Impactos ambientais causados pela obras de construção e ampliação de portos marítimos no Brasil com ênfase nas comunidades pesqueiras

Analisa os impactos ambientais decorrentes das obras de construção e ampliação de portos marítimos no Brasil, abrangendo também as atividades de dragagem, sejam elas relativas à manutenção da profundidade do canal de navegação ou à ampliação de capacidade. Pela importância da atividade pesqueira no cenário nacional, será dada ênfase a esse aspecto.

Ab Initio Study Of Zno-Based Gas-Sensing Mechanisms: Surface Reconstruction And Charge Transfer

Density functional theory (DFT) calculations were employed to explore the gas-sensing mechanisms of zinc oxide (ZnO) with surface reconstruction taken into consideration. Mix-terminated (10 (1) over bar0) ZnO surfaces were examined. By simulating the adsorption process of various gases, i.e., H-2, NH3, CO, and ethanol (C2H5OH) gases, on the ZnO (10 (1) over bar0) surface, the changes of configuration and electronic structure were compared. Based on these calculations, two gas-sensing mechanisms were proposed and revealed that both surface reconstruction and charge transfer result in a change of electronic conductance of ZnO. Also, the calculations were compared with existing experiments.

Electronic entanglement purification scheme enhanced by charge detections

We present an entanglement purification scheme for the mixed entangled states of electrons with the aid of charge detections. Our scheme adopts the electronic polarizing beam splitters rather than the controlled-NOT (CNOT) operations, but the total successful probability of our scheme can reach the quantity as large as that of the the CNOT-operation-based protocol and twice as large as that of linear-optics-based protocol for the purification of photonic entangled states. Thus our scheme can achieve a high successful prabability without the usage of CNOT operations.

Charge symmetry in ^(13)N and ^(13)C a coupled-channel model

A set of coupled-channel differential equations based on a rotationally distorted optical potential is used to calculate the wave functions required to evaluate the gamma ray transition rate from the first excited state to the ground state in ^(13)C and ^(13)N. The bremsstrahlung differential cross section of low energy protons is also calculated and compared with existing data. The marked similarity between the potentials determined at each resonance level in both nuclei supports the hypothesis of the charge symmetry of nuclear forces by explaining the deviation of the ratios of the experimental E1 transition strengths from unity.

Charge displacement in ultraintense laser-plasma interaction

The distribution of optical held and charge density in the interaction between ultraintense ultrashort pulse laser and plasma is studied by numerical computation. The plasma considered has an exponential density profile. which corresponds to isothermal expanding. Our calculation shows that electrons are pushed forward by the incident laser, but ions, due to their much greater inertia, remain stationary. The resulting charge displacement forms a strong electrostatic field in the plasma. After the interaction of laser pulse and plasma. electrostatic energy still exists even after the laser pulse and will be absorbed by the plasma finally. This serves as an explanation to the mechanism of laser energy deposited into plasma.

The application of metallointercalators in recognition of and charge transport in nucleic acids

Metal complexes that utilize the 9,10-phenanthrene quinone diimine (phi) moiety bind to DNA through the major groove. These metallointercalators can recognize DNA sites and perform reactions on DNA as a substrate. The site-specific metallointercalator Λ-1-Rh(MGP)_2phi^(5+) competitively disrupts the major groove binding of a transcription factor, yAP-1, from an oligonucleotide that contains a common binding site. The demonstration that metal complexes can prevent transcription factor binding to DNA site-specifically is an important step in using metallointercalators as therapeutics.

The distinctive photochemistry of metallointercalators can also be applied to promote long range charge transport in DNA. Experiments using duplexes with regions 4 to 10 nucleotides long containing strictly adenine and thymine sequences of varying order showed that radical migration is more dependent on the sequence of bases, and less dependent on the distance between the guanine doublets. This result suggests that mechanistic proposals of long range charge transport must involve all the bases.

RNA/DNA hybrids show charge migration to guanines from a remote site, thus demonstrating that nucleic acid stacking other than B-form can serve as a radical bridge. Double crossover DNA assemblies also provide a medium for charge transport at distances up to 100 Å from the site of radical introduction by a tethered metal complex. This radical migration was found to be robust to mismatches, and limited to individual, electronically distinct base stacks. In single DNA crossover assemblies, which have considerably greater flexibility, charge migration proceeds to both base stacks due to conformational isomers not present in the rigid and tightly annealed double crossovers.

