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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 den wirkungswert von schwefel-saurem ammoniak und chilesalpeter als düngemittel ...

Blobel, Ernst Adolf Hermann, January 1908 (has links)
Inaug.-diss.--Leipzig.
2

Protein fractionation by aqueous two-phase systems and differential ammonium sulfate precipitation /

Sookkumnerd, Terasut, January 2000 (has links)
Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 170-174).
3

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

Rothe, Carl Reinhold Walther, January 1904 (has links)
Inaug.-Diss.--Königsberg.
4

The Nitrification of Ammonium Sulfate in Polyethylene Bags in the Field and Laboratory

Smith, Carlos Dean 01 May 1963 (has links)
There are many advantages and some disadvantages associated with the fall application of nitrogen fertilizers. The advantages of applying fertilizer at this time appear very convincing. It is easier to get onto the land in the fall. During the fall, famers usually have more time to apply fertilizer than they do in the spring. In the fall the fertilizer companies offer better service. This is because the fall application of fertilizer lengthens out their season, thus making it possible for them to handle more fertilizer.
5

Fertilizante nitrogenado alternativo na produção de matéria seca, nutrientes da parte aérea e atributos químicos do solo da Brachiaria brizantha cv. Xaraés /

Parra, Fabiane Bicharelli Guimarães. January 2009 (has links)
Resumo: O objetivo do trabalho foi analisar o Ajifer L40 como fonte alternativa de fertilizante nitrogenado na produção de matéria seca, nutrientes da folha e atributos químicos do solo da Brachiaria brizantha cv. Xaraés (capim-Xaraés). O experimento foi conduzido em área do Sindicado Rural no município de Araçatuba, localizado na região da Alta Noroeste do Estado de São Paulo, no período de outubro de 2005 a maio de 2009 em solo classificado como Latossolo Vermelho Amarelo. O delineamento experimental foi em blocos casualizados com 10 tratamentos e três repetições. Os tratamentos foram arranjados em esquema fatorial 3 x 3 + 1, sendo três doses de nitrogênio (100, 200 e 400 kg ha-1 ano-1) e três fontes (uréia, sulfato de amônio e Ajifer L40) e um tratamento adicional (testemunha com dose 0 de N). Os fertilizantes apresentaram resposta máxima média dos quatro anos de avaliação na dose de 322 kg ha-1 de N. O teor de proteína bruta na parte aérea do capim-Xaraés foi linearmente crescente até a dose de 400 kg ha-1 de N para as três fontes estudadas. O Ajifer L40 e o sulfato de amônio foram importante fonte de enxofre para a nutrição das plantas. As fontes nitrogenadas Ajifer L40 e sulfato de amônio apresentaram comportamento semelhante, proporcionando maior acidez na camada superficial do solo em relação à fonte uréia. A utilização dos fertilizantes Ajifer L40, sulfato de amônio e uréia não alterou a concentração de sódio e a condutividade elétrica no solo. A fonte alternativa Ajifer L40 é similar às outras fontes de fertilizantes convencionais / Abstract: The aim was to evaluate the Ajifer L40 as an alternative source of nitrogen fertilizer on dry matter production, leaf nutrients and soil chemical properties of Brachiaria brizantha cv. Xaraés (Xaraés-grass). The experiment was conducted in Syndicate Rural area in the municipality of Araçatuba, located in Upper Northwest of São Paulo, from October 2005 to May of 2009 in a soil classified as Latosol Yellow Red. The experimental design was randomized blocks with 10 treatments and three replications. The treatments were arranged in a 3 x 3 + 1, three nitrogen levels (100, 200 and 400 kg ha-1 yr-1) and three sources (urea, ammonium sulfate and Ajifer L40) and an additional treatment (control dose of 0 N). Fertilizers showed a mean maximum of four years of evaluation at a dose of 322 kg ha-1 N. The crude protein content in leaves of Xaraés-grass was increasing linearly with doses up to 400 kg ha-1 of N for the three sources studied. The Ajifer L40 and ammonium sulfate were an important source of sulfur for plant nutrition. The nitrogen sources, Ajifer L40 and ammonium sulfate were similar, providing greater acidity in the topsoil is in relation to urea. The use of fertilizers Ajifer L40, ammonium sulfate and urea did not alter the concentration of sodium and electrical conductivity in the soil. The alternative source Ajifer L40 is similar to other conventional sources fertilizers / Orientador: Cecílio Viega Soares Filho / Coorientador: Reges Heinrichs / Banca: Ana Cláudia Ruggieri / Banca: Sílvia Helena Venturoli Perri / Mestre
6

