“Num só crio pra vender, não” : etnicidade, gênero e saberes domésticos em Moita Verde (Parnamirim, RN)

O presente trabalho consiste em etnografia realizada na comunidade quilombola de Moita Verde, Parnamirim (RN). Pensada a partir do processo de emergência étnica, tendo como campo de analise o espaço doméstico para pensar a relação entre as mulheres e as distintas arenas políticas, das relações entre famílias, com o entorno e agentes de Estado. Em especial, o envolvimento das mulheres com a criação de porcos vinculada a um sistema que se relaciona com outros saberes do sítio que vão para além da dimensão técnica, levando em consideração os saberes e práticas do grupo. Além disso, este saber, associado com outros saberes políticos, em contexto de relações étnico-raciais, pode ser usado dos debates sobre identidade e especificidade de direitos.

Avaliação da influência de surfactantes químico e biológico na hidrólise enzimática de casca de coco verde após pré-tratamento ácido/alcalino e com peróxido de hidrogênio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolipíd for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Avaliação da influência de surfactantes químico e biológico na hidrólise enzimática de casca de coco verde após pré-tratamento ácido/alcalino e com peróxido de hidrogênio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolipíd for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Práticas da ti verde que contribuem para o desenvolvimento sustentável: um estudo de caso em indústrias do RN

This dissertation aims to describe the practices of Information Technology Green contributing to sustainable development, in computers and textile industries in the state of Rio Grande do Norte. The goal is to understand the importance and contribution of IT Green for sustainable development. The research methodology used involved a survey of the theoretical approach prepared, involving two case studies in industries of Rio Grande do Norte. The analysis was supported by an analysis of content, which allowed the understanding of the phenomenon of the Information Technology Green sustainable development in the case studies. In conclusion, is that the Green Information Technology contributes to sustainable development, even so through incipient aspects that highlight the competitive business with a focus on cost reduction, and efforts in sustainable practices

Investigação e avaliação da toxicidade aguda dos agrotóxicos mais utilizados no cinturão verde da Grande Natal (RN, Brasil) para o peixe-zebra (Danio rerio Hamilton Buchanan, 1822, Teleostei, Cyprinidae

The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species