Finally, a rapid, efficient, gel-based technique was developed to investigate thymine dimer repair. Two oligonucleotides, one radioactively labeled, are photoligated via the bases of a thymine-thymine interface; reversal of this ligation is easily visualized by gel electrophoresis. This assay was used to show that the repair of thymine dimers from a distance through DNA charge transport can be accomplished with different photooxidants.

Thus, nucleic acids that support long range charge transport have been shown to include A-track DNA, RNA/DNA hybrids, and single and double crossovers, and a method for thymine dimer repair detection using charge transport was developed. These observations underscore and extend the remarkable finding that DNA can serve a medium for charge transport via the heteroaromatic base stack.

Investigations of charge-carrier dynamics at semiconductor/liquid interfaces

Theoretical and experimental investigations of charge-carrier dynamics at semiconductor/liquid interfaces, specifically with respect to interfacial electron transfer and surface recombination, are presented.

Fermi's golden rule has been used to formulate rate expressions for charge transfer of delocalized carriers in a nondegenerately doped semiconducting electrode to localized, outer-sphere redox acceptors in an electrolyte phase. The treatment allows comparison between charge-transfer kinetic data at metallic, semimetallic, and semiconducting electrodes in terms of parameters such as the electronic coupling to the electrode, the attenuation of coupling with distance into the electrolyte, and the reorganization energy of the charge-transfer event. Within this framework, rate constant values expected at representative semiconducting electrodes have been determined from experimental data for charge transfer at metallic electrodes. The maximum rate constant (i.e., at optimal exoergicity) for outer-sphere processes at semiconducting electrodes is computed to be in the range 10^-17-10^-16 cm⁴ s^-1, which is in excellent agreement with prior theoretical models and experimental results for charge-transfer kinetics at semiconductor/liquid interfaces.

Double-layer corrections have been evaluated for semiconductor electrodes in both depletion and accumulation conditions. In conjuction with the Gouy-Chapman-Stern model, a finite difference approach has been used to calculate potential drops at a representative solid/liquid interface. Under all conditions that were simulated, the correction to the driving force used to evaluate the interfacial rate constant was determined to be less than 2% of the uncorrected interfacial rate constant.

Photoconductivity decay lifetimes have been obtained for Si(111) in contact with solutions of CH₃OH or tetrahydrofuran containing one-electron oxidants. Silicon surfaces in contact with electrolyte solutions having Nernstian redox potentials > 0 V vs. SCE exhibited low effective surface recombination velocities regardless of the different surface chemistries. The formation of an inversion layer, and not a reduced density of electrical trap sites on the surface, is shown to be responsible for the long charge-carrier lifetimes observed for these systems. In addition, a method for preparing an air-stable, low surface recombination velocity Si surface through a two-step, chlorination/alkylation reaction is described.

Theoretical and experimental investigations of the flocculation of charged particles in aqueous solutions by polyelectrolytes of opposite charge

An electrostatic mechanism for the flocculation of charged particles by polyelectrolytes of opposite charge is proposed. The difference between this and previous electrostatic coagulation mechanisms is the formation of charged polyion patches on the oppositely charged surfaces. The size of a patch is primarily a function of polymer molecular weight and the total patch area is a function of the amount of polymer adsorbed. The theoretical predictions of the model agree with the experimental dependence of the polymer dose required for flocculation on polymer molecular weight and solution ionic strength.

A theoretical analysis based on the Derjaguin-Landau, Verwey- Overbeek electrical double layer theory and statistical mechanical treatments of adsorbed polymer configurations indicates that flocculation of charged particles in aqueous solutions by polyelectrolytes of opposite charge does not occur by the commonly accepted polymerbridge mechanism.

A series of 1, 2-dimethyl-5 -vinylpyridinium bromide polymers with a molecular weight range of 6x10^3 to 5x10^6 was synthesized and used to flocculate dilute polystyrene latex and silica suspensions in solutions of various ionic strengths. It was found that with high molecular weight polymers and/or high ionic strengths the polymer dose required for flocculation is independent of molecular weight. With low molecular weights and/or low ionic strengths, the flocculation dose decreases with increasing molecular weight.

