bluuebunny/crossref_metadata_2025 huggingface dataset:
Fiber Lasers
Authors: Becker Frank , Brettschneider Corinna , Kallage Peter , Rath Wolfram
Published: January 2014

Fiber lasers have already firmly established themselves within the industrial production sector and are synonymous with efficiency, precision and cost‐effectiveness in a large number of laser material processing applications. They offer excellent single‐mode or multi‐mode beam qualities, which can be precisely adapted to the processing task and therefore represent a universal tool for industrial production. On the basis of selected application examples, the technology and the manifold application possibilities of the Rofin fiber lasers in the power range from 0.5 to 6 kW are reviewed.
Staying in Line
Authors: Thies Maja
Published: January 2014

Sometimes it's a customer request that provides the seed for innovation. LIMO asked material processing specialists from around the world what their ideal energy source for consistent planar heating of thin films would look like. The almost unanimous answer: we need a linear source that scans the surface and thus enables consistent and continuous processing (Fig. 1).
In Situ Generation of Cell‐Laden Porous MMP‐Sensitive PEGDA Hydrogels by Gelatin Leaching
Authors: Sokic Sonja , Christenson Megan , Larson Jeffery , Papavasiliou Georgia
Published: January 2014

Proteolytically degradable poly(ethylene) glycol (PEG) hydrogels have been investigated as tissue engineering scaffolds; however, cell invasion and tissue regeneration are limited by the rate of cell‐mediated degradation due to the small mesh size of the resultant crosslinked network. Gelatin leaching is combined with photopolymerization to form porous matrix‐metalloproteinase (MMP)‐sensitive PEG scaffolds under cytocompatible conditions in the presence of cells. Gelatin leaching allows control over pore size and porosity through selectivity of gelatin bead particle size and porogen loading, respectively. Increases in porogen loading lead to increased porosity, decreased compressive modulus and degradation time, and enhanced proliferation of encapsulated vascular smooth muscle cells.
Complexation of Mefenamic Acid by Low‐Generation PAMAM Dendrimers: Insight from NMR Spectroscopy Studies and Molecular Dynamics Simulations
Authors: Barra Pabla A. , Barraza Luis , Jiménez Verónica A. , Gavín José A. , Alderete Joel B.
Published: January 2014

The complexation of mefenamic acid (MA) with poly(amido amine) dendrimers of the second and third generation (PAMAM‐G2 and PAMAM‐G3) at pH 7.0 is studied by aqueous solubility experiments, DOSY and 2D‐NOESY spectroscopy, and fully atomistic molecular dynamics (MD) simulations. Solubility profiles account for the formation of MA:PAMAM complexes of the type 10:1 and 15:1, for PAMAM‐G2 and PAMAM‐G3, respectively, with a maximum solubilization enhancement of 14.6 mol of MA per mol dendrimer. Diffusion ordered sepectroscopy (DOSY) and nuclear Overhauser effect spectroscopy (NOESY) experiments suggest that MA association occurs through both external electrostatic interactions with the PAMAM surface and internal encapsulation into the deep dendrimer cavities. MD simulations are consistent with these experimental findings and show that the internal drug encapsulation is enhanced as the dendrimer generation increases. The involvement of internal and external interactions in the complexation of MA with low‐generation PAMAM dendrimers differs from the general behavior expected for acidic anionic guests, for which external electrostatic contacts with the positively charged PAMAM surface have been postulated as the most relevant factor for drug association.

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Monte Carlo Simulation Studies of the Size and Shape of Regular Three Generation Dendrimers
Authors: Wawrzyńska Edyta , Eisenhaber Stephan , Parzuchowski Paweł , Sikorski Andrzej , Zifferer Gerhard
Published: January 2014

By the use of a dynamic Monte Carlo method, three‐generation dendrimers of type F1F2F2 with functionalities F1 = 3 to 6 and F2 = 2 to F1–1 are simulated and investigated as functions of spacer lengths, with a total chain length up to 200 000 segments. Highly diluted athermal and theta solutions are studied as well as properties of non‐reversal random walk dendrimers for comparison. For athermal conditions mean square dimensions obey the same scaling law regarding the total number of bonds as linear chains, irrespective of functionality and complexity. Likewise the theta parameter is the same for all systems investigated. Dimensions of theta systems are slightly expanded as compared to non‐reversal random walk data, the effect increasing with increasing F1 and F2 while shape data near to theta conditions fairly well coincide with those of non‐reversal random walks.
Antiweathering effects of vitamin E on wood flour/polypropylene composites
Authors: Peng Yao , Liu Ru , Cao Jinzhen , Luo Shupin
Published: January 2014

The purpose of this research was to investigate the influence of vitamin E (Ve) with different loading levels (0.1, 0.2, 0.4, and 1.2 %wt) on the photodegradation of wood flour/polypropylene composites. Five groups of composites were exposed in a QUV‐accelerated weathering tester for 960 h and then the surface color and the flexural properties were tested. Besides, the surface morphology and chemical changes of the composites during weathering were analyzed by scanning electron microscopy, attenuated total reflectance fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. The results revealed that (1) the addition of Ve had a positive effect on hindering the photooxidation process of the composites; (2) composites with higher Ve loading levels (0.4 and 1.2 %wt) showed better flexural properties, less color fading, cracks, and disclosure of wood fibers on surface after weathering; (3) Ve alleviated the chain scission of PP and the formation of carbonyl groups by reacting with free radicals that generated from photodegradation during weathering. Therefore, it could be an effective antiphotodegradation agent for the composites. POLYM. COMPOS., 35:2085–2093, 2014. © 2014 Society of Plastics Engineers
HDPE reinforced with glass fibers: Rheology, tensile properties, stress relaxation, and orientation of fibers
Authors: Saeed U. , Hussain K. , Rizvi G.
Published: January 2014

