Thermoluminescence, electron paramagnetic resonance and optical absorption in natural and synthetic rhodonite crystals

Thermoluminescence, electron paramagnetic resonance and optical absorption properties of rhodonite, a natural silicate mineral, have been investigated and compared to those of synthetic crystal, pure and doped. The TL peaks grow linearly for radiation dose up to 4 kGy, and then saturate. In all the synthetic samples, 140 and 340 degrees C TL peaks are observed; the difference occurs in their relative intensities, but only 340 degrees C peak grows strongly for high doses. Al(2)O(3) and Al(2)O(3) + CaO-doped synthetic samples presented several decades intenser TL compared to that of synthetic samples doped with other impurities. A heating rate of 4 degrees C/s has been used in all the TL readings. The EPR spectrum of natural rhodonite mineral has only one huge signal around g = 2.0 with width extending from 1,000 to 6,000 G. This is due to Mn dipolar interaction, a fact proved by numerical calculation based on Van Vleck dipolar broadening expression. The optical absorption spectrum is rich in absorption bands in near-UV, visible and near-IR intervals. Several bands in the region from 540 to 340 nm are interpreted as being due to Mn(3+) in distorted octahedral environment. A broad and intense band around 1,040 nm is due to Fe(2+). It decays under heating up to 900 degrees C. At this temperature it is reduced by 80% of its original intensity. The pink, natural rhodonite, heated in air starts becoming black at approximately 600 degrees C.

Optical and dielectric relaxor behaviour of Ba(Zr(0.25)Ti(0.75))O(3) ceramic explained by means of distorted clusters

In this work, Ba(Zr(0.25)Ti(0.75))O(3) ceramic was prepared by solid-state reaction. This material was characterized by x-ray diffraction and Fourier transform Raman spectroscopy. The temperature dependent dielectric properties were investigated in the frequency range from 1 kHz to 1 MHz. The dielectric measurements indicated a diffuse phase transition. The broadening of the dielectric permittivity in the frequency range as well as its shifting at higher temperatures indicated a relaxor-like behaviour for this material. The diffusivity and the relaxation strength were estimated using the modified Curie-Weiss law. The optical properties were analysed by ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurements at room temperature. The UV-vis spectrum indicated that the Ba(Zr(0.25)Ti(0.75))O(3) ceramic has an optical band gap of 2.98 eV. A blue PL emission was observed for this compound when excited with 350 nm wavelength. The polarity as well as the PL property of this material was attributed to the presence of polar [TiO(6)] distorted clusters into a globally cubic matrix.

Preparation and structural characterization of rare-earth doped lead lanthanum zirconate titanate ceramics

A new preparation route towards rare-earth (RE) doped polycrystalline lead lanthanum zirconate titanate (PLZT) ceramics (RE = Y(3+), Nd(3+), Yb(3+)), based on the use of doped lanthanum oxide or zirconia, is reported. Structural characterization by X-ray powder diffraction reveals that secondary phase formation can be substantially diminished in comparison to conventional preparation methods. The distribution of the rare-earth dopants was investigated as a function of concentration by static (207)Pb spin echo NMR spectra, using Fourier Transformation of Carr-Purcell-Meiboom-Gill spin echo trains. For the Nd- and Yb-doped materials, the interaction of the (207)Pb nuclei with the unpaired electron spin density results in significant broadening and shifting of the NMR signal, whereas these effects are absent in the diamagnetic Y(3+) doped materials. Based on different concentration dependences of the NMR lineshape parameters, we conclude that the structural role of the Nd(3+) dopants differs significantly from that of Yb(3+). While the Nd(3+) ions appear to be statistically distributed in the PLZT lattice, incorporation of Yb(3+) into PLZT appears to be limited by the appearance of doped cubic zirconia as a secondary phase. (C) 2009 Elsevier Masson SAS. All rights reserved.

