bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is sour crude or sour gas a potential source of Se and Te?
Authors: Green Martin A. 
Published: March 2011

ABSTRACTIncreasing dependence on high sulphur ‘sour’ crude oil combined with increasingly stringent requirements on the sulphur content of processed fuels has rapidly made sour crude and sour gas the major commercial sources of sulphur. Production is outstripping demand, resulting in large S stockpiles. Since other chalcogens, Se and Te in particular, could be concentrated by the same processes that concentrate S, sour crude has been suggested as a possible source of Te for photovoltaics. The possibilities are explored for both Se and Te in the present paper. Suppressed concentrations of Se in crude oil and gas relative to sulphur and the even lower likely concentrations of Te mitigate against this prospect. Copyright © 2011 John Wiley & Sons, Ltd.
Novel clues on abiotic stress tolerance emerge from embryo proteome analyses of rice varieties with contrasting stress adaptation
Authors: Farinha Ana P. , Irar Sami , de Oliveira Eliandre , Oliveira M. Margarida , Pagès Montserrat 
Published: March 2011

AbstractCereal embryos sustain severe water deficit at the final stage of seed maturation. The molecular mechanisms underlying the acquisition of desiccation tolerance in seed embryos are similar to those displayed during water deficit in vegetative tissues. The genetic variation among six rice genotypes adapted to diverse environmental conditions was analysed at the proteome level to get further clues on the mechanisms leading to water‐stress tolerance. MS analysis allowed the identification of 28 proteins involved in stress tolerance (late embryogenesis abundant proteins), nutrient reservoir activity, among other proteins implicated in diverse cellular processes potentially related to the stress response (e.g., mitochondrial import translocase). Hierarchical clustering and multidimensional scaling analyses revealed a close relationship between the stress‐sensitive genotypes, whereas the stress‐tolerant varieties were more distantly related. Besides qualitative and significant quantitative changes in embryo proteins across the distinct varieties, we also found differences at post‐translational level. The results indicated that late embryogenesis abundant Rab21 was more strongly phosphorylated in the embryos of the sensitive varieties than in the embryos of the tolerant ones. We propose that the differences found in the phosphorylation status of Rab21 are related to stress tolerance.
Genomic and proteomic characterization ofStaphylococcus aureusmastitis isolates of bovine origin
Authors: Wolf Carmen , Kusch Harald , Monecke Stefan , Albrecht Dirk , Holtfreter Silva , von Eiff Christof , Petzl Wolfram , Rainard Pascal , Bröker Barbara M. , Engelmann Susanne 
Published: March 2011

AbstractStaphylococcus aureuscolonizes and infects humans as well as animals. In the present study, 17S. aureusstrains isolated from cows suffering from mastitis were characterized. The well‐established multilocus sequence typing (MLST) technique and a diagnostic microarray covering 185S. aureusvirulence and resistance genes were used for genetic and epidemiological analyses. Virulence gene expression studies were performed by analyzing the extracellular protein pattern of each isolate on 2‐D gels. By this way, a pronounced heterogeneity of the extracellular proteome between the bovine isolates has been observed which was attributed to genome plasticity and variation of gene expression. Merely 12 proteins were expressed in at least 80% of the isolates, i.e. Atl, Aur, GlpQ, Hla, LtaS, Nuc, PdhB, SAB0846, SAB2176, SAB0566, SspA, and SspB forming the core exoproteome. Fifteen extracellular proteins were highly variably expressed and only present in less than 20% of the isolates. This includes the serine proteases SplB, C, and F, and the superantigens SEC‐bov, SEL and TSST‐1. Compared to human isolates we identified at least six proteins with significantly different expression frequencies. While SAB0846 was expressed more frequently in bovine isolates, LytM, EbpS, Spa, Geh, and LukL1 were seen less frequently in these isolates.
Female urinary proteomics: New insight into exogenous and physiological hormone‐dependent changes
Authors: Castagna Annalisa , Olivieri Oliviero , Milli Alberto , Dal Bosco Miriam , Timperio Anna Maria , Zolla Lello , Gunasekaran Muthukumar , Raffaelli Ricciarda , Pizzolo Francesca , Cecconi Daniela 
Published: March 2011

