3,532 research outputs found

    The biochemical, physiological, and metabolic evaluation of human subjects wearing pressure suits and on a diet of precooked freeze dehydrated foods

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    Biochemical, physiological and metabolic evaluation of human subjects wearing pressure suits and on diet of precooked frozen dehydrated food

    Biochemical and physiological evaluation of human subjects in a life support systems evaluator

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    Biochemical and physiological evaluation of human nutritional requirements under simulated aerospace condition

    Casimir repulsion between metallic objects in vacuum

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    We give an example of a geometry in which two metallic objects in vacuum experience a repulsive Casimir force. The geometry consists of an elongated metal particle centered above a metal plate with a hole. We prove that this geometry has a repulsive regime using a symmetry argument and confirm it with numerical calculations for both perfect and realistic metals. The system does not support stable levitation, as the particle is unstable to displacements away from the symmetry axis.Comment: 4 pages, 4 figures; added references, replaced Fig.

    Modeling near-field radiative heat transfer from sharp objects using a general 3d numerical scattering technique

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    We examine the non-equilibrium radiative heat transfer between a plate and finite cylinders and cones, making the first accurate theoretical predictions for the total heat transfer and the spatial heat flux profile for three-dimensional compact objects including corners or tips. We find qualitatively different scaling laws for conical shapes at small separations, and in contrast to a flat/slightly-curved object, a sharp cone exhibits a local \emph{minimum} in the spatially resolved heat flux directly below the tip. The method we develop, in which a scattering-theory formulation of thermal transfer is combined with a boundary-element method for computing scattering matrices, can be applied to three-dimensional objects of arbitrary shape.Comment: 5 pages, 4 figures. Corrected background information in the introduction, results and discussion unchange

    A novel use of a classification system to audit severe maternal morbidity

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    Objective: obstetric haemorrhage remains a significant cause of maternal morbidity and mortality worldwide and is significant in terms of patient safety and quality of care. One drastic outcome of haemorrhage is the need for peripartum hysterectomy. A classification system that can be used to audit severe events such as peripartum hysterectomy would be a useful adjunct to patient safety systems, but it would need to account for pre-existing risk factors, such as previous caesarean section. One system that accounts for important risk factors is the Robson Ten Group Classification System (TGCS). The aim of this study was to examine whether the TGCS could be extended in a novel way to classify who required peripartum hysterectomy. Setting: population-based matched case-control study data from the UK Obstetric Surveillance System was used. All eligible UK hospitals participated. Participants: women who underwent peripartum hysterectomy between February 2005 and February 2006 and their matched controls. Methods: cases and controls were categorised using the TGCS. The odds of having a peripartum hysterectomy in each classification group were calculated using logistic regression. An adjusted analysis was undertaken controlling for potential confounders. Findings: 307 of the 315 women who had a peripartum hysterectomy were classified into one of the 10 groups; 606 of the 608 control women were classified. Women who underwent a peripartum hysterectomy were predominantly from the more complex classification groups. After adjusting for age, ethnicity and socio-economic status, the groups with an increased odds of peripartum hysterectomy were those who had a previous caesarean section. Conclusions: the TGCS can be used in a novel way, that is, to examine an outcome other than caesarean section, and could be part of a new system to monitor patient safety. Population-based data were used as an example of how an existing classification system could be used in a different way from that for which it was created, and could make comparisons across institutions and countries while adjusting for case mix in a simple manner. The TGCS may not necessarily be a useful way to monitor other events in childbirth. Further work is needed to develop other classification systems which could be used as a benchmarking tools to monitor patient safety in maternity care. © 2010 Elsevier Ltd

    Assessment of friction from compression ring conjunction of a high performance internal combustion engine: a combined numerical and experimental study

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    The paper presents direct measurement of in-cylinder friction from a single cylinder motocross race engine under motored conditions and compares the same with a new analytical predictive method. These conditions are encountered in piston-cylinder system with the application of cylinder deactivation (CDA) technology, which is a growing trend. The analytical method takes into account the various regions within instantaneous contact of compression ring-cylinder liner, including lubricant film rupture, cavitation zone and the subsequent lubricant film reformation. The analysis also includes the effect of boundary friction and lubricant rheology. The predictions and direct measurements of cyclic friction show good agreement and indicate dominance of viscous friction under the investigated engine running conditions. In particular, it is shown that the compression ring contribution to in-cycle friction is most pronounced in the region of high cylinder pressures because of combined Poiseuille friction and some boundary solid interactions. The combined experimental-analytical approach has not hitherto been reported in literatur
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