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Ma, Li. "Soil Organic Nitrogen - Investigation of Soil Amino Acids and Proteinaceous Compounds." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51960.
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Soil carbon (C) and nitrogen (N) are predominantly in organic form. Proteins/ peptides, as an important organic form of N, constitute a substantial part of soil organic matter. On one hand, proteins/peptides are an important N source for plants and microorganisms, particularly in soils where inorganic N is limited. On the other hand, their stabilization in soils by forming organo-mineral associates or macromolecule complex reduces the C loss as CO2 into the atmosphere. Therefore, studies on the turnover, abundance, composition, and stability of proteins/peptides are of crucial importance to agricultural productivity and environmental sustainability. In the first part of this study, the bioavailability and distribution of amino acids, (building block of proteins/peptides), were investigated, in soils across the North-South and West-East transects of continental United States. The second part of this study aimed to understand the variations of organic C speciation in soils of continental United States. Previous investigations of the interactions between soil minerals and proteins/peptides were mostly limited to batch sorption experiments in labs, seldom of which gave the details at the molecular scales. Therefore, in the third part of this study, the molecular orientation of self-assembled oligopeptides on mineral surfaces was investigated by employing synchrotron based polarization-dependent Near Edge X-ray Adsorption Fine Structure Spectroscopy (NEXAFS) techniques. Specific aims of this study were: 1) to assess potentially bioavailable pool of proteinaceous compounds and the immediately bioavailable pool of free amino acids in surface and subsurface soils of various ecosystems; 2) to evaluate the relationship between environmental factors and levels/composition of the two pools; 3) to investigate the organic C speciation in soils of various land use; and 4) to understand molecular level surface organization of small peptides on mineral surfaces.
The levels of free amino acids and hydrolysable amino acids which represent the potentially bioavailable pool of proteinaceous compounds in A-horizon soils were significantly high than in C-horizon soils due to the accumulation of organic matter in surface. On average, free amino acids accounted for less than 4 % of hydrolysable amino acids which represent the total proteinaceous compounds in soils. The composition of free amino acids was significantly different between surface soil and subsurface soil and was significantly influenced by mean annual temperature and precipitation. A relatively uniform composition of hydrolysable amino acids was observed irrespective of a wide range of land use. Significant variations were observed for the levels of free and hydrolysable amino acids along mean annual temperature and precipitation gradients, as well as among vegetation types of continental USA, suggesting levels of free and hydrolysable amino acids were associated with the above-ground biomass and root distribution. Organic C speciation investigation revealed the presence of carboxylic-C (38%), aliphatic-C (~ 22%), aromatic-C (~ 18%), O/N-alkyl-C (~ 16%), and phenolic-C (< 6%). Factors such as temperature and vegetation cover were revealed in this study to account for the fluctuations of the proportions of aromatic-C and phenolic-C, in particular. Phenolic-C may serve as a good indicator for the effect of temperature or vegetation on the composition of SOC. The average composition of soil organic C, over the continental scale, was relatively uniform over various soil ecosystems and between two soil horizons irrespective of surface organic C content. Polarization dependent NEXAFS analysis showed the oligopeptides tend to orient on mineral surface with an average tilt angle of 40 ° between the molecular chain and the mineral surface.<br>Ph. D.
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Moon, Jinyoung. "Selective accrual and dynamics of proteinaceous compounds during pedogenesis: testing source and sink selection hypotheses." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/77030.
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The emerging evidence of preferential accumulation and long residence time of proteinaceous compounds in soil are counter to the traditional view that their structure is readily broken down through microbial activity. The shift in thinking of their residence time is, however, heavily influenced by physical and chemical protections in soil, representing an important change for understanding global biogeochemical carbon and nitrogen cycling. We investigated the accumulation patterns of proteinogenic amino acids for a long term (thousands of years) related to their sources and sinks. We found clear patterns of change in the amino acids in a 4000 year-chronosequence adjacent to Lake Michigan, USA (Michigan chronosequence) and they were tightly related to the shifts in their biological sources, namely aboveground vegetative community (r2=0.66, p<0.0001) and belowground microbial community (r2=0.71, p<0.0001). Results also showed great variations of approximately 49% between seasons (summer and winter). Moreover, seasonal dynamic patterns (22% variations) of the amino acids in soil mineral associated fraction were rather counter to the conceptual view that it represents a slow soil organic pool with long residence times. The amino acids enriched in the mineral associated fraction, (e.g., positively charged, aromatic, and sulfur containing amino acids), tended to preferentially accumulate in whole soil pool during the 4000 years of ecosystem development. Their interaction with soil minerals, therefore, may play a critical role in the long-term sink and selective accumulation of proteinaceous compounds with some degree of the displacement. This was further confirmed by another chronosequence system near Haast River, New Zealand, which is geologically separated and climatically- and ecologically- different from the Michigan chronosequence. Common trends between two chronosequences suggested that either polar interactions or redox reactions may be relatively more important in the mineral interaction of amino acids than non-polar interactions. The consistency of results at two disparate locations in the southern and northern hemispheres is strong evidence that the processes of pedogenesis and ecosystem development are parsimonious and predictable. Our research demonstrated fundamental understanding of behavior of proteinaceous compounds at the molecular species level, and further provided their partitioning mechanisms associated with soil components.<br>Ph. D.
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Kothawala, Dolly N. "Controls on the soil solution partitioning of dissolved organic carbon and nitrogen in the mineral horizons of forested soils." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115565.
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Note:<br>The soil-solution partitioning of dissolved organic carbon (DOC) withinmineral soil horizons is primarily controlled by processes of adsorption and desorption. These abiotic processes largely occur within a short equilibration time of seconds to minutes, which generally occur faster than microbial processes. To characterise the adsorption of DOC to mineral soils, I used the Langmuir adsorption isotherm, which holds several advantages to the commonly used linear initial mass (IM) isotherm. One advantage to using the Langmuir isotherm is anestimation of the maximum DOC adsorption capacity (Qmax). The Qmax estimates the number of remaining DOC binding sites available on the mineral soil particle surfaces. I modified the traditional Langmuir isotherm in order to estimate the DOC desorption potential of native soil organic matter (SOC).[...]<br>Le partitionnement entre les solutions de sols du carbone organiquedissous (COD) dans les horizons des sols minéraux est essentiellement contrôle par les processus d'adsorption et de désorption. Ces processus abiotiques se déroulent normalement dans un bref temps d'équilibration variant de quelques secondes a quelques minutes, ce qui est en général plus rapide que les processus microbiens. Pour caractériser Fadsorption de COD aux sols minéraux, nous avons utilise l'isotherme d'adsorption de Langmuir. Cette isotherme présente plusieurs avantages par rapport a Fisotherme de masses initiales (IM) linéaires couramment utilisée, en particulier F estimation de la capacité d'adsorption maximale du COD (Qmax). Le Qmax estime le nombre de sites de liaison de COD restants a la surface du sol minéral. Nous avons aussi modifie Fisotherme de Langmuir traditionnelle afin d'évaluer le potentiel de désorption de COD de la matière organique du sol indigène (MOS).[...]
