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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.
461

Enhanced voltage regulation in lightly-loaded, meshed distribution networks using a phase shifting transformer

Sithole, Frederick Silence 03 June 2013 (has links)
M.Ing. (Electrical and Electronic Engineering) / Long transmission lines in power system require high line loading in order to lower voltage limits due to line losses. For relatively long lines, line charging is high and thus higher voltage limits reached at low loading. It follows then that it is a challenge to maintaining the voltages between the acceptable limits for relatively long lines. This dissertation highlights the problems experienced when load varying from very low to very high is supplied by very long parallel lines of different impedance characteristic. When the load is extremely high, there are low voltages experienced which are solved by use of shunt capacitors and/or adding more lines. When the load is extremely low, there are high voltages experienced which are solved by use of shunt reactors and/or switching some of the lines off. The type of solutions to this two loading extremes as indicated above, can be problematic, in that; new lines requires servitudes which can take too long, shunt capacitors and reactors in this type of the network is not desirable since the introduction of too many of these devices have maintenance implications and they would require continuous switching to maintain acceptable voltages, resulting in complicated operation of the network. This research proposes the use of a phase shifting transformer located on one of two parallel corridors supplying power to a load located remotely from the rest of the system. The transformer is able to rearrange the active power flows to vary loadings of the corridors and the improvements in voltage regulation can be realised during both low and high load conditions.
462

Strawberry and cranberry response to growth regulators and fertilizers

McArthur, David Albert James January 1987 (has links)
The growth and yield response of strawberry (Fragaria X annassa Duch.) and cranberry (Vaccinium macrocarpon Ait) to various growth inhibitors, but especially to paclobutrazol (PP333), and fertilizers were investigated in glasshouse and field studies. PP333 decreased vegetative growth in a rate-dependent manner in both strawberry and cranberry. PP333 delayed fruit ripening in strawberry and decreased fruit set and fruit size in cranberry. PP333 decreased pollen germination of strawberry. Soil residues of PP333 were biologically active when measured 11 weeks after application in the strawberry study and when measured after 50 weeks in a cranberry study. In a field study with cranberry, PP333 caused a decrease in vegetative growth and an increase in flowering in the next season after treatment. Two-dimensional partitioning was used to account for yield variation from treatment effects on adjusted yield variates. The truss number was the most important contributor to yield variation in the strawberry, but was not affected by treatments. PP333 made a substantial contribution to yield variation in strawberry through its effect on fruit development and ripening. In the cranberry, fruit set was the major contributor to yield variation and PP333 influenced yield substantially through its effect on fruit set. In glasshouse studies, PP333 decreased shoot elongation in cranberry within 3 weeks of application, and increased the number of branches on primary shoots. Buds were formed within 7 weeks of treatment and some of the buds contained flowers. Shoot growth was greater with a high rate of NPK fertilizer than with the low fertilizer rate and was greater in peaty soil than in sandy soil. While bud set was not modified by soil type or fertilizer rate, high NPK fertilizer decreased floral induction. Some effects of PP333 treatment were decreased by gibberellic acid, but generally these effects here not reversed. In a field study with the cranberry, PP333 increased flower bud set for flowering and non-flowering uprights but slightly decreased floral induction for non-flowering uprights. / Land and Food Systems, Faculty of / Graduate
463

Otimização da regeneração in vitro de Urochloa spp. via embriogênese somática / Optimization of in vitro regeneration of Urochloa spp via somatic embryogenesis

