bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunability of terahertz random lasers with temperature based on superconducting materials
Authors: Ghasempour Ardakani Abbas , Reza Bahrampour Ali , Mohammad Mahdavi Seyed , Hosseini Mehdi
Published: September 2012

We theoretically demonstrate the tunabiltiy of terahertz random lasers composed of high temperature superconductor YBCO and ruby layers as active medium. The considered system is a one-dimensional disordered medium made of ruby grain and YBCO. Finite-difference time domain method is used to calculate the emission spectrum and spatial distribution of electric field at different temperatures. Our numerical results reveal that the superconductor based random lasers exhibit large temperature tunability in the terahertz domain. The emission spectrum is significantly temperature dependent, the number of lasing modes and their intensities increase with decreasing temperature. Also, we make some discussion to explain the reason for the observed tunability and the effect of temperature variation on the spatial distribution of the electric field in the disordered active medium.
Study of strain fields caused by crystallization of boron doped amorphous silicon using scanning transmission electron microscopy convergent beam electron diffraction method
Authors: Nakanishi Nobuto , Arie Hiroyuki , Kunimune Yorinobu , Ide Takashi , Hirose Yukinori , Hattori Nobuyoshi , Koyama Toru
Published: September 2012

Study of strain fields around boron doped silicon electrodes in silicon devices was carried out with scanning transmission electron microscopy convergent beam electron diffraction. Leak current, which was one of the crucial failures of this kind of structure, depends on boron concentration in the electrodes. Transmission electron microscopy and diffraction analysis showed that the electrodes consist of epitaxial phase and poly-Si phase, and the proportion of these phases depends on the boron concentration in the electrode. Strain distribution obtained with scanning transmission electron microscopy convergent beam electron diffraction revealed that the origin of the strain is volume shrinkage of the epitaxial phase in the electrode, and the poly-Si phase acts as buffer against this strain. Electron energy-loss spectroscopy analyses revealed that boron segregation occurred in samples having a higher boron concentration, and prevented epitaxial growth in the electrodes. As a result, the core of the electrode remains as poly-Si or amorphous Si and acts as strain buffer. Our analysis concluded that boron concentration in the electrodes is one of the most important factors enabling high production yield for the structure.
Optical characteristic of sol-gel synthesized lead lanthanum titanate-cobalt iron oxide multiferroic composite thin film
Authors: Roy Subhasis , Majumder S. B.
Published: September 2012

In the present work, we have investigated the optical characteristics of (1 − x) Pb0.85La0.15TiO3 (PLT15)-x CoFe2O4 (CFO) (x, volume fraction of CFO 0.0 ≤ x ≤ 0.12) composite multiferroic thin films. It has been demonstrated that the analysis of wavelength dispersion of refractive indices is an effective tool to comment on the magnetostrictive (CFO) phase distribution in perovskite (PLT15) matrix. Thus, in case of 0-3 type (1 − x) PLT15-x CFO composite films, it has been demonstrated that as long as CFO phase is distributed homogeneously in PLT15 matrix, the measured refractive indices follow Sellmeir dispersion formalism. Interestingly, for percolative magnetostrictive phase (CFO) distribution, the refractive index variation of the composite films deviates from the Sellmeir type dispersion. Absorption coefficient and the band gap energy are estimated for PLT15 and (1 − x) PLT15-x CFO composite films with varying CFO volume contents. Both refractive indices and packing fraction of (1 − x) PLT15-x CFO composite films are found to be marginally reduced with the increase in CFO volume contents. The band gap of these films is found to be systematically reduced with the increase in CFO volume contents. The change in band gap is argued to be due to cation/(s) diffusion across PLT15 and CFO interface.
Dynamics of a Holstein polaron with off-diagonal coupling
Authors: Zhao Yang , Luo Bin , Zhang Yuyu , Ye Jun
Published: September 2012

Dynamics of a one-dimensional Holstein polaron with off-diagonal exciton-phonon coupling is studied by employing the Dirac-Frenkel time-dependent variational principle. The trial state used is the Davydov D2 Ansatz with two sets of variational parameters, one for each constituting particle in the linearly coupled exciton-phonon system. Validity of the approach is carefully checked by quantifying how faithfully the trial state follows the Schrödinger equation. A close examination of variational outputs reveals fine details of polaron dynamics and intricacies of dynamic exciton-phonon correlations. In the absence of diagonal coupling, the change in the polaron effective mass hinges on the sign of the transfer integral due to the antisymmetric nature of the off-diagonal coupling. The role of the off-diagonal coupling switches from being an agent of transport at moderate coupling strengths to that of localization at large coupling strengths. Increasing the phonon bandwidth leads to a reduced polaron effective mass at the zone center and an overall lowering of the polaron band.
Separation of ion components produced by plasma-assisted catalytic ionization
Authors: Oohara W. , Hibino T. , Higuchi T. , Ohta T.
Published: September 2012