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Kothawala, Dolly N. 1972. "Controls on the soil solution partitioning of dissolved organic carbon and nitrogen in the mineral horizons of forested soils." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115858.
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The soil-solution partitioning of dissolved organic carbon (DOC) within mineral soil horizons is primarily controlled by processes of adsorption and desorption. These abiotic processes largely occur within a short equilibration time of seconds to minutes, which generally occur faster than microbial processes. To characterise the adsorption of DOC to mineral soils, I used the Langmuir adsorption isotherm, which holds several advantages to the commonly used linear initial mass (IM) isotherm. One advantage to using the Langmuir isotherm is an estimation of the maximum DOC adsorption capacity (Qmax). The Qmax estimates the number of remaining DOC binding sites available on the mineral soil particle surfaces. I modified the traditional Langmuir isotherm in order to estimate the DOC desorption potential of native soil organic matter (SOC).<br>Sorption characteristics were derived for a broad range of52 mineral soils collected from 17 soil profiles spanning across Canada from British Columbia to Quebec. Mineral horizons with the greatest Qmax included the Fe-enriched B horizons of acidic Podzols and Volcanic soils, followed by B horizons not enriched in Fe, followed by A and C horizons. Podzol B horizons were distinct from all other horizons due to significantly higher desorption potential. Soil properties predicting the adsorption characteristics of DOC also predicted the adsorption characteristics of dissolved organic nitrogen (DON). Adsorption of DOC and DON was tightly coupled (R 2 = 0.86), however the ratio of DOC:DON in the final equilibrium solution lowered for 48 out of 52 minerals horizons. These results suggest that DON may be slightly more mobile than DOC.<br>A short-term (32 day) incubation was perform to establish the fate of indigenous soil C, relative to newly adsorbed soil C to four mineral soils with different adsorption characteristics. Soil columns were leached periodically and sampled for DOC and CO2 production. Two Fe-enriched mineral horizons with high adsorption capacity released low amounts of old SOC, yet released almost all of the newly adsorbed SOC. In contrast, two B horizons without Fe-enrichment released greater amounts of old SOC, and retained a greater fraction of the newly adsorbed SOC than the Fe-enriched horizons. These results identify a contrast between the fate of indigenous and newly adsorbed SOC on mineral soils with differing Qmax.<br>The final component of this study examined changes to the molecular structure of DOC after equilibration with mineral soils. Multiple techniques were used to assess changes in the molecular composition of DOC, including the analysis of aromatic content by specific UV absorbance (SUVA) and fluorescence spectroscopy, analysis of molecular weight distribution (MWD) with high performance size exclusion chromatography (HPSEC) and functional group analysis with Fourier transform infra-red spectroscopy (FTIR). The solution phase DOC generally showed a reduced aromatic content, along with the removal of organic compounds with carboxyl groups. The MWD of DOC was reduced after equilibration to mineral soils, and the reduction in average molecular weight was related to the Qmax of mineral soils.<br>The various components of this thesis have contributed to the overall understanding of controls on the adsorption of DOC and DON species to mineral soils of the Canadian temperate and boreal forest.
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Svoboda, Ilona. "Základní charakterizace vybraných vzorků krmiv živočišného původu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240518.
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The aim of the diploma thesis was to choose poper parameters for a quick and simple characterization of animal feed, to verify working procedures and to apply these on chosen samples. Within the scope of this work, samples of animal dog feed produced in a private company „Adamkovy tlacenky“ were analyzed. The feed is in the form of brawn, stored in artificial casing; it consists of up to 80% of animal components and up to 20% of vegetable components, while the rest of the weight is the pork gelatine. The feed does not contain preservatives, colourings as well as any other chemically produced additives. For the analysis three formulas were chosen: "Hovězinka", "Kuřátko" and "Srdcovka", the composition of which is protected by the patent. The choice was made to include samples of different composition. The content of raw crude protein, fat, fibre, dry basis, and ash was determined. The obtained values were compared with the standards for feed normally utilized by the feed industry. The results will be used to improve the formulas and to develop new types of feed.
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Sun, Chaode. "Syntheses and reactivities of [pi]-electron rich phosphorus-nitrogen and sulfur-nitrogen ligands." HKBU Institutional Repository, 1999. http://repository.hkbu.edu.hk/etd_ra/140.
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Lipton, Catherine Elizabeth. "Studies on caged nitrogen compounds." Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407949.
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Cui, Jian. "Synthesis and characterization of new boron-nitrogen and boron-nitrogen-phosphorus systems." [Fort Worth, Tex.] : Texas Christian University, 2009. http://etd.tcu.edu/etdfiles/available/etd-03162010-123538/unrestricted/Cui.pdf.
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Willison, Toby W. "Mineral nitrogen dynamics of a lowland spruce plantation." Thesis, University of Exeter, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305755.
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Burnett, Duane Arthur. "Synthesis of nitrogen containing heterocycles /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487264603219377.
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Ocando, Mavarez Edgar. "Phosphonitriles, nouveaux synthons en chimie heterocyclique." Toulouse 3, 1988. http://www.theses.fr/1988TOU30069.
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Saunders, Eleanor Margaret. "The effect of mineral nitrogen on ectomycorrhizas with special reference to nitrogen deposition." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299547.
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Matuska, Vit. "Five-membered sulfur-nitrogen ring compounds." Thesis, St Andrews, 2009. http://hdl.handle.net/10023/828.
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Brahme, K. C. "Studies in organic compounds containing nitrogen." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1987. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3282.
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Khatiwada, Raju, and Raju Khatiwada. "Mineral Surface-Mediated Transformation of Insensitive Munition Compounds." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621565.