Perfil fermentativo da linhagem CAT-1 em mosto contendo alta concentração de açúcar em sistema descontínuo alimentado / CAT-1 yeast strain fermentation profile in medium with very high gravity in fed batch system

Francischetti, Graziela 09 August 2017 (has links)
O etanol é o combustível que mais se destaca como alternativa à gasolina no setor do transporte. No entanto, a melhoria da eficiência da fermentação, aprimorando o processo de conversão de biomassa em etanol combustível e reduzindo o custo de produção são desafios ainda pertinentes. Neste cenário, as fermentações com alta concentração de açúcar ou VHG (very high gravity) estão sendo cada vez mais estudadas. A adição de compostos como fonte de nitrogênio pode gerar benefícios para a produção de etanol, entretanto, a maioria dos estudos com suplementação de fontes nitrogenadas é realizada em sistema descontínuo simples e em escala laboratorial, embora os processos fermentativos industriais sejam conduzidos em sistema descontínuo alimentado. Neste contexto, este trabalho visou avaliar o perfil fermentativo da linhagem CAT-1 em mosto contendo alta concentração de açúcar fermentescível e suplementado com as fontes nitrogenadas peptona e sulfato de amônio, nas concentrações 5 e 10 g/L, em sistema de descontínuo simples e descontínuo alimentado com reciclo de células, utilizando diferentes escalas produtivas. Nos experimentos em sistema descontínuo simples, os tratamentos controle e peptona (5 g/L) apresentaram uma melhor produção de etanol, maior rendimento e produtividade em comparação com os demais tratamentos. Nos experimentos em sistema descontínuo alimentado não houve diferença significativa entre os tratamentos controle e peptona 5 e 10g/L, porém, o tratamento com sulfato de amônio (10 g/L) apresentou parâmetros fermentativos de produção de etanol e produtividade superiores ao tratamento controle, o oposto do descontínuo simples. Os resultados mostraram que quando as células de levedura foram submetidas a concentrações crescentes de açúcar, como é o caso do sistema descontínuo alimentado, ocorre uma adaptação das mesmas, proporcionando melhores resultados, com uma redução no tempo de fermentação para 16h. Além disso, a alta concentração de etanol no meio fermentativo causa um efeito prejudicial às células, já que nos tratamentos onde houve teores mais elevados de etanol ocorreu menor viabilidade e maior quantidade de açúcar residual. / Ethanol is the fuel that stands out as an alternative to gasoline in the transportation sector. However, improving the efficiency of fermentation, improving the process of converting biomass to fuel ethanol and reducing the cost of production are still relevant challenges. In this scenario, fermentations with high sugar concentration or very high gravity (VHG) are being studied more and more. The addition of compounds as a source of nitrogen can generate benefits for ethanol production, however, most of the studies with nitrogen supplementation are carried out in a simple discontinuous system and in laboratory scale, although the industrial fermentation processes are conducted in a fed batch system . In this context, the objective of this work was to evaluate the fermentation profile of the CAT-1 strain in must containing high fermentable sugar concentration and supplemented with nitrogen peptone and ammonium sulfate at 5 and 10 g / L in a simple discontinuous system and fed batch system, fed with recycle of cells, using different productive scales. In the simple discontinuous system experiments, the control and peptone treatments (5 g / L) presented better ethanol production, higher yield and productivity in comparison to the other treatments. However, the treatment with ammonium sulfate (10 g / L) showed fermentative parameters of ethanol production and productivity higher than the control treatment, the opposite of simple discontinuity. The results showed that when the yeast cells were submitted to increasing concentrations of sugar, as is the case of the fed batch system, an adaptation occurs, providing better results, with a reduction in the fermentation time to 16h. In addition, the high concentration of ethanol in the fermentation medium causes a detrimental effect on the cells, since in the treatments with higher levels of ethanol; less viability and more residual sugar were observed.
7

