Measurement of atmospheric formaldehyde using a drop collector and in-situ colorimetry

A sensitive and affordable approach is described for the in-situ measurement of ambient formaldehyde. Air is sampled around a 100 microliter aqueous drop containing 3-methyl-2-benzothiazoline hydrazone. After a desired period of sampling (typ. 5 min) and a waiting period of 10 min for the reaction to be completed, a second reagent (FeCl3) is added to the drop by means of a conjoined conduit. A blue product is formed and is read after an additional 10 min of reaction by a fiber-optic/light emitting diode based photodetector. A fresh drop is then formed and the process begins anew. As demonstrated here, the limit of detection is similar to 6.25 mu g m(-3) HCHO but can be significantly improved by using longer sampling times and a sampling rate higher than 100 mi min(-1) used in most of this work. This is the first example of a chromogenic drop sensor that utilizes sequential reagent addition.

MONTE-CARLO SIMULATION OF POLYAMPHOLYTE CHAINS

Polyampholyte copolymers containing both positive and negative monomers regularly dispersed along the chain were studied. The Monte Carlo method was used to simulate chains with charged monomers interacting by screened Coulomb potential. The neutral polyampholyte chains collapse due to the attractive electrostatic interactions. The nonneutral chains are in extended conformations due to the repulsive polyelectrolyte effects that dominate the attractive polyampholyte interactions. The results are in good agreement with experiment.

Synthesis and structural studies of (1,10-phenanthroline)(thiocyanate-N)-(triphenylphosphine)copper(I)

The compound (1,10-phenanthroline)(thiocyanate-N)(triphenylphosphine)copper(I), was synthesized and studied by IR spectroscopy and X-ray diffraction techniques. It is monomeric with the thiocyanate acting as a N-donor ligand. The copper atom shows a distorted tetrahedral coordination geometry.

Multiresidue analysis of pesticides in water from rice cultures by on-line solid phase extraction followed by LC-DAD

An automated on-line solid phase extraction procedure followed by liquid chromatography with diode array detection was investigated for the determination of different classes of pesticides in water samples containing varied amount of humic substances. The different pesticides used were: carbendazin, carbofuran, atrazine, diuron, propanil, molinate, alachlor, parathion-ethyl, diazinon, trifluralin and the degradation products deisopropylatrazine and deethylatrazine. Humic substances extracted from a Brazilian sediment were used from 5 to 80 mg/l and their influence on recoveries was evaluated in neutral and acidic media. Recoveries higher than 70% were obtained for all the pesticides, from the preconcentration of 75 mi of aqueous sample fortified at 2 ng/ml using precolumns packed with PLRP-S. Good recoveries were obtained at neutral pH for most of the analytes up to 40 mg/l of humic acid. Only at 80 mg/l the recoveries were significantly affected, both at acidic and neutral pH. The method was applied to the determination of pesticides in river water spiked at 0.1 to 1 ng/ml. Detection limits obtained for water containing 10 mg/l of humic acid were between 0.05 and 0.3 ng/ml.

Analysis of the ethical aspects of professional confidentiality in dental practice

From the point of view of deontological ethics, privacy is a moral right that patients are entitled to and it is bound to professional confidentiality. Otherwise, the information given by patients to health professionals would not be reliable and a trustable relationship could not be established. The aim of the present study was to assess, by means of questionnaires with open and closed questions, the awareness and attitudes of 100 dentists working in the city of Andradina, São Paulo State, Brazil, with respect to professional confidentiality in dental practice. Most dentists (91.43%) reported to have instructed their assistants on professional confidentiality. However, 44.29% of the interviewees showed to act contradictorily as reported talking about the clinical cases of their patients to their friends or spouses. The great majority of professionals (98.57%) believed that it is important to have classes on Ethics and Bioethics during graduation and, when asked about their knowledge of the penalties imposed for breach of professional confidentiality, only 48.57% of them declared to be aware of it. Only 28.57% of the interviewees affirmed to have exclusive access to the files; 67.14% reported that that files were also accessed by their secretary; 1.43% answered that their spouses also had access, and 2.86% did not answer. From the results of the present survey, it could be observed that, although dentists affirmed to be aware of professional confidentiality, their attitudes did not adhere to ethical and legal requirements. This stand of health professionals has contributed to violate professional ethics and the law itself, bringing problems both to the professional and to the patient.