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Abiotic transformation of compounds in the natural environment by metal oxides plays a significant a role in contaminant fate and behavior in soil. The ability of birnessite, ferrihydrite and green rust to abiotically transform insensitive munitions compounds (IMCs) parent (2,4 dinitroanisole [DNAN] and 3-nitro-1,2,4-triazol-5-one [NTO]), and daughter products (2-methoxy-5-nitro aniline [MENA], 2,4-diaminoanisole [DAAN]of DNAN; and 5-amino-1, 2, 4-triazol-3-one [ATO] of NTO) was studied in batch reactors under strictly controlled pH and ionic strength. The objectives of the study were to (i) assess the abiotic transformation potential of soluble DNAN, MENA, DAAN, NTO and ATO by birnessite, ferrihydrite and green rust, and (ii) identify inorganic reaction products. The study was carried out at metal oxide solid to IMC solution ratios (SSR) of 0.15, 1.5 and 15 g kg⁻¹ for birnessite and ferrihydrite and 10 g kg⁻¹ for green rust. Aqueous samples were collected at time intervals between 0 to 3 days after the reaction initiation and analyzed using HPLC with UV detection. Results indicated that DNAN was resistant to oxidation by birnessite and ferrihydrite at given solid to solution ratios. MENA was susceptible to rapid oxidation by birnessite (first order rate constant, 𝑘=1.36 h⁻¹ at 15 g kg⁻¹ SSR). The nitro groups from MENA largely mineralized to nitrite (NO₂⁻). In contrast, ferrihydrite did not oxidize MENA. DAAN was susceptible to oxidation by both birnessite and ferrihydrite, but about a six times higher oxidation rate was observed with birnessite (𝑘=1.18 h⁻¹) as compared to ferrihydrite (𝑘=0.22 h⁻¹) at an SSR of 1.5 g kg⁻¹. There was a complete loss of DAAN from solution after 5 min with birnessite at an SSR 15 g kg⁻¹ (𝑘≥90.5 h⁻¹). CO₂ evolution experiments indicate mineralization of 15 and 12 % of carbon associated with MENA and DAAN, respectively; under aerobic conditions with birnessite at an SSR of 15 g kg⁻¹. NTO was resistant to oxidation by birnessite and ferrihydrite at any SSR; however, there was slight initial loss from solution upon reaction with ferrihydrite at 0.15 and 1.5 g kg⁻¹ SSR and complete loss at 15 g kg⁻¹ SSR due to adsorption. ATO was susceptible to oxidation by birnessite and sorption by ferrihydrite. The first order rate constants (𝑘) for ATO with birnessite at 0.15 and 1.5 g kg⁻¹ SSR are 0.04 and 3.03 h⁻¹ respectively. There was complete loss of ATO from solution with birnessite at 15 g kg⁻¹ SSR (𝑘 ≥ 90.2 h⁻¹) within 5 min of reaction. Transformation products analysis revealed urea, CO₂ and N₂ as major reaction products with 44 % urea recovery and recovery of 51.5 % of ATO carbon as CO₂ and 47.8 % of ATO nitrogen as N₂ at 15 g kg⁻¹ SSR. The oxidation of ATO in the presence of birnessite was found to be independent of dissolved O₂. The results indicate that ATO, the major reductive (bio)transformation product of NTO, is readily oxidized by birnessite in soil. NTO was found strongly sorbed to ferrihydrite as compared to that of ATO. The results of the green rust experiment indicate rapid abiotic reduction of parent compounds NTO and DNAN to their reduced aminated daughter products. NTO was generally reductively transformed to 5-amino-1, 2, 4-triazol-3-one (ATO) within 10 min and completely reacted in 20 min. DNAN was rapidly transformed to its reduced daughter products MENA and 4-methoxy-5-nitroaniline (iMENA). The reduction occurred with a distinctive, staggered regioselectivity. Over the first 10 min, the para-nitro group of DNAN was selectively reduced, generating iMENA. Thereafter the ortho-nitro group was preferentially reduced, generating MENA. Both iMENA and MENA were subsequently transformed to the final reduction product DAAN within 1 day. X-ray absorption near edge spectroscopy data suggested oxidative transformation of green rust to lepidocrocite-like mineral forms, accounting for 94 % of the mineral products in the case of NTO reaction as compared to 62 % in the case of DNAN. The results taken as whole suggest that complete abiotic transformation of IMCs could be achieved by coupled stepwise green rust and birnessite treatments.
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Liang, Jianglin, and 梁江林. "Ruthenium-catalyzed carbon-nitrogen bond formations." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31245729.
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Hutley, T. J. "Structure-property relationships mineral-filled thermoplastics." Thesis, Cranfield University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380475.
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Williams, Christopher Ian. "A computational study of nitrogen heterocyclic compounds." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq30417.pdf.
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Kelly, P. F. "Sulphur-nitrogen compounds of platinum and palladium." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/46826.
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Merwin, Lawrence Hale. "NMR of solid phosphorus and nitrogen compounds." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/1683/.
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Brooks, George Benjamin Jr. "Dissolved Nitrogen Compounds in Integrated Aquaculture Effluent." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208657.
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Integrated aquaculture utilizing pre- irrigation water will hypothetically increase the levels of dissolved nitrogen products in the resulting effluent. Research was performed to assess the levels of additional nutrients added. The results suggest however, that integrated aquaculture may reduce the amount of nitrogen as nitrate applied to the fields.
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Yang, Yi. "Fluorinated Nitrogen Compounds : Design, Synthesis and Applications." Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10218.
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L'objectif de cette thèse est de développer de nouvelles méthodes et de nouveaux réactifs pour l'incorporation de groupes fluorés qui ont une large gamme d'applications dans les domaines agrochimiques et pharmaceutiques. Plus précisément, nous avons établi un nouveau programme de recherche axé sur la synthèse et la valorisation de groupes fluorés contenant de l'azote. Dans le chapitre 1, nous présentons une nouvelle méthode douce et efficace pour la synthèse de N-((trifluorométhyl)thio)-N-(trifluorométhyl)amines à partir d'isothiocyanate et de réactifs trifluorométhylthio électrophiles. En outre, nous avons démontré que le PhPh-N-(SCF3)(CF3) peut être utilisé comme réactif SCF3 électrophile et comme précurseur de radicaux SCF3 dans des réactions avec divers nucléophiles. Nous l'avons également utilisé avec le 4CzIPN comme photocatalyseur organique pour générer des radicaux SCF3 sous l'irradiation de LED bleues. Le chapitre 2 se concentre sur la conception de nouveaux moyens d'accès aux blocs de construction N-SF5. Ces structures peuvent être utilisées comme des réactifs de longue conservation pour l'incorporation de motifs SF5, ce qui constitue une alternative intéressante aux méthodes actuelles de pointe qui reposent sur l'utilisation de Cl-SF5 toxique avec une réactivité limitée.Nous avons conçu avec succès de nouveaux réactifs N-SF5 de longue conservation et démontré leur efficacité dans le transfert de motifs SF5 pendant la photo-oxydation<br>The aim of this thesis is to develop novel methods and reagents for incorporating fluorinated motifs, which have numerous applications in both agrochemicals and pharmaceuticals. Specifically, we established a new research program focused on the synthesis and valorization of nitrogen-containing fluorinated motifs. In Chapter 1, we present a novel, mild, and efficient protocol for synthesizing N-((trifluoromethyl)thio)-N-(trifluoromethyl)amines from isothiocyanates and an electrophilic trifluoromethylthiolation reagent. Additionally, we demonstrated that PhPh-N-(SCF3)(CF3) serves as an electrophilic SCF3 reagent and a precursor to SCF3 radicals, reacting with various nucleophiles. We also used it with 4CzIPN as an organophotocatalyst under blue LED irradiation to generate SCF3 radicals. Chapter 2 focuses on designing new routes to access N-SF5 building blocks. These structures can serve as shelf-stable reagents for incorporating the SF5 motif, offering an attractive alternative to the current state-of-the-art method, which relies on the use of toxic Cl-SF5 with limited reactivity. We successfully designed new shelf-stable N-SF5 reagents and demonstrated their efficiency in transferring SF5 motifs under photoredox processes
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Zaccaro, Julien. "Cristallogénèse et caractérisations de la solution solide dihydrogénophosphate-arseniate de 2-amino-5-nitropyridinium, cristaux organo-minéraux pour l'optique non linéaire." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10069.
