bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction between Dislocation Sliding and Damage Structure in Ion-irradiated Stainless Steels
Authors: Miura Terumitsu , Fujii Katsuhiko , Fukuya Koji 
Published: August 2010

ABSTRACTThe interaction between dislocation sliding and damage structure in ion-irradiated austenitic stainless steels was investigated. Solution annealed type 316 and 304 stainless steels (316SS and 304SS) were irradiated with 2.8 MeV Fe2+ ions at 300 °C up to 10 dpa and tensiled to 2% plastic strain at 300 °C. Dislocations moving from unirradiated matrix were prevented due to the interactions with the damage structures consisted of dislocation loops and voids in the damage region. The prevention of dislocation movements by the damage structures became strong in 304SS compared in 316SS; probably due to lower stacking fault energy in 304SS. The prevention of dislocation movements was weak for Fe ion-irradiated specimens in which the increase in shear strength calculated from the size and number density of the defects was small compared to He ion-irradiated specimens.
Preparation of Asymmetric Thermosensitive Double-layer Gel
Authors: Iizawa Takashi , Terao Akihiro 
Published: August 2010

AbstractHeterogeneous amidation of poly(acrylic acid) gel-1,8-diazabicyclo-[5,4,0]-7-undecene salt (DAA) in N-methyl-2-pyrrolidone containing an excess of alkylamine and triphenylphosphite occurred from the surface to give the corresponding DAA-poly(N-alkylacrylamide) (PNAA) core-shell type gel, consisting of an unreacted DAA core and a quantitatively amidated shell layer. Further amidation of the DAA-PNAA core-shell type gel with a second alkylamine afforded a novel core-shell type gel consisting of two PNAA layers: PNAA(2) and PNAA(1). The resulting cylindrical PNAA(2)-PNAA(1) core-shell type gels were resistant to marked deformation caused by swelling/de-swelling because of their axial symmetry. This paper proposes a new approach to the preparation of asymmetric thermosensitive PNAA(2)-PNAA(1) double-layer gels by several procedures using the synthetic method of the core-shell type gels containing of poly(N-isopropylacrylamide) and poly(N-n-propylacrylamide) layers. Among the obtained asymmetric double-layer gels the model I type gel (cylindrical grooved PNNPA-PNIPA core-shell type gel) was markedly bent in water at temperatures between the lower critical solution temperatures of both layers.
Optical Fiber Loop Sensors for Structural Health Monitoring of Composites
Authors: Nguyen Nguyen Q , Gupta Nikhil 
Published: August 2010

AbstractIn the present work a fiber-optic loop-sensor is designed and tested for possible applications in structural health monitoring of composite materials. It is known that bending an optical fiber beyond a critical curvature leads to loss of optical power through the curved region. The optical power loss depends on the radius of curvature of the loop. The optical power can be measured by a photodetector and a change in the power due a change to the curvature can be measured. In the present research optical fiber-optic loop-sensors are developed that can exploit this concept. Single-mode optical fiber sensors having different loop radii, from 6-10 mm, are fabricated and calibrated for applied strain on the loop. The calibration is carried out using a 0.098 N load cell and a computer controlled translation stage having 50 nm step resolution. Results show that the sensors provide highly repeatable curves for loading and unloading cycles. Smaller loop radii lead to higher optical power losses, resulting in higher sensitivity. Calibration results show that such sensors can be used in structural health monitoring applications. In this approach the coating and cladding of optical fibers are maintained intact; therefore, the sensors are robust and can withstand several composites fabrication processes.
6 Watt Segmented Power Generator Modules using Bi2Te3 and (InGaAs)1-x(InAlAs)x Elements Embedded with ErAs Nanoparticles
Authors: Zeng Gehong , Bahk Je-Hyeong , Ramu Ashok T , Bowers John E , Lu Hong , Gossard Arthur C , Bian Zhixi , Zebarjadi Mona , Shakouri Ali 
Published: August 2010