Positive and negative hydrogen ions are produced by plasma-assisted catalytic ionization using a porous nickel plate, where the irradiation current density and energy of positive ions produced by discharge to the porous plate are controlled. The ion energy distributions are analyzed from the properties of current densities of positive and negative ions extracted from the porous surface. Positive ions passing through fine pores of the porous plate and positive and negative ions produced on the porous surface are observed. It is clarified that the produced fluxes of positive and negative ions and the flux balance between them are controlled by the irradiation current density and energy, respectively.
Quantum beats of type-I and type-II excitons in an InxGa1−xAs/GaAs strained single quantum well
Authors: Kojima Osamu , Mizoguchi Kohji , Nakayama Masaaki
Published: September 2012

We have investigated the quantum beat of the type-I heavy-hole (HH) and the type-II light-hole (LH) excitons in an In0.15Ga0.85As/GaAs strained single quantum well (SQW) using a reflection-type pump-probe technique. The type-II LH exciton consists of the electron and LH located in the In0.15Ga0.85As and GaAs layers, respectively. The energies of the type-I and the type-II excitons were evaluated with photoreflectance spectroscopy. The exciton states were calculated based on a variational method. The time-domain signals clearly show the oscillatory structure with the period corresponding to the splitting energy of the HH and the LH excitons. From the pump-energy dependence of the Fourier transform spectrum and intensity, it is concluded that the oscillation originates from the quantum beat of the type-I HH and the type-II LH excitons.
Wave modeling in a cylindrical non-uniform helicon discharge
Authors: Chang L. , Hole M. J. , Caneses J. F. , Chen G. , Blackwell B. D. , Corr C. S.
Published: September 2012

A radio frequency field solver based on Maxwell's equations and a cold plasma dielectric tensor is employed to describe wave phenomena observed in a cylindrical non-uniform helicon discharge. The experiment is carried out on a recently built linear plasma-material interaction machine: The magnetized plasma interaction experiment [Blackwell et al., Plasma Sources Sci. Technol. (submitted)], in which both plasma density and static magnetic field are functions of axial position. The field strength increases by a factor of 15 from source to target plate, and the plasma density and electron temperature are radially non-uniform. With an enhancement factor of 9.5 to the electron-ion Coulomb collision frequency, a 12% reduction in the antenna radius, and the same other conditions as employed in the experiment, the solver produces axial and radial profiles of wave amplitude and phase that are consistent with measurements. A numerical study on the effects of axial gradient in plasma density and static magnetic field on wave propagations is performed, revealing that the helicon wave has weaker attenuation away from the antenna in a focused field compared to a uniform field. This may be consistent with observations of increased ionization efficiency and plasma production in a non-uniform field. We find that the relationship between plasma density, static magnetic field strength, and axial wavelength agrees well with a simple theory developed previously. A numerical scan of the enhancement factor to the electron-ion Coulomb collision frequency from 1 to 15 shows that the wave amplitude is lowered and the power deposited into the core plasma decreases as the enhancement factor increases, possibly due to the stronger edge heating for higher collision frequencies.
Critical size of self-propelled motion of droplets on GaAs (100) surface
Authors: Wu Jiang , Wang Zhiming M. , Li Alvason Z. , Benamara Mourad , Lee Jihoon , Koukourinkova Sabina D. , Soo Kim Eun , Salamo Gregory J.
Published: September 2012

The running liquid Ga droplets on GaAs surface (001) are presented and analyzed by scanning electron microscope and atomic force microscope. Self-motion of Ga droplet on GaAs surface is confirmed by microscope measurements. The liquid droplets are found to move with an initial critical diameter and constantly increase size during motion. The critical diameter of moving Ga droplets is observed to be 1.9 μm on GaAs (011) surface at preparation temperature 680 °C. A linear relationship is found between droplet diameter and trail length. These experiment results are qualitatively analyzed to understand the phenomenon of self-running Ga droplets on GaAs surface.
Optical transport through finite superlattice modulated with three-component quasiperiodic defect
Authors: Yu Xia , Chen Ke-Qiu , Zhang Yan
Published: September 2012

The optical transmission properties in finite periodic superlattice modulated with three-component quasiperiodic defect are presented. The results show that when the multilayered defect is composed of frequency-independent refractive index material, the number of band gaps is increased with the increase of the number of the defect order, and more localized modes emerge. Perfect and wide band gap can be observed when the structural defect is composed of negative refractive index materials. Moreover, the band gap can be adjusted by the incident angle. For a more realistic case where the multilayered defect is composed of frequency-dependent refractive index, the transmission spectra present a rich transmission profile without symmetry.
In memory of Niels Bohr
Authors: Pasachoff Naomi
Published: September 2012

A crossword puzzle honoring the upcoming 100th anniversary of the Bohr atom.
The Higgs particle, or something much like it, has been spotted
Authors: Miller Johanna L.
Published: September 2012

Further work will show whether it’s the last piece of the standard model or a sign of new physics.
Archimedes’s principle gets updated
Authors: Wilson R. Mark
Published: September 2012

When a fluid is complex, a venerable buoyancy law breaks down.
Dance of the microswimmers
Authors: Lauga Eric , Goldstein Raymond E.
Published: September 2012

