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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.
11

Comprimidos de liberação modificada: análise dos pedidos de patente depositados no Brasil e da utilização destes na prática do evergreening / Modified release tablets: analysis of patent applications filed in Brazil and their use in the evergreening of pharmaceutical patents

Zalfa, Viviane Mega de Andrade January 2008 (has links)
Made available in DSpace on 2014-07-28T18:10:45Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 87.pdf: 692507 bytes, checksum: e3a37710da30b2110d2adef882a97ca9 (MD5) Previous issue date: 2008 / Made available in DSpace on 2014-12-22T16:56:33Z (GMT). No. of bitstreams: 2 87.pdf: 692507 bytes, checksum: e3a37710da30b2110d2adef882a97ca9 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde / Since 1945, Brazil did not issue pharmaceutical patents. This situation has change following the new Industrial Property Law (LPI nº. 9279/96) enactment in 14/05/1996, according to TRIPS Agreement disposal on patentability of all technological sectors. By one hand, pharmaceutical patents are an important mechanism to encourage innovation. By the other, they create monopolies, ensuring pharmaceutical companies the power to establish high prices during the protection period. Also, they delay the introduction of generic competitors into the market, which could enhance access to medicines. Brazilian National Health Surveillance Agency (ANVISA) participates in the examination of pharmaceutical patent applications by means of a legal mechanism of “prior consent”. This examination is aimed at a more restrictive interpretation of patentability criteria. The goal is not to enact undue patents, which do not aggregate any technological or therapeutic advance, but generally contributes to improperly extend market exclusivity of pharmaceutical products. Secondary patents on new pharmaceutical dosage forms are one kind of market exclusivity extension, as may be the case for modified release tablets. This work analyzes the profile of patent applications filed in Brazil for modified release tablets from 01/01/95 to 31/12/07. Applications were searched in the European Patent Office and in the Brazilian National Institute of Indústrial Property databases. Analysis was aimed at investigating whether the development of these formulations would be justifiable by a therapeutic advance point of view or would only serve as strategies of market dominance. Results showed that the United States, along with European countries, were responsible for 80% of the applications, while only 1% were carried out by Brazilians. Most of applications for modified release tablets were directed for active ingredients acting in the nervous system (33.3%), in the alimentary treat and metabolism (16.4%), and in the cardiovascular system (15.5%). Detailed analysis of patent applications identified cases where this kind of formulation is useful, even crucial, as is the case of proton pump inhibitors. Nevertheless, it was also observed that in most situations this kind of incremental modification does not represent a real advance, being only a patent extension strategy.
12

Efeito de atmosfera modificada no controle de podridões pós-colheita e na qualidade de caqui cv. Fuyu

Cia, Patrícia [UNESP] 04 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-04Bitstream added on 2014-06-13T18:30:21Z : No. of bitstreams: 1 cia_p_me_botfca.pdf: 896307 bytes, checksum: f65ca650e818311ed8928ea299e165ce (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho teve por objetivo avaliar o efeito de atmosfera modificada (AM) no controle de podridões pós-colheita e na extensão do período de armazenamento de caqui cv. Fuyu. Realizou-se, primeiramente, a identificação dos agentes causais das principais doenças pós-colheita de caqui, coletados em diferentes regiões produtoras do Estado de São Paulo. Dentre os patógenos identificados, Lasiodiplodia theobromae, Pestalotiopsis sp. e Rhizopus stolonifer apresentaram maior incidência. Posteriormente, avaliou-se o efeito de composições gasosas sobre o crescimento micelial in vitro de L. theobromae, Pestalotiopsis sp., R. stolonifer e Alternaria alternata. Placas com os respectivos patógenos foram expostas a misturas gasosas (3% O2 e 5%, 8%, 10% ou 12% CO2; 5% O2 e 5%, 8%, 10% ou 12% CO2) sob fluxo contínuo de gases, à 25°C. Como testemunha utilizou-se 21% O2/0,03% CO2. Os resultados mostraram que para L. theobromae, houve tendência de estímulo do crescimento micelial para todas as atmosferas. Para Pestalotiopsis sp. e A. alternata, as atmosferas de 3% O2 e 10% ou 12% CO2 exerceram maior efeito de inibição, enquanto que, para R. stolonifer, as atmosferas de 3% O2 e 8%, 10% ou... . / This study was conducted to evaluate the effect of modified atmosphere (MA) on postharvest disease control and shelf life of ‘Fuyu’ persimmons. Firstly, it was carried out the identification of causal organisms related to the main postharvest diseases in persimmon fruits, from different producing areas of the State of São Paulo. Among the pathogens identified, Lasiodiplodia theobromae, Pestalotiopsis sp. and Rhizopus stolonifer had the highest incidence. Secondly, it was evaluated the in vitro effect of gas compositions on the mycelial growth of L. theobromae, Pestalotiopsis sp, R. Stolonifer and Alternaria alternata. These pathogens were exposed to gas mixtures (3% O2 + 5%, 8%, 10% or 12% CO2 and 5% O2 + 5%, 8%, 10% or 12% CO2) under continuous flow at 25°C. Plates with pathogens exposed to 21% O2/0,03% CO2 were used as the control. The results showed that L. theobromae mycelial growth was stimulated by all atmospheres. The atmosphere of 3% O2 + 10% or 12% CO2 had the greatest inhibition effect on Pestalotiopsis sp. and A. alternata. For R. stolonifer the atmospheres of 3% O2 + 8%, 10% or 12% CO2 and 5% O2 + 10% or 12% CO2 significantly inhibited the pathogen growth. In order to check the effect of MA on the fruit quality, persimmons were enclosed in packaging systems: 12-μm PVC (polyvinyl chloride); 80-μm LDPE (low density polyethylene); 80-μm LDPE (3% O2/8% CO2); 63-μm PO (multilayer polyolephynic); 63-μm PO (3% O2/8% CO2); 58-μm PO; 50-μm LDPE; 38- μm microperforated PO; 50-μm LDPE (3% O2/8% CO2); 50-μm LDPE (3% O2/10% CO2). Furthermore, to verify the effect of MA on disease control, persimmons were inoculated with spore suspension of R. stolonifer (5x105 cfu.mL-1) and enclosed in the packaging systems: 50- μm LDPE; 50-μm LDPE (3% O2/8% CO2); 50-μm LDPE (3% O2/10% CO2). Fruits in corrugated cardboard boxes were used as control... (Complete abstract, click electronic address below).
13