Structural and spectroscopic characterization of poly(styrene sulfonate) films doped with neodymium ions

This work reports the structural and spectroscopy characterization of poly(styrene sulfonate) (PSS) films doped with neodymium (Nd) ions. Nd-PSS films were processed using the acid of poly(styrene sulfonate) - H-PSS and neodymium nitrate - Nd(NO(3))(3); the maximum incorporation of Nd ions in the polymeric matrix was equal 19.3%. The absorption in the UV-Vis-NIR spectral region presents typical electronic transitions of Nd 3, ions, with well resolved peaks. The infrared spectra present the transition bands of PSS with characteristic line shape broadening, and the presence of vibrational modes of N-O groups in the range of 1400-720 cm(-1), prove the permanence of Nd(NO(3))(x), with x = 1, 2 and/or 3. in the H-PSS matrix. UV-Vis site selective photoluminescence data indicate that the incorporation of Nd 31 introduces a blue shift in PSS emission (325-800 nm), decreasing the interaction between adjacent PSS lateral groups (aromatic rings). Nd(3+) reabsorption and energy transfer effects between the PSS matrix and Nd(3+) were also observed. The IR emission of Nd-PSS films at 1076 rim ((4)F(3/2) -> (4)I(11/2)) present constant efficiency, independent on Nd(3+) concentration. The Judd-Ofelt theory was employed to analyze radiative properties. The excitation spectra prove the energy transfer between the polymeric matrix and Nd(3+). Complex impedance data was used to probe relaxation processes during the charge transport within the polymeric matrix. (C) 2008 Elsevier B.V. All rights reserved.

Evidence for magnetic phase separation in La(0.86)Sr(0.14)Mn(1-x)Cu(x)O(3+delta) manganites from NMR and magnetic measurements

Polycrystalline La(0.86)Sr(0.14)Mn(1-x)Cu(x)O(3+delta) (x = 0, 0.05, 0.10, 0.15, 0.20) manganites were investigated by means of magnetic measurements and zero-field (139)La and (55)Mn nuclear magnetic resonance (NMR) spectroscopy. Magnetization versus temperature measurements revealed a paramagnetic to ferromagnetic transition in most samples, with lower Curie temperatures and broader transitions for samples with higher Cu contents. The details of the magnetization measurements suggested a phase-separated scenario, with ferromagnetic clusters embedded in an antiferromagnetic matrix, especially for the samples with large Cu contents (x = 0.15 and 0.20). Zero-field (139)La NMR measurements confirmed this finding, since the spectral features remained almost unchanged for all Cu-doped samples, whereas the bulk magnetization was drastically reduced with increasing Cu content. (55)Mn NMR spectra were again typical of ferromagnetic regions, with a broadening of the resonance line caused by the disorder introduced by the Cu doping. The results indicate a coexistence of different magnetic phases in the manganites studied, with the addition of Cu contributing to the weakening of the double-exchange interaction in most parts of the material.

Peroxymonocarbonate and Carbonate Radical Displace the Hydroxyl-like Oxidant in the Sod1 Peroxidase Activity under Physiological Conditions

Despite being one of the most important antioxidant defenses, Cu,Zn-superoxide dismutase (Sod1) has been frequently associated with harmful effects, including neurotoxicity. This toxicity has been attributed to immature forms of Sod1 and extraneous catalytic activities. Among these, the ability of Sod1 to function as a peroxidase may be particularly relevant because it is increased in bicarbonate buffer and produces the reactive carbonate radical. Despite many studies, how this radical forms remains unknown. To address this question, we systematically studied hSod1 peroxidase activity in the presence of nitrite, formate, and bicarbonate-carbon dioxide. Kinetic analyses of hydrogen peroxide consumption and of nitrite, formate, and bicarbonate-carbon dioxide oxidation showed that the Sod1-bound hydroxyl-like oxidant functions in the presence of nitrite and formate. In the presence of bicarbonate-carbon dioxide, this oxidant is replaced by peroxymonocarbonate, which is then reduced to the carbonate radical. Peroxymonocarbonate intermediacy was evidenced by (13)C NMR experiments showing line broadening of its peak in the presence of Zn,ZnSod1. In agreement, peroxymonocarbonate was docked into the hSod1 active site, where it interacted with the conserved Arg(143). Also, a reaction between peroxymonocarbonate and Cu(I)Sod1 was demonstrated by stopped-flow experiments. Kinetic simulations indicated that peroxymonocarbonate is produced during Sod1 turnover and not in bulk solution. In the presence of bicarbonate-carbon dioxide, sustained hSod1-mediated oxidations occurred with low steady-state concentrations of hydrogen peroxide (4-10 mu M). Thus, carbonate radical formation through peroxymonocarbonate may be a key event in Sod1-induced toxicity.

