1,868 research outputs found

    Study to determine experimentally the feasibility of new methods for improving thermal conductance of mechanical joints in a vacuum Summary research report, 8 Apr. - 30 Sep. 1966

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    Surface-plateauing techniques, and flexible surface membranes for improved thermal conductance of mechanical joints in vacuu

    Development and Applications of a Self-Contained, Non-Invasive EVA Joint Angle and Muscle Fatigue Sensor System

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    The University of Maryland Space Systems Laboratory, as a participant in NASA's INSTEP program, is developing a non-invasive, self-contained sensor system which can provide quantitative measurements of joint angles and muscle fatigue in the hand and forearm. The goal of this project is to develop a system with which hand/forearm motion and fatigue metrics can be determined in various terrestrial and zero-G work environments. A preliminary study of the prototype sensor systems and data reduction techniques for the fatigue measurement system are presented. The sensor systems evaluated include fiberoptics, used to measure joint angle, surface electrodes, which measure the electrical signals created in muscle as it contracts; microphones, which measure the noise made by contracting muscle; and accelerometers, which measure the lateral muscle acceleration during contraction. The prototype sensor systems were used to monitor joint motion of the metacarpophalangeal joint and muscle fatigue in flexor digitorum superficialis and flexor carpi ulnaris in subjects performing gripping tasks. Subjects were asked to sustain a 60-second constant-contraction (isometric) exercise and subsequently to perform a repetitive handgripping task to failure. Comparison of the electrical and mechanical signals of the muscles during the different tasks will be used to evaluate the applicability of muscle signal measurement techniques developed for isometric contraction tasks to fatigue prediction in quasi-dynamic exercises. Potential data reduction schemes are presented

    Drying Rough Rice in Storage.

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    20 p

    Transmission Properties of the oscillating delta-function potential

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    We derive an exact expression for the transmission amplitude of a particle moving through a harmonically driven delta-function potential by using the method of continued-fractions within the framework of Floquet theory. We prove that the transmission through this potential as a function of the incident energy presents at most two real zeros, that its poles occur at energies nω+εn\hbar\omega+\varepsilon^* (0<Re(ε)<ω0<Re(\varepsilon^*)<\hbar\omega), and that the poles and zeros in the transmission amplitude come in pairs with the distance between the zeros and the poles (and their residue) decreasing with increasing energy of the incident particle. We also show the existence of non-resonant "bands" in the transmission amplitude as a function of the strength of the potential and the driving frequency.Comment: 21 pages, 12 figures, 1 tabl

    Students as co-creators of teaching approaches, course design and curricula: implications for academic developers

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    Within higher education, students’ voices are frequently overlooked in the design of teaching approaches, courses and curricula. In this paper we outline the theoretical background to arguments for including students as partners in pedagogical planning processes. We present examples where students have worked collaboratively in design processes along with the beneficial outcomes of these examples. Finally we focus on some of the implications and opportunities for academic developers of proposing collaborative approaches to pedagogical planning

    Entrepreneurship and Urban Success: Toward a Policy Consensus

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    Like all politics, all entrepreneurship is local. Individuals launch firms and, if successful, expand their enterprises to other locations. But new firms must start somewhere, even if their businesses are conducted largely or exclusively on the Internet. Likewise, policymakers at local and state levels increasingly recognize that entrepreneurship is the key to building and sustaining their economies\u27 growth. Although this is a seemingly obvious proposition, it represents something of a departure from past thinking about how local, state, or regional economies grow. Historically, state and local policymakers have put their energies into trying to attract existing firms from somewhere else, either to relocate to a particular area or to build new facilities there. Such smokestack chasing - or, in this cleaner era, simply firm chasing - often has degenerated into what is essentially a zero-sum game for the national economy. When one city or state offers tax breaks or other financial inducements to encourage firms to locate new plants or headquarters, and succeeds, some other city or state loses out in the process. Local, state, and regional economic development centered on entrepreneurship, however, is a fundamentally different phenomenon. The formation and growth of new firms, especially those built around new products or ways of doing things, wherever this occurs, is clearly a positive sum game, not just for the locality, but for the nation as a whole. This essay provides a guide to policymakers and citizens to what is known about the effects of various local and state policies aimed at fostering entrepreneurially driven growth. There is also much we do not know; thus, the essay identifies subjects that require further research

    Critical animal and media studies: Expanding the understanding of oppression in communication research

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    Critical and communication studies have traditionally neglected the oppression conducted by humans towards other animals. However, our (mis)treatment of other animals is the result of public consent supported by a morally speciesist-anthropocentric system of values. Speciesism or anthroparchy, as much as any other mainstream ideologies, feeds the media and at the same time is perpetuated by them. The goal of this article is to remedy this neglect by introducing the subdiscipline of Critical Animal and Media Studies. Critical Animal and Media Studies takes inspiration both from critical animal studies – which is so far the most consolidated critical field of research in the social sciences addressing our exploitation of other animals – and from the normative-moral stance rooted in the cornerstones of traditional critical media studies. The authors argue that the Critical Animal and Media Studies approach is an unavoidable step forward for critical media and communication studies to engage with the expanded circle of concerns of contemporary ethical thinking
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