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Virtanen, Vesa. "Determination of clodronate and clodronic acid esters in aqueous solutions and urine using different analytical methods." Oulu, Finland : Dept. of Chemistry, University of Oulu, 1993. http://catalog.hathitrust.org/api/volumes/oclc/34155043.html.
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Körtvélyesi, Zsolt. "Analytical Methods for the Measurement of Chlorine Dioxide and Related Oxychlorine Species in Aqueous Solution." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1088030135.
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Hochstrasser-Kurz, Sabine [Verfasser]. "Mechanistic Study of the Corrosion Reactions on WC-Co Hardmetal in Aqueous Solution – An Investigation by Electrochemical Methods and Elemental Solution Analysis / Sabine Hochstrasser-Kurz." Aachen : Shaker, 2006. http://d-nb.info/1170529100/34.
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Suhandy, Diding. "Studies on Glucose and L-Ascorbic Acid Determination in Aqueous Solution Using FTIR-ATR Terahertz Spectroscopy Combined with Chemometric Methods." Kyoto University, 2013. http://hdl.handle.net/2433/175067.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第17638号
農博第2000号
新制||農||1012(附属図書館)
学位論文||H25||N4759(農学部図書室)
30404
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 近藤 直, 准教授 小川 雄一, 教授 清水 浩
学位規則第4条第1項該当
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Gabes, Yamina. "Étude de la faisabilité et mise au point d'un dispositif de mesure des équilibres liquide-vapeur : application à l'étude des solutions aqueuses d'électrolytes." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL104N.
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L’objectif du présent travail concerne la construction d'un dispositif manométrique statique destiné à mesurer la pression de vapeur totale à l'équilibre au-dessus de solutions aqueuses d'électrolytes. Deux dispositifs ont été construits. Le premier a permis de mettre au point le protocole expérimental permettant, en particulier, de faire des séries de mesures à composition constante. Le second a été construit avec une instrumentation de haut niveau. Le système H2O-NaCl a été étudié entre la température ambiante et 100°C environ et les résultats expérimentaux ont été traités à l'aide des modèles de PITZER et NRTL-électrolytes. Des ultimes améliorations du dispositif sont proposées afin d'atteindre une précision moyenne de l'ordre de 0,1% avec une durée d'expérimentation optimisée
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Zanain, Mabrouk Ali Masaud. "Removal of low concentrations of silver from aqueous solutions using adsorption methods." Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678471.
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Lilly, Arnys Clifton. "Monte Carlo simulation of aqueous dilute solutions of polyhydric alcohols." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54388.
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In order to investigate the details of hydrogen bonding and solution molecular conformation of complex alcohols in water, isobaric-isothermal Monte Carlo simulations were carried out on several systems. The solutes investigated were ethanol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol and glycerol. In addition, propane, which does not hydrogen bond but does form water hydrates, was simulated in aqueous solution. The complex alcohol-water systems are very nonideal in their behavior as a function of solute concentration down to very dilute solutions. The water model employed was TIP4P water¹ and the intermolecular potentials employed are of the Jorgensen type² in which the interactions between the molecules are represented by interaction sites usually located on nuclei. The interactions are represented by a sum of Coulomb and Lennard-Jones terms between all intermolecular pairs of sites. Intramolecular rotations in the solute are modeled by torsional potential energy functions taken from ethanol, 1-propanol and 2-propanol for C-O and C-C bond rotations. Quasi-component pair correlation functions were used to analyze the hydrogen bonding. Hydrogen bonds were classified as proton acceptor and proton donor bonds by analyzing the nearest neighbor pair correlation function between hydroxyl oxygen and hydrogen and between solvent-water hydrogen and oxygen.
The results obtained for partial molar heats of solution are more negative than the experimental values by 3.0 to 14 kcal/mol. In solution, all solutes reached a contracted molecular geometry with the OH groups generally on one side of the molecule. There is a tendency for the solute OH groups to hydrogen bond with water, with more proton acceptor bonds than proton donor bonds. The water-solute binding energies correlate with experimental measurements of the water-binding properties of the solute.
1. Jorgensen, W.L. et al, J. Chem. Phys., 79, 926 (1983).
2. Jorgensen, W.L., J. Phys Chem., 87, 5304 (1983).Ph. D.
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Liu, Deqi. "Thermomechanical modeling of the solidification process of an aqueous urea solution." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI029.
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De nombreux liquides subissent un changement de volume lorsqu'ils gèlent. Pour l'eau et certaines solutions aqueuses, l'expansion volumétrique au cours de la solidification peut entraîner une série de problèmes mécaniques. Dans l'industrie automobile, l'expansion de changement de phase (ECP) met en cause la sécurité des réservoirs des véhicules aux saisons froides. Une des questions les plus problématiques est l'expansion de la solution aqueuse d'urée (SAU) dans le réservoir du système SCR des véhicules diesels. Lorsque le liquide gèle, les composants intérieurs ainsi que le réservoir lui-même peuvent être endommagés dû à la pression apportée par la dilatation du liquide solidifié. Dans le centre , une méthode numérique est fortement attendue afin de prévoir la répartition de la température, des contraintes ainsi que de la déformation des composants lors d'un processus de solidification. Du fait que les informations sur la solution d'urée restent limitées, la structure de la glace cristalline ainsi que ses comportements mécaniques sont principalement passés en revue. La préférence d'orientation de croissance des grains de glace à l'interface de cristallisation met en évidence, l'hypothèse de l'ECP non-isotropique pour des problèmes de solidification. Une série de tests mécaniques a été réalisée afin d'obtenir les propriétés basiques de SAU à l'état solide à différentes températures. Une méthode « différence-volume » a été appliquée pour mesurer la variation de la densité de la SAU lors du processus de solidification. Pour la suite, des études analytiques thermiques et mécaniques sont effectuées. Pour l'aspect thermique, le problème classique de Stefan est passé en revue. Un schéma de différence-finie est proposé et il permet de calculer la position de l'interface et les profils de température pour un modèle sphérique. Pour l'aspect mécanique, un modèle sphérique similaire est établi à la base de l'ECP non-isotropique. Les solutions analytiques des contraintes et de la pression liquide sont présentées en fonction de la position de l'interface. Une méthode éléments-finis thermo-mécaniquement couplée est développée afin de simuler efficacement les contraintes thermiques, les déformations et la pression liquide dans un problème de solidification avec des relations constitutives de comportement non-linéaires. Les contraintes thermiques sont calculées en chaque point d'intégration en résolvant les équations elasto-viscoplastiques avec l'ECP non-isotropique. Le problème aux limites est résolu par la méthode de Newton-Raphson. Cette procédure est implémentée dans le package Abaqus via un UMAT. La méthode est validée d'abord pour les aspects algorithmiques par les solutions analytiques, puis pour les paramètres de comportement retenus par une série de tests expérimentaux. De plus, une étude de cas réaliste sur un réservoir de la SAU est introduite. Les avantages et les limitations de la méthode numérique lors d'une application sont évaluésMany liquids involve a change in volume when they freeze. For water and some aqueous solutions, the volumetric expansion during solidification may invoke a series of mechanical issues. In automobile industries, the security of tanks installed in vehicles is challenged by the Phase-Change Expansion (PCE) of the freezing liquid in cold conditions. One of the most problematic issues is the expansion of Aqueous Urea Solution (AUS) in the SCR tank of diesel vehicles. As the liquid freezes, interior components may be deformed under the stress or pressure of the expanding AUS, potentially leading to failures of the storage tank. In the product center, a numerical method is of high demand to perform thermo-mechanical analysis to predict the temperature and stress distribution during a liquid solidification process in their tanks. In this work, a bibliographic study is carried out first on the basic knowledge of the ice and AUS. Due to the very limited information on urea solution in the literature, the structure and behaviors of freshwater ice are mainly reviewed. The grain orientation preference at the growth interface of polycrystalline ice provides the evidence of non-isotropic PCE for the solidification problem. A series of mechanical tests have been performed to characterize the basic properties of the solidified AUS at different temperatures. The density evolution is measured using a volume-difference method. Then, both thermal and mechanical analytical studies are performed. The classical thermal Stefan problem is reviewed and a finite-difference scheme is proposed to calculate the interface position and temperature profiles of a spherical solidification model. Mechanically, a similar spherical model is established based on the non-isotropic PCE phenomenon of ice growth. The solutions of stress distribution and liquid pressure evolution are given as a function of the solidification interface position. Finally, an efficient thermo-mechanical FEM is proposed to evaluate the thermal stress, strain, displacement and pressure in solidification problems with highly nonlinear relations. Three particular methods for treating the liquid phase with fixed-grid approaches are introduced. The thermal stress is computed at each integration point by integrating the elasto-viscoplastic constitutive equations with non-isotropic PCE. Then, the boundary value problem is solved using the full Newton-Raphson method. This procedure is implemented into the FE package Abaqus via a UMAT subroutine. The numerical model is validated first for the algorithmic aspect by the analytical solutions, and then for the parametric calibration by a series of benchmark tests. In the end, a realistic study case on a real-size AUS storage tank is introduced. Advantages and limitations of the numerical method in the application are evaluated
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BINANA-LIMBELE. "Contribution a l'etude des amphiphiles en solution aqueuse par les methodes de fluorescence." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13077.
