bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal Friction and Dynamic Modulus in High Temperature Ru-Nb Shape Memory Intermetallics
Authors: Dirand Laura , Nó Maria L. , Chastaing Karine , Denquin Anne , San Juan Jose 
Published: February 2013

ABSTRACTNowadays, aeronautic and aerospace are the more demanding sectors for shape memory alloys (SMA) after the bio-medical one. In particular the interest has been recently focused on very high temperature SMA, which would be able of working as sensors and actuators in the hot areas of the engines and exaust devices.In the present work we undertook a study of the Ru-Nb SMA Intermetallics, which undergo two succesive martensitic transformations around 1050 K and 1180 K respectively, depending on composition. This study has been focused on measurements of internal friction spectra and dynamic modulus variation up to 1700 K, which have been carried out in a sub-resonant torsion mechanical spectrometer.The internal friction and dynamic modulus have been studied as a function of the heating-cooling rate and the frequency in order to compare experimental behaviour with theoretical models for martensitic transformations. In addition to the internal friction peaks linked to both martensitic transformations we have also observed a complex relaxation process around 950 K, which seems to be linked to the interaction of the martensite interfaces with structural defects. An analysis and discusion of the potential microscopic mechanisms are also presented.
Effect of Re addition on microstructure and mechanical properties of Ni base dual-two phase intermetallic alloys
Authors: Ishii S. , Moronaga T. , Kaneno Y. , Tsuda H. , Takasugi T. 
Published: February 2013

ABSTRACTThe effect of Re addition on microstructure and hardness of the Ni3Al (L12) and Ni3V (D022) dual two-phase intermetallic alloys was investigated as functions of alloying (substituting) method of Re and aging condition (temperature and time). Re was added to the base alloy composition by three methods: Re was substituted for Ni, Al and V, respectively. The Re-added alloys were solution-treated at 1553 K and then aged at lower temperatures of 1123 K-1248 K. Apparent age hardening occurred in the alloy where Re was substituted for Ni while no age hardening was observed in the alloys where Re was substituted for Al or V. In the case of the latter two alloys, the hardness was unchanged or reduced with a progression of aging time. These results were discussed in terms of phase separation and ordering in the channel region, and hardening due to Re-rich phase precipitation.
Compression of Micro-pillars of a Long Period Stacking Ordered Phase in the Mg-Zn-Y system
Authors: Inoue Atsushi , Kishida Kyosuke , Inui Haruyuki , Hagihara Koji 
Published: February 2013

ABSTRACTDeformation behavior of an 18R-type long period stacking ordered (LPSO) phase in the Mg-Zn-Y system was studied by micro-pillar compressions of single crystalline specimens prepared by focused ion beam (FIB) technique as a function of loading axis orientation and specimen dimensions. When the loading axis is inclined to the basal plane of the LPSO phase by 42°, basal slip of (0001)<11$\bar 2$0>-type is activated irrespective of the specimen dimensions. When the loading axis is parallel to the basal plane, the formation of thick deformation bands are observed for all specimens tested. Strong size-dependence of yield stress values is observed for both types of micro-pillar specimens with different loading axis orientations.
The Mechanical Properties of Near-equiatomic B2/f.c.c. FeNiMnAl Alloys
Authors: Wu Xiaolan , Baker Ian , Wu Hong , Munroe Paul R. 
Published: February 2013

ABSTRACTTwo types of as-cast microstructures have been observed in a series of near-equiatomic FeNiMnAl alloys: 1) an ultrafine microstructure in Fe30Ni20Mn20Al30 [1] and Fe25Ni25Mn20Al30, which consists of (Fe, Mn)-rich B2-ordered (ordered b.c.c.) and (Ni, Al)-rich L21-ordered (Heusler) phases aligned along <100>; and 2) a fine two-phase microstructure in Fe30Ni20Mn30Al20 and Fe25Ni25Mn30Al20, which consists of alternating (Fe, Mn)-rich f.c.c. and (Ni, Al)-rich B2-ordered platelets with an orientation relationship close to f.c.c (002) // B2 (002); f.c.c. [011] // B2 [001] [2]. The phases in Fe25Ni25Mn20Al30 coarsened upon annealing with no significant change in the chemical partitioning. The hardness behavior was studied as a function of the annealing time at 823 K. AnL21-to-B2 transition, which occurred at 573-623K, was observed using in-situ heating in a TEM. After annealing at 973 K for 100 h, needle-shaped clusters of (Fe, Mn)-rich precipitates were observed along the grain boundaries and in the matrix. The temperature dependence of the yield strength of as-cast Fe25Ni25Mn20Al30 was also studied.
Synthesis and Characterization of Boron-Doped Single Crystal Diamond
Authors: Karna Sunil K. , Martyshkin D. V. , Vohra Yogesh K. , Weir Samuel T. 
Published: February 2013

