Advanced Materials Research Vols. 1044-1045

Abstract: Because public areas in Taiwan such as hostels, movie theaters, supermarkets, stadiums, and large entertainment venues are typically packed with people, when fires occur, the smoke and high heat often lead to human casualties. Therefore, the studies on fire dynamic characteristics are essential. In this paper, we studied a major fire accident occurred in one of Taipei’s major hostels, during which the lodgers awoke and attempted escape. This accident led to eight deaths; the victims either died from the burns they sustained or choked to death in their bedrooms or in the staircase. The fire accident resulted in the greatest amount of human casualties in Taipei over the past two decades. The fire dynamics simulator developed by the National Institute of Standards and Technology was used in this study to analyze the fire dynamic field behavior. The data showed that the fire started in a room on the second floor and that the smoke spread to the entire building within approximately 3 min. Our simulation produced similar results. It is hoped that the findings can be used to improve the safety features and enhance the future fire protection designs of similar buildings so that the heavy human casualties and property losses would be greatly reduced.

Abstract: In the operation process of permanent magnet governor, the temperature rises due to eddy current loss, and demagnetization of permanent magnet occurs at high temperature. The numerical simulation of fluid flow field and temperature field was carried out with the method of computational fluid dynamics (CFD) and ANSYS-Fluent software. And then we improved the structure of permanent magnet governor on the basis of analysis of the flow field and temperature distribution. The result indicates that the flow of improved structure increases, and temperature drops 46.°C, fulfilling the desired temperature range of permanent magnet can bear, which provides a theory basis for the design of ventilation-cooling structure of permanent magnet governor.

Abstract: In order to realize single longitudinal mode (SLM) output, an erbium-doped fiber (EDF) laser with fiber ring cavity is proposed which uses an un-pumped EDF saturated absorber as a SLM selector. Ring cavity length, coupler ratio and insertion loss which affect ring cavity filter performance are analyzed theoretically and simulated numerically. Un-pumped EDF length and Er³⁺ concentration are analyzed theoretically and simulated. Research shows that, the bigger coupling output ratio of ring cavity, the greater transmission peak; the greater mode line width; the shorter ring cavity length, the wider free spectral range; the bigger coupling loss, the smaller transmission peak; when the difference between two cavities length is big, cursor effect is not obvious. Laser threshold increases with absorber length increasing; the bigger saturated absorber concentration, the higher laser threshold.

Abstract: As the resources & environment issues faced by various countries and regions in social and economic development become more and more prominent, green government procurement has drawn widespread attention of all the countries. Implementation of green government procurement can guide the society’s concept of green consumption, promote the development of green industries and technologies, guide and cultivate a host of green products and industries, and enhance the public’s environmental awareness. Through analyzing the modes of green government procurement adopted by the US, the EU and Japan, especially the performance indexes of green products, this paper has comparatively analyzed the differences between China and developed countries in green procurement measures, and put forward the direction for our country to improve the policies of green government procurement.

Abstract: In order to predict the sedimentation deposition in the Shuidonggou reservoir in next few years, the flow in this reservoir is studied using the two dimensional (2D) hydraulic mathematical model. The governing equations of the model are discredited with finite volume method (FVM) on unstructured grids, and the 2-D flow movement are simulated under several different conditions. The results showed that: when the amount of the water inflow and the water drawn unchanged, as the water level drops, water flow velocity increases in the reservoir; at high water level (1179 m), the left bank of the south side of the intake eroded; at low water level (1174.4m), north and south sides of the mainstream of water have a recirculation zone; when the water level is constant, with the increase of the amount of water, the recirculation zone on the right side of the intake became smaller and close to the water intake.

