bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative study of electrical breakdown properties of deionized water and heavy water under pulsed power conditions
Authors: Veda Prakash G. , Kumar R. , Saurabh K. , Nasir  , Anitha V. P. , Chowdhuri M. B. , Shyam A.
Published: January 2016

A comparative study of electrical breakdown properties of deionized water (H2O) and heavy water (D2O) is presented with two different electrode materials (stainless steel (SS) and brass) and polarity (positive and negative) combinations. The pulsed (∼a few tens of nanoseconds) discharges are conducted by applying high voltage (∼a few hundred kV) pulse between two hemisphere electrodes of the same material, spaced 3 mm apart, at room temperature (∼26-28 °C) with the help of Tesla based pulse generator. It is observed that breakdown occurred in heavy water at lesser voltage and in short duration compared to deionized water irrespective of the electrode material and applied voltage polarity chosen. SS electrodes are seen to perform better in terms of the voltage withstanding capacity of the liquid dielectric as compared to brass electrodes. Further, discharges with negative polarity are found to give slightly enhanced discharge breakdown voltage when compared with those with positive polarity. The observations corroborate well with conductivity measurements carried out on original and post-treated liquid samples. An interpretation of the observations is attempted using Fourier transform infrared measurements on original and post-treated liquids as well as in situ emission spectra studies. A yet another important observation from the emission spectra has been that even short (nanosecond) duration discharges result in the formation of a considerable amount of ions injected into the liquid from the electrodes in a similar manner as reported for long (microseconds) discharges. The experimental observations show that deionised water is better suited for high voltage applications and also offer a comparison of the discharge behaviour with different electrodes and polarities.
Analysis of ionic photofragments stored in an electrostatic storage ring
Authors: Svendsen Annette , Teiwes Ricky , Kiefer Hjalte V. , Andersen Lars H. , Pedersen Henrik B.
Published: January 2016

A new method to analyze the properties of fragment ions created in storage ring experiments is presented. The technique relies on an acceleration of ionic fragments immediately after production whereby the fragments are stored in the storage ring. To obtain a fragment mass spectrum, the storage ring is exploited as an electrostatic analyzer (ESA) in which case the number of stored fragment ions is recorded as a function of the applied acceleration potential. However, the storage ring can additionally be employed as a time-of-flight (TOF) instrument by registering the temporal distribution of fragment ions. It is demonstrated that the combined ESA-TOF operation of the ring allows not only to determine fragment masses with much better resolution compared to the ESA mode alone but also enables the extraction of detailed information on the fragmentation dynamics. The method is described analytically and verified with photodissociation experiments on stored Cl2− at an excitation wavelength of 530 nm.
Determination of ground and excited state dipole moments via electronic Stark spectroscopy: 5-methoxyindole
Authors: Wilke Josefin , Wilke Martin , Meerts W. Leo , Schmitt Michael
Published: January 2016

The dipole moments of the ground and lowest electronically excited singlet state of 5-methoxyindole have been determined by means of optical Stark spectroscopy in a molecular beam. The resulting spectra arise from a superposition of different field configurations, one with the static electric field almost parallel to the polarization of the exciting laser radiation, the other nearly perpendicular. Each field configuration leads to different intensities in the rovibronic spectrum. With an automated evolutionary algorithm approach, the spectra can be fit and the ratio of both field configurations can be determined. A simultaneous fit of two spectra with both field configurations improved the precision of the dipole moment determination by a factor of two. We find a reduction of the absolute dipole moment from 1.59(3) D to 1.14(6) D upon electronic excitation to the lowest electronically excited singlet state. At the same time, the dipole moment orientation rotates by 54∘ showing the importance of the determination of the dipole moment components. The dipole moment in the electronic ground state can approximately be obtained from a vector addition of the indole and the methoxy group dipole moments. However, in the electronically excited state, vector addition completely fails to describe the observed dipole moment. Several reasons for this behavior are discussed.
Response of complex networks to compression: Ca, La, and Y aluminoborosilicate glasses formed from liquids at 1 to 3 GPa pressures
Authors: Bista Saurav , Morin Elizabeth I. , Stebbins Jonathan F.
Published: January 2016

Aluminoborosilicate glasses containing relatively high field strength modifiers (Ca, La, and Y) have been compressed at pressures up to 3 GPa and near the glass transition temperature (Tg) and quenched to room temperature at high pressure followed by decompression. Structural changes were quantified with high-resolution 27Al and 11B MAS nuclear magnetic resonance at 14.1–18.8 T. The changes with pressure in Al and B coordinations in the recovered samples are quite large with more than 50% decreases in tetrahedral aluminum (IVAl) and 200%-300% increases in tetrahedral boron (IVB). Glasses with higher field strength modifiers (La and Y) contain more high coordinated aluminum (V,V IAl) at all pressures studied. More high coordinated boron also correlates with higher field strength modifier if all three compositions are compared on an isothermal basis. Although lowering fictive temperature and increasing pressure both increase Al and B coordinations, our study shows that the actual mechanisms for structural changes are most probably different for temperature and pressure effects. Using a rough thermodynamic model to extrapolate to higher pressures, it appears that a simple non-bridging oxygen (NBO) consumption mechanism is not sufficient to convert all the aluminum to octahedral and boron to tetrahedral coordination, suggesting other mechanisms for structural changes could occur at high pressure as NBO becomes depleted.
Band-to-band tunneling distance analysis in the heterogate electron–hole bilayer tunnel field-effect transistor
Authors: Padilla J. L. , Palomares A. , Alper C. , Gámiz F. , Ionescu A. M.
Published: January 2016

