bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion-Beam-Induced Destruction of Superconducting Phase Coherence in YBa2Cu3O7-δ
Authors: White Alice E. , Short K. T. , Jacobson D. C. , Poate J. M. , Dynes R. C. , Mankiewich P. M. , Skocpol W. J. , Howard R. E. , Anzlowar M. , Baldwin K. W. , Levi A. F. J. , Kwo J. R. , Hsieh T. , Hong M.
Published: March 2011

We have explored the effects of ion beam irradiation on the electrical and structural properties of superconducting thin films of YBa2Cu3O7-δ. Damage created by nuclear energy loss processes degrades the superconducting transitions. In general, the onset temperatures do not vary significantly with ion fluence, but the transition widths broaden until the resistance no longer reaches zero. This behavior is strikingly similar to that observed in granular superconducting films where islands of superconductor are progressively decoupled from each other, destroying the phase coherence. Data from resistance measurements as well as from Rutherford Backscattering and channeling measurements suggest that ion bombardment is not changing the volume fraction of superconducting material substantially.
Site Exchange in High Temperature Superconductors
Authors: Li D. J. , Shibahara H. , Zhang J. P. , Marks L. D.
Published: March 2011

Electron microscopical analysis of brown powders of composition YBa2Cu3O6.5 produced by oil quenching and conventionally produced orthorhombic GdBa2Cu3O7-δ show in both cases clear evidence for site exchange both between the different heavy metals and the heavy metals and the copper sites. For instance, the brown powder is a mixture of phases which are based upon two trigonal phases, both with a=0.536 and c=0.666 nm, one with the Y atoms stacked on the (111) planes of the parent perovskite structure and the second where the Y atoms of this structure have interchanged with one of the copper sites. The GdBa2Cu3O7-δ, material shows numerous planar defects on (001) planes which can be understood as copper rich regions with additional copper planes in the Ba or Gd sites. These results, together with earlier reports of order-disorder in YBa2Cu3O7-δ, strongly indicate that there exist ordering energies in these materials which may be important with respect to the current indications of the important of grain boundary phases in degrading the performance of some superconductors.
Ion Beam Sputtering and Properties of Superconducting YBaCuO thin Films
Authors: Pavona D. , Baer H. , Berger H. , GasParov V. , Schmidt M. , Vasey F. , Reinhart F-K.
Published: March 2011

We describe single-target ion beam sputtering of superconducting YBaCuO thin films mainly onto R-sapphire and (100) SrTiO3 substrates. We discuss different thermal treatments and consequent X-ray and resistivity results and conclude with X-ray photoelectron spectroscopy data which indicate formation of hydroxydes on the surface of films exposed to atmosphere.
Electrical, Chemical, and Structural Properties of Plasma Sprayed Y-Ba-Cu-Oxide Superconducting Coatings
Authors: Neiser R. A. , Kirkland J. P. , Elam W. T. , Herman H. , Rangaswamy S. , Letourneau V. M. , Osofsky M.
Published: March 2011

Thick coatings of Y-Ba-Cu-oxide superconductors have been prepared by plasma spray processing. This paper reports a number of the important properties of coatings sprayed at two different power levels. The microstructure, porosity, and chemical composition of the coatings were studied in their as-sprayed and annealed states. Critical current and magnetic susceptibility measurements were made on the annealed coatings. X-ray diffraction was used to identify non-superconducting phases present in the coatings and to determine the superconducting phase's lattice constants.
Microstructural Characterization of Ba2YCu3O7 Films Produced by Co-Evaporation
Authors: Fisanick G. J. , Mankeewicht P. , Skocpolt W. , Howardt R. E. , Dayem A. , Fleming R. M. , White A. E. , Liou S. H. , Moore R.
Published: March 2011

Ba2YCu3O7 films produced by co-evaporation of BaF2, Cu and Y onto <100> S1TiO3 substrates in an O2 ambient followed by post-annealing were analyzed using RBS, X-ray diffraction and Auger microscopy. These films exhibit Tc's (R=0) of =90K and a best Jc of > 1.0×106 A/cm2 at 81K for a =2500A thick film. RBS and Auger depth profiling limit the level of F present in the post-annealed films to <5 at. %, although F is evident in the as-deposited material. RBS channeling experiments yield a Xmin=31%, demonstrating the epitaxial quality of the films. X-ray diffraction shows that the films are predominantly oriented with c-axis perpendicular to the substrate, with narrow mosaic spread in-plane. A small portion of the film is in the form of needles oriented with a-axis perpendicular to the substrate, whose areal density is dependent on annealing conditions and local film stoichiometry. Scanning Auger microscopy confirms that the needles and c-axis plateaus have the same metal and oxygen stoichiometry. Also present in the film are insulating balls which appear to nucleate terraces in the c-axis perpendicular structure. Scanning Auger shows that these features are also close to the metals stoichiometry, but are C rich compared to the needles. The plateaus are covered with =11 times more C than the needles, indicating that the basal plane surface is highly reactive. Auger depth profiling and RBS show little evidence for interdiffusion.
Orientation Dependent X-Ray Absorption Near Edge Structure in YBa2Cu3O7 and La1.85Sr0.15ISCUO4
Authors: Heald S. M. , Tranquada J. M. , Moodenbaugh A. R. , Xu Y.
Published: March 2011

X-ray absorption measurements have been made on powder samples of YBa2Cu3O7 and La1.85sr0.15CuO4 oriented in a magnetic field. Measurements made at the Cu K edge with the x-ray polarization oriented perpendicular and parallel to the c-axis show distinct differences for both materials, indicating a strong anisotropy of the electronic states about the Cu atoms. The Y edge measurements show a much smaller anisotropy as expected due to its more symmetric environment. Preliminary analysis indicates these measurements should be useful in choosing between the conflicting interpretations of the near edge structure in these materials.
Transport and Meissner Effect Studies for YBa2(Cuy1−xZnx)3O7
Authors: Bloom S. H. , Kuric M. V. , Yao Y. S. , Guertin R. P. , Nichols D. , Jee C. , Kebede A. , Crow J. E. , Mihalisin T. , Myer G. N. , Schlottmann P.
Published: March 2011

