bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localized Corrosion Susceptibility of Alloy 22 as a Waste Package Container Material
Authors: Cragnolino Gustavo A. , Dunn Darrell S. , Pan Yi-Ming 
Published: April 2011

ABSTRACTAlloy 22 is the material preferred by the U.S. Department of Energy for the waste package outer container for geological disposal of high-level radioactive waste at the proposed repository site in Yucca Mountain, Nevada. The susceptibility of Alloy 22 to localized corrosion is an important consideration in the evaluation of the waste package behavior and the assessment of the overall performance of the proposed repository. The effects of the environment chemical composition and temperature on localized corrosion susceptibility were examined by measuring the repassivation potential for crevice corrosion in chloride-containing solutions at temperatures ranging from 80 to 150°C. The effect of potentially inhibiting anionic species, such as nitrate, was also determined. In addition to the mill annealed material, tests were conducted on both welded and thermally aged material to evaluate microstructural effects related to container fabrication processes. The resistance of Alloy 22 to localized corrosion decreased with increasing temperature and chloride concentration. Welding and thermal aging also decreased the localized corrosion resistance of the alloy.
Effects of Lead, Mercury, and Reduced Sulfur Species on the Corrosion of Alloy 22 in Concentrated Groundwaters as a Function of pH and Temperature
Authors: Pulvirenti April L. , Needhama Karen M. , Adel-Hadadi Mohamad A. , Marks Charles R. , Gorman Jeffrey A. , Barkatt Aaron 
Published: April 2011

ABSTRACTThe effect of Pb, Hg, thiosulfate and sulfide on the corrosion of Alloy 22 was studied. In solutions of 1000xJ13 groundwater doped with these contaminants, disks and U-bend specimens exhibited general corrosion and pitting at pH 1, and some dissolution at pH 13. One specimen exposed to the presence of Pb cracked catastrophically. In basic media thiosulfate and sulfide caused both oxide spalling and enhanced general corrosion.
Radiation Damage in Titanate Ceramics for Plutonium Immobilization
Authors: Strachan Denis M. , Scheele Randall D. , Kozelisky Anne E. , Sell Richard L. , Schaef H. Todd , O'Hara Matthew J. , Brown Christopher F. , Buchmiller and William C. 
Published: April 2011

ABSTRACTRadiation damage experiments are being performed with pyrochlore and zirconolite in support of the disposition of surplus weapons-ready Pu. Pyrochlore becomes amorphous in approximately 1 year from the alpha recoil damage of ∼ 1018 alphas/g from the decay of 238Pu. The dissolution rate of 238Pu-bearing ceramics increases with increasing radiation damage as measured in a 3 d MCC-1 test at 90°C. Over the same period, zirconolite retains substantial crystallinity albeit with broadened diffraction peaks. The dissolution rate also increases with increasing radiation damage.
Corrosion of Glass-Bonded Sodalite and its Components as a Function of ph and Temperature
Authors: Jeong Seung-Young , Morss Lester R. , Ebert William L. 
Published: April 2011

ABSTRACTA glass-bonded sodalite ceramic waste form (CWF) has been developed to immobilize electrorefiner salt wastes from electrometallurgical treatment of spent sodium-bonded reactor fuel for disposal. A degradation model is being developed to support qualification of the CWF for disposal in the federal high-level waste disposal system. The parameter values in the waste form degradation model were previously determined from the dissolution rates measured in MCC-1 tests conducted at 40, 70, and 90°C. The results of several series of tests that were conducted to confirm the applicability of the dissolution rate model and model parameters are presented in this paper: (1) Series of MCC-1 tests were conducted in five dilute buffer solutions in the pH range of 4.8 – 9.8 at 20°C with hot isostatic pressing (HIP) sodalite, HIP glass, and HIP CWF. The results show that the model adequately predicts the dissolution rate of these materials at 20°C. (2) Tests at 20 and 70°C with CWF made by pressureless-consolidation (PC) indicate that the model parameters extracted from the results of tests with HIP CWF can be applied to PC CWF. (3) The dissolution rates of a glass made with a composition corresponding to 80 wt. % glass and 20 wt. % sodalite were measured at 70°C to evaluate the sensitivity of the rate to the composition of binder glass in the CWF. The dissolution rates of the modified binder glass were indistinguishable from the rates of the binder glass.
Development of a Preliminary Performance Assessment Methodology for Design and Siting of a LLW Repository in Italy
Authors: Risoluti Piero , Ventura Giancarlo , Ciabatti Piercarlo 
Published: April 2011