In this work, we analyze the behavior of the band-to-band tunneling distance between electron and hole subbands resulting from field-induced quantum confinement in the heterogate electron–hole bilayer tunnel field-effect transistor. We show that, analogously to the explicit formula for the tunneling distance that can be easily obtained in the semiclassical framework where the conduction and valence band edges are allowed states, an equivalent analytical expression can be derived in the presence of field-induced quantum confinement for describing the dependence of the tunneling distance on the body thickness and material properties of the channel. This explicit expression accounting for quantum confinement holds valid provided that the potential wells for electrons and holes at the top and bottom of the channel can be approximated by triangular profiles. Analytical predictions are compared to simulation results showing very accurate agreement.
Modeling heart rate variability including the effect of sleep stages
Authors: Soliński Mateusz , Gierałtowski Jan , Żebrowski Jan
Published: January 2016

We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.
High-level theoretical rovibrational spectroscopy beyond fc-CCSD(T): The C3 molecule
Authors: Schröder Benjamin , Sebald Peter
Published: January 2016

An accurate local (near-equilibrium) potential energy surface (PES) is reported for the C3 molecule in its electronic ground state (X̃1Σg+). Special care has been taken in the convergence of the potential relative to high-order correlation effects, core-valence correlation, basis set size, and scalar relativity. Based on the aforementioned PES, several rovibrational states of all 12C and 13C substituted isotopologues have been investigated, and spectroscopic parameters based on term energies up to J = 30 have been calculated. Available experimental vibrational term energies are reproduced to better than 1 cm−1 and rotational constants show relative errors of not more than 0.01%. The equilibrium bond length has been determined in a mixed experimental/theoretical approach to be 1.294 07(10) Å in excellent agreement with the ab initio composite value of 1.293 97 Å. Theoretical band intensities based on a newly developed electric dipole moment function also suggest that the infrared active (1, 11, 0)←(0, 00, 0) combination band might be observable by high-resolution spectroscopy.
Phase transitions and magnetocaloric and transport properties in off-stoichiometric GdNi2Mnx
Authors: Aryal Anil , Quetz Abdiel , Pandey Sudip , Samanta Tapas , Dubenko Igor , Mazumdar Dipanjan , Stadler Shane , Ali Naushad
Published: January 2016

The structural, magnetic, magnetocaloric, transport, and magnetoresistance properties of the rare-earth intermetallic compounds GdNi2Mnx (0.5 ≤ x ≤ 1.5) have been studied. The compounds with x = 0.5 and 0.6 crystallize in the cubic MgCu2 type phase, whereas samples with x ≥ 0.8 form a mixed MgCu2 and rhombohedral PuNi3 phase. A second order magnetic phase transition from a ferromagnetic to paramagnetic state was observed near the Curie temperature (TC). The GdNi2Mnx (0.5 ≤ x ≤ 1.5) compounds order in a ferrimagnetic structure in the ground state. The largest observed values of magnetic entropy changes (at TC for ΔH = 5T) were 3.9, 3.5, and 3.1 J/kg K for x = 0.5, 0.6, and 0.8, respectively. The respective relative values of the cooling power were 395, 483, and 220 J/kg. These values are greater than some well-known prototype magnetocaloric materials such as Gd (400 J/kg) and Gd5Si2Ge2 (240 J/kg). Analysis of the resistivity data showed a T2 dependence at low temperatures, suggesting strong electron-phonon interactions, whereas at higher temperatures s-d scattering was dominated by the electron-phonon contribution, resulting in a slow increase in resistivity. Magnetoresistance values of ∼−1.1% were found for x = 0.5 near TC, and −7% for x = 1.5 near T = 80 K.
A simple method to control nanotribology behaviors of monocrystalline silicon
Authors: Wang X. D. , Guo J. , Chen C. , Chen L. , Qian L. M.
Published: January 2016

