bluuebunny/crossref_metadata_2025 huggingface dataset:
Charge-Transfer Type Excitations in Layered Cupric Halides
Authors: Moritomo Y. , Tokura Yoshinori
Published: March 2014

Optical conductivity spectra and their polarization dependence have been investigated for the layered cupric halides A2CuCl4 (A=C
n
H2n+1NH3), which form CuCl4-layers analogous to the CuO2-sheets of the cuprate superconductors. In the visible region (2–4 eV), we found two distinct electronic transitions localized on the CuCl4-layer, whose peak energies shift to lower energy (ca. 0.8 eV) by substitution of chlorine with bromine. We ascribed these transitions to charge-transfer (CT) excitations from the ligand (Cl or Br) to metal (Cu) sites.
Magnetic Properties of Nanocrystalline Fe68.5Co5Ta3Cu1Si13.5B9 Alloys
Authors: Kim Kyeong-Sup , Yu Seong-Cho , Cho Yong-Soo , Lee Kyu-Won , Kim Chang-Seok , Kim Taik-Kee
Published: March 2014

The effect of annealing temperature on the spin wave excitations for the nanocrystalline Fe68.5Co5Ta3Cu1Si13.5B9 alloy have been investigated. The thermomagnetization curve at low temperature is found to obey the Bloch's T
3/2 law. From these experimental results, spin wave stiffness constants within the annealing condition were calculated. In addition, initial permeability, coercive force and core loss of the annealed alloys have been studied systematically.
Magneto-Optical Properties of Cd1-xMnxTe with High Mn Concentration
Authors: Anno Hiroaki , Hosoki Yugo , Miura Ken , Koyanagi Tsuyoshi , Matsubara Kakuei
Published: March 2014

The magneto-circular dichroism (MCD) spectra of Cd1-x
Mn
x
Te films with high Mn concentrations beyond the bulk limit have been studied. The MCD peak height monotonously increases as the Mn concentration x increases, reaches a maximum at x∼0.6, and then drastically decreases. This is attributed not only to the Mn concentration dependence of the magnetization but also to the anomalous behavior of the Zeeman splitting corresponding to a decrease in the sp-d exchange energies with an increase in x.
Electronic Structure of 3d Transition-Metal Impurities in Semiconductors
Authors: Mizokawa Takashi , Fujimori Atsushi
Published: March 2014

The d-d optical absorption spectra, photoemission spectra and donor and acceptor ionization energies of 3d transition-metal impurities in II-VI semiconductors have been investigated using the cluster and Anderson impurity models with configuration interaction. It is shown that both systematic chemical trends and multiplet effects are essential to explain the variations of the donor and acceptor levels with transition-metal elements.
Magnetism and Superconductivity in Copper Spinels
Authors: Miyatani Kazuo , Tanaka Toshiro , Sakita Shigenobu , Ishikawa Masayasu , Snirakawa Naoki
Published: March 2014

Spinel type copper sulfides, Cu1+x
Rh2-x
S4(x=0–1) and Cu1-x
Co2-x
S4(x=0–0.75), were synthesized, and the crystallographic properties, ac and dc susceptibilities and electrical resistivity were experimentally studied in relation with their magnetic and superconductive properties.
Cu1+x
Rh2-x
S4 showed Pauli paramagnetism, metallic conductivity and a superconducting transition at 4.75 K with a ∼100% Meissner fraction. The copper doping in the B site did not cause any prominent effect on these properties. In contrast to this, Cu1+x
Co2-x
S4 showed a Curie-Weiss type antiferromagnetic susceptibility with a constant term χ0=2.35×10-6 emu/Oe·g, Néel temperature T
n=18.0 K, effective Bohr magneton µeff=0.89µB/f.u. and paramagnetic Curie temperature θP=-52 K. AC susceptibility showed diamagnetism due to superconductivity as x increases and reached ∼100% Meissner fraction at x=0.5. Metallic type resistivity was observed for the whole range of x. The zero resistivity temperature depends on x and is 2.3 K for x=0.5. It was concluded that the magnetic moment of the itinerant 3d hole of Cu2+(3d9) in the system Cu1+x
Co2-x
S4 orders antiferomagnetic way below the Néel temperature and transfers to or coexists with a superconductive state below the critical temperature. The copper doping in the B site thus caused a prominent effect on the superconductivity, on which collaborative effect of the coexisting second phases of Cu7S4 and Cu9S4 with the XRD intensity of 0.5–5% still remains to be clarified.
Metal-Insulator Transition in Nearly Stoichiometric CaVO3
Authors: Inoue Isao H. , Morikawa Keiji , Fukuchi Hideo , Tsujii Tetsuya , Iga Fumitoshi , Nishihara Yoshikazu
Published: March 2014

A metal-to-insulator (MI) transition in perovskite-type vanadium oxide CaVO
y
in the vicinity of oxygen stoichiometry is reported. In spite of good metallic conductivity for Stoichiometric CaVO
y
(y=3.00), very slight oxidation (y\cong3.05) causes the system to be insulating but does not induce any significant structural changes. This type of MI transition is contrary to that reported on another d
1 system LaTiO
y
, which is a Mott-Hubbard insulator for y=3.00 but becomes metallic by oxidation. We suggest that in CaVO
y
, extra oxygens primarily induce additional scattering which causes the metallic CaVO3 to be insulating.
Luminescence Discontinuity and Local Crystal Field Continuity in Mixed Crystals of SrF2 and BaF2 Doped with Eu2+ Monitors
Authors: Kawano Katsuyasu , Nakata Ryouhei , Sumita Minoru
Published: March 2014

