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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

Trocas gasosas e desidratação do capim Vaquero: valor nutricional no armazenamento de feno / Gas exchange and dehydration of Grass Vaquero: nutritional value hay storage

Machado, Ivaldir Willian Junior 28 February 2014 (has links)
Made available in DSpace on 2017-07-10T17:48:02Z (GMT). No. of bitstreams: 1 Ivaldir_Willian_Junior_Machado.pdf: 731803 bytes, checksum: d1256115f91e0fff92ddd0d2baf6db7b (MD5) Previous issue date: 2014-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Two experiments were conducted to evaluate the Vaquero grass destined to haymaking, one in summer and other in winter 2012. . In the summer experiment evaluated the dehydration curve of different plant parts (stem and blade + sheath), gas exchange during the first hours of dehydration, nutritional value and occurrence of fungi. The dehydration curve of grass Vaquero was determined in whole plant, leaf and stem + sheath in seven times. Time 0 corresponded to the sample taken before the court, held at 19:00 hours - daylight saving time (time 0), and on other days always 08.00, 13:00 and 17:00 hours. The times evaluted were at 0, 13, 18, 22, 37, 42 and 44 pm (moment of baling) after cutting. The experimental design for the dehydration curve was randomized blocks with split-plot in time with three regions of collection in the plant to determine the dry matter and seven times of collecting as a sub portion with five replications.. To determine gas exchange during dehydration of grass Vaquero evaluations were made on fully expanded leaves located in the upper middle third of each tillers before the cutting - 0 time (19:00), time 14 (9:00), time 19 (14:00). In a second step, was evaluated the nutritional value of grass Vaquero under two storage systems, using the experimental delineation in blocks randomized with split plot an additional treatment (before cutting). In a third step was performed the determination of fungi present in green plants and hay, where we collected samples of hay in moment of cutting , 30, 60 and 90 days of storage in open shed and enclosed shed. It was found that dehydration of the hay Vaquero occurred in 44 hours, is considered a optimal time for drying hay, with faster rates for leaf, and slower for stem. Gas exchanges were more intense before the cutting and 14 hours after cutting. The crude protein rates were higher at the time of cutting, decreasing with storage. The soluble carbohydrates decreased after 60 days of storage. The in vitro digestibility of dry matter was high and showed no reduction in both seasons and storage systems. There was no significant growth of fungi. In a second experiment, was characterized the dehydration curve of the vaquero grass in winter in different strata of the windrow (12 cm), the chemical composition and in vitro digestibility of dry matter of hay of grass Vaquero (Cynodon dactylon) stored at different times. The dehydration curve was characterized during a period of 0, 7, 21, 28, 42 and 49 hours after cutting, in 3 extracts (upper, middle and lower). The experimental design was adopted in randomized blocks with split plot in the time. Were evaluated the levels of crude protein, NDF, ADF, PIDA, NDIP and in vitro digestibility of dry matter of hay Vaquero before cutting and in storage. The experimental design was randomized blocks with seven sampling times and five reps. There was no difference in the different parts of the windrow of grass in dehydration. In response to the dehydration time, there was a linear increase in dry matter. The crude protein levels were elevated with an average grade of 137.00 g kg -1 and did not differ between sampling times. The levels NDF and ADF, with 14 days of storage were below than the others times. The contents of PIDA and NDIP showed no difference in moments