A simple method was proposed to control the nanotribology behaviors of monocrystalline silicon against SiO2 microsphere by adjusting relative humidity (RH). Experimental results indicated that adhesion work, friction coefficient, and nanowear of silicon against SiO2 microsphere significantly varied between 60% and 90% RH. Under 60% RH, adhesion work was 119 mN/m, and friction coefficient was about 0.53. However, adhesion work and friction coefficient decreased to ∼70 mN/m and ∼0.3 under 90% RH, respectively. An apparent wear track ∼13 nm deep formed on the silicon surface under 60% RH, whereas no obvious wear scar was observed on the silicon surface under 90% RH. Analysis indicated that such tribological behaviors were due to different water condensations on the silicon surface under 60% and 90% RH. Under 60% RH, the water that condensed on the surfaces of the silicon sample and SiO2 tip mainly consisted of ice-like water. As a result, adhesion work was enlarged by the breaking force of the ice-like water bridge in the contact area. Given that a ≡Si–O–Si≡ bonding bridge easily formed between the silicon surface and the SiO2 tip with the help of water condensation under 60% RH instead of 90% RH, the friction coefficient was large and the nanowear of the silicon sample was severe under 60% RH. These results may help elucidate the nanotribology behaviors of silicon and facilitate the tribological design of dynamic microelectromechanical systems working under humid conditions.
Double photoionization of halogenated benzene
Authors: AlKhaldi Mashaal Q. , Wehlitz Ralf
Published: January 2016

We have experimentally investigated the double-photoionization process in C6BrF5 using monochromatized synchrotron radiation. We compare our results with previously published data for partially deuterated benzene (C6H3D3) over a wide range of photon energies from threshold to 270 eV. A broad resonance in the ratio of doubly to singly charged parent ions at about 65 eV appears shifted in energy compared to benzene data. This shift is due to the difference in the bond lengths in two molecules. A simple model can explain the shape of this resonance. At higher photon energies, we observe another broad resonance that can be explained as a second harmonic of the first resonance.
Ion beam enhancement in magnetically insulated ion diodes for high-intensity pulsed ion beam generation in non-relativistic mode
Authors: Zhu X. P. , Zhang Z. C. , Pushkarev A. I. , Lei M. K.
Published: January 2016

High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation.
Demonstration of Johnson noise thermometry with all-superconducting quantum voltage noise source
Authors: Yamada Takahiro , Urano Chiharu , Maezawa Masaaki
Published: January 2016

We present a Johnson noise thermometry (JNT) system based on an integrated quantum voltage noise source (IQVNS) that has been fully implemented using superconducting circuit technology. To enable precise measurement of Boltzmann's constant, an IQVNS chip was designed to produce intrinsically calculable pseudo-white noise to calibrate the JNT system. On-chip real-time generation of pseudo-random codes via simple circuits produced pseudo-voltage noise with a harmonic tone interval of less than 1 Hz, which was one order of magnitude finer than the harmonic tone interval of conventional quantum voltage noise sources. We estimated a value for Boltzmann's constant experimentally by performing JNT measurements at the temperature of the triple point of water using the IQVNS chip.
Note: Spin-exchange optical pumping in a van
Authors: Chauvin C. , Liagre L. , Boutin C. , Mari E. , Léonce E. , Carret G. , Coltrinari B. , Berthault P.
Published: January 2016

The advent of spin-hyperpolarization techniques designed to overcome the sensitivity issue of nuclear magnetic resonance owing to polarization transfer from more ordered systems has recently raised great enthusiasm. However, the out-of-equilibrium character of the polarization requires a close proximity between the area of production and the site of use. We present here a mobile spin-exchange optical pumping setup that enables production of laser-polarized noble gases in a standalone mode, in close proximity to hospitals or research laboratories. Only compressed air and mains power need to be supplied by the host laboratory.
Mechanical characterization of suspended strips of meshed single-walled carbon nanotubes
Authors: Wang Xin , Li Bo , Hao Ji , Jung Yung Joon , Wan Kai-tak
Published: January 2016

A thin film of single walled carbon nanotube (SWCNT) mesh has good potential to integrate the existing electromechanical functions with flexible devices. In this paper, SWCNT mats are transferred to a patterned polymer SU-8 substrate using a wet contact print method, forming a suspended bridge over a groove in the substrate. The front edge of a tipless AFM cantilever loads the suspension at the centerline, causing it to deform into a V-shape by mixed bending and stretching. The mechanical response of load versus AFM displacement is fitted to a linear elastic model to extract the average elastic modulus. Reversible loading-unloading shows little or no permanent damage due to mechanical loads.
Identification of ferroelectric domain structure sensitive phonon modes in potassium titanyl phosphate: A fundamental study
Authors: Rüsing M. , Eigner C. , Mackwitz P. , Berth G. , Silberhorn C. , Zrenner A.
Published: January 2016

