bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energetics of Oxygen Interstitials in Cr and V
Authors: Good Brian S. , Copland Evan 
Published: April 2011

ABSTRACTDissolved oxygen in group IIIA-VA (Nb, Ti, Zr, Y) based alloys is a fundamental problem, affecting both mechanical properties and oxidation resistance, yet details of the phenomenon are poorly understood. In these alloys, oxygen is more stable dissolved in the metal than as an oxide-compound. In contrast, alloys based on Ni, Fe, Al and Cr exhibit almost no oxygen solubility. To improve the performance of Nb and Ti based alloys it is necessary to understand the differences in oxygen solubility between these two groups of metals. As a first step we considered the energetics of interstitial oxygen in α-V and α-Cr. Both of these metals have a BCC structure, yet the oxygen solubility in V is much higher than that in Cr. We obtain total energies, densities of states and population analyses using the CASTEP plane-wave pseudopotential density functional computer code. The differences in the energetics and electronic structures of the two materials, particularly the partial densities of states associated with the interstitial oxygen, are discussed.
Volatile Evolution from Polymer Materials Induced by Irradiation with Accelerated He++ Ions
Authors: Murphy Julian.J. , Wetteland Christopher.J. 
Published: April 2011

ABSTRACTExperimentally investigating ageing caused by irradiation with energetic particles is very difficult. Radioactive sources can be employed but these are difficult to handle and contaminate the material being irradiated precluding subsequent chemical and physical characterisation. The penetration of energetic particles also tends to be small so any change is localised in the near surface region so only a small amount of material is irradiated. Analysing changes in such thin layers causes a number of problems. To simulate ageing induced by particle radiation polymer samples have been exposed to fast He++ ions in an accelerated ion beam. The ions pass through a 10μm thick window of Havar foil before impacting upon the sample. Volatile species evolved from the materials upon bombardment are contained within the irradiation chamber by the foil window. Analysis of such species is shown to be a highly sensitive probe for investigating chemical changes in the exposed materials. A number of important chemical changes induced in polymer materials have been identified. Trends in the relative rates of volatile evolution have been identified which correlate with chemical changes identified in other radiation experiments. As these experiments are performed at far slower irradiation rates the large acceleration factors used in ion beam irradiation are discussed along with the implications for using ion beams to simulate alpha particle irradiation.
The Application of Modern Metallurgical Principles And Knowledge to the Manufacture of Mokumé Gane (Wood-Grain Metal) Decorative Alloy
Authors: Ferguson Ian T. , Derby Brian , Thompson G. E. 
Published: April 2011

ABSTRACTMokumé Gane layered metal is a 300-year old decorative metal laminate technique peculiar to the isolated culture of the Japanese Shogunate. Like many complex craft practices handed down through individual experience, the manufacture and development of Mokumé Gane has changed minimally over time. The application of contemporary metallurgical knowledge and solid state bonding techniques such as Hot Press Diffusion Bonding and Hot Roll Bonding provide for further development of Mokumé Gane: bonding success rates are improved, and manufacturing times are reduced. In addition, the range of possible metal combinations is substantially increased; 42 different combinations to date have been successfully bonded, including a new type of Mokumé Gane employing aluminium alloys. This research has allowed a very large increase in the variety of colours, patterns, and visual effects, available to contemporary metalsmiths and jewellers.
Magnetic and Structural Properties of Mn-implanted Si
Authors: Bolduc M. , Awo-Affouda C. , Stollenwerk A. , Huang M. B. , Ramos F. , Agnello G. , LaBella V. P. 
Published: April 2011

ABSTRACTP-type Si wafers (∼1019 cm−3) were implanted with 300 keV Mn+ ions at 350°C to a dose of 1×1016 cm−2, and then annealed at 800°C for 5 min. The magnetic properties with dependence upon temperature were measured by using a Superconducting Quantum Interference Device (SQUID) magnetometer. The Mn-implanted Si compound shows ferromagnetic ordering above room temperature. The saturation magnetization increases by ∼ 2 × after annealing and the Curie temperature is TC > 400 K. The structural properties have been investigated by means of Secondary Ion Mass Spectroscopy (SIMS) depth profiling and Transmission Electron Microscope (TEM) imaging. Measurements showed that the Mn atoms redistribute in the Si crystal due to the thermal annealing and form a band layer composed of nanoscale structures such as crystallites or defects.
Effective Modulus and Stress Relaxation of Freestanding Aluminum Microtensile Beams
Authors: El-Deiry P. A. , Barbosa N. , Brown W. L. , Vinci R. P. 
Published: April 2011

