| 11. |
- Abeysekera, John
(författare)
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Some ergonomics issues in the design of personal protective devices
- 1992
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Ingår i: Performance of protective clothing. - Philadelphia, Pa. : ASTM International. - 0803114303 ; , s. 651-659
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Konferensbidrag (refereegranskat)abstract
- The use of personal protective devices (ppd) is an important method to safeguard workers from occupational hazards both in industrialized and developing countries. Surveys have indicated that majority of those exposed to hazards are reluctant to use ppd because they are uncomfortable for such reasons as hotness, heaviness, ill fit, inconvenient, etc. Investigations have revealed that user-centered designs which satisfy the human factors needs of ppd, can reverse this trend and make ppd more acceptable. Because a questionnaire survey has shown that manufacturers are more inclined to adhere to standards, developing ergonomic standards seems to be a feasible method to persuade the manufacturers to provide the user needs in the design. Any unavoidable discomforts in ppd can be controlled by adaptation of users to ppd wearing.
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| 12. |
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| 13. |
- Abrahamsson, Hans, 1966, et al.
(författare)
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Turbulence in a Two-Dimensional Wall-Jet - Experiments and Modeling
- 1992
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Ingår i: 13th Turbulence Conference in Missouri-Rolla..
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Konferensbidrag (refereegranskat)abstract
- An experimental and numerical investigation of the turbulence field in a two-dimensional wall-jet has been carried out in a well-defined geometry. The measurements were performed using a hot-wire technique and the calculations were carried out with a standard k-ε model as well as an algebraic stress model (ASM), using elliptic solvers. For the mean velocity field, good agreements were found between the measurements and the calculations. The measurements of the turbulence intensities reveal two maxima in the stream-wise and span-wise components, while only one maximum was found in the normal component. Also in the shear stress two maxima were found. A comparison between calculations and measurements indicates that improved turbulence models are needed.
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| 14. |
- Abrahamsson, Hans, 1966, et al.
(författare)
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Turbulence Measurements in a Two-Dimensional Wall-Jet
- 1991
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Ingår i: Eight Turbulent Shear Flow Conference, München.
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Konferensbidrag (refereegranskat)abstract
- The high capacity of todays computers has enabled the extension of turbulence models to strongly anisotropic flow fields, i.e. the interest has been focused on the use of the models based on the transport equations for the Reynolds stresses (RST models). To improve these turbulence models well-defined, simple and fundamental experiments are needed, in which gradients of the different turbulence parameters are determined. Together with direct simulations of the Navier-Stokes equations these experiments yield a good base for the improvement of the modelling of different terms in the Reynolds equations. An excellent presentation of the closure problem and the terms of interest for the development of turbulence models has recently been published by Groth (1991). A fundamental, well-defined and simple flow case is the wall-jet, where an interaction between a wall boundary layer and a free shear layer forms the anisotropy as well as the inhomogeneous character of the flow field. A comprehensive literature survey of wall-jets was carried out already in the beginning of the eighties by Launder and Rodi (1980), who studied a large number of more or less well-defined wall-jet experiments. The main conclusion of this survey was a lack of well-defined experiments in simple and fundamental geometries. If the study is limited to the two-dimensional case, a further conclusion from the work of Launder and Rodi was that many of the studied flow cases did not fulfil the condition of two-dimensionality. Although more than ten years have passed since the work of Laundry and Rodi was presented, very few investigations have been reported in which fundamental wall-jets have been studied. Especially well-defined turbulence measurements are needed, since anisotropy of the two-dimensional wall-jet yields a case well suited for the evaluation of e.g. new dissipation models, see Hallbäck et al. (1990). The purpose of the present work was to determine the turbulence field of a two-dimensional wall-jet in a simple and also well-defined geometry without influence of an outer disturbing flow field. To accomplish these measurements was a wall-jet rig used. All turbulence measurements were carried out using hot-wire techniques, single- and cross wires. The measurements presented here were performed at a Reynolds number of ___, based on the slot height and the extensions of the measurements in the flow direction was in the range of x/h=25 through x/h=156 (x-coordinate in the main flow direction and h-slot height).
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| 15. |
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Adiels, L., et al.
(författare)
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Investigations on baryonium and other rare pmacrp annihilation modes using high resolution pi0 spectrometers (PS 182)
- 1985
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Ingår i: Antiproton 1984. Proceedings of the VII European Symposium on Antiproton Interactions. - : Institution of Electrical Engineers (IEE). ; , s. 297-304
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Konferensbidrag (refereegranskat)abstract
- In the search for heavy, narrow exotic states such as baryonium or glueballs, carried out so far, various methods of high- and low-energy production, low-energy formation, and e+e- reactions were used. In particular, a search for baryonium states below threshold (mxlsimmppmacr) has shown some evidence [Richter et al., 1983, Brando et al., 1984] for a few states. However, the results of these measurements suffer from poor statistics. Among the possible methods which can be applied in the baryonium bound state research at LEAR, the authors consider the study of the reaction ppmacrrarrX+pi0 as the most promising. They have performed an experiment to study this reaction by means of an experimental set-up especially tailored for measuring monoenergetic pi0,s, allowing for both angular distribution measurements and high-resolution spectroscopy. They report on the preliminary results from our actual measurements of the inclusive pi0 and eta spectra following the antiproton annihilation at rest.
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| 20. |
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