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Exigências de valina para frangos de corte / Requirements of valine for broilersNayara Tavares Ferreira 15 December 2011 (has links)
O presente estudo teve como objetivo avaliar níveis ótimos de valina digestível. Foram conduzidos três ensaios com frangos de corte da linhagem Cobb nas fases inicial (1-14 dias), crescimento (14-28 dias) e terminação (28-42 dias), com ensaios realizados separadamente para cada fase, tendo como base o método dose-resposta. Para os ensaios de 1 a 14dias e de 14 a 28 dias, 672 amimais foram distribuídos em delineamento inteiramente ao acaso, em oito tratamentos (7 níveis de valina e 1 controle), com 7 repetições, sendo cada unidade experimental composta por 12 aves , porém no ensaio de 28 a 42 dias foram utilizados 560 frangos, igualmente distribuídos como nos ensaios anteriores em 8 tratamentos com 7 repetições com 10 aves cada. Foram formuladas dietas basais pela técnica da diluição, deficientes em valina, contendo níveis de energia, minerais e vitaminas conforme recomendações de Rostagno et al. (2005), para cada fase. As recomendações dos níveis de valina digestível para cada fase, obtidas no presente estudo, foram realizadas com base nas respostas de CA. As recomendações obtidas pelo método dose resposta são de 0,917; 0,905 e 0,783% de valina digestível para frangos de 1 a 14 dias, 14 a 28 e 28 a 42 dias de idade, respectivamente. / This study was to evaluate optimal levels of digestible valine. Three trials were conducted with broiler chickens of Cobb in the initial phase (1-14 days), growth (14-28 days) and termination (28-42 days), with tests performed separately for each phase, based on the method dose-response. For tests 1 to 14 days and 14 to 28 days, 672 animals it were distributed in a completely randomized in eight treatments (seven levels of valine and 1 control), with 7 replicates, each replicate consisting of 12 birds but the test of 28 to 42 days 560 chickens were used, equally distributed as in previous trials in 8 treatments with 7 replicates of 10 birds each. Basal diets were formulated by the dilution technique, deficient in valine, containing levels of energy, minerals and vitamins as recommended by Rostagno et al. (2005), for each phase. The recommended levels of digestible valine for each phase, obtained in this study were based on responses from CA. The recommendations obtained by the dose response are 0.917, 0.905 and 0.783% of digestible valine for broilers from 1-14 days, 14-28 and 28-42 days of age, respectively.
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Distribuição da marcação com nitrogenio 15 de frações proteicas de feijão-comum (Phaseolus vulgars L.) e diluição isotopica no processo de digestibilidade in vitro / Distribution of the marking with nitrogen 15 of protéicas fractions of beans-common (PHASEOLUS VULGARIS, L.) e isotópica dilution in the digestibilidade process in vitroChaud, Saula Goulart 24 November 1998 (has links)
Orientador: Admar Costa de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-24T13:58:49Z (GMT). No. of bitstreams: 1
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Previous issue date: 1998 / Resumo: O presente trabalho teve por objetivo verificar se a marcação com nitrogênio 15 (15N) de feijão integral, liofilizado, marcado isotopicamente com 1,385 átomos%, é a mesma na proteína e frações protéicas extraídas do feijão, assim como verificar a diluição isotópica do 15N ocorrida na digestibilidade in vitro, pela autodigestão das enzimas utilizadas. As proteínas foram extraídas com NaCl 0,5M em pH 7,0. Na avaliação da digestibilidade in vitro, utilizou-se o método da hidrólise pela pepsina mais pancreatina. As marcações isotópicas na farinha integral de feijão, o extrato protéico total, a fração globulina e a fração albumina foram, respectivamente: 1,394±0,011; 1,403±0,012; 1,399±0,007 e 1,399±0,028 átomos% de 15N, não sendo encontrada diferença estatística entre as mesmas (P>0,05). Entretanto, foram encontradas diferenças significativas (P<0,05) entre as marcações acima citadas e a marcação isotópica encontrada para o resíduo da extração, que foi de 0,969±0,084 e o nitrogênio originalmente solúvel, que apresentou um valor de 0,923±0,007 átomos% 15N. O digerido da farinha integral apresentou um valor de 1,026±0,014 átomos% de 15N, o que indica que efetivamente ocorreu autodigestão relativamente alta das enzimas utilizadas para a obtenção da digestibilidade in vitro, uma vez que não estão marcadas e, conseqüentemente, foram em parte responsáveis pela diluição isotópica encontrada. A diluição isotópica encontrada nas substâncias nitrogenadas existentes no digerido do branco da farinha integral, indicou que tais substâncias são marcadas em menor magnitude do que o próprio grão e suas proteínas, o que também influiu no resultado do digerido da