65 research outputs found

    TransHab: NASA's Large-Scale Inflatable Spacecraft

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    TransHab is a, 27-foot diameter by 40-foot, lightweight inflatable habitation module for space applications. TransHab consists of a lightweight graphite-composite core, 11-foot diameter by 23-foot tall, surrounded by a 27-foot diameter inflatable shell. Originally envisioned to be the habitation module of an interplanetary transit vehicle, TransHab is currently being considered as a module for use on the International Space Station (ISS). During the past two years, several tests have been performed at the NASA/Johnson Space Center to demonstrate and prove the technologies required in building a large-scale inflatable habitation module. This paper discusses the results of these tests which including the following: 1) a structural integrity development test article hydJ"Ostatically tested to four times ambient pressure, 2) a full-scale development test article manufactured, assembled, folded and deployed at vacuum, and 3) extensive hypervelocity impact testing of the micro meteoroid and orbital debris protection system

    Advanced resistive exercise device

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    The present invention relates to an exercise device, which includes a vacuum cylinder and a flywheel. The flywheel provides an inertial component to the load, which is particularly well suited for use in space as it simulates exercising under normal gravity conditions. Also, the present invention relates to an exercise device, which has a vacuum cylinder and a load adjusting armbase assembly

    Hybrid Inflatable Pressure Vessel

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    Figure 1 shows a prototype of a large pressure vessel under development for eventual use as a habitable module for long spaceflight (e.g., for transporting humans to Mars). The vessel is a hybrid that comprises an inflatable shell attached to a rigid central structural core. The inflatable shell is, itself, a hybrid that comprises (1) a pressure bladder restrained against expansion by (2) a web of straps made from high-strength polymeric fabrics. On Earth, pressure vessels like this could be used, for example, as portable habitats that could be set up quickly in remote locations, portable hyperbaric chambers for treatment of decompression sickness, or flotation devices for offshore platforms. In addition, some aspects of the design of the fabric straps could be adapted to such other items as lifting straps, parachute straps, and automotive safety belts. Figure 2 depicts selected aspects of the design of a vessel of this type with a toroidal configuration. The bladder serves as an impermeable layer to keep air within the pressure vessel and, for this purpose, is sealed to the central structural core. The web includes longitudinal and circumferential straps. To help maintain the proper shape upon inflation after storage, longitudinal and circumferential straps are indexed together at several of their intersections. Because the web is not required to provide a pressure seal and the bladder is not required to sustain structural loads, the bladder and the web can be optimized for their respective functions. Thus, the bladder can be sealed directly to the rigid core without having to include the web in the seal substructure, and the web can be designed for strength. The ends of the longitudinal straps are attached to the ends of the rigid structural core by means of clevises. Each clevis pin is surrounded by a roller, around which a longitudinal strap is wrapped to form a lap seam with itself. The roller is of a large diameter chosen to reduce bending of the fibers in the strap. The roller also serves to equalize the load in the portions of the strap on both sides of the clevis pin. The lap seam is formed near the clevis by use of a tapered diamond stitch: This stitch is designed specifically to allow fibers in the stitch and strap to relax under load in such a manner that the load becomes more nearly evenly distributed among all fibers in the stitch region. Thus, the tapered diamond stitch prevents load concentrations that could cause premature failure of the strap and thereby increases the strength of the strap/structural-core joint. The lap seam can be rated at >90 percent of the strength of the strap material

    Electrically-driven amplification of terahertz acoustic waves in graphene

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    In graphene devices, the electronic drift velocity can easily exceed the speed of sound in the material at moderate current biases. Under this condition, the electronic system can efficiently amplify acoustic phonons, leading to the exponential growth of sound waves in the direction of the carrier flow. Here, we demonstrate that such phonon amplification can significantly modify the electrical properties of graphene devices. We observe a super-linear growth of the resistivity in the direction of the carrier flow when the drift velocity exceeds the speed of sound, causing up to a 7 times increase over 8 micrometers. The resistance growth is observable for carrier densities away from the Dirac point and is enhanced at cryogenic temperatures. These observations are explained by a theoretical model for the electrical-amplification of acoustic phonons, which reach frequencies up to 2.2 terahertz with the nanoscale wavelength set by gate-tunable ~kF transitions across the Fermi surface. These findings offer a route to high-frequency on-chip sound generation and detection, which can be used to modulate and probe electronic physics in van der Waals heterostructures in the terahertz frequency range

    If I Had My Way, I'd Have Been a Killer: Songwriting and its Motivations for Leisure and Work

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    This paper builds on our earlier work (Henderson and Spracklen, 2014) which looked at folk musicians exercising agency in careers that can develop from casual leisure through serious leisure to work. In looking specifically at songwriting, it synthesises theories on the underlying motivations refelecting the view of Born (2010, p.171) who suggests that the ‘theory of cultural production requires reinvention’ citing key themes of ’aesthetics and the cultural object; agency and subjectivity; the place of institutions; history, temporality and change; and problems of value and judgement.’ It examines in a phenomenological way, through songwriter interviews, the cultural production of songs and the motivational factors within the songwriting process. Highlighting that this form of cultural production challenges the hierarchical view of Maslow’s needs and suggests the career arc proposed by Stebbins (1992, p. 68) is not a case of work simply following sequentially from serious and casual leisure