AbstractWe report the fabrication and characterization of segmented element power generator modules of 16 x 16 thermoelectric elements consisting of 0.8 mm thick Bi2Te3 and 50 μm thick ErAs:(InGaAs)1-x(InAlAs)x with 0.6% ErAs by volume. Erbium Arsenide metallic nanoparticles are incorporated to create scattering centers for middle and long wavelength phonons, and to form local potential barriers for electron filtering. The thermoelectric properties of ErAs:(InGaAs)1-x(InAlAs)x were characterized in terms of electrical conductivity and Seebeck coefficient from 300 K up to 830 K. Generator modules of Bi2Te3 and ErAs:(InGaAs)1-x(InAlAs)x segmented elements were fabricated and an output power of 6.3 W was measured. 3D finite modeling shows that the performance of thermoelectric generator modules can further be enhanced by the improvement of the thermoelectric properties of the element materials, and reducing the electrical and thermal parasitic losses.
Density Functional Theory Calculations and Molecular Dynamics Simulations of the Interaction of Bio-molecules with Hydroxyapatite Surfaces in an Aqueous Environment
Authors: Almora-Barrios Neyvis , de Leeuw Nora H 
Published: August 2010

AbstractIn view of the importance of the hydroxyapatite/collagen composite of both natural bone tissue and synthetic biomaterials for hard tissue replacement, we have employed a combination of electronic structure calculations based on the Density Functional Theory and molecular dynamics simulations to investigate the adsorption of three major collagen I amino acids, as well as a complete peptide strand, at two hydroxyapatite surfaces, bothin vacuoand in a liquid water environment. The free amino acids as well as the peptide form multiple interactions with the surfaces and bind more strongly to the (01.0) surface than the (0001) surface, in agreement with experiment, which has found that in natural bone the (01.0) surface grows preferentially from a collagen matrix.
Fabrication of Novel Magnetic Janus Microparticles
Authors: Dyab Amro K. F. , Paunov Vesselin N. 
Published: August 2010

ABSTRACTWe have designed a novel technique for fabrication of magnetic Janus microparticles based on “trapping” the alignment of magnetite nanoparticles dispersed within the oil drops of polymerizable oil-in-water emulsion. We polymerized the oil drops after gelling the continuous aqueous phase in the presence of an external magnetic filed. This allowed us to produce magnetic Janus particles with optical and magnetic anisotropy which form unusual zigzag chains and structures when an external magnetic field is applied to a suspension of such particles. These novel microparticles retain high remanence magnetization and coercivity values indicative of ferromagnetic behavior, which indicates that the composite polymeric Janus microparticles posses a net magnetic dipole and behave like micro-magnets due to the “trapped” orientation of the magnetite nanoparticles in their polymeric matrix.
Crystallization-induced Stress in Phase Change Random Access Memory
Authors: Li Minghua , Li Jianming , Shi Luping , Yang Hongxin , Chong Tow Chong , Li Yi 
Published: August 2010

AbstractSwitched phase change material in Phase Change Random Access Memory (PCRAM) is confined within a solid surrounding. As a result of mechanical properties and microstructure differences between the crystalline and the amorphous phases, strains and stresses are generated and may degrade the performance of PCRAM devices. This paper investigated the crystallization-induced stress in phase change Ge2Sb2Te5 (GST) nano film. The electric-thermal and thermo-mechanical simulation results show that the increases of both of the Young's modulus and Coefficient of Thermal Expansion (CTE) are responsible for the stress generation upon crystallization. The XRD studies correlate the strains and stresses with the lattice deformation in crystalline GST films.
Bioconjugated Nanoparticle Disease Therapy Concept
Authors: Bianchi Maurice Peter 
Published: August 2010

