bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison and Abstraction of the Commercial Spent Fuel Corrosion Experiments in the U.S.
Authors: Siegmann Eric R. 
Published: April 2011

ABSTRACTThis paper compares the results of three different fuel corrosion experiments by taking the existing corrosion data reported for various temperatures and recalculating corrosion rates at a single temperature of 25°C using a temperature dependent model developed elsewhere. Three types of light water reactor fuel corrosion tests (sometimes called dissolution or alteration tests) were performed in support of Yucca Mountain Project. The tests used three water contact modes and various fuel burnups. All measurements were adjusted for temperature differences and then compared. Five different isotopes (cesium, technetium, iodine, strontium, and, in the flow-through tests, uranium) were considered as a measure of corrosion. The data used represent over ten years of experiments with about nine different fuel types. Most experiments were with repository type fluids, containing dissolved constituents such as carbonate, calcium and silicon. The results show that all of the experiments predict similar fuel corrosion rates. Small differences in the isotope release rates are observed and incorporated in the abstracted uncertainty. Water contact mode (flow-through, batch, or drip) does not seem to be very important although the drip tests introduced larger variations. In developing a corrosion abstraction, all of the isotope measurements were considered equally. The distribution of release rates was used directly to develop the uncertainty. The mean corrosion rate was 1.8 × 10-4 fraction/year at 25°C (5%-95% range = 5.7 × 10-5 to 1.7 × 10-3). Using the derived corrosion rate for 25°C, and considering rapid axial splitting of the cladding, the CSNF fuel rod is expected to corrode in less than 2,000 years. The abstraction uses all the available experiments performed with water containing carbonates, silicon, or calcium and irradiated fuel to produce a corrosion rate distribution. Sensitivity studies using this corrosion rate abstraction in the TSPA-SR analysis show very small changes in dose (3%) in response to changes in the UO2 corrosion abstraction.
Development of PZT Suspensions for Ceramic Ink-Jet Printing
Authors: Derby B. , Lee D. H. , Wang T. , Hall D. 
Published: April 2011

ABSTRACTThe direct ink-jet printing of ceramic powders requires the development of highly fluid suspensions of ceramic particles with viscosity < 40 mPas. Here we describe the development of two such ceramic suspensions, which contain up to 30% by volume of PZT particles in either an azeotropic mixture of MEK and ethanol or in an alkane wax at 120 °C. The influence of various processing parameters on fluid rheology are investigated and trial fluids have been passed through an ink-jet printing head.
Fabrication of Micro- and Nanoscale SiC Structures Using Selective Deposition Processes
Authors: Chen L. , Fu X. A. , Zorman C. A. , Mehregany M. 
Published: April 2011

ABSTRACTA method to fabricate nanometer scale SiC beams and nanoporous SiC shells using conventional microlithographic techniques combined with selective APCVD has been developed as an alternative to nanolithographic patterning and electrochemical etching. The process involves the selective deposition of poly-SiC films on patterned SiO2/polysilicon/SiO2 thin film multilayers on (100) Si substrates using a carbonization-based 3C-SiC growth process. This technique capitalizes on significant differences in the nucleation of SiC on SiO2 and polysilicon surfaces in order to form mechanically durable and chemically stable structures.
Polymer Microvalve Based on Anisotropic Expansion of Polypyrrole
Authors: Berdichevsky Yevgeny , Lo Y.-H. 
Published: April 2011

ABSTRACTAn actuator fabricated from the conductive polymer polypyrrole using microfabrication techniques is presented. This actuator utilizes the anisotropic volume change, which occurs under application of an electric field in polypyrrole grown in the presence of NaDBS. This volume change is in direction normal to the substrate, and is several times larger than lateral volume change utilized in polypyrrole microactuators to date. The actuator is applied in a microfluidic valve where membrane and microchannels are fabricated from a transparent elastomer using soft lithography. The use of elastomer enabled a good valve seal and encapsulation of the electrolyte used for polypyrrole actuation.
Self-Organized Criticality in Nanotribology
Authors: Adler Micha , Ferrante John , Schilowitz Alan , Yablon Dalia , Zypman Fredy 
Published: April 2011

