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Kahmann, Cindy. "Quantifizierung von DNA-Schäden an adhaerenten Zelllinien nach Bestrahlung mit 188 Re- bzw. Röntgenstrahlung unter Zugabe von Methimazol, Nicotinamid und Perchlorat durch den Comet Assay." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1219154119996-02487.
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Kahmann, Cindy. "Quantifizierung von DNA-Schäden an adhaerenten Zelllinien nach Bestrahlung mit 188 Re- bzw. Röntgenstrahlung unter Zugabe von Methimazol, Nicotinamid und Perchlorat durch den Comet Assay." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1219154119996-02487.
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MacLean, Donald William John. "The kinetics of zinc extraction in the di(2-ethylhexyl) phosphoric acid, n-heptane-zinc perchlorate, perchloric acid, water system." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30023.
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The kinetics of zinc extraction from perchlorate solutions with di(2-ethylhexyl) phosphoric acid in n-heptane have been measured using the rotating diffusion cell technique.
The extraction of zinc is controlled by the mass transfer of reactants (Zn²⁺ and D2EHPA) to the interface. At low zinc concentrations, the system is controlled by the aqueous transport of Zn²⁺ to the interface; at higher zinc concentrations transport of D2EHPA becomes rate controlling. For the range of D2EHPA concentrations examined, the transport of D2EHPA is rate controlling. Bulk pH has a negligible effect, except perhaps at the lowest pH values examined, where there may be a slight decrease in extraction rate. This decrease was attributed to less favourable thermodynamics at low interfacial pH values. It appears that the chemical reaction rate is fast enough that it has a negligible effect on the overall extraction rate. A basic mathematical model was developed which is adequate for predicting the extraction rate under variable conditions of zinc concentration, D2EHPA concentration, and pH.
The effect of using a partially loaded organic extractant was also investigated, and the system was found to be mass transfer controlled. An extended mathematical model was developed which predicts that the speciation of organic complexed zinc changes with increasing preload, and at high loadings the direction of ZnL₂HL and ZnL₂(HL)₂ flux reverses, with these species providing extractant to the interface. At very high loadings, ZnL₂HL provides almost all the extractant to the interface.
Experimental studies of the effect of temperature on the rate of zinc extraction resulted in a calculation of the activation energy which was consistent with a diffusion controlled mechanism. Finally, the effect of different filter pore sizes on extraction was examined. The extraction rate decreases significantly with a very small filter pore size, while there appeared to be little or no effect for larger filter pore sizes. For the filter pore size used in this study, it was therefore concluded that the filter pores do not pose an additional resistance to mass transfer.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
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Ahn, Se Chang. "Removal of perchlorate in ammunition wastewater by zero-valent iron and perchlorate respiring bacteria." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 138 p, 2008. http://proquest.umi.com/pqdweb?did=1601522481&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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He, Yuanyuan. "Search for organic compounds with MTBSTFA/DMF derivatization and TMAH thermochemolysis on Mars." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPAST003.
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La recherche de biosignatures sur Mars fait parti des sujets scientifiques populaire à la fois dans le grand publique mais également au sein de notre communauté scientifique. Les instruments Mars Organic Molecule Analyzer (MOMA) et Sample Analysis at Mars (SAM) respectivement à bord des rovers Rosalind Franklin (Exomars 2022) et Curiosity (Mars Science Laboratory), sont capables de détecter la matière organique présente en surface et subsurface à des concenrtations inférieures au ppb. Afin d’identifier la matière organique, ces deux instruments utilisent la pyrolyse couplée à de la chromatographie gazeuse couplée à la spectrométrie de masse (Pyr-GC/MS). Afin d’analyser la matière organique refractaire les agents de thermochémiolyse, le tétraméthylammonium hydroxyde (TMAH) et de foncitonnalisation, le N-tert-butyldiméthylsilyl-N-méthyltrifluoroacetamide (MTBSTFA) mélangé avec son solvant le N,N-dimethylformamide (DMF) sont utilisés. Cependant, la mise en évidence récente de composés fortement oxydant (perchlorate) à compliqué l’analyse des résultats obtenus par l’expérience SAM. En efet, le MTBSTFA/DMF, en plus de ses sous produits de décomposition peut réagir à haute température avec les perchlorates présents dans le sol martien. Le mélange MTBSTFA/DMF est donc une possible source de carbone correspondant à certains composés organiques qui ont été détectés sur Mars par SAM. Par conséquent, les sous-produits de la dégradation des réactifs avec et sans perchlorates ont été listés et référencés, et des voies possibles de dégradation des réactifs ont été proposées.La thermomchémolyse au TMAH a recemment étéutilisé à bord de SAM pour analyser un echantillon prélévé à GR. Afin d’aider à l’interprétation de ces nouveaux resultats nous avons utilisé la thermochemiolyse au TMAH pour analyser des composés organiques d’intéret pur et d’autres contenus dans des échantillons naturels. Parmis les composés organiques testés nous avons inclus des biosignatures telles que les acides deoxyribonucleique (ADN) et ribonucleique (ARN) qui ont certainement été à la base de la formation de la vie sur Terre. Nous les avons étudiées seules et encapsulées dans leur cellule afin de mimmer au plus prês leurs conditions naturelles. Les températures de thermochimolyse ont alors été étudiées et optimisées. Les bactéries extrémophiles étudiées dans ce travail comprennent les cyanobactéries (Chroococcidiopsis cubana), les anctinoctériens (Rubrobacter radiotolerans) et l’archée halophile (Halobacterium salinarum). Des fragments d’ADN ou d’ARN ont alors été détectés. Parmis eux les dérivés de l’adénine sont les plus faciles et ont la plus grande abondance par rapport aux autres nucléobases. Cependant, les principaux composés détectés dans ces échantillons naturels sont les acides gras tels que le glucopyranoside, l’un des composés détectés majoritairement dans les trois bactéries extrémophiles utilisées. Les résultats ont démontré que la thermomchémolyse au TMAH pouvait être une méthode chimique efficace pour détecter des signatures de vie sur Mars et d’autres planètes lors de futures missions spatialesSearching for life biosignatures on Mars has been a very popular topic in the world. The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in Martian samples. To identify organics, these instruments both utilize Pyrolysis-Gas Chromatography coupled to Mass Spectrometry (Pyr-GC/MS), and thermochemolysis using the reagent tetramethylammonium hydroxide (TMAH) and derivatization using a mixture of N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA) and N,N-dimethylformamide (DMF). Both thermochemolysis and derivatization help to increase organic volatility of labile and refractory compounds. However, with the detection of chloride-bearing compounds on Mars, MTBSTFA/DMF, which is leaking on SAM, was considered as a possible carbon source of some organics that have been detected on Mars. Therefore, the reagent byproducts following degradation, both in the presence of and the absence of perchlorates, are proposed as a data reference, as well as possible routes of reagent degradation.In addition to MTBSTFA, TMAH is also