Wastenet

... Cameron; Lowell A. Miller; Miller, Lowell A. CSIRO PUBLISHING - Wildlife Research Books Journals Multimedia About Us Shopping Cart You are here: Journals Wildlife Research Ecology, Management and Conservation in Natural and Modified Habitats Search ... Cameron and Lowell A. Miller Abstract Context. Contraception is increasingly used as a management technique to reduce fertility in wildlife populations; however, the feasibility of contraceptive formulations has been limited until recently because they have required multiple treatments to achieve prolonged infertility. ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of Formula Not Shown compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.

UK PubMed Central (United Kingdom)

It has been sixty years since the Millers first described the covalent binding of carcinogens to tissue proteins. Protein covalent binding was gradually overshadowed by the emergence of DNA...Full Text Available

Science.gov (United States)

... Although cytologic evaluation of urine specimens is a standard Cesar Angeletti, MD ... 3. Rodriguez-Alonso A, Pita-Fernandez S, Gonzalez-Carrero J, ...

Science.gov (United States)

Rich Baldwin. Phone : 301-286-3031. Email : Building/Office : 22/163. Mailing Address : NASA/GSFC, Code 921, Greenbelt, MD 20771 ...

UK PubMed Central (United Kingdom)

Here we describe the fabrication, optimization, and application of a microfluidic device that integrates microdialysis (MD) sampling, microchip electrophoresis (ME), and electrochemical detection...Full Text Available

Science.gov (United States)

Composite Sandwich Panels," Proceedings of the American Helicopter Society 60th Annual. Forum, Baltimore, MD, June 7-10, 2004. [7]. Soutis, C., and Fleck, ...

International Nuclear Information System (INIS)

We studied age-related microstructural changes in the subcortical white matter from adolescence to middle age in 16 healthy male subjects (age range: 12 to 47 years) using diffusion-weighted magnetic resonance (MR) imaging (DWI). Mean diffusivity (MD) of subcortical white matter was mapped onto the overlying cortical surface using our original method. The mean MD values within 76 cortical regions were measured using atlas-based gray matter segmentation and then correlated with age. A significant negative correlation with age was observed in subcortical MD values in several cortical regions, primarily over the bilateral temporal and occipital lobes. Our results demonstrated subcortical microstructural change in postadolescence that may reflect continuing myelination. (author)

Science.gov (United States)

Dolores Beasley Headquarters, Washington, DC July 19, 2000 (Phone: 202/358- 1753) Bill Steigerwald Goddard Space Flight Center, Greenbelt, MD (Phone: ...

Medline Plus

... Hospital & University Hospital Basel) If I Had - Pre-diabetes - Dr. Venkat Narayan, MD, MSc, MBA, Rollins School ... School, Massachusetts General Hospital, Discusses the Treatment of Diabetes Back to Home Page If I Had - A ...

Science.gov (United States)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...

International Nuclear Information System (INIS)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...

International Nuclear Information System (INIS)

Full text: The focused ion beam (FIB) miller is becoming well established as a machine for the structural analysis of materials and for the rapid preparation of transmission electron microscope specimens. It has also been used for some time in the semiconducting materials industry for the analysis, repair and redesign of device materials. However, one emerging technique is the use of the FIB for micromachining. The FIB software can also be used to manufacture and machine components. This process can occur through converting software, typically in the form of bitmaps or TIF files, to proprietary 'stream' files. These files allow, often complex, patterns to be generated and milled into the specimen and thus the generation of micro-electromechanical systems. Frequently, this involves largely two-dimensional patterns and structures, however, more complex patterns and file types can be generated which allow, for example, device prototyping or the preparation of ...

Energy Technology Data Exchange (ETDEWEB)

Continental facies of Scythian-early Anisian age (Buntsandstein) of East of the Paris Basin form the underground gas storage reservoir exploited by Gaz de France in the area of Nancy (east of France). An accurate sedimentological study and the application of Genetic Stratigraphy principles lead to the understanding of the deposition of fluvial, which form the reservoirs, and to the reconstruction of their geometries. The subsurface data are calibrated on outcrops. Three types of fluvial systems (braided, sinuous to straight and anastomosed) are defined. A special focus on anastomosed channels permits to differentiate a proximal and a distal facies. Study of laterally continuous outcrops induces recurrent cycles of thickness, velocity and time variations (few tens to hundred ka). These correspond to the highest frequence stratigraphic units, i.e. parasequences or genetic units. Maximum of channel and levee presentation occurs during base-level rise: base-level fall ...

