66 resultados para Reciclagem a frio


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With the increase of asphalt milling services was also a significant increase in recycling services pavements. The techniques used today are basically physical processes in which the milled material is incorporated into new asphalt mixtures or executed on site, with the addition of virgin asphalt and rejuvenating agent. In this paper seeks to analyze the efficiency of extraction of CAP (Petroleum Asphalt Cement) mixtures from asphalt milling, using commercial solvents and microemulsions. The solvents were evaluated for their ability to solubilize asphalt using an extractor reflux-type apparatus. Pseudoternary diagrams were developed for the preparation of microemulsion O/W surfactant using a low-cost coconut oil saponified (OCS). Microemulsions were used to extract the CAP of asphalt through physicochemical process cold. Analysis was performed concentration of CAP in solution by spectroscopy. The data provided in the analysis of concentration by the absorbance of the solution as the basis for calculating the percentage of extraction and the mass flow of the CAP in the solution. The results showed that microemulsions prepared with low concentration of kerosene and butanol/OCS binary has high extraction power of CAP and its efficiency was higher than pure kerosene, reaching 95% rate of extraction

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O modelo civilizatório da sociedade global fundamenta-se na produção à larga escala e no aumento exponencial e diversificado do consumo. Este modelo impacta o meio ambiente já que demanda grandes quantidades de recursos naturais e provoca contaminação ambiental. No leque desta contaminação, a geração de resíduos sólidos surge como uma das principais devido a seus efeitos nocivos serem sentidos de forma imediata pelas pessoas. Em países como o Brasil, uma das soluções requeridas para se minimizar e/ou equacionar a problemática engendrada pelos resíduos sólidos é a reciclagem dos materiais. A justificativa oficial pelo esforço à reciclagem está nas características da atividade já que o uso de materiais reciclados reduz a demanda por recursos naturais em processos produtivos industriais, aumenta o tempo de vida útil dos aterros sanitários (local de destino final dos resíduos), além de gerar emprego e renda para os catadores, sujeitos que sobrevivem da coleta e separação dos materiais recicláveis. A partir de uma ética ambiental, a pergunta que deve ser feita quando nos propomos a analisar as implicações da geração dos resíduos é: por que a sociedade global gera resíduos sólidos de maneira acentuada? Contudo, à luz dos pressupostos mercadológicos do capitalismo, a pergunta que move as discussões acerca da problemática dos resíduos sólidos é: o que fazer com a crescente geração de resíduos sólidos? O presente artigo se propõe a uma reflexão dos elementos justificativos dessa ode à reciclagem. Em nossa perspectiva, a reciclagem fomenta ao que denominamos de ambientalismo econômico, no qual o discurso pró-reciclagem se apropria dos elementos e potencialidades ambientais da atividade da reciclagem para justificar as ações de caráter econômico no que se refere ao que fazer com os resíduos gerados diariamente.

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At present, the material of choice for performing aesthetic dental prosthetic work is in the ceramic. Among them, the ceramic base of stabilized zirconia with 3% yttria (3Y - TZP) stand out for having excellent physical and mechanical properties. During the machining of blocks of zirconia in the laboratory to prepare the various types of prostheses, much of the material is given off in the form of powder, which is subsequently discarded. The waste of this material results in financial loss, reflecting higher final cost treatment for patients, as well as damage to the environment, thanks to the processes involved in the manufacture and disposal of the ceramic. This research, pioneered the recycling of zirconium oxide powder obtained during milling of dental crowns and bridges, we highlight the social and environmental aspects and aims to establish a protocol for the reuse of waste (powder of zirconia Zirkonzahn® system) discarded to obtain a new block of compacted zirconia to maintain the same mechanical and microstructural properties of commercial high-cost imported material. To compare with the commercial material, samples were uniaxially (20 MPa) and isostatically (100 MPa), and its mechanical and microstructural characterization was performed through tests of density, porosity, dilatometry, X-ray diffraction (XRD), hardness, fracture toughness, resistance to fracture electron microscopy (SEM) and analysis of grain size. The results observed in the samples were isostatically pressed similiares those obtained with samples from the commercial material demonstrating the viability of the process

