This paper proposes a design method for a wide-area measurements based power system stabilizer to improve the mode of concern, which is the dominant inter-area mode, in each system operating point. The design method, which is an iterative one, includes two steps: feedback signal selection and controller parameter tuning. The principle of the feedback signal selection is to maximize the residue of the mode of concern for the feedback signal while minimizing that of other modes. Then the tuning process can focus on only the mode of concern. The proposed method has been tested on the day time operating point of the IEEJ West 10-machine system. The result shows that the designed controller can improve the mode of concern significantly, while it can not affect much the others.

关键词：广域测量；电力系统稳定器；反馈信号选择

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We attempted to image atmospheric fluorescence in the short-wave infrared (SWIR) from several radioactive sources. Our detection system was an InGaAs camera, fitted with a 25 mm lens to image the scene. No definitive fluorescence was detected. We also used our system to observe the SWIR emission from a proton beam source and established certain criteria for use as fluorescence diagnostics. For example, we clearly observed an enhancement at 1050 nm relative to 1600 nm, consistent with known emission features of molecular nitrogen and with previously published results. However, even for a high activity cobalt-60 source, our recorded signal was not consistent with these diagnostics. Rather, we hypothesize that the small signal which was recorded may have been due to direct incidence of gamma rays on our detector. Compared with the ultraviolet (UV), the infrared emission is expected to be only 20% as bright. We suggest that to increase the signal to noise in the SWIR may require either a telescope to collect a greater fraction of the emission or to image a more localized source than the gamma emission. Further research should include coincident UV and SWIR observations.

关键词：大气；气候变化；空气治理

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This paper describes a simple triangular wave generator with which the slope of triangular wave is regulated based on the input and output voltages of a DC-DC buck converter. With the proposed triangular wave generator, both load and line transient responses are improved. The proposed method builds inversely proportional relationships between the slope and the output error signal for the load transient response, and proportional relationships between them for the line transient response. Required additional circuit components for this method are only a voltage controlled linear resistor and a voltage controlled current source. Compared with the conventional voltage control, the proposed method significantly improves line and load transient response. Furthermore this triangular wave slope regulation scheme is simple compared to digital feed-forward control scheme that requires non-linear calculation. Comparison of simulation results proves the improvement and feasibility of the proposed method.

关键词：可调式三角波；DC-DC降压转换器；瞬态响应

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A new kind of constraint, fuzzy constraint, has been introduced in this chapter, which is useful in many design optimization problems. The fuzzy selection-based constraint handling mechanism has presented a solution for problems with such constraints. Its combination with DE and NSGA-Ⅱ has generated single- and multi-objective analog IC sizing methods. From the experimental results, it has been shown that the human's flexibility and the EA's high optimization ability have been integrated to obtain intelligent automatic analog IC sizing methodologies. The useful relaxation of specifications can automatically be recognized by the method and the designer's intentions are correctly reflected by controlling the degree of relaxation. By using fuzzy analog circuit sizing, the designer avoids tedious manual tunings of the crisp specifications to improve the circuit performance, which is achieved by a single fuzzy optimization. This technique is very useful when investigating a new circuit configuration and also in practical design.

关键词：模糊约束；手工调音；改善电路

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The greenhouse gas (GHG) nitrous oxide (N2O) is produced by soil microorganisms. Nitrogen (N) inputs, soil moisture and carbon stimulate the production of this gas, which accounts for about one third of all GHGs from Californias agriculture sector. Nitrogen inputs, crop N removal, and cumulative N2O emissions were measured from spring 2011 to fall 2012 in three dairy forage production systems receiving liquid and solid manure, as well as synthetic N fertilizer. The annual N2O emissions ranged from 4.87.4 kg N2O-N (mass of N in the form of N2O) ha-1 from sites with sandy soil (>70% sand) and from 11.416.5 kg N2O-N ha-1 in clayey soils (>40% clay) and were comparable to those of similar systems in other regions (1.213.8 kg N loss as N2O) although the California systems received higher N inputs (694-1281 kg N ha-1) than those systems (150225 kg N ha-1). The periods of N2O release after irrigation events were longer (weeks) in a clayey than in sandy soils (days). Nitrous oxide fluxes up to 1.4 kg N2O-N ha-1 d-1 were recorded after large applications of synthetic N fertilizer (>100 kg N ha-1) whereas moderate additions of liquid manure and/or synthetic N fertilizer supplied together with the irrigation water resulted in lower, albeit consistent, N2O emissions of up to 100 g N2O-N ha-1 d-1. To lower N2O emission potential, applying N incrementally in moderate doses with the irrigation water according to crop N demand is recommended.