Single phase orthorhombic YBa2(Cuy1−xZnx)3O7 samples were formed for 0<x<0.16. The high T superconductivityXfor x=6 (T =90 K) is rapidly depressed with increasing x, and is quenched for x>0.08. Low field (<100 G) cooled magnetization studies show that the superconducting component decreases as x approaches the critical value for suppression of superconductivity, and this is supported by high resolution specific heat measurements in the vicinity of T. Temperature dependent electrical resistivity studies for x<0.08 show metallic behavior; for x>0.10 semiconducting behavior. The electrical resistance was studied at high quasihydrostatic pressures also, and for x=0.08 showed that T is depressed with increasing pressure: T → 0 K for P >10 GPa. This is in°contrast to YBa2(Cuy1−xZnx)3O7 where dT /dP>0. The data support evidence for the high sensitivity to chemical and ice perturbations of the physical properties of samples near the superconducting-normal transition region.
Phonons in YBa2Cu3O7−x Type Materials
Authors: Burns Gerald , Dacol F. H. , Freitas P. , König W. , Plaskett T. S.
Published: March 2011

Infrared reflectivity results of YBa2Cu3O7x and SmBa2Cu3O7−x, in the tetragonal semiconducting phase, are reported. At least 10 of the 11 group theoretically allowed modes are observed, and the 11th may be observed in the Sm-material. Due to the fact that the modes are clearly resolved from each other, and, in some cases, have large shifts when Y is replaced by Sm, severial these modes can be assigned to definate vibrations. This and other aspects of the data are discussed.
Normal-State Infrared Anisotropy of Polycrystalline La1.85Sr0.15CuO4-y
Authors: Doll G. L. , Steinbeck J. , Dresselhaus M. S. , Dresselhaus G. , Strauss A. J. , Zeiger H. J. , Phillips G. , Waldman J.
Published: March 2011

By examining the reflectance spectra of polycrystalline La1.85Sr0.15CuO4-y and La2NiO4-y in relation to the results of ir studies on single-crystal La2NiO4-y, we have determined the normal-state (room temperature) optical anisotropy of La1.85Sr0.15CuO4-y in the frequency range 40 cm-1 to 4800 cm-1. Vibrational and electronic properties corresponding to this anisotropy are examined, and a method is presented for extracting the optical properties of the superconducting state of La1.85Sr0.15CuO4-y.
Logarithmic Rounding Above the Superconducting Transition in YBa2Cu3O7 Crystals
Authors: Fiory A. T. , Hebard A. F. , Schneemeyer L. F. , Waszczak J. V.
Published: March 2011

The temperature dependence of the electrical conductivity measured in the a-b basal plane of YB2Cu3O7 crystals displays a weak, nearly logarithmic divergence near Tc, which is weaker than the power-law functions predicted by superconducting fluctuations in 1, 2, or 3 dimensions. On the other hand, we find that quasi-particle fluctuations and pair-breaking in two-dimensions as given by Maki and Thompson, where the pair-breaking parameter δ is assumed to be proportional to temperature, gives by itself an excellent fit to the data.
Use of High-Temperature Superconductors in High Speed Electronic Switches with Current Gain
Authors: Biegel Bryan A. , Singh R.
Published: March 2011

Recent developments in superconductivity have taken 77 K superconducting electronics from a dream to a likelihood. Rather than following the conventional path by developing Josephson junction-based devices, this paper discusses the unique possibilities of hybrid superconductor/semiconductor devices. The two devices discussed are a true three-terminal hybrid resonant tunneling transistor and the semiconductor-coupled Josephson junction. Also, a list is given of as yet uninvestigated issues concerning the new superconductors and their proximity effects with semiconductors -issues that are critical to the operation of these hybrid superconductor/semiconductor devices.
Effect of Ambient Atmosphere on YBa2Cu3O7-y
Authors: Horowitz H. S. , Bordia R. K. , Flippen R. B. , Johnson R. E.
Published: March 2011

The reactivity of sintered samples of YBa2Cu3O7-y with moisture at elevated temperatures has recently been reported [1]. The reaction sequence proposed was:

Such instability of the 1–2–3 phase has serious implications regarding not only the use of the sintered material, but powder processing as well. While the need for fine particle 1–2–3 powder exhibiting good sinterability is recognized, it is also anticipated that the degradation of this material will accelerate with decreasing particle size because of the larger surface area. Thus, we have conducted a series of experiments to monitor the effect of ambient atmosphere on fine particle 1–2–3 powder. The powder was monitored as a function of time by x-ray diffraction, scanning electron microscopy, sintering characteristics and magnetic flux exclusion.
Governmental as anything
Authors: Homan Shane
Published: February 2011

On 23 February 2010, shoppers and café patrons in Swanston Street in Melbourne’s Central Business District were confronted by the sight of an estimated 20,000 musicians, fans, publicans, school children, parents and music industry workers marching to state parliament to protest the branding of music venues as part of the city’s problems relating to alcohol consumption and law and order. In this paper I document the arguments of both the government and the live music industry in a battle that raised important questions about Melbourne’s self-image as the cultural capital of Australia. It also provides a recent case study of how the live music venue remains a constant test case in government attempts to reconcile conflicting cultural, economic and urban policy.
Gilding the pearl
Authors: Hayward Philip , Li John
Published: February 2011