reviews. The in vitro digestibility of dry matter a mean submitted an average content of 595.95 g kg-1, with at two sampling times / Foram realizados dois experimentos avaliando o capim Vaquero, destinado à produção de feno; um no verão e outro no inverno de 2012. No experimento de verão, avaliou-se a curva de desidratação de diferentes partes da planta (colmo e lâmina + bainha), trocas gasosas durante as primeiras horas de desidratação, valor nutricional e a ocorrência de fungos. A curva de desidratação do capim Vaquero foi determinada na planta inteira, folha e colmo + bainha em sete tempos. O tempo 0 correspondeu a amostra, retirada antes do corte, realizado às 19:00 horas horário de verão (tempo 0), e nos demais dias sempre as 08h00, 13:00 e 17:00 horas. Os tempos avaliados foram 0, 13, 18, 22, 37, 42 e 44 horas (momento do enfardamento) após o corte. O delineamento experimental para curva de desidratação foi em blocos ao acaso com parcelas subdivididas no tempo com três regiões de coleta na planta para determinação da matéria seca e sete tempos de coleta como sub parcela, com cinco repetições. Para determinar as trocas gasosas durante a desidratação do capim Vaquero foram feitas avaliações em folhas completamente expandidas, situadas no terço médio superior de cada perfilho antes do corte tempo 0 (18:30), tempo 14 (9:00), tempo 19 (14:00). Numa segunda etapa, avaliou-se o valor nutricional do capim Vaquero sob dois sistemas de armazenamento (galpão aberto e galpão fechado), utilizando o delineamento experimental em blocos casualizados com parcelas subdivididas no tempo com um tratamento adicional (antes do corte). Numa terceira etapa foi realizada a determinação dos fungos presentes nas plantas verdes e no feno, coletando-se amostras de feno no momento do corte, 30, 60 e 90 dias de armazenamento. Verificou-se que a desidratação do feno de capim Vaquero ocorreu em 44 horas, sendo considerado um tempo ideal para secagem de feno, com taxas mais rápidas para folha e mais lentas para colmo. As trocas gasosas foram mais intensas antes do corte e 14 horas após o corte. Os teores de proteína bruta foram superiores no momento do corte, reduzindo-se com o armazenamento. Os carboidratos solúveis apresentaram redução, após 60 dias de armazenamento. A digestibilidade in vitro da matéria seca mostrou-se elevada e não apresentou redução em nenhum dos períodos avaliados e sistemas de armazenamento. Não ocorreu crescimento significativo de fungos. Em um segundo experimento caracterizou-se a curva de desidratação do capim Vaqueiro no inverno em diferentes estratos da leira que apresentava altura de 12 cm, a composição bromatológica e a digestibilidade in vitro da matéria seca do feno de capim Vaquero (Cynodon dactylon) armazenado em diferentes tempos. A curva de desidratação foi caracterizada durante um período de 0, 7, 21, 28, 42 e 49 horas após o corte, em 3 estratos (superior, médio e inferior). Foram avaliados os teores de proteína bruta, FDN, FDA, PIDA, PIDN e digestibilidade in vitro da matéria seca do feno de capim Vaquero antes do corte e no armazenamento. O delineamento experimental utilizado foi em blocos casualizados com sete tempos de amostragem e cinco repetições. Não houve diferença nos diferentes pontos da leira de capim em desidratação. Em resposta ao tempo de desidratação, houve um aumento linear nos teores de matéria seca. Os teores de proteína bruta foram elevados com um teor médio de 137,00 g kg -1 e não apresentaram diferenças entre tempos de amostragem. Os teores de FDN e FDA, com 14 dias de armazenamento foram inferiores 724,00 e 338,20 g kg-1 respectivamente aos demais tempos. Os teores de PIDA e PIDN não apresentaram diferenças nos tempos avaliados. A digestibilidade in vitro da matéria seca apresentou um teor médio de 595,95 g kg-1. O capim vaqueiro pode ser utilizado para produção de feno tanto no verão quanto no inverno
12

