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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A Finite Elements Based Approach For Fracture Analysis Of Welded Joints In Construction Machinery

Karagoz, Taner 01 August 2007 (has links) (PDF)
This study aims to develop a computer program to perform finite elements based fracture mechanics analyses of three dimensional surface cracks in T-welded joints of construction machinery. The geometrical complexity of the finite elements models and the requirement of large computer resources for the analyses necessitate the use of shell elements for general stress distribution optimization. A sub-modeling technique, together with a shell to solid conversion method, enables the user to model a local region and analyze it by defining the weld and crack parameters. It is assumed that the weld material is the same with the sheet metal material and the surface cracks are considered to occur on two weld toes and weld root. The surface cracks are assumed to have a semi elliptical crack front profile. In order to simulate the square-root strain singularity around the crack front, collapsed 20-node three dimensional brick elements are utilized. The rest of the local model is modeled by using 20-node three dimensional brick elements. The main objective of this work is to calculate the mixed mode energy release rates around the crack front for a sub-model of a global shell model by using J-integral method.
22

MODEL ANALYSIS AND PREDICTIVE CONTROL OF DOUBLE ELECTRODE SUBMERGED ARC WELDING PROCESS FOR FILLET JOINTS WITH ROOT OPENING

Lu, Yi 01 January 2014 (has links)
Submerged Arc Welding (SAW) for fillet joints is one of the major applications in the shipbuilding industry. Due to the requirement for the weld size, a sufficient amount of metal must be deposited. In conventional SAW process, the heat input is proportional to the amount of metal melted and is thus determined by the required weld size. To meet this requirement, an excessive amount of heat is applied causing large distortions on the welded structures whose follow-up straightening is highly costly. In order to reduce the needed heat input, Double-Electrode (DE) technology has been practiced creating the Double-Electrode SAW (DE-SAW) method for fillet joints. The reduction in the heat input, however, also reduces the penetration capability of the process, and the ability to produce required weld beads has to be compromised. To eliminate the unwanted side effect after using DE-SAW, a root opening between the panel and the tee has been proposed in this dissertation to form a modified fillet joint design. Experimental results verified that the use of root opening improves the ability of DE-SAW to produce the required weld beads at reduced heat input and penetration capability. Unfortunately, the use of root opening decreases the stability of the process significantly. To control the heat input at a minimally necessary level that guarantees the weld size and meanwhile the process stability, a feedback is needed to control the currents at their desired levels. To this end, the fillet DE-SAW process is modeled and a multivariable predictive control algorithm is developed based on the process model. Major parameters including the root opening size, travel speed and heat input level have been selected/optimized/minimized to produce required fillet weld beads with a minimized heat input based on qualitative and quantitative analyses. At the end of this dissertation, a series of experiments validated the feasibility and repeatability of the predictive control based DE-SAW process for fillet joints with root opening.
23

Estratégias para agregação de valor à cadeia agroindustrial da tilapicultura: subsídios técnicos para implantação do selo de Indicação Geográfica / Strategies for adding value to the agribusiness chain of tilapicultura: technical subsidies for the implementation of the Geographical Indication seal