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La technique de fluorescence a ete utilisee pour etudier differents types de solutions aqueuses d'amphiphiles et de polyamphiphiles. Elle permet d'acceder a certains parametres statiques (tels que le nombre moyen d'agregation des tensioactifs dans une micelle, la conformation des polyamphiphiles en solution aqueuse) mais aussi a des parametres sur la dynamique des micelles si celles-ci rentrent en collision
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Pötschke, Markus. "Simulation of electric field-assisted nanowire growth from aqueous solutions." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-194735.
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The present work is aimed at investigating the mechanisms of nanowire growth from aqueous solutions through a physical and chemical modeling. Based on this modeling, deriving an optimized process control is intended. The work considers two methods of nanowire growth. The first is the dielectrophoretic nanowire assembly from neutral molecules or metal clusters. Secondly, in the directed electrochemical nanowire assembly metal-containing ions are reduced in an AC electric field in the vicinity of the nanowire tip and afterwards deposited at the nanowire surface. To describe the transport and growth processes, continuum models are employed. Furthermore, it has been necessary to consider electro-kinetic fluid flows to match the experimental observations. The occurring partial differential equations are solved numerically by means of finite element method (FEM). The effect of the process parameters on the nanowire growth are analyzed by comparing experimental results to a parameter study. The evaluation has yielded that an AC electro-osmotic fluid flow has a major influence on the dielectrophoretic nanowire assembly regarding the growth velocity and morphology. In the case of directed electrochemical nanowire assembly, the nanowire morphology can be controlled by the applied AC signal shape. Based on the nanowire growth model, an optimized AC signal has been designed, whose parametrization allows to adjust to the chemical precursor and the desired nanowire diameterZiel der vorliegenden Arbeit ist es, mittels physikalischer und chemischer Modelle die Mechanismen des Nanodrahtwachstums aus wässrigen Lösungen zu erforschen und daraus eine optimierte Prozesskontrolle abzuleiten. Dabei werden zwei Verfahren des Nanodrahtwachstums näher betrachtet: Dies sind die dielektrophoretische Assemblierung von neutralen Molekülen oder Metallclustern sowie die gerichtete elektrochemische Nanodrahtabscheidung (engl. directed electrochemical nanowire assembly), bei der metallhaltige Ionen im elektrischen Wechselfeld an der Nanodrahtspitze zunächst reduziert und anschließend als Metallatome abgeschieden werden. Zur Beschreibung der Transport- und Wachstumsprozesse werden Kontinuumsmodelle eingesetzt. Darüber hinaus hat es sich als notwendig erwiesen, elektrokinetische Fluidströmungen zu berücksichtigen, um die experimentellen Beobachtungen zu reproduzieren. Die auftretenden partiellen Differenzialgleichungen werden mittels der Finiten Elemente Methode (FEM) numerisch gelöst. Die Auswirkungen der Prozessparameter auf das Nanodrahtwachstum werden durch den Vergleich von experimentellen Ergebnissen mit Parameterstudien analysiert. Die Auswertung hat ergeben, dass für das dielektrophoretische Wachstum ein durch Wechselfeldelektroosmose (engl. AC electro-osmosis) angetriebener Fluidstrom die Drahtwachstumsgeschwindigkeit und -morphologie maßgeblich beeinflusst. Im Falle der gerichteten elektrochemischen Nanodrahtabscheidung lässt sich die Drahtmorphologie über das angelegte elektrische Wechselsignal steuern. Unter Verwendung des Wachstumsmodells ist ein optimiertes Signal generiert worden, dessen Parametrisierung eine gezielte Anpassung auf den chemischen Ausgangsstoff und den gewünschten Drahtdurchmesser erlaubt
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Deschrevel, Brigitte. "Réversibilité de réactions enzymatiques de type hydrolyse/synthèse en milieu partiellement aqueux/partiellement organique." Rouen, 1993. http://www.theses.fr/1993ROUES006.
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L'objectif de ce travail était d'étudier la réversibilité de réactions enzymatiques de type hydrolyse/synthèse dans des milieux partiellement aqueux/partiellement organiques. Nous avons choisi d'étudier le cas particulier de la réaction d'hydrolyse/synthèse du dipeptide, N-Cbz-L-tryptophanyl-glycineamide, dans un système monophasique dans lequel le milieu réactionnel était composé d'un mélange d'eau et de 1,4-butanediol. Cette étude nous a permis d'observer plusieurs effets de la présence du 1,4-butanediol sur les comportements cinétique et thermodynamique du système réactionnel. En particulier, il est apparu que i) l'alpha-chymotrypsine conserve son activité catalytique quelles que soient les proportions relatives d'eau et de 1,4-butanediol dans le milieu réactionnel, sauf dans les milieux à très faible teneur en eau, et ii) la présence de 1,4-butanediol dans le milieu réactionnel permet de déplacer l'équilibre d'hydrolyse/synthèse du dipeptide dans le sens de la synthèse en réduisant l'activité de l'eau ainsi que l'énergie nécessaire à la neutralisation des substrats. A l'issue de cette étude, il s'est révélé possible de définir des conditions expérimentales cinétiquement et thermodynamiquement favorables à la synthèse du dipeptide. Expérimentalement, ceci s'est traduit par un bon rendement de synthèse du dipeptide. Enfin, le système réactionnel étudié constitue un modèle dont le traitement et les conclusions peuvent être étendus à d'autres systèmes réactionnels
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Bolch, Wesley Emmett. "Monte Carlo simulation of indirect damage to biomolecules irradiated in aqueous solution--the radiolysis of glycylglycine." Gainesville, FL, 1988. http://www.archive.org/details/montecarlosimula00bolc.
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Norlin, Elin. "Nitrogen isotope analysis of ammonium and glycine : method development for aqueous solutions and soil extracts /." Umeå : Dept. of Forest Ecology, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200584.pdf.
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Åkervall, Anton. "Development of a GC Method for the Quantification of Short Chain Carboxylic Acids in Aqueous Solution." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166367.
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Petroleum powered vehicles emit volatile organic compounds (VOCs) through combustion that contributes to the pollution of the environment. A technique in the 1970s was developed to decrease these emissions, especially for nitrogen oxides (NOx) and sulphuric oxides (SOx) which is called exhaust gas recirculation (EGR). The technique works by recirculating a portion of the combusted gas back into the engine, this limits the NOx and SOx emissions because of lower temperatures and less available oxygen. The problems that follow these effects is the formation and condensation of acids that corrode the material of the EGR system, which are created by many different reactions. It is of importance to understand how the compounds in the EGR system behaves through analysis of authentic and simulated condensates, which is why a quantitative method for these compounds are of interest. The aim of the project was to develop a simple quantitative analysis method for formic acid, acetic acid, and lactic acid in aqueous solution, which was done at Gränges Sweden AB. The technique used for detection and quantification was gas chromatography (GC) coupled to a flame ionization detector (FID) and a water compatible polyethylene glycol (PEG) column. Fractional factorial design (FFD) was used for determination of adequate operating parameters of the GC method and the sample preparation. Sample preparation only required filtration and pH adjustment prior to direct aqueous injection (DAI) to the chromatographic instrument. Detection of the analytes was very difficult because of non-compatibility with the FID, and quantification of asymmetric peak shapes made this problem worse, omitting lactic acid from further analysis. Limit of detection (LOD) and limit of quantification (LOQ) was 490 and 1640 ppm for formic acid and 120 and 400 ppm for acetic acid, with an injection volume of 0.3 μL and split ratio 10:1. Limits were too high for every EGR sample leaving no peaks detected for the sample preparation used. Further development should be done with complementary techniques and sample reprocessing in order to quantify the compounds.