Takamori, Luciana Midori 05 November 2014 (has links)
Made available in DSpace on 2016-01-26T18:56:31Z (GMT). No. of bitstreams: 1 Luciana Midori Takamori.pdf: 833111 bytes, checksum: 9cc8e066771c7d927c3b5a8b15bc398c (MD5) Previous issue date: 2014-11-05 / The establishment of an efficient methodology for regeneration in Urochloa spp via somatic embryogenesis is an essential step for genetic engineering works and to support the breeding programs of the signal grass. The aim of this study was to evaluate different concentrations of growth regulators on callus induction, somatic embryogenesis and plant regeneration of Urochloa spp. using mature seeds as the initial explant. Firstly, eight treatments were tested containing different concentrations (1, 2, 4 and 8 mg L-1) of 2,4-D or picloram, using Marandu cultivar. After, the same concentrations of picloram were tested for others genotypes: cultivars Xaraés and Piata of U. brizantha, U. decumbens cv. Basilisk, U. humidicola. cv. Llanero and U. ruziziensis cv. Ruziziensis. The experiments were conducted in a completely randomized design with four replications per treatment, and each replicate consisted of a petri dish containing 10 seeds each. The experiments were repeated three times. Seeds were sterilized in 5% NaOCl containing three drops of Tween 20, washed five times in sterile distilled water and inoculated onto MS medium containing the treatments described above. The experiments were maintained in growth chamber at 25 ° C ± 2 ° C in the dark, and sub-cultured every 14 days until the emergence of embryogenic calluses. To induce plant regeneration, these calluses were transferred to hormone-free MS medium for 14 days in indirect light followed by transfer to MS/2 medium containing 2 mg/L-BA in direct light with a photoperiod of 16 hours. The number of seeds that produced primary calluses, the number of calluses with shoots and the number of regenerated plants were analyzed in each treatment. To demonstrate embryogenic competence, the different calluses types were cyto-chemically analyzed by double staining with acetic carmine and Evans blue. There was no significant difference between concentration of 2,4D or picloram for production of primary calluses of U. brizantha Marandu ranging from 58.5% to 69.2%. Calluses induced under picloram showed the highest percentage of shoot formation differing significantly from those induced under 2.4D. The genotypes U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Xaraés showed the significant highest number of regenerated plants at 1 mg/L picloram. Green and morphologically normal plants were regenerated and acclimatized, opening the possibility of using this protocol to obtain transgenic plants in Urochloa spp. / O estabelecimento de uma metodologia eficiente para regeneração in vitro de Urochloa spp. via embriogênese somática é essencial para trabalhos de manipulação genética e, para dar suporte ao melhoramento do capim braquiária. O objetivo deste trabalho foi avaliar diferentes concentrações de reguladores de crescimento na indução de calos, embriões somáticos e na regeneração de plantas de Urochloa spp., utilizando sementes maduras como explante inicial. Inicialmente, foram testados quatro tratamentos contendo 2,4-D ou picloram, nas concentrações de 1, 2, 4 e 8 mg/L usando a cultivar Marandu (1cultivar x 2 reguladores x 4 concentrações x 12 repetições). Posteriormente, as mesmas concentrações de picloram foram testadas para as cultivares Xaraés e Piatã de U. brizantha e para as espécies de U. decumbens cv. Basilisk, U. humidicola cv. Llanero e U. ruziziensis cv. Ruziziensis (6 cultivares x 1 regulador x 4 concentrações x 12 repetições). Os experimentos foram conduzidos em delineamento inteiramente casualizado, com quatro repetições por tratamento, sendo que cada repetição foi composta por uma placa contendo 10 sementes cada. Os experimentos foram repetidos três vezes. As sementes foram desinfestadas em NaOCl a 5% contendo três gotas de Tween 20, lavadas cinco vezes em água destilada esterilizada e inoculadas em meio MS contendo as diferentes concentrações dos reguladores de crescimento. Os experimentos foram mantidos em câmara de crescimento a 25 ºC ± 2 ºC, na ausência de luz, sendo sub-cultivados a cada 14 dias até o surgimento de calos embriogênicos. Estes calos foram transferidos para o meio MS sem adição de fitorreguladores por 14 dias, em luz indireta e, em seguida, transferidos para o meio MS/2 contendo 2 mg/L de BA, sob luz direta, com fotoperíodo de 16 horas para regeneração de plantas. Foram analisados o número de sementes que produziram calos primários, número de calos que produziram brotos e número de plantas regeneradas. Os diferentes tipos de calos produzidos foram avaliados citoquimicamente por meio da dupla coloração com Carmim acético e azul de Evans para certificar a competência embriogênica. Para a U. brizantha cv Marandu não houve diferença significativa entre os tratamentos para o percentual médio de sementes que produziram calos primários variando de 58,5% a 69,2%. Calos embriogênicos induzidos com o regulador de crescimento picloram certificaram o maior percentual de formação de brotos diferindo significativamente daqueles induzidos sob 2,4-D. O maior número de plantas regeneradas foi observado na concentração de 1 mg/L de picloram para os genótipos U. decumbens cv. Basilisk, U. brizantha cv. Marandu e Xaraés e não apresentando diferença significativa entre eles. Plantas verdes e morfologicamente normais foram regeneradas e aclimatizadas, abrindo a possibilidade do uso deste protocolo para obtenção de plantas transgênicas em Urochloa spp.
464

