978 resultados para cooking losses
Resumo:
Bearing in mind the potential adverse health effects of ultrafine particles, it is of paramount importance to perform effective monitoring of nanosized particles in several microenvironments, which may include ambient air, indoor air, and also occupational environments. In fact, effective and accurate monitoring is the first step to obtaining a set of data that could be used further on to perform subsequent evaluations such as risk assessment and epidemiologic studies, thus proposing good working practices such as containment measures in order to reduce occupational exposure. This paper presents a useful methodology for monitoring ultrafine particles/nanoparticles in several microenvironments, using online analyzers and also sampling systems that allow further characterization on collected nanoparticles. This methodology was validated in three case studies presented in the paper, which assess monitoring of nanosized particles in the outdoor atmosphere, during cooking operations, and in a welding workshop.
Resumo:
Tese de Doutoramento, Física, 17 de Dezembro de 2013, Universidade dos Açores.
Resumo:
Dissertação de Mestrado, Engenharia Zootécnica, 04 de Junho de 2014, Universidade dos Açores.
Resumo:
Total petroleum hydrocarbons (TPH) are important environmental contaminants which are toxic to human and environmental receptors. Several analytical methods have been used to quantify TPH levels in contaminated soils, specifically through infrared spectrometry (IR) and gas chromatography (GC). Despite being two of the most used techniques, some issues remain that have been inadequately studied: a) applicability of both techniques to soils contaminated with two distinct types of fuel (petrol and diesel), b) influence of the soil natural organic matter content on the results achieved by various analytical methods, and c) evaluation of the performance of both techniques in analyses of soils with different levels of contamination (presumably non-contaminated and potentially contaminated). The main objectives of this work were to answer these questions and to provide more complete information about the potentials and limitations of GC and IR techniques. The results led us to the following conclusions: a) IR analysis of soils contaminated with petrol is not suitable due to volatilisation losses, b) there is a significant influence of organic matter in IR analysis, and c) both techniques demonstrated the capacity to accurately quantify TPH in soils, irrespective of their contamination levels.
Resumo:
Copyright © 2014 Entomological Society of America.
Resumo:
Mestrado em Engenharia Química
Resumo:
Analyses of species-diversity patterns of remote islands have been crucial to the development of biogeographic theory, yet little is known about corresponding patterns in functional traits on islands and how, for example, they may be affected by the introduction of exotic species. We collated trait data for spiders and beetles and used a functional diversity index (FRic) to test for nonrandomness in the contribution of endemic, other native (also combined as indigenous), and exotic species to functional-trait space across the nine islands of the Azores. In general, for both taxa and for each distributional category, functional diversity increases with species richness, which, in turn scales with island area. Null simulations support the hypothesis that each distributional group contributes to functional diversity in proportion to their species richness. Exotic spiders have added novel trait space to a greater degree than have exotic beetles, likely indicating greater impact of the reduction of immigration filters and/or differential historical losses of indigenous species. Analyses of species occurring in native-forest remnants provide limited indications of the operation of habitat filtering of exotics for three islands, but only for beetles. Although the general linear (not saturating) pattern of trait-space increase with richness of exotics suggests an ongoing process of functional enrichment and accommodation, further work is urgently needed to determine how estimates of extinction debt of indigenous species should be adjusted in the light of these findings.
Resumo:
High salinity causes remarkable losses in rice productivity worldwide mainly because it inhibits growth and reduces grain yield. To cope with environmental changes, plants evolved several adaptive mechanisms, which involve the regulation of many stress-responsive genes. Among these, we have chosen OsRMC to study its transcriptional regulation in rice seedlings subjected to high salinity. Its transcription was highly induced by salt treatment and showed a stress-dose-dependent pattern. OsRMC encodes a receptor-like kinase described as a negative regulator of salt stress responses in rice. To investigate how OsRMC is regulated in response to high salinity, a salt-induced rice cDNA expression library was constructed and subsequently screened using the yeast one-hybrid system and the OsRMC promoter as bait. Thereby, two transcription factors (TFs), OsEREBP1 and OsEREBP2, belonging to the AP2/ERF family were identified. Both TFs were shown to bind to the same GCC-like DNA motif in OsRMC promoter and to negatively regulate its gene expression. The identified TFs were characterized regarding their gene expression under different abiotic stress conditions. This study revealed that OsEREBP1 transcript level is not significantly affected by salt, ABA or severe cold (5 °C) and is only slightly regulated by drought and moderate cold. On the other hand, the OsEREBP2 transcript level increased after cold, ABA, drought and high salinity treatments, indicating that OsEREBP2 may play a central role mediating the response to different abiotic stresses. Gene expression analysis in rice varieties with contrasting salt tolerance further suggests that OsEREBP2 is involved in salt stress response in rice.
