bluuebunny/crossref_metadata_2025 huggingface dataset:
Teoria final, unificação e reducionismo: opiniões da comunidade brasileira de física
Authors: Zylbersztajn Arden
Published: May 2009

A primeira parte do artigo consta de uma breve discussão centrada nas idéias de Steven Weinberg, um defensorda unificação reducionista, e que acredita que a física de partículas e campos já tenha trilhado boa parte do caminho em direção a uma teoria final, e de Philip Anderson, um crítico de posturas reducionistas, que trouxe para a física a visão emergentista. Na segunda parte são apresentados resultados de uma pesquisa realizadacom o propósito de investigar qual a receptividade que idéias como "unificação", "reducionismo" e "teoria final", encontram entre membros da comunidade de físicos no Brasil. Os resultados indicam uma tendênciade rejeição à possibilidade de uma teoria final e, em menor grau, ao reducionismo, sendo a idéia de unificaçãomais aceitável.
Bobina de Helmholtz
Authors: Robert Renê
Published: May 2009

É mostrada uma técnica para o cálculo do campo magnético gerado por uma bobina de Helmholtz em torno de seu centro de simetria. São descritos detalhes experimentais e citados experimentos que podem ser realizados com esta bobina, enfatizando que alguns são de custo baixo.
Potência elétrica irradiada e potência mecânica dissipada no sistema de dois dipolos oscilantes próximos e em fase
Authors: Ferreira G. F. Leal
Published: May 2009

Mostra-se diretamente que a potência média irradiada por um sistema de dois dipolos oscilantes próximos, paralelos e em fase, é igual à potência mecânica média dissipada nos osciladores necessária para manter o movimento harmônico simples.
Gases bosônicos armadilhados
Authors: Sousa A.G. de , Bagnato V.S.
Published: May 2009

O espectro dos modos coerentes para gás atômico de Bose diluído, confinado em uma armadilha harmônica não isotrópica é determinado e utiliza-se da teoria de perturbação otimizada e a técnica das raízes aproximantes auto-similares. As expressões obtidas são válidas para níveis de energia arbitrários de todos os modos coerentes excitados. Este artigo deve ser utilizado como ponto de início para os alunos que querem se aprofundar no tema de condensação de Bose-Einstein atualmente presente em quase todos periódicos de Física.
A energia elétrica da Termodinâmica, a entalpia elétrica da Mecânica Estatística e as energias livres elétricas
Authors: Leal Ferreira G.F.
Published: May 2009

Nota-se que os conceitos de energia elétrica empregados usualmente em Termodinâmica e em Mecânica Estatística não são os mesmos e mostra-se que, de fato, estão relacionados por uma transformação de Legendre, aquele originário da Mecânica Estatística sendo o análogo da entalpia em relação à energia interna no esquema P-V-T. As energias livres elétricas são também definidas.
Gravitação semiclássica
Authors: Matsas George E.A.
Published: May 2009

Fazemos aqui uma breve descrição da teoria semiclássica da gravitação que tem conseguido antecipar de forma bastante robusta alguns efeitos de gravitação quântica.
O potencial efetivo e sua expansão em "loop'', interpretação e convexidade
Authors: Possa Denimar , Pereira Flávio , Nogueira José Alexandre
Published: May 2009

Neste trabalho nós mostramos como obter o potencial efetivo a partir do funcional gerador das funções de Green da teoria e qual é sua interpretação. A convexidade do potencial efetivo também é provada.
Obstáculos conceptuales en el aprendizaje de la energía de las ondas
Authors: Welti Reinaldo
Published: May 2009

Se analizan algunas de las dificultades que tienen los estudiantes universitarios para comprender los mecanismos físicos asociados con la energía de una onda mecánica unidimensional.
Análise do processo cognitivo na construção das figuras de Lissajous
Authors: Andrade D. , Campos M. de
Published: May 2009

Fazemos uma breve análise da hierarquia de objetivos educacionais no domínio cognitivo seguindo a taxonomia sugerida por Bloom. Por outro lado, usamos a computação algébrica para construir as figuras de Lissajous e as comparamos com as já existentes na literatura. Classificamos a comparação das figuras obtidas com as já existentes como um processo ao terceiro nível da taxonomia de Bloom, o de aplicação.
Prego voador: um desafio para estudantes de eletromagnetismo
Authors: Krapas Sonia , Rodrigues Luiz Cláudio , Miranda Neto Álvaro Vieira de , Cavalcanti Gildo de Holanda
Published: May 2009

Neste trabalho apresentamos um experimento didático de baixo custo, produzido por um aluno de uma disciplina do curso de licenciatura em Física da Universidade Federal Fluminense, que tem sua ênfase no estudo dos movimentos - inesperados - de materiais ferromagnéticos sob a ação de campos magnéticos produzidos por um solenóide. O experimento, incluindo material utilizado, montagem e procedimentos, é mostrado em detalhe. São apresentadas, na forma de uma discussão, as várias tentativas de explicação para os movimentos obtidos. Objetiva-se a capacitação de professores em sustentar uma discussão com seus alunos.
Sobre a contração de Lorentz-Fitzgerald
Authors: Barros A. , Monte E.M. , Araújo I.G. , Oliveira J.C.T. , Vieira Sumaia
Published: May 2009

Discutimos a contração do comprimento de Lorentz-Fitzgerald nos contextos do éter de Fresnel e da relatividade especial. Pretendemos esclarecer alguns equívocos que podem ocorrer no entendimento da relacão entre contração do comprimento, éter e relatividade especial.
Transições de fase sem termodinâmica
Authors: Dickman Adriana G. , Dickman Ronald , Barbosa Fabrício Almeida
Published: May 2009