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Research for better performance materials in biomedical applications are constants. Thus recent studies aimed at the development of new techniques for modification of surfaces. The low pressure plasma has been highlighted for its versatility and for being environmentally friendly, achieving good results in the modification of physic chemical properties of materials. However, it is requires an expensive vacuum system and cannot able to generate superficial changes in specific regions. Furthermore, it is limits their use in polymeric materials and sensitive terms due to high process temperatures. Therefore, new techniques capable of generating cold plasma at atmospheric pressure (APPJ) were created. In order to perform surface treatments on biomaterials in specific regions was built a prototype capable of generating a cold plasma jet. The prototype plasma generator consists of a high voltage source, a support arm, sample port and a nozzle through which the ionized argon. The device was formed to a dielectric tube and two electrodes. This work was varied some parameters such as position between electrodes, voltage and electrical frequency to verify the behavior of glow discharges. The disc of titanium was polished and there was a surface modification. The power consumed, length, intensity and surface modifications of titanium were analyzed. The energy consumed during the discharges was observed by the Lissajous figure method. To check the length of the jets was realized with Image Pro Plus software. The modifications of the titanium surfaces were observed by optical microscopy (OM ) and atomic force microscopy (AFM ). The study showed that variations of the parameters such as voltage, frequency and geometric position between the electrodes influence the formation of the plasma jet. It was concluded that the plasma jet near room temperature and atmospheric pressure was able to cause modifications in titanium surface

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The chemical recycling of polyolefins has been the focus of increasing attention owing potential application as a fuel and as source chemicals. The use of plastic waste contributes to the solution of pollution problems.The use of catalysts can enhance the thermal degradation of synthetic polymers, which may be avaliated by Themogravimetry (TG) and mass spectrometry (MS) combined techniques. This work aims to propose alternatives to the chemistry recycling of low-density polyethylene (LDPE) on mesoporous silica type SBA-15 and AlSBA-15.The mesoporous materials type SBA-15 and AlSBA-15 were synthesized through the hydrothermal method starting from TEOS, pseudobohemite, cloridric acid HCl and water. As structure template was used Pluronic P123. The syntheses were accomplished during the period of three days. The best calcination conditions for removal of the organic template (P123) were optimized by thermal analysis (TG/DTG) and through analyses of Xray diffraction (XRD), infrared spectroscopy (FT-IR), nitrogen adsorption and scanning electron microscopy (SEM) was verified that as much the hydrothermal synthesis method as the calcination by TG were promising for the production of mesoporous materials with high degree of hexagonal ordination. The general analysis of the method of Analog Scan was performed at 10oC/min to 500 oC to avoid deterioration of capillary with very high temperatures. Thus, with the results, we observed signs mass/charge more evident and, using the MID method, was obtained curve of evolution of these signals. The addition of catalysis produced a decrease in temperature of polymer degradation proportional to the acidity of the catalyst. The results showed that the mesoporous materials contributed to the formation of compounds of lower molecular weight and higher value in the process of catalytic degradation of LDPE, representing an alternative to chemical recycling of solid waste

