A virtude dos sacrifícios versus a ciência das transações: Tenório Cavalcanti e o campo político do Rio de Janeiro

Este trabalho tem como objetivo interpretar o fenômeno político expressado por Tenório Cavalcanti - político popular que atuou fundamentalmente em áreas periféricas e pobres da cidade e do estado do Rio de Janeiro entre as décadas de 1930 e 1960. Pretendo mostrar a narrativa, os símbolos e os códigos culturais que construíram a sua imagem pública e como a sua atuação marcou a dinâmica e a estruturação do campo político do Rio de Janeiro. A pesquisa baseia-se, fundamentalmente, no jornal Luta Democrática, entre os anos de 1954 e 1964, e nos seus discursos pronunciados na Câmara dos Deputados, entre 1951 e 1964. A partir da análise das fontes procuro mostrar de que maneira os elementos que constituem o fenômeno servem como ferramenta analítica para compreender melhor a construção de identidades sociais, os mecanismos de representação política, a forma como foram percebidos os processos de inclusão e exclusão social, assim como os conflitos sociais daquele período.

Caracterização e manejo de resíduos gerados nos laboratórios do Instituto de Biologia da Universidade do Estado do Rio de Janeiro, IBRAG, UERJ.

O crescimento da população mundial, aumento da industrialização e consumo de bens e serviços, tem aumentado significativamente a geração de resíduos que vem causando impactos negativos na saúde humana e ambiental. Neste contexto, se destaca a geração de produtos perigosos, tais como, os resíduos de serviços de saúde- RSS. Por apresentarem riscos à saúde da população e do meio ambiente, recomendações, normas e legislações surgiram para orientar a melhor maneira o manejo e disposição final destes resíduos. No Brasil, as resoluções NBR 306/04 e CONAMA 358/05 dão diretrizes para a elaboração de um Plano de Gerenciamento de Resíduos de Serviços de Saúde-PGRSS. Os laboratórios de pesquisa e ensino, como geradores de RSS, precisam se adequar à legislação, porém existem poucos estudos e a legislação não aborda especificamente os resíduos destes laboratórios. Os laboratórios e unidades da UERJ, geradores de RSS, não possuem PGRSS. Na UERJ, somente dois estudos levantaram os resíduos gerados em laboratórios, entretanto os dados levantados para o Instituto de Biologia são incompletos. Este estudo buscou avaliar o manejo dos resíduos biológico, químico, radioativo e perfurocortante nos laboratórios do Instituto de Biologia. Os dados foram coletados pelas informações dadas pelos professores, funcionários ou alunos dos laboratórios e por observação direta. Os dados de manejo foram analisados de acordo com a RDC 306/04 Anvisa, da Resolução CONAMA 358/05 e das fichas de segurança dos produtos químicos. Foram estudados 83% dos laboratórios do Instituto de Biologia. Destes, 43% geram resíduos químicos. Dos laboratórios caracterizados, 19 laboratórios geram somente resíduo químico. No pavilhão Américo Piquet estão localizados 63% dos laboratórios geradores de resíduos biológicos, químicos, perfurocortantes ou radioativos. Do total de resíduos gerados nos laboratórios, cerca de 80% foi de resíduo biológico, 15% de resíduo químico e 5% de resíduo perfurocortante. O manejo dos resíduos nos laboratórios é realizado de maneira confusa, geralmente os erros estão na segregação, identificação e acondicionamento. De maneira geral, as informações sobre o manejo utilizado para os resíduos são incompletas, desconhecidas ou imprecisas. As ações incorretas do manejo de resíduos são características para cada tipo de resíduo; no resíduo biológico, freqüentemente, encontraram-se resíduos comuns. O resíduo químico é geralmente descartado sem tratamento prévio na rede de esgoto. O resíduo radioativo não possui identificação e acompanhamento do decaimento, para posterior descarte. No resíduo perfurocortante encontrou-se, freqüentemente, resíduo biológico e químico misturados. Para o sucesso de um futuro Plano de Gerenciamento de Resíduos, a capacitação dos profissionais é muito importante. A Instituição deve investir na consolidação desse trabalho, considerando que ela não pode se furtar de adotar uma postura pró-ativa com relação aos problemas ambientais, sejam eles dirigentes da instituição, ou profissionais que ali atuam. Espera-se que essa pesquisa possa auxiliar neste sentido.

