bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of SiC semiconductors switching transition speed on insulation health state monitoring of traction machines
Authors: Zoeller Clemens , Vogelsberger Markus A. , Wolbank Thomas M. , Ertl Hans
Published: July 2016

In modern traction propulsion applications, voltage source inverter (VSI) fed traction motors today operate very close to borderline conditions. With new emerging semiconductor technologies, higher inverter switching frequencies will be possible and high inverter dv/dt‐rates appear, resulting in transient overvoltages at the machine which increase the stress on the insulation system and lead to insulation degradation. Thus, insulation condition monitoring is getting more and more important to ensure a safe and reliable operation of traction motors in trains and locomotives, trams and so on. This study proposes an online insulation monitoring approach that is able to detect incipient insulation defects by evaluation of the motor transient current response on voltage pulses injected by standard inverter switching. Experimental results of this concept are obtained with tests on a 1.4 MW induction machine for railway application. Additionally, the influence of different dv/dt‐rates up to 20 kV/µs on the monitoring performance is verified using a VSI‐inverter equipped with SiC semiconductors.
Ambiguous Encounters, Uncertain Foetuses: Women's Experiences of Obstetric Ultrasound
Authors: Stephenson Niamh , McLeod Kim , Mills Catherine
Published: July 2016

We examine pregnant women's experiences with routinised obstetric ultrasound as entailed in their antenatal care during planned pregnancies. This paper highlights the ambiguity of ultrasound technology in the constitution of maternal–foetal connections. Our analysis focusses on Australian women's experiences of the ontological, aesthetic and epistemological ambiguities afforded by ultrasound. We argue that these ambiguities offer possibilities for connecting to the foetus in ways that maintain a kind of unknowability; they afford an openness and ethical responsiveness irrespective of the future of the foetus. This suggests that elucidating women's experience has implications for theorising ethics across maternal–foetal relations and, more specifically, for the ‘moral pioneering’ (Rapp, 2000) that reproductive technologies can demand of women. Moral pioneering cannot be reduced to moments or processes of decision-making; it must allow for greater recognition of the affective commitments entailed in and incited by ultrasound. Furthermore, focussing on experiences of the ambiguity of ultrasound allows for understanding the ways in which affectivity circulates across domains commonly understood as medical or social, public or private. In doing so, it contributes to undermining a series of tensions that currently shape feminist analysis of obstetric ultrasound, often at the expense of the experience of women.
Spin-wave thermal population as temperature probe in magnetic tunnel junctions
Authors: Le Goff A. , Nikitin V. , Devolder T.
Published: July 2016

We study whether a direct measurement of the absolute temperature of a Magnetic Tunnel Junction (MTJ) can be performed using the high frequency electrical noise that it delivers under a finite voltage bias. Our method includes quasi-static hysteresis loop measurements of the MTJ, together with the field-dependence of its spin wave noise spectra. We rely on an analytical modeling of the spectra by assuming independent fluctuations of the different sub-systems of the tunnel junction that are described as macrospin fluctuators. We illustrate our method on perpendicularly magnetized MgO-based MTJs patterned in 50 × 100 nm2 nanopillars. We apply hard axis (in-plane) fields to let the magnetic thermal fluctuations yield finite conductance fluctuations of the MTJ. Instead of the free layer fluctuations that are observed to be affected by both spin-torque and temperature, we use the magnetization fluctuations of the sole reference layers. Their much stronger anisotropy and their much heavier damping render them essentially immune to spin-torque. We illustrate our method by determining current-induced heating of the perpendicularly magnetized tunnel junction at voltages similar to those used in spin-torque memory applications. The absolute temperature can be deduced with a precision of ±60 K, and we can exclude any substantial heating at the spin-torque switching voltage.
The allosteric switching mechanism in bacteriophage MS2
Authors: Perkett Matthew R. , Mirijanian Dina T. , Hagan Michael F.
Published: July 2016

We use all-atom simulations to elucidate the mechanisms underlying conformational switching and allostery within the coat protein of the bacteriophage MS2. Assembly of most icosahedral virus capsids requires that the capsid protein adopts different conformations at precise locations within the capsid. It has been shown that a 19 nucleotide stem loop (TR) from the MS2 genome acts as an allosteric effector, guiding conformational switching of the coat protein during capsid assembly. Since the principal conformational changes occur far from the TR binding site, it is important to understand the molecular mechanism underlying this allosteric communication. To this end, we use all-atom simulations with explicit water combined with a path sampling technique to sample the MS2 coat protein conformational transition, in the presence and absence of TR-binding. The calculations find that TR binding strongly alters the transition free energy profile, leading to a switch in the favored conformation. We discuss changes in molecular interactions responsible for this shift. We then identify networks of amino acids with correlated motions to reveal the mechanism by which effects of TR binding span the protein. We find that TR binding strongly affects residues located at the 5-fold and quasi-sixfold interfaces in the assembled capsid, suggesting a mechanism by which the TR binding could direct formation of the native capsid geometry. The analysis predicts amino acids whose substitution by mutagenesis could alter populations of the conformational substates or their transition rates.
A digital matched filter for reverse time chaos
Authors: Bailey J. Phillip , Beal Aubrey N. , Dean Robert N. , Hamilton Michael C.
Published: July 2016