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This study is the analysis of cultural, political and organizational interfaces of "Caminhos do Frio Rota Cultural" Project in the context of tourism regionalization in Brejo Paraibano and it presents the characterization, routing and inventory of six municipalities of the Project, as well as the identification of cultural elements used for tourist in the routing of the pond, the investigation of political and organizational articulation and the verification of participation of each producing agent in the development of tourism resulting from the swamp of Paraiba. This is a qualitative descriptive and exploratory study, which makes use of the interpretive paradigm to perform an analysis of the environment where occurs the regionalization of tourism in Brejo of Paraíba and the social actors involved in this process in order to pursue development of the region through culture and tourism, with the collection spot in the six counties of the Project participants collected through interviews with managers, community, government agencies and tourist trade, and the use of the technique of direct observation. This time, with the data analysis it was possible to establish the production situation and its cultural and tourist development in the region of Brejo (PB), where culture has become a developmental tool within the tourism industry due to its innovation potential. It was possible to ratify the undisputed vocation of cultural tourism in the region in question, since other projects being developed with the use of cultural resources with a strong influence on the policies of regional tourism. Thus, the main result was that was seen is that the regional development has triggered a refunctionalisation / reappropriation of space just rebuilding a new territorial organization through the development of a regional autonomy of management, a capacity of collective ownership and the use of economic surplus, a spontaneous process of social inclusion as well as awareness and mobilization tourist (even if initial and shy), an appreciation of natural and cultural assets for all stakeholders and especially identification of the population with its region and its culture, as to achieve regional development is not enough to increase the economic, but above all the promotion of endogenous social factors such as changes in social and cultural values and the integration of social actors in this process. Finally, taking into account the definitions of sustainability, it is considered that cannot be said that the development model seen in the swamp of Paraiba is sustainable, but it is a model of regional development based on the unique characteristics that each municipality has and create a regional identity and have correponded expectations / desired results and therefore the viability of the region through the development of cultural tourism was proven

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A indústria de reciclagem vem se desenvolvendo no Brasil desde o começo dos anos noventa, o que resulta em elevados índices de reciclagem e tecnologia de ponta na reciclagem de alguns materiais. Requisitada como estratégia para a gestão dos resíduos no destino final, a reciclagem possui a particularidade de ser uma atividade econômica bastante rentável. Este artigo analisa os índices da indústria de reciclagem dos materiais no Brasil. Com base nos resultados obtidos através da consulta bibliográfica e dados estatísticos oriundos de fontes primárias e secundárias, conclui-se que a atividade da reciclagem dos materiais no Brasil se presta a satisfazer exclusivamente às demandas econômicas do setor. Neste sentido, a contribuição ambiental da reciclagem perde relevância visto que o crescimento da atividade está condicionado às demandas da cadeia produtiva industrial

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In recent decades, the collective leadership of the Solidary Economical Enterprises (ESS) that are active in providing collection and recycling services, has been presented as a proposal for the organization of urban space with the creation of new enterprises and solidarity production chains. Are activities that have gained a new stimulus to the creation of the National Secretariat of Solidarity Economy and the National Policy on Solid Waste that assigned a leading role in these social actors. These experiences contribute to building a participatory development path, resembling with the pluralistic perspective of development of the Indian economist Amartya Sen, that goes beyond the simplistic design of the increased income, focusing on the process of expanding freedoms that people enjoy. The aim of this work is to situate the perspective of endogenous development with the Collection Services segment and Material Recycling in the field of Solidarity Economy, through the analysis of the experience of the Cooperative of Selective Collection and Recycling Friends of the planet, located in the municipality of Lauro to Freitas - BA, from 2004 to 2013. for this the following procedures were adopted: analysis of the main contributions of the international literature on the phenomenon of pluriactivity; review of national literature that analyzes the emergence and evolution of the projects of solidarity economy in Brazil; bibliographical and documentary research; and socio-economic evaluation of the EES. The guiding problem of this work, understandably, is: what is the meaning of endogenous perspective with the Materials Collection and Recycling Services segment in the field of Solidarity Economy? It starts with the hypothesis that the development of these practices requires an environment that removes the main sources of deprivation involving the conditions of existence of these enterprises. The results show that not enough development to be built with the participation of social actors, but there are minimally necessary conditions for such experiences can take hold in order to achieve their goals. Thus, not only is it a strictly economic issue, but requires political actions for a process of social transformation.