Chidichima, Antonio Carlos 23 August 2018 (has links)
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-11-12T16:25:48Z No. of bitstreams: 1 Antonio_Chidichima_2018.pdf: 2854651 bytes, checksum: bf52210cdff033bae114add926692ed4 (MD5) / Made available in DSpace on 2018-11-12T16:25:48Z (GMT). No. of bitstreams: 1 Antonio_Chidichima_2018.pdf: 2854651 bytes, checksum: bf52210cdff033bae114add926692ed4 (MD5) Previous issue date: 2018-08-23 / In a globalized economic environment and with the free competition making possible rivalry between diverse economy sectors, it is common for those who can manage their potential and better explore their skills and capabilities to stand out before their competitors. Such strategy may be applied for the Tilapia (Oreochromis niloticus) fillet production sector. This study aimed to analyze conditions that could appreciate the Tilapia fillet produced in the Western Paraná region, using Geographical Indication (GI) as a strategy of adding value to the product. The study was performed between 2014 and 2017 by contacting all 50 Western Paraná's cities. It identified the quantity of fish slaughtering and processing plants (driving agents) existent in the Tilapia (Oreochromis niloticus) production chain. A total of 24 plants with Municipal Inspection System (Sistema de Inspeção Municipal - SIM/POA), Brazilian Inspection System (Sistema Brasileiro de Inspeção - SISBI/POA) and Federal Inspection System (Sistema de Inspeção Federal - SIF) were found. After identifying Toledo city, state of Paraná, as the region that concentrates most slaughtering plants, this study focused those plants located in that city’s micro region. The field research was divided into three stages. Firstly, a diagnosis on the production chain characteristics was conducted by analyzing social relations between the main actors that make up this productive network. This part of the study consisted in evaluating whether there were conditions to form a cluster as well as to structure a governance model based on Social Network Analysis (SNA) technique. The existence of potential agents and the network between the actors of the chain was evident. In the second stage, studies focused on measuring the density of relationships between actors of the network were conducted to identify leaders able to articulate such relations, aiming at a possible strategy of Geographical Indication implementation. Ucinet Software usage made possible to evaluate and to identify the intensity of relations in network, the main actors and the possible leaders. Finally, in order to define the "Tilapia fillet" product, a research was conducted by collecting samples of water from purification process and from the slaughtering, manipulation process of fillet extraction, and samples of fresh and frozen fillet at nine slaughtering plants. Thus, it was possible to evaluate the product quality standardization or items that could influence the microbiological, physicochemical, components quality. As a conclusion, considering the production aspects in the region – including the similar conditions of management and of slaughtering and processing procedures among the agents of the productive chain, the Western Paraná's Tilapia fillet is a product which meets the requirements of the legislation. Therefore, this product can be applied for registration of the Geographical Indication (GI) by the National Institute of industrial Property, designating its Appellation of Origin (DO). / Em um cenário econômico globalizado e com a dinâmica da livre concorrência possibilitando a rivalidade entre dos vários setores da economia, é comum que se destaquem aqueles que conseguem administrar bem suas potencialidades, e explorar melhor suas capacidades e competências, se destacando perante aos concorrentes, o que, por exemplo, pode ser aplicado como estratégia ao setor de produção de filé de tilápia (Oreochromis niloticus). Este estudo teve como objetivo realizar uma pesquisa sobre a estrutura atual na cadeia produtiva da tilápia no oeste do Paraná, com foco em diagnosticar as condições e características inerentes ao processo produtivo, para uma possível obtenção do selo de IG para o “Filé de Tilápia do Oeste Paranaense”. O estudo foi realizado entre 2014 e 2017, através de contatos com todos os 50 municípios do oeste paranaense, para identificar quantos frigoríficos de abate e processamento de pescado (agentes motrizes) existiam na cadeia de produção da tilápia (Oreochromis niloticus), gerando um resultado de 24 unidades frigoríficas com Sistema de Inspeção Municipal (SIM/POA), Sistema Brasileiro de Inspeção (SISBI/POA), e Sistema de Inspeção Federal (SIF). Após a identificação da região onde se concentram a maior parte das plantas frigorificas, a pesquisa foi direcionada de forma aprofundada para os frigoríficos situados na microrregião de Toledo /PR. O trabalho de pesquisa de campo foi dividido em três fases, em um primeiro momento foi realizado um diagnóstico que apresentou a caracterização da cadeia, analisando as relações sociais entre os principais atores que compõem esta cadeia produtiva em forma de rede. Nesta parte do estudo consistia em avaliar se existiam condições para ser formado um Arranjo Produtivo Local (APL), e se existiam condições para estruturar um modelo de governança baseado em técnica de Análise de Redes Sociais (ARS), ficou destacada a existência de agentes potenciais e a importante rede de relacionamentos entre os elos e atores da cadeia produtiva. No segundo momento, foram realizados estudos focados em mensurar a densidade de relacionamentos entre os atores da rede, para identificar as lideranças que pudessem articular as relações visando uma possível estratégia de implementação de Indicação Geográfica. Com o uso do software Ucinet, foi possível avaliar a intensidade das relações em rede, identificando quem são os principais atores e possíveis líderes. Por último, e para caracterizar o produto “Filé de Tilápia” foi conduzida uma pesquisa com coleta de amostra de água de depuração, água do processo de abate e manipulação para a extração do filé, amostras de filé fresco e amostras de filé congelado em nove frigoríficos, objetivando avaliar a padronização da qualidade dos produtos ou pontos capazes de influenciar a qualidade microbiológica, físico-química e de componentes. Conclui-se que o produto “Filé de Tilápia da Região Oeste Paranaense” em virtude das condições da produção na região, incluindo manejo e os procedimentos de abate e processamento são semelhante entre os agentes da cadeia produtiva, o produto atende praticamente todas as conformidades exigidas pela legislação, e, portanto a cadeia produtiva tem condições de se organizar, e pleitear junto ao Instituto Nacional de Propriedade Industrial, o registro de IG na designação de Indicação de procedência (IP).
24

