Advanced Materials Research Vol. 650

Abstract: The low silicon sintered ores are prepared, where C content is 3.3%, 3.5%, 3.7%, 3.9% and 4.1%, respectively. Their metallurgical properties are also measured. The results state that the low temperature reduction degradation property in low silicon sintered ore is to achieve the best when the carbon content was 3.7%. With increasing carbon content, it has a trend that the low silicon sintered reducing gradually become variation. In this range of carbon content, softening initial temperature exceed 1230 oC, the softening interval is less than 120 oC, so suitable C content are helpful to improve metallurgical properties for low silicon sintered ore.

Abstract: This research was to study the effect of face milling on the surface finish of stainless steel: AISI 304. The experiment was applied on three factors and were consisted of three levels of cutting speed, depth of cut and feed rate. The face milling process was chosen to experiment which used face milling cutter with insert carbide tool. The surface roughness average (Ra) was applied to indicating for surface finish. The experiment results were analyzed by ANOVA. The main factors and factors interaction that affected to surface finish were investigated. Effect of cutting speed, feed rate and depth of cut on surface finish of stainless steel: AISI 304 was discussed.

Abstract: The research was study the effect of post weld heat treatment parameters on microstructure and hardness in heat affected zone. The specimen was carbon steel AISI 1050 which thickness of 6 mm. The experiments with full factorial design. The factors used in this study were post weld heat treatment(PWHT) temperature of 500, 550, 600, 650 and post weld heat treatment time of 10 and 15 hour. The welded specimens were tested by tensile strength testing and hardness testing according to ASTM code. The result showed that both of post welds heat treatment temperature and post weld heat treatment time had interaction on hardness at 95% confidential (P value < 0.05). A factor affecting the hardness was the most PWHT temperature 550 ๐C and PWHT time 10 hr. of 279 HV. Microstructure can be concluded that low PWHT temperature and time effect on temper martensite with a coarse grain and martensite scattered throughout. Martensite was a smaller and greater fine grain, the ferrite and the volume decrease due to a higher temperature.This research can be used as data in the following appropriate PWHT parameters to carbon steel weld.

Abstract: The purpose of this research was to study rivets parameters which were affecting to strength of joint of aluminium. Full factorial experimental design was conducted as 3 factors and 3 levels. The parameters were consisted of three levels of drilled holes, buck-tail length and upset distance. Furthermore, the experiment was done by pan-head rivet. The lap joint was selected to experiments on the specimens that were consisting of three thicknesses of 1, 2 and 3 mm. The main factors and interaction between factors that affected to strength of joint was analyzed. Effect of drilled holes size, buck-tail length and upset distance on strength of joint was discussed. The effect of thickness on strength of joint was reported. In order to finding suitable of upset distance, the tension load was analyzed and compared.

Abstract: In the foundation of generous field test and theoretical research, we presented a calculated model of middle thickness in cold tandem mill by combining applied mathematical theory and production technology and taking advantage of Taylor series expansion, matrix analysis, Newton iteration method and other mathematical methods. This model was used for setting original middle thickness on 1220 cold tandem mill in some plant. After field usage, the result was fine and correlative precision was over 90%. It completely satisfies required precision in project and has the value to be further popularized and applied.

Abstract: To gasify the mixture of sludge coming from urban sewage treatment residual and MSW is an ideal way to control the combustion of dioxins and other substances which pollute the atmosphere. Due to the complex composition of MSW and changing rapidly in the gasification parameters as much as possible, engineering require main ingredients and calorific value. The main ingredients of typical municipal sewage sludge and MSW are measured on thermobalance pyrolysis. The kinetics parameters of the gasification reaction are obtained, such as the activation energy and pre-exponential factor. These parameters synthesis mixture parameters provide the basis for hybrid gasification of the actual sludge and MSW reactor design, construction and operation.

Abstract: Based on the analysis of the problems about the reverse circulation drilling in the practical application, such as the ability of the drilling depth, application in the loose layer, the construction of the pile hole with large diameter, three optimization programs are put forward, and evaluated in combination with the project examples of Wuhan Baishazhou cable-stayed bridge. Finally, some experiences in construction practices are given.

Abstract: BAS (Biochemical Adsorption Separation) process is a kind of municipal wastewater advanced treatment process which could treat municipal wastewater directly to meet the Ⅳ class of surface water standard. BAS process integrated by 4 technologies: (1) high elastic cilia filler biochemical treatment technology, (2) effluent from the facultative oxygen zone technology, (3) AZ - 01 ammonia nitrogen adsorption technology and (4) active ceramic filtration technology. The effluent quality of BAS process could reach COD_Cr≤30mg/L, BOD₅≤6mg/L, TP≤0.3mg/L, TN≤1.5mg/L and SS≤1.5mg/L. BAS process has the advantages of easy operation, stable treatment effect, little construction and low operation cost. It is suitable use in our country special sensitive area such as Tai Lake, Dian Chi, etc. and some area which requires higher water quality.

Abstract: The mean radiant temperature is one of the meteorological key parameters governing human energy balance and the thermal comfort of human body. This variable can be considered as the sum of all direct and reflected radiation fluxes to which the human body is exposed. After the basics of the T_mrt calculation a comparison between two methods suitable for obtaining T_mrt in a street canyon will be presented. One of the discussed methods of obtaining T_mrt is based on the utilization of a globe thermometer. The other method is the radiation environment simulation through three PC software (RayMan, ENVI-met and SOLWEIG).

Abstract: This Regular evaluation and analysis of river quality helps accurate management to reach acceptable quality. In this study, water quality indices (WQI) method applied to evaluate quality of Jajrood River which is one of the main sources of Tehran drinking water. It helps to subsidize management actions in Jajrood watershed. Sampling carried out for 9 years during 2001-2010 in 10 stations along the river in wet and dry stations to identify water quality and the main source of pollution. Results show water quality in all stations classifies as medium according to National Sanitation Foundation (NSF) and water quality index in wet season is better than the corresponding value in dry seasons. Entrance of pollution during the upstream of Latian Dam (especially in populated centers) has negative effect on the water quality, however river has a good natural attenuation capacity, therefore quality index of river in the main inlet of Latian dam (Lashkarak Bridge) classifies as medium. Collecting wastewater at the populated centers and developing soil conservation and controlling erosion at the upstream of watershed can effectively improve the water quality of river.