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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.
1

Adequação da metodologia do teste de frio para a avaliação do vigor de sementes de sorgo / Adjust the cold test metodology to evaluate the vigor of sorghum seeds

Andriazzi, Cinthia Vieira Golfi 27 February 2007 (has links)
This research had the purpose to adjust the cold test metodology to evaluate the vigor of sorghum seeds (Sorghum bicolor L. Moench), using samples of two lots about AG1018 hybrid, one with marginal quality, called test lot, and other with high quality, called control lot, in the cropping season 2005/2005. The experiments were made at Monsanto do Brasil Ltda seeds analysis laboratory, with Instituto de Ciências Agrárias da Universidade Federal de Uberlândia, in Uberlândia MG. Five experiments were made in this work. The first had the purpose to determine the soil blend and the best humidity to conduct the cold test. The others were made to determine the profundity to plant, the time inside the cold chamber, and the best temperature of growth room. The experimental design was randomized blocks, with four repetitions. In the first experiment analysed 13 treatments made of four soil blends with three humidities, one more control treatment. The other experiments were made for diferents temperatures of growth room (22, 25, 28 e 31ºC), distributed in a (4x3) factorial one more additional treatmet. The factorial was made of four times inside the cold chamber (120; 144; 168 e 192h) and three profundities to plant (1,5; 3,0 e 4,5cm). The control lot was the additional treatmet. The percentage of plant emergence was analysed and it can be concluded that: the best soil blend was made of two parts of washed sand and one part of soil with humidity 65%; the time to keep inside the cold chamber for five days was enough to analyse the vigor of sorghum seeds; the best percentage of plant emergence for 1,5 e 3,0cm profundity was with growth room on 25ºC and 4,5cm the temperature was 29ºC. / Este trabalho objetivou adequar a metodologia do teste de frio para avaliação do vigor de sementes de sorgo (Sorghum bicolor L. Moench), utilizando-se amostras de dois lotes do híbrido AG1018, sendo um com qualidade marginal, designado lote teste, e outro com alta qualidade, designado lote controle, produzidos na safra 2005/2005. Os experimentos foram realizados no laboratório de análises de sementes da Monsanto do Brasil Ltda, em parceria com o Instituto de Ciências Agrárias da Universidade Federal de Uberlândia, em Uberlândia MG. Neste estudo foram conduzidos cinco experimentos. O primeiro visou definir o substrato e a umidade ideal para condução do teste de frio. Os demais foram conduzidos no intuito de definir a profundidade de semeadura, o tempo de permanência na câmara fria e a temperatura da sala de crescimento, ideal para a condução do referido teste. O delineamento experimental foi em blocos casualizados, com quatro repetições. No primeiro experimento avaliou-se 13 tratamentos constituídos pela combinação de quatro substratos com três teores de umidade, acrescidos do tratamento controle. Os outros experimentos foram constituídos por diferentes temperaturas da sala de crescimento (22, 25, 28 e 31ºC), nos quais os tratamentos foram distribuídos no esquema fatorial (4x3) mais um tratamento adicional. O fatorial foi composto por quatro tempos de permanência na câmara fria (120; 144; 168 e 192h) e três profundidades de semeadura (1,5; 3,0 e 4,5cm). O lote controle constituiu o tratamento adicional. Avaliou-se a porcentagem de emergência e concluiu-se que: o melhor substrato foi o constituído por duas partes de areia lavada e uma parte de solo umedecido com 65% da capacidade de retenção; o tempo de permanência na câmara fria por cinco dias foi suficiente para avaliar o vigor de sementes de sorgo; a melhor porcentagem de emergência de plântulas para a profundidade de 1,5 e 3,0cm foi com a sala de crescimento regulada a 25ºC e para a profundidade de 4,5cm a temperatura foi de 29ºC. / Mestre em Agronomia
2

Avaliação da saturação de oxigênio em polpas humanas de molares hígidos / Evaluation of oxygen saturation in human pulps of healthy molars

