Analysis of a Hybrid Solar Collector Photovoltaic Thermal (PVT)

AbstractA solar hybrid photovoltaic thermal (PVT) is a set of combined solar collector, which consists of a photovoltaic module (PV) for the conversion of electrical energy and solar plan for the high efficiency thermal energy conversion, in the same frame.An attempt made to analyze the hybrid solar collector using Computational Fluid Dynamics (CFD) to simulate the PVT solar collector to a better understanding of heat transfer capabilities in this type of systems. In the present work, the fluid flow and heat transfer in the module are studied using the ANSYS14 software. The heat transfer phenomenon conjugate between the photovoltaic cells and the coolant is modeled using the FLUENT software. The transfer of heat by the solar radiation is not modeled; however, the effects of radiation are taken for consideration when calculating the conditions for heat flux limit for the collector region. The geometric model and fluid domain for the CFD analysis is generated using ANSYS software DesingModeler, mesh geometry is carried out by ANSYS Meshing Software

Effect of O2 increase on properties of vanadium oxide coatings

The present research was carried out with the aim of studying the influence of oxygen concentration during processing on the properties of the VOx coatings deposited by cathodic magnetron sputtering on a stainless steel AISI 316L substrate. Mechanical and tribological properties were measured by nanoindentation and sliding wear tests respectively. Adhesion was evaluated by means of the scratch test. In order to determine the texture of the coatings, complementary characterization methods including X-ray diffraction in grazing incidence and Bragg Brentano configurations, as well as V scans, were performed. It was found that the texture of the crystalline coatings is strongly influenced by the amount of partial pressure of oxygen in the reactor atmosphere. The V2O5 phase, with an orthorhombic symmetry, was produced in the coating, which had a pronounced texturing for the (001) plane, exhibiting the best values of hardness and Young modulus. It was shown that, as the oxygen concentration drops to ,1 sccm, the mechanical and tribological characteristics, as well as the coating adhesion, tend to decrease considerably

Historical Scientific Racism and Psychiatric Publications: A Necessary International Anti-racist Code of Ethics

Ethical aspects of publishing in scientific journals are an important issue addressed since the late 1970s by the International Committee of Medical Journal Editors (1978). Today, medical journals also benefit from other international organizations’ recommendations such as the Committee on Publication Ethics, World Association of Medical Editors, and World Health Organization (WHO). These international best practices guidelines cover various ethical issues related to integrity in research, authorship, conflicts of interest, and so on

Projet « cabinets de groupe » : collaboration entre médecine de premier recours et psychiatrie [« Group medical practices » project : collaboration between primary care medicine and institutional public psychiatry]

Collaboration between primary care medicine and psychiatry is a well-known challenge. In order to improve access to psychological care for patients undergoing primary care, the « group medical practices » project proposes a collaborative care model in which a psychiatrist employed by a public psychiatric institution integrates group medical practices in order to provide assistance to primary care physicians. It is thus able to evaluate patients directly in the practices and to offer supervision and consilium spaces to primary care physicians

Central factorials under the Kontorovich-Lebedev transform of polynomials

We show that slight modifications of the Kontorovich-Lebedev transform lead to an automorphism of the vector space of polynomials. This circumstance along with the Mellin transformation property of the modified Bessel functions perform the passage of monomials to central factorial polynomials. A special attention is driven to the polynomial sequences whose KL-transform is the canonical sequence, which will be fully characterized. Finally, new identities between the central factorials and the Euler polynomials are found.Comment: also available at http://cmup.fc.up.pt/cmup/ since the 2nd August 201

Micrometastasis Detection Guidance by Whole-Slide Image Texture Analysis in Colorectal Lymph Nodes

