Advanced Materials Research Vols. 317-319

Abstract: The self-rotating kinetic moment formula is derived through theoretical dynamic research on self-cleaning and rotating steel spiral with plastic coat. The moment is proportional to d (spiral wire diameter), sin2α (α-helical angle), D2 (D-spiral O.D), u2 (u-flow velocity), ρ (fluid density). The theoretical formula is consistent with experimental results. As a result, the formula can be the theoretical foundation to optimally design the steel spiral with plastic coat. The spiral is thicker with coat but the experiment results show the flow resistance is still in the general range of industry limitation.

Abstract: Grating is a widely-used standard to calibrate the horizontal plane of almost all kinds of microscopes. A grating standard consisting of 1D grating and 2D grating was designed and fabricated by Shanghai Institute of Measurement and Testing Technology (SIMT). In this paper, a metrological large-range nano measuring machine integrated with atomic force microscope (AFM) and laser focus sensor (LFS) is used to calibrate this standard. In order to guarantee the measurement accuracy, cosine error, a significant error source which is caused by deviation angle between the scan direction and the perpendicular direction of the grating line, is analysed. Therefore, the scan direction should be determined accurately. For 1D grating, the scan direction is determined by two scanning profiles with deflection angle. Different beginning directions and deflection angles are analyzed to find the best beginning direction and deflection angle for fast and accurate scan direction determination. For 2D grating, the application of the same scan direction determination procedure is extended by using beginning direction and deflection angle which is opposite for 1D grating. Mean pitch is calculated through another profile which is scanned along the calculated scanning direction. Data from different probes are evaluated and the results demonstrate the method well.

Abstract: This paper is concerned with the non-fragile decentralized controller design problem for uncertain singular large-scale system with time-delay. Sufficient condition for the controller is expressed in terms of linear matrix inequalities(LMIs). When this condition is feasible, the desired controller can be obtained with additive gain perturbations and multiplicative gain perturbations. Finally, a numerical example is also given to illustrate the effectiveness.

Abstract: Response surface methodology was used to optimize proteolysis of egg yolk solution using Alcalase and Flavorase according to three conditions, the ratio of two enzyme concentration (Alcalase and Flavorase), pH values and hydrolytic time. The responses degree of hydrolyzation (DH) and peptide yield were studied. The protein subunit from egg yolk was purified and hydrolyzed by Alcalase and Flavorase step by step. The results showed that the best ratio of enzyme concentration was 0.8% for Alcalase, and 0.4% for Flavorase to hydrolyzed 10% yolk solution. The hydrolytic time of the two enzymes was 2h respectively. Then the solution was incubated for 4h at 55°C while rotating at 60 r./min. To evaluate the hydrolysate, both the degrees of hydrolysis (DH) and the yields of the polypeptides were taken into consideration. The optimum ratios of enzyme and hydrolytic time were 2.43 and 1.14 respectively, and the optimum pH was 6.64. The optimized DH was 13.233%, and peptide yield was up to 45.573mg/ml.

Abstract: In high-rise building fires, a great deal of fresh air will be sent into the fire floor when pressurization is taken. Smoke is diluted by the fresh air, and the efficiency of mechanical smoke exhaust is reduced. The assumption that set atria buffer zone in straight corridor of high-rise building is put forward, and mathematic model of smoke flow in high-rise building. The results show that, for straight corridor, setting atria buffer zone the efficiency of mechanical smoke exhaust is about 3.6% higher than which atria buffer zone is not set, and smokeless zone is formed in the corridor nearby atria, and it is helpful to escaping from fire floor for people.

Abstract: The multiple simultaneous faults diagnosis is not deeply studied so far. The methods for multiple simultaneous faults diagnosis are put forward. According to the characteristics of hydropower unit, the hierarchical faults decoupling methods are discussed in detail. The simulation calculation of the cylinder controlled by valve is taken as an example for decoupling of hierarchical fault .

Abstract: Recently, the power system equipped in elevator contains motor and gear reducer to get large output torque. The purpose of this paper is to propose a desgin methodology for the kinematic design and efficiency analysis of planetary gear reducer for elevator. First, according to the concept of train value equation of the train circuit, the 2 stage planetary gear reducer is synthesized. Then, according to the latent power theorem, the mechanical efficiency of 2 stage planetary gear reducer is analyzed to be 95.43%. One planetary gear reducer is designed to illustrate the design methodology. Based on the proposed methodology, all planetary gear reducers for elevator can be synthesized.

Abstract: Dissolved gases analysis is the essence to diagnose and forecast power transformer fault. This paper utilized an Auto Regression model to predict contents of gases dissolved in power transformer oil, and adopted Akaike's Information Criterion to determine model order. Then, the prediction results of AR model are compared with results of Gray model. Finally, gray artificial immune algorithm diagnosed power transformer fault types through gases contents predicted by Auto Regression model. Experiments demonstrates that Auto Regression model has a higher accuracy than Gray Model, and the fault prediction results of the proposed algorithm are in accord with the results using real gases contents, thus , the power transformer fault prediction algorithm present in the paper is effective and reliable.

Abstract: The effects of timber production (mainly refers to cutting) on forest carbon storage can be studied from two aspects as follows:(1) calculate the original carbon storage of the forest vegetation carbon pools based on the forest survey results in the year of 2002, and then calculate carbon storage of 2006 in two cases according to the growth rate of wood. The first case is that calculate the forest carbon storage assuming the forest has not been cut. The second case is to calculate the carbon storage of the residual trees in 2006. The difference in value is the result this study needs to calculate. (2) Automatic measurement system LI-8100, commonly used for measuring carbon dioxide emission flux in soil, was adopted in this paper, and soil respiration rate of forest land in the growing season was measured according to coniferous and deciduous broadleaved mixed forest plots of different selective cutting intensity in Dongfanghong Forest Farm of Dailing Forestry Bureau of the Xiaoxing’anling Mountains. Then the effects of timber production on forest carbon storage were determined based on an overall consideration of the changes of vegetation and carbon storage of soil carbon pool.

Abstract: The crude oil in Kuidong region of Liaohe Tanhai Oilfield is characterized by high oil viscosity, high density, high content of colloid asphalt, low content of wax and low freezing point. In the shallow region, the large current, high content of silt, long-distance subsea buried pipeline and drift ice in winter have brought great challenge to offshore construction and oil-gas transportation. In this paper, the investigations of offshore construction project and platform process are shown. Based on the well production rate, gas-oil ratio, water cut, wellhead back pressure and outlet temperature, the range of daily transportation volume was acquired, as well as the maximum inlet pressure and pressure difference of the pump. The paper also selected technically and economically feasible pumps, then designed the public projects, corresponding electric power and self-control facilities. The selected skidded twin screw multiphase pump system can smoothly transport produced liquid to the terminal systems onshore without any effect on the daily output.