ABSTRACTA preliminary performance assessment (PA) analysis for the LLW Repository in Italy is described in this paper. In particular, the PA analysis of the so called SA site is reported. The AMBER code has been used for the setting up of radionuclides transport simulation model both in the near-field and geosphere. The performance assessment analysis preliminarily showed that the SA site was likely to be suitable, in geological and hydrogeological terms, for hosting a LLW Repository. Total dose to the critical group for both a normal evolution scenario and cover degradation scenario was 4.2 × 10−3 mSv/year, approximately one order of magnitude lower than the 10−2 mSv/year dose constraint adopted in this study.
A Stochastic Assessment of Nuclear Waste Management Practices at the Hanford Site, Washington
Authors: Kincaid Charles T. , Eslinger Paul W. , Engel Dave W. , Nichols William E. , Bryce Robert W. , Bunn Amoret L. 
Published: April 2011

ABSTRACTWaste management and disposal decisions at the Hanford Site, Washington, depend in part on an understanding of the risks and impacts associated with alternate disposal and remedial actions. A proof-of-principle site-wide assessment of the risks and impacts associated with all wastes that will remain at the Hanford Site following cleanup has been performed for the first time. It simulates contaminant release, migration, and fate from the initiation of site operations in 1944 forward, and, thus, illustrates historical and near-term influences on long-term risk and impact.A stochastic simulation tool capable of addressing 1000 waste discharge and disposal sites and 10 contaminants for a period of 1000 years has been created and applied. Human health and ecological risks as well as impacts to the regional economy and local cultures are estimated. The methodology developed is known as the System Assessment Capability (SAC). It is currently in a Revision 0 state corresponding to a proof-of-principle demonstration.An initial assessment based on the planning baseline of the U.S. Department of Energy (Richland Operations office and office of River Protection) has been undertaken. Preliminary results of the assessment indicate variability in predictions is most influenced by uncertainty in:- geochemical adsorption (i.e., distribution coefficients, Kd) for contaminant release, vadose zone, and groundwater models; especially for uranium and iodine which are somewhat but not greatly adsorbed,- solid waste burial ground inventories of iodine-129, and- liquid discharge site inventories of technetium-99.It is apparent that variables governing change in performance are a function of space and time. Initially, these results point to the need for related models and data to be examined, and, if necessary, augmented through future laboratory and field studies to better quantify or reduce uncertainty.
Self-Assembly of Glass-Ceramic / CdSe / Protein Aggregations in the Optical Trap
Authors: Zavalin Andrey , Eugene Collins W. , Morgan Steven 
Published: April 2011

ABSTRACTAggregations, created in 2-component suspension inside the optical trap zone were studied. Particles of porous glass-ceramic of CaO-TiO2-P2O5 composition and 1–50 um size were mixed with BSA molecules in water or with CdSe-TOPO 20 nm particles in toluene. Dynamic aggregations up to 300 um size were created inside the optical trap. These aggregations in comparison with one-component aggregations have a 30% higher growth rate. This effect could be explained by the stronger bonding of the protein molecules and CdSe-TOPO particles inside the glass-ceramic particle aggregations. Micro-Raman spectra, taken from dynamic and stable permanent aggregations show several new peaks, possibly associated with creation of chemical bonds.
Nanoparticulate Hydroxyapatite Enhances the Bioactivity of a Resorbable Bone Graft
Authors: Doherty Stephen A. , Hile David D. , Wise Donald L. , Ying Jackie Y. , Sonis Stephen T. , Trantolo Debra J. 
Published: April 2011