Influência de biorreguladores sobre a fisiologia e crescimento inicial de cana-de-açúcar submetida ao déficit hídrico / Influência de biorreguladores sobre a fisiologia e crescimento inicial de cana-de-açúcar submetida ao déficit hídrico / Bioregulators influence on the physiology and initial growth of sugarcane submitted to water deficit / Bioregulators influence on the physiology and initial growth of sugarcane submitted to water deficit

Zilliani, Rafael Rebes 02 March 2015 (has links)
Made available in DSpace on 2016-01-26T18:56:31Z (GMT). No. of bitstreams: 1 Rafael Rebes Zilliani.pdf: 603873 bytes, checksum: 841c569299d71ab210698b9255ac75ba (MD5) Previous issue date: 2015-03-02 / Several environmental factors can alter the physiological processes of sugarcane plants, however, water deficit is the main factor limiting the productivity of this crop. The use of plant growth regulators can mitigate the effects of the drought, because these substances improve the regulation of physiological processes in the plant. In this context, the aim of this study was to evaluate the effects of a plant growth regulators solution (auxin, cytokinin and gibberellin) on the initial development and photosynthesis of sugarcane under water deficit. It was adopted a completely randomized 2 x 3 factorial design, two water regimes - control (100% of field capacity) and water deficit (20% of field capacity), and three doses of the bioregulators solution (0, 0.5 and 1.0 L h-1). The experimental plot consisted of plastic pots containing 12.0 kg of soil with one plant per pot of RB867515 and SP81-3250 cultivars, with ten replicates. The treatments with bioregulators solution was carried out with the commercial solution of plant growth regulators Stimulate® on stalks at planting and at 64 days after planting (DAP) by foliar application. Water deficit was initiated at 55 DAP and during this period were held biometric and physiological evaluations in plants. At 110 DAP biomass evaluation was performed. The drought reduced the relative water content of the plants, and all physiological parameters, maximum CO2 assimilation (Amax), stomatal conductance (Gs), maximum speed of Rubisco carboxylation and PEPCase enzymes (Vcmax and Vpmax) and, reduced plant growth and biomass production. However, plants that were treated with Stimulate® showed lower reduction in all physiological parameters, biometric and a smaller reduction in biomass when compared to plants not receiving treatment with the bioregulator solution. The bioregulators mainly stimulated the growth of the root system, which promoted greater absorption of water by plants and, consequently, better physiological performance under drought. The Stimulate® attenuated the effects of drought on physiological processes, promoting smaller reduction in Amax, Vcmax and Vpmax and also lower photochemical damage. This condition was responsible for the largest growth (height and leaf area) increasing the total biomass of plants (root, leaf and stem). / Vários fatores ambientais podem alterar os processos fisiológicos das plantas de cana-de-açúcar, porém o déficit hídrico é o principal fator que limita a produtividade desta cultura. O uso de reguladores vegetais pode atenuar os efeitos causados pelo déficit hídrico, em vista de que essas substâncias podem auxiliar na regulação dos processos fisiológicos da planta. Nesse contexto, o objetivo deste estudo foi avaliar os efeitos de uma solução de biorreguladores (auxina, citocinina e giberelina) sobre o desenvolvimento inicial e fotossíntese de cana-de-açúcar sob déficit hídrico. Foi adotado o delineamento inteiramente casualizado no esquema fatorial 2x3, sendo dois regimes hídricos, controle (100% da capacidade de campo) e déficit hídrico (20% da capacidade de campo) e três doses da solução de biorreguladores (0, 0,5 e 1,0 L ha-1). A parcela experimental foi constituída de vasos plásticos contendo 12,0 kg de solo com uma planta por vaso das cultivares RB867515 e SP81-3250, para cada tratamento utilizou-se dez repetições. Realizou-se o tratamento das plantas com a solução comercial de biorreguladores Stimulate® nos toletes no momento do plantio e aos 64 dias após o plantio (DAP) via aplicação foliar. O déficit hídrico foi iniciado aos 55 DAP e durante este período foram realizadas avaliações biométricas e fisiológicas nas plantas. Aos 110 DAP realizou-se a avalição de biomassa. O déficit hídrico reduziu o conteúdo relativo de água das plantas, bem como todos os parâmetros fisiológicos, assimilação máxima de CO2 (Amax), condutância estomática (Gs), velocidade máxima de carboxilação das enzimas Rubisco e PEPcase (Vcmax e Vpmax) e ainda, reduziu o crescimento das plantas e a produção de biomassa. No entanto, as plantas que foram tratadas com Stimulate® tiveram menor redução em todos os parâmetros fisiológicos, biométricos e menor redução na produção de biomassa quando comparadas as plantas que não receberam o tratamento com a solução de biorreguladores. Os biorreguladores estimularam principalmente o crescimento do sistema radicular, que promoveu maior absorção de água pelas plantas e, consequentemente, melhor desempenho fisiológico sob déficit hídrico. O Stimulate® atenuou os efeitos do déficit hídrico nos processos fisiológicos, promovendo menor redução em Amax, Vcmax e Vpmax e também menor dano fotoquímico. Essa condição foi responsável pelo maior crescimento (altura e área foliar) aumentando a produção de biomassa total das plantas (raiz, folhas e colmo).
465

