a high production of foundry metals and residues, and does not have natural sandy soils deposits for pavement construction. This study used the mechanic

Whole Language-Based English Reading Materials

Directory of Open Access Journals (Sweden)

Dian Erlina

2016-05-01

Full Text Available This Research and Development (R&D aims at developing English reading materials for undergraduate EFL students of Universitas Islam Negeri (UIN Raden Fatah Palembang, Indonesia. Research data were obtained through questionnaires, tests, and documents. The results of the research show that the existing materials are not relevant to the students’ need, so there is a need for developing new materials based on whole language principles. In general, the new developed materials are considered reliable by the experts, students, and lecturers. The materials are also effective in improving students’ reading achievement. The final product of the materials consists of a course book entitled Whole Language Reading (WLR and a teacher’s manual. WLR provides rich input of reading strategies, variety of topics, concepts, texts, activities, tasks, and evaluations. Using this book makes reading more holistic and meaningful as it provides integration across language skills and subject areas.

Wearable energy sources based on 2D materials.

Science.gov (United States)

Yi, Fang; Ren, Huaying; Shan, Jingyuan; Sun, Xiao; Wei, Di; Liu, Zhongfan

2018-05-08

Wearable energy sources are in urgent demand due to the rapid development of wearable electronics. Besides flexibility and ultrathin thickness, emerging 2D materials present certain extraordinary properties that surpass the properties of conventional materials, which make them advantageous for high-performance wearable energy sources. Here, we provide a comprehensive review of recent advances in 2D material based wearable energy sources including wearable batteries, supercapacitors, and different types of energy harvesters. The crucial roles of 2D materials in the wearable energy sources are highlighted. Based on the current progress, the existing challenges and future prospects are outlined and discussed.

Silicon based light-emitting materials and devices

International Nuclear Information System (INIS)

Chen Weide

1999-01-01

Silicon based light-emitting materials and devices are the key to optoelectronic integration. Recently, there has been significant progress in materials engineering methods. The author reviews the latest developments in this area including erbium doped silicon, porous silicon, nanocrystalline silicon and Si/SiO 2 superlattice structures. The incorporation of these different materials into devices is described and future device prospects are assessed

Listener: a probe into information based material specification

DEFF Research Database (Denmark)

Ramsgaard Thomsen, Mette; Karmon, Ayelet

2011-01-01

This paper presents the thinking and making of the architectural research probe Listener. Developed as an interdisciplinary collaboration between textile design and architecture, Listener explores how information based fabrication technologies are challenging the material practices of architecture....... The paper investigates how textile design can be understood as a model for architectural production providing new strategies for material specification and allowing the thinking of material as inherently variegated and performative. The paper traces the two fold information based strategies present...

Development of bio-hybrid material based on Salmonella ...

African Journals Online (AJOL)

The immobilization of a whole microbial cell is an important process used in nanotechnology of biosensors and other related fields, especially the development of bio-hybrid materials based on live organisms and inorganic compounds. Here, we described an essay to develop a bio-hybrid material based on Salmonella ...

Supramolecular materials based on hydrogen-bonded polymers

NARCIS (Netherlands)

ten Brinke, Gerrit; Ruokolainen, Janne; Ikkala, Olli; Binder, W

2007-01-01

Combining supramolecular principles with block copolymer self-assembly offers unique possibilities to create materials with responsive and/or tunable properties. The present chapter focuses on supramolecular materials based on hydrogen bonding and (block co-) polymers. Several cases will be

Friction behavior of cobalt base and nickel base hardfacing materials in high temperature sodium

International Nuclear Information System (INIS)

Mizobuchi, Syotaro; Kano, Shigeki; Nakayama, Kohichi; Atsumo, Hideo

1980-01-01

A friction behavior of the hardfacing materials such as cobalt base alloy ''Stellite'' and nickel base alloy ''Colmonoy'' used in the sliding components of a sodium cooled fast breeder reactor was investigated in various sodium environments. Also, friction tests on these materials were carried out in argon environment. And they were compared with those in sodium environment. The results obtained are as follows: (1) In argon, the cobalt base hardfacing alloy showed better friction behavior than the nickel base hardfacing alloy. In sodium, the latter was observed to have the better friction behavior being independent of the sodium temperature. (2) The friction coefficient of each material tends to become lower by pre-exposure in sodium. Particularly, this tendency was remarkable for the nickel base hardfacing alloy. (3) The friction coefficient between SUS 316 and one of these hardfacing materials was higher than that between latter materials. Also, some elements of hardfacing alloys were recognized to transfer on the friction surface of SUS 316 material. (4) It was observed that each tested material has a greater friction coefficient with a decrease of the oxygen content in sodium. (author)

Dielectric loss property of strong acids doped polyaniline (PANi)

Science.gov (United States)

Amalia, Rianti; Hafizah, Mas Ayu Elita; Andreas, Manaf, Azwar

2018-04-01

In this study, strong acid doped polyaniline (PANi) has been successfully fabricated through the chemical oxidative polymerization process with various polymerization times. Nonconducting PANi resulting from the polymerization process at various polymerization times were then doped by a strong acid HClO4 to generate dielectric properties. Ammonium Persulfate (APS) as an initiator was used during Polymerization process to develop dark green precipitates which then called Emeraldine Base Polyaniline (PANi-EB). The PANi-EB was successively doped by strong acid HClO4 with dopant and PANi ratio 10:1 to enhance the electrical conductivity. The conductivity of doped PANi was evaluated by Four Point Probe. Results of evaluation showed that the conductivity values of HClO4 doped PANi were in the range 337-363 mS/cm. The dielectric properties of doped PANi were evaluated by Vector Network Analyzer (VNA) which suggested that an increase in the permittivity value in the conducting PANi. It is concluded that PANi could be a potential candidate for electromagnetic waves absorbing materials.

Corrosion of candidate iron-base waste package structural barrier materials in moist salt environments

International Nuclear Information System (INIS)

Westerman, R.E.; Pitman, S.G.

1984-11-01

Mild steels are considered to be strong candidates for waste package structural barrier (e.g., overpack) applications in salt repositories. Corrosion rates of these materials determined in autoclave tests utilizing a simulated intrusion brine based on Permian Basin core samples are low, generally <25 μm (1 mil) per year. When the steels are exposed to moist salts containing simulated inclusion brines, the corrosion rates are found to increase significantly. The magnesium in the inclusion brine component of the environment is believed to be responsible for the increased corrosion rates. 1 reference, 4 figures, 2 tables

Photochemistry of Fe(Iii)-Carboxylates in Polysaccharide-Based Materials with Tunable Mechanical Properties

Science.gov (United States)

Giammanco, Giuseppe E.

We present the formulation and study of light-responsive materials based on carboxylate-containing polysaccharides. The functional groups in these natural polymers allow for strong interactions with transition metal ions such as Fe(III). The known photochemistry of hydroxycarboxylic acids in natural waters inspired us in exploring the visible light induced photochemistry of the carboxylates in these polysaccharides when coordinated to Fe(III) ions. Described in this dissertation are the design and characterization of the Fe(III)-polysaccharide materials, specifically the mechanistic aspects of the photochemistry and the effects that these reactions have on the structure of the polymer materials. We present a study of the quantitative photochemistry of different polysaccharide systems, where the presence of uronic acids was important for the photoreaction to take place. Alginate (Alg), pectate (Pec), hyaluronic acid (Hya), xanthan gum (Xan), and a polysaccharide extracted from the Noni fruit (NoniPs), were among the natural uronic acid-containing polysaccharide (UCPS) systems we analyzed. Potato starch, lacking of uronate groups, did not present any photochemistry in the presence of Fe(III); however, we were able to induce a photochemical response in this polysaccharide upon chemical manipulation of its functional groups. Important structure-function relationships were drawn from this study. The uronate moiety present in these polysaccharides is then envisioned as a tool to induce response to light in a variety of materials. Following this approach, we report the formulation of materials for controlled drug release, able to encapsulate and release different drug models only upon illumination with visible light. Furthermore, hybrid hydrogels were prepared from UPCS and non-responsive polymers. Different properties of these materials could be tuned by controlling the irradiation time, intensity and location. These hybrid gels were evaluated as scaffolds for tissue

Vortex trapping in Pb-alloy Josephson junctions induced by strong sputtering of the base electrode

International Nuclear Information System (INIS)

Wada, M.; Nakano, J.; Yanagawa, F.

1985-01-01

It is observed that strong rf sputtering of the Pb-alloy base electrodes causes the junctions to trap magnetic vortices and thus induces Josephson current (I/sub J/) suppression. Trapping begins to occur when the rf sputtering that removes the native thermal oxide on the base electrode is carried out prior to rf plasma oxidation. Observed large I/sub J/ suppression is presumably induced by the concentration of vortices into the sputtered area upon cooling the sample below the transition temperature. This suggests a new method of the circumvention of the vortex trapping by strongly rf sputtering the areas of the electrode other than the junction areas

Characterization of asphalt treated base course material

Science.gov (United States)

2010-06-01

Asphalt-treated bases are often used in new pavements; the materials are available and low-cost, but there is little data on how these materials perform in cold regions. : This study investigated four ATB types (hot asphalt, emulsion, foamed asphalt,...

A strong-topological-metal material with multiple Dirac cones

OpenAIRE

Ji, Huiwen; Pletikosić, I; Gibson, Q. D.; Sahasrabudhe, Girija; Valla, T.; Cava, R. J.

2015-01-01

We report a new, cleavable, strong-topological-metal, Zr2Te2P, which has the same tetradymite-type crystal structure as the topological insulator Bi2Te2Se. Instead of being a semiconductor, however, Zr2Te2P is metallic with a pseudogap between 0.2 and 0.7 eV above the fermi energy (EF). Inside this pseudogap, two Dirac dispersions are predicted: one is a surface-originated Dirac cone protected by time-reversal symmetry (TRS), while the other is a bulk-originated and slightly gapped Dirac cone...

Recent Advances in the Sound Insulation Properties of Bio-based Materials

Directory of Open Access Journals (Sweden)

Xiaodong Zhu

2013-12-01

Full Text Available Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulation products. Furthermore, principal models of sound transmission are discussed in order to aid in an understanding of sound transmission properties of bio-based materials. In addition, the review presents discussions on the composite structure optimization and future research in using co-extruded wood plastic composite for sound insulation control. This review contributes to the body of knowledge on the sound transmission properties of bio-based materials, provides a better understanding of the models of some multiporous bio-based materials and multilayered structures, and contributes to the wider adoption of bio-based materials as sound absorbers.

Degradation of carbon-based materials under ablative conditions produced by a high enthalpy plasma jet

Directory of Open Access Journals (Sweden)

Gilberto Petraconi

2010-04-01

Full Text Available A stationary experiment was performed to study the degradation of carbon-based materials by immersion in a plasma jet. In the experiment, graphite and C/C composite were chosen as the target materials, and the reactive plasma jet was generated by an air plasma torch. For macroscopic study of the material degradation, the sample’s mass losses were measured as function of the exposure time under various temperatures on the sample surface. A microscopic analysis was then carried out for the study of microscopic aspects of the erosion of material surface. These experiments showed that the mass loss per unit area is approximately proportional to the exposure time and strongly depends on the temperature of the material surface. The mass erosion rate of graphite was appreciably higher than the C/C composite. The ablation rate in the carbon matrix region in C/C composite was also noticeably higher than that in the fiber region. In addition, the latter varied according to the orientation of fibers relatively to the flow direction. These tests indicated an excellent ablation resistance of the C/C composite, thus being a reliable material for rocket nozzles and heat shielding elements of the protection systems of hypersonic apparatuses from aerodynamic heating.

Advanced superconducting materials

International Nuclear Information System (INIS)

Fluekiger, R.

1983-11-01

The superconducting properties of various materials are reviewed in view of their use in high field magnets. The critical current densities above 12 T of conductors based on NbN or PbMo 6 S 8 are compared to those of the most advanced practical conductors based on alloyed by Nb 3 Sn. Different aspects of the mechanical reinforcement of high field conductors, rendered necessary by the strong Lorentz forces (e.g. in fusion magnets), are discussed. (orig.) [de

S-containing copolymer as cathode material in poly(ethylene oxide)-based all-solid-state Li-S batteries

Science.gov (United States)

Gracia, Ismael; Ben Youcef, Hicham; Judez, Xabier; Oteo, Uxue; Zhang, Heng; Li, Chunmei; Rodriguez-Martinez, Lide M.; Armand, Michel

2018-06-01

Inverse vulcanization copolymers (p(S-DVB)) from the radical polymerization of elemental sulfur and divinylbenzene (DVB) have been studied as cathode active materials in poly(ethylene oxide) (PEO)-based all-solid-state Li-S cells. The Li-S cell comprising the optimized p(S-DVB) cathode (80:20 w/w S/DVB ratio) and lithium bis(fluorosulfonyl)imide/PEO (LiFSI/PEO) electrolyte shows high specific capacity (ca. 800 mAh g-1) and high Coulombic efficiency for 50 cycles. Most importantly, polysulfide (PS) shuttle is highly mitigated due to the strong interactions of PS species with polymer backbone in p(S-DVB). This is demonstrated by the stable cycling of the p(S-DVB)-based cell using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/PEO electrolyte, where successful charging cannot be achieved even at the first cycle with plain elemental S-based cathode material due to the severe PS shuttle phenomenon. These results suggest that inverse vulcanization copolymers are promising alternatives to elemental sulfur for enhancing the electrochemical performance of PEO-based all-solid-state Li-S cells.

Material recognition based on thermal cues: Mechanisms and applications.

Science.gov (United States)

Ho, Hsin-Ni

2018-01-01

Some materials feel colder to the touch than others, and we can use this difference in perceived coldness for material recognition. This review focuses on the mechanisms underlying material recognition based on thermal cues. It provides an overview of the physical, perceptual, and cognitive processes involved in material recognition. It also describes engineering domains in which material recognition based on thermal cues have been applied. This includes haptic interfaces that seek to reproduce the sensations associated with contact in virtual environments and tactile sensors aim for automatic material recognition. The review concludes by considering the contributions of this line of research in both science and engineering.

Extracting dimer structures from simulations of organic-based materials using QM/MM methods

Energy Technology Data Exchange (ETDEWEB)

Pérez-Jiménez, A.J., E-mail: aj.perez@ua.es; Sancho-García, J.C., E-mail: jc.sancho@ua.es

2015-09-28

Highlights: • DFT geometries of isolated dimers in organic crystals differ from experimental ones. • This can be corrected using QM/MM geometry optimizations. • The QM = B3LYP–D3(ZD)/cc-pVDZ and MM = GAFF combination works reasonably well. - Abstract: The functionality of weakly bound organic materials, either in Nanoelectronics or in Materials Science, is known to be strongly affected by their morphology. Theoretical predictions of the underlying structure–property relationships are frequently based on calculations performed on isolated dimers, but the optimized structure of the latter may significantly differ from experimental data even when dispersion-corrected methods are used for it. Here, we address this problem on two organic crystals, namely coronene and 5,6,11,12-tetrachlorotetracene, concluding that it is caused by the absence of the surrounding monomers present in the crystal, and that it can be efficiently cured when the dimer is embedded into a general Quantum Mechanics/Molecular Mechanics (QM/MM) geometry optimization scheme. We also investigate how the size of the MM region affects the results. These findings may be helpful for the simulation of the morphology of active materials in crystalline or glassy samples.

Network-Based Material Requirements Planning (NBMRP) in ...

African Journals Online (AJOL)

Network-Based Material Requirements Planning (NBMRP) in Product Development Project. ... International Journal of Development and Management Review ... To address the problems, this study evaluated the existing material planning practice, and formulated a NBMRP model out of the variables of the existing MRP and ...

Towards socio-material approaches in simulation-based education: lessons from complexity theory.

Science.gov (United States)

Fenwick, Tara; Dahlgren, Madeleine Abrandt

2015-04-01

Review studies of simulation-based education (SBE) consistently point out that theory-driven research is lacking. The literature to date is dominated by discourses of fidelity and authenticity - creating the 'real' - with a strong focus on the developing of clinical procedural skills. Little of this writing incorporates the theory and research proliferating in professional studies more broadly, which show how professional learning is embodied, relational and situated in social - material relations. A key concern for medical educators concerns how to better prepare students for the unpredictable and dynamic ambiguity of professional practice; this has stimulated the movement towards socio-material theories in education that address precisely this question. Among the various socio-material theories that are informing new developments in professional education, complexity theory has been of particular importance for medical educators interested in updating current practices. This paper outlines key elements of complexity theory, illustrated with examples from empirical study, to argue its particular relevance for improving SBE. Complexity theory can make visible important material dynamics, and their problematic consequences, that are not often noticed in simulated experiences in medical training. It also offers conceptual tools that can be put to practical use. This paper focuses on concepts of emergence, attunement, disturbance and experimentation. These suggest useful new approaches for designing simulated settings and scenarios, and for effective pedagogies before, during and following simulation sessions. Socio-material approaches such as complexity theory are spreading through research and practice in many aspects of professional education across disciplines. Here, we argue for the transformative potential of complexity theory in medical education using simulation as our focus. Complexity tools open questions about the socio-material contradictions inherent in

[Evidence-based management of medical disposable materials].

Science.gov (United States)

Yang, Hai

2009-03-01

Evidence-based management of medical disposable materials pays attention to collect evidence comprehensively and systematically, accumulate and create evidence through its own work and also evaluate evidence strictly. This can be used as a function to guide out job. Medical disposable materials evidence system contains product register qualification, product quality certification, supplier's behavior, internal and external communication evidence. Managers can find different ways in creating and using evidence referring to specific inside and outside condition. Evidence-based management can help accelerating the development of management of medical disposable materials from traditional experience pattern to a systematic and scientific pattern. It also has the very important meaning to improve medical quality, control the unreasonable growth of medical expense and make purchase and supply chain be more efficient.

Molybdenum silicide based materials and their properties

International Nuclear Information System (INIS)

Yao, Z.; Stiglich, J.; Sudarshan, T.S.

1999-01-01

Molybdenum disilicide (MoSi 2 ) is a promising candidate material for high temperature structural applications. It is a high melting point (2030 C) material with excellent oxidation resistance and a moderate density (6.24 g/cm 3 ). However, low toughness at low temperatures and high creep rates at elevated temperatures have hindered its commercialization in structural applications. Much effort has been invested in MoSi 2 composites as alternatives to pure molybdenum disilicide for oxidizing and aggressive environments. Molybdenum disilicide-based heating elements have been used extensively in high-temperature furnaces. The low electrical resistance of silicides in combination with high thermal stability, electron-migration resistance, and excellent diffusion-barrier characteristics is important for microelectronic applications. Projected applications of MoSi 2 -based materials include turbine airfoils, combustion chamber components in oxidizing environments, missile nozzles, molten metal lances, industrial gas burners, diesel engine glow plugs, and materials for glass processing. On this paper, synthesis, fabrication, and properties of the monolithic and composite molybdenum silicides are reviewed

Identifying and Analyzing Strong Components of an Industrial Network Based on Cycle Degree

Directory of Open Access Journals (Sweden)

Zhiying Zhang

2016-01-01

Full Text Available In the era of big data and cloud computing, data research focuses not only on describing the individual characteristics but also on depicting the relationships among individuals. Studying dependence and constraint relationships among industries has aroused significant interest in the academic field. From the network perspective, this paper tries to analyze industrial relational structures based on cycle degree. The cycle degree of a vertex, that is, the number of cycles through a vertex in an industrial network, can describe the roles of the vertices of strong components in industrial circulation. In most cases, different vertices in a strong component have different cycle degrees, and the one with a larger cycle degree plays more important roles. However, the concept of cycle degree does not involve the lengths of the cycles, which are also important for circulations. The more indirect the relationship between two industries is, the weaker it is. In order to analyze strong components thoroughly, this paper proposes the concept of circular centrality taking into consideration the influence by two factors: the lengths and the numbers of cycles through a vertex. Exemplification indicates that a profound analysis of strong components in an industrial network can reveal the features of an economy.

Room temperature ferromagnetism in a phthalocyanine based carbon material

International Nuclear Information System (INIS)

Honda, Z.; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N.; Hagiwara, M.; Kida, T.

2014-01-01

We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T c  = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material

Room temperature ferromagnetism in a phthalocyanine based carbon material

Energy Technology Data Exchange (ETDEWEB)

Honda, Z., E-mail: honda@fms.saitama-u.ac.jp; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N. [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Hagiwara, M.; Kida, T. [KYOKUGEN (Center for Quantum Science and Technology under Extreme Conditions), Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

2014-02-07

We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T{sub c} = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material.

Starting Strong: Talent-based Branching of Newly Commissioned U.S. Army Officers

Science.gov (United States)

2016-04-01

security policy formulation. iii v Strategic Studies Institute and U.S. Army War College Press STARTING STRONG: TALENT -BASED BRANCHING OF NEWLY...public release; distribution is unlimited. ***** This publication is subject to Title 17, United States Code , Sections 101 and 105. It is in the public...SSI website at www.StrategicStudiesInstitute.army.mil/newsletter. ***** This volume is the 9th in a series of monographs on officer talent management

Utilizing strongly absorbing materials for low-loss surface-wave nonlinear optics

Science.gov (United States)

Grosse, Nicolai B.; Franz, Philipp; Heckmann, Jan; Pufahl, Karsten; Woggon, Ulrike

2018-04-01

Optical media endowed with large nonlinear susceptibilities are highly prized for their employment in frequency conversion and the generation of nonclassical states of light. Although the presence of an optical resonance can greatly increase the nonlinear response (e.g., in epsilon-near-zero materials), the non-negligible increase in linear absorption often precludes the application of such materials in nonlinear optics. Absorbing materials prepared as thin films, however, can support a low-loss surface wave: the long-range surface exciton polariton (LRSEP). Its propagation lifetime increases with greater intrinsic absorption and reduced film thickness, provided that the film is embedded in a transparent medium (symmetric cladding). We explore LRSEP propagation in a molybdenum film by way of a prism-coupling configuration. Our observations show that excitation of the LRSEP mode leads to a dramatic increase in the yield of second-harmonic generation. This implies that the LRSEP mode is an effective vehicle for utilizing the nonlinear response of absorbing materials.

Strong anisotropy effect in an iron-based superconductor CaFe0.882Co0.118AsF

Science.gov (United States)

Ma, Yonghui; Ji, Qiucheng; Hu, Kangkang; Gao, Bo; Li, Wei; Mu, Gang; Xie, Xiaoming

2017-07-01

The anisotropy of iron-based superconductors is much smaller than that of the cuprates and that predicted by theoretical calculations. A credible understanding for this experimental fact is still lacking up to now. Here we experimentally study the magnetic-field-angle dependence of electronic resistivity in the superconducting phase of an iron-based superconductor CaFe{}0.882Co{}0.118AsF, and find the strongest anisotropy effect of the upper critical field among the iron-based superconductors based on the framework of Ginzburg-Landau theory. The evidence of the energy band structure and charge density distribution from electronic structure calculations demonstrates that the observed strong anisotropic effect mainly comes from the strong ionic bonding in between the ions of Ca2+ and F-, which weakens the interlayer coupling between the layers of FeAs and CaF. This finding provides a significant insight into the nature of the experimentally-observed strong anisotropic effect of electronic resistivity, and also paves the way for designing exotic two-dimensional artificial unconventional superconductors in the future.

Material Discrimination Based on K-edge Characteristics

Directory of Open Access Journals (Sweden)

Peng He

2013-01-01

Full Text Available Spectral/multienergy CT employing the state-of-the-art energy-discriminative photon-counting detector can identify absorption features in the multiple ranges of photon energies and has the potential to distinguish different materials based on K-edge characteristics. K-edge characteristics involve the sudden attenuation increase in the attenuation profile of a relatively high atomic number material. Hence, spectral CT can utilize material K-edge characteristics (sudden attenuation increase to capture images in available energy bins (levels/windows to distinguish different material components. In this paper, we propose an imaging model based on K-edge characteristics for maximum material discrimination with spectral CT. The wider the energy bin width is, the lower the noise level is, but the poorer the reconstructed image contrast is. Here, we introduce the contrast-to-noise ratio (CNR criterion to optimize the energy bin width after the K-edge jump for the maximum CNR. In the simulation, we analyze the reconstructed image quality in different energy bins and demonstrate that our proposed optimization approach can maximize CNR between target region and background region in reconstructed image.

Attenuation relations of strong motion in Japan using site classification based on predominant period

International Nuclear Information System (INIS)

Toshimasa Takahashi; Akihiro Asano; Hidenobu Okada; Kojiro Irikura; Zhao, J.X.; Zhang Jian; Thio, H.K.; Somerville, P.G.; Yasuhiro Fukushima; Yoshimitsu Fukushima

2005-01-01

A spectral acceleration attenuation model for Japan is presented. The data set includes a very large number of strong ground motion records up to the end of 2003. Site class terms, instead of individual site correction terms, are used based on a recent study on site classification for strong motion recording stations in Japan. By using site class terms, tectonic source type effects are identified and accounted in the present model. Effects of faulting mechanism for crustal earthquakes are also accounted for. For crustal and interface earthquakes, a simple form of attenuation model is able to capture the main strong motion characteristics and achieves unbiased estimates. For subduction slab events, a simple distance modification factor is employed to achieve plausible and unbiased prediction. Effects of source depth, tectonic source type, and faulting mechanism for crustal earthquakes are significant. (authors)

Mechanical properties of wood-based composite materials

Science.gov (United States)

Zhiyong Cai; Robert J. Ross

2010-01-01

The term composite is used to describe any wood material bonded together with adhesives. The current product mix ranges from fiberboard to laminated beams and components. In this chapter, wood-based composite materials are classified into the following categories: panel products (plywood, oriented strandboard (OSB), particleboard, fiberboard, medium-density fiberboard...

Study of New Materials Design based on Hadoop

Directory of Open Access Journals (Sweden)

Wu Jun

2016-01-01

Full Text Available With the rapid development of information technology, the scientific research shows that the data mining and other information technology could be used in the design of new materials. It is explicit that Intelligent Materials research focuses on using physical and chemical principles combined with computer techniques such as Big Data, Cloud computing and Intelligent modeling and simulation to solve chemical problems. In this paper, based on the cluster based outlier algorithm as the main body, this paper discusses the definition New Materials research In the Hadoop cloud platform, and the parallel processing of Map-Reduce model. The performance this model of new material was established by using the method of Map-Reduction provided the basis for the performance optimization.

Plasma deposition of amorphous silicon-based materials

CERN Document Server

Bruno, Giovanni; Madan, Arun

1995-01-01

Semiconductors made from amorphous silicon have recently become important for their commercial applications in optical and electronic devices including FAX machines, solar cells, and liquid crystal displays. Plasma Deposition of Amorphous Silicon-Based Materials is a timely, comprehensive reference book written by leading authorities in the field. This volume links the fundamental growth kinetics involving complex plasma chemistry with the resulting semiconductor film properties and the subsequent effect on the performance of the electronic devices produced. Key Features * Focuses on the plasma chemistry of amorphous silicon-based materials * Links fundamental growth kinetics with the resulting semiconductor film properties and performance of electronic devices produced * Features an international group of contributors * Provides the first comprehensive coverage of the subject, from deposition technology to materials characterization to applications and implementation in state-of-the-art devices.

Materials interaction tests to identify base and coating materials for an enhanced in-vessel core catcher design

Energy Technology Data Exchange (ETDEWEB)

Rempe, J.L.; Knudson, D.L.; Condie, K.G.; Swank, W.D. [Idaho National Engineering and Environmental Laboratory, Idaho Falls ID (United States); Cheung, F.B. [Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park PA (United States); Suh, K.Y. [Seoul National University, Department of Nuclear Engineering, Seoul (Korea, Republic of); Kim, S.B. [Korea Atomic Energy Research Institute, Severe Accident Research Project, Taejon (Korea, Republic of)

2004-07-01

An enhanced in-vessel core catcher is being designed and evaluated, it must ensure In-Vessel Retention of core materials that may relocate under severe accident conditions in advanced reactors. To reduce cost and simplify manufacture and installation, this new core catcher design consists of several interlocking sections that are machined to fit together when inserted into the lower head. If needed, the core catcher can be manufactured with holes to accommodate lower head penetrations. Each section of the core catcher consists of two material layers with an option to add a third layer (if deemed necessary): a base material, which has the capability to support and contain the mass of core materials that may relocate during a severe accident; an insulating oxide coating material on top of the base material, which resists interactions with high-temperature core materials; and an optional coating on the bottom side of the base material to prevent any potential oxidation of the base material during the lifetime of the reactor. Initial evaluations suggest that a thermally-sprayed oxide material is the most promising candidate insulator coating for a core catcher. Tests suggest that 2 coatings can provide adequate protection to a stainless steel core catcher: -) a 500 {mu}m thick zirconium dioxide coating over a 100-200 {mu}m Inconel 718 bond coating, and -) a 500 {mu}m thick magnesium zirconate coating.

Using learning materials for design-based interventions

DEFF Research Database (Denmark)

Gissel, Stig Toke

2015-01-01

This article considers a methodological issue concerning the use of learning materials for interventions in design-based research. When the researcher uses existing or creates new didacticised learning materials for research purposes and tests their applicability in authentic contexts, many...... variables are in play. When using or designing a learning material a lot of choices have to be made and effects are difficult to isolate. The advantage of using learning materials for interventions is that results could have high ecological validity. In the article this methodological issue is exemplified...... through a research project using and developing digital learning materials for developing literacy in the early grades. One of many important choices to be made in elaborating this learning material concerns which texts should be used for supporting students’ literacy development in the lower grades...

Knitted radar absorbing materials (RAM) based on nickel–cobalt magnetic materials

International Nuclear Information System (INIS)

Teber, Ahmet; Unver, Ibrahim; Kavas, Huseyin; Aktas, Bekir; Bansal, Rajeev

2016-01-01

There has been a long-standing interest in the development of flexible, lightweight, thin, and reconfigurable radar absorbing materials (RAM) for military applications such as camouflaging ground-based hardware against airborne radar observation. The use of polymeric Polyacrylonitrile (PAN) fabrics as a host matrix for magnetic metal nano-particles (either at the yarn-stage or after weaving the fabric) for shielding and absorbing applications has been described in the literature. In our experimental investigation, the relative concentrations of Nickel and Cobalt as well as the coating time are varied with a view to optimizing the microwave absorption characteristics of the resulting PAN-based composite material in the radar-frequency bands (X, K_u, and K). It is found that the PAN samples with the shortest coating time have the best return losses (under −20 dB return loss over a moderate bandwidth). - Graphical abstract: Here, we added the graphical abstract that provides summary the contents of the article in a concise pictorial form. - Highlights: • Flexible lightweight, thin, reconfigurable radar absorbing materials are proposed. • Polyacrylonitrile (PAN) fabrics are coated with nickel, cobalt magnetic materials. • The coating times affects microwave constitutive parameters and absorption. • Microwave absorption measurements were done via transmission line technique. • Microwave absorption is due to dielectric losses rather than magnetic losses.

