2 resultados para essência
em Repositório Institucional da Universidade Tecnológica Federal do Paraná (RIUT)
Resumo:
Starch has properties that make it one of the most studied biopolymers today. It is biodegradable, biocompatible, stable and non-toxic. This work has synthesis of starch and tapioca microparticles, through chemical modification by crosslinking with sodium tripolyphosphate agent in concentrations 7.5 and 15% (m / m). The amylose content was measured for starch and commercial cassava starch at 21.8% and 28.6%, respectively. According to the solubility index, processing in basic medium does not change the solubility of the material, but the addition of crosslinking agent increases this index, which changed from 12.8% for the control unprocessed, to 22.4% for the A5R15 sample. Soluble starch-based materials had a significant increase in the crosslinking density by increasing the concentration of crosslinker, from 1.4 in A5R7,5 sample, to 1.9 in A5R15. The cassava starch-based materials exhibited an opposite behavior: to increase the concentration of crosslinker crosslinking density decreased significantly in F5R7.5 from 2.9, to 1.9 in F5R15 sample. The point of zero charge (PZC) shows that below pH 4 the surface is positively charged. The surface area data is between 3,04 and 1,15 m2.g-1. The pore volume between 2.94 and 1.33 cm3.g-1 and pore size around 1.5 nm. The SEM indicates uneven distribution of microparticles, which are smooth, with no ridges. The maximum adsorption capacity of the materials were tested at pH 7.7 and for A5R15 and CA sample, at pH 2, 5, 6 and 9. It is noted that the processing in basic medium reduces the adsorption capacity of CA and CF in respect fo A and F. The adsorption in A5R15 sample has great dependency on the pH, reaching a value of 587 μg.g-1 in pH 7.7. The samples A5R15 and F5R7,5 adsorbed similar amounts, according to the statistical analysis, and significantly higher than their respective controls and showed lower desorption, indicating that the modification process was effective to control the release of methylene blue. The infrared spectra not show the characteristic bands of the phosphate bonds to the material formed, however, developments in hydroxyl characteristic band suggest modification in the way this group was linked after the reaction. After adsorption, the infrared spectra show different format in the band of hydroxyl. PCA analysis shows that the greatest changes observed in the IR spectra are observed in the region of 3500 cm-1. Thermal analysis showed three thermal events related to dehydration and material degradation. It is observed that the processing increases the temperature to the first mass loss, fixed at 12%, but not observed increased stability due to the presence of crosslinker or process.
Resumo:
This study was a critical investigation of the configuration of discourse on work in the Brazilian criminal legal discourse. We problematized the discourse of an alleged reintegrative social function proposed by the criminal legal system and analyzed the role of such discourse in the core of disciplinary power strategies that impose on individuals the honest worker condition as a major criterion for their rehabilitation and return to society as citizens. This critique is our starting point to build the argument that discourse on work as it appears in current criminal legal texts operates more as a criminalization index of those who do not have a lawful occupation than a guarantee of legitimate social transit for convicts and recognition of their dignity. For this purpose, we used as corpus the main sources of Law, namely the Federal Constitution of 1988, the Penal Code, the Penal Execution Law, the Brazilian criminal doctrine and an extensive, more recent penal jurisprudence with regard to techniques of resocialization through work. This critical line enabled us to recognize complexity and plurality of discourses - antagonistic, at times - that build the world of work as portrayed in legal texts. We also sought reference in the discussion on the centrality of work as a formative category of the social being as well as theories that defend the non-centrality of work. Throughout our investigation, we sough to question the very condition of such centrality and to understand the ways in which it was possible to produce a legitimating discourse on work as a model of emancipatory social conduct defended and demanded by the Brazilian punitive system. In a context of precariousness, unemployment and flexibilization of the world of work in contemporary society, convicts hardly ever succeed to resume the identity of honest, hard-working citizens - and no longer offenders. In this context, we also questioned the formulation of a discourse that speaks about human labor as the essence of man and criticizes the Marxist vision that is based on work centrality, and we approached the concept of Michel Foucault, our theoretician of reference, who understands work more as a mechanism of power that promotes the individuals’ submission and adaptation to a goods-producing society than the natural activity of man. We ascribe our study to the field of questions that tackle the political conception of the body as subject to labor imposed as productive and political force. It is about the issue of political technology of individuals, a technology of power, as named by the French author. The intended analysis has not dismissed the material existence of labor relations but sought to discuss the validity of a discourse that considers work the main resource for convict rehabilitation and index for the recognition of dignity and honesty. The Foucauldian discourse analysis was the foundation for the investigation of our object, especially if we understand discourses as social practices with power to institute knowledge and produce truths.