Otimização da regeneração in vitro de Urochloa spp. via embriogênese somática / Optimization of in vitro regeneration of Urochloa spp via somatic embryogenesis

Takamori, Luciana Midori 05 November 2014 (has links)
Made available in DSpace on 2016-07-18T17:51:13Z (GMT). No. of bitstreams: 1 Luciana Midori Takamori.pdf: 833111 bytes, checksum: 9cc8e066771c7d927c3b5a8b15bc398c (MD5) Previous issue date: 2014-11-05 / The establishment of an efficient methodology for regeneration in Urochloa spp via somatic embryogenesis is an essential step for genetic engineering works and to support the breeding programs of the signal grass. The aim of this study was to evaluate different concentrations of growth regulators on callus induction, somatic embryogenesis and plant regeneration of Urochloa spp. using mature seeds as the initial explant. Firstly, eight treatments were tested containing different concentrations (1, 2, 4 and 8 mg L-1) of 2,4-D or picloram, using Marandu cultivar. After, the same concentrations of picloram were tested for others genotypes: cultivars Xaraés and Piata of U. brizantha, U. decumbens cv. Basilisk, U. humidicola. cv. Llanero and U. ruziziensis cv. Ruziziensis. The experiments were conducted in a completely randomized design with four replications per treatment, and each replicate consisted of a petri dish containing 10 seeds each. The experiments were repeated three times. Seeds were sterilized in 5% NaOCl containing three drops of Tween 20, washed five times in sterile distilled water and inoculated onto MS medium containing the treatments described above. The experiments were maintained in growth chamber at 25 ° C ± 2 ° C in the dark, and sub-cultured every 14 days until the emergence of embryogenic calluses. To induce plant regeneration, these calluses were transferred to hormone-free MS medium for 14 days in indirect light followed by transfer to MS/2 medium containing 2 mg/L-BA in direct light with a photoperiod of 16 hours. The number of seeds that produced primary calluses, the number of calluses with shoots and the number of regenerated plants were analyzed in each treatment. To demonstrate embryogenic competence, the different calluses types were cyto-chemically analyzed by double staining with acetic carmine and Evans blue. There was no significant difference between concentration of 2,4D or picloram for production of primary calluses of U. brizantha Marandu ranging from 58.5% to 69.2%. Calluses induced under picloram showed the highest percentage of shoot formation differing significantly from those induced under 2.4D. The genotypes U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Xaraés showed the significant highest number of regenerated plants at 1 mg/L picloram. Green and morphologically normal plants were regenerated and acclimatized, opening the possibility of using this protocol to obtain transgenic plants in Urochloa spp. / O estabelecimento de uma metodologia eficiente para regeneração in vitro de Urochloa spp. via embriogênese somática é essencial para trabalhos de manipulação genética e, para dar suporte ao melhoramento do capim braquiária. O