Análise do desenvolvimento de infestações de Sitophilus spp. em milho orgânico embalado em atmosfera modificada (am) / Development of sitophilus spp. infestation on organic corn grain wrapped in modified atmosphere (MAP)

De Carli, Marcelo January 2007 (has links)
O milho (Zea mays L.) é um dos grãos de maior importância econômica no mundo, requerendo grandes áreas para sua estocagem. Uma das etapas importantes no armazenamento é o expurgo, empregado para controle de pragas de insetos das espécies Sitophilus spp. Atualmente, a cultura de milho orgânico está em constante aumento devido à crescente exigência do mercado por produtos livres de resíduos químicos. Para produtos orgânicos, o emprego do dióxido de carbono (CO2) como agente de controle de insetos, é uma alternativa interessante, pois este tem como principal vantagem a de não deixar resíduos após aplicação. O objetivo desta pesquisa foi avaliar o controle de insetos Sitophilus spp no milho orgânico embalado mediante o uso de CO2 (atmosfera modificada). Para esse fim, foram criados insetos e colocados em milho (previamente limpo e selecionado) contidos em potes plásticos com tampa com tela. Após 45 dias, as amostras contendo os insetos foram colocadas em embalagens barreira e fechadas em embaladora a vácuo compensado em diferentes níveis de CO2: 0 (ar sintético), 20, 40, 60 e 80% e tempos de exposição de: 1, 2, 3, 4, 5, 15 e 30 dias. Após aplicação dos tratamentos foi realizada a contagem dos insetos vivos de acordo com metodologia proposta pela FAO. Durante os períodos de aplicação dos tratamentos, foram analisados o teor de umidade, acidez e pH no milho e a concentração de CO2, dentro da embalagem. Também foi avaliado o efeito dos tratamentos sobre a capacidade dos insetos de gerarem descendência (efeito progênie). Foi constatado que as maiores taxas de mortalidade de insetos adultos foram nos primeiros cinco dias de exposição à AM em todos os níveis de concentração de CO2 estudados. Para períodos de exposição de 15 e 30 dias, foi observado que foram eliminados todos os insetos adultos nas concentrações de 20, 40, 60 e 80% de CO2. Durante os experimentos verificou-se que as concentrações de CO2 no interior das embalagens, em atmosfera modificada, se mantiveram estáveis até o quinto dia de exposição e a partir do qual começaram a diminuir, comportamento este observado em todas as concentrações de atmosfera estudadas. Para o teor de umidade e a acidez houve interação entre o tempo de exposição e a composição atmosférica, enquanto para o pH existiram diferenças significativas e com médias muito próximas para as atmosferas testadas, porém sem variação de pH significativa em 30 dias. A aplicação de AM com tempos menores que cinco dias não afetou a progênie dos insetos, no entanto, a partir do décimo quinto dia, qualquer concentração de CO2 estudada foi efetiva na eliminação de todas as fases de desenvolvimento dos insetos. Dos resultados pode-se concluir que o emprego de concentrações não menores que 20% de CO2 com tempo de aplicação mínimo de 15 dias é recomendado para a eliminação de insetos adultos, ovos, larva e pupa. Também foi verificado que o vácuo não teve efeito sobre a morte dos insetos. / Maize grain (Zea mays L.) is one of the grains of largest economical importance in the world, requesting great areas for this storage. One of the most important stages in the storage is its purge, for control of insects of the species Sitophilus spp. Nowadays, the culture of organic corn is in constant increase due to growing demand of the market for products free of chemical residues. For this kind of product the use of carbon dioxide (CO2) as agent for insect control is an interesting alternative, because the main advantage of not leaving residues after application. The objective of this investigation was to evaluate the control of insects Sitophilus spp in organic maize in packing using CO2 (modified atmosphere). Insects were created and placed in maize (previously cleaned and selected) contained in plastic flasks with screen cover. After 45 days, the samples containing insects were placed in packings barrier and closed in packer machine whith vacuum compensated in different levels of CO2: 0 (synthetic air), 20, 40, 60 and 80% and times of exposition of: 1, 2, 3, 4, 5, 15 and 30 days. These treatments the number of alive insects were counted in according to the methodology proposed by FAO. During the period of application of the treatments, the moisture contend, acidity and pH were analyzed in the corn, and the concentrations of CO2 inside of the packing was measured. The effect of the treatments on the capacity of the insects to create descendants (progeny effect), was also evaluated. It was verified that the largest rates of mortality of adult insects were in the first five days of exposition to AM to all levels of CO2 concentration studied. For periods of exposition of 15 and 30 days, it was observed that all the adult insects were eliminated in the concentrations of 20, 40, 60 and 80% of CO2. During the experiment it was verified that the CO2 concentrations inside the packings, in modified atmosphere, remained stable until the fifth day of exposition and after this time CO2 concentrations started to decrease. This behavior was observed in all atmosphere concentrations studied. For the moisture and acidity was verified that there was significant interaction between the time of exposition and the atmospheric composition, while, for the pH differences were significant with very next averages, for any atmospheric condition during the storage, however without variation of significant pH in 30 days. The application of AM in times smaller than five days no affect the progeny of the insects, however, starting from the fifteenth day, for any CO2 concentration studied they were effective in the elimination of all the phases of development of the insects. From the results it can be concluded that the use of concentrations from 20% of CO2, with time of application minimum of 15 days are recommended for the elimination of adult insects, eggs, larva and pupa. It was also verified that the vacuum have no effect on the death of the insects.
14

Novel catalyst systems based on Ni(II), Ti(IV), and Cr(III) complexes for oligo-and polymerization of ethylene

