bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Science and Technology the Basis of the Hydrogen Economy
Authors: Ovshinsky Stanford R. 
Published: April 2011

ABSTRACTHydrogen is called the “ultimate fuel.” It is also the ultimate element. It was born in the Big Bang and almost all of known matter is composed of it. Its condensation into a star, our sun, through fusion, provides us the energy and the photons which power our earth and which we can utilize in the form of photovoltaics to break apart water and generate hydrogen as an energy source on earth.The hydrogen economy is here. It has been initiated by the electric and hybrid vehicles which depend upon it for their operation through nickel metal hydride batteries and hydrogen as a fuel for the internal combustion engine and by outwitting the Carnot cycle for use as a fuel cell.I will discuss the complete system needed for the hydrogen economy from generation to storage to infrastructure and use. Any one part of this loop is necessary but not sufficient.Our global economy is based upon energy and the societal needs for a nonpolluting, non-climate change fuel which does not require strategic military defense as does oil. The transition from fossil fuels to hydrogen is of revolutionary import not only for its societal impact but also for the new materials science that it absolutely requires in all of its aspects. New science and new technologies build much needed new industries, which provide not only jobs but also feedback on our educational system.Recall that the ages of civilization are known by their materials. Truly, the presentage will be known by the materials that make up the twin pillars of our global economy – energy and information. Therefore, I will address the new science, technology and atomic engineering of the materials so necessary to make positive, realistic and productive this revolutionary transition of energy from its fossil fuel beginnings to the present.
Recent Advances in Solid Hydrogen Storage Systems
Authors: Chao B.S. , Young R.C. , Myasnikov V. , Li Y. , Huang B. , Gingl F. , Ferro P.D. , Sobolev V. , Ovshinsky S.R. 
Published: April 2011

ABSTRACTHydrogen energy offers great promise as an energy alternative. Hydrogen technologies can reduce and eliminate the release of carbon dioxide from fossil-fuel combustion, the main cause of global warming. One of the main challenges is hydrogen storage. Storing hydrogen in the solid-state hydride form holds a volumetric advantage over compressed and liquid hydrogen states. Solid hydrogen storage systems also have features of low-pressure operation, compactness, safety, tailorable delivery pressure, excellent absorption /desorption kinetics, modular design for easy scalability, and long cycle life.In this paper, solid hydrogen storage systems (such as portable power canisters, lightweight fiber wrapped vessels, and aluminum tubular vessels, developed by Texaco Ovonic Hydrogen Systems LLC) will be discussed. A system of four canisters each storing approximately 80 grams of reversible hydrogen is shown to run a 1 kW PEM fuel cell for more than 247 minutes at full power. Canisters show no plastic deformation after more than 500 charge/discharge cycles. The measured strain on canister surfaces indicates that DOT stress limits are not exceeded. The canisters are in the early commercialization stage for uninterrupted power supply (UPS) and auxiliary power unit (APU) applications.A lightweight fiber-wrapped vessel engineered with metal hydride and internal heat exchanger is being developed for onboard applications. At the system level, the vessel has a volumetric energy density of 50 grams of hydrogen per liter and a gravimetric density of 1.6 wt.%. The vessel is capable of storing 3 kg of hydrogen with a fast refueling capability. Ninety percent of the storable hydrogen can be refueled in 10 minutes at 1500 psig. The vessel can easily release the hydrogen at a rate of 350 slpm at 70°C.Aluminum tubular vessels are being designed and tested for bulk storage and infrastructure applications including stationary power, hydrogen shipment and hydrogen service stations. The tubular vessel dimensions may be designed for specific applications. For example, a tubular vessel 6 inches in diameter and 62 inches in length can store up to 1 kg of hydrogen.
Properties of the Magnetic Hydride YFe2H4 from First Principles Calculations
Authors: Singh D.J. , Gupta M. 
Published: April 2011

ABSTRACTYFe2H4 is a ferromagnetic metal with magnetization higher than the Laves phase parent compound, YFe2. Here, the electronic and magnetic properties of YFe2H4 are studied using density functional calculations, in order to elucidate the reasons for this. The electronic structure of YFe2H4 differs from that of YFe2 both because of the lattice expansion upon hydriding and because of chemical interactions involving H. However, the main reason for the increased magnetization is found to be the lattice expansion.
Hydrogen absorption of C14 Laves NiTiZr-NiVNb pseudo-binary alloys
Authors: Ishikawa Kazuhiro , Noda Shintaro , Suzuki Kiyonori , Aoki Kiyoshi 
Published: April 2011