The use of reverse time chaos allows the realization of hardware chaotic systems that can operate at speeds equivalent to existing state of the art while requiring significantly less complex circuitry. Matched filter decoding is possible for the reverse time system since it exhibits a closed form solution formed partially by a linear basis pulse. Coefficients have been calculated and are used to realize the matched filter digitally as a finite impulse response filter. Numerical simulations confirm that this correctly implements a matched filter that can be used for detection of the chaotic signal. In addition, the direct form of the filter has been implemented in hardware description language and demonstrates performance in agreement with numerical results.
Unraveling wall conditioning effects on plasma facing components in NSTX-U with the Materials Analysis Particle Probe (MAPP)
Authors: Bedoya F. , Allain J. P. , Kaita R. , Skinner C. H. , Buzi L. , Koel B. E.
Published: July 2016

A novel Plasma Facing Components (PFCs) diagnostic, the Materials Analysis Particle Probe (MAPP), has been recently commissioned in the National Spherical Torus Experiment Upgrade (NSTX-U). MAPP is currently monitoring the chemical evolution of the PFCs in the NSTX-U lower divertor at 107 cm from the tokamak axis on a day-to-day basis. In this work, we summarize the methodology that was adopted to obtain qualitative and quantitative descriptions of the samples chemistry. Using this methodology, we were able to describe all the features in all our spectra to within a standard deviation of ±0.22 eV in position and ±248 s−1 eV in area. Additionally, we provide an example of this methodology with data of boronized ATJ graphite exposed to NSTX-U plasmas.
Photoelectron imaging spectroscopy of niobium mononitride anion NbN−
Authors: Berkdemir Cuneyt , Gunaratne K. Don Dasitha , Cheng Shi-Bo , Castleman A. W.
Published: July 2016

In this gas-phase photoelectron spectroscopy study, we present the electron binding energy spectrum and photoelectron angular distributions of NbN− by the velocity-map imaging technique. The electron binding energy of NbN− is measured to be 1.42 ± 0.02 eV from the X band maximum which defines the 0-0 transition between ground states of anion and neutral. Theoretical binding energies which are the vertical and adiabatic detachment energies are computed by density functional theory to compare them with experiment. The ground state of NbN− is assigned to the 2Δ3/2 state and then the electronic transitions originating from this state into X3ΔΩ (Ω = 1-3), a1Δ2, A3Σ1−, and b1Σ0+ states of NbN are reported to interpret the spectral features. As a prospective study for catalytic materials, spectral features of NbN− are compared with those of isovalent ZrO− and Pd−.
Quantitative resonant soft x-ray reflectivity of ultrathin anisotropic organic layers: Simulation and experiment of PTCDA on Au
Authors: Capelli R. , Mahne N. , Koshmak K. , Giglia A. , Doyle B. P. , Mukherjee S. , Nannarone S. , Pasquali L.
Published: July 2016

Resonant soft X-ray reflectivity at the carbon K edge, with linearly polarized light, was used to derive quantitative information of film morphology, molecular arrangement, and electronic orbital anisotropies of an ultrathin 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) film on Au(111). The experimental spectra were simulated by computing the propagation of the electromagnetic field in a trilayer system (vacuum/PTCDA/Au), where the organic film was treated as an anisotropic medium. Optical constants were derived from the calculated (through density functional theory) absorption cross sections of the single molecule along the three principal molecular axes. These were used to construct the dielectric tensor of the film, assuming the molecules to be lying flat with respect to the substrate and with a herringbone arrangement parallel to the substrate plane. Resonant soft X-ray reflectivity proved to be extremely sensitive to film thickness, down to the single molecular layer. The best agreement between simulation and experiment was found for a film of 1.6 nm, with flat laying configuration of the molecules. The high sensitivity to experimental geometries in terms of beam incidence and light polarization was also clarified through simulations. The optical anisotropies of the organic film were experimentally determined and through the comparison with calculations, it was possible to relate them to the orbital symmetry of the empty electronic states.
“Virtual IED sensor” at an rf-biased electrode in low-pressure plasma
Authors: Bogdanova M. A. , Lopaev D. V. , Zyryanov S. M. , Rakhimov A. T.
Published: July 2016