Effects of phosphate type, antimicrobials and processing methods on the quality, shelf-life and sensory characteristics of enhanced catfish fillets

Kin, Sovann 30 April 2011 (has links)
Catfish fillets that were enhanced with salt and various phosphate treatments through vacuum tumbling or multi-needle injection were evaluated for yield, protein exudate (only tumbling), surface color, pH, cooking loss, tenderness, purge loss and shelf-life. An agglomerated sodium phosphate blend (AGSP) was the optimum treatment for both vacuum tumbling and multi-needle injection and was further utilized in conjunction with potassium lactate (PL) and/or potassium acetate (PA) through vacuum tumbling to determine their effect on the quality, shelf-life and sensory characteristics of enhanced catfish fillets. In addition, the combination of AGSP and PA+PL that maximized shelf-life was further utilized in conjunction with liquid or wood smoking to evaluate the quality and inhibition of L. monocytogenes growth in ready-to-eat (RTE) smoked catfish fillets. All phosphate treatments increased (P<0.05) tenderness, but AGSP that contained mono-, tri-, and polyphosphates increased (P<0.05) pH and yield and decreased (P<0.05) yellowness in both tumbling and injection systems when compared to the control treatment. In addition, AGSP decreased (P<0.05) protein exudate when fillets were tumbled and increased (P<0.05) solution pick-up when injected. Psychrotrophic plate counts (PPC) for all phosphate treatments were similar to the control at each storage time and reached 7 log CFU/g by day 7 of storage; however, when AGSP was used in conjunction with PA+PL, PPC and sensory spoilage scores of raw catfish fillets were lower (P<0.05) than the control at each storage time. Marinating with a combination of 0.25% PA and 0.58% PL increased shelf-life (P<0.05) to between 10 and 14 days when compared to the control which had a shelf-life between 7 and 10 days. In addition, consumers preferred (P<0.05) fried catfish fillets that were treated with AGSP with and without PA+PL when compared to non-marinated controls with respect to appearance, flavor and overall acceptability. In conclusion, AGSP optimized yield and improved the quality of refrigerated catfish fillets, and extended shelf-life three days over other treatments when combined with PA+PL. This combined treatment also enhanced sensory properties of fried catfish fillets and had a synergistic effect with wood smoke constituents that inhibited the growth of L. monocytogenes on RTE smoked catfish fillets.
25

Technologies for tissue preservation: the role of endogenous and exogenous antioxidants in preserving tissue function in chinook salmon, Oncorhynchus tshawytscha

