bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial community dynamics and activity in relation to dissolved organic matter availability during sea‐ice formation in a mesocosm experiment
Authors: Eronen‐Rasimus Eeva , Kaartokallio Hermanni , Lyra Christina , Autio Riitta , Kuosa Harri , Dieckmann Gerhard S. , Thomas David N.
Published: January 2014

The structure of sea‐ice bacterial communities is frequently different from that in seawater. Bacterial entrainment in sea ice has been studied with traditional microbiological, bacterial abundance, and bacterial production methods. However, the dynamics of the changes in bacterial communities during the transition from open water to frozen sea ice is largely unknown. Given previous evidence that the nutritional status of the parent water may affect bacterial communities during ice formation, bacterial succession was studied in under ice water and sea ice in two series of mesocosms: the first containing seawater from the North Sea and the second containing seawater enriched with algal‐derived dissolved organic matter (DOM). The composition and dynamics of bacterial communities were investigated with terminal restriction fragment length polymorphism (T‐RFLP), and cloning alongside bacterial production (thymidine and leucine uptake) and abundance measurements (measured by flow cytometry). Enriched and active sea‐ice bacterial communities developed in ice formed in both unenriched and DOM‐enriched seawater (0–6 days). γ‐Proteobacteria dominated in the DOM‐enriched samples, indicative of their capability for opportunistic growth in sea ice. The bacterial communities in the unenriched waters and ice consisted of the classes Flavobacteria, α‐ and γ‐Proteobacteria, which are frequently found in natural sea ice in polar regions. Furthermore, the results indicate that seawater bacterial communities are able to adapt rapidly to sudden environmental changes when facing considerable physicochemical stress such as the changes in temperature, salinity, nutrient status, and organic matter supply during ice formation.
Human leukocyte antigen haplotype phasing by allele‐specific enrichment with peptide nucleic acid probes
Authors: Murphy Nicholas M. , Pouton Colin W. , Irving Helen R.
Published: January 2014

Targeted capture of large fragments of genomic DNA that enrich for human leukocyte antigen (HLA) system haplotypes has utility in haematopoietic stem cell transplantation. Current methods of HLA matching are based on inference or familial studies of inheritance; and each approach has its own inherent limitations. We have designed and tested a probe–target‐extraction method for capturing specific HLA haplotypes by hybridization of peptide nucleic acid (PNA) probes to alleles of the HLA‐DRB1 gene. Short target fragments contained in plasmids were initially used to optimize the method followed by testing samples of genomic DNA from human subjects with preselected HLA haplotypes and obtained approximately 10% enrichment for the specific haplotype. When performed with high‐molecular‐weight genomic DNA, 99.0% versus 84.0% alignment match was obtained for the specific haplotype probed. The allele‐specific target enrichment that we obtained can facilitate the elucidation of haplotypes between the 65 kb separating the HLA‐DRB1 and the HLA‐DQA1 genes, potentially spanning a total distance of at least 130 kb. Allele‐specific target enrichment with PNA probes is a straightforward technique that has the capability to improve the resolution of DNA and whole genome sequencing technologies by allowing haplotyping of enriched DNA and crucially, retaining the DNA methylation profile.
Mucosal C‐terminal maltase‐glucoamylase hydrolyzes large size starch digestion products that may contribute to rapid postprandial glucose generation
Authors: Lee Byung‐Hoo , Lin Amy Hui‐Mei , Nichols Buford L. , Jones Kyra , Rose David R. , Quezada‐Calvillo Roberto , Hamaker Bruce R.
Published: January 2014

Scope

The four mucosal α‐glucosidases, which differ in their digestive roles, generate glucose from glycemic carbohydrates and accordingly can be viewed as a control point for rate of glucose delivery to the body. In this study, individual recombinant enzymes were used to understand how α‐glucan oligomers are digested by each enzyme, and how intermediate α‐amylolyzed starches are hydrolyzed, to elucidate a strategy for moderating the glycemic spike of rapidly digestible starchy foods.

Methods and results

The C‐terminal maltase‐glucoamylase (ctMGAM, commonly termed “glucoamylase”) was able to rapidly hydrolyze longer maltooligosaccharides, such as maltotetraose and maltopentaose, to glucose. Moreover, it was found to convert larger size maltodextrins, as would be produced early in α‐amylase digestion of starch, efficiently to glucose. It is postulated that ctMGAM has the additional capacity to hydrolyze large α‐amylase products that are produced immediately on starch digestion in the duodenum and contribute to the rapid generation of glucose from starch‐based meals.

