Synthesis and characterization of CaCoSi2O6 – Co2Si2O6 pyroxenes

This thesis concerns cobalt pyroxenes and it is mostly based on the join CaCoSi2O6-Co2Si2O6. This series has an interest both in Mineralogy and Ceramic Science. If we consider Mineralogy it is interesting to stress the analogy with the rock forming quadrilateral pyroxenes formed by diopside - enstatite (CaMgSi2O6 - Mg2Si2O6) and hedenbergite - ferrosilite (CaFeSi2O6 - Fe2Si2O6) series. Moreover, Ca,Co-pyroxenes (CaCoSi2O6-Co2Si2O6) provide a crystal chemical model to study the solid solutions of pyroxenes with a large ionic radius cation in the M2 site, such as diopside (CaMgSi2O6) and hedenbergite (CaFeSi2O6) and those with a smaller cation, such as enstatite, (Mg2Si2O6) and ferrosilite, (Fe2Si2O6). Regarding Ceramic Sciences Ca,Co-pyroxenes may be used as a ceramic pigment, with good chemical stability and colour properties, whose stability field and physical properties are poorly constrained. This work is dived in three parts. In an introductory first part, the use of cobalt as an industrial inorganic pigment is reported. Cobalt is an important colour agent, giving different hues, obtained by the different coordination number of this element in the structure. If cobalt is in tetrahedral coordination the colour is deep blue (e.g. blue cobalt pigment, based on CoAl2O4 spinel); otherwise, if the coordination number is higher, six or eight, the hue swings to pink (e.g. Co-olivine Co2SiO4, Ca,Co-pyroxenes (Ca,Co)Si2O6, or Co-garnet Co3Al2Si3O12). The possible use of Ca,Co-pyroxenes as a pigment is then introduced; being Ca,Co-pyroxenes a member of the pyroxene mineral family, and in view of planning subsequent experiments, phase equilibria in the closely related group of quadrilateral pyroxenes, constituents of most rock forming pyroxenes, are presented. The presence of a miscibility gap between Ca-rich and Ca-poor pyroxenes, and the coexistence at low pressure of non-pyroxene phases are reported and discussed. The detailed crystal structure of pyroxenes has been then shown, for monoclinic and orthorhombic pyroxenes, in order to provide the basis for an interpretation of the Ca,Co-pyroxene properties at the atomic level. The different pyroxene varieties are related to the phase diagram stability conditions and crystal chemistry. In the second part, based on a ceramic approach, Co-pyroxenes are synthesized at room pressure, with particular attention to the end member or close to end member CoCaSi2O6: this composition is most promising for a possible use as pigment, being stable also at room pressure. The conditions at which the end member is stable as a single phase are sought, as the coexistence with other phases, mostly Co-ackermanite (Ca2CoSi2O7) significantly modifies the colour response of the mixture, from pink in pure Ca,Co-pyroxene, to blue if some Co-ackermanite is present. The colorimetric properties of the mixtures obtained at room pressure for the starting materials along the CaCoSi2O6-Co2Si2O6 series, are also determined at different temperature, relating the colour effect to the percentage of the phases. In the third part we use a mineralogical crystal chemical approach: a series of pyroxenes with compositions spanning along the CaCoSi2O6-Co2Si2O6 join are synthesized at high pressure and characterized to understand the effect of Ca with Co substitution on the crystal-chemical and physical properties of pyroxenes. A pyroxene only phase-diagram is obtained: the observed miscibility gap and the phase transition between C2/c and P21/c pyroxenes are compared with those of quadrilateral pyroxenes and related to the structural changes obtained by single crystal investigation. The results constrain the chemical properties of pyroxenes, discussing the general point of the substitution of a smaller cation vs a larger one in pyroxenes in view of a simple ionic model. The crystal structure, the symmetry variations, the phase diagram, and the physical properties of the Co-pyroxenes are analyzed by means of a multi-technique approach, using X-Ray Diffraction (powder and single crystal), Transmission and Scanning Electron Microscopy with Energy Dispersive System analysis and Raman micro-spectroscopy

