The asymptotic near-tip solution for mode-iii crack in steady growth in power hardening media

Two local solutions, one perpendicular and one parallel to the direction of solar gravitational field, are discussed. The influence of gravity on the gas-dynamical process driven by the piston is discussed in terms of characteristic theory, and the flow field is given quantitatively. For a typical piston trajectory similar to the one for an eruptive prominence, the velocity of the shock front which locates ahead the transient front is nearly constant or slightly accelerated, and the width of the compressed flow region may be kept nearly constant or increased linearly, depending on the velocity distribution of the piston. Based on these results, the major features of the transient may be explained. Some of the fine structure of the transient is also shown, which may be compared in detail with observations.

One-dimensional improvement and two-dimensional and 3-dimensional treatments for stable oscillation condition, mode structure and power output in high-speed-flow lasers

For high-speed-flow lasers, the one-dimensional and first-order approximate treatment in[1] under approximation of geometrical optics is improved still within the scope of approx-imation of geometrical optics. The strict accurate results are obtained, and what is more,two- and three-dimensional treatments are done. Thus for two- and three-dimensional cases, thestable oscillation condition, the formulae of power output and analytical expression of modesunder approximation of geometrical optics (in terms of gain function) are derived. Accord-ing to the present theory, one-and two-dimensional calculations for the typical case of Gerry'sexperiment are presented. All the results coincide well with the experiment and are better thanthe results obtained in [1].In addition, the applicable scope of Lee's stable oscillation condition given by [1] is ex-panded; the condition for the approximation of gcometrical optics to be applied to mode con-structure in optical cavity is obtained for the first time and the difference between thiscondition and that for free space is also pointed out in the present work.

Valuing Flexibility: The case of an Integrated Gasification Combined Cycle Power Plant

In this paper we analyze the valuation of options stemming from the flexibility in an Integrated Gasification Combined Cycle (IGCC) Power Plant. First we use as a base case the opportunity to invest in a Natural Gas Combined Cycle (NGCC) Power Plant, deriving the optimal investment rule as a function of fuel price and the remaining life of the right to invest. Additionally, the analytical solution for a perpetual option is obtained. Second, the valuation of an operating IGCC Power Plant is studied, with switching costs between states and a choice of the best operation mode. The valuation of this plant serves as a base to obtain the value of the option to delay an investment of this type. Finally, we derive the value of an opportunity to invest either in a NGCC or IGCC Power Plant, that is, to choose between an inflexible and a flexible technology, respectively. Numerical computations involve the use of one- and two-dimensional binomial lattices that support a mean-reverting process for the fuel prices. Basic parameter values refer to an actual IGCC power plant currently in operation.

Income risk of EU coal-fired power plants after Kyoto

Coal-fired power plants may enjoy a significant advantage relative to gas plants in terms of cheaper fuel cost. Still, this advantage may erode or even turn into disadvantage depending on CO2 emission allowance price. This price will presumably rise in both the Kyoto Protocol commitment period (2008-2012) and the first post-Kyoto years. Thus, in a carbon-constrained environment, coal plants face financial risks arising in their profit margins, which in turn hinge on their so-called "clean dark spread". These risks are further reinforced when the price of the output electricity is determined by natural gas-fired plants' marginal costs, which differ from coal plants' costs. We aim to assess the risks in coal plants' margins. We adopt parameter values estimated from empirical data. These in turn are derived from natural gas and electricity markets alongside the EU ETS market where emission allowances are traded. Monte Carlo simulation allows to compute the expected value and risk profile of coal-based electricity generation. We focus on the clean dark spread in both time periods under different future scenarios in the allowance market. Specifically, bottom 5% and 10% percentiles are derived. According to our results, certain future paths of the allowance price may impose significant risks on the clean dark spread obtained by coal plants.

Analysis of the legislative framework in the Brazilian policymaking process

Analisa os aspectos da estrutura política brasileira que contribuem para falhas nos processos decisórios e ineficácia nos resultados finais de políticas de governo, com ênfase nos problemas institucionais do poder legislativo. Aborda os seguintes tópicos: fragmentação do sistema partidário, infidelidade partidária, modelo de federalismo, preenchimento de cargos públicos, larga utilização de medidas provisórias, disfunções do processo legislativo.

O poder coercitivo do Conselho de Ética e Decoro Parlamentar da Câmara dos Deputados

Propõe reflexão sobre a atuação do Conselho de Ética e Decoro Parlamentar da Câmara dos Deputados, instituído pela Resolução nº 25 de 2001. São enumeradas e caracterizadas algumas de suas deficiências operacionais, especialmente a ausência de poder coercitivo específico para convocar testemunhas. São apresentados os conceitos de ética, moral e decoro, tanto no sentido que se aplica às relações pessoais de indivíduos em sociedade, como nas implicações inerentes à atividade política, no interior do Parlamento. São focalizados os episódios recentes da política brasileira que demandaram a primeira grande atuação do Conselho de Ética, como órgão recém-instituído no âmbito do Poder Legislativo. Como problema específico de pesquisa, destaca-se o poder testemunhal nos processos judiciais para ressaltar a importância da testemunha no processo de julgamento político, conduzido pelo Conselho de Ética. Discutem-se, finalmente, a necessidade e algumas possibilidades de aprimoramento da estrutura normativa que forma a base para o funcionamento do Conselho de Ética e Decoro Parlamentar da Câmara dos Deputados.

Market Power in the Spanish Electricity Auction

Published as an article in: Journal of Regulatory Economics, 2010, vol. 37, issue 1, pages 42-69.

O sobrestamento de pauta no processo legislativo

Estudo descritivo, desenvolvido sob o enfoque do novo institucionalismo, que trata do sobrestamento de pauta resultante da aplicação das regras constitucionais e regimentais. Busca identificar as razões da gênese desse instituto no presidencialismo brasileiro, assim como entender seu papel tanto na tramitação das proposições para as quais foi concebido, quanto nos trabalhos dos Plenários das Casas do Congresso Nacional. Procura compreender os mecanismos por meio dos quais o sobrestamento de pauta, além de garantir a apreciação célere de algumas proposições consideradas urgentes, contribui decisivamente para transformar o chefe do Poder Executivo no principal controlador da agenda do processo legislativo brasileiro.