Energy Technology Data Exchange (ETDEWEB)

The Fredericksberg of South Florida may have a great oil potential that has been overlooked as a primary target in past decades. Previous exploration in the area has targeted the Lower Cretaceous oil-producing Sunniland Formation lower in the stratigraphic section. The Fredericksberg Dollar Bay Formation has hydrocarbon shows in many wells occurring in limestone biohermal deposits as well as in an upper dolomitic section. The Dollar Bay Formation is part of the Big Cypress Group of the Comanchean Series of the Lower Cretaceous. The Lower Cretaceous lithology is composed of evaporitic-carbonate cycles consisting of anhydrites, dolomites, and limestones. There are also present some calcareous shales, mudstones, salt, lignitic material, and carbonaceous material, especially in the anhydrite and limestone intervals. The limestones are usually micritic, chalky, calcarenitic, sometimes argillaceous, containing skeletal particles of gastropods, pelecypods, ostracods, algae, and forams ...

British Library Electronic Table of Contents (United Kingdom)

I. S. Kirbis, P. Maxwell, M. S. Flear, K. Miller and M. Ibrahim External quality control for immunocytochemistry on cytology samples: a review of UK NEQAS ICC (cytology module) results Objective:- To date, external quality control for immunocytochemistry on cytology samples is provided only by the United Kingdom national external quality assessment service for immunocytochemistry and in situ hybridisation (UK NEQAS ICC & ISH). For the purpose of this study a retrospective analysis of a comprehensive collection of quality-related data regarding immunocytochemistry on cytology samples collected through this service was analysed. Methods:- The quality of immunocytochemical reactions, using on-line collected data, was analysed for the last 23 UK NEQAS ICC cytology module external quality asses...

Energy Technology Data Exchange (ETDEWEB)

Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The current data reveal an orientation dependence of the transition ...

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid ...

Energy Technology Data Exchange (ETDEWEB)

One example of basic and applied research at LLNL that has produced major, highly visible scientific and engineering advances has been the research related to controlled fusion energy. Continuing experimentation at LLNL and elsewhere is likely to demonstrate that fusion is a viable, inexhaustible alternative source of energy. Having conducted major fusion energy experiments for over 30 years at LLNL, it scientists and engineers recognized the enormous challenges that lay ahead in this important endeavor. To be successful, it was clear that collaborative efforts with universities, private industry, and other national laboratories would need to be greatly expanded. Along with invention and scientific discovery would come the challenge of transferring the myriad of new technologies from the laboratories to the private sector for commercialization of the fusion energy process and the application of related technologies to yet unimagined new industries and products. Therefore, using fusion ...

British Library Electronic Table of Contents (United Kingdom)

Predicted by stochastic models and observed experimentally in a number of isomerization reactions, viscosity-induced solvent effects manifest themselves in a significant departure of the reaction rates from the values expected on the basis of transition state theory. These effects are well understood within the framework of stochastic models; however, the predictive power of such models is limited by the fact that their parameters are not readily available. Experiment and molecular dynamics (MD) simulations can provide such information and can serve as the testing grounds for various stochastic models. In real solvents, a change in viscosity is inevitably associated with variation of at least one of the three factors - temperature, pressure, or solvent identity, resulting in different solv...

International Nuclear Information System (INIS)

A theoretical analysis is presented for the method of determining the concentration distribution of admixtures in zone melting and in the study of diffusion in melts. Continuous mode X-ray fluorescence analysis is considered. The convolution integral interpreting the analog output of the ratemeter was solved applying the mathematical apparatus of Z transformation. The feasibility of the method is tested on an example of the determination of tin distribution in tungsten. With respect to the statistical error (#delta#<1.5%), the maximum integration constant (100 s) and a very slow sample feed (0.025 mm/s) were used. The calculated transfer function reflects the total transfer function of the ratemeter and the recorder used. (M.D.).