AbstractThe concept uses nanoparticles or quantum dots that possess a bandgap that when an electron hole pair is generated by irradiating with photons above their bandgap would emit photons with a wavelength in the far ultraviolet (UV) region from about 300 down to 180 nanometers.This is the so-called germicidal ultraviolet light regime whose peak is centered at about 270 nm where all organisms (viruses, bacteria, parasites and molds) or cells that contain DNA or RNA are susceptible to mitigation.It has been shown by Shreier, et al (Thymine Dimerization in DNA is an Ultrafast Photoreaction, Science, Vol 315, 2 Feb. 2007, pgs 625-629) that when DNA, for example, is irradiated with UV light of 272 nm in wavelength the chemical bonds of the thymine base pairs of the DNA helix are broken and the ends dimerize to open up the helix thereby preventing it being a template for the production of another cell or organism resulting in apoptosis. By using femto-second time resolved infrared spectroscopy they found that the dimers are fully formed in about 1 picosecond. In this therapy concept the nanoparticle or quantum dot would first be made biocompatible with a coating such as dextrin to make it compatible with the body. Then an appropriate ligand, conjugate or monoclonal antibody would be attached to the particle that would be specific for attaching to the target organism or cell. In the case of cancer cells most have surface specific antigens that are unique to the cancer cell and not to normal cells. Monoclonal antibodies have and can be made to bind to these sites and not to normal cells. The treatment then would entail injecting these bioconjugated nanoparticles that possess the appropriate bandgap into the patient. The particles that did not attach would be excreted through the patient's renal system. After an appropriate interval the patient would be irradiated with x-rays in the KeV to MeV range. The particles would then emit large quantities of UV photons for every KeV or MeV absorbed x-ray photon that would disrupt the cell or organism's DNA that it was attached to leading to apoptosis of the cell or organism.U.S. and international patents have been applied for on the concept and, currently, two cancer researchers are in the process of being licensed to carry out research and development on the concept for the treatment of cancer.
A Lab-on-a-Chip for Clinical Analysis with Acoustic Microagitation based on Piezoelectric Poly(Vinilidene Fluoride)
Authors: Martins P. , Cardoso V. , Serrado Nunes J. , Rebouta L. , Rocha G. , Minas G. , Lanceros-Mendez Senentxu 
Published: August 2010

AbstractThis paper reports on the incorporation and validation of a microagitation system based on a piezoelectric polymer, Poly(vinylidene fluoride) in its beta phase, β-PVDF, in a fully-integrated disposable lab-on-a-chip for point-of-care testing and monitoring of biochemical parameters in biological fluids. The lab-on-a-chip concept offers a novel approach for clinical analyses, especially in biological fluids analyses, due to its portability, ensuring that the analysis can be performed at any location with quick results. Its microagitation system performance was successfully demonstrated by quantitative measurements of uric acid in human urine, though other molecules or biological fluids can be also measured. The optimization tests prove that it is possible to use lower frequencies than resonance with no major changes in the mixing process. The effect of area and location within the lab-on-a-chip of the microagitation system was also considered.
Diamond-like Carbon Film Coating for Tissue Engineering
Authors: Ohgoe Yasuharu , Matsuo Haruki , Nonaka Kazuhiro , Yaguchi Toshiyuki , Kanasugi Kazuya , Hirakuri Kenji , Funakubo Akio , Fukui Yasuhiro 
Published: August 2010

AbstractIn this study, we focus on effect of diamond-like carbon (DLC) coating on scaffold for tissue engineering. DLC film was deposited on segmented polyurethane (SPU) scaffold sheet which consists of micro SUP fibers. Structural and compositional effects of the DLC film coating were investigated on cell growth as an investigation of biological response. The surface composition, morphology, structures, and wettability of the DLC film coating was estimated by using X-ray photoelectron spectrometer (XPS), Scanning Electron Microscope (SEM), Ar-laser Raman spectrophotometer (Raman), and contact angle measurement. And then, human umbilical vein endothelial (HUV-EC-C) cells were grown on the DLC coated scaffold sheet. The results presented here suggest that DLC film coating is promising approach to improve biological for tissue engineering.
Electrical and structural properties of ultrathin polycrystalline and epitaxial TiN films grown by reactive dc magnetron sputtering
Authors: Magnus Fridrik , Ingason Arni Sigurdur , Olafsson Sveinn , Gudmundsson Jon Tomas 
Published: August 2010

AbstractUltrathin TiN films were grown by reactive dc magnetron sputtering on amorphous SiO2 substrates and single-crystalline MgO substrates at 600°C. The resistance of the films was monitored in-situ during growth to determine the coalescence and continuity thicknesses. TiN films grown on SiO2 are polycrystalline and have coalescence and continuity thicknesses of 8 Å and 19 Å, respectively. TiN films grow epitaxially on the MgO substrates and the coalescence thickness is 2 Å and the thickness where the film becomes continuous cannot be resolved from the coalescence thickness. X-ray reflection measurements indicate a significantly higher density and lower roughness of the epitaxial TiN films.
Rutherford Backscattering Spectrometry Analysis of Growth Rate and Activation Energy for Self-formed Ti-rich Interface Layers in Cu(Ti)/Low-k Samples
Authors: Kohama Kazuyuki , Ito Kazuhiro , Mori Kenichi , Maekawa Kazuyoshi , Shirai Yasuharu , Murakami Masanori 
Published: August 2010