As aplicações de transições de fase vão muito além do contexto da termodinâmica de equilíbrio, de onde surgiu. Nós revisamos um dos principais exemplos de uma transição de fase em um sistema sem termodinâmica, o processo de contato (PC), com ênfase no método de campo médio. Apresentamos um estudo de campo médio aplicado a um modelo para a transmissão da malária em uma população. Discutimos também as novas abordagens da distribuição quase-estacionária e o processo de contato conservativo.
A capacitância de um condensador com placas planas não paralelas
Authors: Precker Jürgen W. , Silva Wilton P. da
Published: May 2009

Analisamos neste artigo três métodos para obter a capacitância de um condensador com placas planas não paralelas: a solução por integração, a solução por limites e uma solução proposta. Apesar de cada uma das soluções envolver aproximações diferentes, as três capacitâncias obtidas são coerentes.
F=ma?!! O nascimento da lei dinâmica
Authors: Dias Penha Maria Cardoso
Published: May 2009

Neste artigo, faço uma revisão dos métodos de resolução de problemas dinâmicos usados antes que as equações de Newton fossem descobertas, escritas na forma diferencial e fossem universalmente aceitas. Os argumentos que fundamentam essas soluções tornam inteligíveis equações, que, de outra forma, permaneceriam misteriosas e frutos de um pensamento mágico.
Quatro abordagens para o movimento browniano
Authors: Silva J.M. , Lima J.A.S.
Published: May 2009

A "dança" aleatória de pequenas partículas em suspensão num líquido, um fenômeno conhecido como movimento browniano, foi primeiramente explicado por Einstein na sua famosa tese de doutorado. Seguindo uma perspectiva histórica, mostramos como este fenômeno pode ser descrito de quatro maneiras distintas, a saber: o tratamento difusivo de Einstein, a variante estocástica ou de força flutuante proposta por Paul Langevin, a abordagem via equação de Fokker-Planck, e finalmente, as caminhadas aleatórias de Mark Kac. Discutiremos também as limitações presentes na abordagem difusiva. Em particular, mostramos que a equação parabólica na qual Einstein baseou sua explicação deve ser substituída por uma equação do tipo hiperbólica que também surge naturalmente no tratamento via caminhadas aleatórias. A solução geral dessa equação é obtida e comparada com o resultado padrão. Para tempos curtos, comparados com as escalas de tempo características do sistema, o movimento das partículas segue um comportamento ondulatório.
Uma definição natural de energia cinética e potencial em termodinâmica
Authors: Ferreira G.F. Leal
Published: May 2009

Na tentativa de tornar a termodinâmica mais familiar e sem violação do seu formalismo, define-se a partir de expressão do diferencial da energia, já incorporando as conseqüências da 2 Lei, o diferencial da energia cinética como associado às variações de temperatura a volume constante e o de energia potencial às de volume, à temperatura constante. A comparação entre os diferenciais é realizada pela normalização das variações de temperatura e de volume às de pressão. Ver-se-á que na fase gasosa, as variações de energia cinética prevalecem em muito sobre as potenciais enquanto na condensada, elas se ombreiam.
Violação da simetria de Lorentz
Authors: Belich H. , Costa-Soares T. , Santos M.A. , Orlando M.T.D.
Published: May 2009

Recentemente, com o advento da teoria das cordas, existe um consenso de que uma simetria fundamental da relatividade, a simetria de Lorentz, deve ser quebrada na escala de energia do modelo padrão da física de partículas. Esta quebra de simetria de Lorentz ocorre pela presença de campos vetoriais e tensoriais de fundo resultantes de processos de transição de fase, que causam uma anisotropia no espaço-tempo. Deve-se observar que a violação ocorre apenas quando realizamos uma transformação de referencial ativa de Lorentz, o que acarretou uma nova nomenclatura para as mudanças de coordenadas no espaço-tempo: as transformações de observador e partícula. O objetivo deste trabalho é torna claro estas transformações, e através de dois exemplos simples, explorar a quebra da simetria de Lorentz pela presença de um campo de fundo.
Deformações geométricas e velocidade superluminal aparentes em objetos em movimento relativístico
Authors: Cavalcanti Cláudio José de Holanda , Ostermann Fernanda
Published: May 2009

Neste trabalho, como continuação do trabalho de Ostermann e Ricci (Caderno Catarinense de Ensino de Física 19, 176 (2002)), analisamos as deformações geométricas aparentes de três objetos em movimento relativístico: uma barra retilínea, um aro circular e uma esfera. Os livros didáticos de Física normalmente induzem o leitor a pensar que objetos em movimento relativístico em relação a um certo observador são vistos, por esse observador, contraídos na direção do movimento. Isso na verdade é o que seria medido por esse observador e não o que seria visto. É destacada neste trabalho a diferença entre medir e ver, já apontada no artigo anterior. Mostramos também que a velocidade aparente de alguns pontos do objeto pode ser superluminal quando o mesmo se aproxima do observador, confirmando resultados anteriores (Am. J. Phys. 73, 663 (2005)).
Uma generalização do polinômio dos quadrados mínimos condicionado
Authors: Dotto Oclide J. , Dornelles Filho Adalberto A.
Published: May 2009

Este artigo descreve um programa de computador em MATLAB para a obtenção de um polinômio de ajuste dos quadrados mínimos, condicionado a passar por um conjunto arbitrário de nodos de ancoramento, contanto que ainda retenha um conveniente número de graus de liberdade.
Demonstração experimental da dilatação do tempo e da contração do espaço dos múons da radiação cósmica
Authors: Fauth A.C. , Penereiro J.C. , Kemp E. , Grizolli W.C. , Consalter D.M. , Gonzalez L.F.G.
Published: May 2009

