934 research outputs found

    Definition of smolder experiments for Spacelab

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    The feasibility of conducting experiments in space on smoldering combustion was studied to conceptually design specific smoldering experiments to be conducted in the Shuttle/Spacelab System. Design information for identified experiment critical components is provided. The analytical and experimental basis for conducting research on smoldering phenomena in space was established. Physical descriptions of the various competing processes pertaining to smoldering combustion were identified. The need for space research was defined based on limitations of existing knowledge and limitations of ground-based reduced-gravity experimental facilities

    METHODS OF CALCULATION OF MSW STRUCTURES

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    The paper reviews the existing methods for the solution of structures supporting propaga- tion of magnetostatic waves. Due to the fact that these are mostly multilayered structures the mostly used numerical techniques for their calculation are the method of the surface permeability, finite element method and the boundary element method. Because each of them is more or less suitable in special cases, the advantages of each are discussed and pointed out in the paper. The general magnetic anisotropy formulation has been introduced into boundary element method

    Who knows who we are? Questioning DNA analysis in disaster victim identification

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    The use of DNA analysis as a mode of identification of disaster victims has become increasingly predominant to other, traditional, methods of identification in recent years. Scientific advances of the technological processes, high-profile use in identification efforts across the globe (such as after 9/11 or in the Asian Tsunami of 2004), and its inclusion in popular media, have led to its popular adoption as one of the primary modes of identification in disaster scenarios, and to the expectation of its use in all cases by the lay public and media. It is increasingly argued to be integral to post-disaster management. However, depending on the circumstances, location, and type of disaster, this technology may not be appropriate, and its use may instead conflict with socio-political and cultural norms and structures of power. Using examples primarily from Cambodia and Iraq this article will explore what these conflicts may be, and in doing so, question the expanding assumption that DNA analysis is a universally appropriate intervention in disaster victim identification. It will argue instead that its use may be a result of a desire for the political and social capital that this highly prestigious technological intervention offers rather than a solely humanitarian intervention on behalf of survivors and the dead

    Using technology to find the secret places of the heart

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    Combustion contribution to noise in jet engines

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    The relative importance of combustion as a source of noise in a flow regime representative of a subsonic jet engine exhaust was investigated. The combustion noise source characteristics were obtained from pressure and temperature fluctuation measurements in the combustor and exhaust nozzle. The similarity between the fluctuations in this source region and the far field noise were compared. In the jet exhaust velocity range between 450 and 660 ft/sec investigated in detail, the frequencies of dominant pressure and temperature fluctuations in the combustor were also the frequencies of the dominant far field noise. The overall noise levels were 14 to 20 dB higher than from a corresponding clean jet in the same velocity range. Thus it seemed clear that the unsteadiness associated with the combustion process was responsible for the dominant noise in the far field. A simple analysis to predict the far field noise due to the internal pressure fluctuations causing exit plane velocity fluctuations produced trends closely resembling the measured results, but under predicted the far field noise over the spectral range examined. The possible reason for the higher far field noise is direct transmission of acoustic waves through the nozzle, which was not accounted for in the prediction scheme

    Acupuncture for the treatment of phantom limb syndrome in lower limb amputees: a randomised controlled feasibility study

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    Background: Post amputation, the complication phantom limb pain (PLP) is prevalent and difficult to manage. This study aimed to determine whether it was feasible and acceptable to undertake a definitive multi-centred randomised controlled trial assessing the effectiveness of acupuncture for treating lower limb amputees with PLP. Methods: A mixed methods embedded design including a randomised controlled trial and semi-structured interviews was undertaken. A total of 15 participants with PLP were randomly assigned to receive either 8 pragmatic Traditional Chinese Medicine acupuncture treatments and usual care or usual care alone over four weeks. Outcomes measures were completed at baseline, weekly throughout the study and at one month post completion of the study and included; a numerical pain rating scale, Short-Form McGill Pain Questionnaire 2, EQ-5D-5L, Hospital Anxiety and Depression Scale, Perceived Stress Scale 10 item, Insomnia Severity Index, Patient Global Impression of Change. Post completion of the trial, participants in the acupuncture group were interviewed about their experience. Feasibility specific data were also collected. Results: Of 24 amputees meeting the study inclusion criteria 15 agreed to participate (recruitment rate 62.50%). Qualitatively acupuncture was perceived to be beneficial and effective. Quantitatively acupuncture demonstrated clinically meaningful change in average pain intensity (raw change=2.69) and worst pain intensity (raw change = 4.00). Feasibility specific data identified that before undertaking a definitive trial, recruitment, practitioner adherence to the acupuncture protocol, completion of outcome measures at one month follow up and blinding should be addressed. Appropriate outcome measures were identified for use in a definitive trial. Data were generated for future sample size calculations (effect size 0.64). Allowing for a 20% dropout rate, a sample size of 85 participants per group would be needed in a future definitive trial. Conclusions: A future definitive trial may be possible if the areas identified in this study are addressed. As acupuncture may be effective at treating PLP and as this feasibility study suggests a definitive trial may be possible, a multi-centred trial with adequate sample size and blinding is now needed. Trial registration: ClinicalTrials.gov: NCT02126436. Registration date: 9.4.2014