Energy Technology Data Exchange (ETDEWEB)

Investigation of an HP-blade damage in 1996 and an MP-blade damage in 1007 at the mounting showed that fretting and creep fatigue had caused the damage. Break-down occurred when creep-related cracks developed between radial bridge to the upper blade tooth and weight relief boreholes. After disassembly of the HP-blades the lower blade tooth was found to be cracked after fretting (some cracks along the whole length of the tooth). The lower teeth of MP-bladedes showed merely superficial cracks (depth about 0.4mm). The massive cracks of the lower blade tooth were caused by instationary clearance changes combined with hard blade underground.(orig.) [German] Das Ergebnis der Untersuchung nach einem HD-Schaufelschaden 1996 sowie einem MD-Schaufelschaden 1997 an der Vierzackenfussbefestigung ergab Zeitstanderschoepfung und Fretting als auszuloesende Schadensmechanismen. Die Havarien wurden durch zeitstandbedingte Brueche zwischen Radienuebergang zum oberen Schaufelzacken ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes total phenolics content and antioxidant activity in the ethanolic extract of leaves, bark and roots of five medicinal plants: Terminalia brasiliensis Camb., Terminalia fagifolia Mart. and Zucc., Copernicia cerifera (Miller) H.E. Moore, Cenostigma macrophyllum Tul. var. acuminata Teles Freire and Qualea grandiflora Mart. The total phenolics content of the plant extracts, determined by the Folin-Ciocalteu method, varied from 250.0 {+-}8,2 to 763,63 {+-}13.03 mg of gallic acid equivalent/g dry EtOH extract. The antioxidant activity of extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay system. Extract of bark from T. brasiliensis, the most active, with an EC{sub 50} value of 27.59 {+-} 0.82 {mu}g/mL, was comparable to rutin (EC{sub 50} = 27.80 {+-} 1.38) and gallic acid (EC{sub 50} = 24.27 {+-} 0.31), used as positive controls. The relationship between total phenolic content and antioxidant activity was positive and ...

International Nuclear Information System (INIS)

A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with ...

Energy Technology Data Exchange (ETDEWEB)

In order to evaluate the effects of radioactivity on active vegetal substances, samples of Fennel (Foeniculum vulgare Miller., fructus), Guarana (Paulinia cupana, Kunth, semen), Gingko (gingko biloba, L., folium), and Kawa-Kawa (Piper methysticum G. Forst, rhizoma), were treated with scaling doses (0 to 25 KGy) of gamma radiation (Co{sup 60}). The 'blind test' methodology was used. The active substances from each sample were analysed by qualitative and quantitative methods after radiation. There were no significant differences seen between the control sample (0 KGy) and the irradiated samples. Microbe contamination was significantly reduced, about 10000 CFU/g, with the initial 5 KGy dose. It was concluded that gamma radiation can be used as an alternative procedure to reduce microbiologic contamination in medicinal plants. Before this procedure can be extended to other medicinal plants, more specific analytical methods are recommended to verify ...

Energy Technology Data Exchange (ETDEWEB)

The buckling behaviors of double-walled carbon nanotubes (DWCNTs) under torsion are investigated by using molecular dynamics (MD) simulations. The effect of length on the torsional buckling behaviors of DWCNTs is examined for the first time. The simulation results show that the DWCNTs experience gradual or simultaneous buckling deformations depending on their lengths. In addition, the effect of the inner tube in a DWCNT on its torsional buckling behavior is also examined. The presence of the inner tube triggers van der Waals (vdW) interactions between it and the outer tube and thus leads to a stiffening effect of the DWCNT against torsional deformation. Whether the ends of the inner tube are free or fixed and whether it is subject to a torque or not, the critical torque and the critical torsional angle of the outer tube are only marginally affected.

International Nuclear Information System (INIS)

The book presents a very good account of all aspects of protection from ionizing radiation. The quantities and units are given and defined used in nuclear physics and dosimetry. The effects of ionizing radiation on cells and on man are described. The principles are presented of radiation protection including limits and valid regulations and decrees. Also discussed is internal irradiation and its modelling. A great part of the book is devoted to aspects of monitoring persons, the living and working environment and to the determination of internal contamination. The system of radiation protection in Czechoslovakia is described and some practical questions are discussed of protection during radiodiagnosis and radiotherapy, in the nuclear fuel cycle, in the operation of nuclear power installations and in crack detection. In conclusion a survey is given of the population exposure from various natural and artificial sources. (M.D.). 57 figs., 34 tabs., 138 refs.

