Energy Technology Data Exchange (ETDEWEB)
Moreira, S R.D.
1994-12-31
Concentration levels of {sup 210} Pb have been analyzed in 12 mineral spring waters of Aguas da Prata city. The {sup 210} Pb concentration was determined through {sup 210} Bi, by measuring the gross beta activity of the {sup 210} Pb Cr O{sub 4} precipitate after separation from interfering elements by complexation with nitrile tri acetic acid at basic pH. The {sup 210} Bi beta activity was carried out in a low background gas flow proportional counter. Concentrations ranging from lower limit of detection to 1240 mBq/L were observed for {sup 210} Pb. The radiochemical procedure adopted presented a chemical yield around 85% and a lower limit of detection of 4,9 mBq/L. Dose calculations were performed in order to evaluate the importance of this radionuclide to the radiation exposure due to the ingestion of these waters. Based upon measured concentrations, committed effective doses up to 1,1 mSv/y and committed doses to the bone up to 1.7 x 10{sup 1} mSv/y were observed for {sup 210} Pb. (author). 64 refs, 6 figs, 7 tabs.
Energy Technology Data Exchange (ETDEWEB)
Pinto, L M.V.G.; Pereira, M V.F. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil); Nunes, A [ELETROBRAS, Rio de Janeiro, RJ (Brazil)
1990-12-31
A computational model for determining an economical transmission expansion plan, based in the decomposition techniques is presented. The algorithm was used in the Brazilian South System and was able to find an optimal solution, with a low computational resource. Some expansions of this methodology are been investigated: the probabilistic one and the expansion with financier restriction. (C.G.C.). 4 refs, 7 figs.
Energy Technology Data Exchange (ETDEWEB)
Pellegatti, Fabio
2000-07-01
Sepetiba Bay, located about 60 km south of the city of Rio de Janeiro, Brazil, is one of the most important fishery areas in the State of Rio de Janeiro. A large harbor brought up a lot of industrial investment in that area. Since the 1970's, the Sepetiba region has undergone fast industrial expansion, leading to high levels of pollution by metals. For the last two decades, an industrial park composed of about 400 industrial plants, basically metallurgical, was established in the Sepetiba Bay basin, releasing its industrial waste either straight into the bay or through local rivers. Metal contamination in the bay for some metals, such as Zn, has already exceeded acceptable levels. Many authors have studied the distribution and behavior of heavy metals and another elements in the bay, but only few elements have been focused (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). This is probably due to the fact that the analytical technique most employed has been atomic absorption spectrometry, which is not a multi-elemental technique. In this work, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of the elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn in 28 bottom sediment samples and four sediment cores from Sepetiba Bay. The elements Co, Cr, Cs, Fe, Sc, Ta and Zn presented similar behavior in the bottom sediments, showing higher concentration along the Northern coast of the bay, where most of the fluvial water flows out to the bay. The contamination of Sepetiba Bay was also assessed by the analysis of four sediment cores. Two of them were sampled in the Eastern part of the bay, where the industrial park is located, whereas the other two were sampled in the Western part of the bay, a more preserved region. For each region, two cores were sampled within the mangrove trees and the others at the edge of the tidal flat. The results showed that, the sediments displayed higher metal concentration within
Energy Technology Data Exchange (ETDEWEB)
Andrade, W.G.; Santos, P.A.L.; Lima, F.R.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos-Graduacao em Tecnologia Energetica; Lima, F.F., E-mail: wellington.gandrade@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)
2012-07-01
The paper chromatography and the thin layer chromatography are separation techniques in which the radioactive components migrate because of their affinity with the eluent (mobile phase) or stationary phase, respectively. In radiopharmaceuticals labeled with {sup 99m}Tc, besides its own radiopharmaceutical, {sup 99m}TcO{sup 4-} free and TcO{sub 2} can be identified and quantified. The evaluation of radiochemical purity of radiopharmaceuticals is essential to produce images free of artifacts as well as avoid unnecessary absorbed dose to the patient. Once they are managed in humans it is important and necessary that they undergo to strict quality control. Because of this, ANVISA in its 'Resolucao da Diretoria Colegiada (RDC) 38 of June 4th, 2008 states the obligation of performing a minimum of tests in nuclear medicine services routine prior to human administration. This work evaluated, by the method of thin layer chromatography (TLC), radiochemical purity, determined the pH of the radiopharmaceutical DEXTRAN- 500, DMSA, DTPA, PHYTATE, MDP, MIBI and Sn-Col used in nuclear medicine services in the states of Paraiba and Rio Grande do Norte - Brazil. The results show that the use of thin layer chromatography (TLC) as a standard method in routine of nuclear medicine services is possible, because it provides important data for the evaluation of radiochemical purity, allowing the exclusion of a radiopharmaceutical poorly marked. (author)
Directory of Open Access Journals (Sweden)
Daniela Gamba Garib
2005-08-01
Full Text Available Este trabalho descreve os efeitos dentoesqueléticos e periodontais da expansão rápida da maxila (ERM, avaliados por meio da tomografia computadorizada (TC, em uma jovem de 11,6 anos de idade com má oclusão de Classe I e mordida cruzada posterior unilateral funcional. Durante a fase ativa da ERM, o expansor dentossuportado com parafuso Hyrax foi ativado 7mm. A paciente submeteu-se ao exame de TC helicoidal, antes da expansão e após a remoção do aparelho expansor, findo o período de três meses de contenção. Realizaram-se cortes axiais, de um milímetro de espessura, paralelamente ao plano palatino, englobando as regiões dentoalveolar e basal da maxila, até o terço inferior da cavidade nasal. Utilizando-se o recurso de reconstruções multiplanares, mensuraram-se pelo método computadorizado: as dimensões transversas maxilares, a inclinação dos dentes posteriores, a espessura das tábuas ósseas vestibular e lingual, e o nível da crista óssea alveolar vestibular. A expansão rápida da maaxila ocasionou um significante aumento transverso em todas as regiões aferidas, com magnitude decrescente do arco dentário para a base óssea. Os dentes posteriores foram movimentados para vestibular, com um componente de inclinação e translação associados. Tal efeito ortodôntico ocasionou uma redução na espessura da tábua óssea vestibular, e um concomitante aumento na espessura da tábua óssea lingual. Após a expansão, observou-se o desenvolvimento de deiscências ósseas por vestibular dos dentes de ancoragem.This paper presents a computed tomography (CT evaluation of rapid maxillary expansion dentoskeletal and periodontal effects, in a 11.6 year-old girl presenting Class I malocclusion with posterior unilateral crossbite. The tooth-borne expander with Hyrax screw was activated 7-mm. The patient was submitted to helicoidal CT scan before expansion and after the three-month retention period when the expander was removed. Axial
Energy Technology Data Exchange (ETDEWEB)
Kazay, Heloisa Firmo
2001-07-01
The generation expansion-planning problem is a non-linear large-scale optimisation problem, which is even larger when it refers to the Brazilian system, and when one considers the multiple intervening uncertainty sources. To handle the complexity of the problem, decomposition schemes have been used. Usually, such schemes divide the expansion problem into two sub-problems: one related to the construction of new plants (investment sub-problem) and another dealing with the task of operating the system (operation sub-problem). This thesis proposes a genetic algorithm to solve the investment sub-problem. Initially, an analysis of the state of the art on the generation expansion planning and the field of the genetic algorithms are presented. Then follows a practical application of the proposed algorithm in a model of generation expansion planning under uncertainty. Finally, the results obtained in two case studies are presented and analysed. These results indicate that the proposed genetic algorithm is an effective alternative to the solution of the investment sub-problem. (author)
Directory of Open Access Journals (Sweden)
Edmilsson Pedro Jorge
2011-02-01
Full Text Available A finalidade deste artigo é avaliar o efeito da expansão rápida da maxila (ERM na via aérea superior. Por intermédio de um caso clínico, será relatado como indivíduos com atresia da maxila e com comprometimento da função naso-respiratória podem beneficiar-se com a ERM. Para entender melhor as alterações morfológicas decorrentes do paciente com problemas respiratórios, deve-se conhecer a anatomia e a fisiologia do sistema respiratório. Entretanto, não se pode esquecer que o tratamento deste paciente é multidisciplinar, envolvendo o ortodontista, otorrinolaringologista e a fonoaudióloga.The aim of the present investigation is to evaluate the effect of rapid maxillary expansion (RME on the upper airway. A clinical case is presented to describe how patients with atresic maxilla and reduced naso-respiratory function can have benefits from rapid maxillary expansion. In order to better understand the morphological alterations present in patients with respiratory disorders, it is necessary to understand the respiratory system's anatomy and physiology. However, it is relevant to mention that this patient undergoes a multidisciplinary treatment, involving the orthodontist, the otorhinolaryngologist and the phonoaudiologist.
Directory of Open Access Journals (Sweden)
Pedro Luis Scattaregi
2009-10-01
Full Text Available OBJETIVO: avaliar as possíveis alterações e a estabilidade dentária e esquelética no sentido transversal, bem como as possíveis alterações verticais da face (AFAI, produzidas pela Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC. MÉTODOS: a amostra selecionada para este estudo retrospectivo foi composta por 60 telerradiografias em norma frontal, de 15 pacientes, sendo 6 do gênero masculino e 9 do gênero feminino, com média de idades de 23 anos e 3 meses. O disjuntor Hyrax foi instalado e o procedimento cirúrgico adotado envolveu a separação da sutura palatina mediana e não-abordagem da sutura pterigomaxilar. A ativação foi realizada do terceiro dias após a cirurgia até o término da expansão, determinada por critérios clínicos. Todos os pacientes foram radiografados nas fases pré-expansão (T1; pós-expansão imediata (T2; 3 meses pós-expansão, com o próprio disjuntor como contenção (T3; e 6 meses pós-expansão, com a placa removível de acrílico como contenção (T4. Medidas lineares foram obtidas a partir dos traçados cefalométricos gerados por um programa computadorizado (Radiocef Studio 2 e analisadas estatisticamente pelos testes de variância (ANOVA e Tukey ao nível de 5% de significância. RESULTADOS E CONCLUSÕES: concluiu-se que a ERMAC produziu aumentos estatisticamente significativos da cavidade nasal, da largura maxilar e da distância intermolares superiores, de T1 para T2, os quais se mantiveram em T3 e T4. A largura facial e as distâncias intermolares inferiores não apresentaram alterações após a ERMAC. Avaliando o comportamento vertical da face, notou-se um aumento da AFAI nas fases T1 para T2, que diminuiu após a contenção de 3 meses (T3 e permaneceu estável em T4, embora aumentada se comparada com T1.AIM: This study evaluated the stability of the dental and skeletal changes produced by the Surgically Assisted Rapid Maxillary Expansion (SARME in transversal and vertical
Directory of Open Access Journals (Sweden)
Paulo Jorge de Oliveira Ponte de Souza
2013-06-01
Full Text Available O desmatamento da Amazônia, em especial para o uso da pecuária, tem sido explorado por diversos pesquisadores, os quais têm apontado como conseqüência, sérios problemas ambientais. O contínuo avanço da fronteira agrícola sobre as áreas de pecuária na Amazônia, e mesmo sobre áreas nativas, merece atenção pelo fato de poucos estudos terem sido realizados com o intuito de investigar quais os prováveis impactos ambientais da presença da monocultura da soja na região. Este trabalho teve como objetivo avaliar os impactos nos componentes do balanço de radiação devido à nova mudança no uso da terra em uma área de avanço da fronteira agrícola no leste da Amazônia. Realizaram-se experimentos micrometeorológicos no município de Paragominas-PA em uma área de cultivo de soja (Glycine max (L. Merrill e em uma área do ecossistema florestal localizada na Floresta Nacional de Caxiuanã em Melgaço-PA nos anos de 2006 e 2007. Durante o ciclo da soja o impacto médio encontrado representou uma redução 17,9% no saldo de radiação em relação ao ecossistema de floresta natural. Durante a entressafra observou-se um impacto negativo no saldo de radiação de 15,5%. Os principais forçantes deste impacto foram o maior albedo da soja e a perda de radiação de onda longa em relação à cobertura original. Ressalta-se que apesar do maior impacto ocorrer durante o ciclo da cultura, o tempo de ocorrência deste impacto negativo restringe-se a apenas 1/3 do ano, o que, implica em maior impacto da entressafra no saldo de energia em termos cumulativos.The deforestation of the Amazon, especially for pasture use, has been explored by several researchers who have pointed out as a consequence, serious environmental problems. The continuous expansion of agriculture on areas of cattle ranching in the Amazon, as well as on native areas, must be seen with caution since few studies have been conducted in order to investigate which probable
Directory of Open Access Journals (Sweden)
Paulo Domingos Ribeiro Jr.
2006-02-01
Full Text Available OBJETIVO: avaliação clínica dos procedimentos de expansão cirurgicamente assistida da maxila. METODOLOGIA: foram avaliados 10 pacientes tratados através da expansão ortopédica com auxílio cirúrgico, conhecida como expansão cirurgicamente assistida da maxila (ECAM. Avaliou-se a efetividade deste procedimento cirúrgico no auxílio à expansão transversal da maxila proporcionada através de aparelho do tipo Hyrax, a estabilidade desta expansão, as ocorrências pós-operatórias, a quantidade e qualidade da expansão conseguida e alterações estéticas deste procedimento. RESULTADOS E CONCLUSÕES: concluiu-se, com um acompanhamento a longo prazo, que a ECAM trata-se de um procedimento eficiente, estável, que proporciona mudanças funcionais e pouca alteração estética facial.AIM: clinical evaluation of surgically assisted maxillary expansion. METHODS: the present study evaluated 10 patients who underwent surgically assisted maxillary expansion. The efficacy of the surgical procedure helping transverse maxillary expansion given by the Hyrax, expansion stability, post-operatory discomfort during the activation of the device, the quantity and quality of the expansion achieved, the age of the patients, nasal base alteration, and nasal breathing were analyzed. RESULTS AND CONCLUSIONS: from the results, it was possible to observe that surgically assisted maxillary expansion is an efficient and stable treatment, which offers functional changes and minimal aesthetic alterations.
Directory of Open Access Journals (Sweden)
Pedro Roberto Jacobi
2000-12-01
Full Text Available Este artigo apresenta uma reflexão sobre educação e as possibilidades de ampliação da cidadania e da participação, considerando especialmente as condições em que está se construindo um espaço público no Brasil, assim como os alcances e limites do processo de consolidação de engenharias institucionais inovadoras na gestão da coisa pública. Os dados foram colhidos em pesquisa realizada em quatro municípios paulistas São Paulo, Santo André, Itu e Botucatu com a finalidade de examinar em que medida e de que forma se dá a participação na gestão da educação. Os resultados permitem avaliar as possibilidades e impossibilidades de viabilização de dinâmicas inovadoras na relação gestão local/população usuária. Dada a diversidade de formas de ação, foi possível analisar o papel dos diversos atores intervenientes, num contexto em que ainda convivem formas tradicionais de gestão e experiências inovadoras que começam a se legitimar aos olhos da população. O argumento que está no centro da reflexão sustenta que a participação encontra-se em estreita vinculação com o processo de descentralização e pode ser um mecanismo essencial para a democratização do poder público, além de constituir um espaço vital para o fortalecimento de uma cidadania ativa e para o processo de democratização da ação do Estado e das suas práticas institucionalizadoras. O tema articulador tem em vista a participação popular na gestão pública e as transformações qualitativas na relação Estado/Sociedade Civil, consideradas como referência de um ponto de inflexão e reforço das políticas públicas centradas na ampliação da cidadania ativa.This article presents a reflection on education and the possibilities of the expansion of citizenship and participation, taking into account the conditions under which a public space is being built in Brazil, the reach and limits of the consolidation process of innovative institutional
Energy Technology Data Exchange (ETDEWEB)
Marreco, Juliana de Moraes
2007-05-15
This thesis considers uncertainty on the long term generation expansion planning in the Brazilian Electric System, under a Real Options Approach . First, Real Options Theory is used to demonstrate the importance of thermo power plants insertion in Brazil, through a flexibility valuation on hydrothermal system. This is the first objective of this thesis. In the second part a Real Options Model is proposed to support long term expansion studies, based in a levelized costs analysis. The adequacy of proposed models to real problem is illustrated by a case study of the Brazilian Power System. The results show the importance of the energetic matrix diversification on the Long Term Planning. In the expansion model proposed, results are in favor of higher participation of biomass, nuclear power and coal in Brazilian electricity generation matrix. (author)
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Rosangela Magda de
1994-12-31
In this paper, phosphors determination by neutron activation analysis in milk and bone samples was studied employing both instrumental and radiochemical separation methods. The analysis with radiochemistry separation consisted of the simultaneous irradiation of the samples and standards during 30 minutes, dissolution of the samples, hold back carrier, addition precipitation of phosphorus with ammonium phosphomolibdate (A.M.P.) and phosphorus-32 by counting by using Geiger-Mueller detector. The instrumental analysis consisted of the simultaneous irradiation of the samples and standards during 30 minutes, transfer of the samples into a counting planchet and measurement of the beta radiation emitted by phosphorus-32, after a suitable decay period. After the phosphorus analysis methods were established they were applied to both commercial milk and animal bone samples, and data obtained in the instrumental and radiochemical separation methods for each sample, were compared between themselves. In this work, it became possible to obtain analysis methods for phosphorus that can be applied independently of the sample quantity available, and the phosphorus content in the samples or interference that can be present in them. (author). 51 refs., 7 figs., 4 tabs.
Energy Technology Data Exchange (ETDEWEB)
Sousa, C.H.S.; Peixoto, J.G.P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Araujo, G.; Padilha, L.G. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)
2016-07-01
Radiation detectors must pass periodically recommended quality control tests and standardized to certify the quality of measurements, however, many studies have shown that several parameters can influence the results, however, some instrument components that can not be adjusted during calibrations may have significant importance in measurement results over the operating time. This study sought to determine the influence of the use of time in the activity measurements. The results show a trend of decreased activity measured for equipment with detectors with more operating time. (author)
Directory of Open Access Journals (Sweden)
Wellington da Silva Mendes
2002-06-01
Full Text Available Descreve-se a ocupação espacial no município de São Luis e a expansão da leishmaniose visceral americana(LVA na mesma. Foram analisadas as fichas de registro de atendimento de casos de leishmaniose visceral da Diretoria Regional da Fundação Nacional de Saúde do Maranhão no período de setembro de 1982 a dezembro de 1996, assim como documentos oficiais sobre a ocupação espacial do município. Foi observado que os casos de LVA ao longo da evolução da epidemia em São Luis apresentaram distribuição espacial e concentração semelhantes a apresentada pelo fluxo migratório na cidade no mesmo período.The space occupation and the expansion of American visceral leishmaniasis (AVL were described in the municipality of São Luis, Maranhão, Northeast Brazil. AVL medical notes from the Fundação Nacional de Saúde as well as official documents about the space occupation were analyzed from September 1982 to December 1996. AVL cases were more likely to occur in recently settled suburbs and tended to follow the same spatial pattern observed for land occupations secondary to migratory fluxes.
Directory of Open Access Journals (Sweden)
Daniela Gamba Garib
2007-06-01
Full Text Available OBJETIVO: este trabalho apresenta um método para expansão ortopédica da maxila, na dentadura permanente, utilizando implantes como ancoragem. METODOLOGIA: detalharam-se os procedimentos cirúrgicos e laboratoriais da confecção de um expansor com ancoragem dento-óssea em crânio seco humano. Dois implantes de titânio foram colocados na região anterior do palato, e o parafuso Hyrax adaptado de modo que a expansão ancorou-se nos implantes e nos primeiros molares permanentes. RESULTADOS: o experimento laboratorial em crânio seco mostrou que o procedimento apresenta-se anatômica e operacionalmente viável. Os implantes suportaram a força gerada pela ativação do parafuso expansor, redundando na separação transversal das hemimaxilas. CONCLUSÕES: vislumbra-se que a expansão rápida da maxila ancorada em implantes (ERMAI poderá potencializar a eficiência da expansão ortopédica, assim como reduzir o custo periodontal dos procedimentos convencionais de expansão. Futuros estudos clínicos são necessários para testar essas hipóteses.AIM: This study presents a method for maxillary orthopedic expansion, in the permanent dentition, using implants as anchorage. METHODS: Surgical and laboratorial procedures for the construction of a tooth-bone-borne expansor was detailed in a human dry skull. Two titanium implants were placed in the anterior region of the palate and a Hyrax screw was adapted in a way that the expansion was anchored both on the palatal implants and on permanent first molars. RESULTS: The laboratorial experiment in dry skull showed that the procedure is operationally and anatomically possible. The implants supported the force generated by the expansion screw activation and the maxilla halves were transversally split. CONCLUSIONS: Rapid maxillary expansion anchored on implants can increase the efficiency of orthopedic expansion and decrease the periodontal sequela caused by conventional RME. Further clinical studies are
International Nuclear Information System (INIS)
Yun, Y.
2015-01-01
Thermal expansion of fuel pellet is an important property which limits the lifetime of the fuels in reactors, because it affects both the pellet and cladding mechanical interaction and the gap conductivity. By fitting a number of available measured data, recommended equations have been presented and successfully used to estimate thermal expansion coefficient of the nuclear fuel pellet. However, due to large scatter of the measured data, non-consensus data have been omitted in formulating the equations. Also, the equation is strongly governed by the lack of appropriate experimental data. For those reasons, it is important to develop theoretical methodologies to better describe thermal expansion behaviour of nuclear fuel. In particular, first-principles and molecular dynamics simulations have been certainly contributed to predict reliable thermal expansion without fitting the measured data. Furthermore, the two theoretical techniques have improved on understanding the change of fuel dimension by describing the atomic-scale processes associated with lattice expansion in the fuels. (author)
Energy Technology Data Exchange (ETDEWEB)
Lucio, Joao Carlos Martins
1990-12-31
This work presents the proposal of a methodology which, by exploring the interaction between generation and transmission systems expansion studies, aims for an Integrated Planning of Power Systems. It intends to emphasize the Integrated Planning importance so as to improve the utilization of the available resources in the electric sector and to reduce the expansion and operational costs. The work describes a procedure to consider explicitly the network for the determination of a generation system construction schedule. It considers that the transmission lines construction costs have a significant weight so that it can modify the initial generation expansion plan with the anticipation of some investments and the postponement of others, decreasing the global expansion costs. The generation and transmission systems expansion is made in an optimal way using a Graph Search Algorithm. Finally the best Integrated Plan is obtained from a final algorithm that generates a sequence of integrated plans from combination of generation and transmission algorithms. These plans are compared from a global cost point of view until a convergence criterion has been satisfied. (author) 18 refs., 5 figs., 28 tabs.
Energy Technology Data Exchange (ETDEWEB)
Lucio, Joao Carlos Martins
1991-12-31
This work presents the proposal of a methodology which, by exploring the interaction between generation and transmission systems expansion studies, aims for an Integrated Planning of Power Systems. It intends to emphasize the Integrated Planning importance so as to improve the utilization of the available resources in the electric sector and to reduce the expansion and operational costs. The work describes a procedure to consider explicitly the network for the determination of a generation system construction schedule. It considers that the transmission lines construction costs have a significant weight so that it can modify the initial generation expansion plan with the anticipation of some investments and the postponement of others, decreasing the global expansion costs. The generation and transmission systems expansion is made in an optimal way using a Graph Search Algorithm. Finally the best Integrated Plan is obtained from a final algorithm that generates a sequence of integrated plans from combination of generation and transmission algorithms. These plans are compared from a global cost point of view until a convergence criterion has been satisfied. (author) 18 refs., 5 figs., 28 tabs.
Energy Technology Data Exchange (ETDEWEB)
Haffner, Sergio Luis
2000-07-01
An integrated dynamic expansion planning model of electric energy systems model is proposed. Such model can be used by an independent structure of planning, compatible with the current competitive environment of the electric industry. The investments in generation and transmission are obtained simultaneously, taking into account a long term planning horizon that is split in multiple stages. In the proposed model, the entity responsible for the expansion planning, the Independent Expansion Planner, divulges the indicative expansion plan and other information that will be used by the sector agents to guide its investments in that area. Three network models are used (transport, DC load flow and hybrid transport-DC) in an hierarchical algorithm that uses the Benders decomposition to solve the problem of capacity expansion, considering the investment and operation costs. The original problem is separated in a master subproblem (investment) and several slave subproblems (operation). Each stage is represented by an operation subproblem and the master subproblem is solved by an specialized branch-and-bound algorithm. The operation subproblems (LP problems) are solved through the MINOS package. Strategies to improve the performance of the described algorithm are discussed and presented. The efficiency of those strategies is shown through tests using theoretical and realistic electric systems. The developed branch-and-bound algorithm and the selection techniques employed are described in details and illustrated through examples. It is presented, also, the Independent Planner role and its relevance in the current context of the national electric industry is pointed out. (author)
Energy Technology Data Exchange (ETDEWEB)
Coelho, Suani Teixeira [Centro Nacional de Referencia em Biomassa (CENBIO), Sao Paulo, SP (Brazil); Lora, Beatriz Acquaro; Monteiro, Maria Beatriz C.A.
2008-07-01
The present work aimed at analyze the sugar cane culture expansion in substitution to the other cultures in the Sao Paulo state from available georeferred and statistical data. The results had evidenced clear expansion of the sugar cane culture in the state, having totalized a growth of 26.04% in the period from 2003 to 2006, with expressive increase in the regions of President Prudente, Sao Jose do Rio Preto, Barretos and Marilia that had, each one, more than 40% of increase in the period. Concomitantly it had reduction of the maize areas in the studied region and pasture areas stability, followed of a small increase of the cattle heads number. (author)
Directory of Open Access Journals (Sweden)
Omar Gabriel da Silva Filho
2008-04-01
Full Text Available OBJETIVO: o presente trabalho tem como objetivo acompanhar radiograficamente a evolução da ossificação da sutura palatina mediana em pacientes submetidos à expansão rápida da maxila, bem como comprovar a validade de se avaliar a neoformação óssea através deste exame complementar de diagnóstico. METODOLOGIA: a amostra constou de 38 pacientes no estágio de dentadura mista que se submeteram ao protocolo de expansão rápida da maxila, sendo 2/4 de volta pela manhã e 2/4 de volta à noite, totalizando 1 volta completa por dia, compreendendo um período de 7 dias. RESULTADOS: radiografias oclusais de maxila tomadas no pós-tratamento evidenciaram uma variação individual quanto ao período necessário para a completa neoformação óssea da sutura palatina mediana. A imagem radiográfica apresentou-se como um método confiável para a determinação da época correta de remoção do aparelho expansor. Tendo em vista a estabilidade pós-tratamento a longo prazo, o aparelho expansor deve ser removido somente após a completa ossificação da sutura. CONCLUSÕES: os resultados revelaram que são necessários mais de três meses para que o processo de ossificação e reorganização sutural se processe após o procedimento de expansão rápida da maxila.OBJECTIVE: the current study aims at following up radiographically the evolution of the midpalatal suture during the expansion procedure since the opening of the suture until bone formation. METHODS: the sample comprised 38 patients in the mixed dentition stage submitted to the rapid palatal expansion protocol of the Hospital for Rehabilitation of Craniofacial Anomalies. RESULTS: it was observed an individual variation on the period of bone ossification of the midpalatal suture, which justifies the radiographic follow-up as determinant for the appliance removal. Due to long-term post-treatment stability, the expander should be removed after the new suture is completely formed. CONCLUSIONS
Directory of Open Access Journals (Sweden)
Almiro José Machado Júnior
2006-04-01
Full Text Available A expansão da maxila é um procedimento que objetiva o aumento do arco dental maxilar para correção de desvios oclusais. Amplamente empregada em crianças, há controvérsias sobre sua eficácia em adultos, quando o crescimento crânio-facial já atingiu sua maturidade óssea. OBJETIVO: O presente estudo tem como objetivo avaliar modificações cefalométricas decorrentes da expansão da maxila em pacientes adultos, observando as seguintes medidas lineares: largura facial, largura nasal, altura nasal, largura maxilar, largura mandibular e largura molar-maxilar. MATERIAL E MÉTODOS: A amostra constituiu-se de 24 telerradiografias frontais, tomadas antes e imediatamente após as expansões, obtidas de 12 pacientes, ambos os sexos, com idade entre 18 anos e dois meses e 37 anos e oito meses. Todos os pacientes foram submetidos à expansão lenta dos ossos maxilares com o uso do aparelho expansor da técnica denominada "reabilitação dinâmica e funcional dos maxilares". Foi utilizado teste estatístico de Wilcoxon pareado, para amostras relacionadas e nível de significância 5%. RESULTADOS: Ocorreu aumento médio de 1,92mm na largura nasal e altura nasal 2,5mm. Nas medidas lineares largura maxilar e largura mandibular o aumento médio foi de 2,42mm e 1,92mm respectivamente. Para largura facial encontrou-se aumento médio de 1,41mm e largura molar-maxilar 2,0mm, sendo tais alterações estatisticamente significativas, obtidas em um tempo médio de 5,3 meses. CONCLUSÃO: Baseado nos resultados obtidos conclui-se que o uso da expansão maxilar induz o aumento das medidas faciais estudadas em adultos.Maxilla expansion is a procedure that aims at increasing the maxillary dental arch to correct occlusal disharmony. Largely used in children, its efficacy in adults, when craniofacial growth has attained bone maturity, is controversial. AIM: The present study has the objective of evaluating cephalometric modifications resulting from maxilla expansion
Energy Technology Data Exchange (ETDEWEB)
Firmino, Rafaelle Gomes; Fonseca, Marcia Batista da [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)
2008-07-01
This work is a survey about the environmental impacts caused by the increasing expansion of productive activity and in particular agriculture, before any alarm world in search of renewable energy. The purpose of this study is to discuss the sources of resources that are considered clean energy, the constant demand for biofuels in international trade and the effect on the environment created by the increasing expansion of agriculture. The research is descriptive and qualitative data are analyzed. Clearly that is to expand cultivation of sugar cane, maize, castor bean, sunflower, soybean, peanut and others for the use of renewable fuels are often forgotten their devastating effects on soil wear and the down of forests that attack the entire ecosystem, and even the replacement of biofuel production by the agricultural production of food. (author)
International Nuclear Information System (INIS)
Knoll, J.
1985-10-01
A quantum dynamical model is suggested which describes the expansion and disassembly phase of highly excited compounds formed in energetic heavy-ion collisions. First applications in two space and one time dimensional model world are discussed and qualitatively compared to standard freeze-out concepts. (orig.)
Indian Academy of Sciences (India)
of a system under investigation is to model the system in terms of some ... The organization of the paper is as follows: In §2, a brief account of the (G /G)- expansion ...... It is interesting to note that from the general results, one can easily recover.
Energy Technology Data Exchange (ETDEWEB)
Gorenstin, B.G.; Costa, J.P. da [CEPEL, Rio de Janeiro, RJ (Brazil); Pereira, M.V.F.; Campodonico, N.M.
1993-12-31
This issue presents a methodology for planning the systems expansion of hydraulic and thermic power generation associated considering several uncertainly factors, such as: demand growing, fuel costs, delays on the work construction, financial restrictions, etc. The solution focus is based on stock optimize techniques, decision analysis. This work is being developed by the Brazilian Electrical Centre (ELETROBRAS) and rely on the Energy Latin-American Organization (OLADE), Development Inter-American Bank (BID), World Bank (BIRD) and International Energy Agency (IAEA) support. An example case with Costa Rica system is also discussed 19 refs., 4 figs., 2 tabs.
Energy Technology Data Exchange (ETDEWEB)
NONE
2009-10-15
The evaluation of the potential areas for the expansion of the sugar cane cultivation was based on the estimation of the agricultural productivity aptitude as function of the soil and climate characteristics using maps with geo referred in scales of 1/5,000,000. Areas had been discarded which integrate of three large biomass of the country: Amazonia, Pantanal and Mata Atlantica, and all the areas with some type of restriction, such as environmental reservations, national parks, indigenous, military and urban areas. Were not considered areas with crop mechanization essential for the environmental and social sustainability with declivity more than 12%.
Directory of Open Access Journals (Sweden)
Emilia Teruko Kobayashi
2010-12-01
Full Text Available INTRODUÇÃO: a expansão da maxila induz a formação de novo osso na sutura palatina mediana por um processo de proliferação e diferenciação celular. A força de expansão pode estimular, nas células progenitoras, a produção de citocinas com atividade osteoindutiva, tais como o transforming growth factor β1(TGFβ1. OBJETIVOS: o principal objetivo deste estudo foi determinar a função dessa citocina nos estágios iniciais de expansão da sutura palatina mediana. MÉTODOS: um aparelho ortodôntico foi instalado entre os molares superiores direito e esquerdo de ratos com 4 semanas de idade. A força de expansão inicial foi de 50g. Os grupos controle e experimental foram sacrificados nos dias 0, 2 e 5. Cortes bucais de 6µm foram obtidos e sujeitos à técnica de hibridização in-situ. RESULTADOS: dois dias após a aplicação de força, as células osteocondroprogenitoras, distribuídas no lado interno do tecido cartilaginoso, exibiram altos níveis de transcrição de transforming growth factor β1. No dia 5, o nível de transcrição de TGFβ1 foi observado nos osteócitos e nas células osteoblásticas, na superfície do novo osso. A atividade osteoblástica foi confirmada por meio de um estudo imunohistoquímico utilizando-se Osteocalcina-Pro (OC-Pro. CONCLUSÕES: os dados sugerem que a expansão da sutura palatina induz a diferenciação de células osteocondroprogenitoras em osteoblastos, estimuladas pela produção de citocinasINTRODUCTION: The application of an orthodontic expansion force induces bone formation at the midpalatal suture because of cell proliferation and differentiation. Expansion forces may stimulate the production of osteoinductive cytokines, such as transforming growth factor β1 (TGFβ1, in the progenitor cells. OBJECTIVES: This study determined the role of TGFβ1 in the early stage of midpalatal suture cartilage expansion. METHODS: A rectangular orthodontic appliance was placed between the right and left
Energy Technology Data Exchange (ETDEWEB)
Canciam, Cesar Augusto [Universidade Tecnologica Federal do Parana (UTFPR), Campus Ponta Grossa, PR (Brazil)], e-mail: canciam@utfpr.edu.br
2012-07-01
When evaluating the consumption of bio fuels, the knowledge of the density is of great importance for rectify the effect of temperature. The thermal expansion coefficient is a thermodynamic property that provides a measure of the density variation in response to temperature variation, keeping the pressure constant. This study aimed to predict the thermal expansion coefficients of ethyl bio diesels from castor beans, soybeans, sunflower seeds and Mabea fistulifera Mart. oils and of methyl bio diesels from soybeans, sunflower seeds, souari nut, cotton, coconut, castor beans and palm oils, from beef tallow, chicken fat and hydrogenated vegetable fat residual. For this purpose, there was a linear regression analysis of the density of each bio diesel a function of temperature. These data were obtained from other works. The thermal expansion coefficients for bio diesels are between 6.3729x{sup 10-4} and 1.0410x10{sup -3} degree C-1. In all the cases, the correlation coefficients were over 0.99. (author)
Energy Technology Data Exchange (ETDEWEB)
Castagna, Annemarlen Gehrke [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Blesl, Markus [Institute of Economics and the Rational Use of Energie (IER), Stuttgart (Germany)
2010-07-01
South America combines economic and population growth with a consequent rapid increase in electricity demand. This can only be covered by building new power plants, use of the remaining renewable potential and expansion of transmission lines. The expansion of supply in all regions, with reliable generation and transmission systems is the greatest challenge for the continent in order to reduce social differences and not to curb economic development. To support the energy planning the application of system models represents useful method. This paper intends to analyze the expansion effect of power plant parks in regard of greenhouse gases emissions using a regionalized model system 'TIMES (The Integrated Markal - EFOM System)'. The model includes 10 South American countries (Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay and Venezuela) with their respective power parks and transmission lines, demand divided in sectors, potential use of renewable energy sources, gas pipelines and possibilities of new interconnections within and between countries. As results are obtained the future installed capacity and generation according the energy use, greenhouse gases emissions, as well as the investments needed to expand the electric system in different scenarios. (author)
Directory of Open Access Journals (Sweden)
Alvaro Renato Guerra Dias
2007-12-01
Full Text Available Amidos de mandioca e de milho comum foram fermentados em laboratório a 20 °C, sendo uma fração seca ao sol e outra oxidada com peróxido de hidrogênio e secada artificialmente, visando o desenvolvimento da propriedade de expansão. Estudou-se a fermentação em 0, 10, 30 e 50 dias, sendo a propriedade de expansão no forneamento avaliada pelo teste do biscoito e o comportamento viscoamilográfico pelo RVA. Verificou-se que a fermentação promove modificação que auxilia na oxidação dos amidos de mandioca e de milho elevando a acidez titulável do produto. O amido de mandioca fermentado oxidado com exposição solar ou com peróxido de hidrogênio pode desenvolver a propriedade de expansão, já o amido de milho comum nessas condições não tem essa capacidade. Os melhores resultados para a propriedade de expansão foram no amido de mandioca oxidado com peróxido de hidrogênio aos 50 dias de fermentação.Cassava and corn starches were fermented in the laboratory at 20 °C, and a fraction was in the sun while another fraction was oxidized with hydrogen peroxide and dried artificially to develop the expansion property. Fermentation in 0, 10, 30 and 50 days was checked and the expansion property was evaluated by the baking test and viscoamilograph behavior (RVA. Fermentation was found to cause changes that help the oxidation of cassava and corn starches, increasing the product's titrable acidity. The fermented cassava starch, oxidized by exposure to sunlight or hydrogen peroxide, may develop the expansion property, but the corn starch did not display that ability under these conditions. The best results for the expansion property were obtained with cassava starch oxidized with hydrogen peroxide after 50 days of fermentation.
Directory of Open Access Journals (Sweden)
Nakatani, Paulo
2014-01-01
Full Text Available Grande parte das abordagens acerca da China trata de maneira insuficiente as suas estratégias internas de desenvolvimento, apenas conferindo a este país diferentes papéis no âmbito do capitalismo mundial. Este artigo busca identificar uma estratégia específica da China, a aquisição de terras pelo mundo, refletindo acerca dos possíveis motivos inter nos para essa atuação, bem como a abrangência deste fenômeno no plano mundial e, de maneira ilustrativa, considerando alguns impactos dessa ação sobre o Brasil
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, Sonia Marta Carpinelli; Abreu, Igor Melo de [UTC Engenharia S.A., Sao Paulo, SP (Brazil)
2008-07-01
The UTC Engineering S.A. search for excellence results to develop the Health, Environmental, and Safety Integrated Management System (SMS) which is addressed to the Petrochemical Uniao S.A. Project for Productivity Capacity Expansion. Despite challenges to set and maintain the System and besides risks associated to electro-mechanical industrial assembly and civil construction, the plan is being implemented. Due to activity changes associated with distinct enterprise steps execution there is a need of tight control related to alteration and immediate blockage actions as procedure to prevent accidents. Innovative programs as the 'Motivation Program for Prevention of Losses' and the 'Qualification Program and Training of Work', bring up to the workers sense of responsibilities and professional values related to SMS issues. As an aid, the Programs supplied by DuPont as STOP{sup TM} - (Program of Safety for Observation) and IAS (Index of Safe Actions) constituted important tools. But, its production leadership taking part, concerned SMS commitment and responsibilities, was crucial. The good results achievements are expressed by reduction of SMS distortions and by reduction of labor accidents as man hour exposed to the risk. (author)
Energy Technology Data Exchange (ETDEWEB)
Martinez, Aquilino S.; Pereira, Valmir; Silva, Fernando C. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica
1997-12-01
It is presented a concept of a system which may be used to calculate and anticipate the subcritical multiplication of a PWR nuclear power plant. The system is divided into two different modules. The first module allows the theoretical prediction of the subcritical multiplication factor through the solution of the multigroup diffusion equation. The second module determines this factor based on the data acquired from the neutron detectors of a NPP external nuclear detection system. (author). 3 refs., 3 figs., 2 tabs.
Energy Technology Data Exchange (ETDEWEB)
Nogueira, M.S. [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil); Rodas Duran, J.E. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica
2001-07-01
The teeth are organs of complicated structure that consist, partly, of hard tissue containing in its interior the dental pulp, rich in vases and nerves. The main mass of the tooth is constituted by the dentine, which is covered with hard tissues and of epithelial origin called enamel. The dentine of the human teeth used in this work were completely removed and the teeth were cut with a device with a diamond disc. In this work the chemical composition of the human enamel was determined, which showed a high percentage of Ca and P, in agreement with the results found in the literature. The effective atomic number of the material and the half-value layer in the energy range of diagnostic X-ray beams were determined. Teeth could be used to evaluated the public's individual doses as well as for retrospective dosimetry what confirms the importance of their effective atomic number and composition determination. (author)
Directory of Open Access Journals (Sweden)
Belini Augusto Villalba Freire-Maia
2005-04-01
Full Text Available O objetivo deste estudo foi avaliar a eventual alteração na posição craniocervical de pacientes orientados na Posição Natural da Cabeça (PNC, após o procedimento de expansão rápida da maxila (ERM. Utilizaram-se telerradiografias em norma lateral, selecionadas do acervo de documentação da Clínica de Ortodontia Preventiva da Faculdade de Odontologia da Universidade de São Paulo, de 20 pacientes, com idades entre 5 a 11 anos (média de 9,0 anos, sendo 7 do gênero masculino e 13 do feminino, obtidas no início do tratamento e imediatamente após a fase ativa da expansão da maxila. Os pacientes eram portadores de atresia da maxila e foram tratados com aparelho disjuntor tipo Biederman modificado. A partir dos cefalogramas pré e pós-ERM foram obtidas as grandezas angulares craniovertical (SN.VER, craniocervical (OPT.SN e CVT.SN, cervicohorizontal (OPT.HOR, CVT.HOR e o ângulo da curvatura cervical (OPT.CVT. Após análise estatística e interpretação dos resultados obtidos concluímos que a posição da cabeça não apresentou alteração estatisticamente significativa. Não foram observadas diferenças estatisticamente significativas entre os gêneros quando comparadas as fases pré e pós-ERM para as grandezas estudadas. O método de obtenção de telerradiografias laterais em Orientação Natural da Cabeça mostrou-se confiável e reproduzível na amostra estudada, mesmo na presença de intervenção ortodôntica-ortopédica entre as séries de radiografias.The aim of this study was to evaluate the eventual alteration in the craniocervical position of patients, oriented in the Natural Head Position (NHP, after the rapid maxillary expansion (RME procedure. We have used lateral radiographs, selected from the documentation file of the Preventive Orthodontics Clinic, School of Dentistry, University of São Paulo. Our sample consisted of 20 patients (7M:13F, with ages ranging from 5.08 up to 11.08 years (mean of 9,0. The
Directory of Open Access Journals (Sweden)
Constança Simões Barbosa
1996-12-01
Full Text Available A esquistossomose continua a ser um problema de saúde pública no Nordeste do Brasil embora o emprego, em larga escala, da quimioterapia venha sendo apontado como um dos fatores responsáveis pela redução das formas graves. O Estado de Pernambuco vem apresentando taxas crescentes de infecção humana para esquistossomose com perfil epidemiológico de prevalências crônicas (até 80% na região rural e casos recentes de infecção aguda no litoral. Discute-se a reprodução e expansão da esquistossomose a partir de uma concepção estrutural e histórica de causas, onde se inserem fatores não só de ordem biológica mas também sociais, políticos e culturais que vêm contribuindo para a formação dos quadros endêmicos: a forma de ocupação e do uso da terra, desemprego, desnutrição, migração e outros. Questionam-se as crescentes dificuldades para o controle da doença e o papel da investigação epidemiológica na compreensão da essência social do processo saúde/doença.Schistosomiasis mansoni can be considered an important public health problem in Northeastern Brazil, in spite of the reduction in the prevalence of the hepatosplenic clinical forms which have been attributed to the large scale use of chemotherapy in this country. However, the rise in the prevalence rates and the spread of this endemic disease to new areas show that schistosomiasis is assuming its must cruel expression: less lethal but more greatly incapacitating in terms of irreversible physical and moral damage to human beings. The state of Pernambuco presents growing rates for schistosomiasis infection in humans. The epidemiological profile of this disease displays high and consistent prevalence rates (up to 80% in rural areas, and new cases of acute infection on the coast, where schistosomiasis has recently been introduced. The reproduction and expansion of this endemic disease can be better understood on the basic of a conception of structural and historical
Directory of Open Access Journals (Sweden)
Dayse Mysmar Tavares Rodrigues
2008-03-01
Full Text Available
The objective of this study was to identify factors that may explain the development of cattle raising in Central Brazil, starting from middles of the decade of 1970, concomitant with the expansion of agricultural frontiers. Through an innovative theoretical model, it is possible to identify the fundamental variables of that process: location, topography and fertility. Data analyses allowed verifying that the ";location"; variable best explains the development of cattle raising in Goiás State.
KEY-WORDS: Agricultural frontier; agricultural modernization; technological change.
O objetivo deste trabalho foi identificar fatores que possam explicar a espacialização da atividade pecuária na região central do Brasil, a partir de meados da década de 1970, com a expansão da fronteira agrícola. Para tanto, é estudado o caso do Estado de Goiás. Por meio de um inovador modelo baseado na teoria da renda fundiária, é possível identificar as variáveis fundamentais desse processo: localização, topografia e fertilidade. A análise dos dados permitiu constatar que a variável "localização" é a que melhor explica a espacialização da agropecuária nesse Estado.
PALAVRAS-CHAVE: Fronteira agrícola; modernização da agropecuária; mudança tecnológica.
Directory of Open Access Journals (Sweden)
Milleni Campos Fernandes Martins
2009-10-01
Full Text Available OBJETIVO: avaliar a neoformação óssea da sutura palatina mediana em diferentes fases do procedimento de expansão rápida da maxila por meio de imagem digitalizada e comparar a densidade radiográfica das diferentes áreas selecionadas ao longo dessa sutura nos períodos estabelecidos. MÉTODOS: a amostra foi constituída por 23 indivíduos, na faixa etária de 9 a 12 anos, que foram submetidos à expansão rápida da maxila de acordo com um protocolo que consistiu, inicialmente, em uma volta completa no parafuso, seguida por ¼ de volta pela manhã e ¼ de volta à noite, durante duas semanas. Foram obtidas 69 radiografias oclusais em diferentes momentos do procedimento, as quais passaram pelo processo de digitalização via scanner e, posteriormente, foram submetidas ao programa Digora for Windows 5.6, para a realização das leituras de densidade radiográfica. RESULTADOS: em todas as fases do procedimento, os valores obtidos dos níveis de cinza foram, em média, diferentes entre si, comprovando uma recuperação óssea parcial da sutura palatina mediana. CONCLUSÕES: os resultados revelaram que são necessários mais de três meses para a completa recuperação sutural após a expansão rápida da maxila e que o método utilizado para a leitura das densidades mostrou-se fiel, devido à sua capacidade de exibir detalhes. Portanto, conclui-se que o expansor deve ser removido somente após a total recuperação óssea sutural, a fim de evitar as recidivas.AIM: To evaluate the new bone formation of the midpalatal suture in different phases of the rapid maxillary expansion procedure by means of the scanned image and to compare the radiographic density of the different selected areas along this suture in predetermined periods. METHODS: The sample consisted of 23 individuals, aged from 9 to 12 years who underwent rapid maxillary expansion in accordance with a protocol which consisted initially of a full turn on the screw, followed by ¼ turn by
Directory of Open Access Journals (Sweden)
Paulo Roberto Pelucio Camara
2009-12-01
Full Text Available OBJETIVO: avaliar as alterações nos arcos dentários superiores no sentido transversal e a quantidade de inclinações nos dentes de apoio do aparelho de expansão tipo Hyrax em pacientes submetidos à expansão rápida da maxila assistida cirurgicamente (ERMAC e a efetividade dessa técnica cirúrgica utilizada. A amostra foi composta por 34 pares de modelos de gesso de 17 pacientes, sendo 6 do gênero masculino e 11 do gênero feminino. MÉTODOS: as medidas foram realizadas em modelos de gesso por meio de medição das alterações nos planos vertical e transversal. O procedimento cirúrgico adotado foi uma osteotomia nas paredes laterais da maxila sem o envolvimento da lâmina pterigoide, osteotomia da espinha nasal à linha média dentária (incisivos centrais anteriores, separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início das ativações ocorreu no terceiro dia pós-operatório, sendo uma pela manhã e uma à noite. RESULTADOS: houve expansão significativa estatisticamente na região dos caninos, primeiros e segundos pré-molares, primeiros e segundos molares, respectivamente de 6,03mm, 9,82mm, 8,66mm, 9,72mm e 5,67mm. Avaliando o comportamento dos dentes de apoio do disjuntor quanto às inclinações das coroas dentárias, notou-se que ocorreu uma vestibularização assimétrica, pois para os primeiros molares os valores encontrados foram 6,89º (direito e 9,56º (esquerdo, e para os primeiros pré-molares os valores obtidos foram 4,74º (esquerdo e 3,26º (direito, sendo esse considerado estatisticamente não-significativo. CONCLUSÕES: a técnica cirúrgica empregada para esta pesquisa mostrou ser eficiente para se obter alteração transversal maxilar, ocorrendo inclinação dentoalveolar dos dentes de apoio do disjuntor.AIM: To assess the changes to the superior dental arches, in the transversal direction, and the amount of inclinations in the support teeth of the Hyrax expansion
Energy Technology Data Exchange (ETDEWEB)
Torres, Luiz Carlos; Gamboa, Luiz Antonio Pierantoni [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Lagemar; Gomes, Benedito Souza [PETROBRAS, Rio de Janeiro, RJ (Brazil)
1997-07-01
Seismic multichannel, gravity and magnetometry measurements were carried out in the region of West coast of the Antarctic Peninsula, Bransfield Strait, South Shetland Islands and South Shetland Trench, by Brazilian Antarctic Program during the summers of 1987 and 1988. The present work, using a continue seismic and gravity and gravity data profile crossing the area, intends to present a two-dimensional model of the crust thickness in this region. By this model, the Moho discontinuity would lie at a depth of 14.5 km below the axis of the Bransfield trough. This anomalous behaviour in addition to compressional processes identified in the accretionary prism and trench, was interpreted as an evidence of the continued opening of the Bransfield basin. (author)
Energy Technology Data Exchange (ETDEWEB)
Silva, Renata de Azevedo Moreira da
2008-05-15
The objective of this dissertation is to develop an application from one of the techniques of 'soft' operational research, the Robustness Analysis, to the problem of decision making under uncertainty, as part of the planning of the electricity expansion planning process in Brazil. Initially are shown desirable characteristics of a methodology that will complement the traditional methods used in determining the expansion of the sector. Departing from the Decenal Plan for Power Expansion (2007/2016), an analysis of the different trends that can occur during the planning process is presented, so as to facilitate the visualization of the consequences of uncertainties that may change the schedule of the planned expansion and also help the interaction between actors working in the expansion planning of electricity generation. (author)
Energy Technology Data Exchange (ETDEWEB)
Silva, Renata de Azevedo Moreira da
2008-05-15
The objective of this dissertation is to develop an application from one of the techniques of 'soft' operational research, the Robustness Analysis, to the problem of decision making under uncertainty, as part of the planning of the electricity expansion planning process in Brazil. Initially are shown desirable characteristics of a methodology that will complement the traditional methods used in determining the expansion of the sector. Departing from the Decenal Plan for Power Expansion (2007/2016), an analysis of the different trends that can occur during the planning process is presented, so as to facilitate the visualization of the consequences of uncertainties that may change the schedule of the planned expansion and also help the interaction between actors working in the expansion planning of electricity generation. (author)
Negative thermal expansion materials
International Nuclear Information System (INIS)
Evans, J.S.O.
