bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion and self‐healing behaviour of AZ91D magnesium alloy in ethylene glycol/water solutions
Authors: Wang L. , Zhou T. , Liang J.
Published: June 2011

Corrosion behaviour of magnesium alloy‐based engine parts in cooling system is an urgent fundamental issue in automotive field where magnesium alloys are increasingly used. In the present work, the corrosion behaviour of AZ91D magnesium alloys in various ethylene glycol/water solutions was studied by electrochemical measurements and immersion tests at room temperature. The surfaces of the samples after immersion tests were examined using scanning electron microscope (SEM) and X‐ray diffraction (XRD). The results showed that the corrosion rates of AZ91D magnesium alloys decreased with the increase of ethylene glycol concentration in ethylene glycol/water solutions and the corrosion process was dominated by pitting corrosion. A continuous protective film transferred from corrosion products was formed on the corroded surface after sufficient immersion duration in ethylene glycol/water solutions, which is able to heal the corrosion pits. The self‐healing behaviour inhibited the further corrosion of AZ91D magnesium alloy.
The Effect of Leasing versus Buying on Entry Deterrence
Authors: Mao Wen , Zaleski Peter
Published: June 2011

Models of entry deterrence typically require that incumbents possess a cost advantage as a prerequisite for deterring entry. Potential entrants possess a cost advantage over incumbents, however, if input costs fall over time. This paper models the behavior of an incumbent and a potential entrant when the input cost falls over time and the firms have the option of buying or leasing the input. The model shows that if the future cost savings from new technology exceed the marginal transaction costs of leasing the current equipment, then leasing increases the incumbent's ability to deter entry. Copyright © 2011 John Wiley & Sons, Ltd.
Numerical modelling of multiphase immiscible flow in double‐porosity featured groundwater systems
Authors: Ngien Su Kong , Rahman Norhan A. , Lewis Roland W. , Ahmad Kamarudin
Published: June 2011

A numerical model describing the flow of multiphase, immiscible fluids in a deformable, double‐porosity featured soil has been developed. The model is focused on the modelling of the secondary porosity features in soil, which is more relevant to groundwater contamination problems. The non‐linear saturation and relative permeabilities were expressed as functions of the capillary pressures. The governing partial differential equations in terms of soil displacement and fluid pressures were solved numerically. Galerkin's weighted‐residual finite element method was employed to obtain the spatial discretization whereas temporal discretization was achieved using a fully implicit scheme. The model was verified against established, peer‐reviewed works, and the assumption that the immiscible fluids (non‐aqueous phase liquids) will flow preferentially through the secondary porosity features in soil was validated. Copyright © 2011 John Wiley & Sons, Ltd.
Specific and extensive endometrial deregulation is present before conception in IVF/ICSI repeated implantation failures (IF) or recurrent miscarriages
Authors: Lédée Nathalie , Munaut Carine , Aubert Julie , Sérazin Valérie , Rahmati Mona , Chaouat Gérard , Sandra Olivier , Foidart Jean Michel
Published: June 2011

The objective was to examine if IVF/ICSI repeated implantation failures (IF) or recurrent miscarriages (RM) could be related to preconceptional endometrial deregulations. IF was defined as the absence of pregnancy despite the transfer of at least ten IVF/ICSI good quality embryos, and RM as having at least three unexplained miscarriages. Fertile controls (FC) were women who had given birth at least once. Endometrial biopsy was performed in the mild luteal phase of a non‐conceptual cycle (five women were selected in each group). Affymetrix chips (GeneChip Human Genome U133 Plus2.0 Array) were used for hybridization. Data were normalized by the gcRMA method, and raw p values adjusted by the Bonferroni procedure (1%). Differential expression of selected genes was analysed using real‐time PCR. Gene networks and biological functions were explored using the Ingenuity Pathways Analysis software. Endometrial gene expression profiles at the time of uterine receptivity differ dramatically in the endometrium among FC, RM, and IF patients. Compared to FC, 2126 and 2477 genes are differentially expressed in IF and RM groups, respectively, and 2363 between IF and RM. In both conditions, differential gene expression referred mainly to DNA transcription and expression. Other main cellular functions deregulated in IF conditions correspond to cell morphology, cellular development, cell cycle, and cellular assembly, while in RM conditions, deregulated cellular functions relate to cell signalling (degradation of cyclic AMP and calcium metabolism) and cellular maintenance. In both conditions, there is an over‐representation of deregulations related to the haematological system. In the IF condition, cell‐mediated immune response and nervous system development and function are highly deregulated, while in RM patients, main deregulations are in organ and tissue development, humoral immune response, and muscular system development and function. Extensive endometrial deregulations are present before conception in patients who experienced IF or RM with both distinct and common deregulation. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Three‐Dimensional Simulation of Pressure Fluctuation in a Granular Solid Propellant Chamber within an Ignition Stage
Authors: Miura Hiroaki , Matsuo Akiko , Nakamura Yuichi
Published: June 2011