used to search for organic compounds that could possibly be bioindicators and biosignatures in Martian samples. Deoxyribonucleic acids (DNA) as an information carrier and ribonucleic acid (RNA) form the basis for life on Earth. However, the optimal experimental conditions for the detection of DNA or RNA fragments and other organic compounds important to Earth life were poorly understood. Therefore, in this thesis, the building blocks of nucleic acids, such as nucleobases, nucleosides, nucleotides, PolyA, andbacteria were analyzed by Pyrolysis-GC/MS with TMAH thermochemolysis using a SAM-like ramp and flash pyrolysis at different temperatures (from 100 to 600 °C). The methylated nucleobases, ribose, and phosphate were detected at the highest intensities at 200 and 300 °C, respectively. Methylated adenine and adenosine are the main thermochemolysis products of Poly A. In addition, bacteria such as E. coli were also analyzed with TMAH thermochemolysis. Results demonstrated that TMAH thermochemolysis is able to characterize the fragments of DNA and RNA even at high temperatures with a limit of detection lower than 104 cells of E.coli.TMAH thermochemolysis was also applied to analyze the organic compounds from natural samples such as bacterial cells. The important organic compounds of extremophile bacteria have been studied and the thermochemolysis temperatures were optimized. The extremophile bacteria include cyanobacteria (Chroococcidiopsis cubana), anctinobacteria (Rubrobacter radiotolerans), and halophilic Archaea (Halobacterium salinarum). DNA or RNA fragments could be detected, with Adenine-derivatives being the easiest to detect and with the highest abundance compared with other nucleobases. However, the main compounds and the most detectable organic compounds from these natural samples are fatty acids. Glucopyranoside is one of the most important target compounds from the three extremophile bacteria used herein. Results demonstrated that TMAH thermochemolysis could be an efficient chemical method to detect life signatures on other planets for future missions
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Xiao, Yeyuan. "Perchlorate reduction using salt-tolerant cultures." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/41024.
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The wide use of ion-exchange processes to remove perchlorate from drinking water creates an urgency for the regeneration or treatment of perchlorate-laden ion-exchange resins and/or regenerant brines. The use of biological processes with a salt-tolerant culture NP30 has been demonstrated as a promising cost-effective approach. In this study, the kinetics and ecology of NP30 were studied. A pure culture was isolated from the mixed culture, identified and characterized.
Perchlorate–laden ion-exchange resins were effectively regenerated by the mixed culture in laboratory batch reactors. A numerical model was developed to describe the regeneration process and for design predictions. A unique “resin phase” regeneration, in which the culture degraded perchlorate on the resin instead of only what desorbed into the bulk medium, was proposed in the model. The model generated an acceptable correlation to experimental data and the degradation from the “resin phase” accounted for the majority of the perchlorate removal.
The microbial composition of NP30 and the changes during a pilot plant experiment treating perchlorate- and nitrate-laden ion-exchange brine were analyzed using DGGE (denaturing gradient gel electrophoresis) and FISH (fluorescence in situ hybridization). Halomonas was the dominant (>18%) nitrate-reducing organism and Azoarcus/Denitromonas was the dominant (>22%) perchlorate-reducing organism. A shift towards nitrate-reducing organisms with time in the reactors was observed and attributed to the non-obvious perchlorate reduction seen in operation data.
A pure salt-tolerant, perchlorate-reducing strain P4B1 (Marinobacter multirespiro sp. nov. proposed name) was successfully isolated from the mixed culture. P4B1 could grow in the presence of 1.8%-10.2% NaCl. A molar Mg²⁺/Na⁺ ratio of ~0.11 optimized the perchlorate degradation and cell growth when perchlorate was the sole electron acceptor. It could use perchlorate, nitrate and oxygen as electron acceptors. P4B1 preferred perchlorate to nitrate as the electron acceptor. A perchlorate reductase, which is only induced by perchlorate, is active in both perchlorate and nitrate reduction. When nitrate was used as the sole electron acceptor, the strain eventually lost the ability to reduce nitrate. The maximum specific substrate utilization rate (Vm) and the half saturation coefficient (Ks) for P4B1 were determined to be 0.050 ±0.007 mg ClO₄⁻/mg VSS-hr and 22±12 mg ClO₄⁻/L respectively.
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Faccini, Johanna. "Sustainable treatment of perchlorate contaminated water." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/37677.
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Perchlorate is a stable and soluble substance that can last for decades in the
environment. Studies have shown that it can reduce iodine uptake into the thyroid gland
which is of concern for people with decreased iodine intake, pregnant women and small
children. Perchlorate is removed from drinking water using highly selective ion exchange
(IX) resins that are replaced after exhaustion and incinerated or disposed in a landfill
since there are no viable methods for regenerating them. One of the major limitations in
regeneration of these single use resins is achieving complete desorption of perchlorate.
The sustainability of treatment processes for perchlorate contaminated water can be
achieved by regenerating the exhausted resin. A study on the adsorption and desorption
equilibrium, kinetics and biological regeneration of perchlorate from a trybutylamine
strong base anion (SBA) exchange resin was conducted. Adsorption and desorption
equilibrium could be described using the Freundlich model with estimated parameters
KF = 50 (mg/g)(L/mg)1/n and n = 2.36. The calculated average perchlorate-chloride
separation factor was 4700 ± 1700 and the resin capacity was 1.4 meq/mg. The kinetics
of adsorption and desorption of perchlorate from the resin were found to be controlled by
chemisorption since a pseudo-second order rate model fit the data the best.
The results from the physical/chemical studies were then applied to model the
biological regeneration of the resin using the culture NP30. Experiments conducted with
the exhausted resin inside a membrane to avoid direct contact with the culture,
demonstrated the biological regeneration of the resin by degradation of the desorbed
perchlorate. The model was able to describe the desorption and biodegradation of
perchlorate from the exhausted resin and the results were comparable to the experimental
data. The model was found to be sensitive to the Freundlich adsorption intensity
parameter n.
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Pisarenko, Aleksey N. "Analytical Measurements and Predictions of Perchlorate Ion Concentration in Sodium Hypochlorite Solutions and Drinking Water: Kinetics of Perchlorate Ion Formation and Effects of Associated Contaminants." Oxford, Ohio : Miami University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1258154594.
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Son, Ahjeong. "Microbial reduction of perchlorate with elemental iron." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 1.83 Mb., 152 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3200522.
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Lenferink, Hendrik J. 1985. "Weakening of ice by magnesium perchlorate hydrate." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78478.
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Thesis (S.M. in Geophysics)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 21-23).