1997-01-01
The recent discovery of negative thermal expansion over an unprecedented temperature range in ZrW 2 O 8 (which contracts continuously on warming from below 2 K to above 1000 K) has stimulated considerable interest in this unusual phenomenon. Negative and low thermal expansion materials have a number of important potential uses in ceramic, optical and electronic applications. We have now found negative thermal expansion in a large new family of materials with the general formula A 2 (MO 4 ) 3 . Chemical substitution dramatically influences the thermal expansion properties of these materials allowing the production of ceramics with negative, positive or zero coefficients of thermal expansion, with the potential to control other important materials properties such as refractive index and dielectric constant. The mechanism of negative thermal expansion and the phase transitions exhibited by this important new class of low-expansion materials will be discussed. (orig.)
Directory of Open Access Journals (Sweden)
Gustavo Mattos Barreto
2005-12-01
Full Text Available OBJETIVO: na presente pesquisa utilizou-se o aparelho Hyrax tendo como objetivo avaliar as alterações transversais e verticais da maxila. Foram selecionados 20 pacientes de ambos os gêneros, entre 7 e 11 anos de idade, que apresentavam mordida cruzada posterior uni ou bilateral. METODOLOGIA: foram realizadas telerradiografias em norma frontal (PA antes e após a expansão. A fim de evitar que a falta de padronização dessas radiografias pudesse influenciar nos resultados, idealizou-se um método de padronização para tais radiografias. RESULTADOS E CONCLUSÕES: os resultados mostraram que a correção da mordida cruzada posterior com o aparelho Hyrax, que ocorreu em todos os casos, foi em função tanto da abertura da sutura palatina mediana como também da inclinação dos molares. A medida JgE-JgD relacionada com a expansão maxilar aumentou significantemente em todos os casos tratados. Nas avaliações dentárias, as medidas verticais não apresentaram diferenças significantes, ao contrário das medidas transversais (FTE-FTD; FBE-FBD; LO.BTE; LO.BTD; BTE.BTD. A largura da cavidade nasal também aumentou significantemente (CNE-CND. O método de padronização proposto permite, portanto, utilizar as medidas que avaliam a expansão rápida da maxila, através das radiografias póstero-anteriores, com segurança, também no sentido vertical.AIM: in the atresia maxillary cases, the most indicated treatment is rapid maxillary expansion that can be achieved by different therapies. In the present research the Hyrax appliance was used in order to evaluate the transverse and vertical outcomes in maxillary base. METHODS: twenty patients of both gender, from 7 to 11 years old, presenting uni or bilateral posterior crossbite were selected. Posteroanterior radiographs were performed before and after expansion. These radiographs were standardized in order to avoid that problems with lack of standardization influence the results. RESULTS AND CONCLUSION
Energy Technology Data Exchange (ETDEWEB)
Santos Henrique Luz
2008-02-15
This dissertation presents the development of a mathematical model to be used in the hydrothermal generation expansion planning taking into account uncertainties, the guarantee of energy supply and issues related to the social and environmental problems caused by the power sector. Named 'MELP Ambiental', it is a version of MELP, a model developed by Machado Junior (2000). The environmental valuation was based on results of previous studies. The analysis of the environmental costs scenarios showed that the inclusion of a variable linked to externalities implies in changes on the investment schedule. These changes decrease the total cost (economic and environmental) related to long-term power supply expansion. (author)
Energy Technology Data Exchange (ETDEWEB)
Dzenus, M.; Hundhausen, W.; Jansing, W.
1979-10-15
This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of development reviewed. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows.
Energy Technology Data Exchange (ETDEWEB)
NONE
1994-12-31
This document collects papers presented in the 4. Symposium of specialists in electric operation and expansion planning. The main problems affecting this sector in the world are discussed. Several cases studies are presented as well as state of the art and new developing technologies
Energy Technology Data Exchange (ETDEWEB)
NONE
1994-12-31
This symposium about electric operational and expansion planning presents several articles that approaches issues such as, monitoring the power system stability, electrical load modelling, reliability in power systems, optimization in power systems, integrated resources planning in power systems, reactive control through static compensators, power flow analysis, system modelling, etc
Directory of Open Access Journals (Sweden)
De la Fare, Mónica
2015-01-01
Full Text Available Neste artigo apresentamos uma reflexão acerca do papel da Educação de Jovens e Adultos (EJA no contexto atual de expansão da escolaridade obrigatória. Para isso partimos de uma análise introdutória desse contexto em América Latina para posteriormente focalizar em dois países: Argentina e Brasil. Nesse marco buscamos interrogar as características atuais da EJA assim como aspectos da invenção da figura do adulto como aluno e dos processos de juvenilização dessa modalidade educativa. Para tanto evocamos a EJA como analisador, ou seja, aproveitamos o potencial de práticas educacionais possíveis quando se volta a atenção para jovens e adultos e o modo particular em que esse público se dispõe à ação educacional e propomos pensar ações educacionais com esse público sem assimilá-las e reduzi-l as à educação escolar
Energy Technology Data Exchange (ETDEWEB)
Bandeira, Maria Ines V.Q.B.; Arruda, Joao Bosco F. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)
2004-07-01
The search for sustainability and the largest efficiency in the energy supply has implied in the gradual substitution of the electric power source for the use of the Natural Gas in the residential, automotive, services and industrial sectors. This paper reports a study which aims at the construction of a methodology to support the expansion of the Natural Gas distribution network using concepts of Space Syntax Theory. Through the analysis of the geographical location of urban land use activity system it is expected to define priority roadway routes in terms of potential demand for Natural Gas. A case study is on process in Fortaleza city, in the Northeastern Brazil, which is adequate to such an approach given its disperse density pattern and the present low scale of Natural Gas use in the four above mentioned urban sectors. (author)
Convergence of mayer expansions
International Nuclear Information System (INIS)
Brydges, D.C.
1986-01-01
The tree graph bound of Battle and Federbush is extended and used to provide a simple criterion for the convergence of (iterated) Mayer expansions. As an application estimates on the radius of convergence of the Mayer expansion for the two-dimensional Yukawa gas (nonstable interaction) are obtained
Energy Technology Data Exchange (ETDEWEB)
Silva, Conceicao Elaine Cardoso
2010-03-15
Various countries have studied the possibility of adding ethanol to gasoline or using pure fuel ethanol as an alternative to petroleum derivatives. Brazil occupies a leading position in this scenario because with its National Alcohol Program (Programa Nacional do Alcool - PROALCOOL), created in 1975, it became the pioneer in setting up a biofuels program. Since then it has accumulated experience and gained mastery of the technology to produce ethanol from sugarcane. Hence there is a strong expectation that the country can become the world's main ethanol exporter. This thesis examines the main environmental impacts associated with the ethanol productive chain, which are relevant conditioning factors for the expansion of this industry in Brazil. The study describes the evolution of PROALCOOL and the overview of current structure of the brazilian sugar-alcohol sector, identifies technologies and environmental management policies, and presents the perspective of expansion of ethanol production. Thus, the study undertakes an extensive review of the literature and examines to what extent the creation and implementation of public and private environmental management policies (legal restrictions and market instruments, respectively) interfere with the expansion of these productive activities. (author)
Energy Technology Data Exchange (ETDEWEB)
Alves, Jefferson Douglas Soares, E-mail: radiologia@unifeob.edu.b [Fundacao de Ensino Octavio Bastos (UNIFEOB), Sao Joao da Boa Vista, SP (Brazil). Fac. de Medicina e Veterinaria; Sterman, Franklin de Almeida [Universidade de Sao Paulo (USP), Butanta, SP (Brazil). Fac. de Medicina Veterinaria e Zootecnia. Dept. de Cirurgia
2010-06-15
This study allowed the standardization of the bone mineral density (BMD) of the distal extremity of the radio of 36 dogs adults in Rottweiler breed by radiographic optic densitometry. The limbs of the animals were radiographed with scale of aluminum that served as a reference. The radiographs images were digitalized and analyzed by a computer program for comparison of gray tones between the standard image and the image of the reference scale radiographed with the bone. Afterwards the values of density were expressed in millimeters of aluminum. Also studied the correlations between BMD and the sex, weight and external measures as the length of spine, height of the animal and circumference the distal extremity of the limb in study. The mean values and standard deviations of the bone mineral density of the distal extremity of the radio were: for the metaphyseal region the average of BMD of 7,88+-0,89 mmAl, the diaphyseal region 1 the average of BMD of 8,58+-0,80 mmAl and for diaphyseal region 2 of BMD of 9,00+-0,74 mmAl. (author)
Directory of Open Access Journals (Sweden)
Claudine Haroche
2005-12-01
Full Text Available Refletindo sobre os fins da universidade, este ensaio se questio-na quanto à possibilidade mesma do ensino e, além disso, à possibilidade de conhecimento e de sentido nas sociedades contemporâneas, nas quais as condições de apropriação e de transmissão dos saberes estão profundamente transtornadas: uma incerteza às vezes radical quanto a si mesmo e quanto ao outro abre caminho para uma insegurança psíquica profunda. Os fluxos sensoriais contínuos provocam uma divisão inédita do trabalho dos sentidos, acentuando o papel da visão em detrimento dos demais; induzem a uma redistribuição das relações entre sensação, percepção, reflexão; e fortalecem a contingência, a instabilidade, a incerteza que se encontram no âmago da crise da cultura e da educação. O pensamento se encolhe, traduzido numa especialização, uma compartimentalização dos saberes. Que tipo de personalidade e de consciência, que forma de sensibilidade são estimuladas por essa educação? O que designa hoje em dia a palavra consciência? Poderemos ainda falar de atividade crítica? O pensamento individual, original, parece ter declinado diante da corporação, do grupo, do coletivo, legitimado pelo número, a quantidade, as exigências de produtividade e a avaliação por gestores, e tende, a partir daí, a se tornar cada vez mais homogêneo e conformista. Contudo, o ensaio busca mostrar que essas características, não sendo novas, foram apenas aceleradas e intensificadas na contemporaneidade, paradoxalmente, não nos privando de toda esperança quanto aos fins da universidade e às possibilidades do pensamento crítico.Reflecting on the purposes of university, this essay enquires as to the very possibility of teaching, and more than that, to the possibility of knowledge and meaning in contemporary societies, in which the conditions for the incorporation and transmission of knowledges are in disarray: an uncertainty, sometimes radical, about oneself
Controlled Thermal Expansion Alloys
National Aeronautics and Space Administration — There has always been a need for controlled thermal expansion alloys suitable for mounting optics and detectors in spacecraft applications. These alloys help...
Directory of Open Access Journals (Sweden)
R. R. Menezes
2008-06-01
Full Text Available Argilas organofílicas apresentam uma vasta gama de aplicações industriais, desde a indústria do petróleo à farmacêutica e de cosméticos, passando pela retenção de resíduos e produção de nanocompósitos argila-polímeros. Este trabalho tem por objetivo analisar a influência do teor de sais quaternários de amônio na organofilização de argilas bentoníticas. As argilas utilizadas foram caracterizadas através da determinação de sua composição química, distribuição do tamanho de partículas e capacidade de troca de cátions. As argilas organofílicas foram preparadas utilizando dois sais quaternários de amônio: cloreto de alquil benzil amônio (Dodigen e brometo de cetil trimetil amônio (Cetremide. As argilas organofilizadas foram caracterizadas por difração de raios X e espectroscopia de infravermelho. Os resultados mostraram que o espaçamento basal aumenta com o aumento na quantidade de sal utilizado para a organofilização e que o comportamento desse aumento depende do sal e da argila utilizados, sendo, linear quando da utilização do sal Dodigen e dependente do tipo da argila quando da utilização do sal Cetremide.Organoclays are used in a wide range of industrial applications, from the petroleum to the pharmaceutical and cosmetic industry, reaching the waste adsorption applications and production of polymer-clay nanocomposites. This work has as aim study the influence of the amount of quaternary ammonium salts in the organophilization of bentonite clays. The used clays were characterized by chemical composition, particle size distribution and cation exchange capacity determination. The organoclays were prepared using two quaternary ammonium salts: alkyl dimethyl benzyl ammonium chloride (Dodigen and cetyl trimethyl ammonium bromide (Cetremide. The organoclays were characterized by X-ray diffraction and IR spectroscopy. The results showed that the interlayer spacing increase with the rise in the amount of salt
Fuel Thermal Expansion (FTHEXP)
International Nuclear Information System (INIS)
Reymann, G.A.
1978-07-01
A model is presented which deals with dimensional changes in LWR fuel pellets caused by changes in temperature. It is capable of dealing with any combination of UO 2 and PuO 2 in solid, liquid or mixed phase states, and includes expansion due to the solid-liquid phase change. The function FTHEXP models fuel thermal expansion as a function of temperature, fraction of PuO 2 , and the fraction of fuel which is molten
International Nuclear Information System (INIS)
Lind, P.
1993-02-01
The completeness properties of the discrete set of bound state, virtual states and resonances characterizing the system of a single nonrelativistic particle moving in a central cutoff potential is investigated. From a completeness relation in terms of these discrete states and complex scattering states one can derive several Resonant State Expansions (RSE). It is interesting to obtain purely discrete expansion which, if valid, would significantly simplify the treatment of the continuum. Such expansions can be derived using Mittag-Leffler (ML) theory for a cutoff potential and it would be nice to see if one can obtain the same expansions starting from an eigenfunction theory that is not restricted to a finite sphere. The RSE of Greens functions is especially important, e.g. in the continuum RPA (CRPA) method of treating giant resonances in nuclear physics. The convergence of RSE is studied in simple cases using square well wavefunctions in order to achieve high numerical accuracy. Several expansions can be derived from each other by using the theory of analytic functions and one can the see how to obtain a natural discretization of the continuum. Since the resonance wavefunctions are oscillating with an exponentially increasing amplitude, and therefore have to be interpreted through some regularization procedure, every statement made about quantities involving such states is checked by numerical calculations.Realistic nuclear wavefunctions, generated by a Wood-Saxon potential, are used to test also the usefulness of RSE in a realistic nuclear calculation. There are some fundamental differences between different symmetries of the integral contour that defines the continuum in RSE. One kind of symmetry is necessary to have an expansion of the unity operator that is idempotent. Another symmetry must be used if we want purely discrete expansions. These are found to be of the same form as given by ML. (29 refs.)
International Nuclear Information System (INIS)
Dzenus, M.; Hundhausen, W.; Jansing, W.
1980-01-01
This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of the development reviewed. Large Na (sodium)-heat transfer systems require a lot of valuable space if the component lay-out does not include compensation devices. So, in order to condense the spatial requirement as much as possible, expansion joints must be integrated into the pipe system. There are two basic types to suit the purpose: axial expansion joints and angular expansion joints. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows. Expansion joints must be designed and mounted in a manner to completely withstand seismic forces. The design must exclude any damage to the bellows during intermittent operations, that is, when sodium is drained the bellows' folds must be completely empty; otherwise residual solidified sodium could destroy the bellows when restarting. The expansion joints must be engineered on the basis of the following design data for the secondary system of the SNR project: working pressure: 16 bar; failure mode pressure: 5 events; failure mode: 5 sec., 28.5 bar, 520 deg. C; working temperature: 520 deg. C; temperature transients: 30 deg. C/sec.; service life: 200,000 h; number of load cycles: 10 4 ; material: 1.4948 or 1.4919; layer thickness of folds: 0.5 mm; angular deflection (DN 800): +3 deg. C or; axial expansion absorption (DN 600): ±80 mm; calculation: ASME class. The bellows' development work is not handled within this scope. The bellows are supplied by leading manufacturers, and warrant highest quality. Multiple bellows were selected on the basis of maximum elasticity - a property
Accelerating the loop expansion
International Nuclear Information System (INIS)
Ingermanson, R.
1986-01-01
This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi 4 theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs
Tate, Stephen James
2013-10-01
In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.
Conformal expansions and renormalons
Energy Technology Data Exchange (ETDEWEB)
Rathsman, J.
2000-02-07
The coefficients in perturbative expansions in gauge theories are factorially increasing, predominantly due to renormalons. This type of factorial increase is not expected in conformal theories. In QCD conformal relations between observables can be defined in the presence of a perturbative infrared fixed-point. Using the Banks-Zaks expansion the authors study the effect of the large-order behavior of the perturbative series on the conformal coefficients. The authors find that in general these coefficients become factorially increasing. However, when the factorial behavior genuinely originates in a renormalon integral, as implied by a postulated skeleton expansion, it does not affect the conformal coefficients. As a consequence, the conformal coefficients will indeed be free of renormalon divergence, in accordance with previous observations concerning the smallness of these coefficients for specific observables. The authors further show that the correspondence of the BLM method with the skeleton expansion implies a unique scale-setting procedure. The BLM coefficients can be interpreted as the conformal coefficients in the series relating the fixed-point value of the observable with that of the skeleton effective charge. Through the skeleton expansion the relevance of renormalon-free conformal coefficients extends to real-world QCD.
International Nuclear Information System (INIS)
Taylor, D.
1984-01-01
This paper gives regression data for a modified second order polynomial fitted to the expansion data of, and percentage expansions for dioxides with (a) the fluorite and antifluorite structure: AmO 2 , BkO 2 , CeO 2 , CmO 2 , HfO 2 , Li 2 O, NpO 2 , PrO 2 , PuO 2 , ThO 2 , UO 2 , ZrO 2 , and (b) the rutile structure: CrO 2 , GeO 2 , IrO 2 , MnO 2 , NbO 2 , PbO 2 , SiO 2 , SnO 2 , TeO 2 , TiO 2 and VO 2 . Reduced expansion curves for the dioxides showed only partial grouping into iso-electronic series for the fluorite structures and showed that the 'law of corresponding states' did not apply to the rutile structures. (author)
Energy Technology Data Exchange (ETDEWEB)
Vasconcelos, Fabia; Aguirre, Eder Aguirre, E-mail: fabiavasco@hotmail.com, E-mail: ederuni01@gmail.com [Fundacao do Cancer, Rio de Janeiro, RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)
2016-07-01
This work studies the calculations of uncertainties and the level of confidence that involves the process for obtaining the dose absorbed in water using the method of Fricke dosimetry, developed at Laboratorio de Ciencias Radiologicas (LCR). Measurements of absorbance of samples Fricke, irradiated and non-irradiated is going to use in order to calculate the respective sensitivity coefficients, along with the expressions of the calculation of Fricke dose and the absorbed dose in water. Those expressions are used for calculating the others sensitivity coefficients from the input variable. It is going to use the combined uncertainty and the expanded uncertainty, with a level of confidence of 95.45%, in order to report the uncertainties of the measurement. (author)
Energy Technology Data Exchange (ETDEWEB)
Frazao, Selma Violato
2008-07-01
Human hair analysis studies have been subject of continuous interest due to the fact that they can be used as an important tool to evaluate trace element levels in the human body. These determinations have been carried out to use hair for environmental and occupational monitoring, to identify intoxication or poisoning by toxic metals, to assess nutritional status, to diagnose and to prevent diseases and in forensic sciences. Although hair analysis presents several advantages over other human tissue or fluid analyses, such as organ tissue, blood, urine and saliva, there are some controversies regarding the use of hair analysis data. These controversies arise from the fact that it is difficult to establish reliable reference values for trace elements in hair. The purpose of this study was to evaluate the factors that affect element concentrations in hair samples from a population considered healthy and residing in the Sao Paulo metropolitan area. The collected human head hair was cut in small pieces, washed, dried and analyzed by neutron activation analysis (NAA). Aliquots of hair samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor for 16 h under a thermal neutron flux of about 5x10{sup 12} n cm{sup -2} s{sup -1} for As, Br, Ca, Co, Cr, Cs, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn determinations. The induced gamma activities of the standards and samples were measured using a gamma ray spectrometer coupled to an hiperpure Ge detector. For quality control of the results, IAEA- 85 Human Hair and INCT-TL-1 Tea Leaves certified reference materials (CRMs) were analyzed. Results obtained in these CRMs presented for most of elements, good agreement with the values of the certificates (relative errors less than 10%) and good precision (variation coefficients less than 13.6%). Results of replicate hair sample analysis showed good reproducibility indicating homogeneity of the prepared sample. Results obtained in the analyses of dyed and non-dyed hair showed that element adsorption or desorption occurs due to the dye. Analysis of hair samples collected from different regions of the head presented significant differences for the elements Fe, Sc, Se and Cr, indicating the importance of defining head regions for hair sample collection. Results of hair analysis from individuals residing in Sao Paulo metropolitan area showed individual differences for age, gender and natural hair color. Results obtained in this population also showed, that the mean element concentrations found are within the literature values. (author)
Energy Technology Data Exchange (ETDEWEB)
Miyake, Eloisa Tamie
1994-12-31
Concrete is widely used in final radioactive waste repository construction and must have well defined characteristics. The permeability is a property that allows to evaluate the durability of concrete which guarantee the protection of the surroundings. Durable concretes have low permeability which reduces liquids intrusion into the repository and decreases the probability of leaching of soluble radioactive compounds and gases escapes to the human habitat. This work includes: the construction of a camera to measure the permeability coefficient of hydraulic products, by using gaseous nitrogen as a permeation fluid; determination of characteristics of material used in concrete compositions; and tests in concretes with different compositions in which ordinary Portland cement and blast-furnace cement were used. (author). 61 refs., 33 figs., 16 tabs.
Energy Technology Data Exchange (ETDEWEB)
Beck, J.C.P.C.; Cauduro, Carlos R.; Schaeffer, Lirio [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)
1990-12-31
This work performs a evaluation of the characteristics hot leaking of a 8620 stainless steel, deformed at 870 deg C. The tools associated with the measurements was described and a comparison between the theoretical values and the values experimentally obtained from the performed tests. 5 figs., 3 refs.
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Elcio C.; Ferreira, Ana Luisa A.S. [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil); Orlando, Alcir F.; Val, Luiz G. do [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)
2004-07-01
The INMETRO/ANP 1 regulation (2000), presents rules to be followed for measuring and calibrating cylindrical vertical oil storage tanks in Brazil, according to ISO 7507-1 (1993) standard. A methodology for estimating the uncertainty (95,45 % confidence level) of the volume in a custody transfer process was developed, based on ISO GUM (1998) standard. The strapping method was selected for this study, because it has been used as a standard procedure by INMETRO. In this study, the same uncertainty values, as suggested by the standard, were used to estimate the uncertainty of the liquid volume in the tank. This study showed that the uncertainty of the transferred liquid volume from the tank varies from 0,2% to 0,4%, being smaller for larger volumes, which is thus the recommended application. The uncertainty of the ring height measurement is the largest contribution to the volume measurement uncertainty, and, thus, must be accurately measured. The tank internal diameter uncertainty is a small contribution to it. This paper calculates the uncertainty of liquid volume transferred from the tank by three methods, namely, this paper's, ISO 7507- 1's and INMETRO's, and shows that the most important contribution to the measurement uncertainty is the density measurement uncertainty, which must be accurately measured, at least, to within {+-} 0,0005, if the volume uncertainty is to remain in the 0,5 % to 1 % range. (author)
Energy Technology Data Exchange (ETDEWEB)
Loureiro, Bruno Venturini; Siqueira, Renato do Nascimento [Faculdade do Centro Leste (UCL), Serra, ES (Brazil). Lab. de Fenomenos de Transporte], e-mail: brunovl@ucl.br, e-mail: renatons@ucl.br
2006-07-01
Drilling of horizontal wells for oil and gas production needs an efficient cleaning process due to settling of particles removed during the drilling process, which settles on the inferior part of the annular space between the drilling column and the walls of the well. The erosion of the bed is an important physical phenomenon to petroleum and gas industry since it can improve the opening of the wells. This work aims to estimate the threshold shear stress necessary to start the erosion process in a sediment bed. An experimental apparatus was built from simplifications of the problem in order to measure the flow rate and identify the beginning of the process. The experiment consists of a rectangular duct with aspect ratio ({lambda} = h/b) of 1/3 and non dimensional length (L{sup *} = L/h) of 75. The sediment bed to be eroded was placed at 60< x{sup *}<66. Using the flow rate and the boundary conditions, a discretization of the problem was carried out to permit a computational solution using the finite volume method and hence, determine the shear stress. This work used particles with up to 3.0 mm and modeled the flow considering a bed with equivalent roughness. (author)
Energy Technology Data Exchange (ETDEWEB)
Freire, Fernando S.; Silva, Fernando C.; Martinez, Aquilino S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: ffreire@con.ufrj.br; fernando@con.ufrj.br; aquilino@.con.ufrj.br
2005-07-01
Frequently it is necessary to compute the change in core multiplication caused by a change in the core temperature or composition. Even when this perturbation is localized, such as a control rod inserted into the core, one does not have to repeat the original criticality calculation, but instead we can use the well-known pseudo-harmonics perturbation method to express the corresponding change in the multiplication factor in terms of the neutron flux expanded in the basis vectors characterizing the unperturbed core. Therefore we may compute the control rod worth to find the most reactivity control rod to calculate the fast shutdown margin. In this thesis we propose a simple and precise method to identify the most reactivity control rod. (author)
Energy Technology Data Exchange (ETDEWEB)
Prataviera, Rogerio; Bretas, Rosario E.S.; Lucas, Alessandra de A., E-mail: lucas@ufscar.br [Universidade Federal de Sao Carlos, (UFSCar), Sao Carlos, SP (Brazil); Poullet, Eric; Averous, Luc [Universidade de Strasbourg, Strasbourg (France)
2015-07-01
In this work, casting films were obtained from TPU reinforced with cellulose nanocrystals. The structural nano periodicity of these system was evaluated by Small Angle X-Ray Scattering, SAXS. The results indicated that the used TPU has a atypical phase separated morphology of rigid and soft segments, being observed 3 different distances them, probably due to the large polyol polyester molecule derived from colza oil used in the TPU synthesis. (author)
Energy Technology Data Exchange (ETDEWEB)
Siqueira, Denilson Soares de; Pereira, Alberto dos Santos; Aquino Neto, Francisco Radler de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: ladetec@iq.gov.br; Cabral, Jose Augusto; Ferreira, Carlos Alberto Cid [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil); Simoneit, Bernd R.T. [Oregon State Univ., Corvallis, OR (United States). College of Oceanic and Atmospheric Sciences. Petroleum and Environmental Geochemistry Group; Elias, Vladimir O. [Analytical Solution, Rio de Janeiro, RJ (Brazil)
2003-10-01
The fractions of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuacu (Theobroma grandiflorum - Sterculiaceae), marupa (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data ({sup 1}H and {sup 13}C NMR, IR). (author)
Energy Technology Data Exchange (ETDEWEB)
Carvalho, Marcos Rodrigues de
1995-07-01
This work presents a methodology developed to determinate the efficiency of air monitors used to measure the concentration of beta emitters noble gases in nuclear power stations. Efficiency values, obtained by means of theoretical computation are compared with experimental values. The experimental part of the work was performed using three different point beta source, to simulate small amounts of gas uniformly distributed in small volume. The comparison shows that theoretical an experimental values agree within 4,2 % for {sup 90}Sr + {sup 90}Y, {sup 204}Tl and {sup 45}Ca beta sources. (author)
Energy Technology Data Exchange (ETDEWEB)
Bittencourt, Marcelo de Siqueira Queiroz; Fonseca, Manoel Antonio da Costa [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Oliveira, Carlos Henrique Francisco de [PETROBRAS S.A., Rio de de Janeiro, RJ (Brazil)
2008-07-01
To preserve the environment and avoid financial losses resulting from leaks in the transport of natural oil and gas the industry is particularly concerned to ensure the structural integrity of their pipelines. Grounded pipes may be exposed to damages due to unstable soil movement, and in extreme cases, to failure. Then, techniques to assess stress in pipelines are of central importance. The ultrasonic birefringence technique is an efficient method to measure residual stress. It is based on the changing velocity of the shear wave when it crosses a material under stress; this phenomenon is known as acoustoelasticity. The knowledge of the parameter called acoustoelastic constant is necessary to measure stress using this technique. By the mechanical conformation in the manufacture of welded tubes, from rolled plates, different anisotropy degrees are showed around the cross section of these tubes. In this paper it was studied the acoustoelastic constant for the API-5L-X70 steel pipes, with different thicknesses, diameters and manufacturing processes so as to be able to use this technique to stress measurement in pipelines. (author)
Energy Technology Data Exchange (ETDEWEB)
Teixeira, Antonio C.F.; Silva, Antonio J.R. da [Universidade Federal, Rio de Janeiro (Brazil). Nucleo de Pesquisas de Produtos Naturais
1994-12-31
This work describes the process of analysis of a mixture of polar compounds obtained from the extract of Phyllanthus tennellus, a plant known in Brazil as `quebra-pedra`, which is extensively used in Brazilian popular medicine. The methodology, which includes the use of chromatography and NMR, is described. The proposed composition of the mixture is presented. A discussion is presented concerning one component which could not be identified
Energy Technology Data Exchange (ETDEWEB)
Scheibel, Viviane
2006-07-01
The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of {sup 228}Th, {sup 228}Ra, {sup 226}Ra, {sup 40}K, {sup 7}Be and {sup 137}Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of {sup 60}Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with {chi}{sup 2} tests, assuring the fittings quality. The highest concentration levels of {sup 228}Th and {sup 40}K were 3.5 {+-} 0.4 and 1469 {+-} 17 Bq.kg{sup -1} for soy flour, respectively, with 95% of confidence level. The lower limit of detection for {sup 137}Cs ranged from 0.04 to 0.4 Bq.kg{sup -1}. The highest committed effective dose was 0.36 {mu}Sv.y{sup -1} for {sup 228}Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 {mu}Sv.y{sup -1} and much lower than the ICRP (1991) limits of 1 mSv.y{sup -1}, for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and {sup 7}Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Elcio Cruz de [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)
2008-07-01
In order to assess the anhydrous alcohol evaporated amount in vertical cylindrical tanks was developed a calculation methodology based on the rate of mass transfer of the product, the Reynolds number and the mass transfer coefficient. An Excel spreadsheet was prepared with data entry of the tank and physical and chemical properties of the product (temperature and density). For a temperature of 50 deg C, the volume evaporated reaches values of 0.8% by day. (author)
Energy Technology Data Exchange (ETDEWEB)
Rocha, Rodrigo Luis da
2007-07-01
In earliest works devoted to proton computed tomography it was shown that the advantage of pCT image reconstruction appears when the energy is close to the Bragg peak region, since the proton passes the object. This effect provided by the Bragg peak makes the computerized tomography with protons possible. However, when decreasing the initial proton energy, with the increase of the irradiation dose, there are two effects that work simultaneously in opposite ways. First, the energy loss of a proton in an object becomes bigger at small initial energy. At the same time decreasing of the proton energy results in the increase of the energy straggling, requiring a larger number of protons. In this work the radiation dose dependence on the proton initial energy was studied using analytical formulas and computer simulations. The investigation determined that the radiation dose practically does not depend on the initial energy, except in the energy region very close to the minimum energy necessary to pass the object. (author)
Energy Technology Data Exchange (ETDEWEB)
Armelin, Maria Jose Aguirre
1978-07-01
This work consists in the development of an analytical method using activation by thermal neutrons for the determination of some minor elements and traces present in cassiterite (tin ore). This method was then applied to determine these elements in samples of cassiterite from different regions of Brazil. An analysis was made of the mineralogy characteristic of cassiterite as well as of the minerals most commonly associated with it. Four main types of interference were found to occur in the analysis by activation of trace elements in samples of cassiterite. The method involves the analysis without chemical separation for the determination of some elements and the analysis with chemical separation for the determination of other elements. The steps involved in both types of analysis are described. In the analysis with chemical separation the matrix element (tin) is separated by distillation in an H{sub 2}SO{sub 4}-HBr medium, after fusion of the ore with Na{sub 2}O{sub 2}. Arsine and antimony are determined in the distilled, whereas some lanthanide elements and uranium are determined in the distillation residue by separating them as a group by precipitation with lanthanum fluoride. A discussion on the precision, accuracy and sensibility of the method is also included. (author)
Energy Technology Data Exchange (ETDEWEB)
Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)
2014-07-01
Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)
Energy Technology Data Exchange (ETDEWEB)
Silveira, Patricia B.; Valentim, Eliane; Lima, Ricardo A. [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil)]. E-mail: pbrandao@cnen.gov.br; Medeiros, Carmem [Pernambuco Univ., Recife, PE (Brazil). Dept. de Oceanografia; Oliveira, Joselene [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)
2005-07-01
Groundwater plays an important role in the transport of nutrients and pollutants to the coastal marine environment s and other surfaces water. Concentrations of {sup 223}Ra, {sup 224}Ra and {sup 226}Ra in marine water of the Itamaraca coastal region, PE, were measured during the winter of 2004, aiming to investigate the presence of radionuclides as a tracer of submarine groundwater discharges (SGD) in the environment studied. Measurements of temperature, salinity and nutrients were also carried out. (author)
Giovannini, Massimo
2015-01-01
Cosmological singularities are often discussed by means of a gradient expansion that can also describe, during a quasi-de Sitter phase, the progressive suppression of curvature inhomogeneities. While the inflationary event horizon is being formed the two mentioned regimes coexist and a uniform expansion can be conceived and applied to the evolution of spatial gradients across the protoinflationary boundary. It is argued that conventional arguments addressing the preinflationary initial conditions are necessary but generally not sufficient to guarantee a homogeneous onset of the conventional inflationary stage.
Directory of Open Access Journals (Sweden)
R. A. Andrade
2011-09-01
Full Text Available O fenômeno da expansão por umidade (EPU resulta da ação da água e seus vapores causando a expansão dos materiais cerâmicos, podendo provocar danos no material e prejudicar sua vida útil. Na literatura existe muita ênfase nos problemas gerados pela EPU e nas tensões resultantes dessa expansão, porém até o presente não há dados relativos ao comportamento mecânico dos materiais cerâmicos após ação da EPU. Trabalhos recentemente desenvolvidos na UFCG tratam especificamente desse problema em blocos cerâmicos de vedação. Inicialmente verificou-se que, no caso de massas cerâmicas para uso em cerâmica vermelha queimadas em diversas temperaturas na faixa de 700 a 1100 ºC, e com a EPU induzida por imersão, fervura e autoclavagem, a EPU tem correlação com o comportamento mecânico dos corpos queimados, observando-se redução no módulo de ruptura à flexão à medida que a EPU aumenta. Trabalhos desenvolvidos com massas para uso em cerâmica vermelha aditivadas com carbonato de cálcio e carbonato de magnésio e queimadas entre 850 e 1000 ºC, evidenciaram o efeito benéfico do carbonato de cálcio na redução da EPU e aumento da resistência à flexão, sendo observada correlação entre EPU e módulo de ruptura à flexão, mas, no entanto, não foi observada correlação entre a EPU e o módulo quando da utilização do carbonato de magnésio. Pesquisas efetuadas com massas para cerâmica vermelha aditivadas com quartzo fino, visando o desenvolvimento de fases vítreas, não mostraram correlações bem definidas entre EPU e módulo de ruptura, sendo observado que adições de 10 e 20% de quartzo melhoram a resistência mecânica dos corpos cerâmicos após autoclavagem e que a adição de 30% de quartzo reduz seu módulo de ruptura.Moisture expansion (ME phenomenon results from the action of water and water vapors causing the expansion of ceramic materials, which may damage the material damage and jeopardize its useful life
Low-temperature thermal expansion
International Nuclear Information System (INIS)
Collings, E.W.
1986-01-01
This chapter discusses the thermal expansion of insulators and metals. Harmonicity and anharmonicity in thermal expansion are examined. The electronic, magnetic, an other contributions to low temperature thermal expansion are analyzed. The thermodynamics of the Debye isotropic continuum, the lattice-dynamical approach, and the thermal expansion of metals are discussed. Relative linear expansion at low temperatures is reviewed and further calculations of the electronic thermal expansion coefficient are given. Thermal expansions are given for Cu, Al and Ti. Phenomenologic thermodynamic relationships are also discussed
Bolthausen, Erwin; Van Der Hofstad, Remco; Kozma, Gady
2018-01-01
We show Green's function asymptotic upper bound for the two-point function of weakly self-Avoiding walk in d >4, revisiting a classic problem. Our proof relies on Banach algebras to analyse the lace-expansion fixed point equation and is simpler than previous approaches in that it avoids Fourier
OPEC future capacity expansions
International Nuclear Information System (INIS)
Sandrea, I.
2005-01-01
This conference presentation examined OPEC future capacity expansions including highlights from 2000-2004 from the supply perspective and actions by OPEC; OPEC spare capacity in 2005/2006; medium-term capacity expansion and investments; long-term scenarios, challenges and opportunities; and upstream policies in member countries. Highlights from the supply perspective included worst than expected non-OPEC supply response; non-OPEC supply affected by a number of accidents and strikes; geopolitical tensions; and higher than expected demand for OPEC crude. OPEC's actions included closer relationship with other producers and consumers; capacity expansions in 2004 and 2005/2006; and OPEC kept the market well supplied with crude in 2004. The presentation also provided data using graphical charts on OPEC net capacity additions until 2005/2006; OPEC production versus spare capacity from 2003 to 2005; OPEC production and capacity to 2010; and change in required OPEC production from 2005-2020. Medium term expansion to 2010 includes over 60 projects. Medium-term risks such as project execution, financing, costs, demand, reserves, depletion, integration of Iraq, and geopolitical tensions were also discussed. The presentation concluded that in the long term, large uncertainties remain; the peak of world supply is not imminent; and continued and enhanced cooperation is essential to market stability. tabs., figs
Physics suggests that the interplay of momentum, continuity, and geometry in outward radial flow must produce density and concomitant pressure reductions. In other words, this flow is intrinsically auto-expansive. It has been proposed that this process is the key to understanding...
Directory of Open Access Journals (Sweden)
Nádia Cristina Jussani
2007-04-01
Full Text Available Estudo de natureza qualitativa que estudou a rede de suporte de famílias durante a gravidez. Os dados foram coletados em maio de 2003, através de entrevista semi-estruturada, junto à 16 mulheres. Os resultados revelaram que apenas uma mulher não recorreu à rede de apoio e que diferentes pessoas são procuradas conforme o tipo de problema vivenciado: dificuldades econômicas ou de aceitação da gravidez, necessidade de apoio emocional ou de esclarecimentos, ajuda para os afazeres domésticos, entre outros. Conclui-se que a rede social favorece o bom desenvolvimento da gestação e que para uma assistência mais eficaz é indicado que os profissionais de saúde atentem para o fato de a mulher ter uma rede de suporte com que possa contar durante a gravidez.Estudio descriptivo, de naturaleza cualitativa desarrollado con el objetivo de estudiar la red de soporte de familias durante el embarazo. Los datos han sido colectados en mayo de 2003, a través de entrevista semiestructurada, junto a 16 mujeres. Los resultados han revelado que apenas una mujer no ha recorrido a la red de apoyo durante el embarazo y que diferentes personas son procuradas de acuerdo con el tipo de problemas vivenciado: dificultades económicas o de aceptación del embarazo, necesidad de apoyo emocional o de esclarecimiento, ayuda para los quehaceres domésticos, entre otros. Se concluí que la red social ayuda el buen desarrollo de la gestación y que los profesionales de salud necesitan saber si hay una red de soporte que pueda contar durante el embarazo.This is a research of qualitative nature developed with the objective of studying the support net of families during pregnancy. Data were collected through semi-structured interview, from 16 women in May 2003. The results showed that just one woman did not appeal to the support net during pregnancy and that different people are sought according to the type of problem experienced at the time: economical difficulties or of
International Nuclear Information System (INIS)
Lewis, C.
1997-01-01
The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date
Financing electricity expansion
International Nuclear Information System (INIS)
Hyman, L.S.
1994-01-01
Expansion of electricity supply is associated with economic development. The installation and enlargement of power systems in developing countries entails a huge financial burden, however. Energy consumers in such countries must pay not only for supplies but for the cost of raising the capital for expansion on the international markets. Estimates are presented for the capital expenditure for electricity supply over the period 1990 to 2020 for the major world regions, using approximations for the cost of plant and capital and for the returns earned. These data lead to the conclusion that the five regions with the lowest per capita incomes are those which will need the major part of the capital expenditure and the highest percentage of external finance. (6 tables) (UK)
Bigravity from gradient expansion
International Nuclear Information System (INIS)
Yamashita, Yasuho; Tanaka, Takahiro
2016-01-01
We discuss how the ghost-free bigravity coupled with a single scalar field can be derived from a braneworld setup. We consider DGP two-brane model without radion stabilization. The bulk configuration is solved for given boundary metrics, and it is substituted back into the action to obtain the effective four-dimensional action. In order to obtain the ghost-free bigravity, we consider the gradient expansion in which the brane separation is supposed to be sufficiently small so that two boundary metrics are almost identical. The obtained effective theory is shown to be ghost free as expected, however, the interaction between two gravitons takes the Fierz-Pauli form at the leading order of the gradient expansion, even though we do not use the approximation of linear perturbation. We also find that the radion remains as a scalar field in the four-dimensional effective theory, but its coupling to the metrics is non-trivial.
International Nuclear Information System (INIS)
Suess, S.T.
1987-01-01
Magnetic clouds are a carefully defined subclass of all interplanetary signatures of coronal mass ejections whose geometry is thought to be that of a cylinder embedded in a plane. It has been found that the total magnetic pressure inside the clouds is higher than the ion pressure outside, and that the clouds are expanding at 1 AU at about half the local Alfven speed. The geometry of the clouds is such that even though the magnetic pressure inside is larger than the total pressure outside, expansion will not occur because the pressure is balanced by magnetic tension - the pinch effect. The evidence for expansion of clouds at 1 AU is nevertheless quite strong so another reason for its existence must be found. It is demonstrated that the observations can be reproduced by taking into account the effects of geometrical distortion of the low plasma beta clouds as they move away from the Sun
IKEA's International Expansion
Harapiak, Clayton
2013-01-01
This case concerns a global retailing firm that is dealing with strategic management and marketing issues. Applying a scenario of international expansion, this case provides a thorough analysis of the current business environment for IKEA. Utilizing a variety of methods (e.g. SWOT, PESTLE, McKinsey Matrix) the overall objective is to provide students with the opportunity to apply their research skills and knowledge regarding a highly competitive industry to develop strategic marketing strateg...
International Nuclear Information System (INIS)
Matsuki, Takayuki
1976-01-01
Symmetric eikonal expansion for the scattering amplitude is formulated for nonrelativistic and relativistic potential scatterings and also for the quantum field theory. The first approximations coincide with those of Levy and Sucher. The obtained scattering amplitudes are time reversal invariant for all cases and are crossing symmetric for the quantum field theory in each order of approximation. The improved eikonal phase introduced by Levy and Sucher is also derived from the different approximation scheme from the above. (auth.)
Series expansions without diagrams
International Nuclear Information System (INIS)
Bhanot, G.; Creutz, M.; Horvath, I.; Lacki, J.; Weckel, J.
1994-01-01
We discuss the use of recursive enumeration schemes to obtain low- and high-temperature series expansions for discrete statistical systems. Using linear combinations of generalized helical lattices, the method is competitive with diagrammatic approaches and is easily generalizable. We illustrate the approach using Ising and Potts models. We present low-temperature series results in up to five dimensions and high-temperature series in three dimensions. The method is general and can be applied to any discrete model
Directory of Open Access Journals (Sweden)
Rogério Christofoletti
2008-12-01
Full Text Available Three ideas would suffice for the reading of “Cultura da Convergência” (Culture of Convergence by Henry Jenkins to be of interest to journalists and researchers in the area: media convergence as a cultural process; the strengthening of an emotional economy which guides consumers of symbolic goods and media creators; the expansion of trans-media narrative forms.
Directory of Open Access Journals (Sweden)
Rogério Christofoletti
2011-02-01
Full Text Available Three ideas would suffice for the reading of “Cultura da Convergência” (Culture of Convergence by Henry Jenkins to be of interest to journalists and researchers in the area: media convergence as a cultural process; the strengthening of an emotional economy which guides consumers of symbolic goods and media creators; the expansion of trans-media narrative forms.
Expansions for Coulomb wave functions
Boersma, J.
1969-01-01
In this paper we derive a number of expansions for Whittaker functions, regular and irregular Coulomb wave functions. The main result consists of a new expansion for the irregular Coulomb wave functions of orders zero and one in terms of regular Coulomb wave functions. The latter expansions are
Radial expansion and multifragmentation
International Nuclear Information System (INIS)
Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Kerambrun, A.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Meslin, C.; Nakagawa, T.; Patry, J.P.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.
1998-01-01
The light systems 36 Ar + 27 Al and 64 Zn + nat Ti were measured at several bombarding energies between ∼ 35 and 95 MeV/nucleon. It was found that the predominant part of the cross section is due to binary collisions. In this paper the focus is placed on the properties of the quasi-projectile nuclei. In the central collisions the excitation energies of the quasi-projectile reach values exceeding largely 10 MeV/nucleon. The slope of the high energy part of the distribution can give only an upper limit of the apparent temperature (the average temperature along the decay chain). The highly excited quasi-projectile may get rapidly fragmented rather than sequentially. The heavy fragments are excited and can emit light particles (n, p, d, t, 3 He, α,...) what perturbs additionally the spectrum of these particles. Concerning the expansion energy, one can determine the average kinetic energies of the product (in the quasi-projectile-framework) and compare with simulation values. To fit the experimental data an additional radial expansion energy is to be considered. The average expansion energy depends slightly on the impact parameter but it increases with E * / A, ranging from 0.4 to 1,2 MeV/nucleon for an excitation energy increasing from 7 to 10.5 MeV/nucleon. This collective radial energy seems to be independent of the fragment mass, what is possibly valid for the case of larger quasi-projectile masses. The origin of the expansion is to be determined. It may be due to a compression in the interaction zone at the initial stage of the collision, which propagates in the quasi-projectile and quasi-target, or else, may be due, simply, to the increase of thermal energy leading to a rapid fragment emission. The sequential de-excitation calculation overestimates light particle emission and consequently heavy residues, particularly, at higher excitation energies. This disagreement indicates that a sequential process can not account for the di-excitation of very hot nuclei
DEFF Research Database (Denmark)
Kolbæk, Ditte; Lundh Snis, Ulrika
Abstract: This paper analyses an online community of master’s students taking a course in ICT and organisational learning. The students initiated and facilitated an educational design for organisational learning called Proactive Review in the organisation where they are employed. By using an online...... discussion forum on Google groups, they created new ways of reflecting and learning. We used netnography to select qualitative postings from the online community and expansive learning concepts for data analysis. The findings show how students changed practices of organisational learning...
Load regulating expansion fixture
International Nuclear Information System (INIS)
Wagner, L.M.; Strum, M.J.
1998-01-01
A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located there between. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig
Directory of Open Access Journals (Sweden)
Maria José Scochi
1999-04-01
Full Text Available OBJETIVO: Avaliar a evolução do perfil da mortalidade por doenças evitáveis, em Maringá, PR, relacionando-o à qualidade de assistência á saúde. MÉTODOS: A partir da proposição de estudos de resultado da assistência foram selecionadas 11 causas de mortes. À evolução dos óbitos foi associada a evolução dos recursos disponíveis, bem como ao grau de escolarização e saneamento básico, no período de 1983-1993. RESULTADOS E CONCLUSÕES: Os dados revelaram que as taxas de mortalidade da maioria das causas evitáveis tenderam ao declínio, com uma redução de 39%, em contraposição a 16% das demais. Observou-se uma melhora das condições de escolarização e de saneamento. A evolução positiva das condições gerais da população dificulta atribuir imediatamente aos serviços a responsabilidade sobre o declínio das mortes evitáveis, mas a diferença entre estas mortes e as demais permite inferir que, se diante de condições satisfatórias de vida ocorresse um recrudescimento desses indicadores, poder-se-ia constatar uma falta de efetividade dos serviços. A constatação do arrefecimento dos indicadores pode fazer supor que a expansão dos serviços auxiliou no declínio.OBJECTIVE: An assessment of the evolution of the profile of mortality from avoidable diseases, in the municipality of Maringá, PR (Brazil, 1980 through 1993, as related to the quality of health attendance. METHODS: Based on the proposal to study caregiving results, eleven causes of avoidable deaths were selected. The evolution of resources available, level of schooling and sanitation were associated with the evolution of mortality. RESULTS AND DISCUSSION: The data revealed that the mortality rates for most of the avoidable causes tended to decline faster than those for other causes (a reduction of 39% as against 16%. A significant improvement in schooling and sanitary conditions was also observed over the same period. The positive evolution of the general
Directory of Open Access Journals (Sweden)
Sandra Maria Nobre David
2009-10-01
Full Text Available OBJETIVOS: avaliar e mensurar a sutura palatina mediana por meio de radiografias oclusais totais de maxila digitalizadas, antes e depois da sua disjunção. MÉTODOS: a amostra constou de 17 pacientes, com idades entre 7 e 22 anos. Radiografias oclusais totais da maxila foram executadas antes e depois da abertura da sutura palatina mediana, e digitalizadas em scanner HP Scanjet 6110 C com adaptador de transparências HPC 6261 6100 C, utilizando-se o programa Deskscan II. Para a avaliação e medição, foi utilizado o programa Radioimp® (Radiomemory, MG/Brasil. Na análise estatística, foram utilizados a média, o desvio-padrão, o coeficiente de variação e os testes "t" e ANOVA. CONCLUSÕES: após os resultados, foi possível concluir que (1 na região dos incisivos, houve uma abertura palatina mediana estatisticamente significativa; (2 houve abertura de diastema entre os incisivos centrais superiores em torno de 69,37% dos casos; (3 houve uma maior abertura da sutura palatina mediana na região a 10mm a partir da crista para posterior, em comparação com a região a 3mm para posterior do parafuso expansor; (4 na região a 3mm para posterior do parafuso expansor houve uma abertura de 35,97%, e na região a 10mm para posterior da crista uma abertura de 69,37%.AIM: to evaluate and to measure the midpalatal suture through digitalized occlusal radiographies before and after its disjunction. METHODS: The sample was comprised by 17 patients, with ages from 7 to 22 years. Occlusal radiographies of these patients were obtained before and after the suture's opening. The occlusal radiographies were digitalized in a HP Scanjet 6100 C scanner with the HPC 6261 6100 C transparencies adaptor and the Deskscan II software. The statistical analysis used average, standard deviation, variation coefficient, "t" test and ANOVA. CONCLUSIONS: After the results, it was possible to conclude that: (1 statistically, there was a significant midpalatal opening in the
Thermal expansion of granite rocks
International Nuclear Information System (INIS)
Stephansson, O.