Vliv různé technologie mletí a mechanické aktivace na vlastnosti hydraulických pojiv / Effects of the different grinding technology and of mechanical activation on the properties of hydraulic binders

Hladík, Václav January 2018 (has links)
This diploma thesis mainly tracks the effect of grinding technology on the final properties of portland cement and selected pozzolanic materials. For grinding of portland cement, was also observed the effect of storage time on the final mechanical properties and hydratation process. Pozzolan activity of selected materials was monitored by evaluation of the reaction with CaO by differential thermal analysis.
13

INFLUÊNCIA DOS TIPOS DE ORDENHA, TRANSPORTE E TEMPO DE ARMAZENAMENTO NA QUALIDADE DO LEITE CRU REFRIGERADO DA REGIÃO SUDOESTE DO ESTADO DE GOIÁS / Influence of the milking types, transport and storage time in the cooled raw milk quality of the goiano southwest

SILVA, Marco Antônio Pereira da 19 December 2008 (has links)
Made available in DSpace on 2014-07-29T15:13:40Z (GMT). No. of bitstreams: 1 dissertacaoMarcoAntonio.PDF: 791526 bytes, checksum: 7a8a829a082433a7f23c3880ef18467d (MD5) Previous issue date: 2008-12-19 / The objective of the research were evaluate cooled raw milk gotten in dairy properties of the Southwest Goiano in the periods rainy and dry of 2008. The samples were collected of individual producers where the storage in bulk tanks were carried for until 72 hours, with 24-hour intervals. Somatic cells count, total bacterial count and centesimal composition were carried in the Laboratório de Qualidade do Leite of the Centro de Pesquisa em Alimentos of the Escola de Veterinária of the Universidade Federal de Goiás. The microbiological analysis and titratable acidity were carried in the Laboratories of the Unidade de Agroindústria of the Instituto Federal de Educação, Ciência e Tecnologia Goiano Campus Rio Verde GO. Data were submitted to the variance analysis and the analyzed factors were: period, type of milking and storage time, in entirely casualized delineation and factorial arrangement 2 x 2 x 4. The comparison of period and type of milking was carried through by means of test F of the variance analysis. The storage time was analyzed by means of regression models. Software SISVAR was used for analysis. The results of the physical-chemical composition were in accordance with the legislation. The total bacterial count of cooled raw milk to the 24 hours of storage was above of the limit of the legislation. The count of psychrotrophic, psychrotrophic proteolytic and Pseudomonas spp., was bigger in the rainy period. / O objetivo da pesquisa foi avaliar o leite cru refrigerado obtido em propriedades rurais do Cerrado Goiano nos períodos chuvoso e seco de 2008. As amostras foram coletadas de produtores individuais onde o armazenamento em tanques de expansão era realizado por até 72 horas, com intervalos de 24 horas. As análises eletrônicas (contagem de células somáticas, contagem bacteriana total e composição centesimal) foram realizadas no Laboratório de Qualidade do Leite do Centro de Pesquisa em Alimentos da Escola de Veterinária da Universidade Federal de Goiás. As análises microbiológicas e de acidez titulável foram realizadas nos Laboratórios de Microbiologia e Processamento de Leite e Derivados da Unidade de Agroindústria do Instituto Federal de Educação, Ciência e Tecnologia Goiano Campus Rio Verde GO. Os dados foram submetidos à análise de variância, e os fatores analisados foram: período (chuvoso ou seco), tipo de ordenha (manual ou mecânica) e tempo de estocagem (zero, 24, 48 e 72 horas), em delineamento inteiramente casualizado e arranjo fatorial 2 x 2 x 4. A comparação do período e tipo de ordenha foi realizada por meio do teste F da análise de variância. Os tempos de estocagem foram analisados por meio de modelos de regressão. Para atender as pressuposições da análise de variância a contagem de psicrotróficos, psicrotróficos proteolíticos, Pseudomonas spp., CCS e CBT foram transformadas por meio do logaritmo na base 10. Foi utilizado o Software SISVAR para análise. A contagem bacteriana total do leite cru refrigerado às 24 horas de armazenamento ficou acima do limite exigido pela legislação. A contagem de psicrotróficos, psicrotróficos proteolíticos e Pseudomonas spp., foi maior no período chuvoso. Deverão ser alertados, produtores e indústrias para a obtenção e processamento de leite com qualidade higiênico-sanitária adequada.
14

Vliv různé technologie mletí na vlastnosti Portlandského cementu / Effects of the different grinding technology on the properties of Portland cement

Švéda, Matěj January 2017 (has links)
This diploma thesis compares impact of various high-energy grinding technologies on crystallographic and granulometric properties of portland cement. It also observes the influence of the conventional and high-speed grinding technology on the resulting physical and mechanical properties of portland cement, depending on the storage time.
15

Nutzung der Photolumineszenz von Quantenpunkten für die Belastungsdetektion an Leichtbaumaterialien

