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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

Untersuchungen über das verhalten einiger mikroorganismen des bodens zu ammonium sulfat und natriumnitrat ...

Rothe, Carl Reinhold Walther, January 1904 (has links)
Inaug.-Diss.--Königsberg.
2

Respostas fisiológicas de plantas transgênicas de tabaco com alto acúmulo de prolina sob níveis de nitrogênio / Physiological responses of transgenic tobacco plants with high accumulation of proline under nitrogen levels

Viudes, Elaine Batista 24 November 2016 (has links)
Submitted by Michele Mologni (mologni@unoeste.br) on 2017-08-29T18:26:47Z No. of bitstreams: 1 Eliane Batista Viudes.pdf: 1015185 bytes, checksum: 988509ea575caceeed70fa62e6a8e173 (MD5) / Made available in DSpace on 2017-08-29T18:26:47Z (GMT). No. of bitstreams: 1 Eliane Batista Viudes.pdf: 1015185 bytes, checksum: 988509ea575caceeed70fa62e6a8e173 (MD5) Previous issue date: 2016-11-24 / In this work, tobacco plants with a high proline accumulation due to the insertion of the VaP5CSF129A mutant gene on the control of the promoter constitutive CaMV 35S were used as a model to verify the effect of transgene overexpression on the uptake and utilization of N. The experiment was conducted in a greenhouse for a period of 30 days. The arrangement was completely randomized in the 2x5 factorial scheme, consisting of two genotypes (one transgenic event and one unprocessed control) and five nitrogen fertilization doses (ammonium nitrate (NO3NH4): 25, 50, 100, 200 and 400 kgN ha-¹), totaling 10 treatments with 4 replicates. The plants were evaluated for height, leaf number, dry mass, root/shoot ratio, chlorophyll content, free proline content, nitrogen content, total protein foliar content, carbon/nitrogen ratio and nutritional efficiency for N (Absorption efficiency - EAbs, leaf utilization - EUtil and plant use - EUN). The plants of the transgenic event with high proline accumulation were less efficient than the control plants in terms of nitrogen absorption (lower levels of N in root, leaves and role plant), which resulted in lower EAbs in these plants. For EUtil (given by the relation between leaf dry mass and N content in the plant) there was no difference between the transgenic and control genotypes. However, the transgenic plants presented lower EUN in comparison to the control plants. It was concluded that the use of tobacco plants with overexpression of the VaP5CS129A gene on control of the constitutive promoter CaMV 35S for a high proline accumulation does not present potential of direct use in agricultural systems, since the alteration of the biochemical balance between the metabolisms of nitrogen and carbon did not result in plants with higher EUN. / O aumento da eficiência de uso do nitrogênio (EUN) nas plantas cultivadas é resultado da melhoria da absorção e/ou da utilização do N. Nesse trabalho, plantas de tabaco com alto acúmulo de prolina devido à inserção do gene mutante VaP5CSF129A sobre controle do promotor constitutivo CaMV 35S foram utilizadas como modelo para verificar o efeito da super-expressão do transgene na absorção e utilização de N. O experimento foi conduzido em casa de vegetação por um período de 30 dias. O arranjo foi inteiramente casualizado, no esquema fatorial 2x5, formado por dois genótipos (um evento transgênico e um controle não transformado) e cinco doses de adubação nitrogenada (nitrato de amônio (NO3NH4): 25, 50, 100, 200 e 400 kgN ha-¹), totalizando 10 tratamentos com 4 repetições. As plantas foram avaliadas quanto à altura, número de folhas, massa seca, razão raiz/parte aérea, teor de clorofila, teor de prolina livre, teor de nitrogênio, teor foliar de proteína total e eficiência nutricional quanto ao N (eficiências de absorção - EAbs, utilização na folha - EUtil e uso na planta - EUN). As plantas controle e transgênicas responderam de forma positiva ao incremento de N no solo, tanto em relação às variáveis de crescimento quanto aos parâmetros bioquímicos. As plantas transgênicas apresentaram menor biomassa e maiores teores de compostos nitrogenados nas folhas (na forma de prolina e proteínas) quando comparadas às plantas controle. Quanto à eficiência nutricional, as plantas transgênicas foram menos eficientes que as plantas controle quanto à absorção de nitrogênio (menores teores de N na raiz, nas folhas e na planta); o que resultou portanto em uma menor EAbs nestas plantas. Para a EUtil (dada pela relação entre a massa seca de folhas e o teor de N na planta) não houve diferença entre os genótipos transgênico e controle. Porém, as plantas transgênicas apresentaram menor EUN em comparação às plantas controle. Concluiu-se que o uso de plantas de tabaco com super-expressão do gene VaP5CS129A sobre controle do promotor constitutivo CaMV 35S para um alto acúmulo de prolina não apresenta potencial de utilização direta em sistemas agrícolas, desde que a alteração do equilíbrio bioquímico entre os metabolismos de nitrogênio e do carbono não resultou em plantas com maior EUN.
3