Conformational Properties of Angiotensin II and Its Active and Inactive TOAC-Labeled Analogs in the Presence of Micelles. Electron Paramagnetic Resonance, Fluorescence, and Circular Dichroism Studies

The interaction between angiotensin II (AII, DRVYIHPF) and its analogs carrying 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid (TOAC) and detergents-negatively charged sodium dodecyl sulfate (SDS) and zwitterionic N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS)-was examined by means of EPR, CD, and fluorescence. EPR spectra of partially active TOAC(1)-AII and inactive TOAC(3)-AII in aqueous solution indicated fast tumbling, the freedom of motion being greater at the N-terminus. Line broadening occurred upon interaction with micelles. Below SDS critical micelle concentration, broader lines indicated complex formation with tighter molecular packing than in micelles. Small changes in hyperfine splittings evinced TOAC location at the micelle-water interface. The interaction with anionic micelles was more effective than with zwitterionic micelles. Peptide-micelle interaction caused fluorescence increase. The TOAC-promoted intramolecular fluorescence quenching was more, pronounced for TOAC(3)-AII because of the proximity between the nitroxide and Tyr(4). CD spectra showed that although both AII and TOAC(1)-AII presented flexible conformations in water, TOAC(3)-AII displayed conformational restriction because of the TOAC-imposed bend (Schreier et al., Biopolymers 2004, 74, 389). In HPS, conformational changes were observed for the labeled peptides at neutral and basic pH. In SDS, all peptides underwent pH-dependent conformational changes. Although the spectra suggested similar folds for All and TOAC(1)-AII, different conformations were acquired by TOAC(3)-AII. The membrane environment has been hypothesized to shift conformational equilibria so as to stabilize the receptor-bound conformation of ligands. The fact that TOAC(3)-AII is unable to acquire conformations similar to those of native AII and partially active TOAC(1)-AII is probably the explanation for its lack of biological activity. (C) 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 525-537, 2009.

”En aktiemarknad för alla” : Integritet och marknadsomsorg i (själv)regleringen av den svenska värdepappersmarknaden

”A stock market for all”. Integrity and concern for the market in the (self-)regulation of the Swedish securities market This article deals with the transformation process that led to the substantial growth of the securities markets, and also led to a situation where Sweden became one of the leading countries when it comes to ordinary people investing in shares and mutual funds. The article discusses how social control and regulation of the market changed as a result of this process. A sudden and strong unanimity for knowledge tests in order for a stockbroker to be allowed to conduct brokerage, advisory services and asset management was the significant change in this transformation process. Knowledge tests were first introduced on a voluntary basis by the industry itself, but is now a mandatory requirement by the State. This article argues that the unanimity for knowledge tests best can be understood by studying the broadening of the financial markets. The broadening meant that more groups in society – with very varying capabilities – had started to place their assets in the security markets. They were encouraged to do so since this was considered to be the solution to the growing number of socioeconomic problems. This article is mainly based on market statistics and document analysis supplemented by interviews.