I show that perchlorate hydrates, which have been indirectly detected at high Martian circumpolar latitudes by the Phoenix Mars Lander, have a dramatic effect upon the rheological behavior of polycrystalline water ice under conditions applicable to the north polar layered deposits (NPLD). I conducted subsolidus creep tests on mixtures of ice and magnesium perchlorate hexahydrate (MP6) of 0.02, 0.05, 0.10, and 0.47 volume fraction MP6. I found these mixtures to be increasingly weak with increasing MP6 content. For mixtures with by Hendrik J. Lenferink.
S.M.in Geophysics
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HUANG, HE. "REDUCTION OF PERCHLORATE BY ZERO VALENT IRON." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131047520.
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Affouard, Frédéric. "Simulation numerique de dynamique moleculaire du perchlorate de potassium." Paris 7, 1994. http://www.theses.fr/1994PA077002.
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Le neopentane, les fullerenes et le perchlorate de potassium kc104 sont des cristaux moleculaires qui possedent une phase haute temperature dite plastique ou les centres de masse des molecules sont sur un reseau cristallin et les orientations sont dynamiquement desordonnees. Ils constituent des systemes modeles pour l'etude du desordre dans la matiere condensee. Nous avons simule un echantillon de perchlorate de potassium dans l'ensemble npt (nombre de particules, pression et temperature constants) avec des conditions aux limites periodiques, donc sans surface libre. L'utilisation d'ordinateurs a architecture massivement parallele, connection machine, a permis de simuler un systeme de grande taille (4096 molecules), sur des temps de plusieurs centaines de picosecondes. Les structures obtenues a la fois dans la phase haute temperature (cfc) et basse temperature (orthorhombique) sont compatibles avec les resultats experimentaux connus. Dans la phase plastique, on a montre que les correlations orientation-orientation entre deux ions perchlorate voisins pouvaient etre modelisees par des pseudo-spins antiferromagnetiques. Cette modelisation a permis de mettre en evidence un effet collectif de la dynamique orientationnelle. La fusion orientationnelle (c'est a dire la transition entre la phase basse temperature ou les orientations moleculaires sont fixees et la phase haute temperature ou elles sont liberees) a ete simulee en employant une technique de chauffage quasi-statique dans laquelle l'echantillon n'est jamais eloigne de l'equilibre. Une comparaison a ete faite avec un modele du mecanisme de transition
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Mahmudov, Rovshan. "Removal and destruction of perchlorate by activated carbon-based processes." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 349 p, 2009. http://proquest.umi.com/pqdweb?did=1663060171&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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ATIKOVIC, EMINA. "ANAEROBIC TREATMENT OF ARMY AMMUNITION PRODUCTION WASTEWATER CONTAINING PERCHLORATE AND RDX." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1163767781.
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Atikovic, Emina. "Anaerobic treatment of army ammunition production wastewater containing perchlorate and Rd." Cincinnati, Ohio : University of Cincinnati, 2006. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1163767781.
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Thesis (M.S.)--University of Cincinnati, 2006.Title from electronic thesis title page (viewed Jan. 29, 2007). Includes abstract. Keywords: Perchlorate, RDX, fluidized bed reactors. Includes bibliographical references.
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Lee, Chun Woo. "Perchlorate reduction using electrochemically induced pitting corrosion of zero-valent titanium." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2475.
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Rahman, Shihab. "Modélisation et simulation numérique de flammes planes instationnaires de perchlorate d'ammonium." Paris 6, 2012. http://www.theses.fr/2012PA066806.
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La propulsion solide est aujourd'hui un des principaux modes de propulsion pour les lanceurs et missiles. Les propergols solides sont généralement constitués d'un oxydant, tel que le Perchlorate d'Ammonium (PA), d'un liant en polymère et de particules d'aluminium. La déflagration de ce type d'ingrédients énergétiques dans l'espace confiné de la chambre de combustion d'un MPS peut entraîner l'apparition d'instabilités de combustion destructrice, d'où une forte nécessité d'avancer la recherche sur ces instabilités d'un point de vue numérique. L'objet de la thèse a été de créer, pour le PA, un modèle multiphasique mono-dimensionnel et le solveur numérique associé permettant d'étudier la combustion instationnaire de cet ingrédient. Un modèle prenant en compte la chimie détaillée de la phase gazeuse, l'interface réactive, la propagation d'ondes acoustiques en phase gazeuse et d'ondes élastiques en phase spmide a été mis au point. Le solveur numérique associé a été créé et a permis de simuler l'interaction entre acoustique et combustion pour le PA. Il a été montré que, en fonction des modèles d'interface, la combustion présentait des instabilités notamment caractérisées par des extinctions et ré-allumages de la flamme. La nature de la réponse de cette flamme dépend de la fréquence d'excitation acoustique introduite dans le système. Les ondes entropiques générées en réponde à une onde acoustique incidente à basse fréquence sont responsables de la forte amplitude observée dans le phénomène de couplage entre combustion et acoustique au sein de la flamme de PASolid rocket motors stand among the major propulsion systems used to launch civil and military space devices. They feed on solid propellants, which are usually composed of an oxidizing monopropellant, such as ammonium perchlorate (AP), polymeric binder and aluminum particles. Within the confined chamber of rocket motors, propellant combustion can lead to destructive instability phenomenan, hence numerical research is needed to better understand and overcome those issues. The thesis emphasized in creating a multiphase one-dimensional model to study unsteady combustion of AP. The model takes into account detailed gas-phase chemistry, reactive interface, and acoustic and elastic wave propagation. A numerical solver has been created and has been used to simulate combustion-acoustic coupling for AP. Depending on the interface models used, combustion instabilities were observed across successive spontaneous extinctions and ignitions. Flame response depended on incoming wave frequency and entropic waves were responsible for high amplitude of response
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Littlefield, Joanne. "Measuring Perchlorate Levels in Lettuce: Preliminary Study Analyzes Factors Affecting Uptake." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/622218.
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CARO, SANDRINE. "Place du perchlorate de potassium dans le traitement medical des surcharges iodees." Nice, 1993. http://www.theses.fr/1993NICE6506.
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Weigel, Eric Roan. "The effects of induced hypothyroidism on the glucocorticoid stress response in Japanese quail (Coturnix japonica)." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34190.