Confocal Raman spectroscopy is applied to identify ferroelectric domain structure sensitive phonon modes in potassium titanyl phosphate. Therefore, polarization-dependent measurements in various scattering configurations have been performed to characterize the fundamental Raman spectra of the material. The obtained spectra are discussed qualitatively based on an internal mode assignment. In the main part of this work, we have characterized z-cut periodically poled potassium titanyl phosphate in terms of polarity- and structure-sensitive phonon modes. Here, we find vibrations whose intensities are linked to the ferroelectric domain walls. We interpret this in terms of changes in the polarizability originating from strain induced by domain boundaries and the inner field distribution. Hence, a direct and 3D visualization of ferroelectric domain structures becomes possible in potassium titanyl phosphate.
Short range ferromagnetic, magneto-electric, and magneto-dielectric effect in ceramic Co3TeO6
Authors: Singh Harishchandra , Ghosh Haranath , Chandrasekhar Rao T. V. , Sharma G. , Saha J. , Patnaik S.
Published: January 2016

We report observation of magneto-electric and magneto-dielectric couplings along with short range ferromagnetic order in ceramic Cobalt Tellurate (Co3TeO6, CTO) using magnetic, structural, dielectric, pyroelectric, and polarization studies. DC magnetization along with dielectric constant measurements indicate a coupling between magnetic order and electrical polarization. A strong anomaly in the dielectric constant at ∼17.4 K in zero magnetic field indicates spontaneous electric polarization, consistent with a recent neutron diffraction study. Observation of weak short range ferromagnetic order at lower temperatures is attributed to the Griffiths-like ferromagnetism. Furthermore, magnetic field dependence of the ferroelectric transition follows earlier theoretical predictions, applicable to single crystal CTO. Finally, combined dielectric, pyroelectric, and polarization measurements suggest that the ground state of CTO may possess spontaneous symmetry breaking in the absence of magnetic field.
Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films
Authors: Chase T. , Trigo M. , Reid A. H. , Li R. , Vecchione T. , Shen X. , Weathersby S. , Coffee R. , Hartmann N. , Reis D. A. , Wang X. J. , Dürr H. A.
Published: January 2016

We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.
Complementary inverter from patterned source electrode vertical organic field effect transistors
Authors: Greenman Michael , Yoffis Svetlana , Tessler Nir
Published: January 2016

We report N-type and P-type high performance vertical organic field effect transistors. Insulation layer on top of the source electrode is used to reduce off currents leading to on/off ratio above 105 with on current density higher than 10 mA/cm2. A complementary inverter circuit was assembled from the transistors; examination of the inverter output characteristic indicates that the inverter gain is strong enough to be cascaded.
Local phonon mode in thermoelectric Bi2Te2Se from charge neutral antisites
Authors: Tian Yao , Osterhoudt Gavin B. , Jia Shuang , Cava R. J. , Burch Kenneth S.
Published: January 2016

Local modes caused by defects play a significant role in the thermal transport properties of thermoelectrics. Of particular interest are charge-neutral defects that suppress thermal conductivity, without significantly reducing electrical transport. Here, we report a temperature dependent Raman study that identifies such a mode in a standard thermoelectric material, Bi2Te2Se. One of the modes observed, whose origin has been debated for decades, was shown most likely to be an antisite defect induced local mode. The anomalous temperature independent broadening of the local mode is ascribed to the random arrangement of Se atoms. The temperature renormalization of all modes is well explained by an anharmonic model–Klemens's model.
Spatial identification of traps in AlGaN/GaN heterostructures by the combination of lateral and vertical electrical stress measurements
Authors: Hu Anqi , Yang Xuelin , Cheng Jianpeng , Guo Lei , Zhang Jie , Ge Weikun , Wang Maojun , Xu Fujun , Tang Ning , Qin Zhixin , Wang Xinqiang , Shen Bo
Published: January 2016

We present a methodology and the corresponding experimental results to identify the exact location of the traps that induce hot electron trapping in AlGaN/GaN heterostructures grown on Si substrates. The methodology is based on a combination of lateral and vertical electrical stress measurements employing three ohmic terminals on the test sample structure with different GaN buffer designs. By monitoring the evolution of the lateral current during lateral as well as vertical stress application, we investigate the trapping/detrapping behaviors of the hot electrons and identify that the traps correlated with current degradation are in fact located in the GaN buffer layers. The trap activation energies (0.38–0.39 eV and 0.57–0.59 eV) extracted from either lateral or vertical stress measurements are in good agreement with each other, also confirming the identification. By further comparing the trapping behaviors in two samples with different growth conditions of an unintentionally doped GaN layer, we conclude that the traps are most likely in the unintentionally doped GaN layer but of different origins. It is suggested that the 0.38–0.39 eV trap is related to residual carbon incorporation while the 0.57–0.59 eV trap is correlated with native defects or complexes.
Ionic charging by local imbalance at interfaces in hybrid lead halide perovskites
Authors: Almora Osbel , Guerrero Antonio , Garcia-Belmonte Germà
Published: January 2016

