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Pansu, Robert. "Photochimie dans les membranes synthétiques de chlorure de Di-Octadecyl, Di-méthyl Ammonium DODAC." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376172522.
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Quentin, Fabienne. "Caractérisation et régulation de protéines de transport membranaire du néphron distal impliquées dans la régulation de l'état acide-base et du bilan du chlorure de sodium par le rein." Paris 6, 2005. http://www.theses.fr/2005PA066069.
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Pansu, Robert. "Photochimie dans les membranes synthétiques de chlorure de di-octadecyl, di-méthyl ammonium (DODAC) : la vésicule de DODAC, mythe ou réalité ?" Paris 11, 1988. http://www.theses.fr/1988PA112122.
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Nous avons étudié le DODAC (Chlorure de Di-Octadecyi, Di-methyl Ammonium) en vue d'application en photochimie. L'organisation de surfactants en vésicules leur attribue des propriétés spécifiques:- La micro-compartimentation a été mise à profit pour séparer un compartiment oxydant et un compartiment réducteur. - Le champ électrique membranaire permet de favoriser et d'orienter une séparation de charges photoinduite. Dans une première partie, nous avons montré, par diffusion quasi élastique de la lumière (QELS), la stabilité des préparations à faible force ionique, et mesuré le rayon des vésicules: 80+8nm. La présence d'un volume interne a été contrôlée par chromatographie et par l'existence d'une réponse aux chocs osmotiques. Le système a été exploité pour montrer l'existence, suggérée par le calcul théorique, à faible force ionique, d'un champ électrique membranaire de contact. Pour cela nous avons utilisé la neutralisation, par un réducteur hydrosoluble, du cation de l'anthracène produit au centre de la membrane, par photoionisation biphotonique. Le réducteur neutralise les cations, seulement s'il est présent dans la phase aqueuse externe. Cela montre la localisation sélective des cations sur la surface extérieure des vésicules et l'existence d'un champ membranaire de contact, à condition que les vésicules ne soient pas minoritaires dans l'échantillon. Or nous avons montré par QELS que les vésicules peuvent être détruites par les ultrasons puis régénérées, avec leur rayon d'origine, par recuit. Les fragments produits sont cinétiquement stables. Dans la deuxième partie, nous avons déterminé en RPE, par l'étude de l'incorporation de sondes chargées, le pourcentage de vésicules dans les échantillons et le potentiel transmembranaire. L'incorporation est mesurée par une réduction sélective de la population externe. La localisation membranaire et la perméabilité de 9 nitroxydes et de deux réducteurs ont été mesurées. Les mesures de surface et de volume intérieurs indiquent que seul 16% du DODAC est sous forme de vésicules. Le retraitement quantitatif des résultats publiés par d'autres auteurs montre que, dans tous les cas, la majorité de l'échantillon est effectivement constituée de fragments de membrane. Le potentiel transmembranaire a été mesuré : il est de l'ordre d'une dizaine de millivolts. Un modèle qui rend compte de la coexistence d'une population, très bien organisée, de vésicules monodisperses de 80nm de rayon et d'un mélange hétérogène de fragments membranaires métastables est proposé.
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Guillot, Benjamin. "Etude de procédés de préparation de surface avant nitruration - fiabilité du procédé." Thesis, Paris, ENSAM, 2016. http://www.theses.fr/2016ENAM0068/document.
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La nitruration gazeuse de pièces en acier de construction est un procédé thermochimique permettant de générer un gradient de propriétés mécaniques à la surface des pièces par diffusion d’atomes d’azote. Les pièces traitées présentent un fort gradient de contraintes résiduelles et de dureté, optimales pour les applications de transmission de puissance utilisées dans les domaines de l’aéronautique ou l’automobile de compétition. L’enrichissement en azote est issu de la décomposition catalytique de l’ammoniac à la surface des pièces en acier. Cependant, le procédé reste extrêmement sensible à l’état de surface des pièces, qui inclue les caractéristiques géométriques, mécaniques mais également chimique, pouvant inhiber les propriétés de décomposition catalytique ainsi que la diffusion de l’azote. Cette désactivation peut avoir différentes origines, comme l’adsorption d’un élément poison de la réaction ou l’encrassement de la surface des pièces. Le phénomène de désactivation catalytique est étudié depuis quelques dizaines d’années. Cependant, peu de publications sont disponibles au sujet de son application dans le cas particulier de la nitruration d’aciers de construction. Comprendre l’inhibition de la nitruration permettrait d’améliorer la fiabilité industrielle de ce procédé. Afin de répondre à cette demande, une démarche expérimentale, basée sur des études de cas industriels et sur une étude bibliographique, a été mis en place. Une étude de pollution issue de résidus d’huile de coupe, de dépôt de carbone et d’empoisonnement au soufre est proposée. De plus, une démarche expérimentale visant à déterminer l’impact de pollutions mécaniques (état mécanique initial) sur le procédé de nitruration est proposée. Des analyses thermogravimétriques couplées à des observations et à la détermination des propriétés mécaniques générées par nitruration permettent d’approfondir la compréhension de ces phénomènes de désactivation des surfaces nitrurées. Suite à cette étude, la capacité d’activation de surface de trois éléments de préparation in-situ, que sont l’oxydation, l’urée et le chlorure d’ammonium, a été déterminé sur les pollutions précédemment étudiéesThe gaseous nitriding of steel parts is a thermochemical process that generates a mechanical properties gradient at the surface by nitrogen diffusion. The treated parts indicate an important residual stress and hardness gradient, optimized for power transmission applications used in aeronautics and motor sports. The increase of nitrogen concentration is due to the catalytic decomposition of ammonia at the iron-based surface of parts. However, the process is extremely sensitive to the surface state of parts that includes geometrical, mechanical but also chemical properties. This state can inhibit the catalytic decomposition properties and the nitrogen diffusion. This deactivation can have different origins, such as the adsorption of a poisoning element or the fouling of the surface of the parts. The catalytic deactivation phenomenon is studied since decades. However, few publications are available in the case of its application in the specific case of the gaseous nitriding of steel. A better understanding of the nitriding inhibition would improve the reliability of this industrial process. In order to answer this demand, an experimental approach, based on industrial case and bibliographical study, is proposed. A pollution study obtained from machining oil residues, carbon deposit, or sulfur poisoning is proposed. Moreover, an experimental approach, aiming to determine the impact of initial mechanical properties on the nitriding process is proposed. Thermogravimetric analyses coupled to observations and mechanical properties analyses enable to develop the knowledge of the nitrided surfaces deactivation processes. After this study, the surface activation capacity of three in-situ processes, namely oxidation, urea and ammonium chloride, over the previously studied contaminations is determined
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Mihailovic, Martine. "Étude expérimentale par microscopie électronique, optique et viscoélasticité d'une transition de phases dans un cristal liquide lyotrope." Paris 11, 1988. http://www.theses.fr/1988PA112285.