Junges, Fernando January 2005 (has links)
Le complexe de Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) a été caractérisé après impregnation sur silice (S1) et a silices modifié avec MAO (4,0, 8,0 et 23,0 wt.% Al/SiO2 appelé S2, S3 et S4, respectivement). Le traitement de ces composés greffé avec MAO produit des catalyseurs actifs pour la polymérisation de l'éthylène. Un haute activité catalytique a été obtenue en utilisant le système supporté 1/S3 (196 kg de PE/mol[Ni].h.atm; toluene, Al/Ni = 1000, 30ºC, 60 min et pression atmosphérique d'éthylène). Les effets des conditions de la polymérisation ont été testés avec le catalyseur greffé S2 et la meilleure activité catalytique a été obtenue avec le solvant hexane, MAO comme cocatalyseur, la proportion molaire Al/Ni de 1000 et à la température de 30°C (285 kg de PE/mol[Ni].h.atm). Quand la réaction a été conduite selon la méthodologie in situ, l'activité a pratiquement doublé et les polymères ont montré des propriétés semblables. Les polymères produits par les catalyseurs supportés ont montré l'absence de température de fusion, resultats senblables à seux obtenus avec les systèms homogène par analyse DSC. En revanche, le polymères obtenus avec les système greffé presentent selon les courbes GPC une (MwD) polydispersité qui varie de 1,7 à 7,0. Un mélange de polyéthylène lineaire et ramifié (BPE/LPE) préparé utilisant les complexes Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6-diisopropylphenyl)- acenaphthenediimine) et {TpMs*}TiCl3 (2) (TpMs* = hydridobis(3-mesitylpyrazol-1-yl)(5- mesitylpyrazol-1-yl)) greffés in situ sur silice modifiée avec MAO (4,0 wt. -% Al/SiO2, S2). Les réactions de polymérisation ont été exécutées dans le toluène à deux températures différentes (0 et 30°C), variant la fraction molaires du nickel (xNi), et utilisan MAO comme cocatalyseur externe. A toutes les températures, les activités montrent une tendence de variation linéaire avec xNi et indiquent l´absence d´effet synerque entre les espéces de nickel et du titane. Des activités les plus elèvees ont été trouvées à 0°C. Les températures de fusion pour les mélanges de polyéthylène produits à 0 °C diminuent alors que xNi augmente l'indiquant une bonne compatibilité entre les phases du polyéthylène obtenues avec les deux catalyseurs. La température de fusion des mélanges de polyéthylène dépendre de l'ordre selon lequel les catalyseurs ont été greffés sur la silice modifiée avec MAO. L'immobilisation initiale de 1 sur le support (2/1/S2) produit des polymères avec une temperature de fusion (Tm) inférieure à celle des polymère obtenus lorsque le titane a etè greffé inicialment 1/2/S2. L´observation des polyèthylènes obtenus avec les deux systèms (2/1/S2 et 1/2/S2) par microscopie electronique à balayage (SEM) a montré la formation de polymére sphérique montrant que la morphologie sphérique du support à été reproduite. Sont décrits la synthèse, la caractérisation et les propriètès catalytique pour l'oligomerization de l'éthylène de quatre composés organometalliques du CrIII possèdante les ligands (([bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine]chromiun(III)chloride (3a), [bis[2- (3,5-dimethyl-l-pyrazolyl)ethyl] benzylamine]chromiun(III)chloride (3b), [bis[2-(3,5- dimethyl-l-pyrazolyl)ethyl]ether] chromiun(III)chloride (3c), [bis[2-(3-phenyl-lpyrazolyl) ethyl]ether]chromiun(III)chloride (3d)). Concernent l'oligomerization, exception faite du composè 3a, tous les complexe du chrome se sont montré actif après activation avec MAO et les FR obtenues ont une effet differencie à celles atteintes avec CrCl3(thf)3. La coordination d´un ligand tridentatè sur le centre metallique ne provoque pas de changements considérables sur la formation des C4 et C6, mais la montantè de C8 est diminuèe et celles des C10 et +C12 ont ètè augmentèes. Les polymères produits par le catalyseur 3a à 3 et 20 atm d'éthylène possèdent, selon les analyses par DSC la températures de fusion de 133,8 et 136ºC respectivement. Ceci indique que dans les deux cas la production de polyèthylène de haut densité. Effectivement le masse molar moyenne, obtenus par GPC, est de 46647 g/mol avec Mw/Mn = 2,4 (3 atm). Le système 3c/MAO a montré des valeurs de FR, activité et sélectivité à α-olefins differents selon la pression d´éthylène utilisèe. Se qui montré une grand sensibilitè à la concentration d´éthylène solubilisè. / The complex of Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) has been characterized after impregnation on silica (S1) and MAO-modified silicas (4.0, 8.0 and 23.0 wts.% Al/SiO2 called S2, S3 and S4, respectively). The treatment of these heterogeneous systems with MAO produces some active catalysts for the polymerization of the ethylene. A high catalytic activity has been gotten while using the system supported 1/S3 (196 kg of PE/mol[Ni].h.atm; toluene, Al/Ni = 1000, 30ºC, 60 min and atmospheric pressure of ethylene). The effects of polymerization conditions have been tested with the catalyst supported in S2 and the best catalytic activity has been gotten with solvent hexane, MAO as cocatalyst, molar ratio Al/Ni of 1000 and to the temperature of 30°C (285 kg of PE/mol[Ni].h.atm). When the reaction has been driven according to the in situ methodology, the activity practically doubled and polymers showed some similar properties. Polymers products by the supported catalysts showed the absence of melting fusion, results similar to those gotten with the homogeneous systems by DSC analysis. But then, polymers gotten with the transplanted system present according to the GPC’s curves the polydispersity (MwD) varies between 1.7 and 7.0. A polyethylene blend (BPE/LPE) was prepared using the complex Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediimine) and {TpMs*}TiCl3 (2) (TpMs* = hydridobis(3-mesitylpyrazol-1-yl)(5-mesitylpyrazol-1-yl)) supported in situ on MAO-modified silica (4.0 wts. -% Al/SiO2, S2). Reactions of polymerization of ethylene have been executed in the toluene in two different temperatures (0 and 30°C), varying the molars fraction of nickel (xNi), and using MAO as external cocatalyst. To all temperatures, the activities show a linear variation tendency with xNi and indicate the absence of the effect synergic between the species of nickel and the titanium. The maximum of activity have been found at 0°C. The melting temperature for the blends of polyethylene produced at 0 °C decrease whereas xNi increases indicating a good compatibility between phases of the polyethylene gotten with the two catalysts. The melting temperature for the blends of polyethylene showed be depend on the order according to which catalysts have been supported on the MAO-modified silica. The initial immobilization of 1 on the support (2/1/S2) product of polymers with a melting temperature (Tm) lower to the one of the polymer gotten when the titanium has been supported inicially (1/2/S2). The observation of polyethylenes gotten with the two systems (2/1/S2 and 1/2/S2) by scanning electron microscopy (SEM) showed the spherical polymer formation showing that the spherical morphology of the support to been reproduced. Are described the synthesis, the characterization and the catalytic properties for the oligomerization of the ethylene of four organometallics compounds of CrIII with ligands ([bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine] chromium (III) chloride (3a), [bis[2-(3,5- dimethyl-l-pyrazolyl)ethyl]benzylamine] chromium (III) chloride (3b), [bis[2-(3,5-dimethyl-lpyrazolyl) ethyl]ether] chromiun(III)chloride (3c), [bis[2-(3-phenyl-lpyrazolyl) ethyl]ether]chromiun(III)chloride (3d)). In relation of the oligomerization, at exception made of the compounds 3a, all complex of the chromium showed be active after activation with MAO and the TOF gotten have one effect differentiated to those formed with CrCl3(thf)3. The coordination of a tridentate ligand on the metallic center doesn't provoke any considerable changes on the formation of the C4 and C6, but the amount of C8 are decrease and the C10 and C12+ have increased. The Polymers produced by the catalyst 3a to 3 and 20 bar of ethylene have, according to analyses by DSC, the temperatures of fusion of 133,8 and 136ºC respectively. It indicates that in the two cases the production of high density polyethylene. The molar mass, gotten by GPC, is 46647 g/mols with MwD = 2,4 (3 bar). The system 3c/MAO showed values of TOF, activity and selectivity to different α-olefins according to the pressure of ethylene uses. Himself that shown a big sensibility to the concentration of ethylene solubilized.
15

