930 resultados para Life Cycle Analysis (LCA)
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During the PhD program in chemistry at the University of Bologna, the environmental sustainability of some industrial processes was studied through the application of the LCA methodology. The efforts were focused on the study of processes under development, in order to assess their environmental impacts to guide their transfer on an industrial scale. Processes that could meet the principles of Green Chemistry have been selected and their environmental benefits have been evaluated through a holistic approach. The use of renewable sources was assessed through the study of terephthalic acid production from biomass (which showed that only the use of waste can provide an environmental benefit) and a new process for biogas upgrading (whose potential is to act as a carbon capture technology). Furthermore, the basis for the development of a new methodology for the prediction of the environmental impact of ionic liquids has been laid. It has already shown good qualities in identifying impact trends, but further research on it is needed to obtain a more reliable and usable model. In the context of sustainable development that will not only be sector-specific, the environmental performance of some processes linked to the primary production sector has also been evaluated. The impacts of some organic farming practices in the wine production were analysed, the use of the Cereal Unit parameter was proposed as a functional unit for the comparison of different crop rotations, and the carbon footprint of school canteen meals was calculated. The results of the analyses confirm that sustainability in the industrial production sector should be assessed from a life cycle perspective, in order to consider all the flows involved during the different phases. In particular, it is necessary that environmental assessments adopt a cradle-to-gate approach, to avoid shifting the environmental burden from one phase to another.
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Research has demonstrated that mining activities can cause serious impacts on the environment, as well as the surrounding communities, mainly due to the unsafe storage of mine tailings. This research focuses on the sustainability assessment of new technologies for the recovery of metals from mine residues. The assessment consists in the evaluation of the environmental, economic, and social impacts through the Life Cycle based methods: Life Cycle Assessment (LCA), Life Cycle Costing (LCC), and Social Life Cycle Assessment (SLCA). The analyses are performed on the Mondo Minerals bioleaching project, which aim is to recover nickel and cobalt from the Sotkamo and Vuonos mine tailings. The LCA demonstrates that the project contributes to the avoided production of nickel and cobalt concentrates from new resources, hence reducing several environmental impacts. The LCC analysis shows that the company’s main costs are linked to the bioleaching process, caused by electricity consumption and the chemicals used. The SLCA analyses the impacts on three main stakeholder categories: workers, local community, and society. The results demonstrated that a fair salary (or the absence of it) impacts the workers the most, while the local community stakeholder category impacts are related to the access to material resources. The health and safety category is the most impacted category for the society stakeholder. The environmental and economic analyses demonstrate that the recovery of mine tailings may represents a good opportunity for mine companies both to reduce the environmental impacts linked to mine tailings and to increase the profitability. In particular, the project helps reduce the amounts of metals extracted from new resources and demonstrates that the use of the bioleaching technology for the extraction of metals can be economically profitable.
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This PhD work arises from the necessity to give a contribution to the energy saving field, regarding automotive applications. The aim was to produce a multidisciplinary work to show how much important is to consider different aspects of an electric car realization: from innovative materials to cutting-edge battery thermal management systems (BTMSs), also dealing with the life cycle assessment (LCA) of the battery packs (BPs). Regarding the materials, it has been chosen to focus on carbon fiber composites as their use allows realizing light products with great mechanical properties. Processes and methods to produce carbon fiber goods have been analysed with a special attention on the university solar car Emilia 4. The work proceeds dealing with the common BTMSs on the market (air-cooled, cooling plates, heat pipes) and then it deepens some of the most innovative systems such as the PCM-based BTMSs after a previous experimental campaign to characterize the PCMs. After that, a complex experimental campaign regarding the PCM-based BTMSs has been carried on, considering both uninsulated and insulated systems. About the first category the tested systems have been pure PCM-based and copper-foam-loaded-PCM-based BTMSs; the insulated tested systems have been pure PCM-based and copper-foam-loaded-PCM-based BTMSs and both of these systems equipped with a liquid cooling circuit. The choice of lighter building materials and the optimization of the BTMS are strategies which helps in reducing the energy consumption, considering both the energy required by the car to move and the BP state of health (SOH). Focusing on this last factor, a clear explanation regarding the importance of taking care about the SOH is given by the analysis of a BP production energy consumption. This is why a final dissertation about the life cycle assessment (LCA) of a BP unit has been presented in this thesis.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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We describe growth, longevity, sex ratio, reproductive period, and recruitment of Aegla paulensis from Jaragua Stale Park, Sao Paulo, Brazil (23 degrees 27'27.9 '' S; 46 degrees 45'32.3 '' W). The population was sampled monthly (September 2007 through August 2009) with the aid of traps. Over five thousand individuals were captured, sexed, measured (carapace length = CL) and inspected for reproductive traits (females only), and then released back to the sampling site. The pattern of the reproductive cycle was strongly seasonal (austral mid autumn through late winter), with a single recruitment pulse per year. The obtained von Bertalanffy growth equations were CL = 21.25[1-e(-0.041(t + 1.250))] and CL = 16.52[1-e(-0.049(t + 1.823))] for males and females, respectively. Males (mean CL +/- SD = 11.86 +/- 2.79 mm) attain larger sizes than females (mean CL +/- SD = 10.84 +/- 2.36 mm). Aegla paulensis reproduces twice during an estimated life span of 40.2 months for females and 33.9 months for males. Temporal variation of sex ratio showed a distinctive pattern characterized by a sequence of three distinct periods that repeated from one year to another, and which suggested that a behavioral component influence the proportion of sex in adult specimens sampled with traps during reproductive and non-reproductive periods.