The effects of the conditions of the ignition system in the propellant chamber of a gun system using a granular solid propellant are numerically investigated with respect to ignition performance criteria such as the differential pressure generation between the breech and the projectile base. Simulations, in which the length of the primer and the igniter mass are varied, are performed using a solid/gas two‐phase fluid dynamics code for three‐dimensional calculation of gas flow and discrete solid propellant particles. This code simulates the igniter combustion in the primer, the movement of burning solid propellant grains, and the formation of pressure gradients inside the chamber in the ignition process. The differential pressures between the breech and the projectile base measured in experiments are well predicted by the simulations for various igniter conditions. In the process of igniting the solid propellant, the propellant grains are accelerated toward the projectile base by the igniter gas flows from the primer vents. Fixed‐particle simulation is also carried out in order to examine the effects of the movement of the solid propellant grains on the chamber pressure profile. The simulated results reveal that the movement of solid propellant grains causes differential pressure fluctuations, which depend on the discharge from the primer vents and the locations of these vents.
Apo raver1 structure reveals distinct RRM domain orientations
Authors: Rangarajan Erumbi S. , Lee Jun Hyuck , Izard Tina
Published: June 2011

Raver1 is a multifunctional protein that modulates both alternative splicing and focal adhesion assembly by binding to the nucleoplasmic splicing repressor polypyrimidine tract protein (PTB) or to the cytoskeletal proteins vinculin and α‐actinin. The amino‐terminal region of raver1 has three RNA recognition motif (RRM1, RRM2, and RRM3) domains, and RRM1 interacts with the vinculin tail (Vt) domain and vinculin mRNA. We previously determined the crystal structure of the raver1 RRM1–3 domains in complex with Vt at 2.75 Å resolution. Here, we report crystal structure of the unbound raver1 RRM1–3 domains at 2 Å resolution. The apo structure reveals that a bound sulfate ion disrupts an electrostatic interaction between the RRM1 and RRM2 domains, triggering a large relative domain movement of over 30°. Superposition with other RNA‐bound RRM structures places the sulfate ion near the superposed RNA phosphate group suggesting that this is the raver1 RNA binding site. While several single and some tandem RRM domain structures have been described, to the best of our knowledge, this is the second report of a three‐tandem RRM domain structure.
Nuclear magnetic resonance spectroscopy with the stringent substrate rhodanese bound to the single‐ring variant SR1 of the E. coli chaperonin GroEL
Authors: Koculi Eda , Horst Reto , Horwich Arthur L. , Wüthrich Kurt
Published: June 2011

Nuclear magnetic resonance (NMR) observation of the uniformly 2H,15N‐labeled stringent 33‐kDa substrate protein rhodanese in a productive complex with the uniformly 14N‐labeled 400 kDa single‐ring version of the E. coli chaperonin GroEL, SR1, was achieved with the use of transverse relaxation‐optimized spectroscopy, cross‐correlated relaxation‐induced polarization transfer, and cross‐correlated relaxation‐enhanced polarization transfer. To characterize the NMR‐observable parts of the bound rhodanese, coherence buildup rates by different magnetization transfer mechanisms were measured, and effects of covalent crosslinking of the rhodanese to the apical binding surface of SR1 were investigated. The results indicate that the NMR‐observable parts of the SR1‐bound rhodanese are involved in intracomplex rate processes, which are not related to binding and release of the substrate protein from the SR1 binding surface. Rather, they correspond to mobility of the stably bound substrate, which thus appears to include flexibly disordered polypeptide segments devoid of long‐lived secondary structures or tertiary folds, as was previously observed also with the smaller substrate human dihydrofolate reductase.
The N‐end rule pathway and regulation by proteolysis
Authors: Varshavsky Alexander
Published: June 2011

The N‐end rule relates the regulation of the in vivo half‐life of a protein to the identity of its N‐terminal residue. Degradation signals (degrons) that are targeted by the N‐end rule pathway include a set called N‐degrons. The main determinant of an N‐degron is a destabilizing N‐terminal residue of a protein. In eukaryotes, the N‐end rule pathway is a part of the ubiquitin system and consists of two branches, the Ac/N‐end rule and the Arg/N‐end rule pathways. The Ac/N‐end rule pathway targets proteins containing Nα‐terminally acetylated (Nt‐acetylated) residues. The Arg/N‐end rule pathway recognizes unacetylated N‐terminal residues and involves N‐terminal arginylation. Together, these branches target for degradation a majority of cellular proteins. For example, more than 80% of human proteins are cotranslationally Nt‐acetylated. Thus, most proteins harbor a specific degradation signal, termed AcN‐degron, from the moment of their birth. Specific N‐end rule pathways are also present in prokaryotes and in mitochondria. Enzymes that produce N‐degrons include methionine‐aminopeptidases, caspases, calpains, Nt‐acetylases, Nt‐amidases, arginyl‐transferases, and leucyl‐transferases. Regulated degradation of specific proteins by the N‐end rule pathway mediates a legion of physiological functions, including the sensing of heme, oxygen, and nitric oxide; selective elimination of misfolded proteins; the regulation of DNA repair, segregation, and condensation; the signaling by G proteins; the regulation of peptide import, fat metabolism, viral and bacterial infections, apoptosis, meiosis, spermatogenesis, neurogenesis, and cardiovascular development; and the functioning of adult organs, including the pancreas and the brain. Discovered 25 years ago, this pathway continues to be a fount of biological insights.
The effect of indium concentration on the optical properties of a‐plane InGaN/GaN quantum wells grown on r‐plane sapphire substrates
Authors: Badcock T. J. , Hao R. , Moram M. A. , Dawson P. , Kappers M. J. , Humphreys C. J.
Published: June 2011