From gut-inhabiting bacteria to sea-dwelling algae, microorganisms display a penchant for coordinated movement. Nonlinear dynamics and fluid mechanics can help explain the curious behavior.
Anatomy of a fall: Giovanni Battista Riccioli and the story of g
Authors: Graney Christopher M.
Published: September 2012

A centuries-old Latin text suggests that Earth’s gravitational pull was first measured not by Galileo but by a little-known Italian astronomer and priest.
Protonation state of E71 in KcsA and its role for channel collapse and inactivation
Authors: Bhate Manasi P. , McDermott Ann E.
Published: September 2012

The prototypical prokaryotic potassium channel KcsA alters its pore depending on the ambient potassium; at high potassium, it exists in a conductive form, and at low potassium, it collapses into a nonconductive structure with reduced ion occupancy. We present solid-state NMR studies of KcsA in which we test the hypothesis that an important channel-inactivation process, known as C-type inactivation, proceeds via a state similar to this collapsed state. We test this using an inactivation-resistant mutant E71A, and show that E71A is unable to collapse its pore at both low potassium and low pH, suggesting that the collapsed state is structurally similar to the inactivated state. We also show that E71A has a disordered selectivity filter. Using site-specific K
+
titrations, we detect a local change at E71 that is coupled to channel collapse at low K
+
. To gain more insight into this change, we site specifically measure the chemical shift tensors of the side-chain carboxyls of E71 and its hydrogen bond partner D80, and use the tensors to assign protonation states to E71 and D80 at high K
+
and neutral pH. Our measurements show that E71 is protonated at pH 7.5 and must have an unusually perturbed
pK
a
(> 7.5) suggesting that the change at E71 is a structural rearrangement rather than a protonation event. The results offer new mechanistic insights into why the widely used mutant KcsA–E71A does not inactivate and establish the ambient K
+
level as a means to populate the inactivated state of KcsA in a controlled way.
Homophobia in physical education and sport: The role of physical/sporting identity and attributes, authoritarian aggression, and social dominance orientation
Authors: O'Brien Kerry S. , Shovelton Heather , Latner Janet D.
Published: September 2012

We examined levels of, and reasons for, anti‐gay and anti‐lesbian prejudice (homophobia) in pre‐service physical education (PE) and non‐physical education (non‐PE) university students. Participants (N = 409; 66% female; N = 199 pre‐service physical educators) completed questionnaires assessing anti‐gay and lesbian prejudice, authoritarianism, social dominance orientation (SDO), physical/athletic identity and self‐concept, and physical attributes. ANCOVAs revealed that PE students had higher levels of anti‐gay (p = .004) and lesbian prejudice than non‐PE students (p = .008), respectively. Males reported greater anti‐gay prejudice (p < .001), but not anti‐lesbian prejudice, than females. Authoritarian aggression was positively associated with greater anti‐gay (β = .49) and lesbian prejudice (β = .37) among male participants. Among females, higher authoritarian aggression and SDO was associated with greater anti‐gay (β = .34 and β = .25, respectively) and lesbian (β = .26 and β = .16, respectively) prejudice. The physical identity‐related constructs of athletic self‐concept (β = .−15) and perceived upper body strength (β = .39) were associated with anti‐gay attitudes among male participants. Physical attractiveness (β = −.29) and upper body strength (β = .29) were also associated with male participants’ anti‐lesbian prejudice. Regression analyses showed that the differences between PE and non‐PE students in anti‐gay and lesbian prejudice were largely mediated by authoritarianism and SDO. The present study is the first to examine the relationship between investment in physical/sporting identity and attributes and anti‐gay and lesbian prejudice in PE/sport participants. In the present sample, anti‐gay and lesbian prejudice was greater in pre‐service PE students than non‐PE students, but these differences appear to be explained by differences in conservative ideological traits. Additionally, physical identity and athletic attributes based around masculine ideals also appear to contribute to this prejudice in males.
Matrices with eigenvectors in a given subspace
Authors: Ottaviani Giorgio , Sturmfels Bernd
Published: September 2012

The Kalman variety of a linear subspace in a vector space consists of all endomorphisms that possess an eigenvector in that subspace. We study the defining polynomials and basic geometric invariants of the Kalman variety.
The Advantage of Resource Queues over Spot Resource Markets: Decision Coordination in Experiments under Resource Uncertainty
Authors: Fonseca Miguel A. , Pfaff Alexander , Osgood Daniel
Published: September 2012

Farmers have to make key decisions, such as which crops to plant or whether to prepare the soil, before knowing how much water they will get. They face losses if they make costly decisions but do not receive water, and they may forego profits if they receive water without being prepared. We consider the coordination of farmers’ decisions, such as which crops to plant or whether to prepare the soil when farmers must divide an uncertain water supply. We compare ex‐ante queues (pre‐decision) to an ex‐post spot market (post‐decision & post‐rain) in experiments in rural Brazil and a university in England. Queues have greater coordination success than does the spot market.
Panel Data Estimation Techniques and Farm‐level Data Models
Authors: Platoni Silvia , Sckokai Paolo , Moro Daniele
Published: September 2012

