Evaluation via multivariate techniques of scale factor variability in the rietveld method applied to quantitative phase analysis with X ray powder diffraction

ABSTRACT: The present work uses multivariate statistical analysis as a form of establishing the main sources of error in the Quantitative Phase Analysis (QPA) using the Rietveld method. The quantitative determination of crystalline phases using x ray powder diffraction is a complex measurement process whose results are influenced by several factors. Ternary mixtures of Al2O3, MgO and NiO were prepared under controlled conditions and the diffractions were obtained using the Bragg-Brentano geometric arrangement. It was possible to establish four sources of critical variations: the experimental absorption and the scale factor of NiO, which is the phase with the greatest linear absorption coefficient of the ternary mixture; the instrumental characteristics represented by mechanical errors of the goniometer and sample displacement; the other two phases (Al2O3 and MgO); and the temperature and relative humidity of the air in the laboratory. The error sources excessively impair the QPA with the Rietveld method. Therefore it becomes necessary to control them during the measurement procedure.

Insights of meso and micro-scale processes for the Caxiuanã forest region from high resolution simulation

Dados meteorológicos e simulações numéricas de alta resolução foram usados para estimar campos espaciais na região leste da Amazônia onde se situam a Floresta e a Baía de Caxiuanã, no Estado do Pará. O estudo foi feito para o período de Novembro de 2006, quando foi realizado o experimento de campo COBRA-PARÁ. Análises de imagens do sensor MODIS mostram a ocorrência de vários fenômenos locais como avenidas de nuvens, sistemas convectivos precipitantes, e importante influência das interfaces entre a floresta e as superfícies aquáticas. Simulações numéricas para o dia 7 de novembro de 2006 mostraram que o modelo representou bem as principais variáveis meteorológicas. Os resultados mostram que a Baía de Caxiuanã provoca importante impacto nos campos meteorológicos adjacentes, principalmente, através da advecção pelos ventos de nordeste que induzem a temperaturas do dossel mais frias a oeste da baía. Simulações de alta resolução (LES) produziram padrões espaciais de temperatura e umidade alinhados com os ventos durante o período diurno e mudanças noturnas causadas principalmente pela presença da baía e chuvas convectivas. Correlações espaciais entre os ventos de níveis médios e os fluxos verticais de calor latente mostraram que existe uma mudança de correlações negativas para as primeiras horas do dia passando para correlações positivas para o período da tarde e início da noite.

Sintomas Mentais e Consumo de Álcool por Estudantes da UNESP, Instituto de Biociências de Rio Claro, S.P

Esta pesquisa teve como objetivo caracterizar os padrões de consumo de bebida alcoólica e a prevalência de indicadores de ansiedade e depressão, em universitários. Foram investigados 200 alunos, em série consecutiva, oriundos dos cursos de Biologia, Ecologia, Educação Física e Pedagogia. Os métodos consistiram na aplicação de escalas especializadas para verificação de padrões de consumo de álcool e sintomas de ansiedade e depressão, respectivamente, o SADD (Short Alcohol Dependence Data) e a HAD (Hospital Anxiety and Depression Scale). Os resultados mostraram que, dos 200 alunos, 17 (8,5%) apresentavam comportamento de uso abusivo de álcool, com riscos para a saúde física e mental. Ainda, 53 alunos (26,5%) revelaram indicadores positivos de ansiedade e 16 (8%), de depressão. Destes 53 alunos com indicadores positivos de ansiedade, 8 (15,1%) faziam uso abusivo de álcool e, dos 16 alunos com sintomas depressivos, 8 (50%) tinham comportamento de consumo abusivo de álcool, com riscos para a saúde física e mental. Os autores concluíram que o uso abusivo de álcool pode estar associado à presença de sofrimento psíquico, principalmente ansiedade e depressão. E propõem que se discuta a necessidade de criação de um Serviço de Saúde Mental para atendimento da comunidade universitária.

DNA for nano-bio scale computation of chemical formalisms using Higher Order Logic (HOL) and analysis using an interdisciplinary approach

Bio-molecular computing, 'computations performed by bio-molecules', is already challenging traditional approaches to computation both theoretically and technologically. Often placed within the wider context of ´bio-inspired' or 'natural' or even 'unconventional' computing, the study of natural and artificial molecular computations is adding to our understanding of biology, physical sciences and computer science well beyond the framework of existing design and implementation paradigms. In this introduction, We wish to outline the current scope of the field and assemble some basic arguments that, bio-molecular computation is of central importance to computer science, physical sciences and biology using HOL - Higher Order Logic. HOL is used as the computational tool in our R&D work. DNA was analyzed as a chemical computing engine, in our effort to develop novel formalisms to understand the molecular scale bio-chemical computing behavior using HOL. In our view, our focus is one of the pioneering efforts in this promising domain of nano-bio scale chemical information processing dynamics.

Scale morphology of Prochilodus lineatus with emphasis on the scale epithelium

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Large-Scale Water Productivity Assessments with MODIS Images in a Changing Semi-Arid Environment: A Brazilian Case Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nanometer Scale Titanium Surface Texturing Are Detected by Signaling Pathways Involving Transient FAK and Src Activations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spherical, cylindrical and tetrahedral symmetries; hydrogenic states at high magnetic field in Si:P

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Small-scale landfills: impacts on groundwater and soil

In Brazil, the large quantities of solid waste produced are out of step with public policies, technological developments, and government budgets for the division. In small municipalities, the common lack of technological knowledge and financial conditions for suitable waste disposal has resulted in a large number of illegal dumps. Therefore, small sanitary landfill facilities are working with simplified operations focusing on cost reduction and meeting the economic and technological standards of the city without endangering the environment or public health. Currently, this activity is regulated at a federal level although there is some uncertainty regarding the risk of soil and aquifer contamination as theses facilities do not employ liners. Thus, this work evaluates a small landfill to identify changes in soil and groundwater using geotechnical parameters, monitoring wells, and geophysical tests performed by electrical profiling. It is verified that based on current conditions, no contaminants have migrated via underground water aquifers, and overall no significant changes have occurred in the soil. It is concluded that, despite its simplicity, the method investigated is a viable alternative for the final disposal of municipal solid waste from small cities, especially in developing countries.

Multi-scale structural and chemical analysis of sugarcane bagasse in the process of sequential acid-base pretreatment and ethanol production by Scheffersomyces shehatae and Saccharomyces cerevisiae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and electronic analysis of the atomic scale nucleation of Ag on alpha-Ag2WO4 induced by electron irradiation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Broad-scale spatial patterns of canopy cover and pond morphology affect the structure of a Neotropical amphibian metacommunity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The quest for an intermediate-scale accidental axion and further ALPs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies angular correlation function

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Automatic Orientation of Multi-Scale Terrestrial Images for 3D Reconstruction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)