objetivo deste trabalho foi avaliar diferentes concentrações de reguladores de crescimento na indução de calos, embriões somáticos e na regeneração de plantas de Urochloa spp., utilizando sementes maduras como explante inicial. Inicialmente, foram testados quatro tratamentos contendo 2,4-D ou picloram, nas concentrações de 1, 2, 4 e 8 mg/L usando a cultivar Marandu (1cultivar x 2 reguladores x 4 concentrações x 12 repetições). Posteriormente, as mesmas concentrações de picloram foram testadas para as cultivares Xaraés e Piatã de U. brizantha e para as espécies de U. decumbens cv. Basilisk, U. humidicola cv. Llanero e U. ruziziensis cv. Ruziziensis (6 cultivares x 1 regulador x 4 concentrações x 12 repetições). Os experimentos foram conduzidos em delineamento inteiramente casualizado, com quatro repetições por tratamento, sendo que cada repetição foi composta por uma placa contendo 10 sementes cada. Os experimentos foram repetidos três vezes. As sementes foram desinfestadas em NaOCl a 5% contendo três gotas de Tween 20, lavadas cinco vezes em água destilada esterilizada e inoculadas em meio MS contendo as diferentes concentrações dos reguladores de crescimento. Os experimentos foram mantidos em câmara de crescimento a 25 ºC ± 2 ºC, na ausência de luz, sendo sub-cultivados a cada 14 dias até o surgimento de calos embriogênicos. Estes calos foram transferidos para o meio MS sem adição de fitorreguladores por 14 dias, em luz indireta e, em seguida, transferidos para o meio MS/2 contendo 2 mg/L de BA, sob luz direta, com fotoperíodo de 16 horas para regeneração de plantas. Foram analisados o número de sementes que produziram calos primários, número de calos que produziram brotos e número de plantas regeneradas. Os diferentes tipos de calos produzidos foram avaliados citoquimicamente por meio da dupla coloração com Carmim acético e azul de Evans para certificar a competência embriogênica. Para a U. brizantha cv Marandu não houve diferença significativa entre os tratamentos para o percentual médio de sementes que produziram calos primários variando de 58,5% a 69,2%. Calos embriogênicos induzidos com o regulador de crescimento picloram certificaram o maior percentual de formação de brotos diferindo significativamente daqueles induzidos sob 2,4-D. O maior número de plantas regeneradas foi observado na concentração de 1 mg/L de picloram para os genótipos U. decumbens cv. Basilisk, U. brizantha cv. Marandu e Xaraés e não apresentando diferença significativa entre eles. Plantas verdes e morfologicamente normais foram regeneradas e aclimatizadas, abrindo a possibilidade do uso deste protocolo para obtenção de plantas transgênicas em Urochloa spp.
466

Influência de biorreguladores sobre a fisiologia e crescimento inicial de cana-de-açúcar submetida ao déficit hídrico / Influência de biorreguladores sobre a fisiologia e crescimento inicial de cana-de-açúcar submetida ao déficit hídrico / Bioregulators influence on the physiology and initial growth of sugarcane submitted to water deficit / Bioregulators influence on the physiology and initial growth of sugarcane submitted to water deficit