Knitted radar absorbing materials (RAM) based on nickel–cobalt magnetic materials

Energy Technology Data Exchange (ETDEWEB)

Teber, Ahmet, E-mail: aht10003@engr.uconn.edu [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, CT 06269 (United States); Unver, Ibrahim, E-mail: iunver@gtu.edu.tr [Department of Physics, Gebze Technical University, Kocaeli 41400 (Turkey); Kavas, Huseyin, E-mail: huseyin.kavas@medeniyet.edu.tr [Department of Physics, Istanbul Medeniyet University, Istanbul 34000 (Turkey); Aktas, Bekir, E-mail: aktas@gtu.edu.tr [Department of Physics, Gebze Technical University, Kocaeli 41400 (Turkey); Bansal, Rajeev, E-mail: rajeev@engr.uconn.edu [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, CT 06269 (United States)

2016-05-15

There has been a long-standing interest in the development of flexible, lightweight, thin, and reconfigurable radar absorbing materials (RAM) for military applications such as camouflaging ground-based hardware against airborne radar observation. The use of polymeric Polyacrylonitrile (PAN) fabrics as a host matrix for magnetic metal nano-particles (either at the yarn-stage or after weaving the fabric) for shielding and absorbing applications has been described in the literature. In our experimental investigation, the relative concentrations of Nickel and Cobalt as well as the coating time are varied with a view to optimizing the microwave absorption characteristics of the resulting PAN-based composite material in the radar-frequency bands (X, K{sub u}, and K). It is found that the PAN samples with the shortest coating time have the best return losses (under −20 dB return loss over a moderate bandwidth). - Graphical abstract: Here, we added the graphical abstract that provides summary the contents of the article in a concise pictorial form. - Highlights: • Flexible lightweight, thin, reconfigurable radar absorbing materials are proposed. • Polyacrylonitrile (PAN) fabrics are coated with nickel, cobalt magnetic materials. • The coating times affects microwave constitutive parameters and absorption. • Microwave absorption measurements were done via transmission line technique. • Microwave absorption is due to dielectric losses rather than magnetic losses.

Grassy Silica Nanoribbons and Strong Blue Luminescence

Science.gov (United States)

Wang, Shengping; Xie, Shuang; Huang, Guowei; Guo, Hongxuan; Cho, Yujin; Chen, Jun; Fujita, Daisuke; Xu, Mingsheng

2016-09-01

Silicon dioxide (SiO2) is one of the key materials in many modern technological applications such as in metal oxide semiconductor transistors, photovoltaic solar cells, pollution removal, and biomedicine. We report the accidental discovery of free-standing grassy silica nanoribbons directly grown on SiO2/Si platform which is commonly used for field-effect transistors fabrication without other precursor. We investigate the formation mechanism of this novel silica nanostructure that has not been previously documented. The silica nanoribbons are flexible and can be manipulated by electron-beam. The silica nanoribbons exhibit strong blue emission at about 467 nm, together with UV and red emissions as investigated by cathodoluminescence technique. The origins of the luminescence are attributed to various defects in the silica nanoribbons; and the intensity change of the blue emission and green emission at about 550 nm is discussed in the frame of the defect density. Our study may lead to rational design of the new silica-based materials for a wide range of applications.

Effect of Modifying Prosthetic Socket Base Materials by Adding Nanodiamonds

Directory of Open Access Journals (Sweden)

Lifang Ma

2015-01-01

Full Text Available The curing process of prosthetic socket base materials requires attention owing to a series of associated problems that are yet to be addressed and solved. However, to date, few relevant studies have been reported. In this paper, nanodiamonds modified with a silane coupling agent were dispersed into a prosthetic socket base material, and the performance of the modified base materials was investigated. Adding a predetermined amount of nanodiamonds to the prosthetic socket base material increased the glass transition temperature, improved the mechanical properties of the cured base material, and reduced the influence of the volatile gas formed during the curing process on the environment. With increasing nanodiamond contents, the glass transition temperature increased and the mechanical properties improved slightly. Owing to the high thermal conductivity of the nanodiamonds, the localized heat, as a result of the curing process, could be dissipated and released. Thus, adding nanodiamonds led to a more uniform temperature field forming in the curing system. This improved the curing process and reduced the formation of volatile monomers, thereby decreasing the adverse impact of the generated volatile gases on the environment. All of these provide a potential strategy for modifying prosthetic socket base materials.

Thermomechanical behaviour of two heterogeneous tungsten materials via 2D and 3D image-based FEM

International Nuclear Information System (INIS)

Zivelonghi, Alessandro

2011-01-01

An advanced numerical procedure based on imaging of the material microstructure (Image- Based Finite Element Method or Image-Based FEM) was extended and applied to model the thermomechanical behaviour of novel materials for fusion applications. Two tungsten based heterogeneous materials with different random morphologies have been chosen as challenging case studies: (1) a two-phase mixed ductile-brittle W/CuCr1Zr composite and (2) vacuum plasma-sprayed tungsten (VPS-W 75 vol.%), a porous coating system with complex dual-scale microstructure. Both materials are designed for the future fusion reactor DEMO: W/CuCr1Zr as main constituent of a layered functionally graded joint between plasma-facing armor and heat sink whereas VPS-W for covering the first wall of the reactor vessel in direct contact with the plasma. The primary focus of this work was to investigate the mesoscopic material behaviour and the linkage to the macroscopic response in modeling failure and heat-transfer. Particular care was taken in validating and integrating simulation findings with experimental inputs. The solution of the local thermomechanical behaviour directly on the real material microstructure enabled meaningful insights into the complex failure mechanism of both materials. For W/CuCr1Zr full macroscopic stress-strain curves including the softening and failure part could be simulated and compared with experimental ones at different temperatures, finding an overall good agreement. The comparison of simulated and experimental macroscopic behaviour of plastic deformation and rupture also showed the possibility to indirectly estimate micro- and mesoscale material parameters. Both heat conduction and elastic behaviour of VPS-W have been extensively investigated. New capabilities of the Image-Based FEM could be shown: decomposition of the heat transfer reduction as due to the individual morphological phases and back-fitting of the reduced stiffness at interlamellar boundaries. The

Strong underwater adhesives made by self-assembling multi-protein nanofibres.

Science.gov (United States)

Zhong, Chao; Gurry, Thomas; Cheng, Allen A; Downey, Jordan; Deng, Zhengtao; Stultz, Collin M; Lu, Timothy K

2014-10-01

Many natural underwater adhesives harness hierarchically assembled amyloid nanostructures to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Despite recent advances, our understanding of the molecular design, self-assembly and structure-function relationships of these natural amyloid fibres remains limited. Thus, designing biomimetic amyloid-based adhesives remains challenging. Here, we report strong and multi-functional underwater adhesives obtained from fusing mussel foot proteins (Mfps) of Mytilus galloprovincialis with CsgA proteins, the major subunit of Escherichia coli amyloid curli fibres. These hybrid molecular materials hierarchically self-assemble into higher-order structures, in which, according to molecular dynamics simulations, disordered adhesive Mfp domains are exposed on the exterior of amyloid cores formed by CsgA. Our fibres have an underwater adhesion energy approaching 20.9 mJ m(-2), which is 1.5 times greater than the maximum of bio-inspired and bio-derived protein-based underwater adhesives reported thus far. Moreover, they outperform Mfps or curli fibres taken on their own and exhibit better tolerance to auto-oxidation than Mfps at pH ≥ 7.0.

Development of barrier coatings for cellulosic-based materials by cold plasma methods

Science.gov (United States)

Denes, Agnes Reka

Cellulose-based materials are ideal candidates for future industries that need to be based on environmentally safe technologies and renewable resources. Wood represents an important raw material and its application as construction material is well established. Cellophane is one of the most important cellulosic material and it is widely used as packaging material in the food industry. Outdoor exposure of wood causes a combination of physical and chemical degradation processes due to the combined effects of sunlight, moisture, fungi, and bacteria. Cold-plasma-induced surface modifications are an attractive way for tailoring the characteristics of lignocellulosic substrates to prevent weathering degradation. Plasma-polymerized hexamethyldisiloxane (PPHMDSO) was deposited onto wood surfaces to create water repellent characteristics. The presence of a crosslinked macromolecular structure was detected. The plasma coated samples exhibited very high water contact angle values indicating the existence of hydrophobic surfaces. Reflective and electromagnetic radiation-absorbent substances were incorporated with a high-molecular-weight polydimethylsiloxane polymer in liquid phase and deposited as thin layers on wood surfaces. The macromolecular films, containing the dispersed materials, were then converted into a three dimensional solid state network by exposure to a oxygen-plasma. It was demonstrated that both UV-absorbent and reflectant components incorporated into the plasma-generated PDMSO matrix protected the wood from weathering degradation. Reduced oxidation and less degradation was observed after simulated weathering. High water contact angle values indicated a strong hydrophobic character of the oxygen plasma-treated PDMSO-coated samples. Plasma-enhanced surface modifications and coatings were employed to create water-vapor barrier layers on cellophane substrate surfaces. HMDSO was selected as a plasma gas and oxygen was used to ablate amorphous regions. Oxygen plasma

1D Piezoelectric Material Based Nanogenerators: Methods, Materials and Property Optimization.

Science.gov (United States)

Li, Xing; Sun, Mei; Wei, Xianlong; Shan, Chongxin; Chen, Qing

2018-03-23

Due to the enhanced piezoelectric properties, excellent mechanical properties and tunable electric properties, one-dimensional (1D) piezoelectric materials have shown their promising applications in nanogenerators (NG), sensors, actuators, electronic devices etc. To present a clear view about 1D piezoelectric materials, this review mainly focuses on the characterization and optimization of the piezoelectric properties of 1D nanomaterials, including semiconducting nanowires (NWs) with wurtzite and/or zinc blend phases, perovskite NWs and 1D polymers. Specifically, the piezoelectric coefficients, performance of single NW-based NG and structure-dependent electromechanical properties of 1D nanostructured materials can be respectively investigated through piezoresponse force microscopy, atomic force microscopy and the in-situ scanning/transmission electron microcopy. Along with the introduction of the mechanism and piezoelectric properties of 1D semiconductor, perovskite materials and polymers, their performance improvement strategies are summarized from the view of microstructures, including size-effect, crystal structure, orientation and defects. Finally, the extension of 1D piezoelectric materials in field effect transistors and optoelectronic devices are simply introduced.

Optimal Control Strategy for Marine Ssp Podded Propulsion Motor Based on Strong Tracking-Epf

Directory of Open Access Journals (Sweden)

Yao Wenlong

2015-09-01

Full Text Available Aiming at the non-linearity of state equation and observation equation of SSP (Siemen Schottel Propulsor propulsion motor, an improved particle filter algorithm based on strong tracking extent Kalman filter (ST-EKF was presented, and it was imported into the marine SSP propulsion motor control system. The strong tracking filter was used to update particles in the new algorithm and produce importance densities. As a result, the problems of particle degeneracy and sample impoverishment were ameliorated, the propulsion motor states and the rotor resistance were estimated simultaneously using strong track filter (STF, and the tracking ability of marine SSP propulsion motor control system was improved. Simulation result shown that the improved EPF algorithm was not only improving the prediction accuracy of the motor states and the rotor resistance, but also it can satisfy the requirement of navigation in harbor. It had the better accuracy than EPF algorithm.

Current status of nanostructured tungsten-based materials development

International Nuclear Information System (INIS)

Kurishita, H; Matsuo, S; Arakawa, H; Hatakeyama, M; Shikama, T; Sakamoto, T; Kobayashi, S; Nakai, K; Okano, H; Watanabe, H; Yoshida, N; Torikai, Y; Hatano, Y; Takida, T; Kato, M; Ikegaya, A; Ueda, Y

2014-01-01

Nanostructured tungsten (W)-based materials offer many advantages for use as plasma facing materials and components exposed to heavy thermal loads combined with irradiation with high-energy neutron and low-energy ion. This paper first presents the recent progress in nanostructured toughened, fine grained, recrystallized W materials. Thermal desorption spectrometry apparatus equipped with an ion gun has been installed in the radiation controlled area in our Center at Tohoku University to systematically investigate the effects of displacement damage due to high-energy neutron irradiation on hydrogen isotope retention in connection with the nano- or micro-structures in W-based materials. In this paper, the effects of high-energy heavy ion irradiation on deuterium retention in W with different microstructures are described as a preliminary work with the prospective view of neutron irradiation effects. (paper)

Ti-Ni-based shape memory alloys as smart materials

International Nuclear Information System (INIS)

Otsuka, K.; Xu, Y.; Ren, X.

2003-01-01

Smart materials consist of three principal materials, ferroelectrics, shape memory alloys (SMA) and electro-active polymers (EAP). Among these SMAs, especially Ti-Ni-based alloys are important, since only they can provide large recoverable strains and high recovery stress. In the present paper the unique characteristics of Ti-Ni-based shape memory alloys are reviewed on an up-to-date basis with the aim of their applications to smart materials and structures. (orig.)

Multifunctional magnetoelectric materials for device applications

International Nuclear Information System (INIS)

Ortega, N; Katiyar, Ram S; Kumar, Ashok; Scott, J F

2015-01-01

Over the past decade magnetoelectric (ME) mutiferroic (MF) materials and their devices are one of the highest priority research topics that has been investigated by the scientific ferroics community to develop the next generation of novel multifunctional materials. These systems show the simultaneous existence of two or more ferroic orders, and cross-coupling between them, such as magnetic spin, polarisation, ferroelastic ordering, and ferrotoroidicity. Based on the type of ordering and coupling, they have drawn increasing interest for a variety of device applications, such as magnetic field sensors, nonvolatile memory elements, ferroelectric photovoltaics, nano-electronics etc. Since single-phase materials exist rarely in nature with strong cross-coupling properties, intensive research activity is being pursued towards the discovery of new single-phase multiferroic materials and the design of new engineered materials with strong magneto-electric (ME) coupling. This review article summarises the development of different kinds of multiferroic material: single-phase and composite ceramic, laminated composite and nanostructured thin films. Thin-film nanostructures have higher magnitude direct ME coupling values and clear evidence of indirect ME coupling compared with bulk materials. Promising ME coupling coefficients have been reported in laminated composite materials in which the signal to noise ratio is good for device fabrication. We describe the possible applications of these materials. (topical review)

A composite material based on recycled tires

Science.gov (United States)

Malers, L.; Plesuma, R.; Locmele, L.

2009-01-01

The present study is devoted to the elaboration and investigation of a composite material based on mechanically grinded recycled tires and a polymer binder. The correlation between the content of the binder, some technological parameters, and material properties of the composite was clarified. The apparent density, the compressive stress at a 10% strain, the compressive elastic modulus in static and cyclic loadings, and the insulating properties (acoustic and thermal) were the parameters of special interest of the present investigation. It is found that a purposeful variation of material composition and some technological parameters leads to multifunctional composite materials with different and predictable mechanical and insulation properties.

Application of Nanotechnology-Based Thermal Insulation Materials in Building Construction

Directory of Open Access Journals (Sweden)

Bozsaky David

2016-03-01

Full Text Available Nanotechnology-based materials have previously been used by space research, pharmaceuticals and electronics, but in the last decade several nanotechnology-based thermal insulation materials have appeared in building industry. Nowadays they only feature in a narrow range of practice, but they offer many potential applications. These options are unknown to most architects, who may simply be afraid of these materials owing to the incomplete and often contradictory special literature. Therefore, they are distrustful and prefer to apply the usual and conventional technologies. This article is intended to provide basic information about nanotechnology-based thermal insulation materials for designers. It describes their most important material properties, functional principles, applications, and potential usage options in building construction.

A direct Eulerian method for the simulation of multi-material compressible flows with material sliding

International Nuclear Information System (INIS)

Motte, R.; Braeunig, J.P.; Peybernes, M.

2012-01-01

As the simulation of compressible flows with several materials is essential for applications studied within the CEA-DAM, the authors propose an approach based on finite volumes with centred variables for the resolution of compressible Euler equations. Moreover, they allow materials to slide with respect to each other as it is the case for water and air, for example. A conservation law is written for each material in a hybrid grid, and a condition of contact between materials under the form of fluxes is expressed. It is illustrated by the case of an intense shock propagating in water and interacting with an air bubble which will be strongly deformed and compressed

Analysis of Metallized Teflon(trademark) Film Materials Performance on Satellites

Science.gov (United States)

Pippin, H. Gary; Normand, Eugene; Wolf, Suzanne L. B.; Kamenetzky, Rachel; Kauffman, William J., Jr. (Technical Monitor)

2002-01-01

Laboratory and on-orbit performance data for two common thermal control materials, silver- and aluminum-backed (metallized) fluorinated ethyl-propylene (TER) was collected from a variety of sources and analyzed. This paper demonstrates that the change in solar absorptance, alpha, is a strong function of particulate radiation for these materials. Examination of additional data shows that the atomic oxygen recession rate is a strong function of solar exposure with an induction period of between 25 to 50 equivalent solar hours. The relationships determined in this analysis were incorporated into an electronic knowledge base, the 'Spacecraft Materials Selector,' under NASA contract NAS8-98213.

Pentanol-based target material with polarized protons

International Nuclear Information System (INIS)

Bunyatova, E.I.

1992-01-01

1-pentanol is a promising material for a target with polarized protons owing to its high resistance to radiation damage. To develop the target, the solutions of 1-pentanol or 2-pentanol with complexes of pentavalent chromium ware investigated. The material based EHBA-Cr(V) solution in a glass-like matrix, consisting of 1-pentanol, 3-pentanol and 1,2-propanediol, was proposed as a target material. It was investigated by the electron paramagnetic resonance and differential scanning calorimetry methods. 24 refs.; 3 figs.; 1 tab

Recent Progress on PEDOT-Based Thermoelectric Materials.

Science.gov (United States)

Wei, Qingshuo; Mukaida, Masakazu; Kirihara, Kazuhiro; Naitoh, Yasuhisa; Ishida, Takao

2015-02-16

The thermoelectric properties of poly(3,4-ethylenedioxythiophene) (PEDOT)-based materials have attracted attention recently because of their remarkable electrical conductivity, power factor, and figure of merit. In this review, we summarize recent efforts toward improving the thermoelectric properties of PEDOT-based materials. We also discuss thermoelectric measurement techniques and several unsolved problems with the PEDOT system such as the effect of water absorption from the air and the anisotropic thermoelectric properties. In the last part, we describe our work on improving the power output of thermoelectric modules by using PEDOT, and we outline the potential applications of polymer thermoelectric generators.

Strong Motion Seismograph Based On MEMS Accelerometer

Science.gov (United States)

Teng, Y.; Hu, X.

2013-12-01

The MEMS strong motion seismograph we developed used the modularization method to design its software and hardware.It can fit various needs in different application situation.The hardware of the instrument is composed of a MEMS accelerometer,a control processor system,a data-storage system,a wired real-time data transmission system by IP network,a wireless data transmission module by 3G broadband,a GPS calibration module and power supply system with a large-volumn lithium battery in it. Among it,the seismograph's sensor adopted a three-axis with 14-bit high resolution and digital output MEMS accelerometer.Its noise level just reach about 99μg/√Hz and ×2g to ×8g dynamically selectable full-scale.Its output data rates from 1.56Hz to 800Hz. Its maximum current consumption is merely 165μA,and the device is so small that it is available in a 3mm×3mm×1mm QFN package. Furthermore,there is access to both low pass filtered data as well as high pass filtered data,which minimizes the data analysis required for earthquake signal detection. So,the data post-processing can be simplified. Controlling process system adopts a 32-bit low power consumption embedded ARM9 processor-S3C2440 and is based on the Linux operation system.The processor's operating clock at 400MHz.The controlling system's main memory is a 64MB SDRAM with a 256MB flash-memory.Besides,an external high-capacity SD card data memory can be easily added.So the system can meet the requirements for data acquisition,data processing,data transmission,data storage,and so on. Both wired and wireless network can satisfy remote real-time monitoring, data transmission,system maintenance,status monitoring or updating software.Linux was embedded and multi-layer designed conception was used.The code, including sensor hardware driver,the data acquisition,earthquake setting out and so on,was written on medium layer.The hardware driver consist of IIC-Bus interface driver, IO driver and asynchronous notification driver. The

Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

Science.gov (United States)

Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

2009-01-01

An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

A sorption model for alkalis in cement-based materials - Correlations with solubility and electrokinetic properties

Science.gov (United States)

Henocq, Pierre

2017-06-01

In cement-based materials, radionuclide uptake is mainly controlled by calcium silicate hydrates (C-S-H). This work presents an approach for defining a unique set of parameters of a surface complexation model describing the sorption behavior of alkali ions on the C-S-H surface. Alkali sorption processes are modeled using the CD-MUSIC function integrated in the Phreeqc V.3.0.6 geochemical code. Parameterization of the model was performed based on (1) retention, (2) zeta potential, and (3) solubility experimental data from the literature. This paper shows an application of this model to sodium ions. It was shown that retention, i.e. surface interactions, and solubility are closely related, and a consistent sorption model for radionuclides in cement-based materials requires a coupled surface interaction/chemical equilibrium model. In case of C-S-H with low calcium-to-silicon ratios, sorption of sodium ions on the C-S-H surface strongly influences the chemical equilibrium of the C-S-H + NaCl system by significantly increasing the aqueous calcium concentration. The close relationship between sorption and chemical equilibrium was successfully illustrated by modeling the effect of the solid-to-liquid ratio on the calcium content in solution in the case of C-S-H + NaCl systems.

Ultra-tough and strong, hybrid thin films based on ionically crosslinked polymers and 2D inorganic platelets

Science.gov (United States)

Ji, Dong Hwan; Choi, Suji; Kim, Jaeyun; nanobiomaterials lab Team

Integration of high strength and toughness tend to be mutually exclusive and synthesized hybrid films with superior mechanical properties have been difficult to fabricate controllable shapes and various scales. Although diverse synthesized hybrid films consisting of organic matrix and inorganic materials with brick-and-mortar structure, show improved mechanical properties, these films are still limited in toughness and fabrication methods. Herein, we report ultra-tough and strong hybrid thin films with self-assembled uniform microstructures with controllable shapes and various scale based on hydrogel-mediated process. Ca2+-crosslinking in alginate chains and well-aligned alumina platelets in alginate matrix lead to a synergistic enhancement of strength and toughness in the resulting film. Consequentially, Ca2+-crosslinked Alg/Alu films showed outstanding toughness of 29 MJ m-3 and tensile strength of 160 MPa. Furthermore, modifying Alu surface with polyvinylpyrrolidone (PVP), tensile strength was further improved up to 200 MPa. Our results suggest an alternative approach to design and processing of self-assembled hydrogel-mediated hybrid films with outstanding mechanical properties.

Complex coacervate-based materials for biomedicine.

Science.gov (United States)

Blocher, Whitney C; Perry, Sarah L

2017-07-01

There has been increasing interest in complex coacervates for deriving and transporting biomaterials. Complex coacervates are a dense, polyelectrolyte-rich liquid that results from the electrostatic complexation of oppositely charged macroions. Coacervates have long been used as a strategy for encapsulation, particularly in food and personal care products. More recent efforts have focused on the utility of this class of materials for the encapsulation of small molecules, proteins, RNA, DNA, and other biomaterials for applications ranging from sensing to biomedicine. Furthermore, coacervate-related materials have found utility in other areas of biomedicine, including cartilage mimics, tissue culture scaffolds, and adhesives for wet, biological environments. Here, we discuss the self-assembly of complex coacervate-based materials, current challenges in the intelligent design of these materials, and their utility applications in the broad field of biomedicine. WIREs Nanomed Nanobiotechnol 2017, 9:e1442. doi: 10.1002/wnan.1442 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

Design and evaluation of foamed asphalt base materials.

Science.gov (United States)

2013-05-01

Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP), recycled : concrete (RC), and/or graded aggregate base (GAB) with a foamed asphalt binder to produce a : partially stabilized base material. The objectives of this study...

Silk Composite with a Fluoropolymer as a Water-Resistant Protein-Based Material

Directory of Open Access Journals (Sweden)

Keiji Numata

2018-04-01

Full Text Available Silk-based materials are water-sensitive and show different physical properties at different humidities and under wet/dry conditions. To overcome the water sensitivity of silk-based materials, we developed a silk composite material with a fluoropolymer. Blending and coating the silk protein-based materials, such as films and textiles, with the fluoropolymer enhanced the surface hydrophobicity, water vapor barrier properties, and size stability during shrinkage tests. This material design with a protein biopolymer and a fluoropolymer is expected to broaden the applicability of protein-based materials.

Highly efficient perovskite solar cells based on a nanostructured WO3-TiO2 core-shell electron transporting material

KAUST Repository

Mahmood, Khalid; Swain, Bhabani Sankar; Kirmani, Ahmad R.; Amassian, Aram

2015-01-01

Until recently, only mesoporous TiO2 and ZnO were successfully demonstrated as electron transport layers (ETL) alongside the reports of ZrO2 and Al2O3 as scaffold materials in organometal halide perovskite solar cells, largely owing to ease of processing and to high power conversion efficiency. In this article, we explore tungsten trioxide (WO3)-based nanostructured and porous ETL materials directly grown hydrothermally with different morphologies such as nanoparticles, nanorods and nanosheet arrays. The nanostructure morphology strongly influences the photocurrent and efficiency in organometal halide perovskite solar cells. We find that the perovskite solar cells based on WO3 nanosheet arrays yield significantly enhanced photovoltaic performance as compared to nanoparticles and nanorod arrays due to good perovskite absorber infiltration in the porous scaffold and more rapid carrier transport. We further demonstrate that treating the WO3 nanostructures with an aqueous solution of TiCl4 reduces charge recombination at the perovskite/WO3 interface, resulting in the highest power conversion efficiency of 11.24% for devices based on WO3 nanosheet arrays. The successful demonstration of alternative ETL materials and nanostructures based on WO3 will open up new opportunities in the development of highly efficient perovskite solar cells. This journal is © The Royal Society of Chemistry 2015.

Photoinduced Electron Transfer in the Strong Coupling Regime: Waveguide-Plasmon Polaritons.

Science.gov (United States)

Zeng, Peng; Cadusch, Jasper; Chakraborty, Debadi; Smith, Trevor A; Roberts, Ann; Sader, John E; Davis, Timothy J; Gómez, Daniel E

2016-04-13

Reversible exchange of photons between a material and an optical cavity can lead to the formation of hybrid light-matter states where material properties such as the work function [ Hutchison et al. Adv. Mater. 2013 , 25 , 2481 - 2485 ], chemical reactivity [ Hutchison et al. Angew. Chem., Int. Ed. 2012 , 51 , 1592 - 1596 ], ultrafast energy relaxation [ Salomon et al. Angew. Chem., Int. Ed. 2009 , 48 , 8748 - 8751 ; Gomez et al. J. Phys. Chem. B 2013 , 117 , 4340 - 4346 ], and electrical conductivity [ Orgiu et al. Nat. Mater. 2015 , 14 , 1123 - 1129 ] of matter differ significantly to those of the same material in the absence of strong interactions with the electromagnetic fields. Here we show that strong light-matter coupling between confined photons on a semiconductor waveguide and localized plasmon resonances on metal nanowires modifies the efficiency of the photoinduced charge-transfer rate of plasmonic derived (hot) electrons into accepting states in the semiconductor material. Ultrafast spectroscopy measurements reveal a strong correlation between the amplitude of the transient signals, attributed to electrons residing in the semiconductor and the hybridization of waveguide and plasmon excitations.

Elastoplastic cup model for cement-based materials

Directory of Open Access Journals (Sweden)

Yan Zhang

2010-03-01

Full Text Available Based on experimental data obtained from triaxial tests and a hydrostatic test, a cup model was formulated. Two plastic mechanisms, respectively a deviatoric shearing and a pore collapse, are taken into account. This model also considers the influence of confining pressure. In this paper, the calibration of the model is detailed and numerical simulations of the main mechanical behavior of cement paste over a large range of stress are described, showing good agreement with experimental results. The case study shows that this cup model has extensive applicability for cement-based materials and other quasi-brittle and high-porosity materials in a complex stress state.

Using Android-Based Educational Game for Learning Colloid Material

Science.gov (United States)

Sari, S.; Anjani, R.; Farida, I.; Ramdhani, M. A.

2017-09-01

This research is based on the importance of the development of student’s chemical literacy on Colloid material using Android-based educational game media. Educational game products are developed through research and development design. In the analysis phase, material analysis is performed to generate concept maps, determine chemical literacy indicators, game strategies and set game paths. In the design phase, product packaging is carried out, then validation and feasibility test are performed. Research produces educational game based on Android that has the characteristics that is: Colloid material presented in 12 levels of game in the form of questions and challenges, presents visualization of discourse, images and animation contextually to develop the process of thinking and attitude. Based on the analysis of validation and trial results, the product is considered feasible to use.

Graphene-Based Materials for Lithium-Ion Hybrid Supercapacitors.

Science.gov (United States)

Ma, Yanfeng; Chang, Huicong; Zhang, Miao; Chen, Yongsheng

2015-09-23

Lithium-ion hybrid supercapacitors (LIHSs), also called Li-ion capacitors, have attracted much attention due to the combination of the rapid charge-discharge and long cycle life of supercapacitors and the high energy-storage capacity of lithium-ion batteries. Thus, LIHSs are expected to become the ultimate power source for hybrid and all-electric vehicles in the near future. As an electrode material, graphene has many advantages, including high surface area and porous structure, high electric conductivity, and high chemical and thermal stability, etc. Compared with other electrode materials, such as activated carbon, graphite, and metal oxides, graphene-based materials with 3D open frameworks show higher effective specific surface area, better control of channels, and higher conductivity, which make them better candidates for LIHS applications. Here, the latest advances in electrode materials for LIHSs are briefly summarized, with an emphasis on graphene-based electrode materials (including 3D graphene networks) for LIHS applications. An outlook is also presented to highlight some future directions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Silk fibroin based antibacterial bionanotextiles as wound dressing materials

Energy Technology Data Exchange (ETDEWEB)

Çalamak, Semih [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey); Erdoğdu, Ceren; Özalp, Meral [Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, 06100 Ankara (Turkey); Ulubayram, Kezban, E-mail: ukezban@hacettepe.edu.tr [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey)

2014-10-01

New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line.

Silk fibroin based antibacterial bionanotextiles as wound dressing materials

International Nuclear Information System (INIS)

Çalamak, Semih; Erdoğdu, Ceren; Özalp, Meral; Ulubayram, Kezban

2014-01-01

New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line

Satellite Contamination and Materials Outgassing Knowledge base

Science.gov (United States)

Minor, Jody L.; Kauffman, William J. (Technical Monitor)

2001-01-01

Satellite contamination continues to be a design problem that engineers must take into account when developing new satellites. To help with this issue, NASA's Space Environments and Effects (SEE) Program funded the development of the Satellite Contamination and Materials Outgassing Knowledge base. This engineering tool brings together in one location information about the outgassing properties of aerospace materials based upon ground-testing data, the effects of outgassing that has been observed during flight and measurements of the contamination environment by on-orbit instruments. The knowledge base contains information using the ASTM Standard E- 1559 and also consolidates data from missions using quartz-crystal microbalances (QCM's). The data contained in the knowledge base was shared with NASA by government agencies and industry in the US and international space agencies as well. The term 'knowledgebase' was used because so much information and capability was brought together in one comprehensive engineering design tool. It is the SEE Program's intent to continually add additional material contamination data as it becomes available - creating a dynamic tool whose value to the user is ever increasing. The SEE Program firmly believes that NASA, and ultimately the entire contamination user community, will greatly benefit from this new engineering tool and highly encourages the community to not only use the tool but add data to it as well.