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Many aspects of biological function are affected by hormones, from physiology to behavior, and the synthesis and release of hormones in vertebrates are regulated by the endocrine axes of control. A growing body of research shows that the mechanisms underlying the endocrine axes of control are complex and interconnected, with many hormones having multiple effects, and with many interactions between axes. In this study, I examined the effects of decreased thyroid function on the glucocorticoid stress response in Japanese quail, a potential interaction between the hypothalamic-pituitary thyroid (HPT) and hypothalamic-pituitary adrenal (HPA) axes of control. I used the thyroid inhibitor ammonium perchlorate (AP) for 2 weeks and 5 weeks to induce two states of decreased thyroid function: a thyroid challenged state, in which birds have depleted thyroidal T4 content, but still maintain euthyroid (normal) concentrations of plasma T4, and a hypothyroid state, in which birds have depleted thyroidal T4 content and decreased concentrations of plasma T4. Thyroid function was assessed by measuring plasma T4 concentrations, thyroidal T4 content, and thyroid gland mass. I took blood samples from birds both immediately prior to and immediately following a 30 minute confinement and agitation stressor to evaluate the effects of decreases in thyroid function on basal and stress-induced plasma corticosterone and plasma T4 concentrations. I found two key results: First, although baseline levels of plasma corticosterone were unchanged, the corticosterone stress response was significantly blunted in both the thyroid challenged and hypothyroid birds as compared to controls. This finding suggests that the HPT and HPA axes are functionally connected in birds, and other evidence suggests this connection is likely at the pituitary or hypothalamic level. Second, in hypothyroid birds, plasma T4 concentrations were elevated (into the euthyroid range) in response to the experimental stressor, although no change in plasma T4 was observed in thyroid challenged or control birds. This finding suggests that plasma T4 may have a permissive role in mounting a stress response.Master of Science in Life Sciences
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Vujosevic, Danilo. "Solvent ordering near cyclohexadienyl type radicals, and ferroelectric ordering of pyridinium perchlorate." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-31836.
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Hubbard, Brian. "Design and operation of novel up-flow bioreactor for microbial perchlorate removal." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 72 p, 2009. http://proquest.umi.com/pqdweb?did=1674961741&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Wang, Demin. "Reduction of perchlorate by indirect electrochemical & catalytic hydrogen processes in dilute aqueous solutions." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 243 p, 2008. http://proquest.umi.com/pqdweb?did=1456290951&sid=10&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Ward, Daniel W. "Tailoring the physical properties of energetic materials." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29531.
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Energetic materials are a class of material that have large amounts of chemical energy stored within their molecular structure. This energy is released upon decomposition, generally in the form of rapidly expanding, hot gases. They are therefore used for a wide range of applications such as; mining, military, and space exploration, and there is therefore a strong desire to improve the overall performance and safety of such materials. On account of reduced sensitivity to initiation by shock and impact, 2,4-dinitroanisole (DNAN) is a potential replacement for 2,4,6-trinitrotoluene (TNT) in melt-cast formulations for military applications. However, up to 15 % irreversible growth of DNAN has been previously observed upon thermal cycling and is a key reason why DNAN has not yet been universally accepted as a replacement for TNT. DNAN exhibits a complex system of polymorphism. One particular transition from DNAN-II to DNAN-III, which occurs at 266 K, has been observed in these studies to cause 8 - 10 % growth of DNAN-II pellets when temperature cycled for 30 cycles between 256 K and 276 K. What was even more concerning was the appearance of cracking of DNAN pellets after being temperature cycled. Doping the crystal structure of DNAN-II with related molecules, such as 2,4-dinitrotoluene or 2,4-dinitroaniline, was investigated in order to probe how steric and electronic factors affect the transition. The addition of varying amounts of 2,4-dinitroaniline suppressed this transition to varying extents and ultimately as low as 150 K with 10 mol% 2,4-dinitroaniline, and potentially eliminated entirely. This doped material has been designated as phase-stabilised DNAN (PS-DNAN). Temperature cycling of PS-DNAN was conducted over the same 256-276 K range, and this material showed no evidence of irreversible growth compared to undoped DNAN pellets, on account of suppression of the II-III transition. The production of PS-DNAN is therefore a possible route to avoiding problematic irreversible growth in DNAN formulations. Melt-casting of DNAN in a sealed environment consistently results in the metastable form-II, which has proven to be stable for in excess of 32 weeks. However, exposure to seeds of form-I, either via deliberate or accidental seeding, rapidly converted the material to the thermodynamically more stable form-I. This transition was accelerated by increasing temperature which rapidly converted pellets of DNAN-II to DNAN-I. When DNAN-I pellets were temperature cycled, they did not undergo a transition to form-III, and as a result did not illustrate irreversible growth. This presents another approach to avoiding problematic growth in DNAN-based materials. Whilst being one of the most widely used oxidisers in propellant formulations, ammonium perchlorate (AP) has several issues; the formation of porous ammonium perchlorate (PAP) can seriously affect the sensitivity of propellants, the hygroscopicity of AP makes handling and manufacture of formulations difficult, and spherical AP exhibits poor binding properties to the polymer binders used in propellant formulations. Several different approaches were taken to combat these issues. Co-crystallisation of AP was attempted in order to produce new AP co-crystals with reduced reactivity towards the formation of PAP. A theoretical based approach using COSMOtherm was used for rapid screening and selection of potential co-formers to be used in lab-based co-crystallisation trials. Co-crystallisation was attempted using multiple stoichiometries and multiple solvents by solvent evaporation, cooling crystallisation, and Resonant Acoustic Mixing methods. Unfortunately no new co-crystals were obtained, presumably on account of the ionic nature of AP which makes co-crystallisation difficult. The mass of untreated AP increased by 0.027% in a humid environment (90% RH) due to the uptake of water, which resulted in significant caking and hence hindering the processability of AP. In an attempt to counteract the hygroscopicity and improve the processability of AP, particles of AP were coated in graphene nanoplatelets using the technique of Resonant Acoustic Mixing. Low mixing energy (G-force) (30 G) resulted in poor coating of AP, but the flowability of this mixure after exposure to moisture was significantly enhanced, most probably as a result of graphene acting as an effective lubricant. Higher mixing energy (90-100 G) was required to break up agglomerates of graphene nanoplatelets and resulted in AP particles efficiently coated with graphene (APGR). Differential scanning calorimetry showed that the energy released upon decomposition of APGR was greater than pure AP, or AP mixed with graphene, due to the intimacy of the AP particle surface and the graphene coating.
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Guruswamy, Sushma. "Uptake and transformation of the propellants 2,4-DNT, Perchlorate and Nitroglycerin by grasses." Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1149562264.
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Moore, Angela Mary. "Anion reactions at iron surfaces : implications for perchlorate remediation using permeable reactive barriers /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Staněk, Vladimír. "Vlastnosti aprotických elektrolytů pro lithno-iontové akumulátory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-221040.
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The present work deals with the properties of suitable electrolytes for lithium-ion batteries. The first part described in the current issue of electrolytes for lithium-ion batteries, types of solvents and their properties and methods of measurement properties. The second part is devoted to the measurement of the properties of solvents and electrolytes such as relative permittivity, density and viscosity. Measurement of relative permittivity was focused on the measurement of the solvent mixture with varying the percentage of the solvent. Viscosity and density were measured on a solvent with a lithium salt added (final electrolyte).
