Simulation of Severe Slugging Formation and Control in Offshore Riser

In this paper, available elimination techniques are assessed. OLGA2000 software is used to simulate severe slugging formation mechanism in certain offshore riser. The simulation results show that pressure fluctuations of riser base and riser top is very large and severe slugging easily forms. Sensibility analysis shows that the measures and methods which include properly reducing pipe riser diameter, reducing water cut increasing terminal pressure, decreasing the height and inclination of riser and increasing GOR can eliminate or control severe slugging in riser pipe.

Early Functional Deficit and Microglial Disturbances in a Mouse Model of Amyotrophic Lateral Sclerosis

11 p.

Growth of Silicon Carbide Bulk Crystals by Physical Vapor Transport Method and Modeling Efforts in the Process Optimization

Silicon carbide bulk crystals were grown in an induction-heating furnace using the physical vapor transport method. Crystal growth modeling was performed to obtain the required inert gas pressure and temperatures for sufficiently large growth rates. The SiC crystals were expanded by designing a growth chamber having a positive temperature gradient along the growth interface. The obtained 6H-SiC crystals were cut into wafers and characterized by Raman scattering spectroscopy and X-ray diffraction, and the results showed that most parts of the crystals had good crystallographic structures.

Invariant-free deduction systems for temporal logic

In this thesis we propose a new approach to deduction methods for temporal logic. Our proposal is based on an inductive definition of eventualities that is different from the usual one. On the basis of this non-customary inductive definition for eventualities, we first provide dual systems of tableaux and sequents for Propositional Linear-time Temporal Logic (PLTL). Then, we adapt the deductive approach introduced by means of these dual tableau and sequent systems to the resolution framework and we present a clausal temporal resolution method for PLTL. Finally, we make use of this new clausal temporal resolution method for establishing logical foundations for declarative temporal logic programming languages. The key element in the deduction systems for temporal logic is to deal with eventualities and hidden invariants that may prevent the fulfillment of eventualities. Different ways of addressing this issue can be found in the works on deduction systems for temporal logic. Traditional tableau systems for temporal logic generate an auxiliary graph in a first pass.Then, in a second pass, unsatisfiable nodes are pruned. In particular, the second pass must check whether the eventualities are fulfilled. The one-pass tableau calculus introduced by S. Schwendimann requires an additional handling of information in order to detect cyclic branches that contain unfulfilled eventualities. Regarding traditional sequent calculi for temporal logic, the issue of eventualities and hidden invariants is tackled by making use of a kind of inference rules (mainly, invariant-based rules or infinitary rules) that complicates their automation. A remarkable consequence of using either a two-pass approach based on auxiliary graphs or aone-pass approach that requires an additional handling of information in the tableau framework, and either invariant-based rules or infinitary rules in the sequent framework, is that temporal logic fails to carry out the classical correspondence between tableaux and sequents. In this thesis, we first provide a one-pass tableau method TTM that instead of a graph obtains a cyclic tree to decide whether a set of PLTL-formulas is satisfiable. In TTM tableaux are classical-like. For unsatisfiable sets of formulas, TTM produces tableaux whose leaves contain a formula and its negation. In the case of satisfiable sets of formulas, TTM builds tableaux where each fully expanded open branch characterizes a collection of models for the set of formulas in the root. The tableau method TTM is complete and yields a decision procedure for PLTL. This tableau method is directly associated to a one-sided sequent calculus called TTC. Since TTM is free from all the structural rules that hinder the mechanization of deduction, e.g. weakening and contraction, then the resulting sequent calculus TTC is also free from this kind of structural rules. In particular, TTC is free of any kind of cut, including invariant-based cut. From the deduction system TTC, we obtain a two-sided sequent calculus GTC that preserves all these good freeness properties and is finitary, sound and complete for PLTL. Therefore, we show that the classical correspondence between tableaux and sequent calculi can be extended to temporal logic. The most fruitful approach in the literature on resolution methods for temporal logic, which was started with the seminal paper of M. Fisher, deals with PLTL and requires to generate invariants for performing resolution on eventualities. In this thesis, we present a new approach to resolution for PLTL. The main novelty of our approach is that we do not generate invariants for performing resolution on eventualities. Our method is based on the dual methods of tableaux and sequents for PLTL mentioned above. Our resolution method involves translation into a clausal normal form that is a direct extension of classical CNF. We first show that any PLTL-formula can be transformed into this clausal normal form. Then, we present our temporal resolution method, called TRS-resolution, that extends classical propositional resolution. Finally, we prove that TRS-resolution is sound and complete. In fact, it finishes for any input formula deciding its satisfiability, hence it gives rise to a new decision procedure for PLTL. In the field of temporal logic programming, the declarative proposals that provide a completeness result do not allow eventualities, whereas the proposals that follow the imperative future approach either restrict the use of eventualities or deal with them by calculating an upper bound based on the small model property for PLTL. In the latter, when the length of a derivation reaches the upper bound, the derivation is given up and backtracking is used to try another possible derivation. In this thesis we present a declarative propositional temporal logic programming language, called TeDiLog, that is a combination of the temporal and disjunctive paradigms in Logic Programming. We establish the logical foundations of our proposal by formally defining operational and logical semantics for TeDiLog and by proving their equivalence. Since TeDiLog is, syntactically, a sublanguage of PLTL, the logical semantics of TeDiLog is supported by PLTL logical consequence. The operational semantics of TeDiLog is based on TRS-resolution. TeDiLog allows both eventualities and always-formulas to occur in clause heads and also in clause bodies. To the best of our knowledge, TeDiLog is the first declarative temporal logic programming language that achieves this high degree of expressiveness. Since the tableau method presented in this thesis is able to detect that the fulfillment of an eventuality is prevented by a hidden invariant without checking for it by means of an extra process, since our finitary sequent calculi do not include invariant-based rules and since our resolution method dispenses with invariant generation, we say that our deduction methods are invariant-free.

