7,170 research outputs found
A Naturalist\u27s Guide to Ontario (book review)
A NATURALIST\u27S GUIDE TO ONTARIO. W. W. Judd and J. M. Speirs (eds.). Published for the Federation of Ontario Naturalists by University of Toronto Press. 210 pp., 6 1/8 x 9 1/4 in. 1964. Price: cloth, 1.95
Brayton heat exchanger unit development program (alternate design)
A Brayton Heat Exchanger Unit Alternate Design (BHXU-Alternate) consisting of a recuperator, a heat sink heat exchanger, and a gas ducting system, was designed and fabricated. The design was formulated to provide a high performance unit suitable for use in a long-life Brayton-cycle powerplant. Emphasis was on double containment against external leakage and leakage of the organic coolant into the gas stream. A parametric analysis and design study was performed to establish the optimum component configurations to achieve low weight and size and high reliability, while meeting the requirements of high effectiveness and low pressure drop. Layout studies and detailed mechanical and structural design were performed to obtain a flight-type packaging arrangement, including the close-coupled integration of the BHXU-Alternate with the Brayton Rotating Unit (BRU)
Synthesis And Characterization Of (pyNOâ)2GaCl: A Redox-Active Gallium Complex
We report the synthesis of a gallium complex incorporating redox-active pyridyl nitroxide ligands. The (pyNOâ)2GaCl complex was prepared in 85% yield via a salt metathesis route and was characterized by 1H and 13C NMR spectroscopies, X-ray diffraction, and theory. UVâVis absorption spectroscopy and electrochemistry were used to access the optical and electrochemical properties of the complex, respectively. Our discussion focuses primarily on a comparison of the gallium complex to the corresponding aluminum derivative and shows that although the complexes are very similar, small differences in the electronic structure of the complexes can be correlated to the identity of the metal
Farmer perception of benefits, constraints and opportunities for silvoarable systems: preliminary insights from Bedfordshire, England
Silvoarable agroforestry integrates the use of trees and arable crops on the same area of land, and such systems can be supported by national governments under the European Unionâs (EU) Rural Development Regulations (2014â2020). In order to improve the understanding of farmersâ perceptions of such systems, detailed face-to-face interviews were completed with 15 farmers in Bedfordshire, England. Most of these farmers thought that silvoarable systems would not be profitable on their farms and that benefits would tend to be environmental or social rather than economic. Most farmers also thought that management and use of machinery would become more difficult. They felt that the tree component could potentially disrupt field operations and drainage and expressed concerns over the uncertain and long-term nature of timber revenue and the effect of intercrop yield reductions on crop revenue. Even so, 20% of the farmers stated they would use silvoarable systems if convinced that they were more profitable than conventional arable farming. A further 20% said they would farm the intercrop area belonging to someone else, if the rent was reduced to compensate for crop yield reductions. These results suggest that for most arable farmers, an economic advantage over current practice needs to exist before silvoarable systems are likely to be adopted. However, a minority might rent the crop component of a silvoarable system from another party or implement a full system for perceived environmental or social benefits
Distributions of eight meteorological variables at Cape Kennedy, Florida and Vandenberg Air Force Base, California
Extreme values, median values, and nine percentile values are tabulated for eight meteorological variables at Cape Kennedy, Florida and at Vandenberg Air Force Base, California. The variables are temperature, relative humidity, station pressure, water vapor pressure, water vapor mixing ratio, density, and enthalpy. For each month eight hours are tabulated, namely, 0100, 0400, 0700, 1000, 1300, 1600, 1900, and 2200 local time. These statistics are intended for general use for the space shuttle design trade-off analysis and are not to be used for specific design values
Evidence based care and prioritisation of people waiting for elective hip and knee replacement surgery : the new Victorian management and prioritsation system
Semi-automatic segmentation of subcutaneous tumours from micro-computed tomography images
Cataloged from PDF version of article.This paper outlines the first attempt to segment the boundary of preclinical subcutaneous tumours, which are frequently used in cancer research, from micro-computed tomography (microCT) image data. MicroCT images provide low tissue contrast, and the tumour-to-muscle interface is hard to determine, however faint features exist which enable the boundary to be located. These are used as the basis of our semi-automatic segmentation algorithm. Local phase feature detection is used to highlight the faint boundary features, and a level set-based active contour is used to generate smooth contours that fit the sparse boundary features. The algorithm is validated against manually drawn contours and micro-positron emission tomography (microPET) images. When compared against manual expert segmentations, it was consistently able to segment at least 70% of the tumour region (n = 39) in both easy and difficult cases, and over a broad range of tumour volumes. When compared against tumour microPET data, it was able to capture over 80% of the functional microPET volume. Based on these results, we demonstrate the feasibility of subcutaneous tumour segmentation from microCT image data without the assistance of exogenous contrast agents. Our approach is a proof-of-concept that can be used as the foundation for further research, and to facilitate this, the code is open-source and available from www.setuvo.com. © 2013 Institute of Physics and Engineering in Medicine
NASA Data Acquisition System Software Development for Rocket Propulsion Test Facilities
Current NASA propulsion test facilities include Stennis Space Center in Mississippi, Marshall Space Flight Center in Alabama, Plum Brook Station in Ohio, and White Sands Test Facility in New Mexico. Within and across these centers, a diverse set of data acquisition systems exist with different hardware and software platforms. The NASA Data Acquisition System (NDAS) is a software suite designed to operate and control many critical aspects of rocket engine testing. The software suite combines real-time data visualization, data recording to a variety formats, short-term and long-term acquisition system calibration capabilities, test stand configuration control, and a variety of data post-processing capabilities. Additionally, data stream conversion functions exist to translate test facility data streams to and from downstream systems, including engine customer systems. The primary design goals for NDAS are flexibility, extensibility, and modularity. Providing a common user interface for a variety of hardware platforms helps drive consistency and error reduction during testing. In addition, with an understanding that test facilities have different requirements and setups, the software is designed to be modular. One engine program may require real-time displays and data recording; others may require more complex data stream conversion, measurement filtering, or test stand configuration management. The NDAS suite allows test facilities to choose which components to use based on their specific needs. The NDAS code is primarily written in LabVIEW, a graphical, data-flow driven language. Although LabVIEW is a general-purpose programming language; large-scale software development in the language is relatively rare compared to more commonly used languages. The NDAS software suite also makes extensive use of a new, advanced development framework called the Actor Framework. The Actor Framework provides a level of code reuse and extensibility that has previously been difficult to achieve using LabVIEW. Th
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