    L’usage de la poésie haïku en psycho-oncologie

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    International audienceAbstract Aim: Our study aims to describe the discourseeffects of specific and structured protocol focused on severalhaiku poems about one patient, who have experienced cancer.Procedure: The protocol consists of 4 steps: a preliminaryexploratory interview, fifteen haiku proposed without a partof the poem (a creative writing filled in by the patient), a freeform haiku composed by the patient, and finally, a finalinterview.Clinical case: A man, D., aged 25, had tumor.Result: Using this protocol, we showed discourse variationson the illness before and after the experience of poetrywriting, by Tropes V8.4 software.Conclusion: Haiku poetry can be a useful tool in the contextof supportive interventions or as preparatory work for engagementin psychotherapeutic intervention. We believe thatthe formal structure of haikus can create conditions for aspecific poetic work composed of: poetic evocation, synthesis,and mapping of the most intimate experiences in oncologyenvironment.Résumé Objectif : Cette étude qualitative et exploratoirevise à décrire les effets d’un protocole poétique centré surles haïkus en psycho-oncologie sur l’approche de la maladiechez un patient atteint de cancer.Matériel et méthodes : Il s’agit d’un protocole d’écriturepoétique composé de quatre étapes : un entretien préliminaire,la proposition de 15 haïkus (sans le vers du milieu)tirés de grands auteurs japonais, la réalisation d’un poèmecomposé librement par deux patients atteints de cancer, unentretien final sur l’expérience de l’écriture poétique.Cas clinique : Un homme, M. D., âgé de 25 ans, qui est entraitement pour un cancer.Résultats : Nous montrons les variations discursives utiliséesavant et après l’expérience de l’écriture poétique, à travers lelogiciel Tropes V8.4.Conclusion : Le travail poétique avec le haïku peut être unoutil utile, dans un contexte de support clinique en institutionou comme préparation à un travail de psychothérapie. Nouspensons que la structure formelle des haïkus peut inviter à untravail poétique spécifique : évocation poétique, synthèse etschématisation des vécus plus intimes en milieu oncologique

    The Effect of Oxidant and the Non-Oxidant Alteration of Cellular Thiol Concentration on the Formation of Protein Mixed-Disulfides in HEK 293 Cells

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    Cellular molecules possess various mechanisms in responding to oxidant stress. In terms of protein responses, protein S-glutathionylation is a unique post-translational modification of protein reactive cysteines forming disulfides with glutathione molecules. This modification has been proposed to play roles in antioxidant, regulatory and signaling in cells under oxidant stress. Recently, the increased level of protein S-glutathionylation has been linked with the development of diseases. In this report, specific S-glutathionylated proteins were demonstrated in human embryonic kidney 293 cells treated with two different oxidative reagents: diamide and hydrogen peroxide. Diamide is a chemical oxidizing agent whereas hydrogen peroxide is a physiological oxidant. Under the experimental conditions, these two oxidants decreased glutathione concentration without toxicity. S-glutathionylated proteins were detected by immunoblotting and glutathione concentrations were determined by high performance liquid chromatography. We further show the effect of alteration of the cellular thiol pool on the amount of protein S-glutathionylation in oxidant-treated cells. Cellular thiol concentrations were altered either by a specific way using buthionine sulfoximine, a specific inhibitor of glutathione biosynthesis or by a non-specific way, incubating cells in cystine-methionine deficient media. Cells only treated with either buthionine sulfoximine or cystine-methionine deficient media did not induce protein S-glutathionylation, even though both conditions decreased 65% of cellular glutathione. Moreover, the amount of protein S-glutathionylation under both conditions in the presence of oxidants was not altered when compared to the amount observed in regular media with oxidants present. Protein S-glutathionylation is a dynamic reaction which depends on the rate of adding and removing glutathione. Phenylarsine oxide, which specifically forms a covalent adduct with vicinal thiols, was used to determine the possible role of vicinal thiols in the amount of glutathionylation. Our data shows phenylarsine oxide did not change glutathione concentrations, but it did enhance the amount of glutathionylation in oxidant-treated cells

    Voicing passion: The emotional economy of songwriting

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    This article examines articulations of the role of passion in accounts of the life and work of the songwriter. It draws upon a range of interviews with successful artists captured in the Sodajerker On Songwriting podcast. It is suggested that these interviews capture the ‘voicing’ of the conventions of creativity in popular music, exploring a context in which passionate motivation, expression and understanding of the (potentially) affective responses to songs are paramount to the labour of the songwriter. The article explores how the core of this labour deals in emotion, attempting to articulate feelings in recognisable, tradable form. This is a process that is both instrumentally rationalised but often felt to be a deeply authentic process, understood (and believed) to spring from the individual’s emotional experience, so conferring identity in a generic field. In light of current debates about the nature of creative work and emotional labour, the accounts drawn upon here can be seen to epitomise many of the qualities of what constitutes ‘good work’ through a mode of self-actualisation

    A Process Algebra for Supervisory Coordination

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    A supervisory controller controls and coordinates the behavior of different components of a complex machine by observing their discrete behaviour. Supervisory control theory studies automated synthesis of controller models, known as supervisors, based on formal models of the machine components and a formalization of the requirements. Subsequently, code generation can be used to implement this supervisor in software, on a PLC, or embedded microprocessor. In this article, we take a closer look at the control loop that couples the supervisory controller and the machine. We model both event-based and state-based observations using process algebra and bisimulation-based semantics. The main application area of supervisory control that we consider is coordination, referred to as supervisory coordination, and we give an academic and an industrial example, discussing the process-theoretic concepts employed.Comment: In Proceedings PACO 2011, arXiv:1108.145
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