Estudos de adsorção de tetraciclina em partículas de quitosana

Due to its physico-chemical and biological properties, related to the abundance and low cost of raw material, chitosan has been recognized as a material of wide application in various fields, such as in drug delivery systems. Many of these properties are associated with the presence of amino groups in its polymer chain. A proper determination of these amino groups is very important, in order to properly specify if a given chitosan sample can be used in a particular application. Thus, in this work, initially, a comparison between the determination of the deacetylation degree by conductometry and elemental analysis was carried out using a detailed analysis of error propagation. It was shown that the conductometric analysis resulted in a simple and safe method for the determining the degree of deacetylation of chitosan. Subsequently, experiments were performed to monitor and characterize the adsorption of tetracycline on chitosan particles through kinetic and equilibrium studies. The main models of kinetics and adsorption isotherms, widely used to describe the adsorption on wastewater treatment systems and the drug loading, were used to treat the experimental data. Firstly, it was shown that an apparent linear t/q(t) × t relationship did not imply in a pseudo-second-order adsorption kinetics, differently of what has been repeatedly reported in the literature. It was found that this misinterpretation can be avoided by using non-linear regression. Finally, the adsorption of tetracycline on chitosan particles was analyzed using insights obtained from theoretical analysis, and the parameters generated were used to analyze the kinetics of adsorption, the isotherm of adsorption and to ropose a mechanism of adsorption

Estudos de sorção de um corante aniônico modelo em partículas de quitosana reticulada

Textile activity results in effluents with a variety of dyes. Among the several processes for dye-uptaking from these wastewaters, sorption is one of the most effective methods, chitosan being a very promising alternative for this end. The sorption of Methyl Orange by chitosan crosslinked particles was approached using equilibrium and kinetic analyses at different pH s. Besides the standard pseudo-order analysis normally effectuated (i.e. pseudo-first-order and pseudo-second-order), a novel approach involving a pseudo-nth-order kinetics was used, nbeing determined via non-linear regression, using the Levenberg-Marquardt method. Zeta potential measurements indicated that electrostatic interactions were important for the sorption process. Regarding equilibrium experiments, data were well fitted to a hybrid Langmuir-Freundlich isotherm, and estimated Gibbs free energy of adsorption as a function of mass of dye per area of chitosan showed that the process of adsorption becomes more homogeneous as the pH of the continuous phase decreased. Considering the kinetics of sorption, although a pseudo-nth-order description yielded good fits, a kinetic equation involving diffusion adsorption phenomena was found to be more consistent in terms of a physicochemical description of the sorption process

O sistema de garantia dos direitos da criança e do adolescente: análise da trajetória e do processo de resolubilidade dos casos de violência doméstica sexual em Recife PE (2007-2011)

This work discourses about the child and adolescent s Guaranty System of Rights (GSR), on the intervention in cases of juvenile domestic sexual violence, in Recife. The course (trajectory) is analyzed, where circulate cases of sexual violence, until its resolution, in (GSR). Actually, the violence represents a serious problem of public health. Was thought about the difficulties and the limits that make GSR become a full field of contradictions and challenges for the effectiveness of the children and adolescents rights. Therefore, it was verified the treatments that are developed by GSR, how this system is structured and articulated and how occurs the resolution of the sexual violence cases against children and adolescents. Proceedings of the quantitative and qualitative research were used, was done observation, directed interview and analysis of documents. Thus, the field research was the visits in these institutions: Restauração Hospital, Police Management of the Child and Adolescent (PMCA) three Guardianship Councils, Dom Helder Camara Center of Studies and Social Action (CENDHEC) and the Tribunal of Childhood and Adolescence. The research subjects were seven professionals of GSR. The theoretical discussion is guided in reflections about the children and youth rights, in the violence theme and in the construction and institutionalization process of GSR. In this experiment, was noticed there are many difficulties for working together the GSR, because many obstacles are found when we call the responsible institutions, besides some violence cases happen again. This system is not totally institutionalized and articulated, faces structural problems, material, poorly qualified professionals, underinvestment, low transfer of public resources, among other difficulties, causing many losses in the implementation of public policies that enforce secured rights by legislation

STREAM-AP: um processo para sistematizar a escolha de padrões arquiteturais baseado em requisitos não-funcionais

The importance of non-functional requirements for computer systems is increasing. Satisfying these requirements requires special attention to the software architecture, since an unsuitable architecture introduces greater complexity in addition to the intrinsic complexity of the system. Some studies have shown that, despite requirements engineering and software architecture activities act on different aspects of development, they must be performed iteratively and intertwined to produce satisfactory software systems. The STREAM process presents a systematic approach to reduce the gap between requirements and architecture development, emphasizing the functional requirements, but using the non-functional requirements in an ad hoc way. However, non-functional requirements typically influence the system as a whole. Thus, the STREAM uses Architectural Patterns to refine the software architecture. These patterns are chosen by using non-functional requirements in an ad hoc way. This master thesis presents a process to improve STREAM in making the choice of architectural patterns systematic by using non-functional requirements, in order to guide the refinement of a software architecture

O processo de (re)produção do espaço urbano de Nova Parnamirim

The public and private politics that was implemented in Natal, have always been attracting, great contingent of people in search of employments. However, not always, they can attend the migratory demands. Recently, Nova Parnamirim that is situated in the municipal district of Parnamirim - RN, due to proximity with Natal, it is passing for an intensive and accelerated occupation process impelled by the urban politics that created and they determined new diversities, leaning in the growth of the modern tertiary. In this context, Nova Parnamirim is suffering, along the time, substantial transformations in your espace, so much of nature social as environmental, that are affecting in the quality of your residents' life. This fact is mainly linked in the absence of an appropriate urban planning that have to be considered as an instrument norteador of the development of the city in its constant construction process. The study has as objective to analyze the social-space dynamics of the area and their implications, identifying the principal agents that promote and they benefit of that urbanization process. For the ccomplishment of this research it was executed bibliographical readings that turn of theoretical studies about the urban subjects and enviroments, besides field activities for the rising of the data investigated in the methodological approach