Carbon material based microelectromechanical system (MEMS): Fabrication and devices

Science.gov (United States)

Xu, Wenjun

This PhD dissertation presents the exploration and development of two carbon materials, carbon nanotubes (CNTs) and carbon fiber (CF), as either key functional components or unconventional substrates for a variety of MEMS applications. Their performance in three different types of MEMS devices, namely, strain/stress sensors, vibration-powered generators and fiber solar cells, were evaluated and the working mechanisms of these two non-traditional materials in these systems were discussed. The work may potentially enable the development of new types of carbon-MEMS devices. Carbon nanotubes were selected from the carbon family due to several advantageous characteristics that this nanomaterial offers. They carry extremely high mechanical strength (Ey=1TPa), superior electrical properties (current density of 4x109 A/cm2), exceptional piezoresistivity (G=2900), and unique spatial format (high aspect ratio hollow nanocylinder), among other properties. If properly utilized, all these merits can give rise to a variety of new types of carbon nanotube based micro- and nanoelectronics that can greatly fulfill the need for the next generation of faster, smaller and better devices. However, before these functions can be fully realized, one substantial issue to cope with is how to implement CNTs into these systems in an effective and controllable fashion. Challenges associated with CNTs integration include very poor dispersibility in solvents, lack of melting/sublimation point, and unfavorable rheology with regard to mixing and processing highly viscous, CNT-loaded polymer solutions. These issues hinder the practical progress of CNTs both in a lab scale and in the industrial level. To this end, a MEMS-assisted electrophoretic deposition technique was developed, aiming to achieve controlled integration of CNT into both conventional and flexible microsystems at room temperature with a relatively high throughput. MEMS technology has demonstrated strong capability in developing

Preparation of Natural Rubber (NR) Based Nano-Sized Materials Using Sol-Gel Technique

International Nuclear Information System (INIS)

Dahlan Mohd; Mahathir Mohamed

2011-01-01

The objectives of this project are to prepare nano-sized natural rubber-based hybrid coating material by sol-gel technique; to explore the possibility of producing ENR-Si (epoxidized natural rubber-silica) cramer with toughening effects; and to use it in radiation curing of surface coating. Since early 1960s Malaysia has introduced various forms of value-added natural rubber such as Standard Malaysian Rubber (SMR), methylmethacrylate-grafted natural rubber (MG rubber), followed by liquid natural rubber and epoxidized natural rubber (ENR). Products such as liquid epoxidized natural rubber acrylate (LENRA) and thermoplastic natural rubber (TPNR) are still on-going research projects in Nuclear Malaysia. The former has strong possibility to be used as radiation-sensitive comparabilities in TPNR blends, besides its original purpose for example in radiation curing of surface coating. But earlier findings indicated that, to make it (as for surface coating) more effective, reinforcement system is needed to be introduced. Strong candidate is silica by sol-gel technique, since common reinforcement filler for example carbon black has drawbacks in this particular case. This technique was introduced in late 1960s to produce metal oxides such as silica and titanium oxides in solution. (author)

Strong transthyretin immunostaining: potential pitfall in cardiac amyloid typing.

Science.gov (United States)

Satoskar, Anjali A; Efebera, Yvonne; Hasan, Ayesha; Brodsky, Sergey; Nadasdy, Gyongyi; Dogan, Ahmet; Nadasdy, Tibor

2011-11-01

Although systemic amyloidosis commonly presents with renal disease, cardiac involvement usually determines the patient's prognosis. Cardiac involvement is seen in light chain amyloid and transthyretin amyloidosis. Distinguishing between these two is critical because prognosis and treatment differ. Our study demonstrates the unreliability of transthyretin immunostaining in subtyping cardiac amyloid. Between January 2003 and August 2010, we retrieved 229 native endomyocardial biopsies, of which 24 had amyloid. Immunohistochemistry for κ, λ, transthyretin, and serum amyloid A protein was performed on formalin-fixed, paraffin-embedded sections. Staining was graded as weak (trace to 1+) or strong (2 to 3+). Mass spectrometry (MS)-based proteomic typing of microdissected amyloid material was performed on selected cases. Fifteen patients had monoclonal gammopathy/plasma cell dyscrasia with cardiac amyloid. Eight of them (53%) showed strong transthyretin staining in the cardiac amyloid deposits. MS was performed in 5 of these 8 biopsies, and all 5 biopsies revealed light chain amyloid-type amyloid. Two of these 5 light chain amyloid biopsies did not even have concomitant strong staining for the appropriate light chain. Among the 15 cases with plasma cell dyscrasia, only 7 biopsies showed strong staining for the corresponding monoclonal light chain. Strong, false-positive immunostaining for transthyretin in cardiac amyloid is a potential pitfall, augmented by the frequent lack of staining for immunoglobulin light chains. Therefore, the presence of amyloid in the cardiac biopsy should prompt a search for plasma cell dyscrasia irrespective of transthyretin staining. Confirmation with MS should be sought, particularly if there is any discrepancy between κ/λ staining and serum immunofixation results.

Strong Plasmon-Phonon Splitting and Hybridization in 2D Materials Revealed through a Self-Energy Approach

DEFF Research Database (Denmark)

Settnes, Mikkel; Saavedra, J. R. M.; Thygesen, Kristian Sommer

2017-01-01

splitting due to this coupling, resulting in a characteristic avoided crossing scheme. We base our results on a computationally efficient approach consisting in including many-body interactions through the electron self-energy. We specify this formalism for a description of plasmons based upon a tight...... nanotriangles with varied size, where we predict remarkable peak splittings and other radical modifications in the spectra due to plasmon interactions with intrinsic optical phonons. Our method is equally applicable to other 2D materials and provides a simple approach for investigating coupling of plasmons...

[Status of traditional Chinese medicine materials seed and seedling breeding bases].

Science.gov (United States)

Li, Ying; Huang, Lu-Qi; Zhang, Xiao-Bo; Wang, Hui; Cheng, Meng; Zhang, Tian; Yang, Guang

2017-11-01

Seeds and seedlings are the material basis of traditional Chinese medicine materials production, and the construction of traditional Chinese medicine materials seed and seedling breeding bases is beneficial to the production of high-quality traditional Chinese medicine materials. The construction of traditional Chinese medicine materials seed and seedling breeding bases is one of the major topics of Chinese medica resources census pilot. Targets, tasks of traditional Chinese medicine materials seed and seedling breeding bases based on Chinese medica resources census pilot were expounded.Construction progress including hardware construction, germplasm conservation and breeding, procedures and standardsestablishment, social servicesare presented. Development counter measures were proposed for the next step: perfect the standard and system, maintain and strengthen the breeding function, strengthen the cultivation of multi-level talents, explore market development model, joint efforts to deepen services and development. Copyright© by the Chinese Pharmaceutical Association.

Graphene-based Materials for Photoanodes in Dye-sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Xiaoru eGuo

2015-12-01

Full Text Available This article reviews the research on the use of graphene and related materials in the photoanode of dye-sensitized solar cells (DSSCs. Graphene-based materials, such as pristine graphene, graphene oxide, and reduced graphene oxide, have properties attractive for various components of the DSSC photoanode. We first provide a brief introduction to graphene properties and analyze requirements for making a high-performance photoanode. Then we introduce applications of graphene-based materials in each part of the DSSC photoanode, i.e., the transparent conducting electrode, the sensitizing material, and the semiconducting layer. Particularly, we discuss how the incorporation of graphene-based materials in those components can enhance the photoanode performance. It is clear that the outstanding properties of graphene, such as the fast electron transfer ability, high Young’s modulus, and good transparency, benefit DSSC photoanode research, and doping or surface modifications of graphene nanosheets with other materials can also improve the photoanode and thus the resulting cell performance. Finally, we present an outlook for current issues and further trends for using graphene materials in DSSC photoanodes.

Graphene-Based Materials for Photoanodes in Dye-Sensitized Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Guo, Xiaoru [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI (United States); Lu, Ganhua [Department of Mechanical Engineering, University of Alaska Anchorage, Anchorage, AK (United States); Chen, Junhong, E-mail: jhchen@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI (United States)

2015-12-14

This article reviews the research on the use of graphene and related materials in the photoanode of dye-sensitized solar cells (DSSCs). Graphene-based materials, such as pristine graphene, graphene oxide, and reduced graphene oxide, have properties attractive for various components of the DSSC photoanode. We first provide a brief introduction to graphene properties and analyze requirements for making a high-performance photoanode. Then, we introduce applications of graphene-based materials in each part of the DSSC photoanode, i.e., the transparent conducting electrode, the sensitizing material, and the semiconducting layer. Particularly, we discuss how the incorporation of graphene-based materials in those components can enhance the photoanode performance. It is clear that the outstanding properties of graphene, such as the fast electron transfer ability, high Young’s modulus, and good transparency, benefit DSSC photoanode research, and doping or surface modifications of graphene nanosheets with other materials can also improve the photoanode and, thus, the resulting cell performance. Finally, we present an outlook for current issues and further trends for using graphene materials in DSSC photoanodes.

Carbon-based nanomaterials: multifunctional materials for biomedical engineering.

Science.gov (United States)

Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

2013-04-23

Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications.

Multiscale experimental mechanics of hierarchical carbon-based materials.

Science.gov (United States)

Espinosa, Horacio D; Filleter, Tobin; Naraghi, Mohammad

2012-06-05

Investigation of the mechanics of natural materials, such as spider silk, abalone shells, and bone, has provided great insight into the design of materials that can simultaneously achieve high specific strength and toughness. Research has shown that their emergent mechanical properties are owed in part to their specific self-organization in hierarchical molecular structures, from nanoscale to macroscale, as well as their mixing and bonding. To apply these findings to manmade materials, researchers have devoted significant efforts in developing a fundamental understanding of multiscale mechanics of materials and its application to the design of novel materials with superior mechanical performance. These efforts included the utilization of some of the most promising carbon-based nanomaterials, such as carbon nanotubes, carbon nanofibers, and graphene, together with a variety of matrix materials. At the core of these efforts lies the need to characterize material mechanical behavior across multiple length scales starting from nanoscale characterization of constituents and their interactions to emerging micro- and macroscale properties. In this report, progress made in experimental tools and methods currently used for material characterization across multiple length scales is reviewed, as well as a discussion of how they have impacted our current understanding of the mechanics of hierarchical carbon-based materials. In addition, insight is provided into strategies for bridging experiments across length scales, which are essential in establishing a multiscale characterization approach. While the focus of this progress report is in experimental methods, their concerted use with theoretical-computational approaches towards the establishment of a robust material by design methodology is also discussed, which can pave the way for the development of novel materials possessing unprecedented mechanical properties. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Task-Based Approach to Materials Development

Science.gov (United States)

Nunan, David

2010-01-01

The purpose of this chapter is to present a task-based approach to materials development. In the first part of the chapter, I sketch out the evolution of task based language teaching, drawing on a distinction between synthetic and analytical approaches to syllabus design first articulated by Wilkins (1976).

Development of knowledge base system linked to material database

International Nuclear Information System (INIS)

Kaji, Yoshiyuki; Tsuji, Hirokazu; Mashiko, Shinichi; Miyakawa, Shunichi; Fujita, Mitsutane; Kinugawa, Junichi; Iwata, Shuichi

2002-01-01

The distributed material database system named 'Data-Free-Way' has been developed by four organizations (the National Institute for Materials Science, the Japan Atomic Energy Research Institute, the Japan Nuclear Cycle Development Institute, and the Japan Science and Technology Corporation) under a cooperative agreement in order to share fresh and stimulating information as well as accumulated information for the development of advanced nuclear materials, for the design of structural components, etc. In order to create additional values of the system, knowledge base system, in which knowledge extracted from the material database is expressed, is planned to be developed for more effective utilization of Data-Free-Way. XML (eXtensible Markup Language) has been adopted as the description method of the retrieved results and the meaning of them. One knowledge note described with XML is stored as one knowledge which composes the knowledge base. Since this knowledge note is described with XML, the user can easily convert the display form of the table and the graph into the data format which the user usually uses. This paper describes the current status of Data-Free-Way, the description method of knowledge extracted from the material database with XML and the distributed material knowledge base system. (author)

Microporous carbon derived from polyaniline base as anode material for lithium ion secondary battery

International Nuclear Information System (INIS)

Xiang, Xiaoxia; Liu, Enhui; Huang, Zhengzheng; Shen, Haijie; Tian, Yingying; Xiao, Chengyi; Yang, Jingjing; Mao, Zhaohui

2011-01-01

Highlights: → Nitrogen-containing microporous carbon was prepared from polyaniline base by K 2 CO 3 activation, and used as anode material for lithium ion secondary battery. → K 2 CO 3 activation promotes the formation of amorphous and microporous structure. → High nitrogen content, and large surface area with micropores lead to strong intercalation between carbon and lithium ion, and thus improve the lithium storage capacity. -- Abstract: Microporous carbon with large surface area was prepared from polyaniline base using K 2 CO 3 as an activating agent. The physicochemical properties of the carbon were characterized by scanning electron microscope, X-ray diffraction, Brunauer-Emmett-Teller, elemental analyses and X-ray photoelectron spectroscopy measurement. The electrochemical properties of the microporous carbon as anode material in lithium ion secondary battery were evaluated. The first discharge capacity of the microporous carbon was 1108 mAh g -1 , whose first charge capacity was 624 mAh g -1 , with a coulombic efficiency of 56.3%. After 20 cycling tests, the microporous carbon retains a reversible capacity of 603 mAh g -1 at a current density of 100 mA g -1 . These results clearly demonstrated the potential role of microporous carbon as anode for high capacity lithium ion secondary battery.

Fracture behavior of W based materials

International Nuclear Information System (INIS)

Hack, J.E.

1991-01-01

This report describes the results of a program to investigate the fracture properties of tungsten based materials. In particular, the role of crack velocity on crack instability was determined in a W-Fe-Ni-Co ''heavy alloy'' and pure polycrystalline tungsten. A considerable effort was expended on the development of an appropriate crack velocity gage for use on these materials. Having succeeded in that, the gage technology was employed to determine the crack velocity response to the applied level of stress intensity factor at the onset of crack instability in pre-cracked specimens. The results were also correlated to the failure mode observed in two material systems of interest. Major results include: (1) unstable crack velocity measurements on metallic specimens which require high spatial resolution require the use of brittle, insulating substrates, as opposed to the ductile, polymer based substrates employed in low spatial resolution measurements; and (2) brittle failure modes, such as cleavage, are characterized by relatively slow unstable crack velocities while evidence of high degrees of deformation are associated with failures which proceed at high unstable crack velocities. This latter behavior is consistent with the predictions of the modeling of Hack et al and may have a significant impact on the interpretation of fractographs in general

The research of establishing reactor materials thermophysical properties data base

International Nuclear Information System (INIS)

Luo Danhui; Zhong Jianguo; Zhang Lili; Zhao Yongming

1992-01-01

In the process of nuclear reactor design and safety analysis, the reactor materials thermophysical properties parameters are very important as the main input data of reactor design and calculation. The goal of this work is to establish a practical, reliable data base of reactor materials thermophysical properties parameters with obvious function in reactor design, operation and safety analysis. At present phase, the focal point of this data base is to collect the materials thermophysical properties data based on the need of safety analysis in light water reactor and heavy water reactor. The materials to be chosen are as follows: Uranium, U-Al alloy, UO 2 , UO 2 -PuO 2 mixture, Zr-2, Zr-4, Zr-1% Ni alloy, Inconel-625, ZrO 2 (oxidic layer), boron carbide, cadmium in stainless steel, silver-indium-cadmium alloy, light water and heavy water, etc. The following thermophysical properties parameters are mainly included in the data base: thermal conductivity, thermal diffusivity, specific heat capacity, heat of melting, coefficient of thermal expansion, emittance, density, heat of vaporization, kinematic viscosity etc. The first phase of this work has been finished, which includes the method of establishing reactor materials thermophysical properties data base, the requirement of data collection, the requirement of establishing data base and the method of the data evaluation. This data base has been established and used on PC computer

Strong coupling and polariton lasing in Te based microcavities embedding (Cd,Zn)Te quantum wells

Energy Technology Data Exchange (ETDEWEB)

Rousset, J.-G., E-mail: j-g.rousset@fuw.edu.pl; Piętka, B.; Król, M.; Mirek, R.; Lekenta, K.; Szczytko, J.; Borysiuk, J.; Suffczyński, J.; Kazimierczuk, T.; Goryca, M.; Smoleński, T.; Kossacki, P.; Nawrocki, M.; Pacuski, W. [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, PL-02-093 Warszawa (Poland)

2015-11-16

We report on properties of an optical microcavity based on (Cd,Zn,Mg)Te layers and embedding (Cd,Zn)Te quantum wells. The key point of the structure design is the lattice matching of the whole structure to MgTe, which eliminates the internal strain and allows one to embed an arbitrary number of unstrained quantum wells in the microcavity. We evidence the strong light-matter coupling regime already for the structure containing a single quantum well. Embedding four unstrained quantum wells results in further enhancement of the exciton-photon coupling and the polariton lasing in the strong coupling regime.

Moisture measurement in wood, wood-based materials and building materials - a literature review

International Nuclear Information System (INIS)

Kober, A.; Mehlhorn, L.; Plinke, B.

1989-10-01

Methods of moisture measurement in solid substances, especially on wood, wood-based materials and building materials were examined and evaluated according to the literature available. The question was which methods of examining the moisture distribution in building elements at climate loading offer the best accuracy and spatial resolution as well as which methods are the most appropriate at present and in future for the solution of measurement problems in the wood and wood-based industry. The most common methods are electric measurement methods which are utilizing either the moisture-depending conductivity or the dielectric constant or the reflectivity of the material for infrared radiation but they offer only a limited accuracy. The same is valid for the rarely used microwave methods or X-ray and NMR tomography. Simple electric methods will further on play an important role in the industrial process measuring technique. For the examination of building elements, methods using nuclear radiation still offer possibilities for a further development. (orig.) With 207 refs., 13 figs [de

Radiation hardened equipment and material data base

International Nuclear Information System (INIS)

Sumita, Kenji; Yamaoka, Hitoshi; Kakuta, Tsunemi; Shono, Yoshihiko; Nakamura, Tetsuo; Nakase, Yoshiaki; Furuta, Junichiro.

1988-01-01

In order to collect and put in order the results regarding radiation-withstanding equipment and materials, the Osaka Nuclear Science Association organized the committee composed of the experts in various fields in fiscal year 1986 for the purpose of building up the data base, and began the activity. From the trend of the research and development and the usefulness for the future, the fields of collecting data were decided as organic materials, optical fibers, semiconductor elements and compound semiconductors. By fiscal year 1987, the building-up of the prototype data base was aimed at, and system configuration, the making of the formats on the items and attributes of collected data, the action test of the system and so on were carried out. Under the background of the upgrading of LWRs, the development of FBRs and nuclear fusion reactors, the construction of a reprocessing plant and a low level waste storage facility, and the progress of various advanced technologies, the research on the equipment and materials having excellent radiation resistance and the development for heightening the performance have been carried out in many places separately, accordingly the activity for building up the prototype data base was begun, and about 600 cases were collected. (Kako, I.)

The Crucial Role of the K+-Aluminium Oxide Interaction in K+-Promoted Alumina- and Hydrotalcite-Based Materials for CO2 Sorption at High Temperatures

Energy Technology Data Exchange (ETDEWEB)

Walspurger, S.; Boels, L.; Cobden, P.D.; Elzinga, G.D.; Haije, W.G.; Van den Brink, R.W. [Energy Research Centre of the Netherlands ECN, Westerduinweg 3, 1755LE, Petten (Netherlands)

2008-09-15

CO2-free hydrogen can be produced from coal gasification power plants by pre-combustion decarbonisation and carbon dioxide capture. Potassium carbonate promoted hydrotalcite-based and alumina-based materials are cheap and excellent materials for high-temperature (300-500C) adsorption of CO2, and particularly promising in the sorption-enhanced water gas shift (SEWGS) reaction. Alkaline promotion significantly improves CO2 reversible sorption capacity at 300-500C for both materials. Hydrotalcites and promoted hydrotalcites, promoted magnesium oxide and promoted -alumina were investigated by in situ analytical methods (IR spectroscopy, sorption experiments, X-ray diffraction) to identify structural and surface rearrangements. All experimental results show that potassium ions actually strongly interact with aluminium oxide centres in the aluminium-containing materials. This study unambiguously shows that potassium promotion of aluminium oxide centres in hydrotalcite generates basic sites which reversibly adsorb CO2 at 400C.

Periodic materials-based vibration attenuation in layered foundations: experimental validation

International Nuclear Information System (INIS)

Xiang, H J; Shi, Z F; Wang, S J; Mo, Y L

2012-01-01

Guided by the recent advances in solid-state research in periodic materials, a new type of layered periodic foundation consisting of concrete and rubber layers is experimentally investigated in this paper. The distinct feature of this new foundation is its frequency band gaps. When the frequency contents of a wave fall within the range of the frequency band gaps, the wave, and hence its energy, will be weakened or cannot propagate through the foundation, so the foundation itself can serve as a vibration isolator. Using the theory of elastodynamics and the Bloch–Floquet theorem, the mechanism of band gaps in periodic composites is presented, and a finite element model is built to show the isolation characteristic of a finite dimensional periodic foundation. Based on these analytical results, moreover, a scaled model frame and a periodic foundation were fabricated and shake table tests of the frame on the periodic foundation were performed. Ambient, strong and harmonic vibration attenuations are found when the exciting frequencies fall into the band gaps. (fast track communication)

Infrared hyperbolic metasurface based on nanostructured van der Waals materials

Science.gov (United States)

Li, Peining; Dolado, Irene; Alfaro-Mozaz, Francisco Javier; Casanova, Fèlix; Hueso, Luis E.; Liu, Song; Edgar, James H.; Nikitin, Alexey Y.; Vélez, Saül; Hillenbrand, Rainer

2018-02-01

Metasurfaces with strongly anisotropic optical properties can support deep subwavelength-scale confined electromagnetic waves (polaritons), which promise opportunities for controlling light in photonic and optoelectronic applications. We developed a mid-infrared hyperbolic metasurface by nanostructuring a thin layer of hexagonal boron nitride that supports deep subwavelength-scale phonon polaritons that propagate with in-plane hyperbolic dispersion. By applying an infrared nanoimaging technique, we visualize the concave (anomalous) wavefronts of a diverging polariton beam, which represent a landmark feature of hyperbolic polaritons. The results illustrate how near-field microscopy can be applied to reveal the exotic wavefronts of polaritons in anisotropic materials and demonstrate that nanostructured van der Waals materials can form a highly variable and compact platform for hyperbolic infrared metasurface devices and circuits.

Dual-mode operation of 2D material-base hot electron transistors

KAUST Repository

Lan, Yann-Wen; Jr., Carlos M. Torres,; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

2016-01-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Dual-mode operation of 2D material-base hot electron transistors

KAUST Repository

Lan, Yann-Wen

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Development of structural materials on the base of new technology

International Nuclear Information System (INIS)

Belov, A.F.; Anoshkin, N.F.

1982-01-01

Some results are considered and possibilities which discovered in development of structural materials connected with development of such new technological processes as skull melting of titanium alloys, granule metallurgy, hot isostatic, diffusion welding are estimated. The method of skull melting with remelted skull is developed. The method assures sufficient possibilities for dissolving of high-heat components of charge and obtaining homogeneous ingots of series of new alloys. Granule metallurgy based on crystallization of the metal with high rate in the form of small (up to 300 μkm) particles and subsequent consolidation of them into compact billet discoveres a wide possibilities of creation of new structural material with more high operation indexes. It is noted that developed processes of granule production, their treatment, compacting and thermal treatment of the billets assure production of metal of high quality, satisfied the strong requirements of present standards. The process of hot isostatic pressing at which the workable metal is subjected to through uniform pressure by compressed gas after heating or semultaneously with its heating up to the temperatures of working in gasostats is one of new technological processes. A certain experience of the HIP use for production of compact billets from granules for diffusion welding of the billets is accumulated. This process has a great possibilities for densification of shaped castings. Investigation and application of the diffusion welding represent combination of elements into details of complex form in vacuum at the temperatures low of melting point under effect of small pressures are investigated both in our country and abroad. Diffusion welding gives a wide possibilities in the development of materials with higher properties at the expence of production of products of large dimensions from thin elements with fine-grained structure as well as products with assigned gradient of chemical composition, structure

Microstructure Images Restoration of Metallic Materials Based upon KSVD and Smoothing Penalty Sparse Representation Approach.

Science.gov (United States)

Li, Qing; Liang, Steven Y

2018-04-20

Microstructure images of metallic materials play a significant role in industrial applications. To address image degradation problem of metallic materials, a novel image restoration technique based on K-means singular value decomposition (KSVD) and smoothing penalty sparse representation (SPSR) algorithm is proposed in this work, the microstructure images of aluminum alloy 7075 (AA7075) material are used as examples. To begin with, to reflect the detail structure characteristics of the damaged image, the KSVD dictionary is introduced to substitute the traditional sparse transform basis (TSTB) for sparse representation. Then, due to the image restoration, modeling belongs to a highly underdetermined equation, and traditional sparse reconstruction methods may cause instability and obvious artifacts in the reconstructed images, especially reconstructed image with many smooth regions and the noise level is strong, thus the SPSR (here, q = 0.5) algorithm is designed to reconstruct the damaged image. The results of simulation and two practical cases demonstrate that the proposed method has superior performance compared with some state-of-the-art methods in terms of restoration performance factors and visual quality. Meanwhile, the grain size parameters and grain boundaries of microstructure image are discussed before and after they are restored by proposed method.

Influence of geometry on mechanical properties of bio-inspired silica-based hierarchical materials

International Nuclear Information System (INIS)

Dimas, Leon S; Buehler, Markus J

2012-01-01

Diatoms, bone, nacre and deep-sea sponges are mineralized natural structures found abundantly in nature. They exhibit mechanical properties on par with advanced engineering materials, yet their fundamental building blocks are brittle and weak. An intriguing characteristic of these structures is their heterogeneous distribution of mechanical properties. Specifically, diatoms exhibit nanoscale porosity in specific geometrical configurations to create regions with distinct stress strain responses, notably based on a single and simple building block, silica. The study reported here, using models derived from first principles based full atomistic studies with the ReaxFF reactive force field, focuses on the mechanics and deformation mechanisms of silica-based nanocomposites inspired by mineralized structures. We examine single edged notched tensile specimens and analyze stress and strain fields under varied sample size in order to gain fundamental insights into the deformation mechanisms of structures with distinct ordered arrangements of soft and stiff phases. We find that hierarchical arrangements of silica nanostructures markedly change the stress and strain transfer in the samples. The combined action of strain transfer in the deformable phase, and stress transfer in the strong phase, acts synergistically to reduce the intensity of stress concentrations around a crack tip, and renders the resulting composites less sensitive to the presence of flaws, for certain geometrical configurations it even leads to stable crack propagation. A systematic study allows us to identify composite structures with superior fracture mechanical properties relative to their constituents, akin to many natural biomineralized materials that turn the weaknesses of building blocks into a strength of the overall system. (paper)

Biogas Filter Based on Local Natural Zeolite Materials

OpenAIRE

Krido Wahono, Satriyo; Anggo Rizal, Wahyu

2014-01-01

UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as ...

SYNTHESIS of MOLECULE/POLYMER-BASED MAGNETIC MATERIALS

Energy Technology Data Exchange (ETDEWEB)

Miller, Joel S. [Univ. of Utah, Salt Lake City, UT (United States)

2016-02-01

We have synthesized and characterized several families of organic-based magnets, a new area showing that organic species can exhibit the technologically important property of magnetic ordering. Thin film magnets with ordering temperatures exceeding room temperature have been exceeded. Hence, organic-based magnets represent a new class of materials that exhibit magnetic ordering and do not require energy-intensive metallurgical processing and are based upon Earth-abundant elements.

Application of extrusion-cooking technique for foamed starch-based materials

Directory of Open Access Journals (Sweden)

Combrzyński Maciej

2018-01-01

Full Text Available Foamed materials are widely used, mainly as a protection objects during transport of various products. Traditionally foams are produced from plastics so they are very difficult for waste management. It is the challenge for many scientific centres to develop a technology for the production of bio-based materials which can be rapidly decomposed. The task for the researcher is to obtain a relatively cheap, easy to use and completely biodegradable materials. The aim of this work was the selection of the main raw materials, functional additives and process parameters to obtain the most effective parameters of extrusion-cooking process for foamed starch-based materials. Properties of the products and processing costs were taken into account. During the study, the extrusion-cooking process was performed under various conditions: temperature, humidity, type of the die, screw rotational speed, various raw materials and additives blends. The best results were obtained for mixtures based on potato starch and with addition the foaming agent Plastron foam PDE and poly(vinyl alcohol PVA.

Microstructural characterization of catalysis product of nanocement based materials: A review

Science.gov (United States)

Sutan, Norsuzailina Mohamed; Izaitul Akma Ideris, Nur; Taib, Siti Noor Linda; Lee, Delsye Teo Ching; Hassan, Alsidqi; Kudnie Sahari, Siti; Mohamad Said, Khairul Anwar; Rahman Sobuz, Habibur

2018-03-01

Cement as an essential element for cement-based products contributed to negative environmental issues due to its high energy consumption and carbon dioxide emission during its production. These issues create the need to find alternative materials as partial cement replacement where studies on the potential of utilizing silica based materials as partial cement replacement come into picture. This review highlights the effectiveness of microstructural characterization techniques that have been used in the studies that focus on characterization of calcium hydroxide (CH) and calcium silicate hydrate (C-S-H) formation during hydration process of cement-based product incorporating nano reactive silica based materials as partial cement replacement. Understanding the effect of these materials as cement replacement in cement based product focusing on the microstructural development will lead to a higher confidence in the use of industrial waste as a new non-conventional material in construction industry that can catalyse rapid and innovative advances in green technology.

Microstructural characterization of catalysis product of nanocement based materials: A review

Directory of Open Access Journals (Sweden)

Mohamed Sutan Norsuzailina

2018-01-01

Full Text Available Cement as an essential element for cement-based products contributed to negative environmental issues due to its high energy consumption and carbon dioxide emission during its production. These issues create the need to find alternative materials as partial cement replacement where studies on the potential of utilizing silica based materials as partial cement replacement come into picture. This review highlights the effectiveness of microstructural characterization techniques that have been used in the studies that focus on characterization of calcium hydroxide (CH and calcium silicate hydrate (C-S-H formation during hydration process of cement-based product incorporating nano reactive silica based materials as partial cement replacement. Understanding the effect of these materials as cement replacement in cement based product focusing on the microstructural development will lead to a higher confidence in the use of industrial waste as a new non-conventional material in construction industry that can catalyse rapid and innovative advances in green technology.

A multifluid model extended for strong temperature nonequilibrium

Energy Technology Data Exchange (ETDEWEB)

Chang, Chong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-08-08

We present a multifluid model in which the material temperature is strongly affected by the degree of segregation of each material. In order to track temperatures of segregated form and mixed form of the same material, they are defined as different materials with their own energy. This extension makes it necessary to extend multifluid models to the case in which each form is defined as a separate material. Statistical variations associated with the morphology of the mixture have to be simplified. Simplifications introduced include combining all molecularly mixed species into a single composite material, which is treated as another segregated material. Relative motion within the composite material, diffusion, is represented by material velocity of each component in the composite material. Compression work, momentum and energy exchange, virtual mass forces, and dissipation of the unresolved kinetic energy have been generalized to the heterogeneous mixture in temperature nonequilibrium. The present model can be further simplified by combining all mixed forms of materials into a composite material. Molecular diffusion in this case is modeled by the Stefan-Maxwell equations.

Bio-based hyperbranched thermosetting polyurethane/triethanolamine functionalized multi-walled carbon nanotube nanocomposites as shape memory materials.