We report on the optical properties of a series of non‐polar a‐plane InGaN/GaN multiple quantum well (QW) structures of constant well width and varying indium concentration. The emission spectrum is dominated by recombination at regions of the QW intersected by basal plane stacking faults. The peak energy of this emission red‐shifts and the emission line width increases significantly with increasing average indium content in the QWs and indium–alloyed basal‐plane stacking faults. Furthermore, the spectral sensitivity of the luminescence decay time weakens as the indium content of the sample increases. These effects are attributed to the increase in compositional and hence electronic disorder of higher indium content samples resulting in stronger carrier localisation, which suppresses relaxation within the band of localised states.
Study of thermoelectric properties of indium nitride nanowire
Authors: Huang Hung‐Hsun , Lu I‐Lin , Wu Yuh‐Renn
Published: June 2011

In this paper, we studied the thermoelectric properties of a free‐standing InN nanowire with wire size ranging from 6 to 100 nm. With elastic continuum model, we calculated the phonon dispersion curves to obtain the phonon group velocity. The Callaway model has been applied to obtain the temperature‐dependent thermal conductivity. We employed the Monte Carlo method to obtain the mobility and electrical conductivity with different doping concentration and temperature.

Finally, the figures of merit ZT have been obtained by the combination of the electrical and thermal properties of InN nanowire. Our results suggest that the thermoelectric properties of InN nanowire are strongly influenced by the carrier density, temperature and nanowire size. The optimization condition for designing the thermoelectric device has been studied in this paper.
A Tersoff‐based interatomic potential for wurtzite AlN
Authors: Tungare Mihir , Shi Yunfeng , Tripathi Neeraj , Suvarna Puneet , Shahedipour‐Sandvik Fatemeh (Shadi)
Published: June 2011

Aluminum nitride (AlN) is a popular buffer layer and interlayer. The understanding of how AlN serves as a wetting and fracture‐mitigating layer relies on molecular pictures of the AlN layer and the interfaces. However, molecular dynamics (MD) simulation studies on AlN system, particularly on its wurtzite phase, have been limited. This is because most existing interatomic force fields of AlN target the less common zinc blende phase. Here, we report a new Tersoff‐based AlN force field for its wurtzite structure. This potential has been extensively tested in terms of lattice parameters, bulk modulus, cohesive energy, and heat capacity. In addition, thermal expansion coefficient (TEC) of wurtzite AlN, a key property to precisely model heterostructures, has been calculated using MD method. The value of 2.66 × 10−6 K−1 calculated at 300 K for TEC is in excellent agreement with the reported experimental value.
Comparing study of magnetic‐ion and nonmagnetic‐ion doping effect at Mn site in La0.825Sr0.175MnO3 compound
Authors: Hao Changyi , Zhao Bangchuan , Kuang Guangli , Sun Yuping
Published: June 2011

Structural, magnetic, and transport properties of La0.825Sr0.175MnO3 samples doped with magnetic (Fe3+, Cr3+) and nonmagnetic (Ga3+, Al3+) ions have been studied comparatively. The structure does not change by nonmagnetic ion doping, whereas magnetic ion substitution can change the structure of the system significantly. All the doped samples show a lower Curie temperature as compared to that of the undoped sample. The change of Curie temperature TC for the magnetic‐ion‐doped samples is quite larger than that of the nonmagnetic‐ion‐doped samples. The electron configuration is suggested to play an important role in determining the change of TC for the magnetic‐ion‐doped samples, whereas the decrease of TC in nonmagnetic‐doped samples is considered to originate mainly from the variation of local lattice. The Fe‐doped sample shows semiconducting transport behavior in the whole studied temperature range besides a kink near TC. Except for two obvious M–I transitions, another inflexion‐like anomaly in the ρ(T) curve at low temperatures is observed for the Ga‐, Cr‐, and Al‐doped samples and the inflexion is suggested to be related to a two transport channel model in these samples.
Emerging physics of oxide heterostructures
Authors: Demkov A. A. , Posadas A. , Seo H. , Lee J. K. , Sai N.
Published: June 2011

We explore novel electronic phenomena that occur at the interface in epitaxial complex oxide heterostructures. We apply ab‐initio theory to predict and analyze the behavior of these heterostructures and use molecular beam epitaxy (MBE) to realize them in practice. Our first system concerns the interface between two insulating oxides, LaAlO3/SrTiO3 and LaAlO3/EuO. Formation of a two‐dimensional electron gas is explored and the electrostatic doping mechanism as a result of the macroscopic electric fields in LaAlO3 is proposed. In the second system, we investigate the possibility of magnetoelectric coupling at a tri‐components ferroelectric/ferromagnetic interface using a Pt/PbTiO3/Fe heterostructure as an example. At last we explore the connection between epitaxial strain and interfacial ferromagnetism in SrTiO3/LaCoO3 interface and demonstrate that such structure can be integrated epitaxially with Si (001).
Effect of basal‐plane stacking faults on the Bragg peak broadening in m‐plane GaN
Authors: Paduano Qing S. , Drehman Alvin J. , Weyburne David W.
Published: June 2011

The effect of basal‐plane stacking faults on the Bragg peak broadening in m‐plane GaN is studied using X‐ray diffraction ω‐scans and ω/2θ‐scans. The analysis considers the coexistence of multiple broadening contributions including tilt, twist, limited coherence length, and micro‐strain. Although the effects of basal‐plane stacking faults are detectable in the different configurations used in this study, we show that the ω‐scans in the asymmetric geometry are better suited for quantifying basal‐plane stacking fault‐related broadening, since the broadening due to twist does not affect the ω‐scan profiles in such diffraction geometries (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transparent electrode for UV light‐emitting‐diodes
Authors: Takehara Kosuke , Takeda Kenichiro , Nagata Kengo , Sakurai Hisashi , Ito Shun , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu , Amano Hiroshi
Published: June 2011