ABSTRACTFreestanding Al thin film microtensile beams 600 μm long, 100 μm wide, and with thicknesses of 0.25 μm, 0.50 μm, 0.75 μm, and 1.00 μm were tested under uniaxial tension with a custom-built microtensile system. Displacement controlled experiments employing five strain rates between 8.3 × 10−4 s−1 and 8.3 × 10−1 s−1 were performed. Three crosshead displacements of 1.00 μm (0.17% strain), 2.60 μm (0.43%), and 3.60 μm (0.60% strain) were exercised in order to investigate behavior in the elastic, anelastic, and the inelastic sections of the stress/strain curve.At a 0.17% strain amplitude, the 0.50 μm thick microtensile beams exhibit an effective modulus that increases with increasing strain rate. The 1.00 μm, 0.75 μm, and 0.25 μm microtensile beams do not show a similar trend. The 0.25 μm and the 0.75 μm thick microtensile beams have similar grain sizes and similar moduli; the 0.50 μm and the 1.00 μm microtensile beams have similar but smaller grain sizes and higher effective moduli. This suggests that grain size is more significant than film thickness in determining the effective modulus of freestanding Al thin films. Furthermore, no stress relaxation behavior was identified for any of the films during the hold at the 0.17% strain amplitude.At a strain amplitude of 0.43%, the effective moduli are very similar to the values measured at a 0.17% strain amplitude; however, the 0.50 μm and 1.00 μm thick microtensile beams show measurable stress relaxation while the 0.25 μm and 0.75 μm microtensile beams do not. This result combined with a lower observed modulus suggests that the particular anelastic mechanisms operating in these films at these time scales activate sooner and provide a faster stress relaxation process in the larger grained films.
Effect of Stress-induced Magnetic Anisotropy on the Properties of Giant Magnetostrictive Single Layer and Multilayer Thin Films
Authors: Tan J. H. , Guerrero V. H. , Wetherhold R. C. , Anderson W. A. 
Published: April 2011

ABSTRACTGiant magnetostrictive thin films deposited on nonmagnetic substrates can constitute effective sensors and actuators for microdevices. In this work, we investigated the effects of a stress-induced anisotropy on the magnetic properties of Tb0.4Fe0.6, Fe0.5Co0.5 single layer films and [Tb0.4Fe0.6/Fe0.5Co0.5]n multilayers deposited on Si substrates. The magnetostrictive thin films were fabricated by means of RF sputtering and were subjected to a post-deposition annealing treatment. The uniaxial magnetic anisotropy was induced by bending the substrate before deposition and then allowing it to resume its original flat shape after depositing the film. The heat treatment was performed in a vacuum system with a vacuum of 10−6 Torr. The magnetic properties of the fabricated specimens were measured using a SQUID. SEM and XRD analyses were performed to ensure that the thermal treatment would relax the internal stresses induced during the deposition process without crystallizing the film. The thickness of the single layer thin films studied was between 300 and 800 nm while multilayer samples consisted of 6 layers with each layer thickness ranged from about 20 to 40 nm. Compared to single layer samples, multilayer samples with stress anneal growth exhibited an improvement in magnetic saturation by a factor of two while maintaining a low coercive field. Manipulations of the magnitude and direction of magnetic anisotropy was observed by introducing various values of tensile and compressive stress into the film.
Magnetostrictive Microcantilever as Micro-Biosensor Platform
Authors: Li Suiqiong , Li Zhimin , Orona Lisa , Cheng Z.-Y. 
Published: April 2011

