26,215 research outputs found

    Finitely generated soluble groups and their subgroups

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    We prove that every finitely generated soluble group which is not virtually abelian has a subgroup of one of a small number of types.Comment: 16 page

    Weak shock waves in the ionosphere

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    Weak shock waves in ionosphere and simple model of chemistry of ionospheric D laye

    Machinery Transportation Management: Case Study of 'Plant-trailer' H&S Incidents

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    Purpose – The purpose of this paper is to investigate causal agents of health and safety (H&S)incidents among “plant-trailers” (as used by construction and utility contractors to transport mechanical machinery); including the relationship(s) of such incidents to routine safety inspections and, plant maintenance functions. Design/methodology/approach – H&S plant-trailer incident data, from a collaborating UK-based case study utility company are analysed using inductive, interpretative and descriptive statistical methods. Findings – Principal incident occurrences relate to trailer wheels, wheel bearings, tyres and braking systems. All forms of incidents observed harbour significant risk and especially, if they occur during travel on public highways. Derived recommendations for incident mitigation and Control, suggest a requirement for improved human behaviour, machinery inspection regimes and maintenance systems. Research limitations/implications – The findings will be valuable to academia as a basis for advancing this new research subject, both empirically and internationally. Direction is offered in this respect. Practical implications – Recommendations will be of practical relevance to machinery management practitioners generally and to plant-trailer stakeholders more Specifically. For the latter, the study encourages introspective consideration of plant-trailer H&S systems. Originality/value – No previous research has targeted these issues relating to plant-trailers. Keywords Risk, Inspection, Maintenance, Machinery, H&S, Trailers Paper type Case stud

    Eye-controlled ''teletypewriter''

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    Oculometer provides dynamic measurement of subject's look direction, and its outputs can be used to generate visual display of his look pattern and/or to cause equipment operation associated with his lookpoint at given times. Measured eye-direction information could be used as control input at man/machine interface

    Study of vortex valve for medium temperature solid propellants

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    Fluid state vortex valve secondary injection control system shows considerable promise for future application to solid propellant rocket engine thrust vector control. The single axis injection system tested would be capable of providing secondary injection thrust vector control using 2000 deg F gas

    Three-body forces and proton-rich nuclei

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    We present the first study of three-nucleon (3N) forces for proton-rich nuclei along the N=8 and N=20 isotones. Our results for the ground-state energies and proton separation energies are in very good agreement with experiment where available, and with the empirical isobaric multiplet mass equation. We predict the spectra for all N=8 and N=20 isotones to the proton dripline, which agree well with experiment for 18Ne, 19Na, 20Mg and 42Ti. In all other cases, we provide first predictions based on nuclear forces. Our results are also very promising for studying isospin symmetry breaking in medium-mass nuclei based on chiral effective field theory.Comment: 5 pages, 4 figures, minor changes, published versio

    Method for repair of thin glass coatings

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    A method of repairing cracks or damaged areas in glass, in particular, glass coatings provided on tile. The method includes removing the damaged area using a high speed diamond burr drilling out a cavity that extends slightly into the base material of the tile. All loose material is then cleaned from the drilled out cavity and the cavity is filled adjacent the upper surface of the coating with a filler material including chopped silica fibers mixed with a binder. The filler material is packed into the cavity and a repair coating is applied by means of a brush or sprayed thereover. The repair includes borosilicate suspended in solution. Heat is applied at approximately 2100 F. for approximately five minutes for curing the coating, causing boron silicide particles of the coating to oxidize forming a very fluid boron-oxide rich glass which reacts with the other frits to form an impervious, highly refractory layer

    Experimental Economics

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    This is the first comprehensive treatment of laboratory experiments designed to evaluate economic propositions under carefully controlled conditions. While it acknowledges that laboratory experiments are no panacea, it argues cogently for their effectiveness in selected situations. Covering methodological and procedural issues as well as theory, Experimental Economics is not only a textbook but also a useful introduction to laboratory methods for professional economists. The emphasis is on organizing and evaluating existing results. The book can be used as an anchoring device for a course at either the graduate or advanced undergraduate level. Applications include financial market experiments, oligopoly price competition, auctions, bargaining, provision of public goods, experimental games, and decision making under uncertainty. The book also contains instructions for a variety of laboratory experiments.laboratory experiments, financial markets, price competition, auctions, bargaining, games, decision making, uncertainty
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