ABSTRACTA nanoparticulate-hydroxyapatite filler augmented osteointegration within a resorbable polymer based bone graft substitute designed for orthopaedic and periodontal applications. The unsaturated polyester poly(propylene glycol-co-fumaric acid) (PPF), was used to prepare the bone graft substitute. The nanoparticulate-hydroxyapatite filler was examined in terms of biocompatibility, bony ingrowth and mechanical stability in a rat calvarial defect model. The nano-hydroxyapatite fillerwas compared against a commercially available micrometer-sized hydroxyapatite(HA) filler. Histological analysis indicated that remodeling of the newly formed bone was more advanced in the defect filled with the nano-hydroxyapatite augmented PPF. Mechanical evaluation showed a more rapid increase in stiffness of the nano-hydroxyapatite PPF. Implants of the nano-HA augmented PPF showed more advanced bone formation and recovery of mechanical properties, suggesting an improved biological response to the nano-sized particles.
Development of Woven Fabric-based Electrical Circuits
Authors: Dhawan Anuj , Ghosh Tushar K. , Seyam Abdelfattah M. , Muth John 
Published: April 2011

ABSTRACTThis paper describes the development of woven electrical circuits, which are formed by interlacing conducting and non-conducting threads into a woven fabric. Conductive threads in these electrical networks are arranged and woven such that they follow desired electrical circuit designs. Electronic devices can be attached to these electrical networks, which can serve as flexible circuit boards. In these woven circuits, an efficient transfer of current from one conductive yarn to an orthogonal one is achieved by the formation of an effective electrical interconnect at the point of intersection of these yarns. Formation of woven conductive networks also involves disconnect formation or cutting of conductive yarns at certain specified points. Different methods and processes were identified and applied in order to form interconnects and disconnects at specified points of these fabrics. Efficacy of these interconnects was evaluated by DC resistance and AC Signal measurements. The results of these evaluations are reported. The conductive threads woven into these fabric-based circuits were also evaluated for signal integrity issues.
Fluorescent fibers coupled to monolithic photovoltaic arrays for sunlight conversion
Authors: Sulima Oleg V. , Cox Jeffrey A. , Sims Paul E. , Mauk Michael G. 
Published: April 2011

ABSTRACTThin fluorescent organic fibers are used to collect short wavelength sunlight, convert it to longer wavelengths and illuminate photovoltaic (PV) arrays. Using this approach, miniature and lightweight PV arrays have been fabricated. The incoming light is collected by many fibers and mixed before reaching the PV array. Thus homogenous illumination is provided even with partially shadowed fibers, which can cover a large area and can be arranged in a form of a fabric. The PV array itself can be located in any (even dark) place.In this work we developed and tested high-performance miniature 21 mm2 AlGaAs/GaAs monolithic arrays consisting of 6 cells connected in series. Output electric power density of 75 mW/cm2 and an open-circuit voltage about 6 V was measured outdoors for the arrays integrated with a bundle of 0.25 – 1.00 mm thick polystyrene fibers. The influence of PV array output parameters on the fluorescent fiber diameter, length, as well as on bandgap and design of solar cells is discussed.
Organic Electrochemical Smart Pixels
Authors: Andersson Peter , Nilsson David , Svensson Per-Olof , Chen Miaoxiang , Malmström Anna , Remonen Tommi , Kugler Thomas , Berggren Magnus 
Published: April 2011

ABSTRACTAn all-printed organic smart pixel is achieved through the combination of an electrochemical transistor and an electrochromic display cell. Smart pixels of this kind are arranged into a cross-point matrix resulting in an active-addressed display. This type of display has been realized on coated fine paper, operates at voltages less than 2 Volts and exhibits good bistability properties. Here we report on the operation characteristics of electrochemical smart pixels in which the ion concentration of the electrolyte has been varied.
Vt-Shift Compensating Amorphous Silicon Pixel Circuits for Flexible OLED Displays
Authors: Sakariya Kapil , Servati Peyman , Striakhilev Denis , Nathan Arokia 
Published: April 2011

ABSTRACTIn this paper, we present design considerations pertinent to amorphous silicon pixel circuits for mechanically flexible active matrix display applications. We describe both circuit topologies and pixel architectures that are amenable to surface emissive pixels in a-Si:H technology. Metastable shifts in the a-Si:H material characteristics after prolonged gate bias or mechanical stress are manifested in the form of increasing TFT threshold voltages and varying mobilities. As a result, the TFT drive current and consequently the OLED brightness decrease, and the pixel eventually turns off. The circuits presented here compensate for this decrease in current through the use of current programming and feedback, and allow for stable OLED brightness over longer time periods. They also enable the implementation of high aperture ratio (close to 100%), low leakage current, surface emissive OLED pixels. Results show that the circuits provide higher linearity and dynamic range than currently available pixel circuits while minimizing the pixel area. Charge injection effects at the gate of the drive TFT have been reduced by using smaller switching TFTs, along with circuit topologies that provide in-pixel current gain. All circuits meet the speed requirements of a QVGA 60 Hz refresh rate display, and occupy less than 300um x 300um area.
Up-Conversion Luminescence in Colloidal CdTe Nanocrystals
Authors: Filonovich S. A. , Gomes M. J. M. , Rakovich Yu. P. , Donegan J. F. , Talapin D. V. , Gaponik N. P. , Rogach A. L. , Eychmüller A. 
Published: April 2011