ABSTRACTIn this paper, a novel micro-biosensor platform - magnetostrictive microcantilever (MSMC) - is reported. The resonance behavior and the sensitivity of MSMC as sensor platform were characterized and compared to the theoretical calculation. The detection of yeast cells using the biosensor made of MSMC was reported. The results demonstrate the feasibility of MSMC as a high performance biosensor platform. Compare to current microcantilevers, which is widely considered as the state-of-art sensor platform, the MSMCs have following advantages: 1) remote/wireless driving and sensing; 2) easy to fabricate. More importantly, it is experimentally found that the quality merit factor (Q value) of MSMC can reach more than 250, which is much higher than other cantilevers.
Evaluation of the Corrosivity of Dust Deposited on Waste Packages at Yucca Mountain, Nevada
Authors: Bryan Charles , Jarek Russell , Wolery Thomas , Shields David , Sutton Mark , Hardin Ernest , Barr Deborah 
Published: April 2011

ABSTRACTPotentially corrosive brines can form during post-closure by deliquescence of salt minerals in dust deposited on the surface of waste packages at Yucca Mountain during operations and the pre-closure ventilation period. Although thermodynamic modeling and experimental studies of brine deliquescence indicates that brines are likely to form, they will be nitrate-rich and noncorrosive. Processes that modify the brines following deliquescence are beneficial with respect to inhibition of corrosion. For example, acid degassing (HCl, HNO3) could dry out brines, but kinetic limitations are likely to limit the effect to increasing their passivity by raising the pH and increasing the NO3/Cl ratio.Predicted dust quantities and maximum brine volumes on the waste package surface are small, and physical isolation of salt minerals in the dust may inhibit formation of eutectic brines and decrease brine volumes. If brines do contact the WP surface, small droplet volumes and layer thicknesses do not support development of diffusive gradients necessary for formation on separate anodic-cathodic zones required for localized corrosion. Finally, should localized corrosion initiate, corrosion product buildup will stifle corrosion, by limiting oxygen access to the metal surface, by capillary retention of brine in corrosion product porosity, or by consumption of brine components (Cl−).
A Study on Gas Migration Behavior in Buffer Material using X-ray CT Method
Authors: Tanai K. , Yui M. 
Published: April 2011

ABSTRACTThis paper presents a study on gas migration behavior in a bentonite specimen with the aid of X-ray computer tomography (CT) scan data. The laboratory experiment was carried out to clarify gas migration behavior through saturated, compacted bentonite. X-ray CT was used to estimate the spatial distribution of gas and water saturation during gas migration test in the bentonite. For the gas migration test, the controlled flow rate of gas injection was adopted for pre-compacted samples of Kunigel V1 bentonite using helium gas, which is safer than hydrogen gas.A specimen was isotropically consolidated and saturated by synthetic seawater, simultaneously, by applying a backpressure. This was followed by injecting the gas using a syringe pump. Inlet and outlet gas fluxes were monitored. This test exhibited a significant threshold pressure for breakthrough, somewhat larger than the sum of the swelling pressure and the backpressure.The procedure of the X-ray CT measurement is as follows; i) measurement of the initial condition (saturated condition) of the compacted bentonite, ii) measurement of the gas injection condition as a function of time. The digital data obtained from the X-ray CT usually includes some noise. The stacking method can reduce the noise in CT values and enables to identify the gas migration area. The results indicate that gas is transported through preferential pathways in compacted bentonite, and is not homogenous.
The Belgian Demonstration Programme for the Disposal of High-Level and Long-Lived Radioactive Waste
Authors: Frédéric Bernier , Marc Demarche , Johan Bel 
Published: April 2011

ABSTRACTThe EIG EURIDICE is responsible for performing large-scale tests, technical demonstrations and experiments so as to assess the feasibility of a final disposal of vitrified radioactive waste in deep clay layers. This programme is part of the Belgian Research and Development programme managed by ONDRAF/NIRAS. The research infrastructure includes the Underground Research Facilities HADES (URF HADES) in the Boom Clay geological formation and surface facilities. The achievements of the demonstration programme are the demonstration of the construction of shafts and galleries at industrial scale, the characterisation of the hydro-mechanical response of the host rock, and the “OPHELIE mock-up” a large scale hydration test under thermal load of pre-fabricated bentonite blocks. The future works will consist mainly in the realisation of the “PRACLAY experiments” including a large scale heater test. The large scale heater test has to demonstrate that Boom Clay is suitable, in terms of performance of the disposal system, to undergo the thermal load induced by the vitrified waste. The combined effect of the excavation and the thermal load will be investigated. A long term (more than 10 years) large scale heater test would be representative of the most penalizing conditions that could be encountered in the real disposal. The results of this test will constitute an important input for the Safety and Feasibility Cases 1 (SFC-1, 2013) and 2 (SFC-2, 2020).
Importance of the Excavation Damaged Zone (EDZ) in the General Performance of the Near-Field of a Geological Disposal System; Input of the EDZ Component to the EC Integrated Project on the Near-Field (NF-PRO)
Authors: Aranyossy Jean François , Blümling Peter , Alheid Hans Joachim , Geet Maarten Van , Mayor Juan Carlos , Marschall Paul , Plas Frederic 
Published: April 2011