Hainan island, located between 108–111 degrees east and 18–20 degrees north (on a similar latitude to northern Vietnam), is a southern tropical ‘outlier’ of continental China that has developed as a major tourist centre over the last two decades. Following an introduction to the socio-cultural history of the region, the article analyses the manner in which a series of post-war media and performance texts created an exotic and erotic image for the island (and for its indigenous Li population in particular) that has been perpetuated and extended in a range of contemporary performance practices. While this article addresses issues of representation, its discussions are not primarily concerned to identify the misrepresentation of an essential island referent (i.e. the ‘real’ Hainan) but rather to address the interplay between a set of media representations of the island and contemporary cultural performance on it. The final section analyses the manner in which the recently opened ‘Impression Hainan’ showcase in Haikou provides an early twenty-first-century inflection of a range of the representational tendencies we discuss. Our conclusion reflects on the impact of the exoticist and eroticist commodification of the island on its indigenous minorities.
Emo online
Authors: Overell Rosemary
Published: February 2011

This article examines Australian emo subcultural practices and new media technologies. I use subcultural studies to analyse whether emo is, indeed, a subculture. I respond to framings of emo as an ‘Other’ (sub)culture, in mainstream Australian media and Australian alternative music scenes. I interrogate whether, as dominant media claims, emo subculturalists’ internet usage inevitably leads to ‘social alienation’. First, I present a case study of a mediatized moral panic concerning the so called ‘emo suicides’ of Jodie Gater and Stephanie Gestier in 2007. Media reports positioned emo adherents as non-normative ‘dark’ users of new technologies, particularly the internet. I counter this representation with a textual analysis of emo micro media, in the form of MySpace homepages, which demonstrate emo sociality online. However, in my final section I look at how such sociality is limited by gate-keeping practices mobilizing discourses of subcultural capital.
Pesquisas cooperativas entre universidades e institutos públicos no setor agropecuário brasileiro: um estudo na Embrapa
Authors: Dossa Alvaro Augusto , Segatto Andréa Paula
Published: March 2011

A presente pesquisa objetivou a caracterização das cooperações entre universidades e institutos de pesquisa (U-IP) no setor agropecuário. O referencial teórico aborda temas como tecnologia e inovação tecnológica, sistema nacional de inovação (SNI), cooperação interinstitucional para inovação tecnológica, transferência de tecnologia, além dos papéis de universidades e institutos de pesquisa dentro do SNI. Também aborda os temas de tipos de pesquisa e o contexto da pesquisa agropecuária brasileira. A revisão teórica foi fundamentada na cooperação entre universidades e empresas (U-E), dada a reduzida literatura a respeito da cooperação U-IP. A metodologia utilizada foi a de estudo de caso, de natureza exploratória e qualitativa, utilizando roteiros de entrevista semiestruturados, questionários semiestruturados, bem como análise documental. O caso estudado foi o da Empresa Brasileira de Pesquisa Agropecuária (Embrapa), onde foram coletados dados em três unidades de pesquisa, três universidades que cooperam com essas unidades e três unidades administrativas da Embrapa que apresentam contato com as universidades, totalizando nove entrevistas e questionários. Foi possível dessa forma identificar motivadores, tipos de ligações, barreiras, facilitadores e resultados percebidos nessas cooperações.
Knowledge of common pediatric cancers among medical students in northeast Brazil
Authors: Barros Cynthia de Araújo , Samico Isabella , Feliciano Kátia Virginia de Oliveira , Oliveira Felipe Araújo Andrade de
Published: March 2011

BACKGROUND: In recent decades, early diagnosis of childhood cancer has taken an important place on the international agenda. The authors of this study evaluated a group of medical students in Recife, Brazil, regarding knowledge and practices related to early diagnosis of common childhood cancers. METHODS: Cross-sectional study with a sample of 82 medical students, from a total of 86 eligible subjects. Data were collected using self-completed questionnaires. Subgroups were defined according to knowledge of the theme and students' perceptions of their own skills and interest in learning. RESULTS: 74.4% of the sample demonstrated a minimum level of knowledge. The group without minimum knowledge or self-perceived competence to identify suspected cases (23.3%) was in the worst position to perform early diagnosis. All subjects expressed interest in learning more about this topic. CONCLUSIONS: Despite acceptable levels of knowledge among these medical students, the definition of central aspects of the teaching and learning processes would be useful for training physicians with the skills for diagnosing and treating pediatric cancers
A inclusão da perspectiva do paciente na consulta médica: um desafio na formação do médico
Authors: Ballester Denise , Zuccolotto Sandra M.C , Gannam Silmar de S. A , Escobar Ana Maria U
Published: March 2011

A insuficiência do modelo biomédico para a resolução da maioria dos problemas de saúde da população vem sendo discutida. Diversos autores referem que a realização da consulta médica se associa a melhores resultados quando apoiada nos pressupostos do modelo centrado no paciente, dentre os quais se destaca a inclusão da perspectiva do paciente. Para que isso ocorra, é necessário conhecer as dimensões físicas, psicossociais e culturais que a compõem e incluí-las na realização de entrevistas médicas. Como a formação do médico na graduação ainda é apoiada no modelo biomédico, a mudança de paradigma para a realização de consultas médicas suscita mudanças curriculares significantes
Efeito da granulometria do milho no desempenho de juvenis de pacu, Piaractus mesopotamicus (Holmberg, 1887)
Authors: Polese M.F , Vidal Junior M.V , Mendonça P.P , Tonini W.C.T , Radael M.C , Andrade D.R
Published: March 2011

