Advanced Materials Research Vols. 347-353

Abstract: Fe-Mn-Ce metal oxides nanosized particles have been prepared by co-precipitation approach using three kinds of precipitants NaOH, NH4OH and Na2CO3. The products were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and larger sulfur capacity at low calcinations temperature. At high reaction temperatures, the samples prepared with Na2CO3 as precipitator exhibited much better activities for SCR of nitric oxide with ammonia than catalysts prepared with NH4OH and NaOH as the precipitants.

Abstract: Implementing computer monitoring system in the small hydropower station can improve the degree of automation power and economic benefits, increase their operational reliability and stability. Through the inspection and investigation of some small hydropower station, It is analyzed the implementation status and common problems of the small hydropower station in computer monitor system.

Abstract: In this paper, a detailed description of a project designed to recovery and utilize waste heat in a cotton manufacturing enterprise in Shandong, Jin Mao Textile Co., Ltd(China) is presented: both energy saving and emission reduction(ESER) aspects have been thoroughly considered. First of all, an accurate analysis of the status of the previous cotton mill for production process was developed, to identify possible improvement opportunities; then an energy saving reformation of waste heat recovery in cotton mill was proposed and designed. After that, by means of a comprehensive feasibility analysis, the ESER indices were calculated assuring good environmental benefits of the plant modification investment. The modifications to the system make it possible to achieve consistent annual savings of coal, electricity and waste heat, CO₂, SO₂ emissions through effective recovery and utilization of the waste heat that was discharged into the atmosphere in the original production. Implementation of the reformation system fulfilled the waste heat recovery and utilization. And also create good environmental benefits.

Abstract: The synthesis of a new triazene reagent 1-(4-antipyrine)-3-(sulfanilic acid)-triazene (ASTA) and is proposed as a new sensitive reagent for the extractive spectrophotometric determination of Zinc(II) was established. The results showed that in the presence of micromulsion Tween-80, ASTA could reacted with Zn ( Ⅱ) to form a red stable complex of which the molar ratio of reagent︰metal was 2︰1 in Na2B4O7-NaOH medium. The maximum absorption peak of the complex was located at 520 nm with the apparent molar absorption of 1.7×105 L•mol-1•cm-1. Beers law was obeyed in the range of 0.3～5.0 μg/10 mL for Zn (Ⅱ) and the detection limit was 0.11 mg/L. Many ions did not interfere the colour reaction system due to the existence of ammonia. This method was applied to determination of Zn (Ⅱ) in water samples, and the results were in accordance with those obtained by AAS method. Recovery was in the range of 96.5～101.5 % and the RSD(n=6) was not more than 1.4%.

Abstract: In this study, the bacterium was identified as Sphingomonas sp. XJ2 by means of microscopic examination, physiological, biochemical detection, and modern molecular biology technology. After acclimatization for several times, this bacterium has good performance in removing heavy metals and organic matter from seawater. Alginate immobilized cells has obvious holes on the surface and has big specific surface area, which are conducive to the adsorption of metal ions. Hydration heat of Pb2+ is small, and is most likely to drop out of ligand water then become exposed Pb2+; in addition, the ionic radius of Pb2+ and is very similar to the ball K+ and is adsorbed by the ball easily. FTIR and XPS study indicated that Pb (II) was complexed by C-H and C-O bonds. The concentration of Pb(Ⅱ)of mine wastewater reach the first class of irrigation water quality standards after the first time of adsorption treatment, and reach the first class of fishery water quality standard after the second treatment. 1． Introduction Mine waste water mainly comes from mine production, the main pollutants including heavy metals, acid, organic pollutants, oil pollutants, cyanide, fluoride and soluble salts and so on. Heavy metal pollution and acid pollution are the most common water pollutions, the mainly heavy metals from wastewater are lead, zinc, nickel, copper, mercury, chromium, cadmium, cobalt, manganese, titanium, vanadium and bismuth. Hazards of mine waste water including environmental degradation and toxic to organisms; mine waste water contains heavy metal ions and other metal ions, through infiltration, percolation and runoff channels walk into the environment, then pollute water. After precipitation, absorption, complexation, chelation and redox, migrate and change in the water, and ultimately affect human health and aquatic growth. Heavy metals and metalloids and other pollutants in wastewater once enter the water environment, they can not be biodegradable, but by precipitation - dissolution, oxidation - reduction, coordinate effect, colloid formation effect, adsorption - desorption process and a series of physical and chemical migration transformation, which will eventually as one or more form stay in the environment for a long term, causing permanent potentially damage [1]. How to prevent non-ferrous metal mine waste water polluting water and farmland is one of the current problems which arising large public attention. Traditional treat methods of heavy metal waste water are chemical precipitation, ion exchange, evaporation and electrolysis, etc., these methods have disadvantages of high investment and operating costs, precipitation removal is not satisfactory, and could easily lead to secondary pollution and other defects. Since 1980s, people began to turn to research microbial treatment of heavy metal waste water, and found that microbial treatment of wastewater had advantages of low cost, effective and no secondary pollution. The economical and ecological feasibility of biosorption processes depend on the biosorbent metal uptake capacity to reach metal concentration legal limits for wastewater discharge and the ability of eluants to release sequestered metal in subsequent recovery [2-4]. Recovery allows metal recycling, leading to energy savings and materials conservation[5]. Finally, biosorbent regeneration used in multiple adsorption–desorption cycles [6], contributes to process cost effectiveness. Living cells have so broad assortment of mechanisms for surviving in environment that have elevated metal concentrations, including transport and intracellular and extracellular sequestration .The active process of metal accumulation by cells is usually referred to as bioaccumulation, while the passive metal sequestration by cell components is generally called biosorption. The physicochemical basis for metal sequestration at the cell surface may include complexation, coordination, chelation, ion exchange, adsorption, and inorganic microprecipitation processes. Bacteria make excellent biosorbents because of their high surface-to-volume ratios. Metal-binding behaviour has been evaluated on the basis of bacterial cell Gram reaction for viable cells and cell walls and envelopes. In this study, we conducted separation domesticated culture to Sphingomonas sp. XJ2 and used them to treat waste water preliminarily. Establishing an efficient, cheap, adaptable and easy to operate way of treating non-ferrous metal mine wastewater is a new development.