ABSTRACTThe boron-doped single crystal diamond films were grown homoepitaxially on synthetic (100) oriented Type Ib diamond substrates using a Microwave Plasma Chemical Vapor Deposition (MPCVD) technique. Raman spectrum showed a few additional bands at the lower wavenumber regions along with the zone center optical phonon mode for diamond. The change in the peak profile of the zone center optical phonon mode and its downshift were observed with the increasing boron content in the film. A modification in surface morphology of the film with increasing boron content had been observed by atomic force microscopy. Four point probe electrical measurement indicated that different conduction mechanisms are operating in various temperature regions for these semiconducting films.
Study and Optimization of PECVD Films Containing Fluorine and Carbon Layered with Diamond Like Carbon Films as Ultra Low Dielectric Constant Interlayer Dielectrics
Authors: Sundaram Nandini G. , Ramachandran Seetharaman , Lee Gil-Sik , Overzet Lawrence 
Published: February 2013

ABSTRACTLayered dielectric films comprising of Diamond like Carbon (DLC) and Amorphous Fluorocarbon (a:C-F) were generated using three different stack configurations for ultra low dielectric constant (ULK) applications. These include a DLC – a:C-F – DLC sandwich, a:C-F – DLC topcoat only and an annealed a:C-F – DLC topcoat only film stack. These films were subsequently evaluated for thickness, dielectric constant, contact angle, surface roughness and chemical structure using IR analysis. Thermal stability was analyzed after annealing in Argon ambient at 400°C for 1 hour. Deposition conditions were optimized for film thickness, roughness, dielectric constant and contact angle using Minitab by tuning process pressure, substrate temperature and FRR. The modified Gaseous Electronics Conference (mGEC) reference cell was used to deposit DLC films using CH4 and Argon as precursors. Structural properties of the deposited thin film were studied using laser excitation of 633 nm in a Jobin Yvon Labram high-resolution micro-Raman spectrometer. Multiple points on each sample were analyzed in terms of the disordered carbon (D-peak) and graphitic carbon (G-peak). The thin film of DLC was subsequently annealed in Ar ambient for 1 hr at 400°C and analyzed. Commercially available graphing software was utilized to deconvolute peaks and the ratio of their intensities as well as the shift in their positions were determined to characterize the as-deposited and annealed film. The film was further characterized using AFM, FTIR, XRD, goniometry and electrical testing. Average film roughness as measured by AFM was less than 1 nm, the k-value was 2.5 and the contact angle with water was 42°. A:C-F films were separately deposited using CF4 and Si2H6 (5% by volume in He) as precursors in a UNAXIS PECVD system. Films deposited using substrate temperatures between 120°C – 200°C, chamber pressure of 300 and 500 mTorr and power of 100 W were independently evaluated in terms of their electrical, physical, structural and optical properties prior to layering with DLC films. After process optimization, seven unique process conditions generated promising layered films with k-values between 1.69 and 1.95. Of these, only one film exhibited very low shrinkage rates acceptable for semiconductor device processing.
Research and development activities for cleanup of the Fukushima Daiichi Nuclear Power Station
Authors: Sasaki Toshiki , Kaminishi Shuji , Miyamoto Yasuaki , Funasaka Hideyuki 
Published: February 2013

ABSTRACTThe Fukushima Daiichi nuclear power station accident and restoration works have produced significant volume of radioactive waste. The waste has very different characteristics from usual radioactive waste produced in nuclear power stations and it requires extensive research and development for management of the waste. R&D works such as analysis of the waste properties, hydrogen generation by radiolysis and diffusion in a storage vessel and corrosion of storage vessels, etc. have been performed for characterization and safe storage of the waste. The detailed R&D plan for processing and disposal waste will be established by the end of FY2012.
Preparation and Characterization of Blends of Polyaniline with Poly(Hydroxybutyrate-Co-Valerate)
Authors: da Silva David C. , Lemes Ana Paula , Guerrini Lilia M. , Cristovan Fernando H. 
Published: February 2013