1978-04-01
The thermal expansion of rocks is strongly controlled by the thermal expansion of the minerals. The theoretical thermal expansion of the Stripa Granite is gound to be 21 . 10 -6 [deg C] -1 at 25 deg C and 38 . 10 -6 [deg C] -1 at 400 deg C. The difference in expansion for the rock forming minerals causes micro cracking at heating. The expansion due to micro cracks is found to be of the same order as the mineral expansion. Most of the micro cracks will close at pressures of the order of 10 - 20 MPa. The thermal expansion of a rock mass including the effect of joints is determined in the pilot heater test in the Stripa Mine
Energy Technology Data Exchange (ETDEWEB)
Froschauer, K J
1993-01-01
A study of the development of five provincial hydroelectric utilities in Canada indicates that power companies and the state invited manufacturers to use hydroelectricity and natural resources in order to diversify provincial economies. These hydro expansions also show that utilities and government designed hydro projects to serve continental requirements; serving both objectives became problematic. It is argued that when the Canadian state and firms such as utilities use hydro expansions to serve both continentalism and industrialization, then at best they foster dependent industrialization and staple processing. At worst, they overbuild the infrastructure to generate provincial surplus energy for continental, rather than national, integration. Hydro developments became subject to state intervention in Canada mainly through the failures of private utilities to provide power for the less-lucrative industrial markets within provincial subregions. Although the state and utilities invited foreign firms to manufacture hydro equipment within the provinces and others to use electricity to diversify production beyond resource processing, such a diversification did not occur. Since 1962, ca 80% of industrial energy was used to semi-process wood-derived products, chemicals, and metals. The idea for a national power network became undermined by interprovincial political-economic factors and since 1963, the federal national/continential power policy prevailed. 187 refs., 6 figs., 52 tabs.
International Nuclear Information System (INIS)
Vogeleer, J. P.
1985-01-01
The expansion of the primary tubes or sleeves of the steam generator of a nuclear reactor plant are measured while the tubes or sleeves are being expanded. A primary tube or sleeve is expanded by high pressure of water which flows through a channel in an expander body. The water is supplied through an elongated conductor and is introduced through a connector on the shank connected to the conductor at its outer end. A wire extends through the mandrel and through the conductor to the end of the connector. At its inner end the wire is connected to a tapered pin which is subject to counteracting forces produced by the pressure of the water. The force on the side where the wire is connected to the conductor is smaller than on the opposite side. The tapered pin is moved in the direction of the higher force and extrudes the wire outwardly of the conductor. The tapered surface of the tapered pin engages transverse captive plungers which are maintained in engagement with the expanding tube or sleeve as they are moved outwardly by the tapered pin. The wire and the connector extend out of the generator and, at its outer end, the wire is connected to an indicator which measures the extent to which the wire is moved by the tapered pin, thus measuring the expansion of the tube or sleeve as it progresses
Directory of Open Access Journals (Sweden)
Túlio da Silva Junqueira
2010-05-01
Full Text Available Analisar a lógica da organização da gestão de recursos humanos em nível da atenção primária em saúde, desde a perspectiva dos gestores municipais - protagonistas das ações de saúde nos municípios brasileiros -, repensando o processo de descentralização a partir da mediação entre as orientações do Governo Federal e a dimensão do cotidiano dos serviços. Estudo transversal, com utilização de questionário semi-estruturado, aplicado aos secretários municipais de saúde da macrorregião sanitária Leste do Sul (Minas Gerais, Brasil. Os secretários municipais de saúde tinham média de idade de 39,4 anos, reduzido nível de escolaridade, observando-se que boa parte dos mesmos não era da área de saúde. Em relação aos trabalhadores do Programa Saúde da Família, as prefeituras são responsáveis por 93,3% dos contratos dos profissionais de saúde, os quais são vinculações tipicamente temporárias. Os achados ratificam a defasagem dos direitos políticos e sociais dos trabalhadores, com o paradoxo de ser o Estado - via gestão municipal - o responsável pelo descumprimento das leis, importante questão a ser ponderada.This article analyzes the logic behind human resources management in primary health care from the perspective of municipal health systems administrators in Brazil, rethinking the decentralization process based on mediation between Federal government guidelines and the health services' daily practice. This was a cross-sectional study using a semi-structured questionnaire applied to municipal health secretaries in the Southeastern Health Macro-Region (Minas Gerais State. The municipal health secretaries had a mean age of 39.4 years and low schooling, and a large proportion did not belong to the health field. As for the workforce in the Family Health Program, the municipal governments hired 93.3% of the health professionals, mostly on temporary contracts. The findings confirm gaps in the workers' political and
Directory of Open Access Journals (Sweden)
Marco Antônio Scanavini
2006-02-01
Full Text Available OBJETIVO: avaliar cefalometricamente os efeitos da expansão rápida da sutura palatina mediana sobre o posicionamento vertical e sagital da maxila, comparando os aparelhos de Haas e Hyrax. METODOLOGIA: a amostra consistiu de 93 telerradiografias obtidas de 31 pacientes jovens, brasileiros, de ambos os gêneros, na faixa etária inicial média de 13 anos e 2 meses. As radiografias foram tomadas ao início do tratamento (pré-disjunção, imediatamente após a disjunção (pós-disjunção e ao final do nivelamento. RESULTADOS E CONCLUSÕES: constatou-se que os dois aparelhos disjuntores apresentaram resultados semelhantes, com a ocorrência de deslocamento da maxila em direção inferior, sem rotação, que se manteve ao final do nivelamento e ocorrência de um deslocamento anterior logo após a disjunção, que retornou aos valores pré-disjunção ao final do nivelamento.AIM: the purpose of this cephalometric study was to evaluate, by lateral cephalograms, the changes in maxilar positioning after rapid disjunction of the midpalatal suture, following the use of two types of maxillary disjunction appliances, checked in different phases, and the likely differences between the two appliances Haas and Hyrax. METHODS: the sample comprised of 93 lateral cephalograms, taken before treatment (pre-disjunction, immediately after disjunction and at the end of levelling, obtained from 31 brazilian youths with both genres and average age of 13 years and 2 months. RESULTS AND CONCLUSIONS: both types of appliances showed similar results, with anterior and lower displacement of maxila right after disjunction. Lower displacement was without rotation, and mainttened stable until the end of levelling. Anterior displacement, however, was not stable and cephalometric measurements like SNA and Nperp-A tended to returned to initial values at the end of levelling.
Thermal expansion of coking coals
Energy Technology Data Exchange (ETDEWEB)
Orlik, M.; Klimek, J. (Vyzkumny a Zkusebni Ustav Nova Hut, Ostrava (Czechoslovakia))
1992-12-01
Analyzes expansion of coal mixtures in coke ovens during coking. Methods for measuring coal expansion on both a laboratory and pilot plant scale are comparatively evaluated. The method, developed, tested and patented in Poland by the Institute for Chemical Coal Processing in Zabrze (Polish standard PN-73/G-04522), is discussed. A laboratory device developed by the Institute for measuring coal expansion is characterized. Expansion of black coal from 10 underground mines in the Ostrava-Karvina coal district and from 9 coal mines in the Upper Silesia basin in Poland is comparatively evaluated. Investigations show that coal expansion reaches a maximum for coal types with a volatile matter ranging from 20 to 25%. With increasing volatile matter in coal, its expansion decreases. Coal expansion increases with increasing swelling index. Coal expansion corresponds with coal dilatation. With increasing coal density its expansion increases. Coal mixtures should be selected in such a way that their expansion does not cause a pressure exceeding 40 MPa. 11 refs.
Identity Expansion and Transcendence
Directory of Open Access Journals (Sweden)
William Sims Bainbridge
2014-05-01
Full Text Available Emerging developments in communications and computing technology may transform the nature of human identity, in the process rendering obsolete the traditional philosophical and scientific frameworks for understanding the nature of individuals and groups. Progress toward an evaluation of this possibility and an appropriate conceptual basis for analyzing it may be derived from two very different but ultimately connected social movements that promote this radical change. One is the governmentally supported exploration of Converging Technologies, based in the unification of nanoscience, biology, information science and cognitive science (NBIC. The other is the Transhumanist movement, which has been criticized as excessively radical yet is primarily conducted as a dignified intellectual discussion within a new school of philosophy about human enhancement. Together, NBIC and Transhumanism suggest the immense transformative power of today’s technologies, through which individuals may explore multiple identities by means of online avatars, semi-autonomous intelligent agents, and other identity expansions.
Thermal expansion of beryllium oxide
International Nuclear Information System (INIS)
Solodukhin, A.V.; Kruzhalov, A.V.; Mazurenko, V.G.; Maslov, V.A.; Medvedev, V.A.; Polupanova, T.I.
1987-01-01
Precise measurements of temperature dependence of the coefficient of linear expansion in the 22-320 K temperature range on beryllium oxide monocrystals are conducted. A model of thermal expansion is suggested; the range of temperature dependence minimum of the coefficient of thermal expansion is well described within the frames of this model. The results of the experiment may be used for investigation of thermal stresses in crystals
Directory of Open Access Journals (Sweden)
Luciana Maria Viviani
2011-07-01
Full Text Available O objetivo deste estudo é analisar os discursos produzidos por Almeida Jr. sobre o ensino rural, entre as décadas de 1930 e 1940, e as formas sob as quais ele utilizou dados estatísticos para sustentar as suas opiniões e a sua atuação como administrador do ensino paulista. O estudo dessas questões pretende colaborar na ampliação do entendimento acerca das propostas para o ensino rural, tema bastante debatido nesse período. Por meio da análise de publicações oficiais paulistas e de artigos da Revista Brasileira de Estudos Pedagógicos, verificou-se que Almeida Jr., médico e educador ligado ao grupo dos chamados renovadores do ensino, defendia propostas voltadas para a qualidade do ensino e para a organização de uma escola básica comum, ainda que adaptada ao meio rural.Palavras-chave: educação rural, estatísticas educacionais, intelectuais da educação. THE EXPANSION AND THE EFFICIENCY OF THE RURAL SCHOOL IN SÃO PAULO: THE PERFORMANCE AND THE THINKING OF ALMEIDA JR. BASED ON OFFICIAL STATISTICSAbstractThe objective of this paper is to analyze de speeches made by Almeida Jr. about the rural education, between the decades of 1930 and 1940, and the way under which he used the statistics data to sustain his opinions and his performance as the manager of education in São Paulo. By analyzing the São Paulo’s official publications and the articles published in the Revista Brasileira de Estudos Pedagógicos, it has been found that Almeida Jr., a doctor and an educator connected to the group composed by some men who were called the renewers of education, sustained proposals which were bent to the good quality of education and to the organization of a unique elementary school, though to fit the country environment.Key-words: rural education, educational statistics, intellectuals in education. LA EXPANSIÓN Y LA EFICIENCIA DE LA ESCUELA RURAL EN SAN PABLO: ACTUACIÓN Y OPINIONES DE ALMEIDA JR. A PARTIR DE ESTAD
Renormalization group and Mayer expansions
International Nuclear Information System (INIS)
Mack, G.
1984-02-01
Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U(1) lattice gauge theory by Goepfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear sigma-model, and elsewhere. (orig.)
Isotropic Negative Thermal Expansion Metamaterials.
Wu, Lingling; Li, Bo; Zhou, Ji
2016-07-13
Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.
Renormalization group and mayer expansions
International Nuclear Information System (INIS)
Mack, G.
1984-01-01
Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U (1) lattice gauge theory by Gopfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear σ-model, and elsewhere
On summation of perturbation expansions
International Nuclear Information System (INIS)
Horzela, A.
1985-04-01
The problem of the restoration of physical quantities defined by divergent perturbation expansions is analysed. The Pad'e and Borel summability is proved for alternating perturbation expansions with factorially growing coefficients. The proof is based on the methods of the classical moments theory. 17 refs. (author)
Plasma expansion: fundamentals and applications
International Nuclear Information System (INIS)
Engeln, R; Mazouffre, S; Vankan, P; Bakker, I; Schram, D C
2002-01-01
The study of plasma expansion is interesting from a fundamental point of view as well as from a more applied point of view. We here give a short overview of the way properties like density, velocity and temperature behave in an expanding thermal plasma. Experimental data show that the basic phenomena of plasma expansion are to some extent similar to those of the expansion of a hot neutral gas. From the application point of view, we present first results on the use of an expanding thermal plasma in the plasma-activated catalysis of ammonia, from N 2 -H 2 mixtures
Energy Technology Data Exchange (ETDEWEB)
Fonseca, Katia Aparecida
1997-07-01
The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)
Energy Technology Data Exchange (ETDEWEB)
Boffo, Elisangela Fabiana; Ferreira, Antonio Gilberto [Sao Carlos Univ., SP (Brazil). Dept. de Quimica
2006-05-15
The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using {sup 2}H and {sup 1}H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acitained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C{sub 3}, C{sub 4}, and CAM biosynthetic mechanisms, blends of C{sub 3} and C{sub 4} (agrins) and synthetic acetic acid. (author)
Energy Technology Data Exchange (ETDEWEB)
Pereira, Valmir; Martinez, Aquilino Senra; Silva, Fernando Carvalho da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear
2002-07-01
Determination of the subcritical multiplication curve profile (1/M) as a function of control rod bank position is of paramount importance to the development of a system which allows to foresee and also anticipate determination of criticality of a PWR reactor core. This work aims at determining this profile. For that, the 3D- two group-diffusion equations for a subcritical PWR reactor core with external neutron source is solved for different control rod bank positions. Results obtained are compared with the results from the corresponding eigenvalue problem, in order to verify how the external neutron source interferes with the reactor criticality search. (author)
Energy Technology Data Exchange (ETDEWEB)
Borges, N.C. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Escola de Veterinaria]. E-mail: naida@vet.ufg.br; Vasconcellos, R.S.; Canola, J.C.; Carciofi, A.C.; Pereira, G.T. [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias; Paula, F.J.A. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina
2008-07-01
A short-term precision error of the individual subject and the DEXA technique, such as the effect of the repositioning of the cat on the examination table, were established. Four neutered adult cats (BW=4342 g) and three females (BW=3459 g) were submitted to five repeated scans with and without repositioning between them. Precision was estimated from the mean of the five measurements and expressed by the individual coefficient of variation (CV). The precision error of the technique was estimated by the variance of scan pool (n=35) and expressed in CV for the technique (CVt). The degrees of freedom and confidence intervals were determined to avoid underestimation of precision errors. Bone mineral content (BMC), lean mass (LM), and fat mass (FM) averages were higher (P<0.05) when animals were repositioned. The CVt was significantly higher (P<0.05) for bone mineral density (BMD), LM, and FM when the animals were repositioned. For short-term precision measurements, the repositioning of the animal was important to establish the precision of the technique. The dual energy xray absorptiometry method provided precision for body composition measurements in adult cats. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, L A.P. dos
1992-08-01
This study was done to verify the viability of photodiodes, as gamma radiation detector ({sup 241} Am - Energy=60 KeV), to measure soil water content. The photodiodes used had different mechanical and electrical characteristics, and were tested on soils of different textures. A good linear correlation between the logarithm of the attenuation factor and soil-moisture demonstrated such viability, and that the low photopeak efficiency of these devices is not a limitation to the measurement of soil water content. Furthermore, the stability, the portability, and low cost of such semiconductor devices, including its electronic system, represent relevant characteristics that may justify the development of a reliable gamma meter system for field studies. (author). 37 refs, 21 figs, 20 tabs.
Energy Technology Data Exchange (ETDEWEB)
Fonseca, Katia Aparecida
1997-07-01
The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, Mariana M.; Fernandes, Heloisa H.F; Pontedeiro, Elizabeth M.; Su, Jian, E-mail: mariana@lasme.coppe.ufrj.br, E-mail: heloisa@lasme.coppe.ufrj.br, E-mail: bettinadulley@hotmail.com, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COOPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos em Engenharia
2013-07-01
To determine the concentration of heavy metals and other contaminants in soils, aimed at evaluating the environmental impact, the use of the distribution coefficient is required (Kd), defined as the relationship between the concentrations adsorbed and in solution. The objective of this study was to determine the rates for the Lead and Barium metals in soil collected in Caetite, the state of Bahia, in two different depths. The importance of determining the distribution coefficient lies in the fact that being performed using a tropical soil. For the isotherms of Kd was used batch test method by adsorption to obtain the final concentrations. The first step was to determine the best ratio soil: solution obtained after equilibration time and finally the equilibrium concentration of the contaminant. Were also calculated percentages of the metal adsorbed by the soil and the amount of solute by the adsorbent. With the values obtained in experiments and using Mathematica 8.0 software, were made graphics equilibrium concentration versus quantity adsorbed (C vs. S). It can also plot isotherms for different models of Kd: linear, Langmuir and Freundlich in order to determine which adsorption model would fit best to the measured data and thus determine the distribution coefficient of the metal in the soil analyzed. The Freundlich isotherm was better adapted to the points of the two metals in both soils.
Energy Technology Data Exchange (ETDEWEB)
Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R., E-mail: erpf@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica
2014-04-15
Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L{sup -1} were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)
Warp drive with zero expansion
Energy Technology Data Exchange (ETDEWEB)
Natario, Jose [Department of Mathematics, Instituto Superior Tecnico (Portugal)
2002-03-21
It is commonly believed that Alcubierre's warp drive works by contracting space in front of the warp bubble and expanding the space behind it. We show that this contraction/expansion is but a marginal consequence of the choice made by Alcubierre and explicitly construct a similar spacetime where no contraction/expansion occurs. Global and optical properties of warp-drive spacetimes are also discussed.
International Nuclear Information System (INIS)
Andro, Jean.
1973-01-01
The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr
Estimates of expansion time scales
International Nuclear Information System (INIS)
Jones, E.M.
1979-01-01
Monte Carlo simulations of the expansion of a spacefaring civilization show that descendants of that civilization should be found near virtually every useful star in the Galaxy in a time much less than the current age of the Galaxy. Only extreme assumptions about local population growth rates, emigration rates, or ship ranges can slow or halt an expansion. The apparent absence of extraterrestrials from the solar system suggests that no such civilization has arisen in the Galaxy. 1 figure
Strategic Complexity and Global Expansion
DEFF Research Database (Denmark)
Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina
2012-01-01
The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....
Range expansion of heterogeneous populations.
Reiter, Matthias; Rulands, Steffen; Frey, Erwin
2014-04-11
Risk spreading in bacterial populations is generally regarded as a strategy to maximize survival. Here, we study its role during range expansion of a genetically diverse population where growth and motility are two alternative traits. We find that during the initial expansion phase fast-growing cells do have a selective advantage. By contrast, asymptotically, generalists balancing motility and reproduction are evolutionarily most successful. These findings are rationalized by a set of coupled Fisher equations complemented by stochastic simulations.
On genus expansion of superpolynomials
Energy Technology Data Exchange (ETDEWEB)
Mironov, Andrei, E-mail: mironov@itep.ru [Lebedev Physics Institute, Moscow 119991 (Russian Federation); ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Morozov, Alexei, E-mail: morozov@itep.ru [ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Sleptsov, Alexei, E-mail: sleptsov@itep.ru [ITEP, Moscow 117218 (Russian Federation); Laboratory of Quantum Topology, Chelyabinsk State University, Chelyabinsk 454001 (Russian Federation); KdVI, University of Amsterdam (Netherlands); Smirnov, Andrey, E-mail: asmirnov@math.columbia.edu [ITEP, Moscow 117218 (Russian Federation); Columbia University, Department of Mathematics, New York (United States)
2014-12-15
Recently it was shown that the (Ooguri–Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present paper we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are β-deformed to Hamiltonians of the Calogero–Moser–Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials. However, even for the thin knots the beta-deformation is non-innocent: already in the simplest examples it seems inconsistent with the positivity of colored superpolynomials in non-(anti)symmetric representations, which also happens in I. Cherednik's (DAHA-based) approach to the torus knots.
Directory of Open Access Journals (Sweden)
Guilherme Rebechi Zuiani
2009-09-01
Full Text Available OBJETIVO: avaliar os resultados clínicos e radiográficos pós-operatórios da correção de cifose congênita em pacientes com mielomeningocele de nível torácico, utilizando a prótese vertical expansível de titânio para costela (VEPTR. MÉTODOS: estudo retrospectivo de 19 pacientes com mielomeningocele torácica e cifose congênita submetidos a tratamento com VEPTR, entre Outubro de 2005 e Outubro de 2008, com avaliação radiográfica e clínica pré e pós-operatória imediata. Foram avaliadas também a duração do procedimento cirúrgico, a necessidade de transfusão sanguínea e as complicações pós-operatórias. RESULTADOS: a média de idade dos pacientes foi de 70 meses ou cinco anos e dez meses (32 a 130 meses. A média de seguimento dos pacientes foi de 13,5 meses (2 a 26 meses. A duração média do procedimento foi de 117 minutos (variação de 70 a 195 minutos. Todas as crianças adquiriram equilíbrio de tronco, sendo que 13 delas não apresentavam isto no pré-operatório. A média da cifose pré-operatória foi de 115° (80° a 150° e pós-operatória de 77° (50° a 104°, com porcentagem média de correção de 31,2% (1,1 a 61,5%. O desequilíbrio do tronco pré-operatório foi de 7,9 cm, em média (1,0 a 15,5 cm e pós-operatório de 3,4 cm (0 a 8 cm. A correção média desse desequilíbrio foi de 50,4% (0 a 100%. Com relação ao peso, no pré-operatório a média foi de 15,4 kg (8 a 30 kg, e no pós-operatório de 20,6 kg (8,5 a 35 kg. O ganho médio de peso foi de 36,6% (9,8 a 100%. Dos 19 pacientes, cinco (26,3% apresentaram complicações pós-operatórias. Nenhum paciente necessitou de transfusão sanguínea. CONCLUSÃO: a utilização do VEPTR nos pacientes portadores de mielomeningocele torácica com cifose congênita tem se mostrado uma alternativa eficaz e promissora de controle da deformidade em pacientes esqueleticamente imaturos.OBJETIVO: evaluar los resultados clínicos y radiográficos postoperatorios
Low Thermal Expansion Glass Ceramics
Bach, Hans
2005-01-01
This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...
Low thermal expansion glass ceramics
1995-01-01
This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...
Regulation of gas infrastructure expansion
International Nuclear Information System (INIS)
De Joode, J.
2012-01-01
The topic of this dissertation is the regulation of gas infrastructure expansion in the European Union (EU). While the gas market has been liberalised, the gas infrastructure has largely remained in the regulated domain. However, not necessarily all gas infrastructure facilities - such as gas storage facilities, LNG import terminals and certain gas transmission pipelines - need to be regulated, as there may be scope for competition. In practice, the choice of regulation of gas infrastructure expansion varies among different types of gas infrastructure facilities and across EU Member States. Based on a review of economic literature and on a series of in-depth case studies, this study explains these differences in choices of regulation from differences in policy objectives, differences in local circumstances and differences in the intrinsic characteristics of the infrastructure projects. An important conclusion is that there is potential for a larger role for competition in gas infrastructure expansion.
The loop expansion as a divergent-power-series expansion
International Nuclear Information System (INIS)
Murai, N.
1981-01-01
The loop expansion should be divergent, possibly an asymptotic one, in the Euclidean path integral formulation. This consideration is important in applications of the symmetric and mass-independent renormalization. The [1,1] Pade approximant is calculated in a PHI 4 model. Its classical vacua may be not truely stable for nonzero coupling constant. (author)
Cosmological expansion and local physics
International Nuclear Information System (INIS)
Faraoni, Valerio; Jacques, Audrey
2007-01-01
The interplay between cosmological expansion and local attraction in a gravitationally bound system is revisited in various regimes. First, weakly gravitating Newtonian systems are considered, followed by various exact solutions describing a relativistic central object embedded in a Friedmann universe. It is shown that the 'all or nothing' behavior recently discovered (i.e., weakly coupled systems are comoving while strongly coupled ones resist the cosmic expansion) is limited to the de Sitter background. New exact solutions are presented which describe black holes perfectly comoving with a generic Friedmann universe. The possibility of violating cosmic censorship for a black hole approaching the big rip is also discussed
Temperature expansions for magnetic systems
International Nuclear Information System (INIS)
Cangemi, D.; Dunne, G.
1996-01-01
We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the proper-time method for the background field effects, and zeta function regularization for developing the expansions. We emphasize the essential difference between even and odd dimensions, focusing on 2+1 and 3+1 dimensions. We concentrate on the high temperature limit, but we also discuss the T=0 limit with nonzero chemical potential. Copyright copyright 1996 Academic Press, Inc
Bearing-Mounting Concept Accommodates Thermal Expansion
Nespodzany, Robert; Davis, Toren S.
1995-01-01
Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.
Energy expansion planning by considering electrical and thermal expansion simultaneously
International Nuclear Information System (INIS)
Abbasi, Ali Reza; Seifi, Ali Reza
2014-01-01
Highlights: • This paper focused on the expansion planning optimization of energy systems. • Employing two form of energy: the expansion of electrical and thermal energies. • The main objective is to minimize the costs. • A new Modified Honey Bee Mating Optimization (MHBMO) algorithm is applied. - Abstract: This study focused on the expansion planning optimization of energy systems employing two forms of energy: the expansion of electrical and thermal energies simultaneously. The main objective of this investigation is confirming network adequacy by adding new equipment to the network, over a given planning horizon. The main objective of the energy expansion planning (EEP) is to minimize the real energy loss, voltage deviation and the total cost of installation equipments. Since the objectives are different and incommensurable, it is difficult to solve the problem by the conventional approaches that may optimize a single objective. So, the meta-heuristic algorithm is applied to this problem. Here, Honey Bee Mating Optimization algorithm (HBMO) as a new evolutionary optimization algorithm is utilized. In order to improve the total ability of HBMO for the global search and exploration, a new modification process is suggested such a way that the algorithm will search the total search space globally. Also, regarding the uncertainties of the new complicated energy systems, in this paper for the first time, the EEP problem is investigated in a stochastic environment by the use of probabilistic load flow technique based on Point Estimate Method (PEM). In order to evaluate the feasibility and effectiveness of the proposed algorithm, two modified test systems are used as case studies
The Thermal Expansion Of Feldspars
Hovis, G. L.; Medford, A.; Conlon, M.
2009-12-01
Hovis and others (1) investigated the thermal expansion of natural and synthetic AlSi3 feldspars and demonstrated that the coefficient of thermal expansion (α) decreases significantly, and linearly, with increasing room-temperature volume (VRT). In all such feldspars, therefore, chemical expansion limits thermal expansion. The scope of this work now has been broadened to include plagioclase and Ba-K feldspar crystalline solutions. X-ray powder diffraction data have been collected between room temperature and 925 °C on six plagioclase specimens ranging in composition from anorthite to oligoclase. When combined with thermal expansion data for albite (2,3,4) a steep linear trend of α as a function of VRT emerges, reflecting how small changes in composition dramatically affect expansion behavior. The thermal expansion data for five synthetic Ba-K feldspars ranging in composition from 20 to 100 mole percent celsian, combined with data for pure K-feldspar (3,4), show α-VRT relationships similar in nature to the plagioclase series, but with a slope and intercept different from the latter. Taken as a group all Al2Si2 feldspars, including anorthite and celsian from the present study along with Sr- (5) and Pb-feldspar (6) from other workers, show very limited thermal expansion that, unlike AlSi3 feldspars, has little dependence on the divalent-ion (or M-) site occupant. This apparently is due to the necessitated alternation of Al and Si in the tetrahedral sites of these minerals (7), which in turn locks the tetrahedral framework and makes the M-site occupant nearly irrelevant to expansion behavior. Indeed, in feldspar series with coupled chemical substitution it is the change away from a 1:1 Al:Si ratio that gives feldspars greater freedom to expand. Overall, the relationships among α, chemical composition, and room-temperature volume provide useful predictive tools for estimating feldspar thermal expansion and give insight into the controls of expansion behavior in
Crude oil pipeline expansion summary
International Nuclear Information System (INIS)
2005-02-01
The Canadian Association of Petroleum Producers has been working with producers to address issues associated with the development of new pipeline capacity from western Canada. This document presents an assessment of the need for additional oil pipeline capacity given the changing mix of crude oil types and forecasted supply growth. It is of particular interest to crude oil producers and contributes to current available information for market participants. While detailed, the underlying analysis does not account for all the factors that may come into play when individual market participants make choices about which expansions they may support. The key focus is on the importance of timely expansion. It was emphasized that if pipeline expansions lags the crude supply growth, then the consequences would be both significant and unacceptable. Obstacles to timely expansion are also discussed. The report reviews the production and supply forecasts, the existing crude oil pipeline infrastructure, opportunities for new market development, requirements for new pipeline capacity and tolling options for pipeline development. tabs., figs., 1 appendix
Asymptotic Expansions - Methods and Applications
International Nuclear Information System (INIS)
Harlander, R.
1999-01-01
Different viewpoints on the asymptotic expansion of Feynman diagrams are reviewed. The relations between the field theoretic and diagrammatic approaches are sketched. The focus is on problems with large masses or large external momenta. Several recent applications also for other limiting cases are touched upon. Finally, the pros and cons of the different approaches are briefly discussed. (author)
Model of clinker capacity expansion
CSIR Research Space (South Africa)
Stylianides, T
1998-10-01
Full Text Available This paper describes a model which has been applied in practice to determine an optimal plan for clinker capacity expansion. The problem was formulated as an integer linear program aiming to determine the optimal number, size and location of kilns...
The bootstrap and edgeworth expansion
Hall, Peter
1992-01-01
This monograph addresses two quite different topics, in the belief that each can shed light on the other. Firstly, it lays the foundation for a particular view of the bootstrap. Secondly, it gives an account of Edgeworth expansion. Chapter 1 is about the bootstrap, witih almost no mention of Edgeworth expansion; Chapter 2 is about Edgeworth expansion, with scarcely a word about the bootstrap; and Chapters 3 and 4 bring these two themes together, using Edgeworth expansion to explore and develop the properites of the bootstrap. The book is aimed a a graduate level audience who has some exposure to the methods of theoretical statistics. However, technical details are delayed until the last chapter (entitled "Details of Mathematical Rogour"), and so a mathematically able reader without knowledge of the rigorous theory of probability will have no trouble understanding the first four-fifths of the book. The book simultaneously fills two gaps in the literature; it provides a very readable graduate level account of t...
Liflyand, E.
2012-01-01
We study an extension to Fourier transforms of the old problem on absolute convergence of the re-expansion in the sine (cosine) Fourier series of an absolutely convergent cosine (sine) Fourier series. The results are obtained by revealing certain relations between the Fourier transforms and their Hilbert transforms.
On persistently positively expansive maps
Directory of Open Access Journals (Sweden)
Alexander Arbieto
2010-06-01
Full Text Available In this paper, we prove that any C¹-persistently positively expansive map is expanding. This improves a result due to Sakai (Sakai 2004.Neste artigo, mostramos que todo mapa C¹-persistentemente positivamente expansivo e expansor. Isto melhora um resultado devido a Sakai (Sakai 2004.
Directory of Open Access Journals (Sweden)
R. R. Menezes
2003-04-01
Full Text Available Expansão por umidade (EPU é o aumento das dimensões do corpo cerâmico devido à adsorção de água, podendo ter grande influência na vida útil dos materiais cerâmicos. Este trabalho tem por objetivo relacionar a EPU e a absorção de água de pisos cerâmicos comerciais, com a sua composição química e a quantidade estimada de fase vítrea, calculada utilizando-se o diagrama de equilíbrio de fases do sistema SiO2.Al2O3.K2 O e a regra da alavanca. Foram estudadas amostras de vinte e três tipos de pisos cerâmicos comerciais. Foi realizada a análise química das amostras (via úmida e determinada a sua EPU e absorção de água (ensaios realizados de acordo com a norma Brasileira NBR 13818. Foi também determinada a área superficial específica de algumas amostras por adsorção de nitrogênio (BET. Os resultados obtidos mostram genericamente uma proporcionalidade inversa entre a EPU e a absorção de água, para a maioria das amostras, e a análise utilizando o diagrama de fases sugere uma relação decrescente entre a absorção de água e a quantidade estimada de fase vítrea, e uma relação crescente entre a EPU e a quantidade estimada de fase vítrea.Moisture expansion is the size increase of the ceramic body due to water adsorption and can have a great influence in the ceramic material service life. This work aims to relate the moisture expansion and water absorption of commercial ceramic tiles with their chemical composition and estimated glassy phase content, calculated from the phase equilibrium diagram of the system SiO2.Al2O3.K2 O using the lever rule. Samples of twenty three commercial ceramic tiles were studied. The chemical composition of the samples was obtained (wet route and their moisture expansion and water absorption were determined (according to the Brazilian standard NBR 13818. The specific surface area of some samples was also determined, using the nitrogen adsorption methodology (BET. The results obtained
Exponential Expansion in Evolutionary Economics
DEFF Research Database (Denmark)
Frederiksen, Peter; Jagtfelt, Tue
2013-01-01
This article attempts to solve current problems of conceptual fragmentation within the field of evolutionary economics. One of the problems, as noted by a number of observers, is that the field suffers from an assemblage of fragmented and scattered concepts (Boschma and Martin 2010). A solution...... to this problem is proposed in the form of a model of exponential expansion. The model outlines the overall structure and function of the economy as exponential expansion. The pictographic model describes four axiomatic concepts and their exponential nature. The interactive, directional, emerging and expanding...... concepts are described in detail. Taken together it provides the rudimentary aspects of an economic system within an analytical perspective. It is argued that the main dynamic processes of the evolutionary perspective can be reduced to these four concepts. The model and concepts are evaluated in the light...
Production expansion continues to accelerate
International Nuclear Information System (INIS)
Anon.
1992-01-01
This paper reports that Saudi Arabian Oil Co. (Saudi Aramco) is continuing its accelerated Crude Oil Expansion Program initiated in 1989 that aims at achieving a 10 million bpd productive capacity by 1995. In addition to major engineering, construction and renovation work related to production expansion, Saudi Aramco drilling and workover operations have been markedly expanded. Since January 1991, rig activity has doubled. As an indication of aging of Saudi production, projects include modernizing current injection water treatment facilities, installing a new seawater injection plant on the Persian Gulf, installing dewatering facilities in a number of locations and installing a pilot gas lift project. In addition, equipment orders indicate the new discoveries south of Riyadh may also need the assistance of water injection from inception of production
Shrub expansion in SW Greenland
DEFF Research Database (Denmark)
Jørgensen, Rasmus Halfdan
Arctic regions have experienced higher temperatures in recent decades, and the warming trend is projected to continue in the coming years. Arctic ecosystems are considered to be particularly vulnerable to climate change. Expansion of shrubs has been observed widely in tundra areas across the Arctic......, and has a range of ecosystem effects where it occurs. Shrub expansion has to a large extend been attributed to increasing temperatures over the past century, while grazing and human disturbance have received less attention. Alnus viridis ssp. crispa is a common arctic species that contributes...... to increasing shrub cover. Despite this, there is only limited experimental evidence that growth of the species responds to warming. Plant populations in fragmented and isolated locations could face problems adapting to a warming climate due to limited genetic variation and restricted migration from southern...
RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS
Directory of Open Access Journals (Sweden)
Gabriel BURLACU,
2011-11-01
Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator
A Power Series Expansion and Its Applications
Chen, Hongwei
2006-01-01
Using the power series solution of a differential equation and the computation of a parametric integral, two elementary proofs are given for the power series expansion of (arcsin x)[squared], as well as some applications of this expansion.
Strain expansion-reduction approach
Baqersad, Javad; Bharadwaj, Kedar
2018-02-01
Validating numerical models are one of the main aspects of engineering design. However, correlating million degrees of freedom of numerical models to the few degrees of freedom of test models is challenging. Reduction/expansion approaches have been traditionally used to match these degrees of freedom. However, the conventional reduction/expansion approaches are only limited to displacement, velocity or acceleration data. While in many cases only strain data are accessible (e.g. when a structure is monitored using strain-gages), the conventional approaches are not capable of expanding strain data. To bridge this gap, the current paper outlines a reduction/expansion technique to reduce/expand strain data. In the proposed approach, strain mode shapes of a structure are extracted using the finite element method or the digital image correlation technique. The strain mode shapes are used to generate a transformation matrix that can expand the limited set of measurement data. The proposed approach can be used to correlate experimental and analytical strain data. Furthermore, the proposed technique can be used to expand real-time operating data for structural health monitoring (SHM). In order to verify the accuracy of the approach, the proposed technique was used to expand the limited set of real-time operating data in a numerical model of a cantilever beam subjected to various types of excitations. The proposed technique was also applied to expand real-time operating data measured using a few strain gages mounted to an aluminum beam. It was shown that the proposed approach can effectively expand the strain data at limited locations to accurately predict the strain at locations where no sensors were placed.
Expansion of protein domain repeats.
Directory of Open Access Journals (Sweden)
Asa K Björklund
2006-08-01
Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.
Nuclear fuel reprocessing expansion strategies
International Nuclear Information System (INIS)
Gallagher, J.M.
1975-01-01
A description is given of an effort to apply the techniques of operations research and energy system modeling to the problem of determination of cost-effective strategies for capacity expansion of the domestic nuclear fuel reprocessing industry for the 1975 to 2000 time period. The research also determines cost disadvantages associated with alternative strategies that may be attractive for political, social, or ecological reasons. The sensitivity of results to changes in cost assumptions was investigated at some length. Reactor fuel types covered by the analysis include the Light Water Reactor (LWR), High-Temperature Gas-Cooled Reactor (HTGR), and the Fast Breeder Reactor (FBR)
Thermal expansion of LATGS crystals
International Nuclear Information System (INIS)
Kassem, M.E.; Kandil, S.H.; Hamed, A.E.; Stankowska, J.
1989-04-01
The thermal expansion of triglycine sulphate crystals doped with L-α alanine (LATGS) has been studied around the phase transition temperature (30-60 deg. C) using thermomechanical analysis TMA. With increasing the content of admixture, the transition temperature (T c ) was shifted towards higher values, while the relative changes in the dimension of the crystals (ΔL/L 0 ) of the studied directions varied both in the para- and ferroelectric phases. The transition width in the case of doped crystals was found to be broad, and this broadening increases with increasing the content of L-α alanine. (author). 12 refs, 3 figs
Contribution of thermal expansion and
Directory of Open Access Journals (Sweden)
O.I.Pursky
2007-01-01
Full Text Available A theoretical model is developed to describe the experimental results obtained for the isobaric thermal conductivity of rare gas solids (RGS. The isobaric thermal conductivity of RGS has been analysed within Debye approximation with regard to the effect of thermal expansion. The suggested model takes into consideration the fact that thermal conductivity is determined by U-processes while above the phonon mobility edge it is determined by "diffusive" modes migrating randomly from site to site. The mobility edge ω0 is determined from the condition that the phonon mean-free path restricted by the U-processes cannot be smaller than half of the phonon wavelength.
Energy Technology Data Exchange (ETDEWEB)
Estrada, F.R.; Eiras, J.A.; Garcia, D., E-mail: frestrada@df.ufscar.br, E-mail: eiras@df.ufscar.br, E-mail: ducinei@df.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Fisica. Grupo de Materiais Ferroicos
2017-01-15
Ceramic samples of lead modified calcium titanate (Pb{sub 1-x}Ca{sub x} TiO{sub 3}) with calcium concentration between 0.24≤x≤0.55 were prepared and analyzed in order to determine the structural origin of the negative thermal expansion observed in this ferroelectric system. The Rietveld structural refinement method was used to assess the thermal evolution of the structural parameters using powder X-ray diffraction data collected between 150 and 570 K. Since the Pb{sub 1-x}Ca{sub x} TiO{sub 3} phase diagram and space groups are still unknown for the temperature range investigated, the structural analyses were based on adjustments of the refinement protocol. The results revealed the existence of a correlation between symmetry transitions and anomalies in the thermal expansion of the unit cell, being such transitions not necessarily of the ferroelectric-paraelectric nature. (author)
Energy Technology Data Exchange (ETDEWEB)
Vieira, Rafael; Chaves, Alison; Coutinho, Douglas; Alves, Joberson [Instituto Superior de Tecnologia, Paracambi, RJ (Brazil); Freitas, Marcos A.V. [Universidade Federal do Rio de Janeiro (PPE/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Planejamento Energetico
2010-07-01
This paper analyses the potential social and environmental impacts from the implementation and operation of the SHPP which will guarantee the energy offer expansion in the order of 25 MW, proposing the viabilization of growing and local economic development with environmental sustainability, assured by the environmental programs and mitigatory measurements and/or compensatories as disposed in the EIA/Rima of the enterprising and observed in the data systematization of in loco research.
High thermal expansion, sealing glass
Brow, R.K.; Kovacic, L.
1993-11-16
A glass composition is described for hermetically sealing to high thermal expansion materials such as aluminum alloys, stainless steels, copper, and copper/beryllium alloys, which includes between about 10 and about 25 mole percent Na[sub 2]O, between about 10 and about 25 mole percent K[sub 2]O, between about 5 and about 15 mole percent Al[sub 2]O[sub 3], between about 35 and about 50 mole percent P[sub 2]O[sub 5] and between about 5 and about 15 mole percent of one of PbO, BaO, and mixtures thereof. The composition, which may also include between 0 and about 5 mole percent Fe[sub 2]O[sub 3] and between 0 and about 10 mole percent B[sub 2]O[sub 3], has a thermal expansion coefficient in a range of between about 160 and 210[times]10[sup [minus]7]/C and a dissolution rate in a range of between about 2[times]10[sup [minus]7] and 2[times]10[sup [minus]9]g/cm[sup 2]-min. This composition is suitable to hermetically seal to metallic electrical components which will be subjected to humid environments over an extended period of time.
Nonperturbative path integral expansion II
International Nuclear Information System (INIS)
Kaiser, H.J.
1976-05-01
The Feynman path integral representation of the 2-point function for a self-interacting Bose field is investigated using an expansion ('Path Integral Expansion', PIE) of the exponential of the kinetic term of the Lagrangian. This leads to a series - illustrated by a graph scheme - involving successively a coupling of more and more points of the lattice space commonly employed in the evaluation of path integrals. The values of the individual PIE graphs depend of course on the lattice constant. Two methods - Pade approximation and Borel-type extrapolation - are proposed to extract information about the continuum limit from a finite-order PIE. A more flexible PIE is possible by expanding besides the kinetic term a suitably chosen part of the interaction term too. In particular, if the co-expanded part is a mass term the calculation becomes only slightly more complicated than in the original formulation and the appearance of the graph scheme is unchanged. A significant reduction of the number of graphs and an improvement of the convergence of the PIE can be achieved by performing certain sums over an infinity of graph elements. (author)
Fei-Ran Shen; Hao Kuang; Feng-Xia Hu; Hui Wu; Qing-Zhen Huang; Fei-Xiang Liang; Kai-Ming Qiao; Jia Li; Jing Wang; Yao Liu; Lei Zhang; Min He; Ying Zhang; Wen-Liang Zuo; Ji-Rong Sun
2017-01-01
Materials with zero thermal expansion (ZTE) or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE) materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn–Co–Ge–In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE o...
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, Junior, O
1994-07-01
After an intake of radioactive material, its behaviour in the human body can be described by mathematical models, where organs, tissues or regions of the body are treated as a chain of linked compartments. The mathematical approach for such metabolic models is usually done through a system of differential equations of first order with constant coefficients. The solutions of this system of equations associates the radionuclide intake, with the fraction excreted or retained in the organ of interest. A computer program - called INCORP and for running in PC compatible microcomputers - was developed in order to find the solutions of such system of equations, using an analytical method based on expansion of series of exponential matrices. The metabolic model presented in the ICRP-30 publication was simulated using the INCORP program, in order to find the respective retention and excretion curves for selected radionuclides. (author)
Expansion of passive safety function
International Nuclear Information System (INIS)
Inai, Nobuhiko; Nei, Hiromichi; Kumada, Toshiaki.
1995-01-01
Expansion of the use of passive safety functions is proposed. Two notions are presented. One is that, in the design of passive safety nuclear reactors where aversion of active components is stressed, some active components are purposely introduced, by which a system is built in such a way that it behaves in an apparently passive manner. The second notion is that, instead of using a passive safety function alone, a passive safety function is combined with some active components, relating the passivity in the safety function with enhanced controllability in normal operation. The nondormant system which the authors propose is one example of the first notion. This is a system in which a standby safety system is a portion of the normal operation system. An interpretation of the nondormant system via synergetics is made. As an example of the second notion, a PIUS density lock aided with active components is proposed and is discussed
On the Equisummability of Hermite and Fourier Expansions
Indian Academy of Sciences (India)
We prove an equisummability result for the Fourier expansions and Hermite expansions as well as special Hermite expansions. We also prove the uniform boundedness of the Bochner-Riesz means associated to the Hermite expansions for polyradial functions.
Directory of Open Access Journals (Sweden)
Lucrêncio Silvestre Macarringue
2017-05-01
Full Text Available Em 2009, foi implementado um programa de cooperação trilateral entre Moçambique, Brasil e Japão (ProSAVANA na região norte de Moçambique (Corredor de Nacala. Os objetivos desse estudo foram: caracterizar a precipitação, o relevo e os solos dessa região; e analisar o potencial de expansão agrícola com base no modelo adotado para o Cerrado. Os materiais básicos incluíram dados de: precipitação, derivados do Tropical Rainfall Measuring Mission (TRMM; topografia, obtidos pelo Shuttle Radar Topography Mission (SRTM; e textura de solos, obtidos da literatura, os quais foram comparados com os do Oeste da Bahia. Os critérios adotados para analisar o potencial de expansão agrícola no Corredor de Nacala foram: declividade ≤ 12% e textura argilosa ou média de solos. Aproximadamente 82%, 94% e 71% da área de estudo moçambicana apresentaram precipitação média anual > 1.000 mm, declividade ≤ 12% e solos com textura argilosa ou média, respectivamente. As áreas favoráveis à expansão agrícola no Corredor de Nacala totalizaram 4,6 milhões de hectares. A ocupação agrícola dessas áreas potenciais deve levar em consideração outros aspectos como poluição dos recursos hídricos pelos fertilizantes químicos, melhoria do índice de desenvolvimento humano da população local e legislação que regulamenta o uso e ocupação de terras em Moçambique.
Energy Technology Data Exchange (ETDEWEB)
Buratini, Ricardo [Universidade Estadual de Campinas (IE/UNICAMP), SP (Brazil). Inst. de Economia
2008-07-01
The purpose of this paper is to analyze the methodology for power consumption projection presented in the Ten-year (2007-2016) Plan of Power Expansion (PDEE 2007/2016) and to propose some questions for discussion. Indeed, bearing in mind the progress achieved in the recent past with respect to the resumption of long term planning in the Brazilian electric power sector, it is pertinent to promote a discussion about the possible limitations of the expansion methodology proposed in PDEE. In short, it is believed that, starting from such a discussion, it could be possible to contribute towards the aim of making the planning process of the Brazilian electric power sector expansion more transparent, more consistent and more participative, consequently bringing a greater convergence of the expectations of the agents of the sector. The main questions raised in this paper about the PDEE's methodology are with respect to the absence of sufficient detail about the interactive adjustment of the several models used to project the consumption, as well as to the lack of information about the models themselves. The general conclusion of this paper is that, in order that the PDEE meets its objective of providing correct signals to all the agents, it is necessary to include more incisively the sector's specialists and the private agents in the methodological discussions, so that no important doubts will remain about the various projections. In our understanding, the success of such an enterprise will depend not only on the disposition of the agents, but on the greater detail and depth that should be previously given to the questions raised in this paper. It is certainly a significant challenge, of a high complexity but of an even higher importance to the electric power sector and to the Brazilian economy. (author)
[Tissular expansion in giant congenital nevi treatment].