The contribution of archeometry in characterization of decorative materials from the site of Villa di Teodorico in Galeata (Italy)

Villa di Teodorico in Galeata (Forlì-Cesena, Emilia Romagna) is an important archeological site in the north of Italy occupied from sixth century BC to twelfth century AD. The most interesting results concern the Roman age, when a large villa was built, and the late antiquity, when the Ostrogothic king Theodoric decided to build in this area his palatium (early sixth century AD). The archeometric investigation was performed on Roman wall paintings fragments and on late antique glass sectilia fragments belonging to Palazzo di Teodorico by using a multi-technique approach that included micro-Raman spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, X-ray powder diffraction, UV–visible–NIR diffuse reflectance spectrophotometry with optic fibers and optical stereo-microscopy. This analytical approach allowed the identification of all components, collecting molecular, elemental, microscopic, morphological and chromatic data. The characterization of samples supplied essential archeological, historical and technological information. The production techniques and the rich materials employed suggest the importance of the site in different periods. The evolution of the manufacturing technologies and the possible trade routes mainly during late antique period are witnessed by the change in the raw materials. Graphical abstract: [Figure not available: see fulltext.]

O PAPEL SOCIAL DA MULHER EM ESTÁTUAS DE SAL, DE EVEL ROCHA

The historical records show that to gain social prestige the woman faced many struggles. The light of the literary work of Rocha (2003), author cabo-verdiano, who narrates the adventures of a family salense, and presents us feminine symbolic characters that allows a reflection about the social role of Cabo-Verdiana woman, who since colonial period fights for justice, intends to analyze the conduct of the feminine, figures of the work Estátuas de Sal (2003), who represent the roles of mother, daughter, wife, head of family, etc. In the central proposal of this work it was observed that the female characters live in a colonialist and patriarchal society. However, some characters achieve financial, psychological autonomy with the possibility of gaining their own recognition and thereby mastering the meaning of life itself. In this understanding, it is plausible to note a dialogue with the reality experienced by many women in the history of humanity. This work was carried out through the bibliographic method, which used essentially the theoretical contributions of Candido (2011), Hirata (2009), Alves (2007), that were of great importance for the analyzes of the novel of Evel Rocha and later construction of meanings.Os registros históricos mostram que para obter prestígio social a mulher enfrentou muitas lutas. A luz da produção literária de Rocha (2003), autor cabo-verdiano, que narra as peripécias de uma família salense, e, nos apresenta personagens femininas simbólicas que possibilita uma reflexão acerca do papel social da mulher cabo-verdiana, que desde período colonial luta por justiça, pretende-se analisar a conduta das figuras femininas da obra Estátuas de Sal (2003), que representam os papeis de mãe, filha, esposa, chefe de família, etc. Na proposta central deste trabalho observou-se que as personagens femininas vivem em uma sociedade colonialista e patriarcal. Contudo, algumas personagens conseguem autonomia financeira, psicológica com a possibilidade de obter o próprio reconhecimento e, desse modo, dominar o sentido da própria vida. Neste entendimento, é plausível notar um diálogo com a realidade experimentada por muitas mulheres na história da humanidade. Este trabalho foi realizado através do método bibliográfico, que utilizou essencialmente as contribuições teóricas de Candido (2011), Hirata (2009), Alves (2007), que foram de grande importância para as análises do romance de Evel Rocha e posterior construção de significados