Discontinuity in photoluminescence has been investigated contrasting with the continuity in local crytal field in mixed crystals or solid solutions Sr1-x
Ba
x
F2 with the fine mixed ratios between SrF2 and BaF2. The signal from the doped Eu2+ ions has been monitored by means of optical measurements as well as electron spin resonance (ESR).
Dysonian Line in the Electron Spin Resonance of Highly Conductive CuIn2S4 Single Crystals
Authors: Takizawa Takeo , Nomura Shigetaka , Goltzené Alfred , Schwab Claude
Published: March 2014

Electron spin resonance (ESR) spectra have been measured in CdIn2S4 single crystals with various resistivities (ρ=106-10-3 Ω·cm). As the conductivity increases, samples vary from insulator-like semiconductors to degenerate ones. ESR spectra due to donor electrons are observed under illumination in high resistive samples, whereas Dysonian lines appear in low resistive ones. From the line shape analysis, we conclude that the variation in ESR line shapes with the concentration of donors arises from the motion of electrons in the paramagnetic centers.
The Growth of CuInSe2 Films Deposited by Sputtering and Its Application to Solar Cells
Authors: Nakada Tokio , Migita Kazuo , Kunioka Akio
Published: March 2014

CuInSe2 films have been deposited onto Mo-coated glass substrates by elemental three-source sputtering and hybrid sputtering. Near-stoichiometric films by three-source sputtering exhibited considerably small grain size and poor crystallinity which led to low cell performance. On the other hand, hybrid-deposited films exhibited much larger grain sizes ranging from 0.5 to 1 µm, although a large number of planar defects such as twins on {112} plane of chalcopyrite structure. Preliminary solar cells with ZnO/CdS/CuInSe2 structure using hybrid-deposited material resulted in a conversion efficiency of 7.8%.
Optical and ESR Characterization of Transition Atoms in CuAlS2
Authors: Sato Katsuaki , Aksenov Igor , Nishikawa Nobuyuki , Kai Tetsuya
Published: March 2014

The optical and ESR properties of the CuAlS2 single crystals, doped with transition atom (TA) elements of the iron group, i.e. Ti, V, Cr, Mn, Fe, Co, and Ni, have been studied. It has been found that TA impurities in the CuAlS2 host lattice are present in their different valence states, the relative concentrations of these impurities in each valence state being dependent on the position of the Fermi level in the band gap of the host compound in relation to deep energy (demarcation) levels introduced by TA ions.
Non-Linear Raman Scattering in II–III2–VI4 Compounds
Authors: Fomin V. M. , Tiginyanu I. M. , Ursaki V. V.
Published: March 2014

The paper presents an experimental substantiation of the theory (based on the optical vibration anharmonism) of non-linear Raman scattering (RS) in defective II-III2-VI4 compounds. In the transparency region of those compounds the anharmonicity assures processes of direct photon-phonon interaction resulting in the independence of RS characteristics upon the free carrier concentration. When the laser quantum energy approaches the band gap E
g an effective thermalization of the absorbed radiation takes place which in one's turn gives rise to the anharmonic generation of two or more phonons by a laser photon. These phenomena are shown to result in a non-linear dependence of the RS intensity upon the laser beam power.
The Study of p-d Hybridization of Sulfur-Annealed Copper Indium Disulfide by Photoreflectance
Authors: Hsu T. M.
Published: March 2014

The p-d hybridization of as grown, sulfur-annealed and prolonged sulfur-annealed copper indium disulfide have been studied by photoreflectance and a simple theoretical model. The sulfur-annealed sample has been found to have larger d electron contribution to the upper valence bands. This is explained as the decrease of energy separation between p-d energy level caused by the compensation of dominated defects in the crystal.
The Theory of Optical Absorption due to Multiphonon Processes in CdGeAs2
Authors: Tyuterev V. G. , Skachkov S. I.
Published: March 2014

The theory of Bendow et al. for multiphonon absorption process in tetrahedral A3B5 semiconductors is modified for the crystals with chalcopyrite structure. Frequency and temperature dependences of the calculated absorption coefficient for CdGeAs2 agree well with experimental results in the three phonon region.
Local Structure of CuInSe2 Thin Film Studied by EXAFS
Authors: Kuwahara Yuji , Oyanagi Hiroyuki , Yamaguchi Hirotaka , Aono Masakazu , Shirakata Sho , Isomura Shigehiro
Published: March 2014

We have investigated the local structure of CuInSe2 (CIS) thin films by surface-sensitive EXAFS on the Cu K- and Se K-edges using synchrotron radiation. We estimated the Cu–Se and In–Se bond lengths as a function of In/Cu ratio. The local structure of the thin film CIS is quite similar to that of the bulk chalcopyrite over a wide range of the In/Cu ratio. It is found that with decreasing the In/Cu ratio from the stoichiometric composition, the Cu–Se and In–Se bond lengths systematically deviate from those of stoichiometric bulk CuInSe2, which is attributed to the chemical disorder of the cation site in the chalcopyrite structure.
High-Pressure Behavior of Raman Modes in CuGaSe2
Authors: González J. , Chervin J. C.
Published: March 2014