Apresentamos uma atividade experimental de física moderna realizada com um telescópio de múons da radiação cósmica. A montagem do telescópio, feita com cintiladores plásticos, e a eletrônica utilizada são descritas. Utilizando a mecânica clássica e a teoria especial da relatividade, calculamos a intensidade esperada para os múons na superfície da Terra. Medimos uma intensidade vertical de (141 ± 1) múons/(m².s.sr) em Campinas e demonstramos que somente com a dilatação do tempo de vida dos múons, ou a contração do espaço no referencial do múon, podemos explicar os resultados experimentais.
Secções eficazes numa colisão inelástica entre duas esferas
Authors: Silva M.F. Ferreira da
Published: May 2009

No estudo das colisões, os conceitos de secção eficaz e coeficiente de restituição são bem conhecidos; no entanto, muito raramente eles são aplicados no mesmo contexto. Neste trabalho usa-se o coeficiente de restituição para obter a secção eficaz diferencial de uma colisão inelástica entre duas esferas. Conclui-se que a descrição envolve um único parâmetro, e confirma-se por integração directa o valor da secção eficaz total.
Contadores eletrônicos no laboratório didático: parte II. Medida de intervalos de tempo sucessivos
Authors: Hessel R. , Oliveira C.S. de , Santarine G.A. , Vollet D.R. , Perinotto A.C.
Published: May 2009

Neste trabalho descrevemos um procedimento para medir uma série de intervalos de tempo, em rápida sucessão, utilizando vários contadores eletrônicos alimentados por uma base de tempo comum. Para ilustrar o procedimento, uma aplicação envolvendo a conservação da quantidade de movimento linear em colisões entre dois carrinhos descolando-se num trilho de ar é discutida. Apesar da proposta exigir um contador para cada intervalo de tempo a ser medido, em vez de um único cronômetro digital com memória, ela ainda assim é vantajosa, porque o custo da montagem de um contador eletrônico é muito pequeno quando comparado com o preço de um cronômetro comercial com memória apropriado para uso em laboratório didático.
Strongly coupled overdamped pendulums
Authors: De Luca R.
Published: May 2009

It is shown, by a first-order perturbation expansion, that the dimensionality of the dynamical equations for the angular variables of two strongly coupled identical overdamped pendulums can be reduced from two to one. The resulting dynamical equation is seen to be similar to the one of a single pendulum with an additional fictitious torque characterized by a second harmonic contribution.
Corrente de absorção e reabsorção em dielétricos
Authors: Robert Renê , Kowalski Edemir Luiz , Gomes Daisy de Melo
Published: May 2009

O objetivo do trabalho é mostrar o uso da função de Dissado-Hill para o cálculo dos parâmetros desta função, estimar a susceptibilidade como função da freqüência e apresentar uma interpretação com relação à estrutura do material. A estimativa é feita usando-se o método dos mínimos quadrados para as medidas experimentais da corrente de reabsorção.
Ultrasonic Study of Osmium and Ruthenium
Authors: Pandey By D. K. , Singh Devraj , Yadawa P. K.
Published: May 2009

Ultrasonic properties of two platinum group metals, osmium and ruthenium, are presented for use in characterisation of their materials. The angle-dependent ultrasonic velocity has been computed for the determination of anisotropic behaviour of these metals. For the evaluation of ultrasonic velocity, attenuation and acoustic coupling constants, the higher-order elastic constants of Os and Ru have been calculated using the Lennard-Jones potential. The nature of the angle-dependent ultrasonic velocity is found to be similar to those of molybdenum-ruthenium-rhodium-palladium alloys, Group III nitrides and lave-phase compounds such as TiCr
2
, ZrCr
2
and HfCr
2
. The results of this investigation are discussed in correlation with other known thermophysical properties.
The Platinum Development Initiative: Platinum-Based Alloys for High Temperature and Special Applications: Part II
Authors: Douglas By A. , Hill P. J. , Murakumo T. , Cornish L. A. , Süss R.
Published: May 2009

Under the Platinum Development Initiative, platinum-based alloys were being developed for high-temperature and special applications requiring good corrosion and oxidation resistance. Work on ternary alloys had previously identified that the best of these alloys for both mechanical properties and oxidation resistance were Pt-Al-Cr and Pt-Al-Ru, as reported in Part I of the present series (). This paper (Part II) describes transmission electron microscopy work undertaken on a range of ternary alloys to understand the strengthening mechanisms of the alloys, ascertain the nature of the ~ Pt
3
Al precipitates and deduce the misfits between the precipitates and the matrix. A binary Pt-Al alloy was also studied in an attempt to resolve the two different versions of the phase diagram. A modified D0’
c
tetragonal version of one of the lower temperature forms of ~ Pt
3
Al was discovered. The transformation producing the D0’
c
structure was confirmed as displacive, since there were distinct bands in the precipitates, which were identified as twins at higher magnifications. The dislocation interactions were also studied, and found to be more complex than nickel-based superalloys, mostly due to the different precipitate types.
The StrongWomen–Healthy Hearts Program: Reducing Cardiovascular Disease Risk Factors in Rural Sedentary, Overweight, and Obese Midlife and Older Women
Authors: Folta Sara C. , Lichtenstein Alice H. , Seguin Rebecca A. , Goldberg Jeanne P. , Kuder Julia F. , Nelson Miriam E.
Published: May 2009

Objectives. We tested a community-based intervention designed to reduce cardiovascular disease risk in sedentary midlife and older women who were overweight or obese.

