This study proposes a novel adaptive spatial-temporal data generation method to achieve precise ceiling temperature perception in tunnel fires based on the modified BP neural network. In the method, an automatic updat...
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This study proposes a novel adaptive spatial-temporal data generation method to achieve precise ceiling temperature perception in tunnel fires based on the modified BP neural network. In the method, an automatic update of training data set procedure is coupled in the BP neural network, which establishes an effective coarse-to-fine data generation method from coarse monitored data to fine ceiling temperature prediction in spatial-temporal scale. The method belongs to a kind of data-driven algorithms for ceiling temperature prediction in tunnel fires, which is not limited to the special fire scene. Additionally, full-scale fire experiment was conducted to verify the effectiveness of the method in China's largest tunnel fire experimental platform. Twenty-three thermocouples measured the ceiling temperature of the tunnel fire experiment. In contrast to the experimental results and the results obtained from the traditional BP neural network, the method can be used an effective numerical tool to predict the precise fine ceiling temperature spatial-temporal distribution, and the prediction precision is higher than the traditional BP neural network algorithm.
Polyurethane flexible foam materials have a wide range of industrial applications. These applications include flexible foams for packaging, polyurethane-based foam materials for seat cushions in buses, railways, the a...
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Polyurethane flexible foam materials have a wide range of industrial applications. These applications include flexible foams for packaging, polyurethane-based foam materials for seat cushions in buses, railways, the airline industry, prisons, and domestic bedding. There is a substantial need for the development of flexible molded foam materials with low heat release rates and smoke release rates. In this study, an extensive series of flexible, molded polyurethane seat cushion materials based on polymeric MDI and polyether polyols were prepared and further modified with commercially available flame retardant additives. The flame retardant behavior of these foam materials was evaluated using Cone Calorimeter (ASTM-E 1354), vertical Bunsen burner test for cabin and cargo component materials [FAR 25.853 (a), Appendix F, Part I, (a)(1)(i) and (a)(1)(ii)], and oil burner test for seat cushions [FAR 25.853 (c), Appendix F, Part IT]. Several formulations that passed the 12-second vertical Bunsen burner test were identified. These include the formulations modified with Firemaster(R) HP-36, Decabromodiphenyl oxide/antimony oxide/Firemaster(R) HP-36, Fyrol(R) FR-2, and Fyrol(R) FR-2/graphite powder. A formulation modified with Antiblaze(R)-230 and a cross-linking agent passed both 12-second and 60-second vertical Bunsen burner tests. But, all of these materials did not pass the oil burner tests for seat cushions. Using the cone calorimeter, materials with a reduction in peak heat release rate of up to 57% were prepared and with up to a fourfold increase in char residue in the cone. However, most FR formulations showed an increase in carbon monoxide and smoke generation. Lowest peak HRR data were obtained with Firemaster(R) HP-36/Sb2O3 and Dow Silicones(R) 1-9641 at 25 kW/m(2) and with Fyrol(R) FR2/cross-linker at 35 kW/m(2) exposure. It appears that there is no correlation between cone calorimeter results and vertical Bunsen burner test results.
Lafourcade M. and Paluzie E. European integration, foreign direct investment (FDI), and the geography of French trade, Regional Studies. An augmented gravity model is used to investigate whether the 1978-2000 process ...
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Lafourcade M. and Paluzie E. European integration, foreign direct investment (FDI), and the geography of French trade, Regional Studies. An augmented gravity model is used to investigate whether the 1978-2000 process of European integration has changed the geography of trade within France, with a particular focus on border regions. It is found that once controlled for bilateral distance, origin- and destination-specific characteristics, French border regions trade on average 73% more with neighbouring countries than predicted by the gravity norm. The regions perform even better if they have good transport connections with these countries. However, French border regions at the periphery of Europe experienced a downward trend over the period that was partly due to the decrease in the propensity of Spanish and Italian foreign affiliates to trade with their home countries.
This study was designed to differentiate the general practice perceptions of physicians who affiliate with an HMO and those not affiliated with an HMO as well as the ''within physician'' comparison of ...
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