Applied Mechanics and Materials Vols. 260-261

Abstract: This paper reports an investigation regarding the effects of temperature, pH, dissolved oxygen (DO) concentration and agitation on total phosphorus (TP) release in sediment form Baihua Lake. The results showed that an increase in the temperature led to a sharp increase in the TP release in the examined sediment. The TP release from the sediment decreased as the pH value increased until approximately pH = 7, and increased when pH > 7. There was phosphorus release in both aerobic and anoxic conditions, although the release quantities of TP were significantly higher in the anoxic condition than those in the aerobic condition. In addition, the TP release increased with agitation.

Abstract: The electrical model of a capacitive soil moisture sensor is considered in this paper. In the new model established, the contact resistor and contact capacitance are taken into account. It is pointed out that the electric double layer causes the formation of the contact resistor and contact capacitance. The electrical properties of the electric double layer are the effect of both physical electricity and electrochemistry, so the relationship between the contact capacitance and the soil relative permittivity does not follow the formula of the parallel plate capacitor. Based upon the diffuse electric double layer model, this paper successfully derives the formula of the contact capacitor , whose coefficients are determined by MATLAB simulation based on experimental data, and the soil relative permittivity. Besides, this paper has established the sensor-output-voltage-Vo -soil-moisture-θ curve and compared it to that derived from the model without considering the electric double layer. It is demonstrated that the correlation coefficient between the curve derived from the model this paper established and the experimental data is 0.9997, more accurately describing the relation between the sensor output voltage Vo and soil moisture θ.

Abstract: This paper presents an investigation of satellite data and ground data about aerosols and then modelsthe mentioned data over Shiraz using artificial neural networks. MODIS satellite data are available on 36 various frequency bands. In this study, a good correlation between ground data and the 10 first satellite image bands is being shown. Specially, the best correlation was found in band number 8. Therefore, using neural networks and ground data along with satellite information, a model of aerosols is constructed. In the mentioned model, satellite data of band 8 and ground data are used as network input and output, respectively. The results show the effectiveness of the proposed model.

Abstract: This study, by means of GC-MS and HPLC, investiagted the characteristics of volatile organic compounds (VOCs) released from fiber dryer in a high density fiberboard (HDF) production line with a production capacity of 100,000 m³/a. The quantity of total volatile organic compounds (TVOC), aldehydes and ketones were calculated. The results showed that the concentration of VOCs reached 0.5275 mg/m³. The main components include benzenes series (42.7%), terpenes (11.0% alpha pinene), alkanes (11.2%), anhydrides (4.7%) and aldehydes (3.1%). The concentration of the mixture of aldehydes and ketones was 8.8594 mg/m³. The annual emission of TVOC and the mixture of aldehydes and ketones from HDF fiber dryer were 836 kg/a and 14033 kg/a, respectively.

Abstract: Sustainable supply chains are now growing in importance as shareholders, employees and consumers question whether the company and its associate suppliers are socially and environmentally responsible. This fact has been seriously considered in the auto industry supply chain where companies seem to be concerned with the environment performance of their vendors. In order to verify to what extent the environmental requirements have been imposed by the auto industry companies to their suppliers, this paper examines the case of a first tier multinational Brazilian auto parts manufacturer. The case analysis was able to demonstrate that environmental requirements are of key importance in the evaluation, selection and maintenance of a supplier as part of the respective supply chain.

Abstract: This paper constructs an optimization model about carbon dioxide emissions problem for production process of a large-scale iron and steel corporation in China. Then how to realize maximal profits of corporation is studied under the subjective conditions about production, raw material supply and emissions abatement amount. And the optimized production structure in accordance with production benefits and environment benefits are obtained by non linear programming methodology. Finally the carbon dioxide emissions per unit of steel production are compared with the level of whole China and developed countries, and how to utilize the byproducts of coal gas for multipurpose is also discussed.

Abstract: In order to improve the spray dust suppression effect, the method of dust suppression by self-priming spray was put forward, the principle of dust suppression by self-priming spray was analyzed.The numerical simulation of self-priming spray and conventional spray characteristics were made by Fluent software,and the verification test had been completed. The results showed that the velocity distribution of self-priming spray was more uniform than that of conventional spray; the value of SMD of self-priming spray was smaller than conventional spray. What’s more, the spray efficiency of self-priming spray was better; the results of the test and numerical simulation had the consistent trend.

Abstract: In this study, investigations were carried out to find the best possible way of lowering the concentration of suspended solids at the blast furnace gas scrubbing systems which have long been a problem in steel making industries. The analyses of the experimental results showed that the Bulab 5615 that is currently being used is the best possible chemical polymer. At very low concentration the chemical has shown its ability to reduce suspended solids to desired levels. The three other chemicals used required a much higher dosing rate. Experiment was also conducted on controlling the conductivity and to solve the issues of high COD, ammonia and phenols using a pilot bio-plant and reverse osmosis. This work will make the adhering to the policy implemented in 2006 of zero effluent discharge of the Department of Water and Forestry and contribution towards saving our water.

Abstract: This study investigated the effects of flotation parameters on the recovery of low grade nickel sulphide ore. The parameters investigated are the particle size, flotation time, temperature and pH of the pulp. The analyses of the results obtained showed that particle size, pH, and flotation time had significant effects on the recovery of nickel sulphide ore. The particle size distribution showed that the breakage rate increased in coarse particles and decreased with reduction in particle size. The optimum particle size was found to be 87% passing 75 µm with the highest nickel recovery of 35% at 15 minutes while 68, 79, and 97% passing 75 µm produced nickel recovery of 15, 20 and 16% respectively. The maximum nickel recovery of 35% was achieved at pH of 10.5 which indicated that the nickel sulphide ore has good floatability at alkaline pH range. It was also observed that the recovery of nickel increased with flotation time and the highest recovery was obtained at flotation time of 15 minutes.

Abstract: The treatment of wastewater with activated sludge process has been received with a great attention for decades. However, the effective application of this field is not as widely spread. In this study, the treatment of wastewater was investigated, and samples were collected and ascertained. The process operation was monitored and major observation and findings were noted. Consistent pH of 7.4 was almost maintained. High nutrients removal efficiency was sustained with low concentration of nitrates and phosphates in effluent wastewater. Suspended solids removal was satisfactory, although undesired spike of 19 mg/l and three undesired values beyond >15mg/l were measured. The micronutrient metals such as Al and Zn were found to be high with highest concentration of 113600 mg/kg and 940 mg/kg. The maximum concentration of 300 mg/kg and 332 mg/kg of Mn and Cr respectively were recorded.