Econometric models estimating parameters for agricultural policy analysis increasingly rely on unbalanced panels of farm‐level data. Since such models have often been estimated through simplified approaches, in this paper we show that adopting more sophisticated panel data techniques may be very important for obtaining more reliable estimates of policy parameters. We also extend the two‐stage procedure proposed by Shonkwiler and Yen (1999) and Tauchmann (2005) for the analysis of censored data to account for heteroskedasticity and correlation of the error terms of the first‐stage probit models.
FSelector: a Ruby gem for feature selection
Authors: Cheng Tiejun , Wang Yanli , Bryant Stephen H.
Published: September 2012

Summary: The FSelector package contains a comprehensive list of feature selection algorithms for supporting bioinformatics and machine learning research. FSelector primarily collects and implements the filter type of feature selection techniques, which are computationally efficient for mining large datasets. In particular, FSelector allows ensemble feature selection that takes advantage of multiple feature selection algorithms to yield more robust results. FSelector also provides many useful auxiliary tools, including normalization, discretization and missing data imputation.

Availability: FSelector, written in the Ruby programming language, is free and open-source software that runs on all Ruby supporting platforms, including Windows, Linux and Mac OS X. FSelector is available from https://rubygems.org/gems/fselector and can be installed like a breeze via the command gem install fselector. The source code is available (https://github.com/need47/fselector) and is fully documented (http://rubydoc.info/gems/fselector/frames).

Contact:  ywang@ncbi.nlm.nih.gov or bryant@ncbi.nlm.nih.gov

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Assignment of protein sequences to existing domain and family classification systems: Pfam and the PDB
Authors: Xu Qifang , Dunbrack Roland L.
Published: September 2012

Motivation: Automating the assignment of existing domain and protein family classifications to new sets of sequences is an important task. Current methods often miss assignments because remote relationships fail to achieve statistical significance. Some assignments are not as long as the actual domain definitions because local alignment methods often cut alignments short. Long insertions in query sequences often erroneously result in two copies of the domain assigned to the query. Divergent repeat sequences in proteins are often missed.

Results: We have developed a multilevel procedure to produce nearly complete assignments of protein families of an existing classification system to a large set of sequences. We apply this to the task of assigning Pfam domains to sequences and structures in the Protein Data Bank (PDB). We found that HHsearch alignments frequently scored more remotely related Pfams in Pfam clans higher than closely related Pfams, thus, leading to erroneous assignment at the Pfam family level. A greedy algorithm allowing for partial overlaps was, thus, applied first to sequence/HMM alignments, then HMM–HMM alignments and then structure alignments, taking care to join partial alignments split by large insertions into single-domain assignments. Additional assignment of repeat Pfams with weaker E-values was allowed after stronger assignments of the repeat HMM. Our database of assignments, presented in a database called PDBfam, contains Pfams for 99.4% of chains >50 residues.

Availability: The Pfam assignment data in PDBfam are available at http://dunbrack2.fccc.edu/ProtCid/PDBfam, which can be searched by PDB codes and Pfam identifiers. They will be updated regularly.

Contact: Roland.Dunbracks@fccc.edu
CSB: a Python framework for structural bioinformatics
Authors: Kalev Ivan , Mechelke Martin , Kopec Klaus O. , Holder Thomas , Carstens Simeon , Habeck Michael
Published: September 2012

Summary: Computational Structural Biology Toolbox (CSB) is a cross-platform Python class library for reading, storing and analyzing biomolecular structures with rich support for statistical analyses. CSB is designed for reusability and extensibility and comes with a clean, well-documented API following good object-oriented engineering practice.

Availability: Stable release packages are available for download from the Python Package Index (PyPI) as well as from the project’s website http://csb.codeplex.com.

Contacts:  ivan.kalev@gmail.com or michael.habeck@tuebingen.mpg.de
Rosette Tracker: An Open Source Image Analysis Tool for Automatic Quantification of Genotype Effects
Authors: De Vylder Jonas , Vandenbussche Filip , Hu Yuming , Philips Wilfried , Van Der Straeten Dominique
Published: September 2012

Image analysis of Arabidopsis (Arabidopsis thaliana) rosettes is an important nondestructive method for studying plant growth. Some work on automatic rosette measurement using image analysis has been proposed in the past but is generally restricted to be used only in combination with specific high-throughput monitoring systems. We introduce Rosette Tracker, a new open source image analysis tool for evaluation of plant-shoot phenotypes. This tool is not constrained by one specific monitoring system, can be adapted to different low-budget imaging setups, and requires minimal user input. In contrast with previously described monitoring tools, Rosette Tracker allows us to simultaneously quantify plant growth, photosynthesis, and leaf temperature-related parameters through the analysis of visual, chlorophyll fluorescence, and/or thermal infrared time-lapse sequences. Freely available, Rosette Tracker facilitates the rapid understanding of Arabidopsis genotype effects.
Characterization of the procera Tomato Mutant Shows Novel Functions of the SlDELLA Protein in the Control of Flower Morphology, Cell Division and Expansion, and the Auxin-Signaling Pathway during Fruit-Set and Development
Authors: Carrera Esther , Ruiz-Rivero Omar , Peres Lazaro Eustaquio Pereira , Atares Alejandro , Garcia-Martinez Jose Luis
Published: September 2012

