7,451 research outputs found

    Wind power development : economics and policies

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    This study reviews the prospects of wind power at the global level. Existing studies indicate that the earth's wind energy supply potential significantly exceeds global energy demand. Yet, only 1 percent of the global electricity demand is currently derived from wind power despite 40 percent annual growth in wind generating capacity over the past 25 years. More than 98 percent of total current wind power capacity is installed in the developed countries plus China and India. It has been estimated that wind power could supply 7 to 34 percent of global electricity needs by 2050. However, wind power faces a large number of technical, economic, financial, institutional, market, and other barriers. To overcome these barriers, many countries have employed various policy instruments, including capital subsidies, tax incentives, tradable energy certificates, feed-in tariffs, grid access guarantees and mandatory standards. Besides these policies, climate change mitigation initiatives resulting from the Kyoto Protocol (e.g., CO2-emission reduction targets in developed countries and the Clean Development Mechanism in developing countries) have played a significant role in promoting wind power.Energy Production and Transportation,Carbon Policy and Trading,Windpower,Environment and Energy Efficiency,Energy and Environment

    Wind Power Development: Opportunities and Challenges

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    In this study, the prospects of wind power at the global level are reviewed. Existing studies indicate that the earth’s wind energy supply potential significantly exceeds global energy demand. Yet, only 1% of the global electricity demand is currently derived from wind power despite 40% annual growth in wind generating capacity over the last 25 years. More than 98% of total current wind power capacity is installed in the developed countries plus China and India. Existing studies estimate that wind power could supply 7% to 34% of global electricity needs by 2050. Wind power faces a large number of technical, financial, institutional, market and other barriers. To overcome these, many countries have employed various policy instruments, including capital subsidies, tax incentives, tradable energy certificates, feed-in tariffs, grid access guarantees and mandatory standards. Besides these policies, climate change mitigation initiatives resulting from the Kyoto Protocol (e.g., CO2-emission reduction targets in developed, the Clean Development Mechanism in developing countries) have played a pivotal role in promoting wind power.wind energy, renewable energy, electricity grids

    INITIAL APPLICATIONS OF FUZZY SET PROCEDURES FOR ESTIMATION OF EXPORT BASE EMPLOYMENT

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    Current export base methods that calculate basic and non-basic employment are too restrictive because they fail to account for uncertainty involved in the process. This paper shows the assignment of industries as either basic or non-basic by the location quotient procedure does not consistently represent the data for Nevada counties. Using fuzzy set procedures and membership functions in conjunction with the location quotient allow more flexibility in terms of matching the data for each industry in the region of interest. Using fuzzy set procedures we determine the proportion of employment that is basic and non-basic in nine non-governmental industries.Labor and Human Capital,

    Measuring the Fraction of Obscured Quasars by the Infrared Luminosity of Unobscured Quasars

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    Recent work has suggested that the fraction of obscured AGN declines with increasing luminosity, but it has been difficult to quantify this trend. Here, we attempt to measure this fraction as a function of luminosity by studying the ratio of mid-infrared to intrinsic nuclear bolometric luminosity in unobscured AGN. Because the mid-infrared is created by dust reprocessing of shorter wavelength nuclear light, this ratio is a diagnostic of f_obsc, the fraction of solid angle around the nucleus covered by obscuring matter. In order to eliminate possible redshift-dependences while also achieving a large dynamic range in luminosity, we have collected archival 24 micron MIPS photometry from objects with z~1 in the Sloan Digital Sky Survey (SDSS), the Great Observatories Origins Deep Survey (GOODS) and the Cosmic Evolution Survey (COSMOS). To measure the bolometric luminosity for each object, we used archival optical data supplemented by GALEX data. We find that the mean ratio of 24 microns to bolometric luminosity decreases by a factor of ~3 in the L_bol=10^44-3x10^47 ergs s^-1 range, but there is also a large scatter at constant L_bol. Using radiation transfer solutions for model geometries, we show how the IR/bolometric ratio relates to f_obsc and compare these values with those obtained obtained from samples of X-ray selected AGN. Although we find approximate agreement, our method indicates somewhat higher values of f_obsc, particularly in the middle range of luminosities, suggesting that there may be a significant number of heavily obscured AGN missed by X-ray surveys.Comment: ApJ, in press. 10 pages in emulateapj style, 4 figures, 3 table

    Studi Kinerja Jalan Akibat Hambatan Samping Di Jalan Timor Raya Depan Pasar Oesao Kabupaten Kupang

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    Poor land use management systems and transportation management systems nowadays more visible in various areas in the East often lead to complicated problems. One segment of Timor Raya street is often jammed in Oesao Market area, this happens because of the many traders who trade on the curb lane to the shoulder of the road . In addition the number of vehicles parked on the shoulder of the road further aggravate the condition of the road especially at busy times. From the results of the analysis indicate that the side friction road values were very high at 3998.60 events caused by the presence of market activity in the left and right side of the road, too many parked vehicles and pedestrian which is reducing the effective width of the road that directly affect the performance of the road itself . This problem caused actual speed at the road segment becoming increasingly low at 23,49 km/h with average travel time of 0.0125 hours . The results of analysis show that the level of service is at grade E. The biggest factor that is very influential in determining the level of service at the location is the market activity at the sides of the which increase the side frictio

    Universal Algebraic Relaxation of Velocity and Phase in Pulled Fronts generating Periodic or Chaotic States

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    We investigate the asymptotic relaxation of so-called pulled fronts propagating into an unstable state. The ``leading edge representation'' of the equation of motion reveals the universal nature of their propagation mechanism and allows us to generalize the universal algebraic velocity relaxation of uniformly translating fronts to fronts, that generate periodic or even chaotic states. Such fronts in addition exhibit a universal algebraic phase relaxation. We numerically verify our analytical predictions for the Swift-Hohenberg and the Complex Ginzburg Landau equation.Comment: 4 pages Revtex, 2 figures, submitted to Phys. Rev. Let

    LEP Operation and Performance with 100 GeV Colliding Beams

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    Luminosity production in LEP was extended to 101 GeV beam energy in 1999 and 104.4 GeV in 2000. The performance was continually optimised, resulting in 1999 peak and integrated luminosities higher than in any previous year of LEP operation. In particular, the beam-beam tune shift reached 0.083 per interaction point. This was achieved with the help of a faster luminosity monitoring, a new tune working point, a reduced design vertical dispersion and new dispersion and coupling optimisation tools. A higher beam rate from the injectors, a better injection efficiency, a faster ramp and a newly automated control of the horizontal damping partition number Jx maximised the time available for physics and thus contributed to the higher integrated luminosity

    Exact Solutions to the Sine-Gordon Equation

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    A systematic method is presented to provide various equivalent solution formulas for exact solutions to the sine-Gordon equation. Such solutions are analytic in the spatial variable xx and the temporal variable t,t, and they are exponentially asymptotic to integer multiples of 2π2\pi as x±.x\to\pm\infty. The solution formulas are expressed explicitly in terms of a real triplet of constant matrices. The method presented is generalizable to other integrable evolution equations where the inverse scattering transform is applied via the use of a Marchenko integral equation. By expressing the kernel of that Marchenko equation as a matrix exponential in terms of the matrix triplet and by exploiting the separability of that kernel, an exact solution formula to the Marchenko equation is derived, yielding various equivalent exact solution formulas for the sine-Gordon equation.Comment: 43 page
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