Tuckey, Nicholas Pierre Lemieux January 2008 (has links)
The seafood industry is of considerable importance to both the New Zealand and global economies and therefore tissue preservation technologies that increase product quality and/or prolong shelf life have the potential to add significant value. Technologies for maintaining the viability of isolated tissues also have a wide range of other medical and industrial applications. This thesis examines the relationship between metabolic function, oxidation and cell death and the resulting stability of the non-viable tissues during long term storage in chinook salmon (Oncorhynchus tshawytscha) red and white skeletal muscle tissue. This research also looks at the role of the aquatic anaesthetic AQUI-S™, in which the active ingredient is isoeugenol (a lipid soluble antioxidant), and other antioxidant compounds in preserving metabolic function in viable tissues and tissue stability in nonviable tissues. Perfusion of salmon tails at 15℃ over 5 or 10 hours with oxygen saturated saline resulted in significant increases in protein and lipid oxidation (protein carbonyl and TBARS concentrations respectively) in the red muscle, but not the white muscle. The introduction of ascorbic acid and uric acid into the saline did not reduce the oxidation in the red muscle despite significantly increasing their respective concentrations in the tissue. This indicates the difficulties associated with attempting to extend tissue viability by delivering free oxygen to the tissue and also highlights the difference in susceptibility of the two muscle types to oxidation. Tail fillets from salmon harvested in both rested and exhausted physiological states using AQUI-S™, and fillets from exhausted salmon harvested without AQUI-S™, were exposed to air at 15℃ for up to 96 hours. Protein carbonyls increased in a roughly linear fashion over the entire 96 hours in all three groups. Both lipid peroxides (TBARS) and uric acid concentrations began to increase in the exhausted group after 30 hours. In contrast, no significant increases in lipid peroxides or uric acid was seen in the fillets from either group harvested using AQUI-S™. Vitamin E concentrations reduced slowly but did not change significantly despite the oxidation that was evident in the tissue. These processes also occurred in salmon tail fillets during storage at 6℃. The measurement of ATP related compounds provides an effective indicator of both the metabolic state of the tissue post-harvest and the quality. The breakdown of these compounds is also associated with the production of ammonia and hydrogen peroxide. Fresh rested salmon fillets had high concentrations of ATP and creatine phosphate, which were both depleted after 12 hours storage at 15℃. This indicates that cell viability lasted a number of hours following harvesting. These metabolites were depleted in exhausted fillets and metabolic potential appeared to be immediately compromised. The concentration of the taste enhancing compound IMP was significantly reduced in fresh rested tissue, but increased during storage, and was significantly higher than in exhausted tissues following 12 hours of storage at 15℃. This indicates that some properties of rested tissues may improve with limited storage times. The accumulation of uric acid - the metabolic end point for ATP related compounds - was also significantly reduced in rested tissue and increases in K-value were slowed. AQUI-S™ showed an ability to preserve tissue function through its anaesthetic action allowing tissue to be harvested in a rested state, and to reduce late stage lipid oxidation in stored salmon tail fillets. The antioxidant action of isoeugenol in salmon fillets may be mediated through its ability to chelate transition metals released during tissue degradation. This research shows that during reperfusion and during fillet storage there is a significant level of oxidative stress, which needs to be minimized while maintaining basic tissue metabolism to prolong tissue and cellular viability. The development of future technologies to preserve tissue viability may depend on the development of a synthetic oxygen carrying compound with properties similar to red blood cells. This may allow more control over oxygen delivery, potentially reducing the oxidative stress associated with high concentrations of free oxygen in solution. However, preserving cell viability will also require the maintenance of endogenous antioxidant function and there is also the potential to use iron chelating compounds including plant derived flavonoids to preserve non-viable tissues. Future research in these areas is necessary.
26

Technologies for tissue preservation: the role of endogenous and exogenous antioxidants in preserving tissue function in chinook salmon, Oncorhynchus tshawytscha