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Chigane, Masaya. "Nickel Oxide and Manganese Oxide Thin Films : Novel Prepration Method from Aqueous Solution and Characterization of Electrochromic Properties." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150730.
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Deodhar, Anirudh M. "Computational Study of Adiabatic Bubble Growth Dynamics from Submerged Orifices in Aqueous Solutions of Surfactants." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337100942.
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ZHANG, JUNTAO. "EXPERIMENTAL AND COMPUTATIONAL STUDY OF NUCLEATE POOL BOILING HEAT TRANSFER IN AQUEOUS SURFACTANT AND POLYMER SOLUTIONS." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1077304904.
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CASTRO, KELLY NEOOB DE CARVALHO. "METHODS FOR THE IMIDACLOPRID QUANTIFICATION IN AQUEOUS SOLUTIONS: METROLOGICAL VALIDATION AND COMPARISON BETWEEN UV-VIS SPECTROPHOTOMETRY AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9960@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROUm procedimento analítico é considerado apropriado para uma aplicação específica quando é capaz de gerar resultados confiáveis, que possibilitem a tomada de decisão com grau de confiança adequado, sendo sua adequação consolidada mediante a realização de ensaios de validação. Este trabalho propõe a utilização de um procedimento analítico alternativo, mais simples e econômico, baseado na técnica espectrofotométrica de absorção molecular, para quantificação de imidacloprid, um inseticida sistêmico, em amostras de solução aquosa. Foi demonstrado que o procedimento proposto é adequado ao uso pretendido descrevendo-se, detalhadamente, cada etapa da validação, considerando-se os limites estabelecidos para cada parâmetro de validação e aplicando-se técnicas estatísticas apropriadas na avaliação dos mesmos: análise de variância, análise de regressão, testes de significância, gráficos de controle e a estimativa da incerteza de medição. As incertezas de medição dos procedimentos de rotina e alternativo foram estimadas e comparadas às tolerâncias estipuladas, estabelecendo o procedimento alternativo como adequado. Uma comparação experimental deste procedimento com o de rotina (baseado em HPLC) foi realizada como parte do protocolo de validação. Além da avaliação do procedimento para quantificação de imidacloprid em nível de traços, foi investigada também a possibilidade de sua utilização, para a quantificação do mesmo ingrediente ativo em produtos formulados. Neste caso, foi demonstrado, através da comparação das incertezas estimadas às tolerâncias estabelecidas, que o procedimento alternativo não é adequado, por apresentar incertezas na ordem de aproximadamente 50% do valor destas tolerâncias, não possuindo assim o rigor metrológico requerido para esta aplicação.
Fit for purpose analytical procedures must be sufficiently reliable to support any decision taken based on the generated results. In order to achieve that, consolidated adequacy evaluation of the analytical procedure must be obtained by performing validation experiments. In this work, an alternative and simpler spectrophotometric method for the quantification of imidacloprid in aqueous samples was compared to the HPLC-UV based reference method used in routine. The overall validation procedure started with a detailed description of each validation stage, followed by the settling of the limits for each of the validation parameters and then, applying the following statistical techniques to evaluate each of the parameters: ANOVA, regression analysis, significance tests, control charts and uncertainty estimation. The measurement of uncertainties estimation, based on ISO-GUM recommendations, was done for both analytical procedures (the alternative one and the reference one). After comparing these uncertainties with the tolerance values, the adequacy of the alternative proposed procedure was confirmed. Finally, by consolidating the validation, the experimental comparison of quantification methods was conducted. Besides evaluating the analytical procedure for trace-level imidacloprid quantification in water samples, the proposed method was also evaluated as the analytical procedure for imidacloprid based formulated products. In this case, it was demonstrated that the spectrophotometric method did not present the requested metrological requirements for such application, since the estimated uncertainties of the alternative procedure were about 50 % of the tolerance values.
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BRIONIZIO, JULIO DUTRA. "STUDY OF THE MEASURING METHOD OF THERMAL CONDUCTIVITY AND WATER CONTENT BY MEANS OF SPHERICAL GEOMETRY: APPLICATIONS ON AQUEOUS SOLUTIONS OF ETHANOL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=22034@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROA presente tese tem por objetivo o estudo teórico e experimental, seguindo as boas práticas metrológicas, de um método baseado em uma fonte esférica de calor para medição da condutividade térmica de líquidos, com foco em soluções aquosas de etanol, e posterior determinação do teor de água da substância. O estudo e o desenvolvimento de métodos de medição de condutividade térmica são essenciais em diversas aplicações de engenharia, visto que, em consequência das justificadas demandas atuais de economia e uso racional de energia térmica, a transferência de calor com a máxima eficiência possível é de extrema relevância. A medição do teor de água também é um relevante parâmetro em muitas áreas de pesquisa e nos setores industriais, pois a quantidade de água nas substâncias influencia vários processos físicos, químicos e biológicos. Contudo, a quantidade de equipamentos disponíveis no mercado para a medição de ambas as grandezas não é vasta. O método da esfera quente, em principio, é um método absoluto de medição da condutividade térmica, o que significa que o sensor pode fornecer um resultado sem ser calibrado. Porém, alguns parâmetros do modelo precisam ser analisados isoladamente ou obtidos por meio de calibração. Embora haja alguns estudos sobre este método, poucos têm os meios líquidos como foco principal. Ademais, tais estudos não correlacionam a condutividade térmica do material com o seu teor de água e nem realizam uma análise metrológica mais criteriosa, de modo a determinar minuciosamente as incertezas de medição. A aplicabilidade do método para medição da condutividade térmica e do teor de água das soluções analisadas mostrou-se bastante satisfatória, pois os resultados obtidos neste estudo apresentaram muito boa concordância com os valores propostos por vários pesquisadores e com as medições realizadas no Inmetro por outros métodos.
The aim of this thesis is the experimental and theoretical study, following the good metrological practices, of a method based on a spherical heat source in order to measure thermal conductivity of liquids, focusing on aqueous solutions of ethanol, with later determination of the water content of the substance. The study and the development of measuring methods of thermal conductivity are essentials in several engineering applications, since as a consequence of the current justified demands on saving and rational use of thermal energy, the heat transfer with the maximum efficient as possible is of great relevance. The measurement of the water content is also a relevant parameter in several research areas and industrial sectors, since the quantity of water in the substances influences several biological, chemical and physical processes. However, the amount of equipment available on the market for the measurement of both quantities is not vast. The heated sphere method, in principle, is an absolute one for the measurement of the thermal conductivity, which means that the sensor may furnish a result without a calibration. Nevertheless, some parameters of the model need to be analyzed separately or obtained by means of calibration. Although there are some studies on this method, few of them have liquids as the main focus. Moreover, these studies do not correlate the thermal conductivity of the material with its water content, and they do not perform a more careful metrological analysis in order to determine the measurement uncertainties. The applicability of the method to measure the thermal conductivity and the water content of the analyzed substances proved to be satisfactory, because the obtained results of this study presented a very good agreement with the values proposed by several researches and with the measurements performed at Inmetro by other methods.
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Bardez, Élisabeth. "Relation entre structure et reactivite acido-basique de l'eau incluse dans les micelles inverses." Paris 6, 1987. http://www.theses.fr/1987PA066033.
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Chgoura, Mohammed. "Adsorption par des charbons actifs de molécules organiques à partir de solutions aqueuses." Aix-Marseille 1, 1987. http://www.theses.fr/1987AIX11082.
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Choy, de Martinez Marisela. "Etude par méthodes électrochimiques et spectroscopiques (réflexion uv-visible et infrarouge) de la chimisorption de l'acide formique sur électrodes de rhodium en milieu aqueux." Poitiers, 1988. http://www.theses.fr/1988POIT2321.
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L'adsorption de l'acide formique a ete etudiee par voltammetrie cyclique, voltammetrie a potentiel programme, spectroscopie uv-visible de reflexion, et spectroscopie de reflexion infrarouge electro-modulee. Determination du nombre d'electrons par site necessaires a l'oxydation de la couche chimisorbee
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Hajji, Mohammed Saïd. "Etude comparative de l'association hydrophobe en solution aqueuse de tensioactifs anioniques et cationiques et de divers alcane-diols et alcane-triols par mesures des masses volumiques, de la diffusion élastique et quasi-élastique de la lumière et des." Paris 13, 1987. http://www.theses.fr/1987PA132016.