Caracterização física, química, sensorial e nutricional de batatas minimamente processadas

Pineli, Lívia de Lacerda de Oliveira January 2005 (has links)
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Departamento de Nutrição, 2005. / Submitted by Kelly Marques (pereira.kelly@gmail.com) on 2009-10-27T14:54:41Z No. of bitstreams: 1 2005_LíviadeLacerdadeOliveiraPineli.pdf: 3388835 bytes, checksum: 08b28dbb79a3d4e68553deb614bbec7a (MD5) / Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2009-10-27T15:24:57Z (GMT) No. of bitstreams: 1 2005_LíviadeLacerdadeOliveiraPineli.pdf: 3388835 bytes, checksum: 08b28dbb79a3d4e68553deb614bbec7a (MD5) / Made available in DSpace on 2009-10-27T15:24:57Z (GMT). No. of bitstreams: 1 2005_LíviadeLacerdadeOliveiraPineli.pdf: 3388835 bytes, checksum: 08b28dbb79a3d4e68553deb614bbec7a (MD5) Previous issue date: 2005 / A batata e a hortaliça de maior importância econômica no Brasil, sendo comercializada quase exclusivamente in natura. O processamento mínimo desta hortaliça tem-se revelado alternativa viável para sua industrialização, atendendo a demanda por produtos frescos, saudáveis e práticos ao mesmo tempo. O objetivo deste trabalho foi avaliar os efeitos das temperaturas de armazenamento, das diferenças varie tais, da aplicação de atmosferas modificadas e dos antioxidantes em importantes características físicas, químicas, nutricionais e sensoriais de batatas minimamente processadas. Batatas (Solanum tuberosum, L.) ‘Agata’ e ‘Monalisa’ foram minimamente processadas como mini-batatas. Apos o processamento, as batatas foram embaladas em filmes de nylon multicamadas. As atmosferas aplicadas nos diversos experimentos foram o vácuo parcial, a atmosfera modificada passiva e a atmosfera modificada ativa com misturas gasosas de 10% CO2, 2% O2, 88% N2 ou 5%CO2, 5% O2 e 90%N2, sendo armazenadas em câmaras frias a 5 e 15oC, por 9 dias. Os tratamentos antioxidantes utilizados foram o acido cítrico a 2%, o acido eritrorbico a 3%, o acido cítrico a 2% + acido eritrorbico a 3%, em atmosfera modificada passiva, e acido cítrico a 3% + acido eritrorbico a 5% em atmosfera com 10% CO2, 2%O2 e 88% N2. A avaliação da taxa de evolução de CO2 em batatas intactas e minimamente processadas armazenadas a 5 e 15oC, realizada por meio de cromatografia gasosa, revelou que o processamento mínimo eleva a taxa metabólica de batatas, sendo a temperatura de 5oC a mais recomendada no controle deste processo. Batatas armazenadas a esta temperatura apresentaram melhor conservação no que diz respeito à manutenção das características físicas e químicas durante o armazenamento. Por meio de analise sensorial verificou-se que as analises instrumentais de firmeza e de escurecimento foram satisfatórias na predição de seus julgamentos sensoriais. A aplicação do vácuo parcial não foi capaz de manter os atributos de qualidade do produto, sendo, por isto, avaliada a influencia de outros tipos de atmosferas. A cultivar Agata foi selecionada por seu formato mais arredondado e regular, pela sua menor susceptibilidade ao escurecimento em relação a ‘Monalisa’ e por sua boa disponibilidade no mercado. Observou-se nos produtos embalados sob atmosfera modificada ativa o desenvolvimento do escurecimento de forma muito rápida e intensa, inviabilizando a sua aplicação para a cultivar ‘Agata’ de forma isolada. A associação de tratamentos antioxidantes as atmosferas modificadas passiva e ativa foram, posteriormente, avaliadas. A aplicação de antioxidantes em atmosfera modificada passiva não foi eficaz no controle do escurecimento de batatas minimamente processadas, dada a ocorrência de escurecimento gradual em alguns tubérculos das embalagens de todos os tratamentos, inviabilizando o produto já no terceiro dia de armazenamento. O tratamento combinado de antioxidantes em associação com atmosfera modificada ativa mostrou ser bastante eficaz no controle do escurecimento e manutenção da firmeza e outros atributos de qualidade de batatas minimamente processadas. Para este ultimo tratamento, a análise sensorial revelou boa aceitação tanto para o produto embalado como para o produto cozido em domicilio e uma vida de prateleira de nove dias, suficiente para o atendimento a cadeia de comercialização e distribuição. ________________________________________________________________________________________ ABSTRACT / Potato is the most important vegetable crop grown in Brazil, being commercialized mostly as a fresh product. Fresh-cut potatoes are a viable alternative to the processing industry, attending the demand for fresh, healthful and practical products. This work aimed at evaluating the effect of storage temperatures, cultivars differences, the application of modified atmospheres and antioxidants substances in important physical, chemical nutritional and sensory characteristics of fresh-cut potatoes. Potatoes (Solanum tuberosum, L.) ‘Agata' and ‘Monalisa', grade “primeirinha” had been minimally processed as baby potatoes. After processing, potatoes were packed in multilayers nylon plastic films. The atmospheres applied in the experiments were partial vacuum, passive modified atmosphere and the active modified atmosphere with gaseous mixtures of 10% CO2, 2% O2, 88% N2 or 5%CO2, 5% O2 and 90%N2. Tubers were stored under 5 and 15oC, for 9 days. The evaluated antioxidants treatments were citric acid (2%), eritrorbic acid (3%), citric acid (2%) + eritrorbic acid (3%), in passive modified atmosphere, and citric acid (3%) + eritrorbic acid (5%) in atmosphere with 10% CO2, 2%O2 and 88% N2. The evaluation of CO2 evolution in intact and fresh cut potatoes stored the 5 and 15oC, carried out by means of gaseous chromatography, revealed that minimal processing increased potato metabolism, being the temperature of 5oC the most recommended to control this process. Potatoes stored under this temperature presented better quality in respect to the maintenance of physical and chemical characteristics during storage. Through sensorial analysis it was verified that the instrumental analyses of firmness and browning were satisfactory in the prediction of its sensory judgments. The application of partial vacuum was not capable to keep quality attributes of product; other types of atmospheres were evaluated. ‘Agata’ cultivar was selected by its rounded and regular shape, by its lower susceptibility to browning compared to ‘Monalisa' and by its higher availability in the market. The development of fast and very intense browning was observed in fresh cut potatoes packed under active modified atmosphere, making unfeasible its application to ‘Agata' potatoes without any other treatment. The association of antioxidants treatments to passive and active modified atmospheres were also evaluated. The antioxidants application in combined with passive modified atmosphere was not efficient in the control of browning, given the occurrence of gradual browning in some tubers of all treatments, starting at the third day of storage. Antioxidants in association with active modified atmosphere were efficient in the control of browning and maintenance of firmness and other quality attributes of fresh cut potatoes. For this last treatment, sensory analysis revealed good acceptance both for the packed or cooked form with a shelf life of nine days, which is considered enough for commercialization and distribution chain.
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Carburização na liga HP modificada utilizada em fornos de pirólise / Carburization in alloy HP modified used in pyrolysis furnaces

