1,721,354 research outputs found
Fabrication and studying the dielectric properties of (polystyrene-copper oxide) nanocomposites for piezoelectric application
Get PDFThe preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure
Fabrication of (Polymer Blend-magnesium Oxide) Nanoparticle and Studying their Optical Properties for Optoelectronic Applications
Get PDFNanocomposites used in many optical devices applications. This aims to preparation of new type of polymer and study their optical properties. The polyvinyl pyrrolidone-carboxymethyl cellulose blend and magnesium oxide nanocomposites have been fabricated. The nanocomposites are prepared for different concentrations of polymer blend and magnesium oxide nanoparticles. The optical properties of nanocomposites were studied. The experimental results showed that the absorbance, absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity of (PVP-CMC) blend are increased with increase of the MgO nanoparticles concentration. The transmittance and energy band gap are decreased with increase of the MgO nanoparticles concentration. The nanocomposites have high absorbance in UV region which may be used for radiation shielding application
Synthesis of (Poly-methyl Methacrylate-lead Oxide) Nanocomposites and Studying their A.C Electrical Properties for Piezoelectric Applications
Get PDFPiezoelectric materials have been prepared from (poly-methyl methacrylatelead oxide) nanocomposites for electronic applications. The lead oxide nanoparticles were added to poly-methyl methacrylate by different concentrations are (4, 8, and 12) wt%. The structural and dielectric properties of nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of nanocomposites decrease with increase in frequency of applied electric field. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of poly-methyl methacrylate increase with increase in lead oxide nanoparticles concentrations. The results of pressure sensor showed that the electrical resistance of (PMMA-PbO2 ) nanocomposites decreases with increase in pressure
Educational challenges faced by international medical graduates in the UK
Get PDFAhmed Hashim Gastroenterology Department, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK Introduction: International medical graduates (IMGs) in the UK constitute approximately one-quarter of the total number of doctors registered in the General Medical Council (GMC). The transition of IMGs into the health care system in the UK is accompanied by significant sociocultural and educational challenges. This study aims to explore the views of IMGs in medical training on the educational challenges they face.Methods: This study was conducted in the Kent, Surrey and Sussex region in 2015. All IMGs who work in medical (physicianly) training programs were included. Data were collected through a questionnaire and semi-structured interviews. Thematic approach was used to analyze the qualitative data.Results: Of the total 61 IMGs included, 17 responded to the survey and 3 were interviewed. The common educational barriers faced by IMGs were related to lack of appreciation of the values and structure of the National Health Service (NHS), ethical and medicolegal issues, receiving feedback from colleagues and the different learning strategies in the UK. IMGs suggested introduction of a mandatory dedicated induction program in the form of formal teaching sessions. They also believed that a supervised shadowing period prior in the first job in the UK would be beneficial. Further assessment areas should be incorporated into the prequalifying examinations to address specific educational needs such as NHS structure and hospital policies. Other measures such as buddying schemes with senior IMGs and educating NHS staff on different needs of IMGs should also be considered.Conclusion: This study highlighted important educational challenges faced by IMGs and generated relevant solutions. However, the opinions of the supervisors and other health care professionals need to be explored. Keywords: international medical graduates, IMG, educational barrier
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Computer-aided diagnosis of prostate cancer using multiparametric MRI and clinical features:A patient-level classification framework
No full textComputer-aided diagnosis (CAD) of prostate cancer (PCa) using multiparametric magnetic resonance imaging (mpMRI) is actively being investigated as a means to provide clinical decision support to radiologists. Typically, these systems are trained using lesion annotations. However, lesion annotations are expensive to obtain and inadequate for characterizing certain tumor types e.g. diffuse tumors and MRI invisible tumors. In this work, we introduce a novel patient-level classification framework, denoted PCF, that is trained using patient-level labels only. In PCF, features are extracted from three-dimensional mpMRI and derived parameter maps using convolutional neural networks and subsequently, combined with clinical features by a multi-classifier support vector machine scheme. The output of PCF is a probability value that indicates whether a patient is harboring clinically significant PCa (Gleason score ≥3+4) or not. PCF achieved mean area under the receiver operating characteristic curves of 0.79 and 0.86 on the PICTURE and PROSTATEx datasets respectively, using five-fold cross-validation. Clinical evaluation over a temporally separated PICTURE dataset cohort demonstrated comparable sensitivity and specificity to an experienced radiologist. We envision PCF finding most utility as a second reader during routine diagnosis or as a triage tool to identify low-risk patients who do not require a clinical read.</p
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