ABSTRACTWe report on the efficient photoluminescence up-conversion in colloidally synthesized CdTe nanocrystals. We demonstrate that the efficiency of photon energy up-conversion and magnitude of spectral shift can be controlled: (i) by the size of the nanocrystals; (ii) by the temperature dependence of the excited state absorption coefficient; (iii) by the dependence on excitation intensity. From the analysis of the experimental data we can suggest that intrinsic gap states are involved as intermediate states in the photoluminescence up-conversion rather than nonlinear two-photon absorption or Auger processes.
GaSb-based Nanocomposites as IR-Emitters
Authors: Bakueva Ludmila , Musikhin Sergei , Sargent Edward H. , Schulz Stephan 
Published: April 2011

ABSTRACTNanocomposites consisting of GaSb nanocrystals in a conducting polymer matrix were fabricated and investigated. The current-voltage characteristics of the nanocomposite-based diode structures have a symmetric but strongly nonlinear character. Capacitance-voltage characteristics of the structures were investigated both in the dark and under illumination and compared with those of a pure polymer. At applied voltages exceeding 7–10 V (for different samples) electroluminescence begins and steeply increases. The position of the maximum of the measured electroluminescence spectra can be made to vary in the 1.3 – 1.6 μm wavelengths region by changing nanocrystal size. Photoluminescence spectra have a maximum nearly coinciding with that of electroluminescence but of considerably larger width. The results demonstrate the promise of GaSb-based nanocomposites for infrared light-emitting devices operating in the 1.3–1.6 μm spectral region used in optical communication systems.
Spectroscopic Study of Rare Earth Doped Nano-Crystalline Silicon in Sio2Films
Authors: Rozo C. , Fonseca L. F. , Resto O. , Weisz S. Z. 
Published: April 2011

ABSTRACTSi-rich SiO2, Nd-doped Si-rich SiO2and Nd-doped SiO2thin films were prepared. Photoluminescence (PL) spectra for visible and infrared were obtained for each as-deposited film. The samples were annealed by steps to different temperatures within the range 600°C-1100°C for 30 minutes at each annealing temperature. PL spectra were obtained at each step and their characteristics were studied. The best annealing temperature for the PL of the rare earth (RE) ions was obtained. The PL spectra of the films were compared with one another. Energy transfer from the silicon nanocrystals (Si nc) to the RE ions is verified using excitation wavelength and excitation power spectra.
Tunable Porous Silicon Mirrors for Optoelectronic Applications
Authors: Weiss Sharon M. , Haurylau Mikhail , Fauchet Philippe M. 
Published: April 2011

ABSTRACTTunable porous silicon mirrors were fabricated as building blocks for optical interconnects and as a first step towards efficient routing of information on a small size scale. The basic structures for the tunable mirrors are porous silicon microcavities infiltrated with liquid crystals. The optical properties of the mirrors are influenced by thermal or electric field modulation. When the device is heated or a voltage is applied, the orientation of the liquid crystals changes, causing a change in the effective refractive index of the liquid crystals within the mirror. The position of the reflectance resonance of the porous silicon microcavity is particularly sensitive to such changes in the refractive index. A reversible 10nm shift of the reflectance resonance of the mirror, leading to a 30% change in the amplitude of reflectance, has been observed due to thermal effects. Not only do these results show potential for future devices, but they also confirm that the liquid crystals are able to rotate in the constricted geometry of the porous silicon microcavities. For voltage driven devices, careful attention needs to be given to the configuration of the electrical contacts. The effectiveness of various device geometries has been investigated. Using standard lithographic techniques, aluminum contacts with minimum feature sizes of 10 microns were patterned directly on the porous silicon surface. A study on the use of free-standing porous silicon films was also performed.
Effective Medium Calculations of the Electromagnetic Behavior of Single Walled Carbon Nanotube Composites
Authors: Schultz John W. , Moore Rick L. 
Published: April 2011