Energy Technology Data Exchange (ETDEWEB)

Protein motions on all timescales faster than molecular tumbling are encoded in the spectral density. The dissection of complex protein dynamics is typically performed using relaxation rates determined at high and ultra-high field. Here we expand this range of the spectral density to low fields through field cycling using the nucleocapsid protein of the SARS coronavirus as a model system. The field-cycling approach enables site-specific measurements of R{sub 1} at low fields with the sensitivity and resolution of a high-field magnet. These data, together with high-field relaxation and heteronuclear NOE, provide evidence for correlated rigid-body motions of the entire {beta}-hairpin, and corresponding motions of adjacent loops with a time constant of 0.8 ns (mesodynamics). MD simulations substantiate these findings and provide direct verification of the time scale and collective nature of these motions.

British Library Electronic Table of Contents (United Kingdom)

The atomic mechanism of a glass-to-liquid transition in a monatomic Lennard-Jones (LJ) glass was studied using the molecular dynamics (MD) method. Glassy models were heated up from low temperature at two different heating rates and a glass-to-liquid transition found to occur at the higher heating rate. The temperature dependence of the potential energy, mean-squared-displacements (MSD) of the atoms and the self-intermediate scattering function indicate clearly that a glass transition occurs in the system. The atomic mechanism of the glass-to-liquid transition was investigated by analyzing the spatio-temporal arrangement of liquid-like atoms in the system upon heating. Liquid-like atoms were detected using the Lindemann-melting-like criterion. Upon heating, liquid-like atoms occur at temper...

British Library Electronic Table of Contents (United Kingdom)

The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...

Science.gov (United States)

Understanding the influence of interfacial structures on the nanoarchitecture mechanical properties is of particular importance for its mechanical applications. Due to a small size of constituting nanostructural units and a consequently high volume ratio of such interfacial regions, this question becomes crucial for the overall mechanical performance. Boron nitride bamboo-like nanotubes, called hereafter boron nitride nanobamboos (BNNBs), are composed of short BN nanotubular segments with specific interfaces at the bamboo-shaped joints. In this work, the mechanical properties of such structures are investigated by using direct in situ transmission electron microscopy tensile tests and molecular dynamics simulations. The mechanical properties and deformation behaviors are correlated with the interfacial structure under atomic resolution, and a geometry strengthening effect is clearly demonstrated. Due to the interlocked joint interfacial structures and compressive interfacial stresses, ...

International Nuclear Information System (INIS)

We have measured the lattice relaxation around As in Si at a homogeneous As concentration of 4x10"1"8 cm"-"3 by EXAFS spectroscopy. From the absorption spectra, distances up to the 4th shell could be extracted. A sizeable misfit due to an increased distance is only observed for the 1st shell. Complementing our experimental work we have performed ab initio calculations based on the density functional theory with the WIEN97 package which uses the linearised augmented plane wave method and with the FHI96md program which uses first-principles pseudo-potentials and a plane wave basis set to investigate the size dependence of the super-cells constructed around one substitutional As atom. The calculations yielded good agreement with our EXAFS experiment so that the determined relaxations can be used as a solid basis for further interpretations of derived parameters such as hyperfine interaction parameters in defect complexes.

CERN Document Server

Three-flavor lattice QCD simulations and two-loop perturbation theory are used to make the most precise determination to date of the strange-, up-, and down-quark masses, $m_s$, $m_u$, and $m_d$, respectively. Perturbative matching is required in order to connect the lattice-regularized bare- quark masses to the masses as defined in the \\msbar scheme, and this is done here for the first time at next-to-next-to leading (or two-loop) order. The bare-quark masses required as input come from simulations by the MILC collaboration of a highly-efficient formalism (using so-called ``staggered'' quarks), with three flavors of light quarks in the Dirac sea; these simulations were previously analyzed in a joint study by the HPQCD and MILC collaborations, using degenerate $u$ and $d$ quarks, with masses as low as $m_s/8$, and two values of the lattice spacing, with chiral extrapolation/interpolation to the physical masses. With the new perturbation theory presented here, the ...