Energy distribution and the flux of the ions coming on a surface are considered as the key-parameters in anisotropic plasma etching. Since direct ion energy distribution (IED) measurements at the treated surface during plasma processing are often hardly possible, there is an opportunity for virtual ones. This work is devoted to the possibility of such indirect IED and ion flux measurements at an rf-biased electrode in low-pressure rf plasma by using a “virtual IED sensor” which represents “in-situ” IED calculations on the absolute scale in accordance with a plasma sheath model containing a set of measurable external parameters. The “virtual IED sensor” should also involve some external calibration procedure. Applicability and accuracy of the “virtual IED sensor” are validated for a dual-frequency reactive ion etching (RIE) inductively coupled plasma (ICP) reactor with a capacitively coupled rf-biased electrode. The validation is carried out for heavy (Ar) and light (H2) gases under different discharge conditions (different ICP powers, rf-bias frequencies, and voltages). An EQP mass-spectrometer and an rf-compensated Langmuir probe (LP) are used to characterize plasma, while an rf-compensated retarded field energy analyzer (RFEA) is applied to measure IED and ion flux at the rf-biased electrode. Besides, the pulsed selfbias method is used as an external calibration procedure for ion flux estimating at the rf-biased electrode. It is shown that pulsed selfbias method allows calibrating the IED absolute scale quite accurately. It is also shown that the “virtual IED sensor” based on the simplest collisionless sheath model allows reproducing well enough the experimental IEDs at the pressures when the sheath thickness s is less than the ion mean free path λi (s < λi). At higher pressure (when s > λi), the difference between calculated and experimental IEDs due to ion collisions in the sheath is observed in the low energy range. The effect of electron impact ionization in the sheath on the origin and intensity of low-energy peaks in IED is discussed compared to ion charge-exchange collisions. Obviously, the extrapolation of the “virtual IED sensor” approach to higher pressures requires developing some other sheath models, taking into account both ion and electron collisions and probably including even a model of the whole plasma volume instead of plasma sheath one.
Computationally efficient characterization of potential energy surfaces based on fingerprint distances
Authors: Schaefer Bastian , Goedecker Stefan
Published: July 2016

An analysis of the network defined by the potential energy minima of multi-atomic systems and their connectivity via reaction pathways that go through transition states allows us to understand important characteristics like thermodynamic, dynamic, and structural properties. Unfortunately computing the transition states and reaction pathways in addition to the significant energetically low-lying local minima is a computationally demanding task. We here introduce a computationally efficient method that is based on a combination of the minima hopping global optimization method and the insight that uphill barriers tend to increase with increasing structural distances of the educt and product states. This method allows us to replace the exact connectivity information and transition state energies with alternative and approximate concepts. Without adding any significant additional cost to the minima hopping global optimization approach, this method allows us to generate an approximate network of the minima, their connectivity, and a rough measure for the energy needed for their interconversion. This can be used to obtain a first qualitative idea on important physical and chemical properties by means of a disconnectivity graph analysis. Besides the physical insight obtained by such an analysis, the gained knowledge can be used to make a decision if it is worthwhile or not to invest computational resources for an exact computation of the transition states and the reaction pathways. Furthermore it is demonstrated that the here presented method can be used for finding physically reasonable interconversion pathways that are promising input pathways for methods like transition path sampling or discrete path sampling.
Structural transition, subgap states, and carrier transport in anion-engineered zinc oxynitride nanocrystalline films
Authors: Xian Fenglin , Ye Jiandong , Gu Shulin , Tan Hark Hoe , Jagadish Chennupati
Published: July 2016

In this work, anion alloying is engineered in ZnON nanocrystalline films, and the resultant evolution of the structural transition, subgap states, and carrier transport is investigated. A broad distribution of sub-gap states above the valence band maximum is introduced by nitrogen due to the hybridization of N 2p and O 2p orbitals. The phase transition from partially amorphous states to full crystallinity occurs above a characteristic growth temperature of 100 °C, and the localized states are suppressed greatly due to the reduction of nitrogen composition. The electronic properties are dominated by grain boundary scattering and electron transport across boundary barriers through thermal activation at band edge states at high temperatures. The conductivity below 130 K exhibits a weak temperature dependence, which is a signature of variable-range hopping conduction between localized states introduced by nitrogen incorporation.
A theoretical study for parallel electric field in nonlinear magnetosonic waves in three-component plasmas
Authors: Toida Mieko
Published: July 2016

The electric field parallel to the magnetic field in nonlinear magnetosonic waves in three component plasmas (two-ion-species plasma and electron-positron-ion plasma) is theoretically studied based on a three-fluid model. In a two-ion-species plasma, a magnetosonic mode has two branches, high-frequency mode and low-frequency mode. The parallel electric field E∥ and its integral along the magnetic field, F=−∫E∥ds, in the two modes propagating quasiperpendicular to the magnetic field are derived as functions of the wave amplitude ϵ and the density ratio and cyclotron frequency ratio of the two ion species. The theory shows that the magnitude of F in the high-frequency-mode pulse is much greater than that in the low-frequency-mode pulse. Theoretical expressions for E∥ and F in nonlinear magnetosonic pulses in an electron-positron-ion plasma are also obtained under the assumption that the wave amplitudes are in the range of (me/mi)1/2<ϵ<1, where me/mi is the electron to ion mass ratio.
Kinetic models of magnetic flux ropes observed in the Earth magnetosphere
Authors: Vinogradov A. A. , Vasko I. Y. , Artemyev A. V. , Yushkov E. V. , Petrukovich A. A. , Zelenyi L. M.
Published: July 2016