Methods. In a randomized controlled trial conducted in 8 counties in Arkansas and Kansas, counties were assigned to the intervention (a 12-week twice-weekly heart health program) group or to the delayed-intervention control group. Ten to fifteen women were selected from each site, and participants' weight, waist circumference, diet, physical activity, and self-efficacy were measured before and after the intervention. Data were analyzed with multiple regressions.

Results. Compared with the control group, participants in the intervention group had a significant decrease in body weight (−2.1 kg; 95% confidence interval [CI] = −3.2, −1.0), waist circumference (–2.3 in; 95% CI = −4.2, −0.5), and energy intake (–390 kcal/day; 95% CI = −598, −183); an increase in activity (+1637 steps/day; 95% CI = 712, 2562); and an increase in self-efficacy for dietary and physical activity behaviors.

Conclusions. Our results suggest that a community-based program can improve self-efficacy, increase physical activity, and decrease energy intake, resulting in decreased waist circumference and body weight among at-risk women.
Simulated nitrogen leaching patterns and adaptation to climate change in two Finnish river basins with contrasting land use and climatic conditions
Authors: Rankinen Katri , Valpasvuo-Jaatinen Pirkko , Karhunen Anni , Kenttämies Kaarle , Nenonen Suvi , Bärlund Ilona
Published: May 2009

Inorganic nitrogen (N) loading was simulated by the catchment scale INCA-N model from two large river basins with contrasting land use. The main aim was to analyze the timing and origin of inorganic N loading and the effectiveness of different water protection methods. Predicted changes in precipitation and temperature increases the nutrient load from catchments to water bodies in future climate. The total inorganic N load from the forested Simojoki river basin located in northern Finland was about 5% of that from the Loimijoki river basin in south western Finland. In the Loimijoki river basin agriculture dominated inorganic N loading. When applying realistic water protection methods (limits on manure spreading) the simulated inorganic N load from the river basin decreased by 11%. With more drastic methods (no manure spreading + catch crop) a decrease up to 34% was achieved. In the Simojoki river basin there were several equally significant sources, so suitable combinations of different water protection measures would be the most efficient way to decrease the inorganic N load. As the inorganic N load may be composed of very different sources, depending on land use in the river basin, efficient allocation of water protection measures requires detailed analysis of different sources of loading.
Modelling seasonal nitrate concentrations in runoff of a heathland catchment in SW Norway using the MAGIC model: I. Calibration and specification of nitrogen processes
Authors: Sjøeng Anne Merete S. , Wright Richard F. , Kaste Øyvind
Published: May 2009

MAGIC (the Model of Acidification of Groundwater In Catchments) has been widely applied on catchments all over the world. The model has been used with annual time resolution to simulate the long-term effects of acidic deposition on surface water chemistry. Here MAGIC was applied using a monthly time step. The purpose was to simulate observed seasonal nitrate (NO3) concentrations and fluxes at an upland heathland catchment in southwestern Norway during the period 1993–2004. The rates of the key ecosystem nitrogen (N) processes (mineralization, plant uptake, litterfall and immobilization) were assumed to be governed by temperature. A snow accumulation and melt routine was used. The rates were calibrated to obtain the best match between the observed and simulated NO3 patterns. The best fit was obtained with standard yearly cycles for deposition and N parameters. The results show that MAGIC can explain 68 and 88% of the variation in seasonal NO3 concentrations and fluxes, respectively. The calibrated model provides a tool for exploring the effects of future scenarios of climate change and N deposition on NO3 in streamwater.
Impacts of acid deposition at Plastic Lake: forecasting chemical recovery using a Bayesian calibration and uncertainty propagation approach
Authors: MacDougall George , Aherne Julian , Watmough Shaun
Published: May 2009

Given the importance of models in the development of environmental polices it is necessary to assess the uncertainty introduced by model parameterisation and its impact on predictions. In the current study, an uncertainty framework designed to perform automated calibrations and developed for use with the Model of Acidification of Groundwater in Catchments (MAGIC) was applied to Plastic Lake, a long-term study site in Southern Ontario, Canada. The primary objectives were to investigate the chemical response of soil and surface water at Plastic Lake to proposed acid (sulfur and nitrogen) emissions and assess the use of the framework at a regional level. Despite the relatively high amount of uncertainty associated with many of the model parameters, calibration resulted in relatively narrow parameter convergence. The importance of time-series stream data was clearly evident, with uncertainty decreasing with more observation years. The forecast improvements in stream Acid Neutralizing Capacity at Plastic Lake from–40 μeq/L in 1988 to 14 μeq/L in 2060 had 5 and 95% confidence bounds of–3 and 29 μeq/L, respectively. Despite the limited availability of soil chemical data in Ontario, the approach applied at Plastic Lake is viable on a regional basis given the abundance of water chemistry data.
A long-term simulation of the effects of acidic deposition and climate change on surface water dissolved organic carbon concentrations in a boreal catchment
Authors: Futter M. N. , Forsius M. , Holmberg M. , Starr M.
Published: May 2009

Concentrations of dissolved organic carbon (DOC) are increasing in many surface waters across Europe. Two of the main mechanisms proposed to explain this increase are declines in sulfate (SO42−) deposition and changes in climate. Many of the reductions in SO42− have already occurred; climate change related effects are occurring now and will continue in the future. This paper presents the first application of a new version of INCA-C, the Integrated Catchments model for Carbon, which simulates the effects of both climate and SO42− deposition on surface water DOC concentration ([DOC]). The model was applied to Valkea-Kotinen, a small headwater catchment in Finland, where it was able to simulate present-day (1990–2007) trends in [DOC] in the lake and catchment outflow as functions of observed climate and European Monitoring and Evaluation Programme (EMEP)-modelled SO42− deposition. Using a parameter set derived from a present-day calibration, the model was run with two climate scenarios from the Special Report on Emissions Scenarios (SRES) and three EMEP deposition scenarios to simulate surface water [DOC] between 1960 and 2100. The results show that much of the historical increase in [DOC] can be explained as a result of historical declines in SO42− deposition and that surface water [DOC] will continue to increase as climate changes.
Drying Strategies for Fluidized-Bed Drying of Paddy
Authors: Tirawanichakul Supawan , Prachayawarakorn Somkiat , Varanyanond Warunee , Soponronnarit Somchart
Published: May 2009