ABSTRACTIn this study the PANI/PHBV blends were prepared and thermal properties, crystallization behavior, microstructure of the blends were investigated. The PANI/PHBV blends were prepared by dissolution of PANI (emeraldine base doped with dodecylbenzenesulphonic acid, DBSA) and PHBV in chloroform and films were obtained by casting. PANI amount in the blend was varied from 0.1 to 1% wt. PANI/PHBV blends were characterized by FTIR spectroscopy and the thermal behavior were analyzed by differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). FTIR spectra of the pure PHBV and PANI/PHBV blend had similar peaks. However, blends spectra show an enlargement of bands, due interaction of the chain PANI with PHBV matrix. The crystallization behaviors were investigated using DSC, with at a scanning rate of 10oCmin−1. Curve of pure PHBV showed two melting peaks (159.1°C and 172.3°C). With the increase of PANI amount in the PHBV matrix, both of the melting peaks became wider and shifted to lower temperatures. The decrease trend of first and second melting points with increase of PANI amount, suggests a reduction in the crystallinity of the blends.
Decontamination of School Facilities in Fukushima-city
Authors: Yoshikawa Hideki , Iijima Kazuki , Sasamoto Hiroshi , Fujiwara Kenso , Mitsui Seiichiro , Kitamura Akira , Kurikami Hiroshi , Tokizawa Takayuki , Yui Mikazu , Nakayama Shinichi 
Published: February 2013

ABSTRACTFollowing the release of radionuclides into the environment as a result of the accident at Fukushima Daiichi nuclear power plant, Japan Atomic Energy Agency (JAEA) had to develop an immediate and effective method of reducing the dose rate received by students in school facilities. A demonstration of a reducing method was carried out by JAEA at a junior high school ground and kindergarten yard in the center of Fukushima-city. Dose rates of the released radionuclides are largely controlled by the ground level contamination and accumulation of mainly Cesium137 (Cs-137) and Cesium 134 (Cs-134) in populated areas. An effective means of reducing dose rate was to remove the surface soil and to bury it on-site under fresh uncontaminated soil or soil collected under deep depth at the site for shielding. The dose rate at1 m above ground level was reduced from 2.5 µSv/h to 0.15 µSv/h.
Amorphous Bismuth: Structure-Property Relations and the Size of the Supercell
Authors: Mata-Pinzón Zaahel , Valladares Ariel A. , Valladares Alexander , Valladares R. M. 
Published: February 2013

ABSTRACTIt has been argued that for the simulation of amorphous materials, the larger the periodic supercell the better the representation. We contend that for certain properties there is a minimum supercell size above which one obtains a good representation of the topological and electronic collective properties of the material independent of the size. To show this contention we have chosen two periodic supercells of bismuth, one with 64 atoms and another with 216 atoms, which were amorphized using ourundermelt-quenchapproach [1]. The originally crystalline structures were subjected to a heating-and-cooling process starting at an initial temperature of 300 K and linearly going up to 540 K, in 100 simulational steps, 4.5 K just below the melting temperature of bismuth (theundermeltsection of the process) under normal conditions of pressure. Next, the sample was cooled down to 0K (thequenchsection of the process), in 225 simulational steps with the same absolute cooling rate as the heating process. Then the samples obtained were geometry-optimized to find the final metastable amorphous structures. These structures were analyzed by calculating their radial (pair) distribution functions, the plane angle distributions and the electron densities of states. Results will be presented that manifest that after proper normalization due to the difference in the number of atoms and the number of electron energy levels, the two structures are, for all practical purpose, the same, indicating that in this case, the size of the cell does not seem to play a major role in the properties determined.
Sensitivity Analysis for the Scenarios on Deterioration or Loss of Safety Functions Expected in Disposal System Due to Human Error on Application of Engineering Technology
Authors: Takeda Seiji , Inoue Yoshihisa , Kimura Hideo 
Published: February 2013