ABSTRACTHydrogen absorption and desorption properties of C14 Laves NiTiZr-NiVNb and NiTiZr-NiVZr pseudo-binary alloys were investigated by using the Sieverts' apparatus, XRD and the hydrogen analyzer. The hydrogen capacity and the 50% hydrogen desorption temperature, Td, of the C14 Laves NiTiZr alloy is 1.5 (H/M) and 850 K, respectively. On the other hand, the hydrogen capacity of the C14 NiVNb alloy is 0.2 H/M. In the Ni(TiZr)1−x(VNb)x pseudo-binary system, the hydrogen capacity of the alloys is decreased with increasing x, but the 50% hydrogen desorption temperature is almost constant. The substitution of VNb reduces the hydrogen absorption capacity of the C14 Laves NiTiZr alloy. The hydrogen desorption temperature of Ni(Ti1−xVx)Zr alloy is reduced to 580 K without serious decrease of the hydrogen capacity with increasing x.
Changing Np Redox Speciation in the Synchrotron Beam
Authors: Skanthakumar S. , Gorman-Lewis D. , Locock A. , Chiang M.-H. , Jensen M. P. , Burns P. C. , Fein J. , Jonah C. D. , Attenkofer K. , Soderholm L. 
Published: April 2011

ABSTRACTX-ray absorption data, obtained from Np(V) in two environmentally-related samples, show evidence of significant metal-ion reduction in the synchrotron beam. The data are presented and possible sources of reduction are discussed.
In SituActinide X-ray Absorption Spectroelectrochemistry
Authors: Antonio Mark R. , Chiang Ming-Hsi , Williams Clayton W. , Soderholm L. 
Published: April 2011

ABSTRACTBy using electrochemical techniques in simultaneous combination with EXAFS, we can stabilize a targeted charge state of a solution complex and probe the coordination of selected actinide (An) ions. In addition, we can acquire sufficient XANES over a range of controlled electrochemical potentials, in the vicinity of a redox couple, to perform a Nernst analysis. The prospect of this technique to provide here-to-fore unattainable information is demonstrated through examples of Np, Pu, and Bk speciation in solution.
Role of Spin-Orbital Splitting of 5f-Orbitals of Uranium Atom in the Formation of Its Chemical State
Authors: Batrakov Yuri F. , Krivitsky Andrey G. , Puchkova Elena V. 
Published: April 2011

ABSTRACTChemical shifts (ChSh) of nine emission lines of the uranium L-series in uranium oxides UO2+x (x=0−1) with respect to UO2 were studied by using a precise crystal-diffraction X-ray spectrometer and the changes in energy of spin-orbital splitting (SOS) − Δδnl± of inner nl-orbitals of the uranium atom were calculated from the data of ChSh of spin-doublet lines. For UO2+x oxides, a linear decrease in Δδnl± values with increasing degree of uranium oxidation was found.On the basis of the comparison of experimental Δδnl± values with Dirac-Hartree-Fock atomic calculations, it was concluded that the observed variations in Δδnl± values are due to the redistribution of electron and spin density between the 5f7/2- and 5f5/2-levels of the fine structure of the uranium atom without changes in atomic charge state.
Electronic structure calculations of δ-Pu based alloys
Authors: Landa Alex , Söderlind Per , Ruban Andrei 
Published: April 2011

ABSTRACTFirst-principles methods are employed to study the ground-state properties of δ-Pu-based alloys. The calculations show that an alloy component larger than δ-Pu has a stabilizing effect. Detailed calculations have been performed for the δ-Pu1−cAmc system. Calculated density of Pu-Am alloys agrees well with the experimental data. The paramagnetic → antiferromagnetic transition temperature (Tc) of δ-Pu100−cAmc alloys is calculated by the Monte-Carlo technique. By introducing Am into the system, one could lower Tc from 548 K (pure Pu) to 372 K (Pu70Am30). We also found that, contrary to pure Pu where this transition destabilizes δ-phase, Pu3Am compound remains stable in the antiferromagnetic phase that correlates with the recent discovery of the Curie-Weiss behavior of δ-Pu100−cAmc alloys at c ≥ 24 at. %.
Imaging polymer supported organic molecules by mass spectrometry Application in combinatorial chemistry
Authors: Enjalbal C. , Maux D. , Combarieu R. , Martinez J. , Aubagnac J-L. 
Published: April 2011