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Langille, Meredith Caitlyn. "Perchlorate ion (C104) removal using an electrochemically induced catalytic reaction on modified activated carbon." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1085.
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Thyer, Aubrey Maurice. "Chain processes in the Tc(VII)-catalysed oxidation of hydrazine by nitrate and perchlorate ions." Thesis, University of Warwick, 1990. http://wrap.warwick.ac.uk/108024/.
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Studies of the reaction between pertechnetate ion and hydrazine in solutions in several different acids have been carried out In order to establish the reaction mechanism and, where possible, the Individual rate constants of each step. Computer simulation of the experimental data has been utilised to enable the formulation of reaction schemes for these very complex chain reactions. In nitric acid the reaction typically exhibits an Induction period of variable length depending on the acidity and concentrations of nitrate, hydrazine and technetlium. This is followed by a stage of rapid loss of hydrazine from the solution due to its oxidation by TcVI, while the TcIV produced is re-oxidised to TcVI by nitrate. The termination step is considered to be the acid-catalysed oxidation of TcVI to TCO4- by nitrate. The effect of increasing acidity is to Increase the length of the induction stage and to decrease the rate of hydrazine oxidation during the fast reaction stage: this causes the reaction to be terminated with increasingly greater residual concentrations of unoxidized hydrazine: at 5 aol da-3 HN03 no loss of N2h4 from the solution is observed. Replacing nitric acid by acids such as HCIO4, HBF4, HC1 or CF3COOH shows that nitric acid Is unique in Its inhibiting effect on the hydrazine destruction reaction. In the presence of these acids the length of the Induction stage is decreased, and the rate of the fast reaction stage is increased, with increasing acidity, i.e. in direct contrast to the situation for HNO3 media.
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Zhao, Qiuming. "Reduction of Perchlorate from Contaminated Waters Using Zero Valent Iron and Palladium under UV Light." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1300118443.
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Meynet, Nicolas. "Simulation numérique de la combustion d'un propergol solide." Paris 6, 2005. http://www.theses.fr/2005PA066605.
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Struckhoff, Garrett Cletus Parkin Gene F. "Plant-assisted bioremediation of perchlorate and the effect of plants on redox conditions and biodiversity in low and high organic carbon soil." [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/441.
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Park, Chanjae. "Microbial anaerobic respiration of perchlorate with the presence of either high salinity or reductive dechlorinaton of trichloroethylene." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3210299.
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Cunin, Frédérique. "Synthèses, études structurales par spectroscopie de vibration, diffraction de rayons x sur poudre, analyse Rietveld de perchlorates covalents et ioniques." Montpellier 2, 2000. http://www.theses.fr/2000MON20016.
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La synthese de perchlorates de metaux precieux, or, platine, palladium, a ete menee par reaction du trioxyde de chlore cl 2o 6 sur des chlorures, des nitrates ou des metaux. La synthese de perchlorates de metaux rares, rhenium, iridium, ruthenium, a ete tentee de la meme facon. Seuls les perchlorates de au, pd, pt, re ont pu etre prepares : clo 2au(clo 4) 4, (no 2) 2pd(clo 4) 4, (clo 2) 2pd(clo 4) 4, pd(clo 4) 2, pto x(clo 4) 4 2 x ycl 2o 6, reo 3clo 4. Ir ou ircl 3 ne reagissent pas avec cl 2o 6, k 2ircl 6 conduit a kclo 4 et ircl 3. On obtient ruocl 2 et ruo 4 volatil par reaction de cl 2o 6 avec rucl 3. Les complexes perchlorato prepares ont fait l'objet d'une etude structurale par spectroscopie de vibration et diffraction de rayons x sur poudre. Dans tous les cas clo 4 est lie au metal et montre sa diversite : monodente dans clo 2au(clo 4) 4, (no 2) 2pd(clo 4) 4, (clo 2) 2pd(clo 4) 4, pto x(clo 4) 4 2 x ycl 2o 6, bidente pontant dans reo 3clo 4 et bidente chelatant dans pd(clo 4) 2. La structure cristalline de clo 2au(clo 4) 4 a pu etre resolue par analyse rietveld a partir de donnees de diffraction de rayons x sur poudre. On retrouve l'environnement plan carre attendu pour au(iii). Notre champ d'investigation dans le domaine des etudes structurales s'est etendu a la serie des metaux alcalino-terreux et au lithium. Clo 4 est coordine dans les complexes de magnesium (bidente pontant dans mg(clo 4) 2 haute temperature et tridente pontant dans mg(clo 4) 2 basse temperature). Dans les complexes de li, ca, sr, ba, clo 4 est ionique. Les structures cristallines de liclo 4, ca(clo 4) 2, ba(clo 4) 2 ont ete decrites, a partir de donnees de diffraction de rayons x sur poudre et affinement de rietveld.
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Denise, Bertrand. "Etude par spectrométrie neutronique de la phase à désordre d'orientation du néopentane et du perchlorate de potassium." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37597048r.
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Denise, Bertrand. "Etude par spectrométrie neutronique de la phase à désordre d'orientation du néopentane et du perchlorate de potassium." Paris 6, 1986. http://www.theses.fr/1986PA066342.
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Utilisation du formalisme des fonctions adaptées à la symétrie pour développera les différentes densités de probabilité intéressant les cristaux à désordre d'orientation. Obtention des sections efficaces de diffusion neutronique en fonction d'un petit nombre de coefficients independants, reflétant les propriétés de symétrie du cristal et de la molécule. Application à l'analyse des facteurs de structure de diffraction de monocristaux de néopentane et de perchlorate de potassium.
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Felix-Balderrama, Sandra. "COMPARISON OF THE ELECTROCHEMICAL PROPERTIES OF ETHANOL IN PERCHLORIC ACID AND IONIC LIQUIDS." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1258588847.
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Akca, Nazmiye Bihter. "Synthesis Of 2-aminopyrrole-3-carboxylates Via Zinc Perchlorate Mediated Annulation Of Alpha-cyano-gamma-ketoesters With Amines." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609715/index.pdf.
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2-Aminopyrrole-3-carboxylate derivatives are important starting materials for biologically active compounds like pyrrolotriazole, pyrrolotriazine so their synthese has great importance in the synthetic organic chemistry.
There are only two methods for the synthesis of 2-aminopyrrole-3-carboxylates in the literature. Therefore, there is a great need for the design and development of a new method for the synthesis of 2-aminopyrrole-3-carboxylates.