ABSTRACTWe present experimental results on dry friction, which are consistent with the hypothesis that the stick-slip mechanism for energy release is described by self-organized criticality. The data, obtained with an Atomic Force Microscope set to measure lateral forces– examines the variation of the friction force as a function of time – or sliding distance. The materials studied were nominally flat surfaces of mica, quartz, silica and steel. An analysis of the data shows that the probability distribution of slip sizes follows a power law. Our data strongly supports the existence of self-organized criticality for nano-stick-slip in dry sliding friction.
Polyurethane Nanofiber Webs for Sensor and Actuator Applications in Microelectromechanical Systems (MEMS)
Authors: Demir Mustafa M. , Naseer Mansoor , Bechteler Thomas F. , Gurbuz Yasar , Menceloglu Yusuf Z. 
Published: April 2011

ABSTRACTSensor application of Polyurethane Nanofiber Webs (PNW) has been explored in this study. PNW were prepared by electrospinning of the polyurethane solution in dimethylformamide. Silver nanoparticles with a size of 60 nm on PNW were produced by precipitation of AgNO3 in alkaline media. A micromachined capacitive pressure sensor has been designed using a special elastic and conducting thin membrane (PNW) as an active electrode sensing the pressure. With an additional inductor and a metal-semiconductor field effect transistor (MESFET), a microwave oscillator has also been designed as part of the system. The capacity variation due to changing pressure results in a frequency shift of this oscillator. This frequency shift is measured and corresponds to the pressure. The simulations performed on this structure show a very good linearity over a wide range of applied pressure which could be detected by change in oscillator frequency. These results indicate that an implementation of PNW as an active material in capacitative sensing applications of MicroElectroMechanical Systems (MEMS) could be feasible.
Structure Analysis of Co/Re Superlattice Grown on an Al2O3 (110) Substrate
Authors: Xu Wentao , Charlton Timothy , De Long Lance E. , Lederman David 
Published: April 2011

ABSTRACTThe structure of a Re(5 nm)/(Co(2 nm)/Re(3 nm))19 sample grown via magnetron sputtering was thoroughly analyzed via x-ray reflectivity (XRR) and transmission electron microscopy (TEM). Cross-sectional TEM results indicate that the sample is epitaxial, with the in-plane c-axis of the superlattice pointing along the c-axis of the substrate. A quantitative analysis of XRR yielded an average thickness of each layer and an interface roughness ∼ 0.4 nm between the Co and Re layers. A careful analysis of the TEM data reveals that the in-plane lattice parameters for Co, Re and Al2O3 are approximately 0.24 nm, 0.43 nm; 0.26 nm, 0.44 nm; and 0.24 nm, 0.44 nm, respectively. The lattice spacings of Al2O3 correspond to a/2 and c/3, where a, and c are lattice parameters, respectively. Interestingly, both high resolution and Z-contrast images show a very uniform period thickness. Z-contrast images, however, show that the initial interface roughness between the Re buffer layer and the first Co layer is amplified as the layers get farther away from the substrate. A high magnification TEM analysis shows that the bottom Co-Re interface roughness is about 0.2 nm, whereas the top Re-Co interface roughness is about 0.7 nm. Previous anistropic magnetoresistance measurements are discussed in light of these new structural data.
Magnetic Properties of Nanocrystalline Fe50Co50 Powders
Authors: Basavaraju Shashishekar , Baker Ian 
Published: April 2011

ABSTRACTNanocrystalline stoichiometric FeCo powders were prepared by mechanically alloying elemental Fe and Co powders using a high-energy ball mill. The microstructural evolution was studied as a function of milling time and subsequent annealing using X-ray diffractometry and differential scanning calorimetry. The magnetic behavior of the specimens was characterized using a vibrating sample magnetometer and a magnetic force microscope. A reduction in grain size coupled with an increase in coercivity was observed as function of milling time. The smallest grain size of 4 nm, which exhibited a coercivity of 122 Oe and magnetization of 2 T at room temperature, was obtained after 240 h of milling. The reduction in grain size during milling was not accompanied by enhanced soft magnetic properties.
Genesis and Growth of Nanoparticles during Sol-Gel Synthesis
Authors: Yao Nan , Yeung King Lun , Xiong Guoxing , Sheng Shishan 
Published: April 2011