Identification of specific operating mechanisms becomes particularly challenging when mixed ionic-electronic conductors are used in optoelectronic devices. Ionic effects in perovskite solar cells are believed to distort operation curves and possess serious doubts about their long term stability. Current hysteresis and switchable photovoltaic characteristics have been connected to the kinetics of ion migration. However, the nature of the specific ionic mechanism (or mechanisms) able to explain the operation distortions is still poorly understood. It is observed here that the local rearrangement of ions at the electrode interfaces gives rise to commonly observed capacitive effects. Charging transients in response to step voltage stimuli using thick CH3NH3PbI3 samples show two main polarization processes and reveal the structure of the ionic double-layer at the interface with the non-reacting contacts. It is observed that ionic charging, with a typical response time of 10 s, is a local effect confined in the vicinity of the electrode, which entails absence of net mobile ionic concentration (space-charge) in the material bulk.
Vortex circulation and polarity patterns in closely packed cap arrays
Authors: Streubel Robert , Kronast Florian , Reiche Christopher F. , Mühl Thomas , Wolter Anja U. B. , Schmidt Oliver G. , Makarov Denys
Published: January 2016

We studied curvature-driven modifications to the magnetostatic coupling of vortex circulation and polarity in soft-magnetic closely packed cap arrays. A phase diagram for the magnetic remanent/transition states at room temperature as a function of diameter and thickness was assembled. For specimens with vortex remanent state (40 nm-thick Permalloy on 330 nm spherical nanoparticles), both vortex circulation and polarity were visualized. Intercap coupling upon vortex nucleation leads to the formation of vortex circulation patterns in closely packed arrays. The remanent circulation pattern can be tailored choosing the direction of the applied magnetic field with respect to the symmetry axis of the hexagonal array. An even and random distribution of vortex polarity indicates the absence of any circulation-polarity coupling.
Selective-area growth and magnetic characterization of MnAs/AlGaAs nanoclusters on insulating Al2O3 layers crystallized on Si(111) substrates
Authors: Sakita Shinya , Hara Shinjiro , Elm Matthias T. , Klar Peter J.
Published: January 2016

We report on selective-area metal-organic vapor phase epitaxy and magnetic characterization of coupled MnAs/AlGaAs nanoclusters formed on thin Al2O3 insulating layers crystallized on Si(111) substrates. Cross-sectional transmission electron microscopy reveals that poly-crystalline γ-Al2O3 grains are formed after an annealing treatment of the amorphous Al2O3 layers deposited by atomic layer deposition on Si(111) substrates. The ⟨111⟩ direction of the γ-Al2O3 grains tends to be oriented approximately parallel to the ⟨111⟩ direction of the Si substrate. We observe that hexagonal MnAs nanoclusters on AlGaAs buffer layers grown by selective-area metal-organic vapor phase epitaxy on partially SiO2-masked Al2O3 insulator crystallized on Si(111) substrates are oriented with the c-axis along the ⟨111⟩ direction of the substrates, but exhibit a random in-plane orientation. A likely reason is the random orientation of the poly-crystalline γ-Al2O3 grains in the Al2O3 layer plane. Magnetic force microscopy studies at room temperature reveal that arrangements of coupled MnAs nanoclusters exhibit a complex magnetic domain structure. Such arrangements of coupled MnAs nanoclusters may also show magnetic random telegraph noise, i.e., jumps between two discrete resistance levels, in a certain temperature range, which can be explained by thermally activated changes of the complex magnetic structure of the nanocluster arrangements.
Utilizing self-assembled-monolayer-based gate dielectrics to fabricate molybdenum disulfide field-effect transistors
Authors: Kawanago Takamasa , Oda Shunri
Published: January 2016

In this study, we apply self-assembled-monolayer (SAM)-based gate dielectrics to the fabrication of molybdenum disulfide (MoS2) field-effect transistors. A simple fabrication process involving the selective formation of a SAM on metal oxides in conjunction with the dry transfer of MoS2 flakes was established. A subthreshold slope (SS) of 69 mV/dec and no hysteresis were demonstrated with the ultrathin SAM-based gate dielectrics accompanied by a low gate leakage current. The small SS and no hysteresis indicate the superior interfacial properties of the MoS2/SAM structure. Cross-sectional transmission electron microscopy revealed a sharp and abrupt interface of the MoS2/SAM structure. The SAM-based gate dielectrics are found to be applicable to the fabrication of low-voltage MoS2 field-effect transistors and can also be extended to various layered semiconductor materials. This study opens up intriguing possibilities of SAM-based gate dielectrics in functional electronic devices.
Effect of gaseous hydrogen charging on the tensile properties of standard and medium Mn X70 pipeline steels
Authors: Hejazi D. , Calka A. , Dunne D. , Pereloma E.
Published: January 2016