farinha integral. O digerido do extrato protéico total apresentou um valor de 1,067±0,009. Os valores estão indicando a existência de diluição isotópica dos digeridos da farinha integral e do extrato protéico total, em relação à marcação isotópica da farinha e frações protéicas originais, aparentemente devido à autodigestão das enzimas e, em parte, ao nitrogênio originalmente solúvel da amostra, conforme descrito. A fim de monitorar os processos de extração e fracionamento das proteinas, foi determianda a metionina disponível in vitro, utilizando-se a reação do nitroprussiato de sódio. Os valores encontrados foram: farinha integral 0,30±0,04; extrato protéico 0,41±0,01; albumina 0,37±0,01 e globulina 0,41±0,05 g/100g proteína, que estão de acordo com resultados usualmente encontrados na literatura. Como conclusão geral, pôde ser inferido que os índices de qualidade protéica, como a digestibilidade e o valor biológico por balanço de nitrogênio e diluição isotópica, não serão afetados no caso de proteínas extraídas do feijão com NaCl 0,5M, uma vez que a marcação isotópica (15N) da farinha integral e frações protéicas não diferiram (p > 0,05). No caso de se trabalhar com farinhas integrais, estes índices poderão apresentar resultados irreais, uma vez que as marcações isotópicas tanto do nitrogênio do resíduo de extração como do nitrogênio originalmente solúvel foram menores / Abstract: The aim of the present work was to verify if the isotope labelling with nitrogen 15 (15N) obtained in whole lyophilized beans, which had been labelled isotopically with 1.385% of 15N atoms of the total, was the same in the protein and protein fractions extracted from the beans. The aim was also to verify isotopic dilution of 15N, which occurs during in vitro digestibility through selfdigestion of the enzymes used. Proteins were extracted using 0.5M NaCl at pH 7.0. In order to assess digestibility in vitro the hydrolysis method was applied using pepsin plus pancreatine. The isotope labelling of the whole bean flour, the total protein extract, the globulin fraction and the albumin fraction were, respectively: 1.394±0.011; 1.403±0.012; 1.399±0.007 and 1.399±0.028% of 15N atoms. No statistical difference was found between these data (P>0.05). Nevertheless, significant differences (P<0.05) were found between the isotopic labelling mentioned above and those found for the extraction residue which was 0.969±0.084 and the original soluble nitrogen which showed a value of 0.923±0.007% 15N atoms. The in vitro digested part of the whole flour showed a value of 1.026±0.014 atoms of 15N, which indicates a relatively high selfdigestion by the enzymes used in the in vitro digestibility, since they had not been labeled and consequently were in part responsible for the isotopic dilution found. The isotopic dilution found in the nitrogen substances of the blank of the digested whole flour showed that such substances were less marked than the grain and its proteins which also had an influence on the digested fraction of the whole flour. The digested fraction of the total protein extract showed a result of 1.067±0.009. The values pointed out to the occurrence of isotopic dilution of the digested fractions of the whole flour and the total protein extract, in relation to the isotope label of the original flour and protein fractions, which is apparently due to selfdigestion by the enzymes used and to the original soluble nitrogen as a flour, as already described. In order to control the extraction and fragmentation processes of proteins, the in vitro methionine available was determined, using the reaction of sodium nitroprusside. The values found were: whole flour 0.30±0.04; protein extract 0.41±0.01; albumin fraction 0.37±0.01 and globulin fraction 0.41±0.05 g/100g protein, which correspond to results usually found in the literature. Concluding, it can be inferred that the protein quality indexes, such as digestibility and biological value using nitrogen balance and isotopic dilution, will not be affected in the case of bean proteins extracted by 0.5M NaCl, since isotopic labelling (15N) of the whole flour and protein fractions did not differ (p>0.05). However, in the case of whole flours, these indexes might produce false results, since the isotope labelling of both residual nitrogen extraction and the original soluble nitrogen were lower than those referred above / Mestrado / Mestre em Ciência da Nutrição
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Aspects of flow injection atomic absorption spectrometryOffley, Stephen George January 1992 (has links)