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Étude du mélange ternaire chlorure de decylammonium-nh(4)cl-eau. Par cryofracture, cryodecapage et microscopie électronique, observation des micelles de la phase nématique, puis de l'organisation de leurs centres de gravite dans des plans à la transition nématique-smectique; proposition d'un modelé de propagation de la surface de rupture. Au niveau macroscopique (microscopie optique, viscoélasticité), étude d'une instabilité en zig-zag d'une ligne de desinclinaison dans la phase lyotrope nématique, avec même variation thermique des constantes d'élasticité que pour un thermotrope, et de l'augmentation de la viscosité apparente de cisaillement pour laquelle on donne une interprétation purement lyotrope.
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Buchert, Pascale. "Polymerisation d'un monomere cationique, le chlorure de methacryloxyethyltrimethylammonium, en microemulsion inverse : formulation, caracterisation et comportement rheologique des microlatex formes." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13106.
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Des poly (chlorure de methacryloyloethyltrimethylammonium) (madquat) solubilises dans des microgouttelettes d'eau dispersees dans une huile ont ete prepares par polymerisation en microemulsion inverse. Les microlatex formes presentent des comportements newtoniens sous cisaillement jusqu'a des fractions volumiques de 50% et rheo-fluidifiantes au dela
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Talbaoui, Ahmed. "Etude en microscopie électronique par cryofracture des systèmes chlorures et bromure de dodécylamine-eau." Rouen, 1989. http://www.theses.fr/1989ROUES006.
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Après une importante bibliographie concernant les phases lyotropes et les techniques cryogéniques en microscopie électronique, l'auteur expose les résultats de ses observations en cryofracture sur les systèmes du titre. Description de la transition lamellaire-nématique et comparaison aux modèles présentés par d'autres auteurs. Discussion de la validité de la technique de cryofracture pour ce type de systèmes
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Gudgel, Katherine Ann. "Growth of ammonium chloride dendrites." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/289878.
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The ammonium chloride-water system has been used extensively as a transparent metal analog to model solidification in binary metal alloys. In this work, the growth rate and morphology of NH₄Cl dendrites grown from aqueous solutions were studied. Since an accurate knowledge of the materials parameters is essential to predicting the growth behavior, the equilibrium segregation coefficient was measured and a detailed analysis of the other NH₄Cl-H₂O materials properties cited in the literature was conducted. Isothermal experiments on bulk NH₄Cl-H₂O samples confirmed that the previously reported discontinuity in the growth rate as function of undercooling and associated transition from <100> oriented slowly growing dendrites to rapidly growing <111> dendrites are not artifacts of the sample geometry. Directional solidification experiments conducted to study the dendrite growth morphology revealed oscillations in both the growth rate and orientation. Results from these studies show that both the undercooling at which the <100> to <111> transition occurs and the peak velocity vary with composition. However, the observed shifts toward smaller apparent undercoolings and the narrowing of the oscillations at higher drive velocities result from changes in the local composition caused by the velocity and orientation dependencies of the partition coefficient. The oscillatory behavior of the <111> dendrites can be predicted using the residual <100> compositional field and the applied temperature gradient. By using an anisotropic segregation coefficient, the slow and fast growth rates can be separately modeled as a function of undercooling using the standard dendrite growth equations. While the transition to the <111> morphology can be attributed to the anisotropy in the k-value, several modifications need to be made to the existing dendritic growth models in order to describe the critical transition. Due to the complex relationships between the non-equilibrium segregation coefficient, composition, and growth rate, some of these modeling efforts have been left to future researchers. In addition to the inclusion of the overall anisotropy, our experiments indicate that the long-range compositional and thermal field effects must be incorporated into the dendrite growth models to explain the difference in growth rates of <111> Primary branches when <111> or <100> side-branches are present.
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Lavigne, André. "Oxydations cupro-catalysees des amines aliphatiques : etudes mecanistiques et applications synthetiques." Paris 6, 1987. http://www.theses.fr/1987PA066470.
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Preparation de nitriles a partir d'amines primaires et d'alpha -aminoacides. Les acides amines monosubstutitues rch(nh::(2))co::(2)h donnent le nitrile rcn, alors que les acides amines disubstitues rr'c(nh::(2))co::(2)h conduisent a l'azine rr'c=n-n=cr'r. Les mecanismes proposes font intervenir le cuivre (iii), forme in situ a partir du cuivre (i) et de l'oxygene
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Mejdi, Hechmi. "Synthèse et étude du comportement dans l'amidure de sodium des chlorures d'azoniaspiro(x,y)alcanes substitués." Lille 1, 1992. http://www.theses.fr/1992LIL10133.
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Dans une première partie nous avons synthétisé des chlorures de 1-aryl-6-azonia (et de 6-aryl-5-azonia) spiro[5,5] ( et [4,5]) undécanes (et décanes). Les sels de benzyltrialkylammonium, une fois traités par des bases fortes, génèrent des ylures qui donnent principalement des réarrangements (2,3) type SOMMELET-HAUSER et (1,2) type STEVENS. Nous avons soumis aux mêmes conditions réactionnelles, les chlorures de 1-aryl-6-azoniaspiro[5,5]undécanes ; ces sels conduisent principalement aux 1-pipéridino-2-arylcyclopentanes résultant d'un réarrangement sigmatropique (1,2) hautement diastéréosélectif et à des amines éthyléniques provenant d'un mécanisme d'élimination d'HOFMANN. L'action de l'amidure de sodium sur les chlorures de 6-aryl-5-azoniaspiro[4,5]décanes donne suivant le substituant différents composés provenant de réactions de réarrangements, de bêta élimination et de «réduction». L'étude en résonance magnétique nucléaire des sels d'azoniaspiro[x,y]alcanes, montre que tous les protons sont différenciés, elle a permis de prévoir la structure de ces molécules
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Yang, Jeongwoo. "Fate and effect of alkyl benzyl dimethyl ammonium chloride in mixed aerobic and nitrifying cultures." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19871.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Spyros G. Pavlostathis; Committee Member: Ching-Hua Huang; Committee Member: John A. Pierson.