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Surface defects on steel parts borne costs of smelting industries due to the need of rework. Sand molds are frequently used in foundry industries and largely responsible for providing surface defects. This study aims to optimize the levels of the molding process variables to minimize the occurrence of surface defects in steel castings in silica sand molds chemically linked by cold cure process. The methodology used the experimental design with split plot, being considered in the study the resin percentage factors in the mold formulation, addition of iron oxide, type of paint, the paint application method, amount of ink layers, use of hot air along the lines and waiting time of the mold before casting. They were analyzed as response variables erosion defects, sand inclusion, penetration, porosity and surface finish. Tensile strength tests were performed to evaluate the influence of factors on mechanical parameters and the microstructural parameters were carried out the analysis of X-ray diffraction, scanning electron microscopy (SEM) and thermal analysis (TG / DSC / dilatometry). The results elucidate that for the faulty erosion, the only significant factor with a 95% confidence level was the type of ink and the ink alumina-based superior results obtained. For the sand inclusion of defect, there were three significant factors, with best results obtained with alumina-based paint and spray applied using hot air in the mold before casting the metal. For the defect penetration, there were four significant factors, the best results being achieved with 0.8% of resin and addition of iron oxide in the molding formulation, the paint being applied by brush and standby time of 24 hours before leak. For the defect porosity with a 95% confidence level, no significant factors. For the defect surface finish, the best results were achieved with the 0.8% formulation of the resin in the mold and application of the paint brush. To obtain the levels of the factors that optimize all defects simultaneously, we performed a weighted average of the results of each type of fault, concluding that the best levels of the factors were: 0.8% resin and addition of iron oxide in the formulation of the template, application of two coats of paint applied with a brush or spray, using hot air in the mold before casting and 24 hours of waiting ready the mold before casting. These levels of the optimized factors were used in an experiment to confirm that ratified the results, helping to reduce rework and consequently reducing costs of cast steel parts.

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O modelo civilizatório da sociedade global fundamenta-se na produção à larga escala e no aumento exponencial e diversificado do consumo. Este modelo impacta o meio ambiente já que demanda grandes quantidades de recursos naturais e provoca contaminação ambiental. No leque desta contaminação, a geração de resíduos sólidos surge como uma das principais devido a seus efeitos nocivos serem sentidos de forma imediata pelas pessoas. Em países como o Brasil, uma das soluções requeridas para se minimizar e/ou equacionar a problemática engendrada pelos resíduos sólidos é a reciclagem dos materiais. A justificativa oficial pelo esforço à reciclagem está nas características da atividade já que o uso de materiais reciclados reduz a demanda por recursos naturais em processos produtivos industriais, aumenta o tempo de vida útil dos aterros sanitários (local de destino final dos resíduos), além de gerar emprego e renda para os catadores, sujeitos que sobrevivem da coleta e separação dos materiais recicláveis. A partir de uma ética ambiental, a pergunta que deve ser feita quando nos propomos a analisar as implicações da geração dos resíduos é: por que a sociedade global gera resíduos sólidos de maneira acentuada? Contudo, à luz dos pressupostos mercadológicos do capitalismo, a pergunta que move as discussões acerca da problemática dos resíduos sólidos é: o que fazer com a crescente geração de resíduos sólidos? O presente artigo se propõe a uma reflexão dos elementos justificativos dessa ode à reciclagem. Em nossa perspectiva, a reciclagem fomenta ao que denominamos de ambientalismo econômico, no qual o discurso pró-reciclagem se apropria dos elementos e potencialidades ambientais da atividade da reciclagem para justificar as ações de caráter econômico no que se refere ao que fazer com os resíduos gerados diariamente.

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At present, the material of choice for performing aesthetic dental prosthetic work is in the ceramic. Among them, the ceramic base of stabilized zirconia with 3% yttria (3Y - TZP) stand out for having excellent physical and mechanical properties. During the machining of blocks of zirconia in the laboratory to prepare the various types of prostheses, much of the material is given off in the form of powder, which is subsequently discarded. The waste of this material results in financial loss, reflecting higher final cost treatment for patients, as well as damage to the environment, thanks to the processes involved in the manufacture and disposal of the ceramic. This research, pioneered the recycling of zirconium oxide powder obtained during milling of dental crowns and bridges, we highlight the social and environmental aspects and aims to establish a protocol for the reuse of waste (powder of zirconia Zirkonzahn® system) discarded to obtain a new block of compacted zirconia to maintain the same mechanical and microstructural properties of commercial high-cost imported material. To compare with the commercial material, samples were uniaxially (20 MPa) and isostatically (100 MPa), and its mechanical and microstructural characterization was performed through tests of density, porosity, dilatometry, X-ray diffraction (XRD), hardness, fracture toughness, resistance to fracture electron microscopy (SEM) and analysis of grain size. The results observed in the samples were isostatically pressed similiares those obtained with samples from the commercial material demonstrating the viability of the process