The literature relevant to the generation of volatile hydrides for analytical atomic spectroscopy has been reviewed, with particular reference to atomic absorption spectrometry (AAS). This reveals some conflicting information concerning the nature of various interference effects and strategies to overcome them. The use of flow injection (FI) procedures has been demonstrated by several research groups, to be beneficial. A review of the literature concerning the application of FI techniques to AAS shows that there is a sustained interest in the use of such a combination for analytical purposes. In particular, an interest in the on-line coupling of chemical pretreatment of samples is evident. Atomic absorption spectrometry has a limited working range and requires frequent calibration, consequently, there is a need for a rapid, precise on-line dilution procedure. The potential of FI systems with wide bore manifold tubing for on-line dilution was assessed and found to be limited by variations in dispersion coefficient arising from differences in specific gravities between the sample and carrier fluids. This could be overcome only by the use of unrealistically high flow rates. The use of FI procedures for the generation of volatile hydrides of selenium and arsenic was investigated. Optimization studies of system parameters, including the atomization step, were undertaken which demonstrated the benefits in applying FI in hydride generation atomic absorption spectrometry (HGAAS). Analytical methods were devised and evaluated for the determination of Se in copper metal and As in nickel alloy. These procedures involved the use of an on-line matrix removal step in which potentially interfering matrix elements were retained on a strong cation exchange resin (Dowex 50W). The manifold was designed so that the FI value acted as the interface between the matrix isolation stage and the vapour generation stage, a strategy which allowed independent optimization of each stage. Location of the ion exchange resin in the sample loop of a six-port rotary valve allowed the resin to be regenerated easily and rapidly, with a throughput capability of the order of 50 h⁻¹ and permit the proposed full automation of the whole analytical procedure. In the determination of As in nickel alloy a novel stopped-flow pre-reduction step was developed to permit AsIII quantification, therefore, achieve optimum sensitivity. The two systems permitted limits of detection for Se and As of 2.1 and 3.9 ng ml⁻¹ respectively. Direct comparisons were made with existing matrix isolation systems to emphasise the benefits of system design.
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Issues of particulate matter emission from diesel engine and its controlAlozie, Nehemiah Sabinus Iheadindueme January 2016 (has links)
Particulate matter (PM) emitted from diesel engines encompasses soluble (volatile) and insoluble (non-volatile) matter. The concept of volatility or solubility depends on the method of separation. The volatile matter includes sulphates and nitrates which are bound to water vapour; and myriads of hydrocarbon species. The solid matter is comprised of black carbon and ash. Its mitigation combines the use of internal engine design and operating factors like fuel injection and spray, air and fuel mixing, chamber designs and fuel improvements. Control technologies that act on the exhaust gases are called ‘after-treatments' which include the use of oxidation catalysts, filter trap and reductant of nitrogen oxides along the exhaust system. The central issues of this thesis are measurement schemes that involve stripping the PM of volatile matter in order to determine the actual values of nano-size solid carbon particles that pose significant health risk and their mitigations. In the experimental measurements, exhaust gases were generated at low engine load which are rich in unburnt hydrocarbons that nucleate into particles at low temperatures. Similarly, exhaust gases generated at medium load contain volatile and soot components; these were used to study dilution effects on PM emission. The interplay of mixing and cooling was used to explain the behaviour of saturation characteristics of the volatile fractions in the dilution process which influenced nucleation of volatile species. The parameters of particle number concentration reduction factor (PCRF) and volatile removal efficiency (VRE) were used to give extended interpretation to dilution of PM during conditioning, than mere dilution ratios. On this basis, comparison was made on the effect of carrier gases on dilution process and it was found that air is superior when there is need for volatile reduction while nitrogen is better when it is necessary to freeze further reaction, especially at low dilution ratios. In addition, a two-stage hot dilution technique was used to mimic the Particle Measurement Programme (PMP) prescription, and it gave better PCRF and VRE values. The study of PM mitigation by filter traps focused on burning-off the accumulated matter to allow free flow of exhaust gases, and the energy it takes to initiate and maintain PM combustion. Therefore