Applied Mechanics and Materials Vols. 209-211

Abstract: Practical teaching is very important in training innovative and practical abilities of college students. On the basis of nonferrous metallurgy teaching characteristics, practical situation and deficiencies had been analyzed and the teaching reforms in the experiment, practice and design had been proposed. A variety of beneficial attempts have been carried out to strengthen the students engineering consciousness and application ability in the reform practice. Through the reform and practice on the teaching methods, it has reached the aim to cultivate the students and improve the quality of practice teaching.

Abstract: This paper proceeds from the cost problems in low-rent housing projects and proposes that the cost control of such programs consist of subjective control and objective control. With analysis on subjective and objective controls, it gives the government detailed suggestions for cost control in low-rent housing program, specifically developing policies and regulations for cost control and introducing non-governmental funds into the program.

Abstract: This paper states the definition of evolutionary dynamic of project organization, finds out the dynamic factors of evolution of the project organization basing on talks, questionnaires and analysis, constructs the diagram of dynamic factors, basing on which a three-dimension graph of the interaction between dynamic factors is constructed, and a model about the interaction process between dynamic factors basing on Haken Model is built and a analysis about the process is made. The author concludes it’s an effective way to make the organization change from criticality to orderly state faster and the evolution of the organization by means of designing dynamic factors rationally, dynamic construction of the relationship of competition and cooperation and enhancing the rational actions the behavior subjects.

Abstract: To assess environmental feasibility of integrated circuit industry and predict it’s influence on air and acoustic emvironment, the current situations and impact assesment on air and sound environment were done. Survey on air pollution sources indicated that smoke dust was the main exhaust pollutants accounting for 88.5% of the total and SO2 was the second. Current situation of monitoring shows that all measured items can satisfy the requirements of the standards except the daily average concentration of PM10. Gas pollutants in waste gases can be removed 85~ 95% after purified. Noises on proposed project area during night and day are all accord with the third or fourth class standards of 《Standard of Environmental Noise of Urban Area》. Noises in the project can meet level Ⅲ standards of 《Standard of Noise at Boundary of Industrial Enterprises》. So this project has little influence on surrounding air and sound environment. Therefore on the condition of adopting corresponding treatment measures, this project is feasible on aspects of air and sound environment.

Abstract: All sources of the particulate matter less than 10 micrometers (PM10) were collected in Tangshan. Inorganic elements, water-solvent ions and carbon species of PM10 samples were investigated to identify the sources of PM10. Contribution and sharing rate of suspended dust, soil dust, coal smoke dust, construction dust, vehicles exhaust, SO42-, NO3- and sea dust to PM10 was determined based on the chemical mass balance (CMB) receptor model. The results showed that suspended dust was the most important PM10 source with a contribution of 42%; flying ash from coal combustion, particle dust from soil, vehicle exhaust were also important sources with contributions of 20%, 12% and 11%, respectively.

Abstract: The important step for increasing gaseous elemental mercury (Hg⁰) removal in wet scrubber systems is altering the chemical form of the Hg⁰ to a water-soluble oxidized species. This work focuses on the removal of elemental mercury from simulated flue gas by aqueous K₂S₂O₈ in a bubble reactor. In the system of K₂S₂O₈ oxidize Hg⁰, the reaction velocity of K₂S₂O₈ and Hg⁰ is soon. Reached a higher removal rate after 10min. Increase the concentration of K₂S₂O₈ can remarkably improve the removal rate of Hg⁰to 85% With the rise of import mercury concentration has increased mercury removal rate to 89.5%.

Abstract: The pedestrian level wind environment including wind comfort and wind safety was assessed with the Computational Fluid Dynamics (CFD) method. The joint probability distribution of the local wind speed and direction information was obtained using the raw meteorological data. The aerodynamic information of the entire flow field was obtained using CFD software. The results of the assessment of pedestrian wind environment were obtained using the Lawson's criterion of wind comfort and wind safety. The results indicated that there are potential safety risks near the corners around the high-rise buildings (5-10m regions). Pedestrians should avoid accessing these areas. The areas can be set to green areas. Most of other areas are comfortable and safe for pedestrians. Some areas are not suitable for long-term standing or sitting.

Abstract: Volatile organic compounds (VOCs) are major constituents of the indoor air pollutants. The indoor air quality has caused wide concern for VOCs may affect human health in many ways. The VOCs in general rooms volatilize from building materials, furniture and so on. In print shops the print equipment and materials may produce a large amount of VOCs that may affect the health of the long-term print shop workers. The author has measured the VOC content and the air indexes in a seventy square-meter print shop in Xi’an with comprehensive functions, then, evaluated the pollution and proposed the preventions of the VOC content in print shops.

Abstract: To solve the moisture problem at the hallway near the protective door of the underground engineering, an air curtain dehumidification technology program has been proposed and discussed. For the moist air from the protective door, the air curtain dehumidifier can be used to control its flow direction: all moist air will directly enter the inlet of the dehumidifier by the action of negative pressure gradient without any ventilation duct. The main technical features of the program are that, the air curtain dehumidifier should be installed at the corner of the ground or hanged on the wall beside the inner side of the protective door, which inlet and outlet should be collocated in the level and along the long direction of the underground engineering; the dehumidifier rotating speed should be controlled by the humidity and the inflow speed of the fresh air. Preliminary studies indicates that this technical solution is feasible, but still there are a lot of details that need to be studied in follow-up research process.

Abstract: Carbon dioxide (CO₂) absorption performance from flue gas was investigated using monoethanolamine (MEA) solution in porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes contactor. The influence of operating parameters on CO₂ removal efficiency and flux were studied in the immersion operating mode. The experimental results indicated that the CO₂ removal efficiency and flux decreased with the increase of flue gas load and carbonization degrees, but the increase of the absorbent concentration and temperature promoted membrane performance of CO2 capture. An increase of 84 m³•m^-2•h^-1 in the flue gas load resulted in a 68% decrease in the removal efficiency. Absorbent carbonation degree increased to 0.45 mol CO₂•mol^-1MEA led to the decrease of active ingredient amounts in the absorption solution, and the corresponding removal efficiency and membrane flux dropped by 50% of the initial amounts, respectively. The increase of concentration and temperature of absorbent also benefited membrane absorption performance of CO₂ absorption, so that the concentration and temperature of the solvent increased lead to the CO₂ removal efficiency and flux increased.