Electrical spin injection in p-type Si using Fe/MgO contacts

We report the successful electrical creation of spin polarization in p-type Si at room temperature by using an epitaxial MgO(001) tunnel barrier and Fe(001) electrode. Reflection high-energy electron diffraction observations revealed that epitaxial Fe/MgO(001) tunnel contacts can be grown on a (2 x 1) reconstructed Si surface whereas tunnel contacts grown on the (1 x 1) Si surface were polycrystalline. Transmission electron microscopy images showed a more flat interface for the epitaxial Fe/MgO/Si compared to that of the polycrystalline structure. For the Fe/MgO/p-Si devices, the Hanle and inverted Hanle effects were clearly observed at 300 K by using a three-terminal configuration, proving that spin polarization can be induced in the Si at room temperature. Effective spin lifetimes deduced from the width of the Hanle curve were 95 +/- 6 ps and 143 +/- 10 ps for the samples with polycrystalline and epitaxial MgO tunnel contacts, respectively. The observed difference can be qualitatively explained by the local magnetic field induced by the larger roughness of the interface of the polycrystalline sample. The sample with epitaxial Fe/MgO tunnel contact showed higher magnitude of the spin accumulation with a nearly symmetric behavior with respect to the bias polarity whereas that of the polycrystalline MgO sample exhibited a quite asymmetric evolution. This might be attributed to the higher degree of spin polarization of the epitaxial Fe/MgO(001) tunnel contact, which acts as a spin filter. Our experimental results suggest that an epitaxial MgO barrier is beneficial for creating spins in Si.Comment: Paper presented at SPIE Nanoscience + Engineering, Spintronics V session in San Diego, US on August 13th, 201

A longitudinal study of financial difficulties and mental health in a national sample of British undergraduate students

Previous research has shown a relationship between financial difficulties and poor mental health in students, but most research is cross-sectional. To examine longitudinal relationships over time between financial variables and mental health in students. A national sample of 454 first year British undergraduate students completed measures of mental health and financial variables at up to four time points across a year. Cross-sectional relationships were found between poorer mental health and female gender, having a disability and non-white ethnicity. Greater financial difficulties predicted greater depression and stress cross-sectionally, and also predicted poorer anxiety, global mental health and alcohol dependence over time. Depression worsened over time for those who had considered abandoning studies or not coming to university for financial reasons, and there were effects for how students viewed their student loan. Anxiety and alcohol dependence also predicted worsening financial situation suggesting a bi-directional relationship. Financial difficulties appear to lead to poor mental health in students with the possibility of a vicious cycle occurring

Longitudinal study of financial difficulties and mental health in a national sample of British undergraduate students

Background: Previous research has shown a relationship between financial difficulties and poor mental health in students, but most research is cross-sectional.Objectives: To examine longitudinal relationships over time between financial variables and mental health in students.Methods: A national sample of 454 first year British undergraduate students completed measures of mental health and financial variables at up to four time points across a year.Results: Cross-sectional relationships were found between poorer mental health and female gender, having a disability and non-white ethnicity. Greater financial difficulties predicted greater depression and stress cross-sectionally, and also predicted poorer anxiety, global mental health and alcohol dependence over time. Depression worsened over time for those who had considered abandoning studies or not coming to university for financial reasons, and there were effects for how students viewed their student loan. Anxiety and alcohol dependence also predicted worsening financial situation suggesting a bi-directional relationship.Conclusions: Financial difficulties appear to lead to poor mental health in students with the possibility of a vicious cycle occurring

Transrectal ultrasound of the prostatic urethra related to urodynamically assessed urethral resistance. A pilot study

In this pilot study on 17 men who underwent urodynamic investigation for various dysuric complaints, real-time transrectal ultrasonography (TRUS) was performed. From the images anatomical parameters were identified that correlated with obstructive urodynamic findings and urethral resistance parameters based on pressure-flow analysis. This study gives support for further clinical investigations to determine the value of TRUS for male patients with dysuric disorders. It also illustrates the anatomical basis of prostatic obstruction as quantified by objective urodynamic parameters

CNN Architectures for Large-Scale Audio Classification

Convolutional Neural Networks (CNNs) have proven very effective in image classification and show promise for audio. We use various CNN architectures to classify the soundtracks of a dataset of 70M training videos (5.24 million hours) with 30,871 video-level labels. We examine fully connected Deep Neural Networks (DNNs), AlexNet [1], VGG [2], Inception [3], and ResNet [4]. We investigate varying the size of both training set and label vocabulary, finding that analogs of the CNNs used in image classification do well on our audio classification task, and larger training and label sets help up to a point. A model using embeddings from these classifiers does much better than raw features on the Audio Set [5] Acoustic Event Detection (AED) classification task.Comment: Accepted for publication at ICASSP 2017 Changes: Added definitions of mAP, AUC, and d-prime. Updated mAP/AUC/d-prime numbers for Audio Set based on changes of latest Audio Set revision. Changed wording to fit 4 page limit with new addition

Spin Accumulation in Nondegenerate and Heavily Doped p-Type Germanium

Spin accumulation induced in p-type germanium from Fe/MgO tunnel contacts is studied as a function of hole concentration p (10^16 - 10^19 cm-3). For all p, the contacts are free of rectification and Schottky barrier, guaranteeing spin injection into the Ge and preventing spin accumulation enhancement by two-step tunneling via interface states. The observed spin accumulation is smallest for nondegenerate doping (p ~ 10^16 cm-3) and increases for heavily doped Ge. This trend is opposite to what is expected from spin injection and diffusion theory. For heavily doped Ge, the observed spin accumulation is orders of magnitude larger than predicted.Comment: To appear in Appl. Phys. Expres

Initial service management architecture

This document describes D2.2 of the Internet Next Generation project. Internet Next Generation is a project performed within the context of the Gigaport programme, and is funded by many organizations within the Netherlands. The architecture that is described within this document explains how customers of a Differentiated Services (DiffServ) network can manage the service that is provided by them, by reading and modifying QoS parameters in an interactive way. Which parameters are available and which values these parameters can take, is defined in the Service Level Specification (SLS), which is part of the Service Level Agreement (SLA). The form of management in which customers can modify the behaviour of the provided service is called Customer Service Management (CSM); the idea that customers can manage the behaviour of the provided service is not only interesting in case of DiffServ, but also in cases like Mobile IP, IP security or Virtual Private Networks (VPNs). The scope of this deliverable is restricted to QoS management in a DiffServ environment; a subsequent deliverable will extend this work and address how service .management can be performed in other environments, like IntServ / RSVP. This new deliverable will also address the problem of inter domain management

Вплив бюджетних інструментів на економічний розвиток регіонів України

В статье проанализировано влияние бюджетных инструментов на выравнивание экономического развития регионов Украины и предложены пути по снижению дифференциации экономического развития регионов.У статті проаналізовано вплив бюджетних інструментів на вирівнювання економічного розвитку регіонів України та запропоновані шляхи по зниженню диференціації економічного розвитку регіонів.There is the influence of budget instruments on the leveling economic development of Ukrainian regions and the ways to go down differentions of regional economic development