The pressure dependence of the Raman modes of CuGaSe2 have been investigated up to 20 GPa in a gasketed diamond-anvil cell using neon gas as pressure transmitting medium. An assignment of the symmetry of the zone-center modes is proposed on the basis of their pressure dependence as compared to that of the corresponding modes in zinc-blende ZnSe. The effect of pressure on the phonon frequencies is discussed in terms of the Gr\"neisen parameters. From changes in the Raman spectra of the samples under pressure, a first-order phase transition, from the chalcopyrite to the disorder rocksalt structure, was observed at 14 GPa.
Structural Instability and Photoconduction of Tl1+(Tl3+S2
2-)
Authors: Katayama Shin-ichi , Kashida Shoji , Hori Tetsuya
Published: March 2014

The structural instability and the photoconduction of mixed-valence compounds Tl1+(Tl3+S2
2-) are studied by means of X-ray diffraction and photocurrent measurements. From the temperature dependence of observed dark currents and photocurrents, we estimate the band gap energy and discuss the occurrence of thermal quenching as well as possible electron scattering from both the ferroelectric domain boundaries and the soft-phonon modes.
Detection of Defect Activated Phonon Modes in Subband Transitions of GaAs–AlGaAs Quantum Well Structures
Authors: Joshi N. V. , Vleuten Willem van der , Wolter J. H.
Published: March 2014

Inter-subband excitations and contributions of defect-induced phonon modes for undoped GaAs–AlGaAs quantum well structures were examined by using Fourier Transform Spectroscopy. Transitions corresponding to n
1–n
2 for 70 Å, 110 Å and 160 Å as well as higher transitions for 110 Å and 160 Å well widths were identified. The obtained values are in good agreement with the computed ones for the barrier heights 262 meV and m
*=0.063m
0. It is found that inter subband transitions are assisted by the combination of defect-activated modes corresponding to TO (DATO) and LO (DALO) phonons. The values obtained in the present investigation are in good agreement with the earlier reported studies.
Electronic Structures and Band Offsets of II–VI Strained Superlattices
Authors: Nakayama Takashi
Published: March 2014

Electronic structures and band offsets of various II–VI compound superlattices are calculated by the first-principles pseudopotential method in the local density approximation. The differences of band structures of CdS and CdSe between wurtzite and zinc-blende crystal structures are analyzed. The calculated band offsets drastically vary with changing strain surroundings, and are tabled for the practical usage.
Spontaneous and Stimulated Emissions of Confined Excitons in Zn1-xCdxSe Multi-Quantum Wells
Authors: Jen Jen Y. , Tsutsumi Takeharu , Souma Izuru , Oka Yasuo
Published: March 2014

Photoluminescence in Zn1-x
Cd
x
Se/ZnSe multi-quantum wells (MOWs) have been studied under various excitation intensities and compared with the absorption spectrum. A stimulated emission by the quantum well (QW) excitons appears shifted by 8 meV from the peak of the spontaneous emission band at an excitation power density of 0.25 MW/cm2. Above 1 MW/cm2 the emission spectrum broadens and shifts further to the lower energy side. The observed stimulated emissions are interpreted by the recombination due to the exciton-exciton scattering and by the electron hole plasma recombination in the MQWs.
Optical Second Harmonic Generation as a Method for Characterization of the Semiconductor Surfaces
Authors: Kulyuk L. L. , Kravetsky I. V.
Published: March 2014

The phase transition in CdIn2S4 as well as the symmetry properties of GaAs and InP arbitrary oriented surfaces were investigated by second harmonic generation (SHG) method. The isostructural first order phase transition in CdIn2S4 single crystals at T∼400 K was identified. It was shown the crystallographic orientation of III–V semiconductor surfaces leads to a very pronounced effect on the anisotropy and intensity of the SHG from these surfaces.
Electron-Energy-Loss Spectroscopy of Misfit-Layer Compounds
Authors: Ohno Youichi
Published: March 2014

Misfit-layer compounds roughly denoted by MTS3 (M=Sn, Pb, Bi, Ce, Sm; T=Ti, V, Nb) have been studied by means of electron-energy-loss spectroscopy. The valence-electrons-excited spectra depend much more strongly on electronic structure of TS2 layers than that of MS layers. The Sn N
4,5 and Pb and Bi O
4,5 inner-shell-electron energy-loss spectra show that for MS (M=Sn, Pb, and Bi) layers the lowest conduction band consists mainly of metal p-derived states.
The Layered Composite Crystal Structure of the Ternary Sulfide, (SnS)1.15TaS2 “SnTaS3”
Authors: Gotoh Yoshito , Onoda Mitsuko , Akimoto Junji , Goto Midori , Oosawa Yoshinao
Published: March 2014

The crystal structure of a new type of ternary sulfide with a layered composite crystal structure, (SnS)1.15TaS2 was studied by the single crystal X-ray diffraction method. The precession photograph of (SnS)1.15TaS2 revealed the composite diffraction patterns of C-centered orthorhombic SnS subsystem with a=5.749(4) Å, b
2=5.737(4) Å, c=11.8755(24) Å and C-centered orthorhombic TaS2 subsystem with a=5.750(4) Å, b
1=3.308(3) Å, c=23.760(5) Å. The structure analysis has shown that the C-centered TaS2 is the disordered subsystem with the trigonal-prismatic sites formed by S atoms are statistically occupied by Ta atoms.
X-Ray Photoelectron Spectroscopy Studies on Surface Modification of CuInSe2
Authors: Cheng Y. H. , Tseng B. H. , Hwang H. L.
Published: March 2014