Global Climate Change Impacts in the United States: a state of knowledge report from the U.S. Global Change Research Program

Executive Summary: Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases. These emissions come mainly from the burning of fossil fuels (coal, oil, and gas), with important contributions from the clearing of forests, agricultural practices, and other activities. Warming over this century is projected to be considerably greater than over the last century. The global average temperature since 1900 has risen by about 1.5ºF. By 2100, it is projected to rise another 2 to 11.5ºF. The U.S. average temperature has risen by a comparable amount and is very likely to rise more than the global average over this century, with some variation from place to place. Several factors will determine future temperature increases. Increases at the lower end of this range are more likely if global heat-trapping gas emissions are cut substantially. If emissions continue to rise at or near current rates, temperature increases are more likely to be near the upper end of the range. Volcanic eruptions or other natural variations could temporarily counteract some of the human-induced warming, slowing the rise in global temperature, but these effects would only last a few years. Reducing emissions of carbon dioxide would lessen warming over this century and beyond. Sizable early cuts in emissions would significantly reduce the pace and the overall amount of climate change. Earlier cuts in emissions would have a greater effect in reducing climate change than comparable reductions made later. In addition, reducing emissions of some shorter-lived heat-trapping gases, such as methane, and some types of particles, such as soot, would begin to reduce warming within weeks to decades. Climate-related changes have already been observed globally and in the United States. These include increases in air and water temperatures, reduced frost days, increased frequency and intensity of heavy downpours, a rise in sea level, and reduced snow cover, glaciers, permafrost, and sea ice. A longer ice-free period on lakes and rivers, lengthening of the growing season, and increased water vapor in the atmosphere have also been observed. Over the past 30 years, temperatures have risen faster in winter than in any other season, with average winter temperatures in the Midwest and northern Great Plains increasing more than 7ºF. Some of the changes have been faster than previous assessments had suggested. These climate-related changes are expected to continue while new ones develop. Likely future changes for the United States and surrounding coastal waters include more intense hurricanes with related increases in wind, rain, and storm surges (but not necessarily an increase in the number of these storms that make landfall), as well as drier conditions in the Southwest and Caribbean. These changes will affect human health, water supply, agriculture, coastal areas, and many other aspects of society and the natural environment. This report synthesizes information from a wide variety of scientific assessments (see page 7) and recently published research to summarize what is known about the observed and projected consequences of climate change on the United States. It combines analysis of impacts on various sectors such as energy, water, and transportation at the national level with an assessment of key impacts on specific regions of the United States. For example, sea-level rise will increase risks of erosion, storm surge damage, and flooding for coastal communities, especially in the Southeast and parts of Alaska. Reduced snowpack and earlier snow melt will alter the timing and amount of water supplies, posing significant challenges for water resource management in the West. (PDF contains 196 pages)