ABSTRACTIn combinatorial chemistry, most libraries are prepared according to solid-phase synthesis strategies using resins or pins. Although synthesis and purification steps are facilitated, reaction monitoring presents difficulties. Since the polymeric support is not soluble, an analytical method able to cope with a solid sample is thus required to perform direct identification of the anchored molecules without any chemical treatment. Static-Secondary Ion Mass Spectrometry (S-SIMS) was investigated in that purpose. Positive and negative ion mass spectra were acquired to identify single beads whereas mixtures (Mix and Split libraries or pooled beads issued from different batches) were profiled through imaging experiments.
High-Throughput Adhesion Evaluation and Scale-up of Combinatorial Leads of Organic Protective Coatings
Authors: Ezbiansky Karin , Medford George , Reitz Hariklia , Potyrailo Radislav A. , Chisholm Bret J. , Morris William G. , Cawse James N. , Flanagan William P. , Hassib Lamyaa , Molaison Chris A. 
Published: April 2011

ABSTRACTCoupling of combinatorial chemistry methods with high-throughput (HT) performance testing and measurements of resulting properties has provided a powerful set of tools for the 10-fold accelerated discovery of new high-performance coating materials for automotive applications. This approach replaces labor-intensive steps with automated systems for evaluation of adhesion of 8 × 6 arrays of coating elements that are discretely deposited on a single 9 × 12 cm plastic substrate. Performance of coatings is evaluated with respect to their resistance to adhesion loss. This parameter is one primary consideration in end-use automotive applications. Coating leads identified from the HT screening have been validated on the traditional scale. Details of these validation studies are discussed.
Management of Combinatorially Acquired Multi-dimensional Data through Object-Oriented Virtual Sample Library
Authors: Todoroki Shin-ichi , Inoue Satoru 
Published: April 2011

ABSTRACTCombinatorial methods bring about plentiful data not only in size but also in dimension. To handle multi-dimensional data easily, a virtual container of combinatorially acquired data is developed which is called “virtual sample libraries” (VSL). VSL stores the data hierarchically in the order of (1) coordinates in the sample library, (2) names of the measurements performed, and (3) data obtained from each measurement. Thus, the loads for analysis and visualization of multi-dimensional data are reduced because the stored data can be accessed intuitively, that is, just by tracing the hierarchy structure. This framework is easily constructed by the aid of object-oriented script language which is good at describing complicated data structure. Visualization of combinatorially acquired 7-dimensional data is demonstrated.
Sensors for High-Throughput Materials Characterization: 24-channel Array of Quartz Crystal Microbalances
Authors: Morris William G. , Potyrailo Radislav A. 
Published: April 2011

ABSTRACTWe have developed a multichannel materials characterization system based on thickness-shear mode (TSM) sensors, also known as quartz crystal microbalances (QCMs). The sensors are arranged as a 6 × 4 array that is compatible with available 24-well plates that can be manipulated with standard robotic equipment. Our sensor system can measure frequencies from 5 MHz to 20 MHz with a noise level of less than 0.1 Hz for a 1 sec acquisition interval. The sensors can be placed in a gas-flow-though cell for studies of vapor-sorption properties, or they can be immersed into a 24-well plate array for studies of materials solubility. The sensor array is connected to the measurement electronics through a multi-conductor cable, enabling the sensors to be operated in a temperature, pressure, or chemical environment, which would otherwise adversely affect the electronic stability. The 24-channel array has been applied to the screening of sensor materials for determination of chlorinated organic solvents at part per billion levels in groundwater wells. The primary screen is the discovery screen where materials are exposed to a single analyte concentration. The secondary screen is the focused evaluation where the best subset of these materials is exposed to analytes and interferences. The tertiary screen involves evaluation of material performance under conditions mimicking the long-term application. Six families of potential sensor materials were examined with rapid downselection by using this approach.
Automatic Reaction Modeling in Chemical Vapor Depositions Using Multiple Process Simulators
Authors: Takahashi Takahiro , Funatsu Kimito , Ema Yoshinori 
Published: April 2011