Educação On-line na Cibercultura: Desafio de literaturalizar a ciência em E-book

O artigo discute os desafios da educação on-line na cibercultura. Evidenciamos que, apesar desse contexto tecnologizado, ainda há muitas críticas em relação à educação on-line referente às concepções paradigmáticas, epistemológicas e metodológicas. Nesse sentido, discutimos o desenvolvimento de práticas pedagógicas decorrentes de um e-book que articula conhecimentos e Tecnologias Digitais. No contexto do grupo de pesquisa COTEDIC UNILASALLE/CNPq, emerge a questão: Como ressignificar os recursos utilizados na educação on-line para potencializar a aprendizagem? Considerando a emergência dessa reflexão, desenvolvemos uma pesquisa exploratória a fim de refletir e superar as tensões vivenciadas em relação ao uso de e-books na educação on-line. Para tanto, encontramos na literaturalização da ciência possibilidades de estabelecer metáforas na construção do conhecimento, desenvolver processos criativos e utilizar múltiplas linguagens, potencializando a aprendizagem dos estudantes na utilização de recursos para educação on-line. Portanto, destacamos a necessidade de ressignificar as práticas pedagógicas em congruência com o contexto contemporâneo

Experimentar Artaud: sobre a cartografia como metodologia de pesquisa e investigação artística em artes cênicas

Um dos aspectos mais importantes de uma investigação artística é a necessidade de utilização da metodologia de pesquisa mais apropriada a cada caso. Quando se trata das Artes Cênicas, que somente na segunda metade do século XX ganharam força enquanto campo independente do saber, essa necessidade se faz ainda mais fremente –e metodologias adequadas que deem conta do processo criativo do ator-pesquisador ainda estão em fase de consolidação. Neste trabalho, através de um estudo de caso, pretendemos investigar a Cartografia como metodologia possível para a pesquisa baseada em artes na área das Artes Cênicas. O Estudo de caso aborda alguns aspectos da Oficina de Criação realizada, ao longo de um semestre letivo, no âmbito da Universidade Federal de Ouro Preto (UFOP/ Brasil). O referencial teórico utilizado engloba autores como Antonin Artaud, Gilles Deleuze Jacques Derridae Sueli Rolnik. Nesta disciplina, ministrada pelas autoras, proposições artísticas para uso da voz e do corpo, extraídas do pensamento artaudiano para criação de um ‘novo teatro’ no século XX, foram experimentadas pelos alunos e mapeadas em sua evolução até a apresentação das cenas/performances finais, que encontram neste artigo a discussão de alguns aspectos observados.One of the most important aspects of an artistic research is the need to use the most appropriate research methodology to each case. When it comes to the Performing Arts, which have gained strength in the latter half of 20th Century as an independent field of knowledge, this need becomes even more frequent –and the appropriate methodologies that take the creative process of the actor as researcher into account are still at a consolidation stage. In this work, through a case study, we intend to investigate Cartography as a possible methodology for research based on arts in the Performing Arts field. The Case Study addresses some aspects of the Creation Workshop held during a semester at the Federal University of Ouro Preto (UFOP / Brazil). The theoretical reference includes authors like Antonin Artaud, Gilles Deleuze Jacques Derrida and Sueli Rolnik. In this course, given by the authors, artistic propositions for the use of voice and body, extracted from the Artaudian thought for the creation of a ‘new theatre’ in the twentieth century, were experimented by the students and mapped in their evolution until the presentation of the final scenes / performances. This paper discusses some observed aspects of the process

Micro-Raman mapping of the polymorphs of serpentine

Serpentinites are rocks, often used in buildings, formed in large extent by minerals of the serpentine group: chrysotile, antigorite, lizardite, and polygonal serpentine. The fibrous type (e.g. chrysotile) of serpentine group minerals, along with several amphibole varieties (e.g. actinolite and tremolite), are the major components of asbestos family. The exposure to fine fibrous asbestos powder is linked to diseases such as pleural mesothelioma and asbestosis. The identification of the main varieties of the serpentine group, laminated or fibrous, becomes an issue of great interest for public health. This work introduces an analytical strategy able to distinguish the different serpentine polymorphs directly on the sample, allowing the analysiswithin their textural environment, evidencing at themicrometer scale the mineral reactions of the phases. Samples coming from the Koniambo massif (Grande Terre Island, New Caledonia) were studied by means of optical microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, and Raman spectroscopy. Raman peaks observed in the high wavenumber spectral range of 3550–3850 cm-1, associated with OH stretching vibrations, allow the iscrimination of the all four serpentine varieties. The relationship between the different varieties of serpentine, at a micrometric scale, in complex samples, has been investigated by two-dimensional Raman mapping