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Bahri, Hamed. "Thermodynamique dans les milieux diphasés dispersés : cas des solutions micellaires et des microémulsions." Paris 6, 1986. http://www.theses.fr/1986PA066280.
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Déduction de relations théoriques générales liant dans les systèmes liquides diphasés, les grandeurs observables "globales" aux grandeurs "locales" dans les différentes phases. Exposé de définitions et de notions thermodynamiques. Etablissement de relations générales pour les grandeurs molaires partielles. Etudes du cas d'un système réel : bromures d'alkyltrimethylammonium en milieu eau-kcl, qui montre que les solutions micellaires en milieu salin concentré peuvent être considérées comme un système diphasé. Données sur le partage d'un soluté moléculaire aniline en milieu micellaire. Etudes des volumes molaires partiels des constituants d'une microémulsion, etc. . .
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Dorreyatim, Mohammad. "Cyclic Polarization of AA 3102 in Corrosive Electrolytes Containing Sodium Chloride and Ammonium Sulfate." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc955069/.
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Corrosion of all aluminum microchannel heat exchangers present a challenge in automotive and heating, ventilation, and air conditioning (HVAC) industries. Reproducibility of Salt Water Acetic Acid Test (SWAAT) has been questioned and a need to new corrosion tests with better reproducibility has risen. Cyclic polarization, that is an electrochemical test, was explored for its suitability for the assessment of AA 3102 tube material that is currently a popular aluminum alloy used in manufacturing of heat exchanger.
Corrosive electrolytes containing 3.5 % sodium chloride with 0.5 % ammonium sulfate (high chloride) or 0.5 % sodium chloride with 3.5 % ammonium sulfate (high sulfate) at their pH or acidic (pH=4) were used to measure corrosion potential (Ecorr), protection potential (Epp), pitting potential (Epit), Tafel constants (βa and βc), corrosion rate (mpy). Corrosive electrolyte used in SWAAT test (4.2% Sea Salt at pH 2.9) was also used to compare corrosion resistance of AA 3102 in SWAAT electrolyte compared to the other electrolytes used in this research. Scanning electron microscopy (SEM) was used to observe and document sample surface corrosion damage after each electrochemical test on all samples.
Results of the cyclic polarization tests indicated that SWAAT electrolytes was the most aggressive electrolyte resulting in highest corrosion rates compared to all other electrolytes used in this investigation. SEM results indicated AA 3102 alloy exhibited higher pitting tendency in electrolytes with high sodium chloride whereas high sulfate electrolytes cause appearance of uniform corrosion surface damage on this alloy. Both high sulfate and SWAAT electrolytes showed intergranular corrosion but high chloride electrolyte showed severe pitting of AA 3102.
Mohammad Navid Dorreyatim- Cyclic Polarization of AA 3102 in Corrosive Electrolytes Containing Sodium Chloride and Ammonium Sulfate. Master of Science (Mechanical and Energy Engineering), December 2016, 98 pp., references, 31 titles.
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Yu, Jiefei. "Coupled Nitrate Reduction and Ammonium Oxidation in Electrochemical Treatment for Nitrate Brine Wastes." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1289943689.
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Wills, Peter. "Novel biocidal formulation." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/novel-biocidal-formulation(776ed624-6717-496f-9b31-ad2edce8e24b).html.
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In this modern age, society has become much more aware of the danger bacteria can have on people's health. Personal and household antimicrobial formulations are commonly used within the home to lower the levels of harmful bacteria such as E. Coli, Salmonella and Pseudomonas. The active which kills the bacteria within the formulation is described as a biocide. This research looks at the often neglected potential of cationic polyelectrolyte as a biocide, firstly within solution and secondly in creating an antimicrobial surface. The solution properties and antimicrobial activity for a range of commercially available cationic polyelectrolytes (polymeric quaternary ammonium compounds (QAC) and biguanides) of differing molecular weights were investigated. All polyelectrolytes were observed to have some level of antimicrobial activity. The second phase of this research investigated polyelectrolyte/surfactant/water mixture of similar charge (cationic). Two QAC surfactants were investigated: Alkyl (C12 70%; C14 30%) dimethyl benzyl ammonium chloride (BAC) and Didecyldimethylammonium chloride (DDQ). At a critical concentration, these mixtures segregatively phase separate into a surfactant rich upper phase and polyelectrolyte rich lower phase. This phase separation phenomenon was investigated in respect of surfactant and polyelectrolyte type as well as polyelectrolyte molecular weight. Surfactant type was observed to be the dominant factor in determining the onset of phase separation and by mixing different ratios of surfactants the ability to tune this phase separation concentration was shown. Dilute solutions of these mixtures well below their respective phase separation concentration were then deposited onto glass substrates via a drop cast or inkjet printer method. The surfactant/polyelectrolyte film composites left after drop evaporation ranged from an amorphous film to nodular like structures. The ability to order/structure actives onto a surface could alter active adhesion and surface roughness properties of the film. This change in surface property could consequently affect antimicrobial performance.
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Svensson, David. "Synthesis and characterisation of polyelectrolytes based on polymers of diallyldimethyl ammonium chloride and poly(styrene-co-butadiene)." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-82344.
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In printed electronics there are many polyelectrolytes to choose from. While polyelectrolytes such as polystyrene sulfonic acid can fulfill many ofthe desired functionalities of a semiconductor, there is a need for other polyelectrolytes with other functionalities, such as functionality at low airhumidity and better cross-linking possibilities, while still functioning as a good semiconductor.Within this thesis, there is a description of general polyelectrolytes, as well as various usages.The synthesis and characterization of new polyelectrolytes that have been developed, based upon diallyldimethyl ammonium chloride (DADMAC)and a derivative of polystyrene sulfonic acid (PSSH) is described.The study and experimental testing of the polymers as polyelectrolytes under different conditions is described.