Möbius, Martin 17 February 2021 (has links)
Die vorliegende Arbeit beschäftigt sich mit der Entwicklung eines neuartigen, autarken, folienbasierten Sensorsystems für die Belastungsdetektion an Leichtbaumaterialien. Das integrierte Sensorsystem ist in der Lage mechanische Belastungen über die Photolumineszenz von Quantum Dots visuell darzustellen, wodurch strukturelle Defekte in Leichtbaumaterialien frühzeitig erkannt und ein Totalausfall einer gesamten Leichtbaukonstruktion verhindert werden kann. Dies führt neben einer erhöhten Sicherheit einzelner Komponenten und kompletter Konstruktionen auch zu Gewichts-, Kosten- und Rohstoffersparnissen. Die gezielte Beeinflussung der Photolumineszenz von Quantum Dots durch Ladungsträgerinjektion als Hauptmechanismus des Sensorsystems erfordert spezielle Lagenaufbauten von Dünnschichtsystemen. Durch die Kombination dieser Dünnschichtsysteme mit piezoelektrischen Materialien entsteht ein autarkes Sensorsystem, wodurch eine Auswertung, Visualisierung und Speicherung der Information über eine stattgefundene mechanische Belastung an Leichtbaumaterialien auf kleinsten Raum erreicht wird.:Inhaltsverzeichnis Formelverzeichnis Abkürzungsverzeichnis Vorwort 1 Einleitung 1.1 Motivation 1.2 Zielstellung 2 Autarker Sensor für mechanische Beanspruchungen 2.1 Sensorkonzept, -aufbau und Funktionsweise 2.2 Anforderungen an die Funktionalität 2.3 Stand der Technik 3 Theoretische Grundlagen 3.1 Quantum Dots 3.1.1 Größenquantisierungseffekt 3.1.2 Photolumineszenz 3.1.3 Aufbau und Materialien 3.1.4 Kommerziell erhältliche Quantum Dots 3.2 Mechanismen zur Beeinflussung der Photolumineszenz 3.2.1 Ladungsträgerinjektion in den QD Kern 3.2.2 Feldinduzierte Ionisation des Exzitons 3.2.3 Weitere Mechanismen 3.3 Ladungsträgertransportschichten 3.3.1 Poly(N-vinylkarbazol) 3.3.2 N,N,N´,N´-Tetrakis(3-methylphenyl)-3,3´-dimethylbenzidin 3.3.3 Poly(3,4-ethylendioxythiophen)-poly(styrolsulfonat) 3.4 Lithiumfluorid als elektrischer Isolator 3.5 Modellsysteme 3.5.1 Einbettung der QDs in organische Lochtransportschichten 3.5.2 QDs zwischen Elektrode und organischer Lochtransportschicht 3.5.3 QDs zwischen Elektrode und Nichtleiter 4 Experimentelle Vorgehensweise 4.1 Layout und Kontaktierung von Teststrukturen 4.2 Verfahren zur Herstellung dünner Schichten 4.2.1 Physikalische Gasphasenabscheidung 4.2.2 Rotationsbeschichtung 4.2.3 Weitere Verfahren 4.3 Charakterisierung der Schichten und der Gesamtfunktionalität 4.3.1 Mikrospektroskopieaufbau 4.3.2 Weitere Messverfahren 4.4 Integration der Schichtstapel in Faserkunststoffverbund 5 Experimentelle Untersuchungen 5.1 Einordnung der einzelnen Schichten der Modellsysteme 5.1.1 Elektroden 5.1.2 Matrixmaterial und Quantum Dots 5.2 Einordnung des elektrischen Verhaltens der Modellsysteme 5.2.1 Modellsystem I 5.2.2 Modellsystem II 5.2.3 Modellsystem III 5.3 Einfluss externer Beleuchtung am Modellsystem II und III 5.3.1 Modellsystem II 5.3.2 Modellsystem III 5.4 Wiederholbarkeit der elektrischen Beanspruchung am Modellsystem III 5.4.1 Photolumineszenzintensität 5.4.2 Stromdichte 5.4.3 Gesamtwiderstand im Schichtstapel 5.5 Einfluss des elektrischen Feldes am Modellsystem III 5.5.1 Photolumineszenzintensität 5.5.2 Stromdichte 5.5.3 Widerstand 5.6 Einfluss der Integration auf das Verhalten von Modellsystem III 5.6.1 Optisches Verhalten der Laminiertasche und des Harzsystems 5.6.2 Funktionalität des Schichtstapels nach der Integration 5.7 Temperaturwechseltest am integrierten Schichtstapel 5.8 Speicherzeit elektrischer Ladungsträger am Modellsystem III 5.8.1 Stabilität des Lasers und der PL Intensität 5.8.2 Reproduzierbarkeit 5.8.3 Langzeitmessung 5.9 Kopplung des Schichtsystems mit piezoelektrischem Element 6 Zusammenfassung und Ausblick 6.1 Zusammenfassung 6.2 Ausblick Anhang A : Layouts für untere Elektrode E1 und obere Elektrode E2 Anhang B : Halter für die Kontaktierung der Teststrukturen Anhang C : Frontpanel zur Aufnahme der Photolumineszenz Anhang D : Messdaten Profilometer Veeco Dektak 150 Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Lebenslauf / This work focuses on the development of a novel, self-sufficient, film-based sensor system for load detection on lightweight materials. The integrated sensor system is capable to visualize mechanical loads on lightweight structures by quenching the photoluminescence of quantum dots. Structural defects in lightweight materials can thus be detected at an early stage and total failure of an entire lightweight structure can be prevented. In addition to increased safety of individual components and complete structures, this also leads to weight, cost and raw material savings. The quenching of the photoluminescence of quantum dots by charge carrier injection as the main mechanism of the sensor system requires special thin-film layer stacks. By combining these thin-film layer stacks with piezoelectric materials, a self-sufficient sensor system is created. An evaluation, visualization and storage of the information about a mechanical load that has taken place on lightweight materials is thus achieved in a very small space.:Inhaltsverzeichnis Formelverzeichnis Abkürzungsverzeichnis Vorwort 1 Einleitung 1.1 Motivation 1.2 Zielstellung 2 Autarker Sensor für mechanische Beanspruchungen 2.1 Sensorkonzept, -aufbau und Funktionsweise 2.2 Anforderungen an die Funktionalität 2.3 Stand der Technik 3 Theoretische Grundlagen 3.1 Quantum Dots 3.1.1 Größenquantisierungseffekt 3.1.2 Photolumineszenz 3.1.3 Aufbau und Materialien 3.1.4 Kommerziell erhältliche Quantum Dots 3.2 Mechanismen zur Beeinflussung der Photolumineszenz 3.2.1 Ladungsträgerinjektion in den QD Kern 3.2.2 Feldinduzierte Ionisation des Exzitons 3.2.3 Weitere Mechanismen 3.3 Ladungsträgertransportschichten 3.3.1 Poly(N-vinylkarbazol) 3.3.2 N,N,N´,N´-Tetrakis(3-methylphenyl)-3,3´-dimethylbenzidin 3.3.3 Poly(3,4-ethylendioxythiophen)-poly(styrolsulfonat) 3.4 Lithiumfluorid als elektrischer Isolator 3.5 Modellsysteme 3.5.1 Einbettung der QDs in organische Lochtransportschichten 3.5.2 QDs zwischen Elektrode und organischer Lochtransportschicht 3.5.3 QDs zwischen Elektrode und Nichtleiter 4 Experimentelle Vorgehensweise 4.1 Layout und Kontaktierung von Teststrukturen 4.2 Verfahren zur Herstellung dünner Schichten 4.2.1 Physikalische Gasphasenabscheidung 4.2.2 Rotationsbeschichtung 4.2.3 Weitere Verfahren 4.3 Charakterisierung der Schichten und der Gesamtfunktionalität 4.3.1 Mikrospektroskopieaufbau 4.3.2 Weitere Messverfahren 4.4 Integration der Schichtstapel in Faserkunststoffverbund 5 Experimentelle Untersuchungen 5.1 Einordnung der einzelnen Schichten der Modellsysteme 5.1.1 Elektroden 5.1.2 Matrixmaterial und Quantum Dots 5.2 Einordnung des elektrischen Verhaltens der Modellsysteme 5.2.1 Modellsystem I 5.2.2 Modellsystem II 5.2.3 Modellsystem III 5.3 Einfluss externer Beleuchtung am Modellsystem II und III 5.3.1 Modellsystem II 5.3.2 Modellsystem III 5.4 Wiederholbarkeit der elektrischen Beanspruchung am Modellsystem III 5.4.1 Photolumineszenzintensität 5.4.2 Stromdichte 5.4.3 Gesamtwiderstand im Schichtstapel 5.5 Einfluss des elektrischen Feldes am Modellsystem III 5.5.1 Photolumineszenzintensität 5.5.2 Stromdichte 5.5.3 Widerstand 5.6 Einfluss der Integration auf das Verhalten von Modellsystem III 5.6.1 Optisches Verhalten der Laminiertasche und des Harzsystems 5.6.2 Funktionalität des Schichtstapels nach der Integration 5.7 Temperaturwechseltest am integrierten Schichtstapel 5.8 Speicherzeit elektrischer Ladungsträger am Modellsystem III 5.8.1 Stabilität des Lasers und der PL Intensität 5.8.2 Reproduzierbarkeit 5.8.3 Langzeitmessung 5.9 Kopplung des Schichtsystems mit piezoelektrischem Element 6 Zusammenfassung und Ausblick 6.1 Zusammenfassung 6.2 Ausblick Anhang A : Layouts für untere Elektrode E1 und obere Elektrode E2 Anhang B : Halter für die Kontaktierung der Teststrukturen Anhang C : Frontpanel zur Aufnahme der Photolumineszenz Anhang D : Messdaten Profilometer Veeco Dektak 150 Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Lebenslauf

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