Glass fiber‐reinforced high‐density polyethylene of varying concentrations was mixed with ethylene copolymer and maleic anhydride‐grafted polypropylene (coupling agents) separately. The viscosity, tensile strength, and stress relaxation properties of the composites were investigated. The orientation and anisotropy of glass fibers were studied using micro computed tomography scanner. It was found out that the orientation and anisotropy of fiber are strongly affected by the increase in glass fiber concentration. POLYM. COMPOS., 35:2159–2169, 2014. © 2014 Society of Plastics Engineers
Narcissistic biographies—third age self‐transcendence abilities
Authors: Nirestean Aurel , Lukacs Emese , Cimpan Dana , Nirestean Tudor
Published: January 2014

Narcissistic traits interfere in the process of self‐determination and the individual motivational strategies of human beings. The grandiose and vulnerable narcissistic personality subtypes have difficulties in their education, interpersonal relationships and quality of life. The latter is also affected by ageing, whose attributes influence, above all, one's self‐esteem, especially in women. Though very fearful of suffering and death, narcissists have a powerful desire to overcome them by cultivating their grandiosity, especially through the mystical and paranormal experiences they relate. The spiritual means of transcending one's self, including the components of magical thinking, can prevent the destruction of self‐esteem in narcissists in their third‐age. Copyright © 2014 John Wiley & Sons, Ltd.
Kinetic study of the formation of N‐chloro compounds using N‐chlorosuccinimide
Authors: Pastoriza Cristina , Antelo Juan Manuel , Crugeiras Juan , Peña‐Gallego Angeles
Published: January 2014

Second‐order rate constants were determined for the chlorination reaction of 2,2,2‐trifluoethylamine and benzylamine with N‐chlorosuccinimide at 25 °C and an ionic strength of 0.5 M. These reactions were found to be of first order in both reagents. According to the experimental results, a mechanism reaction was proposed in which a chlorine atom is transferred between both nitrogenous compounds. Kinetics studies demonstrate that the hydrolysis process of the chlorinating agent does not interfere in the chlorination process, under the experimental conditions used in the present work. Free‐energy relationships were established using the results obtained in the present work and others available in the literature for chlorination reactions with N‐chlorosuccinimide, being the pKa range included between 5.7 and 11.22. Copyright © 2014 John Wiley & Sons, Ltd.
Composite Propellant Based on a New Nitrate Ester
Authors: Reese David A. , Son Steven F. , Groven Lori J.
Published: January 2014

Composite propellants based on the solid nitrate ester 2,3‐hydroxymethyl‐2,3‐dinitro‐1,4‐butanediol tetranitrate (SMX) were theoretically and experimentally examined and compared to formulations based on ammonium perchlorate (AP). Thermochemical equilibrium calculations show that aluminized SMX‐based formulations can achieve theoretical sea level specific impulse values upwards of 260 s. Both ignition sensitivity (tested via drop weight impact, electrostatic discharge, and BAM friction) and physical properties (hardness and thermal properties) are comparable to those of the AP‐based formulations. However, the SMX‐based formulation could be detonated using a high explosive donor charge in contact with the propellant. Differential scanning calorimetry of the SMX‐based propellant indicated an exotherm onset of 140 °C, which corresponds to the known decomposition temperature of SMX. The propellant has a high burning rate of 1.57 cm s−1 at 6.89 MPa, with a pressure exponent of 0.85. This high pressure sensitivity might be addressed using various energetic and/or stabilizing additives. With good performance and high density, SMX‐based composite propellants may offer a promising perchlorate‐free alternative to existing AP‐based formulations.
Fabrication, Thermoanalysis, and Performance Evaluation Studies on RDX‐based Microcellular Combustible Objects
Authors: Yang Weitao , Li Yuxiang , Ying Sanjiu
Published: January 2014

In the development of weapons, the current trend is to replace incombustible constituent elements with combustible ones. The traditional porous combustible objects are composed of nitrocellulose as energetic component, which is highly sensitive and inflammable. Formulations composed of high content RDX and inert polymer binder were employed to replace the tradional ones. This paper reports the fabrication process of microcellular combustible objects with skin‐core structure using supercritical CO2 (SC‐CO2) as foaming agent. The objects were foamed in designed foaming molds with expansion ratios of 1.1, 1.2 and 1.35. The influence of foaming temperature, saturation pressure, expansion ratio and RDX content on porous structure was investigated by scanning electron microscopy (SEM). Thermogravimetric analysis was conducted and the results revealed a two‐stage decomposition process of RDX and binder. Performance in terms of heat resistance and moisture resistance was evaluated and compared with the traditional ones. A comparative study indicated that microcellular combustible objects are superior to traditional ones in respect of their survivability.
Herbicides and plant hormesis
Authors: Belz Regina G , Duke Stephen O
Published: January 2014