procera (pro) is a tall tomato (Solanum lycopersicum) mutant carrying a point mutation in the GRAS region of the gene encoding SlDELLA, a repressor in the gibberellin (GA) signaling pathway. Consistent with the SlDELLA loss of function, pro plants display a GA-constitutive response phenotype, mimicking wild-type plants treated with GA3. The ovaries from both nonemasculated and emasculated pro flowers had very strong parthenocarpic capacity, associated with enhanced growth of preanthesis ovaries due to more and larger cells. pro parthenocarpy is facultative because seeded fruits were obtained by manual pollination. Most pro pistils had exserted stigmas, thus preventing self-pollination, similar to wild-type pistils treated with GA3 or auxins. However, Style2.1, a gene responsible for long styles in noncultivated tomato, may not control the enhanced style elongation of pro pistils, because its expression was not higher in pro styles and did not increase upon GA3 application. Interestingly, a high percentage of pro flowers had meristic alterations, with one additional petal, sepal, stamen, and carpel at each of the four whorls, respectively, thus unveiling a role of SlDELLA in flower organ development. Microarray analysis showed significant changes in the transcriptome of preanthesis pro ovaries compared with the wild type, indicating that the molecular mechanism underlying the parthenocarpic capacity of pro is complex and that it is mainly associated with changes in the expression of genes involved in GA and auxin pathways. Interestingly, it was found that GA activity modulates the expression of cell division and expansion genes and an auxin signaling gene (tomato AUXIN RESPONSE FACTOR7) during fruit-set.
Altered Starch Turnover in the Maternal Plant Has Major Effects on Arabidopsis Fruit Growth and Seed Composition
Authors: Andriotis Vasilios M.E. , Pike Marilyn J. , Schwarz Sabine L. , Rawsthorne Stephen , Wang Trevor L. , Smith Alison M.
Published: September 2012

Mature seeds of both the high-starch starch-excess1 (sex1) mutant and the almost starchless phosphoglucomutase1 mutant of Arabidopsis (Arabidopsis thaliana) have 30% to 40% less lipid than seeds of wild-type plants. We show that this is a maternal effect and is not attributable to the defects in starch metabolism in the embryo itself. Low lipid contents and consequent slow postgerminative growth are seen only in mutant embryos that develop on maternal plants with mutant phenotypes. Mutant embryos that develop on plants with wild-type starch metabolism have wild-type lipid contents and postgerminative growth. The maternal effect on seed lipid content is attributable to carbohydrate starvation in the mutant fruit at night. Fruits on sex1 plants grow more slowly than those on wild-type plants, particularly at night, and have low sugars and elevated expression of starvation genes at night. Transcript levels of the transcription factor WRINKLED1, implicated in lipid synthesis, are reduced at night in sex1 but not in wild-type seeds, and so are transcript levels of key enzymes of glycolysis and fatty acid synthesis. sex1 embryos develop more slowly than wild-type embryos. We conclude that the reduced capacity of mutant plants to convert starch to sugars in leaves at night results in low nighttime carbohydrate availability in the developing fruit. This in turn reduces the rate of development and expression of genes encoding enzymes of storage product accumulation in the embryo. Thus, the supply of carbohydrate from the maternal plant to the developing fruit at night can have an important influence on oilseed composition and on postgerminative growth.
Effect of optical activity on electro-optic measurements in crystals of the potassium dihydrogen phosphate family
Authors: Izdebski Marek
Published: September 2012

Crystals of the potassium dihydrogen phosphate family in their paraelectric phase belong to point group \overline 4 2m, which allows for natural optical activity and electric field-induced optical activity related to the linear and nonlinear electrogyration effects. This work presents a theoretical analysis of the influence of these effects on measurements of the linear, quadratic and fourth-order electro-optic coefficients. Both the polarimetric technique and a method based on Michelson interferometry are considered. A number of configurations of the light path and the electric field directions were analyzed, and it was found that the influence, when it appears, is usually negligibly small. Thus, no previously reported experimental data need a new interpretation. However, in future measurements of some effective coefficients of the quadratic electro-optic effect using the dynamic polarimetric technique, the contribution of the quadratic electrogyration may no longer be negligible after improving the resolution from 10−21to 10−22 m2 V−2. This work also shows that the quadratic electrogyration described by the β31coefficient may be decoupled from the linear and quadratic electro-optic effects in measurements performed by the polarimetric method.
Polarized neutron diffraction at a spallation source for magnetic studies
Authors: Pramanick A. , Lauter V. , Wang X.-L. , An K. , Ambaye H. , Goyette Jr R. J. , Yi J. , Gai Z. , Stoica A. D.
Published: September 2012