Kinetics of Deliquescence of Ammonium Sulfate Particles

Pancescu, Rocsana Gabriela January 2008 (has links)
The goal of this project was to study the deliquescence kinetics of aerosol particles of atmospheric significance. In the course of this work a novel experimental method was developed, which utilizes the measurement of the water vapor loss in laminar aerosol flow to determine vapor uptake on the aerosol surface. The newly designed flow tube apparatus uses a system of Nafion based dryers and humidifiers, which greatly simplifies the optimization and control of the relative humidity in the aerosol flow. The design, which also utilizes a movable inlet, enables easy variation of the aerosol residence time in the deliquescence reactor, while keeping other experimental conditions constant. In this study, a numerical retrieval procedure was used to characterize aerosols in situ from their IR extinction spectra. The procedure allows that the aerosol size, number distribution, phase and composition be determined, provided the optical constants of all the components (materials) comprising the aerosol are known. For the purpose of studying the deliquescence kinetics of ammonium sulfate aerosol and monitoring their evolution from solid to liquid (state), we have acquired a set of optical constants for a range of (NH4)2SO4 compositions. A set of experiments in a somewhat modified flow tube set up was performed to produce AMS aerosols of known composition, including solid, saturated (water) solution (40 % wt.) and a series of diluted solutions with composition ranging between 40 and 10 % wt. in 5 % increments. The IR spectra of these model aerosols were used to derive the optical constants, using an inversion method proposed by Clapp. The derived refractive indices, which cover the spectral range from 590 to 5990 cm-1 with 2 cm-1 resolution, were compared with those already available in the literature. Using various examples to compare the quality of fittings to experimental spectra, we demonstrated that our optical constants present an improvement relative to those previously reported by B. Toon’s (for crystalline AMS) and S. Martin’s (for AMS solution). The suitability of applying this procedure to ammonium sulfate aerosols and its sensitivity to spectral range was also investigated and discussed. As a preparatory step for the deliquescence kinetics study, our new flow tube apparatus and the tools for the characterization of aerosol were verified in a standard deliquescence experiment performed on (NH4)2SO4 aerosols. The deliquescence process of an equilibrated aerosol flow was monitored as a function of increasing humidity and the deliquescence relative humidity (DRH) determined to be 79.6 ± 0.85 % which is, within experimental uncertainty, in an excellent agreement with the results reported by other research groups. In the kinetic experiment, a flow of solid (NH4)2SO4 aerosols is pre-humidified to a humidity close to, but enough below DRH that there is no detectable amount of liquid aerosols in the system. Such an equilibrated aerosol flow was introduced to the deliquescence reactor where it is further humidified in a controllable manner, by varying the position of the movable inlet. The amount of water transferred to the aerosol through the Nafion membrane was closely monitored, as well as the resulting increase in the water content in the aerosol flow (both gaseous and liquid). This was achieved by measuring the RHs and flow rates of the aerosol and humidification flow, and the characterization of aerosol composition and concentration using their IR spectra. The experimental conditions and aerosol residence times in the reactor where chosen such that no other diluted solution except for saturated (NH4)2SO4 droplets were produced in the process. The number distribution of deliquesced aerosols and the corresponding change in the water content in the aerosol flow were used by a newly developed kinetic model to determine the kinetics of the deliquescence process. Assuming fully developed laminar flow conditions, the water vapor concentration in the flow and its depletion in the presence of aerosol was modeled, to retrieve the value of the water vapor uptake. In the case of micron-sized ammonium sulfate aerosols, which were used in this study, the uptake coefficient,, was determined to be 0.0072 ± 6.54x10-3. The uncertainty associated with this value, as well as the suggested improvements to the experimental procedure and the kinetic model in order to reduce the uncertainty were discussed.
8

