Superconductivity in heavily compensated Mg-doped InN

We report superconductivity in Mg-doped InN grown by molecular beam epitaxy. Superconductivity phase transition temperature occurs Tc = 3.97 K as determined by magnetoresistance and Hall resistance measurements. The two-dimensional (2D) carrier density of the measured sample is n2D = 9×1014 cm−2 corresponding to a three-dimensional (3D) electron density of n3D = 1.8×1019 cm−3 which is within the range of values between Mott transition and the superconductivity to metal transition. We propose a plausible mechanism to explain the existence of the superconductivity in terms of a uniform distribution of superconducting InN nanoparticles or nanosized indium dots forming microscopic Josephson junctions in the heavily compensated insulating bulk InN matrix

Instrumenting the Interaction: Affective and Psychophysiological Features of Live Collaborative Musical Improvisation

NIME’14, June 30 – July 03, 2014, Goldsmiths, University of London, UK. Copyright remains with the author(s)

Measuring Affect for the Study and Enhancement of Co-Present Creative Collaboration

© 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

High carrier concentration induced effects on the bowing parameter and the temperature dependence of the band gap of Ga_xIn_1−xN

The influence of intrinsic carrier concentration on the compositional and temperature dependence of the bandgap of GaxIn1-xN is investigated in nominally undoped samples with Ga fractions of x = 0.019, 0.062, 0.324, 0.52, and 0.56. Hall Effect results show that the free carrier density has a very weak temperature dependence and increases about a factor of 4, when the Ga composition increases from x = 0.019 to 0.56. The photoluminescence (PL) peak energy has also weak temperature dependence shifting to higher energies and the PL line shape becomes increasingly asymmetrical and broadens with increasing Ga composition. The observed characteristics of the PL spectra are explained in terms of the transitions from free electron to localized tail states and the high electron density induced many-body effects. The bowing parameter of GaxIn1-xN is obtained from the raw PL data as 2.5 eV. However, when the high carrier density induced effects are taken into account, it increases by about 14% to 2.9 eV. Furthermore, the temperature dependence of the PL peak becomes more pronounced and follows the expected temperature dependence of the bandgap variation

The Highly Miniaturised Radiation Monitor

We present the design and preliminary calibration results of a novel highly miniaturised particle radiation monitor (HMRM) for spacecraft use. The HMRM device comprises a telescopic configuration of active pixel sensors enclosed in a titanium shield, with an estimated total mass of 52 g and volume of 15 cm$^3$. The monitor is intended to provide real-time dosimetry and identification of energetic charged particles in fluxes of up to 10$^8$ cm$^{-2}$ s$^{-1}$ (omnidirectional). Achieving this capability with such a small instrument could open new prospects for radiation detection in space.Comment: 17 pages, 15 figure

Effects of Prolonged Intravenous Flunixin Meglumine in Healthy Dogs

This study was designed to evaluate possible side effects on liver and kidney functions and haematological indices, associated with long-term intravenous (IV) administration of flunixin meglumine in healthy dogs. For this purpose, 12 dogs were divided into 2 equal groups. Group 1 was intravenously given flunixin meglumine at the dose of 1.1 mg/kg/day for 5 days and g-roup 11 received 2.2 mg/kg/day IV for 5 days. Blood samples were withdrawn before treatment (day 0), 2 h post injection on each day of treatment and one day after the last injection for biochemical (glucose, sodium-Na, potassium-K, chloride-Cl, creatinine, urea, alkaline phosphatase-AP, alanine amino transferase-ALT and total protein) and haematological (bleeding time, coagulation time, red blood cell, white blood cell, platelet count, differential leukocyte count, haematocrit and haemoglobin) analyses. Faecal and urine samples were collected on the same days as blood samples for the presence of any abnormalities. The results revealed a significant increase in bleeding (P < 0.001) and coagulation time (P < 0.001) and a decrease in platelet count (P < 0.001) in both groups. There was also a significant increase in the concentration of Na and Cl in group 1 and an elevation in AP (P < 0.00 07 ALT (P < 0.001) and glucose (P < 0.001) in group II. Blood in urine and faeces was also evident in both groups. The results may suggest that the dose of 1.1 mg/kg IV for 5 d does not cause any significant side effects provided that no bleeding disorder exists. and the dose of 2.2 mg/kg IV for 5 d should not exceed 3 d as liver enzymes began to increase significantly afterwards

Semiquantitative promoter methylation of MLH1 and MSH2 genes and their impact on sperm DNA fragmentation and chromatin condensation in infertile men

To investigate the semiquantitative methylation alterations of MLH1 and MSH2 and the possible association among methylation of MLH1 and MSH2, sperm DNA fragmentation and sperm chromatin condensation in idiopathic oligoasthenoteratozoospermic men. Seventy-five idiopathic infertile men and 52 fertile and/or normozoospermic men were included in the study. SDF was analysed using the TUNEL assay in semen samples of 100 men. Promoter methylation of MLH1 and MSH2 genes was assessed by semiquantitative methylight analysis in semen samples of 39 and 40 men respectively. Sperm chromatin condensation was evaluated using aniline blue staining in 114 men. MLH1 promoter methylation was positively correlated with the percentage of aniline blue positive spermatozoa (r = 0.401, p = 0.0188). On the other hand, MSH2 promoter methylation was negatively correlated with sperm concentration and total sperm count (r = −0.421, p = 0.0068 and r = 0.4408, p = 0.009 respectively)

Unimodal late fusion for NIST i-vector challenge on speaker detection

Speaker detection is a very interesting machine learning task for which the latest i-vector challenge has been coordinated by the National Institute of Standards and Technology (NIST). A simple late fusion approach for the speaker detection task on the i-vector challenge is presented. The approach is based on the late fusion of scores from the cosine distance method (the baseline) and the scores obtained from linear discriminant analysis. The results show that by adapting the simple late fusion approach, the framework can outperform the baseline score for the decision cost function on the NIST i-vector machine learning challenge

GaInNAs-based Hellish-vertical cavity semiconductor optical amplifier for 1.3 μm operation

Hot electron light emission and lasing in semiconductor heterostructure (Hellish) devices are surface emitters the operation of which is based on the longitudinal injection of electrons and holes in the active region. These devices can be designed to be used as vertical cavity surface emitting laser or, as in this study, as a vertical cavity semiconductor optical amplifier (VCSOA). This study investigates the prospects for a Hellish VCSOA based on GaInNAs/GaAs material for operation in the 1.3-μm wavelength range. Hellish VCSOAs have increased functionality, and use undoped distributed Bragg reflectors; and this coupled with direct injection into the active region is expected to yield improvements in the gain and bandwidth. The design of the Hellish VCSOA is based on the transfer matrix method and the optical field distribution within the structure, where the determination of the position of quantum wells is crucial. A full assessment of Hellish VCSOAs has been performed in a device with eleven layers of Ga0.35In0.65N0.02As0.08/GaAs quantum wells (QWs) in the active region. It was characterised through I-V, L-V and by spectral photoluminescence, electroluminescence and electro-photoluminescence as a function of temperature and applied bias. Cavity resonance and gain peak curves have been calculated at different temperatures. Good agreement between experimental and theoretical results has been obtained