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Thomas, Fabien. "Mécanismes de rétention à l'interface alumine-solution aqueuse." Nancy 1, 1987. http://www.theses.fr/1987NAN10444.
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Le mécanisme d'adsorption à l'interface alimine-solution aqueuse a été étudié dans le cas de tensioactifs anioniques (alkylbenzènesulfonate de sodium) et de tensioactifs cationiques (chlorure d'alkyldiméthylbenzyl ammonium). Les propriétés structurales, texturales, superficielles des adsorbants ainsi que les propriétés électrochimiques ont été déterminées
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Duggirala, Ravi Kumar. "Double diffusive convection during solidification of ammonium chloride - water (NH4CL-H20) mixture in a trapezoidal cavity." FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/3095.
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The effect of the initial concentration of ammonium chloride (sub eutectic: C < 19.8 wt. % and eutectic Ce= 19.8 wt. %) and boundary temperatures (Tcold = -30 0C to -10 0C) on the solidification process is examined. Particle Image Velocimetry (PIV) is used in this study to measure the velocity fields in the melt during the solidification process. The distributions of temperatures at discrete locations in the solution and the boundary walls were measured. This study focuses on the solidification of an ammonium chloride-water (NH4Cl- H2O) solution in a trapezoidal cavity with one and two inclined cooling walls.
The thermosolutal convective flow strongly influenced the rate of freezing. An increase in thermal driving force increased the rate of freezing. Increased initial concentration retarded the freezing process and primarily affected the structure of the solid and mush regions.
The results of this study will contribute in understanding the phenomena and bridge the gap between the engineering aspect and physics background for the dynamics of solid phase formation during castings, ingots, and polymerization.
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Brooks, Matthew A. "Breakpoint Chlorination as an Alternate means for Ammoia-Nitrogen removal at a Water Reclamation Plant." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/9858.
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Numerous wastewater treatment processes are currently available for nitrogen removal or ammonia conversion to nitrate. Those that are economically feasible rely mostly on microbiological processes, which are only effective when the microorganisms remain in a healthy state. If a biological process upset was to occur, due to a toxic shock load or cold weather, it may result in a discharge of ammonia or total nitrogen into the receiving water body. The impact of such a discharge could have deleterious effects on aquatic life or human health. The main objective of the breakpoint pilot study was to define optimum breakpoint pilot plant operating conditions which could then be applied to the design of a full scale breakpoint facility and serve as an emergency backup to biological nitrification.
A pilot study was built on site at the Upper Occoquan Sewage Authority's Regional Water Reclamation Facility in Centreville Virginia. Testing was conducted in two phases (I and II) over a two year period in order to determine the operating conditions at which the breakpoint reaction performed best. Tests were performed during Phase I to determine the optimum operating pH, Cl₂:NH₃-N dose ratio, S0₂:Cl₂ dose ratio, and the minimum detention time for completion of the breakpoint reaction. Other testing done during Phase I included several special studies; including examination of appropriate analytical methods for monitoring breakpoint reactions, and investigation of the breakpoint reaction by-product nitrogen trichloride. Phase II testing examined how varying breakpoint operating temperatures, varying influent ammonia concentrations, higher influent organic nitrogen concentrations, and higher influent nitrite concentrations influenced the performance of the breakpoint pilot operation.
Averages of data from operation at three different rapid mix pHs (7.0, 7.5, and 8.0) showed that pilot performance (i.e., ammonia oxidation) improved and the reaction was more stable at the higher operating pHs 7.5 and 8.0. Examination of dose ratios used during the study showed that the ideal operating ratios for this particular water was around 8:1 Cl₂:NH₃-N for the breakpoint reaction and 1.3:1 S0₂:Cl₂ for the dechlorination reaction. Although detention times for completion of the breakpoint reaction varied with pilot influent temperature, it generally required around 30-35 minutes to reach ammonia concentrations of < 0.2 mg/L NH₃-N at 8-12°C. Completion of the breakpoint reaction was found to be quickest at 20°C (the highest water temperature tested at the pilot).
The tests of varying influent ammonia concentrations showed that although higher influent ammonia concentrations (11.0 mg/L) resulted in faster ammonia oxidation rates initially, the pilot operated better and had the same final performance results when the influent ammonia was lowered.
Increasing the organic nitrogen concentrations (~ 1.0 mg/L) in the pilot influent resulted in a slightly higher Cl₂:NH₃-N dose ratio needed to reach breakpoint, a higher S0₂:Cl₂ dose needed to dechlorinate, and resulted in the formation of numerous disinfection byproducts. Increasing the nitrite concentration in the pilot influent increased the chlorination dose requirement.Master of Science
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Oh, Seung Dae. "Metagenomic and metatranscriptomic investigation of microorganisms exposed to benzalkonium chloride disinfectants." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52928.
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Benzalkonium chlorides (BACs) are widely used, broad-spectrum disinfectants and frequently detected in the environment, even at toxic levels for life. Since such disinfectants can induce broad resistance capabilities, BACs may fuel the emergence of antibiotic resistance in the environment. A substantial body of literature has reported that exposure to BACs causes antibiotic resistance; yet, other studies suggest that the resistance linkage is rare, unsystematic, and/or clinically insignificant. Accordingly, whether or not disinfectant exposure mediates antibiotic resistance and, if so, what molecular mechanisms underlie the resistance link remains to be clearly elucidated. Further, understanding how microbial communities degrade BACs is important not only for alleviating the possible occurrence of antibiotic resistance but also reducing the potential risks to environmental and public health.
An integrated strategy that combines metagenomics, metatranscriptomics, genetics, and traditional culture-dependent approaches was employed to provide novel insights into these issues. The integrative approach showed that a microbial community exposed to BACs can acquire antibiotic resistance through two mechanisms: i) horizontal transfer of previously uncharacterized efflux pump genes conferring resistance to BACs and antibiotics, which were encoded on a conjugative plasmid and co-selected together upon BACs and ii) selective enrichment of intrinsically multi-drug resistant organisms. Further, a microbial community adapts to BAC exposure via a variety of mechanisms, including selective enrichment of BAC-degrading species and amino acid substitutions and horizontal transfer of genes related to BAC resistance and degradation. The metatranscriptomic data suggests that the BAC-adapted microbial community metabolized BACs by cooperative interactions among its members. More specifically, Pseudomonas nitroreducens cleaved (i.e., dealkylated) BACs, metabolized the alkyl chain (the dealkylated product of BACs), and released benzyldimethylamine (the other product of BACs), which was further metabolized by other community members (e.g., Pseudomonas putida).