Surface properties of CuInSe2 have been rarely treated. In the present work, we studied surface modification by (NH4)2S
x
sulfurization and surface treatment by chemisorbed ruthenium. X-ray photoelectron Spectroscopy (XPS) measurements were performed to determine the binding energies. (NH4)2S
x
treatment cannot remove the native oxide and CuS is formed on CuInSe2. Upon the Ru treatment, the indium is reduced and the oxygen is increased. It might form a thin oxide layer containing Ru, Se and O.
Optical Absorption and Photoconductivity in Oxygen and Gold Doped CuInSe2
Authors: Hernández E. , Albornoz J. G. , González J. , Wasim S. M. , Sánchez J. C. , Pérez F. Sánchez
Published: March 2014

From a combined measurement of the spectral dependence of the optical absorption and photoconductivity and its comparison with the theoretical model, the diffusion length and surface recombination velocity of the minority carriers in oxygen and gold doped CuInSe2 are calculated. These are compared with the reported values.
Photoluminescence and Photoreflectance of CuGa(S1-xSex)2 and Cu(Ga1-xInx)S2 Alloys
Authors: Shirakata Sho , Ogawa Akihiro , Isomura Shigehiro , Kariya Tetsuya
Published: March 2014

Systematic photoluminescence (PL) and photoreflectance (PR) measurements have been carried out at 77 K on single crystals of CuGa(S1-x
Se
x
)2 and Cu(Ga1-x
In
x
)S2 alloys grown by iodine-transport method. Energies of A, B and C excitons have been determined as a function of composition. An exciton-related PL peak has been observed for both alloys over the whole composition range.
Analytical model of rotating two‐cell convection at Saturn
Authors: Goldstein J. , Hill T. W. , Waite J. H. , Burch J. L.
Published: March 2014

We use an analytical model of magnetosphere‐ionosphere coupling to show that an asymmetric ring current (RC) pressure with an m=1 longitudinal dependence can initiate a rotating two‐cell interchange potential. The model extends prior similar work by considering both cold plasma interchange and warm plasma pressure. This model predicts that within 7 h the magnitude of the interchange potential equals the RC seed potential. Within 13 to 26 h, the model reproduces the degree of cold density nonaxisymmetry at the outer density gradient of the Enceladus plume, as observed by the Cassini Plasma Spectrometer. The interchange growth time bears a strong dependence on the particular value of height‐integrated ionospheric conductivity and a weaker dependence on the magnitude of the initial RC perturbation. The model also extends prior work by including an outer boundary. We discuss the qualitative effect of a realistically shaped magnetopause that is anchored to the nonrotating frame. For high‐m interchange, the magnetopause presence has no significant effect. In contrast, low‐m interchange modes experience a rotating, asymmetric boundary condition that alternately enhances and inhibits interchange growth each rotation period. Several published studies have proposed interchange‐driven, rotating two‐cell convection; our results suggest that an asymmetric RC pressure distribution, coupled to Saturn's ionosphere, is one possible means of generating it. Our model predicts that the two‐cell interchange potential should be long‐lived and relatively insensitive to subsequent ring current injections, because after two Saturnian rotations the interchange potential is an order of magnitude larger than the seed potential that initiated it.
Spatial variability of phosphorus sorption dynamics in Louisiana salt marshes
Authors: Marton John M. , Roberts Brian J.
Published: March 2014

Phosphorus (P) biogeochemistry has been studied in multiple wetland ecosystems, though few data exist on P sorption in U.S. Gulf Coast marshes. There also is a limited understanding of how oil spills in coastal zones can influence P dynamics in wetland soils. In this study, we measured P sorption potential, using the P sorption index (PSI), soil properties, and P saturation at increasing distances from the marsh edge in oiled and unoiled marshes in three regions along the southeastern Louisiana coast (Terrebonne Bay, western, and eastern Barataria Bay). Individual PSI values were highly variable, ranging from 19.5 to 175.6 mg P 100 g−1 and varying by at least a factor of five within each of the three regions, and did not significantly differ between regions or between oiled and unoiled marshes. Soil pH, organic matter, total N, N:P ratio, moisture content, cation exchange capacity, and P saturation differed between regions, and all soil parameters showed great variability between and within individual marshes. Extractable iron was the strongest predictor of PSI across all regions, explaining between 51 and 95% of the variability in individual regions. PSI increased with distance from marsh edge in Terrebonne Bay where other soil properties exhibited similar trends. Results suggest mineral composition of marsh soils, influenced by elevation‐inundation gradients, are critical in dictating P loading to estuaries and open waters, and overall marsh functioning. Further, within 2 years of the Deepwater Horizon oil spill, oiled marshes are able to sorb phosphorus at comparable levels as unoiled marshes.
Estimating the human contribution to groundwater depletion in the Middle East, from GRACE data, land surface models, and well observations
Authors: Joodaki Gholamreza , Wahr John , Swenson Sean
Published: March 2014

Data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are used to estimate monthly changes in total water storage across the Middle East during February 2003 to December 2012. The results show a large negative trend in total water storage centered over western Iran and eastern Iraq. Subtracting contributions from the Caspian Sea and two large lakes, Tharthar and Urmiah, and using output from a version of the CLM4.5 land surface model to remove contributions from soil moisture, snow, canopy storage, and river storage, we conclude that most of the long‐term water loss is due to a decline in groundwater storage. By dividing the region into seven mascons outlined along national boundaries and fitting them to the data, we find that the largest groundwater depletion is occurring in Iran, with a mass loss rate of 25 ± 3 Gt/yr during the study period. The conclusion of significant Iranian groundwater loss is further supported by in situ well data from across the country. Anthropogenic contributions to the groundwater loss are estimated by removing the natural variations in groundwater predicted by CLM4.5. These results indicate that over half of the groundwater loss in Iran (14 ± 3 Gt/yr) may be attributed to human withdrawals.
Direct‐Current Triboelectric Generator
Authors: Yang Ya , Zhang Hulin , Wang Zhong Lin
Published: March 2014