We have investigated the transparent electrodes using indium tin oxide (ITO) for UV light‐emitting diodes (LEDs). The carrier concentration of ITO was increased from 1.1×1018 to 1.5×1021cm‐3 after annealing under N2 ambient at 600 °C. The fundamental absorption edge was also shifted to a shorter wavelength owing to the increase in carrier concentration, through the so‐called the Burstein‐Moss effect. The annealed ITO forms an ohmic contact with p‐GaN with a specific contact resistance of 1.2×10‐3Ωcm2. The light output power of a 350 nm LED with the annealed ITO contact is 1.2 times higher than that with a conventional Ni/Au contact. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaInN‐based solar cells using GaInN/GaInN superlattices
Authors: Fujii Takahiro , Kuwahara Yousuke , Iida Daisuke , Fujiyama Yasuharu , Morita Yoshiki , Sugiyama Toru , Isobe Yasuhiro , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu , Amano Hiroshi
Published: June 2011

We report on the fabrication of GaInN‐based solar cells using GaInN/GaInN superlattices as active layers and also as underlying layers beneath the active layers. We obtained pit‐free surfaces, even with a high InN molar fraction, using the superlattices. As a result, the maximum external and internal quantum efficiencies reached 60%, and 88%, respectively. The open‐circuit voltage of the soalr cells was 1.77 V, the short‐circuit current density was 3.08 mA/cm2, and the fill factor was 70.3%. A conversion efficiency of 2.46% was achieved at room temperature under simulared 1.5 sun × AM1.5G illumination using a solar simulator. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative study of buffer designs for high breakdown voltage AlGaNGaN HFETs
Authors: Brunner Frank , Bahat‐Treidel Eldad , Cho Melanie , Netzel Carsten , Hilt Oliver , Würfl Joachim , Weyers Markus
Published: June 2011

A comparison of different epilayer concepts to achieve high breakdown voltage AlGaN‐GaN HFETs is presented. A double heterostructure with a low Al‐content Al0.05Ga0.95N back‐barrier as well as a carbon‐doped GaN buffer are investigated with regard to material and device properties. Material analysis reaffirms the incorporation of carbon on a nitrogen lattice site without creation of extended defects or causing memory effects. It is demonstrated that carrier trapping in the buffer using carbon deep acceptors reduces sub‐threshold drain leakage currents in HFET devices enabling breakdown voltages above 1 kV. An undoped GaN channel layer is shown to suppress drain current reduction under pulsed transistor operation. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characteristics of the vertical GaN rectifiers fabricated on bulk GaN wafer
Authors: Wang Yaqi , Xu Hui , Alur Siddharth , Sharma Yogesh , Tong Fei , Gartland Patrick , Issacs‐Smith Tamara , Ahyi Claude , Williams John , Park Minseo , Wheeler Ginger , Johnson Mark , Allerman Andrew A. , Hanser Andrew , Paskova Tanya , Preble Edward A. , Evans Keith R.
Published: June 2011

Vertical Schottky rectifiers were fabricated on two GaN wafers synthesised by hydride vapor phase epitaxy (HVPE) process: n‐ epilayer on n+ bulk and n‐ bulk. Full backside ohmic contact and circular Schottky contacts were deposited on the N face and Ga face of the substrate, respectively. The devices showed excellent electrical characteristics. The device fabricated on n‐ epilayer on n+ bulk substrate showed a breakdown voltage of 348 V, a specific on‐state resistance of 4.2 mΩ·cm2 and a leakage current density of 9.2×10‐6 A/cm2 at ‐90 V. The device fabricated on n‐ bulk substrate showed a breakdown voltage of 600 V, a specific on‐state resistance of 1.3 mΩ·cm2 and a leakage current density of 8.1×10‐8 A/cm2 at ‐100 V. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DNA hybridization sensor based on AlGaN/GaN HEMT
Authors: Alur Siddharth , Thapa Resham , Gnaprakasa Tony , Wang Yaqi , Sharma Yogesh , Javalosa Edritz , Smith Elizabeth , Ahyi Claude , Simonian Aleksandr , Bozack Michael , Williams John , Park Minseo
Published: June 2011

AlGaN/GaN based heterostructures are used to fabricate high electron mobility transistors for the purpose of a DNA hybridization sensor. Photodefinable PDMS is used to encapsulate the entire device except the gold sputtered gate area. The gold coated gate contacts are functionalized with thiolated ssDNA. The fabricated device is used to detect DNA hybridization of Salmonella DNA of two different concentrations of 1 μM and 4 μM. There is a higher drop in drain current when a higher DNA concentration is used. The device is also checked for reusability, thereby confirming the stability of the device and the encapsulation. The measurements are carried out at zero gate bias. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling and experimental study of MOS channel mobility of etched GaN on silicon substrate
Authors: Li Zhongda , Naik Harsh , Chow T. Paul
Published: June 2011

We report on the experimental results of the MOS field‐effect and Hall mobilities measured on etched surface of GaN grown on silicon substrate. The peak MOS Hall mobility was extracted to be 23 cm2/V‐s, and the Hall mobility was then modelled using physics‐based model. The effects of Columbic scattering, phonon scattering, and surface roughness were evaluated, and the limiting factor of the GaN MOS mobility was identified as Columbic scattering caused by the combination of high interface charges and traps at the GaN MOS interface. The GaN MOS surface roughness extracted from the modelling was comparable to silicon MOS interface. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Control of AlN buffer/sapphire substrate interface for AlN growth
Authors: Miyagawa Reina , Yang Shibo , Miyake Hideto , Hiramatsu Kazumasa
Published: June 2011

