4,215 research outputs found
The Analysis of design and manufacturing tasks using haptic and immersive VR - Some case studies
The use of virtual reality in interactive design and manufacture has been researched extensively but the practical application of this technology in industry is still very much in its infancy. This is surprising as one would have expected that, after some 30 years of research commercial applications of interactive design or manufacturing planning and analysis would be widespread throughout the product design domain. One of the major but less well known advantages of VR technology is that logging the user gives a great deal of rich data which can be used to automatically generate designs or manufacturing instructions, analyse design and manufacturing tasks, map engineering processes and, tentatively, acquire expert knowledge. The authors feel that the benefits of VR in these areas have not been fully disseminated to the wider industrial community and - with the advent of cheaper PC-based VR solutions - perhaps a wider appreciation of the capabilities of this type of technology may encourage companies to adopt VR solutions for some of their product design processes. With this in mind, this paper will describe in detail applications of haptics in assembly demonstrating how user task logging can lead to the analysis of design and manufacturing tasks at a level of detail not previously possible as well as giving usable engineering outputs. The haptic 3D VR study involves the use of a Phantom and 3D system to analyse and compare this technology against real-world user performance. This work demonstrates that the detailed logging of tasks in a virtual environment gives considerable potential for understanding how virtual tasks can be mapped onto their real world equivalent as well as showing how haptic process plans can be generated in a similar manner to the conduit design and assembly planning HMD VR tool reported in PART A. The paper concludes with a view as to how the authors feel that the use of VR systems in product design and manufacturing should evolve in order to enable the industrial adoption of this technology in the future
NASA Contributions to Mathematical Modeling and Simulation and Their Potential Use Outside the Aerospace Industry
Potentials for technology transfer can be found where you would least expect them. I approached the task in the title with great skepticism. Although NASA had undoubtedlymade extensive use of mathematical modeling and computer simulation, it seemed unlikely that they could be used for anything except the special purpose for which they were intended. But I developed a methodical approach to try to find out.
First, a week in a NASA library with catalogues of report titles, abstracts and microfiche produced about 150 possible candidates - much to my surprise. The filtering process included discussions with other staff members at Abt Associates with first-hand knowledge of current problems in business, education, transportation, social programs, etc. and âąwith senior people in NASA Headquarters who were generally familiar with the work that had been done and, more importantly, knew about current programs. With this background information, I knew who to visit in the NASA centers and what to talk about. Because of the time lag between completion of a project and publication of an abstract in a catalog of reports, memories fade about projects that were usually carried out by someone else several years ago. But there are usually more important projects whose abstracts have not yet made the archives
Cholesterol metabolism in the endoplasmic reticulum of rat liver
In work directed towards the purification of a liver microsomal
cytochrome P-450 species capable of supporting cholesterol 7a-hydroxylase
activity in a reconstituted system, the use of the detergent Renex 690
for the solubilisation of microsomal protein resulted in an unacceptable
inhibition of cholesterol 7ct-hydroxylation. This confirmed previous
work, showing that Nonidet P42 is the optimum choice of solubilising
agent for this purpose. DEAE-cellulose chromatography of microsomal
protein solubilised with Nonidet P42 was confirmed to be a suitable
first step in the purification of liver microsomal cytochrome P-450,
since there is a good separation of this species from NADPH cytochrome c
reductase activity. However, the recovery and purification of total
cytochrome P-450 was low. Dithiothreitol, 4-phenyl-imidazole, diethyldithiocarbamate
and glycerol, by themselves or in combination with each
other, were shown to be useful agents in liver microsomal cytochrome
P-450 purification. It was further demonstrated that increasing the
recovery of cytochrome P-450 gave a concomitant improvement in its
purification. Chromatography on quaternary aminoethyl-Sephadex or on
carboxymethylcellulose did not result in any purification of cytochrome
P-450. Hydroxyapatite chromatography of cytochrome P-450 - containing
fractions from the DEAE-cellulose eluate gave a further small purification
of cytochrome P-450. The use of chemical donors of "active oxygen"
in the reconstitution of cholesterol 7a-hydroxylase activity with liver
microsomal cytochrome P-450 was shown to be limited by the rapid
destruction of the cytochrome by these agents
Automated knowledge capture in 2D and 3D design environments
In Life Cycle Engineering, it is vital that the engineering knowledge for the product is captured throughout its life cycle in a formal and structured manner. This will allow the information to be referred to in the future by engineers who did not work on the original design but are wanting to understand the reasons that certain design decisions were made. In the past, attempts were made to try to capture this knowledge by having the engineer record the knowledge manually during a design session. However, this is not only time-consuming but is also disruptive to the creative process. Therefore, the research presented in this paper is concerned with capturing design knowledge automatically using a traditional 2D design environment and also an immersive 3D design environment. The design knowledge is captured by continuously and non-intrusively logging the user during a design session and then storing this output in a structured eXtensible Markup Language (XML) format. Next, the XML data is analysed and the design processes that are involved can be visualised by the automatic generation of IDEF0 diagrams. Using this captured knowledge, it forms the basis of an interactive online assistance system to aid future users who are carrying out a similar design task
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Evidence for clonal selection of gamma/delta T cells in response to a human pathogen.