AbstractA new fabrication technique to prepare ultra-thin barrier layers for nano-scale Cu wires was proposed in our previous studies. Ti-rich layers formed at the Cu(Ti)/dielectric-layer interfaces consisted of crystalline TiC or TiSi and amorphous Ti oxides. The primary control factor for Ti-rich interface layer composition was the C concentration in the dielectric layers rather than the formation enthalpy of the Ti compounds. To investigate Ti-rich interface layer growth in Cu(Ti)/dielectric-layer samples annealed in ultra high vacuum, Rutherford Backscattering Spectrometry (RBS) was employed in the present study. Ti peaks were obtained only at the interface for all the samples. Molar amounts of Ti atoms segregated to the interface (n) were estimated from Ti peak areas. Thenvalue was defined byn=Z·exp(-E/RT) · tm, whereZis a preexponential factor andEthe activation energy for the reaction. TheZ,E, andmvalues were estimated from plots of lognvs logtand lognvs 1/T. Themvalues are similar in all the samples. TheEvalues for Ti atoms reacting with the dielectric layers containing carbon (except SiO2) tended to decrease with decreasing C concentration (decreasingk), while reaction rate coefficients (Z·exp(-E/RT)) were insensitive to C concentration in the dielectric layers. These factors lead to conclusion that growth of the Ti-rich interface layers is controlled by chemical reactions of the Ti atoms with the dielectric layers represented by theZandEvalues, rather than diffusion in the Ti-rich interface layers.
Photonic Crystal Structures as Spectral Control for Thermophotovoltaic Energy Conversion
Authors: Fourspring Patrick Michael 
Published: August 2010

AbstractSpectral control is an enabling technology for greater than 10% efficient thermophotovoltaic (TPV) energy conversion [1-3]. Without control of the spectral distribution of photons reaching a TPV cell, the efficiency of a TPV energy conversion system suffers dramatically. Spectral control is the selection, design, and development of materials and structures used in TPV energy conversion systems to maximize the net flux of convertible (above band gap) photons, minimize the net flux of unconvertible (below band gap) photons, and recuperate (or reflect) any net flux of unconvertible (below band gap) photons that reach the TPV cell back to the radiating surface. Front surface, tandem filters consisting of an edge pass filter (short pass) in series with a highly doped, epitaxially grown layer have achieved the highest energy weighted spectral efficiency to date.The performance, however, of these tandem filters is limited by at least two fundamental physical phenomena: the variation in performance with the incident angle of the photons and absorption in the filter materials. Three dimensional (3D), photonic crystal structures offer a potential solution to these fundamental limitations of tandem filters as well as the potential of spectral control for the radiating surfaces of TPV energy conversion system. First, 3D photonic crystal structures, in theory, perform equally for all incident angles. Second, the fabrication techniques for 3D photonic crystal structures may allow the use of materials (such as crystalline Si) with less absorption in the spectral range of interest (1-15μm) than the materials currently used in tandem filters. The fabrication techniques for 3D photonic crystal structures may also allow the use of high temperature (1000°C) materials for use as radiating surface spectral control. If so, 3D photonic crystal structures may be used to mitigate several of the inefficiencies associated with TPV systems.The conclusion of this assessment is that 3D, photonic crystal structures can, in theory, provide near perfect TPV spectral control. If so, these structures may allow a 20% improvement over the performance achieved by tandem filters. Realizing this potential for TPV spectral control, however, will likely require significant development. At least two major challenges exist:• Design techniques will likely need to be developed that will allow the analysis and design of 3D photonic crystal structures.• Fabrication techniques will need to be developed for these structures that provide sufficient fidelity to a design to achieve the required performance and can be scaled to provide the area required for a given TPV application.
Fabrication of Cu(In,Ga)Se2 Films by a Combination of Mechanochemical Synthesis, Wet Bead Milling, and a Screen Printing/sintering Process
Authors: Kubo Junya , Matsuo Yoshihiro , Wada Takahiro , Yamada Akira , Konagai Makoto 
Published: August 2010