The availability of high-power spallation neutron sources, along with advances in the development of coupled moderators and neutron polarizers, has made it possible to use polarized neutrons on time-of-flight diffractometers forin situstudies of phenomena contributing to field-induced magnetization of a material. Different electronic and structural phenomena that contribute to the overall magnetization of a material can be studied and clearly identified with polarized neutron diffraction measurements. This article reports the first results from polarized neutron diffraction experiments on a time-of-flight instrument at a spallation source. Magnetic field-induced rotation of electron spins in an Ni–Mn–Ga single crystal was measured with polarized neutron diffraction at the MAGICS reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. The difference in intensities measured with spin-up and spin-down polarized neutrons is proportional to the field-induced magnetization of the crystal. The polarized neutron measurements indicate that the magnetic form factor for the 3delectrons of Mn in Ni–Mn–Ga is lower than the value reported earlier for an ideal spherical symmetry of electronic distribution. Future experiments for studying field-induced magnetization in materials following the current methodology are outlined.
Bis(tert-butyldimethylsilyl)(2,6-diisopropylphenyl)phosphane: the first structure of an organophosphane with twotert-butyldimethylsilyl (TBDMS) substituents
Authors: Boeré René T. , Taghavikish Mona
Published: September 2012

The title compound, C24H47PSi2, is the first organophosphane bearing twotert-butyldimethylsilyl (TBDMS) groups to be crystallographically characterized, even though TBDMS is a very popular bulky silyl group. The structure is a considerably flattened trigonal pyramid, with the sum of the C/Si—P—C/Si angles being 333.35 (6)°, which can be attributed to the steric pressure from the three bulky groups. The P—Si distances [2.2605 (6) and 2.2631 (6) Å] are normal, while the P—C distance [1.8646 (12) Å] is long (outside the s.u. values) compared with related structures. The plane of the aryl ring approximately bisects the Si—P—Si angle, quite unlike the secondary (tert-butyldimethylsilyl)(2,6-diisopropylphenyl)phosphane bearing only one TBDMS group, in which the single Si atom is perpendicular to the aryl ring. The title structure conforms closely to that predicted from B3LYP/6-31G(d) calculations, although the calculations overestimate the degree of planarity. The compound crystallizes centrosymmetrically in the space groupP\overline{1} as isolated molecules.
Instantaneous impedance evaluation of dissolution of AISI 304 stainless steel during intergranular corrosion
Authors: Arutunow Anna
Published: September 2012

Purpose

The purpose of this paper is to focus on diversification between electrical parameters determined on the basis of instantaneous impedance measurements within the activation and reactivation scan of dissolution of sensitized AISI 304 stainless steel during a proceeding intergranular corrosion process.

Design/methodology/approach

The investigations were carried out by means of dynamic electrochemical impedance spectroscopy (DEIS). DEIS measurements were conducted “on‐line” while the samples were polarized in agreement with a measurement procedure presented in the ASTM G108‐94 standard, in order to guarantee conditions equivalent with the DL‐EPR tests performed on AISI 304 stainless steel.

Findings

Performed researches revealed the advantages of the DEIS technique over standard double‐loop electrochemical potentiokinetic reactivation (DL‐EPR) tests in the field of intergranular corrosion investigations. Application of the DEIS technique made it possible to trace instantaneous changes in the examined system's impedance versus potential during the intergranular corrosion process. The form of recorded DEIS spectra and obtained distribution of measurement frequencies within the reactivation potential range were equivalent to those obtained for pure iron dissolution in sulfuric acid medium. As a result, instantaneous changes of electrical double layer capacitance and charge transfer resistance as a function of potential have been obtained in the range of activation and reactivation scans.

Originality/value

The paper provides information regarding diversification between the electrical double layer capacitance and the charge transfer resistance determined for sensitized AISI 304 stainless steel with respect to polarization conditions during the standard DL‐EPR test, which were obtained in order to evaluate the susceptibility to intergranular corrosion.
Formation process and properties of phytic acid conversion coatings on magnesium
Authors: Liu Jian‐Rui , Guo Yi‐Na , Huang Wei‐Dong
Published: September 2012

Purpose

The purpose of this paper is to investigate a chromium‐free conversion coating treatment for magnesium with phytic acid solution.

Design/methodology/approach

Pure magnesium was selected for the tests. Phytic acid solution was used as the conversion solution of surface treatment. The samples of magnesium were immersed in the solution under certain conditions to form a conversion coating on the surface of magnesium. The formation process of phytic acid conversion coating was studied by detecting the open circuit potential (OCP) and weight change of the pure magnesium for different conversion treatment times. Scanning electron microscopy (SEM) and electron energy spectrum (EDS) were used to examine the morphologies and compositions of the coatings, respectively.

Findings

The experimental results showed that the conversion coating had a multideck structure with netlike morphology, which is similar in nature to chromate conversion coatings, and was composed mainly of Mg, P, O and C. The contents of C and P and the size of the cracks in different conversion layers decreased from the external layer to the inner layer. The thickness of the conversion coating varied from 1.0μm to 15μm according to the processing parameters. The hydroxyl groups and phosphate carboxyl groups in the coating, which have similar properties to an organic paint coat, are beneficial to the combination of substrate and organic paint coating. The formation mechanism and thickness variation of the conversion coatings also are discussed.