ABSTRACTIn situ observation of the genesis and growth of silica-alumina structures during the sol-gel process has been carried out. Although the gross structure of the gel network is kinetically stabilized, in situ AFM study reveals that at nanometer scale, the internal structure of the gel is dynamic as shown by the rich and complex morphological transformations.
Mechanism of Surfactant Removal from Ordered Nanocomposite Silica Thin Films by Deep-UV Light Exposure
Authors: Dattelbaum Andrew M. , Amweg Meri L. , Ruiz Julia D. , Ecke Laurel E. , Shreve Andrew P. , Parikh Atul N. 
Published: April 2011

ABSTRACTIn recent years, methods have been developed for the generation of complex ordered nanocomposite materials through organic templating of inorganic structures. One approach involves preparation of composite materials by an evaporation induced self-assembly process involving organization of organic surfactants and formation of inorganic silica from soluble precursors. Recently, we have shown that deep-UV light (185–254nm) is efficient at removing the surfactant microphase for a routine production of well-ordered mesoporous silica thin films. Here we probe the evolution of surfactant removal from nanocomposite thin film silica mesophases as a function of deep-UV exposure using a combined application of FTIR and single wavelength ellipsometry. Taken together, these data indicate that surfactant removal occurs in a step-wise fashion with the formation of oxidized intermediates prior to complete removal of the surfactant from the thin film.
Synthesis and electrochemical properties of mesostructured 12-phosphotungstic acid thin films with hierarchical structures by triblock copolymer templating
Authors: Yun Hui-suk , Kuwabara Makoto , Zhou Haoshen , Honma Itaru 
Published: April 2011

ABSTRACTHexagonally mesostructured 12-phosphotungstic acid (PWA) thin films with both large pore size and hierarchical structures have been successfully prepared by using triblock copolymer templates for the first time. The films is composed by three kind of structures; PWA Keggin anion, monoclinic crystal structure consisting of PWA Keggin anion and organic part (hydrophilic component) of block copolymers, and the hexagonal mesostructure of self-arrayed PWA and block copolymers. The calcined PWA films show better electrochemical properties such as a faster faradic processes and larger specific capacity than normal P WA clusters.
Solution Electrospinning of Nylon/Ferrite Nanofibers
Authors: Dhanote Autumn , Ugbolue Samuel C. , Warner Steven B. , Patra Prabir K. , Katangur Phaneshwar , Mhetre Shamal K. 
Published: April 2011

ABSTRACTWith an average diameter of 80–200 nm, nylon fibers embedded with ferrite nanoparticles were electrospun using a point to plate geometry. The nickel-ferrite particles with a diameter range of 20–30 nm were used to prepare the composite electrospun nanofibers. The ferrite nanoparticles were dispersed in the polymer solution using a surfactant dodecyl benzene sulfonic acid (DBSA). Ultrasonication was used to dissolve nylon-6 into the formic acid/particle dispersion. Electrospinning of virgin polymer solution and particle filled polymer system was carried out with polymer concentration of 15% w/v. The particle loading was 3%w/w. SEM of the particle filled fibers show some bead formations and a diameter distribution of about 80–200 nm. The DSC analyses of the neat nylon polymer fibers and ferrite filled nanofibers show an increase in glass transition temperature from 55°C to 72°C. The melting temperature showed a decrease from 226°C to 201°C. The TEM images show the presence and some alignment of particles in the polymer. The electron diffraction pattern of ferrite nanoparticles confirms its crystalline nature.
Carbon/Nafion® Nanocomposite Thin Films as Potential Matrix-free Laser Desorption-Ionization Mass Spectroscopy Substrates
Authors: Kalkan A. Kaan , Fonash Stephen J. 
Published: April 2011

ABSTRACTCarbon/Nafion® nanocomposite thin films developed through a low-cost procedure were shown to function as high-sensitivity, low-noise, high-throughput laser desorption-ionization mass spectroscopy substrates for small molecule detection without the need of organic matrices. Our nanocomposite approach combines the strong light absorption feature of amorphous carbon with Nafion®'s efficient protonating capability to yield superior laser desorption-ionization.
Hook Formation of Electrically Driven DNA Collisions with Finite-Sized Obstacles
Authors: Randall Greg C. , Doyle Patrick S. 
Published: April 2011