Nguyen Van Nuoi, V; Francois-Fiquet, C; Diner, P; Sergent, B; Zazurca, F; Franchi, G; Buis, J; Vazquez, M-P; Picard, A; Kadlub, N
2014-08-01
Surgical management of giant melanotic naevi remains a surgical challenge. Tissue expansion provides tissue of the same quality for the repair of defects. The aim of this study is to review tissular expansion for giant melanotic naevi. We conducted a retrospective study from 2000 to 2012. All children patients who underwent a tissular expansion for giant congenital naevi had been included. Epidemiological data, surgical procedure, complication rate and results had been analysed. Thirty-tree patients had been included; they underwent 61 procedures with 79 tissular-expansion prosthesis. Previous surgery, mostly simple excision had been performed before tissular expansion. Complete naevus excision had been performed in 63.3% of the cases. Complications occurred in 45% of the cases, however in 50% of them were minor. Iterative surgery increased the complication rate. Tissular expansion is a valuable option for giant congenital naevus. However, complication rate remained high, especially when iterative surgery is needed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Petersen, Claudio Zen
2008-07-01
In this dissertation we use the Laplace transform to derive expressions for nonstandard albedo boundary conditions for one and two non-multiplying regions at the ends of one dimensional domains. In practice, the fuel regions of reactor cores are surrounded by reflector regions that reduce neutron leakage. In order to exclude the reflector regions from the calculations, we introduce a reflection coefficient or albedo. We use the present albedo boundary conditions to solve numerically slab-geometry monoenergetic and multigroup diffusion equations using the conventional finite difference method. Numerical results are generated for fixed source and eigenvalue diffusion problems in slab geometry(author)
Energy Technology Data Exchange (ETDEWEB)
Zucchini, Ricardo R.; Hinata, Patricia [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Gioseffi, Carla S.; Franco, Joao B.S. [Instituto Brasileiro de Petroleo, Gas e Biocombustiveis (IBP), Rio de Janeiro, RJ (Brazil); Nascimento, Cristina R.; Torres, Eduardo S. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)
2008-07-01
The determination of repeatability and reproducibility standard deviations of an analytical method, s{sub r} and s{sub R}, obtained by Interlaboratory program, makes it possible to calculate many kinds of precision limits of the method, which are needed in every laboratory's routine result comparisons and also in between-laboratories comparisons. This paper presents the results of the first interlaboratory trial, accomplished in the Brazilian petroleum sector, performed to define the trueness and precision of the Brazilian standard method for the determination of fuel anhydrous ethylic alcohol content in gasoline, that was performed by 34 experienced laboratories. The r and R values were 0,7 and 2,3 and main factors that would improve and optimize the method are presented. (author)
Energy Technology Data Exchange (ETDEWEB)
Andrade, Wellington; Santos, Poliane, E-mail: wellington.gandrade@gmail.com, E-mail: polianeangelo@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lima, Fernando de Andrade; Lima, Fabiana Farias de, E-mail: falima@cnen.gov.br, E-mail: ffmima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)
2013-07-01
The radiopharmaceutical is a chemical compound associated with a radionuclide, which is selected so that meets the need cf diagnosis and capable of producing quality images. Drugs labeled with {sup 99m}Tc radionuclide kits consist of lyophilized, and be handled by the nuclear medicine services (NMS) must pass tests as the resolution of ANVISA (RDC 38) published in 2008. Among these tests are those of radiochemical purity and pH determination. This study evaluated the radiochemical purity of radiopharmaceuticals and pH SMN manipulated in the Northeast. The radiochemical purity (RCP) was determined by thin layer chromatography, which were used Whatman Registered-Sign and silica gel, with dimensions of 1 x 10 cm, as stationary phase, and solvents indicated in the inserts of manufacturers. The chromatographic strips were placed in sealed containers so as not to touch the walls thereof. After the chromatographic run, the tape was cut every centimeter and the activities determined in doses of each calibrator NMS. The pH of the radiopharmaceutical was assessed through the use of universal pH paper (Merck Registered-Sign ) and obtained staining compared with its color scale. The results showed (hat 82.6% and 100% of the radiopharmaceuticals of the samples were within the limits recommended by international pharmacopoeias for radiochemical purity and pl-l, respectively. There is then the need to include in routine tests indicated SMN by ANVISA. Well, they can detect possible problems in the marking of radiopharmaceuticals administered to the patient and avoid inappropriate material. (author)
Energy Technology Data Exchange (ETDEWEB)
Leite, Sandro Passos; Silva, Ademir Xavier da [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Energia Nuclear; Pereira, Walsan Wagner; Fonseca, Evaldo S. da; Patrao, Karla C. de Souza [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI); Castro, Leonardo Curvello de [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Programa de Pos-Graduacao; Bittencourt, Guilherme Rodrigues [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). PIBIC
2009-07-01
This work studied, through the Monte Carlo modelling, a irradiation system for the aqueous solution MnSO{sub 4} to be used in the proceeding of determination of counting efficiency of the manganese sulfate bath
Energy Technology Data Exchange (ETDEWEB)
Scroccaro, Karine Isabel; Tanobe, Valcineide Oliveira de Andrade; Cocco, Lilian Cristina; Yamamoto, Carlos Itsuo, E-mail: karineisabel@yahoo.com.br [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Engenharia Quimica; Wypych, Fernando [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Quimica
2012-07-01
Catalyst based on Kegging-type heteropolyacids (H{sub 3}PW{sub 12}O{sub 40} - HPA), supported on SiO{sub 2} (H{sub 3}PW), were prepared by the impregnation method under different thermal treatment conditions. The materials were characterized by different instrumental techniques and used as catalysts in the methyl esterification reactions of stearic acid. Using the catalyst with 15% of HPA, conversions higher than 60% were obtained after 2 h of reaction at 65 deg C. Recovery studies using hot-filtration with ethanol at 75 deg C showed satisfactory activity for two additional reaction cycles. (author)
Energy Technology Data Exchange (ETDEWEB)
Marques, Maria Jose; Batista, A.C.; Nobre, J.P. [Universidade de Coimbra (Portugal). Dept. de Fisica. Centro de Estudos de Materiais por Difraccao de Raios X (CEMDRX); Loureiro, Altino [Universidade de Coimbra (Portugal). Dept. de Engenharia Mecanica. Centro de Engenharia Mecanica (CEMUC); Kornmeier, Joana R., E-mail: mjvaz@fe.up.pt [Technische Universitaet Muenchen, Garching (Germany). FRM II
2013-04-15
The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be minimized by performing post-weld stress relief heat treatments. The samples analyzed in this study were made of carbon steel plates, coated by submerged arc welding two types of stainless steel filler metals. For the first layer was used one EN 12 072 - S 2 U 23 12 electrode, while for the second and third layers were used an EN 12 072 - 19 12 3 S L electrode. After cladding, the samples were submitted to a post-weld heat treatment for 1 hour at 620 deg C. The residual stress profiles obtained by neutron diffraction evidence the relaxation of residual stress given by the heat treatment. (author)
Energy Technology Data Exchange (ETDEWEB)
Gomes, Bruna G.; Maihara, Vera A.; Avegliano, Roseane P., E-mail: brunagabrielegomes@gmail.com, E-mail: vmaihara@ipen.br, E-mail: pagliaro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2013-07-01
The eggs are among the twenty foods consumed by the population of the five major regions of Brazil. Among the types of eggs, there are differences in nutritional value, which can vary according to the food of the bird. This study evaluating the elements Cl, K, Mg, Mn and Na considered essential micronutrients in food, because they are fundamental in several metabolic processes necessary for the maintenance and training of the human body. We analyzed three types of eggs: egg whites, of the quail, and the colonial in cooked and raw form, using the Instrumental Neutron Activation Analysis method (INAA). The egg samples were lyophilized and pulverized before analysis. To validate the methodology, reference materials NIST RM 8415 Whole Egg Powder and NIST SRM 1567 Wheat Flour were analyzed. The samples, reference materials and standards of the elements were irradiated for 20 seconds under a thermal neutron flux of 6,6x10{sup 12} cm -2 s -1 in the nuclear research reactor IEA-R1 of IPEN-CNEN / SP. The results were consistent with the values of the Brazilian Table of Food Composition (TACO)
Energy Technology Data Exchange (ETDEWEB)
Ramos, Guilherme da Franca
2010-07-01
The objective of the present work is to determine the activity concentration of uranium and thorium isotopes and polonium in estuarine sediments from Baixada Santista. The area comprehends nine cities in the Brazilian coast (Bertioga, Guaruja, Santos, Sao Vicente, Cubatao, Praia Grande, Mongagua, Itanhaem and Peruibe). It is one of the most important industrial areas in Brazil due to the large number of industries operating in Cubatao, such as steel, petrochemical and fertilizer industries. That, together with a large population, causes a negative impact on the marine biota. In the present work 10 profiles of sediment cores, with depth varying from 41 to 98 cm, were analyzed. The cores were obtained from Santos, Cubatao, Sao Vicente and Bertioga. The cores were sliced every 2 cm and were treated with both physical and chemical processes, including drying, grinding and sieving. The samples were dissolved by acid digestion, till total dissolution and destruction of organic matter. After the acid digestion, the samples were filtered and evaporated till dryness. The radiochemical techniques used to separate the radionuclides and to prepare the final source for alpha counting were ion exchange chromatography and spontaneous deposition for polonium and electrodeposition for U and Th. The final sources were counted in a surface barrier alpha spectrometer. Values obtained for the radionuclides analyzed were similar to the activity concentrations of sediments in non polluted areas, with the exception of a few samples that showed anthropic influence. (author)
Energy Technology Data Exchange (ETDEWEB)
Mazo, Eduin Orlando Munoz; Barreto, Carlos Eduardo Andrade Gomes; Schiozer, Denis Jose [Centro de Estudos de Petroleo (CEPETRO/UNICAMP), SP (Brazil); Teixeira, Lucas Breda [Universidade Estadual de Campinas (DEP/FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Petroleo
2012-07-01
The use of water cut as a parameter for determining the shut-in point of production wells is very frequent. However, in most cases, the value of this parameter that is used in the process is not optimized, which can lead to suboptimal performance, as shown in this work. An additional way to improve the water management strategy of the field is set by controlling the injection rate by determining the optimal shut-in point of an injection well, which should be closed when its interaction with the producing wells is negative for their financial performance. To know the interaction between the injector and the producer wells becomes important in order to determine the most appropriate time for the closure of the injector wells. The objective of this study is to illustrate a methodology that allows the optimization of the development and water management strategy of oil fields by using the shut-in control of injection wells, in addition to managing production wells, using numerical reservoir simulation. For this study three case studies are proposed: (1) simulation of a homogeneous and isotropic reservoir model, with the purpose of determining the injection shut-in point by the water cut value obtained from the economic scenario, (2) simulation of the process in simplified cases of heterogeneous reservoirs and (3) application of the methodology to a case of more complex reservoir geology and well configuration in different economic scenarios. The results show that for reservoirs with expected production of large volumes of water and flow high injection rates, the isolated use of water cut for producing wells control as the only procedure to manage the flow of water within the reservoir may be insufficient. Moreover, depending on the price scenario used in economic forecasting and considering cases with heterogeneities, the determination of the shut-in point of injection and producing wells individually can be the most appropriate option for the development and water management strategy of the field. (author)
Energy Technology Data Exchange (ETDEWEB)
Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila, E-mail: vlsouza@cnen.gov.br, E-mail: mayaradqf@hotmail.com, E-mail: rodriguesss@hootmail.com, E-mail: waldecy@cnen.gov.br, E-mail: riziakeila@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)
2014-07-01
This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose.
Energy Technology Data Exchange (ETDEWEB)
Vicentini, Caio M.; Marques, Leila S., E-mail: caio.vicentini@usp.br, E-mail: leila@iag.usp.br [Universidade de Sao Paulo (IAG/USP), Sao Paulo, SP (Brazil). Instituto de Astronomia, Geofisica e Ciencias Atmosfericas; Figueiredo, Ana Maria G., E-mail: anamaria@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2013-07-01
The analysis of trace elements such as rare earths, Th, U, Ta, Hf, Ba, Rb and Ba, is a very important tool for petrogenetic studies. In order to study these processes in dykes of Enxame Serra do Mar (Coast of Sao Paulo and Rio de Janeiro), belonging to the Parana Magmatic Province (PMP), one of the most significant provinces of continental basalts in the world, were perform analyzes by neutron activation in these dikes. The technique, employed in Centro de Reator de Pesquisa of the Instituto de Pesquisas Energeticas e Nucleares, provided concentrations of trace elements with accuracy levels of 10% and 9%, which are suitable for petrogenetic studies. Due to the low concentrations of the elements analyzed, the experimental routine sample preparation processes covered very careful to avoid contamination. The samples investigated can be divided into four groups: basic rocks (SiO{sub 2} <55%) with Ti / Y> 500; basic rocks with Ti / Y <500; intermediate rocks (55%
Energy Technology Data Exchange (ETDEWEB)
Almeida, Wagner B. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica
2000-10-01
The determination of the molecular structure of molecules is of fundamental importance in chemistry. X-rays and electron diffraction methods constitute in important tools for the elucidation of the molecular structure of systems in the solid state and gas phase, respectively. The use of quantum mechanical molecular orbital ab initio methods offer an alternative for conformational analysis studies. Comparison between theoretical results and those obtained experimentally in the gas phase can make a significant contribution for an unambiguous determination of the geometrical parameters. In this article the determination for an unambiguous determination of the geometrical parameters. In this article the determination of the molecular structure of the cyclooctane molecule by electron diffraction in the gas phase an initio calculations will be addressed, providing an example of a comparative analysis of theoretical and experimental predictions. (author)
Energy Technology Data Exchange (ETDEWEB)
Rocha, Fabio Guimaraes; Bulhoes, Fernando Cesar Chagas [PETROBRAS, Rio de Janeiro, RJ (Brazil)], Emails: fg.rocha@petrobras. com.br, fernando.bulhoes@petrobras.com.br
2010-07-01
This paper considers that, given the complexity of the involved factors (environmental, social, technological, economical and financial questions), the multi criteria approach can be viewed as important help tool in the definition of politic related to new hydrocarbon exploratory frontiers. To give subsides to this argument, it was made a bibliographical review, being highlighted the involved risks in exploitation and production activities, and the importance of taking into consideration the preferences of the individuals decision. Methodologies are presented, highlighting the different viewing of the american and french schools. A panorama of random variables involved in decision making of investments in new exploratory frontiers also is presented, emphasizing the importance their importance in the future offer petroleum and the challenges involved in that activity.
Energy Technology Data Exchange (ETDEWEB)
Ilha, Marina Sangoi de Oliveira [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil. Dept. de Hidraulica e Saneamento; Goncalves, Orestes Marracini [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia de Construcao Civil
1996-07-01
This work presents models for design flow rate and gas volume determination in residential buildings. First, an experimental investigation, applied on a sample of residential buildings at Sao Paulo, Brazil, is described, which essentially consisted in the filling of a form and measurement of gas volume at one minute interval during 10 days (mean). From this data, it was performed a regression analysis in order to explain design flow rate (demand) and gas volume values (consumption), based on different variables. Models proposed on this work are different from the current applied methodology due to their 'open' approach, that is, involved variables can be explicitly found in formulas. (author)
Energy Technology Data Exchange (ETDEWEB)
Mundstock, Rene [Refinaria Alberto Pasqualini (REFAP), Canoas, RS (Brazil); Correa, Eduardo Coelho [PETROBRAS, Rio de Janeiro, RJ (Brazil)
2000-07-01
The necessity of increasing the crude processing with operation periods even greater, are resulting in Atmospheric Distillation Units in severe conditions, requiring even more rigorous operational procedures. The crude fired heaters are the critical equipment in this context, because they are the most susceptible to failures, if some determined limits are exceeded. This work was originated from the tube failure analysis of the fired heater F-101 of Alberto Pasqualini Refinery (REFAP), occurred in july/98, due to internal cocking, with unit emergency shut-down. During this analysis, it was verified that the operational limit of a fired heater cannot be determined only by its design thermal duty, it must be also taken into account the influence of the crude composition. This will determine, due to its film coefficient, the region of the radiation zone of the fired heater where it will begin the crude vaporization and will occur the greater temperatures. The work conclusions resulted on the revision of the Unit operational procedures and definition of new crude processing limits. The fired heater operates with no problems since then. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, Andreia Ferreira dos
1997-07-01
The aim of this study was to determinate: 1) the radio sensibility of Salmonella typhimurium ATCC 14028 in soy trypticase broth; 2) the radio sensibility of Salmonella typhimurium ATCC 14028 in chicken thigh and; 3) to recommend a radiation dose which can be non hazardous for human consumption
Energy Technology Data Exchange (ETDEWEB)
Rosa, Daniel M. [Universidade de Brasilia (UnB-Gama), DF (Brazil)], E-mail: danielrosa@unb.br; Fadel, Aida A.; Araujo, Jose Alexander; Ferreira, Jorge Luiz A.; Henriques, Antonio Manoel D. [Universidade de Brasilia (EnM/UnB), DF (Brazil). Dept. de Engenharia Mecanica], Emails: aida@unb.br, alex07@unb.br, jorge@unb.br, Henriques@unb.br; Hortencio, Tania M.O.S. [Companhia Energetica de Goias Distribuicao S.A. (CELG D), Goiania, GO (Brazil)], E-mail: tania.hortencio@celg.com.br
2009-07-01
The aim of this work was to present a fretting fatigue experimental rig for overhead conductors and to carry out a set of experiments to obtain life estimative for a standard Ibis ACSR, Aluminium Conductor Steel Reinforced. A preliminary S-N (Wohler) Curve was obtained in the medium high cycle fatigue regime. Experiments considered the occurrence of at least two wire breaks to obtain each point of the S-N curve, which was compared to CIGRE's Safe Border Line (CSBL). The experimental results showed five to ten times large lives than the ones provided by CSBL adoption. (author)
Energy Technology Data Exchange (ETDEWEB)
Araujo, Nathalia Souza de; Saiki, Mitiko, E-mail: natsouzaraujo@yahoo.com.b, E-mail: mitiko@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2009-07-01
This work determined the blood serum concentration of Cl, K, and Na from a healthy elderly population of the city of Sao Paulo, Sao Paulo, Brazil viewing the comparison with reference values used in clinical laboratories. For collecting these samples the present work were approved by the Ethic Committee of the FMUSP and IPEN-CNEN/SP. The quality of the analytical results were evaluated by the analysis of the reference material certification NIST 1577b Bovine Liver. The results presented good accuracy and precision due to the fact that they presented relative errors less than 5.2 % and standard deviation less than 8.6 %. The average concentrations (mmol L{sup -1}) of Cl in the analysed serum were 99.1; the K were 3.9 and the Na were 136.9. The obtained data allows the to conclude that the mostly of the elderly presented Cl, K and Na concentrations in the range of reference values used in the clinical laboratories
Energy Technology Data Exchange (ETDEWEB)
Faria, Ligia Santana de
2013-07-01
The municipalities of Brumadinho and Nova Lima are located in the metropolitan area of Belo Horizonte city. They are of ecological interest since they belong to an Environmental Protection Area, which is located on a very important deposit of iron ore. In addition of mineral wealth, the region has a geological characteristic that includes quartzitic conglomerates associated with uranium and significant potential underground water with hydrogeological characteristics very particular and complex, as the Quartzite Aquifer, which belongs to a geological formation called the 'Moeda Formation'. In the present work radiometric measurements were performed for 44 water samples. The samples were collected in four geographical points, three of them situated in Brumadinho (surface water) and one point situated in Nova Lima municipality (underground water). The period of sampling extended for a thirteen months period. Some of these locations was used as an alternative sampling point. Uranium and thorium concentrations of the samples were determined using an Inductively Coupled Plasma Mass Spectrometer. The content of gross alpha and gross beta activity, and the concentration of the radionuclides {sup 226}Ra, {sup 228}Ra e {sup 210}Pb were determinate by using Spectrometer Liquid Scintillation. In this case was necessary to calibrate the spectrometer using {sup 241}Am e {sup 90}Sr/{sup 90}Y standards. The resultants values were compared with those recommended by the World Health Organization, Ministry of Health and the National Council of the Environment. The maximum level of water natural radioactivity found was 0,275 ± 0,052 Bq.L{sup -1} for gross alpha radiation, 0,130 ± 0,046 Bq.L{sup -1} for {sup 226}Ra and 0,096 ± 0,005 Bq.L-1 for {sup 228}Ra. The levels of gross beta activity and {sup 210}Pb were below the detection limit. The maximum concentrations of uranium and thorium found were 0,068 μg.L{sup -1} and 0.027 μg.L{sup -1} respectively. (author)
Energy Technology Data Exchange (ETDEWEB)
Damato, Murilo; Alem Sobrinho, Pedro; Morita, Dione Mari [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Hidraulica e Sanitaria]. E-mail: palem@usp.br
1997-07-01
The organisms from fresh water are sensible to variations of environmental parameters. The criteria of water quality for these animals are derived from laboratorium tests. The following physical and chemical parameters have been determined: DO, BOD, COD, alkalinity, hardness, ammoniacal nitrogen, sulphides, chlorides, cyanides, oils and greases, aluminium, arsenium, cadmium, chromium, copper, iron, lead, vanadium, zinc, phenols, benzene, toluene, xylene, solids in total suspensions. Acute toxicity tests have been performed on Daphnia similis. The flotation and activated waste systems was efficient in removing acute toxicity.
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Hebert Pinto Silveira de
2010-07-01
Along the latest years, the LNMRI has been proceeding a continuous research work with a concentric cylinders type free air ionizing chamber (VICTOREEN, model 481), aiming to establish it as a new national standard, and, as a consequence, replace the worldwide accepted secondary standard, calibrated by PTB. Taking into account that the absolute determination of kerma in air with a free air ionizing chamber implies the acquirement of a number of correction factors. The main objective of the present work comprises the determination of the two factors, specifically, electronic loss (k{sub e}) and air attenuation (k{sub a}). The correction factors were obtained through mammography qualities reference spectrum, using Monte Carlo simulation method. The Penelope code was used in the simulation procedures. Simulations took place in two stages, the acquirement of specters related to the qualities of interest (mammography) with the x ray tube (Pantak, model HF160 e Panalytical, model XRF window), and the free-air ionization chamber. The data were compared to those related to the BIPM chamber, to electronic loss were not detected. The comparison between air attenuation factors was obtained data bellow 0.13%. (author)
Energy Technology Data Exchange (ETDEWEB)
Pereira, Thiago Martini
2009-07-01
In this work it was developed a software that calculates automatically, the thermal diffusivity value as a function of temperature in materials. The infrared thermography technique was used for data acquisition of temperature distribution as a function of time. These data were used to adjust a temperature function obtained from the homogeneous heat equation with specific boundary conditions. For that, an infrared camera (detecting from 8 {mu}m to 9 {mu}m) was calibrated to detect temperature ranging from 185 degree C up to 1300 degree C at an acquisition rate of 300 Hz. It was used, 10 samples of dental enamel and 10 samples of dentin, with 4 mm x 4 mm x 2 mm, which were obtained from bovine lower incisor teeth. These samples were irradiated with an Er:Cr:YSGG pulsed laser ({lambda} = 2,78 {mu}m). The resulting temperature was recorded 2 s prior, 10 s during irradiation and continuing for 2 more seconds after it. After each irradiation, all obtained thermal images were processed in the software, creating a file with the data of thermal diffusivity as a function of temperature. Another file with the thermal diffusivity values was also calculated after each laser pulse. The mean result of thermal diffusivity obtained for dental enamel was 0,0084 {+-} 0,001 cm2/s for the temperature interval of 220-550 degree C. The mean value for thermal diffusivity obtained for dentin was 0,0015 0,0004 cm2/s in temperatures up to 360 degree C; however, this value increases for higher temperatures. According to these results, it was possible to conclude that the use of infrared thermography, associated with the software developed in this work, is an efficient method to determine the thermal diffusivity values as a function of temperature in different materials. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, Elias Antunes dos
2001-02-01
Using the method of {sup 137} Cs and gamma-ray spectrometry, soil samples of two plots erosion were studied at Londrina city. the soil class studied was a dystrophic dark red soil (LRd), with erosion indexes measured by Agronomic Institute of Parana State (IAPAR) using a conventional method, since 1976. Through the percentage reduction of {sup 137} Cs related to the reference site, the soil losses were calculated using the proportional, mass balance and profile distribution models. Making the correlation between the {sup 137} Cs concentrations and the erosion measured by IAPAR, two calibration equations were obtained and applied to the data set measured in the basin of the Unda river and compared to those models in the literature. As reference region, was chosen a natural forest located close to the plots. The average inventory of {sup 137} Cs was 555{+-} 16 Bq.m{sup -2}. The inventories of the erosion plots varied from 112 to 136 Bq.m{sup -2} for samples collected until 30 cm depth. The erosion rates estimated by the models varied from 64 to 85 ton.ha{sup -1}.yr{sup -1} for the proportional and profile distribution models, respectively, and 137 to 165 ton.ha{sup -1} for the mass balance model, while the measured erosion obtained by IAPAR was 86 ton.ha{sup -1}.yr{sup -1}. From the two calibration equations obtained, the one that take into account the {sup 137} Cs distribution with the soil profile was that showed the best consistence with the erosion rated for the basin of the Unda river (same soil class) in the range from 4 to 48 ton.ha{sup -1}.yr{sup -1}, while the proportional and profile distribution models applied rates from 7 to 45 ton.ha{sup -1}.yr{sup -1} and 6 to 69 ton.ha{sup -1}.yr{sup -1}, respectively. (author)
Energy Technology Data Exchange (ETDEWEB)
Moura, J.A.; Moura, E.S.; Sprenger, F.E.; Nagatomi, H.R.; Zeituni, C.A.; Feher, A.; Manzoli, J.E.; Souza, C.D.; Rostelato, M.E.C.M., E-mail: elisaros@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2009-07-01
Iodine-125 seeds are radioactive sources used in the prostate cancer treatment. This work objective was to determine the necessary conditions and procedures for decontamination of liquid transfer tubes when a radioactive material leakage occurs during the process of seed quality control
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Romero Marcilio Barros Matias de
2002-08-01
Biological dosimetry estimates the absorbed dose taking into account changes in biological parameters. The most used biological indicator of an exposition to ionizing radiation is the quantification of chromosomal aberrations of lymphocytes from irradiated individuals. The curves of dose versus induced biological effects, obtained through bionalyses, are used in used in retrospective evaluations of the dose, mainly in the case of accidents. In this research, a simple model for electrons and photons transports was idealized to simulate the irradiation of lymphocytes with {sup 99m} Tc, representing a system used for irradiation of blood cells. The objective of the work was to establish a curve of dose versus frequencies of chromosomal aberrations in lymphocytes of human blood. For the irradiation of blood samples micro spheres of human serum of albumin (HSAM) market with {sup 99m} Tc were used, allowing the irradiation of blood with different administered activities of {sup 99m} Tc, making possible the study the cytogenetical effects as a function of such activities. The conditions of irradiation in vivo using HSAM spheres marked with {sup 99m} Tc were simulated with MCNP 4C (Monte Carlo N-Particle) code to obtain the dose-response curve. Soft tissue composition was employed to simulate blood tissue and the analyses of the curve of dose versus biological effect showed a linear quadratic response of the unstable chromosomal aberrations. As a result, the response of dose versus chromosomal aberrations of blood irradiation with {sup 99m} Tc was best fitted by the curve Y=(8,99 {+-}2,06) x 1-{sup -4} + (1,24 {+-}0,62) x 10{sup -2} D + (5,67 {+-} 0,64) x 10{sup -2} D{sup 2}. (author)
Simulation program for multiple expansion Stirling machines
International Nuclear Information System (INIS)
Walker, G.; Weiss, M.; Fauvel, R.; Reader, G.; Bingham, E.R.
1992-01-01
Multiple expansion Stirling machines have been a topic of interest at the University of Calgary for some years. Recently a second-order computer simulation program with integral graphics package for Stirling cryocoolers with up to four stages of expansion were developed and made available to the Stirling community. Adaptation of the program to multiple expansion Stirling power systems is anticipated. This paper briefly introduces the program and presents a specimen result
Semiclassical expansions for confined N fermion systems
International Nuclear Information System (INIS)
Krivine, H.; Martorell, J.; Casas, M.
1989-01-01
A new derivation of the Wigner Kirkwood expansion for N-fermion systems is presented, showing explicitly the connection to the WKB approximation for a single level. This allows to study separately the two ansatz required to obtain the semiclassical expansions: the asymptotic expansions in powers of ℎ and the smoothing of quantal effects. We discuss the one dimensional and three dimensional, with spherical symmetry, cases. Applications for standard potentials used in nuclear physics are described in detail
Thermal and hygroscopic expansion characteristics of bamboo
Huang, Puxi; Chang, Wen-shao; Ansell, Martin P.; Bowen, Chris R.; Chew, John Y. M.; Adamak, Vana i
2017-01-01
The expansion and contraction of bamboo caused by temperature and moisture variations must be evaluated\\ud if bamboo is to be utilised as a building material. However, detailed expansion data, especially data in the ascent and\\ud descent processes of temperature and moisture are unexplored. The aim of this study is to investigate the expansion\\ud characteristics of Phyllostachys edulis (Moso bamboo) in ascent and descent processes of temperature and moisture.\\ud The measurement of linear ther...
$\\delta$-Expansion at Finite Temperature
Ramos, Rudnei O.
1996-01-01
We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.
Chromatic Derivatives, Chromatic Expansions and Associated Spaces
Ignjatovic, Aleksandar
2009-01-01
This paper presents the basic properties of chromatic derivatives and chromatic expansions and provides an appropriate motivation for introducing these notions. Chromatic derivatives are special, numerically robust linear differential operators which correspond to certain families of orthogonal polynomials. Chromatic expansions are series of the corresponding special functions, which possess the best features of both the Taylor and the Shannon expansions. This makes chromatic derivatives and ...
Thermal expansion in small metallic particles
International Nuclear Information System (INIS)
Ivanov, A.S.
1985-01-01
An anomalously low thermal expansion observable in small particles is attributed to extending effect of the shell. It is shown that the coefficient of thermal expansion of the oxide-film-coated aluminium particles calculated using elastic constants and coefficients of thermal expansion of massive materials agres well with those measured experimentally. The linear dilatation of the shell, its stress to rupture and the values of the structural tension are estimated vs the temperature
Disjoint sum expansion method in FTA
International Nuclear Information System (INIS)
Ruan Keqiang
1987-01-01
An expansion formula for transforming boolean algebraic expressions into disjoint form was proved. Based on this expansion formula, a method for transforming system failure function into disjoint form was devised. The fact that the expansion can be done for several elements simulatneously makes the method flexible and fast. Some examples from fault tree analysis (FTA) and network analysis were examined by the new method to show its algorithm and its merit. Besides, by means of the proved expansion formula some boolean algebraic relations can proved very easily
Thermal expansion of L-ascorbic acid
Nicolaï, B.; Barrio, M.; Tamarit, J.-Ll.; Céolin, R.; Rietveld, I. B.
2017-04-01
The specific volume of vitamin C has been investigated by X-ray powder diffraction as a function of temperature from 110 K up to complete degradation around 440 K. Its thermal expansion is relatively small in comparison with other organic compounds with an expansivity α v of 1.2(3) × 10-4 K-1. The structure consists of strongly bound molecules in the ac plane through a dense network of hydrogen bonds. The thermal expansion is anisotropic. Along the b axis, the expansion has most leeway and is about 10 times larger than in the other directions.
Adiabatic supernova expansion into the circumstellar medium
International Nuclear Information System (INIS)
Band, D.L.; Liang, E.P.
1987-01-01
We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs
Directory of Open Access Journals (Sweden)
Kiyomori de Quental Tyba
2011-01-01
Full Text Available OBJETIVO: Avaliar o uso da prótese vertical expansível de titânio (VEPTR como opção de tratamento inicial da escoliose em crianças de baixa idade portadoras de paralisia cerebral. MÉTODOS: Foram avaliados 10 pacientes portadores de paralisia cerebral (PC tratados com VEPTR pelo grupo de escoliose da AACD de São Paulo. Caracterizavam-se por imaturidade esquelética e escoliose progressiva; sem deformidade grave no plano sagital. Realizamos avaliação da curva pelo método de Cobb no pré e pós-operatório e após dois anos de seguimento. RESULTADOS: A correção obtida com o uso do VEPTR no pós-operatório imediato foi em média de 41,4% nas radiografias iniciais sem tração (p = 0,005 e 9,1% (p = 0,055 nas radiografias com tração. Após quatro meses de pós-operatório mantiveram-se ganhos de 27,2% com relação ao início. Houve correção da obliquidade pélvica de 10,2º no pré-operatório para 5,4º em média (p = 0,007. As complicações ocorreram em seis pacientes (60% e em apenas um paciente foi necessária a retirada do VEPTR. CONCLUSÃO: O VEPTR é um método que obteve correção significativa no tratamento provisório das escolioses na PC, apesar de frequentes complicações de baixa morbidade.OBJETIVO: Evaluar el uso de la prótesis vertical expansible de titanio (VEPTR como opción de tratamiento inicial para la escoliosis en niños pequeños con parálisis cerebral. MÉTODOS: 10 pacientes con parálisis cerebral (PC fueron evaluados y tratados con VEPTR por el grupo de escoliosis de la AACD en Sao Paulo. Caracterizados por escoliosis progresiva inmadurez esquelética, sin deformidad grave en el plano sagital. Se evaluó la curva por el método de Cobb en el preoperatorio, posoperatorio, y después de dos años de seguimiento. RESULTADOS: LA CORRECCIón, obtenida con el uso de VEPTR en el posoperatorio inmediato, fue en promedio 41,4% en relación a las radiografías iniciales sin tracción (p = 0,005 y 9,1% (p = 0
Hubble expansion in static spacetime
International Nuclear Information System (INIS)
Rossler, Otto E.; Froehlich, Dieter; Movassagh, Ramis; Moore, Anthony
2007-01-01
A recently proposed mechanism for light-path expansion in a static spacetime is based on the moving-lenses paradigm. Since the latter is valid independently of whether space expands or not, a static universe can be used to better see the implications. The moving-lenses paradigm is related to the paradigm of dynamical friction. If this is correct, a Hubble-like law is implicit. It is described quantitatively. A bent in the Hubble-like line is predictably implied. The main underlying assumption is Price's Principle (PI 3 ). If the theory is sound, the greatest remaining problem in cosmology becomes the origin of hydrogen. Since Blandford's jet production mechanism for quasars is too weak, a generalized Hawking radiation hidden in the walls of cosmic voids is invoked. A second prediction is empirical: slow pattern changes in the cosmic microwave background. A third is ultra-high redshifts for Giacconi quasars. Bruno's eternal universe in the spirit of Augustine becomes a bit less outlandish
Primordial vorticity and gradient expansion
Giovannini, Massimo
2012-01-01
The evolution equations of the vorticities of the electrons, ions and photons in a pre-decoupling plasma are derived, in a fully inhomogeneous geometry, by combining the general relativistic gradient expansion and the drift approximation within the Adler-Misner-Deser decomposition. The vorticity transfer between the different species is discussed in this novel framework and a set of general conservation laws, connecting the vorticities of the three-component plasma with the magnetic field intensity, is derived. After demonstrating that a source of large-scale vorticity resides in the spatial gradients of the geometry and of the electromagnetic sources, the total vorticity is estimated to lowest order in the spatial gradients and by enforcing the validity of the momentum constraint. By acknowledging the current bounds on the tensor to scalar ratio in the (minimal) tensor extension of the $\\Lambda$CDM paradigm the maximal comoving magnetic field induced by the total vorticity turns out to be, at most, of the or...
Directory of Open Access Journals (Sweden)
Adriana Roseli Wünsch Takahashi
2008-06-01
Full Text Available A discussão sobre a retomada da Educação Profissional no Brasil, enquanto promotora da inserção no mercado de trabalho e da inclusão social, tangencia outros importantes tópicos como o desenvolvimento da Economia Baseada no Conhecimento - EBC e a difusão de um Sistema Nacional de Inovação. Dentro deste panorama, um pilar essencial é composto pelo setor educacional e, dentro dele, pelas universidades e a sua capacidade de criação e transferência de conhecimento para a sociedade como um todo. A tarefa posta para um dos segmentos do nível universitário - a Educação Tecnológica Superior - é o preenchimento ágil e de qualidade de lacunas de mão-de-obra surgidas no mercado de trabalho por conta da chegada e disseminação de novas tecnologias. Com tais considerações, este artigo se propõe a discutir o papel organizador do Estado e as políticas públicas implementadas nos últimos anos para a reformulação e expansão do sistema profissional de educação, em específico nos Cursos Superiores de Tecnologia. Por fim, busca-se oferecer referências para a organização de uma agenda de pesquisas com vistas à melhoria nas políticas públicas voltadas para esta área, bem como de suas formas de avaliação de impacto.La discusión sobre la retomada de la Educación Profesional en Brasil, como promotora de la inserción en el mercado de trabajo y de la inclusión social, toca otros importantes puntos como el desarrollo de la Economía Basada en el Conocimiento - EBC y la difusión de un Sistema Nacional de Innovación. Dentro de este escenario, un pilar esencial es compuesto por el sector educacional y, en este contexto, por las universidades y su capacidad de creación y transferencia de conocimiento para la sociedad como un todo. La tarea puesta para un de los segmentos del nivel universitario - la Educación Tecnológica Superior - es rellenar de modo ágil y con calidad la carencia de trabajadores en el mercado de trabajo
Negative thermal expansion materials: technological key for control of thermal expansion
Koshi Takenaka
2012-01-01
Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K−1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining pra...
Energy Technology Data Exchange (ETDEWEB)
Torres, Luiz Carlos [Diretoria de Hidrografia e Navegacao, XX (Brazil); Gomes, Benedito Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Gamboa, Luiz Antonio P. [Universidade Federal Fluminense, Niteroi, RJ (Brazil)
1999-07-01
Geophysical measurements were carried out in the Western Margin of the Antarctic Peninsula and Bransfield Strait by the Brazilian Antarctic Program during the summers of 1987 and 1988. The present work, using a continued seismic multi channel and magnetometry data profile crossing the area, intends to present a two-dimensional model of the interface sediment/basement and contribute to the understanding of the complex geology verified in the studying area. By this model, the main provinces of the are (Deep Ocean, South Shetland Trench, Accretionary Prism, Volcanic Arc South Shetland Islands and Bransfield Basin) could be determined. The seismic and magnetic measurements information when superposed can attribute more consistencies to the interpreted basement; although each method has its particular resolution. This way, when the seismic interpretation was not possible due to complex structures disposition, magnetic measurements could offer good estimation about basement depth. The fit between both methods (seismic and magnetic measurements) was reasonable both on the oceanic basin and in the region of Bransfield Strait. The magnetometry, as as well seismic, was sensible to the dip of Drake Plate at South Shetland Trench and the Intrusive occurrence at Bransfield Basin axis. (author)
Finnish Higher Education Expansion and Regional Policy
Saarivirta, Toni
2010-01-01
This paper concentrates on the expansion of Finnish higher education between the 1960s and 1970s, exposes its background in the light of the policy decisions that were made, compares the unique features of this expansion with those of certain other countries, discusses the impact of the controlled "top down" governance of higher…
The δ expansion for stochastic quantization
International Nuclear Information System (INIS)
Bender, C.M.; Cooper, F.; Milton, K.A.; Department of Physics, Brown University, Providence, Rhode Island 02912; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexic o 87545; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Department of Physics and Astronomy, University of Oklahoma, Norman, Oklaho ma 73019)
1989-01-01
Using a recently proposed perturbation expansion called the δ expansion, we show how to solve the Langevin equation associated with a gphi 4 field theory. We illustrate the technique in zero- and one-dimensional space-time, and then generalize this approach to d dimensions
The heavy quark expansion of QCD
International Nuclear Information System (INIS)
Falk, A.F.
1997-01-01
These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs
The heavy quark expansion of QCD
Energy Technology Data Exchange (ETDEWEB)
Falk, A.F. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy
1997-06-01
These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs.
Thermal expansion of doped lanthanum gallates
Indian Academy of Sciences (India)
Administrator
Since the components are in intimate mechanical contact, any stress generated due to their thermal expansion mis- match during thermal cycling could lead to catastrophic failure of the cell. The functional materials must have similar thermal expansions to avoid mechanical stresses. Hence it is useful to study the thermal ...
Platform Expansion Design as Strategic Choice
DEFF Research Database (Denmark)
Staykova, Kalina S.; Damsgaard, Jan
2016-01-01
In this paper, we address how the strategic choice of platform expansion design impacts the subse-quent platform strategy. We identify two distinct approaches to platform expansion – platform bun-dling and platform constellations, which currently co-exist. The purpose of this paper is to outline...
Series expansion of the modified Einstein Procedure
Seema Chandrakant Shah-Fairbank
2009-01-01
This study examines calculating total sediment discharge based on the Modified Einstein Procedure (MEP). A new procedure based on the Series Expansion of the Modified Einstein Procedure (SEMEP) has been developed. This procedure contains four main modifications to MEP. First, SEMEP solves the Einstein integrals quickly and accurately based on a series expansion. Next,...
Maxwell superalgebras and Abelian semigroup expansion
Directory of Open Access Journals (Sweden)
P.K. Concha
2014-09-01
Full Text Available The Abelian semigroup expansion is a powerful and simple method to derive new Lie algebras from a given one. Recently it was shown that the S-expansion of so(3,2 leads us to the Maxwell algebra M. In this paper we extend this result to superalgebras, by proving that different choices of abelian semigroups S lead to interesting D=4 Maxwell Superalgebras. In particular, the minimal Maxwell superalgebra sM and the N-extended Maxwell superalgebra sM(N recently found by the Maurer–Cartan expansion procedure, are derived alternatively as an S-expansion of osp(4|N. Moreover, we show that new minimal Maxwell superalgebras type sMm+2 and their N-extended generalization can be obtained using the S-expansion procedure.
Use of expansion joints in power stations
International Nuclear Information System (INIS)
Birker; Rommerswinkel.
1976-01-01
The paper discusses the mode of action of different systems of expansion joints. Special regard is given to the problems of expansion of pipelines of high rated diameter as employed in today's large power plant turbines. Due to the limited space available, the important role of the spring rate of the bellows for the reaction forces and moments acting on the connection points is pointed out. Apart from this details are given on the fabrication and materials selection of expansion joint bellows, and problems are discussed which arise in connection with the mechanical or hydraulic deformation of bellows with one or more walls. The non-destructive methods now in use for the testing of expansion pipe joints are mentioned along with experiments to test their behaviour under changing loads. The paper concludes on some remarks concerning proper transport, storage and installation of expansion pipe joints. (orig./AK) [de
Maxwell superalgebras and Abelian semigroup expansion
Energy Technology Data Exchange (ETDEWEB)
Concha, P.K.; Rodríguez, E.K. [Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria, 1, 10125 Torino (Italy)
2014-09-15
The Abelian semigroup expansion is a powerful and simple method to derive new Lie algebras from a given one. Recently it was shown that the S-expansion of so(3,2) leads us to the Maxwell algebra M. In this paper we extend this result to superalgebras, by proving that different choices of abelian semigroups S lead to interesting D=4 Maxwell Superalgebras. In particular, the minimal Maxwell superalgebra sM and the N-extended Maxwell superalgebra sM{sup (N)} recently found by the Maurer–Cartan expansion procedure, are derived alternatively as an S-expansion of osp(4|N). Moreover, we show that new minimal Maxwell superalgebras type sM{sub m+2} and their N-extended generalization can be obtained using the S-expansion procedure.
Energy Technology Data Exchange (ETDEWEB)
Torres, Carlos Alberto Rodrigues; Vicente, Ana Paula Camargo de; Lopes, Jorge Antonio; Silveira Filho, Celso Rodrigues da [Petrobras Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)
2012-07-01
This article addresses a subject that has been target of requirements from environmental agencies for renewal of licenses, expansions, or implementation of new enterprises. That subject refers to the checking of the permeability of tank basins and verifying its adequacy against certain criteria. The Brazilian standard that regulates those criteria is ABNT NBR 17505-2 - Flammable and Combustible Liquid Storage. In order to check compliance with the established criteria, it is best to perform geotechnical tests to check the permeability and main characteristics of the soil. Some difficulties may arise in the execution of those services, as for example, the scarce existence of qualified firms, relative complexity, high cost and considerable time for the execution. In that regard, this article is intended to present a differentiated methodology proposed by Zangar (1953) for the checking of the permeability of the basins and also a practical case applied to a petroleum by-product storage terminal. The methodology is complemented with the presentation of the results obtained in a plant containing iso-value curves, thereby getting a geographic representation of the permeability indexes of the basins. In the case study, 21 tests have been performed encompassing 7 tank basins. As a result therefrom, it was verified that 98.3% of the studied area met the criteria, with an average permeability of 6.84 x 10{sup -5} cm/s. With this paper, one may conclude that the proposed methodology is reliable, quick, low-cost and easily applicable, and may be used for checking the compliance of the tank basin permeability with the criterion of ABNT NBR 17505-2 standard. (author)
Directory of Open Access Journals (Sweden)
Stella Cecilia Duarte Segenreich
2009-03-01
Full Text Available A proposta do presente trabalho é, com base nos Censos da Educação Superior de 1996 a 2006, aprofundar questões relativas à privatização e à diferenciação do sistema brasileiro de educação superior, no contexto de sua expansão, explorando as categorias referentes a instituições, cursos e corpo discente. A análise assumiu como marco divisório o Plano Nacional de Educação de 2001, que vem servindo de parâmetro para as tendências de evolução do sistema. Verificou-se que as políticas públicas de expansão para este nível de ensino estão tendendo a enfatizar a diferenciação do sistema com ênfase na esfera pública, seja por meio de novos tipos de curso/instituições - cursos superiores de tecnologia nos Institutos Federais de Educação, Ciência e Tecnologia, - seja pela institucionalização da educação a distância pela Universidade Aberta do Brasil. O processo de privatização continua, menos acelerado, sob outras formas tais como a concessão de bolsas do MEC para o ProUni.La propuesta del presente trabajo es, con base en los Censos de la Educación Superior de 1996 a 2006, profundizar cuestiones relativas a la privatización y a la diferenciación del sistema brasileño de educación superior, en el contexto de su expansión. El análisis asumió como marco divisorio el Plan Nacional de Educación de 2001, que viene sirviendo de parámetro para las tendencias de evolución del sistema. Se identificó que las políticas públicas de expansión para este nivel de enseñanza han inclinado para resaltar la diferenciación del sistema con énfasis en la esfera pública, sea por medio de nuevos tipos de curso/instituciones - cursos superiores de tecnología en los Institutos Federales de Educación, Ciencia y Tecnología - sea por la institucionalización de la educación a distancia en las universidades federales - Universidade Aberta de Brasil. El proceso de privatización sigue, menos acelerado y bajo otras formas
δ expansion applied to quantum electrodynamics
International Nuclear Information System (INIS)
Bender, C.M.; Boettcher, S.; Milton, K.A.
1992-01-01
A recently proposed technique known as the δ expansion provides a nonperturbative treatment of a quantum field theory. The δ-expansion approach can be applied to electrodynamics in such a way that local gauge invariance is preserved. In this paper it is shown that for electrodynamic processes involving only external photon lines and no external electron lines the δ expansion is equivalent to a fermion loop expansion. That is, the coefficient of δ n in the δ expansion is precisely the sum of all n-electron-loop Feynman diagrams in a conventional weak-coupling approximation. This equivalence does not extend to processes having external electron lines. When external electron lines are present, the δ expansion is truly nonperturbative and does not have a simple interpretation as a resummation of conventional Feynman diagrams. To illustrate the nonperturbative character of the δ expansion we perform a speculative calculation of the fermion condensate in the massive Schwinger model in the limit of large coupling constant
Interbasis expansions for isotropic harmonic oscillator
Energy Technology Data Exchange (ETDEWEB)
Dong, Shi-Hai, E-mail: dongsh2@yahoo.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, Mexico D.F. 07738 (Mexico)
2012-03-12
The exact solutions of the isotropic harmonic oscillator are reviewed in Cartesian, cylindrical polar and spherical coordinates. The problem of interbasis expansions of the eigenfunctions is solved completely. The explicit expansion coefficients of the basis for given coordinates in terms of other two coordinates are presented for lower excited states. Such a property is occurred only for those degenerated states for given principal quantum number n. -- Highlights: ► Exact solutions of harmonic oscillator are reviewed in three coordinates. ► Interbasis expansions of the eigenfunctions is solved completely. ► This is occurred only for those degenerated states for given quantum number n.
Decennial plan of expansion 1994-2003
International Nuclear Information System (INIS)
1993-12-01
The Decennial Plan of Expansion 1994-2003 of Electric sector reproduces the results of the studies occurred during the planning cycle of 1992/93 from the Coordinator Groups of the Electric System Planning. Based in the market forecasting, economic-financier and time for finishing the the works, the Decennial Plan of Expansion presents the schedule of the main generation and transmission works for the next ten years, the annual spend in generation, transmission and distribution, the costs of expansion and the evaluation of attending conditions in electric system in Brazil. (C.G.C.)
Thermal expansion: Metallic elements and alloys. [Handbook
Touloukian, Y. S.; Kirby, R. K.; Taylor, R. E.; Desai, P. D.
1975-01-01
The introductory sections of the work are devoted to the theory of thermal expansion of solids and to methods for the measurement of the linear thermal expansion of solids (X-ray methods, high speed methods, interferometry, push-rod dilatometry, etc.). The bulk of the work is devoted to numerical data on the thermal linear expansion of all the metallic elements, a large number of intermetallics, and a large number of binary alloy systems and multiple alloy systems. A comprehensive bibliography is provided along with an index to the materials examined.
Discrete expansions of continuum functions. General concepts
International Nuclear Information System (INIS)
Bang, J.; Ershov, S.N.; Gareev, F.A.; Kazacha, G.S.
1979-01-01
Different discrete expansions of the continuum wave functions are considered: pole expansion (according to the Mittag-Lefler theorem), Weinberg states. The general property of these groups of states is their completeness in the finite region of space. They satisfy the Schroedinger type equations and are matched with free solutions of the Schroedinger equation at the boundary. Convergence of expansions for the S matrix, the Green functions and the continuous-spectrum wave functions is studied. A new group of states possessing the best convergence is introduced
Semiclassical expansions on and near caustics
International Nuclear Information System (INIS)
Meetz, K.
1984-09-01
We show that the standard WKB expansion can be generalized so that it reproduces the behavior of the wave function on and near a caustic in two-dimensional space time. The expansion is related to the unfolding polynomials of the elementary catastrophes occurring in two dimensions: the fold and the cusp catastrophe. The method determines control parameters and transport coefficients in a self-consistent way from differential equations and does not refer to the asymptotic expansion of Feynman path integrals. The lowest order equations are solved explicitly in terms of the multivalued classical action. The result is a generalized semiclassical approximation on and beyond a caustic. (orig.)
Cosmic growth history and expansion history
International Nuclear Information System (INIS)
Linder, Eric V.