Conclusion

The findings suggest that partial inhibition of ctMGAM, such as by natural inhibitors found in foods, might be used to moderate the early stage of high glycemic response, as well as to extend digestion distally; thereby having relevance in regulating glucose delivery to the body.
Hybrid Cd‐free CIGS solar cell/TEG device with ZnO nanowires
Authors: Hsueh Ting‐Jen , Shieh Jia‐Min , Yeh Yu‐Ming
Published: January 2014

A green energy device with a CuInGaSe2 (CIGS) photovoltaic (PV) cell covered with a passive light‐trapping structure (ZnO nanowires (NWs)) and connected to an active energy‐harvesting device (thermoelectric generator (TEG)) is presented. The efficiency of the ZnO NWs/CIGS PV device obtained using a deposition temperature of 550 °C and Cd‐free processes reaches 16.5%. The series‐connected CIGS PV cell with a TEG had a record‐high efficiency of 22% at a cool‐side temperature (Tc) below 5 °C. The open‐circuit voltage (Voc) of the hybrid CIGS PV/TEG device was increased from 0.64 to 0.85 V. This technology has potential for high‐efficiency energy‐harvesting applications. Copyright © 2014 John Wiley & Sons, Ltd.
Energy Dissipation in Noble Gas Atmospheric Pressure Glow Discharges (APGD)
Authors: Gagnon Hervé , Piyakis Konstantinos , Wertheimer Michael R.
Published: January 2014

We present precision measurements of the energy, Eg, dissipated per period of the applied ac voltage at kHz frequencies (4 ≤ f ≤ 32 kHz) by atmospheric‐pressure glow discharges (APGD) in flows of helium and neon. Such data are important for determining the efficiency of excimer light sources, for example. We report the methodology and specific steps taken to achieve the desired degrees of precision and reproducibility, and compare our results with data published in the literature.
A Novel Cocrystal Explosive of HNIW with Good Comprehensive Properties
Authors: Wang Yuping , Yang Zongwei , Li Hongzhen , Zhou Xiaoqing , Zhang Qi , Wang Jianhua , Liu Yucun
Published: January 2014

In order to improve the safety of the high explosive 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane (HNIW), we cocrystallized HNIW with the insensitive explosive DNB (1,3‐dinitrobenzene) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that it belongs to the orthorhombic system with space group Pbca. Therein, layers of DNB alternate with bilayers of HNIW. Analysis of interactions in the cocrystal indicated that the cocrystal is mainly formed by hydrogen bonds and nitro‐aromatic interactions. Moreover, the thermal behavior, sensitivity, and detonation properties of the cocrystal were evaluated. The results implied that the melting point of the cocrystal is 136.6 °C, which means an increase of 45 °C relative that of pure DNB. The predicted detonation velocity and detonation pressure of the cocrystal are 8434 m s−1 and 34 GPa, respectively, which are similar to that of the reported HNIW/TNT cocrystal, but its reduced sensitivity (H50=55 cm) makes it an attractive ingredient in HNIW propellant formulations.
Costs and effectiveness of on‐farm measures to reduce aquatic risks from pesticides in the Netherlands
Authors: van Eerdt Martha M , Spruijt Joanneke , van der Wal Erna , van Zeijts Henk , Tiktak Aaldrik
Published: January 2014

BACKGROUND

The European Union requires growers to implement the principles of integrated pest management (IPM) by 2014. This paper provides a quantitative overview of the costs and effectiveness of voluntaryIPMmeasures in 15 crops in the Netherlands. The authors will focus on aquatic risks and define effectiveness as the potential to reduce the risks posed to aquatic organisms. They further identify which of these measures have actually been adopted by growers and why certain measures have not been adopted.

RESULTS

Of the 105 measures evaluated, the most effective measures with respect to risk reduction were emission reduction and replacement of high‐risk pesticides (each up to 80% reduction).IPMmeasures directed towards lowering pesticide use generally showed a smaller risk‐reducing potential. However, 40% of these measures reduced the overall cost of pest management. About 60% of all 105 measures were voluntarily implemented by growers. The most commonly adopted measures were pest prevention, low‐dose spraying and spray drift reduction. Cost appeared to be an important incentive for adoption; however, other factors such as risk perception, education and practicability were equally important.

CONCLUSIONS

VoluntaryIPMmeasures have significantly contributed to reducing aquatic risks (15–50% risk reduction, depending on crop type). Further risk reduction could be achieved if more growers were to adopt the most effective measures, such as spray drift reduction and replacement of high‐risk pesticides. However,IPMhas hardly reduced the number of pesticide applications, and therefore the dependence on chemical crop protection continues to be high. © 2014 Society of Chemical Industry
Recommended diagnosis and management of insomnia
Authors: Wilson Sue , Nutt David
Published: January 2014

Insomnia can cause impaired daytime functioning and reduced quality of life. In our Drug review the authors discuss its diagnosis and the available treatment options, followed by an analysis of the prescription data and sources of further information.
Pharmacists as dispensers and formation of the PPA
Authors: Baines Darrin
Published: January 2014

In our series on the history of prescribing policy, Dr Darrin Baines traces how successive governments have attempted to curb drug costs. Here, he explains how pharmacists became dispensers and how the Joint Pricing Committee was replaced by the PPA.
A sequence‐function analysis of the silica precipitating silaffin R5 peptide
Authors: Lechner Carolin C. , Becker Christian F. W.
Published: January 2014

