93,627 research outputs found

    Merchant Transmission Investment

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    We examine the performance attributes of a merchant transmission investment framework that relies on �market driven� transmission investment to provide the infrastructure to support competitive wholesale markets for electricity. Under a stringent set of assumptions, the merchant investment model appears to solve the natural monopoly problem and the associated need for regulating transmission companies traditionally associated with electric transmission networks. We expand the model to incorporate imperfection in wholesale electricity markets, lumpiness in transmission investment opportunities, stochastic attributes of transmission networks and associated property rights definition issues, the effects of the behaviour system operators and transmission owners on transmission capacity and reliability, co-ordination and bargaining considerations, forward contract, commitment and asset specificity issues. This significantly undermines the attractive properties of the merchant investment model. Relying primarily on a market driven investment framework to govern investment is likely to lead to inefficient investment decisions and undermine the performance of competitive markets

    Extreme Star Formation

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    Extreme star formation includes star formation in starbursts and regions forming super star clusters. We survey the current problems in our understanding of the star formation process in starbursts and super star clusters - initial mass functions, cluster mass functions, star formation efficiencies, and radiative feedback into molecular clouds - that are critical to our understanding of the formation and survival of large star clusters, topics that will be the drivers of the observations of the next decade.Comment: appeared in "Astrophysics in the Next Decade: JWST and Concurrent Facilities", Astrophysics and Space Science Proceedings, 2009, ed. H. A. Thronson, M. Stiavelli, and A. G. G. M. Tielens, proceedings of the conference, Astrophysics in the Next Decade, 24-27 September 2007, Tucson, A

    Preparation of organic hydrazides

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    Thesis (M.A.)--Boston UniversityDue to the actual high price of hydrazine, this chemical cannot be used in an economical preparation of organic hydrazides. A synthesis of such hydrazides can be envisaged by the reduction of N-nitroamides. The problem is then to find a set of conditions under which no hydrogenolysis of the nitrogen-nitrogen bond occurs. This had been done with N-nitrocarbamates and it was hoped that the results could be extended to N-nitroamides: N-Nitro-N-methylamides were actually used in order to have a more stable N-nitro group. Dimethylation of the hydrazine could be performed either by acid hydrolysis of the addition product obtained with diethyl azodicarboxylate or by heating with pyridinium chloride. After failure to reduce p-N-dinitro-N-methylbenzamide to hydrazine, a new technique was experienced by which the amide was nitrated and reduced directly without isolation of the N-nitroamide. Preliminary results suggested that the electron shifting ability of the R group in molecules of the type R CO-N(NO2)CH3 is very important in their reduction to hydrazine. Several molecules were then reduced with different R. It was found that the yield of hydrazine increases with the electron repelling ability if R. A mechanism involving formation of an unstable platinum hydride is proposed for the reaction. A survery of the addition reactions of azodicarboxylic esters is given with the description of an attempt of "Azo reaction" between diethyl azodicarboxylate and p-N-dinitro-N-methylbenzamide

    Limits To Certainty in QoS Pricing and Bandwidth

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    Advanced services require more reliable bandwidth than currently provided by the Internet Protocol, even with the reliability enhancements provided by TCP. More reliable bandwidth will be provided through QoS (quality of service), as currently discussed widely. Yet QoS has some implications beyond providing ubiquitous access to advance Internet service, which are of interest from a policy perspective. In particular, what are the implications for price of Internet services? Further, how will these changes impact demand and universal service for the Internet. This paper explores the relationship between certainty of bandwidth and certainty of price for Internet services over a statistically shared network and finds that these are mutually exclusive goals.Comment: 29th TPRC Conference, 200

    Retail Electricity Competition

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    We explore the implications of load profiling of consumers whose traditional meters do not allow for measurement of their real time consumption. We find the competitive equilibrium does not support the Ramsey two-part tariff. By contrast, when consumers are billed on real time prices and consumption, retail competition yields the Ramsey prices even when consumers can only partially respond to variations in real time prices. We then examine the incentive competitive retailers have to install one of two types of advanced metering equipment. Competing retailers overinvest in real time meters compared to the Ramsey optimum, but investment incentives are constrained optimal given load-profiling and retail competition. Finally, we consider the effects of physical limitations on the ability of system operators to cut off individual customers. Competing retailers have no incentive to determine the aggregate value of non-interruption of consumers, preferring instead to free-ride on other retailers serving the same zone

    The Birth of a Super Star Cluster: NGC 5253

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    We present images of the 7mm free-free emission from the radio "supernebula" in NGC 5253 made with the Very Large Array and the Pie Town link. The images reveal structure in the nebula, which has a <~ 1 pc (~50 mas radius) core requiring the excitation of 1200 O7 stars. The nebula is elongated, with an arc of emission curving to the northeast and to the south. The total ionizing flux within the central 1.2" (~20 pc) is 7 x 10^52 s^-1, corresponding to 7000 O7 stars. We propose that the radio source is coincident with a small, very red near-infrared cluster and apparently linked to a larger, optical source some 10 pc away on the sky. We speculate on the causes of this structure and what it might tell us about the birth of the embedded young super star cluster.Comment: Accepted, Astrophysical Journal Letters. 10 pages, including 2 figure
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