The tensile properties of two X70 steels with high (1.14 wt-) and medium (0.5 wt-) Mn contents have been investigated by testing at 25°C of tubular specimens charged with an internal gas pressure of 10 MPa of hydrogen or argon. The hydrogen-charged samples were additionally tested at 50 and 100°C. Tensile testing showed that the equiaxed ferrite–pearlite microstructure of higher Mn steel was most sensitive to hydrogen embrittlement and that the banded ferrite–pearlite microstructure of the higher Mn strip was more susceptible to hydrogen embrittlement than the medium Mn strip. The more highly banded ferrite–pearlite microstructure in the higher Mn steel provided numerous sites for concentration of hydrogen to levels that promoted crack initiation and growth. Test temperatures up to 100°C reduced the yield and tensile strengths, increased the total elongation and decreased the extent of hydrogen embrittlement because of enhanced dislocation mobility and less effective hydrogen trapping.
Quantitative assessment of retained austenite in quenching and partitioning treated multiphase steel
Authors: Zhao H. S. , Li W. , Zhu X. , Lu X. H. , Wang L. , Zhou S. , Jin X. J.
Published: January 2016

For multiphase steel, an efficient and accurate quantitative analysis of constituent phases is critical in understanding the mechanical mechanism and optimising its properties. A method based on image digitisation and the concept of categorised linear interception has been proposed to study the amount of retained austenite (RA) residing in different phases in quenching and partitioning treated multiphase steel. It was found that RA at different locations transformed in different strain stages due to considerable influence from the surrounding phases, and the stability of each type of RA was estimated according to the above mentioned method. The proposed multistage transformation was proved to be more accurate than a single stage stability model.
Escapement of Fishes from Modified Fyke Nets with Differing Throat Configurations
Authors: Smith Bradley J. , Blackwell Brian G. , Wuellner Melissa R. , Graeb Brian D. S. , Willis David W.
Published: January 2016

We performed a field experiment in five eastern South Dakota lakes to investigate fish escapement differences between modified fyke nets with two common throat configurations (restricted and unrestricted). Nets with restricted and unrestricted throats were deployed in pairs for 24 h on similar habitat. Captured fish were measured for TL and were given day-specific marks. The paired nets were redeployed, and marked fish were randomly assigned to be stocked into the restricted or unrestricted net for 24 h; stocking densities (stratified into low, medium, and high) were species specific. Marked fish that were retained after 24 h were used to quantify escapement, whereas newly captured fish were used to estimate differences in mean CPUE and size structure. Mean CPUE of Black Bullheads Ameiurus melas, Black Crappies Pomoxis nigromaculatus, and Bluegills Lepomis macrochirus approximately doubled when restricted nets were used. Mean TL of Black Crappies was 31 mm greater (95% confidence interval [CI] = 6–57 mm greater) and mean TL of Bluegills was 21 mm greater (95% CI = 8–35 mm greater) in restricted nets than in unrestricted nets. Escapement from restricted nets was 4.4% for Black Crappies and 10.3% for Bluegills, whereas escapement from unrestricted nets was 71.7% for Black Crappies and 58.4% for Bluegills. We urge researchers to consider the influence of varying fyke-net throat configurations on calculated population metrics, and we recommend inclusion of the restricted throat feature in gear specifications for North American standard modified fyke nets.

Received April 6, 2015; accepted October 14, 2015
A Case of Butane Hash Oil (Marijuana Wax)–Induced Psychosis
Authors: Keller Corey J. , Chen Evan C. , Brodsky Kimberly , Yoon Jong H.
Published: January 2016

Background: Marijuana is one of the most widely used controlled substances in the United States. Despite extensive research on smoked marijuana, little is known regarding the potential psychotropic effects of marijuana “wax,” a high-potency form of marijuana that is gaining in popularity. Case: The authors present a case of “Mr. B,” a 34-year-old veteran who presented with profound psychosis in the setting of recent initiation of heavy, daily marijuana wax use. He exhibited incoherent speech and odd behaviors and appeared to be in a dream-like state with perseverating thoughts about his combat experience. His condition persisted despite treatment with risperidone 4 mg twice a day (BID), but improved dramatically on day 8 of hospitalization with the return of baseline mental function. Following discharge, Mr. B discontinued all marijuana use and did not exhibit the return of any psychotic symptoms. Discussion: This study highlights the need for future research regarding the potential medical and psychiatric effects of new, high-potency forms of marijuana. Could cannabis have a dose-dependent impact on psychosis? What other potential psychiatric effects could emerge heretofore unseen in lower potency formulations? Given the recent legalization of marijuana, these questions merit timely exploration.
Internal Medicine Resident Knowledge, Attitudes, and Barriers to Naloxone Prescription in Hospital and Clinic Settings
Authors: Wilson J. Deanna , Spicyn Natalie , Matson Pamela , Alvanzo Anika , Feldman Leonard
Published: January 2016