Oliveira, Keila Surama Alves de 08 March 2016 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-07-11T17:01:48Z No. of bitstreams: 2 Dissertação - Keila Surama Alves de Oliveira - 2016.pdf: 2075342 bytes, checksum: 2ef6fd7be76314f6aabeab2fa8fd9e9d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-12T11:28:59Z (GMT) No. of bitstreams: 2 Dissertação - Keila Surama Alves de Oliveira - 2016.pdf: 2075342 bytes, checksum: 2ef6fd7be76314f6aabeab2fa8fd9e9d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-12T11:28:59Z (GMT). No. of bitstreams: 2 Dissertação - Keila Surama Alves de Oliveira - 2016.pdf: 2075342 bytes, checksum: 2ef6fd7be76314f6aabeab2fa8fd9e9d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Objective: to determine the oxygen saturation level (SaO2) in human pulps of molars by pulse oximetry. Methods: the oxygen saturation level was evaluated in 112 healthy molars using the pulse oximeter and the patient's response time to stimulus with the cold refrigerant gas Endo Ice and recorded with digital timer. Statistical analysis was performed using SPSS v program. 18.0. Quantitative variables were described by mean and standard deviation when the distribution was symmetric and median and interquartile range when asymmetric. Variables with symmetric distribution were compared between teeth for independent samples and intra-individual for paired samples by Student t test, and the asymmetric distribution with the Mann-Whitney test. To correlate the variables each other was used the Pearson correlation coefficient, and to compare more than two groups together the analysis of variance (ANOVA) followed by post-hoc Tukey, being statistically significant p <0,05. Results: the average level of SaO2 for the 112 pulps of healthy molars was 85,09%, and there was no correlation with the SaO2 average of the patient´s indicator finger (92,89%). There was a significant difference (P = 0,037) between the average level of SaO2 of the first (85,76%) and second superior molars (81,87%), and it was not significant (P = 0,177) between the first (85,58%) and second (88,15%) inferior molars. The superior molars had lower average level of SaO2 (83,59%) when compared to the inferior molars (86,89%), with a statistically significant difference (P = 0,018). The average of the patient's response time to the cold stimulus was 1,12 seconds, with no statistically significant difference between superior (1,25 seconds) and inferior molars (0,99 seconds). Conclusion: the average level of SaO2 in healthy molars pulps was 85,09%, and the average of the superior molars was 83,59% and inferior molars was 86,89%. The average of the patient's response time to the cold stimulus was 1,12 seconds, with no statistically significant difference between superior (1,25 seconds) and inferior molars (0,99 seconds) and there was no correlation between the patient's response time to the cold stimulus and the oxygen saturation level for healthy molars. / Objetivo: determinar o nível de saturação de oxigênio (SaO2) em polpas humanas de molares hígidos por meio da oximetria de pulso. Material e métodos: o nível de SaO2 foi avaliado em 112 molares hígidos utilizando-se o oxímetro de pulso, e o tempo de resposta do paciente ao estímulo ao frio com gás refrigerante e registrado com cronômetro digital. A análise estatística foi feita pelo programa SPSS v. 18.0. Foram descritas as variáveis quantitativas pela média e desvio padrão quando a sua distribuição foi simétrica e mediana e intervalo interquartil quando assimétrica. As variáveis com distribuição simétrica foram comparadas entre dentes para amostras independentes e intra-indivíduo para amostras pareadas pelo teste t de Student, e as com distribuição assimétrica pelo teste de Mann-Whitney. Para correlacionar as variáveis entre si foi utilizado o coeficiente de correlação de Pearson, e para comparar mais de dois grupos entre si o teste de Análise de Variância (ANOVA) seguido do teste post-hoc de Tukey, sendo estatisticamente significativo p < 0,05. Resultados: o nível médio de SaO2 para as 112 polpas dos molares hígidos foi 85,09%, e não houve correlação com a média do dedo indicador do paciente (92,89%). Houve uma diferença significante (P= 0,037) entre o nível médio de SaO2 dos primeiros (85,76%) e dos segundos molares superiores (81,87%), não sendo significante (P= 0,177) entre os primeiros (85,58%) e segundos (88,15%) molares inferiores. Os molares superiores apresentaram menor nível médio de SaO2 (83,59%) quando comparados aos inferiores (86,89%), sendo a diferença estatisticamente significativa (P= 0,018). A mediana do tempo de resposta do paciente ao estímulo ao frio foi de 1,12 segundos, não havendo diferença estatisticamente significativa entre molares superiores (1,25 segundos) e inferiores (0,99 segundos). Conclusão: o nível médio de SaO2 em polpas de molares hígidos foi de 85,09%, sendo a média dos molares superiores de 83,59% e a dos inferiores de 86,89%. A mediana do tempo de resposta do paciente ao estímulo ao frio em molares hígidos foi de 1,12 segundos, não havendo diferença estatística entre superiores (1,25 s) e inferiores (0,99), e não houve correlação entre o tempo de resposta do paciente ao estímulo ao frio e o nível de saturação de oxigênio para molares hígidos. Palavras-chave: oxímetro de pulso, polpa dentária, saturação de oxigênio, teste frio.
3