The main objective of this work was to determine an effective moisture diffusivity of long grain rice during fluidized-bed drying (FBD) with inlet drying temperatures ranging of 40-150°C by 10°C/step and to investigate the specific energy consumption of the FBD process. Three initial moisture contents of the local indica paddy were set at 25.0, 28.8 and 32.5% dry-basis. The experimental results of thin-layer fluidized-bed drying for the long grain rice variety were determined and statistically analyzed by non-linear regression method. The results showed that an effective diffusion coefficient was highly dependent on the drying temperature, compared to initial moisture content. Consequently, the mathematical simulation of FBD, using the developed thin-layer drying mentioned above, was evaluated and used for predicting the paddy drying system. The simulated value of energy consumption in each of the drying conditions was comparatively simulated. The simulated results showed that a FBD with low temperatures and low initial moisture content gave higher specific energy consumption than drying with high temperatures and high initial moisture contents. The total specific energy consumption increased with a decreased fraction of re-circulated outlet drying air. According to the simulation results and our previous work, the conclusion is that the long grain paddy drying with FBD technique under a high initial moisture content and drying air temperature over 100°C is the good drying condition for recommendation.
Optimization of Chemical Cleaning for Removal of Biofouling Layer
Authors: Madaeni Sayed S , Saedi Sh. , Rahimpour F , Zereshki S
Published: May 2009

Biofouling is one of the most important problems associated with the application of membrane in bioprocessing. A strategy for membrane regeneration is the chemical cleaning of fouled membranes. The choice of chemical cleaning agent and operating parameters are critical to cleaning efficiency. In this work the cleaning efficiency of different cleaning agents for the removal of biofouling layer was studied. The cleaning agents include hydrogen peroxide (H2O2), sodium hydroxide (NaOH), hydrochloric acid (HCl), 1-propanol, urea and Ethylene Diamin Tetra Acetic acid (EDTA). The influences of different experimental variables on the cleaning efficiency were evaluated. Response surface methodology was employed to optimize the cleaning efficiency of the cleaning agents with three variables of concentration of cleaning agent, time of cleaning, and stirring speed for cleaning of GVHP microfiltration membrane fouled by E.coli in a dead end cell. To build the mathematical model and minimize the number of experiments for the design parameters, a response surface methodology with a face-centered central composite design (CCF) was defined. The adequacy of the calculated model for the response was confirmed by means of variance analysis and additional experiments. Predicted optimal conditions to achieve maximum flux recovery were elucidated. The validity of the response model was verified by a good agreement between predicted and experimental results.
Effect of Lateral Excursive Movements on the Progression of Abfraction Lesions
Authors: Wood I. D. , Kassir A. S. A. , Brunton P. A.
Published: May 2009

Clinical Relevance

The results of this randomized controlled trial have direct relevance to clinical practice and provide some evidence that occlusal adjustment to prevent further progression of abfraction lesions cannot be supported currently.
Minimally Retentive Gold Onlays: A Six-Year Case Report
Authors: Brackett M. G. , Kious A. R. , Brackett W. W.
Published: May 2009

PURPOSE

Partial veneer gold restorations, such as gold onlays, have changed little in preparation design over the past 40 years, as evidenced by textbooks that have long been in print.1–2 Such designs must have been based on the assumption that restorations would be luted with zinc phosphate cement but have not altered, despite the introduction of stronger luting cement classes, such as resin composite and resin-modified glass ionomer cements.1

It is well-established that both porcelain and base metal materials, which have been etched on the intaglio surface, can be combined with resin composite luting cements to produce restorations retained largely through adhesion. However, neither of these materials can equal the combination of minimal tooth reduction and margin adaptation that is possible with high noble gold restorative materials.

Although high noble gold alloys cannot be etched, air abrasion of the intaglio surface of restorations likely improves micromechanical retention, but it is unknown whether this, along with a strong luting cement, is sufficient to stabilize high noble gold alloys in preparations with considerably less retention and resistance form than traditional designs.
Bond Strength of Resin Cements to a Zirconia Ceramic with Different Surface Treatments
Authors: Cavalcanti A. N. , Foxton R. M. , Watson T. F. , Oliveira M. T. , Giannini M. , Marchi G. M.
Published: May 2009

Clinical Relevance

Air abrasion and the use of special functional monomers that are able to chemically bond to zirconium dioxide can improve adhesion to a highly dense zirconia ceramic.
Transfusion associated in-hospital mortality and morbidity in isolated Coronary Artery Bypass Graft surgery
Authors: Salehiomran Abbas , Ahmadi Hossein , Karimi Abbasali , Tazik Mokhtar , Dowlatshahi Samaneh , Fathollahi Mahmood , Abbasi Seyed
Published: May 2009