Herbicide hormesis is commonly observed at subtoxic doses of herbicides and other phytotoxins. The occurrence and magnitude of this phenomenon are influenced by plant growth stage and physiological status, environmental factors, the endpoint measured and the timing between treatment and endpoint measurement. The mechanism in some cases of herbicide hormesis appears to be related to the target site of the herbicide, whereas in other examples hormesis may be by overcompensation to moderate stress induced by the herbicides or a response to disturbed homeostasis. Theoretically, herbicide hormesis could be used in crop production, but this has been practical only in the case of the use of herbicides as sugar cane ‘ripeners’ to enhance sucrose accumulation. The many factors that can influence the occurrence, the magnitude and the dose range of hormetic increases in yield for most crops make it too unpredictable and risky as a production practice with the currently available knowledge. Herbicide hormesis can cause undesired effects in situations in which weeds are unintentionally exposed to hormetic doses (e.g. in adjacent fields, when shielded by crop vegetation). Some weeds that have evolved herbicide resistance may have hormetic responses to recommended herbicide application rates. Little is known about such effects under field conditions. A more complete understanding of herbicide hormesis is needed to exploit its potential benefits and to minimize its potential harmful effects in crop production. © 2014 Society of Chemical Industry
Current state of herbicides in herbicide‐resistant crops
Authors: Green Jerry M
Published: January 2014

Current herbicide and herbicide trait practices are changing in response to the rapid spread of glyphosate‐resistant weeds. Growers urgently needed glyphosate when glyphosate‐resistant crops became available because weeds were becoming widely resistant to most commonly used selective herbicides, making weed management too complex and time consuming for large farm operations. Glyphosate made weed management easy and efficient by controlling all emerged weeds at a wide range of application timings. However, the intensive use of glyphosate over wide areas and concomitant decline in the use of other herbicides led eventually to the widespread evolution of weeds resistant to glyphosate. Today, weeds that are resistant to glyphosate and other herbicide types are threatening current crop production practices. Unfortunately, all commercial herbicide modes of action are over 20 years old and have resistant weed problems. The severity of the problem has prompted the renewal of efforts to discover new weed management technologies. One technology will be a new generation of crops with resistance to glyphosate, glufosinate and other existing herbicide modes of action. Other technologies will include new chemical, biological, cultural and mechanical methods for weed management. From the onset of commercialization, growers must now preserve the utility of new technologies by integrating their use with other weed management technologies in diverse and sustainable systems. © 2014 Society of Chemical Industry
Ten things GPs need to know about pharmacists
Authors: Chaplin Steve
Published: January 2014

Steve Chaplin describes a new guide for GPs that aims to foster a better understanding of the role of community pharmacists.
OptimiseRx: patient‐specific guidance for GP prescribing
Authors: Mendis Gita
Published: January 2014

OptimiseRx is a new decision support system produced by First Databank. Here, the author explains what it does and how it can aid GP prescribing decisions.
Constella: new treatment for constipation‐predominant IBS
Authors: Chaplin Steve , Trudgill Nigel
Published: January 2014

Linaclotide (Constella) is guanylate cyclase‐C receptor agonist for the treatment of constipation‐predominant IBS. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects and Dr Nigel Trudgill discusses its place in therapy.
Spectral shift of cresyl violet luminescence on charged silicon oxide nanostructures
Authors: Baumgärtel Thomas , Graaf Harald
Published: January 2014

Nanolithography by local oxidation of dodecyl‐terminated silicon using a scanning probe microscope is a practical method for the generation of silicon oxide nanostructures on a well‐defined substrate. We report on the functionalization of such structures by the selective binding of the cationic dye cresyl violet by electrostatic interactions. The bound dye molecules could be optically excited and showed a clear luminescence emission. Additionally to the fluorescence light from monomers, an additional blue‐shifted emission was found. This emission is an indication of the formation of charge‐transfer complexes between the cationic dye molecules and anions in the oxide nanostructures.

AFM topography and fluorescence image of selectively cresyl violet modified silicon oxide nanostructures on alkyl‐terminated silicon surfaces.
Inclusion of nano‐Ag plasmonic layer enhancing the performance of p‐Si/CdS solar cells
Authors: Ghosh B. , Ghosh D. , Hussain S. , Chakraborty B. R. , Sehgal G. , Bhar R. , Pal A. K.
Published: January 2014

Introduction of plasmonic layer in p‐Si/undoped CdS/indium doped CdS (p‐Si/CdS/In:CdS) solar cell indicated an enhancement of short circuit current which improved the overall increase in efficiency. The location of n‐Ag layer and the possible interdiffusion of n‐Ag at the interface were examined critically by secondary ion mass spectroscopy. The effect of plasmonic layer in the above cell structure and its overall performance has been critically studied in terms of the morphology, particle size distribution, optical absorption, current–voltage (J–V) characteristics, capacitance–voltage (C–V) characteristics, and lifetime of the photo‐generated carriers.
Spatial distribution of free carrier concentration in vertical GaN Gunn‐diode structures studied by confocal micro‐Raman spectroscopy and Kelvin probe force microscopy
Authors: Strelchuk V. V. , Nikolenko A. S. , Lytvyn P. M. , Romanyuk A. S. , Mazur Yu. I. , Ware M. E. , DeCuir E. A. , Salamo G. J. , Belyaev A. E.
Published: January 2014