International Nuclear Information System (INIS)

A detailed outline of the application of the MELCOR and RELAP5/MOD3.1 codes to the analysis of the thermohydraulic response and determination of other parameters of the medium on the floor is given for several classes of secondary coolant circuit accidents along with the description of the related facilities. An overview is presented of the maximum values and time behavior of the thermohydraulic parameters, pressure, temperature, relative humidity, and water level on the floor. Transverse rupture of the steam generator, main steam header, or main feedwater header piping during normal operation is considered as the initiating event. Pressure is only 10% higher than the atmospheric pressure. Air temperature attains a value as high as 100 degC. Relative humidity is 100%, persisting as long as the steam source is available. The water level is typically about 8 cm and never exceeds 15 cm. (M.D.). 16 tabs., 37 figs., 32 refs.

International Nuclear Information System (INIS)

Special T-shaped feedwater distribution pipes were installed in steam generators at the Loviisa (Finland) and Rovno (Russia) nuclear power plants. The new shape was tested in an extensive testing programme. Since the tubes frequently suffer from corrosion damage, large-scale water hammer experiments were performed on a model facility in 1996. The main objectives of the water hammer experiments were to find out the prevailing parameters leading to water hammers, as well as the sensitivity of hammering to boundary conditions. A water hammer may occur when the mass flow rate into the steam generator exceeds 6 kg/s and the temperature difference between steam generator and feedwater exceeds 100 degC. Visual experiments and stress analyses of the pipe were also carried out. The weakest part, the T-joint, may hold against such water hammers only for a limited time of the order of few minutes. (M.D.).

CERN Document Server

Personal authentication is an important process we encounter almost every day; when we are logging on a computer, entering a company where we work, or a restricted area, when we are using our plastic credit cards to pay for a service or to complete some other financial transaction, etc. In each of these processes of personal authentication some kind of magnetic or optical token is required. But by using novel technologies like mobile computing and wireless networking, it is possible to avoid carrying multitude of ID cards or remembering a number of PIN codes. Article shows how to efficiently authenticate users via Personal Area Networks (PAN) like Bluetooth or IrDA using commonplace AES (Rijndel) or MD5 encryption. This method can be implemented on many types of mobile devices like Pocket PC PDA with Windows CE (Windows Mobile 2003) real-time operating system, or any other customized OS, so we will explain all components and key features of such basic system.

Energy Technology Data Exchange (ETDEWEB)

Increased nitrogen levels have been correlated with decreased ductility and elevated ductile-to-brittle transition temperature in pressure vessel steels [1]. However, the exact role played by nitrogen in the embrittlement of steels remains unclear. Miller and Burke have reported atom probe ion microscopy findings from neutron-irradiated low-alloy pressure vessel steel showing the presence of a 1 to 2 ruonolayer thick film of Mo, N, and C at prior austenitic grain boundaries (GB's) [2], suggesting a role for nitrogen as an intergranular embrittler. It is of interest for the development of mitigation strategies whether nitrogen must combine with other impurities to form nitride precipitates in order to exert an embrittling effect. Briant et al [1] have associated the embrittling effect of N in steels exclusively with intergranular nitride formation. This association suggests that high nitrogen levels may be acceptable if nitride precipitation at grain ...

Energy Technology Data Exchange (ETDEWEB)

To achieve sufficient thermodynamic efficiency, space nuclear power systems must operate above 1000/sup 0/C. A quantitative evaluation of the existing mechanical properties data for the refractory alloys relevant to space nuclear power systems design lifetimes up to seven years at temperatures up to 1400/sup 0/C is being conducted. The most important properties for space nuclear power systems are long-term high-temperature (>1000/sup 0/C) creep strength and ductility, low-temperature (<400/sup 0/C) fracture toughness (including ductile-to-brittle transition temperature, (DBTT)), and ductility at high strain rates; of special concern are the above properties for weldments of refractory alloys, composition, applied stress, test temperature, test environment (e.g., vacuum, lithium), and thermomechanical treatment (TMT) history. Currently being evaluated are, in order of ascending mp, selected alloys of niobium (e.g., Nb-1% Zr, Nb-1% Zr-0.1% C), molybdenum (e.g., Mo-13% Re), tantalum ...

Energy Technology Data Exchange (ETDEWEB)

The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties about equally well. The 45A3 ensemble fulfills the atom-atom distance bounds derived ...