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O mundo atual passa por uma crise ambiental sem precedentes na história, o que resulta em conseqüências ambientais perceptíveis e preocupantes. Governos e organizações internacionais têm dado maior relevância à variável ambiental como um dos principais eixos de definição das políticas de crescimento/desenvolvimento econômico, como o intuito de adequar as demandas sociais aos limites naturais. Como consequências dessa forma perdulária de produção e consumo da sociedade global temos a contaminação ambiental ampliada e diversificada. O presente artigo discute a acumulação capitalista no setor dos resíduos sólidos, partindo da hipótese da impossibilidade de se diminuir a geração ampliada dos resíduos, sendo necessário que se crie estratégias de gestão e tratamento para os resíduos baseados na atividade da reciclagem dos materiais. A parte final expõe os paradigmas da questão dos resíduos sólidos na sociedade global.

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The urban growth without the prior infrastructure has caused many environmental impacts such as the damage to quality of the water resources in the cities. Along with natural scarcity in some regions, this is one of the factors that limit the availability of drinking water. As a result, the conservation of drinking water is becoming one of the major concerns in sustainable architectural projects. Within this context, this dissertation proposes to develop the design of an educational building focusing on water consumption rationalization. The proposed project is located in UFRN Campus at Currais Novos, an area of warm and dry climate and low rainfall. The proposal seeks to integrate ways to reduce water consumption o to architecture, in order to exploit the advantages and savings. After quantifying the benefits achieved, it was concluded that it is possible to reduce significantly the drinking water consumption in educational buildings in universities using three principles: reduction the water consumption at the point of use, replacement of the water source and internal recycling. Calculations and simulations indicated that the proposed building may have water consumption up to 56% lower than if it would be provided by conventional facilities. Rationalization of water consumption brings direct and indirect benefits, with influences on the environmental, social and economic fields

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without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming

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The present work shows a contribution to the studies of development and solid sinterization of a metallic matrix composite MMC that has as starter materials 316L stainless steel atomized with water, and two different Tantalum Carbide TaC powders, with averages crystallite sizes of 13.78 nm and 40.66 nm. Aiming the metallic matrix s density and hardness increase was added different nanometric sizes of TaC by dispersion. The 316L stainless steel is an alloy largely used because it s high resistance to corrosion property. Although, its application is limited by the low wear resistance, consequence of its low hardness. Besides this, it shows low sinterability and it cannot be hardened by thermal treatments traditional methods because of the austenitic structure, face centered cubic, stabilized mainly in nickel presence. Steel samples added with TaC 3% wt (each sample with different type of carbide), following a mechanical milling route using conventional mill for 24 hours. Each one of the resulted samples, as well as the pure steel sample, were compacted at 700 MPa, room temperature, without any addictive, uniaxial tension, using a 5 mm diameter cylindrical mold, and quantity calculated to obtain compacted final average height of 5 mm. Subsequently, were sintered in vacuum atmosphere, temperature of 1290ºC, heating rate of 20ºC/min, using different soaking times of 30 and 60 min and cooled at room temperature. The sintered samples were submitted to density and micro-hardness analysis. The TaC reforced samples showed higher density values and an expressive hardness increase. The complementary analysis in optical microscope, scanning electronic microscope and X ray diffractometer, showed that the TaC, processed form, contributed with the hardness increase, by densification, itself hardness and grains growth control at the metallic matrix, segregating itself to the grain boarders