Avaliou-se o efeito de diferentes granulometrias do milho da ração no desempenho de juvenis de pacu, Piaractus mesopotamicus. Foram utilizados 120 juvenis com peso inicial de 8,42±0,89, comprimento total de 7,03±0,20cm, comprimento padrão de 6,32±0,13cm e altura de 3,21±0,11cm, distribuídos em 20 aquários (300L), na densidade de seis peixes por unidade experimental (aquário), em delineamento inteiramente ao acaso, com cinco tratamentos constituídos por diferentes granulometrias - 850, 710, 500, 300, 150µm - do milho na composição da ração. Cada tratamento tinha quatro repetições. O tratamento que proporcionou melhor desempenho dos animais foi o com granulometria do milho de 150µm, destacando-se a conversão alimentar de 1,38, enquanto no tratamento com maior granulometria a conversão alimentar foi de 1,61. Assim, recomenda-se usar a granulometria de 150µm.
Colaboração na produção científica na Ciência Política e na Sociologia brasileiras
Authors: Soares Glaucio Ary Dillon , Souza Cíntia Pinheiro Ribeiro de , Moura Tatiana Whately de
Published: March 2011

A colaboração entre autores para a produção científica é maior nas ciências naturais e exatas do que nas ciências humanas. Mas esse cenário tem sofrido alterações e é crescente o número de artigos com mais de um autor nas ciências humanas. Não só o número de coautoria tem aumentado, mas também o interesse sobre esse fenômeno. As pesquisas sobre as redes de produção buscam identificar características de colaboração em determinadas disciplinas e/ou instituições. Neste trabalho, procuramos identificar padrões de produção científica em oito revistas de ciência política e sociologia do Brasil. O objetivo geral é demonstrar a tendência de colaboração nessas disciplinas em comparação com outras áreas. E o objetivo particular é identificar características e estilos cognitivos de produção em rede. A hipótese é que trabalhos experimentais e empíricos apresentam maior cooperação entre autores, enquanto que trabalhos teóricos tendem a ser escritos individualmente. Para isso, analisamos variáveis que indiquem se os artigos têm enfoque no tempo, no espaço e/ou em algum autor, se utilizam dados quantitativos e recursos gráficos. As características da produção em coautoria na ciência política e na sociologia podem indicar padrões de colaboração e tendência de estruturação de redes nessas disciplinas.
Diversidade cultural, patrimônio cultural material e cultura popular: a Unesco e a construção de um universalismo global
Authors: Alves Elder Patrick Maia
Published: March 2011

Este artigo procura situar o advento e a operacionalização de uma formação discursiva responsável pela emergência de um novo universalismo global. Tal universalismo traz como imperativo ético-moral a defesa e a promoção de valores como a diversidade cultural. Para compreender as implicações políticas e culturais desse universalismo, este trabalho elege como eixo empírico a atuação da Organização das Nações Unidas Para Educação, a Ciência e a Cultura (UNESCO), destacando as ações dessa organização na coordenação e dinamização de um trânsito simbólico e discursivo transnacional envolvendo governos, organizações não-governamentais e grupos políticos.
Métodos utilizados na avaliação psicofísica da visão de cores humana
Authors: Lima Monica Gomes , Gomes Bruno Duarte , Ventura Dora Fix , Silveira Luiz Carlos de Lima
Published: March 2011

A cor é um atributo perceptual que nos permite identificar e localizar padrões ambientais de mesmo brilho e constitui uma dimensão adicional na identificação de objetos, além da detecção de inúmeros outros atributos dos objetos em sua relação com a cena visual, como luminância, contraste, forma, movimento, textura, profundidade. Decorre daí a sua importância fundamental nas atividades desempenhadas pelos animais e pelos seres humanos em sua interação com o ambiente. A psicofísica visual preocupa-se com o estudo quantitativo da relação entre eventos físicos de estimulação sensorial e a resposta comportamental resultante desta estimulação, fornecendo dessa maneira meios de avaliar aspectos da visão humana, como a visão de cores. Este artigo tem o objetivo de mostrar diversas técnicas eficientes na avaliação da visão cromática humana através de métodos psicofísicos adaptativos.
Comparación de dos test psicofísicos de sensibilidad al contraste en un entorno clínico
Authors: Colombo Elisa , Santillán Javier , Arellano Walter , Berman Myriam , Sanchez Roberto , Paz Clemente , Issolio Luis
Published: March 2011

El objetivo de este estudio fue comparar el desempeño de dos test psicofísicos de sensibilidad al contraste, uno basado en un sistema informatizado - FVC 100 - y otro en láminas impresas - VCTS 6500, ambos empleando la discriminación de redes sinusoidales en condiciones de adaptación fotópica. Fueron medidos 45 ojos de 23 personas con edades entre 28 y 70 años. Los sujetos fueron reclutados en un Servicio de Oftalmología al cual concurrieron tanto por consulta como por control. A partir de tomar el criterio clínico como referencia, los resultados muestran que, de los 23 sujetos, en 16 casos ambos sistemas detectaron correctamente su estado visual, en cinco casos (10 ojos) sólo el FVC 100 consiguió hacerlo, mientras que en dos casos este sistema no detectó el problema visual y sí lo hizo el VCTS 6500. Considerando los datos obtenidos se aprecia un mejor desempeño del test informatizado, destacándose la necesidad de continuar trabajando para conseguir un atlas con información de la función de sensibilidad al contraste que considere las diferentes patologías visuales.
Balanço eletrolítico para suínos machos castrados em crescimento mantidos em ambiente de alta temperatura
Authors: Brêtas Anilce de Araujo , Ferreira Rony Antonio , Amarante Júnior Valene da Silva , Pereira Walter Esfrain , Fonseca José Brandão , Caldas Flavio Roberto Lima
Published: March 2011