聚合物共混物的相容性及热力学研究

近二十年来，共混已经成为简便而有效地制备新的具有各种附加性能的高分子材料的一种重要方法。共混物间的相容性及相容的程度往往决定其最终性质，因此，高聚物共混物的相容性和相行为成为高聚物共混热力学研究的热点。我们选取了二乙酸纤维素(CDA)／聚乙烯基砒烙烷酮(PVP)、聚氧化乙烯(PEO)／聚醋酸乙烯酯(PVAc)和聚氧化乙烯(PEO)／聚甲基丙烯酸甲酯(PMMA)三个共混体系作为研究对象，用溶液法、量热法和红外光谱等实验手段研究了三个体系的相容性及相容程度，用现代热力学理论预测了它们的相容性及相行为。CDA/PVP共混体系 1．用DSC和DMA测定了不同组成的CDA/PVP共混物的玻璃化转变温度，所有组成的共混物均只有一个介于两个纯组分玻璃化转变温度之间的T_g，且不同组成共混物的玻璃化转变温度高于用Fox方程计算得到的玻璃化转变温度，说明该体系是相容性共混体系，且两组分间存在特殊相互作用。2．用奥氏粘度计和乌氏粘度计分别测定的不同组成共混物的绝对粘度和稀溶液特性粘数，都远远大于按相应比例的CDA和PVP计算的相关粘度和特性粘数的数学平均值，这应该归结为两组分间的特殊相互作用使共混溶液中线团的尺寸变大，导致粘度增大。3．共混物的红外光谱谱图显示PVP的加入使CDA的羟基吸收峰向低频率方向移动，同时，随CDA含量的增加，PVP的羰基吸收峰也向低频率方向移动，说明CDA与PVP分子间形成了氢键，使官能团的电子云密度降低，吸收峰频率降低。4．溶液量热法得到的不同组成共混物的混合热焓均为负值，直接证明该共混体系是热力学相容体系，而且随CDA含量的增加，混合热焓的绝对值也增大，表明体系的相容程度与共混组成有关。PEO/PVAc共混体系 1．用乌氏粘度计测定了不同组成不同分子量的PEO/PVAc共混物的稀溶液特性粘数，计算出表征分子间相互作用的参数，△b。发现随PVAc分子量的增加，体系的相容性降低，体系的相容程度还与共混组成及溶液浓度有关。2．用DSC方法首次得到不同分子量的PEO/PVAc共混体系的“云点”和混合热焓。随着PVAc分子量的增加，“云点”曲线向低温方向移动。不同组成共混物的混合热焓值都小于零，直接证明该体系是热力学相容体系。溶液量热法得到的混合热焓值也都为负，与DSC方法得到的结果一致。3．PEO与PVAc间只存在弱相互作用，所以，选择Hamada等人改进的Flory状态方程理论对PEO/PVAc共混体系的相容性和相行为进行预测。利用溶液量热法的混合热焓值，得到该体系的Flory相互作用参数与温度和共混组成的关系，结果表明该体系是相容性共混体系，而且应该存在LCST相行为，体系的相容程度随PEO含量的增加而降低。4．Sanchez-Lacombe(SL)格子流体理论也适用于PEO/PVAc共混体系，通过PVAc分子量与相互作用能的定量关系建立了该共混物的热力学参数的预测体系。将SL理论拟合出的spinodal曲线和binodal曲线组成的相图与DSC法得到的相图（用“云点”表示）对比，发现二者完全相符。随PVAc分子量的增加，binodal曲线向低温方向移动，临界点向富含PEO的方向移动。混合热焓的实验值也与理论值相符。Flory相互作用参数随温度和共混组成的变化与Hamada等人改进的Flory状态方程理论预测的结果一致。PEO/PMMA共混体系 1．用乌氏粘度计测定了不同组成、不同分子量的PEO/PMMA共混物的稀溶液特性粘数，计算出表征分子间相互作用的参数，Δb。发现PEO与分子量最小的PMMA共混的体系是相容性共混体系，与分子量最大的PMMA共混的是不相容性共混体系，说明随PMMA分子量的增加，体系的相容性降低。2．溶液量热法得到PEO/PMMA = 50/50（重量比）的共混物的混合热焓为负值，表明该体系是热力学相容体系。DSC法得到的不同组成共混物的混合热焓值也都为负，与溶液量热法结论一致。3．Hamada等人改进的Flory状态方程理论也适用于PEO/PMMA体系，因为PEO与PMMA之间不存在特殊相互作用。用溶液量热法得到的混合热焓值，计算出该体系的Flory相互作用参数与温度的关系，结果表明该体系是相容性共混体系，而且应该存在LCST相行为。

