bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma agriculture based on quantitative monitoring of reactions between fungal cells and atmospheric-pressure plasmas
Authors: Ito Masafumi , Ohta Takayuki , Takeda Keigo 
Published: November 2012

ABSTRACTA high-density non-equilibrium atmospheric pressure plasma (NEAPP) applied for inactivating fungal spores of P. digitatum is introduced as an environmentally safe and rapid-inactivation method. The contributions of ozone, ultra violet (UV) radiation and ground-state atomic oxygen in the NEAPP on the inactivation of the spores are evaluated using colony count method.The absolute densities of ozone were measured by using ultraviolet absorption spectroscopy. The ozone density increased from 2 to 8 ppm with an increase in the distance from the plasma source, while the inactivation rate decreased. The inactivation rate of plasma was evaluated to be thousand times higher than that of an ozone generator using the integrated number density of ozone. In addition, it was clarified that the contribution of UV radiation to inactivation was not dominant for P. digitatum inactivation by NEAPP by filtering the active species using quartz plate. From these results, we can speculate that the inactivation efficiency of reactive oxygen species (ROS) will be larger than those of others.In order to investigate the effect of ground-state atomic oxygen as one of ROS, the inactivation of P. digitatum spores using an oxygen radical source that employs a high-density atmospheric-pressure O2/Ar plasma. The absolute O density was measured to be 1.4×1014 and 1.5×1015 cm–3 using vacuum ultra violet absorption spectroscopy (VUVAS) using a microdischarge hollow cathode lamp. The behaviors of the O densities as a function of O2/(Ar+O2) mixture flow rate ratio correspond to that of the inactivation rate. This result indicates that ground-state atomic oxygen is concluded to be the dominant species that causes inactivation.
Microencapsulation of Liquid Cyanoacrylate via In situ Polymerization for Self-healing Bone Cement Application
Authors: Gandham Vineela D. , Brochu Alice B.W. , Reichert William M. 
Published: November 2012

ABSTRACTStructural polymers are susceptible to accumulated damage in the form of internal microcracks that propagate through the material, resulting in mechanical failure. Self- healing approaches offer a solution to repair these damages automatically. The first generation self-healing material system includes a microencapsulated healing agent within a catalyst-embedded matrix. Propagating microcracks rupture the microcapsules, releasing the liquid healing agent into the damaged region. Catalyst-triggered polymerization of the released healing agent repairs the damage. Our research focuses on a similar approach for addressing “damage accumulation failure” of poly(methyl methacrylate) (PMMA) bone cement caused by microcrack initiation and propagation. In this study, polyurethane (PU) microcapsules containing a tissue adhesive, 2-octylcyanoacrylate (OCA) were synthesized using in situ interfacial polymerization of toluene-2,4-diisocynate (TDI) and polyethylene glycol 200 (PEG 200) through an oil-in-oil-in-water microemulsion (o/o/w). The process was optimized by studying different combinations of organic solvents, surfactants, temperatures, agitation rates, pH, and reaction times and their effects on microencapsulation were observed. Microcapsule surface morphology, size, shell thickness, encapsulated OCA viability, thermal degradation, and chemical structure of the microcapsule shell were evaluated using a stereoscope, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FT-IR).
Stability of Electrical Characteristics of SiC “Super” Junction Transistors under Long-Term DC and Pulsed Operation at various Temperatures
Authors: Sundaresan Siddarth G. , Soe Aye-Mya , Singh Ranbir 
Published: November 2012

ABSTRACTThe reliability of the electrical characteristics of SiC “Super” Junction Transistors (SJTs) is investigated under long-term avalanche-mode, DC and pulsed-current operation. There is absolutely no change in the blocking I-V characteristics after a 934 hour repetitive avalanche stress test. Long-term operation of the Gate-Source diode (open-Drain mode) alone does not result in any degradation of the on-state voltage drop (VF) or current gain (β). Long-term operation in common-Source mode results in negligible VF or β degradation, if the base-plate is maintained at 25 °C. A greater degradation of β results with increasing base-plate temperature. The same total electrical charge, if passed through the SJT as a pulsed current instead of a DC current results in a smaller β reduction. It is also shown that this β degradation can be reversed by annealing at ≥ 200 °C, suggesting the possibility of degradation-free operation of SiC SJTs, when operating in pulsed current mode at ≥ 200 °C temperatures.
Growth and processing of heteroepitaxial 3C-SiC films for electronic devices applications
Authors: Severino A. , Mauceri M. , Anzalone R. , Canino A. , Piluso N. , Vecchio C. , Camarda M. , Via F.La 
Published: November 2012