Avaliou-se o efeito do balanço eletrolítico (BE) em rações com diferentes níveis de eletrólitos para suínos na fase de crescimento criados em alta temperatura. Foram utilizados 200 suínos machos castrados, com peso inicial de 25,3±1,3 kg e final de 68,8±3,4 kg, distribuídos em delineamento experimental inteiramente casualizado com cinco tratamentos e quatro repetições com dez animais por unidade experimental, para a fase de crescimento T1(testemunha) ração sem suplementação de eletrólitos 191 mEq/kg; T2 (NaHCO3) ração suplementada bicarbonato de sódio (NaHCO3) 250 mEq/kg; T3 (NaHCO3+KCl) ração suplementada NaHCO3 e cloreto de potássio (KCl) 250 mEq/kg; T4 (NaHCO3) ração suplementada NaHCO3 300 mEq/kg; e T5 (NaHCO3+KCl) ração suplementada com NaHCO3 e KCl 300 mEq/kg. As variáveis avaliadas foram consumo de ração, ganho de peso, consumo de nitrogênio, consumo de lisina, eficiência de utilização de nitrogênio para ganho, eficiência de utilização de lisina para ganho, conversão alimentar e os parâmetros fisiológicos, frequência respiratória e temperatura retal. Foi coletado sangue para mensurar as concentrações sorológicas de Na, Cl e K. A temperatura média foi 29,65±3,80º C com UR do ar 69,6±10,4%, Temperatura do Globo Negro de 31,95±1,98º C e Índice de Temperatura do Globo Úmido em 80,51±2,44. Os níveis de BE reduziram (P<0,05) consumo de ração e melhoram o consumo de nitrogênio. Os demais parâmetros de desempenho avaliados não foram afetados pelos diferentes balanços eletrolíticos (P>0,05). A correção do BE não influenciou o desempenho dos suínos.
Variabilidade espacial de atributos físicos do solo sob diferentes usos e manejos
Authors: Cavalcante Eloiza G. S. , Alves Marlene C. , Souza Zigomar M. de , Pereira Gener T.
Published: March 2011

O preparo de solo e as espécies vegetais têm expressivo efeito na variabilidade espacial do solo. Portanto, objetivou-se com este trabalho estudar a variabilidade espacial de alguns atributos físicos de um Latossolo Vermelho do cerrado do Mato Grosso do Sul, sob diferentes usos e manejos. O solo foi amostrado em uma malha, com intervalos regulares de 2,0 m, perfazendo o total de 64 pontos, nas profundidades de 0-0,10 m e 0,10-0,20 m para densidade do solo e nas profundidades de 0-0,15 m; 0,15-0,30 m; 0,30-0,45 m e 0,45-0,60 m para resistência do solo à penetração e teor de água no solo, em áreas com vegetação natural (cerrado), plantio direto, preparo convencional e pastagem. O maior coeficiente de variação e efeito pepita ocorreram para a resistência do solo à penetração. O sistema plantio direto apresentou maior alcance quando comparado com o do cerrado, preparo convencional e área com pastagem. As formas de uso e de manejo empregadas induziram, em ordem crescente, plantio direto, preparo convencional e pastagem à degradação dos atributos físicos do solo em relação ao cerrado.
Aplicações do método de ensaio esclerométrico em peças de eucalipto saligna sm
Authors: Soriano Julio , Gonçalves Raquel , Bertoldo Cinthya , Trinca Alex J.
Published: March 2011

Neste trabalho é avaliada a tendência de correlações entre as resistências a compressão paralela e normal às fibras, por meio de ensaios destrutivos normalizados e parâmetros do ensaio do método esclerométrico. Também se fez comparação com o método de ensaio não destrutivo de ultrassom. Três séries de corpos de prova foram extraídas de uma tora de Eucalyptus saligna e ensaiadas na condição de madeira saturada. Dos resultados dos impactos esclerométricos para as três direções anatômicas avaliadas (paralela às fibras, radial e tangencial) foram verificados coeficientes de variação inferiores a 9%. Da análise das tendências de correlações de resistência a compressão com os resultados da esclerometria e ultrassonografia, foram constatados os melhores ajustes para a direção paralela às fibras. Tendo em vista os resultados obtidos, pode-se concluir que a técnica de esclerometria mostrou-se capaz para identificar a homogeneidade do lote ensaiado, justificando haver possibilidades de aplicações do método à madeira.
Uma investigação dos efeitos do ensino explícito da pronúncia na aula de inglês como língua estrangeira
Authors: Lima Júnior Ronaldo Mangueira
Published: March 2011

O presente estudo investigou os efeitos, e sua durabilidade, do ensino explícito da pronúncia em aulas de inglês como língua estrangeira. Foi conduzida uma pesquisa-ação intervencionista com duas turmas de aprendizes pré-adolescentes do nível básico de inglês. Em uma das turmas houve intervenção de aulas explícitas de pronúncia semanais durante um semestre. Todos os participantes foram gravados uma vez antes e duas vezes após as intervenções e suas gravações foram transcritas e analisadas foneticamente. Os resultados indicam, entre outras conclusões, que há efeitos positivos na instrução explícita da pronúncia e que esses efeitos são duráveis.
A gramática no ensino de língua portuguesa: à busca de compreensão
Authors: Angelo Graziela
Published: March 2011

O presente artigo discute a ideia amplamente divulgada na esfera acadêmica de que o ensino da gramática de Língua Portuguesa, de décadas atrás, no Brasil, se constituiu como um panorama contínuo e homogêneo. Na busca de compreender esse passado, foram analisadas entrevistas com algumas professoras de Língua Portuguesa que trabalharam nas décadas de 1950 a 1970 no ensino público paulista, a fim de investigar como se constituíram seus discursos a respeito do ensino de gramática no processo de rememoração. Foi possível verificar que a permanência de uma tradição e a instauração de novas posturas coexistiram num mesmo período de tempo, havendo espaço para posturas distintas no ensino da gramática.
A língua em funcionamento nas práticas discursivas
Authors: Gonçalves Adair Vieira , Saito Cláudia Lopes Nascimento , Nascimento Elvira Lopes
Published: March 2011