Transfusion after cardiac surgery is very common. This rate varies between institutions and has remained high despite established transfusion guidelines. We analyzed our database of patients who underwent isolated CABG (Coronary Artery Bypass Graft) to determine the predictive factors of homologous transfusion and associated postoperative morbidity, mortality and resource utilization. All 14,152 patients who underwent first-time isolated CABG, with or without cardiopulmonary bypass (CPB) who had postoperative homologous transfusion between February 2002 and March 2008 in Tehran Heart Center, were evaluated retrospectively. Overall, 16.5% of patients received transfusion. Transfused patients demonstrated a significantly higher incidence of postoperative complications (cardiac, infectious, ischemic, reoperation) and mortality (p<0.001). Homologous blood transfusion effect on mortality, morbidity and resource utilization. By Multivariable logistic regression analysis adjusted for confounders: Homologous blood transfusion effect on Mortality (30-days) (OR=3.976, p<0.0001), Prolonged ventilation hours (OR=4.755, p<0.0001), Total ICU hours (β =14.599, p<0.0001), Hospital length of stay (β =1.141, p<0.0001), Post surgery length of stay (β =0.955, p<0.0001). We conclude that the isolated CABG patients receiving blood transfusion have significantly higher mortality, morbidity and resource utilization. Homologous blood transfusion is an independent factor of increased resource utilization, morbidity and mortality.
Terahertz Time-Domain Spectroscopy Study of the Conductivity of Hole-Transporting Materials
Authors: Brauer Jan C. , Thorsmølle Verner K. , Moser Jacques-E.
Published: May 2009

Some redox-active ionic liquids, organic amorphous solids containing electron-donating moieties, and conductive polymers can efficiently transport positive electrical charges. These hole-conducting media find increasing applications in unconventional solar cells and organic light-emitting
diodes. Appropriate methods are required to unravel the detailed conduction and trapping mechanisms in these materials as well as to fully understand the interplay of molecular vibrations and charge transportprocesses. Here we present terahertz time-domain spectroscopy (THz-TDS) as a powerful
technique, that allows the direct determination of the complex conductivity of hole transporting materials in a contactless, purely optical manner. Beyond the measurement of the conductivity of solid and liquid materials, THz (far infrared) spectroscopy also provides direct information of
the librational and vibrational modes coupled to charge transport processes and therefore is invaluable in the study of themechanism of polaronic transport in matter. Application of this technique is illustrated by examples provided by the study of the ionic liquid 3-methyl-1-propylimidazolium
bis(trifluoromethane) sulfonimide (PMIT FSI) and that of the molecular liquid hole conductor 10-methylphenoxazine. Both systems are of particular interest, as both types of holetransporting media are successfully used as alternatives to solvent-based electrolytes in dye sensitized solar cells
Registration of ‘RB07’ Wheat
Authors: Anderson J. A. , Linkert G. L. , Busch R. H. , Wiersma J. J. , Kolmer J. A. , Jin Y. , Dill-Macky R. , Wiersma J. V. , Hareland G. A. , McVey D. V.
Published: May 2009

‘RB07’ (Reg. No. CV‐1028, PI 652930) hard red spring wheat (Triticum aestivum L.) was developed by the University of Minnesota Agricultural Experiment Station and released in 2007. RB07 was tested as MN99436‐6 in statewide yield trials from 2003 to 2006 and in the Uniform Hard Red Spring Wheat Regional Nursery in 2003 and 2004. RB07 was released based on its high and consistent grain yield, earliness, disease resistance and good grain end‐use quality. It is well adapted to hard red spring wheat–growing regions in Minnesota, North Dakota, and South Dakota.
‘Don’, a Diploid Falcata Alfalfa for Western U.S. Rangelands
Authors: Peel Michael D. , Asay Kay H. , Waldron Blair L. , Jensen Kevin B. , Robins Joseph G. , Mott Ivan W.
Published: May 2009

‘Don’ (Reg. No. CV‐205, PI 655519), a diploid falcata alfalfa (Medicago sativa subsp falcata L.), was developed by the Forage and Range Research Laboratory in Logan, UT, in cooperation with the Utah Agricultural Experiment Station, Utah State University. Recent interest in falcata alfalfa has been high due to its value for increasing the productivity of rangelands. Don was selected for persistence under harsh conditions, uniform yellow flower color, increased seed production, and large‐stature plants. Don traces to PI20725, an original collection made by N.E. Hansen in the Don Province of Russia. Don was tested as AU021. Don is significantly more persistent than typical sativa (M. sativa Subsp sativa L.)–type alfalfas and is meant for use in mixed plantings with grasses either in range or pasture situations typical of the Intermountain region of the western United States. In comparative trials, including irrigated and nonirrigated, where 25 to 50% mortality was observed on sativa alfalfas, Don showed no mortality. When used in mixtures, the production advantage of Don with tall fescue [Schedonorus phoenix (Scop.) Holub; syn. Festuca arundinaceae Schreb.] and meadow brome (Bromus riparius Rehm.) ranged from 10 to 32% When Don is grown with crested wheatgrass on dry rangelands, similar production advantages are expected, which will make rangelands more productive. Furthermore, when grown in mixtures with grasses, Don will not dominate; rather, it has a low growth habit and stays well below the canopy of most cool‐season grasses.
Registration of ‘Sabine’ Dallisgrass
Authors: Burson Byron L. , Venuto Brad C. , Hussey Mark A.
Published: May 2009

‘Sabine’ dallisgrass (Paspalum dilatatum Poir.) (Reg. No. CV‐2, PI 655527) was released by the USDA‐ARS, Louisiana State University Agricultural Center, and Texas AgriLife Research on 2 Sept. 2008. Sabine is phenotypically and cytologically different from common dallisgrass because it is a different P. dilatatum biotype, called the Uruguayan biotype. Sabine is a single plant selection from an off‐type plant that originated from the facultative apomictic accession PI 404826. It was selected because it usually produced more forage and was consistently more persistent under defoliation than common dallisgrass in multiyear forage evaluation plots in Louisiana and Texas. Its forage nutritive value is equivalent to that of common dallisgrass. Since common is the only dallisgrass biotype grown for forage throughout the southern United States, Sabine was released to provide livestock producers in the southeastern United States with a new, more productive, and more persistent dallisgrass option.
Registration of ‘Georgia‐08V’ Peanut
Authors: Branch W. D.
Published: May 2009