T cells bearing gamma/delta antigen receptors comprise a resident population of intraepithelial lymphocytes in organs such as skin, gut, and lungs, where they are strategically located to contribute to the initial defense against infection. An important unsolved question about antigen-driven gamma/delta T cell responses regards the breadth of their T cell receptor (TCR) repertoire, since many specific epithelial compartments in mice display limited diversity. We have examined the diversity of TCR delta gene expression among human gamma/delta T cells from skin lesions induced by intradermal challenge with Mycobacterium leprae. We show that the vast majority of gamma/delta cells from M. leprae lesions use either V delta 1-J delta 1 or V delta 2-J delta 1 gene rearrangements and, within a given region of the lesion, display limited junctional diversity. This contrasts markedly with the extensive diversity of gamma/delta T cells from peripheral blood of these same individuals, as well as skin from normal donors. These results indicate that the gamma/delta response to M. leprae involves the selection of a limited number of clones from among a diverse repertoire, probably in response to specific mycobacterial and/or host antigens
Forages for swine
11/79/8MATTENTION SMALL FARM FAMILIESH. N. Wheaton (Department of Agronomy), John Rea (Department of Animal Husbandry College of Agriculture
IODP Proposal 626: "Cenozoic Equatorial Age Transect â Following the Palaeo-equator"
As the largest ocean, the Pacific is intricately linked to major changes in the global climate system that took place during the Cenozoic. Throughout the Cenozoic the Pacific plate has had a northward component. Thus, the Pacific is unique, in that the thick sediment bulge of biogenic rich deposits from the currently narrowly focused zone of equatorial upwelling is slowly moving away from the equator. Hence, older sections are not deeply buried and can be recovered by drilling. Previous ODP Legs 138 and 199 were designed as transects across the paleo-equator in order to study the changing patterns of sediment deposition across equatorial regions, while this proposal aims to recover an orthogonal âage-transectâ along the paleo-equator. Both previous legs were remarkably successful in giving us new insights into the workings of the climate and carbon system, productivity changes across the zone of divergence, time dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the ITCZ, and evolutionary patterns for times of climatic change and upheaval. Together with older DSDP drilling in the eastern equatorial Pacific, both Legs also helped to delineate the position of the paleo-equator and variations in sediment thickness from approximately 150°W to 110°W. As we have gained more information about the past movement of plates, and where in time âcriticalâ climate events are located, we now propose to drill an age-transect (âflow-lineâ) along the position of the paleo-equator in the Pacific, targeting selected time-slices of interest where calcareous sediments have been preserved best. Leg 199 enhanced our understanding of extreme changes of the calcium carbonate compensation depth across major geological boundaries during the last 55 million years. A very shallow CCD during most of the Paleogene makes it difficult to obtain well preserved sediments, but we believe our siting strategy will allow us to drill the most promising sites and to obtain a unique sedimentary biogenic carbonate archive for time periods just after the Paleocene- Eocene boundary event, the Eocene cooling, the Eocene/Oligocene transition, the âone cold poleâ Oligocene, the Oligocene-Miocene transition, and the Miocene, contributing to the objectives of the IODP Extreme Climates Initiative, and providing material that the previous legs were not able to recover
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