Science.gov (United States)

Kalita, Hemjyoti; Karak, Niranjan

2014-07-01

Here, bio-based shape memory polymers have generated immense interest in recent times. Here, Bio-based hyperbranched polyurethane/triethanolamine functionalized multi-walled carbon nanotube (TEA-f-MWCNT) nanocomposites were prepared by in-situ pre-polymerization technique. The Fourier transform infrared spectroscopy and the transmission electron microscopic studies showed the strong interfacial adhesion and the homogeneous distribution of TEA-f-MWCNT in the polyurethane matrix. The prepared epoxy cured thermosetting nanocomposites exhibited enhanced tensile strength (6.5-34.5 MPa), scratch hardness (3.0-7.5 kg) and thermal stability (241-288 degrees C). The nanocomposites showed excellent shape fixity and shape recovery. The shape recovery time decreases (24-10 s) with the increase of TEA-f-MWCNT content in the nanocomposites. Thus the studied nanocomposites have potential to be used as advanced shape memory materials.

Designing Web-Based Educative Curriculum Materials for the Social Studies

Science.gov (United States)

Callahan, Cory; Saye, John; Brush, Thomas

2013-01-01

This paper reports on a design experiment of web-based curriculum materials explicitly created to help social studies teachers develop their professional teaching knowledge. Web-based social studies curriculum reform efforts, human-centered interface design, and investigations into educative curriculum materials are reviewed, as well as…

Development of data base system for nuclear material accountancy data at PNC

International Nuclear Information System (INIS)

Hirosawa, N.; Akiba, Mitsunori; Nakagima, Kiyoshi; Usui, Shinichi; Tosa, Kiyofumi; Hashimoto, Kazuyuki.

1993-01-01

PNC is developing a wide area of nuclear fuel cycle. Therefore, much nuclear material with a various form exists at each facility in the Works, and the controls of the inventory changes and the physical inventories of nuclear material are important. Nuclear material accountancy is a basic measure in safeguards system based on Non-Proliferation Treaty(NPT). In the light of such importance of material accountancy, the data base of nuclear material control and the material accountancy report system for all facilities has been developed by using the computer. By this system, accountancy report to STA is being presented certainly and timely. Property management and rapid corresponding to inquiries from STA can be carried out by the data base system which has free item searching procedure. The present paper introduces 'Development of Data Base System for Nuclear Material Accountancy Data at PNC'. (author)

Self-healing phenomena in cement-based materials state-of-the-art report of RILEM Technical Committee 221-SHC Self-Healing Phenomena in Cement-Based Materials

CERN Document Server

Tittelboom, Kim; Belie, Nele; Schlangen, Erik

2013-01-01

Self-healing materials are man-made materials which have the built-in capability to repair damage. Failure in materials is often caused by the occurrence of small microcracks throughout the material. In self-healing materials phenomena are triggered to counteract these microcracks. These processes are ideally triggered by the occurrence of damage itself. Thus far, the self-healing capacity of cement-based materials has been considered as something "extra". This could be called passive self-healing, since it was not a designed feature of the material, but an inherent property of it. Centuries-old buildings have been said to have survived these centuries because of the inherent self-healing capacity of the binders used for cementing building blocks together. In this State-of-the-Art Report a closer look is taken at self-healing phenomena in cement-based materials. It is shown what options are available to design for this effect rather than have it occur as a "coincidental extra".

Novel Au- and Ge-based two-dimensional materials formed through topotactic transitions of AlB2-like structures

Science.gov (United States)

Tsetseris, Leonidas

2016-07-01

The topotactic reaction of a layered compound, for example CaGe2, with HCl solution is a common and facile method to produce two-dimensional (2D) materials. In this work we demonstrate with first-principles calculations that this technique can potentially lead to a whole new family of 2D materials starting from three-dimensional crystals with AlB2-like structures. As representative cases, we show here that the de-intercalation of Sc and Ca atoms from ScAuGe and Ca2AuGe3 crystals is strongly exothermic and produces the stable 2D monolayers AuGeH and AuGe3H3, respectively. Remarkably, both metals (AuGeH) and semiconductors (AuGe3H3) can be prepared by this method. Based on the broad availability of AlB2-like structures with varying stoichiometries, there are several possibilities to prepare novel functional 2D materials with suitable topotactic transitions.

Base technology development of new materials for FBR performance innovations

International Nuclear Information System (INIS)

Kano, Shigeki; Koyama, Masahiro; Nomura, Shigeo; Morikawa, Satoru; Ueno, Fumiyoshi

1989-01-01

This paper describes the base technology development of new materials for FBR performance innovations at the Power Reactor and Nuclear Fuel Development Corporation. The contents are as follows: (1) development of sodium and radiation resistant new materials, (2) development of high performance shielding material, (3) development of high performance control material, (4) development of new functional materials for reactor instrumentation. (author)

Graphene-based materials for supercapacitor electrodes – A review

Directory of Open Access Journals (Sweden)

Qingqing Ke

2016-03-01

Full Text Available The graphene-based materials are promising for applications in supercapacitors and other energy storage devices due to the intriguing properties, i.e., highly tunable surface area, outstanding electrical conductivity, good chemical stability and excellent mechanical behavior. This review summarizes recent development on graphene-based materials for supercapacitor electrodes, based on their macrostructural complexity, i.e., zero-dimensional (0D (e.g. free-standing graphene dots and particles, one-dimensional (1D (e.g. fiber-type and yarn-type structures, two-dimensional (2D (e.g. graphenes and graphene-based nanocomposite films, and three-dimensional (3D (e.g. graphene foam and hydrogel-based nanocomposites. There are extensive and on-going researches on the rationalization of their structures at varying scales and dimensions, development of effective and low cost synthesis techniques, design and architecturing of graphene-based materials, as well as clarification of their electrochemical performance. It is indicated that future studies should focus on the overall device performance in energy storage devices and large-scale process in low costs for the promising applications in portable and wearable electronic, transport, electrical and hybrid vehicles.

Organic molecules based on dithienyl-2,1,3-benzothiadiazole as new donor materials for solution-processed organic photovoltaic cells

Energy Technology Data Exchange (ETDEWEB)

Wu, Zhonglian; Fan, Benhu; Ouyang, Jianyong [Department of Materials Science and Engineering, National University of Singapore, Singapore 117574 (Singapore); Xue, Feng [Department of Chemistry, National University of Singapore, Singapore 117573 (Singapore); Adachi, Chihaya [Center for Future Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

2010-12-15

Polymers based on dithienyl-2,1,3-benzothiadiazole (TBT) have received strong attention as the donor materials of polymer photovoltaic cells (PVs), since they can have a low band gap. But soluble small organic molecules based on TBT have been rarely studied. This paper reports the synthesis of two small organic molecules based on TBT and their application as the donor materials of solution-processed bulk heterojunction organic photovoltaic cells (OPVs). These compounds were soluble in common organic solvents, such as chloroform, chlorobenzene and tetrahydrofuran. They have band gaps comparable to poly(3-hexylthiophene) (P3HT) and lower HOMO and LUMO (HOMO: highest occupied molecular orbital, LUMO: lowest unoccupied molecular orbital) levels than P3HT. These molecules and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were used as the donors and acceptor to fabricate bulk heterojunction OPVs through solution processing. After optimization of the experimental conditions, power conversion efficiency (PCE) of 0.66% was achieved on the solution-processed OPVs under AM 1.5G, 100 mW cm{sup -2} illumination. (author)

Modeling short-pulse laser excitation of dielectric materials

DEFF Research Database (Denmark)

Wædegaard, Kristian Juncher; Sandkamm, Ditte Både; Haahr-Lillevang, Lasse

2014-01-01

A theoretical description of ultrashort-pulse laser excitation of dielectric materials based on strong-field excitation in the Keldysh picture combined with a multiple-rateequation model for the electronic excitation including collisional processes is presented. The model includes light attenuation...

Strategy Iteration Is Strongly Polynomial for 2-Player Turn-Based Stochastic Games with a Constant Discount Factor

DEFF Research Database (Denmark)

Hansen, Thomas Dueholm; Miltersen, Peter Bro; Zwick, Uri

2013-01-01

Ye [2011] showed recently that the simplex method with Dantzig’s pivoting rule, as well as Howard’s policy iteration algorithm, solve discounted Markov decision processes (MDPs), with a constant discount factor, in strongly polynomial time. More precisely, Ye showed that both algorithms terminate...... terminates after at most O(m1−γ log n1−γ) iterations. Second, and more importantly, we show that the same bound applies to the number of iterations performed by the strategy iteration (or strategy improvement) algorithm, a generalization of Howard’s policy iteration algorithm used for solving 2-player turn-based...... for 2-player turn-based stochastic games; it is strongly polynomial for a fixed discount factor, and exponential otherwise....

Data base on structural materials aging properties

International Nuclear Information System (INIS)

Oland, C.B.

1992-01-01

The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period

An eco-friendly molecularly imprinted fluorescence composite material based on carbon dots for fluorescent detection of 4-nitrophenol

International Nuclear Information System (INIS)

Hao, Tongfan; Wei, Xiao; Nie, Yijing; Zhou, Zhiping; Xu, Yeqing; Yan, Yongsheng

2016-01-01

We on report an eco-friendly molecularly imprinted material based on carbon dots (C-dots) via a facile and efficient sol–gel polymerization for selective fluorescence detection of 4-nitrophenol (4-NP). The amino-modified C-dots were firstly synthesized by a hydrothermal process using citric acid as the carbon source and poly(ethyleneimine) as the surface modifier, and then after a sol–gel molecular imprinting process, the molecularly imprinted fluorescence material was obtained. The material (MIP-C-dots) showed strong fluorescence from C-dots and high selectivity due to the presence of a molecular imprint. After the detection conditions were optimized, the relative fluorescence intensity (F_0/F) of MIP-C-dots presented a good linearity with 4-NP concentrations in the linear range of 0.2 − 50 μmol L"-"1 with a detection limit (3σ/k) of 0.06 μmol L"-"1. In addition, the correlation coefficient was 0.9978 and the imprinting factor was 2.76. The method was applicable to the determination of trace 4-NP in Yangtze River water samples and good recoveries from 92.6–107.3 % were obtained. The present study provides a general strategy to fabricate materials based on C-dots with good fluorescence property for selective fluorescence detection of organic pollutants. (author)

Tungsten-based composite materials for fusion reactor shields

International Nuclear Information System (INIS)

Greenspan, E.; Karni, Y.

1985-01-01

Composite tungsten-based materials were recently proposed for the heavy constituent of compact fusion reactor shields. These composite materials will enable the incorporation of tungsten - the most efficient nonfissionable inelastic scattering (as well as good neutron absorbing and very good photon attenuating) material - in the shield in a relatively cheap way and without introducing voids (so as to enable minimizing the shield thickness). It is proposed that these goals be achieved by bonding tungsten powder, which is significantly cheaper than high-density tungsten, with a material having the following properties: good shielding ability and relatively low cost and ease of fabrication. The purpose of this work is to study the effectiveness of the composite materials as a function of their composition, and to estimate the economic benefit that might be gained by the use of these materials. Two materials are being considered for the binder: copper, second to tungsten in its shielding ability, and iron (or stainless steel), the common fusion reactor shield heavy constituent

Advanced three dimensional characterization of silica-based ultraporous materials

OpenAIRE

Foray , Genevieve; Roiban , L.; Rong , Q.; Perret , A.; Ihiawakrim , D.; Masenelli-Varlot , K.; Maire , E.; Yrieix , B.

2016-01-01

International audience; Whatever the field of application (building, transportation, packaging, etc.) energy losses must be reduced to meet the government target of a 40% cut in CO 2 emissions. This leads to a challenge for materials scientists: designing materials with thermal conductivities lower than 0.015 W m À1 K À1 under ambient conditions. Such a low value requires reducing air molecule mobility in highly porous materials, and silica-based superinsulation materials (SIM) made of packed...

All-Metallic Vertical Transistors Based on Stacked Dirac Materials

OpenAIRE

Wang, Yangyang; Ni, Zeyuan; Liu, Qihang; Quhe, Ruge; Zheng, Jiaxin; Ye, Meng; Yu, Dapeng; Shi, Junjie; Yang, Jinbo; Lu, Jing

2014-01-01

It is an ongoing pursuit to use metal as a channel material in a field effect transistor. All metallic transistor can be fabricated from pristine semimetallic Dirac materials (such as graphene, silicene, and germanene), but the on/off current ratio is very low. In a vertical heterostructure composed by two Dirac materials, the Dirac cones of the two materials survive the weak interlayer van der Waals interaction based on density functional theory method, and electron transport from the Dirac ...

Development of a poly(dimethylacrylamide) based matrix material for solid phase high density peptide array synthesis employing a laser based material transfer

International Nuclear Information System (INIS)

Ridder, Barbara; Foertsch, Tobias C.; Welle, Alexander; Mattes, Daniela S.; Bojnicic-Kninski, Clemens M. von; Loeffler, Felix F.; Nesterov-Mueller, Alexander; Meier, Michael A.R.; Breitling, Frank

2016-01-01

Highlights: • New matrix material for peptide array synthesis from a ‘solid solvent’. • Resolution was increased with possible spot densities of up to 20.000 spots per cm"2. • The coupling depth and the effectiveness of washing steps analyzed by ToF-SIMS. • Adaptations and custom changes of the matrix material are possible. - Abstract: Poly(dimethylacrylamide) (PDMA) based matrix materials were developed for laser-based in situ solid phase peptide synthesis to produce high density arrays. In this specific array synthesis approach, amino acid derivatives are embedded into a matrix material, serving as a “solid” solvent material at room temperature. Then, a laser pulse transfers this mixture to the target position on a synthesis slide, where the peptide array is synthesized. Upon heating above the glass transition temperature of the matrix material, it softens, allowing diffusion of the amino acid derivatives to the synthesis surface and serving as a solvent for peptide bond formation. Here, we synthesized PDMA six-arm star polymers, offering the desired matrix material properties, using atom transfer radical polymerization. With the synthesized polymers as matrix material, we structured and synthesized arrays with combinatorial laser transfer. With densities of up to 20,000 peptide spots per cm"2, the resolution could be increased compared to the commercially available standard matrix material. Time-of-Flight Secondary Ion Mass Spectrometry experiments revealed the penetration behavior of an amino acid derivative into the prepared acceptor synthesis surface and the effectiveness of the washing protocols.

Development of a poly(dimethylacrylamide) based matrix material for solid phase high density peptide array synthesis employing a laser based material transfer

Energy Technology Data Exchange (ETDEWEB)

Ridder, Barbara [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Foertsch, Tobias C. [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Welle, Alexander [Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Mattes, Daniela S. [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Bojnicic-Kninski, Clemens M. von; Loeffler, Felix F.; Nesterov-Mueller, Alexander [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Meier, Michael A.R., E-mail: m.a.r.meier@kit.edu [Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Breitling, Frank, E-mail: frank.breitling@kit.edu [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2016-12-15

Highlights: • New matrix material for peptide array synthesis from a ‘solid solvent’. • Resolution was increased with possible spot densities of up to 20.000 spots per cm{sup 2}. • The coupling depth and the effectiveness of washing steps analyzed by ToF-SIMS. • Adaptations and custom changes of the matrix material are possible. - Abstract: Poly(dimethylacrylamide) (PDMA) based matrix materials were developed for laser-based in situ solid phase peptide synthesis to produce high density arrays. In this specific array synthesis approach, amino acid derivatives are embedded into a matrix material, serving as a “solid” solvent material at room temperature. Then, a laser pulse transfers this mixture to the target position on a synthesis slide, where the peptide array is synthesized. Upon heating above the glass transition temperature of the matrix material, it softens, allowing diffusion of the amino acid derivatives to the synthesis surface and serving as a solvent for peptide bond formation. Here, we synthesized PDMA six-arm star polymers, offering the desired matrix material properties, using atom transfer radical polymerization. With the synthesized polymers as matrix material, we structured and synthesized arrays with combinatorial laser transfer. With densities of up to 20,000 peptide spots per cm{sup 2}, the resolution could be increased compared to the commercially available standard matrix material. Time-of-Flight Secondary Ion Mass Spectrometry experiments revealed the penetration behavior of an amino acid derivative into the prepared acceptor synthesis surface and the effectiveness of the washing protocols.

Design of an intelligent materials data base for the IFR

International Nuclear Information System (INIS)

Mikaili, R.; Lambert, J.D.B.; Orth, T.D.

1992-01-01

In the development of the integral fast reactor (IFR) concept, there is a consensus that materials considerations are an important part of the reactor design, operation, and maintenance and that materials performance is central to liquid-metal reactor reliability and safety. In the design of the IRF materials data base, artificial intelligence techniques are being used to ensure efficient control of information. Intelligent control will provide for the selection of menus to be displayed, efficient data-base searches, and application-dependent guidance through the data base. The development of the IRF data base has progressed to the point of (a) completing the design of the data-base architecture and tables, (b) installing computer hardware for storing large amounts of data, (c) outlining strategies for data transferal, and (d) identifying ways to validate and secure the integrity of data

Applying distance-to-target weighing methodology to evaluate the environmental performance of bio-based energy, fuels, and materials

International Nuclear Information System (INIS)

Weiss, Martin; Patel, Martin; Heilmeier, Hermann; Bringezu, Stefan

2007-01-01

The enhanced use of biomass for the production of energy, fuels, and materials is one of the key strategies towards sustainable production and consumption. Various life cycle assessment (LCA) studies demonstrate the great potential of bio-based products to reduce both the consumption of non-renewable energy resources and greenhouse gas emissions. However, the production of biomass requires agricultural land and is often associated with adverse environmental effects such as eutrophication of surface and ground water. Decision making in favor of or against bio-based and conventional fossil product alternatives therefore often requires weighing of environmental impacts. In this article, we apply distance-to-target weighing methodology to aggregate LCA results obtained in four different environmental impact categories (i.e., non-renewable energy consumption, global warming potential, eutrophication potential, and acidification potential) to one environmental index. We include 45 bio- and fossil-based product pairs in our analysis, which we conduct for Germany. The resulting environmental indices for all product pairs analyzed range from -19.7 to +0.2 with negative values indicating overall environmental benefits of bio-based products. Except for three options of packaging materials made from wheat and cornstarch, all bio-based products (including energy, fuels, and materials) score better than their fossil counterparts. Comparing the median values for the three options of biomass utilization reveals that bio-energy (-1.2) and bio-materials (-1.0) offer significantly higher environmental benefits than bio-fuels (-0.3). The results of this study reflect, however, subjective value judgments due to the weighing methodology applied. Given the uncertainties and controversies associated not only with distance-to-target methodologies in particular but also with weighing approaches in general, the authors strongly recommend using weighing for decision finding only as a

Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

Science.gov (United States)

Nicole M. Stark; Zhiyong Cai; Charles Carll

2010-01-01

This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

Graphene-based filament material for thermal ionization

Energy Technology Data Exchange (ETDEWEB)

Hewitt, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shick, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Siegfried, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-19

The use of graphene oxide materials for thermal ionization mass spectrometry analysis of plutonium and uranium has been investigated. Filament made from graphene oxide slurries have been 3-D printed. A method for attaching these filaments to commercial thermal ionization post assemblies has been devised. Resistive heating of the graphene based filaments under high vacuum showed stable operation in excess of 4 hours. Plutonium ion production has been observed in an initial set of filaments spiked with the Pu 128 Certified Reference Material.

Experimental results on performance improvement of doped carbon-base materials

International Nuclear Information System (INIS)

Xu Zengyu

2002-01-01

Carbon-base materials is one of candidate plasma facing materials and have been widely used in current tokamak facilities in the world. But some defect properties are presented on high yield of chemical sputtering , high yield of radiation enhancement sublimate (RES), cracking after heat flux and so on. It can be improved by doped some little other elements into the carbon-base materials, such as boron, silicon, titanium and so on. Experimental results indicate that it is feasible and successful to improve thermo-physics and chemical properties of carbon-base materials by multi-element doped. Doped 12 % silicon can strained RES and chemical sputtering yield do not changed. It is the same level of chemical sputtering yield for B 4 C from 3 % to 10 % , but their resistance thermal shock properties ability increases with B 4 C increases

Graphene-Based Composites as Cathode Materials for Lithium Ion Batteries

Directory of Open Access Journals (Sweden)

Libao Chen

2013-01-01

Full Text Available Owing to the superior mechanical, thermal, and electrical properties, graphene was a perfect candidate to improve the performance of lithium ion batteries. Herein, we review the recent advances in graphene-based composites and their application as cathode materials for lithium ion batteries. We focus on the synthesis methods of graphene-based composites and the superior electrochemical performance of graphene-based composites as cathode materials for lithium ion batteries.

Synthesis and optoelectronic characterization of some triphenylamine-based compounds containing strong acceptor substituents

Energy Technology Data Exchange (ETDEWEB)

Grigoras, Mircea, E-mail: grim@icmpp.ro; Ivan, Teofilia; Vacareanu, Loredana; Catargiu, Ana Maria; Tigoianu, Radu

2014-09-15

Three novel triphenylamine-based compounds containing strong electron acceptor groups have been synthesized and their comparative photophysical properties are presented. These compounds were obtained by a two-step method: (i) triphenylamine compounds with one, two and three phenylacetylene arms were synthesized by Sonogashira reaction between iodine-substituted triphenylamines and phenylacetylene, followed by (ii) post-modification of these electron-rich alkynes by addition of the strong electron acceptor, tetracyanoethylene. Characterization of all oligomers was made by FTIR, {sup 1}H-NMR, UV–vis and fluorescence spectroscopy. A batochromic shifting of the UV and photoluminescence maxima was observed with the increase of the acceptor group number. The electrochemical behavior was studied by cyclic voltammetry. The cyclic voltammograms have evidenced that triphenylamine-phenylacetylene compounds undergo only oxidation processes while compounds modified with tetracyanoethylene show both oxidation and reduction peaks associated with donor and acceptor groups, respectively. The donor–acceptor compounds coordinate metal ions (i.e., Hg{sup 2+} and Sn{sup 2+}) by cyano groups resulting in the decreasing of charge transfer band intensity, and they can be used as chemosensors. - Highlights: • Three triphenylamine-based ethynylene compounds were prepared by Sonogashira reaction. • Post-modification of ethynylene linkages by tetracyanethylene cycloaddition and retroconversion led to donor–acceptor compounds. • Photophysical properties of donor–acceptor oligomers were studied in different solvents.

Transportation of ions through cement based materials

International Nuclear Information System (INIS)

Chatterji, S.

1994-01-01

Transportation of ions, both anions and cations, through cement based materials is one of the important processes in their durability and as such has been studied very extensively. It has been studied from the point of view of the reinforcement corrosion, alkali-silica reaction, sulfate attack on cement and concrete, as well as in the context of the use of the cement based materials in the disposal of nuclear waste. In this paper the fundamental equations of diffusion, i.e. Fick's two equations, Nernst and Nernst-Planck equations have been collected. Attention has been drawn to the fact that Fick's two equations are valid for non-ionic diffusants and that for ions the relevant equations are those of Nernst and Nernst-Planck. The basic measurement techniques have also been commented upon

EB and EUV lithography using inedible cellulose-based biomass resist material

Science.gov (United States)

Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2016-03-01

The validity of our approach of inedible cellulose-based resist material derived from woody biomass has been confirmed experimentally for the use of pure water in organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques of eco-conscious electron beam (EB) and extreme-ultraviolet (EUV) lithography. The water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB and EUV lithography was developed for environmental affair, safety, easiness of handling, and health of the working people. The inedible cellulose-based biomass resist material was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB and EUV sensitive groups. The 50-100 nm line and space width, and little footing profiles of cellulose-based biomass resist material on hardmask and layer were resolved at the doses of 10-30 μC/cm2. The eco-conscious lithography techniques was referred to as green EB and EUV lithography using inedible cellulose-based biomass resist material.

Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery

Directory of Open Access Journals (Sweden)

Yuandong Sun

2017-01-01

Full Text Available Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D, compared with bulky silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. In this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs applications is listed and discussed.

Using Task-based Materials in Teaching Writing for EFL Classes in Indonesia

Directory of Open Access Journals (Sweden)

Hanna Sundari

2018-05-01

Full Text Available Task-based language teaching has been widely used for language classroom. Using tasks as main activities, task-based materials was developed particularly for writing class. This article is intended to present the study of effectiveness of task-based materials in improving writing class for university. To accommodate the research purposes, mixed method approach was carried out by using quasi experimental research and content analysis of sentence complexity. The respondents were 210 students from writing classes as experiment and control with writing test as instrument. The results of data analysis showed that there were significant differences of writing skill to those who taught using developed task-based materials. Despite the fact that the score did not significantly differ on the aspect of writing mechanics, a developed task-based material has been proved to improve students’ writing skill in the aspect of format, content, organization and grammar. Moreover, the levels of lexical complexity and accuracy from the students whose materials use task-based design are higher than those who do not use it. Then, it can be drawn a conclusion that the use of developed task-based materials brings significant effects toward writing performance.

2004 research briefs :Materials and Process Sciences Center.

Energy Technology Data Exchange (ETDEWEB)

Cieslak, Michael J.

2004-01-01

This report is the latest in a continuing series that highlights the recent technical accomplishments associated with the work being performed within the Materials and Process Sciences Center. Our research and development activities primarily address the materials-engineering needs of Sandia's Nuclear-Weapons (NW) program. In addition, we have significant efforts that support programs managed by the other laboratory business units. Our wide range of activities occurs within six thematic areas: Materials Aging and Reliability, Scientifically Engineered Materials, Materials Processing, Materials Characterization, Materials for Microsystems, and Materials Modeling and Simulation. We believe these highlights collectively demonstrate the importance that a strong materials-science base has on the ultimate success of the NW program and the overall DOE technology portfolio.

Neuromimetic Circuits with Synaptic Devices Based on Strongly Correlated Electron Systems

Science.gov (United States)

Ha, Sieu D.; Shi, Jian; Meroz, Yasmine; Mahadevan, L.; Ramanathan, Shriram

2014-12-01

Strongly correlated electron systems such as the rare-earth nickelates (R NiO3 , R denotes a rare-earth element) can exhibit synapselike continuous long-term potentiation and depression when gated with ionic liquids; exploiting the extreme sensitivity of coupled charge, spin, orbital, and lattice degrees of freedom to stoichiometry. We present experimental real-time, device-level classical conditioning and unlearning using nickelate-based synaptic devices in an electronic circuit compatible with both excitatory and inhibitory neurons. We establish a physical model for the device behavior based on electric-field-driven coupled ionic-electronic diffusion that can be utilized for design of more complex systems. We use the model to simulate a variety of associate and nonassociative learning mechanisms, as well as a feedforward recurrent network for storing memory. Our circuit intuitively parallels biological neural architectures, and it can be readily generalized to other forms of cellular learning and extinction. The simulation of neural function with electronic device analogs may provide insight into biological processes such as decision making, learning, and adaptation, while facilitating advanced parallel information processing in hardware.

Interactive multimedia-based teaching material for 3-dimensional geometry

Science.gov (United States)

Prabowo, A.; Anggoro, R. P.; Astuti, D.; Fahmi, S.

2017-12-01

This study aims to develop the interactive multimedia-based teaching material for 3-dimensional geometry in junior high school. The product was produced through the stages of define, design, develop, and disseminate. Two media experts and two teaching experts had validated it. They judged that the product developed was valid. It had been revised based on their advice. It has been disseminated to 15 mathematics teachers and tried to 30 students of junior high school. Teachers stated that this product gives a new form of teaching material in 3-dimensional geometry. According to the student, the product is interesting. It can motivate them to study mathematics, help them to master the material and increase their interest in mathematics.

Quantitative analysis of lead in polysulfide-based impression material

Directory of Open Access Journals (Sweden)

Aparecida Silva Braga

2007-06-01

Full Text Available Permlastic® is a polysulfide-based impression material widely used by dentists in Brazil. It is composed of a base paste and a catalyzer containing lead dioxide. The high toxicity of lead to humans is ground for much concern, since it can attack various systems and organs. The present study involved a quantitative analysis of the concentration of lead in the material Permlastic®. The lead was determined by plasma-induced optical emission spectrometry (Varian model Vista. The percentages of lead found in the two analyzed lots were 38.1 and 40.8%. The lead concentrations in the material under study were high, but the product’s packaging contained no information about these concentrations.

New Procedure for Compacting Prismatic Specimens of Cement-Treated Base Materials

Directory of Open Access Journals (Sweden)

Alaitz Linares-Unamunzaga

2018-06-01

Full Text Available Understanding the long-term behaviour of cement-treated base materials is a key factor to improve its design and obtain environmentally friendly pavement base materials. Their characterization requires manufacturing prismatic specimens. However, various authors highlight the absence of standardized test methods for fabricating beams in the field and laboratory, which is not an easy task because it depends on the qualification and experience of the testing team. The aim of this paper is to present a new device and procedure for compacting prismatic specimens of cement-treated base materials. In this research, it was used for compacting soil-cement to simulate its performance as a road base material. This device employs elements that are generally available in a concrete laboratory test, such as a vibrating table or prismatic moulds. Once the procedure was established, and in order to verify its suitability, flexural and compressive strength tests were carried out. Results showed that the values obtained were consistent with this material and, despite the heterogeneity of the material, specimens from the same batch provided similar results and, hence, validated the compaction process. This new compacting procedure can improve understanding of the long-term performance of cement-treated materials from flexural and fatigue tests.

Unconventional supercapacitors from nanocarbon-based electrode materials to device configurations.

Science.gov (United States)

Liu, Lili; Niu, Zhiqiang; Chen, Jun

2016-07-25

As energy storage devices, supercapacitors that are also called electrochemical capacitors possess high power density, excellent reversibility and long cycle life. The recent boom in electronic devices with different functions in transparent LED displays, stretchable electronic systems and artificial skin has increased the demand for supercapacitors to move towards light, thin, integrated macro- and micro-devices with transparent, flexible, stretchable, compressible and/or wearable abilities. The successful fabrication of such supercapacitors depends mainly on the preparation of innovative electrode materials and the design of unconventional supercapacitor configurations. Tremendous research efforts have been recently made to design and construct innovative nanocarbon-based electrode materials and supercapacitors with unconventional configurations. We review here recent developments in supercapacitors from nanocarbon-based electrode materials to device configurations. The advances in nanocarbon-based electrode materials mainly include the assembly technologies of macroscopic nanostructured electrodes with different dimensions of carbon nanotubes/nanofibers, graphene, mesoporous carbon, activated carbon, and their composites. The electrodes with macroscopic nanostructured carbon-based materials overcome the issues of low conductivity, poor mechanical properties, and limited dimensions that are faced by conventional methods. The configurational design of advanced supercapacitor devices is presented with six types of unconventional supercapacitor devices: flexible, micro-, stretchable, compressible, transparent and fiber supercapacitors. Such supercapacitors display unique configurations and excellent electrochemical performance at different states such as bending, stretching, compressing and/or folding. For example, all-solid-state simplified supercapacitors that are based on nanostructured graphene composite paper are able to maintain 95% of the original capacity at

EFRC: Polymer-Based Materials for Harvesting Solar Energy (stimulus)"

Energy Technology Data Exchange (ETDEWEB)

Russell, Thomas P. [Univ. of Massachusetts, Amherst, MA (United States)

2016-12-08

The University of Massachusetts Amherst is proposing an Energy Frontier Research Center (EFRC) on Polymer-Based Materials for Harvesting Solar Energy that will integrate the widely complementary experimental and theoretical expertise of 23 faculty at UMass-Amherst Departments with researchers from the University of Massachusetts Lowell, University of Pittsburgh, the Pennsylvania State University and Konarka Technologies, Inc. Collaborative efforts with researchers at the Oak Ridge National Laboratory, the University of Bayreuth, Seoul National University and Tohoku University will complement and expand the experimental efforts in the EFRC. Our primary research aim of this EFRC is the development of hybrid polymer-based devices with efficiencies more than twice the current organic-based devices, by combining expertise in the design and synthesis of photoactive polymers, the control and guidance of polymer-based assemblies, leadership in nanostructured polymeric materials, and the theory and modeling of non-equilibrium structures. A primary goal of this EFRC is to improve the collection and conversion efficiency of a broader spectral range of solar energy using the directed self-assembly of polymer-based materials so as to optimize the design and fabrication of inexpensive devices.