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Catonné, Jean-Claude. "Contribution à l'étude du défaut de sélectivité présenté par les membranes échangeuses d'anions, dans le cadre de leurs applications au traitement électrochimique de régénération des solutions aqueuses d'acides minéraux." Paris 6, 1986. http://www.theses.fr/1986PA066030.
Full textAbstract:
Essai d'identification de l'origine de la "fuite h+" et de celle des différentes sources susceptibles d'alimenter le mouvement d'eau au sein des membranes échangeuses d'anions, selon que le matériau est fortement ou non "élusterisé", puis d'établissement de l'existence d'une corrélation étroite entre l'intensité de fuite protonique et celle de la perméabilité osmotique des membranes (ainsi que le laisse prévoir la théorie de Gierke dans le cas des membranes échangeuses de cations). Et enfin, évaluation du rôle du champ électrique, ainsi que celui de la composition de l'électrolyte sur les résultats.
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Jada, Amane. "Etude de la structure et de la dynamique de microemulsions eau dans huile." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13101.
Full textAbstract:
Etude des microemulsions qui sont des solutions transparentes constituees de fines gouttelettes d'eau dispersees dans une phase continue riche en huile. Determination par declin de fluorescence, diffusion de lumiere et conductivite electrique de l'influence de la nature de l'huile, de la temperature et de la structure du tensioactif sur la taille des gouttelettes et les processus d'echange de matiere entre gouttelettes
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Loos-Neskovic, Christiane. "Préparations et propriétés de fixation des hexacyanoferrates II de zinc et de nickel." Paris 6, 1986. http://www.theses.fr/1986PA066592.
Full textAbstract:
Données sur la préparation, la structure et les propriétés de ces composés présentant de nombreuses analogies avec les zéolites. Etudes de l'échange d'ions H**(+) et de la fixation d'éléments ou de polluants (argent, césium, mercure, etc. . ) sur de l'hexacyanoferrate de Zn ou de Ni.
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Somasundaram, Theepaharan. "Simulation studies of molecular transport across the liquid-gas interface." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314223.
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Takky, Driss. "Effet de la structure moléculaire en electrocatalyse : étude mécanistique de l'oxydation des isomères du butanol en milieu aqueux sur diverses électrodes de metaux nobles." Poitiers, 1987. http://www.theses.fr/1987POIT2008.
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Quang, Hong Le, Soo-Jin Chua, Kian Ping Loh, Zhen Chen, Carl V. Thompson, and Eugene A. Fitzgerald. "Characterization of ZnO Nanorods Grown on GaN Using Aqueous Solution Method." 2004. http://hdl.handle.net/1721.1/7360.
Full textAbstract:
Uniformly distributed ZnO nanorods with diameter 70-100 nm and 1-2μm long have been successfully grown at low temperatures on GaN by using the inexpensive aqueous solution method. The formation of the ZnO nanorods and the growth parameters are controlled by reactant concentration, temperature and pH. No catalyst is required. The XRD studies show that the ZnO nanorods are single crystals and that they grow along the c axis of the crystal plane. The room temperature photoluminescence measurements have shown ultraviolet peaks at 388nm with high intensity, which are comparable to those found in high quality ZnO films. The mechanism of the nanorod growth in the aqueous solution is proposed. The dependence of the ZnO nanorods on the growth parameters was also investigated. While changing the growth temperature from 60°C to 150°C, the morphology of the ZnO nanorods changed from sharp tip (needle shape) to flat tip (rod shape). These kinds of structure are useful in laser and field emission application.Singapore-MIT Alliance (SMA)
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Chang, Yu-Shu, and 張祐書. "Electrochemical Destruction of p-Phenylenediamine in Aqueous Solution by Electro-Fenton Methods." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/49161106947466649760.
Full textAbstract:
碩士國立臺灣大學
化學工程學研究所
99
Advanced oxidation process is the best method for wastewater treatment. According to the different classification of reaction mechanisms, Electro-Fenton process and Photo-catalytic reaction have most widely applications. In this study, the AP-CC represented that the anode was Platinum (Pt) or Platinum Titanium mesh (Ti/Pt) ,and the cathode was carbon cloth which was fed with oxygen. The applied current was set to produce H2O2 at the cathode. When the Fe2+ was added into the solution, the system was called AP(T)-CC-Fe2+ system in this research. Next, without O2 injection to cathode, O2 was produced by electrolysis of water from various size of anode to provide to the cathode. Afterward, the iron (Fe) replaced the Pt as the anode with zero applied current, which is the system named AF-CC-Shunt. Besides, the Fe was oxidized to generate current and Fe2+, and the organics would be decomposed by Fenton process. The flow rate of oxygen, the initial pH value, the applied current , and the reaction temperature were discussed in the H2O2 formation. The initial formation rate of H2O2 is proportional to the applied current. Moreover, electrode reaction and overall reaction system were combined to make derive kinetic derivation and fit the data of H2O2 formation. The initial pH value and the applied current were discussed in the Fe2+ reduction to find out the optimal current efficiency. Under pH<3, the formation of Fe(OH)3 and Fe2O3 would be prohibited to increase the efficiency. Due to its popular applications in hair dye and artificial fiber synthetic industry, p-Phenylenediamine causes the quite serious environmental pollution and destroys the metabolism of human being. The initial pH value of reaction system was 2.5. The initial Fe2+ concentration and the applied current were discussed in AP-CC-Fe2+ system. The optimal concentration of Fe2+ is 3mM. Higher anodic surface area would interrupt Fenton process due to the domination of p-Phenylenediamine oxidation on the surface of Platinum Titanium mesh. According to the AF-CC-Shunt system in the self electro-generative process, the influences of the temperature on degradation and self-generative current were studied. The degradation efficiency was enhanced, due to higher current generated by rapid oxidation of Fe at higher temperature. Compared with other Electro-Fenton processes, in AF-CC-Shunt system, p-phenylenediamine can be degraded by self electro-generative process without applied current and Fenton reagents.
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Zheng, Zong-Xian, and 鄭宗賢. "The study of zinx oxide nanostructures synthesis aqueous solution method." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/18886905613569311526.
Full textAbstract:
碩士雲林科技大學
光學電子工程研究所
98
In this study, ZnO seed layer was deposited on glass structure by the RF sputtering system, and then nanorods arrays were prepared by low temperature aqueous solution aqueous solution reaction concentration, temperature, time process Variables on structure of ZnO nanorods, the morphology and composition of the ZnO nanorods was observed using Field-emission scanning electron microscopy (FE-SEM) show that the aspect ratios of the ZnO nanorods are enhanced when the concentration is decreased and the temperature is increased, the Energy dispersive spectrometers (EDS) show that Atomic(%) of zinc content are enhanced when the concentration and time are increased , Atomic(%) of oxide content decreased, Atomic(%) of zinc content more than the oxygen atoms, the X-ray diffraction (XRD) patterns show that ZnO nanorods arrays were similar XRD patterns indicating the nanorods in high crystallinity, indicating excellent orientation in the c-axis direction, PL spectra show that the green/uv ratios decreased when ration concentration is increased, multi-stage increased the ZnO nanorods surface area and DSSC efficiencies, ZnO/TiO2 structure increase in dye adsorption, improve DSSC efficiency.
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Yang, ChuaHao, and 楊家豪. "Grown of carbon nanostructures by low-temperature aqueous solution method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/96419061886904564060.
Full textAbstract:
碩士明志科技大學
材料工程研究所
100
This study present a simple method to produce a lot of carbon as micro and nanostructure in aqueous solution at low temperature (85 °C). The structures have been observed two basic units by transmission electron microscopy (TEM): thin carbon nanoribbons, monolayer graphene. This method addition to obtain two basic units and found that synthesize multi-wall carbon nanotube (MWCNTs) without catalyst and carbon basin-shape structure. We further found that the carbon nanoribbons can self-assembly to form ribbon type of graphite nanofibers, carbon nanorings and MWCNTs without catalyst. The basin-shape structure where constitute came from the graphene and nanoribbons edge of fracture. The MWCNTs can become thicker by sticking nanoribbons on the wall, and growth to the micrometers for future.
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Wang, Chen-Yun, and 王貞雲. "Zinc Oxide Nanowires Synthesized by Low-temperature Aqueous Solution Method." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/8bm48k.