Abilities and Cultural Understanding through Literature in the EFL Classroom : - A Literature Review

The English language can be seen as a lingua franca of contemporary times. Its spread and use in the globalized world has affected most levels of society and it can be argued that, in current times, English is synonymous with communication. This need for communication has shaped the English as a Foreign Language (EFL) syllabus, which is evident in the Swedish national steering documents for the educational system. For the upper secondary school these documents show an emphasis on communication, on cultural understanding, and also on the use of literature within the EFL classroom. The need to possess communicative abilities and cultural understanding, in connection with the use of literature, has sparked an interest to investigate if and how literature itself can be used as a tool to develop and improve EFL students’ communicative skills and cultural understanding. This literature review thesis analyzes five international research articles from different geographical parts of the Globe. The findings are categorized, compared, synthesized, and finally discussed in order to answer the research questions asked, and also compared with the English subject syllabus for the Swedish upper secondary school. The findings indicate that the analyzed articles share a consensus, to a varied degree, regarding the positive aspects of literature use in the EFL setting. The arguments are that communicative skills and cultural understanding are intertwined - enabling each other to exist, develop, and improve. One cannot exist fully without the other, and literature is a good tool to use to develop and improve these abilities. Literature can help develop all skills needed to acquire and produce both written and spoken English, and it also enables cultural understanding and a broadening of the mind. Where the articles differ somewhat is in the ideas of why literature is a good tool, how to implement literature in the classrooms, and what some of the negative aspects might be. The thesis also brings the lack of Swedish studies within EFL to the readers’ attention, as well as the need to do more research focusing on the students’ perspectives towards literature use in the EFL setting.

A Resource Centric Approach For Advancing Collaboration Through Hydrologic Data And Model Sharing

HydroShare is an online, collaborative system being developed for open sharing of hydrologic data and models. The goal of HydroShare is to enable scientists to easily discover and access hydrologic data and models, retrieve them to their desktop or perform analyses in a distributed computing environment that may include grid, cloud or high performance computing model instances as necessary. Scientists may also publish outcomes (data, results or models) into HydroShare, using the system as a collaboration platform for sharing data, models and analyses. HydroShare is expanding the data sharing capability of the CUAHSI Hydrologic Information System by broadening the classes of data accommodated, creating new capability to share models and model components, and taking advantage of emerging social media functionality to enhance information about and collaboration around hydrologic data and models. One of the fundamental concepts in HydroShare is that of a Resource. All content is represented using a Resource Data Model that separates system and science metadata and has elements common to all resources as well as elements specific to the types of resources HydroShare will support. These will include different data types used in the hydrology community and models and workflows that require metadata on execution functionality. The HydroShare web interface and social media functions are being developed using the Drupal content management system. A geospatial visualization and analysis component enables searching, visualizing, and analyzing geographic datasets. The integrated Rule-Oriented Data System (iRODS) is being used to manage federated data content and perform rule-based background actions on data and model resources, including parsing to generate metadata catalog information and the execution of models and workflows. This presentation will introduce the HydroShare functionality developed to date, describe key elements of the Resource Data Model and outline the roadmap for future development.

Análise das dificuldades de ação em equipe numa sociedade relacional: Paradoxos da Gestão no contexto brasileiro, o caso da consultoria ABC.

This study is an analysis of the nature of conflicts in highly qualified teams, searching for its causes and potential consequences for the teams¿ performance. The hypothesis is that establishing a power principle is of utmost importance to provide the team members with parameters for action as well as with an effective coordination, which may lead to the desired outcome. The problem under analysis herein is centered on teamwork, having in mind the growing complexity of the competences necessary for the organizations¿ success, in such a way that, if the human activities in these organizations are not cooperatively developed, the desired outcomes may be threatened. In this context it is perceived that many knowledge organizations lack adequate strategies and tools to promote adequate coordination of highly qualified workers, involved cooperatively in tasks of large intrinsic complexity. ABC Consulting is a particular instance of such problem, that may add to the understanding of the general problem of team work. This study takes into account the more general background of the Brazilian culture, which, in spite of broadening aspects such as social cordiality and the living in others (Holanda, 1995), does not lead naturally to quality teamwork. The research development is anchored in a methodology that combines both field and bibliographical work, with a qualitative approach in the scope of case study.