The growth condition of AlN buffer layer has been studied in order to fabricate a high‐quality AlN layer on a sapphire substrate. The growth of high‐quality AlN is extremely difficult due to the weak surface migration of Al adatoms. Therefore we have focused on the AlN buffer layer, and examined the growth condition while controlling the thickness and growth temperature. The crystalline quality of the AlN layer grown on an AlN buffer layer at a growth temperature of 1250 °C was improved, and the full width at half‐maximum (FWHM) value of the X‐ray rocking curve (XRC) obtained for (0002) and (10‐10) diffractions were 138 and 464 arcsec, respectively. Moreover, AlOxN1‐x was formed when the AlN buffer layer was grown at a high temperature (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of mesa size in nano‐structured green AlGaInN light‐emitting diodes
Authors: Stark Christoph J. M. , Detchprohm Theeradetch , Wetzel Christian
Published: June 2011

The mesa width of green light‐emitting diodes (LEDs) was scaled from the micrometer to the nanometer range. The devices were patterned by electron beam lithography and dry etching and contained up to 100 parallel nano‐stripe LEDs connected to one common contact area. The mesa width was varied over 1 µm, 200 nm, and 50 nm. The LEDs were characterized electrically and optically, and the peak emission wavelength was found to depend on the lateral structure size. Light emission from the patterned region was found to be 4 times brighter than from the un‐patterned regions. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of structural transforma‐ tions in bulk and as‐evaporated optical media under action of polychromatic or photon‐energy dependent monochromatic illumination
Authors: Holomb Roman , Mitsa Volodimir , Petrachenkov Olexandr , Veres Miklos , Stronski Alexander , Vlček Miroslav
Published: June 2011

Light‐induced structural changes of As‐S glasses and films were probed both by macro FT‐Raman and photon‐energy dependent micro‐Raman spectroscopy using different spectral composition of photoactive light: polychromatic or different wavelengths of laser radiation. The polychromatic illumination and thermal treatment leads to continuous decrease in intensity of characteristics vibrational modes of molecular or cage‐like species like As4S4, As4S3, etc. Under laser illumination the picture is different, new observed features in the Raman spectra of As‐rich As‐S glass are related to transformations of As4S4 molecules: α(β)‐As4S4 transform into pararealgar p ‐As4S4 form during laser illumination. The effectiveness of transformations depends mainly on photon energies used for irradiation, but the tendency to transform is observed for all used photon energies ranging from 1.65 to 2.54 eV. Experimental photon‐energy dependent Raman spectroscopy used together with ab initio DFT calculations indicate that the mechanism of photo‐induced changes in As‐S glasses and films is defined by spectral width of illumination source (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Threshold integrated optical chemical sensor with sensitivity controlled by external illumination
Authors: Sakalosh I. I. , Sharkany Y. P. , Ramsden J. J. , Zhitov N. B.
Published: June 2011

Chemical sensor with multilayer sensitive element on the basis of bR containing nanostructured composite layer is analyzed. The results on the modeling of the construction and its optimization are presented. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical absorption and photoluminescence of lumonophore nanocomposites
Authors: Verlan V. I. , Iovu M. S. , Andriesh A. M. , Nistor Yu. H. , Culeac I. , Malahov L. , Turta C. I. , Zubareva V. E.
Published: June 2011

The europium complex tris(dibenzoylmethane)(monophenanthroline)europium (III) (Eu(DBM)3Phen) was successfully incorporated with different molar ratios into organic copolymer matrix of styrene:butylmethacrilate (1:1) (SBMA) via sol–gel process. Spin‐coated thin films were obtained. The layers turn out to be transparent in optical range of investigation. Absorption and luminescence properties of a europium complex on each step of technology nanocomposites of the pure Eu(DBM)3Phen complex powder, its solution with SBMA and the resultant thin films nanocomposites (NC) phosphors (SBMA ‐Eu(DBM)3Phen) were investigated. The microscopic investigations of the morphology of the NC surface show that the dimensions of Eu(DBM)3Phen particles, incorporated in the polymer matrix are less than 100 nm. The forbidden bands of NC were obtained. Photoluminescence (PL) spectra have been measured exciting with N2‐laser (λ = 0.334 μm) and they were revealed the radiative bands between the energy levels of the europium ions centered at 578, 590, 615, 652, and 705 nm and can be attributed to the spin forbidden f‐f transitions 5D0 → 7Fi (i = 0,1,2,3 and 4), respectively (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced vector deformations of semi‐freely fixed glassy As‐S(Se)
Authors: Tanaka Keiji , Mikami Masatoshi
Published: June 2011

The chalcogenide glass is known to exhibit a variety of vector photo‐deformations. The present work studies the deformation in glassy As‐S(Se) films and flakes, which are laid on viscous grease layers. Upon bandgap illumination of linearly polarized cw laser light, the film and flake exhibit anisotropic wrinkles and extensions, respectively, while the directions change with the composition. As2S(Se)3 samples deform in the direction orthogonal to the electric field of the light, but pure Se deforms in parallel to the electric field. And, in the As‐Se system, an orthogonal‐parallel directional change appears at the As content of ∼1 at.%. X‐ray diffraction and Raman‐scattering spectroscopy detect no anisotropic atomic changes. The orthogonal deformation has been ascribed to optical pressure, while the parallel in Se may be triggered by polariton‐plasmon waves. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐bands active media on the basis of BaY2F8 single crystals for up‐conversion solid‐state lasers with diode pumping
Authors: Uvarova T. V. , Pushkar A. A. , Uvarova A. G.
Published: June 2011