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Les cristaux organo-mineraux sont un compromis avantageux entre l'efficacite optique non lineaire (onl) des molecules organiques et la stabilite des cristaux mineraux. La possibilite d'obtenir des solutions solides par substitution de la part minerale est un atout supplementaire que nous avons illustre dans le cas du systeme dihydrogenophosphate-arseniate de 2-amino-5-nitropyridinium (2a5npdp#(#1##x#)as#x (0 x 1)). Nous avons elabore des cristaux de grande taille (cm#3) pour l'ensemble de la solution solide. La realisation de cristaux homogenes en composition a necessite le developpement d'une technique originale de croissance par gradient vertical de temperature. Les premiers resultats obtenus par epitaxie en phase liquide prouvent qu'il est possible de realiser des couches guidantes en deposant une composition de la solution solide sur une autre. La croissance rapide de cristaux (environ 1 cm/jour) mise au point montre la possibilite d'appliquer cette technique a l'ensemble des cristaux hybrides ce qui pourrait etre un point decisif pour l'application eventuelle de ces materiaux. Les differentes techniques de caracterisation de la qualite cristalline (diffraction des rx topographie aux rx et spectroscopie d'absorption) ont permis de mettre clairement en evidence la relation existant entre la purete des cristaux, leur qualite cristalline et leur fenetre de transparence. Grace aux caracterisations optiques, nous avons pu preciser la contribution du chromophore organique aux proprietes optiques lineaires et non lineaires des cristaux de 2a5npdp#(#1#-#x#)as#x. La fenetre de transparence est limitee vers l'uv par la transition a transfert de charge du chromophore et les indices de refraction evoluent peu avec la substitution de la part minerale. L'efficacite onl et electro-optique a ete trouvee elevee et constante pour toute la solution solide ce qui montre que les proprietes onl quadratiques sont majoritairement conditionnees par la part organique de la structure hybride.
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Su, Jinghan. "Nitrogen fertilization and soil mineral nitrogen dynamics to optimize canola yield and nutrition in Québec." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=117231.
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Canola is an ideal feedstock for biodiesel production because of its high oil and low saturated fat concentrations. There is interest in producing more canola in Québec, but producers lack fertilization guidelines to optimize high oilseed yield and quality in canola. Nitrogen (N) is the most important determinate of oilseed yield and quality and N fertilization is important for biomass accumulation during the early vegetative stage and for oil synthesis during the reproductive stage. The first objective of this study was to monitor soil mineral N (NO3-N + NH4-N) dynamics and canola straw nutrition in response to N fertilization. Two fertilization methods - a pre-plant and split application of fertilizer N were studied at the Emile A. Lods Agronomy Research Centre on the Macdonald Campus of McGill University at Ste-Anne-de-Bellevue, Québec, using a fractional factorial experimental design. The second objective was to evaluate N use efficiency (NUE) and harvest index (HI) of canola grown in pots containing soils from Ste-Anne-de-Bellevue, St-Augustin-de-Desmaures and Ottawa using a completely randomized design. Split application of a sidedressed N fertilizer did not increase the post-harvest soil mineral N concentration or increase straw nutrition compared with the pre-plant N application. There was considerable spatio-temporal heterogeneity in soil mineral N dynamics, so additional field trials are warranted. The pot study showed inconsistent correlations between straw N concentration and yield in canola grown in the soils collected from Ste-Anne-de-Bellevue (not related), St-Augustin-de-Desmaures (negative), and Ottawa (positive). Straw N concentrations were related to low straw and oilseed yield, indicating there is an optimal straw N concentration to achieve target yields. Seeding in late May and disease occurrence close to the end of flowering stage reduced the oilseed yield more than straw yield. Future research on the pattern of N translocation (e.g.: from leaf to pod, then to oilseed) under Québec climatic conditions will contribute to the development of an N fertilization guideline. Since some soils in Québec have an appreciable soil N supply, knowledge of how much soil N is used to meet canola N requirement will keep N fertilizer costs low while optimizing oilseed yield and quality.<br>Le canola est une matière première idéale pour la production de biocarburant car il a une teneur élevée en huile et basse en gras saturés. Au Québec, les producteurs sont intéressés à cultiver davantage de canola, mais font face à un manque de directives en matière d'engrais nécessaire afin d'obtenir un haut rendement d'huile de qualité à partir du canola. L'azote (N) est chez les oléagineux le facteur le plus important déterminant le rendement et la qualité de l'huile; l'engrais azoté est important pour l'accumulation de biomasse pendant le premier stade végétatif et pour la production d'huile pendant le stade reproductif. Le premier objectif de la présente étude a été de suivre l'évolution de la dynamique de l'azote minéral du sol (NO3-N + NH4-N) et la nutrition de la paille de canola en réponse à l'engrais azoté. Deux méthodes de fertilisation – fertilisation en présemis et fertilisation partagée fractionnée ont été étudiées au Centre de recherche agronomique Emile A. Lods, au campus Macdonald de l'université McGill à Ste-Anne-de-Bellevue, Québec, utilisant un plan d'expérience factoriel fractionnel. Le deuxième objectif a été d'évaluer l'efficacité d'utilisation de l'azote (NUE) et l'indice de récolte (HI) du canola cultivé en pots avec du sol provenant de Ste-Anne-de-Bellevue, de St-Augustin-de-Desmaures et d'Ottawa, utilisant un plan d'expérience entièrement aléatoire (conception de bloc complètement randomisé). La fertilisation fractionnée et l'application d'azote en bande avec de l'engrais azoté de couverture n'a pas augmenté la concentration d'azote minéral du sol après-récolte, ni la nutrition de la paille de canola comparativement à la fertilisation azotée précoce (see correction above for précoce). Dû à l'importante hétérogénéité spatio-temporelle de la dynamique de l'azote minéral du sol, des études sur le terrain additionnelles sont à recommander. L'étude des plants en pots a démontré une corrélation linéaire négative entre la concentration en azote de la paille et le rendement de la paille. Les concentrations en azote de la paille ont été corrélées avec des bas rendements de paille et d'huile, indiquant qu'il existerait une concentration idéale de l'azote de paille pour obtenir les rendements visés. Certains facteurs réduisent la qualité de l'huile ainsi que le rendement de la paille, soit de semer vers la fin mai ainsi que les maladies qui apparaissent lors de la floraison. D'autres études sur la translocation de l'azote (p. ex. de la feuille à la gousse, puis à la graine) sous les conditions climatiques du Québec contribueront au développement des directives en matière de fertilisation azotée. Puisque certains sols du Québec ont des réserves appréciables d'azote du sol, connaître la quantité d'azote du sol nécessaire afin de satisfaire aux besoins en azote du canola permettra de maintenir de bas coûts pour l'engrais azoté, ainsi que d'optimiser le rendement et la qualité de l'huile des oléagineux.