Desempenho fisiológico de sementes e plântulas de pimenta e de tomateiro sob diferentes temperaturas / Physiological performance of seeds and pepper and tomato seedlings under different temperatures

Gehling, Vania Marques 03 September 2015 (has links)
Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-29T13:15:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_vania_marques_gehling.pdf: 823705 bytes, checksum: bb9a04c4074928df8353da917cbc35a4 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T17:44:43Z (GMT) No. of bitstreams: 2 dissertacao_vania_marques_gehling.pdf: 823705 bytes, checksum: bb9a04c4074928df8353da917cbc35a4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T17:45:44Z (GMT) No. of bitstreams: 2 dissertacao_vania_marques_gehling.pdf: 823705 bytes, checksum: bb9a04c4074928df8353da917cbc35a4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-05T17:45:54Z (GMT). No. of bitstreams: 2 dissertacao_vania_marques_gehling.pdf: 823705 bytes, checksum: bb9a04c4074928df8353da917cbc35a4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-03 / Sem bolsa / O objetivo deste trabalho foi avaliar o desempenho fisiológico de sementes e plântulas de pimenta e de tomateiro sob influência de diferentes temperaturas. Foram conduzidos, separadamente, dois experimentos no Laboratório Didático de Análise de Sementes – FAEM - UFPel. No primeiro experimento foram utilizadas sementes de pimenta Cayenne Long Slim®, e no segundo experimento foram empregadas sementes de tomateiro Gaúcho®. Em ambos os experimentos, os tratamentos consistiram de temperaturas constantes, sendo: 18; 20; 22; 24 e 26ºC. Para a determinação do desempenho fisiológico das sementes e plântulas foram empregadas as avaliações de germinação, primeira contagem de germinação, índice de velocidade de germinação, envelhecimento acelerado, teste de frio, comprimento de parte aérea e de raiz primária, massa da matéria seca de parte aérea e de raízes, emergência de plântulas aos 14 e 21 dias após a semeadura e índice de velocidade de emergência. Os resultados demonstraram que a germinação de sementes de pimenta não é afetada de maneira marcante pelas temperaturas de 18 a 24oC, assim como sementes de tomateiro sob temperatura de 18 a 26oC, que não apresentaram diferença significativa na germinação. A primeira contagem de germinação, o índice de velocidade de germinação e os valores de envelhecimento acelerado foram incrementados linearmente com o aumento da temperatura, em pimenta e tomateiro. Todavia, o teste de frio e de emergência, tanto aos 14 como aos 21 dias após a semeadura, foram influenciados positivamente, até a temperatura aproximada de 22ºC, para ambas as culturas. Deste modo, a expressão do vigor de sementes, de ambas as espécies, é afetada negativamente pela redução da temperatura de desenvolvimento, sendo resultados marcantes obtidos nas temperaturas de 18 e 20oC. / The objective of this study was to evaluate the physiological performance of seeds and pepper and tomato seedlings under the influence of different temperatures. They were conducted separately in two experiments in the Didactic Laboratory of Seed Analysis - FAEM - UFPel. In the first experiment pepper seeds were used Cayenne Long Slim®, and in the second experiment Gaúcho® tomato seeds were employed. In both experiments, the treatments consisted of constant temperatures, as follows: 18; 20; 22; 24 and 26ºC. To determine the physiological performance of the seeds and seedlings were employed germination assessments, first count, germination speed index, accelerated aging, cold test, shoot length and primary root mass of dry matter air and root, seedling emergence at 14 and 21 days after sowing and emergence speed index. The results show that the pepper seed germination is not affected markedly by the temperature from 18 to 24ºC, as well as tomato seeds at a temperature of 18 to 26ºC, which showed no significant difference in germination. The first count, germination speed index and the accelerated aging values were increased linearly with increasing temperature in pepper and tomato. However, the cold test and emergency, both at 14 and at 21 days after sowing, were influenced positively to the approximate temperature of 22°C, for both crops. Thus, the expression of seed vigor of both species is adversely affected by reducing the growth temperature, with remarkable results obtained at temperatures of 18 to 20ºC.
4