ABSTRACTThe sensitive analysis of radionuclide migration for the scenarios on deterioration or loss of safety functions expected in HLW disposal system due to the human error (initial defective scenarios) is performed in this study. Release rates for Cs-135 and Se-79 are estimated from Monte Carlo-based analysis. Maximum release rates of Se-79 and Cs-135 from natural barrier in initial defective scenarios for vitrified waste and overpack are approximately equivalent to that in normal scenario on all safety function working. Maximum release rate of Se-79 in initial defective scenario of buffer under the condition of colloidal migration is about 30 times as high as that in normal scenario. Maximum release rate of Cs-135 in initial defective scenario of plugs is about two orders of magnitude higher than that in normal scenario. These results especially indicate the need to understand the feasibility on two types of initial defective scenario, leading to the loss of restraint for colloidal migration in buffer and the loss of restraint with plugs from short-circuit migration.
NMR Study of Interlayer and Non-interlayer Porewater in Water-saturated Bentonite and Montmorillonite
Authors: Carlsson Torbjörn , Muurinen Arto , Root Andrew 
Published: February 2013

ABSTRACTBentonite is planned to be used in many countries as an important barrier in high-level waste repositories. Assessment of the barrier with regard to,inter alia, its ability to hinder transport of dissolved radionuclides leaking from a damaged canister containing spent nuclear fuel, requires quantitative data about the pore structure inside bentonite. The present NMR study was made in order to determine the number of distinguishable porewater phases in compacted water-saturated samples of MX-80 bentonite and Na-montmorillonite. The samples were compacted to dry densities in the interval 0.7-1.6 g/cm3and subsequently saturated with Milli-Q water or 0.1 M NaCl solution in equilibrium cells. The NMR measurements were performed with a high-field 270 MHz NMR spectrometer using a short inter-pulse CPMG method to study proton T1ρrelaxation. The measured relaxation curves were found to consist of one faster and one slower proton relaxation. Subsequent analysis of the data indicated that the faster relaxation was associated with interlayer (IL) water between montmorillonite unit layers, while the slower one was associated with non-interlayer (non-IL) water located outside the interlayer spaces. The results indicate for compacted samples with a dry density of ≥ 1.0 g/cm3, that Na montmorillonite contains a larger relative volume of non-IL water than the corresponding MX-80 bentonite. This in turn, suggests that the stacking number in Na-montmorillonite is smaller than in MX-80 bentonite. Changing the porewater chemistry seemed to have some effect on the non-IL water content in the Na montmorillonite but not in the MX-80 bentonite.
Transgenic Corn Rootworm Protection Increases Grain Yield and Nitrogen Use of Maize
Authors: Haegele Jason W. , Below Frederick E. 
Published: February 2013

ABSTRACTMaize (Zea mays L.) hybrids expressing Bacillus thuringiensis (Bt) derived resistance to corn rootworm (Diabrotica spp.) are widely grown. Our hypothesis was that Bt hybrids exhibit increased N uptake, resulting in greater grain yield and N use efficiency (NUE) relative to their nonprotected counterparts. In 2008 and 2009, two transgenic corn rootworm resistant (Bt) hybrids with VT3 (YieldGard VT Triple) technology along with their near‐isogenic non‐Bt Roundup Ready Corn 2 (RR2) counterparts were evaluated at Champaign, IL, with supplemental N of 0, 67, 134, 201 or 268 kg N ha−1. Despite minimal corn rootworm feeding pressure on roots, the Bt hybrids produced an average of nearly 1.1 Mg ha−1 more grain than their RR2 counterparts. In the comparison of DKC61‐72 RR2 and DKC61‐69 VT3, Bt protection promoted increased grain yield at low N (+1.0 Mg ha−1; P ≤ 0.01) and a 31% greater response to fertilizer N. With adequate N, grain yields of the comparison DKC63‐45 RR2 and DKC63‐42 VT3 did not differ; however, the latter maximized its yield with an average of 38% less fertilizer N. Increases in NUE (+80%; P ≤ 0.10) and N uptake efficiency (NUpE) (+31%; P ≤ 0.10) at the N rates required to optimize grain yield of Bt hybrids were detected in 2008, but NUE and NUpE were not significantly different between isolines in 2009. We conclude that transgenic corn rootworm protection has supplemental agronomic benefits, with greater N uptake and NUE in some environments.
Improvement of Upland Cotton Fiber Quality through Mutation of TAM 94L‐25
Authors: Brown Nino , Smith C. Wayne , Auld Dick , Hequet Eric F. 
Published: February 2013