Scanning confocal micro‐Raman and PL spectroscopy, Kelvin probe force microscopy (KPFM) and electrostatic force gradient microscopy (EFGM) were applied to study the concentration profiles of free carriers by scanning the cleaved edge along the growth direction of vertical n+/n0/n+‐GaN Gunn‐diode structure. The vertical frequency profile of the L– branch of the plasmon‐LO‐phonon modes was used to evaluate the concentration of free charge carriers. Obtained significant contrast through the undoped n0‐GaN region validates the expected reduction in carrier concentration. Variation of the local contrast in cross‐section KPFM and EFGM electrical images reflects the topology of the device structure and makes it possible to estimate electronic properties of individual GaN layers as well as interface boundaries. The carrier profiles determined from the Raman data and KPFM measurements are in good agreement. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Side gate AlGaN/GaN FET on silicon and sapphire
Authors: Hiller Lars , Tonisch Katja , Pezoldt Jörg
Published: January 2014

AlGaN/GaN heterostructures were grown on sapphire and alternatively on silicon substrates covered with a thin SiC layer by MOCVD. The side gated transistors were fabricated using electron beam lithography. The conductivity of the drain‐source branch could be tuned via the side gate formed by a two‐dimensional electron gas directly connected to the source drain branch or separated by a trench.

The electrical measurements of the fabricated in‐plane‐gated devices revealed unipolar transistor behavior for both types of substrates. The transconductance was 1 µA/V and the output conductance reached 1.9 µA/V for the side gate transisitor on sapphire. The transconductance and output conductance of the side gate device on silicon substrates were 6 and 18 µA/V, respectively. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantitative determination of compositional profiles using HAADF image simulations
Authors: El Bouayadi R. , Korytov M. , van Aken P. A. , Vennéguès P. , Benaissa M.
Published: January 2014

The purpose of this study is to use high‐angle annular‐dark‐field simulation to quantify aluminum fluctuation across the interface formed by a GaN‐quantum dot and an AlGaN barrier layer. For this aim, a basic methodology with theoretical/numerical simulations has been carried out using nanometric, but not atomic, resolution range. A simple multislice method, based on simulations of the HAADF intensity scattered by a GaN/AlGaN interface was performed. Enrichment of aluminum near the GaN/AlGaN interface was confirmed by HAADF simulation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and electronic properties of elastically strained InN/GaN quantum well multilayer heterostructures
Authors: Kioseoglou J. , Komninou Ph. , Chen J. , Nouet G. , Kalesaki E. , Karakostas Th.
Published: January 2014

An important step towards optimization of InN/GaN based devices is identification of the structural characteristics of the corresponding interfaces since the favourable bonding configurations determine materials polarity and consequently the direction of spontaneous polarization. We have addressed this issue through calculations on InN/GaN interfaces comprising misfit dislocations (Kioseoglou et al., J. Mater. Sci. 43, 3982 (2008) [5]). In our present study, additional calculations are performed on subcritical thickness InN/GaN QWs, which exhibit lower dislocation densities as well as reduced InN decomposition and are currently implemented in the fabrication of near‐UV light emitting diodes. Ab initio calculations are performed under modified pseudopotentials, accurately reproducing the InN and GaN band gap values, on supercells comprising multilayers of one monolayer (ML) thick InN elastically strained in 5 nm thick GaN barriers having a wurtzite or zinc blende stacking at the interface. The former is found to be energetically favorable. Subsequent calculations on supercells comprising 1 ML thick InN in 8 and 11 nm thick GaN barriers as well as 3 ML InN in 11 nm thick GaN, depict a variation in III‐N bond lengths. This variation becomes more significant as the barrier thickness decreases or the QW thickness increases. Hence the strain and consequently piezoelectric polarization are modified. Our results scrutinize recent experimental observations and could prove beneficial for tailoring the optoelectronic properties of InN/GaN QWs. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio study of macroscopic polarization of AlN, GaN and AlGaN
Authors: Supryadkina Irina , Abgaryan Karine , Bazhanov Dmitry , Mutigullin Ilya
Published: January 2014

In this work we report the results of theoretical study based on first‐principles calculations of the polarization properties of semiconductors AlN, GaN and AlGaN with wurtzite structure. The values of the spontaneous and the piezoelectric polarizations and the piezoelectric constants were calculated for these nitride compounds. We study the nonlinear dependence of the spontaneous polarization on AlGaN composition. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the SET/RESET current asymmetry in electrochemical metallization memory cells
Authors: Menzel Stephan , Waser Rainer
Published: January 2014

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In this Letter we discuss the SET/RESET current asymmetry of the bipolar resistive switching in electrochemical metallization cells based on an analytical switching model. The model is based on the growth and dissolution of a metallic filament. It accounts for the controllability of the low resistive state and the RESET current by tuning the SET current. Based on this model a possible physical explanation for the SET/RESET asymmetry is presented. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Realization of single and double axial InSb–GaSb heterostructure nanowires
Authors: Ghalamestani Sepideh Gorji , Ek Martin , Dick Kimberly A.
Published: January 2014

Heteroepitaxial growth of III‐Sb nanowires allows for the formation of various interesting complex structures and enables the combination of their remarkable properties. In this Letter, we investigate the heteroepitaxial growth of Au‐seeded InSb and GaSb nanowires using metalorganic vapor phase epitaxy. We demonstrate successful single and double axial InSb–GaSb heterostructures in both directions. The formation properties of the grown nanowires including the compositional change of the particle and the interface sharpness are further discussed. In addition, the decomposition of InSb and GaSb segments and their side facet evolution are explained.