In this work, 2-aminopyrrole-3-carboxylate derivatives were synthesized starting from cyano acetic acid ethyl ester with a new method. In the first step, cyanoacetic acid ethyl ester was
alkylated with bromo acetone in the presence of NaH. Then, obtained gamma-ketoester was reacted with primary amines in the presence of catalytic amount of zincpechlorate (Zn(ClO4)2). As a result, 2-aminopyrrole-3-carboxylate derivatives were obtained. Cyanoacetic acid ethyl ester was also alkylated with various bromo acetophenone derivatives in the presence of DBU
(1,8-Diazabicycloundec-7-ene). As a result of these reactions, different gamma-ketoesters were obtained. The reaction of these gamma-ketoesters with primary amines in the presence of catalytic amount of Zn(ClO4)2 concluded with 2-aminopyrrole-3-carboxylate derivatives.
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Cao, Feifei. "Approche interdisciplinaire pour la caractérisation hydrogéologique du milieu crayeux : application au transfert de perchlorate dans la craie de Champagne." Thesis, Reims, 2020. http://www.theses.fr/2020REIMS013.
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Des analyses ont mis en évidence la présence de perchlorate (ClO4-, suspecté d’être un perturbateur endocrinien) dans des captages d’eau potable de Champagne-Ardenne. Deux sources sont suspectées : une source militaire liée à la Grande Guerre et une source agricole liée à l’utilisation passée de nitrates chiliens. Les objectifs de l’étude sont de déterminer l’origine et le comportement des ClO4- dans les eaux souterraines de la craie de Champagne et d’expliquer les hétérogénéités observées en précisant le fonctionnement de la nappe.La zone d'étude se trouve à l'est de Reims, où une étude historique, hydrologique, géochimique et isotopique est réalisée. Une forte hétérogénéité géochimique des eaux de la nappe est observée. Un modèle conceptuel du fonctionnement de la nappe est proposé, mettant en évidence les facteurs contrôlant la géochimie des eaux souterraines. Les teneurs élevées en ClO4- (> 4 µgL-1) sont détectées principalement en aval des Monts de Champagnes, où de grandes quantités de munitions ont été utilisées, stockées et détruites pendant et après la Grande Guerre. Une origine militaire post-conflit est mise en évidence par l’analyse isotopique des ClO4- et la détermination de l’âge des eaux. L’évolution spatio-temporelle des concentrations est discutée sur la base des teneurs en ClO4-, du fonctionnement de la nappe et des informations historiques, permettant de préciser les sources (e.g. munitions non explosés et sites de destruction des munitions) et les mécanismes de transfert des ClO4-. La contamination en ClO4- de l’aquifère de la craie de Champagne ne semble pas diminuer à court et moyen termes en raison de la forte persistance des sources de ClO4-Perchlorate (ClO4-) has frequently been detected in groundwater at concentrations relevant to human health. Analyzes in Champagne-Ardenne have highlighted the presence of ClO4- in groundwater for drinking water supply. The ClO4- has two suspected sources: a military source related to World War I (WWI) and an agricultural source related to past use of Chilean nitrate fertilizers. The objectives of the study are to determine the sources and behavior of ClO4- in the Champagne Chalk aquifer and to explain the heterogeneities observed by specifying the aquifer functioning.The study area is located east of Reims. A methodology involving historical, hydrodynamic, geochemistry, groundwater dating and isotope analysis has been developed. High spatio-temporal heterogeneities are observed in the Chalk aquifer. A conceptual model of aquifer functioning is proposed, highlighting main factors governing the Chalk groundwater geochemistry. ClO4- is detected throughout the area with high concentrations (> 4 µgL-1) detected mainly downgradient the Champagne Mounts, where large quantities of ammunition were used, stored and destroyed during and after WWI. A post-WWI military origin of ClO4- is inferred from isotopic analysis and groundwater ages. Different tendencies of ClO4- variation are observed and interpreted by a combination of ClO4- concentrations, aquifer functioning and historical investigations, revealing major sources of ClO4- (e.g., unexploded ammunitions, ammunition destruction sites) and its transfer mechanisms in the aquifer. ClO4- contamination in the Champagne Chalk seems unlikely to decrease in the short- to medium-term due to the long persistence time of major sources
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Schaffhauser, Katrin. "Intrathyreoidale Iodkonzentration nach intravenöser Applikation nichtionischer Röntgenkontrastmittel ohne und mit prophylaktischer Gabe von Perchlorat." Doctoral thesis, 2005. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-15467.
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Ziel: Studie zur Klärung der Veränderung der intrathyreoidalen Iodkonzentration nach intravenöser Applikation nicht-ionischer Röntgenkontrastmittel (Iomeprol-300; KM) sowie der Wirksamkeit einer Prophylaxe mit Perchlorat (1380 mg/d) zur Blockade der thyreoidalen Iodaufnahme. Probanden und Methoden: 12 Probanden erhielten 100 ml Iomeprol-300 intravenös, dazu zusätzlich o.g. Perchloratprophylaxe. 12 weiteren Probanden wurde lediglich 100 ml Iomeprol-300 intravenös appliziert. Vor sowie 0,2, 1, 3, 5, 7, 24, 48, 72 und 96 Stunden nach Kontrastmittelgabe wurde die intrathyreoidale Iodkonzentration mittels Röntgenfluoreszenzanalyse bestimmt. Ergebnisse, Schlussfolgerung: Unter Perchlorat veränderte sich die intrathyreodiale Iodkonzentration nicht. Ohne Perchloratprophylaxe sinkt der Iodgehalt der Schilddrüse bei einer initial hohen intrathyreoidalen Iodkonzentration nach Kontrastmittelgabe ab (722 +/- 66 µg/ml vor, 670 +/- 65 µg/ml nach KM; p=0,046), bei initial niedriger Konzentration wird Iod in die Schilddrüse eingelagert (327 +/- 40 µg/ml vor, 381 +/- 25 µg/ml nach KM; p=0,046). Der Effekt, obwohl signifikant, scheint zu gering, um für einen Patienten mit gesunder Schilddrüse die Gefahr einer iodinduzierten Funktionsstörung der Schilddrüse verursachen zu können und kann durch die tägliche Gabe von 1,4 g Perchlorat verhindert werdenAim: This study was designed to show the effect of a non-ionic contrast-medium (Iomeprol-300; CM) on the intrathyroidal iodine concentration with and without a concomitant medication with perchlorate (1380 mg/d) to block the thyroidal iodine uptake. Volunteers and methods: 12 volunteers received 100 ml Iomeprol-300 intravenously and the perchlorate prophylaxis mentioned above. Another 12 volunteers got 100 ml Iomeprol-300 only. By means of X-ray-fluorescence-analysis the intrathyroidal iodine concentration was determined in advance as well as 0.2, 1, 3, 5, 7, 24, 48, 72 and 96 hours after the application of the CM. Results, Conclusion: The intrathyroidal iodine concentration did not change in the group of volunteers on perchlorate medication. Without perchlorate the intrathyroidal iodine concentration decreased after the application of the CM when it was initially high (722 +/- 66 µg/ml before, 670 +/- 65 µg/ml after CM; p=0,046) and increased in case of a low initial concentration (327 +/- 40 µg/ml before, 381 +/- 25 µg/ml after CM; p=0,046). This effect is significant but its magnitude is too small to be harmful for a patient with a healthy thyroid. The oral application of 1.4 g/d perchlorate inhibits the thyroidal iodine uptake and the intrathyroidal iodine concentration is unaffected by the application of a CM
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Schaffhauser, Katrin [Verfasser]. "Intrathyreoidale Iodkonzentration nach intravenöser Applikation nichtionischer Röntgenkontrastmittel ohne und mit prophylaktischer Gabe von Perchlorat / vorgelegt von Katrin Schaffhauser." 2005. http://d-nb.info/97705604X/34.