ABSTRACTThe identification of appropriate reaction models is very helpful for developing chemical vapor deposition (CVD) processes. In this paper we propose a novel system to analyze experimental data of various CVD reactors and identify reaction models automatically using Genetic Algorithms (GA) with multiple process simulators and modeled functions. We demonstrate that this system is able to adequately model reaction systems, and that complex analysis of various experimental data increased the reliability of the reaction modeling results.
Microstructure design in the ternary systems with the only solubility gap
Authors: Lutsyk Vasily I. , Zyryanov Alexandr M. 
Published: April 2011

ABSTRACTNew algorithms to design the microstructures in a ternary system with the solubility gap in one binary system have elaborated. They permit to visualize, to sect and to project a sophisticated surface with a trough.
Combinatorial Materials Design through Database Science
Authors: Suh Changwon , Rajagopalan Arun , Li Xiang , Rajan Krishna 
Published: April 2011

ABSTRACTLarge scale materials databases have been traditionally used for search and retrieval of experimental and theoretical data. In this paper, three different cases are used to illustrate applications of statistical techniques in databases that extend beyond searching. A complete large scale database of molten salts is visualized for pattern seeking. In the second case, a large virtual combinatorial library of chalcopyrite semiconductors is developed from a small experimental and theoretical dataset. This involves selecting statistically appropriate parameters based on the physics of the materials. In the third case, ‘secondary’ descriptors are developed for a zeolites database to better understand the topology of mesoporous structures and as a materials design tool. These examples serve to demonstrate how databases can be used to identify important combinations of parameters relevant to combinatorial experimentation.
The Evolution of Short-Range Order in Ti-Hf-Ni Alloys with Hydrogenation
Authors: Sadoc Anne , Huett Van T. , Kelton K. F. 
Published: April 2011

ABSTRACTThe evolution of the short-range order in a Ti-Hf-Ni 3/2 approximant phase, has been studied as a function of hydrogenation by means of extended X-ray absorption fine structure (EXAFS). The local structure of the non-hydrogenated alloy has been derived from that of 1/1 Ti-Zr-Ni. After hydrogenation, drastic changes are observed in the local structure of Ti-Hf-Ni. Preliminary results of the EXAFS analysis are also presented for an amorphous Ti-Hf-Ni alloy.
Atomic structure, Electronic States, and Stability of Icosahedral Quasicrystals
Authors: Zijlstra Eeuwe S. , Bose Shyamal K. 
Published: April 2011

ABSTRACTSeveral existing models of icosahedral quasicrystals (QCs) are improved upon and studied by ab initio electronic structure methods. The following approach is used to optimize the models: 1) interchange of atoms in the existing (skeletal) models based on available knowledge of the local atomic environments, and 2) subsequent relaxation of the atomic positions using forces determined via first principles density functional methods. After minimizing the total energy, we investigate the ground state, and compare calculated results with available photo-emission spectroscopy (PES) and Mössbauer spectroscopy data. Significant improvement with respect to the starting (skeletal) model is achieved in several cases. We also examine the validity of the concept of negative valences of the transition metal atoms in QCs as advanced by Friedel.
Aging of the surface of an Al-Cr-Fe approximant phase in ambient conditions: chemical composition and physical properties
Authors: Veys D. , Weisbecker P. , Fournée V. , Domenichini B. , Weber S. , Rapin C. , Dubois J. M. 
Published: April 2011

ABSTRACTWe have investigated the surface properties of quasicrystalline and approximant phases in the Al-(Cu)-Cr-Fe system upon aging in ambient conditions. We found that some of these properties (like the electrochemical behavior, wetting or friction) slowly evolves with the length of exposure to normal atmospheric conditions, reaching a stable state only after several days. This report essentially focuses on one of these alloys, an Al65Cr27Fe8 approximant phase with g-brass structure. In a first part, we describe the effect of aging on the electrochemical behavior of this alloy and we propose an interpretation based on a simple electrical model of the oxidized surface. In a second part, we present a model describing the surface as a stacking of several layers (oxides, oxy-hydroxides, contamination) whose thickness evolves with time. The model is supported by X-ray reflectivity, angle-resolved photoemission spectroscopy and secondary neutral mass spectroscopy measurements.
Early stages of Al-nanocrystal formation in Al92Sm8
Authors: Wilde G. , Rösner H. , Boucharat N. , Hamann J. , Tong W. S. , Perepezko J. H. 
Published: April 2011