Full textAbstract:
碩士國立臺北科技大學
材料科學與工程研究所
95
In this study, zinc oxide nanowires was successfully grown on ZnO/Si substrate using low-temperature aqueous solution method. We firstly study the influences of the ZnO buffer layer on the Si substrate on the crystal direction of zinc oxide nanowires. Then the effects of solution concentration, growth time, and the ratio of Zn(NO3)2 and C6H12N4 in the solution on the morphology and size of zinc oxide nanowires were also investigated. Our experimental results indicate that the zinc oxide nanowires have uniform C-axis preferred orientation when the zinc oxide buffer layer grows along [0001] direction. The surface roughness of zinc oxide buffer layer would affect the nucleus sites of zinc oxide nanowires, the higher the surface roughness is, the larger number of the nucleus sites is, which leads to high number density of nanowires grown. If the solution is stirred incessantly, the growth rate of the nanowires increases. The diameter of zinc oxide nanowires is determined by the concentration of solution. In our experiment, we can obtain the high quality columnar grain with hexagonal structure when the concentration of solution is 0.05 M. If the content of Zn(NO3)2 is more than C6H12N4, the length of zinc oxide nanowires is almost equal and is increased with an increase of reaction time. We also can obtain other geometries of zinc oxide such as ZnO thin film or ZnO nanotube, by suitably controlling the processing parameters of reaction time and concentration.
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Ho, Cheng-Hsuan, and 何承軒. "Recycling Process of Lithium from Aqueous Solution by Electrochemical Method." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/ht4w62.
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碩士大同大學
化學工程學系(所)
107
The electrode of the experiment was prepared from commercially available spinel lithium manganese oxide (LiMn2O4, LMO). The spinel LMO powder was treated with 0.5 M hydrochloric acid. After ion exchange, the LMO is transformed to hydrogen manganese oxide (HMO). The crystal structure of the electrode material is determined via X-ray diffraction spectroscopy (XRD). Cyclic Voltammetry (CV) was used to evaluate electrode stability and redox peaks. In addition, the adsorption and desorption capacity of the electrodes were evaluated by the lithium ion concentration measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The results of the study showed that the structure of the electrode did not change much after the preparation procedure. A novel method for increasing the desorption capacity electrochemically by adding sodium chloride is proposed. The effects of different operating conditions such as initial sodium ion concentration of desorption solution, initial pH of solution, and reaction voltage on the desorption rate of lithium ions were investigated. It is known from experiments that the desorption capacity obtained was 26.39 mg-Li/g-LMO at initial sodium ion concentration to be of 500 ppm, reaction voltage of 3.0 v, and reaction time of 30 minutes. When the initial concentration of lithium was 500 ppm, the reaction voltage was 2.0 v, and the reaction time was 120 minutes, the obtained adsorption capacity was 6.64 mg-Li/g-HMO. The effect of adsorbing and desorbing lithium increases as the reaction voltage increases. From the experiment of combined mode, the electrode has been cyclically operated at least five times and has a high adsorption/desorption capacity of lithium. The electrochemical method does effectively recover lithium ions from aqueous solutions.
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"Application of WATR-CPMG method to the quantitative determination of glucose in dilute aqueous solutions." Chinese University of Hong Kong, 1993. http://library.cuhk.edu.hk/record=b5887771.
Full textAbstract:
by Choy Wing Yiu.Thesis (M.Phil.)--Chinese University of Hong Kong, 1993.
Includes bibliographical references (leaves 115-121).
DESCRIPTIVE NOTE --- p.iii
ACKNOWLEDGEMENTS --- p.v
Chapter CHAPTER ONE: --- BRIEF REVIEW OF THE WATR-CPMG AND OTHER SOLVENT SUPPRESSION METHODS --- p.1
Chapter 1.0 --- Introduction --- p.1
Chapter 1.1 --- Some Common Solvent Suppression Techniques --- p.2
Chapter 1.1.1 --- Brief Summary of Some Common Solvent Suppression Techniques --- p.2
Chapter 1.1.2 --- Criteria for the Evaluation of Solvent Suppression Methods --- p.8
Chapter 1.2 --- Application of the WATR-CPMG Method in Solvent Suppression --- p.10
Chapter 1.2.1 --- The CPMG Pulse Sequence --- p.10
Chapter 1.2.2 --- The Theory of Solvent Suppression by WATR Method --- p.12
Chapter 1.3 --- Scope of this Thesis --- p.15
Chapter CHAPTER TWO: --- OPTIMIZATION OF WATR-CPMG PARAMETERS FOR QUANTITATIVE ANALYSIS IN DILUTE AQUEOUS SOLUTION --- p.19
Chapter 2.1 --- Investigation of the WATR-CPMG Parameters --- p.19
Chapter 2.1.1 --- Use of Ammonium Chloride as Proton Exchange Reagent --- p.19
Chapter 2.1.2 --- The pH Dependence of the Proton Exchange Process --- p.21
Chapter 2.1.3 --- Relaxation Delay Time --- p.27
Chapter 2.1.4 --- Measurement of T1 of Protons In Aqueous Solution --- p.31
Chapter 2.1.5 --- The position of the Carrier Frequency --- p.41
Chapter 2.1.6 --- Modelling of the Off-Resonance Effect --- p.46
Chapter 2.1.7 --- The Tau Value Used in the WATR-CPMG Method --- p.51
Chapter 2.2 --- The Setting of Acquisition Parameters and Data Processing --- p.57
Chapter 2.2.1 --- Digital Resolution and Spectral Width --- p.57
Chapter 2.2.2 --- The Setting of Receiver Gain --- p.60
Chapter 2.3 --- Summary --- p.61
Chapter CHAPTER THREE: --- APPLICATION OF THE WATR-CPMG METHOD TO THE QUANTITATIVE ANALYSIS OF GLUCOSE IN BLOOD PLASMA AND DILUTE AQUEOUS SOLUTION --- p.62
Chapter 3.0 --- Introduction --- p.62
Chapter 3.1 --- Experimental Section --- p.62
Chapter 3.1.1 --- Characterization of the Metabolites in Blood Plasma --- p.62
Chapter 3.1.2 --- Reagents --- p.66
Chapter 3.1.3 --- Solution Preparations --- p.66
Chapter 3.1.4 --- Measurement of Plasma Glucose by Glucose Oxidase Method --- p.67
Chapter 3.1.5 --- NMR Measurement --- p.68
Chapter 3.1.6 --- HPLC Measurement --- p.78
Chapter 3.2 --- Results and Discussion --- p.79
Chapter 3.2.1 --- Analysis of Results --- p.79
Chapter 3.2.2 --- Discussion --- p.84
Chapter 3.2.3 --- Conclusion --- p.85
Chapter CHAPTER FOUR: --- HOMODECOUPLED WATR-CPMG METHOD --- p.86
Chapter 4.0 --- Introduction --- p.86
Chapter 4.1 --- Application of Combined Time Sharing Homodecoupling WATR-CPMG Method for Quantitative Analysis in Aqueous Solution --- p.87
Chapter 4.1.1 --- The Time Sharing Homonuclear Decoupling and Average Hamiltonian Theory --- p.87
Chapter 4.1.2 --- Homodecoupling in Aqueous Solution --- p.89
Chapter 4.2 --- Experimental --- p.90
Chapter 4.2.1 --- The Preliminary Investigation --- p.90
Chapter 4.2.2 --- Homodecoupl ing in 30%D20/70%D20 Solution --- p.97
Chapter 4.2.3 --- Homodecoupling-CPMG (HDCPMG) in Quantitative Analysis --- p.102
Chapter 4.3 --- Conclusion --- p.110
Chapter CHAPTER FIVE: --- CONCLUSION --- p.113
BIBLIOGRAPHY --- p.115
APPENDIX I The Computer Simulation of the Off-Resonance Effect on the Water Signal Suppression --- p.122
APPENDIX II The Computer Simulation Program --- p.125
APPENDIX III The Simulation Data --- p.129
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Tsai, Fang-Pei, and 蔡芳珮. "Comparison of Infrared Sensing Methods for Detection Chloroanilines in Aqueous Solutions." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/99161895005831774005.