Pressure effects on thermodynamics of phase behavior in polystyrene/methylcyclohexane solutions

The calculations presented in this paper are based on the Sanchez-Lacombe (SL) lattice fluid theory. The interaction energy parameter, g*(12)/k, required in this approach was obtained by fitting the cloud points of polystyrene (PS) /methyleyclohexane (MCH) polymer solutions under pressure. The SL lattice fluid theory was used to calculate the spinodals, the binodals, and the Flory-Huggins (FH) interaction parameter of the solutions. The calculated results show that the SL lattice fluid theory can describe the dependences of thermodynamics of PS/MCH solutions on temperature and pressure very well. However, the calculated enthalpy and the excess volume changes indicate that the Clausius-Clapeyron equation cannot be suitable to describe pressure effect on PS/MCH solutions. Further analysis on the thermodynamics of this system under pressure shows that the role of entropy is more important than the excess volume in the present case.

Temperature and pressure dependence of phase separation of trans-decahydronaphthalene/polystyrene solution

The cloud-point temperatures (T-c1's) of ti-ans-decahydronaphthalene (TD)/polystyrene (PS, M-w = 270 kg/mol) solutions were determined by fight scattering measurements over a range of temperatures (1-16 degreesC), pressures (100-900 bar), and compositions (4.2-21.6 vol% polymer). The system phase separates upon cooling and the T-c1 was found to increase with the rising pressure for the constant composition. In the absence of special effects this finding indicates positive excess volumes. The special attention was paid to the demixing temperatures as a function of the pressure for the different polymer solutions and the plots in the T-volume fraction plane and P-volume fraction plane. The cloud-point curves of polymer solutions under changing pressures were observed for different compositions, demonstrates that the TD/PS system exhibits UCST (phase separation upon cooling) behavior. With this data the phase diagrams under pressure were calculated applying the Sanchez-Lacombe (SL) lattice fluid theory. Furthermore, the cause of phase separation, i.e., the influence of Flory-Huggins (FH) interaction parameter under pressure was investigated.

Thermodynamical study on pressure-induced compatibility in UCST polymer-containing mixtures

The present calculations were performed on the basis of the Sanchez-Lacombe lattice fluid theory and the new combinatorial rules for block copolymer according to the experimental results on the pressure-induced compatibility in poly(ethylene oxide) (PEO) and poly(ethylene oxide-b-dimethylsiloxane) (P(EO-b-DMS)) mixtures with UCST behavior. The study on enthalpy, combinatorial entropy, vacancy entropy and Gibbs energy upon mixture shows that Sanchez-Lacombe fluid theory and the new combinatorial rules could describe the pressure-induced compatibility (PIC) of polymer mixtures with UCST behavior well.