Fundamentos do quadro epistemológico do interacionismo sociodiscursivo da Escola de Genebra e da vertente funcionalista de estudos da linguagem ecoam nas ideias pressupostas em três documentos oficiais: Proposta Curricular de Língua Portuguesa do Estado de São Paulo (PCLP), Diretrizes curriculares da Educação Básica do estado do Paraná (DCE) e dos Parâmetros Curriculares Nacionais (PCN), considerando que esses documentos postulam, como eixo do trabalho pedagógico, as práticas discursivas nos diferentes contextos de uso da língua. O enfoque na língua contextualizada nas práticas sociais constitui um novo paradigma para a formação de professores e para a didatização de tais práticas. Nesse sentido, os autores dão a sua contribuição, apresentando proposta de modelização didática de uma prática social que contribua para a elaboração de atividades didáticas em que se articulem aspectos linguísticos e discursivos emergentes do funcionamento da linguagem.
A Novel de Novo Mutation Within EFNB1 Gene in a Young Girl with Craniofrontonasal Syndrome
Authors: Apostolopoulou Despina , Stratoudakis Alexander , Hatzaki Angeliki , Kaxira Olga S. , Panagopoulos Kanaris P. , Kollia Panagoula , Aleporou Vassiliki
Published: February 2011

Craniofrontonasal syndrome is mainly characterized by frontonasal dysplasia, telorbitism, a broad nasal root, and frequently a bifid nose and coronal craniosynostosis. Craniofrontonasal syndrome is an X-linked disorder with an unusual pattern of inheritance because heterozygous females are more severely affected than hemizygous males. The craniofrontonasal syndrome–causing gene is EFNB1, localized in the border region of chromosome Xq12 and Xq13.1, encoding for protein ephrin-B1. Here we aim to investigate the underlying genetic defect of a young girl with craniofrontonasal syndrome. The patient underwent surgical correction of her craniofacial deformities. Genetic analysis was carried out by polymerase chain reaction. Products of exon 2 of the EFNB1 gene were sequenced as well as digested with BpmI enzyme. A novel de novo missense mutation 373G>A was identified within the EFNB1 gene, leading to the replacement of glutamic acid at amino acid position 125 with lysine. The replacement of Glu125 with Lys, which lies within the G-H loop, part of the dimerization ligand-receptor interface, is expected to disrupt the interaction between the Eph receptor and ephrin B1 ligand, thus leading to craniofrontonasal syndrome.
Modelling runoff and sediment rate using aneuro-fuzzy technique
Authors: Nayak Purna Chandra , Jain Sharad Kumar
Published: March 2011

This paper demonstrates the estimation and simulation of discharge and sediment concentration for two river basins in the USA and India. The first-order Sugeno fuzzy inference system was utilised to model the stage, discharge and sediment concentration relationship. A subtractive clustering algorithm, along with a least-squares estimation, was used to generate the fuzzy rules that describe the relationship between input and output data of stage, discharge and sediment concentration, which change over time. The fuzzy rules were tuned by a back-propagation algorithm. The results are illustrated using simulation and virtual reality. A comparison was made between the estimates provided by the neuro-fuzzy model and a multi-linear regression model. Different statistical criteria were used to evaluate the performance of both models in estimating discharge and sediment concentration. Comparison of the results reveals that, in general, the neuro-fuzzy model gives better estimates than the multi-linear regression model in terms of root mean square and sum of squares errors. Furthermore, compared with the multi-linear regression model, the neuro-fuzzy model yields statistical properties of estimates that are closer to actual historical data.
Implications of Donor Disseminated Intravascular Coagulation on Kidney Allograft Recipients
Authors: Wang Connie J. , Shafique Shahzad , McCullagh Johanna , Diederich Dennis A. , Winklhofer Franz T. , Wetmore James B.
Published: March 2011

Background and objectives

Disseminated intravascular coagulation (DIC) is common in deceased kidney donors and is considered a relative contraindication to donation. The significance of donor DIC on recipient kidney function is poorly understood. Additionally, the significance of thrombocytopenia in recipients of kidneys from DIC-positive donors is understudied.

Design, setting, participants, & measurements

In a retrospective cohort of 162 kidney transplants, the presence of DIC in donors, the occurrence of thrombocytopenia in recipients, and risk factors for delayed or slow graft function (DGF/SGF) were assessed. The effects of DIC donor status on DGF/SGF in the study sample as a whole, and of thrombocytopenia on DGF/SGF in recipients of DIC-positive kidneys specifically, were examined using multiple logistic regression.

Results

DIC donor status was not associated with occurrence of DGF/SGF, but thrombocytopenia was significantly associated with DIC-positive donor status (P = 0.008). Thrombocytopenia was independently associated with DGF/SGF only in the recipients of DIC-positive kidneys (P = 0.005). Patient and graft survival at 1 year were not affected by donor DIC status or by thrombocytopenia status.

Conclusions

Donor DIC was not associated with short-term suboptimal graft function, defined as DGF/SGF, nor with long-term patient or graft survival. However, thrombocytopenia appears to portend DGF/SGF in recipients of DIC-positive kidneys and may be a clinical sign on which the basis of therapeutic decisions could be undertaken.
Excitatory amino acid beta-N-methylamino-L-alanine is a putative environmental neurotoxin
Authors: Lopicic Srdjan , Stanojevic Marija , Dhruba Pathak , Pavlovic Dragan , Prostran Milica , Nedeljkov Vladimir
Published: March 2011

The amino acid beta-N-methylamino-L-alanine (L-BMAA) has been associated with
the amyotrophic lateral sclerosis/parkinsonismdementia complex in three
distinct western Pacific populations. The putative neurotoxin is produced by
cyanobacteria, which live symbiotically in the roots of cycad trees. L-BMAA
was thought to be a threat only to those few populations whose diet and
medicines rely heavily on cycad seeds. However, the recent discovery that
cyanobacteria from diverse terrestrial, freshwater, and saltwater ecosystems
around the world produce the toxin requires a reassessment of whether it
poses a larger health threat. Therefore, it is proposed that monitoring
L-BMAA levels in cyanobacteria-contaminated water supplies might be prudent.
Crystal structure of an oxalate-bridged tetranuclear 8-hydroxyquinoline Zn(II) cluster: [Zn4Q6(Ox)]0.5n
Authors: Wang Jiajun , Wang Qiang , Sun Yanjun , Wang Yuemei , Zhao Guosheng , Cui Yuncheng
Published: March 2011