关键词：大气；空气污染；空气治理

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In recent years, attention has been given to the processes controlling the emission of oily effluents and their environmental impact. Many industrial processes generate large volumes of water contaminated with oil, called oily waters. The oily water must be treated before its discard in order to meet the criteria established by environmental agencies (for example in Brazil, 20 mg/L). In present days, the process of separating oil/water with ceramic membranes has attracted the attention of many researchers. In this sense, the aim of this study is to evaluate the influence of the tangential inlet shape in the oil/water separation via ceramic membranes. We use a mathematical multiphase flow model to describe the oil-water separation, based on the particle model. Here oil is the dispersed phase while water the continuous phase. To model the turbulence effect we use the RNG κ-ε model. All simulations were carried out using the Ansys CFX ? commercial code. Results of streamlines and velocity, pressure and volume fraction of phase fields are present and analyzed. The numerical results indicate that no significant difference when using a circular or rectangular pipe with the same cross-sectional area.

关键词：陶瓷膜；分离油/水；数值模拟；CFX

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A program was initiated in June 2009 to evaluate the potential of porous organosilicate sorbents in the capture or neutralization of light gas threats. Of primary interest were targets identified by the TIC/TIM Task Force as priority threats. A number of approaches were taken for increasing binding capacity and reactivity in the sorbent materials: grafting of metalloporphyrins, incorporation of sites for metal coordination, and incorporation of acidic and basic groups. In addition, the impact of morphological considerations, such as pore size and organization, were evaluated. Target capture by the sorbents was evaluated using microbreakthrough testing completed at the Edgewood Chemical Biological Center. Development of relevant sorbent morphologies was also pursued. Overall, the sorbents show promise, with several offering improvements in target capture and retention over state-of-the-art materials.

关键词：大气；空气污染；空气净化

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In August 2012, the U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) announced the final standard governing new-vehicle fuel economy for model years 2017 through 2025. The new standard maintains the current system of incremental increases in Corporate Average Fuel Economy (CAFE) requirements for new light-duty vehicles each model year, based on targeted decreases averaging approximately 5% per year in CO2 output per mile. This report compares the recent improvements in fuel economy with the projected CAFE performance levels anticipated by NHTSA. Recent trends in CAFE performance, when compared with the performance levels projected to be achieved by NHTSA, indicate that achieved CAFE performance has exceeded these anticipated levels for 2012 and 2013 model years--the two years that the current standard has been in effect. Additionally, achieved CAFE performance has consistently increased annually from model year 2008 through model year 2013. If the current trends in annual improvements continue, future CAFE performance is expected to continue meeting or exceeding the projected performance levels (and desired greenhouse gas reductions) contained in the latest CAFE standards.

关键词：大气；空气污染；空气健康

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A power converter is needed in almost all kinds of renewable energy systems and drive systems. It is used both for controlling the renewable source and for interfacing with the load, which can be grid-connected or working in standalone mode. Further, it drives the motors efficiently. Increasing efforts have been put into making these systems better in terms of reliability in order to achieve high power source availability, reduce the cost of energy and also increase the reliability of overall systems. Among the components used in power converters, a power device and a capacitor fault occurs most frequently. Therefore, it is important to monitor the power device and capacitor fault to increase the reliability of power electronics. In this chapter, the diagnosis methods for power device fault will be discussed by dividing into open- and short-circuit faults. Then, the condition monitoring methods of DC-link electrolytic capacitor will be introduced.

关键词：功率转换器；能源成本；诊断系统

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Asymptotic solution for the shear stress distributions and velocity profiles of steady electroosmotic (EO) and magnetohydrodynamic (MHD) flows are obtained in a parallel flat plate microchannel. A fully-developed flow is considered and the fluid obeys a constitutive relation based in a simplified Phan-Thien-Tanner model. The effect of the following dimensionless parameters on the fluid flow control is predicted: the viscoelastic parameter and the Hartmann number. The momentum equation, boundary conditions and the constitutive rheological model are combined to formulating a nonlinear differential equation to solve the shear stress, which is expanded in a regular expansion series in powers of small Hartmann numbers. This limit of small Hartmann numbers and low electrical conductivity in the buffer solution correspond to the range where the electric and magnetic effects can be used to move a charged solution in the flow control and sample handling in biomedical and chemical analysis.

关键词：电渗流；磁流体流动；微通道；粘弹性流体

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