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Background: Life cycles of medusozoan cnidarians vary widely, and have been difficult to document, especially in the most recently proposed class Staurozoa. However, molecular data can be a useful tool to elucidate medusozoan life cycles by tying together different life history stages. Methodology/Principal Findings: Genetic data from fast-evolving molecular markers (mitochondrial 16S, nuclear ITS1, and nuclear ITS2) show that animals that were presumed to be a hydrozoan, Microhydrula limopsicola (Limnomedusae, Microhydrulidae), are actually an early stage of the life cycle of the staurozoan Haliclystus antarcticus (Stauromedusae, Lucernariidae). Conclusions/Significance: Similarity between the haplotypes of three markers of Microhydrula limopsicola and Haliclystus antarcticus settles the identity of these taxa, expanding our understanding of the staurozoan life cycle, which was thought to be more straightforward and simple. A synthetic discussion of prior observations makes sense of the morphological, histological and behavioral similarities/congruence between Microhydrula and Haliclystus. The consequences are likely to be replicated in other medusozoan groups. For instance we hypothesize that other species of Microhydrulidae are likely to represent life stages of other species of Staurozoa.45
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Immature bivesiculid trematodes collected from the intestine of Thalassoma lunare (Labridae) are shown to be morphologically consistent with adults of Bivesicula claviformis from Epinephelus fasciatus (Serranidae). In addition, the immature bivesiculids have the same sequence for the second internal transcribed spacer of the ribosomal DNA. Comparison with three other species of Bivesiculidae showed differences of between 23% and 30%. These results show that bivesiculids may have three-host life-cycles in addition to the two-host life-cycles that have been demonstrated previously. The three-host life-cycle enables bivesiculids to infect large carnivorous fishes. (C) 1998 Australian Society for Parasitology. Published by Elsevier Science Ltd. All rights reserved.
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Intraspecific Drosophila studies suggest that resistance to heal and cold stresses are largely independent and that correlations across life cycle stages are low whereas comparisons of Drosophila species indicate correlations between heat and cold resistance as well as between resistance levels in different life cycle stages. These inconsistent results may reflect differences in associations among traits at the interspecific and intraspecific levels or interspecific correlations arising because of correlated selection pressures. These alternatives were tested using Drosophila serrata, D. birchii and hybrids derived from these species. Variation among hybrid lines and families was used to test associations at the interspecific level while intraspecific variation was examined using isofemale lines of D. serrata. There was a significant association between adult heat knockdown time at 38 degreesC and adult cold resistance in one set of hybrid lines. An association between female knockdown resistance to heat and larval heat resistance was also evident in one set of hybrids. Resistance to heat anti cold at the larval stage were not correlated at either the intraspecific or interspecific levels. At the intraspecific level, lan al heat resistance and two measures of adult heat resistance were uncorrelated. Moreover, adult and larval cold resistance measures were not correlated at either the intraspecific or interspecific levels. These results suggest that there are no associations between resistance to heat and cold extremes and that extreme temperature resistance is largely independent across life cycle stages at both the intraspecific and interspecific levels. Species associations may therefore arise from correlated selection pressures rather than trait correlations. (C) 2000 The Linnean Society of London.
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The life cycle of Ixodes luciae was evaluated for five consecutive generations in the laboratory. Wild mice Calomys callosus and laboratory rats Rattus norvegicus were used as hosts for larvae and nymphs. For adult ticks, opossums Didelphis aurita were used as hosts. Off-host developmental periods were observed in an incubator at 27A degrees C and 95% RH. The life cycle of I. luciae lasted 95-97 days, excluding prefeeding periods. C. callosus, one of the natural host species for I. luciae immature stages, was shown to be much more suitable than the artificial host R. norvegicus. Significantly (P < 0.05), more larvae and nymphs successfully fed on C. callosus than on R. norvegicus. When tick-na < ve C. callosus were exposed to three consecutive larval infestations at 24-day intervals, recovery of engorged larvae were greater in the second and third infestations, indicating that previous infestations did not induce acquired resistance to ticks. Larval feeding period typically varied from 5 to 10 days on R. norvegicus, but was significantly (P < 0.05), longer on C. callosus (range, 7-34 days). The majority (71.7%) of I. luciae adult females successfully fed and oviposited after exposed to D. aurita. Mean engorged weight (581.9 mg; range, 237.1-796.0 mg) of these females were much higher than those previously reported for other New World Ixodes species. Our results are in accordance to the current literature that appoints opossums Didelphidae and small rodents (e.g., C. callosus) natural hosts for I. luciae immature and adult stages, respectively.
