Problemas de aprendizagem sobre ligações químicas para estudantes de graduação

This research aims at identifying the learning problems in newly undergraduate students at university, interpreting the nature and causes of these problems, offering subsidies to overcome these difficulties and enabling a meaningful learning through which students give meaning to their learning. As an object for this work was chosen the theme Chemical Bonds - where were studied the forces between atoms to form molecules, compound ions and ionic crystalline structures - and is characterized as one of the most important subjects of Chemistry. In research, it was used a questionnaire with five open questions, answered by 147 students from the early periods of degrees in Chemistry at Universidade Federal do f Rio Grande do Norte. The answers revealed uncertainty on the part of students, both conceptual and representation, with superficial justifications, always using the octet rule to describe models of chemical bonds. Results suggest that these students had inadequate training in high school and that the examinations for entrance into the ranks were made according to flexible criteria less demanding in terms of knowledge. These observations have led to the conclusion that for future changes, it is necessary for high schools and in the early periods in universities favoring the adoption of pedagogical approaches in context and applying strategies to overcome the teaching of superficial memorization on Chemical Bonds, which probably have applied to the teaching of other subjects of chemistry

Remoção, por flotação, de óleo em águas produzidas na indústria de petróleo: eficiência e modelagem do processo

The separation oil-water by the use of flotation process is characterized by the involvement between the liquid and gas phases. For the comprehension of this process, it s necessary to analyze the physical and chemical properties command float flotation, defining the nature and forces over the particles. The interface chemistry has an important role on the flotation technology once, by dispersion of a gas phase into a liquid mixture the particles desired get stuck into air bubbles, being conduced to a superficial layer where can be physically separated. Through the study of interface interaction involved in the system used for this work, was possible to apply the results in an mathematical model able to determine the probability of flotation using a different view related to petroleum emulsions such as oil-water. The terms of probability of flotation correlate the collision and addition between particles of oil and air bubbles, that as more collisions, better is the probability of flotation. The additional probability was analyzed by the isotherm of absorption from Freundlich, represents itself the add probability between air bubbles and oil particles. The mathematical scheme for float flotation involved the injected air flow, the size of bubbles and quantity for second, the volume of float cell, viscosity of environment and concentration of demulsifier. The results shown that the float agent developed by castor oil, pos pH variation, salt quantity, temperature, concentration and water-oil quantity, presented efficient extraction of oil from water, up to 95%, using concentrations around 11 ppm of demulsifier. The best results were compared to other commercial products, codified by ―W‖ and ―Z‖, being observed an equivalent demulsifier power between Agflot and commercial product ―W‖ and superior to commercial product ―Z‖

Instrumentalidade do serviço social: dimensões teórico-metodológica, ético-política e técnico-operativa e exercício profissional

The dissertation proposes a discussion about the instrumentality of the Social Work, in the attempt of visualizing her, as well as the profession, in a totality perspective to the light of the rationality critical-dialetical. Understood as the capacity that the professional subjects acquire of giving answers to the demands that are placed to the profession, itself built partner-historically, in a teleologys conflicts and causalitys. So, it is proposed the discussion of the instrumentality while a group of you know specific, composed essentially by the development of three practical-formative dimensions. The theoretical-methodological refers to the capacity of apprehension of the method and of the theories and, consequently, of the relationship that does with the practice. The dimension ethical-politics concerns the development of the capacity of analyzing the society and the own profession as field of contradictory forces, being considered the character eminently political of the professional exercise, as well as the professional's conscience concerning the social direction that prints in your intervention. And the technician-operative dimension refers more strictly to the technical elements and you score for the development of the intervention. It was looked for to evidence as those dimensions they attend in the professional exercise, starting from the experience lived by the social workers of the Social Attendance Reference Centers, in Natal/RN

A inserção das mulheres na luta pela terra: movimento de participação e/ou submissão

The following dissertation studies the insertion of peasant women in the conflict for land since the occupation process, dispossession and construction of the settlement New Horizon II, in the municipal district of Maxaranguape. It analyses their participation in the conflict Valley of the Hope", that resulted in the settlements New Life II and New Horizon II in the municipal district of Maxaranguape. The analysis exposes the reasons which took the peasant women, after the land conquest, to go back into domestic space and/or to assume positions of lesser relevance in the political organizations of the settlement. In the conflict Valley of the Hope, the women had a fundamental role, facing the police violence, being front line of the conflicts against the repression forces, risking their lives and the life of their families. After the conquest of the land, transformed into the New Horizon II Settlement, there are a lot of changes in the participation of the women. We can observe that, despite the protagonism of the families, in special of the women in the Valley of the Hope conflict, these female workers still experiment unequal social, economic, political and cultural conditions in relation to the men, expressing the gender inequalities which are found in the daily life of the settlement: in the community, in the domestic and agricultural task. The conflict for the land in the Valley of the Hope and the conquest of the settlement did not necessarily mean the incorporation of the emancipation of the peasant women. However, the political participation in the development of the conflicts allowed to the women the self discovering and the beginning of an emancipation process as gender. There are signals of continuities and ruptures of the present culture, almost always stimulated by the organization of the agricultural female workers

Controle democrático no capitalismo contemporâneo: limites e contradições

This study examines the determinations of the structural crisis of capital in the democratic control effected on the councils of rights and policies. Therefore the research aimed to apprehend and analyze the conjunctural and structural determinations and cyclical changes that incide on democratic control established by the Federal Constitution of 1988. The specific objectives turned to: (1) identify and analyze the theoretical and political fundamentals of democratic control in the production of social service in ENPESS 2010, in the productions of CFESS and the journal social services and society, (2) apprehend and analyze the possibilities, limits, contradictions and social direction of democratic control in contemporaneity and (3) identify and analyze the major political forces that constitute support and opposition to the exercise of democratic control. To approximate to the intended objectives the way theoretical and methodological covered was based in a perspective of totality that allows the apprehension of the object of study in their contradictory dimensions of universality, particularity and singularity. The results enabled to develop critical analysis of theoretical production of the Brazilian social service on the subject, having as snip studies of the journals social service and society; works of ENPESS 2010 and CFESS positioning. It was found, so in analysis undertaken, the spaces of democratic control suffer inflections of capital that shape their practices and social direction. In theoretical productions chosen, identified the prevalence of democratic control studied under an endogenous perspective to participatory canals, with incipient connections to the structural/conjunctural determinations of a historical period of crisis and seeks to restore the hegemony of capital. The positioning of the CFESS tends to recognition of democratic control in its contradictory dynamics recognizing the limits imposed by the sociability of the capital at the present time