Tuckey, Nicholas Pierre Lemieux January 2008 (has links)
The seafood industry is of considerable importance to both the New Zealand and global economies and therefore tissue preservation technologies that increase product quality and/or prolong shelf life have the potential to add significant value. Technologies for maintaining the viability of isolated tissues also have a wide range of other medical and industrial applications. This thesis examines the relationship between metabolic function, oxidation and cell death and the resulting stability of the non-viable tissues during long term storage in chinook salmon (Oncorhynchus tshawytscha) red and white skeletal muscle tissue. This research also looks at the role of the aquatic anaesthetic AQUI-S™, in which the active ingredient is isoeugenol (a lipid soluble antioxidant), and other antioxidant compounds in preserving metabolic function in viable tissues and tissue stability in nonviable tissues. Perfusion of salmon tails at 15℃ over 5 or 10 hours with oxygen saturated saline resulted in significant increases in protein and lipid oxidation (protein carbonyl and TBARS concentrations respectively) in the red muscle, but not the white muscle. The introduction of ascorbic acid and uric acid into the saline did not reduce the oxidation in the red muscle despite significantly increasing their respective concentrations in the tissue. This indicates the difficulties associated with attempting to extend tissue viability by delivering free oxygen to the tissue and also highlights the difference in susceptibility of the two muscle types to oxidation. Tail fillets from salmon harvested in both rested and exhausted physiological states using AQUI-S™, and fillets from exhausted salmon harvested without AQUI-S™, were exposed to air at 15℃ for up to 96 hours. Protein carbonyls increased in a roughly linear fashion over the entire 96 hours in all three groups. Both lipid peroxides (TBARS) and uric acid concentrations began to increase in the exhausted group after 30 hours. In contrast, no significant increases in lipid peroxides or uric acid was seen in the fillets from either group harvested using AQUI-S™. Vitamin E concentrations reduced slowly but did not change significantly despite the oxidation that was evident in the tissue. These processes also occurred in salmon tail fillets during storage at 6℃. The measurement of ATP related compounds provides an effective indicator of both the metabolic state of the tissue post-harvest and the quality. The breakdown of these compounds is also associated with the production of ammonia and hydrogen peroxide. Fresh rested salmon fillets had high concentrations of ATP and creatine phosphate, which were both depleted after 12 hours storage at 15℃. This indicates that cell viability lasted a number of hours following harvesting. These metabolites were depleted in exhausted fillets and metabolic potential appeared to be immediately compromised. The concentration of the taste enhancing compound IMP was significantly reduced in fresh rested tissue, but increased during storage, and was significantly higher than in exhausted tissues following 12 hours of storage at 15℃. This indicates that some properties of rested tissues may improve with limited storage times. The accumulation of uric acid - the metabolic end point for ATP related compounds - was also significantly reduced in rested tissue and increases in K-value were slowed. AQUI-S™ showed an ability to preserve tissue function through its anaesthetic action allowing tissue to be harvested in a rested state, and to reduce late stage lipid oxidation in stored salmon tail fillets. The antioxidant action of isoeugenol in salmon fillets may be mediated through its ability to chelate transition metals released during tissue degradation. This research shows that during reperfusion and during fillet storage there is a significant level of oxidative stress, which needs to be minimized while maintaining basic tissue metabolism to prolong tissue and cellular viability. The development of future technologies to preserve tissue viability may depend on the development of a synthetic oxygen carrying compound with properties similar to red blood cells. This may allow more control over oxygen delivery, potentially reducing the oxidative stress associated with high concentrations of free oxygen in solution. However, preserving cell viability will also require the maintenance of endogenous antioxidant function and there is also the potential to use iron chelating compounds including plant derived flavonoids to preserve non-viable tissues. Future research in these areas is necessary.