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Kahmann, Cindy [Verfasser]. "Quantifizierung von DNA-Schäden an adhaerenten Zelllinien nach Bestrahlung mit 188Re- bzw. Röntgenstrahlung unter Zugabe von Methimazol, Nicotinamid und Perchlorat durch den Comet Assay / vorgelegt von Cindy Kahmann." 2008. http://d-nb.info/990765075/34.
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London, Mara Rachel. "Modeling autohydrogenotrophic treatment of perchlorate-contaminated water in the presence of nitrate." 2009. http://hdl.handle.net/2152/6577.
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Perchlorate contamination is widespread. Perchlorate, a water contaminant, disrupts iodide uptake to the thyroid, inhibiting growth and mental development. Recent studies have demonstrated autohydrogenotrophic perchlorate reduction to chloride. Hydrogen gas can be produced in-situ via the corrosion of zero-valent iron (ZVI), thereby avoiding problems related to the low aqueous solubility of hydrogen gas. The presence of nitrate has been shown inhibit autohydrogenotrophic perchlorate reduction. However, no studies have modeled the effects of nitrate on autohydrogenotrophic perchlorate biokinetics or developed a model to function as a design tool to predict long-term performance of ZVI/biotic perchlorate treatment systems in the presence of nitrate.
Batch experiments demonstrated the presence of nitrate significantly inhibited perchlorate degradation by an autohydrogenotrophic microbial consortium. However, the consortium was capable of significant perchlorate reduction while the bulk of the nitrate was still present. A modified competitive inhibition model successfully predicted autohydrogenotrophic perchlorate degradation in the presence of nitrate. The model describes perchlorate degradation as a function of the biomass, perchlorate, hydrogen, and nitrate concentrations, as well as the single-component perchlorate, hydrogen, and nitrate half-saturation coefficients and perchlorate maximum substrate utilization rate. To obtain the single-component parameters, a series of batch experiments were performed under perchlorate-, nitrate-, and hydrogen-limiting conditions. The single-component biokinetic parameters and model predictions indicate the consortium could treat perchlorate-contaminated water with concentrations in the low hundreds of μg/L and in states with perchlorate treatment goals in the low μg/L range.
The consortium biokinetic parameters and modified competitive inhibition model were used in the development of an AQUASIM based biofilm model. The model also integrated physical parameters, ZVI hydrogen production, and abiotic nitrate reduction. The model was calibrated using the long-term performance results of a laboratory-scale ZVI/biotic column. Both laboratory and modeling results showed when the column becomes hydrogen-limited, the presence of nitrate decreases perchlorate removal efficiency. Full-scale simulations demonstrated the model could prove useful as a predictive design tool. Simulations suggest that a permeable reactive barrier that includes 10% ZVI and additional media capable of pH buffering could remove typical contaminated ground water concentrations of perchlorate in the presence of typical oxygen and nitrate concentrations.text
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Yu-Ming, Su, and 蘇昱銘. "The study of ammonium perchlorate recrystallization." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/46243453400027689636.
Full textAbstract:
碩士國防大學中正理工學院
應用化學研究所
93
Crystalline grain of ammonium perchlorate has been widely used as oxidizer of composite propellants in the military industry. It is usually produced by sodium perchlorate, gaseous ammonia and hydrochloric acid. Owing to the requiring of its purity is very high for the military application, we purify the ammonium perchlorate by mean of recrystallization. In this investigation, we applied the batch crystallizer to produce the recrystalline grains from the saturated solution of ammonium perchlorate by cooling it with a linear rate and set the experimental conditions such as: cooling range, agitation speed of impeller and cooling rate, to find out the relationships between these variables and metastable zone. In the 900 rpm agitation speed of impeller, the effections of various cooling rate and cooling range on the crystal size distribution, crystal shape, and moisture concentration were studied. Finally we derived kinetic equations of crystallization to estimate the crystal nucleation and growth kinetic parameters, and the critical crystal size. These research results are very useful criteria for improving recrystallization procedure of ammonium perchlorate.
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Sundberg, Sarah Elizabeth. "Phytoremediation of perchlorate by tobacco plants." 2003. http://purl.galileo.usg.edu/uga%5Fetd/sundberg%5Fsarah%5Fe%5F200305%5Fms.
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Tsai, Tsung-hsien, and 蔡宗憲. "Study on Biodegradation of Perchlorate in Groundwater." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/03333660042245350804.
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碩士朝陽科技大學
環境工程與管理系碩士班
93
Ammonium perchlorate is a strong oxidant mainly used in rocket and missile engine solid propellants. Perchlorate salts are also used in pyrotechnics in the manufacture of matches, munitions and in the chemical analytical industry. Other perchlorate compounds uses include additives in lubricating oils, tanning, finished leather, fabric fixer, dyes, electroplating, aluminum refining, rubber manufacture, paint and enamel production, additive in cattle feed, in magnesium batteries, and as a component of automobile air bag inflators. Because of the high solubility of most perchlorate salts, the resultant perchlorate anion is extremely mobile and becomes a significant soil and groundwater contaminant. When the groundwater contaminated with perchlorate salts is used as potable water, perchlorate anion will interfere with the body’s iodine intake and cause inhibition of thyroid production in the human body. The potential of perchlorate contamination in soil and groundwater was investigated in a firework accidental explosion site in Taiwan. In order to understand perchlorate salts contaminant be adsorbed by the soil in the aquifer of simulation. The soil column experiment indicated that perchlorate contamination will be absorbed by the organic matters in soil matrix. The absorbing amount was in direct proportion to organic matters amount in soil. In addition, an anaerobic suspended-growth system was established in this study to degrade the perchlorate anion in groundwater. The removal efficiency of perchlorate was determined to be more than 99% in the system. The rate of anaerobic degradation followed zero-order kinetics with respect to perchlorate concentration, and the degradation rate was proportional to the biomass concentration in the reactor, the rate constant was calculated to be 0.0093 h-1.