Kvalitet semena samooplodnih linija kukuruza različitih grupa zrenja i genetičke osnove / Seed quality of ZP maize inbred lines of different maturity groups and genetic background

Milivojević Marija 30 September 2016 (has links)
<p>U radu su sprovedena ispitivanja kvaliteta semena samooplodnih linija kukuruza stvorenih u Institutu za kukuruz &bdquo;Zemun Polje&ldquo; razliĉitih grupa zrenja i genetiĉke osnove. U laboratorijskim i poljskim uslovima utvrĊena je klijavost i vigor semena iz 2011. nakon ĉetiri godine ĉuvanja u kontrolisanim uslovima (18 &deg;C i 60% RH) i semena iz 2014. nakon godinu dana ĉuvanja na 5 &deg;C i 60% RH.<br />Cilj je bio utvrditi tolerantnost odabranih linija na niske temperature prilikom klijanja i nicanja, dugoveĉnost semena u kontrolisanim uslovima ĉuvanja, genetiĉku divergentnost linija primenom proteinskih markera i proceniti uticaj genetiĉke osnove na kvalitet semena.<br />U laboratoriji za ispitivanje semena praćeni su sledeći parametri kvaliteta: vitalnost, klijavost, energija klijanja, dužina klijanaca, vigor ispitan tetrazolium testom, hladnim testom, testom ubrzanog starenja, testom pojave primarnog korena i testom provodljivosti.<br />Primenom vigor testova na semenu dva nivoa starosti omogućena je bolja klasifikacija linija u pogledu kvaliteta, nego standardnim testom klijavosti. Rezultati rada ukazuju da su hladni test i test ubrzanog starenja najpogodniji za procenu vigora semena u laboratoriji, s tim da je hladni test bolji pokazatelj nicanja u polju.<br />Ispitivane samooplodne linije pokazale su dobru sposobnost oĉuvanja kvaliteta semena kao i visok nivo toleratnosti na niske temperature u toku klijanja i ranog porasta biljaka. Kontrolisani uslovi ĉuvanja na 18 &deg;C omogućili su da se klijavost i vigor semena u ispitivanom periodu, održi na visokom nivou.<br />Dužina vegetacije samooplodnih linija nije imala znaĉajan uticaj na klijavost i vigor semena. Kvalitet semena ispitivanih samooplodnih linija je prvenstveno bio pod uticajem genetiĉke osnove. Linije poreklom od Lancaster populacije imale su slabiji vigor u odnosu na linije BSSS i Iowa Dent porekla.<br />U radu je potvrĊeno da vigor testovi imaju važnu ulogu u ispitivanju kvaliteta semena samooplodnih linija kukuruza. Dobijeni rezultati direktno se mogu iskoristiti u oplemenjivaĉkim programima u cilju pobolj&scaron;anja klijavosti i vigora semena. Ostvareni rezultati ukazuju da su informacije o genetiĉkom poreklu samooplodnih linija važan indikator vigora semena. Pored podataka o genetiĉkom poreklu linija veliki znaĉaj ima karakterizacija putem biohemijskih markera.</p> / <p>The extensive seed quality evaluations of maize inbred lines developed at the Maize Research Institute Zemun Polje of different maturity groups and genetic background were conducted. In laboratory and field conditions germination and vigour of seed produced in 2011 and 2014 was determined, after four years of storage at 18 &deg;C, 60% RH and one year of storage at 5 &deg;C, 60% RH, respectively.<br />The objective of this research was to determine the chilling tolerance of selected inbred lines during germination and emergence, seed longevity under controlled storage conditions, genetic divergence determined by biochemical markers and to assess the impact of the genetic background on seed quality.<br />Following seed quality parameters were tested: viability, germination, seedling length and vigour examined by cold test, accelerated ageing test, tetrazolium test, radicle emergence test and conductivity test.<br />Vigour tests provided a better classification of inbred lines of different seed age in terms of quality than standard germination test. Obtained results show that cold test and accelerated aging test are the most suitable for assessing seed vigour in the laboratory, but cold test is a better indicator of field emergence.<br />Tested maize inbred lines showed good seed storability and high level of chilling tolerance during germination and early growth of plants. Controlled storage conditions at 18 &deg;C, have enabled that germination and seed vigor remains at the high level in the examined period.<br />Seed germination and vigour of maize inbred lines were not affected by length of vegetation. Seed quality was primarily influenced by genetic background of tested inbred lines. Inbred lines originating from Lancaster populations had lower vigour compared to lines with BSSS and Iowa Dent origin.<br />This research confirmed that vigor tests play an important role in seed quality testing of maize inbred lines. Results of this work can be directly used in breeding programs to improve germination and seed vigour. Achieved results indicate that information about the genetic origin of inbred lines is an important indicator of seed vigour. Finally, data emphasized the importance of inbred line characterization by biochemical markers in addition to genetic origin information.</p>
5