The R5 peptide is derived from silaffin peptides naturally occurring in the diatom Cylindrotheca fusiformis and exhibits outstanding activity in silica precipitation. Because of its ability to cause silicification under mild conditions, several biotechnological applications based on R5‐mediated biomimetic silica formation have already been reported. Yet a more detailed understanding of the R5 peptide and its intrinsic silica precipitation activity will help the rational design of R5 peptide variants as efficient agents for defined silica precipitation. The herein presented analysis of the relationship between the R5 amino acid sequence and its activity in silica precipitation emphasizes the essential role of the lysine residues in mediating silica polycondensation. Furthermore, a tetra amino acid motif (RRIL) has to be present within the R5 sequence, but in contrast to previous reports, we demonstrate that localization of the RRIL motif shows minor impact on silica precipitation activity but rather on morphology of the resulting silica material. The amino acid sequence of silaffin peptides is a well‐balanced arrangement in terms of charges, functional groups and distances. The impact of this pattern of charges and functionalities was highlighted by the disturbed morphology of silica spheres resulting from R5 variants with scrambled sequences. A detailed understanding of the highly evolved silaffin sequence(s) will contribute to unravel the intriguing process of silica biomineralization in diatoms. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Liquid‐phase exfoliation of ultrathin layered transition metal dichalcogenide nanosheets composed of solid‐solution Mo1−xWxS2
Authors: Funaki Kazushi , Tezuka Keitaro , Shan Yue Jin
Published: January 2014

Transition metal dichalcogenide (TMD) nanosheets have attracted attention as novel inorganic materials. Aiming to enhance their availability, we targeted the large‐scale synthesis of TMD solid‐solution nanosheets by liquid‐phase exfoliation. To prepare the nanosheets, bulk polycrystalline Mo1−xWxS2 was sonicated in dimethyl sulfoxide. Transmission electron microscopy and atomic force microscopy showed that few‐layer nanosheets were formed. UV–VIS spectroscopy showed that the band structure could be continuously tuned. Compared with mechanical cleaving, our exfoliation method facilitates larger‐scale production of nanosheets and should be useful for a wide range of applications, such as thin films and composite materials.
AlGaN based MEMS structures
Authors: Hähnlein Bernd , Tonisch Katja , Ecke Gernot , Grieseler Rolf , Michael Steffen , Schaaf Peter , Pezoldt Jörg
Published: January 2014

AlxGa1‐xN solid solutions were heteroepitaxially grown on 3C‐SiC(111)/Si(111) pseudo substrates fabricated by low pressure chemical vapour deposition. Free standing doubly‐clamped resonator bars and cantilevers were fabricated from these AlxGa1–xN layers. The resonance frequencies of the microelectromechanical structures were measured using electrostatic excitation and vibrometry at ambient conditions. The obtained resonance frequencies allowed a self consistent determination of the Young's modulus of the AlxGa1‐xN layers and the residual strain in the free standing structures. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The (0001)A surface phase diagram
Authors: Elyukhin Vyacheslav A.
Published: January 2014

The (0001)A surface phase diagram of InxGa1‐xN is investigated by using different approximations of the cluster variation method with the one‐, two‐ and three‐point basic clusters. The surface layer is considered in the total composition range as a binary regular solution on the triangular lattice. The miscibility gap temperature and concentration of the nearest neighbor surface atoms at this temperature are estimated as functions of the composition. The miscibility gap temperatures of In0.5Ga0.5N obtained by one‐, two‐ and three‐point cluster approximations are 710 °C, 535 °C and 370 °C, respectively. The strong InIn and GaGa pair clustering in comparison with InGa pair formation at temperatures higher than the miscibility gap one is demonstrated in the three‐point approximation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crosstalk suppression of CMOS compatible AlN based SAW devices on low resistive Si(100)
Authors: Kaletta Udo Ch. , Wolansky D. , Wipf M. Fraschke Ch. , Wenger Ch.
Published: January 2014

Aluminum nitride (AlN) based high frequency surface acoustic wave (SAW) devices are produced by using a new CMOS compatible concept. Textured c‐axis oriented AlN films have been deposited on tungsten based embedded interdigital transducers (IDTs) by the reactive pulse DC‐sputter technique within the thermal budget of back end of line (BEOL) processes. Two SAW Rayleigh modes with different acoustic velocities were measured and identified by finite element method (FEM) simulation (Kaletta and Wenger, FEM Simulation of Rayleigh waves for CMOS compatible SAW devices based on AlN/SiO2/Si(100) (Elsevier Ultrasonics, available online 18 April 2013, ISSN 0041‐624X, 10.1016/j.ultras.2013.04.009) [1]). Electromagnetic crosstalk between in‐ and output IDTs via low resistive Silicon substrates is one of the most troublesome sources of integrated SAW devices. The impact of several device parameters like the acoustic aperture, the number of fingers and the delay line length on the electromagnetic crosstalk was studied and routes for optimizing SAW filter designs on low resistive Si(100) will be presented. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sequential multiple‐step europium ion implantation and annealing of GaN
Authors: Miranda S. M. C. , Edwards P. R. , O'Donnell K. P. , Boćkowski M. , Alves E. , Roqan I. S. , Vantomme A. , Lorenz K.
Published: January 2014