AbstractPurpose: In the frame of a research study on possible urinary markers related to physiological hormones cycle, 33 volunteer, healthy, normotensive fertile women were selected. Clinical parameters and renin–angiotensin–aldosterone system (RAAS) components were also investigated, on the basis of the well‐known relation linking sex female hormones and renin and aldosterone levels.Experimental design: A classic proteomic approach was applied to investigate urinary protein changes at different stages of menstrual cycle, specifically mid‐cycle phase (G1), luteal phase (G2) and after 2 months of contraceptive therapy (G3). Analysis of urinary proteome was performed by SDS‐PAGE, 2‐D PAGE, Western blotting, and protein identification by HPLC‐MS/MS.Results: In the four comparisons examined (G1 vs. G2; G1 vs. G3; G2 vs. G3 and G(G1+G2) vs. G3), a total of 115 protein spots were differentially represented among the subgroups. Data validation was performed by replicated experiments of immunoblotting.Conclusions and clinical relevance: The present work highlights for the first time variations with menstrual cycle or estroprogestin pill of newly discovered, or never related, urinary proteins. In particular, possible protein markers could be useful for further applications in contraceptive target research and RAAS modulation‐related topics.
Human urinary peptide database for multiple disease biomarker discovery
Authors: Siwy Justyna , Mullen William , Golovko Igor , Franke Julia , Zürbig Petra 
Published: March 2011

AbstractPurpose: Human urine is an ideal candidate for use in clinical diagnostics. It is easily available, as untrained personnel can collect it. It correlates well with the pathophysiology of a number of diseases, making it a useful source for clinical proteomics.Experimental design: In this article, we give an update of the human urinary peptide database derived from over 13 000 data sets of CE‐MS by now.Results: Urine samples from both patients and healthy subjects were analyzed by CE‐MS; these included 47 different pathophysiological conditions. Besides defining biomarkers by their experimental parameters, information on their sequences provides fundamental data into the pathological pathways of diseases. Therefore, we have sequenced 953 urinary peptides by using state‐of‐the‐art top‐down MS/MS. Identified biomarkers of all clinical proteomic CE‐MS studies including their regulation are also listed in this work.Conclusions and clinical relevance: Biomarker discovery can be used in the management of a wide range of diseases, by combining these data sets of the database. Taking this approach, we can reveal details, at a molecular level, on the pathogenesis of a number of diseases, in particular those associated with urine production and excretion.
Improving color rendering of Y3Al5O12:Ce3+ white light‐emitting diodes based on dual‐blue‐emitting active layers
Authors: Chen Xian‐Wen , Zhang Yong , Li Shu‐Ti , Yan Qi‐Rong , Zheng Shu‐Wen , He Miao , Fan Guang‐Han 
Published: March 2011

AbstractAn InGaN/GaN blue‐violet light‐emitting diode (LED) structure and an InGaN/GaN blue LED structure were grown sequentially on the same sapphire substrate by metal‐organic chemical vapor deposition (MOCVD). At the low injection current, the intensity ratio of blue‐violet light to blue light was almost constant, while the blue light intensity increased gradually with increasing injection current when the latter was more than 40 mA. High color rendering has been realized for a Y3Al5O12:Ce3+ phosphor‐converted white LED based on dual‐blue‐emitting active layers relative to a single blue‐emitting active layer at the same injection current.
First‐principles study on the structural, phonon, and thermodynamic properties of the ternary carbides in Ti–Al–C system
Authors: Chen Yang , Chu Maoyou , Wang Lijun , Bao Xinhua , Lin Yang , Shen Jianyun 
Published: March 2011

AbstractThe structural, phonon, and thermodynamic properties of the ternary carbides Ti2AlC, Ti3AlC, and Ti3AlC2 in the Ti–Al–C system are investigated by using first‐principles calculations in this paper. Phonon dispersion curves and partial density of states have been investigated and revealed the different Ti–C bond characteristics between Ti3AlC and the two other compounds. The Gibbs energy, entropy, heat capacity, and thermal expansion coefficient of the three compounds are predicted by means of the quasi‐harmonic approximation. Furthermore, the thermal electronic contribution has been included in the thermodynamic properties. The obtained results of this study are in good agreement with the available experimental data.
Composition and orientation dependence of the interfacial energy in Fe–Cr stainless steel alloys
Authors: Lu Song , Hu Qing‐Miao , Johansson Börje , Vitos Levente 
Published: March 2011