27

Entre tramas e rendas: a construção de uma agenda política para o artesanato e a economia criativa em Alagoas / Between plots and incomes: the construction of a political agenda for the craft and the creative economy in Alagoas

Silva , Bruno Gabriel Passos 28 September 2015 (has links)
According to recent data from the Brazilian Handicraft Program, Alagoas is the state that emerges with the largest number of registered artisans nationwide. Of this volume, 70% is represented by embroidery fillet, typical craft mode "of the lakes region", which stands as productive core maceioense the neighborhood of Pontal da Barra. With the institutionalization of the creative economy in Brazil crafts stands as one of the core creative industries of this new political-economic arrangement, fitting as an object of state policy under the Ministry of Culture. The playing field of the creative economy features intrainstitucionais direct interfaces with the National Programme of Intangible Heritage and the Living Culture Program. This relationship is forming a conceptual tripod that includes the symbolic dimension, the civic dimension and the economic dimension, forging a cultural policy of full accessibility. Nevertheless, such a full conception of culture has also associated inter interfaces, especially the programs linked to the Ministry of Development, Industry and Foreign Trade, specifically the Geographical Indications and the Local Productive Arrangements. Thus, dominated by the need to identify the institutional network of agents dealing in commercial and symbolic promotion of handicrafts, in line with the principles of creative economy. From the institutional analysis of various directly and indirectly linked to state agents, it seeks to identify the potential embroidery fillet as a vector of the creative economy and regional development. To this end, in addition to the bibliographical and documentary references related to the theme, is undertaken interviews with different actors involved in the production chain of the fillet, as local craftsmen, representative of the State Secretariat for Economic Development and Tourism of Alagoas and the Brazilian Support Service Micro and Small Enterprises in Alagoas. With that, allow yourself an understanding of the inter-institutional fabric that makes up the political agenda for the craft and the creative economy in Alagoas. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / De acordo com dados recentes do Programa do Artesanato Brasileiro, Alagoas é o estado que desponta com o maior número de artesãos cadastrados em nível nacional. Desse volume, 70% é representado pelo bordado Filé, modalidade de artesanato típica da “região das lagoas”, onde se destaca como núcleo produtivo o bairro maceioense do Pontal da Barra. Com a institucionalização da economia criativa no Brasil o artesanato figura como um dos setores criativos nucleares desse novo arranjo político-econômico, enquadrando-se como objeto de uma política de Estado vinculada ao Ministério da Cultura. O campo de atuação da economia criativa apresenta interfaces intrainstitucionais diretas com o Programa Nacional do Patrimônio Imaterial e com o Programa Cultura Viva. Essa relação constitui a formação de um tripé conceitual que contempla a dimensão simbólica, a dimensão cidadã e a dimensão econômica, forjando uma política cultural de plena acessibilidade. Não obstante, essa concepção plena de cultura possui, também, interfaces interinstitucionais associadas, sobretudo, à programas vinculados ao Ministério da Indústria, Desenvolvimento e Comércio Exterior, especificamente as Indicações Geográficas e os Arranjos Produtivos Locais. Dessa forma, impera a necessidade de identificar a rede interinstitucional de agentes que se ocupam na promoção comercial e simbólica do artesanato, alinhado com os princípios da economia criativa. A partir da análise de institucional de diferentes agentes direta e indiretamente vinculados ao Estado, procura-se identificar o potencial do bordado Filé como vetor da economia criativa e do desenvolvimento regional. Para tanto, além das referências bibliográficas e documentais ligadas ao tema, empreende-se entrevistas com diferentes agentes envolvidos na cadeia produtiva do Filé, como artesãos locais, representante da Secretaria de Estado de Desenvolvimento Econômico e Turismo de Alagoas e do Serviço Brasileiro de Apoio às Micro e Pequenas Empresas em Alagoas. Com isso, permite-se uma compreensão de parte da tessitura interinstitucional que compõe a agenda política para o artesanato e a economia criativa em Alagoas
28