Sequential multiple Eu ion implantations at low fluence (1×1013 cm‐2 at 300 keV) and subsequent rapid thermal annealing (RTA) steps (30 s at 1000 °C or 1100 °C) were performed on high quality nominally undoped GaN films grown by metal organic chemical vapour deposition (MOCVD) and medium quality GaN:Mg grown by hydride vapour phase epitaxy (HVPE). Compared to samples implanted in a single step, multiple implantation/annealing shows only marginal structural improvement for the MOCVD samples, but a significant improvement of crystal quality and optical activation of Eu was achieved in the HVPE films. This improvement is attributed to the lower crystalline quality of the starting material, which probably enhances the diffusion of defects and acts to facilitate the annealing of implantation damage and the effective incorporation of the Eu ions in the crystal structure. Optical activation of Eu3+ ions in the HVPE samples was further improved by high temperature and high pressure annealing (HTHP) up to 1400 °C. After HTHP annealing the main room temperature cathodo‐ and photoluminescence line in Mg‐doped samples lies at ∼ 619 nm, characteristic of a known Mg‐related Eu3+ centre, while after RTA treatment the dominant line lies at ∼ 622 nm, typical for undoped GaN:Eu. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optically pumped AlGaN quantum‐well lasers at sub‐250 nm grown by MOCVD on AlN substrates
Authors: Liu Yuh‐Shiuan , Lochner Zachary , Kao Tsung‐Ting , Satter Md. Mahbub , Li Xiao‐Hang , Ryou Jae‐Hyun , Shen Shyh‐Chiang , Yoder P. Douglas , Detchprohm Theeradetch , Dupuis Russell D. , Wei Yong , Xie Hongen , Fischer Alec , Ponce Fernando
Published: January 2014

In this study, we employed bulk (0001) AlN substrates for the metalorganic chemical vapor deposition growth of AlGaN multi‐quantum‐well heterostructures in an Aixtron 6 × 2″ close‐coupled showerhead reactor. The wafers were fabricated into cleaved bars with a cavity length of ∼1 mm. Two different layer structure designs are presented in this work. Both laser bars were optically pumped by a pulsed 193 nm ArF excimer laser at room temperature. The lasing wavelengths are 243.5 nm and 245.3 nm with threshold power density 427 kW/cm2 and 297 kW/cm2, respectively. Both laser bars showed transverse electric‐polarization‐dominated optical emission when operating above threshold. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Properties of AlN based lateral polarity structures
Authors: Kirste Ronny , Mita Seiji , Hoffmann Marc P. , Hussey Lindsay , Guo Wei , Bryan Isaac , Bryan Zachary , Tweedie James , Gerhold Michael , Hoffmann Axel , Collazo Ramón , Sitar Zlatko
Published: January 2014

Growth and characterization of AlN based lateral polarity structures (LPS) are presented. The LPS were grown by MOCVD using patterned low temperature AlN/sapphire substrates: the Al‐polar and N‐polar AlN grew on AlN buffer layer and nitrided sapphire, respectively. AFM images showed a height difference between the two adjacent domains of different polarity on the order of 30 nm, which was equivalent to the low temperature AlN buffer layer thickness. SEM images provided an insight in the growth mode of the two polarities. It was shown that Al‐polar AlN grew two‐dimensionally, leading to a smooth well coalesced layer, while N‐polar AlN grew primarily three‐dimensionally, leading to a columnar structure. This difference in the growth mode led to different properties of domains with opposite polarity, including strain and defect incorporation, as observed by X‐ray diffraction, photoluminescence, and Raman spectroscopy measurements. Finally, an outlook on the applicability and future development of AlN‐based LPS is given. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cubic GaN/AlN multi‐quantum wells grown on pre‐patterned 3C‐SiC/Si (001)
Authors: Kemper R. M. , Mietze C. , Hiller L. , Stauden T. , Pezoldt J. , Meertens D. , Luysberg M. , As D. J. , Lindner J. K. N.
Published: January 2014

We report for the first time on the growth of cubic AlN/GaN multi‐quantum wells (MQWs) on pre‐patterned 3C‐SiC/Si (001) substrates. The sample structure consists of 10 periods of 2 nm c‐AlN barriers with a 4 nm c‐GaN layer in between, which were grown on 3C‐SiC post shaped structures by means of molecular beam epitaxy. Substrate patterning has been realized by electron beam lithography and a reactive ion etching process. The 3C‐SiC posts have a length of about 550 nm and a height of about 700 nm. (Scanning) transmission electron microscopy studies show that the morphology of the MQWs is clearly influenced by {111} stacking faults, modulating the local growth rate. Further, the growth at the edges of the surface pattern is investigated. The MQW layers cover the 90° edges by developing low‐index facets rather than by forming a conformal system of 90° angled layers. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biological detection by high electron mobility transistor (HEMT) based AlGaN/GaN
Authors: Zeggai Oussama , Ould‐Abbas Amaria , Bouchaour Mama , Zeggai Hichem , Sahouane Nordine , Madani Malika , Trari Djamel , Boukais Meriem , Chabane‐Sari N.‐E.
Published: January 2014

Materials based on gallium nitride are characterized by a wide bandgap. The excellent chemical, physical and electronic properties give them a place in various fields: electronics, optoelectronics, photovoltaics, military, biological and medical. The use of biosensors based III‐N has been confirmed for the detection of biological substances in cells, blood or in solutions. This effect of detection results in various chemical and electric changes in a medium that is contacted with the devices without gate metallization of a high electron mobility transistor (HEMT). HEMT sensors can thus be used to detect gases, ions, pH values, proteins and DNA. In this work, we are interested in HEMT‐based heterostructure AlGaN/GaN used in the construction of biosensors. The principle of operation of the HEMT is based on the properties of a high‐mobility two‐dimensional gas (2DEG) and high‐speed saturation channel of a 2DEG AlGaN HEMT is very close to the surface that is very sensitive to absorption of analytes. We use this microsystem for detection of substances found in biological solutions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Void formation during GaN MOVPE on Si (111) employing low temperature AlN interlayers
Authors: Liu Cai , Wang Hongbo , Sodabanlu Hassanet , Sugiyama Masakazu , Nakano Yoshiaki
Published: January 2014