Dissolved Inorganic Nitrogen Removal Efficiency Of The Reed Beds Surrounding Lake Mogan Using Modeling Approaches

Gokmen, Mustafa 01 January 2004 (has links) (PDF)
In this study, yearly and seasonally nitrogen retention dynamics of reed beds surrounding Lake Mogan were investigated by comparing surface aerial nitrogen load and in-lake concentrations. The analyses were performed separately for nitrate-N, ammonium-N and dissolved inorganic nitrogen (sum of nitrate-N and ammonium-N) to reveal differences between them in terms of retention dynamics. 1998, 1999 and 2002 were relatively high-load years in terms of DIN-input to reed beds surrounding Lake Mogan, compared with the DIN-loadings of 1997, 2000 and 2001. A significant difference was observed between NO3-N input and output for the relatively high-load years to Lake Mogan reed beds indicating significantly high NO3-N retention rates for that periods, while no significant difference was observed in the relatively low-load years. Also, a clear linear relationship (R2 = 0.975) was found between amount of NO3-N retention and amount of NO3-N input to the system. NH4-N input and output were not significantly different in none of the study years. Then, a dynamic Wetland Nitrogen Model was utilized to model dissolved inorganic nitrogen removal capacity of the reed beds surrounding Lake Mogan. The model was firstly calibrated and validated using data sets of different study years and then used for prediction under wet and dry year scenarios. The model predictions revealed that NO3-N retention efficiency was distinctively higher in wet rather than the dry year conditions since the reed beds might have limited denitrification capacity in dry years due to unavailability of enough NO3-N load. Finally, the land-use changes occurred in the closer catchment of Lake Mogan and the potential risk areas for non-point nitrogen input to Lake Mogan were determined using aerial photos of the region and Geographical Information Systems (GIS). It was observed that highest potential risk area for non-point nitrogen input around the lake was north-east of the lake whereas, north end of the lake was least potential risk area.
4

Effects of Elevated Carbon Dioxide and Chronic Warming on Nitrogen (N) Uptake and Assimilatory Proteins of Tomato Roots Provided Different Forms of Inorganic N (Nitrate and Ammonium)

Jayawardena, Dileepa M. January 2015 (has links)
No description available.
5

Carbono, nitrogênio e fósforo em latossolo após aplicação de lodo de esgoto por dezoito anos consecutivos / Carbon, nitrogen and phosphorus in oxisol after sewage sludge application for eighteen years consecutive