ABSTRACT3C-SiC is very attractive due the chance to be grown on large-area, low-cost Si substrates. Moreover, 3C-SiC has higher channel electron mobility with respect to 4H-SiC, interesting property in MOSFET applications. Other application fields where 3C-SiC can play a significant role are solar cells and MEMS-based sensors. In this work, we present a general overview of 3C-SiC growth on Si substrate. The influence of growth parameters, such as the growth rate, on the crystal quality of 3C-SiC films is discussed. The main issue for 3C-SiC development is the reduction of the stacking fault density, which shows an exponential decreasing trend with the film thickness tending to a saturation value of about 1000 cm-1. Some aspect of processing will be also faced with the realization of cantilever for Young modulus calculations and the implantation of Al ions for the study of damaging and recovery of the 3C-SiC crystal.
Conversion of Basal Plane Dislocations to Threading Edge Dislocations by High Temperature Annealing of 4H-SiC Epilayers
Authors: Zhang Xuan , Tsuchida Hidekazu 
Published: November 2012

ABSTRACTConversion of basal plane dislocations (BPDs) to threading edge dislocations (TEDs) has been observed in 4H-SiC epilayers by simple high temperature annealing. Grazing incidence reflection synchrotron X-ray topography was used to image the dislocations in the epilayers. By comparing the X-ray topographs before and after annealing, some of the BPDs were confirmed to convert to TEDs from the epilayer surface. The dislocation behaviors during annealing are explained and the mechanism of BPD conversion is discussed. It is argued that the conversion process is realized by constricted BPD segments cross-slipping to the prismatic plane driven by the image force and TED glide on its slip plane driven by the line tension. Certain kinetic processes may assist the formation of constrictions on the BPDs.
Simple Structure and High Efficiency Phosphorescent OLEDs Using Narrow Band-gap Bipolar Host Material
Authors: Son Young Hoon , Kwon Jang Hyuk 
Published: November 2012

ABSTRACTWe report high-efficiency phosphorescent blue OLEDs with an organic three stacked structure. Using a high-triplet-energy-hole transporting material of TAPC and a high-triplet-energy-electron transporting material of TmPyPB, the organic three stacked structure has been realized with three new narrow band-gap blue host materials. These host materials have bipolar characteristics and high triplet energy of >2.8 eV. Very low onset voltages of 2.8~3.0 V and driving voltages of 4.2~4.6 V to obtain a brightness of 1000 cd/m2 are achieved in this three stacked device configuration. Maximum external quantum efficiency above 20% is reported.
One- vs two-step preparation of antimicrobial coatings composed of laser ablated copper nanoparticles and poly-lactic acid
Authors: Longano Daniela , Ditaranto Nicoletta , Cioffi Nicola , Di Niso Francesca , Sibillano Teresa , Mezzapesa Francesco P. , Ancona Antonio , Conte Amalia , Del Nobile Matteo A. , Sabbatini Luigia , Torsi Luisa 
Published: November 2012

ABSTRACTCopper-containing nanomaterials have been developed as antimicrobial additives for food packaging applications. These nano-antimicrobials are composed of copper nanoparticles (CuNPs) embedded in poly-lactic acid (PLA), which has been selected as a biodegradable polymer matrix. Copper nanostructures have been synthesized by laser ablation following two different protocols: (I) one-pot synthesis in presence of PLA and (II) in absence of polymer matrix. In the latter route, the as prepared CuNPs suspension has been subsequently mixed to a PLA solution. The resulting dispersions have been directly drop-cast on several substrates. Nanoantimicrobials have been characterized by UV-Vis and x-ray photoelectron spectroscopies, and transmission electron microscopy. The kinetics of copper release in aqueous solution from antimicrobial nanomaterials have been studied by means of Electro-Thermal Atomic Absorption Spectroscopy. Finally, preliminary biological tests have been performed on Pseudomonas species by JIS methods (Japanese Industrial Standard, JIS Z 2801:2000).
Multi-Scale Modeling of Interstitial Dislocation Loop Growth in Irradiated Materials
Authors: Ye Bei , Yun Di , Insepov Zeke , Rest Jeffrey 
Published: November 2012