Originality/value

The paper shows that phytic acid conversion coating could improve the electrochemical properties of magnesium and provide effective protection, which can improve the corrosion resistance of magnesium.
FeB and FeB/h‐BN based anti‐corrosive composite coatings for aluminium alloys
Authors: Dikici B. , Ozdemir I.
Published: September 2012

Purpose

The purpose of this paper is to investigate the corrosion behaviour of ferroboron (FeB) and FeB/h‐BN (hexagonal boron nitride) coatings deposited onto A383 substrates by atmospheric plasma spraying.

Design/methodology/approach

Potentiodynamic scanning (PDS) and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion susceptibilities of the composite coatings. Microstructural characterizations were carried out by using scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS).

Findings

It was observed that the coatings resisted localized corrosion in NaCl solutions and protective oxide films on the coatings repaired themselves over the corrosion potential. Hexagonal‐BN is not only a limiting factor in the corrosion of the FeB based coatings. The corrosion morphologies of the coatings are strictly dependent on pores and micro‐cracks in the coating.

Practical implications

The iron‐based borides act as solid lubricants and have a positive influence on tribological properties such as hardness, friction and corrosion of the coating.

Originality/value

Knowledge of the effects of FeB on the corrosion behaviour of thermal spray coatings is still incomplete and this is the most important obstacle to the widespread use of the coatings in engineering applications. The paper reports electrochemical test results of the coatings and discusses the morphologic effects of h‐BN on the corrosion behaviour.
Corporate social responsibility: a study of savings banks
Authors: Jesús Barroso María , Galera Clementina , Valero Víctor , Mercedes Galán María
Published: September 2012

Purpose

Society's concern about issues related to development aid to underdeveloped countries has grown significantly in recent years. The gross inequalities between North and South, constant conflicts, political crises, and natural disasters have sensitized society to the urgent need to help these depressed areas. The objective of the present study is to examine the role Spain's savings banks play in international cooperation and development as a field that society and the general public see as ever more crucial.

Design/methodology/approach

The paper describes an exploratory analysis of the interventions carried out by all Spain's savings banks during 2009.

Findings

The results of this exploratory study reflect an increasingly relevant role of these savings banks in cooperation for development, mainly due to pressure from their customers and from society in general. They also show the importance of so‐called “Works in collaboration”, mainly with non‐governmental organizations/non‐governmental development organizations, in designing and implementing corporate social responsibility programs.

Originality/value

Much of the value of the present work is because of the lack of previous studies focused specifically on analyzing the role of Spanish savings banks in the field of cooperation for development. Its originality also lies in its proposing new courses of action in this area to improve that role.
A purchase intention model for foreign banks within Indonesia
Authors: Muchtar Fatimah , Kingshott Russel P.J. , Wong David , Laksamana Patria
Published: September 2012

Purpose

This paper aims to present a conceptual model that highlights the complexities associated with foreign banks wishing to operate with the Indonesian marketplace.

Design/methodology/approach

The paper is conceptual in nature and draws upon the marketing literature and theory to present a number of propositions.

Findings

The paper melds key international marketing constructs by positing that Indonesian consumers using foreign banks yield utilitarian, hedonistic and symbolic benefits. These underlying consumer outcomes are modeled into variables likely to impact purchase intentions.

Research limitations/implications

This paper represents the first attempt to conceptualize the many challenges facing foreign banks operating within an Indonesian setting. As Indonesia has a diverse range of cultures and values systems the model highlights the considerations associated with operating in such a diverse country.

Practical implications

A number of important implications are presented for bank decision makers operating within Indonesia.

Originality/value

A conceptual model is presented and the paper suggests a future research agenda applicable to both the Indonesian and wider banking context.
Market‐creating service innovation: verification and its associations with new service development and customer involvement
Authors: Cheng Colin C. , Chen Ja‐Shen , Tai Tsou Hun
Published: September 2012

Purpose

The present study aims to develop a measure of the market‐creating service innovation (MCSI) proposed by Berry et al., verify the typology, identify the relationship between MCSI and each new service development (NSD) stage, and assess the degree to which the role of customers involved in each NSD stage contributes to each type of MCSI.

Design/methodology/approach

A mail survey was sent to service companies in Taiwan, the target respondents being senior managers with experience in developing successful new services in the past three years. A total of 179 usable questionnaires were collected, resulting in a respondent rate of 21.2 per cent. The responses covered a wide range of service industries.

Findings

The present study confirms that the four MCSIs proposed by Berry et al. do indeed exist in practice. The degree of association between each NSD stage and each type of MCSI varies according to MCSI type. The statistical weights for customers involved in each type of MCSI are also different.

Research limitations/implications

This study extends a theoretical mechanism of NSD that customers indeed contribute to service innovation, but their involvement varies depending on the characteristics of the service innovation.

Practical implications

Utilizing a new scale of MCSI, service providers can evaluate what types of MCSI are a better fit for their business.