We represent the multi‐band's laser media as example principle possibility of application of laser diodes for radiation excitation in visible and UV spectrum ranges. Possibility of excitation luminescence in region from 230 to 650 nm from the high laying 4f and 5d states of ions Pr3+ and Ce3+ in active media of BaY2F8:(Yb3+, Pr3+, Ce3+), excited by radiation of 960 nm, 840‐808 nm and 405 nm laser diodes is considered. Spectra of the realized visible luminescence are shown at one‐wave and multi‐wave pumps by infrared (IR) laser diodes. The up‐conversion schemes of excitation the 5d‐UV luminescence from Pr3+ and Ce3+ by laser diodes is reported. Possibility of the realization 5d‐ luminescence from Pr3+ and Ce3 ions is discussed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equivalent magnetic noise in magnetoelectric Metglas/Pb(Mg1/3Nb2/3)O3‐PbTiO3 laminate composites
Authors: Wang Yaojin , Gray David , Berry David , Gao Junqi , Li Jiefang , Viehland D. , Luo Haosu
Published: June 2011

We have experimentally and theoretically investigated the equivalent magnetic noise in a magnetoelectric Metglas/ 0.7Pb(Mg1/3Nb2/3)O3‐0.3PbTiO3 laminate sensor unit by considering the constituent noise sources of dielectric loss (NDE) and DC leakage resistance (NR). In the low frequency range (f = 1 Hz), theory predicts that NR dominates the noise charge (1.6 times larger than NDE), with a 1 Hz noise of 9.1\;{\rm pt}/\sqrt {\rm Hz}. The experimental equivalent magnetic noise was 10.8\;{\rm pt}/\sqrt {\rm Hz}. This observed value is slightly higher than the predicted one, which might be due to an oversimplification of the theoretical model in terms of electrical charge amplifier and external vibration noise sources. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of the Efficacy and Safety of Salvia officinalis in Controlling Hot Flashes in Prostate Cancer Patients Treated with Androgen Deprivation
Authors: Vandecasteele Katrien , Ost Piet , Oosterlinck Willem , Fonteyne Valérie , De Neve Wilfried , De Meerleer Gert
Published: June 2011

The purpose of this pilot study was to evaluate the efficacy and safety of Salvia officinalis in controlling hot flashes in prostate cancer patients treated with androgen deprivation therapy (ADT). Ten patients experiencing hot flashes were included in a single‐centre prospective pilot study. Treatment consisted of 150 mg of Salvia officinalis extract taken orally three times daily. A diary questionnaire scoring hot flashes, subjective side effects and quality of life (QOL) had to be completed. Clinical examination was performed at every visit and the concentration of ADT‐linked hormones, haemoglobin and cholesterol was measured before, during and after ending treatment. Before the start of treatment, a 1 week baseline registration was performed. An analysis of variance with time of measurement as a within‐subject factor was performed. When analysing the hot flashes score, one patient was excluded due to insufficient diary notes. The mean weekly score declined from 112 (SD = 71) at baseline to 59 (SD = 54) at the end of treatment (p = 0.002). Hot flashes diminished significantly from the first week up to and including week 3. This was maintained during treatment. There was no effect on QOL. There were no side effects. It is concluded that Salvia officinalis is efficient and safe in the treatment hot flashes, without improving QOL. Copyright © 2011 John Wiley & Sons, Ltd.
Optimization of cryo‐XPS analyses for the study of thin films of a block copolymer (PS‐PEO)
Authors: Delcroix Marie F. , Zuyderhoff Emilienne M. , Genet Michel J. , Dupont‐Gillain Christine C.
Published: June 2011

The water‐induced surface reorganization of a thin film of a block copolymer [polystyrene‐b‐poly(ethylene oxide), PS‐PEO], was studied by cryogenic X‐ray photoelectron spectroscopy (cryo‐XPS). Experimental parameters were examined with a view to optimize the analysis. The absence of artifacts due to the low temperature of analysis was checked, and the influence of the procedure used for sample hydration before analysis was investigated. Adequate timing of the different steps of the analysis and temperature program was also established. With this optimized protocol, an important reorganization of the block copolymer was detected, showing more pronounced exposure of the PEO block at the outermost surface in hydrated compared to dry environment. As this type of polymer surface is prone to be used for biomedical applications, an accurate knowledge of the chemical composition of the outermost surface in aqueous environments is crucial. The development of this technique is therefore promising for related systems. Copyright © 2011 John Wiley & Sons, Ltd.
Graphene‐Based Materials: Synthesis, Characterization, Properties, and Applications
Authors: Huang Xiao , Yin Zongyou , Wu Shixin , Qi Xiaoying , He Qiyuan , Zhang Qichun , Yan Qingyu , Boey Freddy , Zhang Hua
Published: June 2011

Graphene, a two‐dimensional, single‐layer sheet of sp2 hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene‐related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene‐based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene‐based materials are discussed.
Production and characterization of oxidized cassava starch (Manihot esculenta Crantz) biodegradable films
Authors: de Pauli Renata Baraldi , Quast Leda Battestin , Demiate Ivo Mottin , Sakanaka Lyssa Setsuko
Published: June 2011