Thermodynamics of phase behavior in PEO/P(EO-b-DMS) homopolymer and block co-oligomer mixtures under pressure

The cloud-point temperatures (T-cl's) of poly(ethylene oxide) (PEO) and poly(ethylene oxide)-block-polydimethylsiloxane (P(EO-b-DMS)) homopolymer and block-oligomer mixtures were determined by turbidity measurements over a range of temperatures (105 to 130degrees), pressures (1 to 800 bar), and compositions (10-40 wt.-% PEO). The system phase separates upon cooling and T-cl was found to decrease with an increase in pressure for a constant composition. In the absence of special effects, this finding indicates negative excess volumes. Special attention was paid to the demixing temperatures as a function of the pressure for the different polymer mixtures and the plots in the T-phi plane (where phi signifies volume fractions). The cloud-point curves of the polymer mixture under pressures were observed for different compositions. The Sanchez-Lacombe (SL) lattice fluid theory was used to calculate the spinodals, the binodals, the Flory-Huggins (FH) interaction parameter, the enthalphy of mixing, and the volume changes of mixing. The calculated results show that modified P(EO-b-DMS) scaling parameters with the new combining rules can describe the thermodynamics of the PEO/P(EO-b-DMS) system well with the SL theory.

具有最高共溶温度高分子共混体系的压力诱导相容性热力学研究

根据具有最高共溶温度高分子共混体系的压力诱导相容实验结果,结合Sanchez-Lacombe格子流体理论和文中给出的关于嵌段共聚物标度参数组合规则,对高分子体系在压力作用下的混合焓、混合组合熵、混合空位熵和Gibbs混合自由能等热力学性质进行了研究。研究结果表明Sanchez-Lacombe格子流体理论和新的关于嵌段共聚物标度参数组合规则可以用来描述压力作用下的具有最高共溶温度高分子共混体系的压力诱导相容性。

What has brought on the effects of number-average molecular weight on the spinodals in polymer mixtures?

On the basis of the thermodynamics of Gibbs, the spinodal for the quasibinary system was derived in the framework of the Sanchez-Lacombe lattice fluid theory. All of the spinodals were calculated based on a model polydisperse polymer mixture, where each polymer contains three different molecular weight subcomponents. According to our calculations, the spinodal depends on both weight-average ((M) over bar (w)) and number-average ((M) over bar (n)) molecular weights, whereas that of the z-average molecular weight is invisible. Moreover, the extreme of the spinodal decreases when the polydispersity index (eta = (M) over bar (w)/(M) over bar (n)) of the polymer increases. The effect of polydispersity on the spinodal decreases when the molecular weight gets larger and can be negligible at a certain large molecular weight. It is well-known that the influence of polydispersity on the phase equilibrium (coexisting curve, cloud point curves) is much more pronounced than on the spinodal. The effect of M, on the spinodal is discussed as it results from the infuluence of composition temperatures, molecular weight, and the latter's distribution on free volume. An approximate expression, which is in the assumptions of v* v(1)* = v(2)* and 1/r --> 0 for both of the polymers, was also derived for simplification. It can be used in high molecular weight, although it failed to make visible the effect of number-average molecular weight on the spinodal.

Statistical thermodynamics of polydisperse polymer systems in the framework of lattice fluid model: Effect of molecular weight and its distribution on the spinodal in polymer solution

With the aid of thermodynamics of Gibbs, the expression of the spinodal was derived for the polydisperse polymer-solvent system in the framework of Sanchez-Lacombe Lattice Fluid Theory (SLLFT). For convenience, we considered that a model polydisperse polymer contains three sub-components. According to our calculation, the spinodal depends on both weight-average ((M) over bar (w)) and number-average ((M) over bar (n)) molecular weights of the polydisperse polymer, but the z-average molecular weight ((M) over bar (z)) dependence on the spinodal is invisible. The dependence of free volume on composition, temperature, molecular weight, and its distribution results in the effect of (M) over bar (n) on the spinodal. Moreover, it has been found that the effect of changing (M) over bar (w) on the spinodal is much bigger than that of changing (M) over bar (n) and the extrema of the spinodal increases with the rise of the weight-average molecular weight of the polymer in the solutions with upper critical solution temperature (UCST). However, the effect of polydispersity on the spinodal can be neglected for the polymer with a considerably high weight-average molecular weight. A more simple expression of the spinodal for the polydisperse polymer solution in the framework of SLLFT was also derived under the assumption of upsilon(*)=upsilon(1)(*)=upsilon(2)(*) and (1/r(1)(0))-(1/r(2i)(0))-->(1/r(1)(0)).