Introduction/ Background Cancer is a disease that affects millions worldwide and accurate determination of whether lymph nodes (LNs) near the primary tumor contain metastatic foci is of critical importance for proper patient management. Histopathological evaluation is the only accepted method to make that determination. However, the current standard of care only examines a single central histological section per LN and yields an unacceptable false-negative rate. Aims To help pathologists in their examination we propose a method that extracts textural features from histopathological LN whole slide images (WSI) and then applies support vector machines (SVMs) to automatically identify regions suspicious for metastatic foci. Methods The database consisted of WSI from 44 LNs. Sections were stained with hematoxylin-eosin and examined at 20x (0.45μm resolution). Twenty-eight of the LNs were identified by an expert pathologist as positive for cancer (P), and the remaining sixteen were negative (N). This database was divided into two groups. Group 1 (15P and 5N) was used for training and Group 2 (13P and 11N) was used for testing the classification technique. For all analysis each WSI was divided into non-overlapping 1000 x 1000 pixel sub-images that will be referred to as high-power fields (HPFs). For each LN in Group 1, at least one WSI was annotated by a pathologist to identify rectangular, HPF-scale regions as locally cancerous or locally non-cancerous. From these annotated slides, 924 HPFs (462 P and 462 N) were obtained. For each of these HPFs, statistical features based on gray-level co-occurrence matrices [1] and Law’s texture energy measures [2, 3] were extracted from 9 derived images [4]. The extracted features were submitted to a sequential forward selection (SFS) method [5] to select few non-redundant features providing best class separation (cancerous vs. non-cancerous region). Combinations of the selected features were tested on the 924 HPFs using k-fold cross-validation to find those that produced the best results and consequently to train our SVM-based classifier. In Group 2, WSI were not annotated for cancerous and non-cancerous zones on a HPF scale. Each LN, however, had been labeled by a pathologist as positive or negative for cancer. For each WSI, each section was divided into contiguous HPFs, and those which mainly contain fatty tissue, background, and tears were automatically excluded. Each selected HPFs was classified as cancerous or non-cancerous using the previously trained classifier to obtain the total number of cancer-classified per LN. A receiver operating characteristics (ROC) curve was traced by changing the discriminator threshold (T) used to label the LN as P for cancer as a function of the total number of cancer-classified HPFs. Results During training, 5 Laws features were selected by SFS. Highly satisfactory k-fold cross-validation with a F-score of 0.996 ± 0.005 was obtained using only 2 statistical features computed at different scales. The ROC curve obtained by applying the SVM-classifier to the test set is shown in the next figure. Two valuable operating points can be identified which both guaranteed no false-negative. At T=11 we got 2 false-positives and an optimal F-score of 0.917, and with a more conservative approach, T=1, we got 7 false-positives and a F-score of 0.759. The top-left part of the slide displayed in next figure would have been proposed to the pathologist as the most suspicious region of the cancerous LN

Exchange Rate Pass-Through into German Import Prices – A Disaggregated Perspective

This study analyzes the exchange rate pass-through into German import prices based on disaggregated data taken on a monthly basis between 1995 and 2012. Our main contribution is twofold: firstly, we employ various time-series techniques to analyze data for different product categories, and also cointegration techniques to carefully distinguish between short-run and long-run pass-through coefficients. Secondly, in a panel data approach we estimate time-varying pass-through coefficients and explain their development with regard to various macroeconomic factors. Our results show that long-run pass-through is only partly observable and incomplete, while short-run pass-through shows a more unique character, although heterogeneity across product groups does exist. We are also able to identify several macroeconomic factors which determine changes in the degree of pass-through, which is especially relevant for policymakers

A Spatially Resolved Single-Cell Genomic Atlas of the Adult Human Breast

The adult human breast is comprised of an intricate network of epithelial ducts and lobules that are embedded in connective and adipose tissue1-3. Although most previous studies have focused on the breast epithelial system4-6, many of the non-epithelial cell types remain understudied. Here we constructed the comprehensive Human Breast Cell Atlas (HBCA) at single-cell and spatial resolution. Our single-cell transcriptomics study profiled 714,331 cells from 126 women, and 117,346 nuclei from 20 women, identifying 12 major cell types and 58 biological cell states. These data reveal abundant perivascular, endothelial and immune cell populations, and highly diverse luminal epithelial cell states. Spatial mapping using four different technologies revealed an unexpectedly rich ecosystem of tissue-resident immune cells, as well as distinct molecular differences between ductal and lobular regions. Collectively, these data provide a reference of the adult normal breast tissue for studying mammary biology and diseases such as breast cancer