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Griffis-Kyle, Kerry L. "The effects of mineral nitrogen on embryonic and larval amphibians." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://proquest.umi.com/login?COPT=REJTPTU0NWQmSU5UPTAmVkVSPTI=&clientId=3739.
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區逸貫 and Yat-kun Au. "Chemical reactivities of triosmium carbonyl clusters with nitrogen heterocycles and organomercurials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31234604.
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Au, Yat-kun. "Chemical reactivities of triosmium carbonyl clusters with nitrogen heterocycles and organomercurials /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17490340.
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Fowbert, John A. "Nodulation and nitrogen fixation by white clover (Trifolium repens L.) in the presence of mineral nitrogen." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329349.
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Judd, M. C. "The reactions of aromatic compounds with nitrogen dioxide." Thesis, University of Canterbury. Chemistry, 1989. http://hdl.handle.net/10092/8578.
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In the first part of this thesis the reactions of 3,4,5-trimethylphenol (58), 3,4-dimethylphenol (71) and 4-methylphenol (88) with nitrogen dioxide in benzene, and in dichloromethane, are investigated. These phenols are unsubstituted at C2 and C6. Typically the products of the reaction are 2,6-dinitrophenols, and 4-nitro or 4-hydroxy cyclohexa-2,5-dienones. The mode of formation of these compounds is described.
In the second part of this thesis 3,4,5-trimethylbiphenyl (91) and 2,3,4- trimethylbiphenyl (92) were treated with nitrogen dioxide in benzene. Reaction of 3,4,5-trimethylbiphenyl (91) gave ring nitrated biphenyls [(97), (98) and (99)], nitromethylbiphenyl (100) and ring nitrated nitromethyl biphenyls [(101), (102) and (103)]. In contrast reaction of 2,3,4-trimethylbiphenyl (92) gave nitratomethylbiphenyls [(111), (112) and (113)] and ketones [(117) and (118)] in addition to the ring nitrated biphenyls [(114), (115) and (116)]. The mode of formation of these compounds is described.
In the third part of this thesis the reaction of phenanthrene (130) with nitrogen dioxide in benzene was carried out. This reaction gave the novel isomeric nitro nitrates [(135) and (136)] in addition to the dimeric nitro nitrate (132) and nitrophenanthrenes [(131), (133) and (134)]. An overall mechanistic scheme for the formation of these compound is proposed.
Throughout this thesis, extensive use is made of high field Fourier transform n.m.r. techniques and in three cases single crystal X-ray structure analyses were necessary for structure determinations.
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Philbin, Simon Patrick. "Studies of novel nitro-substituted nitrogen heterocyclic compounds." Thesis, Brunel University, 2001. http://bura.brunel.ac.uk/handle/2438/2165.
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The novel candidate high energy insensitive explosive; 2,5-diamino-3,6-dinitropyrazine (ANPZ-i) has been prepared in acceptable overall yield. ANPZ-i was synthesised by the nitration of 2,5-diethoxypyrazine using nitronium tetrafluoroborate (NO2+BF4-) in sulfolane and the subsequent amination of 2,5-diethoxy-3,6-dinitropyrazine, under autoclave conditions. Oxidation studies towards the dioxide derivative of ANPZ-i, 2,5-diamino-3,6-dinitropyrazine-1,4-dioxide (PZDO), were unsuccessful. The synthesis of existing high explosives; 2,6-diamino-3,5-dintropyrazine (ANPZ) and 2,6-diamino-3,5-dinitropyrazine-1-oxide (PZO) has been scaled up to produce approximately 25 g batches of material. A number of novel nitrations using NO2+BF4- have been carried out on a range of chloro-, methyl- and hydroxy-functionalised quinoxalines and quinazolines. A range of novel functionalisations have also been carried out on the platform molecule; 2,4-diamino-6,8-dinitroquinazoline giving rise to 2,4-diamino-6,8-dinitroquinazoline-1,3-dioxide (di-N-oxidation product), 2,4,7-triamino-6,8-dinitroquinazoline (monoamination product) and 2,4,6,8-tetra-aminoquinazoline (dihydrogenation product). Detonics molecular modelling was carried out on the following target molecules: 2,5-diamino-3,6-dinitropyrazine-1,4-dioxide (PZDO), 2,5,8-triamino-3,6,7-trinitroquinoxaline-1-oxide and 2,5,7-triamino-4,6,8-trinitroquinazoline-1-oxide. The detonation velocity of the new explosive molecule; 2,5-diamino-3,6-dinitropyrazine (ANPZ-i) was calculated and it was found to be a similar value to that obtained experimentally for the existing high explosive RDX. Calculation by molecular modelling of the steric energies of ANPZ, PZO, ANPZ-i and PZDO gave a quantitative assessment of the difficulty in oxidising ANPZ-i to give PZDO. Extensive analysis of carbon-13 NMR spectroscopy shift values was carried out for approximately twenty nitrogen heterocyclic compounds. Comparison of shift values indicated consistency in the interpretations. On-line literature searches have shown that the following compounds prepared in this project are new: 2,3,6-trichloro-5-nitroquinoxaline, 2,3-dimethoxy-6,7-dinitroquinoxaline, 2,3,6-trichloroquinoxaline-1-oxide, 2,4-diamino-6,8-dinitroquinazoline-1,3-dioxide, 2,4,7-triamino-6,8-dinitroquinazoline and 2,5-diamino-3,6-dinitropyrazine (ANPZ-i). Furthermore, new synthetic routes have been used in the preparation of the following compounds: 2,3-dichloro-5-nitroquinoxaline, 2,3,6,7-tetrachloro-5-nitroquinoxaline, 2-hydroxy-6-nitroquinoxaline, 2-hydroxy-3-methyl-6-nitroquinoxaline and 2,5-diethoxy-3,6-dinitropyrazine.