Resumo:
Besnoitia besnoiti is an apicomplexan parasite responsible for bovine besnoitiosis, a disease with a high prevalence in tropical and subtropical regions and re-emerging in Europe. Despite the great economical losses associated with besnoitiosis, this disease has been underestimated and poorly studied, and neither an effective therapy nor an efficacious vaccine is available. Protein disulfide isomerase (PDI) is an essential enzyme for the acquisition of the correct three-dimensional structure of proteins. Current evidence suggests that in Neosporacaninum and Toxoplasmagondii, which are closely related to B. besnoiti, PDI play an important role in host cell invasion, is a relevant target for the host immune response, and represents a promising drug target and/or vaccine candidate. In this work, we present the nucleotide sequence of the B. besnoiti PDI gene. BbPDI belongs to the thioredoxin-like superfamily (cluster 00388) and is included in the PDI_a family (cluster defined cd02961) and the PDI_a_PDI_a'_c subfamily (cd02995). A 3D theoretical model was built by comparative homology using Swiss-Model server, using as a template the crystallographic deduced model of Tapasin-ERp57 (PDB code 3F8U chain C). Analysis of the phylogenetic tree for PDI within the phylum apicomplexa reinforces the close relationship among B. besnoiti, N. caninum and T. gondii. When subjected to a PDI-assay based on the polymerisation of reduced insulin, recombinant BbPDI expressed in E. coli exhibited enzymatic activity, which was inhibited by bacitracin. Antiserum directed against recombinant BbPDI reacted with PDI in Western blots and by immunofluorescence with B. besnoiti tachyzoites and bradyzoites.
Resumo:
Mestrado em Engenharia Química. Ramo optimização energética na indústria química
Resumo:
Dissertação de Mestrado em Gerontologia Social
Resumo:
Mestrado em Engenharia Química. Ramo optimização energética na indústria química.
Resumo:
Mestrado em Engenharia Química. Ramo Tecnologias de Protecção Ambiental.
Resumo:
Dissertação de Mestrado em Ambiente, Saúde e Segurança.
Resumo:
A Indústria Têxtil do Ave S.A. (ITA) dedica-se, desde 1948, à produção de componentes têxteis para pneus em forma de fio torcido (corda) e tela. Estes componentes são quimicamente activados e impregnados em estufas, possibilitando assim a posterior adesão ao pneu. A máquina de impregnar corda Single End é composta pelos grupos de estiragem, por um recipiente contendo a solução química e por 4 estufas em série. A máquina de impregnar tela Zell é composta pelos grupos de estiragem, pelos acumuladores de saída e entrada, pelos recipientes com as soluções químicas e por um grupo de 7 estufas em série. O aquecimento das estufas é feito através da queima de gás natural. O presente trabalho teve como objectivo a realização de uma auditoria energética à ITA com um especial destaque às máquinas de impregnar corda (Single End) e tela (Zell). As correntes de entrada que contribuem para a potência térmica de impregnação são a combustão do gás natural, o ar de combustão, o ar fresco, o artigo em verde e as soluções químicas. As correntes de saída correspondem aos gases de combustão e exaustão, ao artigo impregnado e às perdas térmicas. A auditoria à máquina Single End mostrou que a potência térmica de impregnação é de 413,1 kW. Dessa potência térmica, 77,2% correspondem à combustão do gás natural, 6,7% ao ar de combustão, 15% ao ar fresco, 0,7% às cordas em verde e 0,4% à solução química. Da potência térmica de saída, 88,4% correspondem aos gases de combustão e exaustão, 3,2% às cordas impregnadas e 8,4% às perdas térmicas. Da auditoria à máquina Zell observou-se que a potência térmica de impregnação é de 5630,7 kW. Dessa potência, 73,3% corresponde à combustão do gás natural, 1,6% ao ar de combustão, 24,5% ao ar fresco, 0,3% à tela em verde e 0,3% às soluções químicas. Da potência térmica de saída, 65,2% correspondem aos gases de combustão e exaustão, 3,1% à tela impregnada e 31,7% às perdas térmicas. Foram sugeridas como medidas de optimização a redução dos caudais de exaustão das estufas e o aumento de temperatura do ar fresco. O aumento da temperatura do ar fresco da máquina de impregnar Single End para 50 ºC, usando ar quente dos torcedores, leva a uma poupança de 0,22 €/h, com um período de retorno do investimento de 13 anos e 4 meses enquanto o aumento para 120 ºC, usando o calor dos gases de combustão e exaustão, reduz os custos em 0,88 €/h, sendo o período de retorno para esse investimento de 2 anos e 6 meses. Na máquina de impregnar Zell, uma redução de 15% no caudal de exaustão numa das estufas leva a ganhos de 3,43 €/h. O aumento de temperatura do ar fresco para 45 ºC, usando o calor de gases de combustão e exaustão, leva a uma poupança de 9,93 €/h sendo o período de retorno para cada uma das duas sugestões de investimento de 5 meses e 9 meses.