Full textAbstract:
碩士中原大學
化學研究所
89
Abstract Infrared optical sensor provides fast and non-destructive method in detection of organic compounds in aqueous solutions. Three modes are frequently used in the infrared sensing devices including the attenuated total reflectance (ATR), transmittance, and reflection-absorption. However, each of them is restrictive for example, ATR is restricted by depth of penetration (dp) and expensive internal reflection elements are required in this method , TA is restricted by materials of film and RA is restricted by the loss of energy. In this work, we suggested two new methods in detection of chloroanilines in aqueous solution. One of them is combined T and SPME, another is combined RA and SPME. Then we compared them with ATR systematically. Because infrared sensing elements are typically coated with hydrophobic film to serve as concentration medium, polyacrylonitril-co-butadiene (PAB) was used in this work for attracting chloroanilines in aqueous solutions. To conduct a fair comparison, analytical parameters, such as the linear range, sensitivity, detection limits, signal-to-noise level, film thickness, and speed of detection, were used in this study. After applied these three modes in detection of seven chloroanilines, we found that each detection mode provides its own advantages in detection.
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Lee, Jian-Hong, and 李建宏. "Growth and characterization of ZnO nanorod arrays by aqueous solution method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/62740394430723619234.
Full textAbstract:
博士國立成功大學
材料科學及工程學系碩博士班
97
To properly utilize the anisotropic properties of one-dimensional ZnO nanostructures in device applications, the control of the ZnO grown on selected positions is necessity since this would largely determine the device functionality and performance. The growth and characterization of ZnO nanorod arrays by aqueous solution method are explored in this study. The main purposes are to develop the patterning techniques and to understand the related mechanisms. ZnO nanorod arrays have been synthesized onto both Si substrate and zinc foil by a low-temperature (＜90℃) aqueous solution method. The effects of the concentration, substrate, and reaction period on the nanorod growth have been investigated in this study. The ZnO nanoparticle seeds were prepared from the zinc acetate in 2-propanol with NaOH, the use of ZnO nanoparticles on substrates as seed-layer helps reduce the diameter of grown ZnO nanorods. The aspect ratios of ZnO nanorods are enhanced when the concentration is decreased. In addition, oriented ZnO nanorod arrays could be obtained onto zinc foil directly without the need of pre-depositing ZnO nanoparticels. A dense and homogeneous ZnO thin film grown on the zinc foil was used as a seed-layer by way of varying the oxidation conditions of zinc foil. The structure of ZnO nanorods onto the zinc foil is single crystalline and grown in the [0001] direction with the wurzite structure. The photocurrent and IPCE are enhanced as the length of the nanorods is increased due to the increase of the surface area of the nanorod. ZnO nanoparticles are the most commonly used as seed-layer materials for the ZnO nanorods growth in the aqueous solution process. However, the preparation of patterned ZnO nanoparticles seedlayer has never been reported. Electrophoretic deposition and nanosphere lithography were combined to fabricate periodic arrays of ZnO nanoparticle seed-layer. The study was focused on the effects of the pH of the suspensions, the surface charge of the particles in the suspension, the deposition characteristics of the deposited ZnO nanoparticle seed-layer, and the ZnO nanorod arrays. By electrophoretic deposition, hollow and solid hexagonal-patterned ZnO nanoparticle seed-layer could be obtained by controlling the processing parameters. Oriented ZnO nanorod arrays are successfully pattern-grown using an organic template by microcontact printing on ZnO-coated Si substrate. The use of SAMs of OTS as a template helps to site-selectively produce ZnO nanorods from an aqueous solution. The growth behavior between contact and noncontact areas was investigated. Different formation mechanisms are proposed, and it is found that the key difference between nanorod and microrod formation is attributed to the direct growth on the ZnO seed-layer and the attraction of homogenerously nucleated microrods by van der Waals force at specific conditions, respectively. The lowest turn-on applied field strength is 4.65 V/μm for dot pattern ZnO nanorod arrays. ZnO nanorods with different array density were synthesized on the hexagonally arranged circular patterns surrounded by nickel membranes prepared by electrodeposition and nanosphere lithography. Electrodeposition of Ni was performed for different durations to control the pore diameter. The pores were used to guide the growth of ZnO nanorods from the exposed ZnO seed-layer. The field emission measurement shows that ZnO nanorod arrays with an array density of 1.73 rods/μm2 has the lowest turn-on field of 2.98 V/μm. The increase of the ZnO array density results in inferior emission properties. Finally, a novel and one-step templating synthetic strategy has been presented in this report for preparation of the aligned TiO2 nanotube and nanorod arrays on Si substrate from a solution and at ambient temperature. In the reported studies, it is common for the template-assisted methods to obtain nanotubes only by removing the core materials through an additional wet etching step and to leave the aligned arrays of inorganic nanotubes on the Si substrate. Therefore, the only structure, i.e. nanotubular structure could be obtained by the template method. However, in our study, we successfully utilized the selective-etching of ZnO nanorod template and the concurrent deposition of TiO2 to prepare the arrays of end-closed TiO2 one-dimensional nanostructures. Furthermore, the different thickness of TiO2 sheaths, leading to the formation of nanotubes or nanorods, can be precisely controlled by the deposition time.
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CHIU, I. LIN, and 邱奕霖. "Photocatalytical Degradation of Dichlorophenols in Aqueous Solution on TiO2 Prepared by CVD Method." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/88040157573130432508.
Full textAbstract:
碩士國立中興大學
環境工程學系
91
This investigation used a tube reactor deposited with TiO2 thin film inside by chemical vapor deposition(CVD)method and a UV lamp with 365nm to study the reaction behavior of dichlorophenols in heterogeneous photocatalysis. The experimental equipment was a batch recycle system. The degradation and dechlorination at different pH’s for 2,3-DCP, 2,5-DCP and 3,4-DCP was determined by HPLC, IC and TOC. The intermediate compounds with the effect of different positions of Cl and OH groups were separated by C-8 column with eluent containing acetonenitrile/H2O (58:42) with 0.1M acetic acid and analysed by HPLC. The results of direct photolysis by UV light indicated the obvious dechlorination of dichloriphenols at higher pH’s. The aromatic intermediate of 2,3-DCP identified by HPLC was chlorohydroquinone(ClHQ). From the comparisons of both [C]/[C0] and Cl- data, it could be stated that complete-dechlorinated intermediates were formed. In the results of the heterogeneous photocatalysis, the removal of dichlorophenols and release of Cl- at high pH’s was better than that at low pH’s. Although different pathway of hydroxyl radials attacking, the aromatic intermediate, ClHQ, was indentified in 2,3-DCP, 2,5-DCP and 3,4-DCP solutions. It was found that the dechlorination intermediate, like phenoxyl product, re-chlorinated in a secondary process. This was supported by the indentified intermediate products : 2,6-DCP from 3,4-DCP and 3,4-DCP from 2,3-DCP. The photodegration of dichlorophenols followed a Lamgmuir-Hinshelwood kinetics, showing rate constant that enhanced with increasing pH’s value.
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Li, Yin-Ming, and 李寅銘. "The Study of Synthesis ZnO Nanorods and Optoelectronic Properties by Aqueous Solution Method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/90792453465024616463.
Full textAbstract:
碩士國立高雄應用科技大學
光電與通訊研究所
99
In this study, we report the aqueous solution method synthesized ZnO nanorods on Si substrate by one-step method and ZnO seed layers assistance. The first part of the experiment, we synthesized ZnO nanorods by one-step method. The influence of precursor concentration was examined by performing the reaction at 95◦C for 13 h with an angle of incline of 45◦ and the concentrations of 0.01, 0.03, 0.05, and 0.1 M. The XRD image shows the relative intensity of the peak corresponding to the (002) plane increases gradually as the concentration increase from 0.01M to 0.1M indicating an improvement in the alignment of ZnO nanorods. We observed that there are two PL peaks in our ZnO nanorods: at UV (375nm) and green (550nm), respectively. In addition, the green emission (550nm) is caused by intrinsic defects in ZnO nanorod. We found that I-V curve shows the dark current reduces as the concentration increases. We also found that the photo-to-dark current ratio reduces as the basic voltage increases. With 0.1V applied bias, it was found that photo-to-dark current ratio were 122, 6.8, 257 and 104, respectively. With 0.5V applied bias, it was found that photo-to-dark current ratio were 53.9, 4.8, 191 and 75.6, respectively. With 3V applied bias, it was found that Saturation Time were 46, 50, 57, and 73min, respectively. The second part of the experiment, we used that Si substrates were first spin-coated with a seed layer to synthesized ZnO nanorods by aqueous solution method. It was perform the reaction at 95◦C for 2 hr with an angle of incline of 45◦ and the concentrations of 0.1M. The XRD image shows the relative intensity of the peak corresponding to the (002) plane were highest than one-step method. The PL spectroscopy shows the FWHM of PL(375nm) peak was less than others. We also found the 550nm peak was less than others. The result shows that defects of ZnO nanorods by seed layers assistance aqueous solution method was lower than one-step method. We found that I-V curve shows the photo-to-dark current ratio were 122, 6.8, 257 and 104, respectively. With 0.1 and 0.5V applied bias, it was found that both the photo-to-dark current ratio were about 326. With 3V applied bias, it was found that Saturation Time were 70min. Finally, we used the ZnO nanorods of possess high crystal quality and the Fabrication of UV Photodetector. We were Design the width spacing and finger width were 100, 150 and 200μm, respectively. With 0.5V applied bias, it was found that Saturation Time were 24.3, 114.9, and 240.2min, respectively. With 3V applied bias, it was found that Saturation Time were 19.16, 73.33 and 175min, respectively. The result shows that the saturation time reduces as the finger width reduces.