2005-01-01
The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part of the energy density. Precision comparison of the two histories can distinguish the nature of the physics responsible for the accelerating cosmic expansion: an additional smooth component--dark energy--or a modification of the gravitational field equations. With the aid of a new fitting formula for linear perturbation growth accurate to 0.05%-0.2%, we separate out the growth dependence on the expansion history and introduce a new growth index parameter γ that quantifies the gravitational modification
Some Improved Nonperturbative Bounds for Fermionic Expansions
Energy Technology Data Exchange (ETDEWEB)
Lohmann, Martin, E-mail: marlohmann@gmail.com [Universita di Roma Tre, Dipartimento di Matematica (Italy)
2016-06-15
We reconsider the Gram-Hadamard bound as it is used in constructive quantum field theory and many body physics to prove convergence of Fermionic perturbative expansions. Our approach uses a recursion for the amplitudes of the expansion, discovered in a model problem by Djokic (2013). It explains the standard way to bound the expansion from a new point of view, and for some of the amplitudes provides new bounds, which avoid the use of Fourier transform, and are therefore superior to the standard bounds for models like the cold interacting Fermi gas.
Oblique photon expansion of QED structure functions
International Nuclear Information System (INIS)
Chahine, C.
1986-01-01
In the oblique photon expansion, the collinear part of photon emission is summed up to all orders in perturbation theory. The number of oblique or non-collinear photons is the expansion order. Unlike in perturbation theory, every term of the expansion is both infrared finite and gauge invariant. The zero oblique photon contribution to the electromagnetic structure tensor in QED is computed in detail. The behaviors of the structure functions F1 and F2 are discussed in the soft and ultra-soft limits
Directory of Open Access Journals (Sweden)
Frederico Carlos Martins de Menezes Filho
2014-04-01
Full Text Available This study examined documents that recorded floods in the municipality of Cuiabá between 1970 and 2010. The steps of research encompassed printed and digital media, municipal civil defense and the collection of the Central Library of the municipality of Cuiabá. The main goal of this study was to establish a relationship between urban sprawl and incidence of floods in the municipality. Fifty-one flood events were recorded, concentrated in the months from December to April, with an average of 1.28 occurrences per year in the period analyzed. The expansion of the urban area in the early 60’s has favored the disordered occupation of land use and the increase of urban floods, either by the intense waterproofing as well as by channeling of urban streams, as observed in the Prainha and Barbado streams. The results revealed that the urbanization of the capital of Mato Grosso State has influenced in increasing the frequency of floods and their impacts have caused in losses of material and human nature.
Filosofia da análise da estabilidade da liquidez
Directory of Open Access Journals (Sweden)
Rodrigo Antônio Chaves da Silva
2005-07-01
Full Text Available A informação foi considerada finalidade de nosso conhecimento, até o período em os pensadores e pesquisadores da contabilidade passaram a raciocinar sobre o conteúdo e o significado dos informes. Nesta busca da razão sobre os estados patrimoniais, surgiu a análise contábil que procura por meio de relações e identidades, o significado da dinâmica expressa da estaticamente na informação. O primeiro aspecto que surgiu no objeto de análise foi o estudo da liquidez, que é um dos principais exercícios do patrimônio. A estabilidade também é outro exercício básico e imprescindível, pois este é que promove o equilíbrio do organismo administrativo. A ciência contábil após a sua dignidade científica passou a trilhar caminhos esplendorosos, amparados em doutrina que permite alcançar os píncaros filosóficos. Os estudos concernentes aos aspectos de interação da estabilidade na liquidez são, complexos e somente com os recursos filosóficos da contabilidade se pode estudá-los com o panorama holístico e sublime. A filosofia da contabilidade não é alheia às suas práticas tecnológicas, podendo buscar pontos sublimes de panoramas abrangentes, para o estudo analítico da liquidez e estabilidade, observando todas as dimensionalidades e essencialidades de acontecimentos, na comprovação e orientação dos estados de ineficácia e eficácia patrimonial.
Improvement of Expansive Soils Using Chemical Stabilizers
Ikizler, S. B.; Senol, A.; Khosrowshahi, S. K.; Hatipoğlu, M.
2014-12-01
The aim of this study is to investigate the effect of two chemical stabilizers on the swelling potential of expansive soil. A high plasticity sodium bentonite was used as the expansive soil. The additive materials including fly ash (FA) and lime (L) were evaluated as potential stabilizers to decrease the swelling pressure of bentonite. Depending on the type of additive materials, they were blended with bentonite in different percentages to assess the optimum state and approch the maximum swell pressure reduction. According to the results of swell pressure test, both fly ash and lime reduce the swelling potential of bentonite but the maximum improvement occurs using bentonite-lime mixture while the swelling pressure reduction approaches to 49%. The results reveal a significant reduction of swelling potential of expansive soil using chemical stabilizers. Keywords: Expansive soil; swell pressure; chemical stabilization; fly ash; lime
Applications of the large mass expansion
International Nuclear Information System (INIS)
Fleischer, J.; Kotikov, A.V.; ); Veretin, O.L.
1998-01-01
The method of the large mass expansion (LME) is investigated for selfenergy and vertex functions in two-loop order. It has the technical advantage that in many cases the expansion coefficients can be expressed analytically. As long as only one non-zero external momentum squared, q 2 , is involved also the Taylor expansion (TE) w.r.t. small q 2 yields high precision results in a domain sufficient for most applications. In the case of only one non-zero mass M and only one external momentum squared, the expansion w.r.t. q 2 /M 2 is identical for the TE and the LME. In this case the combined techniques yield analytic expressions for many diagrams, which are quite easy to handle numerically. (author)
Surgically assisted rapid maxillary expansion in adults.
Pogrel, M A; Kaban, L B; Vargervik, K; Baumrind, S
1992-01-01
Twelve adults with maxillary width discrepancy of greater than 5 mm were treated by surgically assisted rapid maxillary expansion. The procedure consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopedic device postoperatively. Mean palatal expansion of 7.5 mm (range of 6 to 13 mm), measured in the first molar region, was achieved within 3 weeks in all patients. Expansion remained stable during the 12-month study period, with a mean relapse for the entire group of 0.88 +/- 0.48 mm. Morbidity was limited to mild postoperative discomfort. The results of this preliminary study indicated that surgically assisted rapid maxillary expansion is a safe, simple, and reliable procedure for achieving a permanent increase in skeletal maxillary width in adults. Further study is necessary to document the three-dimensional movements of the maxillary segments and long-term stability of the skeletal and dental changes.
Expansion of the Neyveli lignite mine, India
Energy Technology Data Exchange (ETDEWEB)
Kasturi, T S [Neyveli Lignite Corp. Ltd., Tamil Nadu (India); Streck, W [Gold (O.) G.m.b.H. und Co. K.G., Koeln (Germany, F.R.)
1979-08-01
After giving a picture of the difficult winning conditions at the Neyveli open-cast lignite mine, the author states the reasons for the expansions of the open-cast mine and describes the necessary measures and machinery.
Chemical graph-theoretic cluster expansions
International Nuclear Information System (INIS)
Klein, D.J.
1986-01-01
A general computationally amenable chemico-graph-theoretic cluster expansion method is suggested as a paradigm for incorporation of chemical structure concepts in a systematic manner. The cluster expansion approach is presented in a formalism general enough to cover a variety of empirical, semiempirical, and even ab initio applications. Formally such approaches for the utilization of chemical structure-related concepts may be viewed as discrete analogues of Taylor series expansions. The efficacy of the chemical structure concepts then is simply bound up in the rate of convergence of the cluster expansions. In many empirical applications, e.g., boiling points, chromatographic separation coefficients, and biological activities, this rate of convergence has been observed to be quite rapid. More note will be made here of quantum chemical applications. Relations to questions concerning size extensivity of energies and size consistency of wave functions are addressed
Magnetized relativistic electron-ion plasma expansion
Benkhelifa, El-Amine; Djebli, Mourad
2016-03-01
The dynamics of relativistic laser-produced plasma expansion across a transverse magnetic field is investigated. Based on a one dimensional two-fluid model that includes pressure, enthalpy, and rest mass energy, the expansion is studied in the limit of λD (Debye length) ≤RL (Larmor radius) for magnetized electrons and ions. Numerical investigation conducted for a quasi-neutral plasma showed that the σ parameter describing the initial plasma magnetization, and the plasma β parameter, which is the ratio of kinetic to magnetic pressure are the key parameters governing the expansion dynamics. For σ ≪ 1, ion's front shows oscillations associated to the break-down of quasi-neutrality. This is due to the strong constraining effect and confinement of the magnetic field, which acts as a retarding medium slowing the plasma expansion.
Wilson expansion in the minimal subtraction scheme
International Nuclear Information System (INIS)
Smirnov, V.A.
1989-01-01
The small distance expansion of the product of composite fields is constructed for an arbitrary renormalization procedure of the type of minimal subtraction scheme. Coefficient functions of the expansion are expressed explicitly through the Green functions of composite fields. The expansion has the explicity finite form: the ultraviolet (UV) divergences of the coefficient functions and composite fields are removed by the initial renormalization procedure while the infrared (IR) divergences in massless diagrams with nonvanishing contribution into the coefficient functions are removed by the R-operation which is the IR part of the R-operation. The latter is the generalization of the dimensional renormalization in the case when both UV and IR divergences are present. To derive the expansion, a ''pre-subtracting operator'' is introduced and formulas of the counter-term technique are exploited
Treatment of divergent expansions in scattering theory
International Nuclear Information System (INIS)
Gersten, A.; Malin, S.
1978-01-01
One of the biggest obstacles in applying quantum field theory to realistic scattering problems are the divergencies of pertubation expansions for large coupling constants and the divergencies of partial wave expansions for massless particles exchanges. There exist, however, methods of summation of the divergent expansions which can lead to significant application in physics. In this paper we treat the problem of summing such expansions using three methods: (i) a generalization of the Pade approximation to the multivariable case. The suggested definition is unique and preserves unitarity. (ii) The summation of divergent partial waves for arbitrary spins. (iii) A successful application of a series inversion to the 3 P 1 nucleon-nucleon phase shift up to 200 MeV. (orig./WL) [de
foundations on expansive soils introduction characteristic
African Journals Online (AJOL)
the swelling potential of expansive soils have been found to be: initial moisture content, .... behaviour of such huildin1?1>, it is difficult to give definite recommendations. ..... Structures in Black Cotton Soils, Central Building. Research Institute ...
Secret-key expansion from covert communication
Arrazola, Juan Miguel; Amiri, Ryan
2018-02-01
Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.
Boson expansion theory in the seniority scheme
International Nuclear Information System (INIS)
Tamura, T.; Li, C.; Pedrocchi, V.G.
1985-01-01
A boson expansion formalism in the seniority scheme is presented and its relation with number-conserving quasiparticle calculations is elucidated. Accuracy and convergence are demonstrated numerically. A comparative discussion with other related approaches is given
Directory of Open Access Journals (Sweden)
Célia Maria Patriani Justo
2007-12-01
Full Text Available Em coerência com os princípios de integralidade, eqüidade e universalidade presentes na reforma sanitária e na criação do Sistema Único de Saúde (SUS, alguns municípios passaram a oferecer a homeopatia como opção terapêutica. Este artigo aborda o contexto de implantação e consolidação da homeopatia na cidade de Santos (SP, até a sua incorporação como alternativa de atenção médica na rede pública de serviços de saúde. Naquela cidade, a implantação muito se deveu não só a médicos e farmacêuticos, mas também a médiuns receitantes que atuavam nos centros espíritas. Todos esses personagens tornaram possível a reivindicação de oferta dessa modalidade de atendimento pelos serviços de atenção primária do município. Nossa análise baseou-se em entrevistas com profissionais que participaram desse processo, em relatórios técnicos, artigos de jornais, revistas científicas e em livro escrito sobre a primeira sociedade espírita da cidade.In consonance with the principles of comprehensiveness, equity, and universality that underlie Brazil's sanitary reform and creation of its Unified Health System, some municipalities have begun offering homeopathy as a treatment option. The article explores the context in which homeopathic treatment was introduced and gained ground in the city of Santos, São Paulo, down through its incorporation as an alternative in the public healthcare network. Homeopathy was introduced in Santos not only by doctors and pharmacists but also by prescribing mediums from spiritist centers. The request that the municipality's primary-care services offer this alternative was possible thanks to the presence of all these players. The present analysis was based on interviews with the professionals who took part in the process, on technical reports, newspaper articles, and scientific journals, and on a book about the city's first spiritist society.
Operator expansion at short distance in QCD
Energy Technology Data Exchange (ETDEWEB)
Hubschmid, W [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik; Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik
1982-11-01
We present a method of calculating coefficients of gluon operators in the operator product expansion of two-point functions at short distance. It is based on a short-distance expansion of the singular part of the quark propagator in the gluon field, the latter being treated as external. We verify in full generality that the spin zero, gluon operator of dimension six does not contribute to the two-point functions of quark bilinears.
Resolution of hydrodynamical equations for transverse expansions
International Nuclear Information System (INIS)
Hama, Y.; Pottag, F.W.
1984-01-01
The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage one have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. It is only concerned with the formalism and the numerical results will be given in the next paper. (Author) [pt
The critical thermal expansion of gadolinium
International Nuclear Information System (INIS)
Robinson, K.; Lanchester, P.C.
1978-01-01
Measurements have been made of the critical thermal expansion of single crystals of gadolinium, prepared by solid state electrotransport processing. Although the expansion data can be fitted to a simple power law with exponents lambda + =-0.25, lambda - =-0.33, these values are not predicted by theory and a discontinuity remains at Tsub(c)=293.620 K. It is suggested that the results relate to a region of crossover to uniaxial dipolar behaviour. (Auth.)
Cluster expansion for vacuum confining fields
International Nuclear Information System (INIS)
Simonov, Yu.A.
1987-01-01
Colored particle Green functions in vacuum background random fields are written as path integrals. Averaging over random fields is done using the cluster (cumulant) expansion. The existence of a finite correlation length for vacuum background fields is shown to produce the linear confinement, in agreement with the results, obtained with the help of averaged Hamiltonians. A modified form of cluster expansion for nonabelian fields is introduced using the path-ordered cumulants
Synthesis, microstructure and thermal expansion studies
Indian Academy of Sciences (India)
Abstract. We report on the synthesis, microstructure and thermal expansion studies on Ca0.5+/2Sr0.5+/2Zr4P6−2Si2O24 ( = 0.00 to 1.00) system which belongs to NZP family of low thermal expansion ceramics. The ceramics synthesized by co-precipitation method at lower calcination and the sintering temperatures ...
Composite asymptotic expansions and scaling wall turbulence.
Panton, Ronald L
2007-03-15
In this article, the assumptions and reasoning that yield composite asymptotic expansions for wall turbulence are discussed. Particular attention is paid to the scaling quantities that are used to render the variables non-dimensional and of order one. An asymptotic expansion is proposed for the streamwise Reynolds stress that accounts for the active and inactive turbulence by using different scalings. The idea is tested with the data from the channel flows and appears to have merit.
A pedagogical approach to the Magnus expansion
International Nuclear Information System (INIS)
Blanes, S; Casas, F; Oteo, J A; Ros, J
2010-01-01
Time-dependent perturbation theory as a tool to compute approximate solutions of the Schroedinger equation does not preserve unitarity. Here we present, in a simple way, how the Magnus expansion (also known as exponential perturbation theory) provides such unitary approximate solutions. The purpose is to illustrate the importance and consequences of such a property. We suggest that the Magnus expansion may be introduced to students in advanced courses of quantum mechanics.
Local behaviour of negative thermal expansion materials
International Nuclear Information System (INIS)
Fornasini, P.; Dalba, G.; Grisenti, R.; Purans, J.; Vaccari, M.; Rocca, F.; Sanson, A.
2006-01-01
EXAFS can represent a powerful probe of the local behaviour of negative thermal expansion (NTE) materials, thanks to the possibility of measuring the expansion of selected inter-atomic bonds and the perpendicular relative atomic displacements. The effectiveness of EXAFS for NTE studies is illustrated by a comparison of results recently obtained on germanium, CuCl and the cuprites Cu 2 O and Ag 2 O
Resolution of hydrodynamical equations for transverse expansions
International Nuclear Information System (INIS)
Hama, Y.; Pottag, F.W.
1985-01-01
The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage we have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. The present paper is concerned with the formalism and the numerical results will be reported in another paper. (Author) [pt
Stochastic quantization and 1/N expansion
International Nuclear Information System (INIS)
Brunelli, J.C.; Mendes, R.S.
1992-10-01
We study the 1/N expansion of field theories in the stochastic quantization method of Parisi and Wu using the supersymmetric functional approach. This formulation provides a systematic procedure to implement the 1/N expansion which resembles the ones used in the equilibrium. The 1/N perturbation theory for the non linear sigma model in two dimensions is worked out as an example. (author). 19 refs., 5 figs
Foundations on Expansive Soils; A Review
Behzad Kalantari
2012-01-01
This study describes various types of foundation designs to be considered for structural engineering projects when the subsoil foundation consists of expansive or swelling soils. Among civil and architectural engineers expansive soils are known to be difficult foundation materials and problematic. These type of soils swell when they are subjected to moistures and shrink due to moisture loss. Because of this different behaviour upon wetting and drying, they cause minor to major structural dama...
Energy Technology Data Exchange (ETDEWEB)
Santos, Juracir Silva
2011-07-01
The work was developed under the project 993/2007 - 'Development of analytical strategies for uranium determination in environmental and industrial samples - Environmental monitoring in the Caetite city, Bahia, Brazil' and made possible through a partnership established between Universidade Federal da Bahia and the Comissao Nacional de Energia Nuclear. Strategies were developed to uranium determination in natural water and effluents of uranium mine. The first one was a critical evaluation of the determination of uranium by inductively coupled plasma optical emission spectrometry (ICP OES) performed using factorial and Doehlert designs involving the factors: acid concentration, radio frequency power and nebuliser gas flow rate. Five emission lines were simultaneously studied (namely: 367.007, 385.464, 385.957, 386.592 and 409.013 nm), in the presence of HN0{sub 3}, H{sub 3}C{sub 2}00H or HCI. The determinations in HN0{sub 3} medium were the most sensitive. Among the factors studied, the gas flow rate was the most significant for the five emission lines. Calcium caused interference in the emission intensity for some lines and iron did not interfere (at least up to 10 mg L{sup -1}) in the five lines studied. The presence of 13 other elements did not affect the emission intensity of uranium for the lines chosen. The optimized method, using the line at 385.957 nm, allows the determination of uranium with limit of quantification of 30 {mu}g L{sup -1} and precision expressed as RSD lower than 2.2% for uranium concentrations of either 500 and 1000 {mu}g L{sup -1}. In second one, a highly sensitive flow-based procedure for uranium determination in natural waters is described. A 100-cm optical path flow cell based on a liquid-core waveguide (LCW) was exploited to increase sensitivity of the arsenazo 111 method, aiming to achieve the limits established by environmental regulations. The flow system was designed with solenoid micro-pumps in order to improve mixing and
Thermal expansion behavior in fabricated cellular structures
International Nuclear Information System (INIS)
Oruganti, R.K.; Ghosh, A.K.; Mazumder, J.
2004-01-01
Thermal expansion behavior of cellular structures is of interest in applications where undesirable deformation and failure are caused by thermal expansion mismatch. This report describes the role of processing-induced effects and metallurgical aspects of melt-processed cellular structures, such as a bi-material structure designed to contract on heating, as well as uni-material structures of regular and stochastic topology. This bi-material structure utilized the principle of internal geometric constraints to alter the expansion behavior of the internal ligaments to create overall contraction of the structure. Homogenization design method was used to design the structure, and fabrication was by direct metal deposition by laser melting of powder in another part of a joint effort. The degree of porosity and grain size in the fabricated structure are characterized and related to the laser deposition parameters. The structure was found to contract upon heating over a short range of temperature subsequent to which normal expansion ensued. Also examined in this report are uni-material cellular structures, in which internal constraints arise from residual stress variations caused by the fabrication process, and thereby alter their expansion characteristics. A simple analysis of thermal strain of this material supports the observed thermal expansion behavior
Thin foil expansion into a vacuum
International Nuclear Information System (INIS)
Mora, P.
2005-01-01
Plasma expansion into a vacuum is an old problem which has been renewed recently in various contexts: expansion of ultra-cold plasmas, cluster expansion, of dust grains, expansion of thin foils. In this presentation I will first discuss the physics of the expansion of a thin foil irradiated by an ultra-short ultra-intense laser pulse. The expansion results in the formation of high energy ions. For an infinitely steep plasma-vacuum interface the fastest ions are located in the outer part of the expansion and their velocity is given by ν m ax∼ 2 C s (In ω p it) where c s (Zk B T e /m i )''1/2 is the ion-acoustic velocity ω p i=(n e 0Ze''2/m i e 0 )''1/2 is the ion plasma frequency, n e 0 is the electron density in the unperturbed plasma, Z is the ion charge number. In the above expression, t is either the pulse duration or the effective acceleration time (in particular t∼L/2c s , where L is the width of the foil, when the electron cooling is taken into account). A salient characteristic of the expansion is the occurrence of a double layer structure and a peak of the accelerating electric field at the ion front. I will explain the origin of the peak and predict its temporal behavior. This peak has been diagnosed in recent experiments. I will also discuss the effect of a 2-temperatures electron distribution function on the expansion, showing the dominant role of the hot electron component. Finally I will discuss the occurrence of ion spikes in the expansion when the initial density profile is smooth. The ion spike is due to a wave breaking which cannot be handled in a satisfactory way by a fluid code and requires a kinetic description. A. simple collisionless particle code has been used to treat the evolution of the spike after the wave breaking and the results will be shown. (Author)
Negative thermal expansion materials: technological key for control of thermal expansion.
Takenaka, Koshi
2012-02-01
Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over -30 ppm K -1 . Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade.
Negative thermal expansion materials: technological key for control of thermal expansion
Directory of Open Access Journals (Sweden)
Koshi Takenaka
2012-01-01
Full Text Available Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K−1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade.
Negative thermal expansion materials: technological key for control of thermal expansion
International Nuclear Information System (INIS)
Takenaka, Koshi
2012-01-01
Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K −1 . Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade. (topical review)
Expansion Under Climate Change: The Genetic Consequences.
Garnier, Jimmy; Lewis, Mark A
2016-11-01
Range expansion and range shifts are crucial population responses to climate change. Genetic consequences are not well understood but are clearly coupled to ecological dynamics that, in turn, are driven by shifting climate conditions. We model a population with a deterministic reaction-diffusion model coupled to a heterogeneous environment that develops in time due to climate change. We decompose the resulting travelling wave solution into neutral genetic components to analyse the spatio-temporal dynamics of its genetic structure. Our analysis shows that range expansions and range shifts under slow climate change preserve genetic diversity. This is because slow climate change creates range boundaries that promote spatial mixing of genetic components. Mathematically, the mixing leads to so-called pushed travelling wave solutions. This mixing phenomenon is not seen in spatially homogeneous environments, where range expansion reduces genetic diversity through gene surfing arising from pulled travelling wave solutions. However, the preservation of diversity is diminished when climate change occurs too quickly. Using diversity indices, we show that fast expansions and range shifts erode genetic diversity more than slow range expansions and range shifts. Our study provides analytical insight into the dynamics of travelling wave solutions in heterogeneous environments.
Simplified Technique for Predicting Offshore Pipeline Expansion
Seo, J. H.; Kim, D. K.; Choi, H. S.; Yu, S. Y.; Park, K. S.
2018-06-01
In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs, which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio (SDR) versus virtual anchor length (L A ) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline, offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.
Preliminary thermal expansion screening data for tuffs
International Nuclear Information System (INIS)
Lappin, A.R.
1980-03-01
A major variable in evaluating the potential of silicic tuffs for use in geologic disposal of heat-producing nuclear wastes is thermal expansion. Results of ambient-pressure linear expansion measurements on a group of tuffs that vary treatly in porosity and mineralogy are presente here. Thermal expansion of devitrified welded tuffs is generally linear with increasing temperature and independent of both porosity and heating rate. Mineralogic factors affecting behavior of these tuffs are limited to the presence or absence of cristobalite and altered biotite. The presence of cristobalite results in markedly nonlinear expansion above 200 0 C. If biotite in biotite-hearing rocks alters even slightly to expandable clays, the behavior of these tuffs near the boiling point of water can be dominated by contraction of the expandable phase. Expansion of both high- and low-porosity tuffs containing hydrated silicic glass and/or expandable clays is complex. The behavior of these rocks appears to be completely dominated by dehydration of hydrous phases and, hence, should be critically dependent on fluid pressure. Valid extrapolation of the ambient-pressure results presented here to depths of interest for construction of a nuclear-waste repository will depend on a good understanding of the interaction of dehydration rates and fluid pressures, and of the effects of both micro- and macrofractures on the response of tuff masss
Mapping Brazilian Cropland Expansion, 2000-2013
Zalles, V.; Hansen, M.; Potapov, P.
2016-12-01
Brazil is one of the world's leading producers and exporters of agricultural goods. Despite undergoing significant increases in its cropland area in the last decades, it remains one of the countries with the most potential for further agricultural expansion. Most notably, the expansion in production areas of commodity crops such as soybean, corn, and sugarcane has become the leading cause of land cover conversion in Brazil. Natural land covers, such as the Amazon and Cerrado forests, have been negatively affected by this agricultural expansion, causing carbon emissions, biodiversity loss, altered water cycles, and many other disturbances to ecosystem services. Monitoring of change in cropland area extent can provide relevant information to decision makers seeking to understand and manage land cover change drivers and their impacts. In this study, the freely-available Landsat archive was leveraged to produce a large-scale, methodologically consistent map of cropland cover at 30 m. resolution for the entire Brazilian territory in the year 2000. Additionally, we mapped cropland expansion from 2000 to 2013, and used statistical sampling techniques to accurately estimate cropland area per Brazilian state. Using the Global Forest Change product produced by Hansen et al. (2013), we can disaggregate forest cover loss due to cropland expansion by year, revealing spatiotemporal trends that could advance our understanding of the drivers of forest loss.
Hematoma Expansion Following Acute Intracerebral Hemorrhage
Brouwers, H. Bart; Greenberg, Steven M.
2013-01-01
Intracerebral hemorrhage, the most devastating form of stroke, has no specific therapy proven to improve outcome by randomized controlled trial. Location and baseline hematoma volume are strong predictors of mortality, but are non-modifiable by the time of diagnosis. Expansion of the initial hematoma is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for hematoma expansion have been identified, including baseline ICH volume, early presentation after symptom onset, anticoagulation, and the CT angiography spot sign. Although the biological mechanisms of hematoma expansion remain unclear, accumulating evidence supports a model of ongoing secondary bleeding from ruptured adjacent vessels surrounding the initial bleeding site. Several large clinical trials testing therapies aimed at preventing hematoma expansion are in progress, including aggressive blood pressure reduction, treatment with recombinant factor VIIa guided by CT angiography findings, and surgical intervention for superficial hematomas without intraventricular extension. Hematoma expansion is so far the only marker of outcome that is amenable to treatment and thus a potentially important therapeutic target. PMID:23466430
Considering FACTS in Optimal Transmission Expansion Planning
Directory of Open Access Journals (Sweden)
K. Soleimani
2017-10-01
Full Text Available The expansion of power transmission systems is an important part of the expansion of power systems that requires enormous investment costs. Since the construction of new transmission lines is very expensive, it is necessary to choose the most efficient expansion plan that ensures system security with a minimal number of new lines. In this paper, the role of Flexible AC Transmission System (FACTS devices in the effective operation and expansion planning of transmission systems is examined. Effort was taken to implement a method based on sensitivity analysis to select the optimal number and location of FACTS devices, lines and other elements of the transmission system. Using this method, the transmission expansion plan for a 9 and a 39 bus power system was performed with and without the presence of FACTS with the use of DPL environment in Digsilent software 15.1. Results show that the use of these devices reduces the need for new transmission lines and minimizes the investment cost.
Thermal expansion of fibre-reinforced composites
International Nuclear Information System (INIS)
Schneider, B.
1991-07-01
The integral thermal expansion and the coefficient of thermal expansion (CTE) of carbon and Kevlar fibre-reinforced composites were measured with high accuracy from 5 K to room temperature. For this, a laser dilatometer and a sophisticated measuring procedure were used. CTE dependence on the orientation angle ω of angle-ply laminates was determined for samples with 5 different fibre alignments (UD 0deg, +/-30deg, +/-45deg, +/-60deg and UD 90deg). A high variability of the CTE with the orientation angle was shown. At angles of approximately +/-30deg even negative CTEs were found. With suitable reinforcing fibres being selected, their absolute values rose up to 30-100% of the positive CTEs of metals. Hence, composites of this type would be suitable as compensating materials in metal constructions where little thermal expansion is desired. To check the lamination theory, theoretical computations of the CTE- ω -dependence were compared with the measured values. An excellent agreement was found. Using the lamination theory, predictions about the expansion behaviour of angle-ply laminates can be made now, if the thermal and mechanical properties of the unidirectional (UD) laminate are known. Furthermore, it is possible to carry out simulation computations aimed at investigating the influence of a single parameter of the UD-laminate (e.g. shear modulus) on the expansion of the angle-ply laminate. (orig.) [de
Shen, Fei-Ran; Kuang, Hao; Hu, Feng-Xia; Wu, Hui; Huang, Qing-Zhen; Liang, Fei-Xiang; Qiao, Kai-Ming; Li, Jia; Wang, Jing; Liu, Yao; Zhang, Lei; He, Min; Zhang, Ying; Zuo, Wen-Liang; Sun, Ji-Rong; Shen, Bao-Gen
2017-10-01
Materials with zero thermal expansion (ZTE) or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE) materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn-Co-Ge-In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE owing to a martensitic magnetostructural transition. The major finding is that the thermal expansion behavior can be totally controlled by modulating the crystallinity degree and phase transition from atomic scale. Self-compensation effect leads to ultra-low thermal expansion with a linear expansion coefficient as small as +0.68 × 10-6/K over a wide temperature range around room temperature. The present study opens an avenue to reach ZTE particularly from the large class of giant NTE materials based on phase transition.
Directory of Open Access Journals (Sweden)
Fei-Ran Shen
2017-10-01
Full Text Available Materials with zero thermal expansion (ZTE or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn–Co–Ge–In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE owing to a martensitic magnetostructural transition. The major finding is that the thermal expansion behavior can be totally controlled by modulating the crystallinity degree and phase transition from atomic scale. Self-compensation effect leads to ultra-low thermal expansion with a linear expansion coefficient as small as +0.68 × 10−6/K over a wide temperature range around room temperature. The present study opens an avenue to reach ZTE particularly from the large class of giant NTE materials based on phase transition.
Supersonic expansion of argon into vacuum
Energy Technology Data Exchange (ETDEWEB)
Habets, A H.M.
1977-01-21
A theoretical description of a free supersonic expansion process is given. Three distinct regions in the expansion are discussed, namely the continuum region, the gradual transition to the collisionless regime, and the free-molecular-flow stage. Important topics are the peaking-factor formalism, the thermal-conduction model, and the virtual-source formalism. The formation of the molecular beam from the expansion and condensation phenomena occurring in the expanding gas are discussed. The molecular beam machine used in the measurements is described and special attention is given to the cryopumps used in the supersonic sources as well as to the time-of-flight analysis of the molecular beam velocity distributions. Finally, the processing of experimental data is discussed, particularly the least-squares determination of best-fit representations of the measurements.
Origami structures for tunable thermal expansion
Boatti, Elisa; Bertoldi, Katia
Materials with engineered thermal expansion, capable of achieving targeted and extreme area/volume changes in response to variations in temperature, are important for a number of aerospace, optical, energy, and microelectronic applications. While most of the proposed structures with tunable coefficient of thermal expansion consist of bi-material 2D or 3D lattices, here we propose a periodic metastructure based on a bilayer Miura-Ori origami fold. We combine experiments and simulations to demonstrate that by tuning the geometrical and mechanical parameters an extremely broad range of thermal expansion coefficients can be obtained, spanning both negative and positive values. Additionally, the thermal properties along different directions can be adjusted independently. Differently from all previously reported systems, the proposed structure is non-porous.
Radial expansion for spinning conformal blocks
Costa, Miguel S.; Penedones, João; Trevisani, Emilio
2016-07-12
This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.
Thermal expansion of quaternary nitride coatings
Tasnádi, Ferenc; Wang, Fei; Odén, Magnus; Abrikosov, Igor A.
2018-04-01
The thermal expansion coefficient of technologically relevant multicomponent cubic nitride alloys are predicted using the Debye model with ab initio elastic constants calculated at 0 K and an isotropic approximation for the Grüneisen parameter. Our method is benchmarked against measured thermal expansion of TiN and Ti(1-x)Al x N as well as against results of molecular dynamics simulations. We show that the thermal expansion coefficients of Ti(1-x-y)X y Al x N (X = Zr, Hf, Nb, V, Ta) solid solutions monotonously increase with the amount of alloying element X at all temperatures except for Zr and Hf, for which they instead decrease for y≳ 0.5 .
On a generalized oscillator system: interbasis expansions
Energy Technology Data Exchange (ETDEWEB)
Kibler, M [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Mardoyan, L G; Pogosyan, G S [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Theoretical Physics
1997-12-31
This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,.
Anisotropic thermal expansion in flexible materials
Romao, Carl P.
2017-10-01
A definition of the Grüneisen parameters for anisotropic materials is derived based on the response of phonon frequencies to uniaxial stress perturbations. This Grüneisen model relates the thermal expansion in a given direction (αi i) to one element of the elastic compliance tensor, which corresponds to the Young's modulus in that direction (Yi i). The model is tested through ab initio prediction of thermal expansion in zinc, graphite, and calcite using density functional perturbation theory, indicating that it could lead to increased accuracy for structurally complex systems. The direct dependence of αi i on Yi i suggests that materials which are flexible along their principal axes but rigid in other directions will generally display both positive and negative thermal expansion.
On a generalized oscillator system: interbasis expansions
International Nuclear Information System (INIS)
Kibler, M.; Mardoyan, L.G.; Pogosyan, G.S.
1996-01-01
This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,
Supersonic expansion of argon into vacuum
International Nuclear Information System (INIS)
Habets, A.H.M.
1977-01-01
A theoretical description of a free supersonic expansion process is given. Three distinct regions in the expansion are discussed, namely the continuum region, the gradual transition to the collisionless regime, and the free-molecular-flow stage. Important topics are the peaking-factor formalism, the thermal-conduction model, and the virtual-source formalism. The formation of the molecular beam from the expansion and condensation phenomena occurring in the expanding gas are discussed. The molecular beam machine used in the measurements is described and special attention is given to the cryopumps used in the supersonic sources as well as to the time-of-flight analysis of the molecular beam velocity distributions. Finally, the processing of experimental data is discussed, particularly the least-squares determination of best-fit representations of the measurements
Back Reaction And Local Cosmological Expansion Rate
Geshnizjani, G; Geshnizjani, Ghazal; Brandenberger, Robert
2002-01-01
We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.
Longitudinal expansion of field line dipolarization
Saka, O.; Hayashi, K.
2017-11-01
We examine the substorm expansions that started at 1155 UT 10 August 1994 in the midnight sector focusing on the longitudinal (eastward) expansion of field line dipolarization in the auroral zone. Eastward expansion of the dipolarization region was observed in all of the H, D, and Z components. The dipolarization that started at 1155 UT (0027 MLT) from 260° of geomagnetic longitude (CMO) expanded to 351°(PBQ) in about 48 min. The expansion velocity was 0.03-0.04°/s, or 1.9 km/s at 62°N of geomagnetic latitude. The dipolarization region expanding to the east was accompanied by a bipolar event at the leading edge of the expansion in latitudes equatorward of the westward electrojet (WEJ). In the midnight sector at the onset meridian, the Magnetospheric Plasma Analyzer (MAP) on board geosynchronous satellite L9 measured electrons and ions between 10 eV and 40 keV. We conclude from the satellite observations that this dipolarization was characterized by the evolution of temperature anisotropies, an increase of the electron and ion temperatures, and a rapid change in the symmetry axis of the temperature tensor. The field line dipolarization and its longitudinal expansion were interpreted in terms of the slow MHD mode triggered by the current disruption. We propose a new magnetosphere-ionosphere coupling (MI-coupling) mechanism based on the scenario that transmitted westward electric fields from the magnetosphere in association with expanding dipolarization produced electrostatic potential (negative) in the ionosphere through differences in the mobility of collisional ions and collisionless electrons. The field-aligned currents that emerged from the negative potential region are arranged in a concentric pattern around the negative potential region, upward toward the center and downward on the peripheral.
Eigenfunction expansion for fractional Brownian motions
International Nuclear Information System (INIS)
Maccone, C.
1981-01-01
The fractional Brownian motions, a class of nonstationary stochastic processes defined as the Riemann-Liouville fractional integral/derivative of the Brownian motion, are studied. It is shown that these processes can be regarded as the output of a suitable linear system of which the input is the white noise. Their autocorrelation is then derived with a study of their standard-deviation curves. Their power spectra are found by resorting to the nonstationary spectral theory. And finally their eigenfunction expansion (Karhunen-Loeve expansion) is obtained: the eigenfunctions are proved to be suitable Bessel functions and the eigenvalues zeros of the Bessel functions. (author)
New dynamic system suggested for earth expansion
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, J [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias
1972-01-01
It is here suggested that there may have been much more radioactive materials in the deep interior of the earth than bitherto supposed. Trapped heat being generated in the interior would provide a mechanism for earth expansion. An assumption of heat generation in the deep interior of the earth of the order of 0,5 X 10-13 calories per second, per cubic centimeter, would provide sufficient thermal expansion to account for approximately 0.1 mm. change in the radius of the earth per year.
Large J expansion in ABJM theory revisited.
Dimov, H; Mladenov, S; Rashkov, R C
Recently there has been progress in the computation of the anomalous dimensions of gauge theory operators at strong coupling by making use of the AdS/CFT correspondence. On the string theory side they are given by dispersion relations in the semiclassical regime. We revisit the problem of a large-charge expansion of the dispersion relations for simple semiclassical strings in an [Formula: see text] background. We present the calculation of the corresponding anomalous dimensions of the gauge theory operators to an arbitrary order using three different methods. Although the results of the three methods look different, power series expansions show their consistency.
Near threshold expansion of Feynman diagrams
International Nuclear Information System (INIS)
Mendels, E.
2005-01-01
The near threshold expansion of Feynman diagrams is derived from their configuration space representation, by performing all x integrations. The general scalar Feynman diagram is considered, with an arbitrary number of external momenta, an arbitrary number of internal lines and an arbitrary number of loops, in n dimensions and all masses may be different. The expansions are considered both below and above threshold. Rules, giving real and imaginary part, are derived. Unitarity of a sunset diagram with I internal lines is checked in a direct way by showing that its imaginary part is equal to the phase space integral of I particles
Thermal expansion of diamond at low temperatures.
Stoupin, Stanislav; Shvyd'ko, Yuri V
2010-02-26
Temperature variation of a lattice parameter of a synthetic diamond crystal (type IIa) was measured using high-energy-resolution x-ray Bragg diffraction in backscattering. A 2 order of magnitude improvement in the measurement accuracy allowed us to directly probe the linear thermal expansion coefficient at temperatures below 100 K. The lowest value measured was 2x10{-9} K-1. It was found that the coefficient deviates from the expected Debye law (T3) while no negative thermal expansion was observed. The anomalous behavior might be attributed to tunneling states due to low concentration impurities.
Expansion of the whole wheat flour extrusion
DEFF Research Database (Denmark)
Cheng, Hongyuan; Friis, Alan
2008-01-01
A new model framework is proposed to describe the expansion of extrudates with extruder operating conditions based on dimensional analysis principle. The Buckingham pi dimensional analysis method is applied to form the basic structure of the model from extrusion process operational parameters. Us....... Using the Central Composite Design (CCD) method, whole wheat flour was processed in a twin-screw extruder with 16 trials. The proposed model can well correlate the expansion of the 16 trials using 3 regression parameters. The average deviation of the correlation is 5.9%....
Testing the isotropy of the Hubble expansion
Migkas, K.; Plionis, M.
2016-01-01
Abstract: We have used the Union2.1 SNIa compilation to search for possible Hubble expansion anisotropies, dividing the sky in 9 solid angles containing roughly the same number of SNIa, as well as in two Galactic hemispheres. We identified only one sky region, containing 82 SNIa (~15% of total sample with z > 0.02), that indeed appears to share a Hubble expansion significantly different from the rest of the sample. However, this behaviour can be attributed to the joint "erratic" behaviour of ...
Scenarios of Expansion to Electric Generation Capacity
Directory of Open Access Journals (Sweden)
José Somoza-Cabrera
2017-06-01
Full Text Available We show the building scenarios of expansion to electric generation capacity enough to supply the demand to 2050. We were using the LEAP facility (Long-range Energy Alternatives Planning System, to simulate dispatch of electricity at minimum cost. Finally, we show the cost-benefice analysis of the technologies availability, included externality and CO2 emission limited. However that we included the externals cost in this analysis, it results insufficient to closed gap between fossil and renewable technologies of electric generation. Nevertheless, in some opportunities the renewable options had very important participations in the minimal cost scenario of expansion.
The Monetary Policy – Restrictive or Expansive?
Directory of Open Access Journals (Sweden)
Adam Szafarczyk
2007-10-01
Full Text Available The monetary policy plays an important role in macroeconomic policy of government. There is a question concerning type of this policy expansive or restrictive (easy or tidy monetary policy. Unfortunately, we have a lot of criteria. Each of them gives us other answer. So due to equitation of Irving Fisher we have dominantly expansive monetary policy. This same situation exists when we use nominal value of rediscount interest rate of central bank. Opposite result appears when we use real value of this interest rate or level of obligatory reserve. Taking under consideration liquidity on money market we know, that level of interest rate is too high.
Towards finite density QCD with Taylor expansions
International Nuclear Information System (INIS)
Karsch, F.; Schaefer, B.-J.; Wagner, M.; Wambach, J.
2011-01-01
Convergence properties of Taylor expansions of observables, which are also used in lattice QCD calculations at non-zero chemical potential, are analyzed in an effective N f =2+1 flavor Polyakov quark-meson model. A recently developed algorithmic technique allows the calculation of higher-order Taylor expansion coefficients in functional approaches. This novel technique is for the first time applied to an effective N f =2+1 flavor Polyakov quark-meson model and the findings are compared with the full model solution at finite densities. The results are used to discuss prospects for locating the QCD phase boundary and a possible critical endpoint in the phase diagram.
Expansion program is a challenging project
International Nuclear Information System (INIS)
Walker, G.L.
1992-01-01
This paper reports that construction is set to begin on the $1.5 billion PGT-PG and E Pipeline Expansion Project. It will consist of 691 miles of 42-in pipeline and 110 miles of 36-in. pipeline, to be built over 2 years. The project, which will transport additional supplies of natural gas to US West Coast markets, has its US regulatory approval in hand. On Oct. 16, 1991, the Federal Energy Regulatory Commission authorized Pacific Gas Transmission Co. to construct its Pacific Northwest segment of the expansion. Pacific Gas and Electric Co. received approval to build its California segment in late 1990 from the California Public Utilities Commission
Strategic Expansion Models in Academic Radiology.
Natesan, Rajni; Yang, Wei T; Tannir, Habib; Parikh, Jay
2016-03-01
In response to economic pressures, academic institutions in the United States and their radiology practices, are expanding into the community to build a larger network, thereby driving growth and achieving economies of scale. These economies of scale are being achieved variously via brick-and-mortar construction, community practice acquisition, and partnership-based network expansion. We describe and compare these three expansion models within a 4-part framework of: (1) upfront investment; (2) profitability impact; (3) brand impact; and (4) risk of execution. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Munoz Mazo, Eduin Orlando [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Centro de Estudo do Petroleo. Lab. de Simulacao de Fluxo em Meios Porosos (UNISIM); Costa, Odair Jose; Schiozer, Denis Jose [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo
2008-07-01
Water injection under fracturing conditions is a proved manner of overcoming injectivity loss in reservoirs affected by formation damage. Nevertheless, as shown by Munoz Mazo et al. (2006), there is the possibility of the generated and propagated fractures intercept the producer wells making that the injected water shall be re-circulated into the reservoir instead of its main function which is to drive the oil contained in the reservoir pore space. The objective of this work is to determine the influence of well spacing on the determination of the water injection rate under fracturing conditions, aiming to study its effects on the production performance and the sweep efficiency. To accomplish the work, an analytical model for representing the absolute permeability reduction near the wellbore and a model which reproduces the fracture propagation in a coupled manner are used. In this way the model sensitivity to several well spacing and the injection rate effects are analyzed using the Net Present Value and the sweep efficiency is evaluated as a function of the Recovery Factor. The results show that the water injection under fracturing conditions is an effective way of overcoming the injectivity loss problem and evidence its sensitivity to different spacing between the injector and the producer wells. (author)
Directory of Open Access Journals (Sweden)
Luís Antônio Jorge
1993-12-01
Full Text Available A preocupação fundamenta! do trabalho é de caráter ontológico: esboçar o problema das significações apriorísticas e autônomas dos elementos que compõem a sintaxe arquitetônica. O trabalho elege um desses elementos: a janela. Este artigo parte da aproximação histórica entre a janela e a secção da pirâmide visual, construção imaginária da teoria da perspectiva renascentista. A consideração da janela na linguagem arquitetônica implica reconhecer uma ambigüidade essencial: a janela deve inserir-se ordenadamente no plano da parede - raciocínio típico da modenatura - mas também relacionar-se com a imagem vista através dela, que extrapola o plano, ressaltando a tridimensionalidade - herança da perspectiva renascentista, fundamentada no espaço euclidiano. Ver janela ou ver através da janela são alternativas que se colocam tanto ao observador interno ao edifício, quanto ao externo. Texto de duplaface, a sintaxe da janela versa sobre o relacionamento desses dois lados
From greedy to lazy expansions and their driving dynamics
Dajani, K.; Kraaikamp, C.
2001-01-01
In this paper we study the ergodic properties of non-greedy series expansions to non-integer bases β > 1. It is shown that the so-called 'lazy' expansion is isomorphic to the 'greedy' expansion. Furthermore, a class of expansions to base β > 1, β =2 Z, 'in between' the lazy and the greedy
Parabolic cyclinder functions : examples of error bounds for asymptotic expansions
R. Vidunas; N.M. Temme (Nico)
2002-01-01
textabstractSeveral asymptotic expansions of parabolic cylinder functions are discussedand error bounds for remainders in the expansions are presented. Inparticular Poincaré-type expansions for large values of the argument$z$ and uniform expansions for large values of the parameter areconsidered.
Electrical Resistance Alloys and Low-Expansion Alloys
DEFF Research Database (Denmark)
Kjer, Torben
1996-01-01
The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...... thermoelastic coefficients and age hardenable low expansion alloys....
Edgeworth expansion for functionals of continuous diffusion processes
DEFF Research Database (Denmark)
Podolskij, Mark; Yoshida, Nakahiro
This paper presents new results on the Edgeworth expansion for high frequency functionals of continuous diffusion processes. We derive asymptotic expansions for weighted functionals of the Brownian motion and apply them to provide the Edgeworth expansion for power variation of diffusion processes....... Our methodology relies on martingale embedding, Malliavin calculus and stable central limit theorems for semimartingales. Finally, we demonstrate the density expansion for studentized statistics of power variations.......This paper presents new results on the Edgeworth expansion for high frequency functionals of continuous diffusion processes. We derive asymptotic expansions for weighted functionals of the Brownian motion and apply them to provide the Edgeworth expansion for power variation of diffusion processes...
Principles of Thermal Expansion in Feldspars
Hovis, Guy; Medford, Aaron; Conlon, Maricate; Tether, Allison; Romanoski, Anthony
2010-05-01
Following the recent thermal expansion work of Hovis et al. (1) on AlSi3 feldspars, we have investigated the thermal expansion of plagioclase, Ba-K, and Ca-K feldspar crystalline solutions. X-ray powder diffraction data were collected between room temperature and 925 °C on six natural plagioclase specimens ranging in composition from anorthite to oligoclase, the K-exchanged equivalents of these plagioclase specimens, and five synthetic Ba-K feldspars with compositions ranging from 25 to 99 mol % BaAl2Si2O8. The resulting thermal expansion coefficients (α) for volume have been combined with earlier results for end-member Na- and K-feldspars (2,3). Unlike AlSi3 feldspars, Al2Si2 feldspars, including anorthite and celsian from the present study plus Sr- and Pb-feldspar from other workers (4,5), show essentially constant and very limited thermal expansion, regardless of divalent cation size. In the context of structures where the Lowenstein rule (6) requires Al and Si to alternate among tetrahedra, the proximity of bridging Al-O-Si oxygen ions to divalent neighbors (ranging from 0 to 2) produces short Ca-O (or Ba-O) bonds (7,8) that apparently are the result of local charge-balance requirements (9). Gibbs et al. (10) suggest that short bonds such as these have a partially covalent character. This in turn stiffens the structure. Thus, for feldspar series with coupled substitution the change away from a purely divalent M-site occupant gives the substituting (less strongly bonded) monovalent cations increasingly greater influence on thermal expansion. Overall, then, thermal expansion in the feldspar system is well represented on a plot of α against room-temperature volume, where one sees a quadrilateral bounded by data for (A) AlSi3 feldspars whose expansion behavior is controlled largely by the size of the monovalent alkali-site occupant, (B) Al2Si2 feldspars whose expansion is uniformly limited by partially-covalent bonds between divalent M-site occupants and
DEFF Research Database (Denmark)
Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens
1996-01-01
-sum type. For the latter case, it enables “The Trick.” In this article, we extend Gomard and Jones' partial evaluator for the &lgr;-calculus, &lgr;-Mix, with products and disjoint sums; we point out how eta-expansion for (finite) disjoint sums enable The Trick; we generalize our earlier work by identifying...
DEFF Research Database (Denmark)
Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens
1995-01-01
-sum type. For the latter case, it enables “The Trick.” In this article, we extend Gomard and Jones' partial evaluator for the &lgr;-calculus, &lgr;-Mix, with products and disjoint sums; we point out how eta-expansion for (finite) disjoint sums enable The Trick; we generalize our earlier work by identifying...
Thermal Expansion Properties of Aerospace Materials
Green, E. F.