During the growth of GaN on Si (111), voids were found in GaN layers in between AlN interlayers. Void formation mechanism is the decomposition of GaN in H2. Void formation process is carefully studied. It is clarified that voids are formed during the period between the growth of two neighbouring GaN layers, after the growth of AlN interlayer between them. There are some openings in AlN interlayers and they act as the pass for H2 to react with GaN. NH3 partial pressure, temperature, etching time, and conditions such as thickness of AlN interlayers can be utilized to tune the volume, size and shape of the voids. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitons and exciton‐phonon coupling in the optical response of GaN
Authors: Shokhovets S. , Bärwolf F. , Gobsch G. , Runge E. , Köhler K. , Ambacher O.
Published: January 2014

We carried out reflectance and spectroscopic ellipsometry measurements of high‐purity c ‐plane epitaxial films of wurtzite GaN in a temperature range 5‐840 K. Analysis of the data reveals three main contributions to the dielectric function related to optical transitions involving discrete exciton states, excitonic continuum and exciton‐phonon complexes, respectively. The observed contributing mechanisms show different temperature dependence. This behavior is related to specific interactions between optical excitations and thermal LO phonons. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Normally‐off GaN MOSFETs with high‐k dielectric CeO2 films deposited by RF sputtering
Authors: Ogawa Hiroki , Okazaki Takuya , Kasai Hayao , Hara Kenta , Notani Yuki , Yamamoto Yasuhiro , Nakamura Tohru
Published: January 2014

This paper describes normally‐off GaN MOSFETs with high‐k dielectric CeO2 films made by ion implantation. Ion implantation process reduces sheet and contact resistances of source and drain regions of this device. To obtain high Idss and gmmax, high‐k dielectric CeO2 was used as gate oxide films for GaN MOSFETs for the first time. Nitrogen ion implantation isolation processes were also adopted to fabricate isolation region. Normally‐off GaN MOSFETs with Idss of 350 mA/mm, gmmax of 40 mS/mm and threshold voltage of +0.5 V were obtained. The high Idss and normally‐off mode show the potential and advantages of GaN MOSFETs for high voltage operations. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On steady‐state tropical cyclones
Authors: Smith Roger K. , Montgomery Michael T. , Persing John
Published: January 2014

We examine the physical constraints that must be satisfied to allow for a steady‐state tropical cyclone in an isolated environment, paying particular attention to the need to replenish absolute angular momentum at exactly the rate at which it is consumed and to the vanishing of the spin‐up function above the frictional boundary layer. We conclude that it is unlikely that these conditions will be met simultaneously and question whether globally steady‐state tropical cyclone solutions have merit. The implications for previous studies are discussed.
Reliability Assessment of High Voltage Direct Current Grid Protection Schemes
Authors: Chetty L. , Singh Y.
Published: January 2014

Recent renewable energy developments in the power system have prompted a growing interest in high voltage direct current (DC) grids. One of the challenges impeding the progress of high voltage DC grids is the design of DC protection systems. This paper presents the development of an energy reliability program which differentiates between the energy reliability performances of five different DC protection schemes. The energy reliability program utilized contingency enumeration to iterate through all network states of the high voltage DC grid. The conditions used by the program for network state differentiation were formulated from minimal cut‐sets. The energy reliability analysis results discussed in this study illustrate that the double‐bus single breaker protection scheme has the most favourable performance. These results contribute knowledge to the design of DC protection schemes of high voltage DC grids. Copyright © 2014 John Wiley & Sons, Ltd.
Surface and mechanical characterization of ITO coatings prepared by microwave‐assisted magnetron sputtering process
Authors: Mazur Michał , Szymańska Magdalena , Kalisz Małgorzata , Kaczmarek Danuta , Domaradzki Jarosław
Published: January 2014

In this paper, indium–tin oxide (ITO) thin films were deposited on various substrates, such as microscope slides, silica and silicon, using microwave‐assisted reactive magnetron sputtering process. Deposited coatings were amorphous according to the X‐ray diffraction results. Atomic force microscopy investigations revealed that the surface of thin films is homogenous and very smooth. Prepared ITO thin films exhibit high transparency in the visible light range and the transmittance factor is above 80%. Besides very good optical properties, deposited thin films also exhibits low surface resistance, which was measured with the aid of a four‐point probe. To evaluate the properties of prepared thin films as transparent conducting oxide coatings, the figure of merit was calculated. Mechanical properties of deposited thin films were evaluated based on nanoindentation method. The hardness of ITO coatings was high and equal to ca. 16 GPa. To complete the investigation of the tribological properties of prepared thin films, the scratch steel wool test was performed and showed that only few scratches were observed. It did not affect the transparency of the thin film, and scratches were hardly visible with the aid of an optical microscope. However, measurements performed with the use of optical profilometer have shown that the depth of scratches was from ca. 300 to ca. 320 nm, what indicates that in place of scratches, thin film was completely removed from the substrate. Copyright © 2014 John Wiley & Sons, Ltd.
In‐situ spectroscopic study of surfactant adsorption onto hematite from binary mixtures and the effect of inorganic ions
Authors: Potapova E. , Jolsterå R. , Holmgren A. , Grahn M.
Published: January 2014

Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy has proven to be a powerful tool for surfactant adsorption studies. In many practical applications, surfactant mixtures and waters with different chemistry are employed, which significantly complicates adsorption studies. In this work, we investigate the effect of calcium and carbonate ions, frequently found in natural waters, on the co‐adsorption of sodium dodecylbenzenesulfonate (SDBS) and a non‐ionic primary alcohol ethoxylate (NEODOL 25–7) onto hematite at pH 8 and 10.5 using ATR‐FTIR spectroscopy. Adsorption of SDBS was affected by pH and the presence of inorganic ions to a greater extent than the adsorption of NEODOL 25–7. A larger amount of SDBS was adsorbed at pH 8 than at pH 10.5 in all the experiments. The effect of co‐adsorbing ions on the amount of SDBS adsorbed was significant only at pH 10.5 and not at pH 8. Calcium ions promoted adsorption of SBDS onto hematite, whereas addition of carbonate decreased the amount of SDBS adsorbed. In the presence of both calcium and carbonate ions, calcium carbonate precipitate was formed on the hematite surface, promoting accumulation of NEODOL 25–7 at the surface. NEODOL 25–7 was found to have a strong effect on the hydrophilicity of the hematite film when adsorbed in combination with SDBS. A more hydrophilic surface was obtained upon adsorption of the surfactants in the presence of sodium chloride, film dispersion occurred in the presence of calcium chloride, and a less hydrophilic surface was obtained in the presence of both calcium chloride and sodium carbonate. Copyright © 2014 John Wiley & Sons, Ltd.
Applications of AES, XPS and TOF SIMS to phosphor materials
Authors: Swart H. C. , Terblans J. J. , Ntwaeaborwa O. M. , Kroon R. E. , Coetsee E. , Nagpure I. M. , Kumar Vijay , Kumar Vinod , Kumar Vinay
Published: January 2014

The important role of Auger electron spectroscopy (AES), X‐ray photo electron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF‐SIMS) to characterize different phosphor materials is pointed out with examples. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF‐SIMS are used for the surface chemical composition and valence state of the dopants. Copyright © 2014 John Wiley & Sons, Ltd.
Etching rates of blood proteins, blood plasma and polymer in oxygen afterglow of microwave plasma
Authors: Vesel Alenka , Kolar Metod , Stana‐Kleinschek Karin , Mozetic Miran
Published: January 2014

The removal of biomolecules from medical instruments by plasma could be a difficult task due to the fact that many medical instruments are made of polymers, which can be etched in plasma as well. The etching rates of selected blood proteins, platelet‐poor plasma (PPP) and polymer polyethylene terephthalate (PET) were studied. In the case of blood proteins, fibrinogen (FIB) and human serum albumin (HSA) were used. Films of PPP, FIB, HSA and PET were deposited on the quartz crystals and exposed to oxygen atoms in early and late afterglow of microwave plasma at different pressures between 50 and 400 Pa. The thickness of the films versus etching time was measured by quartz crystal microbalance. The thickness of PET film decreased linearly with etching time, while the thickness of both protein films and PPP decreased exponentially with time. In all cases, the etching rates were first increasing with the increasing pressure, while later they reached a constant value. Furthermore, the etching rates were higher in the early afterglow than in the late afterglow. The etching rates of PPP were higher than the etching rates of both proteins HSA and FIB. The slowest etching rate was observed for PET polymer, where the etching rate was lower by two orders of magnitude in comparison to both proteins and PPP. Copyright © 2014 John Wiley & Sons, Ltd.
Services, industry evolution, and the competitive strategies of product firms
Authors: Cusumano Michael A. , Kahl Steven J. , Suarez Fernando F.
Published: January 2014

Services of different types have become increasingly important for product firms. While these firms mainly focus on products, managers and researchers lack a comprehensive framework to understand when to make significant investments in particular kinds of services. We identify three categories of product‐related services from a product firm—smoothing and adapting services, which complement products, and substitution services, which enable customers to pay for the use of a product without buying the product itself. We develop propositions about the relative level of these different kinds of services vis‐a‐vis industry evolution, as well as suggest how these services affect industry structure. We draw upon various literatures, though we conclude that the relationship between products and services is more complex and richer than any one literature suggests. Copyright © 2014 John Wiley & Sons, Ltd.
A Comparative Analysis of International Corporate Social Responsibility Standards as Enterprise Policy/Governance Innovation Guidelines
Authors: Dankova Petya , Valeva Milena , Štrukelj Tjaša
Published: January 2014

This research responds to the market demand for better understanding of the variety of corporate social responsibility (CSR)‐standards from the market actors' perspective. Authors introduce the selected systems theory and holistic thinking needed for the implementation of CSR standards into the innovated enterprise policy. Historically built understanding of CSR is discussed, and existing international CSR initiatives/standards are compared. Taking the perspective of the market actors as participants who need orientation for embedding social responsibility into their enterprise policy, management and practice, authors focus on the most prominent CSR standards to detect their overlaps, distinctions, the extent and depth of CSR in them. On the basis of these findings, three types of CSR standards are identified. Copyright © 2014 John Wiley & Sons, Ltd.
Social Responsibility and Citizen‐Driven Innovation in Sustainably Mastering Global Socio‐Economic Crises
Authors: Steiner Gerald , Risopoulos Filippina , Mulej Matjaz
Published: January 2014

Why solely rely on governmental action, private sector management or science as the principal providers of solutions to societal problems, if most citizens could become fully self‐reliant troubleshooters and problem solvers for the complex challenges and crises our societies face? Even though in times of acute crisis, top–down interventions may be necessary to keep a societal system viable, citizen‐driven innovation policy could be a better long‐term approach to society's challenges. We, as a society, should focus on the collaborative capabilities and creativity of ourselves; civic change processes should be based on a broad system understanding, strong values and citizen participation. To foster a climate inspiring collaboration across various levels of society, changes within governmental, political and private sector management policies must accompany this approach. Further, to equip citizens with the particular competences needed to successfully participate in citizen‐driven innovation when dealing with crises, educational programs from kindergarten to graduate school should include training in social responsibility and sustainable development. Combinations of both top–down interventions and citizen‐driven innovations will likely lead to more sustainable crises resolution than either approach alone. Copyright © 2014 John Wiley & Sons, Ltd.
A New Socio‐economic Order: Evidence About Employees' Values' Influence on Corporate Social Responsibility
Authors: Potocan Vojko , Nedelko Zlatko
Published: January 2014

Realization of a socio‐economic order depends crucially on human values, including employees' personal values. The main purpose of this article is a requisitely holistic examination of the influence of employees' personal values on their attitudes towards economic, environmental and social aspects of corporate social responsibility (CSR). Schwartz values survey questionnaire was used to measure employees' personal values and 25 statements referring to economic, environmental and social aspects of CSR. Results reveal that personal values most strongly influence employees' orientation regarding economic results, whereas the impact on their attitudes towards environmental and social concern is weaker. From all sub‐dimensions of values, only universalism values influence all three aspects of CSR, whereas five sub‐dimensions, also having significant impact, influence either one or both the other two aspects of CSR. Results help managers reflect upon the preferred patterns for development of enterprise employees' behaviors related with CSR. The sample includes 909 employees' responses from Slovenian enterprises, obtained in 2010 and 2011. Copyright © 2014 John Wiley & Sons, Ltd.
A hybrid current controller for dual three‐phase permanent magnet synchronous motors
Authors: Yuan Feixiong , Huang Shenghua
Published: January 2014

Control of the current harmonics is a critical issue for dual three‐phase (DTP) permanent magnet synchronous motors (PMSMs). Considering the limitations of conventional synchronous frame proportional‐integral (PI) current regulator, this paper presents a hybrid current controller that combines the PI current regulator with a multiresonant controller. With the proposed hybrid current controller, precise current control can be achieved with only a slight increase in the computational effort. Theoretical analysis and experimental results confirm the effectiveness of proposed current controller. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Effects of nonuniform incident velocity on a dynamic wind turbine airfoil
Authors: Gharali Kobra , Johnson David A.
Published: January 2014

For further insight into the performance of a horizontal axis wind turbine blade section under yaw loads, a 2D numerical simulation of a pitching S809 airfoil under dynamic stall with an unsteady incident velocity is presented. The streamwise incident velocity and pitch angle of incidence oscillated with the same frequency but with a range of phase differences, − π ≤ Φ ≤ π. Changing Φ caused variation of the results, which can be highlighted as significantly augmented and dramatically damped dynamic stall loads, both increasing and decreasing trends for vortex growth time during Φ increase, a shifted location of the maximum loads and a change in the order of the vortex pair circulation in each cycle. The results showed strong dependency on the velocity and acceleration of the freestream during dynamic stall, which categorized the results in four individual subdomains with different behaviors. Copyright © 2014 John Wiley & Sons, Ltd.
Parametric investigation of the soil–structure interaction effects on the dynamic behaviour of a shallow foundation supported wind turbine considering a layered soil
Authors: Taddei F. , Butenweg C. , Klinkel S.
Published: January 2014

The proposed investigation is concerned with influential factors of soil–structure interaction issues for onshore wind turbines. Indeed, the awareness of these aspects encounters hardly a straightforward application in practical regulations and therefore is often neglected. However, with the rapid recent growth, the wind energy installations are expanding into regions where the soil conditions may be unfavorable. A consciousness raising of the significance of interaction between the wind turbine, its foundation and the underlying soil is lacking. This paper aims to fill this research gap. It involves a three‐blade wind turbine grounded on a layered half space. The layered soil is simplified as a horizontal layer over an homogeneous half space. However, the method can consider multilayered soil and different bottom conditions, such as rigid bedrock or flexible half space. The soil–structure system is modeled by means of a coupling between finite element and boundary element method. The analysis is carried out in frequency domain. At the first stage, the only foundation–soil system is investigated, and subsequently, the focus shifts to the whole turbine‐soil assembly. The effects of different parameters are systematically evaluated, in order to provide a range of values for which the soil–structure interaction has to be accounted for. The investigation highlighted the importance of the relative stiffness of structure and soil. Also, the ratio of the layer stiffness to the half space stiffness plays an important role. Copyright © 2014 John Wiley & Sons, Ltd.
Entropy of controlled invariant subspaces
Authors: Colonius F. , Helmke U.
Published: January 2014