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Su, Te-Cheng, and 蘇特正. "Study on the ATP Generation by Biomimetic Chemistry Method in non-Aqueous Solution." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/52335040528522837399.
Full textAbstract:
碩士國立東華大學
化學研究所
89
In a non-aqueous medium , ATP formation was observed from ADP and inorganic phosphate anion by coupling with the reaction between p-benzoquinone and imidazole . The purpose of this study is to investigate the essential mechanism of phosphorylation reaction . Furthermore , in order to clarity the reaction , efforts were also made to find out the optimum analytical conditions for the separation and quantitative analysis of AMP , ADP , and ATP during the reaction process . First of all , in the reaction system , p-benzoquinone and imidazole were found to produce an addition compound , 2-imidazolyl hydroquinone . This compound was then oxidized readily by aerobic oxygen or by unreacted p-benzoquinone , and produced 2-imidazolyl semiquinone anion radicals in DMAC . Naturally p-benzosemiquinone anion radical was also present in the latter case . However in other less polar , less basic non-aqueous solvents , such as THF and acetonitrile , insoluble quinhydrone-type product between the two rather than two kinds anion radicals was observed when excess p-benzoquinone was present in the system .
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Wang, Pei-Ru, and 王珮茹. "Synthesis and Characterization of Al doped ZnO nanowire arrays by Aqueous Solution Method." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/db22mr.
Full textAbstract:
碩士國立臺北科技大學
材料及資源工程系研究所
98
In this study, the cost-effective and low temperature aqueous solution (Reaction temperature is lower than 100℃) method is employed to synthesis of Al doped ZnO nanowire arrays. The parameters include temperature, time and concentration,which are changed for effects in the microstructure and optical properties. The study is acquired in this study and summarized as below: (1)Vertically aligned ZnO nanowires were synthesized via the aqueous solution method on the ZnO seed layer which is deposited by Spin coating on silicon substrates. (2) Deposition of Al (1~3 at%) doped ZnO nanowire arrays and we will observe nanostructures by the analysis. (3) Following the (2), we try to use the same parameters to synthesize from the ITO substrates, and To investigate the improvement of the substrates. The results show a well rectifying behavior and strong photo response to the ultraviolet (UV) lights. Finally,X-ray diffracmeter, optical spectrumeter and transmission electron microscopy were used to study structure, optical properties and microstructure of the composites. As a result, during this study exhibits Al doping of ZnO nanowire has good optical properties, which is suitable for the short-wavelength device application.
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Peng, Chen-Chi, and 彭成基. "Sythesis of ZnO Nanorods Light Emitting Diode by Low-Temperature Aqueous Solution Method." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/p6t82d.
Full textAbstract:
碩士國立臺灣師範大學
光電科技研究所
96
In this study, the aqueous solution method was employed to synthesize one-dimensional well-aligned ZnO nanorod array on p-type Si wafer, and the ZnO nanorod light emitting diode were fabricated by semiconductor technologies. The optimized quality and aspect ratio of ZnO nanorod array was obtained by the mixed aqueous solution (Zinc Nitrate Hexahydrate: Hexamethylenetetramine = 1:1), fixed the reaction time and temperature in 6 hours and 90ºC, respectively. We investigated the nanorods’ surface morphology and the characteristics of photoluminescence with some factors which including reactants concentration, different seeds and substrates. The crystal structure and growth orientation of the ZnO nanorods were characterized by x-ray diffraction and FESEM analysis, respectively. The various of aspect ratio and density of ZnO nanorods were obtained with different reactants concentration and growth time. Photoluminescence spectra of ZnO nanorods reveal UV and visible emission. The ratio of UV and visible light were increased as the reactants concentration increased and the bluish white region were observed on CIE Chromaticity Diagram. I-V curve measurements of the ZnO nanorods light emitting diode that conform to the typical current-voltage characteristics, the turn on voltage is 3.4 V. Compared with bulk and quantum well structure, nano-structures possesses higher internal quantum efficiency and narrow full width at half maximum (FWHM), therefore, it’s useful to enhance the device efficiency and reduce the threshold current. On the century of inadequate energy sources, high quality ZnO nanorods light emitting diode is one of important topics.
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Pötschke, Markus. "Simulation of electric field-assisted nanowire growth from aqueous solutions." Doctoral thesis, 2014. https://tud.qucosa.de/id/qucosa%3A29190.
Full textAbstract:
The present work is aimed at investigating the mechanisms of nanowire growth from aqueous solutions through a physical and chemical modeling. Based on this modeling, deriving an optimized process control is intended. The work considers two methods of nanowire growth. The first is the dielectrophoretic nanowire assembly from neutral molecules or metal clusters. Secondly, in the directed electrochemical nanowire assembly metal-containing ions are reduced in an AC electric field in the vicinity of the nanowire tip and afterwards deposited at the nanowire surface.
To describe the transport and growth processes, continuum models are employed. Furthermore, it has been necessary to consider electro-kinetic fluid flows to match the experimental observations. The occurring partial differential equations are solved numerically by means of finite element method (FEM).
The effect of the process parameters on the nanowire growth are analyzed by comparing experimental results to a parameter study. The evaluation has yielded that an AC electro-osmotic fluid flow has a major influence on the dielectrophoretic nanowire assembly regarding the growth velocity and morphology. In the case of directed electrochemical nanowire assembly, the nanowire morphology can be controlled by the applied AC signal shape. Based on the nanowire growth model, an optimized AC signal has been designed, whose parametrization allows to adjust to the chemical precursor and the desired nanowire diameter.Ziel der vorliegenden Arbeit ist es, mittels physikalischer und chemischer Modelle die Mechanismen des Nanodrahtwachstums aus wässrigen Lösungen zu erforschen und daraus eine optimierte Prozesskontrolle abzuleiten. Dabei werden zwei Verfahren des Nanodrahtwachstums näher betrachtet: Dies sind die dielektrophoretische Assemblierung von neutralen Molekülen oder Metallclustern sowie die gerichtete elektrochemische Nanodrahtabscheidung (engl. directed electrochemical nanowire assembly), bei der metallhaltige Ionen im elektrischen Wechselfeld an der Nanodrahtspitze zunächst reduziert und anschließend als Metallatome abgeschieden werden. Zur Beschreibung der Transport- und Wachstumsprozesse werden Kontinuumsmodelle eingesetzt. Darüber hinaus hat es sich als notwendig erwiesen, elektrokinetische Fluidströmungen zu berücksichtigen, um die experimentellen Beobachtungen zu reproduzieren. Die auftretenden partiellen Differenzialgleichungen werden mittels der Finiten Elemente Methode (FEM) numerisch gelöst. Die Auswirkungen der Prozessparameter auf das Nanodrahtwachstum werden durch den Vergleich von experimentellen Ergebnissen mit Parameterstudien analysiert. Die Auswertung hat ergeben, dass für das dielektrophoretische Wachstum ein durch Wechselfeldelektroosmose (engl. AC electro-osmosis) angetriebener Fluidstrom die Drahtwachstumsgeschwindigkeit und -morphologie maßgeblich beeinflusst. Im Falle der gerichteten elektrochemischen Nanodrahtabscheidung lässt sich die Drahtmorphologie über das angelegte elektrische Wechselsignal steuern. Unter Verwendung des Wachstumsmodells ist ein optimiertes Signal generiert worden, dessen Parametrisierung eine gezielte Anpassung auf den chemischen Ausgangsstoff und den gewünschten Drahtdurchmesser erlaubt.