Health Technology Assessment on the use of the Wearable Cardioverter Defibrillator in Patients with Myocardial Infarction and with ICD Explant

The objective of the present work is to conduct a Health Technology Assessment (HTA) on the use of the Wearable Cardioverter Defibrillator (WCD) in patients at risk of Sudden Cardiac Arrest (SCA) following Myocardial Infarction (MI) or with an explanted Implantable Cardioverter Defibrillator (ICD)

Obsessive Compulsive Tic Disorder: appropriate diagnosis and treatment as key elements to improve health and rationalize use of resources

Background: Obsessive Compulsive Tic Disorder (OCTD) has been described recently as an early onset and highly disabling endophenotype of Tic Disorder and Obsessive Compulsive Disorder. OCTD has a relevant but largely unknown clinical, social and economic burden for patients and their families. Our paper aimed to explore relevant aspects of the burden of OCTD. Methods: we conducted a literature review and a pilot study using retrospective demographic, clinical and economic data of patients with OCTD accessing the Galeazzi Hospital in Milan. Results: the literature review shows the absence of information on OCTD. From the pilot study we analysed data of 30 patients (80.0% male, 36.7% aged from 7 to 13 years, 63.3% aged from 15 to 48 years), 83.0% declared that obsessions and/or compulsions were the most important factors determining their social impairment. Adult patients refractory to drug treatment underwent Deep Brain Stimulation plus drugs. The mean clinical scores at the time of diagnosis indicated a severe condition for both tics and obsessive compulsive components. The mean time elapsed from symptoms onset to diagnosis of OCTD was 5.6 years, reaching up to 11 years in one case. Before reaching the correct diagnosis, different specialists visited the patients several times, 93.3% underwent diagnostic examinations and 86.7% took 2 or 3 different drugs. Ten patients were hospitalised and 8 had received psychotherapy. Discussion: Albeit preliminary, these results show that attention is mandatory for establishing correct diagnosis and treatment guidelines to improve health and rationally spend resources for OCTD

Esterase screening using whole cells of Brazilian soil microorganisms

A miniaturized enzymatic assay using fluorescent probes to reveal esterase producing microorganisms was optimized and applied to screen 64 soil bacterial strains. The best results were validated using traditional non-fluorogenic assays with acetyl and propanoyl phenylethanol to confirm the miniaturized results. The most active microorganisms belong to the genus Bacillus showing esterase activity and good enantiomeric ratios for the resolution of phenylethanol derivatives (E > 30). Part of the microorganisms are kept in our laboratory in glycerol or freeze-dried and the best microorganisms will be deposited in the CBMAI/CPQBA/Unicamp culture collection.Um ensaio enzimático miniaturizado com sondas fluorescentes para triagem rápida de microrganismos produtores de esterases foi implementado e aplicado a 64 linhagens de bactérias de solo. Os melhores resultados foram validados por métodos convencionais e substratos não fluorogênicos (feniletanol acetilado e propanoilado) e confirmaram os resultados obtidos nas triagens rápidas. Os microrganismos que apresentaram atividades enzimáticas mais relevantes (razão enantiomérica E > 30) na hidrólise de ésteres e na obtenção de boas razões enantioméricas foram identificados como pertencentes ao gênero Bacillus. Parte dos microrganismos se encontra preservada em glicerol e/ou liofilizada no IQ/Unicamp e três linhagens serão depositadas na CBMAI do CPQBA/Unicamp como depósitos abertos.14841489Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES