6,733 research outputs found

    Improvement of chemical vapor deposition process for production of large diameter carbon base monofilaments

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    Research was conducted to develop large diameter carbon monofilament, containing 25 to 35 mole % element boron, in the 2.0 to 10.0 mil diameter range using the chemical vapor deposition process. The objective of the program was to gain an understanding of the critical process variables and their effect on fiber properties. Synthesis equipment was modified to allow these variables to be studied. Improved control of synthesis variables permitted reduction in scatter of properties of the monofilaments. Monofilaments have been synthesized in the 3.0 to nearly 6.0 mil diameter range having measured values up to 552,000 psi for ultimate tensile strength and up to 30 million psi for elastic modulus

    Shaping Metrics for HEI Cultural Engagement - Knowledge Transfer

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    An application was submitted to the Arts and Humanities Research Council (AHRC) for support for a project that would identify and define activities deemed relevant to Knowledge Transfer (KT) - Cultural Engagement (CE), and propose appropriate means to evaluate them. It was acknowledged from the outset that efforts at agreeing “metrics” for the impact of such activities had been attempted before, albeit with limited success. (One such notable example has been lately provided by the Higher Education and Business Community Interaction Survey (HEBCIS) which has collected some data on social, community, and cultural engagement for some years; however, the robustness and consistency of the data for these purposes have often been questioned.

    Further development of chemical vapor deposition process for production of large diameter carbon-base monofilaments

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    The development of large diameter carbon-base monofilament in the 50 micron to 250 micron diameter range using the chemical vapor deposition process is described. The object of this program was to determine the critical process variables which control monofilament strength, monofilament modulus, and monofilament diameter. It was confirmed that wide scatter in the carbon substrate strength is primarily responsible for the scatter in the monofilament strength. It was also shown through etching experiments that defective substrate surface conditions which can induce low strength modular growth in the monofilament layers are best controlled by processing improvements during the synthesis of the substrate. Modulus was found to be linearily proportional to monofilament boron content. Filament modulus was increased to above 27.8MN/sq cm but only by a considerable increase in monofilament boron content to 60 wt. % or more. Monofilament diameter depended upon dwell time in the synthesis apparatus. A monofilament was prepared using these findings which had the combined properties of a mean U.T.S. of 398,000 N/sq cm, a modulus of 18.9 MN/sq cm (24,000,000 psi), and a diameter of 145 microns. Highest measured strength for this fiber was 451,000 N/sq cm (645,000 psi)

    In Memory of Larry Kalevitch: An Appreciation

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    Highlighting the Unique Challenges and Differences of Building with Mass Timber

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    As the construction industry shifts towards sustainability and owners seek to construct buildings that are sustainable - built from natural and renewable materials, and pleasing for their occupants to work in - mass timber is becoming the popular alternative to traditional steel and concrete buildings. An abundance of information is available on mass timber products and their properties and applications, but little information on the process of actually building a mass timber project. This report seeks to extend practical knowledge on building with mass timber. In order to accomplish this, this research will highlight specific differences and challenges related to building with mass timber; create general guidelines and recommendations for contractors tasked with building a mass timber project; and identify new areas of research. Through interviews with two commercial contractors who have built mass timber projects in the California Bay Area, specific challenges have been identified. These challenges include longer project duration; increased preconstruction time and complexity; difficulties getting timely plan approvals; differing design and material procurement methods; necessity of MEP coordination at the beginning of the jobs; unique transportation, storage, and handling requirements; and different installation procedures and requirements

    Torts

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    Sparked in large part by concerns raised by the skyrocketing cost of insurance, particularly in medical malpractice cases, the Florida Legislature enacted the Tort Reform and insurance Act of 1986
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