1969-01-01
Thermal expansion properties of materials used in aerospace systems are compiled into a single handbook. The data, derived from experimental measurements supplemented by information from literature sources, are presented in charts and tables arranged in two sections, covering cryogenic and elevated temperatures.
Cropland expansion in Brazil, 2000 to 2014
Zalles, V.; Hansen, M.; Potapov, P.; Stehman, S. V.; Tyukavina, A.; Pickens, A. H.; Okpa, C.; Aguilar, R.; John, N.; Chavez, S.
2017-12-01
Brazil has become a global leader in the production of commodity row crops such as soybean, sugarcane, cotton, and corn. Here, we employ 30m spatial resolution Landsat data to estimate cropland extent in the year 2000 and its subsequent expansion through 2014. A probability-based sample of reference data allows us to report unbiased estimates of national, biome, and state-scale area of crop expansion with associated uncertainties. We find an increase in Brazilian cropland extent from 26.0 Mha in 2000 to 46.1 Mha in 2014. The cropland frontier states of Maranhao, Tocantins, Piaui, Bahia (MATOPIBA), Mato Grosso, Mato Grosso do Sul, and Para all more than doubled in cropland extent. The states of Goias, Minas Gerais and Sao Paulo experienced >50% increases. The vast majority of expansion, 79%, occurred on repurposed pasture lands, and 20% from the conversion of natural vegetation. Area of converted Cerrado savannas was nearly 2.5 times that of Amazon forests, and accounted for over half of new cropland in MATOPIBA. Spatio-temporal dynamics of cropland expansion are reflected in market conditions, land use policies, and other factors. Continued extensification of cropland is a viable option across Brazil with attendant benefits for and challenges to development.
Territorial expansion and primary state formation.
Spencer, Charles S
2010-04-20
A major research problem in anthropology is the origin of the state and its bureaucratic form of governance. Of particular importance for evaluating theories of state origins are cases of primary state formation, whereby a first-generation state evolves without contact with any preexisting states. A general model of this process, the territorial-expansion model, is presented and assessed with archaeological data from six areas where primary states emerged in antiquity: Mesoamerica, Peru, Egypt, Mesopotamia, the Indus Valley, and China. In each case, the evidence shows a close correspondence in time between the first appearance of state institutions and the earliest expansion of the state's political-economic control to regions lying more than a day's round-trip from the capital. Although additional research will add detail and clarity to the empirical record, the results to date are consistent with the territorial-expansion model, which argues that the success of such long-distance expansion not only demanded the bureaucratization of central authority but also helped provide the resources necessary to underwrite this administrative transformation.
Thermal expansion absorbing structure for pipeline
International Nuclear Information System (INIS)
Nagata, Takashi; Yamashita, Takuya.
1995-01-01
A thermal expansion absorbing structure for a pipeline is disposed to the end of pipelines to form a U-shaped cross section connecting a semi-circular torus shell and a short double-walled cylindrical tube. The U-shaped longitudinal cross-section is deformed in accordance with the shrinking deformation of the pipeline and absorbs thermal expansion. Namely, since the central lines of the outer and inner tubes of the double-walled cylindrical tube deform so as to incline, when the pipeline is deformed by thermal expansion, thermal expansion can be absorbed by a simple configuration thereby enabling to contribute to ensure the safety. Then, the entire length of the pipeline can greatly be shortened by applying it to the pipeline disposed in a high temperature state compared with a method of laying around a pipeline using only elbows, which has been conducted so far. Especially, when it is applied to a pipeline for an FBR-type reactor, the cost for the construction of a facility of a primary systems can greater be reduced. In addition, it can be applied to a pipeline for usual chemical plants and any other structures requiring absorption of deformation. (N.H.)
The asymptotic expansion method via symbolic computation
Navarro, Juan F.
2012-01-01
This paper describes an algorithm for implementing a perturbation method based on an asymptotic expansion of the solution to a second-order differential equation. We also introduce a new symbolic computation system which works with the so-called modified quasipolynomials, as well as an implementation of the algorithm on it.
The Asymptotic Expansion Method via Symbolic Computation
Directory of Open Access Journals (Sweden)
Juan F. Navarro
2012-01-01
Full Text Available This paper describes an algorithm for implementing a perturbation method based on an asymptotic expansion of the solution to a second-order differential equation. We also introduce a new symbolic computation system which works with the so-called modified quasipolynomials, as well as an implementation of the algorithm on it.
Discrete expansions of continuum wave functions
International Nuclear Information System (INIS)
Bang, J.; Ershov, S.N.; Gareev, F.A.; Kazacha, G.S.
1980-01-01
Different methods of expanding continuum wave functions in terms of discrete basis sets are discussed. The convergence properties of these expansions are investigated, both from a mathematical and a numerical point of view, for the case of potentials of Woods-Saxon and square well type. (orig.)
Phase transition from strong-coupling expansion
International Nuclear Information System (INIS)
Polonyi, J.; Szlachanyi, K.
1982-01-01
Starting with quarkless SU(2) lattice gauge theory and using the strong-coupling expansion we calculate the action of the effective field theory which corresponds to the thermal Wilson loop. This effective action makes evident that the quark liberating phase transition traces back to the spontaneous breaking of a global Z(2) symmetry group. It furthermore describes both phases qualitatively. (orig.)
On Learning Ring-Sum-Expansions
DEFF Research Database (Denmark)
Fischer, Paul; Simon, H. -U.
1992-01-01
The problem of learning ring-sum-expansions from examples is studied. Ring-sum-expansions (RSE) are representations of Boolean functions over the base {#123;small infinum, (+), 1}#125;, which reflect arithmetic operations in GF(2). k-RSE is the class of ring-sum-expansions containing only monomials...... of length at most k:. term-RSE is the class of ring-sum-expansions having at most I: monomials. It is shown that k-RSE, k>or=1, is learnable while k-term-RSE, k>2, is not learnable if RPnot=NP. Without using a complexity-theoretical hypothesis, it is proven that k-RSE, k>or=1, and k-term-RSE, k>or=2 cannot...... be learned from positive (negative) examples alone. However, if the restriction that the hypothesis which is output by the learning algorithm is also a k-RSE is suspended, then k-RSE is learnable from positive (negative) examples only. Moreover, it is proved that 2-term-RSE is learnable by a conjunction...
Regulatory Holidays and Optimal Network Expansion
Willems, Bert; Zwart, Gijsbert
2016-01-01
We model the optimal regulation of continuous, irreversible, capacity expansion, in a model in which the regulated network firm has private information about its capacity costs, investments need to be financed out of the firm’s cash flows from selling network access and demand is stochastic. If
On the Convergence of the Virial Expansion
Ramawadh, S.D.
2015-01-01
The virial expansion appears in statistical mechanics, an area where physics and mathematics intersect. Throughout this thesis we will mostly ignore the physics and mainly focus on the mathematical aspects. This is a deliberate choice, made for two reasons. Firstly, there are several books that
The optimizied expansion method for wavefield extrapolation
Wu, Zedong; Alkhalifah, Tariq Ali
2013-01-01
, for inhomogeneous media, we face difficulties in dealing with the mixed space-wavenumber domain operator.In this abstract, we propose an optimized expansion method that can approximate this operator with its low rank representation. The rank defines the number
Asymptotic expansions for the Gaussian unitary ensemble
DEFF Research Database (Denmark)
Haagerup, Uffe; Thorbjørnsen, Steen
2012-01-01
Let g : R ¿ C be a C8-function with all derivatives bounded and let trn denote the normalized trace on the n × n matrices. In Ref. 3 Ercolani and McLaughlin established asymptotic expansions of the mean value ¿{trn(g(Xn))} for a rather general class of random matrices Xn, including the Gaussian U...
Analytic continuation and perturbative expansions in QCD
Czech Academy of Sciences Publication Activity Database
Caprini, I.; Fischer, Jan
2002-01-01
Roč. 24, - (2002), s. 127-135 ISSN 1434-6044 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : perturbative expansion * quantum chromodynamics * infrared ambiguity * essential singularities Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.162, year: 2002
A Pedagogical Approach to the Magnus Expansion
Blanes, S.; Casas, F.; Oteo, J. A.; Ros, J.
2010-01-01
Time-dependent perturbation theory as a tool to compute approximate solutions of the Schrodinger equation does not preserve unitarity. Here we present, in a simple way, how the "Magnus expansion" (also known as "exponential perturbation theory") provides such unitary approximate solutions. The purpose is to illustrate the importance and…
Thermal Expansion Anomaly Regulated by Entropy
Liu, Zi-Kui; Wang, Yi; Shang, Shunli
2014-11-01
Thermal expansion, defined as the temperature dependence of volume under constant pressure, is a common phenomenon in nature and originates from anharmonic lattice dynamics. However, it has been poorly understood how thermal expansion can show anomalies such as colossal positive, zero, or negative thermal expansion (CPTE, ZTE, or NTE), especially in quantitative terms. Here we show that changes in configurational entropy due to metastable micro(scopic)states can lead to quantitative prediction of these anomalies. We integrate the Maxwell relation, statistic mechanics, and first-principles calculations to demonstrate that when the entropy is increased by pressure, NTE occurs such as in Invar alloy (Fe3Pt, for example), silicon, ice, and water, and when the entropy is decreased dramatically by pressure, CPTE is expected such as in anti-Invar cerium, ice and water. Our findings provide a theoretic framework to understand and predict a broad range of anomalies in nature in addition to thermal expansion, which may include gigantic electrocaloric and electromechanical responses, anomalously reduced thermal conductivity, and spin distributions.
Instability of a planar expansion wave.
Velikovich, A L; Zalesak, S T; Metzler, N; Wouchuk, J G
2005-10-01
An expansion wave is produced when an incident shock wave interacts with a surface separating a fluid from a vacuum. Such an interaction starts the feedout process that transfers perturbations from the rippled inner (rear) to the outer (front) surface of a target in inertial confinement fusion. Being essentially a standing sonic wave superimposed on a centered expansion wave, a rippled expansion wave in an ideal gas, like a rippled shock wave, typically produces decaying oscillations of all fluid variables. Its behavior, however, is different at large and small values of the adiabatic exponent gamma. At gamma > 3, the mass modulation amplitude delta(m) in a rippled expansion wave exhibits a power-law growth with time alpha(t)beta, where beta = (gamma - 3)/(gamma - 1). This is the only example of a hydrodynamic instability whose law of growth, dependent on the equation of state, is expressed in a closed analytical form. The growth is shown to be driven by a physical mechanism similar to that of a classical Richtmyer-Meshkov instability. In the opposite extreme gamma - 1 gas with low . Exact analytical expressions for the growth rates are derived for both cases and favorably compared to hydrodynamic simulation results.
Stakeholder Support for School Food Policy Expansions
Pettigrew, Simone; Pescud, Melanie; Donovan, Robert J.
2012-01-01
The aim of this study was to assess the extent to which parents and school-based stakeholders (principals, teachers, canteen managers and Parents & Citizen Committee presidents) are supportive of potential expansions to a new school food policy. Eight additional policy components elicited in preliminary focus groups with parents and 19 additional…
Instability of a planar expansion wave
International Nuclear Information System (INIS)
Velikovich, A.L.; Zalesak, S.T.; Metzler, N.; Wouchuk, J.G.
2005-01-01
An expansion wave is produced when an incident shock wave interacts with a surface separating a fluid from a vacuum. Such an interaction starts the feedout process that transfers perturbations from the rippled inner (rear) to the outer (front) surface of a target in inertial confinement fusion. Being essentially a standing sonic wave superimposed on a centered expansion wave, a rippled expansion wave in an ideal gas, like a rippled shock wave, typically produces decaying oscillations of all fluid variables. Its behavior, however, is different at large and small values of the adiabatic exponent γ. At γ>3, the mass modulation amplitude δm in a rippled expansion wave exhibits a power-law growth with time ∝t β , where β=(γ-3)/(γ-1). This is the only example of a hydrodynamic instability whose law of growth, dependent on the equation of state, is expressed in a closed analytical form. The growth is shown to be driven by a physical mechanism similar to that of a classical Richtmyer-Meshkov instability. In the opposite extreme γ-1 -1/2 , and then starts to decrease. The mechanism driving the growth is the same as that of Vishniac's instability of a blast wave in a gas with low γ. Exact analytical expressions for the growth rates are derived for both cases and favorably compared to hydrodynamic simulation results
Hole expansion test of third generation steels
Agirre, Julen; Mendiguren, Joseba; Galdos, Lander; de Argandoña, Eneko Sáenz
2017-10-01
The trend towards the implementation of new materials in the chassis of the automobiles is considerably making more complex the manufacturing of the components that built it up. In this scenario materials with higher strengths and lower formabilities are daily faced by tool makers and component producers what reduces the process windows and makes the forming processes to be in the limits of the materials. One of the concerns that tool makers must face during the definition of the tools is the expansion ratios that the holes in the sheet may reach before producing a breakage due to the stretching of the material (also known as edge cracks). For the characterization of such limits, a standard test, the hole expansion test, can be applied so that the limits of the material are known. At the present study, hole expansion tests of a third generation steel, Fortiform1050 with a thickness of 1.2 millimeters have been carried out and compared them to a mild steel, DX54D with a thickness of 0.6 millimeters. A comparison for each material in terms of technology used to punch the hole, mechanical punching vs laser cutting has also been conducted. In addition, the measurement technique (online measurement vs offline measurement) followed in the Hole Expansion Ratio (HER) identification has also been analyzed. Finally, differences between both materials and techniques are presented.
Asymptotic behaviour of firmly non expansive sequences
International Nuclear Information System (INIS)
Rouhani, B.D.
1993-04-01
We introduce the notion of firmly non expansive sequences in a Banach space and present several results concerning their asymptotic behaviour extending previous results and giving an affirmative answer to an open question raised by S. Reich and I. Shafir. Applications to averaged mappings are also given. (author). 16 refs
The stagnation of electric system expansion
International Nuclear Information System (INIS)
Santos, A.M. dos
1989-01-01
The main works in the Brazilian electric sector in 1988 is presented, mentioning the fault of financier resources. The electric power tariffs by a real economical cost are also cited, allowing some advantages that can resolve the investment problem in the electric power expansion. (author)
Peruvian Higher Education: Expansions Amid Economic Crisis.
Post, David
1991-01-01
Development of the Peruvian university system is described, focusing on periods of rapid expansion. Enrollment declines in 1974-78 are analyzed in the context of the educational reform program of the military government. The 1983 new university law, following return to civilian government, and future prospects for higher education are discussed.…
Form factor expansion for thermal correlators
Pozsgay, B.; Takács, G.
2010-01-01
We consider finite temperature correlation functions in massive integrable quantum field theory. Using a regularization by putting the system in finite volume, we develop a novel approach (based on multi-dimensional residues) to the form factor expansion for thermal correlators. The first few terms
Expansion patterns and parallaxes for planetary nebulae
Schönberner, D.; Balick, B.; Jacob, R.
2018-02-01
Aims: We aim to determine individual distances to a small number of rather round, quite regularly shaped planetary nebulae by combining their angular expansion in the plane of the sky with a spectroscopically measured expansion along the line of sight. Methods: We combined up to three epochs of Hubble Space Telescope imaging data and determined the angular proper motions of rim and shell edges and of other features. These results are combined with measured expansion speeds to determine individual distances by assuming that line of sight and sky-plane expansions are equal. We employed 1D radiation-hydrodynamics simulations of nebular evolution to correct for the difference between the spectroscopically measured expansion velocities of rim and shell and of their respective shock fronts. Results: Rim and shell are two independently expanding entities, driven by different physical mechanisms, although their model-based expansion timescales are quite similar. We derive good individual distances for 15 objects, and the main results are as follows: (i) distances derived from rim and shell agree well; (ii) comparison with the statistical distances in the literature gives reasonable agreement; (iii) our distances disagree with those derived by spectroscopic methods; (iv) central-star "plateau" luminosities range from about 2000 L⊙ to well below 10 000 L⊙, with a mean value at about 5000 L⊙, in excellent agreement with other samples of known distance (Galactic bulge, Magellanic Clouds, and K648 in the globular cluster M 15); (v) the central-star mass range is rather restricted: from about 0.53 to about 0.56 M⊙, with a mean value of 0.55 M⊙. Conclusions: The expansion measurements of nebular rim and shell edges confirm the predictions of radiation-hydrodynamics simulations and offer a reliable method for the evaluation of distances to suited objects. Results of this paper are based on observations made with the NASA/ESA Hubble Space Telescope in Cycle 16 (GO11122
DEPENDENT STANDARD OF HIGH EDUCATION AND THE BRAZILIAN UNIVERSITY CURRENT EXPANSION
Directory of Open Access Journals (Sweden)
José Renato Bez de Gregório
2014-06-01
Full Text Available This article is based on the theoretical contributions of Florestan Fernandes seeking to analyze the structural and cyclical features of Brazilian higher education, in order to understand to what extent these features constitute the pattern-dependent learning, the historic brand dependent capitalist insertion of Brazil in the global economy and cultural heteronomy associated with it. We assume that such theoretical foundation helps us understand some aspects of the redesign of higher education underway in Brazil conducted by governments Lula da Silva and Dilma Rousseff, particularly the Program of Support to the Restructuring and Expansion of Federal Universities (REUNI. Thus, presenting some data expansion in the two largest public universities in the state of Rio de Janeiro in order to demonstrate the extent to which this process is indicating the precariousness / intensification of teaching and a deep reconfiguration of Brazilian public university.
Cycle expansions: From maps to turbulence
Lan, Y.
2010-03-01
We present a derivation, a physical explanation and applications of cycle expansions in different dynamical systems, ranging from simple one-dimensional maps to turbulence in fluids. Cycle expansion is a newly devised powerful tool for computing averages of physical observables in nonlinear chaotic systems which combines many innovative ideas developed in dynamical systems, such as hyperbolicity, invariant manifolds, symbolic dynamics, measure theory and thermodynamic formalism. The concept of cycle expansion has a deep root in theoretical physics, bearing a close analogy to cumulant expansion in statistical physics and effective action functional in quantum field theory, the essence of which is to represent a physical system in a hierarchical way by utilizing certain multiplicative structures such that the dominant parts of physical observables are captured by compact, maneuverable objects while minor detailed variations are described by objects with a larger space and time scale. The technique has been successfully applied to many low-dimensional dynamical systems and much effort has recently been made to extend its use to spatially extended systems. For one-dimensional systems such as the Kuramoto-Sivashinsky equation, the method turns out to be very effective while for more complex real-world systems including the Navier-Stokes equation, the method is only starting to yield its first fruits and much more work is needed to enable practical computations. However, the experience and knowledge accumulated so far is already very useful to a large set of research problems. Several such applications are briefly described in what follows. As more research effort is devoted to the study of complex dynamics of nonlinear systems, cycle expansion will undergo a fast development and find wide applications.
216-B-3 expansion ponds closure plan
Energy Technology Data Exchange (ETDEWEB)
1994-10-01
This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.
Thermal Expansion of Vacuum Plasma Sprayed Coatings
Raj, S V.; Palczer, A. R.
2010-01-01
Metallic Cu-8%Cr, Cu-26%Cr, Cu-8%Cr-1%Al, NiAl and NiCrAlY monolithic coatings were fabricated by vacuum plasma spray deposition processes for thermal expansion property measurements between 293 and 1223 K. The corrected thermal expansion, (DL/L(sub 0) varies with the absolute temperature, T, as (DL/L(sub 0) = A(T - 293)(sup 3) + BIT - 293)(sup 2) + C(T - 293) + D, where, A, B, C and D are thermal, regression constants. Excellent reproducibility was observed for all of the coatings except for data obtained on the Cu-8%Cr and Cu-26%Cr coatings in the first heat-up cycle, which deviated from those determined in the subsequent cycles. This deviation is attributed to the presence of residual stresses developed during the spraying of the coatings, which are relieved after the first heat-up cycle. In the cases of Cu-8%Cr and NiAl, the thermal expansion data were observed to be reproducible for three specimens. The linear expansion data for Cu-8% Cr and Cu-26%Cr agree extremely well with rule of mixture (ROM) predictions. Comparison of the data for the Cu-8%Cr coating with literature data for Cr and Cu revealed that the thermal expansion behavior of this alloy is determined by the Cu-rich matrix. The data for NiAl and NiCrAlY are in excellent agreement with published results irrespective of composition and the methods used for processing the materials. The implications of these results on coating GRCop-84 copper alloy combustor liners for reusable launch vehicles are discussed.
216-B-3 expansion ponds closure plan
International Nuclear Information System (INIS)
1994-10-01
This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA
Energy Technology Data Exchange (ETDEWEB)
Santos, Afonso Henriques Moreira; Haddad, Jamil; Cruz, Ricardo Alexandre Passos da [Universidade Federal de Itajuba (EXCEN/UNIFEI), MG (Brazil). Centro de Excelencia em Eficiencia Energetica, Recursos Naturais e Energia
2008-07-01
The article presents the basis for the new planning of power distribution highlighting the beginning of the public hearing process for the creation of PRODIST: Procedures for Distribution of Electric Power by the ANEEL - National Agency of Electrical Energy.
Tópicos da teoria da relatividade
Fragata, Paulo Renato Ferreira
2013-01-01
Dissertação de Mestrado, Matemática para Professores, 25 de Outubro 2013, Universidade dos Açores. Qualquer descrição física da natureza tem por base a especificação da posição e do instante em que decorre determinado acontecimento. Para tal, é necessário recorrer a um sistema de coordenadas, escolhido por cada observador, do modo que ele achar mais pertinente. Dada a generalidade na escolha do sistema de coordenadas, é útil conhecer as regras que nos permitem comparar cálculos feitos em d...
Teruo, KISHIMOTO; Tetsuo, KAMMURI; Institute of Physics, University of Tsukuba; Department of Physics, Osaka University
1990-01-01
With the Dynamical Nuclear Field Theory (DNFT) in the Tamm-Dancoff representation we examine higher order corrections in the vibrational mode of a spherical nuclear system. Due to the effects of bubble diagrams, the perturbation expansion in terms of the unrenormalized coupling strength and boson energy fails at full self-consistency. On the other hand, it becomes applicable in the form of linked-cluster expansion when we use thses constants renormalized by the effect of bubble diagrams, in t...
Defining chemical expansion: the choice of units for the stoichiometric expansion coefficient
DEFF Research Database (Denmark)
Marrocchelli, Dario; Chatzichristodoulou, Christodoulos; Bishop, Sean R.
2014-01-01
Chemical expansion refers to the spatial dilation of a material that occurs upon changes in its composition. When this dilation is caused by a gradual, iso-structural increase in the lattice parameter with composition, it is related to the composition change by the stoichiometric expansion coeffi...... are provided for changes in oxygen content in fluorite, perovskite, and Ruddlesden-Popper (K2NiF4) phase materials used in solid oxide fuel cells....
Manuel Gustavo Chávez Sevillano
2015-01-01
Resumo: A Técnica de Expansão Palatina é usada frequentemente para corrigir a mordida cruzada posterior, atresia transversal maxilar e aumentar o perímetro da arcada dentária. O objetivo deste estudo foi avaliar pela análise de elementos finitos o efeito simulado da expansão palatina sobre o processo pterigoide, sincondrose esfeno-occipital e sela turca em dois crânios com relação esquelética tipo Classe II e Classe III, identificando a distribuição das tensões mecânicas nessas estruturas ana...
REGENERATIVE GAS TURBINES WITH DIVIDED EXPANSION
DEFF Research Database (Denmark)
Elmegaard, Brian; Qvale, Einar Bjørn
2004-01-01
Recuperated gas turbines are currently drawing an increased attention due to the recent commercialization of micro gas turbines with recuperation. This system may reach a high efficiency even for the small units of less than 100 kW. In order to improve the economics of the plants, ways to improve...... their efficiency are always of interest. Recently, two independent studies have proposed recuperated gas turbines to be configured with the turbine expansion divided, in order to obtain higher efficiency. The idea is to operate the system with a gas generator and a power turbine, and use the gas from the gas...... divided expansion can be advantageous under certain circumstances. But, in order for todays micro gas turbines to be competitive, the thermodynamic efficiencies will have to be rather high. This requires that all component efficiencies including the recuperator effectiveness will have to be high...
Thermal expansion coefficient determination by CBED
International Nuclear Information System (INIS)
Angelini, P.; Bentley, J.
1984-01-01
The present application of CBED involves measurements of thermal-expansion coefficients by measurement of changes in HOLZ line positions as a function of temperature. Previous work on this subject was performed on Si at a constant accelerating voltage of 100 kV between about 90 and 600 K. Diffraction patterns were recorded and line shifts correlated to lattice parameter changes. Differences were noted between values determined by CBED and accepted thermal expansion values. Significant HOLZ line interactions and splitting occurring in the (111) patterns were noted to contribute to the differences. Preliminary measurements have been made on Al, Al 2 O 3 , and single-crystal tau (Ni/sub 20.3/Ti/sub 2.7/B 6 ). An example of changes in HOLZ lines present in (114) patterns for Al are shown and the effect of temperature on the position of lines in the pattern illustrated
The delta expansion in zero dimensions
International Nuclear Information System (INIS)
Cho, H.T.; Milton, K.A.; Pinsky, S.S.; Simmons, L.M. Jr.
1989-01-01
The recently introduced δ-expansion (or logarithmic-expansion) technique for obtaining nonperturbative information about quantum field theories is reviewed in the zero-dimensional context. There, it is easy to study questions of analytic continuation that arise in the construction of the Feynman rules that generate the δ series. It is found that for six- and higher-point Green's functions, a cancellation occurs among the most divergent terms, and that divergences that arise from summing over an infinite number of internal lines are illusory. The numerical accuracy is studied in some detail: The δ series converges inside a circle of radius one for positive bare mass squared, and diverges if the bare mass squared is negative, but in all cases, low-order Pade approximants are extremely accurate. These general features are expected to hold in higher dimensions, such as four
Ultimate load capacities of expansion anchor bolts
International Nuclear Information System (INIS)
Czarnecki, R.M.; Manrique, M.A.; Samaddar, S.K.
1993-01-01
A summary of available experimental expansion anchor bolt test data is presented. These data were collected as part of programs by the nuclear industry to address generic issues related to verification of seismic adequacy of equipment in nuclear power plants. Some of the data presented are suitable for use in seismic probabilistic risk assessments. For example, mean values of ultimate strength, along with their standard deviation and coefficients of variation, for a range of most typical expansion anchor bolt sizes are presented. Effects of interaction between shear and tension, edge distance, spacing, and cracking of the concrete are presented in a manner that is more suitable for use in deterministic evaluations. Related industry programs to derive anchor bolt capacities are briefly discussed. Recommendations for areas of further investigation are also presented
Collisionless plasma expansion into a vacuum
International Nuclear Information System (INIS)
Denavit, J.
1979-01-01
Particle simulations of the expansion of a collisionless plasma into vacuum are presented. The cases of a single-electron-temperature plasma and of a two-electron-temperature plasma are considered. The results confirm the existence of an ion front and verify the general features of self-similar solutions behind this front. A cold electron front is clearly observed in the two-electron-temperatures case. The computations also show that for a finite electron-to-ion mass ratio, m/sub e//m/sub i/, the electron thermal velocity in the expansion region is not constant, but decreases approximately linearly with xi 0 -(γ-1) xi/2, and comparison with computer simulation results show that the constant γ-1 is proportional to (Zm/sub e//m/sub i/)atsup 1/2at, where Z is the ion charge number
Off-diagonal expansion quantum Monte Carlo.
Albash, Tameem; Wagenbreth, Gene; Hen, Itay
2017-12-01
We propose a Monte Carlo algorithm designed to simulate quantum as well as classical systems at equilibrium, bridging the algorithmic gap between quantum and classical thermal simulation algorithms. The method is based on a decomposition of the quantum partition function that can be viewed as a series expansion about its classical part. We argue that the algorithm not only provides a theoretical advancement in the field of quantum Monte Carlo simulations, but is optimally suited to tackle quantum many-body systems that exhibit a range of behaviors from "fully quantum" to "fully classical," in contrast to many existing methods. We demonstrate the advantages, sometimes by orders of magnitude, of the technique by comparing it against existing state-of-the-art schemes such as path integral quantum Monte Carlo and stochastic series expansion. We also illustrate how our method allows for the unification of quantum and classical thermal parallel tempering techniques into a single algorithm and discuss its practical significance.
Bond return predictability in expansions and recessions
DEFF Research Database (Denmark)
Engsted, Tom; Møller, Stig Vinther; Jensen, Magnus David Sander
We document that over the period 1953-2011 US bond returns are predictable in expansionary periods but unpredictable during recessions. This result holds in both in-sample and out-of-sample analyses and using both univariate regressions and combination forecasting techniques. A simulation study...... but negative in recessions. The results are also consistent with tests showing that the expectations hypothesis of the term structure holds in recessions but not in expansions. However, the results for bonds are in sharp contrast to results for stocks showing that stock returns are predictable in recessions...... but not in expansions. Thus, our results indicate that there is not a common predictive pattern of stock and bond returns associated with the state of the economy....
Expansion planning for electrical generating systems
International Nuclear Information System (INIS)
1984-01-01
The guidebook outlines the general principles of electric power system planning in the context of energy and economic planning in general. It describes the complexities of electric system expansion planning that are due to the time dependence of the problem and the interrelation between the main components of the electric system (generation, transmission and distribution). Load forecasting methods are discussed and the principal models currently used for electric system expansion planning presented. Technical and economic information on power plants is given. Constraints imposed on power system planning by plant characteristics (particularly nuclear power plants) are discussed, as well as factors such as transmission system development, environmental considerations, availability of manpower and financial resources that may affect the proposed plan. A bibliography supplements the references that appear in each chapter, and a comprehensive glossary defines terms used in the guidebook
Intrinsic thermal expansion of crystal defects
International Nuclear Information System (INIS)
Ganne, J.-P.
1981-02-01
Although the phenomenon of thermal expansion has long been known, the intrinsic thermal expansion coefficient (ITEC) βsub(d) of a point defect, derived from its formation volume vsub(d), has never been measured directly. The differential dilatometer by interferometry built by ASTY and GILDER is described. It has allowed βsub(d) to be measured for several defects. Vacancies and small interstitial loops were produced in aluminium by low temperature (20 K) fast neutron irradiation followed by an anneal up to the beginning of stage III (160 K). The very high value of the measured ratio βsub(d)/β 0 (12+-4) is comparable with a lattice statics calculated (42) value (11.5 0 [fr
Polyhomogeneous expansions from time symmetric initial data
Gasperín, E.; Valiente Kroon, J. A.
2017-10-01
We make use of Friedrich’s construction of the cylinder at spatial infinity to relate the logarithmic terms appearing in asymptotic expansions of components of the Weyl tensor to the freely specifiable parts of time symmetric initial data sets for the Einstein field equations. Our analysis is based on the assumption that a particular type of formal expansions near the cylinder at spatial infinity corresponds to the leading terms of actual solutions to the Einstein field equations. In particular, we show that if the Bach tensor of the initial conformal metric does not vanish at the point at infinity then the most singular component of the Weyl tensor decays near null infinity as O(\\tilde{r}-3\\ln \\tilde{r}) so that spacetime will not peel. We also provide necessary conditions on the initial data which should lead to a peeling spacetime. Finally, we show how to construct global spacetimes which are candidates for non-peeling (polyhomogeneous) asymptotics.
6th International Symposium on Thermal Expansion
1978-01-01
This 6th International Symposium on Thermal Expansion, the first outside the USA, was held on August 29-31, 1977 at the Gull Harbour Resort on Hecla Island, Manitoba, Canada. Symposium Chairman was Ian D. Peggs, Atomic Energy of Canada Limited, and our continuing sponsor was CINDAS/Purdue University. We made considerable efforts to broaden the base this year to include more users of expansion data but with little success. We were successful, however, in establishing a session on liquids, an area which is receiving more attention as a logical extension to the high-speed thermophysical property measurements on materials at temperatures close to their melting points. The Symposium had good international representation but the overall attendance was, disappointingly, relatively low. Neverthe less, this enhanced the informal atmosphere throughout the meeting with a resultant frank exchange of information and ideas which all attendees appreciated. A totally new item this year was the presentation of a bursary to ...
DEFF Research Database (Denmark)
Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens
1996-01-01
Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint...
Temporal quadratic expansion nodal Green's function method
International Nuclear Information System (INIS)
Liu Cong; Jing Xingqing; Xu Xiaolin
2000-01-01
A new approach is presented to efficiently solve the three-dimensional space-time reactor dynamics equation which overcomes the disadvantages of current methods. In the Temporal Quadratic Expansion Nodal Green's Function Method (TQE/NGFM), the Quadratic Expansion Method (QEM) is used for the temporal solution with the Nodal Green's Function Method (NGFM) employed for the spatial solution. Test calculational results using TQE/NGFM show that its time step size can be 5-20 times larger than that of the Fully Implicit Method (FIM) for similar precision. Additionally, the spatial mesh size with NGFM can be nearly 20 times larger than that using the finite difference method. So, TQE/NGFM is proved to be an efficient reactor dynamics analysis method
Change in the pace of universe expansion
International Nuclear Information System (INIS)
Palanque-Delabrouille, N.; Yeche, C.
2016-01-01
During the first 8 billion years the universe expansion was slowed down by gravity, at that time the universe was made up mostly of ordinary matter. The accelerating expansion phase we know dates back to 6 billion years ago and now the content of the universe can be divided into: dark energy (73%), dark matter (23%), gas (3.6%) and stars, planets... (0.4%). Quasars which are among the most luminous objects of the universe and whose light can be detected even after having travelled through the universe for 12 billion years, can be used as markers of the matter all along the history of the universe. 3 international projects (SDSS, DESI and LSST) will study, in a complementary way, the period when dark energy overtook ordinary matter. (A.C.)
Separable expansions for virtual states and resonances
International Nuclear Information System (INIS)
Adhikari, S.K.; Fonseca, A.C.; Tomio, L.
1983-01-01
Finite rank expansions for two- and three-body t matrices are analytically continued to the unphysical sheet of the complex energy plane associated with the lowest two-body scattering threshold in order to obtain the position and residue of the virtual state and resonance poles. The present method is applied to study the 1 S 0 virtual state of two nucleons, the Efimov virtual states of three identical bosons, and the doublet virtual state of three nucleons
Asymptotic expansion of the Keesom integral
International Nuclear Information System (INIS)
Abbott, Paul C
2007-01-01
The asymptotic evaluation and expansion of the Keesom integral, K(a), is discussed at some length in Battezzati and Magnasco (2004 J. Phys. A: Math. Gen. 37 9677; 2005 J. Phys. A: Math. Gen. 38 6715). Here, using standard identities, it is shown that this triple integral can be reduced to a single integral from which the asymptotic behaviour is readily obtained using Laplace's method. (comment)
The reference electricity expansion plan of Guatemala
International Nuclear Information System (INIS)
Santizo, Rodolfo
2002-01-01
This presentation prepared by the Deputy Minister of Energy and Mines overviews the following issues: description of electric power infrastructure, price markets, expansion plans, power and energy demand projections through 2010, including bussiness opportunities for private investment on geothermal and hidro electric power production and distribution market. This presentation is intended for private investors who could be interested in bussiness opportunities of energy generation market in Guatemala
Reduction Expansion Synthesis for Magnetic Alloy Powders
2015-12-01
in Figure 1, the Army was able to address its need for printable plastic components, thus enabling a reduction in the total quantity of spare...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited REDUCTION EXPANSION SYNTHESIS FOR...Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202–4302, and to the Office of Management and Budget, Paperwork Reduction Project
Moments expansion densities for quantifying financial risk
Ñíguez, T.M.; Perote, J.
2017-01-01
We propose a novel semi-nonparametric distribution that is feasibly parameterized to represent the non-Gaussianities of the asset return distributions. Our Moments Expansion (ME) density presents gains in simplicity attributable to its innovative polynomials, which are defined by the difference between the nth power of the random variable and the nth moment of the density used as the basis. We show that the Gram-Charlier distribution is a particular case of the ME-type of densities. The latte...
SIMMER analysis of SRI postdisassembly expansion experiments
International Nuclear Information System (INIS)
Bott, T.F.; Bell, C.R.
1982-01-01
Calculations of simulated postdisassembly expansions with SIMMER-II are compared to experimental data. The main features of the fluid motion are reproduced accurately. Good agreement is achieved for the important parameters of kinetic energy and impulse imparted to the vessel head. The most important calculated results are shown to be relatively insensitive to numerical modeling variations and uncertainties in many physical parameters. The geometric configuration of the upper internal structures is shown to affect significantly the vessel head impact energy and impulse
Theory of thermal expansivity and bulk modulus
International Nuclear Information System (INIS)
Kumar, Munish
2005-01-01
The expression for thermal expansivity and bulk modulus, claimed by Shanker et al. to be new [Physica B 233 (1977) 78; 245 (1998) 190; J. Phys. Chem. Solids 59 (1998) 197] are compared with the theory of high pressure-high temperature reported by Kumar and coworkers. It is concluded that the Shanker formulation and the relations based on this are equal to the approach of Kumar et al. up to second order
Electrochemical detection of DNA triplet repeat expansion
Czech Academy of Sciences Publication Activity Database
Fojta, Miroslav; Havran, Luděk; Vojtíšková, Marie; Paleček, Emil
2004-01-01
Roč. 126, č. 21 (2004), s. 6532-6533 ISSN 0002-7863 R&D Projects: GA AV ČR IAA4004402; GA AV ČR IBS5004355; GA AV ČR KJB4004302; GA AV ČR KSK4055109 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA triplet repeat expansion * PCR amplification * neurodegenerative diseases Subject RIV: BO - Biophysics Impact factor: 6.903, year: 2004
Automation of a thermal expansion instrument
Energy Technology Data Exchange (ETDEWEB)
Holland, L.L.
1979-03-01
Automation of a thermal expansion instrument using a minicomputer system and with analog-to-digital converter inputs and flip-flop relay outputs is described. The necessary hardware link and the software were developed to allow equipment control, data acquisition, data reduction, and report generation by the minicomputer. The design of the automation allows non-programmers to run the experiment, reduce the data, and generate the report.
Hubble expansion in a Euclidean framework
International Nuclear Information System (INIS)
Alfven, H.
1979-01-01
There now seems to be strong evidence for a non-cosmological interpretation of the QSO redshift - in any case, so strong that it is of interest to investigate the consequences. The purpose of this paper is to construct a model of the Hubble expansion which is as far as possible from the conventional Big Bang model without coming in conflict with any well-established observational results (while introducing no new laws of physics). This leads to an essentially Euclidean metagalactic model (see Table I) with very little mass outside one-third or half of the Hubble radius. The total kinetic energy of the Hubble expansion need only to be about 5% of the rest mass energy. Present observations support backwards in time extrapolation of the Hubble expansion to a 'minimum size galaxy' Rsub(m), which may have any value in 0 26 cm. Other arguments speak in favor of a size close to the upper value, say Rsub(m) = 10 26 cm (Table II). As this size is probably about 100 times the Schwarzschild limit, an essentially Euclidean description is allowed. The kinetic energy of the Hubble expansion may derive from an intense QSO-like activity in the minimum size metagalaxy, with an energy release corresponding to the annihilation of a few solar masses per galaxy per year. Some of the conclusions based on the Big Bang hypothesis are criticized and in several cases alternative interpretations are suggested. A comparison between the Euclidean and the conventional models is given in Table III. (orig.)
Local product structure for expansive homeomorphisms
Artigue, Alfonso; Brum, Joaquin; Potrie, Rafael
2008-01-01
Let $f\\colon M\\to M$ be an expansive homeomorphism with dense topologically hyperbolic periodic points, $M$ a compact manifold. Then there is a local product structure in an open and dense subset of $M$. Moreover, if some topologically hyperbolic periodic point has codimension one, then this local product structure is uniform. In particular, we conclude that the homeomorphism is conjugated to a linear Anosov diffeomorphism of a torus.
Theory of compression and expansion of hydrogels
Energy Technology Data Exchange (ETDEWEB)
Iwata, M. [Suzuka National College of Tech., Mie (Japan). Dept. of Industrial Chemistry; Koda, S.; Nomura, H. [Nagoya University, Nagoya (Japan). Dept. of Molecular Design and Engineering
1999-10-01
Compression and expansion processes of cross-linked sodium polyacrylate hydrogels under mechanical pressure were investigated. A packed spherical gel bed shows irreversible deformation when the applied pressure is decreased; the expansion behavior depends on the maximum pressure applied to the gel bed. The time required to attain a certain degree of deformation is directly proportional to the square of the total solid volume of the gel bed; this relation is very similar to that observed in expression or expansion processes of ordinary solid-liquid mixtures. The driving force of the deformation is an effective osmotic pressure gradient in the gel bed, where the effective osmotic pressure of the gel is the difference between the swelling pressure of the gel and the pressure applied to the gel. The flow rate of liquid through any gel layer can be expressed by Darcy's equation. The deformation ceases when the swelling pressure of each gel particle is equal to the applied pressure. Thus, the deformation of a packed gel bed can be recognized as a process of equalizing the swelling pressure distribution in the bed. (author)
Renormalizations and operator expansion in sigma model
International Nuclear Information System (INIS)
Terentyev, M.V.
1988-01-01
The operator expansion (OPE) is studied for the Green function at x 2 → 0 (n(x) is the dynamical field ofσ-model) in the framework of the two-dimensional σ-model with the O(N) symmetry group at large N. As a preliminary step we formulate the renormalization scheme which permits introduction of an arbitrary intermediate scale μ 2 in the framework of 1/N expansion and discuss factorization (separation) of small (p μ) momentum region. It is shown that definition of composite local operators and coefficient functions figuring in OPE is unambiguous only in the leading order in 1/N expansion when dominant are the solutions with extremum of action. Corrections of order f(μ 2 )/N (here f(μ 2 ) is the effective interaction constant at the point μ 2 ) in composite operators and coefficient functions essentially depend on factorization method of high and low momentum regions. It is shown also that contributions to the power corrections of order m 2 x 2 f(μ 2 )/N in the Green function (here m is the dynamical mass-scale factor in σ-model) arise simultaneously from two sources: from the mean vacuum value of the composite operator n ∂ 2 n and from the hard particle contributions in the coefficient function of unite operator. Due to the analogy between σ-model and QCD the obtained result indicates theoretical limitations to the sum rule method in QCD. (author)
Hausdorff dimension of unique beta expansions
International Nuclear Information System (INIS)
Kong, Derong; Li, Wenxia
2015-01-01
Given an integer N ⩾ 2 and a real number β > 1, let Γ β, N be the set of all x=∑ i=1 ∞ d i /β i with d i ∈ {0, 1, ···, N − 1} for all i ⩾ 1. The infinite sequence (d i ) is called a β-expansion of x. Let U β,N be the set of all x's in Γ β,N which have unique β-expansions. We give explicit formula of the Hausdorff dimension of U β,N for β in any admissible interval [β L , β U ], where β L is a purely Parry number while β U is a transcendental number whose quasi-greedy expansion of 1 is related to the classical Thue–Morse sequence. This allows us to calculate the Hausdorff dimension of U β,N for almost every β > 1. In particular, this improves the main results of Gábor Kallós (1999, 2001). Moreover, we find that the dimension function f(β) = dim H U β,N fluctuates frequently for β ∈ (1, N). (paper)
Leptodermous expansion of finite-nucleus incompressibility
International Nuclear Information System (INIS)
Nayak, R.C.
1990-01-01
We consider the influence of higher-order terms in the leptodermous expansion used to extract the incompressibility K v of infinite nuclear matter from data on the breathing mode of finite nuclei. The terms we calculate are the curvature term K cv A -2/3 , the surface-symmetry term K ss I 2 A -1/3 , the quartic volume-symmetry term K 4 I 4 , and a Coulomb-exchange term. Working within the framework of the scaling model we derive expressions for their coefficients in terms of quantities that are defined for infinite and semi-infinite nuclear matter. We calculate these coefficients for four different Skyrme-type forces, using the extended Thomas-Fermi (ETF) approximation. With the same forces we also calculate the incompressibility K (A, I) for a number of finite nuclei, fit the results to the leptodermous expansion, and thereby extract new results for the same coefficients. The comparison of the two calculations shows that the leptodermous expansion is converging rapidly. Of the new terms, the term K 4 I 4 is quite negligible, the curvature term should be included, and we discuss to what extent the other higher-order terms are significant. (orig.)
Trace expansions for mixed boundary problems
Energy Technology Data Exchange (ETDEWEB)
Seeley, Robert T
2002-01-01
We discuss the heat trace expansion for a mixed boundary problem for the Laplace operator acting on sections of some bundle V over a manifold M of dimension d. The boundary is divided in two parts N{sub D} and N{sub N}, intersecting in a smooth submanifold {sigma}. Dirichlet conditions are imposed on N{sub D} - {sigma}, and Neumann conditions on N{sub N} - {sigma}. It turns out that it is also necessary to impose a condition along {sigma}. We then obtain an expansion of the trace of the heat operator with these boundary conditions, containing integrals of the usual terms over the interior and the two parts of the boundary, together with integrals over {sigma} of terms that are 'global' in certain operators on a semicircle. The first nonzero such term is computed; it involves the zeta function of an operator on the semicircle, and depends on the boundary condition along {sigma}. We find that no logarithmic terms occur in the expansion.
DEFF Research Database (Denmark)
Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens
1995-01-01
Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint......-expansion, and a popular transformation called “The Trick.” We provide a unified view of these binding-time improvements, from a typing perspective. Just as a proper treatment of product values in partial evaluation requires partially static values, a proper treatment of disjoint sums requires moving static contexts...
Spatial Linkage and Urban Expansion: AN Urban Agglomeration View
Jiao, L. M.; Tang, X.; Liu, X. P.
2017-09-01
Urban expansion displays different characteristics in each period. From the perspective of the urban agglomeration, studying the spatial and temporal characteristics of urban expansion plays an important role in understanding the complex relationship between urban expansion and network structure of urban agglomeration. We analyze urban expansion in the Yangtze River Delta Urban Agglomeration (YRD) through accessibility to and spatial interaction intensity from core cities as well as accessibility of road network. Results show that: (1) Correlation between urban expansion intensity and spatial indicators such as location and space syntax variables is remarkable and positive, while it decreases after rapid expansion. (2) Urban expansion velocity displays a positive correlation with spatial indicators mentioned above in the first (1980-1990) and second (1990-2000) period. However, it exhibits a negative relationship in the third period (2000-2010), i.e., cities located in the periphery of urban agglomeration developing more quickly. Consequently, the hypothesis of convergence of urban expansion in rapid expansion stage is put forward. (3) Results of Zipf's law and Gibrat's law show urban expansion in YRD displays a convergent trend in rapid expansion stage, small and medium-sized cities growing faster. This study shows that spatial linkage plays an important but evolving role in urban expansion within the urban agglomeration. In addition, it serves as a reference to the planning of Yangtze River Delta Urban Agglomeration and regulation of urban expansion of other urban agglomerations.
Directory of Open Access Journals (Sweden)
Antonio Bento Mancio
2006-10-01
Full Text Available Dentre as características de qualidade da carne bovina, a maciez assume posição de destaque, sendo considerada a característica organoléptica de maior influência na aceitação da carne por parte dos consumidores. A dureza da carne pode ser dividida em dureza residual, causada pelo tecido conjuntivo e outras proteínas do estroma, e dureza de actomiosina, causada pelas proteínas miofibrilares. Dentre os fatores que influenciam a maciez da carne, podem ser destacados a genética, a raça, a idade ao abate, o sexo, a alimentação, o uso de agentes hormonais (?-adrenérgicos e os tratamentos post-mortem. A qualidade final da carne é resultante de tudo o que aconteceu com o animal durante toda a cadeia produtiva. Devem-se assegurar procedimentos adequados de transporte, armazenamento, manipulação, exposição e preparo da carne, a fim de se obter um produto de melhor qualidade. PALAVRAS-CHAVE: Calpaínas, calpastatina, qualidade da carne, rigor mortis, tecido muscular.
The holonomy expansion: Invariants and approximate supersymmetry
International Nuclear Information System (INIS)
Jaffe, Arthur
2000-01-01
In this paper we give a new expansion, based on cyclicity of the trace, to study regularity properties of twisted expectations =Tr H (γU(θ)X(s)). Here X(s)=X 0 e -s 0 Q 2 X 1 e -s 1 Q 2 ...X k e -s k Q 2 is a product of operators X j , regularized by heat kernels e -s j Q 2 with s j >0. The twist groups γ(set-membership sign)Z 2 and U(θ)(set-membership sign)U(1) are commuting symmetries of Q 2 . The name ''holonomy expansion'' arises from picturing as a circular graph, with vertices in the graph representing the operators X j , in the order that they appear in the product, and the line-segment following X j representing the heat kernel e -s j Q 2 . The trace functional is cyclic, so the graph is circular. We generate our expansion by ''transporting'' a vertex X k around the circle, ending in its original position. We choose an X k that transforms under a one-dimensional representation of Z 2 xU(1). For θ in the complement of the discrete set γ sing (where the group Z 2 xU(1) acts trivially on X k ) we obtain an identity between the original expectation and some new expectations. We study an example from supersymmetric quantum mechanics, with a Dirac operator Q(λ) depending on a parameter λ and with a U(1) group of symmetries U(θ). We apply our expansion to invariants Z(λ;θ)=Z(Q(λ);θ) suggested by non-commutative geometry. These invariants are sums of expectations of the form above. We investigate this example as a first step toward developing an expansion to evaluate related invariants arising in supersymmetric quantum field theory. We establish differentiability of Z(λ; θ) in λ for λ(set-membership sign)(0,1] and show Z(λ; θ) is independent of λ. We wish to evaluate Z(λ; θ) at the endpoint λ=0, but Z(0; θ) is ill-defined. We regularize the endpoint, while preserving the U(θ)-symmetry, by replacing Q(λ) 2 with H(ε,λ)=Q(λ) 2 +ε 2 |z| 2 . The regularized function Z(ε, λ; θ) depends on all three variables ε, λ, θ; for fixed θ, it
A summation procedure for expansions in orthogonal polynomials
International Nuclear Information System (INIS)
Garibotti, C.R.; Grinstein, F.F.