Effects of pressure and molecular weight on the miscibility of polystyrene and cyclohexane

With the aid of Sanchez-Lacombe lattice fluid theory (SLLFT), the phase diagrams were calculated for the system cyclohexane (CH)/polystyrene (PS) with different molecular weights at different pressures. The experimental data is in reasonable agreement with SLLFT calculations. The total Gibbs interaction energy, g*(12) for different molecular weights PS at different pressures was expressed, by means of a universal relationship, as g(12)* =f(12)* + (P - P-0) nu*(12) demixing curves were then calculated at fixed (near critical) compositions of CH and PS systems for different molecular weights. The pressures of optimum miscibility obtained from the Gibbs interaction energy are close to those measured by Wolf and coworkers. Furthermore, a reasonable explanation was given for the earlier observation of Saeki et al., i.e., the phase separation temperatures of the present system increase with the increase of pressure for the low molecular weight of the polymer whereas they decrease for the higher molecular weight polymers. The effects of molecular weight, pressure, temperature and composition on the Flory Huggins interaction parameter can be described by a general equation resulting from fitting the interaction parameters by means of Sanchez-Lacombe lattice fluid theory.

利用pVT分析仪测定交联PEG的热膨胀系数、等温压缩系数和热压系数

利用 p VT10 0分析仪测得交联聚乙二醇的 p- V- T数据 ,并应用 Sanchez- Lacombe格子流体理论拟合出其 p VT状态方程。同时计算出了交联聚乙二醇 (PEG)的热膨胀系数 α,等温压缩系数 β和热压系数γ,为其在生物化学方面的生产、加工和应用提供了一定的依据

Mixing enthalpy and phase behavior of PEO/PVAc blends

Phase behaviors and heats of mixing of the miscible blends of poly(ethylene oxide) (PEO) and poly(vinyl acetate) (PVAc) with different molecular weights were investigated by DSC. A method proposed by Natasohn and Ebert et al. was adopted to estimate the binodal temperatures and the enthalpies of mixing from onset temperatures and values of areas of a series of endothermic peaks (corresponding to heats of demixing), respectively, in their heating scanning thermograms obtained with different heating rates. Phase diagrams and heats of mixing of this blending system were also predicted by using Sanchez-Lacombe lattice fluid theory. A very good agreement was obtained for both. phase behaviors and heats of mixing obtained with two different methods.

Armazenamento e tratamento mecânico na emergência de plântulas de Passiflora gibertii.

Objetivou-se verificar o efeito do período de armazenamento e da retirada parcial do tegumento na porcentagem de germinação de sementes de Passiflora gibertii. Os tratamentos consistiram de sementes armazenadas por uma semana ou por 2 anos e 7 meses, com tegumento intacto e com tegumento parcialmente removido. Aos 29 dias após a semeadura, a porcentagem de germinação das sementes armazenadas por mais de dois anos foi similar às recém-colhidas, quando na ausência do tratamento mecânico, indicando que o armazenamento de sementes na geladeira é um método satisfatório na conservação de germoplasma dessa espécie a curto prazo. A retirada de parte do tegumento das sementes aumentou a velocidade e uniformidade da germinação, tanto para as sementes novas quanto para as sementes velhas. Contudo, o benefício do tratamento mecânico foi maior para as sementes novas, que apresentaram 64% de plântulas emergidas ao final do experimento, contra os 23% para as sementes intactas, diferentemente do ocorrido para as sementes velhas, que apresentaram valores similares para as que tiveram ou não o tratamento mecânico, 20 e 28%, respectivamente. Desta forma, conclui-se que a quebra de dormência pelo tratamento mecânico ocorre apenas para as sementes novas.