Collectively, this study demonstrates the role of BACs in promoting antibiotic resistance and advances current understanding of a microbial community degrading BACs. The results of this work have important implications for (appropriate) usage of disinfectants and for assessing, predicting, and optimizing biological engineering processes treating BAC-bearing waste streams.
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Galbraith, S. D. "The response of potassium chloride (KCl), ammonium nitrate (AN) solutions and emulsion explosives to plate impact loading." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599271.
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The aim of this study was to investigate the dynamic properties of potassium chloride, AN solutions and a commercial emulsion explosive and to understand their response in terms of shock theory and material properties. A plate impact facility was used to shock the KCl, subjecting it to a uni-axial strain state for the duration of the measurements. Stress and strain histories were recorded using piezo-resistive gauges. KCl is an ionic crystal which, when subject to shocks above 2.2 GPa, has a martensitic phase transformation. The stress histories were explained in terms of the shock and release waves. A novel technique was used to record the reverse phase transformation and to calculate the hysteresis. The assumption that a uni-axial strain state exists behind a phase transformation was verified, for the first time, experimentally. Two techniques were demonstrated that reduce and quantify the piezo-electric response of KCl. Conclusions from this investigation were analysed by two different types of computational simulation. Using a similar methodology to the KCl work a technique has been developed to determine experimentally the Hugoniot of liquids up to pressures of 10 GPa. The Hugoniots of a variety of AN solutions of different strengths and temperatures were recorded. The results were shown to agree with the predictions of two simple equations of state. The technique developed for AN solutions was applied to a commercial emulsion explosive (based on an AN solution) and the Hugoniot determined. The explosive was sensitised by adding quantities of glass micro-balloons and the pressures which induced the first stages of reaction for a given sensitisation were deduced.
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Craig, Matthew Rankin. "RT-PCR Localization of Phosphoenolpyruvate Carboxykinase (PEPCK) mRNA in Rat Proximal Tubule Segments During Ammonium Chloride Acidosis." VCU Scholars Compass, 1999. http://scholarscompass.vcu.edu/etd/4493.
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In metabolic acidosis, the early increase in PEPCK mRNA and enzyme protein content contributes to the accelerated rates of ammonium and glucose formation. In situ hybridization demonstrated that expression of PEPCK was confined to medullary rays of rat kidney cortex in controls and spread throughout the cortex 10 hours following NH4Cl feeding (Am.J. Physiol., 267: F400, 1994). To identify the specific nephron segments expressing PEPCK in control and acidotic conditions, the mRNA for PEPCK along the nephron of the rat kidney was localized using the technique of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected S1, S2 and S3 segments of the rat proximal tubule. Two-millimeter segments of tubule were permeabilized, the mRNA reverse transcribed using oligo-dT as a downstream primer and the eDNA product amplified by PCR (35 cycles). Primers specific for β-actin were used to confirm transfer of tubule, and only tubules positive for β-actin were amplified with primers specific for PEPCK. Both primers were designed to span at least one intron to avoid amplification of genomic DNA. The PCR products were detected using agarose gel electrophoresis and ethidium bromide staining. Verification of PCR product was performed by restriction enzyme digestion.
Under control conditions, the number of tubules expressing PEPCK mRNA as detected by RT-PCR was greatest in the S3 segment, moderate in the S2 segment, and least in the S1 segment of the proximal tubule. Ten hours after gavage feeding of 20- mmol/kg bodyweight NH4Cl, strong signals for PEPCK were detected in all three proximal tubule segments. These data demonstrate the ability of the rat kidney cortex to modulate the expression of PEPCK mRNA along the proximal tubule under physiological conditions, and to increase expression of PEPCK mRNA during metabolic acidosis by the recruitment of additional cells in the proximal nephron.
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Hajaya, Malek Ghaleb. "Fate and effect of quaternary ammonium antimicrobial compounds on biological nitrogen removal within high-strength wastewater treatment systems." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41113.
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High strength wastewater (HSWW) generated in food processing industries is characterized by high organic carbon and nitrogen content, and thus high oxygen demand. Biological nitrogen removal (BNR) is a technology widely used for the treatment of HSWW. Food processing facilities practice sanitation to keep food contact surfaces clean and pathogen-free. Benzalkonium chlorides (BACs) are cationic quaternary ammonium antimicrobial compounds (QACs) common in industrial antimicrobial formulations. BAC-bearing wastewater generated during sanitation applications in food processing facilities is combined with other wastewater streams and typically treated in BNR systems. The poor selectivity and target specificity of the antimicrobial BACs negatively impact the performance of BNR systems due to the susceptibility of BNR microbial populations to BAC. Objectives of the research were: a) assessment and quantification of the inhibitory effect of QACs on the microbial groups, which mediate BNR in HSWW treatment systems while treating QAC-bearing HSWW; b) evaluation of the degree and extent of the contribution of QAC adsorption, inhibition, and biotransformation on the fate and effect of QACs in BNR systems. A laboratory-scale, multi-stage BNR system was continuously fed with real poultry processing wastewater amended with a mixture of three benzalkonium chlorides. The nitrogen removal efficiency initially deteriorated at a BAC feed concentration of 5 mg/L due to complete inhibition of nitrification. However, the system recovered after 27 days of operation achieving high nitrogen removal efficiency, even after the feed BAC concentration was stepwise increased up to120 mg/L. Batch assays performed using the mixed liquors of the BNR system reactors, before, during, and post BAC exposure, showed that the development of BAC biotransformation capacity and the acquisition of resistance to BAC contributed to the recovery of nitrification and nitrogen removal. Kinetic analysis based on sub-models representing BNR processes showed that BAC inhibition of denitrification and nitrification is correlated with BAC liquid-phase and solid-phase concentrations, respectively. Simulations using a comprehensive mathematical BNR model developed for this research showed that BAC degradation and the level of nitrification inhibition by BAC were dynamic brought about by acclimation and enrichment of the heterotrophic and nitrifying microbial populations, respectively. The fate and effect of BACs in the BNR system were accurately described when the interactions between adsorption, inhibition, and resistance/biotransformation were considered within the conditions prevailing in each reactor. This work is the first study on the fate and effect of antimicrobial QACs in a continuous-flow, multi-stage BNR system, and the first study to quantify and report parameter values related to BAC inhibition of nitrification and denitrification. Results of this study enable the rational design and operation of BNR systems for the efficient treatment of QAC-bearing wastewater. The outcome of this research provides information presently lacking, supporting the continuous use of QACs as antimicrobial agents in food processing facilities, when and where needed, while avoiding any negative impacts on biological treatment systems and the environment.