The first direct‐current triboelectric generator (DC‐TEG) based on sliding electrification for harvesting mechanical energy from rotational motion is reported. The DC‐TEG consists of two rotating wheels and one belt for connecting them, which are made of distinctly different triboelectric materials with a specific requirement. During the rotation, the contact‐induced electrification and the relative sliding between the two wheels and the belt can induce a continuous increase of the accumulated positive and negative triboelectric charges at the two rotating wheels, respectively, resulting in a Corona discharge and producing the observed current through an external load. The DC‐TEG can deliver an open‐circuit voltage of larger than 3200 V and a maximum power of 100 μW under an external load of 60 MΩ at a rotational speed of 1000 r min–1. By designing a point metal discharge electrode near the accumulated positive charges on the metal wheel, the instantaneous short‐circuit current can be up to 0.37 mA. The DC‐TEG can be utilized as a direct power source to light up 1020 serially connected commercial light‐emitting diodes (LEDs) and the produced energy can also be stored in a capacitor for other uses. This work presents a DC‐TEG technology to harvest mechanical energy from rotational motion for self‐powered electronics.
Occurrence of nephroblastomatosis with dup(18)(q11.2‐q23) implicates trisomy 18 tumor screening protocol in select patients with 18q duplication
Authors: Starr Lois J. , Sanmann Jennifer N. , Olney Ann Haskins , Wandoloski Melissa , Sanger Warren G. , Coulter Donald W.
Published: March 2014

Duplications of the long arm of chromosome 18 have been previously reported in patients with phenotypic findings similar to full trisomy 18. Trisomy 18 increases the risk for Wilms tumor and it is currently recommended that these patients undergo abdominal ultrasonography screening every 6 months. We report on nephroblastomatosis in a 27‐month‐old male with a 55 Mb duplication of chromosome 18q11.2‐q23 (chr18:22693370–77982126, hg 19) and propose that the trisomy 18 tumor screening protocol could also benefit patients with large 18q duplications. © 2014 Wiley Periodicals, Inc.
The search for peripheral biomarkers for major depression: Benefiting from successes in the biology of smoking
Authors: Philibert Robert , Gunter Helen M. , Kolassa Iris‐Tatjana
Published: March 2014

The search for robust, clinically useful markers for major depression (MD) has been relatively unproductive. This is unfortunate because MD is one of the largest socio‐economic challenges for much of the world and the development of reliable biomarkers for MD could aid in the prevention or treatment of this common syndrome. In this editorial, we compare the approaches taken in the search for biomarkers for MD to that of the more successful searches for biomarkers for tobacco use, and identify several substantive barriers. We suggest that many of the existing clinical repositories used in these biomarkers searches for MD may be of limited value. We conclude that in the future greater attention should be given to the clinical definitions, characterization of confounding environmental factors and age of subjects included in studies. © 2014 Wiley Periodicals, Inc.
Probability Density Function of Bubble Size Based Reagent Dosage Control for Flotation Process
Authors: Zhu Jianyong , Gui Weihua , Yang Chunhua , Liu Jinping , Tang Yongbo
Published: March 2014

As an effective measurement of bubble stability, bubble size structure is believed to be closely related to flotation performance. Reagent dosage has a very important influence on bubble size. A novel probability density function (PDF) of bubble size based reagent dosage control method is proposed in the paper. First, froth images acquired by camera with big and tiny blobs are segmented by use of an improved two‐pass watershed algorithm. With non‐Gaussian features, the PDF of the bubble size is hence approximated by the estimator based on B‐spline such that the PDF of the bubble size is characterized by a weight vector of the B‐spline. Finally, a PDF‐based reagent dosage control algorithm is proposed to make the output PDF track the given PDF according to the linear matrix inequality technique, which is established to solve its stability condition by Lyapunov stability analysis. Experimental results show the effectiveness of the proposed method.
Moving Onwards: An Action Continuation Strategy in Finding the Way
Authors: van Tilburg Wijnand A. P. , Igou Eric R.
Published: March 2014

In four studies, we examined people's strategies when deciding between multiple routes of equivalent length in way‐finding tasks. The results reveal the important role of continuing behavior when faced with a choice from multiple viable routes. After affirming the existence of asymmetric preferences for alternatives (Studies 1 and 2), we observed that variations of simple known‐environment mazes supported action continuation as prevailing process over alternative strategies such as preference for long initial path segments, paths with a least deviating angle, and a modified hill climbing strategy (Study 3). Moreover, asymmetric preferences disappeared with the absence of initial behavior to inform subsequent decision making (Study 4). Results are discussed within the context of decision making, navigation strategies, and everyday life path finding. Copyright © 2014 John Wiley & Sons, Ltd.
Environmentally Sustainable Development through Stakeholder Engagement in Developed and Emerging Countries
Authors: Dögl Corinna , Behnam Michael
Published: March 2014