ABSTRACTWe present a comprehensive study of the hooking mechanism of a single DNA molecule in electrophoretic motion colliding with a single microfabricated obstacle. During a collision, DNA impacts an obstacle and deforms. The impact conditions dictate whether this collision results in a “roll-off” event or “hooking” event. Our objective is to better understand the physics of a collision. Specifically, we note that a finite-sized insulating obstacle induces local electric field gradients that can enhance the size-dependent hooking probability. We validate that the hooking mechanism is analogous to a polymer in a transient, non-homogeneous elongational field with a strength characterized by the Deborah number, De. We then show that hook formation increases with De for finite-sized obstacles in the regime De<40.
Simulations of Polymeric Membrane Formation by Immersion Precipitation: Liquid-liquid Demixing
Authors: Zhou Bo , Powell Adam 
Published: April 2011

ABSTRACTThe immersion precipitation process makes most commercial microporous membranes, which enjoy widespread use in filtration and purification. This process begins with liquid-liquid demixing of a nonsolvent/solvent/polymer ternary system into polymer-rich and polymer-lean phases. This demixing step determines much of the final morphology. In this work, a ternary Cahn-Hilliard formulation incorporating a Flory-Huggins homogeneous free energy function is used to simulate phase separation during demixing. Then the formulation is coupled with constant-viscosity interface-driven fluid flow. Simulations begin with uniform initial conditions with small random fluctuations, and then with two-layer polymer-solvent/nonsolvent initial conditions to simulate actual membrane fabrication conditions. The results are presented in 2-D and 3-D, which demonstrate the effects of mp (degree of polymerization), Kij (gradient penalty coefficients) and χij (Flory-Huggins interaction parameters) on phase separation behavior.
Anomalous Kinetics of Depletion Zone Growth with One-Dimensional Geometry: Photobleaching Experiments and Simulations
Authors: Peng Hailin , Park Sung Hyun , Taitelbaum Haim , Kopelman Raoul 
Published: April 2011

ABSTRACTWe studied the kinetics of a diffusion-limited trapping reaction A + T → T in an effective one-dimensional geometry by experiments, supported by simulation calculations. The experiments are based on the photobleaching reaction of fluorescein dyes. The main parameter of interest is the θ-distance, which is related to the expansion of the depletion zone and can be measured directly from experiment. We found that θ-distance scales with t1/2 asymptotically, as predicted by previous theory. In addition, we found that the θ-distance increases faster than t1/2 inside the trap at early times, which has not been explored previously. Furthermore, there is a third, intermediate regime, with a slow increase of slope. Our experimental results are consistent with our simulation results.
Plasma Coating and Enhanced Dispersion of Carbon Nanotubes
Authors: He Peng , Lian Jie , Shi Donglu , Wang Lumin , Ooij Wim van , Mast David , Li W. Z. , Ren Z. F. 
Published: April 2011

ABSTRACTUltrathin polymer films have been deposited on both multi-wall and aligned carbon nanotubes using a plasma polymerization treatment. TEM experimental results showed that a thin film of polystyrene layer (several nanometers) was uniformly deposited on the surfaces of the nanotubes including inner wall surfaces of the multi-wall nanotubes. The coated multi-wall nanotubes were mixed in polymer solutions for studying the effects of plasma coating on dispersion. It was found that the dispersion of multi-wall carbon nanotubes in polystyrene composite was significantly improved. The deposition mechanisms and the effects of plasma treatment parameters are discussed.
Strength Variations during Mechanical Alloying Through the Nanostructural Range
Authors: Schuh Christopher A. , Schoen David T. , Lund Alan C. 
Published: April 2011

ABSTRACTDuring processes of mechanical alloying the characteristic structural length scales of an alloy, including the phase domain size and the crystallite grain size, decrease gradually to a nanocrystalline or even amorphous final state. This method therefore allows a unique avenue to explore the structure-property relationship over several orders of magnitude in length scale. In this work we have considered an ideal equiatomic Ti-Zr system deformed through multiple cold-rolling passes to refine the structural length scales into the nanometer range. The variation of the hardness of the system with decreasing length scale is discussed in terms of traditional Hall-Petch scaling, chemical mixing and the phase evolution of the system, as well as other possible contributions to the hardness variations during processing.
Structural Stability of Nano-Sized Clusters
Authors: De Hosson J. Th. M. , Palasantzas G. , Vystavel T. , Koch S. 
Published: April 2011