ABSTRACTIn order to tackle the particular issues presented by the existence of an Excavation Damaged Zone (EDZ) along disposal cells and tunnels and the subsequent potential occurrence of preferential flow paths and radionuclide migration, a specific Component on the EDZ has been incorporated into the EC Integrated Project on the Near-Field (NF-PRO)1. This Component is organised into several Work Packages matching the foreseeable EDZ evolution during the repository lifetime: (i) the “initial phase”, corresponding to EDZ development induced by underground excavations and rock stress release; (ii) the “transient phase”, corresponding to the repository operating phase, mainly characterised by desaturation, temperature increase and resaturation processes; (iii) the “long-term phase”, corresponding to the post-closure repository period, mainly characterised by EDZ self-sealing / self-healing and gas transport processes.The scientific results obtained through the numerous tasks included in the Component cover various aspects of EDZ investigation (desk studies, experimental work on representative rock samples, in situ experiments in URLs, numerical modelling) and are integrated into a global EDZ impact evaluation to be forwarded to the Component of the project devoted to process coupling and integration in the general performance assessment of the near-field.
Atmospheric Stress Corrosion Cracking (ASCC) Susceptibility of Stainless Alloys for Metallic Containers
Authors: Nakayama Gen 
Published: April 2011

ABSTRACTMetallic canisters placed in concrete casks and containing spent nuclear fuel elements, will be exposed to a moist oceanic atmosphere while the decay heat generated in the fuel elements cools for more than fifty years. Thus, the surface environment of the metallic canisters will be wet and covered with chloride compounds. The canisters may suffer atmospheric stress corrosion cracking. Therefore, corrosion tests for some potential alloys were conducted in an aqueous bittern solution, containing 22% enriched chloride compounds simulating the expected surface conditions of the canisters, to aid in selecting appropriate alloys based on corrosion resistance. The results suggest that the corrosion resistance of ordinary stainless steels, such as SUS304 and SUS316, is not high enough to avoid ASCC (atmospheric stress corrosion cracking) in the environment. Thus, a higher-grade stainless steel, namely, NSSC270 (20Cr-18Ni-6Mo-0.2N-Low C)or SUS836L (23.5Cr-25Ni-5.5Mo-0.2N-Low C, equivalent to AL-6XN) has been selected for this application.
The Proposed Yucca Mountain Repository from a Corrosion Perspective
Authors: Payer Joe H. 
Published: April 2011

ABSTRACTIn this paper, the proposed Yucca Mountain Repository is viewed from a corrosion perspective. A major component of the long-term strategy for safe disposal of nuclear waste at the Yucca Mountain Repository is first to completely isolate the radionuclides in the waste packages for long times and to greatly retard the egress and transport of radionuclides from penetrated packages. Therefore, long-lived waste packages are important. The corrosion resistance of the waste package outer canister is reviewed, and a framework for the analysis of localized corrosion processes is presented. An overview is presented of the Materials Performance targeted thrust of the U.S. Department of Energy/Office of Civilian Radioactive Waste Management's Office of Science and Technology and International. The thrust program strives for increased scientific understanding, enhanced process models and advanced technologies for corrosion control.
Leach Resistant Cesium and Strontium-bearing Wasteforms from Hexagonal Tungsten Bronze-Polyacrylonitrile Composite Adsorbers
Authors: Griffith Christopher S. , Luca Vittorio , Sebesta Ferdinand , Yee Patrick , Drabarek Elizabeth 
Published: April 2011

