Electrical, Optical and Thermal Investigations of Cobalt Oxide-Antimony Doped Tin Oxide (CoO-ATO) Thin Films and Nanofiber Membranes

The main aim of this thesis work is to investigate the electrical, optical and thermal impact characteristics of cobalt oxide doped antimony tin oxide (CoO-ATO) in the form of thin films and nanofiber membranes. CoO-ATO is a novel composite material that has the potential to be used as reinforced aircraft coatings, military garment coatings, or more specifically as an anti-reflective (AR) top coating for photovoltaic (PV) cells. This work will be critical in determining the effectiveness of using a CoO-ATO layer in these applications. Electrospun nanofibers and spin coated thin films consisting of a polymeric solution of CoO-ATO will be used. Thin films are created using spin coating techniques, and nanofiber membranes are created using an electrospinning technique. Polystyrene (PS) will be used as a solute, and chloroform as a solvent, to create the solution. It is hypothesized that coatings of this material will have improved optical characteristics as compared to traditional ATO coatings and minimum impact from thermal cycling making it a favorable candidate for PV cells. This work will do an electrical, optical and thermal cycling impact characterization of CoO-ATO thin films and nanofiber membranes for a doping range of x% CoO where x ranged from 0.

Investigation of glass corrosion in acid solutions with ²⁹Si-MAS-NMR

Thin foils of potash-lime-silicate glass were corroded in acid solutions for different time periods. The formation of a gel layer was determined by IR spectroscopy and solution analysis. The applicability of ²⁹Si-MAS-NMR spectroscopy as an analytical tool for characterizing gel layers was investigated. The obtained spectra of increasingly corroded foils show the growth of a new peak at the highfield side of the main glass peak. This peak can be attributed to Q4 silicon units. The formation of Q4 silicon is believed to be due to a condensation reaction of previously hydrolyzed Si-OH groups in the gel layer

Muon pair production in electron proton collisions

Events containing pairs of isolated muons at high invariant masses have been detected at HERA with the H1 detector in a data sample corresponding to an integrated luminosity of 70.9 1/pb of electron(positron)-proton scattering at centre of mass energies of 318 GeV. The results are well described by the Standard Model prediction which is dominated by photon-photon collisions. No evidence of processes beyond the standard model has been observed

What explains health in persons with visual impairment?

Background: Visual impairment is associated with important limitations in functioning. The International Classification of Functioning, Disability and Health (ICF) adopted by the World Health Organisation (WHO) relies on a globally accepted framework for classifying problems in functioning and the influence of contextual factors. Its comprehensive perspective, including biological, individual and social aspects of health, enables the ICF to describe the whole health experience of persons with visual impairment. The objectives of this study are (1) to analyze whether the ICF can be used to comprehensively describe the problems in functioning of persons with visual impairment and the environmental factors that influence their lives and (2) to select the ICF categories that best capture self-perceived health of persons with visual impairment. Methods: Data from 105 persons with visual impairment were collected, including socio-demographic data, vision-related data, the Extended ICF Checklist and the visual analogue scale of the EuroQoL-5D, to assess self-perceived health. Descriptive statistics and a Group Lasso regression were performed. The main outcome measures were functioning defined as impairments in Body functions and Body structures, limitations in Activities and restrictions in Participation, influencing Environmental factors and self-perceived health. Results: In total, 120 ICF categories covering a broad range of Body functions, Body structures, aspects of Activities and Participation and Environmental factors were identified. Thirteen ICF categories that best capture self-perceived health were selected based on the Group Lasso regression. While Activities-and-Participation categories were selected most frequently, the greatest impact on self-perceived health was found in Body-functions categories. The ICF can be used as a framework to comprehensively describe the problems of persons with visual impairment and the Environmental factors which influence their lives. Conclusions: There are plenty of ICF categories, Environmental-factors categories in particular, which are relevant to persons with visual impairment, but have hardly ever been taken into consideration in literature and visual impairment-specific patient-reported outcome measures

Variational Autoencoders for Anomalous Jet Tagging

We present a detailed study on Variational Autoencoders (VAEs) for anomalous jet tagging at the Large Hadron Collider. By taking in low-level jet constituents' information, and training with background QCD jets in an unsupervised manner, the VAE is able to encode important information for reconstructing jets, while learning an expressive posterior distribution in the latent space. When using the VAE as an anomaly detector, we present different approaches to detect anomalies: directly comparing in the input space or, instead, working in the latent space. In order to facilitate general search approaches such as bump-hunt, mass-decorrelated VAEs based on distance correlation regularization are also studied. We find that the naive mass-decorrelated VAEs fail at maintaining proper detection performance, by assigning higher probabilities to some anomalous samples. To build a performant mass-decorrelated anomalous jet tagger, we propose the Outlier Exposed VAE (OE-VAE), for which some outlier samples are introduced in the training process to guide the learned information. OE-VAEs are employed to achieve two goals at the same time: increasing sensitivity of outlier detection and decorrelating jet mass from the anomaly score. We succeed in reaching excellent results from both aspects. Code implementation of this work can be found at \href{https://github.com/taolicheng/VAE-Jet}{Github}.Comment: 35 pages, 22 figures. Revised versio