Diário da Constituinte [gravação de vídeo] : [programa n. 656]

Os constituintes começaram a apresentar os pedidos de Destaques para votação das emendas em separados. O prazo para a entrega dos requerimentos vai até o dia 22.7.1988 a meia-noite. Cada constituinte tem o direito de apresentar 4 (quatro) Destaques. O primeiro a chegar foi o Líder do PMDB, Nelson Jobim. Até o final da tarde mais de 180 constituintes já tinham apresentado seu Destaque, como foi o caso dos deputados Francisco Kuster (PMDB-SC) e Nelson Frederich (PMDB-PR). O Centrão que fez algumas reuniões anteriormente, já sabe o que quer retirar do texto e acredita que têm votos suficientes para isto. Os constituintes considerados progressistas acham que os temas que foram objeto de acordo no 1º Turno devem permanecer no texto e acreditam que pouca coisa deve ser modificada. Jair Menegheli (Presidente da CUT) disse que os sindicalistas já estão preparados para a defesa de seus direitos no 2º Turno.

Preparation of acetate peels of valves from the ocean quahog, Arctica islandica, for age determinations

Techniques are described for preparing acetate peels of sectioned valves of ocean quahogs, Arctica islandica, for age determinations. The respective sequence of preparation begins by sectioning left valves oriented to include a single hinge tooth, bleaching to remove the heavy periostracum, embedding the valves in an epoxy resin, grinding and polishing the embedments to a high luster, etching the exposed cut valve surfaces, and applying sheet acetate with acetone. Annuli are clearly defined relative to growth increments in the peel preparations for all sizes and ages of ocean quahogs. (PDF file contains12 pages.)

Diário da Constituinte [gravação de vídeo] : [programa n. 685]

Sob o olhar atento de trabalhadores e empresários foram votados os direitos dos trabalhadores, o plenário aprovou a a licença paternidade e as 6 horas para turnos ininterruptos de revezamento e o aviso prévio para os trabalhadores.

Use of generalised additive models to categorise continuous variables in clinical prediction

13 P.

Diário da Constituinte [gravação de vídeo] : [programa n. 341]

A Sessão do Plenário da Constituinte começou com os líderes de diversos partidos se revesando na tribuna a favor e contra a proposta do Centrão para a mudança do Regimento Interno. Após muita confusão e debate, é posta em votação a proposta do Centrão. O líder Mário Covas comunica que o PMDB se retira da votação. O PMDB e os Partidos Progressistas se retiram e os constituintes começam a votação. O Centrão está sozinho no Plenário. As galerias do Plenário se enchem com participantes de um evento da CUT, CGT e Contag. Vaias e chuvas de papel cobrem o Centrão a cada voto. Finda a votação, a mudança do Regimento é aprovada. Diante da impossibilidade de acordo, o presidente do PMDB, sugere que a Mesa faça um substitutivo com as alterações objeto de divergência. Ulysses Guimarães sugere a apresentação de um projeto de resolução para tentar o acordo entre os constituintes. Emendas e destaques poderão aperfeiçoar a proposta aprovada pelo Centrão.