a fundamental study of soot oxidation relevant to regeneration of diesel particulate filter (DPF) was made. This was extended to investigate if blending of petrodiesel with biodiesel affects PM oxidation. It is deducible that oxidation of PM generated from fuel with biodiesel blends is slightly faster compared to that from pure petrodiesel. A feasible use of microwave power to regenerate catalysed and non-catalysed silicon carbide (SiC) diesel particulate filters (DPFs) using an available multimode microwave cavity was also carried out. Results show that with catalysed DPFs, catalyst light-off temperature reduced by 100oC under the influence of microwave irradiation, while for non-catalysed DPF, regeneration was achieved within 550-600oC at a time estimated to be lower compared to electrical resistance heating approach.
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Unfair advantages associated with likelihood of confusion and dilution in trademark lawTyagi, Manvi January 2017 (has links)
The trademark guarantees market transparency and protecting clear communicative channel between innovative product and consumer rather than rewarding creators or creating direct incentives for the inventor like in Intellectual Property and Patent. However, unfair advantages of the trademark are rising to new challenges because of complex average consumer behaviour. Nevertheless extended protections of the trademark can also create obstacles to innovation and market competition. Therefore, to understand the unfair advantages and associated challenges in the trademark in this thesis the research focus is kept on unfair advantages linked with likelihood of confusion and dilution and its possible limitations, and finally problem with existing approach to determine the unfair advantages.
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A comparison of helium dilution and plethysmography in measuring static lung volumesGuldbrand, Anna January 2008 (has links)
In order to examine the usefulness of the multi breath helium dilution method (MB) it was compared to the single breath helium dilution method (SB) and body plethysmography (BP). Residual volume (RV), total lung capacity (TLC) and vital capacity (VC) were measured in seventeen subjects with obstructive (11) or restrictive (6) lung disease and four normal subjects. With information from professional literature and current periodicals, advantages and disadvantages with all three methods were compared. ANOVA and Student's t-test were performed on the measurement results. The results of the statistical tests tell us there are differences among the methods in the group of obstructive patients. They also reveal a notable difference between the MB and SB methods when measuring the same parameter. In addition, it was noted that none of the existing sets of prediction equations fulfill the requirements established on high quality lung function testing. Although a thorough evaluation of the reproducibility of the method is still required, it appears to be a viable alternative to body plethysmography. We claim that measuring the above mentioned static lung volumes with only the single breath helium dilution method cannot be considered a satisfactory practice.
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Využití konduktometru LTC pro charakterizaci proudění vody ve vrtech: Umělý vrt a terénní měření / Use of conductivity meter LTC to characterize the flow of groundwater in well: Use of artificial well and field monitoringRodovská, Žaneta January 2016 (has links)
My Master thesis is focused on a tracer dilution technique in the well using automatic conductivity logging probes LTC Levelogger (Solinst co. Canada). The main aim of my thesis was to test the application conductivity meters LTC to track the movement of fluids in wells. Different set up were used moving probes with unmodified sensor slit, moving probes with modified sensor slit, probes measuring at fixed points, combined moving and fixed points probes and results were compared. 15 wells in quaternary and 11 wells in Bohemian Cretaceous Basin were measured, some of them repeatedly. The comparison of results indicate that the highest apparent flow velocity have probes with unmodified sensor slit. On the other hand fixed point probes indicate flow velocity, which is 40 - 50% lower at the same wells. The combination of the stable positioned probe LTC and the moving probe LTC has about 40% higher flow velocity than the rate of steady probe LTC placed in the well. The results also indicate that extremely slow velocity values (below approximately 0.02 m/day) can be measured only with LTC probes at fixed points. Modified probe slit was tested in the laboratory in plexi-glass tube using fluorescein and NaCl tracers. Unfortunately the modified geometry of measuring slit does not show distinctively better...