Electroweak Sphalerons with Spin and Charge

We show that, at finite weak mixing angle the sphaleron solution of Weinberg-Salam theory can be endowed with angular momentum proportional to the electric charge. Carrying baryon number 1/2 these sphalerons with spin and charge may contribute to baryon number violating processes.Comment: 5 pages, 2 figure

Samverkan mellan insocialiseringstaktiker, self-efficacy och organisatoriskt engagemang

Denna studie har undersökt eventuella samband mellan isocialiseringstaktiker under introduktionsprocessen för nyanställda och deras upplevda self-efficacy och organisatoriska engagemang. Det är en uppföljning av tidigare forskning gjord av Gareth Jones som använder en modifierad version av den enkät han utvecklade. Urvalet består av enskilda butiker från ett marknadsledande företag inom dagligvaruhandeln från hela landet som har en central styrning av introduktionsprocessen. Syftet med undersökningen är tudelat, dels finns en explorativ ansats som syftar till att studera om upplevelserna av insocialiseringstaktiken och utfallsmåtten kan påverkas av geografisk plats och lokal kultur om flera grupper som har samma arbetsuppgifter, tidigare erfarenheter och introduktionsprocess. Studiens ambition är att även kunna producera resultat som kan användas för vidare utveckling och anpassning av introduktionsprocesser på arbetsmarknaden för att nyanställda medarbetare ska känna sig så engagerade, involverade och kapabla som möjligt. Resultaten stödjer tidigare forskning som har funnit starka samband mellan insocialiseringstaktik och organisatoriskt engagemang. Samband till self-efficacy kunde också observeras, men utan entydiga resultat. Analyser visade också på skillnader mellan urvalsgrupperna beroende på geografisk plats, vilka antyder att fler faktorer än de som mäts i Jones instrument påverkar sambandet.This study examines correlations between socialization tactics for onboarding new employees and their experienced self-efficacy and organizational commitment. The study was proposed and inspired by Gareth Jones who studied socialization tactics and developed a survey for the theorized definition of the different tactics, which is used in a modified version. The sample is drawn from separate stores in a market leading retail company with common policies regarding the onboarding process. The goal of this study is two-fold; one explorative approach, with the purpose to probe potential influence from the geographic location of the workplace and local workplace culture on the experiences of the socialization tactics, self-efficacy and commitment in the case that the samples have similar duties, earlier experiences and onboarding process. The ambition is also to produce results that can be applied in the labor market for further development and enhancement of onboarding processes in order to improve new employees commitment, involvement and efficacy. The analysis support previous research and show strong significant correlations between socialization tactics and organizational commitment. Some partial or ambigious correlations between self-efficacy and socialization tactics could also be observed. Analysis of variance revealed significant differences between the different stores, which suggests that Jones’ survey is incomplete regarding variables that influence the experience of socialization tactics

A prospective, blinded evaluation of a video-assisted ‘4-stage approach’ during undergraduate student practical skills training

BACKGROUND: The 4-stage approach (4-SA) is used as a didactic method for teaching practical skills in international courses on resuscitation and the structured care of trauma patients. The aim of this study was to evaluate objective and subjective learning success of a video-assisted 4-SA in teaching undergraduate medical students. METHODS: The participants were medical students learning the principles of the acute treatment of trauma patients in their multidiscipline course on emergency and intensive care medicine. The participants were quasi- randomly divided into two groups. The 4-SA was used in both groups. In the control group, all four steps were presented by an instructor. In the study group, the first two steps were presented as a video. At the end of the course a 5-minute objective, structured clinical examination (OSCE) of a simulated trauma patient was conducted. The test results were divided into objective results obtained through a checklist with 9 dichotomous items and the assessment of the global performance rated subjectively by the examiner on a Likert scale from 1 to 6. RESULTS: 313 students were recruited; the results of 256 were suitable for analysis. The OSCE results were excellent in both groups and did not differ significantly (control group: median 9, interquantil range (IQR) 8–9, study group: median 9, IQR 8–9; p = 0.29). The global performance was rated significantly better for the study group (median 1, IQR 1–2 vs. median 2, IQR 1–3; p < 0.01). The relative knowledge increase, stated by the students in their evaluation after the course, was greater in the study group (85% vs. 80%). CONCLUSION: It is possible to employ video assistance in the classical 4-SA with comparable objective test results in an OSCE. The global performance was significantly improved with use of video assistance

Strong Resemblance in the Amplitude of Oscillatory Brain Activity in Monozygotic Twins Is Not Caused by "Trivial" Similarities in the Composition of the Skull

Previous twin studies have shown strong heritability of electroencephalogram amplitude characteristics, such as power spectra. However, it has been suggested that these high heritabilities may reflect "trivial" twin resemblance in intervening tissues such as the skull. Here we demonstrate strong monozygotic twin correlation (0.79 < r < 0.88) of eyes-closed resting-state magnetoencephalogram power, which is insensitive to intervening tissues. These results confirm that brain activity itself is highly heritable. © 2008 Wiley-Liss, Inc