AbstractUsing a first‐principles quantum mechanical method, we calculated the (001) and (110) interfacial energies between the low temperature α and α′ phases of Fe–Cr alloys as functions of chemical composition. We show that the interfacial energies and the interfacial energy anisotropy are highly composition dependent. In particular, the increasing interfacial energy anisotropy with decreasing compositional gap may induce different morphology of the decomposed phases for different compositions of the host alloys.
Analysis of interface states in Pd/n‐ GaN by temperature and frequency dependent admittance
Authors: Sellai Azzouz , Mamor Mohammed 
Published: March 2011

AbstractThe measured frequency‐dependent ac admittance over a range of temperatures (100 K–300 K) was used to obtain the admittance Gss + jωCss associated with the displacement current in the Pd/GaN interfacial layer. Using two methods based on C‐V data at two frequencies and conductance data over a wide range of frequencies, the interface states density is determined to be of the order of 1013 cm‐2 eV‐1 at room temperature and shows a slight increase with decreasing temperatures. The derived emission rates range mainly from 105 s‐1 to 106 s‐1 and are to some extent voltage and temperature dependent, showing a decrease with decreasing temperatures. The subsequently obtained capture cross‐sections are thermally activated with values varying from 10‐14to 10‐16 cm2 and reveal also a significant dependence on the applied forward bias. The density of interface states obtained in the ac regime is roughly in line with that previously derived from the ideality factor of the dc I‐V characteristics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of GaN‐based light‐emitting diodes grown on vicinal sapphire substrates
Authors: Liu Yi‐Jung , Chen Huey‐Ing , Cheng Shiou‐Ying , Lin Kun‐Wei , Liu Wen‐Chau 
Published: March 2011

AbstractGaN‐based light‐emitting diodes (LEDs) grown on c‐plane vicinal sapphire substrates are fabricated and characterized. All the electrical characteristics demonstrate that the LED with a 0.2° tilt sapphire substrate exhibits the lowest defect density while that with a 1.0° tilt sapphire exhibits the highest one. At 2 mA, the enhanced output power of 23.3% indicates the substantial reduction of defect‐related nonradiative recombination centers in MQW for the LED device with a 0.2°‐tilt sapphire. At 60 mA, the improved value is up to 45.7%. This is primarily caused by the presence of indium quantum dots (QDs) in MQW which provides increased quantum efficiency (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Longitudinal polar optical phonons in InN/GaN single and double het‐ erostructures
Authors: Ardali Sukru , Tiras Engin , Gunes Mustafa , Balkan Naci , Ajagunna Adebowale Olufunso , Iliopoulos Eleftherios , Georgakilas Alexandros 
Published: March 2011

AbstractLongitudinal optical phonon energy in InN epi‐layers has been determined independently from the Raman spectroscopy and temperature dependent Hall mobility measurements. Raman spectroscopy technique can be used to obtain directly the LO energy where LO phonon scattering dominates transport at high temperature. Moreover, the Hall mobility is determined by the scattering of electrons with LO phonons so the data for the temperature dependence of Hall mobility have been used to calculate the effective energy of longitudinal optical phonons.The samples investigated were (i) single heterojunction InN with thicknesses of 1.08, 2.07 and 4.7 μm grown onto a 40 nm GaN buffer and (ii) GaN/InN/AlN double heterojunction samples with InN thicknesses of 0.4, 0.6 and 0.8 μm. Hall Effect measurements were carried out as a function of temperature in the range between T = 1.7 and 275 K at fixed magnetic and electric fields. The Raman spectra were obtained at room temperature. In the experiments, the 532 nm line of a nitrogen laser was used as the excitation source and the light was incident onto the samples along of the growth direction (c‐axis). The results, obtained from the two independent techniques suggest the following: (1) LO phonon energies obtained from momentum relaxation experiments are generally slightly higher than those obtained from the Raman spectra. (2) LO phonon energy for the single heterojunctions does not depend on the InN thickness. (3) In double heterostructures, with smaller InN thicknesses and hence with increased strain, LO phonon energy increases by 3% (experimental accuracy is < 1%) when the InN layer thickness increases from 400 to 800 nm (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties and phase transitions of CdS under high pressure and moderate temperature
Authors: He Chunyuan , Liu Bingguo , Zhang Dongmei , Gao Chunxiao 
Published: March 2011