Magnetic flux ropes (MFR) are universal magnetoplasma structures (similar to cylindrical screw pinches) formed in reconnecting current sheets. In particular, MFR with scales from about the ion inertial length to MHD range are widely observed in the Earth magnetosphere. Typical MFR have force-free configuration with the axial magnetic field peaking on the MFR axis, whereas bifurcated MFR with an off-axis peak of the axial magnetic field are observed as well. In the present paper, we develop kinetic models of force-free and bifurcated MFR and determine consistent ion and electron distribution functions. The magnetic field configuration of the force-free MFR represents well-known Gold-Hoyle MFR (uniformly twisted MFR). We show that bifurcated MFR are characterized by the presence of cold and hot current-carrying electrons. The developed models are capable to describe MFR observed in the Earth magnetotail as well as MFR recently observed by Magnetospheric Multiscale Mission at the Earth magnetopause.
Effects of anisotropic interaction-induced properties of hydrogen-rare gas compounds on rototranslational Raman scattering spectra: Comprehensive theoretical and numerical analysis
Authors: Głaz Waldemar , Bancewicz Tadeusz , Godet Jean-Luc , Gustafsson Magnus , Haskopoulos Anastasios , Maroulis George
Published: July 2016

A comprehensive study is presented of many aspects of the depolarized anisotropic collision induced (CI) component of light scattered by weakly bound compounds composed of a dihydrogen molecule and a rare gas (Rg) atom, H2–Rg. The work continues a series of earlier projects marking the revival of interest in linear light scattering following the development of new highly advanced tools of quantum chemistry and other theoretical, computational, and experimental means of spectral analyses. Sophisticated ab initio computing procedures are applied in order to obtain the anisotropic polarizability component’s dependence on the H2–Rg geometry. These data are then used to evaluate the CI spectral lines for all types of Rg atoms ranging from He to Xe (Rn excluded). Evolution of the properties of CI spectra with growing polarizability/masses of the complexes studied is observed. Special attention is given to the heaviest, Kr and Xe based, scatterers. The influence of specific factors shaping the spectral lines (e.g., bound and metastable contribution, potential anisotropy) is discussed. Also the share of pressure broadened allowed rotational transitions in the overall spectral profile is taken into account and the extent to which it is separable from the pure CI contribution is discussed. We finish with a brief comparison between the obtained results and available experimental data.
Note: An explicit solution of the optimal superposition and Eckart frame problems
Authors: Cioslowski Jerzy
Published: July 2016

Attention is called to an explicit solution of both the optimal superposition and Eckart frame problems that requires neither matrix diagonalization nor quaternion algebra. A simple change in one variable that enters the expression for the solution matrix T allows for selection of T representing either a proper rotation or a more general orthogonal transformation. The issues concerning the use of these alternative selections and the equivalence of the two problems are addressed.
Nonlinear coherent structures of Alfvén wave in a collisional plasma
Authors: Jana Sayanee , Ghosh Samiran , Chakrabarti Nikhil
Published: July 2016

The Alfvén wave dynamics is investigated in the framework of two-fluid approach in a compressible collisional magnetized plasma. In the finite amplitude limit, the dynamics of the nonlinear Alfvén wave is found to be governed by a modified Korteweg-de Vries Burgers equation (mKdVB). In this mKdVB equation, the electron inertia is found to act as a source of dispersion, and the electron-ion collision serves as a dissipation. The collisional dissipation is eventually responsible for the Burgers term in mKdVB equation. In the long wavelength limit, this weakly nonlinear Alfvén wave is shown to be governed by a damped nonlinear Schrödinger equation. Furthermore, these nonlinear equations are analyzed by means of analytical calculation and numerical simulation to elucidate the various aspects of the phase-space dynamics of the nonlinear wave. Results reveal that nonlinear Alfvén wave exhibits the dissipation mediated shock, envelope, and breather like structures. Numerical simulations also predict the formation of dissipative Alfvénic rogue wave, giant breathers, and rogue wave holes. These results are discussed in the context of the space plasma.
Magnetization ground state and reversal modes of magnetic nanotori
Authors: Vojkovic Smiljan , Nunez Alvaro S. , Altbir Dora , Carvalho-Santos Vagson L.
Published: July 2016

In this work, and by means of micromagnetic simulations, we study the magnetic properties of toroidal nanomagnets. The magnetization ground state for different values of the aspect ratio between the toroidal and polar radii of the nanotorus has been obtained. Besides, we have shown that the vortex and the in-plane single domain states can appear as ground states for different ranges of the aspect ratio, while a single domain state with an out-of-plane magnetization is not observed. The hysteresis curves are also obtained, evidencing the existence of two reversal modes depending on the geometry: a vortex mode and a coherent rotation. A comparison between toroidal and cylindrical nanoparticles has been performed evidencing that nanotori can accommodate a vortex as the ground state for smaller volume than cylindrical nanorings.
Experimental determination of the dynamic tensile strength of liquid Sn, Pb, and Zn
Authors: Zaretsky E. B.
Published: July 2016