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Tsai, Tsung-hsun 1961. "Hydrodynamical instability of the mushy layer during directional solidification of ammonium chloride solution in a Hele-Shaw cell." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282278.
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Experiments of directional solidification in a Hele-Shaw cell, 240 mm x 245 mm x 1 mm, were carried out to study the effects of convective flows and the evolution of structure in the "mushy layer", consisting of fluid and crystallites. Three different concentrations of ammonium chloride (NH₄Cl) solution, 26%, 27% and 28%, with a constant bottom cooling temperature ranging from 5°C to -20°C were used as an analogue model for metallic alloy systems. The experimental design included techniques using Peltier heat pumps along with PID feedback control for temperature regulation. A shadowgraphic visualization method made possible the simultaneous observation of the evolution of convection in the liquid region and the phenomena of chimney formation within the mushy layer. More than one hundred runs were carried out. Temperature information and simultaneously acquired digital images were recorded automatically. The time evolution of the solidification process was traced by image processing technique from the digital images. Results show that the phenomenon of intermittent plumes frequently occurs. The number of plumes near the liquid-mush interface decreases from a larger number in the beginning to about the same number of high plumes in the liquid region or chimneys in the mush. The number of chimneys is more static than that of plumes due to the relatively low speed of solidification or dissolution. The mush consists of three different layers. A thin layer of generally upward oriented crystal forms rapidly in the beginning, followed by a second layer aggregate gradually covering it. Finally a third layer of dendritic crystals dominates the top of the growing mush. Preliminary experiments in a Hele-Shaw cell inclined at 21 degrees caused the mush structures to develop differently than in the normal geometry. The significant differences include the dendritic crystal form, the lacunae of the mush, the shape of the chimneys, and the porosity changes of the structures. Directions for future research are suggested.
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Lang, Christopher M. "Development of quaternary ammonium based electrolytes for rechargeable batteries and fuel cells." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-10262006-140639/.
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Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2007.Kohl, Paul, Committee Chair ; Bottomley, Lawrence, Committee Member ; Eckert, Charles, Committee Member ; Fuller, Tom, Committee Member ; Teja, Amyn, Committee Member.
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Fuska, Jana. "The effect of ammonium chloride and leupeptin on the concentration of prosaposin in endosomes and lysosomes of Marshall cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0025/MQ50770.pdf.
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Buehlmann, Peter Hamilton. "Balancing Bromate Formation, Organics Oxidation, and Pathogen Inactivation: The Impact of Bromate Suppression Techniques on Ozonation System Performance in Reuse Waters." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/93530.
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Ozonation is an integral process in ozone-biofiltration treatment systems and is beginning to be widely adopted worldwide for water reuse applications. Ozone is effective for pathogenic inactivation and organics oxidation: both increasing assimilable organic carbon for biofiltration and eliminating trace organic contaminants which may pose a threat to human health. However, ozone can also form disinfection byproducts such as bromate from the oxidation of naturally occurring anion bromide. Bromate is a known human carcinogen and is regulated by the EU, WHO, and USEPA to a maximum limit of 10µg/L. In waters high in bromide, especially above 100µg/L, bromate formation becomes a major concern. In the secondary wastewater effluent studied, bromide concentration may exceed 500µg/L. Several bromate suppression techniques have been devised in previous work, including free ammonia addition, monochloramination, and the chlorine-ammonia process. While free ammonia addition was not found to adequately reduce bromate formation below the required MCL, monochloramine addition and the chlorine-ammonia process were found to be effective. However, the impact of these chemical suppression techniques on organics oxidation and disinfection has not been fully studied. This study explored the impact of these bromate suppression techniques at a wide range of ozone doses on bromate formation, pathogenic inactivation, ozone-refractory organics oxidation through the surrogate 1,4-dioxane, and N-nitrosodimethylamine (NDMA) formation. Additionally, bromate suppression mechanisms of monochloramine were explored further through a variety of different water quality parameters, such as through hydroxyl radical exposure and ultraviolet absorption spectrum measurements, which were correlated and utilized to develop a hydroxyl radical exposure predictive model.Master of Science
Ozone is a powerful oxidant used in water treatment in order to degrade contaminants of emerging concern into less harmful moieties and to inactivate pathogens. Upon application to process water, ozone quickly reacts with constituents in the water to form hydroxyl radicals: the most powerful oxidant in water treatment. These hydroxyl radicals, though with extremely short half-lives, are able to degrade ozone-recalcitrant organics, such as 1,4-dioxane through a process called advanced oxidation. Ozone itself also has the capability of inactivating a multitude of pathogenic organisms, including viruses Giardia and Cryptosporidium parvum when specific contacts times are met. However, ozone does have the potential to form disinfection byproducts such as Nnitrosodimethylamine (NDMA) and bromate. NDMA, though not currently regulated by the United States’ Environmental Protection Agency (USEPA), has a drinking water health advisory limit of 10ng/L in the State of California. Bromate, on the other hand, is a known human carcinogen regulated to 10µg/L by the USEPA. Formed within the ozone system from the naturally occurring ion bromide, bromate can be limited through various chemical treatments such as ammonia addition, pH adjustment, monochloramination, and the chlorine-ammonia process. To date, these methods of bromate suppression have not been comprehensively studied in terms of bromate suppression as well as disinfection and organics oxidation in water reuse systems. The purpose of this research was to minimize bromate formation while ensuring NDMA formation was minimized, and disinfection and organics oxidation were maximized. Through this study, system efficiencies were improved and water quality for future generations will be improved.