Plastic is one of the most common pollutants in the environment. Therefore, the number of studies on the use of biodegradable packaging is increasing. Starch is the primary material used in the production of biodegradable plastics due to its natural abundance and high biodegradability. Yet, the strong hydrophilic character of starch presents a challenge. Therefore, the modification of its structure through oxidation may yield interesting results as the viscosity reduction. The objectives of this work were to obtain cassava (Manihot esculenta Crantz) starch oxidized with 0.8 and 2.0% active chlorine, to develop biodegradable films and characterize their mechanical properties, solubility in water, permeability to water vapor, degree of swelling, and sorption isotherms. Biodegradable films were produced with starch concentrations of 2, 3, 4, and 5% w/w and 25% glycerol (g/100 g starch) added as a plasticizer. Images of the films were obtained with an atomic force microscope and allow to observe a smooth surface and the absence of starch granules in the film produced with oxidized starches. The tensile strength of the biodegradable film produced with oxidized starch (0.8% active chlorine) was 80 MPa. The value of permeability to water vapor was 1.613 × 10−9 kg/day/m/Pa, and the average solubility was 41%. The sorption isotherms showed that biodegradable films made with oxidized starches cannot be used in environments with relative humidity below 35% or above 90%.
Stochastic security testing of chaos‐based communication systems against error function attack
Authors: Nomura Tatsuya , Irie Takahiko , Suemitsu Haruo , Matsuo Takami
Published: June 2011

This paper proposes two stochastic testing methods for the security analysis of a secure communication scheme based on continuous‐time chaotic systems. First, we define an instantaneous EFA (error function attack) function that does not include the average operation. Second, we propose a statistical testing for cryptanalysis, which calculates a standard deviation of the EFA function obtained by random trial keys. As another stochastic testing, moreover, we propose a stochastic evolutional attack to find a secret key. Finally, simulation results for the proposed security testing are presented. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Tetranuclear Manganese Complex Incorporating 2‐Pyridyloximate Ligand: Synthesis, Crystal Structure and Magnetic Property
Authors: Zhao Yang , Zhang Suyun , Zheng Lina , Chen Yanmei , Hu Bin , Li Yahong
Published: June 2011

A tetranuclear manganese complex of the composition {Mn4[(Py)C(Ph)NO]4(CH3CH2OH)3(CH3CH2O)Cl3}·2H2O (1) was synthesized by solvothermal reaction, and characterized by X‐ray single crystal diffraction, IR spectroscopy, and elemental analysis. X‐ray analysis revealed that complex 1 contains a [Mn4(NO)4]4+ core with three MnII atoms displaying distorted octahedral arrangements and one MnII ion exhibiting a trigonal bipyramidal arrangement. Low‐temperature magnetic susceptibility measurement for the solid sample of 1 revealed antiferromagnetic MnII···MnII interactions.
Quality Assessment of Heated Cooking Oil, Agab, Using a Simple Newly‐Developed Spectrophotometric Method
Authors: Hamed Said Fatouh , abo El‐Wafa Ghada Ahmed , El‐Ghorab Ahmed , Shibamoto Takayuki
Published: June 2011

Deep fat frying is one of the most widely used cooking practices but heat treatment produces many degradation products, some of which may cause health hazards. A simple, rapid, and inexpensive method for assessment of the quality of cooking oil used for frying was developed using a spectrophotometer. Potato slices were heated in Agab oil (soybean/sunflower:1/l volume) at 180 ± 5 °C for 8 h per day for 6 consecutive days. Heated samples were collected at 15‐min intervals and UV absorbance at λ = 370–400 nm was measured; samples were also analyzed for anisidine value (AV), conjugated diene formation (CD), and total polar compounds (TPC). A systematic increase of absorbance in heated oil over frying time was observed. TPC was highest (R2 = 0.99) for the correlation with heating time followed by CD (0.93) and AV (0.89). The spectrophotometric method developed in the present study to assess the quality of heated oils is simple, quick, and reliable because its results were strongly correlated with the results from the TPC.
Enzymatic Extraction of Wheat Germ Oil
Authors: Xie Meizhen , Dunford Nurhan Turgut , Goad Carla
Published: June 2011

In this study enzymatic extraction of oil from wheat germ (WG) was investigated. Four enzymes (Viscozyme L, Multifect CX 13L, Multifect CX GC and Alcalase 2.4L FG) were screened for their efficacy to release oil from WG. Alcalase 2.4L FG treatment of WG improved oil extraction yield as compared to a control (aqueous extraction without enzyme). Alcalase 2.4L FG, which resulted in significantly higher oil yield than the other three enzymes, was chosen for optimization of the enzymatic oil extraction process by using Response Surface Methodology (RSM). Three processing parameters, liquid/solid ratio, extraction time and enzyme concentration, were investigated as the independent variables. Based on the experimental results, the highest oil yield, 66.5% (w/w), was obtained under the following conditions; liquid/solid ratio 16.5, enzyme concentration 1.1% and extraction time 19.25 h. A cubic model with R2 of 0.91 was developed to describe the enzymatic extraction process. Although the cubic model predicted WG oil extraction yields well within the processing conditions studied in this study it was not effective beyond the experimental range. Further research focusing on high liquid/solid ratio, 16–20, and extraction time in 18–24 h and 0.5–5 h ranges is necessary to improve the model developed in this study.
Elastic stable intramedullary nailing of tibial shaft fractures in children
Authors: Griffet Jacques , Leroux Julien , Boudjouraf Nouar , Abou-Daher Ahmad , el Hayek Toni
Published: June 2011

Purpose

Tibial fractures in the skeletally immature patient are usually treated without surgery. Elastic stable intramedullary nailing (ESIN) is commonly used for other diaphyseal fracture locations. Its advantages are minimally invasive surgery with a short hospitalisation duration, primary bone union and early weight bearing. The purpose of this study was to assess the use of ESIN in displaced tibial fractures in children over 6 years old and in cases of polytrauma.