This cross‐country study investigates the antecedents and outcomes of corporate environmental responsibility (CER) practices in developed and emerging countries. Based on stakeholder and institutional theory, we conducted an empirical study among firms in Germany, USA, India and China. We found support for a significant positive relationship between regulatory, market and social stakeholder influences, CER practices and business outcomes in the total and individual country samples. Regarding country differences, our data reveal significant similarities and differences between developed and emerging countries. Market stakeholder influences are stronger in developed countries, whereas regulatory and social stakeholder influences do not differ significantly between the two country groups. The relationship between CER practices and positive business outcomes is stronger in emerging than in developed countries. Implications for institutional theory and organizations are outlined. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment
Cleaning up NMR spectra with reference deconvolution for improving multivariate analysis of complex mixture spectra
Authors: Ebrahimi Parvaneh , Nilsson Mathias , Morris Gareth A. , Jensen Henrik M. , Engelsen Søren B.
Published: March 2014

NMR spectroscopy provides valuable data for metabolomics, but the information sought can be partly obscured by errors from hardware imperfection, causing frequency, phase, and spectral lineshape to change significantly between measurements. Clearly, this is a highly undesirable source of variation in multivariate quantitative studies such as metabolomics. Fortunately, many hardware imperfections affect all resonances in the same way. They can therefore be corrected for by comparing an experimental reference peak with the known correct peak shape, in a procedure known as reference deconvolution. This post‐measurement processing method can correct many systematic errors in data. The aim of this study is to investigate how reference deconvolution can improve the results obtained by multivariate analysis of NMR data. For this purpose, 1H NMR data were recorded for a set of 136 mixture samples. Spectra were then produced with and without reference deconvolution and analyzed by principal component analysis and partial least squares methods. The results showed that reference deconvolution resulted in simpler and improved models, requiring fewer latent variables to explain the same or higher percentage of the variance. It was also evident that the recovery of the design concentrations was significantly enhanced. This confirms that reference deconvolution can significantly improve multivariate data analysis and should be considered as a standard tool in high throughput quantitative NMR spectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.
A Commercially Available Tantalum Catalyst for the Highly Regioselective Intermolecular Hydroaminoalkylation of Styrenes
Authors: Dörfler Jaika , Doye Sven
Published: March 2014

The C–C bond‐forming catalytic hydroaminoalkylation of terminal alkenes or styrenes enables a direct and 100 % atom‐efficient synthesis of amines and can generally result in the formation of two regioisomers, the branched and the linear product. Herein, we report that high‐yielding intermolecular hydroaminoalkylation reactions of styrenes can be achieved with excellent regioselectivities in the presence of the commercially available homoleptic catalyst pentakis(dimethylamino)tantalum. In all cases, the branched regioisomer is formed almost exclusively.
Microfluidic electrophoretic mobility shift assays for quantitative biochemical analysis
Authors: Pan Yuchen , Karns Kelly , Herr Amy E.
Published: March 2014

Electrophoretic mobility shift assays (EMSAs) play an important role in analytical chemistry, quantitative bioscience, and point‐of‐care diagnostics. Emerging microfluidic lab‐on‐a‐chip technologies bring high throughput and multiplexed analysis to affinity‐based electrophoretic separations, greatly advancing the performance of traditional EMSAs. This review elaborates on the relevant theoretical basis for EMSAs, surveys microfluidic‐based EMSA applications in molecular conformation analyses, immunoassays, affinity assays and genomics, and outlines challenges and potential future improvements needed from this powerful assay.
BREAKING THE ADDICTION TO TECHNOLOGY ADOPTION
Authors: Bryan Stirling , Mitton Craig , Donaldson Cam
Published: March 2014

A major driver of cost growth in health care is the rapid increase in the utilisation of existing technology and not simply the adoption of new technology. Health economists and their health technology assessment colleagues have become obsessed by technology adoption questions and have largely ignored ‘technology management’ questions. Technology management would include the life‐cycle assessment of technologies in use, to assess their real‐world performance; and monitoring of technology indication creep. A rebalancing of focus might serve to encourage a more self‐critical and learning culture amongst those involved in technology evaluation analysis. Further, health economists and health technology assessment analysts could make a more significant contribution to system efficiency through rebalancing their efforts away from technology adoption questions towards technology management issues. Copyright © 2014 John Wiley & Sons, Ltd.
ORDER FLOWS, FUNDAMENTALS AND EXCHANGE RATES
Authors: Iwatsubo Kentaro , Marsh Ian W.
Published: March 2014

We examine the links between end‐user order flows as seen by a major European commercial bank and macroeconomic fundamentals. We show that both exchange rate changes and flows are only weakly related to macroeconomic news announcements and hypothesize that ‘the cat is already out of the bag’ by the time the news is announced. Instead, order flows of financial and corporate customers reflect in real time the evolution of macroeconomies. The actions of the banks receiving the order flows in turn reveal the information to the market as a whole, which prices the exchange rate accordingly. By the time the news is announced, the exchange rate already contains the majority of the information. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling of ultra‐wideband indoor channels with the modified leapfrog ADI‐FDTD method
Authors: Zhai Meng‐Lin , Yin Wen‐Yan , Chen Zhizhang (David) , Nie Hong , Wang Xiang‐Hua
Published: March 2014

Full‐wave time‐domain electromagnetic methods are usually effective in rigorously modeling and evaluating ultra‐wideband (UWB) wireless channels. However, their computational expenditures are expensive, when they are used to deal with electrically large‐size problems consisting of fine structures. In order to reduce computational time, the unconditionally stable leapfrog alternating‐direction implicit finite‐difference time‐domain (leapfrog ADI‐FDTD) method has been proposed recently. In this paper, the leapfrog ADI‐FDTD algorithm is developed for simulating lossy objects, such as office walls, floors, and ceilings, for UWB communication channel characterization. It leads to effective UWB channel characterization with power‐decay time constant, path loss exponent, and probability distribution of power gain. In comparison with the conventional FDTD, the proposed method can achieve 60% saving in computational time while retaining good accuracy. Copyright © 2014 John Wiley & Sons, Ltd.
Dynamic behavior of a distributed incinerator power system under output power variation
Authors: Chen Meng‐Jen , Wu Yu‐Chi , Liu Guo‐Tsair , Chen Jong‐Fang
Published: March 2014