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Amblyomma incisum Neumann is a major tick species in the Atlantic Forest of Brazil. Tapir is the main host for adult ticks and a high aggressiveness of nymphs to humans has been reported. In this work data on the biology and life cycle of this tick species is presented for the first time. It was shown that horse is a suitable host for A. incisum adults and rabbit for larvae and nymphs. It was also shown that A. incisum is a big tick species (mean engorged female weight of 1.96 g) with a long life cycle which lasts 262.3 days when maintained at 27A degrees C and 85% RH. These laboratory conditions were, however, inappropriate and egg hatching rate (1.2%) was very low. Nevertheless egg hatching of ticks in a forest patch increased considerably (72.2%) indicating that this A. incisum population is highly dependent on a forest-like environment.
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We use a new molecular phylogeny, developed from small and large subunit ribosomal RNA genes, to explore evolution of the digenean life cycle. Our approach is to map character states on the phylogeny and then use parsimony to infer how the character evolved. We conclude that, plesiomorphically, digenean miracidia hatched from eggs and penetrated gastropod first intermediate hosts externally. Fork-tailed cercariae were produced in rediae and emerged from the snail to be eaten directly by the teleost definitive host. These plesiomorphic characters are seen in extant Bivesiculidae. We infer that external encystment and the use of second intermediate hosts are derived from this behaviour and that second intermediate hosts have been adopted repeatedly. Tetrapod definitive hosts have also been adopted repeatedly. The new phylogeny proposes a basal dichotomy between 'Diplostomida' (Diplostomoidea, Schistosomatoidea and Brachylaimoidea) and 'Plagiorchiida' (all other digeneans). There is no evidence for coevolution between these clades and groups of gastropods. The most primitive life cycles are seen in basal Plagiorchiida. Basal Diplostomida have three-host life cycles and are associated with tetrapods. The blood flukes (Schistosomatoidea) are inferred to have derived their two-host life cycles by abbreviating three-host cycles. Diplostomida have no adult stages in fishes except by life cycle abbreviation. We present and test a radical hypothesis that the blood-fluke cycle is plesiomorphic within the Diplostomida.
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O consumo de energia tem vindo a crescer de uma forma contínua e directamente proporcional ao aumento da população e da industrialização. A maior parte da energia consumida no Mundo é, ainda, proveniente dos combustíveis fósseis. Contudo, a diminuição da reserva e a poluição atmosférica produzida pela sua utilização, estimulam e aumentam a necessidade de fontes alternativas de energia. O biodiesel tem atraído considerável atenção como combustível renovável, biodegradável e não tóxico, e pode contribuir para a resolução do problema energético, reduzindo significativamente a emissão dos gases causadores do aquecimento global. A primeira etapa deste trabalho consistiu na simulação de diferentes alternativas de processos de produção de biodiesel. O método usado para a produção do biodiesel foi a transesterificação entre os óleos vegetais e um álcool, na presença de um catalisador. Entre as matérias-primas figuram os óleos de palma e os óleos alimentares usados que foram objecto de estudo nesta dissertação. Na segunda etapa realizou-se uma análise do ciclo de vida para todas as alternativas em estudo seguida de uma análise económica para as alternativas que apresentassem menores impactos e que fossem mais promissoras do ponto de vista económico. Por fim, procedeu-se à comparação das diferentes alternativas sob o ponto de vista da análise do ciclo de vida e sob o ponto de vista da análise económica. Comprovou-se a viabilidade de todos os processos e o biodiesel obtido apresentou boas especificações. Do ponto de vista da análise do ciclo de vida a melhor alternativa foi o processo de catálise alcalina com pré-tratamento ácido para óleos alimentares usados. O processo que usa como matérias-primas os óleos virgens, o metanol e o hidróxido de sódio apresenta, no entanto, menores custos de investimento. Contudo, o processo de catálise alcalina com pré-tratamento ácido cuja matéria-prima principal são os óleos usados é muito mais rentável e apresenta menores impactes ambientais.
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Dissertação de natureza científica para obtenção do grau de mestre em Engenharia Civil