Originality/value

This study provides a better understanding of MCSI, which helps service providers to properly allocate their limited resources. In addition, this study clarifies the degree to which the values of customer involvement in NSD contribute to MCSI.
The impact of unprofitable customer abandonment on current customers' exit, voice, and loyalty intentions: an empirical analysis
Authors: Haenlein Michael , Kaplan Andreas M.
Published: September 2012

Purpose

The management of unprofitable customer relationships and particularly their abandonment is a topic that has received increasing interest among practitioners and researchers over recent years. Within this manuscript, the authors aim to analyze the impact of unprofitable customer abandonment on the abandoning firm's current customers, specifically their exit, voice, and loyalty intentions toward the abandoning firm.

Design/methodology/approach

The study is based on an online experiment conducted among 385 US customers. Respondents were allocated randomly to one of ten conditions (five levels of tie strength x two types of abandonment strategy) and exposed to a scenario describing a customer abandonment decision implemented by a mobile phone provider. The resulting data were analyzed using a combination of analysis of variance (ANOVA) and structural equation modeling.

Findings

The study shows that current customers are significantly more likely to respond actively to unprofitable customer abandonment (exit/voice) than passively through silence and loyalty. Additionally, it shows that increasing satisfaction or switching cost among current customers are unlikely to limit the potential negative consequences of unprofitable customer abandonment. The only variable that drives the choice between exit, voice, and loyalty is the perceived attractiveness of the best alternative relationship.

Originality/value

This work analyzes for the first time how existing customers that the firm would like to retain react toward the news that the company proactively terminates unprofitable customer relationships. Therefore, insight is provided into the likely cost associated with unprofitable customer abandonment – a question that has not been the subject of any empirical study as of today.
Voluntary corporate governance disclosures by post‐Apartheid South African corporations
Authors: Ntim Collins G. , Opong Kwaku K. , Danbolt Jo , Thomas Dennis A.
Published: September 2012

Purpose

The purpose of this paper is to investigate as to whether post‐Apartheid South African (SA) listed corporations voluntarily comply with and disclose recommended good corporate governance (CG) practices and, if so, the major factors that influence such voluntary CG disclosure behaviour.

Design/methodology/approach

The paper constructs a broad voluntary CG disclosure index containing 50 CG provisions from the 2002 King Report using a sample of 169 SA listed corporations from 2002 to 2006. The authors also conduct regression analysis to identify the main drivers of voluntary CG disclosure.

Findings

The results suggest that while compliance with, and disclosure of, good CG practices varies substantially among the sampled companies, CG standards have generally improved over the five‐year period examined. The authors also find that block ownership is negatively associated with voluntary CG disclosure, while board size, audit firm size, cross‐listing, the presence of a CG committee, government ownership and institutional ownership are positively related to voluntary CG disclosure.

Practical implications

These findings have important implications for policy‐makers and regulators. Evidence of improving CG standards implies that efforts by various stakeholders at improving CG standards in SA companies have had some positive impact on CG practices of SA firms. However, the substantial variation in the levels of compliance implies that enforcement may need to be strengthened further.

Originality/value

There is a dearth of evidence on the level of compliance with the King Report. This study fills this gap by providing evidence for the first time on the level of compliance achieved, as well as contributing generally to the literature on compliance with codes of good governance and voluntary disclosure.
The determinants of board meetings: evidence from categorical analysis
Authors: Al‐Najjar Basil
Published: September 2012

Purpose

The purpose of this paper is to investigate the determinants of the frequency of board meetings as an index for board activity including their monitoring role.

Design/methodology/approach

The research sample is composed of 120 UK firms based on their market capitalization for the period from 2003 to 2008. The study applies multinomial logistic modelling and conditional logistic modelling to investigate the frequency of board meetings.

Findings

The study finds that board size and structure are positively related to the frequency of board meetings. In addition, a negative impact of audit committee diligence on the frequency board meetings is reported. The study finds no evidence that the frequency of board meetings are reduced when there is a CEO duality. Finally, the results show that firm size, leverage, free cash flows, and Tobin's Q have an impact on the frequency of board meetings.

Practical implications

This study shows the factors that affect the board effectiveness in the UK, namely that board meetings, board composition, and board size, are key indicators for good internal governance practices and, in turn, enhance board monitoring activities.

Originality/value

The research offers the first major study to examine the determinants of the frequency of board meetings in UK non‐financial firms. The paucity of the UK literature regarding board effectiveness in the UK reinforces the empirical importance of the results for researchers, managers, and UK policy makers.
May foreign benefits plans invest in new issues under FINRA Rules 5130 and 5131
Authors: Francis Samuel
Published: September 2012

Purpose

The purpose of this article is to analyze whether and how employee benefits plans established in foreign jurisdictions may participate in initial equity public offerings in the USA in compliance with the Financial Industry Regulatory Authority's rules restricting the sale and allocation of such offerings by registered broker‐dealers.

Design/methodology/approach

The article explains the relevant rules and how they affect benefits plans, examines the regulatory guidance specifically pertaining to foreign plans and offers some practical considerations.

Findings

Foreign benefits plans are currently accorded some, albeit limited, means to comply with the rules.

Originality/value

The article presents practical analysis of a particular yet common issue from a financial services lawyer experienced in this area.