The chain structure of a tetranuclear zinc(II) cluster [Zn4Q6(Ox)]0.5n ([Zn4
(C9H6NO)6(C2O4)]0.5n) (1) (Q = 8- hydroxyquinoline anion, Ox = oxalate
dianion) was determined by X-ray crystallography and characterized by
elemental analysis, IR spectroscopy and thermal analysis. It crystallizes in
the monoclinic system, space group P21/n (No. 14), with the lattice
parameters a = 13.2222(15) ?, b = 11.0566(12) ?, c = 16.2224(18) ?, ? =
92.1770(10)?, V = 2369.9(5) ?3, Z = 4, Mr = 607.23 g mol-1, Dc = 1.702 g
cm-3. The tetranuclear zinc(II) clusters form 1D polymeric chains parallel to
the b-axis. The ?-? stacking interactions involving aryl rings support the
formation of the 1D polymeric structure. The neighboring polymeric chains are
connected by C-H???? interactions.
Medico-legal Study of Suspected Homicide Cases in a Teaching Hospital in Eastern Nepal
Authors: Karn A , Jha S , Yadav BK , Thakur D
Published: March 2011

Introduction: Homicide means killing of one human being as a result of conduct of another human being. This study of medico-legal and epidemiological details of homicidal cases would help in enhancement of various stakeholders in law enforcing agencies with the view to benefit the process of scientific crime detection and proper administration of justice at large. Objective: To identify the various medico-legal and epidemiological factors involved in homicide. Materials and method: A prospective cross-sectional study was conducted in fatal homicide victims brought for medico-legal autopsy in BPKIHS, during the period of 15th April 2009 to 14th July 2010.Data were collected using pre tested questionnaire by direct interview to the visitors of victim, information from the police record along with postmortem examination of the victim. Results: Out of the total 50 cases, the ratio of male to female victim was 4:1. More than half of the victims were of age 21-40 years (52%). More of the homicide victims were of rural areas (56%) and illiterate (32%). Injuries by sharp weapon were most common cause of death (36%) very closely followed by firearm injuries (34%). Most of the victim remained totally deprived of any medical help (60%). Conclusion: The homicide victims in eastern Nepal constituted illiterate adult male from rural area a dominant group. Sharp weapons were commonly employed in this region for homicide. Fatality of the victim can be highly minimized if medical and surgical interventions are be promptly prearranged. Proper counselling for developing positive attitude and controlling the aggression in youth have to be Promoted at large by the government. Keywords: Homicide; Medico-legal; sharp weapon injury; firearm injury DOI: 10.3126/hren.v9i1.4356Health Renaissance, 2011: Vol.9 No.1:15-19
Safety Profile of Imatinib in Indian Chronic Myeloid Leukemia Patients
Authors: Meena R , Biswas NR , Kumar Lalit , Velpandian T , Gupta YK
Published: March 2011

Introduction: Imatinib mesylate has become the choice of drug in the treatment of chronic myeloid leukemia. Objective: To study safety profile of Imatinib (specific inhibitor or bcrabl tryosne kinase protein) in Philadelphia chromosome t {(9:22), bcr-abl} positive chronic myeloid leukemia (CML) chronic phase patients. Materials and Methods: After IEC clearance, 36, BCR-ABL positive CML patients in the chronic phase of the disease were recruited. Imatinib mesylate (Gleevec, Novartis), was started (400mg daily) and followed up weekly in first month, two weekly till three months & monthly thereafter. Safety profile data, recorded in pre-designed proforma, were analyzed for time of onset, duration and severity of adverse effects. Causality relationship of recorded adverse events was established with imatinib therapy using WHO-UMC criteria. Results: A total of 222 adverse events were reported in 36 CML-CP patients over 12 months of follow up. Thrombocytopenia was the most commonly reported in 60% of the patients followed by musculoskeletal (17%), dermatological (16%), gastrointestinal disturbances (13%), body weight changes (11%), superficial edema (8%) and liver enzyme rise (4%). More than 80% events reported within months of therapy which persisted for less than 3 months in most of the cases. No treatment was needed in 68% of cases while therapy alteration was not needed in 88% of cases. Most of the reactions (60%) had probable relationship with the therapy. Conclusion: Imatinib was well tolerated, having only mild to moderate grade of toxicities, mostly within 3 months of therapy and most of them persisted for less than 3 months of duration, requiring only symptomatic treatment and drug withhold or dose decrement in only few cases. Keywords: Safety profile; imatinib; causality assessment; adverse events. DOI: 10.3126/hren.v9i1.4358Health Renaissance, 2011: Vol.9 No.1:24-30
Principles of Smile Analysis in Orthodontics- A Clinical Overview
Authors: Singh Varun Pratap , Sharma JN
Published: March 2011

"It all begins with a smile" is a proverb which, highlights the importance of smile in social outlook and quality of life. With the face first paradigm, orthodontics has put more emphasis on the dental and facial appearance as it has a direct psychosocial impact. Modern orthodontics deals with not only the traditional dental and skeletal aspects but soft tissue drape or face as first priorty.Orthodontic treatment planning must incorporate various principles of smile analysis to achieve desirable results. This article describes principles of smile analysis that should be considered during orthodontic treatment planning and various attributes of a pleasing smile. Keywords: smile analysis; esthetic paradigm; smile arc DOI: 10.3126/hren.v9i1.4360Health Renaissance, 2011: Vol.9 No.1:35-40
Extra-skeletal (periosteal Ewing's sarcoma) Ewing's sarcoma of distal femur of right leg in a 10 year old boy - A case report
Authors: Chaudhary P , Karn NK , Shrestha BP , Khanal GP , Maharjan R
Published: March 2011