Abstract: Nowadays, an awareness of health benefits of omega-3 has been found. Polyunsaturated fatty acids, especially DHA, are more attention due to their role in human health. Hence, this study investigated the potential of by-products as freshwater fish source of omega-3 polyunsaturated fatty acids (omega-3 PUFAs). The by-products of processing accounted for approximately 55% of the catfish industry. Supercritical fluid extraction (SFE) of the by-products at 35 MPa, 40 ^◦C, ethanol (95%, v/v) as the co-solvent, and the mass ratio of by-products to co-solvent as 1:1 generated a lipid yield at 30.9% and 21.5 % docosahexaenoic acid (DHA). Additionally, urea complexation was an effective tool to enrich and purify DHA from lipids. DHA purity increased from 21.5% to 38.4% under the optimum complexation condition.

Abstract: Operating temperature and thermal uniformity have great effect on the performance, cycle life and safety of lithium-ion power batteries. In order to investigate the surface temperature change and distribution of a large-capacity and rectangular LiFePO₄/C power battery, this paper conducts experiments on charging and discharging a battery module and cell at different current rates and various ambient temperatures. Results of thermalcouple-measurement show that temperature rising rates at different temperatures during charge and discharge change in accordance with the variation tendency of the resistance at different state of charge (SOC) and oprating temperatures. Under elevated ambient temperatures, the temperature excurtion and maximum temperature difference of the module are all smaller. Under the same ambient temperature, battery temperature at the end moment of discharge increases and the temperature uniformity of the module deteriorate at higher discharging rate. Temperature excurtion over the same time period is in a relationship of a standard quadratic function with the discharge current. Results of the thermal infrared imaging tests show that the maximum surface temperature differences at different discharging currents of 20A, 40A, and 80A are all above 5°C under natral convection heat transfer. The temperature of the lower part is higher than that of the upper part, while that of the central area is the highest. In a comprehensive charging and discharging scheme, the tendency of maximum surface temperature difference changes in accordance with that of the average surface temperature.

Abstract: The article considers the problem of effective protection of the cooling tower shell using the screen with a ventilated air gap. The aim is to determine the optimal parameters of the air gap. In operation, the calculations were performed showing the effects of temperature conditions and the thickness of the gap on the aerodynamic and thermal modes of operation. The article made conclusions based on the done calculations. The optimum thickness of the gap, provided heating air inlet, which provides the ability to assimilate air moisture throughout the layer and delete it in the atmosphere, which in the future will eliminate condensation on the cold surface of a concrete shell.

Abstract: This study, through on-site sampling, performs a content analysis of total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) contained in Kaohsiung Harbor surface sediments, and accordingly evaluates their temporal-spatial distribution and sources. The results indicate that the TOC content of Kaohsiung Harbor sediments ranges from 1.0 to 7.0% (average 2.3±0.3%) with the highest level of 6.8±0.2% in the Salt River estuary. The TN content ranges from 990 to 10,582 mg/kg (average 2,665±1,800 mg/kg) and the TP values are between 178 and 784 mg/kg (average 363±147 mg/kg). The content distribution of TOC, TN and TP demonstrates a high-to-low sequence: estuary, channel and Harbor, indicating that the organics in the sediments are mainly from the upstream inflow of rivers. The TOC, TN and TP contents in the wet season are obviously higher than those in the dry season, which might result from the terrestrial organics flushed into the Harbor by the seasonal abundant and concentrated precipitation. The C/N ratio of Kaohsiung Harbor sediments is between 4.6 and 26.9, with an average value of 11.9±6.6. Through further estimation, 76.5% of the TOC is identified as terrestrial, and the TN is dominated by marine autogenetic sources.

Abstract: The basic mathematical method for power system reliability evaluation was indicated, the simple and complex system was respectively introduced, several methods of reliability analysis of simple was given in this paper, and the reliability evaluation indexes system and methods of composite generation and transmission system was analyzed, then focused on state enumeration method applied in the reliability assessment of system, the detailed example analysis was given and the adequacy reliability indexes were computed in detail. Finally, the current reliability evaluation and status of composite generation and transmission system was summarized simply and its reliability evaluation algorithm steps applied in current actual engineering projects was given.