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Lee, Rou-Han, and 李柔翰. "Adsorption of perchlorate using carbon nanotubes and MIEX." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3z9b56.
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博士國立中山大學
環境工程研究所
102
Several water treatment plants in Southern Taiwan have enhancedtheir traditional treatment processes. Adsorption is an ideal and effective water treatment method because trace amounts of perchlorate have been detectedin the raw water of Southern Taiwan in recent years. This study adopted carbon nanotubes (CNTs) and magnetic ion-exchange (MIEX) resins to adsorb the perchlorate in water for investigating the efficiency of perchlorate removal and the effects of relevant factors. CNTs and MIEX resins are among the multiple types of novel adsorbent available in the market. By using the two adsorbents for conducting equilibrium adsorption tests and model assessment, this study ascertained the adsorption characteristics and behavior of perchlorate. The results indicated that the adsorption behavior of CNTs and MIEX resins on perchlorate was mainly influenced by pH value, ionic strength, and temperature. The adsorption capacity in the dynamic and equilibrium adsorption experiments was analyzed usingadsorption models. The CNTs and MIEX resins achieved equilibrium in approximately 8h, and the adsorption capacity increased astheperchlorate concentration increased and ionic strength decreased. The models of modified Freundlich equation, pseudo-first-order equation, and pseudo-second-order equation were adopted for determining the optimal adsorption model. The results revealed that the modified Freundlich equation was optimal for the perchlorate adsorption by CNTs, whereas the pseudo-first-order equation was optimal for the perchlorate adsorption by MIEX resins. According to the results of the equilibrium adsorption tests,perchlorate at low pH was favorable for the performance of the two adsorbents. The isothermal adsorption results of perchlorate, in which adsorptioncapability and affinity increased as thetemperaturedecreased, were applicable to both the Langmuir and the Freundlich models. In a thermostatic environment of 5–45 °C, the results of isothermal equilibrium adsorption tests indicated that the maximumadsorption capacity of the CNTs,MIEX resins,and the control, granular activated carbon,was 10.03–13.64mg/g, 70.15–82.01 mg/g, and28.21–33.87 mg/g, respectively. Therefore, low pH values, low ionic strength, and low temperature are favorable for CNTs and MIEX resins inremoving perchlorate.
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Borjan, Marija. "Pilot study of perchorate exposure in lactating women in an urban community in New Jersey." 2009. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051786.
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De, Long Susan Kathleen. "Molecular biology tools for identification and quantification of perchlorate-reduction genes in biotreatment applicatins." Thesis, 2009. http://hdl.handle.net/2152/23948.
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Perchlorate contamination of drinking water sources in the United States is widespread and represents a public health concern. Biological treatment is an attractive option because perchlorate-reducing bacteria (PRB) are ubiquitous in the environment and can reduce perchlorate completely to chloride. Treatment of perchlorate-contaminated water in fixed-bed bioreactors has been demonstrated at the laboratory- and pilot-scale. However, full-scale development of reliable biological drinking water treatment processes requires a better understanding of the microbial ecology and activity of perchlorate-reducing communities in bioreactors. The objective of this research was to develop molecular biology tools (MBTs) to quantify PRB and expression of genes required for complete perchlorate reduction (pcrA and cld). The development of MBTs targeting specific genes requires that the sequence of the genes be known. In this work, an MBT called prokaryotic Suppression Subtractive Hybridization (SSH) PCR complementary DNA (cDNA) Subtraction was developed to rapidly isolate target genes for sequencing. This new tool was developed and validated using the model bacterium Pseudomonas putida mt-2 and the model pollutant toluene. For this system, over 90% of the isolated gene fragments encoded toluene-related enzymes, and 20 distinct toluene-related genes from three key operons were identified. Based on these results, prokaryotic SSH PCR cDNA Subtraction shows promise as a targeted method for gene identification; however, application to a PRB did not yield new pcrA and cld sequences. Therefore, to support the development of biological perchlorate treatment processes, quantitative PCR (qPCR) and reverse transcription qPCR (RT-qPCR) assays targeting pcrA and cld were developed using existing sequences. The qPCR and RT-qPCR assays were applied to a laboratory-scale bioreactor and two pilot-scale bioreactors treating perchlorate-contaminated water. Higher quantities of perchlorate reduction genes and transcripts generally were observed when bioreactor performance was superior. Although no quantitative correlations were established, these assays detected differences in the quantity of PRB and changes in gene expression levels during the course of bioreactor operation and between bioreactors with different performance levels. Furthermore, these assays provided an additional line of evidence that microbial perchlorate reduction was occurring. This marks the first application of qPCR assays to quantify perchlorate reduction genes and transcripts in bioreactors.text
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Conneely, Teresa Anne. "Investigation of a sulfur-utilizing perchlorate-reducing bacterial consortium." 2011. https://scholarworks.umass.edu/dissertations/AAI3465186.
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We present research investigating how, with in depth knowledge of the community, microbial communities may be harnessed for bioremediation of hazardous water contaminants. We focused on the bacterial reduction of perchlorate, a common water contaminant. For this we studied the structure and capabilities of a novel sulfur-utilizing, perchlorate-reducing bacterial (SUPeRB) consortium. Initially, we characterized the minimal consortium that retained functional capabilities, using 16S rRNA and functional gene analysis. A diverse functional consortium dominated by Beta-Proteobacteria of the family Rhodocyclaceae and sulfur-oxidizing Epsilon-Proteobacteria was found. We also examined the optimal growth conditions under which perchlorate degradation occurred and uncovered the upper limits of this function. Bacterial isolates were screened for function and the presence of functional genes. We expanded to bioreactor studies at bench- and pilot-scale, and first used a perchlorate-reducing, bench-scale bioreactor to probe the stability of the microbial ecosystem. During stable reactor function, a core consortium of Beta- and Epsilon-Proteobacteria reduced perchlorate and the co-contaminant nitrate. A disturbance of the consortium led to a failure in function and to higher system diversity. This suggests that the SUPeRB consortium was not metabolically flexible and high population diversity was necessary for a return to stable function. In a pilot-scale bioreactor we determined that the SUPeRB consortium could stably degrade low levels of perchlorate to below the EPA maximum recommended limit. Field conditions, such as temperature extremes and intermittent perchlorate feed, did not negatively impact overall function. When all reactor consortia were compared we observed that the volume of the reactor and the initial inoculum were not as important to stable reactor function as the acclimatization of the consortium to the system and maintenance of favorable conditions within the reactor. In summary we found that the SUPeRB consortium successfully degraded perchlorate in multiple systems. The study of this novel consortium expands our knowledge of the metabolic capabilities of perchlorate-reducing bacteria and suggests potential evolutionary pathways for perchlorate-reduction by microorganisms. The SUPeRB consortium may be used to establish bioremediation systems for perchlorate and other environmental contaminants.