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Moundanga, Iniamy Maurice. "Stockage chimique de l'énergie thermique : étude du couple composé d'insertion du graphite-chlorure de magnésium/ammoniac dans un prototype de laboratoire." Grenoble INPG, 1993. http://www.theses.fr/1993INPG0056.
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Le but de ce travail etait l'etude de l'action de l'ammoniac sur les composes d'insertion graphite-chlorure de magnesium en vue du stockage chimique de l'energie thermique. Nous avons montre que, pour obtenir un compose riche de 1er stade, il est necessaire d'effectuer une coinsertion de mgcl#2 avec cocl#2. Les conductivites thermiques de ces composes d'insertion ont ete mesurees. La reaction des composes d'insertion binaires graphite-mgcl#2 (2eme stade) et des composes d'insertion ternaires graphite-mgcl#2-cocl#2 (1er stade) avec l'ammoniac a ete etudiee en lit fixe dans differentes conditions experimentales. Les produits obtenus au cours de cette reaction peuvent etre assimiles a des composes d'inclusion du graphite. La texture de ces composes est favorable aux transferts de chaleur et de matiere au niveau de chaque grain. L'etude des cinetiques de reaction ainsi que l'estimation des puissances extraites par le fluide caloporteur (thermicite de la reaction) donnent des resultats plus satisfaisants que ceux obtenus avec le couple ammoniac-chlorure de magnesium non insere. Ce dernier peut donc etre remplace avantageusement par ses composes d'insertion dans les processus de conversion de l'energie
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Fava, Stefano G. "Effects of chlorine and ammonia compounds on the bioenergetic physiology of rainbow trout, Oncorhynchus mykiss." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0009/MQ31829.pdf.
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Grigonis, Aidas. "Benzalkonio ir metenamino analogų antimikrobinio aktyvumo nustatymas in vitro ir jo priklausomybė nuo aerozolio dalelių krūvio." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070214_152534-59492.
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Antibacterial effectiveness in vitro of the original quaternary ammonium compounds that were synthesized in the Laboratory of Biologically active substances was determined and the dependence of this activity upon chemical structure of the compound was established. Also generalisations have been made concerning the regularity of this dependency, the effectiveness of the compounds was compared to benzalkonium chloride, their advantages and disadvantages were discussed. Acute toxicity of the most effective compound was established and compared to that of benzalkonium chloride.
It was found that these compounds showed good antibacterial activity against Gr+ and Gr- bacteria and low toxicity, thus this original data was summarized in the patent Nr. 4712.
For the first time it was found that upon disintegration of quaternary methenamonium compounds new quaternary ammonium compounds, aldehydes and ammonia are produced. The first two of the three show further antimicrobic activity.
Using quaternary ammonium salts and cholrhexydine a biocide for disinfection was created. The created biocide was tested for effectiveness when used for disinfection of air in the premises, horizontal and vertical surfaces. The compound was used in the form of aerosols and electro-aerosols. The research data showed that strong concentrations of Dezinfektas IV are necessary (up to 30%), but small amount of the solution per volume is enough (20-30 ml/m3). Ten times higher concentration is needed for... [to full text]
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Grimaldos, Osorio Nicolas. "Novel Ammonia Storage Materials for SCR Systems : Carbon Materials – Salt Composites." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75167.
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The emissions of nitrogen oxides (NOx) are a serious environmental problem due to its relationship with the formation of smog, acid rain and because they are dangerous for human and animal health. These gases are produced in high quantities in diesel engines used for automotive applications, and different strategies are being used to reduce them, among which are the Selective Catalytic Reduction (SCR) systems. For its operation, it is necessary a supply of ammonia as NOx reducing agent, but the inefficiency at low temperatures of the systems used nowadays has led to the conception of the solid ammonia storage units (ASS). Unfortunately, the materials currently used, i.e. metal halides, do not meet the ammonia supply requirements at low temperatures and have problems of swelling and agglomeration. In order to find a material with better properties for its application as an ammonia sorbent material, MgCl2 composites with different carbon materials (graphite, graphene, and SWCNTs) were prepared by direct mixing and wet impregnation methods, and characterized in this work. Despite the decrease of total storage capacity, improvements were found in thermal stability and mass retention, as well as in sorption and desorption kinetics, making these materials a first result towards the improvement of the solid ammonia storage units.
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Bales, Dustin William. "Optimization of an Advanced Water Treatment Plant: Bromate Control and Biofiltration Improvement." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4286.
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The David L. Tippin Water Treatment Facility (DLTWTF) serving the city of Tampa, Florida is an advanced drinking water treatment facility consisting of coagulation/flocculation, ozonation, granular activated carbon biofiltration, and disinfection by chloramine. New regulations and the recent economic crisis pushed the facility to investigate methods to decrease costs and meet regulatory requirements easier.
The two major issues identified as priorities for investigation were the optimization of the biofiltration system and the use of a novel process to reduce the formation of bromate during ozonation.
Optimization of the biofiltration system is needed to remove more of the assorted particles that cause biofilms, nitrification in the distribution system, and high chloramine demand. Previous work improved the removal of particles that cause biofilms and nitrification, but was not able address the removal of particles that cause high chloramine demand to a satisfactory degree. Possible factors affecting this high chloramine decay were identified and evaluated at the pilot scale, including filter depth, chloramination of filter backwash water, media material, and nutrient addition. Non-chlorinated backwash water reduced chloramine demand by approximately 30% for GAC filters, and by approximately 50% for anthracite. Generally, anthracite performed slightly worse than GAC. Nutrient addition showed no effect. Filter depth improved chloramine decay, but not significantly enough to warrant the increased material required
Bromate control is necessary to prevent the formation of bromate, a regulated carcinogen. Traditional bromate control methods use pH depression. While effective, at the DLTWTF, this forces the increased use of more expensive caustic soda over lime for raising the pH of process water. A novel process known as the chlorine-ammonia process was investigated at the bench scale to identify the ideal ratio of chlorine and ammonia to decrease the formation of bromate to ensure regulatory compliance and allow greater use of lime to decrease costs. The best ratio in this study is 0.45 mg/L NH3 to 0.75 mg/L Cl2 which produced 1.09 ppb bromate at a CT of 6.8 min*mg/L, representing a 84% improvement over the control.
