Development of a polysilicon process based on chemical vapor deposition, phase 1

The development of a dichlorosilane-based reductive chemical vapor deposition process for the production of polycrystalline silicon is discussed. Experimental data indicate that the ease of ignition and explosion severity of dichlorosilane (DCS)/air mixtures is substantially attenuated if the DCS is diluted with hydrogen. Redesign of the process development unit to accommodate safety related information is described. Several different sources of trichlorosilane were used to generate a mixture of redistributed chlorosilanes via Dowex ion exchange resin. The unseparated mixtures were then fed to an experimental reactor in which silicon was deposited and the deposited silicon analyzed for electrically active impurities. At least one trichlorosilane source provided material of requisite purity. Silicon grown in the experimental reactor was converted to single crystal material and solar cells fabricated and tested

Extreme Precision Antenna Reflector Study Results

Thermal and mechanical distortion degrade the RF performance of antennas. The complexity of future communications antennas requires accurate, dimensionally stable antenna reflectors and structures built from materials other than those currently used. The advantages and disadvantages of using carbon fibers in an epoxy matrix are reviewed as well as current reflector fabrications technology and adjustment. The manufacturing sequence and coefficient of thermal expansion of carbon fiber/borosilicate glass composites is described. The construction of a parabolic reflector from this material and the assembling of both reflector and antenna are described. A 3M-aperture-diameter carbon/glass reflector that can be used as a subassembly for large reflectors is depicted. The deployment sequence for a 10.5M-aperture-diameter antenna, final reflector adjustment, and the deployment sequence for large reflectors are also illustrated

Editorial

Sentinal malaria surveillance - More than a research too

The Oxygen Isotopic Composition of MIL 090001: A CR2 Chondrite with Abundant Refractory Inclusions

MIL 090001 is a large (>6 kg) carbonaceous chondrite that was classified as a member of the CV reduced subgroup (CVred) that was recovered during the 2009-2010 ANSMET field season [1]. Based on the abundance of refractory inclusions and the extent of aqueous alteration, Keller [2] suggested a CV2 classification. Here we report additional mineralogical and petrographic data for MIL 090001, its whole-rock oxygen isotopic composition and ion microprobe analyses of individual phases. The whole rock oxygen isotopic analyses show that MIL 090001 should be classified as a CR chondrite

A discrete time-dependent method for metastable atoms in intense fields

The full-dimensional time-dependent Schrodinger equation for the electronic dynamics of single-electron systems in intense external fields is solved directly using a discrete method. Our approach combines the finite-difference and Lagrange mesh methods. The method is applied to calculate the quasienergies and ionization probabilities of atomic and molecular systems in intense static and dynamic electric fields. The gauge invariance and accuracy of the method is established. Applications to multiphoton ionization of positronium and hydrogen atoms and molecules are presented. At very high intensity above saturation threshold, we extend the method using a scaling technique to estimate the quasienergies of metastable states of the hydrogen molecular ion. The results are in good agreement with recent experiments.Comment: 10 pages, 9 figure, 4 table

A PRELIMINARY INVESTIGATION OF THE RELATIONSHIP BETWEEN PAIN SENSITIVITY, BODY FAT DISTRIBUTION AND BLOOD LEVELS OF IL-6, CRP, TNF-Α AND LEPTIN.

Background and aims: Obese individuals have increased concentrations of pro-inflammatory cytokines and some other markers of inflammationand an increased risk of metabolic disorders. The relationship between obesity, pro-inflammatory cytokines and pain sensitivity response is not fully understood. Aim of the Study:To investigate associations between body fat distribution, C reactive protein (CRP), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-a), leptin and pain sensitivity in adults. Methods: 38 adults (n=18 women) were grouped as normal weight(n=22) or obese (n=16), based on body mass index (BMI).Measurements of pressure pain and cold pressor pain sensitivity response, biomarkers (venous blood), and body composition (dual X-ray absorptiometry) were evaluated for each participant. Results: Pressure pain threshold was significantly lower in obese(mean+SD=340.93±93.58 kpa)compared to the normal weight group(447.45±203.72 kpa, p=0.039, t-test). Forward regression suggested that high gynoid fat (g)was associated with lower pressure pain thresholds (ß=-0.383, p=0.028), high lower limb fat (g) was associated with lower cold pain thresholds (ß=-0.495, p=0.003)and high IL-6 predicted higher cold pain tolerance (ß=0.345, p = 0.049). Women were more sensitive to pressure pain (P=0.03). Conclusion: Gynoid and lower limb fat content correlated with pain sensitivity response in adults, whereby those with greater fat content were more sensitive to pain. However, this may be a reflection of the sex differences in pain sensitivity as women have greater gynoid and leg fat contents

Exploring the interdependencies of research funders in the UK

Investment in medical research is vital to the continuing improvement of the UK's health and wealth. It is through research that we expand our understanding of disease and develop new treatments for patients. Medical research charities currently contribute over £1 billion annually to medical research in the UK, of which over £350 million is provided by Cancer Research UK. Many charities, including Cancer Research UK, receive no government funding for their research activity. Cancer Research UK is engaged in a programme of work in order to better understand the medical research funding environment and demonstrate the importance of sustained investment. A key part of that is the Office of Health Economics‟ (OHE) 2011 report “Exploring the interdependency between public and charitable medical research”. This study found that there are substantial benefits, both financial and qualitative, from the existence of a variety of funders and that reductions in the level of government financial support for medical research are likely to have broader negative effects. This contributed to other evidence which found that the activities and funding of the charity, public and private sectors respectively are complementary, i.e. mutually reinforcing, rather than duplicative or merely substituting for one another. “Exploring the interdependencies of research funders in the UK” by the Office of Health Economics (OHE) and SPRU: Science and Technology Policy Research at the University of Sussex, represents a continued effort to build the evidence base around the funding of medical research. This report uncovers the extent to which funders of cancer research are interdependent, nationally and internationally. Key figures show that two thirds of publications acknowledging external support have relied on multiple funders, while just under half benefited from overseas funding, and almost a fifth are also supported by industry. In addition the analysis shows that the general public would not want tax funding of cancer research to be reduced, but would not donate enough to charities to compensate for any such reduction

An Exploration of Teacher Preparation Practices with Foundational Knowledge of Literacy

The Standards for the Preparation of Literacy Professionals 2017 published by the International Literacy Association provide the basis for high-quality literacy teacher preparation. This study used qualitative survey responses to explore the literacy practices that teacher educators use to promote understandings among preservice teachers for each grade-level band (i.e., Pre-K/Primary, Elementary/Intermediate, Middle/High School). The researchers used conceptualizations of teacher knowledge as a theoretical lens to better understand reported preparation practices. Data analysis revealed three themes: Teacher Educator Pedagogy, Course Content, Student and Program Expectations. Researchers posit that teacher educators do not evenly focus on all components of literacy and contend that preparation programs must examine their respective curricula to ensure that all components of literacy associated with foundational knowledge are addressed sufficiently