Technologies for reusing, recycling and energetic valorization of tires in Brazil

Os pneus usados estão se tornando um problema mundial. O descarte de pneus cresce ano após ano em todo o mundo. Pouca importância foi dada ao descarte de pneus em muitos países. No Brasil, em 1999, foi aprovada a Resolução nº 258/99 do CONAMA (Conselho Nacional do Meio Ambiente) que instituiu a responsabilidade do produtor e do importador pelo ciclo total do produto, ou seja, a coleta, o transporte e a disposição final. Desde 2002, os fabricantes e importadores de pneus devem coletar e dar a destinação final para os pneus usados. Segundo essa lei, os distribuidores, revendedores, reformadores e consumidores finais são co-responsáveis pela coleta dos pneus servíveis e inservíveis, os quais devem colaborar com a coleta. Neste trabalho serão apresentadas as tecnologias utilizadas no Brasil para a reutilização, reciclagem e valorização energética, além de um fluxograma do processo de logística reversa dos pneus novos e usados, dados estatísticos dos canais de distribuição, objetivo da reciclagem e a disposição final, no período de 2002 a 2006. Em 2006, foram reciclados 240,62 mil toneladas de pneus inservíveis, o equivalente a 48,12 milhões de pneus de automóvel. As atividades de laminação, trituração e fabricação de artefatos de borracha representaram 50,02% do total destinado, o co-processamento em fornos de clínquer representou 35,73%, a regeneração de borracha sintética representou 13,22% e a extração e tratamento de minerais 1,03%.Used tires have become a worldwide problem. The discarding of tires rises year after year all over the world. So far little importance has been given to the discarding of tires in many countries. In 1999, the CONAMA (National Council for the Environment) resolution 258/99 made the producer or importer as responsible for the total cycle of the product in Brazil, including the means of collection, transportation and final destination to the product. Since 2002, the manufacturers and importers of tires must collect and give the final destination to the used tires. The distributors, retailers, re-modelers and final consumers are co-responsible for the collection of the used or unserviceable tires. In this study we review the technologies for reusing, recycling and energetic valorization of tires, in addition to presenting a flowchart of the reverse logistic process for new and used tires. Also included are statistical data of distribution channels, recycling goals and final destination for the used tires in the period from 2002 to 2006. In 2006, 240.62 thousand tons of unserviceable tires were recycled, which correspond to 48.12 million of automobile tires. The activities of laminating, grinding and manufacturing of rubber artifacts represented 50.02% of the total; the co-processing in clinker ovens represented 35.73%; the synthetic rubber regeneration represented 13.22% while 1.03% was used in the extraction and treatment of minerals

The wood moisture factor on the biological deterioration of wooden structures

With sustainability as a growing concern, the rehabilitation of buildings arises as one of the main forms of support for the construction sector. Rehabilitation, in comparison with new construction, is seen as a path to minimize the negative impacts of this activity by reducing, for example, the energy consumption of buildings and its consequent impact on energy production (still meeting the current needs for comfort) and the extraction of raw materials. Wood has a high potential for numerous purposes, also, it is a natural, renewable, and sustainable resource, presenting itself as a promising construction material with enormous importance for the bio-based economy. However, despite being a traditional material, reliable service life prediction of wooden structures continues to be a challenge. Like other biobased materials, wood can be subject to biological deterioration by fungi and insects. The biological agents, when combined with favourable conditions (e.g., temperature, air relative humidity, wood moisture content, etc.), can lead to simply aesthetic damage, reduction in indoor air quality, or compromising its resistant load capacity, creating a risk to human health and safety, in addition to an increase of repair and maintenance costs. Many approaches consider wood moisture content as the key factor to control the activation of the decay process, since fungal colonization of wood requires a minimum moisture content of around 20%. Moreover, though subterranean termites (one of the most damaging wood insects) are able to infest dry wood, contact to moisture is fundamental for effective installation of the colonies. This paper addresses moisture as a conditioning factor in the degradation of wood in construction. The role of water on the development of the biodeterioration processes, the transport of water within wooden elements, as well as how the current normative references address the issue are discussed. Finally, this work presents some of the exiting methods for continuous moisture content monitoring systems that, associated with regular maintenance, can be an alternative to chemical treatments, increasingly limited due to current environmental legislation- (undefined

Quantum phase transitions in alternating spin-(1/2, 5/2) Heisenberg chains

The ground state spin-wave excitations and thermodynamic properties of two types of ferrimagnetic chains are investigated: the alternating spin-1/2 spin-5/2 chain and a similar chain with a spin-1/2 pendant attached to the spin-5/2 site. Results for magnetic susceptibility, magnetization and specific heat are obtained through the finite-temperature Lanczos method with the aim in describing available experimental data, as well as comparison with theoretical results from the semiclassical approximation and the low-temperature susceptibility expansion derived from Takahashi's modified spin-wave theory. In particular, we study in detail the temperature vs. magnetic field phase diagram of the spin-1/2 spin-5/2 chain, in which several low-temperature quantum phases are identified: the Luttinger Liquid phase, the ferrimagnetic plateau and the fully polarized one, and the respective quantum critical points and crossover lines