AbstractWe prepared fine Cu(In,Ga)Se2 (CIGS) powder suitable for screen printing using a mechanochemical synthesis and wet bead milling. Particulate precursors were deposited in a layer by a screen-printing technique, and the porous precursor layer was sintered into a dense polycrystalline film by atmospheric-pressure firing in an N2 gas atmosphere. The microstructure of CIGS powder and fired CIGS film were observed in an SEM. The wet bead milling was effective for the reduction and homogenization of the average grain size of CIGS powder. The CIGS grains in the film were well sintered and the size of CIGS grains was as large as about 2 μm. The CIGS solar cell showed an efficiency of 3.1%, with Voc of 0.279 V, Jsc of 28.8 mA/cm2 and FF of 0.386.
Fabrication of TiO2 Nanobelt Network for Dye-Sensitized Solar Cells
Authors: Li Haiyan , Jiao Jun 
Published: August 2010

AbstractInterconnected TiO2 nanobelt networks were prepared to serve as anode materials. The aim is to enhance the electron transport through the anode of dye-sensitized solar cells. Using an alkaline hydrothermal procedure and by controlling the reaction time, two kinds of nanostructures were synthesized: TiO2 nanobelts and the mixture of TiO2 nanobelts/TiO2 nanoparticles. This investigation suggests that TiO2 nanobelts are the result of the rearrangement of the [Ti(OH)6]2- monomers formed during the erosion process of TiO2 nanoparticles. The nanostructures of as-synthesized nanobelts were woven and interconnected, resulting in networks after an annealing process. Raman analysis indicates that both kinds of nanostructures were pure anatase. Electrical characterization suggests that the conductivities of these TiO2 nanobelt networks were higher than those of the TiO2 nanoparticle films. Under simulated sunlight with an intensity of AM 1.5 G, the solar cells made of TiO2 nanobelt networks show exceptional photocurrent in comparison to those made of TiO2 nanoparticles.
A III-nitride Layered Barrier Structure for Hyperspectral Imaging Applications
Authors: Bell Douglas , Tripathi Neeraj , Grandusky James , Jindal Vibhu , Shahedipour-Sandvik Fatemeh 
Published: August 2010

AbstractWe report on a novel photodetector structure based on III-nitride materials. A layered configuration is used to create a barrier with voltage-tunable height. The barrier is used as a filter on photoexcited holes and electrons, and could form the basis for a dynamically tunable pixel in a hyperspectral imaging array. This would eliminate the need for external gratings and filters used in conventional hyperspectral instruments; in addition, the tunability of pixels allows decrease of the array dimension by one. The III-nitride materials family is a good candidate for this device, combining large band offsets with the ability for epitaxial growth. We have demonstrated the feasibility of using III-nitride materials to fabricate layered tunnel barriers, and have demonstrated tunability of photodetection using these structures. External quantum efficiencies of > 12% have been achieved with prototype devices.
Polymer-Titania Composites for Photocatalysis of Organics in Aqueous Environments
Authors: Coutinho Cecil A , Gupta Vinay K 
Published: August 2010

AbstractMicrocomposites composed of titanium dioxide nanoparticles embedded within cross-linked, thermally responsive microgels of poly(N-isopropylacrylamide) were prepared. These microcomposites showed rapid sedimentation, which is useful for gravity separation of the titania nanoparticles in applications such as environmental remediation. To investigate the degradation kinetics using these microcomposites in aqueous suspensions, methyl orange was employed as a model contaminant. The decline in the methyl orange concentration was monitored using UV-Vis spectroscopy. Degradation of methyl orange was also measured using only nanoparticles TiO2 (DegussaTM P25) for comparison with the microcomposites. Experiments were performed at different pH conditions that spanned acidic, neutral, and basic conditions to gain insight into the interplay of TiO2 surface charge, ionization of the polyelctrolyte chains in the microcomposites, and ionization of the methyl orange.
TiO2 anatase nanotubes for the purification of uranium,arsenic and lead containing water: an X-ray Photoelectron Spectroscopy study
Authors: Bonato Marco , Ragnarsdottir Kristin Vala , Allen Geoffrey C. 
Published: August 2010

AbstractTiO2 anatase nanotubes synthesised via anodic oxidation were used as adsorbent for the uptake of U and Pb from aqueous solution and the photoremoval of As(III). An X-ray photoelectron spectroscopy study of the sorbent medium surface revealed a high adsorption of U and Pb at pH 8. The adsorption of the uranyl ion was enhanced in an anoxy (N2) atmosphere, because this prevents the formation of very stable carbonyl complexes. As(III) was adsorbed on TiO2 but in the presence of O2 and UV light was oxidized to As(V). XPS analysis revealed that in the pH range 3-9 As(V) was always the major species detected at the surface of the titania photocatalyst.