‘Georgia‐08V’ (Reg. No. CV‐105, PI 655573) is a new high‐yielding, high‐oleic, Tomato spotted wilt virus (TSWV)–resistant, large‐seeded, virginia‐type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) cultivar released by the Georgia Agricultural Experiment Stations in 2008. It was developed at the University of Georgia, Coastal Plain Experiment Station, Tifton, GA. Georgia‐08V originated from a cross made between ‘C‐99R’ × ‘Georgia Hi‐O/L’. Pedigree selection was practiced within the F2, F3, and F4 generations. Performance testing began in the F4:6 generation with the advanced pure‐line selection, GA 012535, the experimental designation of Georgia‐08V. Averaged over 38 multilocation tests conducted in Georgia during 2004 to 2007, Georgia‐08V had significantly less TSWV disease incidence, higher yield and percentage extra‐large kernels (ELK), larger seed size, and greater dollar value return per hectare compared with the check cultivars, Gregory, Perry, and NC‐V 11. Georgia‐08V also had significantly higher yield, ELK percentage, and dollar value than Georgia Hi‐O/L and was also found to have the largest seed size of all of the virginia‐type cultivars tested, including ‘Georgia‐05E’.
Registration of ‘BIOINTA 2004’ Wheat
Authors: Bainotti C. , Fraschina J. , Salines J. H. , Nisi J. E. , Dubcovsky J. , Lewis S. M. , Bullrich L. , Vanzetti L. , Cuniberti M. , Campos P. , Formica M. B. , Masiero B. , Alberione E. , Helguera M.
Published: May 2009

‘BIOINTA 2004’ (Reg. No. CV‐1030, PI 655312) is a hard red winter wheat (Triticum aestivum L.) developed and released by the Marcos Juárez Experimental Station from the National Wheat Breeding Program of the National Institute of Agricultural Technology, Argentina. BIOINTA 2004, previously designated R4001, was selected for its excellent grain yield potential, resistance to leaf rust (caused by Puccinia triticina Eriks.) conferred mainly by the Lr47 gene selected by marker assisted selection (MAS), and its good bread‐making quality.
Registration of ‘Thunder CL’ Wheat
Authors: Haley Scott D. , Johnson Jerry J. , Westra Phillip H. , Peairs Frank B. , Stromberger John A. , Heaton Emily E. , Seifert Scott A. , Kottke Rebecca A. , Rudolph Jeff B. , Bai Guihua , Bowden Robert L. , Chen Ming-Shun , Chen Xianming , Jin Yue , Kolmer James A. , Seabourn Bradford W.
Published: May 2009

‘Thunder CL’ (Reg. No. CV‐1031, PI 655528) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2008 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State University (CSU), USDA–ARS researchers at Manhattan, KS, St. Paul, MN, and Pullman, WA, participated in the development of Thunder CL. Thunder CL was selected from the cross KS01‐5539/CO99W165 made in 2000 at Fort Collins, CO. KS01‐5539 is an unreleased experimental line from Kansas State University with the pedigree FS2/KS97HW150//KS97HW349, and CO99W165 is an unreleased experimental line from CSU with the pedigree KS92WGRC25/‘Halt’. Thunder CL was derived from a population advanced from the F2 to F4 by single‐seed descent. Thunder CL was selected as an F4:5 line in September 2003 and assigned experimental line number CO03W239. Thunder CL was released because of its superior grain yield under nonirrigated and irrigated production conditions in eastern Colorado, it carries the Als1 gene for tolerance to imazamox herbicide, it is moderately resistant to wheat streak mosaic virus, stripe rust (Puccinia striiformis f. sp. tritici), and stem rust (P. graminis f. sp. tritici), and it has superior milling and bread baking quality.
Effects of Paint Industry Effluent on Soil Productivity
Authors: Jolly YN , Islam A , Quraishi SB , Mustafa AI
Published: May 2009

The impact of various dilutions (2.5, 5, 10, 25 and 50%) of paint industry effluent on physico-chemical properties of soil and the germination, growth and dry matter productions of corn (Zea mays L.) and rice (Oryza sativa L.) have been studied. The effluent was acidic and had low BOD and COD values because of its low content of suspended solid. It contained high concentration of calcium, medium concentrations of nitrogen, sodium, potassium, sulphate, chloride and low concentrations of phosphorus, magnesium and bicarbonate. The trace element like Mn, Ni, Cu, Zn and Pb were measured in the Î¼g L-1 level. On irrigation of soil with the effluent an increase in the water soluble salts, pH, electrical conductivity, cation exchange capacity, nitrogen, phosphorus potassium, sodium, calcium, magnesium and iron contents of the soil for effluent concentrations of 2.5, 5 and 10% were observed but all these parameters were found to decrease on treatment of the soil with the effluent concentration of 25% and above. The effluent of the lower concentrations (2.5, 5 and 10%) enhanced the growth of both crops. However, negative effects on seed germination, dry matter production and the yield of both crops were found for the effluent concentration of 25% and above. doi: 10.3329/jbas.v32i1.2441 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 41-53, 2008
Certain Features of Fuzzy Contra-continuous functions
Authors: Rashid MH , Ali DM
Published: May 2009