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Jones, R. "Structural studies of sulphur-nitrogen compounds and complexes." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47128.
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Montgomery, J. "Synthesis and chemistry of novel bridgehead nitrogen compounds." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/24991.
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Four isomers of pyridpyrrolizinones were made by FVP of the appropriately substituted pyrrole pyridine esters. The mechanism of the cyclisation is believed to follow the cascade mechanism. The structure of two of the ismoers has been confirmed by X-ray crystallography, the NMR properties of all four ismoers is also discussed in detail. The chemistry of 9-azapyrrolo[2,l-a]isoindol-5-one was also investigated, it was shown to undergo ring opening with LAH the product of which can then be repyrolysed to give a pyridopyrrolizine. Ring opening also occurs in methanol to give a nicotinate and the pyrrole ring can be hydrogenated to give a tetrahydropyridopyrrolizinone. The synthesis of pyrrolizin-l-one has been achieved by the FVP of methyl-3- (pyrrol-1-yl)-acrylate over W03 catalyst, the reaction is believed to proceed via an intramolecular electrophilic substitution reaction. The chemistry of pyrrolizin-l-one was investigated, reaction with nucleophiles proceeds via addition across the enone double bond. When a nitrogen nucleophile is used ring opening occurs. Hydrogenation occurs at the enone bond to give a dihydrpyrrolizin-l-one. Pyrrolinzin-l,3-dione was made by the oxidation of l-hydroxypyrrolizin-3-one using pyridinium dichromate. The dione shows ketone properties (eg. Formation of DNP derivative) and, in common with other pyrrolizinones, the lactam unit is readily ring opened by methanol under basic conditions. The active methylene unit of pyrrolinine-l,3dione couples readily with diazonium salts to provide a hydrazone whose structure was confirmed by X-ray crystallography. It also reacts with methoxymethylene Meldrum's acid to give a Meldrumsated pyrrolizine-l,3-dione whose FVP at 700 c gives a pyronopyrrolizinine. Reaction of pyrrolizine-l,3-dione with DMF acetal gives the 2-dimethylaminomethylene derivative which exists as a mixture of rotomers at room temperature. 8-Azaindolizine was made by FVP of DBN over a W03 catalyst. 8-Azaindolizine shows reactivity towards electrophiles in substitution reactions at the 3-position. It also reacts with methoxymethylene Meldrum's acid to give a Meldrumsated derivated whose FVP at 950 C reacts with 3-t-butyl-4-[l-methoxymethylene]-4H-isoxazol-5-one to give a isoxazolone whose FVP at 950 C gives a cyclazine.
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DeGraffenreid, Allison Lynne. "Studies on boron - nitrogen and boron - gadolinium compounds." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1294835746.
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Lee, Ho-man. "Design, synthesis, luminescene and photochromic studies of dithienylethene-containing nitrogen and mixed nitrogen-oxygen donor ligands and their complexes." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B41757890.
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Lee, Ho-man, and 李浩文. "Design, synthesis, luminescene and photochromic studies of dithienylethene-containing nitrogen and mixed nitrogen-oxygen donorligands and their complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B41757890.
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Li, Yang. "Octacalcium phosphate-metabolite composites : model compounds for bone mineral structure." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274877.
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Bone turnover has important impacts on bone health. The process modifies weak primary woven bone into the strong lamellar bone, repairs damage in bone, and maintains appropriate calcium homeostasis. The process relies heavily on controlled osteoclastic resorption by dissolution of mineral in the area undergoing remodelling. Bone degenerative diseases occur when the balance between bone resorption and deposition of new bone in the turnover process is altered. Bone is a nanocomposite material composed of a mineral phase (calcium phosphate) deposited within an organic matrix. In spite of the intensive research on the subject, the precise molecular structure of the bone mineral is still an open question. The incorporation of citrate within the mineral structure introduced by Davies et al has provide a more comprehensive structural model that could explain many observations in terms of the mineral structure. Based on this new structural model, a hypothesis has been proposed: that other metabolites similar to citrate can be incorporated into the mineral structure, and differences in metabolite incorporation cause fundamental differences in the physical properties of bone mineral. Thus understanding the effect of metabolite incorporation on the physical properties of bone mineral will lead to insight into the molecular mechanisms of bone degenerative diseases and provide a link between bone quality and bone cell function that is currently missing. Chapter 1 provides overview of the bone composite and formation, and changes in its properties during ageing. The development of the mineral structural model is described and the shortcoming of existing models are assessed. Chapter 2 introduces the theoretical foundations of solid-state NMR spectroscopy, which is the primary analytical method employed in this study, followed by specific experimental techniques that have been used in this work. Chapter 3 described the characterisation of seven different OCP-metabolite composites that have been synthesized in this work, and proposes possible structural model for these composites based on an NMR crystallography approach to determine a structural model for one of the synthetic OCP-metabolite compounds, OCP-SUC. In Chapter 4, the dissolution rate of OCP-metabolites is measured in acidic solution to mimic the resorption process by osteoclasts and assess the possible effects of different incorporated metabolites on the solubility of bone mineral. Finally, Chapter 5 summarises the conclusions from the work and suggests the next steps that arise from this work to uncover the complete molecular structure of bone mineral and its variability in disease.
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Pan, Bo. "Mineral nitrogen inhibition and signal production in soybean - B. Japonicum symbiosis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0029/NQ64635.pdf.
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Pan, Bo 1963. "Mineral nitrogen inhibition and signal production in soybean-B. japonicum symbiosis." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36670.
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In the N2 fixing legume symbiosis, mineral nitrogen (N) not only decreases N2 fixation, but also delays and inhibits the formation and development of nodules. The purposes of this thesis were to elucidate the role of signaling in the mineral N effects on nodulation and nitrogen fixation in soybean [Glycine max (L.) Merr.] and to attempt to find ways to overcome this inhibition. The responses of soybean plants, in terms of daidzein and genistein synthesis and exudation, to different mineral N levels were studied. Daidzein and genistein distribution patterns varied with plant organs, mineral N levels, and plant development stages. Mineral N inhibited daidzein and genistein contents and concentrations in soybean root and shoot extracts, but did not affect root daidzein and genistein excretion in the same way. In both synthesis and excretion, daidzein and genistein were not affected equally by mineral N treatments. Variability existed among soybean cultivars in the responses of root daidzein and genistein contents and concentrations to mineral N levels. The amount of daidzein and genistein excreted by soybean roots did not always correspond to the daidzein and genistein contents and concentrations inside the roots. On the Bradyrhizobium japonicum side, nod gene expression was inhibited by mineral nitrogen. Genistein was used to pre-incubate B. japonicum cells or was applied directly into the plant growing medium. The results showed that genistein manipulation increased nodule weight and nodule nitrogen fixation under greenhouse conditions, but interactions existed among soybean cultivars, genistein concentrations and nitrate levels. Similar results were found under field conditions. Soybean yield was increased on sandy-loam soil by preincubation of B. japonicum cells with genistein. Addition of genistein beginning at the onset of nitrogen fixation also improved soybean nodulation and nitrogen fixation. Soybean cultivars had different sensitivities to genistein additi<br>Other studies also show that temperature affected genistein and daidzein content and concentration in soybean roots. The effect of temperature varied among soybean cultivars. Some PGPR strains can mitigate the negative effects of nitrate on soybean nodulation and nitrogen fixation, however, this is influenced by soybean genotype. Applying PGPR together with genistein preincubation of B. japonicum cells improved soybean nodulation and increased yield. The level of improvement varied among soybean cultivars and PGPR strains. Preincubation of B. japonicum cells with genistein improved strain competitiveness under greenhouse, but not field conditions.<br>Overall, these findings suggested that both plant-to-Bradyrhizobium and Bradyrhizobium-to-plant signals play important roles in the effects of mineral N on nodulation and N fixation. Signal manipulation could partially overcome the inhibitory effects of mineral N on soybean- B. japonicum N fixation symbiosis.