Micromechanics Based Failure Analysis of Heterogeneous Materials

Science.gov (United States)

Sertse, Hamsasew M.

In recent decades, heterogeneous materials are extensively used in various industries such as aerospace, defense, automotive and others due to their desirable specific properties and excellent capability of accumulating damage. Despite their wide use, there are numerous challenges associated with the application of these materials. One of the main challenges is lack of accurate tools to predict the initiation, progression and final failure of these materials under various thermomechanical loading conditions. Although failure is usually treated at the macro and meso-scale level, the initiation and growth of failure is a complex phenomena across multiple scales. The objective of this work is to enable the mechanics of structure genome (MSG) and its companion code SwiftComp to analyze the initial failure (also called static failure), progressive failure, and fatigue failure of heterogeneous materials using micromechanics approach. The initial failure is evaluated at each numerical integration point using pointwise and nonlocal approach for each constituent of the heterogeneous materials. The effects of imperfect interfaces among constituents of heterogeneous materials are also investigated using a linear traction-displacement model. Moreover, the progressive and fatigue damage analyses are conducted using continuum damage mechanics (CDM) approach. The various failure criteria are also applied at a material point to analyze progressive damage in each constituent. The constitutive equation of a damaged material is formulated based on a consistent irreversible thermodynamics approach. The overall tangent modulus of uncoupled elastoplastic damage for negligible back stress effect is derived. The initiation of plasticity and damage in each constituent is evaluated at each numerical integration point using a nonlocal approach. The accumulated plastic strain and anisotropic damage evolution variables are iteratively solved using an incremental algorithm. The damage analyses

An overview of the applications of graphene-based materials in supercapacitors.

Science.gov (United States)

Huang, Yi; Liang, Jiajie; Chen, Yongsheng

2012-06-25

Due to their unique 2D structure and outstanding intrinsic physical properties, such as extraordinarily high electrical conductivity and large surface area, graphene-based materials exhibit great potential for application in supercapacitors. In this review, the progress made so far for their applications in supercapacitors is reviewed, including electrochemical double-layer capacitors, pseudo-capacitors, and asymmetric supercapacitors. Compared with traditional electrode materials, graphene-based materials show some novel characteristics and mechanisms in the process of energy storage and release. Several key issues for improving the structure of graphene-based materials and for achieving better capacitor performance, along with the current outlook for the field, are also discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sustainable future alternatives to petroleum-based polymeric conservation materials

DEFF Research Database (Denmark)

Shashoua, Yvonne; Jankova Atanasova, Katja; Curran, Claire

2017-01-01

and coating formulations. Bio-polyethylenes, bio-polyesters and bio-cellulose-based products were evaluated against petroleum-based materials. Bio- and petroleum-based polyethylenes shared optical, chemical and thermal properties. Bamboo and sugarcane fibre containers were also chemically stable. Polyester...

Developing Environment–Based Materials to Teach Writing in Recount Texts

Directory of Open Access Journals (Sweden)

Fauziah Ratna Hapsari

2015-10-01

Full Text Available The tenth graders of State Senior High School 2 Semarang had problems to write their experiences. Unfortunately the existing materials were not appropriate to facilitate the learners to write recount texts. Hence, this study would like to develop environment – based materials to teach writing recount texts. It was inspired by the previous studies held by Gürsoy (2010 and Hauschild (2012. The materials were expected to improve learners’ writing competence of recount texts by applying topics which learners found in their daily lives, that is, environmental education. This study employed Research and Development design adapted from Borg and Gall (2003. The study found that applying the environment – based materials to teach writing recount texts gained positive effects. Moreover, the test of effectiveness reported significant improvement. The average score of pre-test was 48.94 and of post-test was 81.61. Therefore, English teachers are suggested to employ the materials. It is also necessary to conduct further studies to gain more positive effects toward teaching and learning process and to improve the learners’ writing competence. Keywords: Teaching writing; recount text; environment – based materials; contextual teaching and learningCopyright © 2015 by Al-Ta'lim All right reserved

Carbon-Based Nanomaterials: Multi-Functional Materials for Biomedical Engineering

Science.gov (United States)

Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R.; Khademhosseini, Ali

2013-01-01

Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications. PMID:23560817

Materials participation in welded joints manufacturing

Science.gov (United States)

Ghenghea, L. D.

2016-08-01

Management of materials dilution to form a joint with higher features asked by complex metallic structures is a problem that took attention and efforts of welding processes researchers and this communication will give a little contribution presenting some scientific and experimental results of dilution processes studied by Welding Research Group from Iasi, Romania, TCM Department. Liquid state welding processes have a strong dependence related to dilution of base and filler materials, the most important are for automatic joining using welding. The paper presents a review of some scientific works already published and their contributions, results of dilution coefficient evaluation using weighing, graphics and software applied for shielded metal arc welding process. Paper results could be used for welders’ qualification, welding procedure specification and other welding processes researchers’ activities. The results of Welding Research Group from Iasi, Romania, TCM Department, show dilution coefficient values between 20-30 % of base material and 70-80 % of filler material for studied welding process.

Application of a net-based baseline correction scheme to strong-motion records of the 2011 Mw 9.0 Tohoku earthquake

Science.gov (United States)

Tu, Rui; Wang, Rongjiang; Zhang, Yong; Walter, Thomas R.

2014-06-01

The description of static displacements associated with earthquakes is traditionally achieved using GPS, EDM or InSAR data. In addition, displacement histories can be derived from strong-motion records, allowing an improvement of geodetic networks at a high sampling rate and a better physical understanding of earthquake processes. Strong-motion records require a correction procedure appropriate for baseline shifts that may be caused by rotational motion, tilting and other instrumental effects. Common methods use an empirical bilinear correction on the velocity seismograms integrated from the strong-motion records. In this study, we overcome the weaknesses of an empirically based bilinear baseline correction scheme by using a net-based criterion to select the timing parameters. This idea is based on the physical principle that low-frequency seismic waveforms at neighbouring stations are coherent if the interstation distance is much smaller than the distance to the seismic source. For a dense strong-motion network, it is plausible to select the timing parameters so that the correlation coefficient between the velocity seismograms of two neighbouring stations is maximized after the baseline correction. We applied this new concept to the KiK-Net and K-Net strong-motion data available for the 2011 Mw 9.0 Tohoku earthquake. We compared the derived coseismic static displacement with high-quality GPS data, and with the results obtained using empirical methods. The results show that the proposed net-based approach is feasible and more robust than the individual empirical approaches. The outliers caused by unknown problems in the measurement system can be easily detected and quantified.

Attribute-Based Signcryption: Signer Privacy, Strong Unforgeability and IND-CCA Security in Adaptive-Predicates Model (Extended Version

Directory of Open Access Journals (Sweden)

Tapas Pandit

2016-08-01

Full Text Available Attribute-Based Signcryption (ABSC is a natural extension of Attribute-Based Encryption (ABE and Attribute-Based Signature (ABS, where one can have the message confidentiality and authenticity together. Since the signer privacy is captured in security of ABS, it is quite natural to expect that the signer privacy will also be preserved in ABSC. In this paper, first we propose an ABSC scheme which is weak existential unforgeable and IND-CCA secure in adaptive-predicates models and, achieves signer privacy. Then, by applying strongly unforgeable one-time signature (OTS, the above scheme is lifted to an ABSC scheme to attain strong existential unforgeability in adaptive-predicates model. Both the ABSC schemes are constructed on common setup, i.e the public parameters and key are same for both the encryption and signature modules. Our first construction is in the flavor of CtE&S paradigm, except one extra component that will be computed using both signature components and ciphertext components. The second proposed construction follows a new paradigm (extension of CtE&S , we call it “Commit then Encrypt and Sign then Sign” (CtE&S . The last signature is generated using a strong OTS scheme. Since, the non-repudiation is achieved by CtE&S paradigm, our systems also achieve the same.

Two inorganic-organic hybrid materials based on polyoxometalate anions and methylene blue: Preparations, crystal structures and properties

International Nuclear Information System (INIS)

Nie Shanshan; Zhang Yaobin; Liu Bin; Li Zuoxi; Hu Huaiming; Xue Ganglin; Fu Feng; Wang Jiwu

2010-01-01

Two novel inorganic-organic hybrid materials based on an organic dye cation methylene blue (MB) and Lindqvist-type POM polyanions, [C 22 H 18 N 3 S] 2 Mo 6 O 19 2DMF (1) and [C 22 H 18 N 3 S] 2 W 6 O 19 2DMF (2) were synthesized under ambient conditions and characterized by CV, IR spectroscopy, solid diffuse reflectance spectrum, UV-vis spectra in DMF solution, luminescent spectrum and single crystal X-ray diffraction. Crystallographic data reveal that compounds 1 and 2 are isostructural and both crystallize in the triclinic space group P1-bar . Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong π...π stacking interactions between dimeric MB cations and near distance interactions among organic dye cations, Lindqvist-type POM polyanions and DMF molecules. The solid diffuse reflectance spectra and UV-vis spectra in DMF solution appear new absorption bands ascribed to the charge-transfer transition between the cationic MB donor and the POM acceptors. Studies of the photoluminescent properties show that the formation of 1 and 2 lead to the fluorescence quenching of starting materials. -- Graphical abstract: Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong π...π stacking interactions between dimeric MB cations. Display Omitted

Exciplex electroluminescence and photoluminescence spectra of the new organic materials based on zinc complexes of sulphanylamino-substituted ligands.

Science.gov (United States)

Kaplunov, Mikhail G; Krasnikova, Svetlana S; Nikitenko, Sergey L; Sermakasheva, Natalia L; Yakushchenko, Igor K

2012-04-03

We have investigated the electroluminescence spectra of the electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and quinolines containing the C-N-M-N chains in their chelate cycles. The spectra exhibit strong exciplex bands in the green to yellow region 540 to 590 nm due to interaction of the excited states of zinc complexes and triaryl molecules of the hole-transporting layer. For some devices, the intrinsic luminescence band of 460 nm in the blue region is also observed along with the exciplex band giving rise to an almost white color of the device emission. The exciplex band can be eliminated if the material of the hole-transporting layer is not a triarylamine derivative. We have also found the exciplex emission in the photoluminescence spectra of the films containing blends of zinc complex and triphenylamine material.

Biogas Filter Based on Local Natural Zeolite Materials

Directory of Open Access Journals (Sweden)

Satriyo Krido Wahono

2014-02-01

Full Text Available UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as increasing methane contents, increasing heating value, reduction of odors, reduction of corrosion potential, increasing the efficiency and stability of the generator.

Diclofenac removal in urine using strong-base anion exchange polymer resins.

Science.gov (United States)

Landry, Kelly A; Boyer, Treavor H

2013-11-01

One of the major sources of pharmaceuticals in the environment is wastewater effluent of which human urine contributes the majority of pharmaceuticals. Urine source separation has the potential to isolate pharmaceuticals at a higher concentration for efficient removal as well as produce a nutrient byproduct. This research investigated the efficacy of using strong-base anion exchange polymer resins to remove the widely detected and abundant pharmaceutical, diclofenac, from synthetic human urine under fresh and ureolyzed conditions. The majority of experiments were conducted using a strong-base, macroporous, polystyrene resin (Purolite A520E). Ion-exchange followed a two-step removal rate with rapid removal in 1 h and equilibrium removal in 24 h. Diclofenac removal was >90% at a resin dose of 8 mL/L in both fresh and ureolyzed urine. Sorption of diclofenac onto A520E resin was concurrent with desorption of an equivalent amount of chloride, which indicates the ion-exchange mechanism is occurring. The presence of competing ions such as phosphate and citrate did not significantly impact diclofenac removal. Comparisons of three polystyrene resins (A520E, Dowex 22, Dowex Marathon 11) as well as one polyacrylic resin (IRA958) were conducted to determine the major interactions between anion exchange resin and diclofenac. The results showed that polystyrene resins provide the highest level of diclofenac removal due to electrostatic interactions between quaternary ammonium functional groups of resin and carboxylic acid of diclofenac and non-electrostatic interactions between resin matrix and benzene rings of diclofenac. Diclofenac was effectively desorbed from A520E resin using a regeneration solution that contained 4.5% (m/m) NaCl in an equal-volume mixture of methanol and water. The greater regeneration efficiency of the NaCl/methanol-water mixture over the aqueous NaCl solution supports the importance of non-electrostatic interactions between resin matrix and benzene rings

Graphene-based materials via benzidine-assisted exfoliation and reduction of graphite oxide and their electrochemical properties

Science.gov (United States)

Vermisoglou, E. C.; Giannakopoulou, T.; Romanos, G.; Boukos, N.; Psycharis, V.; Lei, C.; Lekakou, C.; Petridis, D.; Trapalis, C.

2017-01-01

Benzidine, a compound bearing aromatic rings and terminal amino groups, was employed for the intercalation and simultaneous reduction of graphite oxide (GO). The aromatic diamine can be intercalated into GO as follows: (1) by grafting with the epoxy groups of GO, (2) by hydrogen bonding with the oxygen containing groups of GO. Stacking between benzidine aromatic rings and unoxidized domains of GO may occur through π-π interaction. The role of benzidine is influenced by pH conditions and the weight ratio GO/benzidine. Two weight ratios were tested i.e. 1:2 and 1:3. Under strong alkaline conditions through K2CO3 addition (pH ∼10.4-10.6) both intercalation and reduction of GO via amino groups occur, while under strong acidic conditions through HCl addition (pH ∼1.4-2.2) π-π stacking is preferred. When no base or acid is added (pH ∼5.2) and the weight ratio is 1:2, there are indications that reduction and π-π stacking occur, while at a GO/benzidine weight ratio 1:3 intercalation via amino groups and reduction seem to dominate. The aforementioned remarks render benzidine a multifunctional tool towards production of reduced graphene oxide. The effect of pH conditions and the GO/benzidine weight ratio on the quality and the electrochemical properties of the produced graphene-based materials were investigated. Cyclic voltammetry measurements using three-electrode cell and KCl aqueous solution as an electrolyte gave specific capacitance values up to ∼178 F/g. When electric double-layer capacitors (EDLC) were fabricated from these materials, the maximum capacitance in organic electrolyte i.e., tetraethyl ammonium tetrafluoroborate (TEABF4) in polycarbonate (PC) was ∼29 F/g.

Dual-mode operation of 2D material-base hot electron transistors.

Science.gov (United States)

Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

CMU DeepLens: deep learning for automatic image-based galaxy-galaxy strong lens finding

Science.gov (United States)

Lanusse, François; Ma, Quanbin; Li, Nan; Collett, Thomas E.; Li, Chun-Liang; Ravanbakhsh, Siamak; Mandelbaum, Rachel; Póczos, Barnabás

2018-01-01

Galaxy-scale strong gravitational lensing can not only provide a valuable probe of the dark matter distribution of massive galaxies, but also provide valuable cosmological constraints, either by studying the population of strong lenses or by measuring time delays in lensed quasars. Due to the rarity of galaxy-scale strongly lensed systems, fast and reliable automated lens finding methods will be essential in the era of large surveys such as Large Synoptic Survey Telescope, Euclid and Wide-Field Infrared Survey Telescope. To tackle this challenge, we introduce CMU DeepLens, a new fully automated galaxy-galaxy lens finding method based on deep learning. This supervised machine learning approach does not require any tuning after the training step which only requires realistic image simulations of strongly lensed systems. We train and validate our model on a set of 20 000 LSST-like mock observations including a range of lensed systems of various sizes and signal-to-noise ratios (S/N). We find on our simulated data set that for a rejection rate of non-lenses of 99 per cent, a completeness of 90 per cent can be achieved for lenses with Einstein radii larger than 1.4 arcsec and S/N larger than 20 on individual g-band LSST exposures. Finally, we emphasize the importance of realistically complex simulations for training such machine learning methods by demonstrating that the performance of models of significantly different complexities cannot be distinguished on simpler simulations. We make our code publicly available at https://github.com/McWilliamsCenter/CMUDeepLens.

Particularities of surface plasmon-exciton strong coupling with large Rabi splitting

International Nuclear Information System (INIS)

Symonds, C; Bonnand, C; Plenet, J C; Brehier, A; Parashkov, R; Lauret, J S; Deleporte, E; Bellessa, J

2008-01-01

This paper presents some of the particularities of the strong coupling regime occurring between surface plasmon (SP) modes and excitons. Two different active materials were deposited on a silver film: a cyanine dye J-aggregate, and a two-dimensional layered perovskite-type semiconductor. The dispersion relations, which are deduced from angular resolved reflectometry spectra, present an anticrossing characteristic of the strong coupling regime. The wavevector is a good parameter to determine the Rabi splitting. Due to the large interaction energies (several hundreds of milli-electron-volts), the calculations at constant angle can induce an overestimation of the Rabi splitting of more than a factor of two. Another property of polaritons based on SP is their nonradiative character. In order to observe the polaritonic emission, it is thus necessary to use particular extraction setups, such as gratings or prisms. Otherwise only the incoherent emission can be detected, very similar to the bare exciton emission

Degradation modes of nickel-base alternate waste package overpack materials

International Nuclear Information System (INIS)

Pitman, S.G.

1988-07-01

The suitability of Ti Grade 12 for waste package overpacks has been questioned because of its observed susceptibility to crevice corrosion and hydrogen-assisted crack growth. For this reason, materials have been selected for evaluation as alternatives to Ti Grade 12 for use as waste package overpacks. These alternative materials, which are based on the nickel-chromium-molybdenum (Ni-Cr-Mo) alloy system, are Inconel 625, Hastelloy C-276, and Hastelloy C-22. The degradation modes of the Ni-base alternate materials have been examined at Pacific Northwest Laboratory to determine the suitability of these materials for waste package overpack applications in a salt repository. Degradation modes investigated included general corrosion, crevice corrosion, pitting, stress-corrosion cracking, and hydrogen embrittlement

Solid strong base K-Pt/NaY zeolite nano-catalytic system for completed elimination of formaldehyde at room temperature

Science.gov (United States)

Song, Shaoqing; Wu, Xi; Lu, Changhai; Wen, Meicheng; Le, Zhanggao; Jiang, Shujuan

2018-06-01

Solid strong base nano-catalytic system of K-modification NaY zeolite supported 0.08% Pt (K-Pt/NaY) were constructed for eliminating HCHO at room temperature. In the catalytic process, activation energy over K-Pt/NaY nano-catalytic system was greatly decreased along with the enhanced reaction rate. Characterization and catalytic tests revealed the surface electron structure of K-Pt/NaY was improved, as reflected by the enhanced HCHO adsorption capability, high sbnd OH concentration, and low-temperature reducibility. Therefore, the optimal K-Pt/NaY showed high catalytic efficiency and strong H2O tolerance for HCHO elimination by directly promoting the reaction between active sbnd OH and formate species. These results may suggest a new way for probing the advanced solid strong base nano-catalytic system for the catalytic elimination of indoor HCHO.

Operational advanced materials control and accountability system

International Nuclear Information System (INIS)

Malanify, J.J.; Bearse, R.C.; Christensen, E.L.

1980-01-01

An accountancy system based on the Dynamic Materials Accountability (DYMAC) System has been in operation at the Plutonium Processing Facility at the Los Alamos Scientific Laboratory (LASL) since January 1978. This system, now designated the Plutonium Facility/Los Alamos Safeguards System (PF/LASS), has enhanced nuclear material accountability and process control at the LASL facility. The nondestructive assay instruments and the central computer system are operating accurately and reliably. As anticipated, several uses of the system have developed in addition to safeguards, notably scrap control and quality control. The successes of this experiment strongly suggest that implementation of DYMAC-based systems should be attempted at other facilities. 20 refs

Analytical modeling of light transport in scattering materials with strong absorption.

Science.gov (United States)

Meretska, M L; Uppu, R; Vissenberg, G; Lagendijk, A; Ijzerman, W L; Vos, W L

2017-10-02

We have investigated the transport of light through slabs that both scatter and strongly absorb, a situation that occurs in diverse application fields ranging from biomedical optics, powder technology, to solid-state lighting. In particular, we study the transport of light in the visible wavelength range between 420 and 700 nm through silicone plates filled with YAG:Ce 3+ phosphor particles, that even re-emit absorbed light at different wavelengths. We measure the total transmission, the total reflection, and the ballistic transmission of light through these plates. We obtain average single particle properties namely the scattering cross-section σ s , the absorption cross-section σ a , and the anisotropy factor µ using an analytical approach, namely the P3 approximation to the radiative transfer equation. We verify the extracted transport parameters using Monte-Carlo simulations of the light transport. Our approach fully describes the light propagation in phosphor diffuser plates that are used in white LEDs and that reveal a strong absorption (L/l a > 1) up to L/l a = 4, where L is the slab thickness, l a is the absorption mean free path. In contrast, the widely used diffusion theory fails to describe this parameter range. Our approach is a suitable analytical tool for industry, since it provides a fast yet accurate determination of key transport parameters, and since it introduces predictive power into the design process of white light emitting diodes.

Phosphorene and Phosphorene-Based Materials - Prospects for Future Applications.

Science.gov (United States)

Batmunkh, Munkhbayar; Bat-Erdene, Munkhjargal; Shapter, Joseph G

2016-10-01

Phosphorene, a single- or few-layered semiconductor material obtained from black phosphorus, has recently been introduced as a new member of the family of two-dimensional (2D) layered materials. Since its discovery, phosphorene has attracted significant attention, and due to its unique properties, is a promising material for many applications including transistors, batteries and photovoltaics (PV). However, based on the current progress in phosphorene production, it is clear that a lot remains to be explored before this material can be used for these applications. After providing a comprehensive overview of recent advancements in phosphorene synthesis, advantages and challenges of the currently available methods for phosphorene production are discussed. An overview of the research progress in the use of phosphorene for a wide range of applications is presented, with a focus on enabling important roles that phosphorene would play in next-generation PV cells. Roadmaps that have the potential to address some of the challenges in phosphorene research are examined because it is clear that the unprecedented chemical, physical and electronic properties of phosphorene and phosphorene-based materials are suitable for various applications, including photovoltaics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distribution of Components in Ion Exchange Materials Taken from the K East Basin and Leaching of Ion Exchange Materials by Nitric/Hydrofluoric Acid and Nitric/Oxalic Acid

International Nuclear Information System (INIS)

Delegard, C.H.; Rinehart, D.E.; Hoopes, F.V.

1998-01-01

Laboratory tests were performed to examine the efficacy of mixed nitric/hydrofluoric acid followed by mixed nitric/oxalic acid leach treatments to decontaminate ion exchange materials that have been found in a number of samples retrieved from K East (KE)Basin sludge. The ion exchange materials contain organic ion exchange resins and zeolite inorganic ion exchange material. Based on process records, the ion exchange resins found in the K Basins is a mixed-bed, strong acid/strong base material marketed as Purolite NRW-037. The zeolite material is Zeolon-900, a granular material composed of the mineral mordenite. Radionuclides sorbed or associated with the ion exchange material can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). Elutriation and washing steps are designed to remove the organic resins from the K Basin sludge. To help understand the effects of the anticipated separation steps, tests were performed with well-rinsed ion exchange (IX) material from KE Basin floor sludge (sample H-08 BEAD G) and with well-rinsed IX having small quantities of added KE canister composite sludge (sample KECOMP). Tests also were performed to determine the relative quantities of organic and inorganic IX materials present in the H-08 K Basin sludge material. Based on chemical analyses of the separated fractions, the rinsed and dry IX material H-08 BEAD G was found to contain 36 weight percent inorganic material (primarily zeolite). The as-received (unrinsed) and dried H-08 material was estimated to contain 45 weight percent inorganic material

Glycerol Salicylate-based Pulp-Capping Material Containing Portland Cement.

Science.gov (United States)

Portella, Fernando Freitas; Collares, Fabrício Mezzomo; Santos, Paula Dapper; Sartori, Cláudia; Wegner, Everton; Leitune, Vicente Castelo Branco; Samuel, Susana Maria Werner

2015-01-01

The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59 ± 0.06 and 12.54 ± 0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.

On the hydro-mechanical behaviour of MX80 bentonite-based materials

Directory of Open Access Journals (Sweden)

Yu-Jun Cui

2017-06-01

Full Text Available Bentonite-based materials have been considered in many countries as engineered barrier/backfilling materials in deep geological disposal of high-level radioactive waste. During the long period of waste storage, these materials will play an essential role in ensuring the integrity of the storage system that consists of the waste canisters, the engineered barrier/backfill, the retaining structures as well as the geological barrier. Thus, it is essential to well understand the hydro-mechanical behaviours of these bentonite-based materials. This review paper presents the recent advances of knowledge on MX80 bentonite-based materials, in terms of water retention properties, hydraulic behaviour and mechanical behaviour. Emphasis is put on the effect of technological voids and the role of the dry density of bentonite. The swelling anisotropy is also discussed based on the results from swelling tests with measurements of both axial and radial swelling pressures on a sand-bentonite mixture compacted at different densities. Microstructure observation was used to help the interpretation of macroscopic hydro-mechanical behaviour. Also, the evolution of soil microstructure thus the soil density over time is discussed based on the results from mock-up tests. This evolution is essential for understanding the long-term hydro-mechanical behaviour of the engineered barrier/backfill.

Extracellular matrix elasticity and topography: material-based cues that affect cell function via conserved mechanisms

Science.gov (United States)

Janson, Isaac A.; Putnam, Andrew J.

2014-01-01

Chemical, mechanical, and topographic extracellular matrix (ECM) cues have been extensively studied for their influence on cell behavior. These ECM cues alter cell adhesion, cell shape, and cell migration, and activate signal transduction pathways to influence gene expression, proliferation, and differentiation. ECM elasticity and topography, in particular, have emerged as material properties of intense focus based on strong evidence these physical cue can partially dictate stem cell differentiation. Cells generate forces to pull on their adhesive contacts, and these tractional forces appear to be a common element of cells’ responses to both elasticity and topography. This review focuses on recently published work that links ECM topography and mechanics and their influence on differentiation and other cell behaviors, We also highlight signaling pathways typically implicated in mechanotransduction that are (or may be) shared by cells subjected to topographic cues. Finally, we conclude with a brief discussion of the potential implications of these commonalities for cell based therapies and biomaterial design. PMID:24910444

Data base of radiation-resistant dielectric and insulating materials

International Nuclear Information System (INIS)

Hama, Yoshimasa; Sunazuka, Hideo; Nashiyama, Isamu; Kakuta, Tsunemi.

1987-01-01

In the data base of radiation-resistant dielectric and insulating materials, the data format contains such items as to give the summary; the data sheet contains the data in concrete form of respective properties from the references; the sheet of references contains the references in the former two. In the above three, there are attached code No., data sheet No., reference No. and key words. In the three areas as radiation-resistant dielectric and insulating materials, i.e., organic materials, inorganic materials and optical fibers, the following are explained: data format, data sheet and objectives. (Mori, K.)

Multi-scale modeling of the thermo-hydro- mechanical behaviour of heterogeneous materials. Application to cement-based materials under severe loads

International Nuclear Information System (INIS)

Grondin, Frederic Alain

2005-01-01

The work of modeling presented here relates to the study of the thermo-hydro- mechanical behaviour of porous materials based on hydraulic binder such as concrete, High Performance Concrete or more generally cement-based materials. This work is based on the exploitation of the Digital Concrete model, of the finite element code Symphonie developed in the Scientific and Technical Centre for Building (CSTB), in coupling with the homogenization methods to obtain macroscopic behaviour laws drawn from the Micro-Macro relations. Scales of investigation, macroscopic and microscopic, has been exploited by simulation in order to allow the comprehension fine of the behaviour of cement-based materials according to thermal, hydrous and mechanical loads. It appears necessary to take into account various scales of modeling. In order to study the behaviour of the structure, we are brought to reduce the scale of investigation to study the material more particularly. The research tasks presented suggest a new approach for the identification of the multi-physic behaviour of materials by simulation. In complement of the purely experimental approach, based on observations on the sample with measurements of the apparent parameters on the macroscopic scale, this new approach allows to obtain the fine analysis of elementary mechanisms in acting within the material. These elementary mechanisms are at the origin of the evolution of the macroscopic parameters measured in experimental tests. In this work, coefficients of the thermo-hydro-mechanical behaviour law of porous materials and the equivalent hydraulic conductivity were obtained by a multi-scales approach. Applications has been carried out on the study of the damaged behaviour of cement-based materials, in the objective to determine the elasticity tensor and the permeability tensor of a High Performance Concrete at high temperatures under a mechanical load. Also, the study of the strain evolution of cement-based materials at low

Silane-based hybrid materials for biomedical applications

NARCIS (Netherlands)

Kros, A.; Jansen, J.A.; Holder, S.J.; Nolte, R.J.M.; Sommerdijk, N.A.J.M.

2002-01-01

In this paper, the preparation of different hybrid silane materials is presented and their possible use in biomedical applications is discussed. The first example describes the development of biocompatible coatings based on sol-gel silicates, which can be used as a protective coating for implantable

Strong authentication with physical unclonable functions (Chapter 10)

NARCIS (Netherlands)

Tuyls, P.T.; Skoric, B.; Petkovic, M.; Jonker, W.

2007-01-01

Physical unclonable functions (PUFs) can be used as a cost-effective means to store cryptographic key material in an unclonable way. They can be employed for strong authentication of objects, e.g., tokens, and of persons possessing such tokens, but also for other purposes. We give a short overview

An effective method to screen sodium-based layered materials for sodium ion batteries

Science.gov (United States)

Zhang, Xu; Zhang, Zihe; Yao, Sai; Chen, An; Zhao, Xudong; Zhou, Zhen

2018-03-01

Due to the high cost and insufficient resource of lithium, sodium-ion batteries are widely investigated for large-scale applications. Typically, insertion-type materials possess better cyclic stability than alloy-type and conversion-type ones. Therefore, in this work, we proposed a facile and effective method to screen sodium-based layered materials based on Materials Project database as potential candidate insertion-type materials for sodium ion batteries. The obtained Na-based layered materials contains 38 kinds of space group, which reveals that the credibility of our screening approach would not be affected by the space group. Then, some important indexes of the representative materials, including the average voltage, volume change and sodium ion mobility, were further studied by means of density functional theory computations. Some materials with extremely low volume changes and Na diffusion barriers are promising candidates for sodium ion batteries. We believe that our classification algorithm could also be used to search for other alkali and multivalent ion-based layered materials, to accelerate the development of battery materials.

Modification of clay-based waste containment materials

International Nuclear Information System (INIS)

Adu-Wusu, K.; Whang, J.M.; McDevitt, M.F.