ABSTRACTIn order to reduce the inherent uncertainty in kinetic theory models and promote their transition to become predictive methodologies, a multi-scale modeling approach is proposed and demonstrated in this work. KiValues of key materials properties such as point defect (vacancy and interstitial) migration enthalpies, as well as kinetic factors, such as dimer formation and defect recombination coefficients and self-interstitial atom – interstitial loop reaction rates, were obtained by ab initio/molecular dynamics calculations. A rate theory model was used to interpret the evolution of dislocation loops in irradiated molybdenum. Calculations of the dose dependence of average loop diameter were performed and compared to experimental measurements obtained from irradiations with high-energy electrons. The comparison demonstrates reasonable agreement between model-predicted and experiment-measured data.
Measurement of the Phonon Density of States of PuO2(+2%Ga)
Authors: Manley M. E. , Jeffries J. R. , Said A. H. , Marianetti C. A. , Cynn H. , Leu B. M. , Wall M. 
Published: November 2012

ABSTRACTInelastic x-ray scattering measurements of the phonon density of states (DOS) of PuO2(+2%Ga) were made and compared to recent predictions from the literature made using three leading theoretical approaches; Density Functional Theory (DFT), DFT plus the Hubbard U (DFT+U), and Dynamical Mean-Field Theory (DMFT). The DFT prediction, which does not account for strong electronic correlations, underestimates the measured energies of most features. The DFT+U and DMFT predictions, which include approximations to strong correlation effects, more accurately reflect the low energy features but exaggerate splitting in the highest energy optic oxygen modes. The exaggeration of the splitting is worse for DFT+U than for DMFT. The transverse acoustic mode shows the least sensitivity to calculation type, and is well reproduced by all three theories. The longitudinal acoustic mode, which is thought to control the thermal conductivity, is more sensitive to calculation type, suggesting an important role for electronic correlations in making application-critical predictions.
Thermo-optics of Luminescent Solar Concentrators
Authors: Hajiaboli Ahmadreza , Andrews Mark P. 
Published: November 2012

ABSTRACTWe present a numerical study on effect of temperature on the performance of a waveguide luminescent solar concentrator (LSC). The purpose is to determine how changes in temperature of the ambient environment of an LSC affect device performance. The thermo-optical coefficient of the polymer waveguide is modeled using the well known Prod’homme formulation and applied in a forward Monte Carlo ray-tracing simulation. We show that the number of collected photons decreases almost linearly as the ambient temperature increases from -50 ºC to +50ºC. This behavior is associated with several competing loss mechanisms in the waveguide. For example, increases in optical confinement due to increased refractive index at low temperature are opposed by increases in cone loss (escape loss) of photons. Other competing mechanisms that exhibit temperature dependence are explained in terms of a detailed balance treatment of the LSC as a function of temperature.
Manipulation of 10 – 40 μm Diameter Cells Using a Thermally Actuated Microgripper
Authors: Daunton Rachael , Gallant Andrew J. , Wood David 
Published: November 2012

ABSTRACTThis work presents the successful fabrication of a thermally actuated U-shaped microgripper that has been specially designed to enable low voltage operation for bidirectional in plane deflection. The microgripper tips are carefully designed to match the biological species being manipulated, which has been demonstrated by the successful manipulation of 10 – 40 μm diameter particles used to simulate biological cells.
Improved Temperature Stability of Atomic Layer Deposition Coated Cellulose Nanocrystal Aerogels
Authors: Smith Sean W. , Chan Han , Buesch Christian , Simonsen John , Conley John F. 
Published: November 2012

ABSTRACTAtomic layer deposition (ALD) was used to coat cellulose nanocrystal (CNC) aerogel scaffolds with a thin conformal layer of Al2O3. Electron probe microanalysis indicates that the penetration of Al2O3 into the aerogel was greater than 50 μm. Thermogravimetric analysis (TGA) shows that Al2O3 coated CNC aerogel composites have improved temperature and oxidation resistance.
Antimony sulfide and Silver antimony sulfide absorbers for thin film solar cells
Authors: Jesús Capistrán M. , Nair M.T.S. , Nair P.K. 
Published: November 2012