Celso Donizetti de Souza Filho 26 October 2012 (has links)
Os fornos de pirólise, feitos a partir da liga HP modificada, são equipamentos destinados à produção de hidrocarbonetos leves na indústria petroquímica. A partir da pirólise, é possível obter etileno e outros produtos que são matérias-primas para obtenção de manufaturados formados por polímeros. Nesse processo, grandes moléculas de hidrocarbonetos, na forma gasosa, são craqueadas em condições especiais de temperatura e pressão. Durante o craqueamento, o teor de carbono dos materiais que constituem os fornos é aumentado por meio do ingresso de carbono através da superfície interna dos tubos, sendo oriundo da massa reativa que atravessa as colunas e, como consequência disso, ocorre uma alteração das propriedades mecânicas do material. Aliado a esse fato, existe o depósito nocivo de uma camada de coque a partir da superfície interna das tubulações, que funciona como um isolante térmico, diminuindo a temperatura do gás e exigindo uma maior temperatura de trabalho para o forno, além de causar tensões que podem resultar em trincas ou danos para as colunas dos fornos de pirólise. Durante a carburização, a liga metálica dos fornos de pirólise desenvolve propriedades tipo ferromagnéticas, as quais são resultado do processo de ingresso de carbono. Nesta etapa, a camada magnetizada do material coincide com a região onde houve propagação da carburização. Sendo assim, uma medida da magnetização do material pode resultar em uma medida direta do nível de carburização em que o forno se encontra. Neste trabalho, serão apresentadas técnicas para simulação de ambientes carburizantes em alta temperatura, e as amostras serão testadas tendo o tempo de exposição ao carbono como sua principal variável e as suas propriedades mecânicas serão avaliadas, além da alteração de sua composição química e sua microestrutura. / The pyrolysis heaters, made of HP-modified alloy, are equipments designed to produce lightweight hydrocarbon in the petrochemical industry. Because of the pyrolysis, it is possible to obtain ethylene and other products that are raw material to gain manufactured polymer. In this process, big gaseous hydrocarbon molecules suffer a cracking process under special conditions of temperature and pressure. During the steam cracking process, the amount of carbon from the constituent material of the heaters is increasing as a consequence of the carbon entrance through the inside surface of the tubes. This carbon comes from the reactive mass that crows the columns and, eventually, produces a change in the mechanical proprieties of the material. Besides that, there is a harmful deposit of a coke layer that comes from the internal surface of the heater tubes. This layer works as a thermal insulation and is responsible for the decreasing of the gas temperature and as a consequence, the heater demands a higher temperature to work properly. As a result, rupture or damages can occur in the pyrolysis heater columns. During the carburization, the above mentioned alloy presents magnetic properties in consequence of the increase of the carbon amount in the material. The magnetic layer is observed in the region where the carburization process happened. Therefore, a measure of the material magnetization can lead to a direct measure of the carburization level in which the heater is on. In this work, simulation techniques of the carburizing environment under high temperature will be presented, and the samples will be tested regarding the correlation between carbon exposition time and the mechanical properties, microstructural changes and chemical composition that occur as a result.
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Novel catalyst systems based on Ni(II), Ti(IV), and Cr(III) complexes for oligo-and polymerization of ethylene