1997-01-01

Bentonite clays are used extensively for waste containment barriers to help impede the flow of water in the subsurface because of their low permeability characteristics. However, they do little to prevent diffusion of contaminants, which is the major transport mechanism at low water flows. A more effective way of minimizing contaminant migration in the subsurface is to modify the bentonite clay with highly sorptive materials. Batch sorption studies were conducted to evaluate the sorptive capabilities of organo-clays and humic- and iron-based materials. These materials proved to be effective sorbents for the organic contaminants 1,2,4-trichlorobenzene, nitrobenzene, and aniline in water, humic acid, and methanol solution media. The sorption capacities were several orders of magnitude greater than that of unmodified bentonite clay. Modeling results indicate that with small amounts of these materials used as additives in clay barriers, contaminant flux through walls could be kept very small for 100 years or more. The cost of such levels of additives can be small compared to overall construction costs

Mechanical characterization and force-displacement hysteretic curves from in-plane cyclic tests on strong masonry infills.

Science.gov (United States)

Morandi, Paolo; Hak, Sanja; Magenes, Guido

2018-02-01

This article contains information related to a recent study "Performance-based interpretation of in-plane cyclic tests on RC frames with strong masonry infills" (Morandi et al., 2017 [1]). Motivated by the necessity to improve the knowledge of the in-plane seismic response of rigid strong masonry infills, a wide experimental campaign based on in-plane cyclic tests on full-scale RC infilled frame specimens, supplemented with a complete characterization of the materials, has been conducted at the laboratory of the Department of Civil Engineering and Architecture of the University of Pavia. The masonry is constituted by vertically perforated 35 cm thick clay units with tongue and groove and dry head-joints and general-purpose mortar bed-joints. The paper reports the results of the mechanical characterization and of the force-displacement hysteretic curves from the in-plane cyclic tests.

Multifunctional composite material based on carbon-filled polyurethane

International Nuclear Information System (INIS)

Malinovskaya, T; Melentyev, S; Pavlov, S

2015-01-01

The research paper deals with the performance of composite resistive material heating coatings based on the polyurethane binder, filled with colloidal-graphite preparation C- 1, which can be used in structures of electric heaters. Frequency dependences of transmission and reflection coefficients, dielectric permeability of composite materials with the various content of carbon fillers (technical carbon, graphite) in polyurethane varnish in ranges of frequencies 26-40 GHz and 110-260 GHz are experimentally investigated. (paper)

Advanced fluoride-based materials for energy conversion

CERN Document Server

Nakajima, Tsuyoshi

2015-01-01

Advanced Fluoride-Based Materials for Energy Conversion provides thorough and applied information on new fluorinated materials for chemical energy devices, exploring the electrochemical properties and behavior of fluorinated materials in lithium ion and sodium ion batteries, fluoropolymers in fuel cells, and fluorinated carbon in capacitors, while also exploring synthesis applications, and both safety and stability issues. As electronic devices, from cell phones to hybrid and electric vehicles, are increasingly common and prevalent in modern lives and require dependable, stable chemical energy devices with high-level functions are becoming increasingly important. As research and development in this area progresses rapidly, fluorine compounds play a critical role in this rapid progression. Fluorine, with its small size and the highest electronegativity, yields stable compounds under various conditions for utilization as electrodes, electrolytes, and membranes in energy devices. The book is an ideal reference f...

Strong Mechanoluminescence from Oxynitridosilicate Phosphors

Energy Technology Data Exchange (ETDEWEB)

Zhang Lin; Xu Chaonan; Yamada, Hiroshi, E-mail: cn-xu@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 807-1 Shuku, Tosu, Saga 841-0052 (Japan)

2011-10-29

We successfully developed a novel Mechanoluminescence (ML) material with water resistance, oxynitridosilicate; BaSi{sub 2}O{sub 2}N{sub 2}: Eu{sup 2+}. The crystal structure, photoluminescence (PL) and ML properties were characterized. The ML of BaSi{sub 2}O{sub 2}N{sub 2}: Eu{sup 2+} is so strong that the blue-green emission can be observed by the naked eyes clearly. In addition, it shows superior water resistance property. No changes were found in the ML intensities during the total water treatment test.

New Liquid Phases for the Gas Chromatographic Separation of Strong Bases on Capillary Columns

OpenAIRE

Grob, K.

2017-01-01

The current practice of pretreating the solid support with free alkali to increase separation efficiency for basic compounds proved to be unsuitable for capillary columns. Instead of this, homogenous organic materials of high base strength are required. We found polyethylene imine (PEI) and polypropylene imine (PPI) to be very efficient as liquid phases of capillary columns for the separation of bases. The preparation of polymers is mentioned. Silanization or acetylation of the free hydroxyl ...

Data base concepts for managing the DOE nuclear material inventory

International Nuclear Information System (INIS)

Beams, J.D.

1996-01-01

Information required by nuclear materials managers in the Department of Energy (DOE) is accessible with varying levels of difficulty. Currently, the most readily available information is provided by the Nuclear Materials Management and Safeguards System (NMMSS). Information not provided by NMMSS must be obtained either from field site data bases or collected through physical inventory inspections, both very costly and time-consuming alternatives. This paper discusses the possibility of providing more detailed information at DOE headquarters on nuclear material inventories than is provided by NMMSS. In particular, this paper considers some of the issues associated with managing materials at the lowest-level--the item-level--and uses a hypothetical item-level data base to describe some of the advantages and disadvantages of managing information at the item-level

Multi-scale calculation based on dual domain material point method combined with molecular dynamics

Energy Technology Data Exchange (ETDEWEB)

Dhakal, Tilak Raj [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-27

computation. The numerical properties of the multiscale method are investigated as well as the results from this multi-scale calculation are compared of particles needed for convergence makes the method very expensive especially in our multi-scale method where we calculate stress in each material point using MD simulation. To improve DDMP, the sub-point method is introduced in this dissertation, which provides high quality numerical solutions with a very small number of particles. The multi-scale method based on DDMP with sub-points is successfully implemented for a one dimensional problem of shock wave propagation in a cerium crystal. The MD simulation to calculate stress in each material point is performed in GPU using CUDA to accelerate the computation. The numerical properties of the multiscale method are investigated as well as the results from this multi-scale calculation are compared with direct MD simulation results to demonstrate the feasibility of the method. Also, the multi-scale method is applied for a two dimensional problem of jet formation around copper notch under a strong impact.

Research on technology utilizing data freeway for base nuclear power materials

International Nuclear Information System (INIS)

Fujita, Mitsutane; Kurihara, Yutaka; Noda, Tetsuji; Shiraishi, Haruki; Kitajima, Masahiro; Nagakawa, Josei; Yamamoto, Norikazu

1997-01-01

In order to carry out the selection of the nuclear power materials which are used in radiation, from high temperature to very low temperature, and in corrosive environment, and the development of the materials effectively, the construction of huge material data base is indispensable. The development of the distributed type material data base called 'freeway' is advanced jointly by National Research Institute for Metals, Japan Atomic Energy Research Institute, Power Reactor and Nuclear Fuel Development Corporation and Japan Science and Technology Corporation. It has been aimed at that the results obtained in each research institute are made into a data base by that institute, and those data bases can be utilized mutually through network. In fiscal year 1996, the transfer to the system, by which the function showing the contents of system data and the function of data retrieval can be utilized from internet, was begun jointly. The present state of the data freeway, the operation environment of World Wide Web, and the trial making of the computation program for forecasting the change of the chemical composition of materials by neutron irradiation are reported. (K.I.)

Polyaniline (PANi based electrode materials for energy storage and conversion

Directory of Open Access Journals (Sweden)

Huanhuan Wang

2016-09-01

Full Text Available Polyaniline (PANi as one kind of conducting polymers has been playing a great role in the energy storage and conversion devices besides carbonaceous materials and metallic compounds. Due to high specific capacitance, high flexibility and low cost, PANi has shown great potential in supercapacitor. It alone can be used in fabricating an electrode. However, the inferior stability of PANi limits its application. The combination of PANi and other active materials (carbon materials, metal compounds or other polymers can surpass these intrinsic disadvantages of PANi. This review summarizes the recent progress in PANi based composites for energy storage/conversion, like application in supercapacitors, rechargeable batteries, fuel cells and water hydrolysis. Besides, PANi derived nitrogen-doped carbon materials, which have been widely employed as carbon based electrodes/catalysts, are also involved in this review. PANi as a promising material for energy storage/conversion is deserved for intensive study and further development.

Biocompatibility of poly(lactic acid) with incorporated graphene-based materials

OpenAIRE

Pinto, Artur Moreira; Moreira, Susana Margarida Gomes; Gonçalves, Inês; Gama, F. M.; Mendes, Adélio; Magalhães, Fernão D.

2013-01-01

The incorporation of graphene-based materials has been shown to improve mechanical properties of poly(lactic acid) (PLA). In this work, PLA films and composite PLA films incorporating two graphene-based materials – graphene oxide (GO) and graphene nanoplatelets (GNP) – were prepared and characterized regarding not only biocompatibility, but also surface topography, chemistry and wettability. The presence of both fillers changed the films surface topography, increasing the roughness, and modif...

Bibliographic data base for low activation materials

International Nuclear Information System (INIS)

Alenina, M.V.; Kolotov, V.P.; Ivanov, L.I.

2007-01-01

Full text of publication follows: The analysis of the publications dealing with development of low-activation materials for fusion technology demonstrates that the period of information doubling is about 5-6 years. Such high rate usually is characteristic of the actively developing field of science. To develop an useful instrument for analysis and systematization of the available data a computer based bibliographic system has been developed some time ago. Recently the engine of the system has been significantly modernized. The bibliographic system is based on using of MS SQL server data base which includes main bibliographic information including abstracts. The most important feature of the system is that full-text abstracts searching capabilities are appended with indexing of information by experts to increase its definition. The experts indexes cover the following topics: - Main problems; - Software and methods for calculation; - Libraries of nuclear data; - Spectrum of neutrons for different construction parts of fusion reactor; - Low activation materials; - Technology of production; - Radiation effects; - Utilization of radiation waste; - Estimation of risks; - Designs of fusion reactor; - Nuclear transmutations; - Equipment used for investigations. The primary data base is filling/appending by periodical queries to different bibliographic data bases (INIS, COMPEMDEX and others) via suitable Internet providers including strict analysis of the income information to remove a possible 'information noise' and following data indexing by experts. The data base contains references since 1976 year (when first works in this area have been fulfilled) and until now. The bibliographic system is accessible by means of Internet using different forms developed for queries (http://www.geokhi.ru/~lam_db). (authors)

Strongly correlated electron materials. I. Theory of the quasiparticle structure

International Nuclear Information System (INIS)

Lopez-Aguilar, F.; Costa-Quintana, J.; Puig-Puig, L.

1993-01-01

In this paper we give a method for analyzing the renormalized electronic structure of the Hubbard systems. The first step is the determination of effective interactions from the random-phase approximation (RPA) and from an extended RPA (ERPA) that introduces vertex effects within the bubble polarization. The second step is the determination of the density of states deduced from the spectral functions. Its analysis leads us to conclude that these systems can exhibit three types of resonances in their electronic structures: the lower-, middle-, and upper-energy resonances. Furthermore, we analyze the conditions for which there is only one type of resonance and the causes that lead to the disappearance of the heavy-fermion state. We finally introduce the RPA and ERPA effective interactions within the strong-coupling theory and we give the conditions for obtaining coupling and superconductivity

Materials data base and design equations for the UCLA solid breeder blanket

International Nuclear Information System (INIS)

Sharafat, S.; Amodeo, R.; Ghoniem, N.M.

1986-01-01

The need for a complete and coherent material data base for fusion reactor systems has been an important issue for some time now. Since the choices for materials used in fusion reactors are becoming more apparent, it is important to be able to quickly access this data to facilitate reactor design. The philosophy of a data base is one of expansion and modification. This will lead to a constantly growing collection of most recently acquired information. Based on this philosophy special care has been given to the structure, the accessibility and ease of modification. The data base is developed primarily for use on Personal Computers (PC's). In Section 10.2. materials and properties investigated for this blanket study are listed. Section 10.3. is a list of phenomenological equations and mathematical fits for all materials and properties considered. Section 10.4. describes the authors efforts to develop a swelling equations based on the few experimental data points available for breeder materials. In Section 10.5. the sintering phenomena for ceramics is investigated

Development and validation of science, technology, engineering and mathematics (STEM) based instructional material

Science.gov (United States)

Gustiani, Ineu; Widodo, Ari; Suwarma, Irma Rahma

2017-05-01

This study is intended to examine the development and validation of simple machines instructional material that developed based on Science, Technology, Engineering and Mathematics (STEM) framework that provides guidance to help students learn and practice for real life and enable individuals to use knowledge and skills they need to be an informed citizen. Sample of this study consist of one class of 8th grader at a junior secondary school in Bandung, Indonesia. To measure student learning, a pre-test and post-test were given before and after implementation of the STEM based instructional material. In addition, a questionnaire of readability was given to examine the clarity and difficulty level of each page of instructional material. A questionnaire of students' response towards instructional material given to students and teachers at the end of instructional material reading session to measure layout aspects, content aspects and utility aspects of instructional material for being used in the junior secondary school classroom setting. The results show that readability aspect and students' response towards STEM based instructional material of STEM based instructional material is categorized as very high. Pretest and posttest responses revealed that students retained significant amounts information upon completion of the STEM instructional material. Student overall learning gain is 0.67 which is categorized as moderate. In summary, STEM based instructional material that was developed is valid enough to be used as educational materials necessary for conducting effective STEM education.

Accelerator-Based PIXE and STIM Analysis of Candidate Solar Sail Materials

International Nuclear Information System (INIS)

Hollerman, W.A.; Stanaland, T.L.; Boudreaux, P.; Elberson, L.; Fontenot, J.; Gates, E.; Greco, R.; McBride, M.; Woodward, A.; Edwards, D.

2003-01-01

Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. A totally reflective sail experiences a pressure of 9.1 μPa at a distance of 1 AU from the Sun. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions, enabling new concepts that are difficult by conventional means. One of the current challenges is to develop strong, lightweight, and radiation resistant sail materials. This paper will discuss initial results from a Particle Induced X-Ray Emission (PIXE) and Scanning Transmission Ion Microscopy (STIM) analysis of candidate solar sail materials

Advances in electrode materials for Li-based rechargeable batteries

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hui [China Academy of Space Technology (CAST), Beijing (China); Mao, Chengyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Li, Jianlin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Chen, Ruiyong [Korea Inst. of Science and Technology (KIST), Saarbrucken (Germany); Saarland Univ., Saarbrucken (Germany)

2017-07-05

Rechargeable lithium-ion batteries store energy as chemical energy in electrode materials during charge and can convert the chemical energy into electrical energy when needed. Tremendous attention has been paid to screen electroactive materials, to evaluate their structural integrity and cycling reversibility, and to improve the performance of electrode materials. This review discusses recent advances in performance enhancement of both anode and cathode through nanoengineering active materials and applying surface coatings, in order to effectively deal with the challenges such as large volume variation, instable interface, limited cyclability and rate capability. We also introduce and discuss briefly the diversity and new tendencies in finding alternative lithium storage materials, safe operation enabled in aqueous electrolytes, and configuring novel symmetric electrodes and lithium-based flow batteries.

Advanced cathode materials for polymer electrolyte fuel cells based on pt/ metal oxides: from model electrodes to catalyst systems.

Science.gov (United States)

Fabbri, Emiliana; Pătru, Alexandra; Rabis, Annett; Kötz, Rüdiger; Schmidt, Thomas J

2014-01-01

The development of stable catalyst systems for application at the cathode side of polymer electrolyte fuel cells (PEFCs) requires the substitution of the state-of-the-art carbon supports with materials showing high corrosion resistance in a strongly oxidizing environment. Metal oxides in their highest oxidation state can represent viable support materials for the next generation PEFC cathodes. In the present work a multilevel approach has been adopted to investigate the kinetics and the activity of Pt nanoparticles supported on SnO2-based metal oxides. Particularly, model electrodes made of SnO2 thin films supporting Pt nanoparticles, and porous catalyst systems made of Pt nanoparticles supported on Sb-doped SnO2 high surface area powders have been investigated. The present results indicate that SnO2-based supports do not modify the oxygen reduction reaction mechanism on the Pt nanoparticle surface, but rather lead to catalysts with enhanced specific activity compared to Pt/carbon systems. Different reasons for the enhancement in the specific activity are considered and discussed.

Nanocellulose-Based Materials for Water Purification.

Science.gov (United States)

Voisin, Hugo; Bergström, Lennart; Liu, Peng; Mathew, Aji P

2017-03-05

Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present-in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

Strong plasma shock structures based on the Navier--Stokes equations

International Nuclear Information System (INIS)

Abe, K.

1975-01-01

The structure of a plasma collisional shock wave is examined on the basis of the Navier--Stokes equations and simultaneously on the basis of the Fokker--Planck equation. The resultant structures are compared to check the validity of the Navier--Stokes equations applied to the structures of strong shock waves. The Navier--Stokes equations give quite correct structures for weak shock waves. For the strong shock waves, the detailed structures obtained from the Navier--Stokes equations differ from the results of the Fokker--Planck equation, but the shock thicknesses of the two shock waves are in relatively close agreement

Spintronic materials and devices based on antiferromagnetic metals

OpenAIRE

Wang, Y.Y.; Song, C.; Zhang, J.Y.; Pan, F.

2017-01-01

In this paper, we review our recent experimental developments on antiferromagnet (AFM) spintronics mainly comprising Mn-based noncollinear AFM metals. IrMn-based tunnel junctions and Hall devices have been investigated to explore the manipulation of AFM moments by magnetic fields, ferromagnetic materials and electric fields. Room-temperature tunneling anisotropic magnetoresistance based on IrMn as well as FeMn has been successfully achieved, and electrical control of the AFM exchange spring i...

Enhanced thermoelectric properties of metal film on bismuth telluride-based materials

International Nuclear Information System (INIS)

Chao, Wen Hsuan; Chen, Yi Ray; Tseng, Shih Chun; Yang, Ping Hsing; Wu, Ren Jye; Hwang, Jenn Yeu

2014-01-01

Diffusion barriers have a significant influence on the reliability and life time of thermoelectric modules. Although nickel is commonly used as a diffusion barrier in commercial thermoelectric modules, several studies have verified that Ni migrates to bismuth telluride-based material during high temperature cycles and causes a loss in efficacy. In this paper, the influence of metal layers coated to p-type and n-type Bi 2 Te 3 on the interface characterization and thermoelectric property is studied using a RF magnetron sputtering. The findings from this study demonstrate the structural and thermoelectric properties of p-type and n-type Bi 2 Te 3 coated with different metal layers. The crystalline phase and compositional change of the interface between the Bi 2 Te 3 materials and the metal layers were determined using an X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. Formation of NiTe was observed in the sample of Ni/p-type Bi 2 Te 3 based films post-annealed in an N 2 atmosphere at 200 °C. In contrast, no Co x Te y was formed in the sample of Co/p-type Bi 2 Te 3 based films post-annealed at 200 °C. For as-deposited Ni/p-type and n-type Bi 2 Te 3 based legs, the Ni slightly diffused into the Bi 2 Te 3 based legs. A similar phenomenon also occurred in the as-deposited Co/p-type and n-type Bi 2 Te 3 based legs. The Seebeck coefficients of the Co contacts on the Bi 2 Te 3 based material displayed better behavior than those of the Ni contacts on the Bi 2 Te 3 based legs. Thus Co could be a suitable diffusion barrier for bulk Bi 2 Te 3 based material. The observed effects on the thermoelectric and structural properties of metal/Bi 2 Te 3 based material are crucial for understanding the interface between the diffusion barrier and thermoelectric materials. - Highlights: • Interface characterization of metal coated to p-type and n-type Bi 2 Te 3 is studied. • We examined the phase transformation of metal/Bi 2 Te 3 based films

Charge transport in metal oxide nanocrystal-based materials

Science.gov (United States)

Runnerstrom, Evan Lars

There is probably no class of materials more varied, more widely used, or more ubiquitous than metal oxides. Depending on their composition, metal oxides can exhibit almost any number of properties. Of particular interest are the ways in which charge is transported in metal oxides: devices such as displays, touch screens, and smart windows rely on the ability of certain metal oxides to conduct electricity while maintaining visible transparency. Smart windows, fuel cells, and other electrochemical devices additionally rely on efficient transport of ionic charge in and around metal oxides. Colloidal synthesis has enabled metal oxide nanocrystals to emerge as a relatively new but highly tunable class of materials. Certain metal oxide nanocrystals, particularly highly doped metal oxides, have been enjoying rapid development in the last decade. As in myriad other materials systems, structure dictates the properties of metal oxide nanocrystals, but a full understanding of how nanocrystal synthesis, the processing of nanocrystal-based materials, and the structure of nanocrystals relate to the resulting properties of nanocrystal-based materials is still nascent. Gaining a fundamental understanding of and control over these structure-property relationships is crucial to developing a holistic understanding of metal oxide nanocrystals. The unique ability to tune metal oxide nanocrystals by changing composition through the introduction of dopants or by changing size and shape affords a way to study the interplay between structure, processing, and properties. This overall goal of this work is to chemically synthesize colloidal metal oxide nanocrystals, process them into useful materials, characterize charge transport in materials based on colloidal metal oxide nanocrystals, and develop ways to manipulate charge transport. In particular, this dissertation characterizes how the charge transport properties of metal oxide nanocrystal-based materials depend on their processing and

Integrating UNESCO ICT-Based Instructional Materials in Chemistry Lessons

Directory of Open Access Journals (Sweden)

CHARLIE P. NACARIO

2014-08-01

Full Text Available This study determined the effectiveness of the lessons in Chemistry integrating UNESCO ICT-based instructional material on the achievement of Chemistry students at Central Bicol State University of Agriculture. It aimed to identify lessons that may be developed integrating UNESCO ICT-based instructional materials, determine the effect of the developed lessons using the material on: conceptual understanding; science process skills; and attitude towards chemistry and gather insights from the experiences of the students and teacher. The study used the single group pretest and posttest experimental design. Descriptive, quantitative and qualitative techniques were also utilized. Quantitative data were taken from the pretest-posttest results on the Test on Conceptual Understanding, Science Process Skills and Chemistry Attitudinaire. Qualitative data were drawn from the experts’ assessment of the developed lessons and research instruments, and the insights of students and teacher. The developed lessons integrating UNESCO ICT-based instructional materials were Atomic Model and Structure, Periodic Table of Elements, Chemical Bonding, and Balancing Chemical Equation. These lessons increased the conceptual understanding of the students by topic and skill from very low mastery to average mastery level. The students have slightly improved along the different science process skills. After teaching the lessons, the students’ attitude also improved. The students became more motivated and interested in Chemistry and the lessons were student centered and entailed teacher’s competence and flexibility in computer use.

Single-crystal growth of ceria-based materials

International Nuclear Information System (INIS)

Ulbrich, Gregor

2015-01-01

In this work it could be shown that Skull-Melting is a suitable method for growing ceria single crystals. Twenty different ceria-based single crystals could be manufactured. It was possible to dope ceria single crystals with Gd, Sm, Y, Zr, Ti, Ta, and Pr in different concentrations. Also co-doping with the named metals was realized. However, there remain some problems for growing ceria-based single crystals by Skull-Melting. As ignition metal zirconium was used because no ceria-based material works well. For that reason all single crystals show small zirconium contamination. Another problem is the formation of oxygen by the heat-induced reduction of ceria during the melting process. Because of that the skull of sintered material is often destroyed by gas pressure. This problem had to be solved individually for every single crystal. The obtained single crystals were characterized using different methods. To ensure the single crystal character the y were examined by Laue diffraction. All manufactured crystals are single crystals. Also powder diffraction patterns of the milled and oxidized samples were measured. For the determination of symmetry and metric the structural parameters were analyzed by the Rietveld method. All synthesized materials crystallize in space group Fm-3m known from calcium fluoride. The cubic lattice parameter a was determined for all crystals. In the case of series with different cerium and zirconium concentrations a linear correlation between cerium content and cubic lattice parameter was detected. The elemental composition was determined by WDX. All crystals show a homogeneous elemental distribution. The oxygen content was calculated because the WDX method isn't useful for determination.

Carbon-Based Materials for Photo-Triggered Theranostic Applications

Directory of Open Access Journals (Sweden)

Karunya Albert

2016-11-01

Full Text Available Carbon-based nanomaterials serve as a type of smart material for photo-triggered disease theranostics. The inherent physicochemical properties of these nanomaterials facilitate their use for less invasive treatments. This review summarizes the properties and applications of materials including fullerene, nanotubes, nanohorns, nanodots and nanographenes for photodynamic nanomedicine in cancer and antimicrobial therapies. Carbon nanomaterials themselves do not usually act as photodynamic therapy (PDT agents owing to the high hydrophobicity, however, when the surface is passivated or functionalized, these materials become great vehicles for PDT. Moreover, conjugation of carbonaceous nanomaterials with the photosensitizer (PS and relevant targeting ligands enhances properties such as selectivity, stability, and high quantum yield, making them readily available for versatile biomedical applications.

Materials Integration and Doping of Carbon Nanotube-based Logic Circuits

Science.gov (United States)

Geier, Michael

Over the last 20 years, extensive research into the structure and properties of single- walled carbon nanotube (SWCNT) has elucidated many of the exceptional qualities possessed by SWCNTs, including record-setting tensile strength, excellent chemical stability, distinctive optoelectronic features, and outstanding electronic transport characteristics. In order to exploit these remarkable qualities, many application-specific hurdles must be overcome before the material can be implemented in commercial products. For electronic applications, recent advances in sorting SWCNTs by electronic type have enabled significant progress towards SWCNT-based integrated circuits. Despite these advances, demonstrations of SWCNT-based devices with suitable characteristics for large-scale integrated circuits have been limited. The processing methodologies, materials integration, and mechanistic understanding of electronic properties developed in this dissertation have enabled unprecedented scales of SWCNT-based transistor fabrication and integrated circuit demonstrations. Innovative materials selection and processing methods are at the core of this work and these advances have led to transistors with the necessary transport properties required for modern circuit integration. First, extensive collaborations with other research groups allowed for the exploration of SWCNT thin-film transistors (TFTs) using a wide variety of materials and processing methods such as new dielectric materials, hybrid semiconductor materials systems, and solution-based printing of SWCNT TFTs. These materials were integrated into circuit demonstrations such as NOR and NAND logic gates, voltage-controlled ring oscillators, and D-flip-flops using both rigid and flexible substrates. This dissertation explores strategies for implementing complementary SWCNT-based circuits, which were developed by using local metal gate structures that achieve enhancement-mode p-type and n-type SWCNT TFTs with widely separated and

A self-consistent first-principle based approach to model carrier mobility in organic materials

International Nuclear Information System (INIS)

Meded, Velimir; Friederich, Pascal; Symalla, Franz; Neumann, Tobias; Danilov, Denis; Wenzel, Wolfgang

2015-01-01

Transport through thin organic amorphous films, utilized in OLEDs and OPVs, has been a challenge to model by using ab-initio methods. Charge carrier mobility depends strongly on the disorder strength and reorganization energy, both of which are significantly affected by the details in environment of each molecule. Here we present a multi-scale approach to describe carrier mobility in which the materials morphology is generated using DEPOSIT, a Monte Carlo based atomistic simulation approach, or, alternatively by molecular dynamics calculations performed with GROMACS. From this morphology we extract the material specific hopping rates, as well as the on-site energies using a fully self-consistent embedding approach to compute the electronic structure parameters, which are then used in an analytic expression for the carrier mobility. We apply this strategy to compute the carrier mobility for a set of widely studied molecules and obtain good agreement between experiment and theory varying over several orders of magnitude in the mobility without any freely adjustable parameters. The work focuses on the quantum mechanical step of the multi-scale workflow, explains the concept along with the recently published workflow optimization, which combines density functional with semi-empirical tight binding approaches. This is followed by discussion on the analytic formula and its agreement with established percolation fits as well as kinetic Monte Carlo numerical approaches. Finally, we skatch an unified multi-disciplinary approach that integrates materials science simulation and high performance computing, developed within EU project MMM@HPC

Strong, ductile, and thermally stable Cu-based metal-intermetallic nanostructured composites.

Science.gov (United States)

Dusoe, Keith J; Vijayan, Sriram; Bissell, Thomas R; Chen, Jie; Morley, Jack E; Valencia, Leopolodo; Dongare, Avinash M; Aindow, Mark; Lee, Seok-Woo

2017-01-09

Bulk metallic glasses (BMGs) and nanocrystalline metals (NMs) have been extensively investigated due to their superior strengths and elastic limits. Despite these excellent mechanical properties, low ductility at room temperature and poor microstructural stability at elevated temperatures often limit their practical applications. Thus, there is a need for a metallic material system that can overcome these performance limits of BMGs and NMs. Here, we present novel Cu-based metal-intermetallic nanostructured composites (MINCs), which exhibit high ultimate compressive strengths (over 2 GPa), high compressive failure strain (over 20%), and superior microstructural stability even at temperatures above the glass transition temperature of Cu-based BMGs. Rapid solidification produces a unique ultra-fine microstructure that contains a large volume fraction of Cu 5 Zr superlattice intermetallic compound; this contributes to the high strength and superior thermal stability. Mechanical and microstructural characterizations reveal that substantial accumulation of phase boundary sliding at metal/intermetallic interfaces accounts for the extensive ductility observed.

Accounting systems for special nuclear material control. Technical report

International Nuclear Information System (INIS)

Korstad, P.A.

1980-05-01

Nuclear material accounting systems were examined and compared to financial double-entry accounting systems. Effective nuclear material accounting systems have been designed using the principles of double-entry financial accounting. The modified double-entry systems presently employed are acceptable if they provide adequate control over the recording and summarizing of transactions. Strong internal controls, based on principles of financial accounting, can help protect nuclear materials and produce accurate, reliable accounting data. An electronic data processing system can more accurately maintain large volumes of data and provide management with more current, reliable information

ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

Institute of Scientific and Technical Information of China (English)

X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

2003-01-01

An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

arXiv Strong reduction of the effective radiation length in an oriented PWO scintillator crystal

CERN Document Server

Bandiera, L.; Romagnoni, M.; Argiolas, N.; Bagli, E.; Ballerini, G.; Berra, A.; Brizzolani, C.; Camattari, R.; De Salvador, D.; Haurylavets, V.; Mascagna, V.; Mazzolari, A.; Prest, M.; Soldani, M.; Sytov, A.; Vallazza, E.

We measured a considerable increase of the emitted radiation by 120 GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline electromagnetic field. The data collected at the external lines of CERN SPS were critically compared to Monte Carlo simulations based on the Baier Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of five in case of beam alignment with the [001] crystal axes. The observed effect opens the way to the realization of compact electromagnetic calorimeters/detectors based on oriented scintillator crystals in which the amount of material can be strongly reduced with respect to the state of the art. These devices could have relevant applications in fixed-target experiments as well as in satellite-borne gamma-telescopes.

Noise Spectroscopy in Strongly Correlated Oxides

Science.gov (United States)

Alsaqqa, Ali M.