ABSTRACTDielectric properties of single walled carbon nanotube assemblies were calculated with an effective medium approximation at frequencies from 200 MHz to 200 GHz. The model treats the carbon nanotubes as layered cylinders, each with a core, a graphene layer and an outer layer, to investigate the dielectric properties of coated and filled nanotubes. The graphene and metal layer properties were modeled with a Drude approximation based on literature data. A generalized Bruggeman model was then used to determine the macroscopic behavior of the modified carbon nanotubes in a composite structure as a function of volume fraction, frequency, and aspect ratio. The depolarization factors in this model were scaled by the normalized effective permittivity to better account for percolation behavior. The model showed a wide variety of frequency dependent dielectric properties. Uncoated tubes were calculated to form highly conductive materials at volume fractions of just a few percent and metal-coated tubes enhanced the conductivity by an order of magnitude. Calculations of nanotubes with insulating coatings showed that high dielectric constants with moderate to low dielectric loss were possible.
Formation of 3-Dimensionally Orientated Nano-sized Crystals in an Amorphous Alloy under Ion Beam Irradiation
Authors: Kamikawa Takuya , Tarumi Ryuichi , Takashima Kazuki , Higo Yakichi 
Published: April 2011

ABSTRACTWe have succeeded to form three-dimensionally orientated nano-sized crystals in a Ni-P amorphous alloy under focused ion beam (FIB) irradiation. The FIB micro-fabrication was performed on an electroless deposited Ni-P amorphous alloy and thin films with a thickness of 100 nm were prepared. Transmission electron microscopy (TEM) observation for irradiated areas revealed the formation of crystallographically orientated nano-sized crystals (NCs) in the irradiated region. The grain size of NCs was less than 10 nm in diameter. Electron diffraction analysis showed that the formed NCs have a face-centered-cubic (f.c.c.) structure and the following orientation relationships among the specimen, the NCs and the FIB direction: irradiated plane // {111}f.c.c. and ion beam direction // <110>f.c.c..
Nanometer-scale Pattern Transfer Using Ion Implantation
Authors: Matsuura Naomi , Simpson Todd W. , McNorgan Chris P. , Mitchell Ian V. , Mei Xiang-Yang , Morales Patrick , Ruda Harry E. 
Published: April 2011

ABSTRACTConventional, broad-area, ion implantation has been combined with unconventional masking to create 2-D geometrical patterns of amorphization in single crystals, with selectable motifs. The patterns are fully developed by use of selective etching. Two examples are discussed. In the first example, a self-assembled array (with lattice spacing ∼1 μm) of silica spheres is used as an implant mask over InP. The variation of the mask thickness created by the sphere geometry modulates the implantation depth in a periodic fashion, which is subsequently revealed after selective etching of the associated amorphized volumes. In the second example, nanochannel arrays in an alumina film are used as an implant mask to produce a hexagonal closed packed array of amorphized cylinders in InP and SrTiO3 substrates. The ion beam-amorphized regions of the substrate are then removed by selective chemical etching to achieve the full 3-D patterning of 55 nm diameter holes on a 100 nm lattice spacing.
New Ge-Sn materials with adjustable bandgaps and lattice constants
Authors: Bauer Matthew R. , Tolle John , Chizmeshya A. V. G. , Zollner S. , Menendez J. , Kouvetakis J. 
Published: April 2011

ABSTRACTThe synthesis and optical properties of a new class of Si-based infrared semiconductors in the Ge1-x Snx system are described. Chemical methods based on deuterium-stabilized Sn hydrides and UHV-CVD were used to prepare a wide range of metastable compositions and structures directly on silicon. These materials exhibit high thermal stability, superior crystallinity, and unique crystallographic and optical properties, such as adjustable band gaps and lattice constants. These properties are characterized by Rutherford backscattering, low-energy secondary ion mass spectrometry, high-resolution transmission electron microscopy, x-ray diffraction as well as infrared and Raman spectroscopies and spectroscopic ellipsometry. The films grow essentially strain free and display a strong compositional dependence of the band structure.