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XEDS compositional line scans overlaid on STEM HAADF image along the InSb–GaSb–InSb nanowire indicating sharp interface from GaSb to InSb segment and graded interface in the opposite direction.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Climate system response to stratospheric ozone depletion and recovery
Authors: Previdi Michael , Polvani Lorenzo M.
Published: January 2014

We review what is presently known about the climate system response to stratospheric ozone depletion and its projected recovery, focusing on the responses of the atmosphere, ocean and cryosphere. Compared with well‐mixed greenhouse gases (GHGs), the radiative forcing of climate due to observed stratospheric ozone loss is very small: in spite of this, recent trends in stratospheric ozone have caused profound changes in the Southern Hemisphere (SH) climate system, primarily by altering the tropospheric midlatitude jet, which is commonly described as a change in the Southern Annular Mode. Ozone depletion in the late twentieth century was the primary driver of the observed poleward shift of the jet during summer, which has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, and precipitation at both middle and low latitudes. It is emphasized, however, that not all aspects of the SH climate response to stratospheric ozone forcing can be understood in terms of changes in the midlatitude jet. The response of the Southern Ocean and sea ice to ozone depletion is currently a matter of debate. For the former, the debate is centred on the role of ocean eddies in possibly opposing wind‐driven changes in the mean circulation. For the latter, the issue is reconciling the observed expansion of Antarctic sea‐ice extent during the satellite era with robust modelling evidence that the ice should melt as a result of stratospheric ozone depletion (and increases in GHGs). Despite lingering uncertainties, it has become clear that ozone depletion has been instrumental in driving SH climate change in recent decades. Similarly, ozone recovery will figure prominently in future climate change, with its impacts expected to largely cancel the impacts of increasing GHGs during the next half‐century.
Enhancing the Performance of Exponentially Weighted Moving Average Charts: Discussion
Authors: Abbas Nasir , Riaz Muhammad , Does Ronald J. M. M.
Published: January 2014

Abbas et al. (Abbas N, Riaz M, Does RJMM. Enhancing the performance of EWMA charts. Quality and Reliability Engineering International 2011; 27(6):821–833) proposed the use of signaling schemes with exponentially weighted moving average charts (named as 2/2 and modified − 2/3 schemes) for their improved design structures. A two‐sided control structure of these schemes is given in the paper. The computational results in some of the tables of that paper for modified − 2/3  are mistakenly given for the one‐sided control structure. The corrected two‐sided results are provided here. It is noticed that the superiority of the proposed scheme over the classical exponentially weighted moving average chart remains but is less pronounced. Copyright © 2014 John Wiley & Sons, Ltd.
Development of methodology for surface characterization of vanadium containing slag
Authors: Hryha E. , Rutqvist E. , Björkvall J. , Nyborg L.
Published: January 2014

Swedish steel producers are particularly interested in the recovery of vanadium oxide from the steelmaking slag because of its high content in the LD‐converter slag. Hence, optimization of the vanadium recovery has strong economic and environmental impact. Solving the problem with vanadium recovery from the slag requires development of reliable technique for assessing the oxidation state of vanadium. This paper summarizes methodology for the robust analysis of the Ca‐Si‐based slag materials containing vanadium oxide in different oxidation states utilizing XPS. The measurements show that because of high oxygen affinity of vanadium oxides and number of oxidation states, only fracturing of machined specimens in an ultra‐high vacuum chamber, connected to XPS, allows accurate evaluation of oxidation state of vanadium in slag. Proper charge compensation, required due to non‐conductive nature of the slag specimens, is considered to be the main problem faced during analysis. As neither carbon nor oxygen signals were proven to be appropriate reference point for charge referencing in this material, the calcium 2p peak position at 347.0 eV, characteristic for CaSiO3, shown to be the most stable and reliable binding energy calibration reference and was used during the charge compensation. Results indicated that in the case of the studied slags, vanadium oxides present are formed preferably by mixture of V2O3 and VO2, depending on the reducing potential of the controlled atmosphere applied during the slag synthesis. Copyright © 2014 John Wiley & Sons, Ltd.
Electron spectroscopy of the main allotropes of carbon
Authors: Kaciulis S. , Mezzi A. , Calvani P. , Trucchi D. M.
Published: January 2014