Strongly correlated materials are an interesting class of materials, thanks to the novel electronic and magnetic phenomena they exhibit as a result of the interplay of various degrees of freedom. This gives rise to an array of potential applications, from Mott-FET to magnetic storage. Many experimental probes have been used to study phase transitions in strongly correlated oxides. Among these, resistance noise spectroscopy, together with conventional transport measurements, provides a unique viewpoint to understand the microscopic dynamics near the phase transitions in these oxides. In this thesis, utilizing noise spectroscopy and transport measurements, four different strongly correlated materials were studied: (1) neodymium nickel oxide (NdNiO 3) ultrathin films, (2) vanadium dioxide (VO2) microribbons, (3) copper vanadium bronze (CuxV2O 5) microribbons and (4) niobium triselenide (NbSe3) microribbons. Ultra thin films of rare-earth nickelates exhibit several temperature-driven phase transitions. In this thesis, we studied the metal-insulator and Neel transitions in a series of NdNiO3 films with different lattice mismatches. Upon colling down, the metal-insulator phase transition is accompanied by a structural (orthorohombic to monoclinic) and magnetic (paramagnetic to antiferromagnetic) transitions as well, making the problem more interesting and complex at the same time. The noise is of the 1/f type and is Gaussian in the high temperature phase, however deviations are seen in the low temperature phases. Below the metal-insulator transition, noise magnitude increases by orders of magnitude: a sign of inhomogeneous electrical conduction as result of phase separation. This is further assured by the non-Gaussian noise signature. At very low temperatures (T switches between Gaussian and non-Gaussian over several hours, possibly arising from dynamically competing ground states. VO2 is one of the most widely studied strongly correlated oxides and is important from the

[Realistic theories of heavy electron and other strongly correlated materials

International Nuclear Information System (INIS)

1993-01-01

Research on the following topics is summarized: non-perturbative treatments of multi-channel Kondo models, non-perturbative treatments of multi-band models for the quadrupolar fluctuation model of the cuprates, extension of the two-channel Kondo model to other materials and treatment of the infinite-dimensional Hubbard model within the Non-crossing approximation. Data on the specific heat of Y 0.8 U 0.2 Pd 3 and the c-axis susceptibility and specific heat of U in ThRu 2 Si are shown. 5 figs., 84 refs

X-ray elastic constants in textured Zr-base materials

International Nuclear Information System (INIS)

Ortiz, M.; Pochettino, A.A.; Lebrun, J.L.; Maeder, G.

1993-01-01

A general method for the calculation of the X-ray elastic constants (XREC) for textured hexagonal close-packed (hcp) materials was developed by using the orientation distribution function (ODF) and the Reuss hypothesis. This method was applied to textured zirconium (Zr) sheets and zircaloy 4 (Zry 4) extruded tubes. For these samples, where the elastic anisotropy is not very strong, an 'isotropic approximation' method is proposed using the ODF data. In that case, the classical XREC 1/2S 2 and S, values are calculated and experimentally verified for (10 bar 14) diffracting planes. Theoretical XREC values are also given for different (hkil) that could be chosen according to the experimental conditions, considering texture effects on diffracting peak intensities

Electrical conduction in solid materials physicochemical bases and possible applications

CERN Document Server

Suchet, J P

2013-01-01

Electrical Conduction in Solid Materials (Physicochemical Bases and Possible Applications) investigates the physicochemical bases and possible applications of electrical conduction in solid materials, with emphasis on conductors, semiconductors, and insulators. Topics range from the interatomic bonds of conductors to the effective atomic charge in conventional semiconductors and magnetic transitions in switching semiconductors. Comprised of 10 chapters, this volume begins with a description of electrical conduction in conductors and semiconductors, metals and alloys, as well as interatomic bon

High-Pressure Design of Advanced BN-Based Materials

Directory of Open Access Journals (Sweden)

Oleksandr O. Kurakevych

2016-10-01

Full Text Available The aim of the present review is to highlight the state of the art in high-pressure design of new advanced materials based on boron nitride. Recent experimental achievements on the governing phase transformation, nanostructuring and chemical synthesis in the systems containing boron nitride at high pressures and high temperatures are presented. All these developments allowed discovering new materials, e.g., ultrahard nanocrystalline cubic boron nitride (nano-cBN with hardness comparable to diamond, and superhard boron subnitride B13N2. Thermodynamic and kinetic aspects of high-pressure synthesis are described based on the data obtained by in situ and ex situ methods. Mechanical and thermal properties (hardness, thermoelastic equations of state, etc. are discussed. New synthetic perspectives, combining both soft chemistry and extreme pressure–temperature conditions are considered.

Bio-based materials with novel characteristics for tissue engineering applications - A review.

Science.gov (United States)

Bedian, Luis; Villalba-Rodríguez, Angel M; Hernández-Vargas, Gustavo; Parra-Saldivar, Roberto; Iqbal, Hafiz M N

2017-05-01

Recently, a wider spectrum of bio-based materials and materials-based novel constructs and systems has been engineered with high interests. The key objective is to help for an enhanced/better quality of life in a secure way by avoiding/limiting various adverse effects of some in practice traditional therapies. In this context, different methodological approaches including in vitro, in vivo, and ex vivo techniques have been exploited, so far. Among them, bio-based therapeutic constructs are of supreme interests for an enhanced and efficient delivery in the current biomedical sector of the modern world. The development of new types of novel, effective and highly reliable materials-based novel constructs for multipurpose applications is essential and a core demand to tackle many human health related diseases. Bio-based materials possess several complementary functionalities, e.g. unique chemical structure, bioactivity, non-toxicity, biocompatibility, biodegradability, recyclability, etc. that position them well in the modern world's materials sector. In this context, the utilization of biomaterials provides extensive opportunities for experimentation in the field of interdisciplinary and multidisciplinary scientific research. With an aim to address the global dependence on petroleum-based polymers, researchers have been redirecting their interests to the engineering of biological materials for targeted applications in different industries including cosmetics, pharmaceuticals, and other biotechnological or biomedical applications. Herein, we reviewed biotechnological advancements at large and tissue engineering from a biomaterials perspective in particular and envision directions of future developments. Copyright © 2017 Elsevier B.V. All rights reserved.

Bibliographic data base for low activation materials

Energy Technology Data Exchange (ETDEWEB)

Alenina, M.V.; Kolotov, V.P. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation); Ivanov, L.I. [A.A. Baikov Institute of Metallurgy and Science of Materials, Russian Academy of Sciences, Moscow (Russian Federation)

2007-07-01

Full text of publication follows: The analysis of the publications dealing with development of low-activation materials for fusion technology demonstrates that the period of information doubling is about 5-6 years. Such high rate usually is characteristic of the actively developing field of science. To develop an useful instrument for analysis and systematization of the available data a computer based bibliographic system has been developed some time ago. Recently the engine of the system has been significantly modernized. The bibliographic system is based on using of MS SQL server data base which includes main bibliographic information including abstracts. The most important feature of the system is that full-text abstracts searching capabilities are appended with indexing of information by experts to increase its definition. The experts indexes cover the following topics: - Main problems; - Software and methods for calculation; - Libraries of nuclear data; - Spectrum of neutrons for different construction parts of fusion reactor; - Low activation materials; - Technology of production; - Radiation effects; - Utilization of radiation waste; - Estimation of risks; - Designs of fusion reactor; - Nuclear transmutations; - Equipment used for investigations. The primary data base is filling/appending by periodical queries to different bibliographic data bases (INIS, COMPEMDEX and others) via suitable Internet providers including strict analysis of the income information to remove a possible 'information noise' and following data indexing by experts. The data base contains references since 1976 year (when first works in this area have been fulfilled) and until now. The bibliographic system is accessible by means of Internet using different forms developed for queries (http://www.geokhi.ru/{approx}lam{sub d}b). (authors)

Ultrashort-pulse laser excitation and damage of dielectric materials

DEFF Research Database (Denmark)

Haahr-Lillevang, Lasse; Balling, Peter

2015-01-01

Ultrashort-pulse laser excitation of dielectrics is an intricate problem due to the strong coupling between the rapidly changing material properties and the light. In the present paper, details of a model based on a multiple-rate-equation description of the conduction band are provided. The model...

Unexpected nitrile formation in bio-based mesoporous materials (Starbons®).

Science.gov (United States)

Attard, Jennifer; Milescu, Roxana; Budarin, Vitaliy; Matharu, Avtar S; Clark, James H

2018-01-16

The bio-based mesoporous materials made from polysaccharides, Starbons® can be modified by two different routes to give high levels of N-content, unexpectedly including significant quantities of nitrile groups which can improve the materials performance in applications including metal capture.

BIM-Based Decision Support System for Material Selection Based on Supplier Rating

Directory of Open Access Journals (Sweden)

Abiola Akanmu

2015-12-01

Full Text Available Material selection is a delicate process, typically hinged on a number of factors which can be either cost or environmental related. This process becomes more complicated when designers are faced with several material options of building elements and each option can be supplied by different suppliers whose selection criteria may affect the budgetary and environmental requirements of the project. This paper presents the development of a decision support system based on the integration of building information models, a modified harmony search algorithm and supplier performance rating. The system is capable of producing the cost and environmental implications of different material combinations or building designs. A case study is presented to illustrate the functionality of the developed system.

Radionuclide sorption on granitic drill core material

International Nuclear Information System (INIS)

Eriksen, T.E.; Locklund, B.

1987-11-01

Distribution ratios were determined for Sr-85, Cs-134 and Eu-152 on crushed granite and fissure coating/filling material from Stripa mines. Measurements were also carried out on intact fissure surfaces. The experimental data for Sr-85, Cs-134 on crushed material can be accomodated by a sorption model based on the assumption that the crushed material consists of porous spheres with outer and inner surfaces available for sorption. In the case of Eu-152 only sorption on the outer surfaces of the crushed material was observed. The absence of sorption on inner surfaces is most probably due to high depletion of the more strongly sorbed Eu-152 in the water phase and very low diffusivity of Eu-152 in the sorbed state. (orig./HP)

Effect of material constants on power output in piezoelectric vibration-based generators.

Science.gov (United States)

Takeda, Hiroaki; Mihara, Kensuke; Yoshimura, Tomohiro; Hoshina, Takuya; Tsurumi, Takaaki

2011-09-01

A possible power output estimation based on material constants in piezoelectric vibration-based generators is proposed. A modified equivalent circuit model of the generator was built and was validated by the measurement results in the generator fabricated using potassium sodium niobate-based and lead zirconate titanate (PZT) ceramics. Subsequently, generators with the same structure using other PZT-based and bismuth-layered structure ferroelectrics ceramics were fabricated and tested. The power outputs of these generators were expressed as a linear functions of the term composed of electromechanical coupling coefficients k(sys)(2) and mechanical quality factors Q*(m) of the generator. The relationship between device constants (k(sys)(2) and Q*(m)) and material constants (k(31)(2) and Q(m)) was clarified. Estimation of the power output using material constants is demonstrated and the appropriate piezoelectric material for the generator is suggested.

Mechanical characterization and force-displacement hysteretic curves from in-plane cyclic tests on strong masonry infills

Directory of Open Access Journals (Sweden)

Paolo Morandi

2018-02-01

Full Text Available This article contains information related to a recent study “Performance-based interpretation of in-plane cyclic tests on RC frames with strong masonry infills” (Morandi et al., 2017 [1]. Motivated by the necessity to improve the knowledge of the in-plane seismic response of rigid strong masonry infills, a wide experimental campaign based on in-plane cyclic tests on full-scale RC infilled frame specimens, supplemented with a complete characterization of the materials, has been conducted at the laboratory of the Department of Civil Engineering and Architecture of the University of Pavia. The masonry is constituted by vertically perforated 35 cm thick clay units with tongue and groove and dry head-joints and general-purpose mortar bed-joints. The paper reports the results of the mechanical characterization and of the force-displacement hysteretic curves from the in-plane cyclic tests.

Graphene oxide - Polyvinyl alcohol nanocomposite based electrode material for supercapacitors

Science.gov (United States)

Pawar, Pranav Bhagwan; Shukla, Shobha; Saxena, Sumit

2016-07-01

Supercapacitors are high capacitive energy storage devices and find applications where rapid bursts of power are required. Thus materials offering high specific capacitance are of fundamental interest in development of these electrochemical devices. Graphene oxide based nanocomposites are mechanically robust and have interesting electronic properties. These form potential electrode materials efficient for charge storage in supercapacitors. In this perspective, we investigate low cost graphene oxide based nanocomposites as electrode material for supercapacitor. Nanocomposites of graphene oxide and polyvinyl alcohol were synthesized in solution phase by integrating graphene oxide as filler in polyvinyl alcohol matrix. Structural and optical characterizations suggest the formation of graphene oxide and polyvinyl alcohol nanocomposites. These nanocomposites were found to have high specific capacitance, were cyclable, ecofriendly and economical. Our studies suggest that nanocomposites prepared by adding 0.5% wt/wt of graphene oxide in polyvinyl alcohol can be used an efficient electrode material for supercapacitors.

Cement-Based Materials for Nuclear Waste Storage

CERN Document Server

Cau-di-Coumes, Céline; Frizon, Fabien; Lorente, Sylvie

2013-01-01

As the re-emergence of nuclear power as an acceptable energy source on an international basis continues, the need for safe and reliable ways to dispose of radioactive waste becomes ever more critical. The ultimate goal for designing a predisposal waste-management system depends on producing waste containers suitable for storage, transportation and permanent disposal. Cement-Based Materials for Nuclear-Waste Storage provides a roadmap for the use of cementation as an applied technique for the treatment of low- and intermediate-level radioactive wastes.Coverage includes, but is not limited to, a comparison of cementation with other solidification techniques, advantages of calcium-silicate cements over other materials and a discussion of the long-term suitability and safety of waste packages as well as cement barriers. This book also: Discusses the formulation and production of cement waste forms for storing radioactive material Assesses the potential of emerging binders to improve the conditioning of problemati...

The development of thematic materials using project based learning for elementary school

Science.gov (United States)

Yuliana, M.; Wiryawan, S. A.; Riyadi

2018-05-01

Teaching materials is one of the important factors in supporting on learning process. This paper discussed about developing thematic materials using project based learning. Thematic materials are designed to make students to be active, creative, cooperative, easy in thinking to solve the problem. The purpose of the research was to develop thematic material using project based learning which used valid variables. The method of research which used in this research was four stages of research and development proposed by Thiagarajan consisting of 4 stages, namely: (1) definition stage, (2) design stage, (3) development stage, and (4) stage of dissemination. The first stage was research and information collection, it was in form of need analysis with questionnaire, observation, interview, and document analysis. Design stage was based on the competencies and indicator. The third was development stage, this stage was used to product validation from expert. The validity of research development involved media validator, material validator, and linguistic validator. The result from the validation of thematic material by expert showed that the overall result had a very good rating which ranged from 1 to 5 likert scale, media validation showed a mean score 4,83, the material validation showed mean score 4,68, and the mean of linguistic validation was e 4,74. It showed that the thematic material using project based learning was valid and feasible to be implemented in the context thematic learning.

A Statistics-Based Material Property Analysis to Support TPS Characterization

Science.gov (United States)

Copeland, Sean R.; Cozmuta, Ioana; Alonso, Juan J.

2012-01-01

Accurate characterization of entry capsule heat shield material properties is a critical component in modeling and simulating Thermal Protection System (TPS) response in a prescribed aerothermal environment. The thermal decomposition of the TPS material during the pyrolysis and charring processes is poorly characterized and typically results in large uncertainties in material properties as inputs for ablation models. These material property uncertainties contribute to large design margins on flight systems and cloud re- construction efforts for data collected during flight and ground testing, making revision to existing models for entry systems more challenging. The analysis presented in this work quantifies how material property uncertainties propagate through an ablation model and guides an experimental test regimen aimed at reducing these uncertainties and characterizing the dependencies between properties in the virgin and charred states for a Phenolic Impregnated Carbon Ablator (PICA) based TPS. A sensitivity analysis identifies how the high-fidelity model behaves in the expected flight environment, while a Monte Carlo based uncertainty propagation strategy is used to quantify the expected spread in the in-depth temperature response of the TPS. An examination of how perturbations to the input probability density functions affect output temperature statistics is accomplished using a Kriging response surface of the high-fidelity model. Simulations are based on capsule configuration and aerothermal environments expected during the Mars Science Laboratory (MSL) entry sequence. We identify and rank primary sources of uncertainty from material properties in a flight-relevant environment, show the dependence on spatial orientation and in-depth location on those uncertainty contributors, and quantify how sensitive the expected results are.

N,O-Type Carborane-Based Materials

Directory of Open Access Journals (Sweden)

José Giner Planas

2016-05-01

Full Text Available This review summarizes the synthesis and coordination chemistry of a series of carboranyl ligands containing N,O donors. Such carborane-based ligands are scarcely reported in the literature when compared to other heteroatom-containing donors. The synthetic routes for metal complexes of these N,O-type carborane ligands are summarized and the properties of such complexes are described in detail. Particular attention is paid to the effect that the incorporation of carboranes has into the coordination chemistry of the otherwise carbon-based ligands and the properties of such materials. The reported complexes show a variety of properties such as those used in magnetic, chiroptical, nonlinear optical, catalytic and biomedical applications.

Nanocellulose-Based Materials for Water Purification

Directory of Open Access Journals (Sweden)

Hugo Voisin

2017-03-01

Full Text Available Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present—in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

DEVELOPMENT SCIENTIFIC INQUIRY BASED TEACHING MATERIALS ON DYNAMIC FLUIDS TO IMPROVE STUDENTS ACHIEVEMENT

Directory of Open Access Journals (Sweden)

Jeliana Veronika Sirait

2016-06-01

Full Text Available The study was conducted to investigate whether the developed scientific inquiry-based teaching materials can improve the students’ response, the students’ activity and the students’ achievement. This study is development which based on Borg & Gall product development. Samples were selected randomly by raffling 4 classes into one class, applied teaching materials based scientific inquiry. The instruments which are used in this study consisted of three namely quetionnaires used for validation of teaching material by the expert of the material and the expert of design, the evaluation of physics teacher and students’ response toward teaching materials and observation sheet of students’ activity used in learning process and also test for students’ achievement in the form of multiple choice consisted of 10 quetions provided for end of the learning. The results of this study showed that the developed scientific inquiry-based teaching materials can improve the students’ response, the students’ activity and the students’ achievement in every session.

Competitive light absorbers in photoactive dental resin-based materials.

Science.gov (United States)

Hadis, Mohammed A; Shortall, Adrian C; Palin, William M

2012-08-01

The absorbance profile of photoinitiators prior to, during and following polymerization of light curable resin-based materials will have a significant effect on the cure and color properties of the final material. So-called "colorless" photoinitiators are used in some light-activated resin-based composite restorative materials to lessen the yellowing effect of camphoroquinone (CQ) in order to improve the esthetic quality of dental restorations. This work characterizes absorption properties of commonly used photoinitiators, an acylphosphine oxide (TPO) and CQ, and assesses their influence on material discoloration. Dimethacrylate resin formulations contained low (0.0134 mol/dm(3)), intermediate (0.0405 mol/dm(3)) or high (0.0678 mol/dm(3)) concentrations of the photoinitiators and the inhibitor, butylated hydroxytoluene (BHT) at 0, 0.1 or 0.2% by mass. Disc shaped specimens (n = 3) of each resin were polymerized for 60s using a halogen light curing unit. Dynamic measurements of photoinitiator absorption, polymer conversion and reaction temperature were performed. A spectrophotometer was used to measure the color change before and after cure. GLM three-way analysis of variance revealed significant differences (pphotoinitiator type (df = 1; F = 176.12)>% BHT (df = 2, F = 13.17). BHT concentration affected the rate of polymerization and produced lower conversion in some of the CQ-based resins. Significant differences between photoinitiator type and concentrations were seen in color (where TPO resins became yellower and camphoroquinone resins became less yellow upon irradiation). Reaction temperature, kinetics and conversion also differed significantly for both initiators (presins producing a visually perceptible color change upon polymerization, the color change was significantly less than that produced with CQ-based resins. Although some photoinitiators such as TPO may be a more esthetic alternative to CQ, they may actually cause significant color contamination when

Ceramic materials based on synthetic calcium phosphate for medical uses

OpenAIRE

Toropkov, N. E.; Antonkin, N. S.

2016-01-01

This article discusses the different methods of synthesis of hydroxyapatite and receiving on its base of ceramic materials in various ways. We have also developed our own technology. The conditions of compatibility and saddle the assumption and the suitability of the material for implantation.

Method for recovering aroma concentrate from a caffeine- or theobromine-comprising food base material

NARCIS (Netherlands)

Kattenberg, H.R.; Willemsen, J.H.A.; Starmans, D.A.J.; Hoving, H.D.; Winters, M.G.M.

2002-01-01

Described is a method for recovering aroma concentrate from a caffeine- or theobromine-comprising food base material, such as coffee or tea, and in particular cocoa, at least comprising the steps of: introducing the food base material into an aqueous extractant and incubating the food base material

ELT RESEARCH PAPERS AS AUTHENTIC MATERIALS IN TEACHING RESEARCH-BASED ARTICLE WRITING: A CASE IN INDONESIAN CONTEXT

Directory of Open Access Journals (Sweden)

M. Ali Ghufron

2017-09-01

Full Text Available There are strong shreds of evidence that the choice of instructional materials has large effects on students’ achievement. This study was to assess the efficacy of using ELT research papers as authentic materials in teaching research-based article writing. This study was aimed at revealing whether or not there is a significant difference in students’ writing skill in terms of ELT research paper writing between the students who were taught by using ELT research papers as authentic materials and those who were taught by using textbook materials provided by the faculty. This study belongs to a quasi-experimental study with an experimental and control group pretest-posttest design. The population of this study was 75 students from the fourth semester of English Education Study Program of IKIP PGRI Bojonegoro, East Java, Indonesia. The sample was selected through cluster random sampling and consisted of 50 students that were divided into two groups. The instrument used to collect the data was a writing test. Consequently, normality and homogeneity of the data were tested. A t-test was used to compare the mean of the two groups. The hypothesis was designed and tested at 0.05 level of significance. The results revealed that there is a significant difference in students’ academic writing skill between the students who were taught by using the ELT research papers as authentic materials and those who were taught by using textbook materials. The t-test revealed that t-value is higher than t-table (6.07>2.01. Therefore it is concluded that the authentic instructional materials could significantly improve students’ academic writing skill.

Nanostructured Mo-based electrode materials for electrochemical energy storage.

Science.gov (United States)

Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

2015-04-21

The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

Optimum permeability for a cement based backfill material

International Nuclear Information System (INIS)

Jacobs, F.; Wittmann, F.H.; Iriya, K.

1989-01-01

In Switzerland it is planned to dispose low- and intermediate radioactive waste (LLW/ILW) in an underground repository. Between the materials present in a repository different chemical reactions may occur. Due to radiolytic decomposition, microbiological degradation and corrosion gas (mainly hydrogen) may be produced. The release of gas can cause the build-up of pressure in the cavern and finally lead to the formation of cracks and/or serious damage in the concrete structure or host rock. Through cracks a contamination of the groundwater and the biosphere could be possible. This investigation develops a suitable cement based material which can be used as backfill for the repository. Besides other aspects mentioned later a suitable backfill material has to be characterized by a certain minimum gas permeability and a as low as possible hydraulic conductivity. On the one hand gas permeability is necessary to release gas overpressure and on the other hand a low hydraulic conductivity should prevent leaching of backfill materials and contamination of the environment

Attenuation relation for strong motion in Eastern Java based on appropriate database and method

Science.gov (United States)

Mahendra, Rian; Rohadi, Supriyanto; Rudyanto, Ariska

2017-07-01

The selection and determination of attenuation relation has become important for seismic hazard assessment in active seismic region. This research initially constructs the appropriate strong motion database, including site condition and type of the earthquake. The data set consisted of large number earthquakes of 5 ≤ Mw ≤ 9 and distance less than 500 km that occurred around Java from 2009 until 2016. The location and depth of earthquake are being relocated using double difference method to improve the quality of database. Strong motion data from twelve BMKG's accelerographs which are located in east Java is used. The site condition is known by using dominant period and Vs30. The type of earthquake is classified into crustal earthquake, interface, and intraslab based on slab geometry analysis. A total of 10 Ground Motion Prediction Equations (GMPEs) are tested using Likelihood (Scherbaum et al., 2004) and Euclidean Distance Ranking method (Kale and Akkar, 2012) with the associated database. The evaluation of these methods lead to a set of GMPEs that can be applied for seismic hazard in East Java where the strong motion data is collected. The result of these methods found that there is still high deviation of GMPEs, so the writer modified some GMPEs using inversion method. Validation was performed by analysing the attenuation curve of the selected GMPE and observation data in period 2015 up to 2016. The results show that the selected GMPE is suitable for estimated PGA value in East Java.

Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder

Science.gov (United States)

Thouin, Félix; Neutzner, Stefanie; Cortecchia, Daniele; Dragomir, Vlad Alexandru; Soci, Cesare; Salim, Teddy; Lam, Yeng Ming; Leonelli, Richard; Petrozza, Annamaria; Kandada, Ajay Ram Srimath; Silva, Carlos

2018-03-01

With strongly bound and stable excitons at room temperature, single-layer, two-dimensional organic-inorganic hybrid perovskites are viable semiconductors for light-emitting quantum optoelectronics applications. In such a technological context, it is imperative to comprehensively explore all the factors—chemical, electronic, and structural—that govern strong multiexciton correlations. Here, by means of two-dimensional coherent spectroscopy, we examine excitonic many-body effects in pure, single-layer (PEA) 2PbI4 (PEA = phenylethylammonium). We determine the binding energy of biexcitons—correlated two-electron, two-hole quasiparticles—to be 44 ±5 meV at room temperature. The extraordinarily high values are similar to those reported in other strongly excitonic two-dimensional materials such as transition-metal dichalcogenides. Importantly, we show that this binding energy increases by ˜25 % upon cooling to 5 K. Our work highlights the importance of multiexciton correlations in this class of technologically promising, solution-processable materials, in spite of the strong effects of lattice fluctuations and dynamic disorder.

The possibility of using materials based on secondary gravel in civil construction

Directory of Open Access Journals (Sweden)

Galitskova Yulia

2017-01-01

Full Text Available By now, the wear and tear of housing stock is more than 50%. Each year the number of old and dilapidated housing is growing, but it is gradually replaced by modern buildings. However, wastes accumulated from dismantling of buildings and constructions, are underutilized and, usually are just stored at landfills, or used for temporary roads construction. The purpose of this research is to define construction wastes characteristics and to explore possibilities for recycling of wastes from construction materials production. The paper also analyzes housing stock condition and basic requirements to building materials used in construction; and demonstrates results building materials based on secondary gravel investigation. While working with materials based on waste requirements the authors conducted laboratory research. Thus, the paper presents the analysis of laboratory tests results that made it possible to draw conclusions about the possible use of building materials based on secondary gravel and about their conformity to specified requirements. The researchers also developed proposals and recommendations to improve the competitiveness of such materials.

Cell-Based Fabrication of Organic/Inorganic Composite Gel Material

Directory of Open Access Journals (Sweden)

Takayoshi Nakano

2011-01-01

Full Text Available Biomaterials containing components similar to the native biological tissue would have benefits as an implantable scaffold material. To obtain such biomimetic materials, cells may be great contributors because of their crucial roles in synthetic organics. In addition, the synthesized organics—especially those derived from osteogenic differentiated cells—become a place where mineral crystals nucleate and grow even in vitro. Therefore to fabricate an organic/inorganic composite material, which is similar to the biological osteoid tissue, bone marrow derived mesenchymal stem cells (BMSCs were cultured in a 3D fibrin gel in this study. BMSCs secreted bone-related proteins that enhanced the biomineralization within the gel when the cells were cultured with an osteogenic differentiation medium. The compositions of both synthesized matrices and precipitated minerals in the obtained materials altered depending on the cell culture period. The mineral obtained in the 3D gel showed low crystalline hydroxyapatite. The composite materials also showed excellent osteoconductivity with new bone formation when implanted in mice tibiae. Thus, we demonstrated the contributions of cells for fabricating implantable organic/inorganic composite gel materials and a method for controlling the material composition in the gel. This cell-based material fabrication method would be a novel method to fabricate organic/inorganic composite biomimetic materials for bone tissue engineering.

Technical Education Outreach in Materials Science and Technology Based on NASA's Materials Research

Science.gov (United States)

Jacobs, James A.

2003-01-01

The grant NAG-1 -2125, Technical Education Outreach in Materials Science and Technology, based on NASA s Materials Research, involves collaborative effort among the National Aeronautics and Space Administration s Langley Research Center (NASA-LaRC), Norfolk State University (NSU), national research centers, private industry, technical societies, colleges and universities. The collaboration aims to strengthen math, science and technology education by providing outreach related to materials science and technology (MST). The goal of the project is to transfer new developments from LaRC s Center for Excellence for Structures and Materials and other NASA materials research into technical education across the nation to provide educational outreach and strengthen technical education. To achieve this goal we are employing two main strategies: 1) development of the gateway website and 2) using the National Educators Workshop: Update in Engineering Materials, Science and Technology (NEW:Updates). We have also participated in a number of national projects, presented talks at technical meetings and published articles aimed at improving k-12 technical education. Through the three years of this project the NSU team developed the successful MST-Online site and continued to upgrade and update it as our limited resources permitted. Three annual NEW:Updates conducted from 2000 though 2002 overcame the challenges presented first by the September 11,2001 terrorist attacks and the slow U.S. economy and still managed to conduct very effective workshops and expand our outreach efforts. Plans began on NEW:Update 2003 to be hosted by NASA Langley as a part of the celebration of the Centennial of Controlled Flight.

[Experimental basis of a new material for the manufacture of bases dentures].

Science.gov (United States)

Shturminskiĭ, V G

2013-10-01

The author studied the problem of improving the quality of prosthetic removable prostheses through the development of new basic material based on polypropylene copolymer. To this end, we examined the physical and chemical structure and hygienic properties of the produced material. The studies found that the developed material of polypropylene optimal solution for the partial plate denture bases, without flaws acrylic prosthesis and improves the properties of the previously used polypropylene plastics.

Synthesis of Hafnium-Based Ceramic Materials for Ultra-High Temperature Aerospace Applications

Science.gov (United States)

Johnson, Sylvia; Feldman, Jay

2004-01-01

This project involved the synthesis of hafnium (Hf)-based ceramic powders and Hf-based precursor solutions that were suitable for preparation of Hf-based ceramics. The Hf-based ceramic materials of interest in this project were hafnium carbide (with nominal composition HE) and hafnium dioxide (HfO2). The materials were prepared at Georgia Institute of Technology and then supplied to research collaborators Dr. Sylvia Johnson and Dr. Jay Feldman) at NASA Ames Research Center.

Nickel-based materials and high-alloy, special stainless steels. 2. new rev. and enl. ed.

International Nuclear Information System (INIS)

Heubner, U.; Brill, U.; Hoffmann, T.; Jasner, M.; Kirchheiner, R.; Koecher, R.; Richter, H.; Rockel, M.; White, F.

1993-01-01

The book is intended as a source of information on nickel-based materials and special stainless steels and apart from the up-to-date materials data presents information on recent developments and knowledge gained, so that it may be a valuable aid to materials engineers looking for cost-effective resolutions of their materials problems in the chemical process industry, power plant operation, and high-temperature applications. The book presents eight individual contributions entitled as follows: (1) Nickel-base alloys and high-alloy, special stainless steels. - Materials survey and data sheets (Ulrich Heubner). (2) Corrosion of nickel-base alloys and special stainless steels (Manfred Rockel). (3) Welding of nickel-base alloys and high-alloy, special stainless steels (Theo Hoffmann). (4) High-temperature resistant materials (Ulrich Brill). (5) Application and processing of nickel-base materials in the chemical process industry and in pollution abatement equipment (Reiner Koecher). (6) Selected examples of applications of nickel-base materials in chemical plant (Manfred Jasner, Frederick White). (7) Applications of nickel-base alloys and special stainless steels in power plant. (8) The use of nickel-base alloys and stainless steels in pollution abatement processes (R. Kirchheiner). (orig./MM). 151 figs., 226 refs [de

Antibacterial properties of nanocomposite materials and compositions on there bases

International Nuclear Information System (INIS)

Podol'skaya, V.I.; Vojtenko, O.Yu.; Grishenko, N.I.; Ul'berg, Z.P.; Yakubenko, L.N.

