Applied Mechanics and Materials Vol. 421

Abstract: The present study examines the characteristics of rectangular and circular tuned liquid dampers, which control wind-induced vibration in tall buildings, according to the natural frequency. The tuned liquid dampers (TLD) were of frequencies: 0.44Hz, 0.55Hz, 0.64Hz and 0.73Hz. The tuning feature of TLD water tanks was better in circular water tanks than in rectangular water tanks. Excitation amplitude affected the damping ratio based on energy dissipation capacity. At low excitation (below 5mm) and low natural frequency (0.44Hz), circular water tanks were advantageous over rectangular water tanks. However, at high excitation (over 5mm) and high natural frequency (over 0.55Hz), rectangular water tanks were advantageous over circular water tanks.

Abstract: Shear buckling strength of a web panel with local corrosion damage can be changed by web corrosion pattern. In this study, To find critical corrosion pattern for shear buckling of a web panel with local corrosion. Critical shear bucking loads of the corroded web panels were quantitatively evaluated. Thus, FE analsyis models were creasted cosidering corrosion pattern in the plate girder bridge which was reported from the corroded bridge inpection. As corrosion pattern of the web panel in the plate girder bridge, three corrosion patterns were selected as main corrosion cases such as longitudinal, vertical, and triangular cases. Their critical shear buckling loads were compared according to their corroded web codition.

Abstract: TM/ETM data as the base information combined with a digital elevation model are used to analyze the spatial distribution and temporal variation of soil erosion in Guangxi. The results shows that light, medium and strong are the main three levels of soil erosion in Guangxi. The proportions of light and medium soil erosion are higher which are 6.18% and 4.76% respectively. The total area of soil erosion and its degrees exhibit an upward trend since the 1980s. The area of soil erosion in Guangxi increases 4% in the past 20 years. The five levels of soil erosion performance an upward trend mostly. Medium soil erosion is of the biggest change with an increase of 1.29% while acute soil erosion exhibits a smallest change with an increase of 0.49%.

Abstract: The development of downtown areas causes urban heat island (UHI), which raises the temperature of cities. To remove the causes of UHI, extensive research is underway for securing green spaces and fresh air corridors in urban districts. The development of high-rise apartments in the downtown affected the fresh air corridor of the whole city, decreasing wind velocity by up to 50% compared to that before the development. In addition, with regard to apartment layout in complexes, the front-rear inter-building distance had a higher effect on the change of wind velocity in the complexes than the side-to-side inter-building distance. However, in a layout with the same repetitive form, a wide side-to-side space increased the intensity of turbulent flow in the complex, making the wind velocity almost three times higher at some parts.

Abstract: Activated sludge method is mainly used to sewage water treatment of water injection system in oil field, dissolved oxygen of sewage pond plays a important role in the sewage water treatment process. The proportional control algorithm of dissolved oxygen concentration is developed based on a first time delay model, and the parameter values of the controller is determined by using stability margins design approach. Simulation results are provided to illustrate the design procedure and the effectiveness of the proposed methods. When applying to the wastewater treatment system based on activated sludge, this method can achieve a satisfied treating performance with robustness. Simulation results are given to demonstrate the design procedure and the effectiveness of the proposed methods.

Abstract: A wavelet artificial neural network to forecasting monthly runoff is proposed. The monthly runoff series is firstly decomposed to sub-series on different time scales, and each sub-series is modeled. The weights of the network are replaced by wavelet functions and are corrected by conjugate gradient method in the training iteration. Then the proposed network is trained with 49 years (1952-2000) actual data of one hydro power plant of Jiangxi province and is tested for target year (2001-2003). Finally, some actual results for mid and long term water inflow forecasting are obtained and which show the proposed method has a good precision for forecasting.

Abstract: This paper describes the design of real-time detection of harmful ions for drinking water, mainly introduces the instrument of automatic liquid injection control mechanism and the signal sampling and processing system design and implementation. The dynamic monitoring analyzer can rapidly detect concentration domestic sewage and drinking water of various ions such as arsenic, fluorine. Test equipment mainly consists of automatic sampling software, signal sampling and processing system, wireless data transmission module. Through the instrument in practical application test of arsenic in drinking water, fluoride ion, the performance index analyzer. The detection results, simple operation, low cost, analyzer of strong pertinence, high detection precision, high degree of automation.

Abstract: With the gradual putting into operation of step hydropower stations in a river basin,the combined electricity production patterns of cascade hydropower station group will come into being. The information system of basin-wide electricity production will become the only means of cascade jointed scheduling and achieving maximum efficiency in a river basin. From the angle of the controlling station equipment, production personnel management and scheduling basin cascade hydropower stations group, the information systems framework of electricity production is divided into monitoring system of electricity production, management information systems, decision support system combined electricity production at three levels. A good framework system provides a hierarchical and functional partitioning for system development, and plays a controlling role for guidance to the system development.

Abstract: The effect of physical properties of porous combustor on performance of a non-sprayed porous burner (NSPB) in term of radiant output and fuel-preheated efficiency is studied through numerical modeling. The homogeneous combustion of vaporised kerosene and combustion air within a porous combustor (PC) is instead of the heterogeneous combustion occurs in free space of a conventional sprayed burner. The excellent fuel evaporation without atomisation is accomplished by using porous evaporator (PE). Single global reaction combustion, sub-cooled boiling, local non-thermal equilibrium between fluid and solid phases with phase change under complex radiative heat transfer and sub-cooled boiling are considered. The parametric study of porosity and optical thickness are investigated. The study shows that the radiant output efficiency is decreased with higher porosity while the fuel-preheated efficiency quite constant. The optical thickness has no significant effect on radiant output efficiency whereas the fuel-preheated efficiency is reduced with higher optical thickness. In addition, the evaporation front zone moves deep to downstream of PE when optical thickness increases.

Abstract: The NG dispersion for LNG releasing on water was presented by this paper, and DNVs UDM model and CFD model were combined as a new model, which was validated credibility by simulating a case. The results of numerical simulation were treated by TECPLOT software, and then a 3D concentration of NG can be shown. Box model was also used to simulate the case. The results of two models were compared, 3D concentration and velocity distribution of NG heavy gas was simulated by the new model in this paper, and the effect of heavy gas to the concentration is shown, which cannot be done by Box model.