Kinetics of Deliquescence of Ammonium Sulfate Particles

Pancescu, Rocsana Gabriela January 2008 (has links)
The goal of this project was to study the deliquescence kinetics of aerosol particles of atmospheric significance. In the course of this work a novel experimental method was developed, which utilizes the measurement of the water vapor loss in laminar aerosol flow to determine vapor uptake on the aerosol surface. The newly designed flow tube apparatus uses a system of Nafion based dryers and humidifiers, which greatly simplifies the optimization and control of the relative humidity in the aerosol flow. The design, which also utilizes a movable inlet, enables easy variation of the aerosol residence time in the deliquescence reactor, while keeping other experimental conditions constant. In this study, a numerical retrieval procedure was used to characterize aerosols in situ from their IR extinction spectra. The procedure allows that the aerosol size, number distribution, phase and composition be determined, provided the optical constants of all the components (materials) comprising the aerosol are known. For the purpose of studying the deliquescence kinetics of ammonium sulfate aerosol and monitoring their evolution from solid to liquid (state), we have acquired a set of optical constants for a range of (NH4)2SO4 compositions. A set of experiments in a somewhat modified flow tube set up was performed to produce AMS aerosols of known composition, including solid, saturated (water) solution (40 % wt.) and a series of diluted solutions with composition ranging between 40 and 10 % wt. in 5 % increments. The IR spectra of these model aerosols were used to derive the optical constants, using an inversion method proposed by Clapp. The derived refractive indices, which cover the spectral range from 590 to 5990 cm-1 with 2 cm-1 resolution, were compared with those already available in the literature. Using various examples to compare the quality of fittings to experimental spectra, we demonstrated that our optical constants present an improvement relative to those previously reported by B. Toon’s (for crystalline AMS) and S. Martin’s (for AMS solution). The suitability of applying this procedure to ammonium sulfate aerosols and its sensitivity to spectral range was also investigated and discussed. As a preparatory step for the deliquescence kinetics study, our new flow tube apparatus and the tools for the characterization of aerosol were verified in a standard deliquescence experiment performed on (NH4)2SO4 aerosols. The deliquescence process of an equilibrated aerosol flow was monitored as a function of increasing humidity and the deliquescence relative humidity (DRH) determined to be 79.6 ± 0.85 % which is, within experimental uncertainty, in an excellent agreement with the results reported by other research groups. In the kinetic experiment, a flow of solid (NH4)2SO4 aerosols is pre-humidified to a humidity close to, but enough below DRH that there is no detectable amount of liquid aerosols in the system. Such an equilibrated aerosol flow was introduced to the deliquescence reactor where it is further humidified in a controllable manner, by varying the position of the movable inlet. The amount of water transferred to the aerosol through the Nafion membrane was closely monitored, as well as the resulting increase in the water content in the aerosol flow (both gaseous and liquid). This was achieved by measuring the RHs and flow rates of the aerosol and humidification flow, and the characterization of aerosol composition and concentration using their IR spectra. The experimental conditions and aerosol residence times in the reactor where chosen such that no other diluted solution except for saturated (NH4)2SO4 droplets were produced in the process. The number distribution of deliquesced aerosols and the corresponding change in the water content in the aerosol flow were used by a newly developed kinetic model to determine the kinetics of the deliquescence process. Assuming fully developed laminar flow conditions, the water vapor concentration in the flow and its depletion in the presence of aerosol was modeled, to retrieve the value of the water vapor uptake. In the case of micron-sized ammonium sulfate aerosols, which were used in this study, the uptake coefficient,, was determined to be 0.0072 ± 6.54x10-3. The uncertainty associated with this value, as well as the suggested improvements to the experimental procedure and the kinetic model in order to reduce the uncertainty were discussed.
9