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Mketsu, Moses Clive Masisange. "Screening for subtate tolerant Geobacillus pallidus RAPc8 nitrile hydratase." Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1166_1307514664.
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<p>In this study G. pallidus RAPc8 NHase mutants were screened for reduced substrate inhibition compared to the wild type enzyme. Wild type and mutant enzymes were expressed and purified using hydrophobic interaction chromatography. Amidase coupled enzyme stop assays were conducted using 3-cyanopyridine as a substrate, whereas continuous enzyme kinetics were conducted using acrylonitrile as a substrate.</p>
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Kowlessur, Parikshant. "Engineering homoaromatic substrate specificity into aliphatic-specific Geobacillus pallidus RAPc8 nitrile hydratase." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9829_1297833530.
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<p>Geobacillus pallidus RAPc8 is a thermophilic nitrile-degrading isolate, obtained from thermal sediment samples of a New Zealand hot spring. The G. pallidus RAPc8 NHase gene has been cloned and expressed in E. coli. The recombinant NHase exhibits nitrile-degrading activity at 50 °<br>C, capable of degrading branched, linear and cyclic heteroaromatic nitrile substrates. However, no activity was found on homoaromatic nitrile substrates such as benzonitrile. In the present study, high levels of activity on benzonitrile were detected with a double mutant &beta<br>F52G&beta<br>F55L. Kinetic analysis on the mutant enzyme showed an 8-fold decrease in KM with benzonitrile (0.3mM) compared to acrylonitrile (2.6mM). Specificity constants (kcat/KM) of 5900 and 450 s-1.mM-1 were obtained for the double mutant on benzonitrile and acrylonitrile respectively. The amino acid residues lining the substrate channel were identified and the geometric dimensions measured. Cavity calculations revealed a 29% increase in volume and a 13% increase in inner surface area for the substrate channel of the double mutant when compared to the wild type. Surface representation of the wild type structure revealed two extended, curved channels, which are accessible to the bulk solvent from two locations in the heterodimer. The removal of the &beta<br>F52 may have contributed to the presence of a single channel with two opposing openings across the dimers with no internal blockage. Normal Mode Analysis calculations also indicate a higher intrinsic flexibility of the mutant relative tothe wild type enzyme. The increased flexibility within the mutant NHase could have introduced a functionally relevant aromatic substrate recognition conformation</p>
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Tsui, Kin Chung. "Nitrogen incorporation in nanodiamond deposition." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21175172a.pdf.
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Thesis (M.Sc.)--City University of Hong Kong, 2005.<br>At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.
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Bebbington, Magnus W. P. "Nitrogen-directed free radical rearrangements." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:316d2379-4019-4361-937d-ff1e064f8bb9.
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This thesis describes efforts to develop new methods for the synthesis of bridged azacycles using nitrogen-directed free radical rearrangements. Free radical addition to 7-azanorbornadienes were carried out to give 7-substituted 2- azanorbornenes (Scheme a.l, X-Y = RS-H or PhSe-H). [illustration in text ...] Scheme a. 1 Nitrogen-directed homoallylic radical rearrangement via intermolecular radical addition. A conceptually novel and theoretically interesting nitrogen-directed neophyl rearrangement (Scheme a.2) was developed into a synthesis of 2- azabenzonorbornanes 2. [illustration in text ...] Scheme a.2 Nitrogen-directed neophyl-like rearrangement to 2-azabenzonorbornanes. In this case the radical 1 was generated by Barton deoxygenation of 7- azabenzonorbornanols. The effect on rearrangement of bicyclic core substitution and of aromatic ring electronics was probed in some detail, and the process was synthetically useful for a wide range of substrates. Variation of the protecting group on nitrogen was investigated and the product profiles from neophyl-like rearrangement were consistent with a process driven by the stability of a radical α to nitrogen as a result of SOMO-lone pair orbital interaction. The kinetics and mechanism of these processes are examined where appropriate, leading to estimates of rate constants for the rearrangements.
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Illesinghe, Jayamini P. M. "Synthesis and use of nitrogen heterocycles in metal mediated reactions." Monash University, School of Chemistry, 2004. http://arrow.monash.edu.au/hdl/1959.1/9637.
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Jones, Vera. "Characterisation of dissolved organic nitrogen compounds in aquatic samples." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272777.
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Kizil, Murat. "Radical reactions in the preparation of nitrogen-containing compounds." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321375.
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Hernandes, Mauricio Julio Angeles. "Catalytic supercritical water oxidation of nitrogen-containing organic compounds." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/597/.