Junges, Fernando January 2005 (has links)
Le complexe de Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) a été caractérisé après impregnation sur silice (S1) et a silices modifié avec MAO (4,0, 8,0 et 23,0 wt.% Al/SiO2 appelé S2, S3 et S4, respectivement). Le traitement de ces composés greffé avec MAO produit des catalyseurs actifs pour la polymérisation de l'éthylène. Un haute activité catalytique a été obtenue en utilisant le système supporté 1/S3 (196 kg de PE/mol[Ni].h.atm; toluene, Al/Ni = 1000, 30ºC, 60 min et pression atmosphérique d'éthylène). Les effets des conditions de la polymérisation ont été testés avec le catalyseur greffé S2 et la meilleure activité catalytique a été obtenue avec le solvant hexane, MAO comme cocatalyseur, la proportion molaire Al/Ni de 1000 et à la température de 30°C (285 kg de PE/mol[Ni].h.atm). Quand la réaction a été conduite selon la méthodologie in situ, l'activité a pratiquement doublé et les polymères ont montré des propriétés semblables. Les polymères produits par les catalyseurs supportés ont montré l'absence de température de fusion, resultats senblables à seux obtenus avec les systèms homogène par analyse DSC. En revanche, le polymères obtenus avec les système greffé presentent selon les courbes GPC une (MwD) polydispersité qui varie de 1,7 à 7,0. Un mélange de polyéthylène lineaire et ramifié (BPE/LPE) préparé utilisant les complexes Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6-diisopropylphenyl)- acenaphthenediimine) et {TpMs*}TiCl3 (2) (TpMs* = hydridobis(3-mesitylpyrazol-1-yl)(5- mesitylpyrazol-1-yl)) greffés in situ sur silice modifiée avec MAO (4,0 wt. -% Al/SiO2, S2). Les réactions de polymérisation ont été exécutées dans le toluène à deux températures différentes (0 et 30°C), variant la fraction molaires du nickel (xNi), et utilisan MAO comme cocatalyseur externe. A toutes les températures, les activités montrent une tendence de variation linéaire avec xNi et indiquent l´absence d´effet synerque entre les espéces de nickel et du titane. Des activités les plus elèvees ont été trouvées à 0°C. Les températures de fusion pour les mélanges de polyéthylène produits à 0 °C diminuent alors que xNi augmente l'indiquant une bonne compatibilité entre les phases du polyéthylène obtenues avec les deux catalyseurs. La température de fusion des mélanges de polyéthylène dépendre de l'ordre selon lequel les catalyseurs ont été greffés sur la silice modifiée avec MAO. L'immobilisation initiale de 1 sur le support (2/1/S2) produit des polymères avec une temperature de fusion (Tm) inférieure à celle des polymère obtenus lorsque le titane a etè greffé inicialment 1/2/S2. L´observation des polyèthylènes obtenus avec les deux systèms (2/1/S2 et 1/2/S2) par microscopie electronique à balayage (SEM) a montré la formation de polymére sphérique montrant que la morphologie sphérique du support à été reproduite. Sont décrits la synthèse, la caractérisation et les propriètès catalytique pour l'oligomerization de l'éthylène de quatre composés organometalliques du CrIII possèdante les ligands (([bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine]chromiun(III)chloride (3a), [bis[2- (3,5-dimethyl-l-pyrazolyl)ethyl] benzylamine]chromiun(III)chloride (3b), [bis[2-(3,5- dimethyl-l-pyrazolyl)ethyl]ether] chromiun(III)chloride (3c), [bis[2-(3-phenyl-lpyrazolyl) ethyl]ether]chromiun(III)chloride (3d)). Concernent l'oligomerization, exception faite du composè 3a, tous les complexe du chrome se sont montré actif après activation avec MAO et les FR obtenues ont une effet differencie à celles atteintes avec CrCl3(thf)3. La coordination d´un ligand tridentatè sur le centre metallique ne provoque pas de changements considérables sur la formation des C4 et C6, mais la montantè de C8 est diminuèe et celles des C10 et +C12 ont ètè augmentèes. Les polymères produits par le catalyseur 3a à 3 et 20 atm d'éthylène possèdent, selon les analyses par DSC la températures de fusion de 133,8 et 136ºC respectivement. Ceci indique que dans les deux cas la production de polyèthylène de haut densité. Effectivement le masse molar moyenne, obtenus par GPC, est de 46647 g/mol avec Mw/Mn = 2,4 (3 atm). Le système 3c/MAO a montré des valeurs de FR, activité et sélectivité à α-olefins differents selon la pression d´éthylène utilisèe. Se qui montré une grand sensibilitè à la concentration d´éthylène solubilisè. / The complex of Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) has been characterized after impregnation on silica (S1) and MAO-modified silicas (4.0, 8.0 and 23.0 wts.% Al/SiO2 called S2, S3 and S4, respectively). The treatment of these heterogeneous systems with MAO produces some active catalysts for the polymerization of the ethylene. A high catalytic activity has been gotten while using the system supported 1/S3 (196 kg of PE/mol[Ni].h.atm; toluene, Al/Ni = 1000, 30ºC, 60 min and atmospheric pressure of ethylene). The effects of polymerization conditions have been tested with the catalyst supported in S2 and the best catalytic activity has been gotten with solvent hexane, MAO as cocatalyst, molar ratio Al/Ni of 1000 and to the temperature of 30°C (285 kg of PE/mol[Ni].h.atm). When the reaction has been driven according to the in situ methodology, the activity practically doubled and polymers showed some similar properties. Polymers products by the supported catalysts showed the absence of melting fusion, results similar to those gotten with the homogeneous systems by DSC analysis. But then, polymers gotten with the transplanted system present according to the GPC’s curves the polydispersity (MwD) varies between 1.7 and 7.0. A polyethylene blend (BPE/LPE) was prepared using the complex Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediimine) and {TpMs*}TiCl3 (2) (TpMs* = hydridobis(3-mesitylpyrazol-1-yl)(5-mesitylpyrazol-1-yl)) supported in situ on MAO-modified silica (4.0 wts. -% Al/SiO2, S2). Reactions of polymerization of ethylene have been executed in the toluene in two different temperatures (0 and 30°C), varying the molars fraction of nickel (xNi), and using MAO as external cocatalyst. To all temperatures, the activities show a linear variation tendency with xNi and indicate the absence of the effect synergic between the species of nickel and the titanium. The maximum of activity have been found at 0°C. The melting temperature for the blends of polyethylene produced at 0 °C decrease whereas xNi increases indicating a good compatibility between phases of the polyethylene gotten with the two catalysts. The melting temperature for the blends of polyethylene showed be depend on the order according to which catalysts have been supported on the MAO-modified silica. The initial immobilization of 1 on the support (2/1/S2) product of polymers with a melting temperature (Tm) lower to the one of the polymer gotten when the titanium has been supported inicially (1/2/S2). The observation of polyethylenes gotten with the two systems (2/1/S2 and 1/2/S2) by scanning electron microscopy (SEM) showed the spherical polymer formation showing that the spherical morphology of the support to been reproduced. Are described the synthesis, the characterization and the catalytic properties for the oligomerization of the ethylene of four organometallics compounds of CrIII with ligands ([bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine] chromium (III) chloride (3a), [bis[2-(3,5- dimethyl-l-pyrazolyl)ethyl]benzylamine] chromium (III) chloride (3b), [bis[2-(3,5-dimethyl-lpyrazolyl) ethyl]ether] chromiun(III)chloride (3c), [bis[2-(3-phenyl-lpyrazolyl) ethyl]ether]chromiun(III)chloride (3d)). In relation of the oligomerization, at exception made of the compounds 3a, all complex of the chromium showed be active after activation with MAO and the TOF gotten have one effect differentiated to those formed with CrCl3(thf)3. The coordination of a tridentate ligand on the metallic center doesn't provoke any considerable changes on the formation of the C4 and C6, but the amount of C8 are decrease and the C10 and C12+ have increased. The Polymers produced by the catalyst 3a to 3 and 20 bar of ethylene have, according to analyses by DSC, the temperatures of fusion of 133,8 and 136ºC respectively. It indicates that in the two cases the production of high density polyethylene. The molar mass, gotten by GPC, is 46647 g/mols with MwD = 2,4 (3 bar). The system 3c/MAO showed values of TOF, activity and selectivity to different α-olefins according to the pressure of ethylene uses. Himself that shown a big sensibility to the concentration of ethylene solubilized.
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Análise do desenvolvimento de infestações de Sitophilus spp. em milho orgânico embalado em atmosfera modificada (am) / Development of sitophilus spp. infestation on organic corn grain wrapped in modified atmosphere (MAP)