Vyhodnocení intenzivního chovu candáta obecného (Sander lucioperca) v provozních podmínkách včetně posouzení kvality finálního produktu / Evaluation of the intensive culture of pikeperch (Sander lucioperca) under commercial-scale conditions including the quality of the final product

JABLONICKÁ, Dagmara January 2012 (has links)
The aim of this study was to evaluate the sensory, chemical (fatty acid profile, N-substances, lipid, ash) and technological (texture of meat) parameters of meat of pikeperch reared in intensive culture and compared with the fish from the pond (extensive) culture.
29

ESTUDO DE ENZIMAS DIGESTIVAS, CRESCIMENTO E COMPOSIÇÃO CENTESIMAL DE FILÉS DE JUVENIS DE JUNDIÁ (Rhamdia quelen) ALIMENTADOS COM DIFERENTES FONTES PROTÉICAS / STUDY OF DIGESTIVE ENZYMES, GROWTH AND FILLETS COMPOSITION OF JUNDIÁ (Rhamdia quelen) JUVENILES FED WITH DIFFERENT PROTEIN SOURCES

Lazzari, Rafael 25 February 2005 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was aimed at evaluating the growth, fillet composition and digestive enzyme activity of jundiá (Rhamdia quelen, Heptapteridae) juveniles fed different protein sources for 90 days. Five hundred forty fish (initial weight=15.00±0.62g, total length=11,98±0,35cm) were distributed at random in 18 cages of 280L (30 fish/cage) in a water closed system, with controlled temperature. Water quality (total ammonia, nitrite, alkalinity, pH, dissolved oxygen) was checked daily, being in agreement with the appropriate conditions for the species. There were six treatments (with 3 replicates): MBMY (meat and bone meal + yeast), SY (soybean meal + yeast), S (only soybean meal), MBMS (meat and bone meal + soybean meal), FMY (fish meal + yeast) and FMS (fish meal + soybean meal). Growth measurements and data collection were made every 30 days. Performance was evaluated by weight, total and standard length, weight gain, survival, condition factor, specific growth rate, protein efficiency ratio, total biomass, dressing carcass, feed conversion ratio, voluntary feed intake were considered. Protein and fat deposition in the fillet were calculated. Acidic protease, amylase, trypsin and chymotrypsin activities were verified. Best performance was observed in fish fed the animal protein sources (meat and bone meal and fish) with soybean meal. Fat and protein deposition in the fillet was higher (P<0.05) in these treatments (MBMS e FMS). Lower survival was observed in fish fed fish meal plus soybean meal diet (92.86%). However these fish presented better protein efficiency ratio (1.53). Jundiás fed the diet containing only soybean meal (S) as the protein source had growth.reduction. Amilase and acidic protease activities were variable among the treatments. Trypsin activity was higher in fish fed animal protein sources, and the treatments SY and S suffered enzyme inhibition (P<0.0001). The same tendency was observed for chymotrypsin, where fish fed diets without animal protein sources presented smaller activity. In conclusion, jundiás fed only soybean meal present reduction of alkaline proteases activity and lower growth. The combination of animal protein sources with soybean meal provides good development for jundiá juveniles. / Este trabalho teve por objetivos avaliar o crescimento, composição do filé e atividade de enzimas digestivas em juvenis de jundiá (Rhamdia quelen, Heptapteridae) alimentados com diferentes fontes protéicas, durante 90 dias. Quinhentos e quarenta peixes (peso inicial=15,00±0,62g; comprimento inicial=11,98±0,35cm) foram distribuídos ao acaso em 18 tanques de 280L (30 peixes/tanques) em um sistema de recirculação de água, com temperatura controlada. Os parâmetros de qualidade da água de criação (amônia total, nitrito, alcalinidade, pH, oxigênio dissolvido) foram aferidos diariamente, ficando de acordo com as condições adequadas para a espécie. Testou-se 6 dietas (com 3 repetições), assim denominadas: CL (farinha de carne e ossos + levedura), SL (farelo de soja + levedura), S (somente farelo de soja), CS (farinha de carne e ossos + farelo de soja), PL (farinha de peixe + levedura) e PS (farinha de peixe + farelo de soja). As medições para acompanhamento do crescimento e coleta de dados aconteceram a cada 30 dias. Para avaliação do desempenho produtivo, estimaram-se parâmetros como peso, comprimento total e padrão, ganho em peso diário, sobrevivência, fator de condição, taxa de crescimento específico, taxa de eficiência protéica, biomassa total, rendimento de carcaça, conversão alimentar aparente, consumo diário. A partir dos valores de composição centesimal calcularam-se taxas de deposição de proteína e gordura no filé. Foram verificadas também as atividades de protease ácida, amilase, tripsina e quimotripsina. Os parâmetros de desempenho produtivo foram superiores nos tratamentos compostos pela combinação das farinhas de origem animal (carne e ossos e peixes) com farelo de soja. A quantidade de gordura e proteína depositada no filé dos peixes também foi superior (P<0,05) nestes tratamentos (CS e PS). Menor sobrevivência foi observada no tratamento a base de farinha de peixe mais farelo de soja (92,86%), porém os peixes deste tratamento apresentaram melhor taxa de eficiência protéica (1,53). Jundiás alimentados com ração contendo somente farelo de soja como fonte protéica sofreram redução no crescimento. As atividades de amilase e protease ácida foram variáveis entre os diferentes tratamentos. A atividade de tripsina foi maior nos peixes alimentados com fontes protéicas de origem animal, sendo que os peixes dos tratamentos SL e S apresentaram menor atividade desta enzima (P<0,0001). Mesma tendência foi observada para a quimotripsina, onde os tratamentos sem a inclusão de fontes de origem animal tiveram a menor atividade. Conclui-se que jundiás alimentados somente com farelo de soja apresentam redução na atividade de proteases alcalinas e também menor crescimento. A combinação de farinhas de origem animal com farelo de soja possibilita bom desenvolvimento para juvenis de jundiá (Rhamdia quelen).
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Determinação de disruptores endócrinos em filé de peixe utilizando QuEChERS modificado e GC-(TQ)MS/MS / Determination of endocrine disrupters in fish fillet by modified QuEChERS and GC-(TQ)MS/MS