Zilliani, Rafael Rebes 02 March 2015 (has links)
Made available in DSpace on 2016-07-18T17:51:13Z (GMT). No. of bitstreams: 1 Rafael Rebes Zilliani.pdf: 603873 bytes, checksum: 841c569299d71ab210698b9255ac75ba (MD5) Previous issue date: 2015-03-02 / Several environmental factors can alter the physiological processes of sugarcane plants, however, water deficit is the main factor limiting the productivity of this crop. The use of plant growth regulators can mitigate the effects of the drought, because these substances improve the regulation of physiological processes in the plant. In this context, the aim of this study was to evaluate the effects of a plant growth regulators solution (auxin, cytokinin and gibberellin) on the initial development and photosynthesis of sugarcane under water deficit. It was adopted a completely randomized 2 x 3 factorial design, two water regimes - control (100% of field capacity) and water deficit (20% of field capacity), and three doses of the bioregulators solution (0, 0.5 and 1.0 L h-1). The experimental plot consisted of plastic pots containing 12.0 kg of soil with one plant per pot of RB867515 and SP81-3250 cultivars, with ten replicates. The treatments with bioregulators solution was carried out with the commercial solution of plant growth regulators Stimulate® on stalks at planting and at 64 days after planting (DAP) by foliar application. Water deficit was initiated at 55 DAP and during this period were held biometric and physiological evaluations in plants. At 110 DAP biomass evaluation was performed. The drought reduced the relative water content of the plants, and all physiological parameters, maximum CO2 assimilation (Amax), stomatal conductance (Gs), maximum speed of Rubisco carboxylation and PEPCase enzymes (Vcmax and Vpmax) and, reduced plant growth and biomass production. However, plants that were treated with Stimulate® showed lower reduction in all physiological parameters, biometric and a smaller reduction in biomass when compared to plants not receiving treatment with the bioregulator solution. The bioregulators mainly stimulated the growth of the root system, which promoted greater absorption of water by plants and, consequently, better physiological performance under drought. The Stimulate® attenuated the effects of drought on physiological processes, promoting smaller reduction in Amax, Vcmax and Vpmax and also lower photochemical damage. This condition was responsible for the largest growth (height and leaf area) increasing the total biomass of plants (root, leaf and stem). / Vários fatores ambientais podem alterar os processos fisiológicos das plantas de cana-de-açúcar, porém o déficit hídrico é o principal fator que limita a produtividade desta cultura. O uso de reguladores vegetais pode atenuar os efeitos causados pelo déficit hídrico, em vista de que essas substâncias podem auxiliar na regulação dos processos fisiológicos da planta. Nesse contexto, o objetivo deste estudo foi avaliar os efeitos de uma solução de biorreguladores (auxina, citocinina e giberelina) sobre o desenvolvimento inicial e fotossíntese de cana-de-açúcar sob déficit hídrico. Foi adotado o delineamento inteiramente casualizado no esquema fatorial 2x3, sendo dois regimes hídricos, controle (100% da capacidade de campo) e déficit hídrico (20% da capacidade de campo) e três doses da solução de biorreguladores (0, 0,5 e 1,0 L ha-1). A parcela experimental foi constituída de vasos plásticos contendo 12,0 kg de solo com uma planta por vaso das cultivares RB867515 e SP81-3250, para cada tratamento utilizou-se dez repetições. Realizou-se o tratamento das plantas com a solução comercial de biorreguladores Stimulate® nos toletes no momento do plantio e aos 64 dias após o plantio (DAP) via aplicação foliar. O déficit hídrico foi iniciado aos 55 DAP e durante este período foram realizadas avaliações biométricas e fisiológicas nas plantas. Aos 110 DAP realizou-se a avalição de biomassa. O déficit hídrico reduziu o conteúdo relativo de água das plantas, bem como todos os parâmetros fisiológicos, assimilação máxima de CO2 (Amax), condutância estomática (Gs), velocidade máxima de carboxilação das enzimas Rubisco e PEPcase (Vcmax e Vpmax) e ainda, reduziu o crescimento das plantas e a produção de biomassa. No entanto, as plantas que foram tratadas com Stimulate® tiveram menor redução em todos os parâmetros fisiológicos, biométricos e menor redução na produção de biomassa quando comparadas as plantas que não receberam o tratamento com a solução de biorreguladores. Os biorreguladores estimularam principalmente o crescimento do sistema radicular, que promoveu maior absorção de água pelas plantas e, consequentemente, melhor desempenho fisiológico sob déficit hídrico. O Stimulate® atenuou os efeitos do déficit hídrico nos processos fisiológicos, promovendo menor redução em Amax, Vcmax e Vpmax e também menor dano fotoquímico. Essa condição foi responsável pelo maior crescimento (altura e área foliar) aumentando a produção de biomassa total das plantas (raiz, folhas e colmo).
467