AbstractThe electrical transport properties and phase transitions of CdS were investigated under high pressure and moderate temperature by a microcircuit fabricated on diamond anvil cell. Around 2.0 GPa the resistivity of CdS dropped two orders of magnitude sharply, implying a beginning of a phase transition from wurtzite phase to rock‐salt phase. At about 4.0 GPa the resistivity appeared a local minimum indicating an end of the transition to rock‐salt phase. A local maximum of the resistivity was observed at about 8.0 GPa, which was attributed to the changeover of indirect gap from Σν→Xc to Lν→Xc. Furthermore, two inflexions of resistivity were observed at about 16.0 GPa and 21.0 GPa, which predicting that the indirect band gap of CdS may further change at these pressures. In the range of experimental pressure and temperature CdS still showed the electrical transport property of a semiconductor. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The electrical properties of ZnTe under high pressure and moderate temperature
Authors: Cui Xiaoyan , Hu Tingjing , Yang Jie , Han Yonghao , Li Yan , Liu Cailong , Wang Yue , Liu Bao , Ren Wanbin , Su Ningning , Liu Hongwu , Gao Chunxiao 
Published: March 2011

AbstractThe resistivity of ZnTe powders has been measured under high pressure up to 29 GPa and temperature ranged from 303.0 to 403.0 K by using a diamond anvil cell. The resistivity changed discontinuously at 9.5 and 13.1 GPa, corresponding to the phase transitions from zinc blende to cinnabar and then to Cmcm structure. The decrease of activation energy by one order of magnitude indicates the deep‐to‐shallow transition of acceptor levels at 6.7 GPa. The resistivity decreases with temperature increasing indicates the semiconducting character of ZnTe in zinc blende phase. The resistivity of ZnTe in cinnabar phase decreases slightly with temperature increasing, indicating that this phase is a narrow‐gap semiconductor. After 19.1 GPa, the resistivity increases with temperature increasing, indicating the metallic character of Cmcm phase. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of quantum well numbers and thermal annealing on optical properties of GaInNAs/GaAs quantum well structures
Authors: Basak H. , Erol A. , Donmez O. , Arikan M. C. , Saarinen M. 
Published: March 2011

AbstractAs‐grown and annealed Ga0.6In0.4N0.005As0.995/GaAs with 1, 3, and 7 quantum well structures grown by Molecular Beam Epitaxy (MBE) are investigated using Photoluminescence (PL) and Photo‐Induced Current Transient Spectroscopy (PICTS) measurements in order to determine the effects of the number of quantum wells and thermal annealing on optical properties and qualities of the structures. PICTS results reveal that all the samples with different quantum well numbers have two dominate trap levels which related to GaInNAs layer (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonant soft X‐ray emission and X‐ray absorption studies on Ga1‐xMnxN grown by pulsed laser deposition
Authors: Krishnamurthy Satheesh , Kennedy Brian , McGee Fintan , Venkatesan M. , Coey J. M. D. , Lunney James G. , Learmonth Timothy , Smith Kevin E. , Schmitt Thorsten , McGuinness Cormac 
Published: March 2011

AbstractIn this study thin film samples of Ga1‐xMnxN were grown by pulsed laser deposition on Al2O3 (0001) substrates. X‐ray diffraction measurements have confirmed these thin films exhibit hexagonal wurtzite structure. SQUID measurements show room temperature ferromagnetism of these dilute magnetic semiconductors (DMS). The techniques of X‐ray absorption and soft X‐ray emission spectroscopy at the N K‐edge were used to study the changes in the unoccupied and occupied N 2p partial density of states respectively as a function of dopant concentration. These element and site specific spectroscopies allow us to characterise the electronic structure of these doped materials and reveal the influence of the Mn doping on the valence band as measured through the N 2p partial density of states. X‐ray absorption measurements at the Mn L‐edge confirm significant substitutional doping of Mn into Ga‐sites. Finally, measurements of heavily Mn‐doped films using both soft X‐ray absorption and resonant soft X‐ray emission at the N K edge reveal the presence of trapped molecular nitrogen. The trapped molecular nitrogen may be due to the high instantaneous deposition rate in the PLD process for these samples (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micro‐photoluminescence of GaInNAs layers grown on GaAs substrates of various crystallographic orientations
Authors: Latkowska M. , Kudrawiec R. , Sęk G. , Misiewicz J. , Ibanez J. , Hopkinson M. , Henini M. 
Published: March 2011