An experimental technique capable of determining the dynamic tensile (spall) strength of metals in the liquid state is described. Relying on this technique, spall data on samples of tin, lead, and zinc pre-heated to 20 K above their melting points were obtained. It is found that the spall strength of the metals is low, 40–100 MPa, but not zero and is, seemingly, affected by material purity and by the rate of tensile deformation preceding sample spallation.
A high efficiency Ku-band radial line relativistic klystron amplifier
Authors: Dang Fangchao , Zhang Xiaoping , Zhong Huihuang , Zhang Jun , Ju Jinchuan
Published: July 2016

To achieve the gigawatt-level microwave amplification output at Ku-band, a radial-line relativistic klystron amplifier is proposed and investigated in this paper. Different from the annular electron beam in conventional axial relativistic klystron amplifiers, a radial-radiated electron beam is employed in this proposed klystron. Owing to its radially spreading speciality, the electron density and space charge effect are markedly weakened during the propagation in the radial line drift tube. Additionally, the power capacity, especially in the output cavity, is enhanced significantly because of its large volume, which is profitable for the long pulse operation. Particle-in-cell simulation results demonstrate that a high power microwave with the power of 3 GW and the frequency of 14.25 GHz is generated with a 500 kV, 12 kA electron beam excitation and the 30 kW radio-frequency signal injection. The power conversion efficiency is 50%, and the gain is about 50 dB. Meanwhile, there is insignificant electron beam self-excitation in the proposed structure by the adoption of two transverse electromagnetic reflectors. The relative phase difference between the injected signals and output microwaves keeps stable after the amplifier saturates.
Electrical, optical, and magnetic properties of Sn doped α-Ga2O3 thin films
Authors: Chikoidze E. , von Bardeleben H. J. , Akaiwa K. , Shigematsu E. , Kaneko K. , Fujita S. , Dumont Y.
Published: July 2016

We investigated the effect of Sn doping on the optical, electrical, and magneto transport properties of epitaxial α-Ga2O3 thin films grown by mist-Chemical Vapour Deposition. Sn introduces a shallow donor level at ∼0.1 eV and has a high solubility allowing doping up to 1020 cm−3. The lowest obtained resistivity of the films is 2.0 × 10−1 Ω cm. The Sn doped films with a direct band gap of 5.1 eV remain transparent in the visible and UV range. The electrical conduction mechanism and magneto-transport have been investigated for carrier concentrations below and above the insulator-metal transition. The magnetic properties of the neutral Sn donor and the conduction electrons have been studied by electron spin resonance spectroscopy. A spin S = 1/2 state and C3V point symmetry of the neutral Sn donor is found to be in good agreement with the model of a simple SnGa center.
Direct measurement of vacancy relaxation by dilatometry
Authors: Kotzurek Jaromir A. , Steyskal Eva-Maria , Oberdorfer Bernd , Hohenwarter Anton , Pippan Reinhard , Sprengel Wolfgang , Würschum Roland
Published: July 2016

A model is proposed for directly determining the volume of lattice vacancies by means of dilatometric measurements of the anisotropic irreversible length change which occurs during annealing of lattice vacancies at grain boundaries of shape-anisotropic crystallites. The model is tested using nanocrystalline Ni after the high-pressure torsion deformation which exhibits excess concentration of lattice vacancies and elongated crystallite shape. Different length changes upon annealing parallel and perpendicular to the elongation axis occur from which a vacancy volume can be derived.
Suppression of phase mixing in drift-kinetic plasma turbulence
Authors: Parker J. T. , Highcock E. G. , Schekochihin A. A. , Dellar P. J.
Published: July 2016

Transfer of free energy from large to small velocity-space scales by phase mixing leads to Landau damping in a linear plasma. In a turbulent drift-kinetic plasma, this transfer is statistically nearly canceled by an inverse transfer from small to large velocity-space scales due to “anti-phase-mixing” modes excited by a stochastic form of plasma echo. Fluid moments (density, velocity, and temperature) are thus approximately energetically isolated from the higher moments of the distribution function, so phase mixing is ineffective as a dissipation mechanism when the plasma collisionality is small.
Size effects on negative thermal expansion in cubic ScF3
Authors: Yang C. , Tong P. , Lin J. C. , Guo X. G. , Zhang K. , Wang M. , Wu Y. , Lin S. , Huang P. C. , Xu W. , Song W. H. , Sun Y. P.
Published: July 2016

Scandium trifluoride (ScF3), adopting a cubic ReO3-type structure at ambient pressure, undergoes a pronounced negative thermal expansion (NTE) over a wide range of temperatures (10 K–1100 K). Here, we report the size effects on the NTE properties of ScF3. The magnitude of NTE is reduced with diminishing the crystal size. As revealed by the specific heat measurement, the low-energy phonon vibrations which account for the NTE behavior are stiffened as the crystal size decreases. With decreasing the crystal size, the peaks in high-energy X-ray pair distribution function (PDF) become broad, which cannot be illuminated by local symmetry breaking. Instead, the broadened PDF peaks are strongly indicative of enhanced atomic displacements which are suggested to be responsible for the stiffening of NTE-related lattice vibrations. The present study suggests that the NTE properties of ReO3-type and other open-framework materials can be effectively adjusted by controlling the crystal size.
Thermoelectric properties of MBE-grown HgCdTe-based superlattices from 100K to 300K
Authors: Zhang Kejia , Yadav Abhishek , Shao Lei , Bommena Ramana , Zhao Jun , Velicu Silviu , Pipe Kevin P.
Published: July 2016

