The separation and microdetermination of cobalt in high purity nickel

It has been found that many substances in an extremely pure form or containing certain trace impurities exhibit many unique physical and chemical properties. Investigators studying these properties have encountered many difficulties, especially in preparing the extremely pure substance and/or in accurately determining the quantity of impurities present. These problems arise chiefly from the very similar chemical properties of the constituents being separated and the possibility of contamination during the necessary processing of the substance for purification or analysis. Trace analysis, therefore, has become very important in recent years. Where previously analyses based upon parts per hundred were adequate, now the analyst is being required to determine parts per million and in some cases parts per billion of minor constituents. These analyses have been made possible only by the development of specific methods, which either extend the reliable lower limits of standard analytical procedures or apply new principles or reagents. The United States Bureau of Mines has recently been interested in the production of extremely high purity nickel. They found the standard analytical procedures for the quantitative determination of residual cobalt, necessary to establish the purity of nickel produced, inadequate. The results obtained for a given sample by application or different methods of analysis and by different analysts, both staff and independent, varied widely. Because of this, it was decided to initiate an investigation on the analysis of trace amounts of cobalt in high purity nickel, which would give reproducible results. The purpose of this investigation was to develop a method employing ion exchange techniques for the quantitative separation and concentration of residual amounts of cobalt contained in high purity nickel; so standard analytical procedures could be reliably applied for the quantitative determination of cobalt --Introduction, pages 1-2

Photovoltaic system test facility electromagnetic interference measurements

Field strength measurements on a single row of panels indicates that the operational mode of the array as configured presents no radiated EMI problems. Only one relatively significant frequency band near 200 kHz showed any degree of intensity (9 muV/m including a background level of 5 muV/m). The level was measured very near the array (at 20 ft distance) while Federal Communications Commission (FCC) regulations limit spurious emissions to 15 muV/m at 1,000 ft. No field strength readings could be obtained even at 35 ft distant

Parameters for Twisted Representations

The study of Hermitian forms on a real reductive group $G$ gives rise, in the unequal rank case, to a new class of Kazhdan-Lusztig-Vogan polynomials. These are associated with an outer automorphism $\delta$ of $G$, and are related to representations of the extended group $$. These polynomials were defined geometrically by Lusztig and Vogan in "Quasisplit Hecke Algebras and Symmetric Spaces", Duke Math. J. 163 (2014), 983--1034. In order to use their results to compute the polynomials, one needs to describe explicitly the extension of representations to the extended group. This paper analyzes these extensions, and thereby gives a complete algorithm for computing the polynomials. This algorithm is being implemented in the Atlas of Lie Groups and Representations software

New species, additions and a key to the Brazilian species of the Geminata clade of Solanum L. (Solanaceae) in Brazil

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article.NHM Repositor

Computer-aided detection in musculoskeletal projection radiography: A systematic review

This is the author accepted manuscript. The final version is available from WB Saunders via the DOI in this record.Objectives To investigated the accuracy of computer-aided detection (CAD) software in musculoskeletal projection radiography via a systematic review. Key findings Following selection screening, eligible studies were assessed for bias, and had their study characteristics extracted resulting in 22 studies being included. Of these 22 three studies had tested their CAD software in a clinical setting; the first study investigated vertebral fractures, reporting a sensitivity score of 69.3% with CAD, compared to 59.8% sensitivity without CAD. The second study tested dental caries diagnosis producing a sensitivity score of 68.8% and specificity of 94.1% with CAD, compared to sensitivity of 39.3% and specificity of 96.7% without CAD. The third indicated osteoporotic cases based on CAD, resulting in 100% sensitivity and 81.3% specificity. Conclusion The current evidence reported shows a lack of development into the clinical testing phase; however the research does show future promise in the variation of different CAD systems

The relationship between sagittal curvature and extensor muscle volume in the lumbar spine.

This is the peer reviewed version of the article, which has been published in final form at doi: 10.1111/joa.12047. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.A previous modelling study predicted that the forces applied by the extensor muscles to stabilise the lumbar spine would be greater in spines that have a larger sagittal curvature (lordosis). Because the force-generating capacity of a muscle is related to its size, it was hypothesised that the size of the extensor muscles in a subject would be related to the size of their lumbar lordosis. Magnetic resonance imaging (MRI) data were obtained, together with age, height, body mass and back pain status, from 42 female subjects. The volume of the extensor muscles (multifidus and erector spinae) caudal to the mid-lumbar level was estimated from cross-sectional area measurements in axial T1-weighted MRIs spanning the lumbar spine. Lower lumbar curvature was determined from sagittal T1-weighted images. A stepwise linear regression model was used to determine the best predictors of muscle volume. The mean lower lumbar extensor muscle volume was 281 cm(3) (SD = 49 cm(3)). The mean lower lumbar curvature was 30 ° (SD = 7 °). Five subjects reported current back pain and were excluded from the regression analysis. Nearly half the variation in muscle volume was accounted for by the variables age (standardised coefficient, B = -3.2, P = 0.03) and lower lumbar curvature (B = 0.47, P = 0.002). The results support the hypothesis that extensor muscle volume in the lower lumbar spine is related to the magnitude of the sagittal curvature; this has implications for assessing muscle size as an indicator of muscle strength

Defense Mechanisms of Biological Cells: A Framework for Network Security Thinking

Computer and network security are central issues confronting organizations and individuals. This paper explores the use of biology as a reference discipline that can provide meaningful insight and innovation in the area of network security. Specifically, we propose a framework for thinking about network security by examining the similarities between the defense mechanisms of a cell, and the security processes and methodologies of networked computer systems that defend an organization\u27s information resources. Researchers and commercial developers can use this framework to help spark ideas that lead to further research and development in network security. The framework also provides a platform for educators in teaching students about the functions of computer network concepts. Our analysis of defense mechanisms in biological cells showed that security in cells is integrated, ubiquitous, and continuous. An example illustrates how the framework can generate ideas for improving network security