2012-01-01

The structured nanobiocomposite materials based on microbial cells and colloidal silver can serve as the new adjuvant systems. These composite materials being filled with active components, in particular the medications allow to prepare the long release preparations with synergetic effect or can just contribute to prolonged drug action

Experimental Study of Goaf Filling Materials Based on Red Mud

Science.gov (United States)

Mu, Mangen; Gao, Xiaozhen; Guo, Taoming; Hu, Xinping

2018-01-01

Red mud as soild waste is difficult to treatment. Goaf filling materials can make a large use of red mud. By the experimental study,we find that the red mud, fly ash, ground slag and desulfida-tion gypsum can be used to make goaf filling materials based on the principle of alkali excitation and metalion stability.Through the control variable method, we find that the optimal proportion of goaf filling materials based on red mud is red mud 55%, fly ash 30%, cement 7.5%, fly ash 2.5%, desulfurization gypsum 5%, admixture 1%, and water solid ratio=1:1.2.The 28days final material strength was 2.0 MPa,which achives the technical specification requirements.Through the test of SEM, XRD and IR, it is indicated that the strength formation of goaf filling material based on red mud is from the unformed linking hydration products of amorphous alkali excitation system. With curing time from 3 to 7 days, the unformed linking hydration products grown a lot of vitreous hydration products. When hydration reaction basicly finished after 28 days, the hydration products have developed into a large volume of massive vitreous with an extremely dense structure. The Ca2SiO3 mineral phase is significantly reduced, which is participate in hydration reactions. The decrease of Ca2SiO3 indicates that the Si-O bond in the system have been ruptured and reorganized.

Controlled fabrication of the strong emission YVO4:Eu3+ nanoparticles and nanowires by microwave assisted chemical synthesis

International Nuclear Information System (INIS)

Huong, Tran Thu; Vinh, Le Thi; Phuong, Ha Thi; Khuyen, Hoang Thi; Anh, Tran Kim; Tu, Vu Duc; Minh, Le Quoc

2016-01-01

In this report, we are presenting the controlled fabrication results of the strong emission YVO 4 : Eu 3+ nanoparticles and nanowires by microwave which is assisted chemical synthesis. The effects of incorporated synthesis conditions such as microwave irradiated powers, pH values and concentration of chemical composition on properties of nanomaterials are also investigated to obtain the controllable size and homogenous morphology. Morphological and optical properties of YVO 4 : Eu 3+ prepared products which have been characterized by X-ray diffraction (XRD), field emission micrcroscopy (FESEM) and photoluminescence spectroscopy. As based from result of synthesized samples, we found that the changing of pH values, microwave irradiated powers and chemical composition rise to change reform the size and shape of materials from nanoparticles (diameter about 20 nm) to wires shape (with about 500÷800 nm length and 10÷20 nm width). The photoluminescence (PL) spectroscopy measurements of YVO 4 : Eu 3+ nanostructure materials under UV excitation showed that: the strong luminescence in red region with narrow lines corresponding to the intra-4f transitions of 5 D 0 – 7 F j (j=1, 2, 3, and 4) of Eu 3+ ions with the highest luminescence intensity of 5 D 0 → 7 F 2 transition. - Highlights: • The strong emission YVO 4 :Eu 3+ nanostructure materials were successfully synthesized by microwave assisted chemical synthesis. • The size, morphology and luminescence of the YVO 4 :Eu 3+ nanostructure materials can be controlled by the solution pH, microwave irradiated powers and chemical composition. • These YVO 4 :Eu 3+ nanostructure materials above can potentially applied in various fields of application, especially in luminescent labeling and visualization in biomedical application.

Volta-Based Cells Materials Chemical Multiple Representation to Improve Ability of Student Representation

Science.gov (United States)

Helsy, I.; Maryamah; Farida, I.; Ramdhani, M. A.

2017-09-01

This study aimed to describe the application of teaching materials, analyze the increase in the ability of students to connect the three levels of representation and student responses after application of multiple representations based teaching materials chemistry. The method used quasi one-group pretest-posttest design to 71 students. The results showed the application of teaching materials carried 88% with very good category. A significant increase ability to connect the three levels of representation of students after the application of multiple representations based teaching materials chemistry with t-value > t-crit (11.402 > 1.991). Recapitulation N-gain pretest and posttest showed relatively similar for all groups is 0.6 criterion being achievement. Students gave a positive response to the application of multiple representations based teaching materials chemistry. Students agree teaching materials used in teaching chemistry (88%), and agrees teaching materials to provide convenience in connecting the three levels of representation (95%).

"Smart" Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications.

Science.gov (United States)

Qiu, Xiaoyun; Hu, Shuwen

2013-02-28

Cellulose is the most abundant biomass material in nature, and possesses some promising properties, such as mechanical robustness, hydrophilicity, biocompatibility, and biodegradability. Thus, cellulose has been widely applied in many fields. "Smart" materials based on cellulose have great advantages-especially their intelligent behaviors in reaction to environmental stimuli-and they can be applied to many circumstances, especially as biomaterials. This review aims to present the developments of "smart" materials based on cellulose in the last decade, including the preparations, properties, and applications of these materials. The preparations of "smart" materials based on cellulose by chemical modifications and physical incorporating/blending were reviewed. The responsiveness to pH, temperature, light, electricity, magnetic fields, and mechanical forces, etc. of these "smart" materials in their different forms such as copolymers, nanoparticles, gels, and membranes were also reviewed, and the applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials and smart membranes, etc. were also described in this review.

The Orange Side of Disperse Red 1: Humidity-Driven Color Switching in Supramolecular Azo-Polymer Materials Based on Reversible Dye Aggregation.

Science.gov (United States)

Schoelch, Simon; Vapaavuori, Jaana; Rollet, Frédéric-Guillaume; Barrett, Christopher J

2017-01-01

Humidity detection, and the quest for low-cost facile humidity-sensitive indicator materials is of great interest for many fields, including semi-conductor processing, food transport and storage, and pharmaceuticals. Ideal humidity-detection materials for a these applications might be based on simple clear optical readout with no power supply, i.e.: a clear color change observed by the naked eye of any untrained observer, since it doesn't require any extra instrumentation or interpretation. Here, the introduction of a synthesis-free one-step procedure, based on physical mixing of easily available commercial materials, for producing a humidity memory material which can be easily painted onto a wide variety of surfaces and undergoes a remarkable color change (approximately 100 nm blue-shift of λ MAX ) upon exposure to various thresholds of levels of ambient humidity is reported. This strong color change, easily visible to as a red-to-orange color switch, is locked in until inspection, but can then be restored reversibly if desired, after moderate heating. By taking advantage of spontaneously-forming reversible 'soft' supramolecular bonds between a red-colored azo dye and a host polymer matrix, a reversible dye 'migration' aggregation appearing orange, and dis-aggregation back to red can be achieved, to function as the sensor. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wood-based Tri-Axial Sandwich Composite Materials: Design, Fabrication, Testing, Modeling and Application

Science.gov (United States)

Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

2014-01-01

As the demand for sustainable materials increases, there are unique challenges and opportunities to develop light-weight green composites materials for a wide range of applications. Thus wood-based composite materials from renewable forests may provide options for some niche applications while helping to protect our environment. In this paper, the wood-based tri-axial...

Research on the strong optical feedback effects based on spectral analysis method

Science.gov (United States)

Zeng, Zhaoli; Qu, XueMin; Li, Weina; Zhang, Min; Wang, Hao; Li, Tuo

2018-01-01

The strong optical feedback has the advantage of generating high resolution fringes. However, these feedback fringes usually seem like the noise signal when the feedback level is high. This defect severely limits its practical application. In this paper, the generation mechanism of noise fringes with strong optical feedback is studied by using spectral analysis method. The spectral analysis results show that, in most cases, the noise-like fringes are observed owing to the strong multiple high-order feedback. However, at certain feedback cavity condition, there may be only one high-order feedback beam goes back to the laser cavity, the noise-like fringes can change to the cosine-like fringes. And the resolution of this fringe is dozens times than that of the weak optical feedback. This research provides a method to obtain high resolution cosine-like fringes rather than noise signal in the strong optical feedback, which makes it possible to be used in nanoscale displacement measurements.

A Study of Multimedia Annotation of Web-Based Materials

Science.gov (United States)

Hwang, Wu-Yuin; Wang, Chin-Yu; Sharples, Mike

2007-01-01

Web-based learning has become an important way to enhance learning and teaching, offering many learning opportunities. A limitation of current Web-based learning is the restricted ability of students to personalize and annotate the learning materials. Providing personalized tools and analyzing some types of learning behavior, such as students'…

PENGENDALIAN PERSEDIAAN BAHAN BAKU BASE MATERIAL PADA INDUSTRI KERAMIK DI PT. XYZ

Directory of Open Access Journals (Sweden)

Lidya Susanti

2015-12-01

Full Text Available Inventory of raw materials in the company is very important, so it has to be controlled. A good inventory control of raw materials should be supported with cost efficiency. This study was to analyze factors that cause the base material inventories excess at PT. XYZ and analyze the purpose of the base material inventories to be controlled. The reseacrh was using a fish bone method and continue with using pairwise comparison method assisted with the expert choice 2000 software. The classification result based on ABC analysis, the selected item that was going to be analyzed was the A category items.The items that are included in the A category are clay ex belitung jw, clay ja 1/ja b and sodium feldspar. The EOQ equations model was used to answer the purpose of the base material inventories control. Based from the EOQ model, the needed quantity, order quantity, order frequency, reorder point (ROP, total order cost (TOC, total carrying cost (TCC, and total inventory cost (TIC could be obtained. The comparison of the total cost of inventory among the EOQ model and company policies showed that the EOQ model in seven months can save up to Rp311.612.769. PT. XYZ could minimize the base material inventory costs by calculating the costs incurred. The EOQ model could be implemented if all of the departments involved are well cooperated. PT. XYZ should also be able to make inventory control standards which are quantity order, order frequency, and reorder point. Keywords: Cost, EOQ, frequency, inventory, ROPABSTRAKPersediaan bahan baku pada perusahaan sangatlah penting, sehingga harus dapat dikendalikan. Pengendalian persediaan bahan baku yang baik harus didukung dengan efisiensi biaya. Penelitian ini untuk menganalisis faktor-faktor yang menyebabkan kondisi persediaan bahan baku base material berlebih di PT. XYZ dan menganalisis persediaan bahan baku base material agar dapat dikendalikan. Penelitian ini menggunakan metode fish bone dilanjutkan dengan metode

Durability of low-pH cementitious materials based on OPC or CAC

International Nuclear Information System (INIS)

Garcia Calvo, J.L.; Sanchez, M.; Alonso, M.C.; Fernandez Luco, L.

2015-01-01

Low pH cementitious materials are considered to be used in underground repositories for high level waste but there are still some characteristics related to their long-term durability that must be analyzed in depth. In this sense, different shrinkage tests have been made using low-pH cement formulations based on Ordinary Portland Cement (OPC) or Calcium Aluminate Cement (CAC), on mortar and concrete specimens. The obtained results show that, regarding the autogenous shrinkage, low-pH cementitious materials show similar values than those observed in the reference samples. In fact, the main shrinkage problems in the low-pH materials are related with those based on OPC with high silica fume contents in drying conditions. Besides, as the use of reinforced concrete can be required in underground repositories, the susceptibility of reinforcements to corrosion when using low-pH cementitious materials based on OPC was analyzed, using two different reinforcements: carbon steel and galvanized steel. The lower pore solution pH of the low-pH OPC based materials generates the corrosion of the carbon steel reinforcement. However, when galvanized steels are used, any corrosion problem is detected regardless of the cement formulation. (authors)

Segmentation of low‐cost high efficiency oxide‐based thermoelectric materials

DEFF Research Database (Denmark)

Le, Thanh Hung; Van Nong, Ngo; Linderoth, Søren

2015-01-01

Thermoelectric (TE) oxide materials have attracted great interest in advanced renewable energy research owing to the fact that they consist of abundant elements, can be manufactured by low-cost processing, sustain high temperatures, be robust and provide long lifetime. However, the low conversion...... efficiency of TE oxides has been a major drawback limiting these materials to broaden applications. In this work, theoretical calculations are used to predict how segmentation of oxide and semimetal materials, utilizing the benefits of both types of materials, can provide high efficiency, high temperature...... oxide-based segmented legs. The materials for segmentation are selected by their compatibility factors and their conversion efficiency versus material cost, i.e., “efficiency ratio”. Numerical modelling results showed that conversion efficiency could reach values of more than 10% for unicouples using...

New polyanion-based cathode materials for alkali-ion batteries

Science.gov (United States)

Yaghoobnejad Asl, Hooman

A number of new materials have been discovered through exploratory synthesis with the aim to be studied as the positive electrode (cathode) in Li-ion and Na-ion batteries. The focus has been set on the ease of synthesis, cost and availability of active ingredients in the battery, and decent cycle-life performance through a combination of iron and several polyanionic ligands. An emphasis has been placed also on phosphite (HPO32-) as a polyanionic ligand, mainly due to the fact that it has not been studied seriously before as a polyanion for cathode materials. The concept of mixed polyanions, for example, boro-phosphate and phosphate-nitrates were also explored. In each case the material was first made and purified via different synthetic strategies, and the crystal structure, which dominantly controls the performance of the materials, has been extensively studied through Single-Crystal X-ray Diffraction (SCXRD) or synchrotron-based Powder X-ray Diffraction (PXRD). This investigation yielded four new compositions, namely Li3Fe 2(HPO3)3Cl, LiFe(HPO3)2, Li0.8Fe(H2O)2B[P2O8]•H 2O and AFePO4NO3 (A = NH4/Li, K). Furthermore, for each material the electrochemical performance for insertion of Li+ ion has been studied by means of various electrochemical techniques to reveal the nature of alkali ion insertion. In addition Na-ion intercalation has been studied for boro-phosphate and AFePO4NO3. Additionally a novel synthesis procedure has been reported for tavorite LiFePO4F 1-x(OH)x, where 0 ≤ x ≤ 1, an important class of cathode materials. The results obtained clearly demonstrate the importance of crystal structure on the cathode performance through structural and compositional effects. Moreover these findings may contribute to the energy storage community by providing insight into the solid-state science of electrode material synthesis and proposing new alternative compositions based on sustainable materials.

Packaging based on polymeric materials

Directory of Open Access Journals (Sweden)

Jovanović Slobodan M.

2005-01-01

Full Text Available In the past two years the consumption of common in the developed countries world wide (high tonnage polymers for packaging has approached a value of 50 wt.%. In the same period more than 50% of the packaging units on the world market were made of polymeric materials despite the fact that polymeric materials present 17 wt.% of all packaging materials. The basic properties of polymeric materials and their environmental and economical advantages, providing them such a position among packaging materials, are presented in this article. Recycling methods, as well as the development trends of polymeric packaging materials are also presented.

CHAPTER 9 : Virus-based systems for functional materials

NARCIS (Netherlands)

Verwegen, Martijn; Cornelissen, Jeroen J.L.M.; Boker, Alexander; van Rijn, Patrick

2015-01-01

Virus-based bionanotechnology holds the promise of control over the structure, properties and functionality of materials at the nanometre scale. After all, viruses, and by extension virus-like particles (VLPs), represent some of the largest hierarchical protein constructs found in Nature. Their

Novel hybrid materials based on the vanadium oxide nanobelts

Energy Technology Data Exchange (ETDEWEB)

Zabrodina, G.S., E-mail: kudgs@mail.ru [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Makarov, S.G.; Kremlev, K.V. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Yunin, P.A.; Gusev, S.A. [Institute for Physics of Microstructures Russian Academy of Sciences, Nizhny Novgorod 603087 (Russian Federation); Kaverin, B.S.; Kaverina, L.B. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Ketkov, S.Yu. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation)

2016-04-15

Graphical abstract: - Highlights: • Flat and curved vanadium oxide nanobelts have been synthesized. • Hybrid material was prepared via decoration of flexible nanobelts with zinc phthalocyanine. • Investigations of the thermal stability, morphologies and structures were carried out. - Abstract: Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V{sub 2}O{sub 5}·nH{sub 2}O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB – cetyltrimethylammonium bromide, TBAB – tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA){sub 0.33}V{sub 2}O{sub 5} flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA){sub 0.33}V{sub 2}O{sub 5}, (TBA){sub 0.16}V{sub 2}O{sub 5} nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

Peltier heat measurements at a junction between materials exhibiting Fermi gas and Fermi liquid behaviour

International Nuclear Information System (INIS)

Kuznetsov, V L; Kuznetsova, L A; Rowe, D M

2003-01-01

The feasibility of improving the conversion efficiency of a thermoelectric converter by employing interfaces between materials exhibiting Fermi gas (FG) and Fermi liquid (FL) behaviour has been studied. Thermocouples consisting of a semiconductor and a strongly correlated material have been fabricated and the Peltier heat measured over the temperature range 15 deg 330 K. A number of materials possessing different types of strong electron correlation have been synthesized including the heavy fermion compound YbAl 3 , manganite La 0.7 Ca 0.3 MnO 3 and high-T c superconductor YBa 2 Cu 3 O 7δ . n- and p-Bi 2 Te 3 -based solid solutions as well as n-Bi 0.85 Sb 0.15 solid solution have also been synthesized and used as materials exhibiting FG properties. Experimental measurements of the Peltier heat were compared to the results of calculations based on preliminary measured thermoelectric properties of materials and electrical contact resistance at the interfaces. The potential of employing FG/FL interfaces in thermoelectric energy conversion is discussed

Inconsistent-handed advantage in episodic memory extends to paragraph-level materials.

Science.gov (United States)

Prichard, Eric C; Christman, Stephen D

2017-09-01

Past research using handedness as a proxy for functional access to the right hemisphere demonstrates that individuals who are mixed/inconsistently handed outperform strong/consistently handed individuals when performing episodic recall tasks. However, research has generally been restricted to stimuli presented in a list format. In the present paper, we present two studies in which participants were presented with paragraph-level material and then asked to recall material from the passages. The first study was based on a classic study looking at retroactive interference with prose materials. The second was modelled on a classic experiment looking at perspective taking and the content of memory. In both studies, the classic effects were replicated and the general finding that mixed/inconsistent-handers outperform strong/consistent-handers was replicated. This suggests that considering degree of handedness may be an empirically useful means of reducing error variance in paradigms looking at memory for prose level material.

Molecular Understanding and Structural-Based Design of Polyacrylamides and Polyacrylates as Antifouling Materials.

Science.gov (United States)

Chen, Hong; Zhao, Chao; Zhang, Mingzhen; Chen, Qiang; Ma, Jie; Zheng, Jie

2016-04-12

Design and synthesis of highly bioinert and biocompatible antifouling materials are crucial for a broad range of biomedical and engineering applications. Among antifouling materials, polyacrylamides and polyacrylates have proved so promising because of cheap raw materials, ease of synthesis and applicability, and abundant functional groups. The strong surface hydration and the high surface packing density of polyacrylamides and polyacrylates are considered to be the key contributors to their antifouling property. In this article, we review our studies on the design and synthesis of a series of polyacrylamides and polyacrylates with different molecular structures. These polymers can be fabricated into different architectural forms (brushes, nanoparticles, nanogels, and hydrogels), all of which are highly resistant to the attachment of proteins, cells, and bacteria. We find that small structural changes in the polymers can lead to large enhancement in surface hydration and antifouling performance, both showing a positive correlation. This reveals a general design rule for effective antifouling materials. Furthermore, polyacrylamides and polyacrylates are readily functionalized with other bioactive compounds to achieve different new multifunctionalities.

Molecular tools for the construction of peptide-based materials.

Science.gov (United States)

Ramakers, B E I; van Hest, J C M; Löwik, D W P M

2014-04-21

Proteins and peptides are fundamental components of living systems where they play crucial roles at both functional and structural level. The versatile biological properties of these molecules make them interesting building blocks for the construction of bio-active and biocompatible materials. A variety of molecular tools can be used to fashion the peptides necessary for the assembly of these materials. In this tutorial review we shall describe five of the main techniques, namely solid phase peptide synthesis, native chemical ligation, Staudinger ligation, NCA polymerisation, and genetic engineering, that have been used to great effect for the construction of a host of peptide-based materials.

Algebra of strong and electroweak interactions

International Nuclear Information System (INIS)

Bolokhov, S.V.; Vladimirov, Yu.S.

2004-01-01

The algebraic approach to describing the electroweak and strong interactions is considered within the frames of the binary geometrophysics, based on the principles of the Fokker-Feynman direct interparticle interaction theories of the Kaluza-Klein multidimensional geometrical models and the physical structures theory. It is shown that in this approach the electroweak and strong elementary particles interaction through the intermediate vector bosons, are characterized by the subtypes of the algebraic classification of the complex 3 x 3-matrices [ru

On possibility of fabrication of monolith composite materials on niobium carbide base

International Nuclear Information System (INIS)

Ploshkin, V.V.; Ul'yanina, I.Yu.; Filonenko, V.P.

1984-01-01

An attempt was made to fabricate the composite material on niobium carbide base possessing the elevated heat resistance, erosion and chemical resistance in special media, as well as capable of withstanding sufficient thermal shocks. Powder of niobium carbide of 10 μm fraction was used as base material, the powder of pure copper of 10...12 μm fraction - as binder. It was shown that samples of composite mateiral on niobium carbide base fabricated by the method of hydrostatic pressing possessed the minimal porosity as compared to samples fabricated by usual methods of powder metallurgy. The basic phases of composite material-copper and niobium carbide - distribute uniformly over sample cross-section and don't interact with each other under any conditions. The fabricated composite material possesses sufficient thermal shock resistance and isn't subjected to brittle fracture

Ontology based heterogeneous materials database integration and semantic query

Science.gov (United States)

Zhao, Shuai; Qian, Quan

2017-10-01

Materials digital data, high throughput experiments and high throughput computations are regarded as three key pillars of materials genome initiatives. With the fast growth of materials data, the integration and sharing of data is very urgent, that has gradually become a hot topic of materials informatics. Due to the lack of semantic description, it is difficult to integrate data deeply in semantic level when adopting the conventional heterogeneous database integration approaches such as federal database or data warehouse. In this paper, a semantic integration method is proposed to create the semantic ontology by extracting the database schema semi-automatically. Other heterogeneous databases are integrated to the ontology by means of relational algebra and the rooted graph. Based on integrated ontology, semantic query can be done using SPARQL. During the experiments, two world famous First Principle Computational databases, OQMD and Materials Project are used as the integration targets, which show the availability and effectiveness of our method.

Base isolation for nuclear power and nuclear material facilities

International Nuclear Information System (INIS)

Eidinger, J.M.; Kircher, C.A.; Vaidya, N.; Constantinou, M.; Kelly, J.M.; Seidensticker, R.; Tajirian, F.F.; Ovadia, D.

1989-01-01

This report serves to document the status of the practice for the use of base isolation systems in the design and construction of nuclear power and nuclear material facilities. The report first describes past and current (1989) applications of base isolation in nuclear facilities. The report then provides a brief discussion of non-nuclear applications. Finally, the report summarizes the status of known base-isolation codes and standards

A material based approach to creating wear resistant surfaces for hot forging

Science.gov (United States)

Babu, Sailesh

Tools and dies used in metal forming are characterized by extremely high temperatures at the interface, high local pressures and large metal to metal sliding. These harsh conditions result in accelerated wear of tooling. Lubrication of tools, done to improve metal flow drastically quenches the surface layers of the tools and compounds the tool failure problem. This phenomenon becomes a serious issue when parts forged at complex and are expected to meet tight tolerances. Unpredictable and hence uncontrolled wear and degradation of tooling result in poor part quality and premature tool failure that result in high scrap, shop downtime, poor efficiency and high cost. The objective of this dissertation is to develop a computer-based methodology for analyzing the requirements hot forging tooling to resist wear and plastic deformation and wear and predicting life cycle of forge tooling. Development of such is a system is complicated by the fact that wear and degradation of tooling is influenced by not only the die material used but also numerous process controls like lubricant, dilution ratio, forging temperature, equipment used, tool geometries among others. Phenomenological models available u1 the literature give us a good thumb rule to selecting materials but do not provide a way to evaluate pits performance in field. Once a material is chosen, there are no proven approaches to create surfaces out of these materials. Coating approaches like PVD and CVD cannot generate thick coatings necessary to withstand the conditions under hot forging. Welding cannot generate complex surfaces without several secondary operations like heat treating and machining. If careful procedures are not followed, welds crack and seldom survive forging loads. There is a strong need for an approach to selectively, reliably and precisely deposit material of choice reliably on an existing surface which exhibit not only good tribological properties but also good adhesion to the substrate

Verifiable Distribution of Material Goods Based on Cryptology

Directory of Open Access Journals (Sweden)

Radomír Palovský

2015-12-01

Full Text Available Counterfeiting of material goods is a general problem. In this paper an architecture for verifiable distribution of material goods is presented. This distribution is based on printing such a QR code on goods, which would contain digitally signed serial number of the product, and validity of this digital signature could be verifiable by a customer. Extension consisting of adding digital signatures to revenue stamps used for state-controlled goods is also presented. Discussion on possibilities in making copies leads to conclusion that cryptographic security needs to be completed by technical difficulties of copying.

Development of multimedia learning based inquiry on vibration and wave material

Science.gov (United States)

Madeali, H.; Prahani, B. K.

2018-03-01

This study aims to develop multimedia learning based inquiry that is interesting, easy to understand by students and streamline the time of teachers in bringing the teaching materials as well as feasible to be used in learning the physics subject matter of vibration and wave. This research is a Research and Development research with reference to ADDIE model that is Analysis, Design, Development, Implementation, and Evaluation. Multimedia based learning inquiry is packaged in hypertext form using Adobe Flash CS6 Software. The inquiry aspect is constructed by showing the animation of the concepts that the student wants to achieve and then followed by questions that will ask the students what is observable. Multimedia learning based inquiry is then validated by 2 learning experts, 3 material experts and 3 media experts and tested on 3 junior high school teachers and 23 students of state junior high school 5 of Kendari. The results of the study include: (1) Validation results by learning experts, material experts and media experts in valid categories; (2) The results of trials by teachers and students fall into the practical category. These results prove that the multimedia learning based inquiry on vibration and waves materials that have been developed feasible use in physics learning by students of junior high school class VIII.

Web-Based Learning Materials for Higher Education: The MERLOT Repository

Science.gov (United States)

Orhun, Emrah

2004-01-01

MERLOT (Multimedia Educational Resource for Learning and Online Teaching) is a web-based open resource designed primarily for faculty and students in higher education. The resources in MERLOT include over 8,000 learning materials and support materials from a wide variety of disciplines that can be integrated within the context of a larger course.…

Near-infrared exciton-polaritons in strongly coupled single-walled carbon nanotube microcavities

Science.gov (United States)

Graf, Arko; Tropf, Laura; Zakharko, Yuriy; Zaumseil, Jana; Gather, Malte C.

2016-10-01

Exciton-polaritons form upon strong coupling between electronic excitations of a material and photonic states of a surrounding microcavity. In organic semiconductors the special nature of excited states leads to particularly strong coupling and facilitates condensation of exciton-polaritons at room temperature, which may lead to electrically pumped organic polariton lasers. However, charge carrier mobility and photo-stability in currently used materials is limited and exciton-polariton emission so far has been restricted to visible wavelengths. Here, we demonstrate strong light-matter coupling in the near infrared using single-walled carbon nanotubes (SWCNTs) in a polymer matrix and a planar metal-clad cavity. By exploiting the exceptional oscillator strength and sharp excitonic transition of (6,5) SWCNTs, we achieve large Rabi splitting (>110 meV), efficient polariton relaxation and narrow band emission (<15 meV). Given their high charge carrier mobility and excellent photostability, SWCNTs represent a promising new avenue towards practical exciton-polariton devices operating at telecommunication wavelengths.

Thermal energy storage based on cementitious materials: A review

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Khadim Ndiaye

2018-01-01

Full Text Available Renewable energy storage is now essential to enhance the energy performance of buildings and to reduce their environmental impact. Many heat storage materials can be used in the building sector in order to avoid the phase shift between solar radiation and thermal energy demand. However, the use of storage material in the building sector is hampered by problems of investment cost, space requirements, mechanical performance, material stability, and high storage temperature. Cementitious material is increasingly being used as a heat storage material thanks to its low price, mechanical performance and low storage temperature (generally lower than 100 °C. In addition, cementitious materials for heat storage have the prominent advantage of being easy to incorporate into the building landscape as self-supporting structures or even supporting structures (walls, floor, etc.. Concrete solutions for thermal energy storage are usually based on sensible heat transfer and thermal inertia. Phase Change Materials (PCM incorporated in concrete wall have been widely investigated in the aim of improving building energy performance. Cementitious material with high ettringite content stores heat by a combination of physical (adsorption and chemical (chemical reaction processes usable in both the short (daily, weekly and long (seasonal term. Ettringite materials have the advantage of high energy storage density at low temperature (around 60 °C. The encouraging experimental results in the literature on heat storage using cementitious materials suggest that they could be attractive in a number of applications. This paper summarizes the investigation and analysis of the available thermal energy storage systems using cementitious materials for use in various applications.

A strategy for the preparation of thioantimonates based on the concept of weak acids and corresponding strong bases.

Science.gov (United States)

Anderer, Carolin; Delwa de Alarcón, Natalie; Näther, Christian; Bensch, Wolfgang

2014-12-15

By following a new synthetic approach, which is based on the in situ formation of a basic medium by the reaction between the strong base Sb(V)S4 (3-) and the weak acid H2 O, it was possible to prepare three layered thioantimonate(III) compounds of composition [TM(2,2'-bipyridine)3 ][Sb6 S10 ] (TM=Ni, Fe) and [Ni(4,4'-dimethyl-2,2'-bipyridine)3 ][Sb6 S10 ] under hydrothermal conditions featuring two different thioantimonate(III) network topologies. The antimony source, Na3 SbS4 ⋅ 9 H2 O, undergoes several decomposition reactions and produces the Sb(III) S3 species, which condenses to generate the layered anion. The application of transition-metal complexes avoids crystallization of dense phases. The reactions are very fast compared to conventional hydrothermal/solvothermal syntheses and are much less sensitive to changes of the reaction parameters. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spirobifluorene Core-Based Novel Hole Transporting Materials for Red Phosphorescence OLEDs

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Ramanaskanda Braveenth

2017-03-01

Full Text Available Two new hole transporting materials, named HTM 1A and HTM 1B, were designed and synthesized in significant yields using the well-known Buchwald Hartwig and Suzuki cross- coupling reactions. Both materials showed higher decomposition temperatures (over 450 °C at 5% weight reduction and HTM 1B exhibited a higher glass transition temperature of 180 °C. Red phosphorescence-based OLED devices were fabricated to analyze the device performances compared to Spiro-NPB and NPB as reference hole transporting materials. Devices consist of hole transporting material as HTM 1B showed better maximum current and power efficiencies of 16.16 cd/A and 11.17 lm/W, at the same time it revealed an improved external quantum efficiency of 13.64%. This efficiency is considerably higher than that of Spiro-NPB and NPB-based reference devices.

Density as a factor limiting the workability of P/M materials