Methods

This study was carried out over a 6-year period. The protocol consisted in ESIN of shaft tibial fractures in children over 6. Frontal and sagittal angulation, shortening and lengthening were measured on days 0, 2, 15, 30 and 45. At 6 months, 1 and 2 years, the femoro-tibial axis and eventual shortening or lengthening were assessed.

Results

The study involved 86 children (average age 11.8 years). As early as day 30, all patients had normal knee mobility and symmetrical foot progress angle. At 2-year follow-up, frontal angulation and leg length discrepancy had decreased and affected 2% of patients. Four patients (5%) suffered from superficial infections. There were no cases of osteomyelitis or refracture.

Conclusions

The fixation of paediatric diaphyseal tibial fractures with ESIN is a rapid, well-codified and effective method for treating long-bone closed fractures in children. Advantages over other fixation techniques include a lower infection rate, a lower refracture rate, ease of management, and an aesthetically pleasing scar.
Treatment of late-presenting developmental dislocation of the hip by progressive orthopaedic reduction and innominate osteotomy. Our results with more than 30 years of follow up
Authors: Morin Christian , Bisogno Javier , Kulkarni Shrirang , Morel Georges
Published: June 2011

Background

The treatment of late-presenting developmental dislocation of the hip (DDH) is still controversial. A consecutive series of 32 patients not previously treated (43 hips, Tönnis grade 3 or 4) underwent progressive closed reduction followed immediately by innominate osteotomy between 1964 and 1976. They were between 1.5 and 5 years old at the time of pelvic osteotomy. This study was designed to check the outcome of these patients more than 30 years later.

Methods

Eight patients living outside of France (North Africa) could not be reached and one patient had died of an unrelated cause. The remaining 23 patients (32 hips) were reviewed with clinical assessment (Merle d'Aubigné, Harris and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] scores) and anteroposterior (AP) pelvic radiograph. This represents a 75% rate of follow up at 31 to 44 years post-operatively.

Results

In two patients, surgery was repeated due to residual subluxation. Only one patient needed a total hip replacement (THR) 33 years after initial treatment. The Merle d'Aubigné, Harris and WOMAC scores for the surviving hips were excellent or good in almost 80% of the cases. In four cases, radiographic signs “at risk for” osteoarthritis were present. Regularity of the femoral head was perfect in seven hips, regular in 18 and irregular in six. According to the Severin–Seringe classification, 25 hips could be classified as group I (14 group IA and 11 group IB), three group II and three group VII.

Conclusion

The long-term results of non-previously treated late-presenting DDH by the technique of progressive closed reduction followed by innominate osteotomy are quite good and compare favourably with the long-term results of open reduction with the same osteotomy.
Vegetation vis-à-vis Climate and Glacier History during 12,400 to 5,400 yr BP from Dokriani Valley, Garhwal Himalaya, India
Authors: Bhattacharyya A. , Ranhotra P.S. , Gergan J.T.
Published: June 2011

Palynological analysis from a 10 m deep sediment profile from Dokriani valley, Garhwal Himalaya, provides temporal variation of vegetation vis-à-vis climate and glacier history of the region. This study reveals that between 12,406 and 10,633 cal yr BP vegetation was sparse when the climate was cool-dry and the glacier snout might had been located at lower elevations in comparison to its present position. Subsequently around 10,633 cal yr BP, an increase in the growth of diversified taxa close to the site, indicates the early Holocene climatic amelioration when glacier might have retreated at faster rate. Further, within Holocene some intermittent cool-dry episodes were recorded around 9,670 to 9,000 cal yr BP and 7,100 cal yr BP when glacier might have shown reduction in retreat rate or came to stagnation.
Microstructure-compositional Variation in Iron Oxy-hydroxide Minerals formed with Manganese Mineralization, Eastern Ghats Supergroup, Orissa
Authors: Mohapatra B.K. , Jena S. , Singh P.P.
Published: June 2011

Large volume of iron oxy-hydroxide minerals occur in association with manganese oxide phase in manganese ores of the Eastern Ghats Supergroup, Koraput district, Orissa. On the basis of OH content, the iron mineral can be classified into hydrohematite, goethite, and hydrogoethite. These minerals exhibit eight types of microstructures such as ooloidal, caterpillar, disseminated, reniform, worm, mosaic, globular and spherulitic. Chemical composition of such micro-structures obtained through EPMA, distinguishes them into three domains, developed under different environment. Hydrohematite, having 8-10 % H2O, characteristically contains higher pc of manganese (>5%) and phosphorous (>0.6%) but have low silica and alumina. These are formed syngenetically with Mn-oxide minerals in a manganese rich paragenesis. Goethite containing 11 to 12% water, has relatively low level of manganese and phosphorous, and formed in a later period, as secondary open space filling. Hydrogoethite shows very high water content (>16%), almost devoid of manganese, and impoverished in phosphorous but having higher percentage of alumina, silica and appreciable copper and nickel. This was latest to form in the zone of oxidation under supergene condition.