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The results of the catalytic oxidation in supercritical water of two non-biodegradable and highly toxic nitrogen-containing organic compounds (DBU and quinoline) are presented. The reactions were studied in a tubular xed-bed reactor over three catalysts: Pt/Al\(_2\)O\(_3\), CuO/Al \(_2\)O\(_3\) and MnO\(_2\)/CuO. The effect of operating conditions, namely temperature, pressure, oxygen concentration and initial concentration of the organic compounds were studied to evaluate their influence on its removal. Reaction rates were calculated from the experimental data collected. In addition, the selectivities and stabilities of the catalysts were investigated. Before conducting the experimental study the isothermal and isobaric operation of the reactor was veried together with the complete decomposition of hydrogen peroxide to oxygen and water in the preheating section and the reproducibility of experimental data was verified. Absence of external concentration gradients was determined experimentally for each reaction. The results showed that temperature was the main controlling variable of the catalytic oxidation. On the contrary, the effect of pressure depended on the catalyst used. Increasing the concentration of the organic compound did not aect their oxidation. Meanwhile, oxygen concentration above a stoichiometric ratio of two did not considerably improve the reaction. A power-law kinetic model was proposed to quantify the oxidation reaction. Three Langmuir-Hinshelwood-Hougen-Watson reaction rates were also explored to the experimental data. In the absence of a specic reaction mechanism the kinetic data were best represented by the power-law kinetic model. CO2 was the main carbon product of the reaction with small amounts of inorganic carbon species dissolved in the liquid effluent. Meanwhile, NH\(_4\), NO\(_3\) and NO\(_2\) ions were the only nitrogen species detected in the liquid effluent. Pt/Al\(_2\)O\(_3\) proved to be the most effective catalyst because it promoted faster reactions rates, had higher selectivity towards CO2 and produced lower nitrogen species. Surface analysis of the spent catalysts identied that the loss of activity was due to the 23 reduction of surface area. Leaching of active metals and chemical changes on the surface of the active metals and support of the catalyst were found for CuO/Al \(_2\)O\(_3\) and MnO \(_2\)/CuO. To conclude, it was demonstrated that catalytic supercritical water oxidation is a feasible and effective alternative for the destruction of contaminants in water. The thesis also includes suggestions for further research to continue the development of this technology and consolidate the process at industrial scale.
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Rose, Helen Louise. "New reactions of hypervalent iodine reagents with nitrogen compounds." Thesis, Keele University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283978.
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Thompson, Vanessa R. "Covalent Protein Adduction of Nitrogen Mustards and Related Compounds." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1152.
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Chemical warfare agents continue to pose a global threat despite the efforts of the international community to prohibit their use in warfare. For this reason, improvement in the detection of these compounds remains of forensic interest. Protein adducts formed by the covalent modification of an electrophilic xenobiotic and a nucleophilic amino acid may provide a biomarker of exposure that is stable and specific to compounds of interest (such as chemical warfare agents), and have the capability to extend the window of detection further than the parent compound or circulating metabolites. This research investigated the formation of protein adducts of the nitrogen mustard chemical warfare agents mechlorethamine (HN-2) and tris(2-chloroethyl)amine (HN-3) to lysine and histidine residues found on the blood proteins hemoglobin and human serum albumin. Identified adducts were assessed for reproducibility and stability both in model peptide and whole protein assays. Specificity of these identified adducts was assessed using in vitro assays to metabolize common therapeutic drugs containing nitrogen mustard moieties. Results of the model peptide assays demonstrated that HN-2 and HN-3 were able to form stable adducts with lysine and histidine residues under physiological conditions. Results for whole protein assays identified three histidine adducts on hemoglobin, and three adducts (two lysine residues and one histidine residue) on human serum albumin that were previously unknown. These protein adducts were determined to be reproducible and stable at physiological conditions over a three-week analysis period. Results from the in vitro metabolic assays revealed that adducts formed by HN-2 and HN-3 are specific to these agents, as metabolized therapeutic drugs (chlorambucil, cyclophosphamide, and melphalan) did not form the same adducts on lysine or histidine residues as the previously identified adducts formed by HN-2 and HN-3. Results obtained from the model peptide and full protein work were enhanced by comparing experimental data to theoretical calculations for adduct formation, providing further confirmatory data. This project was successful in identifying and characterizing biomarkers of exposure to HN-2 and HN-3 that are specific and stable and which have the potential to be used for the forensic determination of exposure to these dangerous agents.
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Ho, Yee-Ping. "Some studies in nitrogen heterocyclic chemistry using Reissert compounds." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/33250.
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The thesis reports the first examples of Reissert compounds prepared from five-membered ring heterocycles. The method utilises trimethylsilyl cyanide as the key reagent in a single phase non-aqueous medium. Previous attempts to synthesise such compounds have failed because, under the conventional two phase conditions, the reaction either does not proceed or ring opening of the heterocycle occurs. Reaction of benzothiazole with an acid chloride (aliphatic, aromatic or chloroformate) and trimethylsilyl cyanide in dichloromethane has been shown to give rise to 3-acyl-2-cyano-2,3-dihydrobenzothiazoles. Eight such five-membered ring Reissert compounds have been prepared, mostly in yields exceeding 70%. The mechanistic involvement of trimethylsilyl cyanide is discussed. The novel Reissert compounds have been shown to be versatile intermediates for the further modification of the starting heterocycles.
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Lee, Jimmy Jing-Ming 1955. "Studies of Nitrogen-containing Compounds Having Pyrethroid-like Bioactivity." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc332332/.
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During recent years most of the successful developments in pyrethroids have been primarily concerned with structural or compositional variations. As a part of our continuing interest in pyrethroid insecticides, nitrogen-containing compounds having pyrethroid-like structures were synthesized. Seven prolinate compounds, N-(substituted)-phenyl-prolinates and N-carbobenzoxy-prolinates were coupled with known pyrethroid alcohols. These structural variations which "locked in" a specific conformation between the nitrogen and chiral a-carbon in the acid moiety of fluvalinate were studied to determine the influence of certain conformations on insecticidal toxicity.
The toxicity data for the prolinate compounds showed intermediate mortality against nonresistant cockroaches. It was concluded that the conformation imposed by the proline ring portion of the esters was probably close to the favored conformation for interaction of fluvalinate-like pyrethroids with the insect receptor site.
A second series of nitrogen-containing compounds, twenty-five carbamate esters resulting from the condensation of N-isopropyl-(substituted)-anilines and N-alkyl-(substituted)-benzylamines with appropriate pyrethroid alcohols were studied for insecticidal activity. These studies were conducted on pyrethroid-susceptible houseflies. Some of the carbamate esters exhibited high toxicity when synergized by piperonyl butoxide. For example, the toxicity ( LD 50 ) of O-a-cyano-3-phenoxyfaenzyl-N-a,a-dimethyl-4-bromo-benzyl carbamate was 0.012 ug/g, which is significantly greater than that reported for the potent pyrethroid, fenvalerate.
Correlations of insecticidal activity with respect to structure and conformational factors of the carbamate esters have been made. The N-isopropyl substituent decreases insecticidal activity in the N-benzyl-derived compounds, while the N-isopropyl substituent enhances activity in the N-phenyl-derived compounds. Certain substituents on the phenyl ring of both analogs greatly affect insecticidal potency of the carbamate esters. Also, some alkyl substituents (especially, a,cx-dimethyl and a-cyclopropyl groups) on the benzylic carbon of the benzylamine series enhance toxicity. The a,a-dimethyl branching of the N-benzyl carbamate approximates the steric shape given by the gemdimethyl group for conventional cyclopropane ring-containing pyrethroids. The N-benzyl compounds are significantly synergized by piperonyl butoxide, particularly those in which the carbamate nitrogen atom is mono-substituted.