Recently, carbon spectroscopy became very important due to the growing interest in the applications of new carbon allotropes, especially of 2D structures such as graphene and nanotubes. It is well known that the hybridization of carbon electrons defines most of the properties of these materials. Among the analytical techniques used for the identification of carbon allotropes is the spectroscopy of carbon Auger line, which involves the transitions of valence band electrons and can be excited by electron beam (AES) or X‐ray photons (XAES). From the shape of C KVV spectrum, it is possible not only to recognize the cases of pure sp2 and sp3 configurations but also to quantify their ratio in amorphous carbon films. In present work, an experimental study of three main allotropes of carbon: graphite, diamond, and graphene is reported. The average thickness of graphene was evaluated from the ratio of C 1s and substrate photoelectron peaks, registered at grazing angle. Carbon KVV spectra were investigated by using XAES and AES techniques. Obtained results were compared with the ones acquired for reference samples of graphite and monocrystalline diamond. In addition, some samples of hydrogenated diamond were analyzed. It was demonstrated that the comparison of C KVV spectra excited by electrons and X‐rays can be used for identification of graphene. Diamond‐like C KVV spectrum, observed in XAES experiments, is a very promising fingerprint of graphene. Obtained results are also compared with valence band spectra of graphene, diamonds and graphite that were acquired by using ultraviolet photoemission spectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.
XPS and AES studies of UHTC ZrB2–SiC–Si3N4 treated with solar energy
Authors: Beche E. , Balat‐Pichelin M. , Flaud V. , Esvan J. , Duguet T. , Sciti D. , Alfano D.
Published: January 2014

The microstructure of ultra‐high‐temperature ceramics based on the ZrB2–SiC composition and a sintering additive (Si3N4) was investigated using XPS and AES techniques. These ZrB2–SiC–Si3N4 materials were treated in air plasma at high temperature (T > 1750 K) in the MESOX facility developed at the PROMES‐CNRS laboratory (Moyen d'Essai Solaire d'OXydation for the measurement of atomic oxygen recombination coefficients). The surfaces were characterized before and after the air plasma treatment. Surface modifications were observed and induced by the oxidation process. The elementary composition was determined using AES and XPS. Core level spectroscopy (XPS) was used to determine the atomic composition and the nature of the chemical bonds from the Zr 3d3/2,5/2, Si 2p1/2,3/2, O 1s and C 1s photoelectron peaks. The microstructural analyses revealed the presence of oxide layers: Silica and zirconia compounds were detected at temperatures near 1800 K, and a zirconia compound was mainly detected above 2200 K. Copyright © 2014 John Wiley & Sons, Ltd.
Application of a sensitive catalytic reactor to the study of CO oxidation over SrTiO3(100) and BaTiO3/SrTiO3(100) ferroelectric surfaces
Authors: Nassreddine Salim , Morfin Franck , Niu Gang , Vilquin Bertrand , Gaillard François , Piccolo Laurent
Published: January 2014

The use of ferroelectric materials as adsorbents or catalysts could be a promising way to control surface chemical reactions by tuning the ferroelectric polarization. In this context, the oxidation of carbon monoxide over well‐defined SrTiO3(100) and BaTiO3/SrTiO3(100) perovskite surfaces was investigated under stoichiometric gas‐phase conditions at a total pressure of 3 Torr, in the 100–300 °C temperature range. To this aim, an ultrahigh vacuum‐compatible reactor equipped with external laser heating, and specially designed to detect small yields of gaseous products by mass spectrometry, was used. Prior to the catalytic tests, with the help of Auger electron spectroscopy, a sample cleaning procedure under low oxygen pressure was established in order to remove carbon impurities. The as‐prepared surfaces appear poorly active in CO oxidation, but their activity increases if a high‐temperature pre‐annealing treatment under ultrahigh vacuum is applied in order to produce oxygen vacancies, which act as adsorption and/or reaction sites. The activity of the bare SrTiO3 substrates, whether doped with Nb or not, is similar to that of the supported BaTiO3 films, but the latter lose less activity upon evacuation/reaction cycles. Isotopic labeling experiments using 18O2 show that the reaction involves CO (and O2) dissociation, and that lattice oxygen participates to the reaction via the so‐called Mars–van Krevelen mechanism. Copyright © 2014 John Wiley & Sons, Ltd.
A survey of self‐healing systems frameworks
Authors: Schneider Chris , Barker Adam , Dobson Simon
Published: January 2014

Rising complexity within multi‐tier computing architectures remains an open problem. As complexity increases, so do the costs associated with operating and maintaining systems within these environments. One approach for addressing these problems is to build self‐healing systems (i.e. frameworks) that can autonomously detect and recover from faulty states. Self‐healing systems often combine machine learning techniques with closed control loops to reduce the number of situations requiring human intervention. This is particularly useful in situations where human involvement is both costly to develop, and a source of potential faults. Therefore, a survey of self‐healing frameworks and methodologies in multi‐tier architectures is provided to the reader. Uniquely, this study combines an overview of the state of the art with a comparative analysis of the computing environment, degree of behavioural autonomy, and organisational requirements of these approaches. Highlighting these aspects provides for an understanding of the different situational benefits of these self‐healing systems. We conclude with a discussion of potential and current research directions within this field. Copyright © 2014 John Wiley & Sons, Ltd.
Social Participation of High School Students with Special Needs—A Case of Promotion of Systemic Behavior and Social Responsibility
Authors: Schmidt Majda , Protner Edvard , Čagran Branka
Published: January 2014