We report on the thermoelectric properties of long-period HgCdTe superlattices (MCT SLs) from cryogenic temperature to room temperature. We find that the thermal conductivity is lower than the alloy value especially at low temperatures, the electrical conductivity is similar to that of alloy films, and the Seebeck coefficient is comparable to other SLs. Calculations based on Rytov’s elastic model show that the phonon group velocity is reduced due to folding by more than a factor of two relative to its value in bulk CdTe or HgTe. Thermal conductivity is found to be relatively constant over a wide range of temperatures.
Diamond magnetometry of Meissner currents in a superconducting film
Authors: Alfasi Nir , Masis Sergei , Shtempluck Oleg , Kochetok Valleri , Buks Eyal
Published: July 2016

We study magnetic field penetration into a thin film made of a superconducting niobium. Imaging of magnetic field is performed by optically detecting magnetic resonances of negatively charged nitrogen-vacancy defects inside a single crystal diamond, which is attached to the niobium film under study. The experimental results are compared with theoretical predictions based on the critical state model, and good agreement is obtained.
Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop
Authors: Tan Huanshu , Diddens Christian , Lv Pengyu , Kuerten J. G. M. , Zhang Xuehua , Lohse Detlef
Published: July 2016

Significance

The evaporation of an Ouzo droplet is a daily life phenomenon, but the outcome is amazingly rich and unexpected: Here we reveal the four different phases of its life with phase transitions in-between and the physics that govern this phenomenon. The Ouzo droplet may be seen as a model system for any ternary mixture of liquids with different volatilities and mutual solubilities. Our work may open up numerous applications in (medical) diagnostics and in technology, such as coating or for the controlled deposition of tiny amounts of liquids, printing of light-emitting diode (LED) or organic LED devices, or phase separation on a submicron scale.
Spiritual leadership as a model for performance excellence: a study of Baldrige award recipients
Authors: Fry Louis W. , Latham John R. , Clinebell Sharon K. , Krahnke Keiko
Published: July 2016

Issues regarding workplace spirituality and spiritual leadership have received increased attention in the organizational sciences. The implications of workplace spirituality for leadership theory, research, and practice make this a fast growing area of new research and inquiry by scholars. The purpose of this research was to test a dynamic relationship between the revised spiritual leadership model, consisting of inner life, spiritual leadership (comprised of hope/faith, vision, and altruistic love), spiritual well-being (i.e. a sense of calling and membership), and key organizational outcomes in a sample of Baldrige Performance Excellence Program award recipients. With structural equation modeling, results revealed a positive and significant relationship between spiritual leadership and several outcomes considered essential for performance excellence, including organizational commitment, unit productivity, and life satisfaction. These relationships were explained or mediated by spiritual well-being. Implications for research and practice are discussed.
Assessing the SDGs from the standpoint of eco-social policy: using the SDGs subversively
Authors: Koehler Gabriele
Published: July 2016

The UN 2030 Agenda on Sustainable Development impresses with its ambition of transformation, and because it has succeeded in marrying economic, social and environmental goals. This article looks at two interrelated questions. It asks whether and to what extent the Agenda's goals are transformative, but finds numerous omissions and clashes. It also seeks to examine whether the Agenda refers to eco-social policy. Two schools of thought are examined. Both critical theory and sufficiency economics propose shifts in norms, policies and practice – and argue for a “hierarchy reversal”, whereby social and climate justice goals override the economic rationale. The article concludes with a case for instrumentalising the commitments of the 2030 Agenda, but complemented by a subversive approach – injecting radical thinking and action for economic, environmental and social justice. Whether this could succeed in light of political constellations is open, and requires an idealistic faith in the power of ideas.
A Tutorial in Consumer Research: Knowledge Creation and Knowledge Appreciation in Deductive-Conceptual Consumer Research
Authors: Janiszewski Chris , Labroo Aparna A. , Rucker Derek D.
Published: July 2016

A typical article in a top-tier business journal can require as much as $400,000 in academic labor costs (Terwiesch and Ulrich 2014). This estimate raises the question of what makes a contribution worthy of such a significant financial investment. How does an academic community determine the value of a contribution? We propose that two criteria inform judgments of value: the amount of knowledge creation and the amount of knowledge appreciation. Implicit in our view is the idea that researchers should know how to create valuable knowledge and be able to anticipate how much stakeholders will appreciate that knowledge. In this tutorial, we discuss knowledge creation, knowledge appreciation, and a framework that jointly represents these two sources of value. We hope that this framework will encourage scholars to engage in research activities that are valued by the scientific community.
Carbon-ion radiotherapy for locally advanced cervical cancer with bladder invasion
Authors: Shiba Shintaro , Wakatsuki Masaru , Kato Shingo , Ohno Tatsuya , Okonogi Noriyuki , Karasawa Kumiko , Kiyohara Hiroki , Tsujii Hirohiko , Nakano Takashi , Kamada Tadashi , Shozu Makio ,   The Working Group of the Gynecological Tumor
Published: July 2016