Background: The United States is facing an epidemic of opioid use and misuse leading to historically high rates of overdose. Community-based overdose education and naloxone distribution has effectively trained lay bystanders to recognize signs of overdose and administer naloxone for reversal. There has been a movement to encourage physicians to prescribe naloxone to all patients at risk of overdose; however, the rate of physician prescribing remains low. This study aims to describe resident knowledge of overdose risk assessment, naloxone prescribing practices, attitudes related to naloxone, and barriers to overdose prevention and naloxone prescription. Methods: The HOPE (Hospital-based Overdose Prevention and Education) Initiative is an educational campaign to teach internal medicine residents to assess overdose risk, provide risk reduction counseling, and prescribe naloxone. As part of a needs assessment, internal medicine residents at an academic medical center in Baltimore, Maryland, were surveyed in 2015. Data were collected anonymously using Qualtrics. Results: Ninety-seven residents participated. Residents were overwhelmingly aware of naloxone (80%) and endorsed a willingness to prescribe (90%). Yet despite a high proportion of residents reporting patients in their panels at increased overdose risk (79%), few had prescribed naloxone (15%). Residents were willing to discuss overdose prevention strategies, although only a minority reported doing so (47%). The most common barriers to naloxone prescribing were related to knowledge gaps in how to prescribe and how to assess risk of overdose and identify candidates for naloxone (52% reporting low confidence in ability to identify patients who are at risk) . Conclusions: Medicine residents are aware of naloxone and willing to prescribe it to at-risk patients. Due to decreased applied knowledge and limited self-efficacy, few residents have prescribed naloxone in the past. In order to improve rates of physician prescribing, initiatives must help physicians better assess risk of overdose and improve prescribing self-efficacy.
Hazardous Drinking and Weight-Conscious Drinking Behaviors in a Sample of College Students and College Student Athletes
Authors: Martin Ryan J. , Chaney Beth H. , Vail-Smith Karen , Gallucci Andrew R.
Published: January 2016

Background: “Weight-conscious drinking” refers to behaviors to restrict calories in conjunction with consuming alcohol and is associated with numerous negative consequences. This behavior has been observed in the college student population but has not been examined among college student athletes. Methods: This cross-sectional study assessed drinking, hazardous drinking levels (Alcohol Use Disorders Identification Test—Consumption [AUDIT-C] sum score), and weight-conscious drinking behaviors (for weight loss purposes and for intoxication purposes) using a paper-and-pencil survey that was completed by students at a large, private university in the Southwest United States. The sample for this study included college student nonathletes ( n = 482; 212 males and 270 females) who completed the survey in 1 of 34 classes and college student athletes ( n = 201; 79 males and 122 females) who completed the survey during practice. These analyses examined whether hazardous drinking level and other personal covariates (gender, race, and athlete status) predicted the 2 weight-conscious drinking behaviors of interest. Results: Among the subsample of students who drank, the same proportion of participants indicated weight-conscious drinking behavior for weight loss and weight-conscious drinking behavior for intoxication (both 24.9%; n = 122). In the multivariate analyses, students with higher hazardous drinking scores and females were significantly more likely to report engaging in both weight-conscious drinking behaviors. In those analyses, neither weight-conscious drinking behavior varied by athlete status. Conclusions: In this sample of college students, hazardous drinking most predicted weight-conscious drinking behavior and superseded gender and athlete status. In response, college health professionals should consider evidenced-based approaches to address hazardous drinking.
Relapse Prevention Medications in Community Treatment for Young Adults with Opioid Addiction
Authors: Vo Hoa T. , Robbins Erika , Westwood Meghan , Lezama Debra , Fishman Marc
Published: January 2016

Background: Despite the well-known effectiveness and widespread use of relapse prevention medications such as extended release naltrexone (XR-NTX) and buprenorphine for opioid addiction in adults, less is known about their use in younger populations. Methods: This was a naturalistic study using retrospective chart review of N = 56 serial admissions into a specialty community treatment program that featured the use of relapse prevention medications for young adults (19–26 years old) with opioid use disorders. Treatment outcomes over 24 weeks included retention and weekly opioid-negative urine tests. Results: Patients were of mean age 23.1, 70% male, 86% Caucasian, 82% with history of injection heroin use, and treated with either buprenorphine (77%) or XR-NTX (23%). The mean number of XR-NTX doses received was 4.1. Retention was approximately 65% at 12 weeks and 40% at 24 weeks, and rates of opioid-negative urine were 50% at 12 weeks and 39% at 24 weeks, with missing samples imputed as positive. There were no statistically significant differences in retention ( t = 1.87, P = .06) or in rates of weekly opioid-negative urine tests ( t = 1.96, P = .06) between medication groups, over the course of 24 weeks. The XR-NTX group had higher rates of weekly negative urine drug tests for other nonopioid substances ( t = 2.83, P < .05) compared with the buprenorphine group. Males were retained in treatment longer and had higher rates of opioid-negative weeks compared with females. Conclusions: These results suggest that relapse prevention medications including both buprenorphine and XR-NTX can be effectively incorporated into standard community treatment for opioid addiction in young adults with good results. Specialty programming focused on opioid addiction in young adults may provide a promising model for further treatment development.
Structural characterization of sulfated arabinans extracted fromCladophora glomerataKützing and their macrophage activation
Authors: Surayot Utoomporn , Hun Lee Ju , Kanongnuch Chartchai , Peerapornpisal Yuwadee , Park WooJung , You SangGuan
Published: January 2016