Munaretto, Juliana Scariot 27 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Endocrine Disrupter Compounds (EDCs) like pesticides, alkylphenols and hormones among other classes of compounds are responsible for alterations in the endocrine system functions. Endocrine disruption occurs when EDCs interact with the hormone receptors, altering the natural response patterns of the endocrine system. Aquatic organisms, such as fish, are able to accumulate EDCs residues in concentration several times higher than the surrounding water. Consequently, fish is a major source of contamination for both top predators and human consumers. This study aimed to develop and validate a fast method for the determination of 40 endocrine disrupters in fish fillet, using modified QuEChERS and Gas Chromatography coupled with Mass Spectrometry in tandem, using a triple quadrupole analyzer (GC-(TQ)MS/MS). A factorial design was performed to optimize the extraction procedure, which consist of the extraction of 10.0 g of fish fillet with 10.0 mL of acetonitrile with 1% (v/v) of acetic acid followed by manual shaking for 1 min. In the partition step 2.0 g of sodium chloride, 1.7 g of anhydrous sodium acetate and 0.3 g of anhydrous magnesium sulfate were added, followed by shaking and centrifugation at 3400 rpm for 8 min. Then the extract was transferred to a 15 mL polypropylene tube containing the C18 and PSA sorbents, beyond the anhydrous magnesium sulfate. After shaking and centrifuging, the supernatant was filtered and analyzed by GC-(TQ)MS/MS. The method was validated by spiking the blank sample at three concentration levels (10, 25 and 50 Ug kg-1) obtaining recovery values between 70.1 to 120.0% for 36 of the 40 endocrine disrupters evaluated. RSD values below 20% ensured the good precision of the method. The linearity was evaluated using the coefficient of determination (r2) with values higher than 0.996 for all compounds. The matrix effect was evaluated, and it was pretty intense for most compounds, with values exceeding 10%. This effect was compensated using analytical curves obtained with standards prepared in blank matrix extracts. This method was applied in 6 samples of fish fillet from different species. Residues of bisphenol A, chlorpyrifos and bifenthrin were detected. Therefore, the modified QuEChERS method proved to be appropriated for the determination of endocrine disrupters in fish fillet using GC-(TQ)MS/MS since it showed to be effective and can be applied to routine analysis. / Compostos conhecidos como disruptores endócrinos (DEs), tais como agrotóxicos, alquilfenóis, hormônios, dentre outras classes de substâncias são responsáveis pela alteração de funções do sistema endócrino. Esse efeito ocorre quando os DEs interagem com os receptores hormonais, alterando os padrões de resposta natural do sistema endócrimo. Os organismos aquáticos, como os peixes são capazes de acumular concentrações de DEs várias vezes superiores a água ao seu redor. Consequentemente, os peixes são uma importante fonte de contaminação para seus predadores e consumidores humanos. O presente trabalho teve como objetivo desenvolver e validar um método rápido para a determinação de 40 disruptores endócrinos em filé de peixe (jundiá), utilizando QuEChERS modificado e Cromatografia Gasosa acoplada à Espectrometria de Massas em série, empregando analisador triplo quadrupolo (GC-(TQ)MS/MS). Utilizou-se do planejamento fatorial em estrela para otimização do procedimento de extração, o qual consiste da extração de 10,0 g de filé de peixe com 10,0 mL de acetonitrila/1% (v/v) ácido acético seguido de agitação manual por 1 min. Na etapa de partição adicionou-se 2,0 g de cloreto de sódio, 1,7 g de acetato de sódio anidro e 0,3 g de sulfato de magnésio anidro. Realizou-se agitação por 1 min e centrifugação a 3400 rpm por 8 min. Em seguida, o extrato foi transferido para um tubo de polipropileno de 15 mL contendo os sorventes C18 e PSA, além de sulfato de magnésio anidro. Foi realizada a agitação manual e centrifugação, o extrato foi filtrado e analisado por GC-(TQ)MS/MS. O método foi validado fortificando a amostra branco em três níveis de concentração (10, 25 e 50 Ug kg-1) obtendo valores de recuperação entre 70,1 e 120,0% para 36 dos 40 disruptores endócrinos avaliados. Valores de RSD inferiores a 20% garantiram a boa precisão do método. A linearidade foi avaliada utilizando o coeficiente de determinação (r2) sendo este maior que 0,996 para todos os compostos. O efeito matriz foi avaliado, o qual foi bastante intenso para a maioria dos compostos, com valores superiores a 10%. O efeito matriz foi compensado utilizando-se curvas analíticas preparadas no extrato branco da matriz. A aplicação do método foi realizada em 6 amostras de filé de peixe de diferentes espécies, nas quais resíduos de bisfenol A, clorpirifós etílico e bifentrina foram encontrados. O método QuEChERS modificado proposto para a determinação de disruptores endócrinos em filé de peixe utilizando GC-(TQ)MS/MS mostrou ser eficaz, podendo ser aplicado em análise de rotina.

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