Social integration of students with special needs (SSNs) belongs to efforts for social responsibility as one's responsibility to practise interdependence and requisite holism of approach and wholeness of outcomes. Since the mid‐1990s, Slovenia gradually included SSNs in high school programmes. Schools must prepare individualized programmes (IPs) for each SSN. Authors empirically examined implementation of IPs for SSNs and the roles of teachers, students and parents in IP design with grammar school, vocational and technical school teachers, who had a SSN in their class and offered additional professional support (n = 131). Authors checked the role of the type of school, impairment and teachers' training. Results show that most students know IPs but only rarely participate in expert team meetings. They are excluded from the decision‐making regarding IP learning objectives, particularly students with learning difficulties. Parents are included in the IP implementation and evaluation; however, parents of children with learning difficulties are less involved in this process than the other SSNs. Grammar school teachers are more reserved towards SSNs and IP implementation. Thus, the attained level of systemic behavior via social responsibility, ethics of interdependence and holism differs. Copyright © 2014 John Wiley & Sons, Ltd.
Investigation of Neutral Axis Shifting in Rotary Draw Bending Processes for Tubes
Authors: Engel Bernd , Hassan Hassan Raheem
Published: January 2014

Rotary draw bending is one of the most important methods used for tube forming processes. During the process of tube bending, the neutral axis of the tube moves toward the inner arc. The wall thickness distribution changes for the tube's cross section. Thinning takes place in the outer arc of the tube, whereas thickening occurs in the inner arc of the tube. In this paper, a geometrical model is presented to calculate the neutral axis shifting for different bending angles. The finite element simulation is used to predict the results close to the geometrical model results. In addition, the effect of the different materials (Al alloy 6009 and stainless steel alloy 1.4301) on the rotary draw bending process is compared. Finally, the results of the distributions of the axial strain and wall thickness of the bend are obtained.
Incremental dynamic analysis of steel frames equipped with NiTi shape memory alloy braces
Authors: Moradi Saber , Alam M. Shahria , Asgarian Behrouz
Published: January 2014

This paper determines the seismic performance of four‐storey concentrically braced frames equipped with either steel buckling‐restrained braces or buckling‐restrained superelastic shape memory alloy (SMA) braces through incremental dynamic analysis. The incremental dynamic analysis technique is used to examine the behaviour of four‐storey braced frames with four different bracing configurations (including diagonal, split‐X, chevron‐V and inverted‐V) under 20 different ground motion records. The study reveals a satisfactory performance at the design intensity level for both types of braced frames. The results show that the SMA braces lead to a uniform distribution of inelastic response over the height of the buildings, as well as mitigating seismic response in terms of maximum inter‐storey drift and residual roof displacement. By comparing the responses of SMA and buckling‐restrained braced frames under higher intensities of earthquake loading, it is found that the SMA braces can be more beneficial especially under severe ground motion excitations. Copyright © 2014 John Wiley & Sons, Ltd.
Stochastic modeling of lift and drag dynamics under turbulent wind inflow conditions
Authors: Luhur M. R. , Peinke J. , Schneemann J. , Wächter M.
Published: January 2014

We present a new approach to model the complex dynamics of aerodynamic forces on an airfoil in turbulent inflow conditions. Our ansatz is based on stochastic differential equations and aims at replacing traditional look‐up table methods used in wind turbine simulation systems by the effective response dynamics of lift and drag forces. The parameters of the model are derived directly from empirical data. Measurements were taken in the closed loop wind tunnel of the University of Oldenburg for an airfoil FX 79‐W‐151A. The turbulent inflow was generated using a fractal square grid as it is possible to generate in this way wind speed fluctuations with similar statistics as observed in nature. Forces were measured using two strain gauge force sensors at two end points of the vertically installed airfoil. The modeling is performed by applying a stochastic approach on the measured data. By estimating the first two Kramers–Moyal coefficients, a first‐order stochastic differential equation called the Langevin equation is obtained. The stochastic model achieved through this approach is extended to account for oscillation effects contained in lift and drag dynamics that probably stem from unsteady aerodynamic effects. The results are optimized by applying a χ2 test on the probability density functions (PDFs) of model and measurements. With the knowledge of the Langevin equation, synthetic time series are generated. Their stationary PDFs as well as conditional PDFs show good agreement with the actual measurements. A comparison of classical averaging and the stochastic approach shows that stochastic analysis achieves additional insight into the local dynamics of lift and drag forces. Copyright © 2014 John Wiley & Sons, Ltd.
Transversal isotropy based on a multiplicative decomposition of the deformation gradient within p‐version finite elements
Authors: Al‐Kinani R. , Hartmann S. , Netz T.
Published: January 2014

In this article the multiplicative decomposition of the deformation gradient into one part constrained in the direction of the axis of anisotropy and one part describing the directional deformation is proposed. This leads to a clear division of the deformation and stress states in the direction of anisotropy and a remaining part. The decomposition is explained in detail and a constitutive model of hyper‐elasticity is proposed for the case of transversal isotropy, where the behavior of the model is investigated with the aid of simple analytical examples. The model is also investigated for inhomogeneous deformation states using high‐order finite elements based on hierarchical shape functions showing the sensitivity of the accuracy of the results in the case of anisotropic media.
Friction induced vibrations in shift gearboxes
Authors: Jehle G. , Fidlin A.
Published: January 2014