Accountability de organizações do espaço público não-estatal: uma apreciação crítica da regulação brasileira

Esta dissertação examina as organizações do espaço público não-estatal e suas relações de accountability com o Estado e com outros atores da sociedade, com o propósito de avaliar as necessidades e possibilidades de regulação para a responsabilização de tais organizações no Brasil. A partir de parâmetros normativos e acadêmicos internacionais, a pesquisa busca apreciar em que medida a regulação brasileira das organizações do espaço público não-estatal assegura ― e o que é necessário para que assegure ― a accountability destas organizações perante o Estado e a sociedade, indicando os principais méritos e falhas do correspondente aparato regulatório e apresentando possibilidades para seu aprimoramento. Esta análise salienta que apesar de tais organizações terem numerosos deveres de demonstrar sua probidade administrativa e financeira e as atividades executadas, são pouquíssimas as obrigações de comprovar o cumprimento dos resultados pretendidos. Além disso, depreende-se que o Estado detém amplos poderes para fiscalizar tais organizações e aplicar-lhes sanções, mas a sociedade como um todo tem consideravelmente menos oportunidades de demandar sua accountability. Isto evidencia a importância de tais organizações ampliarem seus deveres de transparência e de assegurar a prevalência do interesse público, de modo a garantir a qualquer cidadão a prerrogativa de fiscalizar as organizações do espaço público não-estatal.

Dinâmica de grupo: instrumento de transformação ou conservação?

O objetivo do presente estudo foi investigar se o Curso de Dinâmica de Grupo na Educação oferecido pelo NUTES/CLATES pôde trabalhar a capacidade de instituir (criar ou transformar) do professor-participante. Para alcançar este objetivo as seguintes questões foram colocadas: (lº) Ao buscarem o curso DGE os professores pretendiam ver satisfeitas que necessidades? (2ª) Até que ponto coordenadores e professores-participantes buscaram no curso DGE trabalhar sua capacidade de instituir? (3ª) Quais são os obstáculos detectados na literatura que poderiam limitar o atingimento do objetivo - trabalhar a capacidade de instituir - e que podem ser encontrados no curso DGE do NUTES/CLATES? Quanto a primeira questão, buscou-se resposta na análise das expectativas diante do curso DGE e avaliações realizadas após o seu término. A resposta a segunda questão foi feita especialmente a partir da análise dos protocolos de cada curso. Finalmente a terceira questão foi respondida de acordo com a visão de Lewin, Moreno, Rogers, Pages, Freud, Bion, e Loureau e Lapassade, estes últimos representando o movimento da Análise Institucional. Os resultados indicaram, em relação a primeira questão, que o curso foi buscado explicitamente por necessidades intelectuais de aprendizagem de técnicas e recursos didáticos e implicitamente por necessidades afetivas (identificadas nas comunicações interpessoais manifestadas durante a realização do curso DGE). Quanto a segunda questão, os resultados se ofereceram a uma dupla interpretação: se se fixa a realidade do grupo apenas no período do curso DGE pode-se afirmar que houve exercício da capacidade de instituir; se se aceita ao contrário que a realidade do grupo é a sua transversalidade que supera o "aqui e agora", a resposta seria que não se trabalhou a capacidade de instituir porque não houve busca de atuação na realidade através da análise da transversalidade. Os principais obstáculos detectados a partir da literatura que teriam limitado o trabalho da capacidade de instituir nos cursos DGE do NUTES/CLATES e que formalizam a resposta a terceira questão foram: o contexto social maior (Lewin); o não-trabalho do papel do professor (Moreno); a idealização do papel de chefe (Freud e Bion); o não enfoque das práticas sociais como reprodutoras de modelos impostos (Pages); o silêncio diante da transversalidade grupal (Lapassade e Loureau). Não se detectou obstáculos tendo Rogers como referência, na bibliografia pesquisada. As conclusões em numero de três foram: (1) reforçou-se a separação dos componentes afetivos e intelectuais do comportamento humano nos cursos DGE; (2) trabalhou- se a capacidade de instituir na medida em que o contexto social o permitiu; (3) os principais obstáculos foram tempo, organização social autoritária no Brasil, adoção de urna perspectiva mecanicista da dinâmica grupal. Frente aos resultados e conclusões sugeriu-se as seguintes modificações na realização de futuros DGE: (1) ampliação do "aqui e agora"; (2) visão dialética do processo grupal; (3) incorporação do conceito de transversalidade; (4) discussão das relações entre técnica e ideologia.

