Rigid open-cell polyurethane foam for cryogenic insulation

Lightweight polyurethane foam assembled in panels is effective spacer material for construction of self-evacuating multilayer insulation panels for cryogenic liquid tanks. Spacer material separates radiation shields with barrier that minimizes conductive and convective heat transfer between shields

The effect of pramipexole extended release on the levodopa equivalent daily dose in Lebanese Parkinson diseased patients

Objective: The objective of this study is to compute the potential benefit of Pramipexole ER on total levodopa equivalent dose (LED) and Unified Parkinson Disease Rating Score (UPDRS-III) compared to mono- or combined therapy of pramipexole IR and/or carbidopa/levodopa. Methods: This is a retrospective observational study conducted in a specialized PD (Parkinson Disease) and movement disease center in Lebanon between January and December 2017. Results: A total of 176 patient’s record was reviewed. Pramipexole ER showed a significant difference on the mean changes in LED and UPDRS-III score. After 13 weeks of initiating Pramipexole ER, the mean decrease in LED was -49.42 mg for all patients (p < 0.001, CI 95% [35.28-63.55]) and the mean decrease in UPDRS-III score for all patients was -6 points (P< 0.001). According to the subgroup analysis, patients aged 65 years and below, the change in mean total LED from baseline ( 350.80 mg) was a decrease of 63.19 mg with a p<0.001, CI 95% [42.07-84.31]. In patients aged more than 65 years and shifted to mono or combined pramipexole ER therapy, the change in mean total LED from baseline (559.25 mg) was a decrease of 34.67 mg with a p<0.001 CI 95% [16.16-53.18]. In addition the results showed that in patients having an UPDRS-III score of less than or equal to 33, the change in mean total LED from baseline (436.73 mg) was a decrease of 56.76 mg (p<0.001; CI 95% [41.32-72.20]). However, in patients having an UPDRS-III score of more than 33 the change in mean total LED from baseline (545.06 mg) was a decrease of 2.96 mg with a p value < 0.844 CI 95% [27.32-33.15]. Conclusions: This study demonstrated the efficacy of Pramipexole ER on decreasing the total levodopa equivalent dose (LED).The role of health care professionals is to maintain the patient on the lowest effective levodopa equivalent daily dose and optimize the treatment therapy, thus decreasing the side effects that might arise from overdosing of antiparkinsonian drugs

Effect of temperature and strain rate on the mechanical behavior of discontinuous glass fibre reinforced thermoplastic composite

International audienceThe use of discontinuous glass fibre reinforced thermoplastic composites is nowadays increasing in many fields, e.g. automotive, marine, industrial, biomedical and aircraft structures due to their good mechanical properties and environmentally-friendly nature (recycleability). Although such types of material show many advantages, their sensitivity to temperature and strain rate complicates their study. During manufacturing processes (thermoforming, compression moulding...), the thermoplastic composites may be subjected to severe conditions : high strain rates and temperatures, complex strain paths, resulting in significant changes of their mechanical properties. In this study, the mechanical behaviour of long glass fibre reinforced polypropylene is evaluated by performing uniaxial tensile tests at strain rates ranging from 0.001s−1 to 10s−1 under different temperatures starting from ambiant up to 120◦C. On the basis of the experimental results, a phenomenological material behavior model that depends on temperature and strain rate is identified. The uniaxial tests are then considered as a preliminary step to prepare for more complex mechanical characterization by means of biaxial tensile tests on cruciform shaped specimens, integrating the effect of strain path in addition to temperature and viscous effects.L'utilisation de composites thermoplastiques renforcés par des fibres de verre discontinues se développe aujourd'hui dans de nombreux secteurs (automobile, marine, biomédical, aéronautique) en raison de leurs bonnes propriétés mécaniques et de leur caractère éco-responsable (recyclabilité). Bien que ces types de matériaux présentent de nombreux avantages, leur sensibilité à la température et à la vitesse de déformation rend leur étude complexe. Au cours de leur mise en forme (thermoformage, moulage par compression...), les composites thermoplastiques peuvent être soumis à des conditions sévères : vitesses de déformation et températures élevèes, chemins de déformation complexes, pouvant entraîner des changements significatifs des propriétés mécaniques. Dans cette étude, le comportement mécanique du polypropylène renforcé de fibres de verre longues est évalué en réalisant des essais de traction uniaxiale à des vitesses de déformation allant de 0,001s −1 à 10s −1 pour des températures allant de l'ambiante jusqu'à 120 • C. Sur la base de ces résultats expérimentaux, un modèle phénoménologique du comportement du matériau utilisé dépendant de la vitesse de déformation et de la température est identifié. Ces essais uniaxiaux sont alors considérés comme une étape préliminaire pour préparer une caractérisation mécanique plus complexe au moyen d'essais de traction biaxiaux sur des éprouvettes de forme cruciforme, intégrant en plus des effets température et visqueux, l'effet du chemin de déformation

Experimental and numerical study on capillary flow along deflectors in plate surface tension tanks in microgravity environment

Surface tension tanks are the most widely used satellite propellant tanks, which use liquid surface tension for liquid transportation and gas-liquid separation to provide pure propellant for thruster. As the second generation surface tension tank, the plate type tank has characteristics of simple structure, easy processing and high reliability, and represents development direction of surface tension tanks. In this paper, drop tower experiments are used to investigate transfer speed of deflectors in plate type tanks, and corresponding numerical simulation is carried out in Fluent with Volume of Fluid method

Pest and disease management: why we shouldn’t go against the grain

Citation: Skelsey, P, . . . & Garrett, K. (2013). Pest and Disease Management: Why We Shouldn't Go against the Grain. PLoS One, 8(9), e75892. https://doi.org/10.1371/journal.pone.0075892Given the wide range of scales and mechanisms by which pest or disease agents disperse, it is unclear whether there might exist a general relationship between scale of host heterogeneity and spatial spread that could be exploited by available management options. In this model-based study, we investigate the interaction between host distributions and the spread of pests and diseases using an array of models that encompass the dispersal and spread of a diverse range of economically important species: a major insect pest of coniferous forests in western North America, the mountain pine beetle (Dendroctonus ponderosae); the bacterium Pseudomonas syringae, one of the most-widespread and best-studied bacterial plant pathogens; the mosquito Culex erraticus, an important vector for many human and animal pathogens, including West Nile Virus; and the oomycete Phytophthora infestans, the causal agent of potato late blight. Our model results reveal an interesting general phenomenon: a unimodal (‘humpbacked’) relationship in the magnitude of infestation (an index of dispersal or population spread) with increasing grain size (i.e., the finest scale of patchiness) in the host distribution. Pest and disease management strategies targeting different aspects of host pattern (e.g., abundance, aggregation, isolation, quality) modified the shape of this relationship, but not the general unimodal form. This is a previously unreported effect that provides insight into the spatial scale at which management interventions are most likely to be successful, which, notably, do not always match the scale corresponding to maximum infestation. Our findings could provide a new basis for explaining historical outbreak events, and have implications for biosecurity and public health preparedness