We deal with fuzzy topological spaces, fuzzy compact space, fuzzy S-closed space, fuzzy graph, fuzzy continuous functions and fuzzy LC-continuous functions. In this paper, we introduce the concepts of fuzzy contra-continuities and explore properties and relationships of such types of functions. Keywords: fuzzy contra-continuity, fuzzy S-closed space, fuzzy graph. AMS Subject Classification: 54A40. doi: 10.3329/jbas.v32i1.2444 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 71-77, 2008
Dielectric studies of cerium doped barium titanate at different frequencies
Authors: Rahman SN , Khatun N , Hossain Md Tofazzal , Khan AH
Published: May 2009

Cerium doped barium titanate is prepared by conventional ceramic method. The dielectric studies of Ba1-x Cex TiO3 have been accomplished at room temperature over a frequency range 75 KHz to 30 MHz for x = 0.1 to 0.4 with pure BaTiO3. The measurements of the real and imaginary part of dielectric constants show strong frequency dependence. The relaxation phenomena that take place cane be attributable to the damping of dipole oscillator due to the application of external field. In the present experiment relaxation occurs at the frequency of about - 1MHZ. doi: 10.3329/jbas.v32i1.2445 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 79-85, 2008
Chaotic Behaviour of Dynamic Systems of Hoeomorphism on Unit Interval
Authors: Ahmed Payer , Islam Md Shahidul
Published: May 2009

In this article, we studied that no homeomorphism on unit interval into itself is chaotic in the sense of R.L. Devaney. We also studied the behavior of orbits of points in the dynamical system defined by homeomorphism on the unit interval. doi: 10.3329/jbas.v32i2.2425 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 194-200
A Theoretical Study on Molar Flux in the Capillary
Authors: Malek Abdul , Hoque Ashabul
Published: May 2009

The paper is concerned with the molar flux of oxygen in the capillary blood when oxygen diffuses from blood to tissue fluid at the middle section of the capillary bed where blood pressure and osmotic pressure of blood are equal. The result shows that the molar flux decreases exponentially with the radius of the capillary. Moreover, it is found that the molar flux increases linearly with the increasing of radial diffusion of oxygen. doi: 10.3329/jbas.v32i2.2429 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 226-233
Structural and Dielectric Properties of Zn1-x-yCdxLiyO Solid Solution
Authors: Kamruzzaman M , Khan MKR , Rahman MM , Shahjahan M , Karal MAS
Published: May 2009

Zn1-x-yCdxLiyO (x=0.30 and y=0.05, 0.10, 0.15, 0.20) have been prepared by solid state reaction method. The prepared samples have been characterized by structural and dielectric measurements. X-ray diffraction (XRD) patterns show a good crystalline nature having double crystal structure and indicates the phase mixing of the constituent components. The hexagonal phase corresponding to ZnO and cubic phase to CdO is well defined and the lattice parameters are consistent with the published values (Grant in Aid report 1987). The estimated lattice parameters, bond length and crystallite size are quite consistent corresponding to the hexagonal ZnO and cubic CdO which suggests the formation of super lattice structure of the system. Crystallite size at different crystallographic planes analyzed from XRD for both ZnO and CdO lie between (15-50) nm. The variation of the dielectric constant of the samples with frequency is systematic and the dielectric constant increases with the increase of Li in the solution. doi: 10.3329/jbas.v32i2.2430 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 234-242
Structural, Dielectric and Electrical Properties of Zirconium Doped Barium Titanate Perovskite
Authors: Choudhury Shamima , Akter Shurayya , Rahman MJ , Bhuiyan AH , Rahman SN , Khatun N , Hossain MT
Published: May 2009

The microstructural and electrical properties of pure and Zirconium (Zr) doped Barium titanate (BT) samples with general formula Ba(Ti1-xZrx)O3 (where x=0.0, 0.1, 0.2 and 0.3), prepared by high temperature solid state reaction at a sintering temperature of 1250Â° C, were investigated. Dielectric and structural properties of BT ceramics is influenced significantly by small addition of ZrO2. Scanning Electron Microscope (SEM) observations revealed enhanced microstructural uniformity and retarded grain growth with increasing Zr content. The dielectric study with frequency at room temperature in the frequency range 75 kHz to 30 MHz shows that dielectric constant decreases with increasing frequency. The resistivity of the samples shows asymptotic behavior with the variation of frequency and was found to be of the order of ~103 Î©-m. Loss factor of the grown materials decreased with increasing frequency but it became independent at higher frequency range. doi: 10.3329/jbas.v32i2.2434 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 151-159
Formation of Î¼-Carbonulmethulidene Moiety from Î¼3-Methylidyne Moiety on the Triosmium Cluster Framework
Authors: Ghosh Shishir , Raha Arun K , Kabir Shariff E
Published: May 2009

doi: 10.3329/jbas.v32i2.2435 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 160-162
Effects of Anode Flow Field Design on CO2 Bubble Behavior in μDMFC
Authors: Li Miaomiao , Liang Junsheng , Liu Chong , Sun Gongquan , Zhao Gang
Published: May 2009

Clogging of anode flow channels by CO2 bubbles is a vital problem for further performance improvements of the micro direct methanol fuel cell (μDMFC). In this paper, a new type anode structure usingthe concept of the non-equipotent serpentine flow field (NESFF) to solve this problem was designed, fabricated and tested. Experiments comparing the μDMFC with and without this type of anode flow field were implemented using a home-made test loop. Results show that the mean-value, amplitude and frequency of the inlet-to-outlet pressure drops in the NESFF is far lower than that in the traditional flow fields at high μDMFC output current. Furthermore, the sequential images of the CO2 bubbles as well as the μDMFC performance with different anode flow field pattern were also investigated, and the conclusions are in accordance with those derived from the pressure drop experiments. Results of this study indicate that the non-equipotent design of the µDMFC anode flow field can effectively mitigate the CO2 clogging in the flow channels, and hence lead to a significant promotion of the μDMFC performance.