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The paper presents the results of research concerning three fiber materials—mineral wool, hemp fiber and wood wool—as loose-fill thermal insulation materials. The analysis used the material parameters determined in previous works conducted by the authors, such as thermal conductivity and air permeability in relation to bulk density. These materials exhibit open porosity; thus, convection is an essential phenomenon in the heat transfer process. The paper aimed at conducting thermal simulations of various frame wall variants which were filled with the above-mentioned insulation materials. The simulations were performed with the Control Volume Method using the Delphin 5.8 software. The studies accounted for the effect of wind pressure and the time of its influence on a wall insulated by means of fiber material with a thickness of 150 as well as 250 mm. The simulation enabled us to obtain such data as maximal R-value reduction and time to return to equilibrium after filtration for the analyzed materials. The study proved that heat transfer in these insulations strongly depends on the bulk density, thickness of the insulation and wind pressure. The decrease in R is reduced as the density increases. This results from the decreased air permeability characterizing the material. Wind washing causes lower R reduction than air filtration in all models. The greater the thickness, the longer it takes for the models to return to the equilibrium state following air filtration (and wind washing). This period is comparable for air filtration and wind washing. Hemp fibers were characterized with the strongest susceptibility to air filtration; in the case of wood wool, it was also high, but lower than for hemp fibers, while mineral wool was characterized with the lowest. 相似文献
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《Digestive and liver disease》2014,46(9):846-853
BackgroundWe performed a retrospective analysis of Asian patients with locally advanced oesophageal cancer to test the hypothesis that an elevated neutrophil-to-lymphocyte ratio is associated with a poor survival rate after definitive concurrent chemoradiotherapy.MethodsIn total, 138 patients diagnosed with locally advanced oesophageal cancer (TNM classification of malignant tumours stage II or III) who were treated with definitive concurrent chemoradiotherapy between January 2005 and December 2010 were retrospectively analysed. Definitive concurrent chemoradiotherapy was performed using two different chemotherapy regimens.ResultsThe median follow-up duration was 39.5 months (range 1.1–93.4). The median progression-free survival was 14.0 months, and the median overall survival was 19.9 months. Compared with the low (<2.0) neutrophil-to-lymphocyte ratio group (n = 43, 31.2%), the high (≥2.0) neutrophil-to-lymphocyte ratio group (n = 95, 68.8%) exhibited significant decreases in the durations of both progression-free survival and overall survival. Using multivariate analysis, an elevated neutrophil-to-lymphocyte ratio was also significantly associated with decreased progression-free survival (HR 1.799; 95% CI, 1.050–3.083; P = 0.032) and overall survival duration (HR 2.115; 95% CI, 1.193–3.749; P = 0.010).ConclusionsThe pretreatment neutrophil-to-lymphocyte ratio is a useful prognostic marker in patients with locally advanced oesophageal cancer treated with definitive concurrent chemoradiotherapy. 相似文献