Impactos das hidrelétricas na Amazônia para a saúde da população : uma proposta de abordagem metodológica

Baseado na insuficiência dos métodos de abordagem até então utilizados para a avaliação dos impactos de grandes hidrelétricas na saúde da população envolvida, em particular na situação de desbravamento de fronteiras em países em desenvolvimento, como é o caso da Amazônia, o autor procura trazer uma análise histórica dos determinantes internos do setor elétrico e da ocupação da Amazônia, para situar uma proposta de abordagem. Destaca as características do desenvolvimento do modo de produção capitalista em sua fase monopolista e os resultados deste processo no padrão de desenvolvimento nacional, determinando as necessidades e usos de energia, assim como a disponibilidade de recursos para a realização de novos projetos. A ocupação da Amazônia é levantada em relação as necessidades de expansão do capital internacional que, em associações diversas com o capital nacional e o Estado, determina a política de população mais propicia, resultando em ondas de ocupação. O autor caracteriza o ciclo atual de ocupação da Amazônia como sendo o de grandes projetos de desenvolvimento e tece considerações sobre os mesmos e a saúde da população da região. Diante da avaliação da experiência nacional e internacional acerca dos impactos na saúde advindos de hidrelétricas, o autor propõe, valendo-se da legislação ambiental em vigor e das etapas de planejamento e construção preconizadas pelo setor elétrico, um método de abordagem destes impactos, dentro de um contexto histórico e sócio-econômico particular para a Amazônia. Conclui o autor ressaltando a necessidade de se levantar dados anteriores, durante e após a realização das obras, no sentido de possibilitar o desenvolvimento do método de avaliação dos impactos de grandes barragens, e outras grandes obras, na saúde da população e ressalta o papel das instituições de saúde e meio ambiente neste processo.

Part I. Influence of membrane morphology on ion-exchange and charge propagation in composite polyelectrolyte electrode coatings. Part II. Dynamic surface tension measurements of polarization relaxation at mercury pool electrodes by the method of Wilhelmy.

Part I. Novel composite polyelectrolyte materials were developed that exhibit desirable charge propagation and ion-retention properties. The morphology of electrode coatings cast from these materials was shown to be more important for its electrochemical behavior than its chemical composition.

Part II. The Wilhelmy plate technique for measuring dynamic surface tension was extended to electrified liquid-liquid interphases. The dynamical response of the aqueous NaF-mercury electrified interphase was examined by concomitant measurement of surface tension, current, and applied electrostatic potential. Observations of the surface tension response to linear sweep voltammetry and to step function perturbations in the applied electrostatic potential (e.g., chronotensiometry) provided strong evidence that relaxation processes proceed for time-periods that are at least an order of magnitude longer than the time periods necessary to establish diffusion equilibrium. The dynamical response of the surface tension is analyzed within the context of non-equilibrium thermodynamics and a kinetic model that requires three simultaneous first order processes.

Space-charge-limited current in fast neutron irradiated silicon

DC and transient measurements of space-charge-limited currents through alloyed and symmetrical n^+ν n^+ structures made of nominally 75 kΩcm ν-type silicon are studied before and after the introduction of defects by 14 MeV neutron radiation. In the transient measurements, the current response to a large turn-on voltage step is analyzed. Right after the voltage step is applied, the current transient reaches a value which we shall call "initial current" value. At longer times, the transient current decays from the initial current value if traps are present.

Before the irradiation, the initial current density-voltage characteristics J(V) agree quantitatively with the theory of trap-free space-charge-limited current in solids. We obtain for the electron mobility a temperature dependence which indicates that scattering due to impurities is weak. This is expected for the high purity silicon used. The drift velocity-field relationships for electrons at room temperature and 77°K, derived from the initial current density-voltage characteristics, are shown to fit the relationships obtained with other methods by other workers. The transient current response for t > 0 remains practically constant at the initial value, thus indicating negligible trapping.

Measurement of the initial (trap-free) current density-voltage characteristics after the irradiation indicates that the drift velocity-field relationship of electrons in silicon is affected by the radiation only at low temperature in the low field range. The effect is not sufficiently pronounced to be readily analyzed and no formal description of it is offered. In the transient response after irradiation for t > 0, the current decays from its initial value, thus revealing the presence of traps. To study these traps, in addition to transient measurements, the DC current characteristics were measured and shown to follow the theory of trap-dominated space-charge-limited current in solids. This theory was applied to a model consisting of two discrete levels in the forbidden band gap. Calculations and experiments agreed and the capture cross-sections of the trapping levels were obtained. This is the first experimental case known to us through which the flow of space-charge-limited current is so simply representable.

These results demonstrate the sensitivity of space-charge-limited current flow as a tool to detect traps and changes in the drift velocity-field relationship of carriers caused by radiation. They also establish that devices based on the mode of space-charge-limited current flow will be affected considerably by any type of radiation capable of introducing traps. This point has generally been overlooked so far, but is obviously quite significant.