ABSTRACTSeveral proposals involving solute effects, phase separation or quenched-in nuclei and heterogeneous nucleation have been advanced to account for the high nanocrystal density that evolves during primary crystallization in marginal glass-forming alloys, but recent crystallization measurements and kinetics analyses provide new evidence for the role of the as-quenched structure on nanocrystal synthesis. Here, isothermal microcalorimetry investigations and quantitative electron microscopy measurements including high-resolution imaging and electron spectroscopy analyses were performed on a model system at different temperatures well below the glass transition to monitor the nanocrystallization isothermally as a function of time. From the combined measurements, the size distribution and the transformed fraction can be determined with a high accuracy for extended ranges of temperatures and times. In addition, calorimetric measurements in the glassy, liquid and crystalline states of the model alloy serves to analyze, for the first time, the fragility characteristics of a marginal glass-former that presents an important parameter in the context of the kinetic stability of the material against premature crystallization.
Formation of High-Strength Zr-Nb-Cu-Ni-Al Alloys by Warm Extrusion of Gas Atomized Powders
Authors: Rozhkova E. A. , Yang X. Y. , Wheelock P. B. , Eckert J. , Kühn U. , Sordelet D. J. 
Published: April 2011

ABSTRACTRecently developed Zr-based metallic glass composites containing a ductile phase demonstrate improved mechanical properties such as high strength combined with good ductility compared to the glass monoliths. Zr-Nb-Cu-Ni-Al amorphous powders with bcc phase precipitates were obtained by high pressure gas atomization. Formation of the bcc phase in the amorphous matrix strongly depends on the material composition and cooling rates during solidification. Melt spinning using various wheel speeds selected to simulate the cooling rates during gas atomization was used to define a specific composition for gas atomization. Gas atomized powders were consolidated by warm extrusion. Various processing conditions including starting powder particle size, extrusion temperature and extrusion ratio were examined to obtain materials having various microstructural features. Structure and thermal stability of consolidated bulk metallic glass composites as well as selected mechanical properties will be discussed.
TEM and XAS Characterization of Hard Magnetic Phase in Nd-Fe Alloys
Authors: Kumar G. , Eckert J. , Löser W. , Schilling P. , Ma E. , Mickel C. , Schultz L. 
Published: April 2011

ABSTRACTNd80Fe20 alloys were prepared by copper mold casting and directional solidification (DS) to obtain a coarse microstructure, which can be identified unambigously. The mold-cast samples exhibit a fine globular eutectic structure and show high room temperature coercivity (∼ 5 kOe). Transmission electron microscopic (TEM) investigations reveal the presence of fcc (a = 5.32 Å) Nd-rich and nanocrystalline non-cubic Fe-rich phases. The directionally solidified (DS) samples exhibit large grains (composition close to NdFe2). The NdFe2 grains (formed in the DS samples) show clear magnetic domains with uniaxial anisotropy indicating that the NdFe2-type phase observed in the present samples is not a cubic phase. X-ray absorption spectroscopy (XAS) was used to analyze the local configuration around Fe atoms in the mold-cast samples. The XAS patterns do not match with the bcc and fcc standards, which supports the presence of NdFe2 phase with uniaxial symmetry in the DS samples.
Ab-initio Study of the Diffusion Coefficients in Fe-based Liquids
Authors: Fuentes-Cabrera Miguel , Nicholson Don , Widom Mike , Wang Yang , Mihalkovic Marek 
Published: April 2011

ABSTRACTWith atomistic force fields derived from ab-initio energies and atomic forces, we cooled Fe80B20from the liquid to the glass state. The pair-distribution functions and the diffusion coefficients were used to characterize the structural changes that Fe80B20underwent during the simulation. In the FeFe and FeB pair-distribution functions, when the temperature is lowered the first neighbor-peak becomes narrower and the second-neighbor peak splits at around 1000K. In the BB pair-distribution we observed that the first peak undergoes a significant change at the glass transition temperature, and that the first BB peak remains present at low temperatures. That the first BB peak exists at low temperature seems to contradict the prevailing view of the structure of transition metal-metalloid glasses.