De Carli, Marcelo January 2007 (has links)
O milho (Zea mays L.) é um dos grãos de maior importância econômica no mundo, requerendo grandes áreas para sua estocagem. Uma das etapas importantes no armazenamento é o expurgo, empregado para controle de pragas de insetos das espécies Sitophilus spp. Atualmente, a cultura de milho orgânico está em constante aumento devido à crescente exigência do mercado por produtos livres de resíduos químicos. Para produtos orgânicos, o emprego do dióxido de carbono (CO2) como agente de controle de insetos, é uma alternativa interessante, pois este tem como principal vantagem a de não deixar resíduos após aplicação. O objetivo desta pesquisa foi avaliar o controle de insetos Sitophilus spp no milho orgânico embalado mediante o uso de CO2 (atmosfera modificada). Para esse fim, foram criados insetos e colocados em milho (previamente limpo e selecionado) contidos em potes plásticos com tampa com tela. Após 45 dias, as amostras contendo os insetos foram colocadas em embalagens barreira e fechadas em embaladora a vácuo compensado em diferentes níveis de CO2: 0 (ar sintético), 20, 40, 60 e 80% e tempos de exposição de: 1, 2, 3, 4, 5, 15 e 30 dias. Após aplicação dos tratamentos foi realizada a contagem dos insetos vivos de acordo com metodologia proposta pela FAO. Durante os períodos de aplicação dos tratamentos, foram analisados o teor de umidade, acidez e pH no milho e a concentração de CO2, dentro da embalagem. Também foi avaliado o efeito dos tratamentos sobre a capacidade dos insetos de gerarem descendência (efeito progênie). Foi constatado que as maiores taxas de mortalidade de insetos adultos foram nos primeiros cinco dias de exposição à AM em todos os níveis de concentração de CO2 estudados. Para períodos de exposição de 15 e 30 dias, foi observado que foram eliminados todos os insetos adultos nas concentrações de 20, 40, 60 e 80% de CO2. Durante os experimentos verificou-se que as concentrações de CO2 no interior das embalagens, em atmosfera modificada, se mantiveram estáveis até o quinto dia de exposição e a partir do qual começaram a diminuir, comportamento este observado em todas as concentrações de atmosfera estudadas. Para o teor de umidade e a acidez houve interação entre o tempo de exposição e a composição atmosférica, enquanto para o pH existiram diferenças significativas e com médias muito próximas para as atmosferas testadas, porém sem variação de pH significativa em 30 dias. A aplicação de AM com tempos menores que cinco dias não afetou a progênie dos insetos, no entanto, a partir do décimo quinto dia, qualquer concentração de CO2 estudada foi efetiva na eliminação de todas as fases de desenvolvimento dos insetos. Dos resultados pode-se concluir que o emprego de concentrações não menores que 20% de CO2 com tempo de aplicação mínimo de 15 dias é recomendado para a eliminação de insetos adultos, ovos, larva e pupa. Também foi verificado que o vácuo não teve efeito sobre a morte dos insetos. / Maize grain (Zea mays L.) is one of the grains of largest economical importance in the world, requesting great areas for this storage. One of the most important stages in the storage is its purge, for control of insects of the species Sitophilus spp. Nowadays, the culture of organic corn is in constant increase due to growing demand of the market for products free of chemical residues. For this kind of product the use of carbon dioxide (CO2) as agent for insect control is an interesting alternative, because the main advantage of not leaving residues after application. The objective of this investigation was to evaluate the control of insects Sitophilus spp in organic maize in packing using CO2 (modified atmosphere). Insects were created and placed in maize (previously cleaned and selected) contained in plastic flasks with screen cover. After 45 days, the samples containing insects were placed in packings barrier and closed in packer machine whith vacuum compensated in different levels of CO2: 0 (synthetic air), 20, 40, 60 and 80% and times of exposition of: 1, 2, 3, 4, 5, 15 and 30 days. These treatments the number of alive insects were counted in according to the methodology proposed by FAO. During the period of application of the treatments, the moisture contend, acidity and pH were analyzed in the corn, and the concentrations of CO2 inside of the packing was measured. The effect of the treatments on the capacity of the insects to create descendants (progeny effect), was also evaluated. It was verified that the largest rates of mortality of adult insects were in the first five days of exposition to AM to all levels of CO2 concentration studied. For periods of exposition of 15 and 30 days, it was observed that all the adult insects were eliminated in the concentrations of 20, 40, 60 and 80% of CO2. During the experiment it was verified that the CO2 concentrations inside the packings, in modified atmosphere, remained stable until the fifth day of exposition and after this time CO2 concentrations started to decrease. This behavior was observed in all atmosphere concentrations studied. For the moisture and acidity was verified that there was significant interaction between the time of exposition and the atmospheric composition, while, for the pH differences were significant with very next averages, for any atmospheric condition during the storage, however without variation of significant pH in 30 days. The application of AM in times smaller than five days no affect the progeny of the insects, however, starting from the fifteenth day, for any CO2 concentration studied they were effective in the elimination of all the phases of development of the insects. From the results it can be concluded that the use of concentrations from 20% of CO2, with time of application minimum of 15 days are recommended for the elimination of adult insects, eggs, larva and pupa. It was also verified that the vacuum have no effect on the death of the insects.
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Avaliação do processo por embalagem do tipo atmosfera modificada na conservação da carne bovina porcionada / The use of modified atmosphere packaging in order to improve the shelf life of case ready beef