ABSTRACTThis contribution presents challenges to control the microstructure in nano-structured materials via a relatively new approach, i.e. using a so-called nanocluster source. An important aspect is that the cluster size distribution is monodisperse and that the kinetic energy of the clusters during deposition can be varied. Interestingly the clusters are grown in extreme non-equilibrium conditions, which allow obtaining metastable structures of metals and alloys. Because one avoids the effects of nucleation and growth on a specific substrate one may tailor the properties of the films by choosing the appropriate preparation conditions.
Bending of Nanoscale Thin Si Film Induced by Growth of Ge Islands: Hut vs. Dome
Authors: Huang Minghuang , Cuma Martin , Lagally M. G. , Liu Feng 
Published: April 2011

ABSTRACTWe perform atomistic simulations to compute bending of freestanding nanoscale thin Si film induced by strained Ge islands. We show that a larger Ge dome island can induce smaller bending than a smaller hut island and explain the surprising experimental observation for growth of Ge islands on patterned silicon-on-insulator substrate (SOI) with Si template layer thinned down to nanometer scale. This counterintuitive bending behavior is caused by strain sharing between the film and the ultra thin substrate.
Direct Measurement of the Nanoscale Mechanical Properties of NiTi Shape Memory Alloy
Authors: Shaw Gordon A. , Crone Wendy C. 
Published: April 2011

ABSTRACTThe mechanical properties of sputter-deposited NiTi shape memory alloy thin films ranging in thickness from 35 nm to 10 μm were examined using nanoindentation and atomic force microscopy (AFM). Indents made in films as thin as 150 nm showed partial shape recovery upon heating, although film thickness was found to have a marked effect on the results. A modified spherical cavity model is used to describe the findings, which suggest that the substrate tends block the shape memory effect as film thickness decreases below a threshold level which is specific to applied load. This has the net effect of decreasing the indent recovery below the critical film thickness. The fact that the spherical cavity model predicts the critical film thickness at which the shape memory effect is blocked indicates that the increased recovery of nanoscale indentations is due to a suppression of plastic processes rather than an enhancement of shape memory processes.
Effect of Coupling Agent on the Dispersion of PETG Montmorillonite Nanocomposite films.
Authors: Ranade Ajit , D'Souza Nandika , Gnade Bruce , Thellen Christopher , Orroth Caitlin , Froio Danielle , Lucciarini Jeanne , Ratto Jo Ann 
Published: April 2011

ABSTRACTPolyethylene terephthalate glycol (PETG) is a clear amorphous polymer, which is extensively used in flexible packaging. The dual packaging requirements of recyclability and long-term shelf life are often difficult to achieve. Meeting these needs become more urgent when considering food packaging for large volumes of soldiers positioned in different parts of the world. Our approach is to develop a high barrier PET packaging system via the Montmorillonite layered silicate (MLS) based nano technology. Prior research has indicated the significant impact of the polymer crystalline regions on the properties of the resultant nanocomposite. Therefore we must first investigate the amorphous PETG. We must also investigate the influence of increased matrix polarity on dispersion of the PETG by incorporating maleic anhydride (MA) onto the PETG backbone. The influence of the clay concentration and maleation are independently investigated. The glass transition of the as-processed and annealed samples are analyzed using Differential Scanning Calorimetry (DSC) while the thermal stability is determined using Thermogravimetric Analysis (TGA). Testing showed a slight depression in the glass transition temperature of PETG film when the MLS is introduced into the system. The nanocomposite films also demonstrated a lower thermal stability in relation to the neat PETG films. The barrier properties were determined on an in-house built calibration unit based on atomic mobility under high vacuum. X-ray diffraction and TEM were utilized to determine the dispersion of the MLS in PETG. The results indicate that the dispersion was concentration independent but maleation of the PETG led to a slight decrease in agglomeration. An increased ultimate tensile strength and modulus was observed in PETG nanocomposites. The barrier properties were improved by incorporating the MLS into the system. Maleation of the PETG resulted in significant yellowing of the nanocomposites.