1977-01-01
Approximants to functions defined by formal series expansions in orthogonal polynomials are introduced. They are shown to be convergent even out of the elliptical domain where the original expansion converges
The epidural expansion in the waist canal - less obvious findings
International Nuclear Information System (INIS)
Nekula, J.; Bucil, J.; Burval, S.
1998-01-01
The authors demonstrated 55 less obvious epidural expansion in the waist canal. These expansions are discussed. The detection of the epidural mass at myeloma multiples has a principal significance for the indication of the radiotherapy or surgical intervention
Dynamics of plasma expansion in the pulsed laser material interaction
Indian Academy of Sciences (India)
at different ambient gas pressures using an adiabatic expansion model. ... Pulsed laser; plasma expansion; plasma ionization; plume dimension. 1. ...... De A, Shakhatov V A, Pascale De O 2001 Optical emission spectroscopy and modeling of.
Expansions for model-independent analyses of inelastic electron scattering
International Nuclear Information System (INIS)
Jackson, D.F.; Hilton, J.M.; Roberts, A.C.M.
1977-01-01
It is noted that the commonly-used Fourier-Bessel expansion for the transition density for inelastic electron scattering depends sensitively on an arbitrary parameter and is not realistic at large distances. Alternative expansions are suggested. (author)
Lessons from Early Medicaid Expansions Under Health Reform..
U.S. Department of Health & Human Services — Lessons from Early Medicaid Expansions Under Health Reform, Interviews with Medicaid Officials In a new study entitled Lessons from Early Medicaid Expansions Under...
Preparation of Shrinkage Compensating Concrete with HCSA Expansive Agent
Li, Changcheng; Jia, Fujia
2017-10-01
Shrinkage compensating concrete (SCC) has become one of the best effective methods of preventing and reducing concrete cracking. SCC is prepared by HCSA high performance expansive agent for concrete which restrained expansion rate is optimized by 0.057%. Slump, compressive strength, restrained expansion rate and cracking resistance test were carried out on SCC. The results show that the initial slump of fresh SCC was about 220mm-230mm, while slump after 2 hours was 180mm-200mm. The restrained expansion rate of SCC increased with the mixing amount of expansive agent. After cured in water for 14 days, the restrained expansion rate of C35 and C40 SCC were 0.020%-0.032%. With the dosage of expansive agent increasing, restrained expansion rate of SCC increased, maximum compressive stress and cracking stress improved, cracking temperature fell, thus cracking resistance got effectively improvement.
A Revisit of Query Expansion with Different Semantic Levels
DEFF Research Database (Denmark)
Zhang, Ce; Cui, Bin; Cong, Gao
2009-01-01
Query expansion has received extensive attention in information retrieval community. Although semantic based query expansion appears to be promising in improving retrieval performance, previous research has shown that it cannot consistently improve retrieval performance. It is a tricky problem to...
Going Up? The Pros and Cons of Vertical Expansion.
Myler, Patricia A.; Boggs, Richard C.
2002-01-01
Describes the advantages and disadvantages of the vertical expansion of school buildings. Considers such factors as fire protection, compliance with the Americans with Disabilities Act, and cost. Discusses alternatives to vertical expansion. (PKP)
Directory of Open Access Journals (Sweden)
Vera M.A.Tordino Brandão
2010-02-01
Full Text Available O Programa de Gerontologia da PUC desenvolve pesquisas focando o ser na perspectiva do envelhecimento. As atividades são interdisciplinares e reúnem docentes, alunos e ex-alunos. Nesta mesa redonda apresentamos um panorama sobre estes estudos. Na área da educação e comunicação o foco está centrado na longevidade e na preparação e representação social da velhice. São ressaltadas como temáticas: a formação continuada de profissionais e pesquisadores; o significado da religiosidade/espiritualidade ao longo da trajetória, e sua repercussão na qualidade de vida do idoso; os programas sócio-educacionais para idosos e concepções sobre educação; o monitoramento da mídia na cobertura da crescente longevidade e seus impactos. Em identidade e modos de morar reflete-se sobre soluções planejadas e sua adequação para a inclusão do envelhecimento populacional como questão fundamental, que implica a elaboração de novas políticas, investigações e, especialmente, apresenta-se como questão a ser analisada, refletida e vivenciada pela sociedade em geral. Quanto à saúde, o Programa desenvolve várias pesquisas numa abordagem interdisciplinar tendo como objetos de estudo: a terapia assistida com animais direcionada a idosos com diagnóstico de Alzheimer; o acompanhamento terapêutico e o atendimento psicoterapêutico em grupo, a aplicação da técnica de Calatonia em idosos moradores de ILPI, além da investigação sobre impasses clínicos no idoso frágil. Palavras-chave: gerontologia, longevidade, envelhecimento
Hamedi-Sangsari, Adrien; Chinipardaz, Zahra; Carrasco, Lee
2017-10-01
The aim of this study was to compare outcome measurements of skeletal and dental expansion with bone-borne (BB) versus tooth-borne (TB) appliances after surgically assisted rapid palatal expansion (SARPE). This study was performed to provide quantitative measurements that will help the oral surgeon and orthodontist in selecting the appliance with, on average, the greatest amount of skeletal expansion and the least amount of dental expansion. A computerized database search was performed using PubMed, EBSCO, Cochrane, Scopus, Web of Science, and Google Scholar on publications in reputable oral surgery and orthodontic journals. A systematic review and meta-analysis was completed with the predictor variable of expansion appliance (TB vs BB) and outcome measurement of expansion (in millimeters). Of 487 articles retrieved from the 6 databases, 5 articles were included, 4 with cone-beam computed tomographic (CBCT) data and 1 with non-CBCT 3-dimensional cast data. There was a significant difference in skeletal expansion (standardized mean difference [SMD], 0.92; 95% confidence interval [CI], 0.54-1.30; P appliances. However, there was no significant difference in dental expansion (SMD, 0.05; 95% CI, -0.24 to 0.34; P = .03). According to the literature, to achieve more effective skeletal expansion and minimize dental expansion after SARPE, a BB appliance should be favored. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Conjecturas da Epistemológia Jurídica e Aspectos da Teoria da Linguagem
Oliveira, Rita de Cássia Cartelli de; Cesumar; Motta, Ivan Dias; Cesumar
2008-01-01
Apresentar-se-ão reflexões em torno da epistemologia jurídica e alguns aspectos da teoria da linguagem; a necessidade de acompanhamento e aprimoramento da linguagem jurídica, para que o direito não se distancie da realidade, mantendo-se apenas como um sistema do status quo; uma breve análise de algumas teorias da ciência do direito e da linguagem; as especificidades dos termos lingüísticos para a análise da ciência do direito, pautada na contemporaneidade sob a perspectiva humanista, buscando...
CONDICIONANTES DA COMPETITIVIDADE EMPRESARIAL
Directory of Open Access Journals (Sweden)
José Luiz Contador
2010-03-01
Full Text Available Este trabalho examina teoricamente os fatores determinantes da competitividade do produto e do negócio, imprescindíveis à elaboração de estratégias competitivas que visam à obtenção e sustentação de vantagens competitivas. Esse tema é objeto tanto da área de marketing estratégico quanto da de estratégia empresarial. Nas duas áreas, há um ponto de consenso que afirma que a empresa deve diferenciar sua oferta para conquistar e manter vantagem competitiva. Mas, os estudos conduzidos por meio do modelo de Campos e Armas da Competição revelaram que a empresa pode diferenciar seu produto e/ou serviço de modo mais amplo, levando em consideração, na formulação da sua estratégia competitiva, também o campo da competição, quer do produto, quer dela própria. Assim, o objetivo deste artigo é evidenciar que, para a empresa ser competitiva, além de diferenciar seu produto e/ou seu serviço no sentido tradicional, ela precisa: 1 diferenciar seu produto incluindo a definição em quais campos vai competir em cada segmento; e 2 escolher as armas da competição que irá utilizar e definir a intensidade de cada arma. Para atingir tal objetivo, foram necessários vários conceitos do modelo de Campos e Armas da Competição: campo da competição, arma da competição, tese do modelo, configuração dos campos da competição, campo coadjuvante, produto coadjuvante e par produto-mercado. Como uma proposta inovadora sempre desperta dúvida, é mostrado o processo de validação do modelo de Campos e Armas da Competição e são discutidas sua universalidade, consistência e completude.
Expansive cements for the manufacture of the concrete protective bandages
Yakymechko, Yaroslav; Voloshynets, Vladyslav
2017-12-01
One of the promising directions of the use of expansive cements is making the protective bandages for the maintenance of pipelines. Bandages expansive application of the compositions of the pipeline reinforce the damaged area and reduce stress due to compressive stress in the cylindrical area. Such requirements are best suited for expansive compositions obtained from portland cement and modified quicklime. The article presents the results of expansive cements based on quick lime in order to implement protective bandages pipelines.
Rapid replacement of bridge deck expansion joints study - phase I.
2014-12-01
Bridge deck expansion joints are used to allow for movement of the bridge deck due to thermal expansion, dynamics loading, and : other factors. More recently, expansion joints have also been utilized to prevent the passage of winter de-icing chemical...
Dynamical effects in the Colomb expansion following nuclear fragmentation
International Nuclear Information System (INIS)
Chung, K.C.; Donangelo, R.J.; Schechter, H.
1987-01-01
The effects of the Colomb expansion on the fragment Kinetic energy spectrum for a fragmentating hot nuclear system is investigated. In particular, 12 C fragment spectra are calculated and compared with those predicted by the uniform expansion approximation. The results indicate that energy spectra of fragments are quite sensitive to the details of the Coulomb expansion treatment. (Author) [pt
Fission gas retention and axial expansion of irradiated metallic fuel
International Nuclear Information System (INIS)
Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.
1986-05-01
Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin
14 CFR 23.969 - Fuel tank expansion space.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 23.969 Section 23.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT....969 Fuel tank expansion space. Each fuel tank must have an expansion space of not less than two...
Hadronic mass-relations from topological expansion and string model
International Nuclear Information System (INIS)
Kaidalov, A.B.
1980-01-01
Hadronic mass-relations from topological expansion and string model are derived. For this purpose the space- time picture of hadron interactions at high energies corresponding to planar diagrams of topological expansion is considered. Simple relations between intercepts and slopes of Regge trajectories based on the topological expansion and q anti q-string picture of hadrons are obtained [ru
Global operator expansions in conformally invariant relativistic quantum field theory
International Nuclear Information System (INIS)
Schoer, B.; Swieca, J.A.; Voelkel, A.H.
1974-01-01
A global conformal operator expansions in the Minkowski region in several models and their formulation in the general theory is presented. Whereas the vacuum expansions are termwise manisfestly conformal invariant, the expansions away from the vacuum do not share this property
Efeito da eutonia no tratamento da fibromialgia
Maeda,Cecília; Martinez,José Eduardo; Neder,Matilde
2006-01-01
OBJETIVO: avaliar a eutonia como método terapêutico auxiliar no tratamento da fibromialgia (FM). MÉTODOS: estudou-se um grupo de 20 mulheres, segundo os critérios do American College of Rheumatology (ACR), com duração mínima de seis meses, sem alterações no tratamento medicamentoso ou prescrição de exercícios nesse período. As pacientes foram avaliadas através do questionário de dados sociodemográficos; Escala Visual Analógica (EVA) para dor e questionário genérico de avaliação da qualidade d...
Boer, M.G. de
2010-01-01
SAMENVATTING In een voorzetselstudie in het kader van Jackendoffs semantische theorie wordt het sterk polyseme Italiaanse voorzetsel da geanalyseerd als een verzameling deelbetekenissen waarbij de meeste door een of meer semantische regels afgeleid kunnen worden van de basisbetekenis ruimtelijke
ESPECTROS INFRAVERMELHOS DA CREATINA
Directory of Open Access Journals (Sweden)
Kumiko K. Sakane
2011-08-01
Full Text Available São apresentados espectros infravermelhos da creatina, na faixa de 4000 a 400 cm−1. Os resultados são comparados com espectros observados e calculados, publicados na literatura.
Significados Ocultos da Enfermagem
Directory of Open Access Journals (Sweden)
Wiliam César alves Machado
2011-04-01
Full Text Available Sabe-se que as ações de cuidar em enfermagem foram sendo moldadas através da história da humanidade e deram-se, majoritariamente, na esfera do subjetivo que permeia as interações existenciais do ser humano que cuida e daquele que recebe cuidados. Campo fecundo para intercâmbios eletromagnéticos. Suas origens remontam ao cuidado prestado por mães, pais, avós, irmãos e demais familiares incumbidos da responsabilidade de ajudar entes recém-natos, crianças, doentes e idosos em suas necessidades de cuidados para preservação da vida.
Energy Technology Data Exchange (ETDEWEB)
Lopez-Lopez, E.; Moreno, R.; Baudin, C.
2011-07-01
Zirconium titanate is a well known compound in the field of electro ceramics, although it has also been used in catalyst and sensors applications. The crystallographic thermal expansion anisotropy of this compound makes it a potential candidate as constituent of structural components. In general, to assure the structural integrity and microstructural homogeneity of a ceramic piece, relatively low cooling rates from the fabrication temperature are required. This requirement is essential for zirconium titanate because thermal expansion as well as phase distribution is affected by small variations in the composition and cooling rate. This work reviews the available data on the phase equilibrium relationships in the systems ZrO{sub 2}-TiO{sub 2} and ZrO{sub 2}-TiO{sub 2}-Y{sub 2}O{sub 3}. The main discrepancies as well as the possible origins of them are discussed. Additionally, the crystallographic thermal expansion data in the current literature are reviewed. (Author) 56 refs.
Expansion control for cementation of incinerated ash
International Nuclear Information System (INIS)
Nakayama, T.; Suzuki, S.; Hanada, K.; Tomioka, O.; Sato, J.; Irisawa, K.; Kato, J.; Kawato, Y.; Meguro, Y.
2015-01-01
A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was mixed with a cement material and water, alkaline components in the ash and the cement were dissolved in the mixing water and then metallic Al reaction with the alkaline compounds resulted in generation of H 2 . Because the H 2 generation began immediately just after the mixing, H 2 bubbles pushed up the mixed grout material and an expanded solidified form was obtained. The expansion leads to lowering the strength of the solidified form and making harmful void. In this study, we tried to control H 2 generation from the reaction of metallic Al in the cementation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. In the pre-treatment, the ash was soaked in water in order to let metallic Al react with it, and then the ash with the immersion solution was dried at 105 Celsius degrees. The pre-treated ash was mixed with an ordinary portland cement and water. The inhibitor of lithium nitrite, sodium nitrite, phosphoric acid, or potassium dihydrogen phosphate was added at the mixing process. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded. Phosphoric acid and sodium nitrite were effective for expansion control, but potassium dihydrogen phosphate did not work. (authors)
Private randomness expansion with untrusted devices
International Nuclear Information System (INIS)
Colbeck, Roger; Kent, Adrian
2011-01-01
Randomness is an important resource for many applications, from gambling to secure communication. However, guaranteeing that the output from a candidate random source could not have been predicted by an outside party is a challenging task, and many supposedly random sources used today provide no such guarantee. Quantum solutions to this problem exist, for example a device which internally sends a photon through a beamsplitter and observes on which side it emerges, but, presently, such solutions require the user to trust the internal workings of the device. Here, we seek to go beyond this limitation by asking whether randomness can be generated using untrusted devices-even ones created by an adversarial agent-while providing a guarantee that no outside party (including the agent) can predict it. Since this is easily seen to be impossible unless the user has an initially private random string, the task we investigate here is private randomness expansion. We introduce a protocol for private randomness expansion with untrusted devices which is designed to take as input an initially private random string and produce as output a longer private random string. We point out that private randomness expansion protocols are generally vulnerable to attacks that can render the initial string partially insecure, even though that string is used only inside a secure laboratory; our protocol is designed to remove this previously unconsidered vulnerability by privacy amplification. We also discuss extensions of our protocol designed to generate an arbitrarily long random string from a finite initially private random string. The security of these protocols against the most general attacks is left as an open question.
Seasonal hydroclimatic impacts of Sun Corridor expansion
International Nuclear Information System (INIS)
Georgescu, M; Mahalov, A; Moustaoui, M
2012-01-01
Conversion of natural to urban land forms imparts influence on local and regional hydroclimate via modification of the surface energy and water balance, and consideration of such effects due to rapidly expanding megapolitan areas is necessary in light of the growing global share of urban inhabitants. Based on a suite of ensemble-based, multi-year simulations using the Weather Research and Forecasting (WRF) model, we quantify seasonally varying hydroclimatic impacts of the most rapidly expanding megapolitan area in the US: Arizona’s Sun Corridor, centered upon the Greater Phoenix metropolitan area. Using a scenario-based urban expansion approach that accounts for the full range of Sun Corridor growth uncertainty through 2050, we show that built environment induced warming for the maximum development scenario is greatest during the summer season (regionally averaged warming over AZ exceeds 1 °C). Warming remains significant during the spring and fall seasons (regionally averaged warming over AZ approaches 0.9 °C during both seasons), and is least during the winter season (regionally averaged warming over AZ of 0.5 °C). Impacts from a minimum expansion scenario are reduced, with regionally averaged warming ranging between 0.1 and 0.3 °C for all seasons except winter, when no warming impacts are diagnosed. Integration of highly reflective cool roofs within the built environment, increasingly recognized as a cost-effective option intended to offset the warming influence of urban complexes, reduces urban-induced warming considerably. However, impacts on the hydrologic cycle are aggravated via enhanced evapotranspiration reduction, leading to a 4% total accumulated precipitation decrease relative to the non-adaptive maximum expansion scenario. Our results highlight potentially unintended consequences of this adaptation approach within rapidly expanding megapolitan areas, and emphasize the need for undeniably sustainable development paths that account for
Private randomness expansion with untrusted devices
Colbeck, Roger; Kent, Adrian
2011-03-01
Randomness is an important resource for many applications, from gambling to secure communication. However, guaranteeing that the output from a candidate random source could not have been predicted by an outside party is a challenging task, and many supposedly random sources used today provide no such guarantee. Quantum solutions to this problem exist, for example a device which internally sends a photon through a beamsplitter and observes on which side it emerges, but, presently, such solutions require the user to trust the internal workings of the device. Here, we seek to go beyond this limitation by asking whether randomness can be generated using untrusted devices—even ones created by an adversarial agent—while providing a guarantee that no outside party (including the agent) can predict it. Since this is easily seen to be impossible unless the user has an initially private random string, the task we investigate here is private randomness expansion. We introduce a protocol for private randomness expansion with untrusted devices which is designed to take as input an initially private random string and produce as output a longer private random string. We point out that private randomness expansion protocols are generally vulnerable to attacks that can render the initial string partially insecure, even though that string is used only inside a secure laboratory; our protocol is designed to remove this previously unconsidered vulnerability by privacy amplification. We also discuss extensions of our protocol designed to generate an arbitrarily long random string from a finite initially private random string. The security of these protocols against the most general attacks is left as an open question.
Private randomness expansion with untrusted devices
Energy Technology Data Exchange (ETDEWEB)
Colbeck, Roger; Kent, Adrian, E-mail: rcolbeck@perimeterinstitute.ca, E-mail: a.p.a.kent@damtp.cam.ac.uk [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5 (Canada)
2011-03-04
Randomness is an important resource for many applications, from gambling to secure communication. However, guaranteeing that the output from a candidate random source could not have been predicted by an outside party is a challenging task, and many supposedly random sources used today provide no such guarantee. Quantum solutions to this problem exist, for example a device which internally sends a photon through a beamsplitter and observes on which side it emerges, but, presently, such solutions require the user to trust the internal workings of the device. Here, we seek to go beyond this limitation by asking whether randomness can be generated using untrusted devices-even ones created by an adversarial agent-while providing a guarantee that no outside party (including the agent) can predict it. Since this is easily seen to be impossible unless the user has an initially private random string, the task we investigate here is private randomness expansion. We introduce a protocol for private randomness expansion with untrusted devices which is designed to take as input an initially private random string and produce as output a longer private random string. We point out that private randomness expansion protocols are generally vulnerable to attacks that can render the initial string partially insecure, even though that string is used only inside a secure laboratory; our protocol is designed to remove this previously unconsidered vulnerability by privacy amplification. We also discuss extensions of our protocol designed to generate an arbitrarily long random string from a finite initially private random string. The security of these protocols against the most general attacks is left as an open question.
Directory of Open Access Journals (Sweden)
Edvino Rabuske
1971-01-01
Full Text Available O tema que me foi proposto "origem da angtia moderna". Por certo, um tema extremamente complexo. Trata-se de surpreender as modalidades modernas de um fenomeno, antigo como o prrio homem. Visando contribuir numa semana de reflexo sobre a esperan crist em, que esta abordada a partir, de diversos gulos, parece indicado que esta exposio n se atenha a um ico aspeto da angtia.
Cosmic expansion from boson and fermion fields
International Nuclear Information System (INIS)
De Souza, Rudinei C; Kremer, Gilberto M
2011-01-01
This paper consists in analyzing an action that describes boson and fermion fields minimally coupled to the gravity and a common matter field. The self-interaction potentials of the fields are not chosen a priori but from the Noether symmetry approach. The Noether forms of the potentials allow the boson field to play the role of dark energy and matter and the fermion field to behave as standard matter. The constant of motion and the cyclic variable associated with the Noether symmetry allow the complete integration of the field equations, whose solution produces a universe with alternated periods of accelerated and decelerated expansion.
Operator product expansion and its thermal average
Energy Technology Data Exchange (ETDEWEB)
Mallik, S [Saha Inst. of Nuclear Physics, Calcutta (India)
1998-05-01
QCD sum rules at finite temperature, like the ones at zero temperature, require the coefficients of local operators, which arise in the short distance expansion of the thermal average of two-point functions of currents. We extend the configuration space method, applied earlier at zero temperature, to the case at finite temperature. We find that, upto dimension four, two new operators arise, in addition to the two appearing already in the vacuum correlation functions. It is argued that the new operators would contribute substantially to the sum rules, when the temperature is not too low. (orig.) 7 refs.
Topological expansion of the chain of matrices
International Nuclear Information System (INIS)
Eynard, B.; Ferrer, A. Prats
2009-01-01
We solve the loop equations to all orders in 1/N 2 , for the Chain of Matrices matrix model (with possibly an external field coupled to the last matrix of the chain). We show that the topological expansion of the free energy, is, like for the 1 and 2-matrix model, given by the symplectic invariants of [19]. As a consequence, we find the double scaling limit explicitly, and we discuss modular properties, large N asymptotics. We also briefly discuss the limit of an infinite chain of matrices (matrix quantum mechanics).
Derivative expansion and renormalisation group flows
Litim, Daniel F
2001-01-01
We study the convergence of the derivative expansion for flow equations. The convergence strongly depends on the choice for the infrared regularisation. Based on the structure of the flow, we explain why optimised regulators lead to better physical predictions. This is applied to O(N)-symmetric real scalar field theories in 3d, where critical exponents are computed for all N. In comparison to the sharp cut-off regulator, an optimised flow improves the leading order result up to 10%. An analogous reasoning is employed for a proper time renormalisation group. We compare our results with those obtained by other methods.
The colour and flavour 1/N expansions
International Nuclear Information System (INIS)
Veneziano, G.
General ideas about the colour and flavour 1/N expansions are presented in a non-specialized fashion according to both: a unified approach to meson dynamics (the basic logical scheme, lepton-hadron interactions, hadronic processes in lowest order, higher order effects and the Reggeon calculus); and a possible extension to baryons (difficulties with baryons in dual and gauge theories, possible definition of dual baryons in quantum chromodynamics, lowest order B anti-B and BB scattering: baryonium, Reggeon calculus for processes involving baryons)
Exponential expansion: galactic destiny or technological hubris?
Finney, B. R.
Is it our destiny to expand exponentially to populate the galaxy, or is such a vision but an extreme example of technological hubris? The overall record of human evolution and dispersion over the Earth can be cited to support the view that we are a uniquely expansionary and technological animal bound for the stars, yet an examination of the fate of individual migrations and exploratory initiatives raises doubts. Although it may be in keeping with our hubristic nature to predict ultimate galactic expansion, there is no way to specify how far expansionary urges may drive our spacefaring descendants.
Kato expansion in quantum canonical perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Nikolaev, Andrey, E-mail: Andrey.Nikolaev@rdtex.ru [Institute of Computing for Physics and Technology, Protvino, Moscow Region, Russia and RDTeX LTD, Moscow (Russian Federation)
2016-06-15
This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson’s ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.
Capacity Expansion Modeling for Storage Technologies
Energy Technology Data Exchange (ETDEWEB)
Hale, Elaine; Stoll, Brady; Mai, Trieu
2017-04-03
The Resource Planning Model (RPM) is a capacity expansion model designed for regional power systems and high levels of renewable generation. Recent extensions capture value-stacking for storage technologies, including batteries and concentrating solar power with storage. After estimating per-unit capacity value and curtailment reduction potential, RPM co-optimizes investment decisions and reduced-form dispatch, accounting for planning reserves; energy value, including arbitrage and curtailment reduction; and three types of operating reserves. Multiple technology cost scenarios are analyzed to determine level of deployment in the Western Interconnection under various conditions.
Kato expansion in quantum canonical perturbation theory
International Nuclear Information System (INIS)
Nikolaev, Andrey
2016-01-01
This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson’s ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.
The Dynamics of Regional and Global Expansion
DEFF Research Database (Denmark)
Geisler Asmussen, Christian; Nielsen, Bo Bernhard; Osegowitsch, Tom
2015-01-01
Purpose – The purpose of this paper is to model and test the dynamics of home-regional and global penetration by multi-national enterprises (MNEs). Design/methodology/approach – Drawing on international business (IB) theory, the authors model MNEs adjusting their home-regional and global market...... domain. Findings – The authors demonstrate that MNEs do penetrate both home-regional and global markets, often simultaneously, and that penetration levels often oscillate within an MNE over time. The authors show firms’ rates of regional and global expansion to be affected by their existing regional...
External momentum expansion in NJL model
International Nuclear Information System (INIS)
Huang Mei; Zhao Weiqin; Zhuang Pengfei
1999-01-01
In the large N c expansion beyond mean-field approximation, the authors develop a general scheme of SU(2) NJL model including current quark mass explicitly. In the scheme, the constituent quark's propagator is expanded in pions external momentum k, and all the Feynman diagrams are naturally expanded to k 2 term in a unified way. The numerical results show that in the mean field approximation, the effect of current quark mass is invisible, however, the effect of current quark mass can be seen explicitly beyond mean-field approximation for reasonable choices of the parameters in NJL model
The replication of expansive production knowledge
DEFF Research Database (Denmark)
Wæhrens, Brian Vejrum; Yang, Cheng; Madsen, Erik Skov
2012-01-01
Purpose – With the aim to support offshore production line replication, this paper specifically aims to explore the use of templates and principles to transfer expansive productive knowledge embedded in a production line and understand the contingencies that influence the mix of these approaches......; and (2) rather than being viewed as alternative approaches, templates and principles should be seen as complementary once the transfer motive moves beyond pure replication. Research limitations – The concepts introduced in this paper were derived from two Danish cases. While acceptable for theory...
Conformal Dimensions via Large Charge Expansion.
Banerjee, Debasish; Chandrasekharan, Shailesh; Orlando, Domenico
2018-02-09
We construct an efficient Monte Carlo algorithm that overcomes the severe signal-to-noise ratio problems and helps us to accurately compute the conformal dimensions of large-Q fields at the Wilson-Fisher fixed point in the O(2) universality class. Using it, we verify a recent proposal that conformal dimensions of strongly coupled conformal field theories with a global U(1) charge can be obtained via a series expansion in the inverse charge 1/Q. We find that the conformal dimensions of the lowest operator with a fixed charge Q are almost entirely determined by the first few terms in the series.
Correlation expansion: a powerful alternative multiple scattering calculation method
International Nuclear Information System (INIS)
Zhao Haifeng; Wu Ziyu; Sebilleau, Didier
2008-01-01
We introduce a powerful alternative expansion method to perform multiple scattering calculations. In contrast to standard MS series expansion, where the scattering contributions are grouped in terms of scattering order and may diverge in the low energy region, this expansion, called correlation expansion, partitions the scattering process into contributions from different small atom groups and converges at all energies. It converges faster than MS series expansion when the latter is convergent. Furthermore, it takes less memory than the full MS method so it can be used in the near edge region without any divergence problem, even for large clusters. The correlation expansion framework we derive here is very general and can serve to calculate all the elements of the scattering path operator matrix. Photoelectron diffraction calculations in a cluster containing 23 atoms are presented to test the method and compare it to full MS and standard MS series expansion
Basis for calculations in the topological expansion
International Nuclear Information System (INIS)
Levinson, M.A.
1982-12-01
Investigations aimed at putting the topological theory of particles on a more quantitative basis are described. First, the incorporation of spin into the topological structure is discussed and shown to successfully reproduce the observed lowest mass hadron spectrum. The absence of parity-doubled states represents a significant improvement over previous efforts in similar directions. This theory is applied to the lowest order calculation of elementary hadron coupling constant ratios. SU(6)/sub W/ symmetry is maintained and extended via the notions of topological supersymmetry and universality. Finally, efforts to discover a perturbative basis for the topological expansion are described. This has led to the formulation of off-shell Feynman-like rules which provide a calculational scheme for the strong interaction components of the topological expansion once the zero-entropy connected parts are known. These rules are shown to imply a topological asymptotic freedom. Even though the nonlinear zero-entropy problem cannot itself be treated perturbatively, plausible general assumptions about zero-entropy amplitudes allow immediate qualitative inferences concerning physical hadrons. In particular, scenarios for mass splittings beyond the supersymmetric level are described
Extended Plefka expansion for stochastic dynamics
International Nuclear Information System (INIS)
Bravi, B; Sollich, P; Opper, M
2016-01-01
We propose an extension of the Plefka expansion, which is well known for the dynamics of discrete spins, to stochastic differential equations with continuous degrees of freedom and exhibiting generic nonlinearities. The scenario is sufficiently general to allow application to e.g. biochemical networks involved in metabolism and regulation. The main feature of our approach is to constrain in the Plefka expansion not just first moments akin to magnetizations, but also second moments, specifically two-time correlations and responses for each degree of freedom. The end result is an effective equation of motion for each single degree of freedom, where couplings to other variables appear as a self-coupling to the past (i.e. memory term) and a coloured noise. This constitutes a new mean field approximation that should become exact in the thermodynamic limit of a large network, for suitably long-ranged couplings. For the analytically tractable case of linear dynamics we establish this exactness explicitly by appeal to spectral methods of random matrix theory, for Gaussian couplings with arbitrary degree of symmetry. (paper)
On the binary expansions of algebraic numbers
Energy Technology Data Exchange (ETDEWEB)
Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.; Pomerance, Carl
2003-07-01
Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.
Optimal separable bases and series expansions
International Nuclear Information System (INIS)
Poirier, B.
1997-01-01
A method is proposed for the efficient calculation of the Green close-quote s functions and eigenstates for quantum systems of two or more dimensions. For a given Hamiltonian, the best possible separable approximation is obtained from the set of all Hilbert-space operators. It is shown that this determination itself, as well as the solution of the resultant approximation, is a problem of reduced dimensionality. Moreover, the approximate eigenstates constitute the optimal separable basis, in the sense of self-consistent field theory. The full solution is obtained from the approximation via iterative expansion. In the time-independent perturbation expansion for instance, all of the first-order energy corrections are zero. In the Green close-quote s function case, we have a distorted-wave Born series with optimized convergence properties. This series may converge even when the usual Born series diverges. Analytical results are presented for an application of the method to the two-dimensional shifted harmonic-oscillator system, in the course of which the quantum tanh 2 potential problem is solved exactly. The universal presence of bound states in the latter is shown to imply long-lived resonances in the former. In a comparison with other theoretical methods, we find that the reaction path Hamiltonian fails to predict such resonances. copyright 1997 The American Physical Society
Is China ready for its nuclear expansion?
International Nuclear Information System (INIS)
Zhou, Yun; Rengifo, Christhian; Hinze, Jonathan; Chen, Peipei
2011-01-01
China's rapid pace of nuclear energy growth is unique, and its impact on the global nuclear market as both a customer and potential future supplier is already tremendous and will continue to expand. It is crucial to understand this energy policy development and its impact on various global areas. Unfortunately, there is relatively limited English-language information available about China's nuclear power industry and its current development. This paper aims to provide a comprehensive assessment of the Chinese nuclear energy program and policy, reviewing its past, present, likely future developments, as well as to consider potential challenges that deserve further attention. This paper will explore reasons that have caused the existing industry, describe China's nuclear bureaucracy and decision making process to understand how different stakeholders play a role in China's nuclear energy development. This study concludes that China's existing nuclear program and industry, in combination with its current stable economic and political environment, provides a sound foundation for the planned nuclear expansion. However, challenges which are crucial to the success of the nuclear expansion will need to be addressed. (author)
International Nuclear Information System (INIS)
Terent'ev, M.V.
1986-01-01
The operator expansion is studied in two dimensional σ-model with O(N) symmetry group at large values of N for the Green function at x 2 → 0 (Here n(x) is the dynamical field of σ-model). As a preliminary step the renormalization scheme is formulated in framework of I/N expansion where the intermediate scale μ 2 is introdused and regions of large (p > μ) and small (p 2 )/N in composite operators (here f(μ 2 ) is the effective coupling constant at the point μ 2 ) and the corrections of order of m 2 x 2 f(μ 2 )/N in the coefficient functions (here m is the dynamical mass-scale factor of σ-model) decisively depend on the recipe of factorization of small and large momenta regions. Due to the analogy between σ-model and quantum chromodynamics (QCD) the obtained result indicates the theoretical limitations to the accuracy of sum rule method in QCD
Tensor integrand reduction via Laurent expansion
Energy Technology Data Exchange (ETDEWEB)
Hirschi, Valentin [SLAC, National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, CA 94025-7090 (United States); Peraro, Tiziano [Higgs Centre for Theoretical Physics, School of Physics and Astronomy,The University of Edinburgh,Edinburgh EH9 3JZ, Scotland (United Kingdom)
2016-06-09
We introduce a new method for the application of one-loop integrand reduction via the Laurent expansion algorithm, as implemented in the public C++ library Ninja. We show how the coefficients of the Laurent expansion can be computed by suitable contractions of the loop numerator tensor with cut-dependent projectors, making it possible to interface Ninja to any one-loop matrix element generator that can provide the components of this tensor. We implemented this technique in the Ninja library and interfaced it to MADLOOP, which is part of the public MADGRAPH5{sub A}MC@NLO framework. We performed a detailed performance study, comparing against other public reduction tools, namely CUTTOOLS, SAMURAI, IREGI, PJFRY++ and GOLEM95. We find that Ninja outperforms traditional integrand reduction in both speed and numerical stability, the latter being on par with that of the tensor integral reduction tool GOLEM95 which is however more limited and slower than Ninja. We considered many benchmark multi-scale processes of increasing complexity, involving QCD and electro-weak corrections as well as effective non-renormalizable couplings, showing that Ninja’s performance scales well with both the rank and multiplicity of the considered process.
Notes on Mayer expansions and matrix models
International Nuclear Information System (INIS)
Bourgine, Jean-Emile
2014-01-01
Mayer cluster expansion is an important tool in statistical physics to evaluate grand canonical partition functions. It has recently been applied to the Nekrasov instanton partition function of N=2 4d gauge theories. The associated canonical model involves coupled integrations that take the form of a generalized matrix model. It can be studied with the standard techniques of matrix models, in particular collective field theory and loop equations. In the first part of these notes, we explain how the results of collective field theory can be derived from the cluster expansion. The equalities between free energies at first orders is explained by the discrete Laplace transform relating canonical and grand canonical models. In a second part, we study the canonical loop equations and associate them with similar relations on the grand canonical side. It leads to relate the multi-point densities, fundamental objects of the matrix model, to the generating functions of multi-rooted clusters. Finally, a method is proposed to derive loop equations directly on the grand canonical model
Charge transfer reactions in Xe plasma expansion
International Nuclear Information System (INIS)
Jiao, C. Q.; Garscadden, A.; Ganguly, B. N.
2007-01-01
Charge transfer reactions of fast Xe ions with hydrocarbons including methane (CH 4 ), ethene (C 2 H 4 ), and propane (C 3 H 8 ) are studied by adding these hydrocarbon gases into a cross flowing Xe plasma expansion. Branching ratios and relative reaction rates for the charge transfers of fast Xe + with each of the three hydrocarbon gases are measured under different rf powers of the inductively coupled Xe discharge. For CH 4 /Xe system, we find that fast Xe + reacts readily with CH 4 generating CH 4 + and CH 3 + in a ratio of 1:0.56, with an estimated rate coefficient of (2.3±0.3)x10 -10 cm 3 /s at 75 W rf power which slowly increases to (2.9±0.3)x10 -10 cm 3 /s at 250 W (error bars reflect only the uncertainties due to the unknown extent of the ion recombination that follows the charge transfer reaction). These observed charge transfer reactions are made possible by the kinetically excited Xe ions produced by free expansion of the plasma. For the C 2 H 4 /Xe system product ions C 2 H 4 + and C 2 H 2 + are observed, and for C 3 H 8 /Xe, C 2 H 4 + and C 2 H 5 + and minor product ions including C 2 H 2 + and C 3 H 7 + are observed
Rapid maxillary expansion in contemporary orthodontic literature
Directory of Open Access Journals (Sweden)
Sabrina Mutinelli
2016-01-01
Full Text Available We have reviewed our retrospective research about rapid maxillary expansion performed in the early mixed dentition to summarize the results of different studies regarding maxillary dental arch width variation and crowding improvement in light of contemporary literature. The aim is to define the effects of treatments followed until the end of dental arch growth. In all studies, a Haas expander anchored to the deciduous dentition was used. The samples consisted of treated patients with and without a lateral crossbite and homogeneous untreated individuals as controls. Two additional control groups of adolescents and adults in dental Class 1 were also compared. As a result of the analysis, rapid maxillary expansion with anchorage to the deciduous dentition was found to be effective in increasing transverse width in intermolar and intercanine areas, and the change was preserved until the full permanent dentition stage. When performed before maxillary lateral incisors have fully erupted, this procedure allows for a rapid increase in the arch length in the anterior area and consequently, in the space available for permanent incisors with a stable reduction in crowding over time.
Extended Plefka expansion for stochastic dynamics
Bravi, B.; Sollich, P.; Opper, M.
2016-05-01
We propose an extension of the Plefka expansion, which is well known for the dynamics of discrete spins, to stochastic differential equations with continuous degrees of freedom and exhibiting generic nonlinearities. The scenario is sufficiently general to allow application to e.g. biochemical networks involved in metabolism and regulation. The main feature of our approach is to constrain in the Plefka expansion not just first moments akin to magnetizations, but also second moments, specifically two-time correlations and responses for each degree of freedom. The end result is an effective equation of motion for each single degree of freedom, where couplings to other variables appear as a self-coupling to the past (i.e. memory term) and a coloured noise. This constitutes a new mean field approximation that should become exact in the thermodynamic limit of a large network, for suitably long-ranged couplings. For the analytically tractable case of linear dynamics we establish this exactness explicitly by appeal to spectral methods of random matrix theory, for Gaussian couplings with arbitrary degree of symmetry.
Directory of Open Access Journals (Sweden)
Profª. Drª. Fátima Antunes da Silva (Yaska Antunes
2009-05-01
Full Text Available O presente trabalho tem por objetivo tentar compreender a produção da imagem visual no teatro. Para isso se vale da apropriação livre do conceito de “dobra? de Gilles Deleuze para se referir à multiplicidade de imagens criadas pelas diversas modalidades artísticas. Como no teatro há o entrelaçamento de imagens verbais – palavras enunciadas pelo texto dramático ou teatral – com imagens visuais – a visualidade advinda da composição cênica concreta que organiza no espaço ator e objeto –, a ênfase só podia recair sobre estas duas formas imagéticas. No caso do teatro, surge ainda a percepção de que para além da materialidade da cena, outras imagens emergem do confronto entre palco e platéia. Nesse sentido, imagem teatral seria então aquilo que surge da interação entre ator e espectador. A contribuição desse trabalho pode estar no fato de atualizar certos conceitos sobre a criação da imagem poética na poesia e no cinema para aplicá-los ao teatro. Ao recuperar o pensa-mento de Otávio Paz, Alfredo Bosi, Sergei Eisenstein, entre outros, bus-ca-se promover uma reflexão mais aprofundada sobre a construção visual no teatro.
Chen, Jun; Hu, Lei; Deng, Jinxia; Xing, Xianran
2015-06-07
Negative thermal expansion (NTE) is an intriguing physical property of solids, which is a consequence of a complex interplay among the lattice, phonons, and electrons. Interestingly, a large number of NTE materials have been found in various types of functional materials. In the last two decades good progress has been achieved to discover new phenomena and mechanisms of NTE. In the present review article, NTE is reviewed in functional materials of ferroelectrics, magnetics, multiferroics, superconductors, temperature-induced electron configuration change and so on. Zero thermal expansion (ZTE) of functional materials is emphasized due to the importance for practical applications. The NTE functional materials present a general physical picture to reveal a strong coupling role between physical properties and NTE. There is a general nature of NTE for both ferroelectrics and magnetics, in which NTE is determined by either ferroelectric order or magnetic one. In NTE functional materials, a multi-way to control thermal expansion can be established through the coupling roles of ferroelectricity-NTE, magnetism-NTE, change of electron configuration-NTE, open-framework-NTE, and so on. Chemical modification has been proved to be an effective method to control thermal expansion. Finally, challenges and questions are discussed for the development of NTE materials. There remains a challenge to discover a "perfect" NTE material for each specific application for chemists. The future studies on NTE functional materials will definitely promote the development of NTE materials.
Directory of Open Access Journals (Sweden)
Gustavo Pereira Fraga
Full Text Available OBJETIVO: O trauma da veia porta é raro e freqüentemente fatal por causa de exsanguinação e alta incidência de lesões de estruturas adjacentes. Devido às pecualiaridades desta lesão e diferentes condutas propostas na literatura, o objetivo dos autores é relatar a experiência neste tipo de lesão. MÉTODO: Estudo retrospectivo, de janeiro de 1994 e dezembro de 2001, de 1370 pacientes submetidos à laparotomia devido trauma abdominal. Entre esses, 15 pacientes apresentavam lesão da veia porta. As lesões foram classificadas conforme a sua extensão e localização. RESULTADOS: O mecanismo de trauma predominante foi o penetrante. O diagnóstico da lesão foi realizado no intraoperatório. Os procedimentos executados foram: sutura, anastomose término-terminal e ligadura da veia porta. A mortalidade foi de 53,3%. CONCLUSÃO: A lesão da veia porta possui alta taxa de mortalidade e o atendimento adequado está diretamente relacionado à sobrevida.
Energy Technology Data Exchange (ETDEWEB)
Pereira, Jose Carlos Alves
1996-07-01
The dispersion of a 51 TBq {sup 137} Cs source to the environment in Goiania city, has originated approximately 3500 m{sup 3} of radioactive waste. In order to segregate such waste in a definite form, a repository is being built in Abadia de Goias, GO near the site where it has been temporarily stored. This study had the following objectives: the determination of the {sup 137} Cs partition rate (K{sub D}) and the estimate of its migration velocity in soil samples from the site where the repository is being built. The determination of {sup 137} Cs K{sub D} was carried out by using two methods: 'batch method' and 'in-situ' method. In relation to the 'batch method'; 6 soil profiles cut into sections according to its pedologic horizons and 13 surface soil samples were collected, whereas for the 'in-situ' method 6 soil profiles with 28 cm depth were collected and each profile has been cut into 14 soil sections of a 1-3 cm range. Studies were carried out by using the 'batch method' to relate the influence from v/m and from shaking in K{sub D} determination and also studies about {sup 137} Cs adsorption reversibility in soil, time necessary for the equilibrium of {sup 137} Cs between water/soil phases to be reached and K{sub D} correlation with pedological parameters (pH values in water and clay, silt and organic material percent concentration, electrical conductivity of solution and the cation exchange - Ca{sup +2}, Mg {sup +2}, K{sup +2}, Na{sup +}, Al{sup +3}, H{sup +}). It has been noticed that in work conditions, K{sub D} has increased according to the rate increase v/m and the use of agitation in water/soil phases had no influence in K{sub D} determination. The absorbed {sup 137} Cs desorption process by water has shown to be slow but continued. Nevertheless, {sup 137} Cs cationic exchange for NH{sub 4}{sup +} has presented two steps: the first one very fast where approximately 50% of {sup 137} Cs adsorbed has been exchanged for NH{sub 4}{sup +} ions in just two days and the second one slow. Results indicate that {sup 137} Cs adsorption process in this kind of soil may be considered reversible. In using the 'batch method', it was noticed a higher {sup 137} Cs when increasing depth from soil profiles (108 - 897 cm{sup 3}.g{sup -1}). Nevertheless, {sup 137} Cs K{sub D} results point out to an average value of 430cm{sup 3}.g{sup -1}. This observation is confirmed when comparing to an average K{sub D} obtained by using 'batch method' and the K{sub D} value of 501 cm{sup 3}.g{sup -1} obtained by using 'in-situ' method. K{sub D} has just presented consistent linear correlation in relation to clay, [r=0,73]. Even though the type of clay found in the analyzed soils (caulinita) possess low adsorptive capacity, results have shown that as long as higher concentrations in clay in soil layers have been found, {sup 137} Cs K{sub D} has proportionally increased. Taking into consideration the hydrogeological medium conditions, {sup 137} Cs migration velocity found for a K{sub D} the average value obtained by using 'batch method' is 0,43 cm.year{sup -1}, whereas, for the 'in-situ' method was 0,37 cm.year{sup -1}. Assuming two meters as the minimum depth for ground water, {sup 137} Cs would take 460 - 500 years to reach it. (author)
Energy Technology Data Exchange (ETDEWEB)
Bordalo, Adriana Oliveira; Moura, Candido Augusto Veloso; Scheller, Thomas [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias]. E-mail: adriana@ufpa.br
2007-07-15
Analytical procedures used for determining the concentrations and isotope composition of strontium in subsurface waters, by mass spectrometry, are described. Sampling was performed in coastal plateaus, salt marsh and mangrove environments in the coastal region of Para. Coastal plateau waters have {delta}{sup 87}Sr between 1.51 and 6.26 per mille and Sr concentration bellow 58 ppb. Salt marsh waters show {delta}{sup 87}Sr between 0.55 and 0.90 per mille and Sr concentration between 93 and 114 ppm, while mangrove waters have {delta}{sup 87}Sr per mille around zero and Sr concentration above 15 ppm. Differences in the {sup 87}Sr/{sup 86}Sr ratio in these subsurface waters are detected, as well as seasonal variations in the coastal plateau waters. (author)
Energy Technology Data Exchange (ETDEWEB)
Garcez, Ricardo Washington Dutra; Lopes, Jose Marques; Silva, Ademir Xavier da, E-mail: rgarcez@con.ufrj.br, E-mail: marqueslopez@yahoo.com.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Domingues, Alessandro Mariano; Lima, Marco Frota, E-mail: slessandrodomingues@fisica.if.uff.br, E-mail: marcofrotalima@yahoo.com.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia
2015-07-01
Use of fertilizer is an established practice worldwide to promote agricultural productivity increased without increasing the planted area, resulting in native forests protection and increase of the food availability. Some kinds of fertilizer have in their chemical composition some radionuclides due the origin of its feedstock, such as {sup 238}U, the {sup 232}Th, and their descendants, beyond {sup 40}K. Knowledge of the radioactivity levels in the environment is great importance to know the gamma radiation dose that the human being is exposed. For identification and quantitation of radionuclides, it was used gamma spectrometry where HPGe detector was used to obtain the spectra, and LabSOCS software for calculating the detection efficiency for each energy. The values of {sup 232}Th specific concentrations ranged from 4.1 to 368.1 Bq.Kg{sup -1} , the values of {sup 238}U specific concentrations ranged from 16.0 to 647.7 Bq.Kg{sup -1} and {sup 40}K specific concentrations ranged from 19.1 to 12713 Bq.Kg{sup -1} . Concentrations of values are consistent with those found in literature. (author)
Energy Technology Data Exchange (ETDEWEB)
Hozumi, Cristiny Gomes
2010-07-01
The human exposure to ionizing radiation coming from natural sources is an inherent feature of human life on earth, for man and all living things have always been exposed to these sources. Ionizing radiation is a known genotoxic agent which can affect the genomic stability and genes related to DNA repair may play a role when they have committed certain polymorphism. This study aimed to analyze the frequency of polymorphisms (SNPs) in genes of DNA repair and cell cycle control: hOGG1 (Ser326Cys), XRCC3 (Thr241 Met) and p53 (Arg72Pro) in saliva samples from a population located Monte Alegre, state of Para were collected in August 2008 and 40 samples of men and 46 samples of women, adding a total of 86 samples. By RFLP was determined the frequency of homozygous genotypes and / or heterozygous for polymorphic genes. The I)OGG1 gene was 5% of the allele 326Cys, XRCC3 gene found about 21 % of the allele 241 Met and p53 gene showed 40.8% of the 72Pro allele. And the genotype frequencies of individuals for the three genes were 91.04%, 88.06% and 59.7% for homozygous wild genotype, 5.97%, 11.94% and 22.39% for heterozygote genotype and 2,99%, zero and 17:91% for homozygous polymorphic hOGG1 genes respectively, XRCC3, p53. These values are similar to those found in previous studies. The influence of these polymorphisms, which are involved in DNA repair and consequent genotoxicity induced by radiation depends on dose and exposure factors such as smoking, which is statistically a factor in public health surveillance in the region. This study gathered information and molecular epidemiology in Monte Alegre, that help to characterization of local population. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, Henrique Machado Moreira [Schlumberger, Itajuba, MG (Brazil)], e-mail: henriquemmsantos@yahoo.com.br; Santos, Afonso Henriques Moreira [Universidade Federal de Itajuba (UNIFEI/GEE/ISSE), MG (Brazil). Inst. de Sistemas Eletricos e Energia. Grupo de Estudos Energeticos], e-mail: afonsohms@gmail.com; Ribeiro Junior, Leopoldo Uberto, e-mail: leopoldo_junior@yahoo.com.br; Nascimento, Jose Guilherme Antloga do, e-mail: jgan@brasilpch.com.br
2008-07-01
This paper seems to develop the economic analysis of Small Hydro Plants - SHP, incorporating in this analysis evaluations of priceless losses for the society, as the environmental damages, taking SHP Paraitinga as the study case. It involves questions related to environmental valuation, economics, and engineering, presenting the concept of the Economic Valuation of Environmental Resources. The main valuation methods are presented. In the economic analysis, the concept of willingness to pay is verified by using demand function, that involves the elasticity and the price. The price is calculated based on costs and the elasticity is calculated based on the essentially of the goods or services, which could be reached by market observation. Only the remaining outflow definition, in the stretch of reduced outflow of the project will be studied. After these studies and valuations, some scenarios will be adopted for the developed model, on current values and projections. A comparison of the present work and the methodology of commitment programming are carried out. Finally the results will be analyzed, trying to get the 'optimum outflow', aiming at balancing power, tourism and environmental interests. (author)
Energy Technology Data Exchange (ETDEWEB)
Santos, Maria de Fatima Pereira dos [Fundacao Gorceix, Ouro Preto, MG(Brazil)]. E-mail: santos@cenpes.petrobras.com.br; Tamanqueira, Juliana Boechat [Universidade Federal Fluminense, Niteroi, RJ (Brazil); Magalhaes, Julio Cesar Dias [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Avaliacao de Petroleo; Oliveira, Elcio Cruz de [Transpetro, Rio de Janeiro, RJ (Brazil). Logistica e Planejamento; Vaitsman, Delmo Santiago [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica
2003-12-01
With the objectives of using a single system of injection and of extending the range of application for the method ASTM D4629/02 'Total Nitrogen in Petroleum Derivatives by the System of Injection with a Syringe and Detection by Chemo- Luminescence', it was studied a procedure by statistical validation with the objective of guaranteeing the analytical reliability of the assay and allowing the inclusion of samples of petroleum and heavy derivatives in one single methodology. The determination of total nitrogen for petroleum and derivatives is traditionally assayed using the method of Kjeldahl - a time-consuming methodology that requires a large amount of time for giving the final result, at the same time that is not recommended for concentrations below 0.1%w/w, which does not meet the requirements for the specifications of the product, in the petroleum industry. An alternative for the method of Kjeldahl is the pyro-chemo luminescence, which allows the achievement of more repetitive results for total nitrogen. In the detection of nitrogen, the technique combines the reliability of oxidative combustion with the sensitivity of chemiluminescence. Therefore, it was developed a protocol of validation in the methodology ASTM D4629/02 for the validation of the extension of the range of application and for the evaluation of the performance of the equipment in analytical conditions, according to the calibration curve. (author)
Energy Technology Data Exchange (ETDEWEB)
Souza, Izabella Soares de
2017-07-01
In the past decade microcomputerized tomography imaging using synchrotron radiation has become a powerful technique to generate high resolution images of Rhodinus prolixus. Images of soft tissues (protocerebrum and muscles) and dense structures (pharynx, trachea and esophagus) of R. prolixus head have been obtained using synchrotron radiation microtomography in mono and polychromatic configuration, respectively. Advancements in conventional microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and widely available technology potentially useful for studies of insect internal morphology. The main goal of this work was to provide a new set of high quality microtomographic images of R. prolixus achieved by means of a desktop X-ray microtomograph. It allows the three-dimensional visualization of important chitinized structures: pharynx and tracheae. Pharyngeal and tracheal volumes were quantitatively evaluated at different days (1, 4, 10, 15 and 20) after feeding. The results suggest that variation of average volumes could be attributed to insect hormone 20-hydroxy-ecdysone (20-OH-Ec) pulse at 11 days after feeding. Pharyngeal volumes decrease 3.80 times. On the other hand, tracheal volumes increase 1.78 times. Head total volume showed similar trends than trachea. (author)
Separable expansion for realistic multichannel scattering problems
International Nuclear Information System (INIS)
Canton, L.; Cattapan, G.; Pisent, G.