Quantitative aqueous ammonium ion analysis by transmission infrared spectroscopy

Grunfeld, Eva January 1987 (has links)
No description available.
10

Efeito da imersão de mudas com fertilizante e cupinicida no crescimento de dois clones de eucalipto sob duas condições de umidade no substrato

Vomero, Paulo Augusto de Souza Zingra [UNESP] 02 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-02Bitstream added on 2014-06-13T20:30:16Z : No. of bitstreams: 1 vomero_pasz_me_botfca.pdf: 1443571 bytes, checksum: 5ec69ec8c36c661017edfbdefbcc0951 (MD5) / Cia Suzano de Papel e Celulose Ltda / Para manter a qualidade das mudas de eucalipto no plantio e garantir rápido desenvolvimento, é recomendada a imersão das mesmas em solução de fertilizantes nitrogenados e cupinicidas. A imersão algumas vezes é realizada com o substrato saturado com água, podendo então, haver redução da ação esperada. Portanto, este trabalho visou avaliar o desenvolvimento inicial em campo de dois clones de eucalipto imersos em solução de fertilizante e cupinicida com diferentes teores de umidade no substrato. Neste estudo foram utilizados dois clones híbridos de eucalipto (“urograndis”), codificados como VT 05 e VT 04, recomendados para região de Luiz Antonio, SP, onde o experimento foi instalado, e identificados no experimento como clone 1 e clone 2 respectivamente. O delineamento experimental foi do tipo fatorial 2x2x3, com dois clones, duas situações de umidade para substrato (denominadas saturada e seco) e três situações de calda (sulfato de amônio com e sem cupinicida e testemunha), interagindo o fertilizante sulfato de amônio a 1 % e o cupinicida fipronil a 0,5 %, totalizando doze tratamentos e quatro repetições. Após o plantio foi mensurado o diâmetro de colo e altura de muda das 12 mudas centrais de cada parcela, realizando essas medições por 2 meses em intervalos de 15 dias. Posteriormente foi determinado as taxas de incremento para altura e diâmetro do colo para cada período, sendo, esses dados submetidos à análise de variância e as médias comparadas pelo teste de Tukey com significância de 5%. Foram verificadas diferenças nas taxas de crescimento entre os dois clones estudados, independentemente dos tratamentos com umidade do substrato... / To maintain the sapling quality at planting and ensure fast development, it is recommended the sapling immersion in solution of nitrogen fertilizers and termiticides. The immersion is sometimes performed with the substrate saturated with water, thus, can occur reduction of expected action. Therefore, this study aimed to analyze the initial development in the field of two eucalyptus clones immersed in solution of fertilizer and termiticide with different levels of moisture in the substrate. In this study, it was used two hybrid clones of eucalyptus (“urograndis ), codified as VT 05 and VT 04, recommended for the region of Luiz Antonio, SP, Brazil, where the experiment was carried out, and identified as clone 1 and clone 2, respectively. The experimental design was 2x2x3 factorial, with two clones, two situations of substrate moisture (wet and dry) and three different solution interacting fertilizer ammonium sulfate at 1% and termiticide fipronil at 0.5%, totaling twelve treatments and four replications. After planting was measured the saplings stem diameter and height of 12 central plants of each plot, with evaluations made during 2 months at intervals of 15 days. Using data from field samples was determined rates of increase for height and stem diameter for each period, and these data were submitted to ANOVA and means compared by Tukey test with a significance of 5%. There were differences in growth rates between the two clones, regardless of treatment with substrate moisture and termiticide. The presence of termiticide did not affect the rates of increase in height and diameter in two eucalyptus clones tested. The variation of moisture from the substrate -root seedlings set of Eucalyptus did not affect the rates of increase in height and diameter in two eucalyptus clones tested. There was better use of the product used during the immersion of seedlings when the substrate is less... (Complete abstract click electronic access below)

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