Water-soluble sulfated heteropolysaccharides were extracted from Cladophora glomerata Kützing and fractionated by ion-exchange chromatography, which yielded two subfractions, F1 and F2. The crude and fractionated polysaccharides (F1 and F2) mostly consisted of carbohydrates (62.8–74.5%) with various amounts of proteins (9.00–17.3%) and sulfates (16.5–23.5%), including different levels of arabinose (41.7–54.4%), galactose (13.5–39.0%), glucose (0.80–10.6%), xylose (6.84–13.4%), and rhamnose (0.20–2.83%). Based on the size exclusion chromatography (SEC) profiles, the crude and fractions mainly contained one peak with shoulders having molecular weight (Mw) ranges of 358–1,501 × 103. The F1 fraction stimulated RAW264.7 cells to produce considerable amounts of nitric oxide and cytokines compared to the crude and F2 fraction. The backbone of the most potent immunostimulating fraction (F1) was α-(1→4)-L-arabinopyranoside with galactose and xylose residues as branches at O-2 position, and sulfates mainly at O-2 position as well.
Blood Pressure Mobile Monitoring for Pregnant Woman Based Android System
Authors: Supriyanti Retno , Erfayanto Uji , Ramadani Yogi , Murdyantoro Eko , Widodo Haris B.
Published: January 2016

Currently, at least 18,000 women die every year in Indonesia due to pregnancy or childbirth. It means that every half hour a woman dies due to pregnancy or childbirth. As a result, every year 36,000 children became orphans. The high maternal mortality rate was put Indonesia on top in ASEAN. The main causes of maternal mortality are high-risk pregnancy. Mothers who have diseases like high blood pressure, pre-eclampsia, diabetes, hyperthyroidism, and already over 40 years old and infectious diseases such as rubella, hepatitis and HIV can be factors that lead to high-risk pregnancy. This paper will discuss the development of a blood pressure monitoring device that is suitable for pregnant women. It is based on convenience for pregnant women to get the equipment that is flexible with her presence. Results indicate that the equipment is in use daily support for pregnant women therefore, one of the causes of maternal mortality can be detected earlier.
Fungi: A Very Short Introduction
Authors: Money Nicholas P.
Published: January 2016

The diversity of the mycological world is far greater than most people imagine. Tens of thousands of fungal species have been described and many more are known only from the abundance of their genes in soil and water. Fungi are hugely important as agents of wood decay in forests, and, as parasites, they have caused the deaths of millions of people by ravaging crops and reshaping natural ecosystems. Fungi perform essential functions in ecosystems, and are important to both agriculture and biotechnology. Fungi: A Very Short Introduction highlights the variety and extraordinary natures of fungi, revealing the remarkable facts of fungal biology and the global significance of these enchanting organisms.
Changes in composition, ecology and structure of high-mountain vegetation: a re-visitation study over 42 years
Authors: Evangelista Alberto , Frate Ludovico , Carranza Maria Laura , Attorre Fabio , Pelino Giovanni , Stanisci Angela
Published: January 2016

High-mountain ecosystems are increasingly threatened by climate change, causing biodiversity loss, habitat degradation and landscape modifications. However, very few detailed studies have focussed on plant biodiversity in the high mountains of the Mediterranean. In this study, we investigated the long-term changes that have occurred in the composition, structure and ecology of high-mountain vegetation in the central Apennines (Majella) over the last 42 years. We performed a re-visitation study, using historical and newly collected vegetation data to explore which ecological and structural features have been the most successful in coping with climatic changes. Vegetation changes were analysed by comparing geo-referenced phytosociological relevés collected in high-mountain habitats (dolines, gentle slopes and ridges) on the Majella massif in 1972 and in 2014. Composition analysis was performed by detrended correspondence analysis, followed by an analysis of similarities for statistical significance assessment and by similarity percentage procedure (SIMPER) for identifying which species indicate temporal changes. Changes in ecological and structural indicators were analysed by a permutational multivariate analysis of variance, followed by a post hoc comparison. Over the last 42 years, clear floristic changes and significant ecological and structural variations occurred. We observed a significant increase in the thermophilic and mesonitrophilic plant species and an increment in the frequencies of hemicryptophytes. This re-visitation study in the Apennines agrees with observations in other alpine ecosystems, providing new insights for a better understanding of the effects of global change on Mediterranean high-mountain biodiversity. The observed changes in floristic composition, the thermophilization process and the shift towards a more nutrient-demanding vegetation are likely attributable to the combined effect of higher temperatures and the increase in soil nutrients triggered by global change. The re-visitation approach adopted herein represents a powerful tool for studying climate-related changes in sensitive high-mountain habitats.