1987-01-01
A new approach to the multichannel scattering problem with realistic local or nonlocal interactions is developed. By employing the negative-energy solutions of uncoupled Sturmian eigenvalue problems referring to simple auxiliary potentials, the coupling interactions appearing to the original multichannel problem are approximated by finite-rank potentials. By resorting to integral-equation tecniques the coupled-channel equations are then reduced to linear algebraic equations which can be straightforwardly solved. Compact algebraic expressions for the relevant scattering matrix elements are thus obtained. The convergence of the method is tasted in the single-channel case with realistic optical potentials. Excellent agreement is obtained with a few terms in the separable expansion for both real and absorptive interactions
Current expansion of the Elliot Lake mines
International Nuclear Information System (INIS)
Stenning, G.
1982-06-01
The Elliot Lake mines are located in northern Ontario, on the north shore of Lake Huron. Mining operations in this area started in the mid-1950's and were curtailed during the 1960's. Starting in 1973 Rio Algom's Quirke mine and Denison, the only producers remaining in the area, started to make plans to expand. Increasing production to 30,000 tpd (milled) requires the reopening of the Panel and Stanleigh Mines of the Rio Algom group and the Stanrock-CanMet area at Denison. The first phase of the expansion was preceded by extensive public hearings. Mine production increases, improvement to the facilities at the reopened mines, and the effects on community facilities are described in this paper
DISRUPTING SHOCKS IN POSTWAR GLOBAL ECONOMIC EXPANSION
Directory of Open Access Journals (Sweden)
Dumitru FILIPEANU
2016-06-01
Full Text Available The coherence of the global economic system, created by its upswing in the first postwar decades, started to crumble in the ’70s. The destabilizing shocks affected the entire world, but in an uneven manner, in different geographical areas and at different times, being felt most acutely, with devastating economic and social effects, in Third World countries. Although the developed countries were affected as well, they always had means to combat or to diminish the adverse effects of the crises, leading to "gentler" consequences. This paper focuses on four main aspects in postwar global economic expansion, namely: the ’70s – the international monetary crisis and the oil shocks; the foreign debt crisis; the Latin American debt crisis, the Asian financial crises and the current global crisis.
The worldwide expansion of the Argentine ant
DEFF Research Database (Denmark)
Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana
2010-01-01
Aim The aim of this study was to determine the number of successful establishments of the invasive Argentine ant outside native range and to see whether introduced supercolonies have resulted from single or multiple introductions. We also compared the genetic diversity of native versus introduced...... supercolonies to assess the size of the propagules (i.e. the number of founding individuals) at the origin of the introduced supercolonies. Location Global. Methods We used mitochondrial DNA (mtDNA) markers and microsatellite loci to study 39 supercolonies of the Argentine ant Linepithema humile covering both......) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not evolve recently as a unique...
Effects of forest expansion on mountain grassland
DEFF Research Database (Denmark)
Guidi, Claudia; Magid, Jakob; Rodeghiero, Mirco
2014-01-01
Background and aims. Grassland abandonment followed by forest succession is the dominant land-use change in the European Alps. We studied the impact of current forest expansion on mountain grassland on changes in physical soil organic carbon (SOC) fractions along a land-use and management gradient......, focusing on changes in aggregate stability and particulate organic matter (POM). Methods. Four successional stages were investigated: managed grassland, two transitional phases in which grassland abandonment led to colonization by Picea abies (L.) Karst., and old mixed forest dominated by Fagus sylvatica L....... Results. The dimension of aggregates assessed by aggregate size fractionation tended to increase, whereas SOC allocation to stable aggregates assessed by sizedensity fractionation decreased following conversion of grassland to forest (e.g. from 81 to 59 % in the 0–5 cm layer). The amount of SOC stored...
Rarefied, superorbital flows in an expansion tube
Energy Technology Data Exchange (ETDEWEB)
Wheatley, V.; Chiu, H.S.; Jacobs, P.A.; Macrossan, M.N.; Mee, D.J.; Morgan, R.G.
2004-04-01
This paper describes a free-piston driven expansion tube and its instrumentation. The facility is used to generate rarefied flows at speeds of approximately 10 km/s. Although the flow in the tube itself is in the continuum regime, rarefied flow conditions are achieved by allowing the test gas to further expand as a free jet into the facility's test section. The test flow is surveyed to provide bar-gauge pressure measurements. Numerical simulation is then used to describe more fully the test flow properties. The flows produced are suitable for the aerodynamic testing of small models at superorbital speeds and should provide data that are suitable for the calibration of Direct Simulation Monte-Carlo codes. (author)
Critical point anomalies include expansion shock waves
Energy Technology Data Exchange (ETDEWEB)
Nannan, N. R., E-mail: ryan.nannan@uvs.edu [Mechanical Engineering Discipline, Anton de Kom University of Suriname, Leysweg 86, PO Box 9212, Paramaribo, Suriname and Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands); Guardone, A., E-mail: alberto.guardone@polimi.it [Department of Aerospace Science and Technology, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Colonna, P., E-mail: p.colonna@tudelft.nl [Propulsion and Power, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)
2014-02-15
From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium. In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.
Expansion into lattice harmonics in cubic symmetries
Kontrym-Sznajd, G.
2018-05-01
On the example of a few sets of sampling directions in the Brillouin zone, this work shows how important the choice of the cubic harmonics is on the quality of approximation of some quantities by a series of such harmonics. These studies led to the following questions: (1) In the case that for a given l there are several independent harmonics, can one use in the expansion only one harmonic with a given l?; (2) How should harmonics be ordered: according to l or, after writing them in terms of (x4 + y4 + z4)n (x2y2z2)m, according to their degree q = n + m? To enable practical applications of such harmonics, they are constructed in terms of the associated Legendre polynomials up to l = 26. It is shown that electron momentum densities, reconstructed from experimental data for ErGa3 and InGa3, are described much better by harmonics ordered with q.
Breeding bird response to juniper woodland expansion
Rosenstock, Steven S.; van Riper, Charles
2001-01-01
In recent times, pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands have expanded into large portions of the Southwest historically occupied by grassland vegetation. From 1997-1998, we studied responses of breeding birds to one-seed juniper (J. monosperma) woodland expansion at 2 grassland study areas in northern Arizona. We sampled breeding birds in 3 successional stages along a grassland-woodland gradient: un-invaded grassland, grassland undergoing early stages of juniper establishment, and developing woodland. Species composition varied greatly among successional stages and was most different between endpoints of the gradient. Ground-nesting grassland species predominated in uninvaded grassland but declined dramatically as tree density increased. Tree- and cavity-nesting species increased with tree density and were most abundant in developing woodland. Restoration of juniper-invaded grasslands will benefit grassland-obligate birds and other wildlife.
Population Genetics of Three Dimensional Range Expansions
Lavrentovich, Maxim; Nelson, David
2014-03-01
We develop a simple model of genetic diversity in growing spherical cell clusters, where the growth is confined to the cluster surface. This kind of growth occurs in cells growing in soft agar, and can also serve as a simple model of avascular tumors. Mutation-selection balance in these radial expansions is strongly influenced by scaling near a neutral, voter model critical point and by the inflating frontier. We develop a scaling theory to describe how the dynamics of mutation-selection balance is cut off by inflation. Genetic drift, i.e., local fluctuations in the genetic diversity, also plays an important role, and can lead to the extinction even of selectively advantageous strains. We calculate this extinction probability, taking into account the effect of rough population frontiers.
Thermal linear expansion coefficient of structural graphites
International Nuclear Information System (INIS)
Virgil'ev, Yu.S.
1995-01-01
The data now available on radiation induced changes of linear thermal expansion coefficients (CTE) for native structural carbon materials (SCM) irradiated with high fluences are summarized. For different types of native and foreign SCM dose dependences of CTE changes in the temperature range of 300...1600 K and at fluences up to (2...3)x10 22 n/cm 2 (E>0.18 meV) are compared. On the base of this comparison factors defined the CTE changes under neutron irradiation are revealed and the explanation of observed phenomena is offered. Large number of the factors revealed does not allowed to calculate CTE radiation induced changes. 39 refs.; 16 figs.; 5 tabs
A non-perturbative operator product expansion
International Nuclear Information System (INIS)
Bietenholz, W.; Cundy, N.; Goeckeler, M.
2009-10-01
Nucleon structure functions can be observed in Deep Inelastic Scattering experiments, but it is an outstanding challenge to confront them with fully non-perturbative QCD results. For this purpose we investigate the product of electromagnetic currents (with large photonmomenta) between quark states (of low momenta). By means of an Operator Product Expansion the structure function can be decomposed into matrix elements of local operators, and Wilson coefficients. For consistency both have to be computed non-perturbatively. Here we present precision results for a set of Wilson coefficients. They are evaluated from propagators for numerous quark momenta on the lattice, where the use of chiral fermions suppresses undesired operator mixing. This overdetermines the Wilson coefficients, but reliable results can be extracted by means of a Singular Value Decomposition. (orig.)
Portugal's Petrogal eyes expansion amid continuing privatization
International Nuclear Information System (INIS)
Anon.
1995-01-01
Portugal's recently privatized state oil company Petrogal is about to embark on a major expansion worldwide. That comes against the backdrop of major change in Portugal's energy sector and the rocky road to Petrogal's partial privatization. Despite the controversy, there remain opportunities for foreign companies investing in Portugal's energy sector. The most attractive opportunities are in Portugal's downstream petroleum sector and in the country's continuing campaign to develop its natural gas industry. Typical of the latter is Portugal's participation in the Trans-Maghreb gas pipeline megaproject. The paper discusses the background to privatization, its current status, Petrogal strategy, modernization of refineries, a joint partnership with Venezuela, constraints, energy policy program, gas pipeline privatization, and concerns of the gas industry
Sectoral and regional expansion of emissions trading
Energy Technology Data Exchange (ETDEWEB)
Boehringer, Christoph; Bouwe, Dijkstra; Rosendahl, Knut Einar
2011-07-01
We consider an international emissions trading scheme with partial sectoral and regional coverage. Sectoral and regional expansion of the trading scheme is beneficial in aggregate, but not necessarily for individual countries. We simulate international CO{sub 2} emission quota markets using marginal abatement cost functions and the Copenhagen 2020 climate policy targets for selected countries that strategically allocate emissions in a bid to manipulate the quota price. Quota exporters and importers generally have conflicting interests about admitting more countries to the trading coalition, and our results indicate that some countries may lose substantially when the coalition expands in terms of new countries. For a given coalition, expanding sectoral coverage makes most countries better off, but some countries (notably the USA and Russia) may lose out due to loss of strategic advantages. In general, exporters tend to have stronger strategic power than importers.(Author)
Expansive focal cemento-osseous dysplasia.
Bulut, Emel Uzun; Acikgoz, Aydan; Ozan, Bora; Zengin, Ayse Zeynep; Gunhan, Omer
2012-01-01
To present a case of expansive focal cemento-osseous dysplasia and emphasize the importance of differential diagnosis. Cemento-osseous dysplasia is categorized into three subtypes on the basis of the clinical and radiographic features: Periapical, focal and florid. The focal type exhibits a single site of involvement in any tooth-bearing or edentulous area of the jaws. These lesions are usually asymptomatic; therefore, they are frequently diagnosed incidentally during routine radiographic examinations. Lesions are usually benign, show limited growth, and do not require further surgical intervention, but periodic follow-up is recommended because occasionally, this type of dysplasia progresses into florid osseous dysplasia and simple bone cysts are formed. A 24-year-old female patient was referred to our clinic for swelling in the left edentulous mandibular premolarmolar region and felt discomfort when she wore her prosthetics. She had no pain, tenderness or paresthesia. Clinical examination showed that the swelling in the posterior mandible that was firm, nonfluctuant and covered by normal mucosa. On panoramic radiography and computed tomography, a well defined lesion of approximately 1.5 cm in diameter of mixed density was observed. The swelling increased slightly in size over 2 years making it difficult to use prosthetics and, therefore, the lesion was totally excised under local anesthesia, and surgical specimens were submitted for histopathological examination. The histopathological diagnosis was focal cemento-osseous dysplasia. In the present case, because of the increasing size of the swelling making it difficult to use prosthetics, young age of the patient and localization of the lesion, in the initial examination, cemento-ossifying fibroma was suspected, and the lesion was excised surgically; the histopathological diagnosis confirmed it as focal cemento-osseous dysplasia. We present a case of expansive focal cemento-osseous dysplasia. Differential diagnosis
Thermal expansion studies on zircaloy-2
International Nuclear Information System (INIS)
Sivabharathy, M.; Senthilkumar, A.; Palanichamy, P.; Ramachandran, K.
2016-01-01
Zircaloy-2 and Zr-2.5% Nb alloys are widely used in the pressurized heavy water reactors (PHWR) as the material for the pressure tubes. The pressure tube operates at 573 K, 11 MPa internal pressures and is subjected to neutron flux of the order of 1013 n/cm 2 /s. These conditions lead to degradations in the pressure tube with respect to dimensional changes, deterioration in mechanical properties due to irradiation embrittlement, thereby reducing its flaw tolerance, the growth of existing flaws, which were too small or 'insignificant' at the time of installation. Physical and chemical properties of materials are also very essential in nuclear industry and the relations among them is of interest in the selection of materials when they are used in the design and manufacturing of devices particularly for atomic reactors.Studies on the relations between mechanical and thermal properties are of interest to the steel and metal industries as these would give useful information on the relation between hardness and thermal diffusivity (α) of steel. Jayakumar et al have already carried out the ultrasonic and metallographic investigations to see that all the heat-treated specimens retained essentially the martensite structure. In this present work, thermal expansion measurements on useful reactor material, Zircaloy-2 with different sample. Given a β-quenching treatment by heating to 1223 K and holding for 2 h, followed by water quenching. These specimens were then thermally aged for 1 h in the temperature range 473 to 973 K and air-cooled. For all samples, the thermal expansion was carried out and the results are correlated with ultrasonic measurements, metallographic and photoacoustic studies. (author)
Expansion of an ultracold Rydberg plasma
Forest, Gabriel T.; Li, Yin; Ward, Edwin D.; Goodsell, Anne L.; Tate, Duncan A.
2018-04-01
We report a systematic experimental and numerical study of the expansion of ultracold Rydberg plasmas. Specifically, we have measured the asymptotic expansion velocities, v0, of ultracold neutral plasmas (UNPs) which evolve from cold, dense samples of Rydberg rubidium atoms using ion time-of-flight spectroscopy. From this, we have obtained values for the effective initial plasma electron temperature, Te ,0=mionv02/kB (where mion is the Rb+ ion mass), as a function of the original Rydberg atom density and binding energy, Eb ,i. We have also simulated numerically the interaction of UNPs with a large reservoir of Rydberg atoms to obtain data to compare with our experimental results. We find that for Rydberg atom densities in the range 107-109 cm-3, for states with principal quantum number n >40 , Te ,0 is insensitive to the initial ionization mechanism which seeds the plasma. In addition, the quantity kBTe ,0 is strongly correlated with the fraction of atoms which ionize, and is in the range 0.6 ×| Eb ,i|≲ kBTe ,0≲2.5 ×|Eb ,i| . On the other hand, plasmas from Rydberg samples with n ≲40 evolve with no significant additional ionization of the remaining atoms once a threshold number of ions has been established. The dominant interaction between the plasma electrons and the Rydberg atoms is one in which the atoms are deexcited, a heating process for electrons that competes with adiabatic cooling to establish an equilibrium where Te ,0 is determined by their Coulomb coupling parameter, Γe˜0.01 .
DEFF Research Database (Denmark)
Nissen, Poul
Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin.......Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin....
Research progress on expansive soil cracks under changing environment.
Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun
2014-01-01
Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.
Directory of Open Access Journals (Sweden)
Renato dos Santos Araújo
1967-12-01
Full Text Available O autor parte da premissa de que a profilaxia da doença infecciosa decorre do encadeamento epidemiológico: fonte de infecção-veículo transmissor - receptivel, para explicar a da peste, baseada no mesmo princípio. Depois de citar os 4 principais complexos epidemiológicos da peste e afirmar que tôda a profilaxia da doença consiste em atingir os dois primeiros elos dessas cadeias e proteger o último, passa a classificar os vários métodos profiláticos empregados em 2 grandes grupos: o das medidas destrutivas ou provisórias e o das medidas supressivas ou definitivas. Entre as primeiras arrola a desratização e a despulização, às quais acrescenta o tratamento e isolamento do doente e do portaãor, e entre as segundas inclui a anti-ratização e a imunização. A seguir, passa a explicar em que consistem essas várias medidas profiláticas e quais os agentes de que se tem lançado mão para executá-las, expendendo ao curso dessa exposição o conceito que formula a respeito de cada uma delas, à guisa de apreciação do seu valor relativo. Enaltece sobretudo as medidas supressivas ou definitivas, às quais empresta a maior significação na luta antipestosa, chamando a atenção, em especial, para a necessidade de estudos imunológicos para aperfeiçoamento do poder imunitário das vacinas de germes vivos avirulentos, que considera um grande recurso para a profilaxia da doença, sobretudo para a proteção do rurícola, cujo labor e modo de vida o expõem inevitavelmente a se infectar, por ocasião da ocorrência de epizootias de origem silvestre. Concluída essa primeira parte, passa a fazer o histórico de como se desenvolveu a campanha contra a peste, no Brasil, desde a época da sua invasão em 1899 pelo pôrto de Santos até os nossos dias. Nesse histórico, detem-se um pouco para expôr a atuação do extinto Serviço Nacional de Peste, o qual, criado em 1941, após a reorganização do Departamento Nacional de Saúde, passou
Controlling Thermal Expansion: A Metal?Organic Frameworks Route
Balestra, Salvador R. G.; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A. Rabdel; Calero, Sofia
2016-01-01
Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal?organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model m...
Negative thermal expansion of lithium aluminosilicate ceramics at cryogenic temperatures
International Nuclear Information System (INIS)
Garcia-Moreno, Olga; Fernandez, Adolfo; Khainakov, Sergei; Torrecillas, Ramon
2010-01-01
Five lithium aluminosilicate compositions of the LAS system have been synthesized and sintered. The coefficient of thermal expansion of the sintered samples has been studied down to cryogenic conditions. The data presented here under cryogenic conditions will be of value in the future design of new composite materials with very low thermal expansion values. The variation in thermal expansion properties with composition and sintering temperature was studied and is discussed in relation to composition and crystal structure.
Modeling of Viscosity and Thermal Expansion of Bioactive Glasses
Farid, Saad B. H.
2012-01-01
The behaviors of viscosity and thermal expansion for different compositions of bioactive glasses have been studied. The effect of phosphorous pentoxide as a second glass former in addition to silica was investigated. Consequently, the nonlinear behaviors of viscosity and thermal expansion with respect to the oxide composition have been modeled. The modeling uses published data on bioactive glass compositions with viscosity and thermal expansion. -regression optimization technique has been uti...
Thermal and Hygric Expansion of High Performance Concrete
J. Toman; R. Černý
2001-01-01
The linear thermal expansion coefficient of two types of high performance concrete was measured in the temperature range from 20 °C to 1000 °C, and the linear hygric expansion coefficient was determined in the moisture range from dry material to saturation water content. Comparative methods were applied for measurements of both coefficients. The experimental results show that both the effect of temperature on the values of linear thermal expansion coefficients and the effect of moisture on th...
Pentoney, Christopher; Harwell, Jeff; Leroy, Gondy
2014-01-01
Searching for medical information online is a common activity. While it has been shown that forming good queries is difficult, Google's query suggestion tool, a type of query expansion, aims to facilitate query formation. However, it is unknown how this expansion, which is based on what others searched for, affects the information gathering of the online community. To measure the impact of social-based query expansion, this study compared it with content-based expansion, i.e., what is really in the text. We used 138,906 medical queries from the AOL User Session Collection and expanded them using Google's Autocomplete method (social-based) and the content of the Google Web Corpus (content-based). We evaluated the specificity and ambiguity of the expansion terms for trigram queries. We also looked at the impact on the actual results using domain diversity and expansion edit distance. Results showed that the social-based method provided more precise expansion terms as well as terms that were less ambiguous. Expanded queries do not differ significantly in diversity when expanded using the social-based method (6.72 different domains returned in the first ten results, on average) vs. content-based method (6.73 different domains, on average).
Studying medium effects with the optimized δ expansion
International Nuclear Information System (INIS)
Krein, G.; Menezes, D.P.; Nielsen, M.; Pinto, M.B.
1995-04-01
The possibility of using the optimized δ expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The δ expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the δ expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the δ expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs
Studying medium effects with the optimized {delta} expansion
Energy Technology Data Exchange (ETDEWEB)
Krein, G [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Menezes, D P [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Fisica; Nielsen, M [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Pinto, M B [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique
1995-04-01
The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.
Thermal and Hygric Expansion of High Performance Concrete
Directory of Open Access Journals (Sweden)
J. Toman
2001-01-01
Full Text Available The linear thermal expansion coefficient of two types of high performance concrete was measured in the temperature range from 20 °C to 1000 °C, and the linear hygric expansion coefficient was determined in the moisture range from dry material to saturation water content. Comparative methods were applied for measurements of both coefficients. The experimental results show that both the effect of temperature on the values of linear thermal expansion coefficients and the effect of moisture on the values of linear hygric expansion coefficients are very significant and cannot be neglected in practical applications.
Operator expansion in quantum chromodynamics beyond perturbation theory
International Nuclear Information System (INIS)
Novikov, V.A.; Shifman, M.A.; Vainshtejn, A.I.; Zakharov, V.I.
1980-01-01
The status of operator expansion at short distances is descussed within the frameworks of nonperturbatue QCD. The question of instanton effects is investigated in various aspects. Two-point functions induced by the gluonic currents are considered. It is shown that certain gluonic correlations vanish in the field of definite duality. It is proved that there does exist a very special relation between the expansion coefficients required by consistancy between instanton calculations and the general operator expansion. At last a certain modification of the naive version of operator expansion is proposed, which allows one to go beyond the critical power and construct, if necessary, an infinite series
Expansion of Tubular with Elastomers in Multilateral Wells
Directory of Open Access Journals (Sweden)
Md Velden
2013-06-01
Full Text Available The use of solid expandable tubular technology during the last decade has focused on solving many challenges in well drilling and delivery including zonal isolation, deep drilling, conservation of hole sizes, etc. not only as pioneered solution but also providing cost effective and long lasting solutions. Concurrently, the technology was extended for construction of multilateral in typical wells. The process of horizontal tubular expansion is similar to the vertical expansion of expandable tubular in down-hole environment with the addition of uniformly distributed force due to its weight. The expansion is targeted to increase its diameter such that post expansion characteristics remain within allowable limits. In this study a typical expandable tubular of 57.15 mm outer diameter and 6.35 mm wall thickness was used with two different elastomer seals of 5 and 7 mm thickness placed at equal spacing of 200 mm. The developed stress contours during expansion process clearly showed the high stress areas in the vicinity of expansion region which lies around the mandrel. These high stresses may result in excessive wear of the mandrel. It was also found out that the drawing force increases as the mandrel angle, expansion ratio, and friction coefficient increases. A mandrel angle of 20o requires minimum expansion force and can be considered as an optimum geometrical parameter to lower the power required for expansion.
Eigenfunction expansions and scattering theory in rigged Hilbert spaces
Energy Technology Data Exchange (ETDEWEB)
Gomez-Cubillo, F [Dpt. de Analisis Matematico, Universidad de Valladolid. Facultad de Ciencias, 47011 Valladolid (Spain)], E-mail: fgcubill@am.uva.es
2008-08-15
The work reviews some mathematical aspects of spectral properties, eigenfunction expansions and scattering theory in rigged Hilbert spaces, laying emphasis on Lippmann-Schwinger equations and Schroedinger operators.
Mechanism of actuation in conducting polymers: Osmotic expansion
DEFF Research Database (Denmark)
Bay, Lasse; Jacobsen, Torben; West, Keld
2001-01-01
Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...
Expansion And International Expansion Of Small-To Medium Sized Firms: The Role Of Finance
Jan Smolarski; Can Kut; Neil Wilner
2011-01-01
Small- to medium-sized firms are expected to show international growth at an early stage. Several factors may affect the outcome of initial efforts to expand and internationalize. Our research examines how equity based venture funding affects SME expansion and internationalization. We divide venture capital financing into two categories: incremental financing where firms receive their venture capital funding in portions and lump-sum venture funding where firms receive their funding in one lum...
Wilson's operator expansion: can it fail
International Nuclear Information System (INIS)
Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.
1984-01-01
The status of poperator product expansion (OPE) in the presence of nonperturbative effects is duscussed within the framework of some simople models 4d Higgs model, 2d sigma-model and Schwinger model are considered. The general formulation of OPE is presented and it is demonstrated that there exists a consistent procedure allowing one to define unabiguously both coefficient functions and matrix elements of compositie operators. One of the key elements of the procedure is introduction of an auxiliary paramparameter, the normalization point μ. The two extremss considered are lambda phi 4 theory with no spontaneous breaking of the symmetry and O(N) sigma model in the limit N→infinity. In the former case there is only perturbative contribution to (phi 2 ) while in the latter case the perturbative pieces are suppressed by 1/N factors. Numerically QCD is much closer to the O(N) sigma model in the large N limit. Comments on specific features of QCD are presented
Density-functional expansion methods: Grand challenges.
Giese, Timothy J; York, Darrin M
2012-03-01
We discuss the source of errors in semiempirical density functional expansion (VE) methods. In particular, we show that VE methods are capable of well-reproducing their standard Kohn-Sham density functional method counterparts, but suffer from large errors upon using one or more of these approximations: the limited size of the atomic orbital basis, the Slater monopole auxiliary basis description of the response density, and the one- and two-body treatment of the core-Hamiltonian matrix elements. In the process of discussing these approximations and highlighting their symptoms, we introduce a new model that supplements the second-order density-functional tight-binding model with a self-consistent charge-dependent chemical potential equalization correction; we review our recently reported method for generalizing the auxiliary basis description of the atomic orbital response density; and we decompose the first-order potential into a summation of additive atomic components and many-body corrections, and from this examination, we provide new insights and preliminary results that motivate and inspire new approximate treatments of the core-Hamiltonian.
Can snowshoe hares control treeline expansions?
Olnes, Justin; Kielland, Knut; Juday, Glenn P; Mann, Daniel H; Genet, Hélène; Ruess, Roger W
2017-10-01
Treelines in Alaska are advancing in elevation and latitude because of climate warming, which is expanding the habitat available for boreal wildlife species, including snowshoe hares (Lepus americanus). Snowshoe hares are already present in tall shrub communities beyond treeline and are the main browser of white spruce (Picea glauca), the dominant tree species at treeline in Alaska. We investigated the processes involved in a "snowshoe hare filter" to white spruce establishment near treeline in Denali National Park, Alaska, USA. We modeled the pattern of spruce establishment from 1970 to 2009 and found that fewer spruce established during periods of high hare abundance. Multiple factors interact to influence browsing of spruce, including the hare cycle, snow depth and the characteristics of surrounding vegetation. Hares are abundant at treeline and may exclude spruce from otherwise optimal establishment sites, particularly floodplain locations with closed shrub canopies. The expansion of white spruce treeline in response to warming climate will be strongly modified by the spatial and temporal dynamics of the snowshoe hare filter. © 2017 by the Ecological Society of America.
Oil refining expansion criteria for Brazil
International Nuclear Information System (INIS)
Tavares, M.E.E.; Szklo, A.S.; Machado, G.V.; Schaeffer, R.; Mariano, J.B.; Sala, J.F.
2006-01-01
This paper assesses different strategies for the expansion of Brazil's oil refining segment, using criteria that range from energy security (reducing imports and vulnerability for key products) through to maximizing the profitability of this sector (boosting the output of higher value oil products) and adding value to Brazil's oil production (reducing exports of heavy acid oil). The development prospects are analyzed for conventional fuel production technology routes, sketching out three possible refining schemes for Brazilian oil and a GTL plant for producing gasoil from natural gas. Market scenario simulations indicate that investments will be required in Brazil's oil refining segment over and above those allocated to planned modifications in its current facilities, reducing the nation's vulnerability in terms of gasoil and petrochemical naphtha imports. Although not economically attractive, oil refining is a key activity that is crucial to oil company strategies. The decision to invest in this segment depends on local infrastructure conditions, environmental constraints and fuel specifications, in addition to oil company strategies, steady growth in demand and the definition of a government policy that eases institutional risks. (author)
Oil refining expansion criteria for Brazil
International Nuclear Information System (INIS)
Tavares, Marina Elisabete Espinho; Szklo, Alexandre Salem; Machado, Giovani Vitoria; Schaeffer, Roberto; Mariano, Jacqueline Barboza; Sala, Janaina Francisco
2006-01-01
This paper assesses different strategies for the expansion of Brazil's oil refining segment, using criteria that range from energy security (reducing imports and vulnerability for key products) through to maximizing the profitability of this sector (boosting the output of higher value oil products) and adding value to Brazil's oil production (reducing exports of heavy acid oil). The development prospects are analyzed for conventional fuel production technology routes, sketching out three possible refining schemes for Brazilian oil and a GTL plant for producing gasoil from natural gas. Market scenario simulations indicate that investments will be required in Brazil's oil refining segment over and above those allocated to planned modifications in its current facilities, reducing the nation's vulnerability in terms of gasoil and petrochemical naphtha imports. Although not economically attractive, oil refining is a key activity that is crucial to oil company strategies. The decision to invest in this segment depends on local infrastructure conditions, environmental constraints and fuel specifications, in addition to oil company strategies, steady growth in demand and the definition of a government policy that eases institutional risks
The consequences of expansion joint bellows failure
International Nuclear Information System (INIS)
Miller, R.F.; Daugherty, W.L.
1993-01-01
Expansion joint (EJ) bellows are thin walled, flexible components of a piping system. As such, they usually are the weakest structural link in the pressure boundary from a failure probability perspective. Previously, a 360 degrees, circumferential rupture of a bellows was conservatively assumed to cause bellows collapse due to internal pressure resulting in a double-ended guillotine break (DEGB) and the associated, large leak rate. A finite element analysis was performed to determine the structural response of a ruptured bellows and its ability to resist large opening areas and hence, large leak rates. The results show that a 360 degrees break can lead to an opening width of up to 0.7 inch following an instantaneous rupture -- provided the equalizing rings and tie rods remain intact. This would result in an initial leak rate reduction equal to 80% of the previously assumed DEGB flow. The reduced flow rate is less than the water removal system capacity-assuring that flooding will not occur
Testing option pricing with the Edgeworth expansion
Balieiro Filho, Ruy Gabriel; Rosenfeld, Rogerio
2004-12-01
There is a well-developed framework, the Black-Scholes theory, for the pricing of contracts based on the future prices of certain assets, called options. This theory assumes that the probability distribution of the returns of the underlying asset is a Gaussian distribution. However, it is observed in the market that this hypothesis is flawed, leading to the introduction of a fudge factor, the so-called volatility smile. Therefore, it would be interesting to explore extensions of the Black-Scholes theory to non-Gaussian distributions. In this paper, we provide an explicit formula for the price of an option when the distributions of the returns of the underlying asset is parametrized by an Edgeworth expansion, which allows for the introduction of higher independent moments of the probability distribution, namely skewness and kurtosis. We test our formula with options in the Brazilian and American markets, showing that the volatility smile can be reduced. We also check whether our approach leads to more efficient hedging strategies of these instruments.
Virial expansion for almost diagonal random matrices
International Nuclear Information System (INIS)
Yevtushenko, Oleg; Kravtsov, Vladimir E
2003-01-01
Energy level statistics of Hermitian random matrices H-circumflex with Gaussian independent random entries H i≥j is studied for a generic ensemble of almost diagonal random matrices with (vertical bar H ii vertical bar 2 ) ∼ 1 and (vertical bar H i≠j vertical bar 2 ) bF(vertical bar i - j vertical bar) parallel 1. We perform a regular expansion of the spectral form-factor K(τ) = 1 + bK 1 (τ) + b 2 K 2 (τ) + c in powers of b parallel 1 with the coefficients K m (τ) that take into account interaction of (m + 1) energy levels. To calculate K m (τ), we develop a diagrammatic technique which is based on the Trotter formula and on the combinatorial problem of graph edges colouring with (m + 1) colours. Expressions for K 1 (τ) and K 2 (τ) in terms of infinite series are found for a generic function F(vertical bar i - j vertical bar ) in the Gaussian orthogonal ensemble (GOE), the Gaussian unitary ensemble (GUE) and in the crossover between them (the almost unitary Gaussian ensemble). The Rosenzweig-Porter and power-law banded matrix ensembles are considered as examples
Inadvertent pump start with gas expansion modules
International Nuclear Information System (INIS)
Campbell, L.R.; Harris, R.A.; Heard, F.J.; Dautel, W.A.
1992-01-01
Previous testing demonstrated the effectiveness of gas expansion modules (GEMs) in mitigating the consequences of a loss-of-flow-without-scram transient in Fast Flux Test Facility (FFTF)-sized sodium cooled cores. As a result, GEMs have been included in the advance liquid-metal reactor (PRISM) design project sponsored by the US Department of Energy. The PRISM design is under review at the US Nuclear Regulatory Commission for licensability. In the unlikely event that the reactor does not scram during a loss of low, the GEMs quickly insert sufficient negative reactivity to limit fuel and cladding temperatures to acceptable values. This is the positive benefit of the GEMs; however, the reverse situation must be considered. A primary pump could be inadvertently started from near-critical conditions resulting in a positive reactivity insertion and a power transient. One mitigating aspect of this event is that as the reactivity associated with the GEMs is inserted, the increasing flow increases core cooling. A test was conducted in the FFTF to demonstrate that the GEM and feedback reactivity are well predicted following pump start, and the reactivity transient is benign
Compression and expansion in central collisions
International Nuclear Information System (INIS)
Danielewicz, P.
1997-01-01
Dynamics of central collisions of heavy nuclei in the energy range from few tens of MeV/nucleon to a couple of GeV/nucleon is discussed. As the beam energy increases and/or the impact parameter decreases, the maximum compression increases. It is argued that the hydrodynamic behaviour of matter sets in the vicinity of balance energy. At higher energies shock fronts are observed to form within head-on reaction simulations, perpendicular to beam axis and separating hot compressed matter from cold. In the semi-central reactions a weak tangential discontinuity develops in-between these fronts. The hot compressed matter exposed to the vacuum in directions parallel to the shock front begin to expand collectively into these directions. The expansion affects particle angular distributions and mean energy components and further shapes of spectra and mean energies of particles emitted into any one direction. The variation of slopes and the relative yields measured within the FOPI collaboration are in a general agreement with the results of simulations. As to the FOPI data on stopping, they are consistent with the preference for transverse over the longitudinal motion in the head-on Au + Au collisions. Unfortunately, though, the data can not be used to decide directly on that preference due to acceptance cuts. Tied to the spatial and temporal changes in the reactions are changes in the entropy per nucleon. (authors)
Global sensitivity analysis using polynomial chaos expansions
International Nuclear Information System (INIS)
Sudret, Bruno
2008-01-01
Global sensitivity analysis (SA) aims at quantifying the respective effects of input random variables (or combinations thereof) onto the variance of the response of a physical or mathematical model. Among the abundant literature on sensitivity measures, the Sobol' indices have received much attention since they provide accurate information for most models. The paper introduces generalized polynomial chaos expansions (PCE) to build surrogate models that allow one to compute the Sobol' indices analytically as a post-processing of the PCE coefficients. Thus the computational cost of the sensitivity indices practically reduces to that of estimating the PCE coefficients. An original non intrusive regression-based approach is proposed, together with an experimental design of minimal size. Various application examples illustrate the approach, both from the field of global SA (i.e. well-known benchmark problems) and from the field of stochastic mechanics. The proposed method gives accurate results for various examples that involve up to eight input random variables, at a computational cost which is 2-3 orders of magnitude smaller than the traditional Monte Carlo-based evaluation of the Sobol' indices
Global sensitivity analysis using polynomial chaos expansions
Energy Technology Data Exchange (ETDEWEB)
Sudret, Bruno [Electricite de France, R and D Division, Site des Renardieres, F 77818 Moret-sur-Loing Cedex (France)], E-mail: bruno.sudret@edf.fr
2008-07-15
Global sensitivity analysis (SA) aims at quantifying the respective effects of input random variables (or combinations thereof) onto the variance of the response of a physical or mathematical model. Among the abundant literature on sensitivity measures, the Sobol' indices have received much attention since they provide accurate information for most models. The paper introduces generalized polynomial chaos expansions (PCE) to build surrogate models that allow one to compute the Sobol' indices analytically as a post-processing of the PCE coefficients. Thus the computational cost of the sensitivity indices practically reduces to that of estimating the PCE coefficients. An original non intrusive regression-based approach is proposed, together with an experimental design of minimal size. Various application examples illustrate the approach, both from the field of global SA (i.e. well-known benchmark problems) and from the field of stochastic mechanics. The proposed method gives accurate results for various examples that involve up to eight input random variables, at a computational cost which is 2-3 orders of magnitude smaller than the traditional Monte Carlo-based evaluation of the Sobol' indices.
The optimizied expansion method for wavefield extrapolation
Wu, Zedong
2013-01-01
Spectral methods are fast becoming an indispensable tool for wave-field extrapolation, especially in anisotropic media, because of its dispersion and artifact free, as well as highly accurate, solutions of the wave equation. However, for inhomogeneous media, we face difficulties in dealing with the mixed space-wavenumber domain operator.In this abstract, we propose an optimized expansion method that can approximate this operator with its low rank representation. The rank defines the number of inverse FFT required per time extrapolation step, and thus, a lower rank admits faster extrapolations. The method uses optimization instead of matrix decomposition to find the optimal wavenumbers and velocities needed to approximate the full operator with its low rank representation.Thus,we obtain more accurate wave-fields using lower rank representation, and thus cheaper extrapolations. The optimization operation to define the low rank representation depends only on the velocity model, and this is done only once, and valid for a full reverse time migration (many shots) or one iteration of full waveform inversion. Applications on the BP model yielded superior results than those obtained using the decomposition approach. For transversely isotopic media, the solutions were free of the shear wave artifacts, and does not require that eta>0.
Orthogonal expansions related to compact Gelfand pairs
DEFF Research Database (Denmark)
Berg, Christian; Peron, Ana P.; Porcu, Emilio
2017-01-01
. The functions of this class are the functions having a uniformly convergent expansion ∑ϕεZB(ϕ)(u)ϕ(x) for xεG,uεL, where the sum is over the space Z of positive definite spherical functions ϕ:G→C for the Gelfand pair, and (B(ϕ))ϕεZ is a family of continuous positive definite functions on L such that ∑ϕε......For a locally compact group G, let P(G) denote the set of continuous positive definite functions f:G→C. Given a compact Gelfand pair (G,K) and a locally compact group L, we characterize the class PK#(G,L) of functions fεP(G×L) which are bi-invariant in the G-variable with respect to K......(d)) and (U(q),U(q-1)) as well as for the product of these Gelfand pairs.The result generalizes recent theorems of Berg-Porcu (2016) and Guella-Menegatto (2016)....
Métodos cromatográficos para determinar aminas biogênicas em alimentos de origem animal
Directory of Open Access Journals (Sweden)
César Aquiles Lázaro de la Torre
2013-12-01
Full Text Available Aminas biogenicas sao formadas como resultado da descarboxilacao de aminoacidos livres especificos. A analise desses metabolitos e de grande importancia na determinacao da qualidade e monitoramento de biogenicas como histamina e tiramina relacionadas com episodios de intoxicacao em humanos. A cromatografia e uma tecnica de separacao química usada para caracterizar aminas biogenicas. Variacoes da tecnica (cromatografia liquida, em camada delgada e gasosa tem sido amplamente usadas, porem a complexidade da matriz alimentar faz com que sejam realizadas mudancas nos processos de extracao, derivatizacao e deteccao em concordancia com cada grupo de alimento. A cromatografia liquida de alta eficiencia (CLAE e o metodo mais utilizado na determinacao de aminas biogenicas em alimentos. Contudo, devido a importancia das aminas biogenicas no controle da qualidade e a seguranca do consumidor, os pesquisadores tentam desenvolver novos metodos com o intuito de uma analise mais rapida e precisa para o controle de alimentos no mercado. O objetivo da revisao e apresentar algumas tecnicas cromatograficas aplicadas no monitoramento de aminas biogenicas em produtos de origem animal.
Directory of Open Access Journals (Sweden)
Necati Akbulut
2015-02-01
Full Text Available Gıda Teknolojisinin gelişmesi ile, gıda maddesinin tüketici için daha alımlı olmasını sağlamak, kısa zamanda bozulmasını engellemek ve pazara yeni çeşitler sunmak için bazı kimyasal maddeler kullanılmaya başlanılmıştır. Bunun yanında tarımda kullanılan kimyasal maddeler artmış, ambalaj sanayi gelişmiş, bu da gıda maddelerine bulaşan maddelerin türlerini arttırmıştır. Ayrıca gıda maddelerine belirli amacı olmadan katılan maddelerde vardır. Diğer taraftan tüketiciyi aldatmak, hile yapmak, çok kar sağlamak veya kötü kaliteyi gizlemek amacı ile de kullanılan maddeler bulunmaktadır. İster teknik zorunluk, ister hile amacıyla olsun bu tür yabancı maddeler öncelikle insan sağlığını ilgilendirmektedir. Bazı maddelerin vücuda alınması sakıncasız olduğu halde, bazıları sakıncalıdır. Sakıncasız olanlarında belirli bir sınırın üzerinde uzun süre alınmaları zararlı olabilmektedir. Bu toplum sağlığı sorunu birçok ülkeyi gıda sanayiinde kullanılan kimyasal maddelerin hoşgörü sınırlarının hesaplanması noktasına götürmüştür.
Higher Education in Ethiopia: Expansion, Quality Assurance and Institutional Autonomy
Akalu, Girmaw Abebe
2014-01-01
This article chronicles the key challenges facing Ethiopia as it embarks on an ambitious, ideologically-driven and aggressive expansion of its higher education system in an effort to address its national goals of economic growth and poverty reduction. It is argued that the urge for higher education expansion has placed undue pressures particularly…
Expansion of a function about a displaced centre
International Nuclear Information System (INIS)
Rashid, M.A.
1981-07-01
We review the progress recently made in obtaining closed form expressions for the expansion of general orbitals about a displaced centre and establish the equivalence between different expansions. We also examine how these expressions do have the desired limit as the displacement approaches zero. (author)
Implementation of centrifuge testing of expansive soils for pavement design.
2017-03-01
The novel centrifuge-based method for testing of expansive soils from project 5-6048-01 was implemented into : use for the determination of the Potential Vertical Rise (PVR) of roadways that sit on expansive subgrades. The : centrifuge method was mod...
Harmonious Expansion of China's Higher Education: A New Growth Pattern
Gu, Jiafeng
2012-01-01
How can one country narrow the regional disparity during the tremendous expansion of higher education? This issue remains unexamined and critical analysis is needed to unveil the spatial dynamics behind expansion of higher education. The spatial analysis shows that there is significant strategic interaction among neighboring provinces in China…
STABILIZATION OF EXPANSIVE SOIL USING BAGASSE ASH & LIME
African Journals Online (AJOL)
tekimerry
expansive soils which depends on the stress and ... been employed to curb or reduce the severity of the damages caused by ... work is collected from Addis Ababa, Bole Sub. City at 8º 59' ..... Construction of flexible Pavements in Expansive ...
Did the Higgs boson drive the universe's expansion?
2008-01-01
The Higgs boson has been moonlighting. Not content with its day job of giving other particles their mass, it may also have driven the expansion of the early universe, given a little tinkering, according to two separate studies. Soon after the big bang the early universe is believed to have undergone a period of rapid expansion, known as inflation.
Asymptotic expansions for high-contrast linear elasticity
Poveda, Leonardo A.; Huepo, Sebastian; Calo, Victor M.; Galvis, Juan
2015-01-01
We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm. © 2015 Elsevier B.V.
Graph approach to the gradient expansion of density functionals
International Nuclear Information System (INIS)
Kozlowski, P.M.; Nalewajski, R.F.
1986-01-01
A graph representation of terms in the gradient expansion of the kinetic energy density functional is presented. They briefly discuss the implications of the virial theorem for the graph structure and relations between possible graphs at a given order of expansion
Generalized approach to the non-backtracking lace expansion
Fitzner, R.; van der Hofstad, R.W.
2017-01-01
The lace expansion is a powerful perturbative technique to analyze the critical behavior of random spatial processes such as the self-avoiding walk, percolation and lattice trees and animals. The non-backtracking lace expansion (NoBLE) is a modification that allows us to improve its applicability in
Studies of Expansive Learning: Foundations, Findings and Future Challenges
Directory of Open Access Journals (Sweden)
Yrjö Engeström
2013-07-01
Full Text Available The paper examines studies based on the theory of expansive learning, formulated in 1987. In recent years the theory has been used in a wide variety of studies and interventions. The theory builds on foundational ideas put forward by Vygotsky, Leont’ev, Il’enkov, and Davydov, key figures in the Russian school of cultural-historical activity theory. Studies based on the theory are reviewed in six sections: expansive learning as transformation of the object, expansive learning as movement in the zone of proximal development, expansive learning as cycles of learning actions, expansive learning as boundary crossing and network building, expansive learning as distributed and discontinuous movement, and formative interventions.A separate section is devoted to critiques of expansive learning. It is concluded that the ultimate test of learning theories is how they help practitioners to generate learning that grasps pressing issues the humankind is facing. The theory of expansive learning currently expands its analyses both up and down, outward and inward. Moving up and outward, it tackles learning in fields or networks of interconnected activity systems with their partially shared and often contested objects. Moving down and inward, it tackles issues of subjectivity, experiencing, personal sense, emotion, embodiment, identity, and moral commitment.
Acoustic waves in shock tunnels and expansion tubes
Paull, A.; Stalker, R. J.
1992-01-01
It is shown that disturbances in shock and expansion tubes can be modelled as lateral acoustic waves. The ratio of sound speed across the driver-test gas interface is shown to govern the quantity of noise in the test gas. Frequency 'focusing' which is fundamental to centered unsteady expansions is discussed and displayed in centerline pitot pressure measurements.
14 CFR 27.969 - Fuel tank expansion space.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 27.969 Section 27.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.969 Fuel tank expansion space...
14 CFR 25.969 - Fuel tank expansion space.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 25.969 Section 25.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.969 Fuel tank expansion space...
14 CFR 29.969 - Fuel tank expansion space.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 29.969 Section 29.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.969 Fuel tank expansion space...