The purpose of this study was to evaluate the efficacy and toxicities of carbon-ion radiotherapy (C-ion RT) for locally advanced cervical cancer with bladder invasion by a subset analysis of pooled data from eight prospective clinical trials at the National Institute of Radiological Sciences. Between June 1995 and January 2014, 29 patients with locally advanced cervical cancer with bladder invasion were identified. The median age was 56 years old (range 31–79 years old). The median tumor size at diagnosis on magnetic resonance imaging was 6.7 cm (range 3.5–11.0 cm). Histologically, 20 patients had squamous cell carcinoma and 9 had adenocarcinoma. C-ion RT was performed as a dose-escalation study in the initial trials. All patients received prophylactic whole-pelvic or extended-field irradiation and local boost. The total dose to the cervical tumor was 52.8–74.4 Gy (relative biological effectiveness) in 20 or 24 fractions. Weekly cisplatin (40 mg/m2/week, five cycles) was concurrently given to four patients. The median follow-up of all patients was 28.6 months (range 8.8–238.6 months). Grade 2 or higher late complications in the bladder were observed in eight patients, with seven developing vesicovaginal fistula. Six patients had Grade 2 or higher complications in the rectosigmoid colon. The 3-year overall survival rate was 47%, the 3-year local control rate was 66%, and the 3-year disease-free survival rate was 28%. In this study, C-ion RT showed favorable local control with reasonable toxicities, but the results were still unsatisfactory. We have the expectation of improvement of therapeutic effects by using C-ion RT with concurrent chemotherapy.
Survey Experiments with Google Consumer Surveys: Promise and Pitfalls for Academic Research in Social Science
Authors: Santoso Lie Philip , Stein Robert , Stevenson Randy
Published: July 2016

In this article, we evaluate the usefulness of Google Consumer Surveys (GCS) as a low-cost tool for doing rigorous social scientific work. We find that its relative strengths and weaknesses make it most useful to researchers who attempt to identify causality through randomization to treatment groups rather than selection on observables. This finding stems, in part, from the fact that the real cost advantage of GCS over other alternatives is limited to short surveys with a small number of questions. Based on our replication of four canonical social scientific experiments and one study of treatment heterogeneity, we find that the platform can be used effectively to achieve balance across treatment groups, explore treatment heterogeneity, include manipulation checks, and that the provided inferred demographics may be sufficiently sound for weighting and explorations of heterogeneity. Crucially, we successfully managed to replicate the usual directional finding in each experiment. Overall, GCS is likely to be a useful platform for survey experimentalists.
Killing by Type VI secretion drives clonal phase separation and the evolution of cooperation
Authors: McNally Luke , Bernardy Eryn , Thomas Jacob , Kalziqi Arben , Pentz Jennifer , Brown Sam , Hammer Brian , Yunker Peter J. , Ratcliff William
Published: July 2016

By nature of their small size, dense growth and frequent need for extracellular metabolism, microbes face persistent public goods dilemmas1–5. Spatial assortment can act as a general solution to social conflict by allowing extracellular goods to be utilized preferentially by productive genotypes1,6,7. Established mechanisms that generate microbial assortment depend on the availability of free space8–14; however, microbes often live in densely-packed environments, wherein these mechanisms are ineffective. Here, we describe a novel class of self-organized pattern formation that facilitates the development of spatial structure within densely-packed bacterial colonies. Contact-mediated killing through the Type VI secretion system (T6SS) drives high levels of assortment by precipitating phase separation, even in initially well-mixed populations that do not necessarily exhibit net growth. We examine these dynamics using three different classes of mathematical models and experiments with mutually antagonistic strains ofVibrio choleraegrowing on solid media, and find that all appear to de-mix via the same ‘Model A’ universality class of order-disorder transition. We mathematically demonstrate that contact killing should favour the evolution of public goods cooperation, and empirically examine the relationship between T6SSs and potential cooperation through phylogenetic analysis. Across 26 genera of Proteobacteria and Bacteroidetes, the proportion of a strain’s genome that codes for potentially-exploitable secreted proteins increases significantly with boththe number of Type 6 secretion systems and the number of T6SS effectors that it possesses. This work demonstrates how antagonistic traits—likely evolved for the purpose of killing competitors—can indirectlylead to the evolution of cooperation by driving genetic phase separation.
Measurements of translation initiation from all 64 codons inE. coli
Authors: Hecht Ariel , Glasgow Jeff , Jaschke Paul R. , Bawazer Lukmaan , Munson Matthew S. , Cochran Jennifer , Endy Drew , Salit Marc
Published: July 2016