A importância da supervisão educacional junto as escolas da rede oficial no Estado do Rio de Janeiro - Município capital

O presente estudo tem como principal objetivo investigar a percepção de Diretores, Coordenadores e demais elementos da equipe administrativa das Unidades Escolares da Rede Oficial do Estado do Rio de Janeiro, Capital, quanto às funções do Supervisor Educacional, ligado à Secretaria de Educação e Cultura em nível de macro-sistema, e verificar a possibilidade de levar esta Supervisão a estes estabelecimentos de ensino a exemplo do que é realizado junto às Escolas da Rede Particular neste Município e nos demais Municípios do Estado, sendo que nestes últimos o trabalho já está sendo desenvolvido em todas as Escolas sejam pertencentes à Rede Particular ou á Rede Estadual. Tomaram parte no estudo 428 Diretores e 607 Coordenadores, totalizando 1035 informantes. Os dados foram coletados por meio de questionário. As hipóteses foram testadas e posteriormente analisadas podendo ser observado que Administradores, Coordenadores e demais elementos das equipes tecnico-pedagogicas em sua maioria, desconhecem o trabalho desenvolvido pela Supervisão Educacional. Observando-se, ainda, o que foi levantado e posteriormente testado, os Administradores admitem que haverá resistência, por parte dos Docentes, ao trabalho do Supervisor Educacional. Observando os dados apresentados, comparando-os com o que foi coletado através da literatura, pode ser verificado que, pelo fato de ser pouco conhecido o verdadeiro trabalho desempenhado pela Supervisão Educacional, o aspecto positivo que representa para o desenvolvimento de toda a estrutura educativa fica prejudicado, privando o contexto educacional de auxílio de capital importância. Concluindo, pode-se dizer que se faz necessário um trabalho de esclarecimento junto aos elementos que constituem as equipes tecnico-administrativas e pedagógicas,no sentido de um conhecimento efetivo das funções exercidas pelo Supervisor Educacional, que é, em verdade, mais um elemento técnico dentro da equipe, que pode ser útil à medida que emana do ápice da pirâmide administrativa, percorre os diversos níveis e permite manter o desempenho do sistema dentro de padrões estabelecidos e estimula desempenhos novos, que possibilitem, por sua vez, o estabelecimento de novos padrões.

Projetos de memória e imagem institucional: um estudo de caso do Banco Itaú

Fenômeno que tem sofrido um crescimento considerável nas últimas décadas, a constituição de projetos de memória empresarial se insere em um panorama mais amplo de valorização do passado na sociedade contemporânea, caracterizada pela 'febre da memória'. Parte de um expediente que tem como objetivo final fortalecer a identidade e a imagem dessas instituições entre seus funcionários e o público mais amplo, essas iniciativas têm gerado diferentes produtos e linhas de ação, sendo inicialmente vinculadas às áreas de marketing e comunicação, mas mostrando sinais de profissionalização e ampliação dos seus horizontes. O presente estudo tomou como objeto de análise o projeto memorial do Banco Itaú, criado em 2003, buscando compreender a natureza dessa iniciativa e de que maneira ela colabora na consolidação da imagem de 'vocação' cultural do Banco.