5,993 research outputs found

    Flammability study of materials in oxygen environments

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    Report presents flame-propagation rates and flammability ratings of 780 specimens of commercially available plastics, elastomers, coatings, fabrics, and other sheet materials. Test results are also given for over 1970 samples of most commonly used electrical harnesses, connectors, and potting compounds

    Innovative all composite multi-pultrusion truss system for stressed arch deployable shelters

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    Trusses are one of the successful structural forms that have been utilised, at extended scale, since the nineteen century. Fibre composite materials are relatively new to civil engineering applications. The increased interest in using composites in civil applications can be attributed to advantages when compared to other construction materials that offset their associated costs. Using conventional approaches for truss systems in composite materials can undermine their efficiency. This is mainly due to concentration of stresses at connections which usually govern the truss design. The Military Modular Shelter System (M2S2) initiative is a research project that aims to develop a fibre composite re-deployable arched shelter system with rigid PVC or fabric cladding. The main frames are formed from modular fibre composite panels that are connected and stressed into position by prestressing cables. Different geometries can be obtained using this system by changing the number of panels per frame and the packer sizes between panels. This paper presents the development and testing of innovative fibre composite truss modules that were investigated as part of this project. The truss system is based on using multi-pultrusion sections for the chord and vertical members. Truss bracing is provided by a double skin laminated web. This structure offers many advantages including semi-ductile failure that occurred outside the joint area and ease of manufacturing. In spite of being developed for the M2S2 system, the concept is similarly applicable as a general purpose truss system

    Alien Registration- Key, Richard G. (Portland, Cumberland County)

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    https://digitalmaine.com/alien_docs/22095/thumbnail.jp

    Cloud cover determination in polar regions from satellite imagery

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    A definition is undertaken of the spectral and spatial characteristics of clouds and surface conditions in the polar regions, and to the creation of calibrated, geometrically correct data sets suitable for quantitative analysis. Ways are explored in which this information can be applied to cloud classifications as new methods or as extensions to existing classification schemes. A methodology is developed that uses automated techniques to merge Advanced Very High Resolution Radiometer (AVHRR) and Scanning Multichannel Microwave Radiometer (SMMR) data, and to apply first-order calibration and zenith angle corrections to the AVHRR imagery. Cloud cover and surface types are manually interpreted, and manual methods are used to define relatively pure training areas to describe the textural and multispectral characteristics of clouds over several surface conditions. The effects of viewing angle and bidirectional reflectance differences are studied for several classes, and the effectiveness of some key components of existing classification schemes is tested

    Cloud cover determination in polar regions from satellite imagery

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    The principal objectives of this project are: (1) to develop suitable validation data sets to evaluate the effectiveness of the International Satellite Cloud Climatology Project (ISCCP) operational algorithm for cloud retrieval in polar regions and to validate model simulations of polar cloud cover; (2) to identify limitations of current procedures for varying atmospheric surface conditions, and to explore potential means to remedy them using textural classifiers; and (3) to compare synoptic cloud data from a control run experiment of the GISS climate model II with typical observed synoptic cloud patterns

    Shareholder Reactions to Judicial Decisions Affecting Sales Tax and Direct Marketing Activities

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    This study examines shareholder reactions to judicial decisions that affect sales tax collection by firms conducting direct marketing activities.  Abnormal returns are measured for four dates related to the 1992 United States Supreme Court decision in Quill.  Results do not indicate statistically significant returns, but some tests indicate differential firm reactions.  Therefore, abnormal returns are also calculated for subsets of firms that are relatively more affected by the court decisions, but no statistically significant results are obtained.  More research is needed in order to determine whether sales tax avoidance is a meaningful incentive for mail order and Internet purchasers

    Minimal PD-sets for codes associated with the graphs Qm2, m even

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    Please read abstract in the article.The National Research Foundation of South Africahttp://link.springer.com/journal/2002021-12-08hj2021Mathematics and Applied Mathematic

    Sales Tax And Consumer Purchase Decisions

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    This study uses an experimental design to investigate the effect of sales tax on consumer mail order purchase intentions.  Economic- and psychology-based theories generate alternative predictions for purchase intentions.  Overall the results show that no conclusion can be made that sales tax affects consumer purchase intentions

    A slow and dark atomic beam

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    We demonstrate a method to produce a very slow atomic beam from a vapour cell magneto-optical trap. Atoms are extracted from the trap using the radiation pressure imbalance caused by a push beam. An additional transfer beam placed near the center of the trap transfers the atomic beam into an off-resonant state. The velocity of the atomic beam has been varied by changing the intensity of the push beam or the position of the transfer beam. The method can be used to generate a continuous, magnetically guided atomic beam in a dark state.Comment: 14 page
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