AbstractLow temperature micro‐photoluminescence (μ‐PL) has been applied to study GaInNAs bulklike layers grown on GaAs substrates with various crystallographic orientations [(100), (111)A, (311)A, (411)A, and (511)A]. At low excitation conditions, the μ‐PL spectra show sharp PL lines of ∼100‐300 μeV widths. The density of these lines changes from sample to sample as well as from place to place within one sample. When the excitation power is increased, an additional smooth PL band appears at the higher‐energy side. This band is located ∼30‐100 meV above the band of sharp PL lines and is attributed to free exciton/carrier recombination. The sharp PL lines are attributed to the recombination of localized excitons trapped at local potential minima. These lines are not resolved in macro‐PL spectra because of their high density. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray diffraction study of GaN grown on patterned substrates
Authors: Sintonen S. , Ali M. , Törmä P. T. , Suihkonen S. , Kostamo P. , Svensk O. , Sopanen M. , Lipsanen H. , Paulmann C. , Tuomi T. O. 
Published: March 2011

AbstractOwing to its great potential in optoelectronic devices, a lot of effort has recently been put into improving the crystal quality of heteroepitaxial GaN. In this study, GaN layers grown on patterned GaN/sapphire substrates are non‐destructively investigated by X‐ray diffraction techniques. The effect of the patterning is characterized by determining the strain and lattice tilt and twist in the overgrown GaN layers.High resolution X‐ray diffraction (HRXRD) scans and reciprocal space maps (RSMs) were utilized for this purpose. Synchrotron radiation X‐ray topography (SR‐XRT) was used to examine the microstructure of the samples. The patterning was found to significantly improve the crystal quality of the GaN layers, especially by reducing the amount of edge dislocations. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of thick GaN layers on 4‐in. and 6‐in. silicon (111) by metal‐organic vapor phase epitaxy
Authors: Frayssinet Eric , Cordier Yvon , Schenk H. P. David , Bavard Alexis 
Published: March 2011

AbstractIn this paper, we report on the growth of thick gallium nitride (GaN) layers on 4‐in. and 6‐in., (111)‐orientated silicon substrates by metalorganic vapor phase epitaxy. Up to 4 µm thick continuous GaN layers have been obtained by inserting both SiN and AlN interlayers into the structure. With dislocation densities of about 1‐2×109 cm‐2 and GaN(002) and (302) X‐ray rocking curve full widths at half maximum of 420 and 1360 arcsec for 4‐in. and 374 and 810 arcsec for 6‐in., respectively, the final continuous GaN layer exhibits excellent crystalline properties (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Suppression of non‐radiative effects in AlGaN through nanometer scale compositional inhomogeneities
Authors: Sampath Anand V. , Garrett Gregory A. , Enck Ryan W. , Rotella Paul , Shen H. , Wraback Michael 
Published: March 2011

AbstractUV light emitting diodes (UVLEDs) emitting at wavelengths shorter than 365 nm remain in the research and development stage, with external quantum efficiencies and device operating lifetimes well below that of commercially available blue LEDs. These limitations are partially attributable to the large density of dislocations in these devices that arise due to heteroepitaxial growth of high AlN mole fraction III‐Nitride semiconductors and act as non‐radiatve recombination centers that reduce efficiency and increase debilitating heating. An approach to mitigating this problem is to incorporate nanometer scale compositional inhomogeneities within the AlGaN (NCI‐AlGaN) active region of a UVLED that can enhance the internal quantum efficiency by concentrating carriers within regions of narrow bandgap surrounded by a wider band gap matrix. In this paper we report on the growth and characterization of NCI‐AlGaN alloys deposited by plasma‐assisted molecular beam epitaxy. Growth under N‐limited and nearly stoichiometric growth conditions promote the spontaneous formation of these NCI regions. This is attributed to lower adatom mobility of group III and N species on the AlGaN layer surface under these conditions as well as the formation of beneficial surface faceting. Optical characterization by both temperature dependent, time‐resolved and time‐integrated photoluminescence demonstrates the capability for NCI regions to suppress non‐radiative recombination in these active regions despite the presence of a large density of defects. However, reduction of the defect density, both dislocations and impurities, improves the performance of these active regions. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)