In shift gearboxes, audible vibrations can arise during the process of clutch engagement. Measurements show an unstable axial motion of the gear unit input shaft. In order to explain this effect, an approach which establishes the interaction of the slipping clutch and the gearing is proposed. The suggested model consists of a pressure plate, a clutch disc, a gear unit input shaft and a tooth contact. The gear unit input shaft is rigidly connected to the gearing and the clutch disc and has translational and rotational degrees of freedom. The tooth contact imposes a kinematic constraint on the system. This is why the sliding friction torque is transformed into forces in axial and radial direction of the shaft. Depending on the gearing parameters and the slip, the contact normal force between clutch disc and pressure plate is amplified (motor accelerating) or reduced (motor slowing down) by the toothing. For both shifting situations, a region of flutter instability in the parameter space can be found. The dynamic behavior of the system with parameters in the latter region is analyzed. It is shown that there exists a stable piecewise‐continuous limit cycle: During one period, the contact between the clutch disc and the pressure plate opens shortly. A variation of parameters is performed to show the dependence of the limit cycle on the geometry and on the operation conditions.
Vortices and impurities
Authors: Tong David , Wong Kenny
Published: January 2014

Abstract

We describe the BPS dynamics of vortices in the presence of impurities. We argue that a moduli space of solitons survives the addition of both electric and magnetic impurities. However, dynamics on the moduli space is altered. In the case of electric impurities, the metric remains unchanged but the dynamics is accompanied by a connection term, acting as an effective magnetic field over the moduli space. We give an expression for this connection and compute the vortex-impurity bound states in simple cases. In contrast, magnetic impurities distort the metric on the moduli space. We show that magnetic impurities can be viewed as vortices associated to a second, frozen, gauge group. We provide a D-brane description of the dynamics of vortices in product gauge groups and show how one can take the limit such that a subset of the vortices freeze.
Quark masses in Higgs production with a jet veto
Authors: Banfi Andrea , Monni Pier Francesco , Zanderighi Giulia
Published: January 2014

Abstract

We study the impact of finite mass effects due to top and bottom loops in the jet-veto distribution for Higgs production. We discuss the appearance of non-factorizing logarithms in the region p
t,veto ≳ m

b
. We study their numerical impact and argue that these terms can be treated as a finite remainder. We therefore detail our prescription for resumming the jet-vetoed cross section and for assessing its uncertainty in the presence of finite mass effects. Resummation for the jet-veto, including mass effects, has been implemented in the public code JetVHeto.
Spatially modulated instabilities of geometries with hyperscaling violation
Authors: Cremonini Sera , Sinkovics Annamaria
Published: January 2014

Abstract

We perform a study of possible instabilities of the infraredAdS2×$ {{\mathbb{R}}^2} $region of solutions to Einstein-Maxwell-dilaton systems which exhibit an intermediate regime of hyperscaling violation and Lifshitz scaling. Focusing on solutions that are magnetically charged, we probe the response of the system to spatially modulated fluctuations, and identify regions of parameter space in which the infraredAdS2geometry is unstable to perturbations. The conditions for the existence of instabilities translate to restrictions on the structure of the gauge kinetic function and scalar potential. In turn, these can lead to restrictions on the dynamical critical exponentzand on the amount of hyperscaling violationθ. Our analysis thus provides further evidence for the notion that the true ground state of ‘scaling’ solutions with hyperscaling violation may be spatially modulated phases.
Connexins, gap junctions and tissue invasion
Authors: Defamie Norah , Chepied Amandine , Mesnil Marc
Published: January 2014

Formation of metastases negatively impacts the survival prognosis of cancer patients. Globally, if the various steps involved in their formation are relatively well identified, the molecular mechanisms responsible for the emergence of invasive cancer cells are still incompletely resolved. Elucidating what are the mechanisms that allow cancer cells to evade from the tumor is a crucial point since it is the first step of the metastatic potential of a solid tumor. In order to be invasive, cancer cells have to undergo transformations such as down‐regulation of cell‐cell adhesions, modification of cell‐matrix adhesions and acquisition of proteolytic properties. These transformations are accompanied by the capacity to “activate” stromal cells, which may favor the motility of the invasive cells through the extracellular matrix. Since modulation of gap junctional intercellular communication is known to be involved in cancer, we were interested to consider whether these different transformations necessary for the acquisition of invasive phenotype are related with gap junctions and their structural proteins, the connexins. In this review, emerging roles of connexins and gap junctions in the process of tissue invasion are proposed.
Is China an Anomaly for the “Law Matters” Hypothesis?
Authors: XU Guangdong
Published: January 2014

It has long been argued that the legal system does not have a strong role in explaining China’s economic miracle; therefore, China is often presented as an anomaly for the “law matters” hypothesis. This study contributes to the debate from a unique perspective by examining the connection between law and the operation of factor markets. In China, laws and regulations governing factor markets have been systematically distorted by the government, intentionally or unintentionally, to facilitate the nation’s enormous economic growth in the short run at the cost of environmental quality, ordinary citizens’ welfare, and long-term economic health. Thus, China has become a fast-growing but unsustainable economy.