Our understanding of translation is one cornerstone of molecular biology that underpins our capacity to engineer living matter. The canonical start codon (AUG) and a few near-cognates (GUG, UUG) are typically considered as the “start codons” for translation initiation inEscherichia coli(E. coli). Translation is typically not thought to initiate from the 61 remaining codons. Here, we systematically quantified translation initiation inE. colifrom all 64 triplet codons. We detected protein synthesis above background initiating from at least 46 codons. Translation initiated from these non-canonical start codons at levels ranging from 0.01% to 2% relative to AUG. Translation initiation from non-canonical start codons may contribute to the synthesis of peptides in both natural and synthetic biological systems
Ethyl 2-(4-cyanophenyl)-1-(4-fluorobenzyl)-1H-benzo[d]imidazole-5-carboxylate
Authors: Madan Kumar S. , Vasantha Kumar , Boja Poojary , Byrappa K. , Warad Ismail
Published: July 2016

The title benzimidazole derivative, C24H18FN3O2, is T-shaped, with the 4-cyanobenzene and 4-fluorobenzyl rings inclined to the imidazole ring system by 32.89 (10) and 83.63 (10)°, respectively, and by 89.00 (12)° to one another. The terminal methyl group of the ethylcarboxylate group is disordered over three sites and was refined with a fixed occupancy ratio of 1/3:1/3:1/3. In the crystal, molecules are essentially linked by offset π–π interactions, involving inversion-related imidazole rings [inter-centroid distance = 3.763 (1) Å], and stack along theb-axis direction.
Measuring food security status among households in Osun State, Nigeria
Authors: Fawole Wasiu Olayinka , Ozkan Burhan , Ayanrinde Festus Ayanwole
Published: July 2016

Purpose

– The purpose of this paper is to investigate the food security status of 150 households in Osun state of Nigeria. The study area was chosen because relatively little energy consumption data are available concerning this geographical location.

Design/methodology/approach

– The study used both primary and secondary data. The suitable households sample was chosen by multi-stage random sampling technique. The methodology employed to group the households into either food secure or food insecure is by comparing daily per capita calorie consumption by each household with the threshold daily per capita calorie requirement of 2,710 kcal/day/adult equivalent. This method has proven to be efficient in measuring food security at household level.

Findings

– The results of the study reveal that majority of the households surveyed are food insecure that is their daily per capita calorie intake falls below the recommended daily per capita calorie requirement. The food insecure households constitute 54 per cent, surplus index of 0.36 per cent and food insecurity gap of 0.0038.

Research limitations/implications

– The greatest limitation to this study is the inability to collect data on the distribution of income, budget share on foods and socio-economic characteristics of the households to determine how their food security status is influenced due to impediments such as time, limited resources to collect a complete dataset used for the study. Also, recalling accurately the foods eaten in the last 24-hour was difficult for some of the household heads especially the aged ones and precise measurement of foods portion were also not accurate in some cases.

Practical implications

– The findings of the study will help the stakeholders in food sector in policy formulations and also serve as reference for other researchers who will work on similar topic.

Social implications

– The revelation that majority of the households are lacking in calorie intake will provide guidance for stakeholders in food sector to put in place efforts that will improve balance between food production and accessibility.

Originality/value

– The study used original data collected directly from the households for the study using structured questionnaires and the reference materials from secondary sources are appropriately cited. Also, it is worthy to note that not many studies have been carried out in the study area on food security especially in the rural areas.
Italian consumers’ income and food waste behavior
Authors: Setti Marco , Falasconi Luca , Segrè Andrea , Cusano Ilaria , Vittuari Matteo
Published: July 2016

Purpose

– The purpose of this paper is to provide insights on the relationships between consumers’ income and household food waste behaviors.

Design/methodology/approach

– Attitude toward food waste is a paradigmatic (economic) non-standard decision making. Based on behavioral economics concepts and empirical evidences, the study analyzes the frequency of household food waste and its main drivers with a focus on individual income. Through a panel of 1,403 Italian consumers, food waste behavior and its determinants are modeled for five food typologies using proportional odds models that adopt stepwise procedures and genetic algorithms.

Findings

– Results suggest the existence of complex relationships between per capita income and household food waste behavior. When considering food typologies that include high value added products, this relation can be explained by an inverse U-shaped curve: mid-to-low income consumers purchase higher amounts of lower quality products and waste more food.

Research limitations/implications

– The research highlights the importance of understanding the main socio-economic and behavioral determinants of household food waste, and the need for further researches.

Practical implications

– The research motivates specific pricing, commercial and policy strategies as well as organizational technological, and educational solutions to prevent/reduce household food waste.

Social implications

– Lower income class consumers show a greater attitude to waste certain food typologies. In turn, this implies that food waste can further worse economic inequality and relative poverty.

Originality/value

– The study identifies different patterns of relationship among individual income and consumers’ food waste behavior, and describes the conditions that limit a household “Food Waste Kuznets Curve.”