Rosana Salles Baracat 17 November 2006 (has links)
O uso de atmosfera modificada (ATM) na embalagem de cortes cárneos tem sido uma alternativa para melhorar a qualidade do produto. Diante disto, o objetivo deste trabalho foi observar a vida útil de carnes armazenadas neste tipo de embalagem. Foram retiradas 96 amostras de 4 novilhos anelorados, divididas em três tratamentos: Tratamento 1 (T1) – referente às amostras analisadas no dia da desossa; Tratamento 2 (T14) – referente às amostras analisadas aos 14 dias de armazenamento; Tratamento 3 (T28) – referente às amostras analisadas aos 28 dias de armazenamento. Cada tratamento tinha oito amostras de cada um dos quatro músculos estudados: Longissimus dorsi (Contrafilé) – LD, Quadricepis femoris (Patinho) – QF, Semitendinosus (Lagarto) - ST e Supraspinatus (Peixinho) – SS, sendo quatro delas (A, B, C e D) usadas para análises de força de cisalhamento, perdas de água ao cozimento e por exsudação, pH e cor, e as outras quatro para análises microbiológicas. As amostras foram embaladas em sacos do tipo masterpack com mistura de gases na proporção de 75% O2 e 25% CO2 e armazenadas por 28 dias em câmara de resfriamento com temperatura de 0 a 1ºC. Ao longo do período de armazenamento foi observada uma redução linear da força de cisalhamento nos músculos LD, ST e QF, e uma associação quadrática em relação ao músculo SS, com um aumento da força após 14 dias. Em relação às perdas de água ao cozimento houve uma interação significativa entre o tempo de armazenamento e os músculos, e as perdas por exsudação apresentaram uma relação linear com o tempo de armazenamento, com valores crescentes de perdas do T1 em relação ao T2 e T3. Os valores de pH apresentaram uma associação linear e quadrática em relação ao tempo de armazenamento. Para as características de cor, o tempo de armazenamento apresentou associação linear e quadrática com o croma L*, quadrática com o croma a* e linear e quadrática com o croma b*. Não foram detectadas presenças de Salmonella e de Coliformes fecais, e nem de Clostridium em nenhuma das amostras analisadas, e as contagens detectadas de Coliformes totais estão abaixo do limite especificado para carne crua. Desta forma, foi concluído que carnes armazenadas em ATM, por um período de até 28 dias, não comprometem a qualidade visual e sensorial dos produtos. / Modified atmosphere packaging and case ready beef have been used to improve quality of beef cuts. With this objective in mind this work was designed to study the shelf life of this kind of packaging on beef cuts and 24 samples from 4 Nellore steers, were collected from each muscle: Longissimus dorsi (LD), Quadriceps femoris (QF), Semitendinosus (ST) and Supraspinatus (SS) in a total of 96 samples which were packaged in masterpack bags with a MAPAX gas with 75% O2 and 25% CO2 and aged for 1, 14 or 28 days or treatment T1 samples analyzed on day 1, T14 samples analyzed on day 14 and T28 samples analyzed on day 28, respectively. Every treatment had 8 samples from every one of the 4 muscles studied (A, B, C, e D). Four samples were used for shear force, cooking losses, pH and color and, the other 4 samples for microbiological analyses. A linear decrease in shear force with aging time was observed for LD, ST and QF muscles. A quadratic association for the SS muscle was seen after 14 days of aging. For cooking losses there was a significant interaction between aging time and muscle, as exudative loss showed a linear relation with aging time, improving loss, when comparing T1 in relation to T2 and T3. Differences were observed for pH showing a linear and quadratic relation with aging time. Muscle color among treatments and results were within acceptable values for both characteristics and results. No Salmonellae, Clostridium or Fecal Coli forms were observed in any of the samples as well as total Coli forms were within acceptable ranges for raw beef.
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Provas de carga dinâmica em estacas escavadas de pequeno diâmetro com ponta modificada / Dynamic load tests on small diameter auger piles with modified tip

Carlos José Marques da Costa Branco 17 July 2006 (has links)
Fundações por estacas escavadas com trado mecânico têm sido largamente empregadas para cargas de pequeno e médio porte. Como o processo executivo não consegue evitar a deterioração das propriedades do solo in situ no fundo da escavação, a única parcela confiável de resistência é aquela referente ao atrito lateral. No entanto, a ponta dessas estacas, muitas vezes, atinge estratos com resistência relativamente elevada e não consegue aproveitar as qualidades do estrato. O presente trabalho visou o estudo do comportamento desse tipo de estaca no perfil geotécnico típico da cidade de Londrina, através da execução de provas de carga dinâmica em 16 estacas de 0,25 m de diâmetro e 12 m de comprimento, sendo três estacas tradicionais e 13 estacas com ponta modificada. Foram feitas, também, provas de carga estática em duas estacas tradicionais, inspeção das pontas de todas as estacas e determinação dos parâmetros de resistência do solo. Os resultados mostraram que todas as modificações pesquisadas permitiram a utilização da carga estrutural nominal das estacas e que a mais eficiente foi a do tipo que promoveu a melhoria do solo na ponta com a adição de um estabilizante de solo. / Auger pile foundations have been widely employed for light to medium loads. As the executive process can’t avoid the degradation of the bottom excavation in situ soil properties, the only reliable resistance is a lateral friction parcel. However, these tip piles, many times, reaches relatively resistant strata and can’t take advantage from these strata qualities. The present paper seems study the performance of this kind of piles in typical geotechnical profile of Londrina, by dynamic load tests on 16 piles with diameter equal 0,25 m and length of 12 m, when three traditional piles and on thirteen kinds with tip modification. Were made, also, static load tests on three traditional piles, tip investigation on all piles and soil resistance parameters determination. The results shaw that all modifications researched was able to use the nominal structural load of piles and that the more efficient of them was the soil improvement by soil stabilizer addition.

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