    Ablation of insulin-producing cells prevents obesity but not premature mortality caused by a high-sugar diet in Drosophila

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    Ageing can be modulated by genetic as well as nutritional interventions. In female Drosophila melanogaster, lifespan is maximized at intermediate concentrations of sucrose as the carbohydrate source, and yeast as the protein source. Dampening the signal through the insulin/IGF signalling (IIS) pathway, by genetic ablation of median neurosecretory cells (mNSCs) that produce insulin-like peptides, extends lifespan and counteracts the detrimental effects of excess yeast. However, how IIS reduction impacts health on a high-sugar diet remains unclear. We find that, while the ablation of the mNSCs can extend lifespan and delay the age-related decline in the health of the neuromuscular system irrespective of the amount of dietary sugar, it cannot rescue the lifespan-shortening effects of excess sugar. On the other hand, ablation of mNSCs can prevent adult obesity resulting from excess sugar, and this effect appears independent from the canonical effector of IIS, dfoxo. Our study indicates that while treatments that reduce IIS have anti-ageing effects irrespective of dietary sugar, additional interventions may be required to achieve full benefits in humans, where excessive sugar consumption is a growing problem. At the same time, pathways regulated by IIS may be suitable targets for treatment of obesity

    Simple Lattice-Models of Ion Conduction: Counter Ion Model vs. Random Energy Model

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    The role of Coulomb interaction between the mobile particles in ionic conductors is still under debate. To clarify this aspect we perform Monte Carlo simulations on two simple lattice models (Counter Ion Model and Random Energy Model) which contain Coulomb interaction between the positively charged mobile particles, moving on a static disordered energy landscape. We find that the nature of static disorder plays an important role if one wishes to explore the impact of Coulomb interaction on the microscopic dynamics. This Coulomb type interaction impedes the dynamics in the Random Energy Model, but enhances dynamics in the Counter Ion Model in the relevant parameter range.Comment: To be published in Phys. Rev.

    Cats with diabetes mellitus have diastolic dysfunction in the absence of structural heart disease

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    Diabetes mellitus (DM) can result in cardiovascular dysfunction and heart failure characterized by diastolic dysfunction with or without the presence of systolic dysfunction in people and laboratory animals. The objective of this prospective study was to determine if cats with newly diagnosed DM had myocardial dysfunction and, if present, whether it would progress if appropriate antidiabetic therapy was commenced. Thirty-two diabetic cats were enrolled and received baseline echocardiographic examination; of these, 15 cats were re-examined after 6 months. Ten healthy age- and weight-matched cats served as controls. Diabetic cats at diagnosis showed decreased diastolic, but not systolic function, when compared to healthy controls, with lower mitral inflow E wave (E) and E/E' than controls. After 6 months, E and E/IVRT' decreased further in diabetic cats compared to the baseline evaluation. After excluding cats whose DM was in remission at 6 months, insulin-dependent diabetic cats had lower E, E/A and E' than controls. When classifying diastolic function according to E/A and E'/A', there was shift towards impaired relaxation patterns at 6 months. All insulin-dependent diabetic cats at 6 months had abnormal diastolic function. These results indicate that DM has similar effects on diastolic function in feline and human diabetics. The dysfunction seemed to progress rather than to normalize after 6 months, despite antidiabetic therapy. In cats with pre-existing heart disease, the development of DM could represent an important additional health risk
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