742,892 research outputs found

    Intensified processes for FAME production from waste cooking oil: a technological review

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    This article reviews the intensification of fatty acid methyl esters (FAME) production from waste cooking oil (WCO) using innovative process equipment. In particular, it addresses the intensification of WCO feedstock transformation by transesterification, esterification and hydrolysis reactions. It also discusses catalyst choice and product separation. FAME production can be intensified via the use of a number of process equipment types, including as cavitational reactors, oscillatory baffled reactors, microwave reactors, reactive distillation, static mixers and microstructured reactors. Furthermore, continuous flow equipment that integrate both reaction and separation steps appear to be the best means for intensifying FAME production. Heterogeneous catalysts have also shown to provide attractive results in terms of reaction performance in certain equipment, such as microwave reactors and reactive distillation

    DSN seven day/twelve week schedule program

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    Deep Space Network scheduling program allocates resources based on the users requirements. The system reviews and allocates the requests for equipment and resources. Depending upon the program input either the seven day or the twelve week schedule is generated

    Apollo experience report. Guidance and control systems: Orbital rate drive electronics for the Apollo command module and lunar module

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    A brief record of the development and use of the orbital-rate-drive assembly in the Apollo Program is presented. This device was procured as government-furnished equipment and was used on both the lunar module and the command module. Reviews of design, development, procurement, and flight experience are included

    Condition-based maintenance at both scheduled and unscheduled opportunities

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    Motivated by original equipment manufacturer (OEM) service and maintenance practices we consider a single component subject to replacements at failure instances and two types of preventive maintenance opportunities: scheduled, which occur due to periodic system reviews of the equipment, and unscheduled, which occur due to failures of other components in the system. Modelling the state of the component appropriately and incorporating a realistic cost structure for corrective maintenance as well as condition-based maintenance (CBM), we derive the optimal CBM policy. In particular, we show that the optimal long-run average cost policy for the model at hand is a control-limit policy, where the control limit depends on the time until the next scheduled opportunity. Furthermore, we explicitly calculate the long-run average cost for any given control-limit time dependent policy and compare various policies numerically.Comment: published at proceedings of the 9th IMA International Conference on Modelling in Industrial Maintenance and Reliability (MIMAR), 201

    FARM EQUIPMENT INDUSTRY PERFORMANCE: PAST AND FUTURE

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    This paper assesses the agricultural equipment industry through the perspective of the three leading firms in the United States. It reviews the salient events of the 1990s and relates the business environment to the firmsÂ’ financial performance. It then assesses the factors likely to impact performance in the future, drawing on lessons from historical performance and on new environmental factors. The firmsÂ’ capital market valuations appear consistent with the expectation that farm equipment firms will resume growth after the farm recession.Agribusiness,

    The PLC: a logical development

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    Programmable Logic Controllers (PLCs) have been used to control industrial processes and equipment for over 40 years, having their first commercially recognised application in 1969. Since then there have been enormous changes in the design and application of PLCs, yet developments were evolutionary rather than radical. The flexibility of the PLC does not confine it to industrial use and it has been used for disparate non-industrial control applications . This article reviews the history, development and industrial applications of the PLC

    О перспективах рынка станкостроения с позиций анализа мировых тенденций, концепции жизненного цикла оборудования и CALS-технологий

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    В статье рассматриваются существующие методики выбора и проектирования нового оборудования с позиций анализа наиболее эффективных видах обработки, проводится анализ недостатков "классического" подхода к выбору оборудования. На основании CALS-технологий, принципа агрегатирования и паспортизации оборудования предлагается новая модель проектирования оборудования, позволяющая продлить жизненный цикл станков, уменьшить стоимость и сроки проектирования и изготовления оборудования.This article reviews the existing methods of choice and design of new equipment from the standpoint of analyzing the most effective forms of treatment, an analysis of the shortcomings of "classical" approach to the choice of equipment. Based on CALS-technologies, the principle of aggregation and certification of equipment, a new model for the design of equipment are proposed. This model allows to extend the life cycle of machines, reduce the cost and terms of designing and manufacturing equipment

    NASA teleconference pilot project evaluation for 1975

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    Tabular data were given to summarize the results of the NASA teleconferencing network pilot project for 1975. The 1,241 evaluation reports received indicate that almost 100,000 man-hours of teleconferences took place. The travel funds reported saved total about 1.44million,whichisabout101.44 million, which is about 10% of the NASA travel costs. Subtracting the cost of providing the teleconferencing networks, the net savings reported are 1.28 million (about 9% of the travel costs). The teleconferencing network has proved to be successful in conducting many management meetings and reviews within NASA and its contractors. In spite of difficulties caused by inexperience in teleconferencing and some equipment and circuit problems, the evaluation reports indicated the system was satisfactory in an overwhelming majority of cases

    Evaluating health risks from occupational exposure to pesticides and the regulatory response.

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    In this study, we used measurements of occupational exposures to pesticides in agriculture to evaluate health risks and analyzed how the federal regulatory program is addressing these risks. Dose estimates developed by the State of California from measured occupational exposures to 41 pesticides were compared to standard indices of acute toxicity (LD50) and chronic effects (reference dose). Lifetime cancer risks were estimated using cancer potencies. Estimated absorbed daily doses for mixers, loaders, and applicators of pesticides ranged from less than 0.0001% to 48% of the estimated human LD50 values, and doses for 10 of 40 pesticides exceeded 1% of the estimated human LD50 values. Estimated lifetime absorbed daily doses ranged from 0.1% to 114,000% of the reference doses developed by the U.S. Environmental Protection Agency, and doses for 13 of 25 pesticides were above them. Lifetime cancer risks ranged from 1 per million to 1700 per million, and estimates for 12 of 13 pesticides were above 1 per million. Similar results were obtained for field workers and flaggers. For the pesticides examined, exposures pose greater risks of chronic effects than acute effects. Exposure reduction measures, including use of closed mixing systems and personal protective equipment, significantly reduced exposures. Proposed regulations rely primarily on requirements for personal protective equipment and use restrictions to protect workers. Chronic health risks are not considered in setting these requirements. Reviews of pesticides by the federal pesticide regulatory program have had little effect on occupational risks. Policy strategies that offer immediate protection for workers and that are not dependent on extensive review of individual pesticides should be pursued
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