Energy Technology Data Exchange (ETDEWEB)

This report summarizes preliminary 2-D reactive-transport simulations on the injection, storage and transport of supercritical CO{sub 2} in dolostone formations in the Ordos Basin in China. The purpose of the simulations was to evaluate the role that basin heterogeneity, permeability, CO{sub 2} flux, and geochemical reactions between the carbonate geology and the CO{sub 2} equilibrated brines have on the evolution of porosity and permeability in the storage reservoir. The 2-D simulation of CO{sub 2} injection at 10{sup 3} ton/year corresponds to CO{sub 2} injection at a rate of 3 x 10{sup 5} ton/year in a 3-D, low permeable rock. An average permeability of 10 md was used in the simulation and reflects the upper range of permeability reported for the Ordos Basin Majiagou Group. Transport and distribution of CO{sub 2} between in the gas, aqueous, and solid phases were followed during a 10-year injection phase and a 10-year post injection phase. Our results show that ...

Energy Technology Data Exchange (ETDEWEB)

Results are presented of molecular dynamics (MD) studies of 1-10 keV displacement cascades in silicon. At these energies, the simulations couple directly to experimental observations of low energy implantation in silicon for shallow junction formation. The simulations are performed with the Stillinger-Weber potential for silicon in computational cells with up to 3.5x10{sup 5} atoms. The author employs periodic boundary conditions in the [100] and [010] directions and a free surface on the top (001) plane. The author discusses the results in terms of the structural evolution and the dynamics of the cascade zones. For sufficiently high energy recoils (>2 KeV), the cascades produce locally molten zones that result in the formation of amorphous silicon pockets upon recrystallization. Frenkel pairs are also produced during the cascade, although their number is very small (less than 10% of the binary collision predictions). Upon annealing of the resulting damage ...

Energy Technology Data Exchange (ETDEWEB)

Mechanisms and associated energetics for adatom diffusion on the (100) and (110) surfaces of Ni, Cu, Rh, Pd, and Ag are investigated. Self-diffusion was studied on (100) and (I 10) surfaces of Ni, Cu, Pd and Ag using corrected effective medium method (CEM) and approximation to CEM used for molecular dynamics and Monte Carlo studies (MD/MC-CEM). Self-diffusion on Pd(100), Ag(100), Ni(110), Cu(110), Pd(110), and Ag(110) is accomplished by classical diffusion: the adatom hops from its equilibrium adsorption site over an intervening bridge site to an adjacent equilibrium site. Self-diffusion on Ni(100) and Cu(100) proceeds by atomic-exchange diffusion: the adatom on the surface displaces an atom in the first surface layer. Aside from explicit inclusion of the kinetic-exchange-correlation energy, it is critical to include enough movable atoms in the calculation to insure correct energetics. Distortions induced by these diffusion mechanisms, especially atomic exchange, ...

Energy Technology Data Exchange (ETDEWEB)

Olive field is oil productive from a thin stratigraphically trapped sandstone within the Upper Cretaceous lower Tuscaloosa Formation. The discovery of Olive in 1981 led to renewed interest in the Mid-Dip Tuscaloosa Trend that continues today. Discovery and development was based on the correlation of the B sandstone to a mappable soft seismic event at a depth of 10,500 ft. The field was developed by 25 wells on 40-acre spacing. Olive has been waterflooded since 1983 and is a target for enhanced recovery using carbon dioxide. A total of 7.5 million stock tank bbl or approximately 75% of the original oil in place is estimated to be recoverable by conventional and enhanced recovery methods. The B sandstone was deposited by a northwest to southeast-flowing high-sinuosity meandering river system. Point bar, channel, and channel abandonment deposits are present. The point bar formed from the lateral migration of the river system from west to east, and channel abandonment is evident at the ...

Energy Technology Data Exchange (ETDEWEB)

In the context of safety assessment of radioactive waste repositories, complex radionuclide transport models covering key safety-relevant processes play a major role. In recent Swiss safety assessments, such as Kristallin-I, an important drawback was the limitation in geosphere modelling capability to account for geosphere heterogeneities. In marked contrast to this limitation in modelling capabilities, great effort has been put into investigating the heterogeneity of the geosphere as it impacts on hydrology. Structural geological methods have been used to look at the geometry of the flow paths on a small scale and the diffusion and sorption properties of different rock materials have been investigated. This huge amount of information could however be only partially applied in geosphere transport modelling. To make use of these investigations the 'PICNIC project' was established as a joint cooperation of PSI/Nagra and QuantiSci to provide a new geosphere transport ...