Oxygen related defects excitation and photoconductivity dependence of SnO2 sol-gel films with several light sources

Since oxygen vacancies act as donors in SnO2, the electrical properties are related to deviation from stoichiometric composition. Depending on stoichiometry SnO2 can be highly insulating or may exhibit fairly high n-type conductivity. Since bandgap transitions are in the ultraviolet range, its photoconductivity is strongly dependent on the excitation source. We have measured variation of photoconductivity excitation with wavelength for tin dioxide grown by dip-coating sol-gel technique using several light sources: tungsten lamp, xenon, mercury and deuterium, and present selected results. The main band is obtained in the range 3-4eV according to light source spectrum in the ultraviolet range. The presence of oxygen in the cryostat also affects the spectrum since electron-hole pairs react with adsorbed oxygen specimens. © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.

Invex nonsmooth alternative theorem and applications

An invex constrained nonsmooth optimization problem is considered, in which the presence of an abstract constraint set is possibly allowed. Necessary and sufficient conditions of optimality are provided and weak and strong duality results established. Following Geoffrion's approach an invex nonsmooth alternative theorem of Gordan type is then derived. Subsequently, some applications on multiobjective programming are then pursued. © 2000 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.

On the solution of bounded and unbounded mixed complementarity problems

A reformulation of the bounded mixed complementarity problem is introduced. It is proved that the level sets of the objective function are bounded and, under reasonable assumptions, stationary points coincide with solutions of the original variational inequality problem. Therefore, standard minimization algorithms applied to the new reformulation must succeed. This result is applied to the compactification of unbounded mixed complementarity problems. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.

The production of statistical data and information in the Caribbean: proposals for increasing efficiency in this sphere

Includes bibliography

Com que corpo eu vou?: a beleza e a performance na construção do corpo midiático

Pós-graduação em Ciências da Motricidade - IBRC

Os desafios dos/as profissionais da Psicologia diante do imperativo da quebra de sigilo nos casos de violência sexual intrafamiliar vivenciada por crianças

Pós-graduação em Psicologia - FCLAS

Saúde entre o social, o científico e o jurídico: o abortamento de anencéfalos

Pós-graduação em Serviço Social - FCHS

Representações sociais da Psicologia do Trabalho: o olhar de formandos em Psicologia da Universidade Federal do Pará

Este estudo percorreu questões sociais contemporâneas que envolveram o Sujeito, o Trabalho e a Psicologia na perspectiva das Representações Sociais: A formação do psicólogo do trabalho na Universidade Federal do Pará. A pesquisa identificou a Psicologia do Trabalho na visão dos estudantes concluintes do curso de Psicologia da UFPA. Analisou-se as questões paradigmáticas que a área está inserida, as vivências dos formandos nos estágios supervisionados, a questão do trabalho como fonte de identidade e as mudanças da pós-modernidade para os futuros profissionais da Psicologia do Trabalho, assim como suas perspectivas no mercado profissional. Embasou-se em Serge Moscovici (1978, 2001, 2005, 2007) e na grande teoria das Representações Sociais-RS, e em Denise Jodelet (2001, 2005, 2009) com a abordagem processual em Representações Sociais. As RS se inseriram como a teoria fundante da temática, que privilegiou as relações cotidianas a partir das comunicações humanas, que foram formadoras de representações, para a proposição de uma nova perspectiva da Psicologia Social. Optou-se pela pesquisa qualitativa e utilizou-se o Método da Explicitação do Discurso Subjacente – MEDS, para os instrumentos de coleta e análise de dados. As análises das representações apontaram para as diversas dificuldades encontradas pelos estudantes que buscavam os estágios: a substituição de atividades de estágio por pesquisas específicas sobre o mundo do trabalho e exercícios acadêmicos on line, por meio da internet; entendiam que a apropriação desses conhecimentos substitutos seriam inadequados e impróprios a alunos em formação; informaram desejar diferenciar-se dos padrões estabelecidos na área da Psicologia do Trabalho, ou seja, da visão deturpada de psicólogos que estavam a serviço da empresa e se esqueceram do trabalhador. Na questão da prática profissional, mostraram que a tentativa dos professores, em substituir os estágios por outras atividades, implicava uma ruptura do compromisso de ensino com o viés interdisciplinar e de caráter prático, explicitados nas diretrizes curriculares dos cursos de graduação da instituição. Sentiam-se desamparados e despreparados para atuação no mercado e bastante preocupados com as exigências dessa área. Todavia, vislumbravam possibilidades quando sugeriam que este campo apresentaria potencialidades inovadoras e de constante atualização, em que o papel da universidade seria fundamental e a preparação dos professores essencial à construção de uma Psicologia do Trabalho com compromisso ético e, que emergisse da prática concreta dos futuros psicólogos formados pela instituição.

Estudo de propagação de ondas em planície de inundação para elaboração de plano de ação emergencial de barragens: UHE Três irmãos estudo de caso

Pós-graduação em Engenharia Civil - FEIS