In Taiwan, the sales revenues of power generation from incinerator power plants with heat recovery power generation sold to the power company were up to NT$4.5bn, making the incinerator power generation play an important role in reduction of impact on environment and substitution of energy in power generation. Studying the dynamic behavior of incinerator power systems under output power variation is thus an essential task for the scheduling, operation, and expansion of incinerator power plants, such as, for cooperating with a scheduling program based on pricing signals to capture energy trading timing economically and to operate the incinerator power system securely. Although there are many studies on incinerator power generation, they seldom discuss the power generation system characteristics. In this paper, mathematical dynamic models for a distributed incinerator power system were derived and implemented using Matlab/Simulink, and dynamic characteristics of the system were further simulated and discussed under two operating modes: increment and decrement of power generation. These developed models can provide dynamic characteristics for these two modes, serving as an important analytic tool for cooperating with a scheduling program based on pricing signals to capture energy trading timing economically and to operate the incinerator power system securely. Copyright © 2014 John Wiley & Sons, Ltd.
Michler's Ketone as an Interesting Scaffold for the Design of High‐Performance Dyes in Photoinitiating Systems Upon Visible Light
Authors: Mokbel Haifaa , Dumur Frédéric , Graff Bernadette , Mayer Cédric R. , Gigmes Didier , Toufaily Joumana , Hamieh Tayssir , Fouassier Jean‐Pierre , Lalevée Jacques
Published: March 2014

Four new push–pull dyes derived from Michler's ketones are investigated. These dyes, based on a donor–π–acceptor (D–π–A) structure, exhibit a tunable character according to the electron‐withdrawing ability of the acceptor used. The new proposed structures can be used in high‐performance photoinitiating systems. Remarkably, two of them are characterized by an excellent reactivity to initiate the free‐radical polymerization of acrylates, the ring‐opening polymerization of epoxides, as well as the synthesis of interpenetrating polymer networks (IPNs) under exposure to a laser diode at 457 nm. The chemical mechanisms are investigated by steady‐state photolysis, fluorescence, and electron spin‐resonance (ESR) experiments.

image
Multi‐objective Approaches to the Unit Crewing Problem in Airline Crew Scheduling
Authors: Tam Bassy , Ryan David , Ehrgott Matthias
Published: March 2014

The goal of the crew pairing problem is to partition a flight schedule into sequences of flights called pairings that crew members can operate at minimum cost. It is solved for each crew rank, for example, captains and first officers. In optimised crew pairings, crew often split and join other crew to operate outgoing flights. Because minimum cost pairings contain little buffer time, crew splitting after a delayed flight contributes to the propagation of delay. This effect can be avoided by unit crewing, that is, by keeping crew of different ranks together for as long as possible during a pairing. However, increasing unit crewing increases cost.

We investigate sequential and parallel methods for unit crewing, explicitly considering the two objectives of minimising cost and maximising unit crewing. We apply multi‐objective techniques in the sequential approach, where the (minimum cost) pairing problem for one crew rank is solved first and both objectives feature when solving for the second crew rank. Because the quality of the pairings obtained by this method is limited by the solution for the first crew rank, we then propose to solve the two crew pairing problems simultaneously, again using multi‐objective optimisation methods. We introduce a multi‐objective optimisation model for this problem and propose a new heuristic branching technique that favours unit crewed pairings when applied to a scalarised model with an auxiliary objective function. We compare this with a direct approach with management of the number of unit crewing constraints and a Dantzig–Wolfe decomposition approach.

Numerical tests on domestic New Zealand data show that the multi‐objective approaches considerably increase the level of unit crewing, without much increase in cost, even in the sequential approach. Moreover, we show that the parallel approach is superior in terms of quality of the pairing solution but computationally more expensive. The heuristic branching technique provides good quality solutions in reasonable time, as compared with the Dantzig–Wolfe method. Copyright © 2014 John Wiley & Sons, Ltd.
A Multicriteria Dial‐a‐Ride Problem with an Ecological Measure and Heterogeneous Vehicles
Authors: Atahran Ahmed , Lenté Christophe , T'kindt Vincent
Published: March 2014

The Dial‐a‐Ride Problem is a complex combinatorial optimization problem with many real‐world applications in transportation of persons. It consists in routing a fleet of vehicles based at a common depot in order to satisfy users' transportation requests. Each request may consist, in a number of persons, a specified pickup location, a destination location, desired departure and arrival time windows. In this paper, we investigate a new and general model for the transportation of persons. It involves three objective functions that have to be optimized in order to measure the potential efficiency of the Dial‐a‐Ride Problem solution on different aspects: the cost for the transportation operator, the quality of service for users and the impact on the environment. For an efficient search through the solution space, we use a multiobjective genetic algorithm, which allows us to identify a good approximation of the set of Pareto optimal solutions. Among this set of solutions, the decision‐maker can select the solution with best compromise according to its preferences, without introducing a priori information about these ones. The proposed genetic algorithm is based on an optimal timing algorithm that computes pickup and delivery dates when the requests are sequenced on the vehicles. Copyright © 2014 John Wiley & Sons, Ltd.
Digital cell quantification identifies global immune cell dynamics during influenza infection
Authors: Altboum Zeev , Steuerman Yael , David Eyal , Barnett‐Itzhaki Zohar , Valadarsky Liran , Keren‐Shaul Hadas , Meningher Tal , Mendelson Ella , Mandelboim Michal , Gat‐Viks Irit , Amit Ido
Published: March 2014