ABSTRACTImmobilization of adsorbed Cs+ and Sr2+ on a molybdenum-doped, hexagonal tungsten bronze (HTB)-polyacrylonitrile (PAN) composite adsorbent can be achieved by heating in air at temperatures in the range 600 – 1200 °C. Thermal treatment of the parent composite material at 800 – 1000 °C undergoes a ca. 60% reduction in volume and retains its spherical morphology. For materials prepared at 800 – 1200 °C the full complement of Cs+ and the majority of Sr2+ partition into HTB phases (A∼0.16-0.3MO3; A = Cs, Sr, Na; M = Mo,W), along with sodium cations. The presence of high concentrations of Na+ relative to either Cs+ or Sr2+ does not appear to interfere with the formation of the HTB phase. The fraction (f) of Cs+ and Sr2+ leached from the tungstate phase assemblages is better or comparable with cesium hollandite (Cs0.8Ba0.4Ti8O18; f = ca. 8 × 10−5; rate = <1.2 × 10−4 g m−2d−1) and strontium titanate (SrTiO3; f = 3.1 × 10−3; rate = 2.63 × 10−4 g m−2 day×1), respectively, using a modified PCT test. Furthermore, where aggressive leaching conditions are employed (0.1M HNO3; 150 oC; 4 days), the tungstate phase assemblages display leach resistance orders of magnitude better than the reference phases (Cs+ - f = ca. 5 × 10−3; rate = ca. 1.4 × 10−3 g m−2 day−1; Sr2+ - f = ca. 8 × 10−2; rate = ca. 2.5 × 10−2 g m−2 day−1).
Analysis Interaction Field Strength and Spectrum from Microhysteresis Loops
Authors: Ye Lin-Xiu , Lee Jia-Mou , Wu Te-ho 
Published: April 2011

ABSTRACTIn this paper, we present a direct method to analyze the mechanism of magnetic domain reversal for a series of amorphous Dyx(FeCo)1-x magnetic thin films and whereby we obtained the distributions of the coercivities and interaction fields from 90,000 measurements of the microhysteresis loops. The standard deviations of the coercivity and the interaction field distributions, σi and σk, can be estimated by fitting the experimental data with the Gaussian- Preisach function. The results show that the interaction field decreases as Dy composition approaches the compensation point. The reversal mechanism is dominated by nucleation when σi is smaller than σk. The relationships between the magnetization reversal and interaction field strength are discussed
Percent Spotted Knapweed (Centaurea stoebe) in the Diets of Grazing Sheep
Authors: Surber Lisa M. M. , Rude Mark E. , Roeder Brent L. , Mosley Tracy K. , Grove Allison V. , Walker John W. , Kott Rodney W. 
Published: April 2011

AbstractThe objective of this study was to use fecal near-infrared reflectance spectroscopy (NIRS) to estimate the percent spotted knapweed in the diet of grazing ewes to fine tune grazing prescriptions. In trial 1, five ewes were randomly selected from a band of 900 ewes to estimate weekly variation in percent spotted knapweed in the diet. Fecal samples from these ewes were collected weekly from June 22 through August 17 (nine collections per ewe for a total of 45 observations). In trial 2, fecal samples were collected from 89 ewes in the band to estimate variability in percent spotted knapweed in the diet among sheep at two sampling dates corresponding to the bud (July 13) and postflowering (August 15) stages of spotted knapweed phenology. In trial 1, the percent spotted knapweed in the diet was similar (P > 0.05) on June 22, June 29, July 13, and July 20 but was greater (P < 0.05) on July 6 than June 22 and 29. Percent spotted knapweed in the diet was also greater (P < 0.05) from July 27 through August 17 than from June 22 through July 20. On July 13 in trial 2, 55% of ewes had 0 to 5% spotted knapweed in their diets, whereas 44% of ewes had 5 to 20% spotted knapweed in their diets. On August 15, only 1% of ewes had < 10% spotted knapweed in their diets, whereas 44% of ewes had 20 to 25% spotted knapweed in their diets. The estimated percent spotted knapweed in the diet of the 89 ewes in trial 2 was similar to that of the five ewes during the same time period in sampling trial 1 (5.3% compared with 5.0% for sampling trials 1 and 2, respectively, on July 13 and 22.0% compared with 20.7% on August 15 and 17 for trials 1 and 2, respectively). This is the first study to estimate percent spotted knapweed in the diet of individual grazing ewes. These data suggest that the best time to graze spotted knapweed–infested pastures would be in late July or early August, when spotted knapweed is flowering, but before viable seed production.