Diário da Constituinte [gravação de vídeo] : [programa n. 342]

O projeto da Mesa da Constituinte, entrou em negociação logo após a aprovação do projeto do Centrão, que tinha o mesmo objetivo: alterar o Regimento Interno. Agora prevalece o projeto de resolução da Mesa da Constituinte que deve ser votado terça ou quarta feira da próxima semana. Os principais pontos são: Ficam mantidas as emendas coletivas assinadas por 280 constituintes; as emendas coletivas podem ser a títulos, mas a votação será feita por capítulos; as propostas com maior número de assinaturas terão preferência para votação; o prazo para apresentação de emendas ao projeto de Constituição será de 7 dias; as emendas velhas não serão aceitas; cada constituinte pode apresentar 4 emendas e 6 destaques. A maioria dos constituintes já sabe o que quer manter e o que quer modificar no projeto aprovado pela Sistematização. Os movimentos sindicais se reunirão durante todo o dia de ontem no Congresso Nacional. Eles querem que o Plenário mantenham os avanços conseguidos na Comissão de Sistematização

Diário da Constituinte [gravação de vídeo] : [programa n. 423]

Ainda não saiu o acordo sobre a estabilidade no emprego. Sindicalistas e constituintes se reúnem para discutir as propostas apresentadas. Nesta reunião, os constituintes ouviram os presidentes da CUT e da CGT e não chegaram a nenhum acordo. Em outra reunião, participou o presidente dos Metalúrgicos de São Paulo. Mas, também não se chegou a um acordo. Manifestação realizada por diversas entidades de classes dá uma abraço a Constituinte. Dando-se as mãos, povo e líderes sindicais deram a volta ao prédio do Congresso, para pedir aos constituintes que garantam os avanços sociais já aprovados nas etapas anteriores. A garantia do direito do preso é votada, estabelecendo de que forma uma pessoa deve ser presa. O destaque que exige a ordem judiciária escrita para se efetuar qualquer prisão em território nacional foi aprovado. O direito de propriedade será votado a seguir.

Diário da Constituinte [gravação de vídeo] : [programa n. 683A]

Inexistência de acordo entre empresários e trabalhadores em torno da proposta da turno de trabalho ininterrupto de 6 horas diárias. Manutenção pelos Constituintes da prisão por ordem de autoridade judiciária competente.

Neues aus der Selektionsforschung am Ostseedorsch

In account of the decision of the IBSFC (International Baltic Sea Fisheries Commission) to admit alternative codend constructions to the presently legal of diamond meshes with 120 mm mesh opening, since seven years a vivid research activity is encouraged at the fishing technology institutions around the Baltic. Though a center of gravity in this field of research lies in the EUproject BACOMA (participants Finland Sweden, Denmark) also the corresponding national institutes of other Baltic countries (Germany, Poland, Russia) have been active with similar investigations. German experiments in 1999 dealt with the effect of the use of netting made of double instead of single yarn on the selectivity. Further research was done on modifications of codends made from netting turned 90° from its original orientation and on simplified versions of the so-called Multipanel codend which consists of three equal diamond and three square mesh panels. The experiments demonstrated on the one hand a definite deterioration of the selective properties in a codend made from double instead of single yarn. Constructional changes in codends made from netting turned 90° on the other hand brought a further improvement of the selectivity of such codends. Finally, the investigations on the Multipanel codend revealed the overwhelming influence of the square mesh panels on the selectivity success. If in a conventional diamond codend three windows are cut out starting 50 cm from the real end of the codend in such a way that the remaining parts have the same breadth as the square mesh panels to insert, the selective effect of such a codend is remarkably improved. According to further preliminary tests this seems to be nearly independent from the type of material used.

Fangquoten für die EU-Mitgliedsländer 1998

The fishery ministers of the EU agreed in their yearly pre-Christmas marathon session on 18th and 19th Dec. 1997 on next year’s TACs and country quota. Main decision was the increase of the TAC for North sea cod and a smaller than feared cut of cod TACs in the West of Scotland zone, the Irish Sea and the English Channel. For the first time ministers set country quota for horse mackerel; until 1997 there had been - with the exception for Portugal and Spain - only a common quota. Also for the much disputed sandeel fishery a TAC of 1 mio. t was finally established, as well as for bluefin tuna and swordfish in the Atlantic and Mediterranean. For 1998 the EU member countries dispose of a total catch quota of 4.46 mio. t in EU waters, and together with quota in third country waters of 5.2 mio. t. Of this total quota, 3.16 mio. t are fish for human consumption and 2.1 mio. t fish for industrial purposes.