Modul pro řízení stejnosměrných motorů / DC motor controller module

Duz, Aleksei January 2020 (has links)
This thesis focuses on the design and creation of control unit for DC motors drives. A principle on which the DC motor is based, a method of its control and a possibility to obtain current information about the position are briefly described in this work. After that, the different types of buses for communication with a superior system and justification of the chosen one, are presented. In the next section, there is a special emphasis on creation of the suitable driver model and a design of the elecrical schematic and PCB. The end of the thesis contains a description of commission a PCB and testing the main functions.
468

Identification of candidate signature genes and key regulators associated with trypanotolerance in the Sheko breed

Mekonnen, Yonatan Ayalew 31 January 2020 (has links)
No description available.
469

The efficacy of topically applied fluazuron and flumethrin in the control of sheep myiasis

Austin, Clinton Mark January 2016 (has links)
Small stock farming and production accounted for approximately 8.4% of total animal product based agricultural output in the 2011 / 2012 season in South Africa. Large scale commercial farming aside, small stock farming also takes on an important role in poorer and developing rural areas of South Africa, where small stock are kept for a combination of economic and non-economic reasons including financial investment or security, food and resource production, as well as religious or traditional reasons. Blowflies are Dipterids with complex life cycles and complete metamorphoses, causing damage to hides and frequent death in their ovine hosts, as a result of cutaneous myiasis caused by the larval stages. All economically important blowfly species causing veterinary myiasis belong to the superfamily Oestroidea, which contains the three major families Oestridae, Calliphoridae and Sarcophidae. The two most significant blowfly genera in South Africa, Lucillia and Chrysomya, both belong to the family Calliphoridae. Chemical means of preventing and treating blowfly strike by topical application remains the most widely used method and appears to be indispensable at this stage. New molecules or formulations effective against blowfly strike are constantly being sought and form part of an active field of research. Bayer currently manufactures and markets Drastic Deadline Extreme ®, a pour-on formulation containing flumethrin and fluazuron for the control of blue ticks (Rhipicephalus decoloratus) in cattle; its possible action against blowflies in sheep was investigated in an in-vitro model, subsequent to a pilot pharmacokinetic study evaluating the kinetics of fluazuron when applied topically to sheep in this particular combination. The first objective of the project was to determine whether fluazuron has any effect at all on the development of blowfly larvae. An active ingredient from the same family of compounds, namely triflumeron, has been successfully used for several years to control blowfly strike in sheep in South Africa (Zapp ® Pour on - Bayer), but it was uncertain whether or not fluazuron would be effective. Raw fluazuron was applied to six pieces of beef according to a dose calculation based on the registered dose of the test product in cattle, while another six pieces were treated with saline in a similar fashion (n=6). Each piece of beef was placed in its own container along with six late instar larvae and placed in the incubator at 35°C for a further nine days. In this instance, the treated group demonstrated significant development defects with regard to pupation (uneclosed pupae) when analysed using the Mann-Whitney non-parametric t-test (p = 0.002). / Dissertation (MSc)--University of Pretoria, 2016. / Paraclinical Sciences / MSc / Unrestricted
470

Developmental regulators and secreted effector molecules of the fungal pathogen Verticillium spp.

Leonard, Miriam 30 September 2019 (has links)
No description available.

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