Mechanical characterization of Iroko wood using small specimens

Despite their favorable physical and mechanical properties for structural use, tropical woods, such as Iroko (Milicia excelsa), present knowledge gaps to be filled mainly about their mechanical characterization, which currently limit their use or result in under- or overdimensioned structural elements. Visual classification, one of the most used methods for characterizing wood, is inaccurate in the case of Iroko due to the wide variety of geographical locations in which this species can be found. In addition, mechanical characterization using test pieces with structural dimensions leads to high and impractical costs. In this context, this study aims to verify the mechanical properties of Iroko (imported from the Republic of the Congo) from small size specimens, a process that is currently standardized only for softwoods, and to verify the correlation of different properties through bending properties and ultrasound tests. Prior to the bending tests, the speed of propagation of ultrasonic waves was measured using the direct method. The results obtained show a good correlation between density and bending properties and the velocity of propagation of ultrasonic waves

Assessment of the density loss in anobiid infested pine using X-ray micro-computed tomography

The present study aims at evaluating the impact of anobiid damage on pine timber elements. Anobiid attack produces a diffuse damage of the elements with a set of tunnels in random directions and sizes, thus confusing quantification. Therefore, a method was developed based on X-ray micro-computed tomography (μ-XCT) to obtain, for naturally infested timber samples, an empirical correlation between lost material percentage (consumed by beetles) and timber apparent density (original, before degradation—OTD and residual, after degradation—RTD). The quantified density loss can then be used in further assessment of the structure. The results of the tests performed showed high correlation between original apparent density and lost material percentage (r2 = 0.60) and between residual apparent density and lost material percentage (r2 = 0.83), which confirms μ-XCT as a valuable tool to the required quantification. The loss of density results can be further applied on the definition of an assessment method for the evaluation of the residual strength of anobiids infested timber, thus contributing to reducing unnecessary replacement. The optimized procedure of the μ-XCT study for infested Maritime pine (Pinus pinaster) is presented and discussed in this article.The authors acknowledge the support given by Portuguese Foundation for Science and Technology (FCT) within research projects: PTDC/EPH-PAT/4684/2014 (DB-HERITAGE), PTDC/ECM-EST/1072/2014 (Pro-Timber), Pest-OE/CTE/UI4028/2011 (CERENA) and UIDB/ 04625/2020 (CERIS)

Materiais Usados em uma Perspectiva Inclusiva no Ensino de Combinatória e de Probabilidade

Neste texto apresentamos dois estudos de caso realizados com estudantes cegos, com vistas a discutiratividades em uma perspectiva inclusiva. Foram, nesse sentido, propostas questões a serem resolvidas comesses alunos com auxílio de recursos materiais que fazem uso de sentidos diferentes – tais como o tato, o olfatoe a visão – uma vez que se objetiva que as atividades possam ser desenvolvidas junto a estudantes cegos evidentes. Os estudos de caso referem-se a conteúdos matemáticos – Combinatória e Probabilidade – que nemsempre têm sido adequadamente trabalhados no Ensino Fundamental, mas que defendemos como essenciaisao desenvolvimento do raciocínio matemático. Os resultados indicam que a linguagem, aliada à exploraçãosensorial, permitem que o estudante com deficiência visual obtenha informações necessárias à formação deconceitos e que os recursos utilizados possibilitam a formação de conceitos combinatórios e probabilísticos

Zeta function method and repulsive Casimir forces for an unusual pair of plates at finite temperature

We apply the generalized zeta function method to compute the Casimir energy and pressure between an unusual pair of parallel plates at finite temperature, namely: a perfectly conducting plate and an infinitely permeable one. The high and low temperature limits of these quantities are discussed; relationships between high and low temperature limits are estabkished by means of a modified version of the temperature inversion symmetry.Comment: latex file 9 pages, 3 figure

A importância da organização da cadeia de valor da tilápia na gestão da crise hídrica.

Introdução. Caracterização produtiva e a estiagem nos polos de piscicultura dos reservatórios de Ilha solteira, submédio e baixo São Francisco e Castanhão e Orós, no período de 2012 a 2015. Ações de Mitigação. Consequências de mercado. A importancia da caracterização climática e do Cerrado no abastecimento das grandes bacias hidrográficas brasileiras. Projeções das mudanças climáticas globais e os impactos sobre os recursos hídricos brasileiros. Considerações finais. Referências.bitstream/item/139187/1/CNPAF-2015-doc24.pd

Discussão sobre a regularização da piscicultura brasileira: da produção à comercialização.

Introdução. Regularização de projetos aquícolas. Regularização de projetos aquícolas. Exemplos da abertura de empresa rural em outros países. Registro de Aquicultor e Licença de Aquicultor. Espécies cultiváveis. Exemplos de permissão de espécies exóticas para cultivo em outros países. Resumo do processo de regularização das pisciculturas em águas da União. Licenciamento ambiental de projetos de piscicultura. Particularidades do licenciamento em viveiros escavados, barragem e PCH e águas Estaduais. Custos do processo de regularização da área aquícola no Brasil. Exemplos internacionais sobre a regularização das áreas produtivas. Outorga de direito de uso de recursos hídricos para a piscicultura. Exemplos internacionais sobre cessão de uso das áreas produtivas. Regularização da produção. Incentivos para a produção. Tarifa da energia elétrica. Contribuição previdenciária. Regularização na comercialização. Despesca e Abate. Transporte. Guia de trânsito animal e outros documentos. Problemas causados pela falta de Inspeção Sanitária. Registros de estabelecimentos de processamento de pescado. SISB - Uma opção. Considerações Finais. Referências. Anexo 1 - Referências de interesse