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Huang, Chin-Yin, and 黃俊嬴. "Development of Infrared Spectroscopic Method for Selectively Detection of Copper Ion in Aqueous Solution." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/82231174042211271520.
Full textAbstract:
碩士中原大學
化學研究所
90
Abstract Infrared (IR) chemical sensors provide fast and simple ways in detection of organic compounds in aqueous solution. However, the detections of high polarity compounds and metal ions in aqueous solution are not achievable by conventional infrared sensing method. In this thesis, we developed evanescent wave type of IR chemical sensors for selective detection of copper ions in aqueous solutions. In this new method, amino acid was derivatized on the surface of hydrophobic film, which has been pre-coated on the sensing element. The metal ion can be detected through the formation of metal complex of ions and the amino acids derivatized phase. This formation of metal complex causes peak shifts in the IR spectra, which can be utilized to monitor the amount of ion quantitatively. Factors, such as the concentration of copper ion, the response time, the pH in the solution, the amount of competing ligands, and the existence of other metal ions, were investigated in order to obtain the optimal conditions for detection of copper ions. Results indicated that formation constants for metal complexes influenced the IR signals significantly. Fortunately, the copper complex exhibits relative large formation constant compared to other commonly co-existed ions in aqueous solution. Therefore, the selective detection of copper in aqueous solution was achievable by amino acid derivatized IR sensor. Other factors, such as pH or concentration of competing ligand, also affected the analytical signals seriously and should be controlled at constant levels. Using the optimal conditions, the detection limited can be lower than 10 ppb and the linear regression coefficients in standard curves can be higher than 0.99 for a concentration range from 5x10-6 M to 2x10-4 M.
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Yang, Chien-Hui, and 楊千蕙. "Synthesis And Characterizations of core/shell-type ZnO/MgO Nanostructures Using Aqueous Solution Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/7ck6y3.
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碩士國立臺北科技大學
材料科學與工程研究所
97
In this study, the cost-effective and low temperature aqueous solution (Reaction temperature lower than 100℃ or less) method is employed to synthesis of ZnO nanorod-MgO shell nanocomposite materials. The processing parameters including temperature, time and concentration are changed to study their effects on the microstructure and properties of the nanocomposites. In the first part, vertically aligned ZnO nanorods were synthesized via the aqueous solution method on the ZnO seed layer which is deposited by RF sputter system on silicon substrates. In the second part, deposition of the MgO shell onto the ZnO core forms the core-shell structures. Finally, the template ZnO nanorods were etched with ammonia to form MgO nanotubes. X-ray diffracmeter, optical spectrumeter and transmission electron microscopy were used to study structure, optical properties and microstructure of the composites. Our experimental results demonstrate that the ZnO/MgO core-shell nanostructures offer better optical properties, which is suitable for the short-wavelength device application.
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Shiu, Chiung-Sh, and 許瓊旭. "Photocatalytical Degradation of 2,4-Dichlorophenol in Aqueous Solution on TiO2 Prepared by CVD Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/35644613613146198914.
Full textAbstract:
碩士國立中興大學
環境工程學系所
94
The tube reactor deposited with TiO2 thin film inside by CVD method and a 365nm UV lamp were used in this investigation to study the reaction behavior of 2,4-DCP in heterogeneous photocatalysis. The experiment equipment was a batch recycle system, and the major controlled parameter was pHs. The photocatalitical degradation of 2,4-DCP in different pH’s were studied with the analysis of HPLC、IC、TOC and GC, varied with reaction time , moreover, the reaction pathway was estmited by identifying the intermediates . The results of the heterogeneous photocatalysis and direct photolysis showed the removal rate of 2,4-DCP was higher at high pH’s .With the addition of titanium dioxide , the removal rate would also increase at the three different pH’s . Totally , we could find the best removal rate of 2,4-DCP in heterogenous photocatalytical system at high pHs . In the UV/TiO2 system , the major mechanism was for dechlorination ; breaking the ring and the mineralization of 2,4-DCP were rarely achieved . Most intermediates existed in the form of organic ring . The photodegradation of 2,4-DCP would follow the simplified Lamgmuir-Hinshelwood kinetics , showing rate constant enchanced with the increasing of pHs .
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Tsai, Shu-Sha, and 蔡淑霞. "Development of Infrared Sensing Method for the Determination ofVolatile Compounds in Aqueous Solutions." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/08716625371462615562.
Full textAbstract:
碩士中原大學
化學研究所
89
ABSTRACT The method based on combination of the technique of headspace solid phase microextraction (HSSPME) to that of attenuated total reflectance (ATR) infrared (IR) sensing probe was developed toward detection of volatile compounds in aqueous solutions. This method can effectively eliminated the problems associated in soaking type of probes, such as pilling hydrophobic film from the sensing elements and the variation of analytical signals caused by the matrix composition. A specially designed sample cell was proposed for this purpose, which allowed to examine the performance of HSSPME/ATR-IR method and its related factors, such as the effect of agitation, headspace volume, sample volume, and temperature. Results showed that a fast speed was observed for the detection of VOCs in the HSSPME/ATR-IR method. The typical time for reaching the maximum analytical signals was around 20 minutes. Much stronger signals were obtained by applying agitation to the aqueous solution and it influences more effectively for lower volatility compounds. The headspace volume influenced the analytical signals strongly for low volatility compounds, but was only slight for highly volatile compounds. An increase in the sample volume can result in stronger analytical signals but limited to a certain signal. By examining five VOCs with different volatility, the obtained linear regression coefficients (R-square) on their standard curves in the concentration range of 5 to 200 ppm were higher than 0.99. The typical detection limit using this method was around a few hundred ppb. The absorbed probe regeneration was highly efficient and typically the regeneration time was shorter than five minutes.
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Lin, Yu-Lung, and 林裕榮. "Application of gold nanoparticles colorimetric method for the detection of mercury ion in aqueous solution." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25763130916226331235.
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碩士高雄醫學大學
醫藥暨應用化學研究所
101
Mercury (II) ion (Hg2+) not only has high toxicity but also causes serious pollution problems. Meanwhile, it also harms people’s health. Therefore, to develop an easy and quick way to detect Hg2+ has become important. This research aims to The main principle of this study is to use the gold nanoparticles’ surface plasmon resonance (SPR) effect. During the detection, the aggregation of AuNPs after the addition of aggregation agents is affected by the presence of Hg2+ and the degree of aggregation shows an inverse proportional to the concentration of Hg2+. Therefore, by observing the absorption maxima of SPR spectra, the concentration of Hg2+ can be predicted. By adjusting the concentration of acetate buffer, pH, anion concentration, the molar ratio between AuNPs and the aggregation agent, the sensing system is optimized. Since the high stability constant between L-cysteine and Hg2+, the proposed method shows high selectivity against Hg2+. As a result, we have developed a simple and fast approach for the detection of Hg2+ by using L-cysteine and unmodified gold nanoparticles. Under the optimal condition, the limit of the detection can be reached down to 100 nM.
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Lin, Hung-che, and 林宏哲. "Development of SPME-IR/ATR method for detection of aromatic amines in aqueous solutions." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/89623315301691736263.
Full textAbstract:
碩士中原大學
化學系
87
The combination of the principle of solid-phase micro-extraction (SPME) with infrared (IR) attenuated total reflection (ATR) provides sensitive method for detection of organic compounds in aqueous solutions. In this work, we employed four types of SPME phases to conjunction with IR/ATR method in detection of aromatic amines in aqueous solutions. These SPME phases include polystyrene, long alkyl chain attached, long-chain alcohol attached polystyrene, and polyisobutylene. Aromatic amines are important pollutants in environmental samples and can be found from various sources. Six chlorinated anilines were studied their basic properties in detection by SPME-IR/ATR method. These compounds include aniline, 4-chloroaniline, 2,4-dichloroaniline, 2,5-dichloroaniline, 3,4-dichloroaniline, and 3,5-dichloroaniline. Results indicated that long-chain alkyl attached polystyrene has the best adsorption properties compared to other polymers. Several parameters were investigated in this work including salt effect, pH, adsorption profiles, partition constants and linearity in detection. The general detection limit for this type of compounds can be lower then ppm.
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Huang, Chien-Lung, and 黃建龍. "Preparation of Aqueous Organically Modified Silicate Solutions for Coatings by the Sol-Gel Method." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/76526659073158584632.
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