ABSTRACTThe United States produces approximately 18 million 218‐kg bales of cotton (Gossypium spp.) annually. The global market places value on longer fibers, mandating that breeders develop cultivars to meet this demand. Mutation has not been used extensively in upland cotton breeding for improving fiber quality traits. The objective of this study was to determine if treating cotton seeds of a genotype that produces longer fibers than most U.S. upland cotton cultivars with ethyl methanesulfonate (EMS) could result in mutant lines with exceptional fiber quality. TAM 94L‐25 (94L‐25) (Smith, 2003) (PI 631440) seeds were treated in 2001 with EMS at three times the least dosage to kill 50% of the seeds (LD50). Thirty mutation (M) lines of 94L‐25, derived as M3:4 progeny rows, 94L‐25 M0, and two check cultivars, FM 832 (Constable et al., 2001) (Plant Variety Protection [PVP] 9800258 or PI 603955) and PSC 355 (PI 612974), were grown in a randomized complete block design with four replications at College Station, TX (CS), and Weslaco, TX (W), in 2008 and 2009. High volume instrument (HVI) fiber properties were determined from hand harvested boll samples. Four M lines exceeded the lint yield of the M0 parent during both years. Fourteen M lines produced longer fibers than the M0 parent and both commercial checks while several M lines exhibited improved strength in 2008 but not in 2009. Treatment of 94L‐25 with the chemical mutagenic agent EMS was successful in producing selectable variation for yield and fiber traits simultaneously.
Grain Nitrogen Source Changes over Time in Maize: A Review
Authors: Ciampitti Ignacio A. , Vyn Tony J. 
Published: February 2013

ABSTRACTUnderstanding the sources of grain N uptake (Grain N) in maize (Zea mays L.) and especially the trade‐off between reproductive‐stage shoot N remobilization (Remobilized N) and reproductive‐stage whole‐plant N uptake (Reproductive N) is needed to help guide future improvements in yield and N use efficiency (NUE). Therefore, a literature review was performed to investigate the knowledge gap concerning changes over time in Grain N sources and on N partitioning to the grain and stover plant fractions at maturity. The synthesis–analysis was based on 100 reports, which were divided into two time intervals: (i) research conducted from 1940 to 1990—“Old Era”—and (ii) research conducted from 1991 to 2011—“New Era.” The most remarkable results were (i) Grain N concentration was the main parameter that has changed over time, (ii) Reproductive N contributed proportionally more to Grain N for the New Era while Reproductive N and Remobilized N contributed equally to Grain N for the Old Era, (iii) Remobilized N was primarily associated with vegetative‐stage whole‐plant N uptake (Vegetative N), which was constant across eras, although the proportion of the Remobilized N itself seems to be driven by the ear demand, (iv) complex plant regulation processes (source:sink) appeared to influence Reproductive N, and (v) stover N concentration gains mirrored the grain N concentration as the plant N uptake increased at maturity in both eras. This new appreciation for the changes over time may assist directed selection for yield and NUE improvements.
Inverted Repeat of Chalcone Synthase 3 Pseudogene Is Associated with Seed Coat Discoloration in Soybean
Authors: Rodriguez Tito O. , Rojas Rodas Felipe , Oyoo Maurice E. , Senda Mineo , Takahashi Ryoji 
Published: February 2013

ABSTRACTThe dominant T allele for tawny pubescence is associated with chilling tolerance in soybean [Glycine max (L.) Merr.]. Yellow hilum cultivars with dominant I allele are preferred in Japan because of superior external seed appearance. The allelic combination of IITT darkens the entire seed coat, giving a dirty appearance to seeds. Previous studies revealed a quantitative trait locus (QTL) for seed coat discoloration in the vicinity of the I locus. This study was conducted to identify a candidate gene for this QTL. A breeding line 0734BW‐1 (IITT) with severe discoloration had an inverted repeat of chalcone synthase 3 pseudogenes (pCHS3s), whereas the 5′ copy of pCHS3 was replaced by a fragment of a DnaJ‐like protein gene in a breeding line 0518BW‐8 (IITT) showing slight discoloration. A marker discriminating this structural polymorphism was mapped at the peak of the QTL, suggesting that pCHS3s might be responsible for seed coat discoloration. The gene structure of 0518BW‐8 was identical to that of a gray pubescent cultivar Toyoharuka (IItt) that is tolerant to seed coat browning induced by low temperatures. These results suggest that pCHS3s may control the intensity of seed coat discoloration in tawny pubescent cultivars (TT) and browning in gray pubescent cultivars (tt). Regardless of pubescence color, the allele may be useful for breeding cultivars producing seeds with acceptable external appearance in high‐latitude regions where low temperatures frequently prevail.