Hundreds of immune cell types work in coordination to maintain tissue homeostasis. Upon infection, dramatic changes occur with the localization, migration, and proliferation of the immune cells to first alert the body of the danger, confine it to limit spreading, and finally extinguish the threat and bring the tissue back to homeostasis. Since current technologies can follow the dynamics of only a limited number of cell types, we have yet to grasp the full complexity of globalin vivocell dynamics in normal developmental processes and disease. Here, we devise a computational method, digital cell quantification (DCQ), which combines genome‐wide gene expression data with an immune cell compendium to inferin vivochanges in the quantities of 213 immune cell subpopulations.DCQwas applied to study global immune cell dynamics in mice lungs at ten time points during 7 days of flu infection. We find dramatic changes in quantities of 70 immune cell types, including various innate, adaptive, and progenitor immune cells. We focus on the previously unreported dynamics of four immune dendritic cell subtypes and suggest a specific role forCD103+CD11b−DCs in early stages of disease andCD8+pDCin late stages of flu infection.
Alternative polyadenylation diversifies post‐transcriptional regulation by selective RNA–protein interactions
Authors: Gupta Ishaan , Clauder‐Münster Sandra , Klaus Bernd , Järvelin Aino I , Aiyar Raeka S , Benes Vladimir , Wilkening Stefan , Huber Wolfgang , Pelechano Vicent , Steinmetz Lars M
Published: March 2014

Recent research has uncovered extensive variability in the boundaries of transcript isoforms, yet the functional consequences of this variation remain largely unexplored. Here, we systematically discriminate between the molecular phenotypes of overlapping coding and non‐coding transcriptional events from each genic locus using a novel genome‐wide, nucleotide‐resolution technique to quantify the half‐lives of 3′ transcript isoforms in yeast. Our results reveal widespread differences in stability among isoforms for hundreds of genes in a single condition, and that variation of even a single nucleotide in the 3′ untranslated region (UTR) can affect transcript stability. While previous instances of negative associations between 3′ UTR length and transcript stability have been reported, here, we find that shorter isoforms are not necessarily more stable. We demonstrate the role of RNA‐protein interactions in conditioning isoform‐specific stability, showing that PUF3 binds and destabilizes specific polyadenylation isoforms. Our findings indicate that although the functional elements of a gene are encoded in DNA sequence, the selective incorporation of these elements into RNA through transcript boundary variation allows a single gene to have diverse functional consequences.
Broadband dielectric properties of multiwalled carbon nanotube/polystyrene composites
Authors: Arjmand Mohammad , Sundararaj Uttandaraman
Published: March 2014

This study investigates the dielectric properties of multiwalled carbon nanotube (MWCNT)/polystyrene (PS) composites over the broadband frequency range, i.e., 10−1 to 106 Hz. The results showed that the real permittivity and imaginary permittivity increased remarkably with increased MWCNT concentration. For instance, at 100 Hz, the real permittivity and imaginary permittivity of the pristine PS was 2.71 and 0.01, respectively, which increased to 5.22 × 104 and 3.28 × 107 at 3.50 wt%, respectively. The increase in the real permittivity was related to the formation of a large number of nanocapacitor structures, i.e., MWCNTs as nanoelectrodes and polymer matrix as dielectric material, i.e., interfacial polarization. The increase in the imaginary permittivity with MWCNT loading was attributed greater number of dissipating charges, enhanced conductive network formation, and boosted polarization loss arising from interfacial polarization. It was also observed that the real and imaginary permittivities were frequency independent in the insulative region, whereas they decreased drastically with frequency in the conductive region. The descending trend of real permittivity with frequency in the conductive region was related to charge polarization relaxation, whereas the reduction in imaginary permittivity with frequency was attributed to lower Ohmic loss and polarization loss. POLYM. ENG. SCI., 55:173–179, 2015. © 2014 Society of Plastics Engineers
Gefangen im Fokus des Lasers
Authors: Kruse Annika , Alpmann Christina , Denz Cornelia
Published: March 2014

Das Experimentierlabor MExLab Physik der WWU Münster hat eine dynamische optische Pinzette entwickelt, die das Prinzip dieser neuen Technologie als mobiles Exponat an Schulen bringt. Beim Experimentieren können Lehrkräfte, Kinder und Jugendliche das physikalische Prinzip des optischen Fangens von Mikropartikeln mit Laserlicht erforschen und verstehen. Die zu fangenden Objekte reichen von mikroskopischen Silicakugeln über stäbchenförmige Bakterien aus Heuaufgüssen bis hin zu Zellen. Schülerinnen und Schüler erkunden damit die aktuelle Schnittstelle zwischen Photonik und Lebenswissenschaften.
Voyager 1 ist im interstellaren Raum
Authors: Fahr Hans J.
Published: March 2014

Neue Messungen der Plasmaeigenschaften in der Umgebung von Voyager 1 belegen, dass die Raumsonde die Heliosphäre verlassen und den interstellaren Raum erreicht hat. Insbesondere Messungen der Ionendichten, Elektronenplasma‐Schwingungen und Magnetfelder entsprechen den Vorhersagen für den Übergang in das interstellare Medium.