ABSTRACTThin films of antimony sulfide (Sb2S3) were prepared with different silver-ion content in a chemical deposition bath, and silver antimony sulfide (AgSbS2) was produced through the addition of higher concentrations of silver-ions in the bath. The chemical deposition solution mixture contained antimony trichloride (SbCl3) and sodium thiosulfate (Na2S2O3). For molar ratio, AgNO3:SbCl3, 0.002 – 0.02, XRD patterns of the Sb2S3-Ag films heated at 280 ºC match that of the mineral stibnite (Sb2S3). The optical band gap (Eg) of these films is in the 1.93-1.80 eV range. At higher molar concentrations of Ag, lower is the Eg of the films. Electrical conductivity under illumination (σph) is 7.4x10-5 Ω-1cm-1 for a film with Ag:Sb 0.002 in the bath, which is about three orders of magnitude higher than that of a film prepared without Ag. At Ag:Sb 0.2, the XRD pattern of the heated film shows the presence of Ag3SbS3 and AgSbS2. Single-phase AgSbS2 (cubic miargyrite, a = 0.5652 nm) film is formed for Ag:Sb 0.4 and the film heated at 260 oC. The Eg of the film is 1.75 eV for the Sb2S3/Ag-Sb-S film and 1.68 eV for AgSbS2. Solar cell structures of TCO(SnO2:F)/CdS(200 nm)/Sb2S3(150 nm)/graphite, as well as with Sb2S3-Ag absorbers were developed through sequential chemical deposition. The cells with the colloidal graphite paint on the absorber were heated at 260 ºC for 15 min each. The Voc of the cells are 620-635 mV, with the cell using Sb2S3-Ag (0.004) film showing a Jsc of 2.00 mA/cm2, which is higher than the 1.69 mA/cm2 observed in cells with Sb2S3 absorber. In cells using AgSbS2 absorber, Voc is 490 mV, and Jsc is very low, 0.12 mA/cm2. The present work offers a wider range of absorber materials for thin film and hybrid solar cells.
Ab initio determination of the elastic properties of cubic Ge1Sb2Te4
Authors: Kohary K. , Marmier A. S. H. , Wright C. D. 
Published: November 2012

ABSTRACTThe elastic properties of chalcogenide materials used for phase change applications in rewritable optical media (such as CD-RW, DVD-RW, etc) are still poorly characterized and the previously published experimental and theoretical values show large discrepancies. In this manuscript, we review these results and carry out a careful analysis of the elastic properties of a model system, crystalline Ge1Sb2Te4, using density functional theory and elastic anisotropy considerations. We show that Ge1Sb2Te4exhibits significant anisotropy in its elastic properties.
A Thin-Film Infrared Absorber using CNT/Nanodiamond Nanocomposite
Authors: Sui Yu , Gokhale Vikrant J. , Shenderova Olga A. , McGuire Gary E. , Rais-Zadeh Mina 
Published: November 2012

ABSTRACTThis paper reports on the fabrication and characterization of thin-film nanocomposites comprised of tangled carbon nanotubes in a polymer matrix. The concentration of nanotubes in the polymer was significantly increased using detonation nanodiamonds. Nanodiamonds reduce the surface forces between the polymer and the nanotubes and mitigate the agglomeration problem of nanotubes in polymer. This resulted in thinner and more uniform networks that are efficient absorbers of infrared energy over a broad spectrum, ranging from the visible to the mid-wavelength infrared. An infrared absorbance of 97% was achieved for a 1.6 μm thick nanocomposite film across the spectral range of 714 nm to 5 μm. The films are mechanically and thermally stable up to 300 °C, and can be integrated with microbolometers to enhance their responsivity.
Electrospun Nylon-Graphene Nanocomposites Synthesis and Microstructure
Authors: Albañil-Sanchez Loyda , Romo-Uribe Angel , Flores Araceli , Cruz-Silva R 
Published: November 2012

ABSTRACTThere has been much interest in the last few years on materials reinforced with nanometer scale particles. These so-called nanocomposites can exhibit hybrid properties derived from its components. One of the most promising nanocomposites is that based on polymers reinforced with single-layered carbon sheets named graphene. The reason is that graphene can significantly improve the physical properties of the polymeric material once it is completely dispersed in the matrix. In this work nylon/graphene nanocomposites were prepared starting from the synthesis of graphite oxide (GO). Direct oxidation of graphite powder was utilized to produce GO. That is, the oxidation reaction produced graphite layers with functional groups containing oxygen. The aim was to increase the polarity of GO to enable a good dispersion in polar solvents. Then, nylon/graphene nanocomposites were prepared by reducing GO in the presence of nylon. Finally, non-woven membranes, with nanometer sized filaments, of nylon/graphene were electrospun. The morphology and microstructure of the nanocomposites was investigated via electron microscopy and X-ray diffraction.
Conductive AFM: Probing Nano-scale Electrical Properties of Model Cell Membranes
Authors: Farrar Paul , Atkinson Del , Gallant Andrew J. 
Published: November 2012