Prediction of field emergence of maize (Zea mays L.) hybrids exposed to cold and wet conditions

Maree, Pieter Hermanus 12 August 2009 (has links)
The cold test is one of the oldest and most acceptable vigour tests as it is used to simulate stress conditions commonly occurring in the field. In recent years, some of South Africa’s top maize hybrids, with high cold test scores, have shown emergence problems under cold, wet planting conditions. It resulted in major complaints from commercial maize producers with sizable claims involved. Therefore, the need arose to find a more sensitive vigour test that takes into account cold, wet conditions. In practice, South African maize producers would not plant if it is too cold and wet. However, cold, wet conditions are commonly experienced during planting time in the main maize production regions of South Africa, especially during October and even November. Furthermore, in most of the commercial maize production areas, such as the western Free State, chances of thunder and hailstorms are high during the planting period. These weather conditions are major causes for sudden drops in temperature and flooding which can expose maize seed and emerging maize seedlings to stress conditions The effects of cold, wet conditions on germination and emergence of nine maize hybrids were investigated in laboratory, glasshouse and field experiments. Growth chamber and glasshouse experiments were conducted under 10°C, 20°C and 30°C and 0, 24, 48 and 72 hours flooding. Field experiments were conducted under different climatic conditions, resulting in cool and wet, cold and wet and favourable conditions during planting. The objectives were to investigate the correlations between different laboratory vigour tests and field emergence of maize hybrids under cold, wet conditions in order to identify the most suitable laboratory vigour test for predicting field emergence under cold, wet conditions. Eight different vigour tests were conducted and each was compared with field emergence under cold, wet conditions. The eight tests conducted, were the cold test, soak test, complex stressing vigour test, electrical conductivity test, accelerated ageing test, tetrazolium test, fast green test and emergence rate test. The soak test was the most sensitive vigour test when considering cold, wet conditions, as it measures seed germination, based on the warm test, after a 48 hour soak in water at 27°C. Correlations found between the soak test and field emergence (53%) under cold, wet conditions was unexpected, since the soak test does not account for low temperatures. The complex stressing vigour test was conducted to study the effect of fluctuating soaking temperatures on germination of maize seed. Seeds of nine maize hybrids were soaked for 48 hours at a moderate temperature (25°C), followed by another 48 hours soak at a low temperature (5°C), and then planted in sand and grown for 4 days at 25°C, before evaluation. Highly significant correlations were found between the complex stressing vigour test and simulated field emergence under both controlled conditions in a glasshouse (89.9%) and cold, wet conditions in the field (90.0%). The complex stressing vigour test was the best test to predict field performance under a wide range of climatic conditions, especially cold, wet conditions. Implementation of the complex stressing test as a routine vigour test, will be to the advantage of maize seed companies, especially in being proactive in predicting emergence of maize hybrids under cold, wet conditions. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2009. / Plant Production and Soil Science / unrestricted
6

Internal Combustion Engine Cold Test Driveline Modeling, Analysis and Development

Tailony, Rauf January 2019 (has links)
No description available.

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