Abstract: The conventional decoupling controls of variable-speed doubly fed wind turbines provide minimal support to the regulation of system frequency. The characteristics of doubly fed induction generator (DFIG) wind turbines and conventional power plans are compared, and the contributions of DFIG to system inertial response and frequency regulation are investigated. The influence of auxiliary loop parameters on the inertial response is illustrated. We also introduce a novel algorithm to enhance the participation of DFIG in existing frequency regulation mechanisms. The proposed approach takes advantage of the fast responses associated with DFIGs. The control system consists of four functional modules, namely, frequency control, rotational speed delay recovery, speed protection, and coordination control with conventional generators. The simulation results show that the control strategy has a fast response speed to the transient frequency error, thereby proving that wind farms can participate in system frequency regulation to a certain extent.

Abstract: There are three subsystems in Microtarget-Automatic-Assembly System which is used in Inertial Confinement Fusion(ICF). It is microscopic image measurement subsystem,confocal probe measurement subsystem and three-dimensional motion subsystem. It is necessary to establish a unified coordinate system in order to interact information in three subsystems and provide accurate and reliable position and attitude information for micro-operating system.Each coordinate system and its errors are analyzed in this paper.In the end,the way to establish the unified coordinate system is given. It is proved that this subsystem meets the requirements for precision.

Abstract: Improved genetic algorithm for solving the transmission network expansion planning is presented in the paper. The module which considered the investment costs of new transmission facilities. It is a large integer linear optimization problem. In this work we present improved genetic algorithm to find the solution of excellent quality. This method adopts integer parameter encoded style and has nonlinear crossover and mutation operators, owns strong global search capability. Tests are carried out using a Brazilian Southern System and the results show the good performance.

Abstract: The most widely used generator type is the Doubly-Fed Induction Generator (DFIG). Because of the close coupling of the generator and the gird, the stator flux of DFIG is distorted while the Grid voltage dip happens. To achieve the LVRT, the LVRT control strategy of DFIG, especially the association of gird side and rotor side converter, is discussed under gird voltage dips. Simulation and experiment have been implemented to prove the idea.

Abstract: This paper focused on the preparation of the grafted modification of humic acid (HA) that was used in coal water slurry (CWS). By means of orthogonal experiment, the grafted humic acid was synthesized with acrylic acid (AA) copolymerized with humic acid, using potassium persulfate as the initiator in the reaction system. The structure of copolymer was characterized by ATR-FTIR. And then, the viscosity, liquidity, and stability of CWS used the dispersant based on the modified humic acid were determined through the CWS viscometer and tests of stability. The optimum conditions of synthesis are that the mass ratio of AA and HA is 0.35:1, dosage of initiator is 5%, reaction temperature of is 75°C, reaction time is 2.0h. Besides, when the dosage of active ingredient of the dispersant for CWS was 0.12%, the viscosity of CWS achieved lower.