Delarica, Denise de Lima Dias [UNESP] 28 July 2016 (has links)
Submitted by DENISE DE LIMA DIAS DELARICA null (denise.delarica@gmail.com) on 2016-11-10T12:01:22Z No. of bitstreams: 1 DISSERTAÇÃO Denise L D Delarica .pdf: 1952635 bytes, checksum: fc6aa11f8dbaba0de5870987c2e0331e (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-10T18:34:32Z (GMT) No. of bitstreams: 1 delarica_dld_me_jabo.pdf: 1952635 bytes, checksum: fc6aa11f8dbaba0de5870987c2e0331e (MD5) / Made available in DSpace on 2016-11-10T18:34:32Z (GMT). No. of bitstreams: 1 delarica_dld_me_jabo.pdf: 1952635 bytes, checksum: fc6aa11f8dbaba0de5870987c2e0331e (MD5) Previous issue date: 2016-07-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso do lodo de esgoto (LE) em áreas agrícolas apresenta-se como uma das práticas mais sustentáveis para manejo e disposição final do resíduo, pois contempla o potencial deste em atuar como condicionador do solo e promover ação fertilizante. O objetivo deste estudo foi avaliar o efeito da aplicação de doses crescentes de LE por dezoito anos consecutivos no teor de carbono das substâncias húmicas e de carboidratos, na concentração de nitrogênio (N) e fósforo (P) de um Latossolo Vermelho distrófico (LVd), até a profundidade 0,60 m. Em plantas de milho cultivadas no LVd objetivou-se avaliar à disponibilidade de N e P a produção de matéria seca e a produtividade. O experimento foi instalado em condições de campo em Jaboticabal, SP com delineamento experimental em blocos casualizados com 4 tratamentos e 5 repetições. Os tratamentos para o décimo oitavo ano de experimentação foram: T0= controle (fertilização mineral, sem aplicação de LE), T5 = 5 Mg ha-1 LE, T10= 10 Mg ha-1 LE e T20= 20 Mg ha-1 LE, todos base seca. Os teores de carboidratos totais e solúveis no LVd variaram tanto em função das doses de LE adicionadas ao solo, quanto em virtude do aumento da profundidade de amostragem. Na camada superficial todas as doses de LE proporcionaram incremento do teor de carboidratos totais no solo, porém, em função do aumento da profundidade notou-se queda nesses teores. Em função da aplicação do LE, os tratamentos que o receberam apresentaram maiores concentrações de C nas frações ácido húmico e fúlvico. A concentração de N-total apresentou decréscimo por efeito do aumento da profundidade do solo, e acréscimo em função do incremento das doses de LE. Os teores de amônio e nitrato elevaram-se com o aumento da profundidade e em função das maiores doses do resíduo, caracterizando um alerta quanto a possível contaminação de águas subterrâneas. Quanto maior a dose de LE, maior o teor disponível de P no solo, em função da profundidade e do tipo de fonte de P a disponibilidade do mesmo foi reduzida, estando na camada 0,40-0,60 m e no tratamento que recebeu fertilização mineral o menor teor do nutriente. O teor de N e P absorvido por plantas encontraram-se dentro da faixa adequada para a cultura do milho. Doses de LE de até 20 Mg ha-1 aplicadas por dezoito anos consecutivos no solo garantiram produtividade de grãos e produção de matéria seca adequadas, já que proporcionaram valores semelhantes ao encontrado no tratamento que recebeu fertilização mineral. / The use of sewage sludge (SS) in agricultural areas is presented as one of the most sustainable practices for management and final disposal of the waste as it contemplates the potential for this to act as soil conditioner, fertilizer promoting action. The objective of this study was to evaluate the effect of application of increasing doses of LE for eighteen consecutive years on the carbon content of humic and carbohydrate substances, the concentration of nitrogen (N) and phosphorus (P) of an Oxisol (LVd) to a depth 0.60 m. In corn plants grown in LVd aimed to evaluate the availability of N and P to dry matter production and productivity. The experiment was conducted under field conditions in Jaboticabal, SP with a randomized block design with 4 treatments and 5 repetitions. Treatments for the eighteenth year of experimentation were: T0 = control (mineral fertilization, without applying SS), T5 = 5 Mg ha-1 SS, T10 = 10 Mg ha-1 SS and T20 = 20 Mg ha-1 SS all on a dry basis. Levels of total and soluble carbohydrates in LVd varied both in terms of doses SS added to the soil, as a result of increased sampling depth. The surface layer all SS doses provided increased the total carbohydrate content in the soil, however, due to the increasing depth was noted decrease in these levels. Depending on the application of the SS, the treatments that received showed higher concentrations of C in fractions humic and fulvic acid. The total N concentration showed a decrease effect of increasing soil depth, and increase due to the increase of SS doses. Ammonium and nitrate levels were elevated with increasing depth, and due to higher doses than residue featuring an alert for possible contamination of groundwater. The higher dose of SS, the greater the available P in soil, depending on the depth and type P source its availability was reduced, 0.40-0.60 m layer being in me received fertilization treatment the lowest level of mineral nutrient. The N content and P uptake by plants were within the range for the corn crop. SS doses up to 20 Mg-1 eighteen consecutive years in soil productivity ensured adequate grain and dry matter production, as provided similar values to those found in treatments with mineral fertilizers.

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