As transformações no ensino na saúde: um estudo sobre a extensão universitária e sua relação com a formação do profissional de saúde para o SUS

HENRIQUES, Regina Lúcia Monteiro.2011. 182 f. Tese (Doutorado em Saúde Coletiva) Instituto de Medicina Social, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, 2011. Este estudo trata dos processos de mudança na formação em saúde, especialmente das questões político estruturais da articulação do ensino e da extensão para a construção de estratégias de transformação dos cursos da área da saúde. Tem por objetivos analisar as perspectiva dos sujeitos envolvidos na transformação curricular no que diz respeito à articulação entre práticas de ensino, extensão universitária e saúde, a constituição de novos cenários de prática e sua relação com a extensão universitária, assim como examinar os sentidos atribuídos pelos sujeitos aos processos políticos internos e externos às instituições de ensino. Parte-se da compreensão de que há em andamento um grande movimento de lutas pela mudança na formação em saúde e de algumas das ideias que têm sido discutidas e difundidas na defesa da reorientação da formação em saúde baseada em princípios e diretrizes consoantes com a política de saúde e com a defesa de direitos de cidadania. Baseia-se em concepções de espaço cotidiano das instituições de formação superior em saúde e dos serviços de saúde e outros cenários de prática. Reflete sobre a responsabilidade política das instituições formadoras e da extensão universitária como lugar de tornar públicas as posições e valores defendidos para as práticas do cuidado e da relação social e política da universidade. Para a operacionalização do estudo, foram escolhidas duas instituições universitárias que se apresentaram e que foram selecionadas no programa do Pro-Saúde. Foram realizadas entrevistas com roteiro semi-estruturado com protagonistas de processos de mudança na formação nestas instituições, em três profissões da área da saúde, enfermagem, medicina e odontologia. Fez-se analise hermenêutica a partir dos sentidos que foram atribuídos a estas experiências concretas pelos atores que as empreenderam. Definiu-se três categorias de análise, a dimensão das políticas governamentais de incentivo a mudanças na formação em saúde e os efeitos das mesmas para as instituições de ensino; a ampliação de cenários de prática, as estratégias de aproximação entre os mundos do ensino e do trabalho e se significaram novas práticas de cuidado; relação existente entre os processos de transformação curricular e a extensão universitária. A extensão vem adquirindo protagonismo na construção de dispositivos de enfrentamento e superação das dificuldades e resistências nos processos de transformação curricular, além de criar com relativa liberdade novas possibilidades espaciais e conceituais para o cuidado em saúde, porém pelos próprios sentidos que assume desde a invisibilidade até a redenção da universidade sua baixa institucionalidade e reflexão impede que sua potencialidade seja tomada como aliada nestes processos de modo mais sistemático e impactante.

Fibromialgia e dor: um estudo de caso sobre mal-estar no trabalho e adoecimento

A fibromialgia é uma síndrome reumática que atinge cerca de 2% da população brasileira, sendo 90% dos pacientes do gênero feminino. Os principais sintomas são dor crônica generalizada, depressão, desânimo e fadiga acentuada, provocando dificuldades sociais e afetivas cotidianas. Objetivo: O objetivo principal deste estudo foi apreender e interpretar sentidos e significados que mulheres com fibromialgia atribuem às práticas terapêuticas corporais realizadas no Projeto de Extensão: Tratamento Multidisciplinar para Pacientes Portadores de Fibromialgia realizado na Universidade do Estado do Rio de Janeiro (UERJ). Todas as mulheres foram diagnosticadas em ambulatórios públicos e privados e depois se inscreveram voluntariamente no tratamento gratuito disponibilizado. Nossa principal hipótese de estudo procura relacionar o adoecimento dessas mulheres com o regime social de trabalho, que aumenta o sofrimento e, por conseguinte, provoca somatização do mal-estar gerado. Métodos: Trata-se de um estudo socioantropológico com campo etnográfico, no qual foram observadas as práticas corporais semanais nos anos 2009-2010. Também foram realizadas fotografias e entrevistas em profundidade com todas as mulheres que participavam regularmente das práticas corporais. De igual modo, realizamos entrevistas por computador e por telefone com mulheres diagnosticadas por fibromialgia em diversas cidades brasileiras. Resultados: Foi possível compreender que estar em um local onde podem se relacionar com outras pessoas com os mesmos sinais e sintomas e que compartilhar situações de sofrimento semelhantes contribui para construção de uma identidade de grupo baseada no cuidado e no acolhimento. Assim, elas constroem coletivamente valores de cuidado com o corpo e com a saúde. Conclusões: A participação assídua no tratamento oferecido aumenta a qualidade de vida e a vitalidade de mulheres com fibromialgia, contribuindo para a promoção da saúde não apenas na sua dimensão físico-orgânica, mas em sua totalidade sócio-afetiva.