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Patent foramen ovale and cryptogenic brain infarctionKarttunen, V. (Vesa) 09 August 2002 (has links)
Abstract
Patent foramen ovale (PFO) is a common finding in the general population and is present in approximately one quarter of adults. The potential role of PFO in the pathogenesis of ischaemic brain infarction of unknown aetiology in young adults has been investigated during the past 15 years, and associations with other diseases have been proposed. The most plausible mechanism of stroke associated with PFO is paradoxical embolism, but there is uncertainty about this because a venous source of emboli is seldom identified. If the theory of venous emboli is relevant, prothrombotic states should be associated with PFO and ischaemic stroke. Relatively little is known about the risk factors of cryptogenic brain infarction, although this subgroup of stroke is relatively common.
As the present diagnostic methods for detecting PFO have certain limitations, new non-invasive, simple and reliable methods would be useful. Two new methods examined here, the dye dilution method and ear oximetry, were both found to be feasible and to be highly specific and sensitive in relation to the present gold standard, contrast transoesophageal echocardiography.
A case-control study among adult patients with PFO and cryptogenic brain infarction showed the presence of a prothrombotic state, particularly factor V Leiden and prothrombin G2021OA gene mutation, to be associated with an increased risk of stroke, and migraine was also identified as a risk factor. Associations with the classical risk factors for venous thrombosis and Valsalva manoeuvre-like activities at the onset of stroke were also observed. The results lend support to the theory that paradoxical embolism is one of the pathogenic mechanisms behind cryptogenic brain infarction with associated PFO.
In another case-control study among adult patients with cryptogenic brain infarction but without associated PFO, prothrombotic states were not identified as risk factors, except that an association was found between elevated factor VIII activity and stroke. The major independent risk factors for such cryptogenic strokes were current cigarette smoking, hypertension and a low level of high density lipoprotein cholesterol.
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Static and Flow Properties of Dilute Polymer SolutionsWhang, Kyu-ho 08 1900 (has links)
Small weight percentages of certain high-molecular weight polymers added to liquids in turbulent flow through conduits can result in dramatic friction reduction. Although many current and potential uses of the drag reduction phenomenon exist, there is a fundamental problem: drag reduction efficacy decreases rapidly with flow time due to the mechanical degradation in flow of the added polymer. In this thesis study, dilute aqueous solutions of polyacrylamide were tested under turbulent flow conditions in an attempt to determine where mechanical degradation in flow occurs.
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Quantity Trumps Quality: Bayesian Statistical Accumulation Modeling Guides Radiocarbon Measurements to Construct a Chronology in Real-timeFiresinger, Devon Robert 28 March 2017 (has links)
The development of an accurate and precise geochronology is imperative to understanding archives containing information about Earth’s past. Unable to date all intervals of an archive, researchers use methods of interpolation to approximate age between dates. Sections of the radiocarbon calibration curve can induce larger chronological uncertainty independent of instrumental precision, meaning even a precise date may carry inflated error in its calibration to a calendar age. Methods of interpolation range from step-wise linear regression to, most recently, Bayesian statistical models. These employ prior knowledge of accumulation rate to provide a more informed interpolation between neighboring dates. This study uses a Bayesian statistical accumulation model to inform non-sequential dating of a sediment core using a high-throughput gas-accepting accelerator mass spectrometer. Chronological uncertainty was iteratively improved but approached an asymptote due to a blend of calibration uncertainty, instrument error and sampling frequency. This novel method resulted in a superior chronology when compared to a traditional sediment core chronology with fewer, but more precise, dates from the same location. The high-resolution chronology was constructed for a gravity core from the Pigmy Basin with an overall 95% confidence age range of 360 years, unmatched by the previously established chronology of 460 years. This research reveals that a larger number of low-precision dates requires less interpolation, resulting in a more robust chronology than one based on fewer high-precision measurements necessitating a higher degree of age interpolation.
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