ABSTRACTBiologically relevant lipid bilayers supported on highly ordered pyrolytic graphite (HOPG) were probed both mechanically and electrically with a Conductive Atomic Force Microscope (C-AFM) capable of measuring ultra-low currents. Results show that these membranes undergo an elastic response up to 26 nN on average when compressed with an AFM tip. Measuring the films with a low contact force demonstrates that contact mode AFM can be used repeatedly to image without damaging the film. Based on current-voltage measurements made with the C-AFM, it is shown that apparently high resistances seen for the films could be the result of variable electrical contact between the tip and surface. As a result, the paper proposes that the deflection of the cantilever should always be measured in order to ensure knowledge of the location of the tip during all electrical measurements.
Electronic Structure, Localization and 5f Occupancy in Pu Materials
Authors: Beaux Miles F. , Joyce John J. , Durakiewicz Tomasz , Graham Kevin S. , Bauer Eric D. , Mitchell Jeremy N. , Tobash Paul H. , Richmond Scott 
Published: November 2012

ABSTRACTThe electronic structure of delta plutonium (δ-Pu) and plutonium compounds is investigated using photoelectron spectroscopy (PES). Results for δ-Pu show a small component of the valence electronic structure which might reasonably be associated with a 5f6 configuration. PES results for PuTe are used as an indication for the 5f6 configuration due to the presence of atomic multiplet structure. Temperature dependent PES data on δ-Pu indicate a narrow peak centered 20 meV below the Fermi energy and 100 meV wide. The first PES data for PuCoIn5 indicate a 5f electronic structure more localized than the 5fs in the closely related PuCoGa5. There is support from the PES data for a description of Pu materials with an electronic configuration of 5f5 with some admixture of 5f6 as well as a localized/delocalized 5f5 description.
Alpha-Decay Effects in 241Am-Doped Gadolinium Zirconate
Authors: Stefanovsky S.V. , Ptashkin A.G. , Yudintsev S.V. , Myasoedov B.F. 
Published: November 2012

ABSTRACTSample of zirconate ceramic with a composition corresponding to formula Gd1.7241Am0.3Zr2O7 was synthesized by heat-treatment of mechanically activated and compacted in pellet oxide mixture at 1500 °C for 30 min. The d values on XRD pattern of the sample soon after synthesis (D = 7.9×1015 α-decays/g or 0.001 dpa) demonstrated fluorite structure with the most intensive peak with d111 =3.042 Å (a = 5.269 Å) and very weak diffuse reflections due to d-pyrochlore. At a dose of 7.9×1017 α-decays/g or 0.11 dpa the reflections were broadened by approximately 20% and their relative intensity slightly reduced. At higher doses all the weak superstructure reflections disappeared and the growth in intensity and narrowing of the main reflection occurred. Lattice parameter a increased with the dose and reached 5.343 Å (d111 = 3.085 Å) at a dose of 4.6×1018 α-decays/g or 0.42 dpa. At a dose of 5.5×1018 α-decays/g or 0.78 dpa positions of reflections were shifted to lower d-spaces (d111 value reduced to 3.071 Å) and the half-width of the major reflection was 67% of initial. For the 241Am-doped Gd-zirconate the structure recovery rate exceeds disordering rate and no amorphization occurred at doses higher than ∼0.2-0.3 dpa.
Adsorption of Atmospheric Gases on Pu Surfaces
Authors: Nelson A.J. , Holliday K.S. , Stanford J.A. , Grant W.K. , Erler R.G. , Allen P. , McLean W. , Roussel P. 
Published: November 2012

ABSTRACTSurface adsorption represents a competition between collision and scattering processes that depend on surface energy, surface structure and temperature. The surface reactivity of the actinides can add additional complexity due to radiological dissociation of the gas and electronic structure. Here we elucidate the chemical bonding of gas molecules adsorbed on Pu metal and oxide surfaces. Atmospheric gas reactions were studied at 190 and 300 K using x-ray photoelectron spectroscopy. Evolution of the Pu 4f and O 1s core-level states were studied as a function of gas dose rates to generate a set of Langmuir isotherms. Results show that the initial gas dose forms Pu2O3 on the Pu metal surface followed by the formation of PuO2 resulting in a layered oxide structure. This work represents the first steps in determining the activation energy for adsorption of various atmospheric gases on Pu.
Melting Temperatures and Thermal Conductivities of Corium Prepared from UO2 and Zircaloy-2
Authors: Kato Masato , Uchida Teppei , Hirooka Shun , Akashi Masatoshi , Komeno Akira , Morimoto Kyoichi 
Published: November 2012

ABSTRACTCorium which simulates the molten core of a Boiling Water Reactor was prepared as a parameter of Zr content, and melting temperatures and thermal conductivities were measured. The melting temperatures were measured by the thermal arrest method and were 2622 oC, 2509 oC and 2540 oC, respectively, in the specimens of 24.3 at%, 49.0 at% and 73.5 at% Zr content. Thermal conductivities had low values of 2.0-3.5 W/m oC at temperatures of 400 to 1600 oC.