For continuous‐time linear control systems invariance entropy of controlled invariant subspaces is introduced. It is shown that it coincides with a variant of topological entropy for linear flows which we call subspace entropy. Using this characterization, upper bounds in terms of eigenvalues of an induced flow are derived. Under additional assumptions (diagonalizability, single inputs) these bounds are improved.
Fractional model of thermoelasticity for a half‐space overlaid by a thick layer
Authors: Abd El‐Latief A.M. , Khader S.E.
Published: January 2014

In this work, we apply the fractional order theory of thermoelasticity to a 1D problem for a half‐space overlaid by a thick layer of a different material. The upper surface of the layer is taken to be traction free and is subjected to a constant thermal shock. There are no body forces or heat sources affecting the medium. Laplace transform techniques are used to eliminate the time variable t. The solution in the transformed domain is obtained by using a direct approach. The inverse Laplace transforms are obtained by using a numerical method based on Fourier expansion techniques. The predictions of the fractional order theory are discussed and compared with those for the generalized theory of thermoelasticity. We also study the effect of the fractional derivative parameters of the two media on the behavior of the solution. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions.
Highly effective actions
Authors: Schwarz John H.
Published: January 2014

Abstract

It is conjectured that the world-volume action of a probe D3-brane in an AdS
5 × S
5 background of type IIB superstring theory, with one unit of flux, can be reinterpreted as the exact effective action (or highly effective action) for U(2)
$ \mathcal{N} $
= 4 super Yang-Mills theory on the Coulomb branch. An analogous conjecture for U(2)
k
× U(2)−k
ABJM theory is also presented. The main evidence supporting these conjectures is that the brane actions have all of the expected symmetries and dualities. Highly effective actions have general coordinate invariance, even though they describe nongravitational theories.
Supersymmetric quiver gauge theories on the lattice
Authors: Joseph Anosh
Published: January 2014

Abstract

In this paper we detail the lattice constructions of several classes of supersymmetric quiver gauge theories in two and three Euclidean spacetime dimensions possessing exact supersymmetry at finite lattice spacing. Such constructions are obtained through the methods of topological twisting and geometric discretization of Euclidean Yang-Mills theories with eight and sixteen supercharges in two and three dimensions. We detail the lattice constructions of two-dimensional quiver gauge theories possessing four and eight supercharges and three-dimensional quiver gauge theories possessing eight supercharges.
The Shelf Life of a Safety Climate Assessment: How Long Until the Relationship with Safety–Critical Incidents Expires?
Authors: Bergman Mindy E. , Payne Stephanie C. , Taylor Aaron B. , Beus Jeremy M.
Published: January 2014

Purpose

This study investigates safety climate as both a leading (climate → incident) and a lagging (incident → climate) indicator of safety–critical incidents. This study examines the “shelf life” of a safety climate assessment and its relationships with incidents, both past and future, by examining series of incident rates in order to determine when these predictive relationships expire.

Design/Methodology/Approach

A survey was conducted at a large, multinational chemical manufacturing company, with 7,467 responses at 42 worksites in 12 countries linked to over 14,000 incident records during the 2 years prior and 2 years following the survey period. Regressions revealed that safety climate predicts incidents of varying levels of severity, but it predicts the most severe incidents over the shortest period of time. The same is true for incidents predicting safety climate, with more severe incidents having a shorter predictive window. For the most critical relationship (climate predicting more severe incidents), the ability of a safety climate assessment to predict incidents expires after 3 months.

Implications

The choice of aggregation period in constructing incident rates is essential in understanding the safety climate–incident relationship. The common yearly count of incidents would make it seem that more severe incidents cannot be predicted by safety climate and also fails to show the strongest predictive effects of less severe incidents.

Originality/Value

This research is the first to examine assumptions regarding aggregation periods when constructing safety-related incident rates. Our work guides organizations in planning their survey program, recommending more frequent measurement of safety climate.
Determination of pKa Values of Oxocholanoic Acids by Potentiometric Titration
Authors: Farkaš Zita , Poša Mihalj , Tepavčević Vesna
Published: January 2014

The pKa and the maximum solubility values of cholic, deoxycholic salts and their oxo‐derivatives have been measured by the method of potentiometric titration. In the monomer phase (under the critical micellar concentration, CMC), the bile salts have different pKa values, as a result of their structural differences (the number of hydroxyl and oxo groups in the steroid skeleton) and different hydration properties of the acid anions. In the micellar phase (above the CMC), the bile salts have higher pKa values than in the monomer phase (under the CMC). This increase in the pKa values is greater in more hydrophobic bile salts (cholate and deoxycholate), than in less hydrophobic oxo derivatives, which can be explained by the different aggregation numbers of these bile salts. The oxo‐derivatives are more likely to form dimeric micelles, where the carboxylic groups are situated on the two sides of the micelle, not causing any electrostatic repulsion. In the more hydrophobic bile salts, aggregation numbers are higher, which causes electrostatic repulsion of the nearby situated carboxylic anions and consequential protonation of these anions (which leads to the stabilization of the micelle). The maximum solubility values are higher for the oxo‐derivatives. If the steroid skeleton of the bile salt is more hydrophobic, the capacity to solubilize the unionized bile acid is higher, i.e. a smaller amount of the bile acid anion is needed for the solubilization of the bile acid monomer. The oxo‐derivatives are less hydrophobic, but alongside their hydrophobicity, the structure of the micelle determines the solubilization capacities.