Extra-skeletal Ewing's sarcoma is quite uncommon.The most common locations of Ewing's sarcoma of bone include metaphysis and diaphysis of long bones and flat bones of shoulder and pelvic girdles. Here, we present a case of a 10 year-old school-going boy who had presented to the Orthopaedic Depatment of B.P.Koirala Institute of Health Sciences, Dharan, Nepal with the complaint of pain and swelling of pasterior aspect of disfal fourth of right thigh. Considering its rarity, we thought that this case needs to be reported. Keywords: Skeletal; Periosteum; Tumor; Sarcoma; Wide excision DOI: 10.3126/hren.v9i1.4364Health Renaissance, 2011: Vol.9 No.1:50-53
Time to Act: Set Up for Non-Invasive ventilation in Tertiary Care Hospital
Authors: Dhakal SS , Bhatta N , Rijal S
Published: March 2011

DOI: 10.3126/hren.v9i1.4365Health Renaissance, 2011: Vol.9 No.1:54-55
Preparation of electrospun titania nanofibers
Authors: Dong Hongying , He Xiaodong , Teng Yingyue , Song Fengyu , Ma Wen
Published: March 2011

In this study, titanium dioxide (TiO2) nanofibers with diameters ranging from 200–500 nm are successfully prepared via an electrospinning technique using a solution that contains polyvinyl pyrrolidone (PVP) and tetrabutyl titanate (TBT). Three key processing parameters are evaluated on the morphology of the fibers formed. Firstly, the PVP: TBT molar ratio is strongly correlated with the morphology of the fibers formed, and two extremes in the fiber morphology are observed as a result of varying the PVP: TBT molar ratio. Secondly, the electric field strength has been found to most strongly affect the fiber diameter, which increases as the electric field strength increases. Thirdly, the electrospun TiO2/PVP composite nanofibers are calcined at different temperatures. The process of removing organic components, the phase formation and the phase transition of the inorganic TiO2 are investigated using thermo-gravimetry–differential scanning calorimetry, infra-red and X-ray diffraction analyses.
Influence of oxygen partial pressure on the growth of Al-doped zinc oxide films by reactive MF magnetron sputtering
Authors: Hong Rui-jiang , Jiang Xin
Published: March 2011

Aluminum-doped zinc oxide thin films have been fabricated by reactive mid-frequency magnetron sputtering from Zn/Al metallic targets (Al 2 wt.%) with a dual magnetron (TwinMag™) configuration. The dependence of the structure, composition, electrical and optical properties of the films on the oxygen partial pressure has been investigated. It is shown that films with low resistivity and high optical transmittance could only be deposited under a narrow range of oxygen partial pressure. The film prepared at a partial pressure of 25 mPa exhibited highly c-axis oriented growth and a lowest resistivity of 4.6 · 10−4 Ω cm.
Phase equilibria studies in alumina-containing high zinc fayalite slags with CaO/SiO2 = 0.55 Part 1
Authors: Zhao Baojun , Hayes Peter C. , Jak Evgueni
Published: March 2011

The phase equilibria and liquidus temperatures in the ZnO–“FeO”–Al2O3–CaO–SiO2 system in equilibrium with metallic iron have been determined experimentally in the temperature range 1343 to 1553 K and for compositions relevant to a number of different non-ferrous smelting slags. The results are presented in the form of a pseudo-ternary section ZnO–“FeO”–(Al2O3 + CaO + SiO2) with CaO/SiO2 = 0.55 and (CaO + SiO2)/Al2O3 = 7.0. It was found that wustite and spinel are the major primary phases in the composition range investigated. Wustite (Fe2+, Zn)O and spinel (Fe2+, Zn)O · (Al, Fe3+)2O3 solid solutions are formed in this system, and the ZnO in slag partitions preferentially to the spinel phase.
Banded structures in dual-phase steels – A novel characterization method
Authors: Krebs Benoit , Germain Lionel , Gouné Mohamed , Hazotte Alain
Published: March 2011

A simple to implement and original automated method is presented to quantify the intensity and wavelength of “banded structures”, i. e. microstructures presenting irregular and parallel bands enriched in a given phase. This method is based on the analysis of the covariance function of binary images. It is firstly tested on model representative images. It is compared with a conventional method derived from the ASTM E-1268 standard and appears to present a higher robustness with regard to preparation artifacts. Then, it is applied to real microstructures of dual-phase steels, which show more or less regular martensite-enriched bands in a ferrite matrix. The method is capable of efficiently discriminating dual-phase microstructures resulting from different thermo-mechanical routes.
Temperature dependence of rapidly thermally annealed Ba0.6Sr0.4TiO3 thin film fabricated on platinized Si substrate
Authors: Lou Jian-Zhong , Sun Jie , Chen Jiang-En , Li Xiao-Hong , Zhao Qing-Xun , Zhang Xiang-Yi , Liu Bao-Ting
Published: March 2011

Sol-gel prepared Ba0.6Sr0.4TiO3 (BST) thin films were prepared on platinized silicon substrate and annealed by rapid thermal annealing at temperatures ranging from 650 °C to 850 °C. X-ray diffraction, atomic force microscopy and electrical measurements were used to investigate the temperature dependence of the structural and physical properties of Ba0.6Sr0.4TiO3 thin film. The dielectric constants of BST samples annealed at 700 °C and 750 °C, measured at zero-bias electric field, are 166 and 193, respectively. It is found that all the prepared BST films show Ohmic-like conduction at low voltages except for the 650 °C annealed BST sample, for which Ohmic conduction covers the whole measured voltage range; BST films annealed at 700 °C, 750 °C and 800 °C demonstrate Poole–Frenkel emission conduction at high voltages, while BST film annealed at 850 °C presents Schottky emission behavior.