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Mdhlovu, Johan. "Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester." Diss., Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-03062006-093400.
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Bezerra, Roseane Madeira. "NÃveis de cloro para codornas japonesas (Coturnix coturnix japonica) nas fases de crescimento e produÃÃo." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5909.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorCom o objetivo de avaliar os efeitos dos nÃveis de cloro da raÃÃo nas fases de crescimento e produÃÃo de codornas japonesas foram realizados dois experimentos, nos quais, foram avaliados os nÃveis de 0,07; 0,12; 0,17; 0,22; 0,27 e 0,32% de cloro. No primeiro experimento (fase de crescimento), 384 codornas com um dia de idade distribuÃdas em um delineamento inteiramente casualizado, com seis tratamentos de oito repetiÃÃes de oito aves cada. Conforme os resultados, no perÃodo de 1 a 42 dias, com o acrÃscimo do nÃvel de cloro na raÃÃo houve aumento linear no consumo de raÃÃo (g/ave) e no ganho de peso (g/ave) e reduÃÃo linear na relaÃÃo consumo de Ãgua/consumo de raÃÃo e na umidade das excretas. Entretanto, a conversÃo alimentar (g/g), a ingestÃo de Ãgua (ml/ave/dia), os coeficientes de digestibilidade da matÃria seca (CDMS), do nitrogÃnio (CDN) e da energia bruta (CDEB) e os valores de energia metabolizÃvel aparente (EMA) e aparente corrigida para nitrogÃnio (EMAn) das raÃÃes nÃo foram influenciados pelo nÃvel de cloro Ainda nesse ensaio, observou-se que os nÃveis de cloro recebido pelas codornas na fase de crescimento nÃo afetaram significativamente o desempenho da fase de postura. No segundo experimento, 288 codornas com dezessete semanas de idade foram distribuÃdas em um delineamento inteiramente casualizado, com seis tratamentos, oito repetiÃÃes e seis aves por unidade experimental. Os nÃveis de cloro nÃo influenciaram significativamente o consumo de raÃÃo (g/ave/dia), o consumo de Ãgua (ml/ave/dia), a percentagem de postura (%), o peso do ovo (g), a massa de ovo (g/ave/dia), a conversÃo alimentar (g/g), a umidade das excretas, os coeficientes de digestibilidade da matÃria seca (CDMS), nitrogÃnio (CDN) e energia bruta (CDEB), os valores de energia metabolizÃvel aparente (EMA) e aparente corrigida (EMAn), as Unidades Haugh, as percentagens de albÃmen, gema e casca. Entretanto, a gravidade especÃfica aumentou linearmente com o acrÃscimo de cloro na raÃÃo. Considerando os resultados, podese recomendar que as raÃÃes para codornas japonesas na fase de crescimento (1 a 42 dias) e de produÃÃo formuladas com milho e farelo de soja podem conter nÃveis de cloro de atà 0,32% sem prejuÃzo para os parÃmetros de desempenho e qualidade dos ovos.
In order to evaluate the effects of chlorine levels in the diet of growing and production of Japanese quails were conducted two experiments in which we assessed the levels of 0.07, 0.12, 0.17, 0.22, 0.27 and 0.32% chlorine. In the first experiment (growing phase), 384 quail on a day-old distributed in a completely randomized design with six treatments of eight replicates of eight birds each. According to the results for the period from 1 to 42 days, with the addition of chlorine level in the diet linearly increased feed intake (g/bird) and weight gain (g/bird) and a linear decrease in the ratio of consumption water/feed intake and excreta moisture. However, feed conversion (g/g), water intake (ml/bird/day), the digestibility of dry matter (CDMS), nitrogen (CDN) and gross energy (GEDC) and the values of metabolizable energy (AME) and apparent nitrogen corrected (AME) of feed were not affected by the level of chlorine still in testing, we found that chlorine levels received by the quails in the growing phase did not significantly affect the performance of phase posture. In the second experiment, 288 quail with seventeen weeks of age were distributed in a completely randomized design with six treatments, eight replicates and six birds per experimental unit. Chlorine levels did not significantly influence feed intake (g/bird/day), water consumption (ml/bird/day), the percentage of stance (%), egg weight (g), the mass of egg (g/bird/day), feed conversion (g/g), the moisture of excreta, the digestibility of dry matter (CDMS), nitrogen (CDN) and gross energy (GEDC), the metabolizable energy apparent (AME) and corrected apparent (AME), Haugh Units, the percentages of albumen, yolk and shell. However, the specific gravity increased linearly with the addition of chlorine in the feed. Considering the results, we can recommend diets for Japanese quails in the growing phase (1 to 42 days) and production made with corn and soybean meal can contain chlorine levels up to 0.32% subject to the parameters performance and egg quality
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Ravel, Sophie. "Mécanisme d'action des immunotoxines : étude de l'intériorisation et du transport intracellulaire." Montpellier 2, 1990. http://www.theses.fr/1990MON20186.
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Les immunotoxines a chaine a de ricine allient une haute specificite de reconnaissance a une puissante toxicite. Neanmoins, ces molecules ont une efficacite inferieure a ce qui est necessaire pour une therapeutique du cancer. En vue d'ameliorer cette efficacite, nous avons examine le mecanisme d'action de ces conjuges. L'entree de l'immunotoxine, indispensable a l'activite cytotoxique, ne semble pas constituer l'etape limitante dans le processus d'intoxication des cellules leucemiques. Apres interiorisation, la majeure partie des molecules d'immunotoxine reste intacte, sans rupture du pont disulfure reliant la chaine a a l'anticorps. Une etude de fractionnement cellulaire a montre que le conjugue n'atteint pas les lysosomes mais se localise plutot dans un compartiment endosomo-golgi a partir duquel la chaine a pourrait etre transferee aux ribosomes. Le chlorure d'ammonium et la monensine qui ameliorent considerablement l'efficacite du conjugue, n'accelerent pas sa cinetique d'interiorisation et ne modifient pas sa degradation, ni sa localisation intracellulaire. Ceci suggere que l'etape limitante se situe tardivement dans le transport du conjugue, probablement au niveau du passage de la chaine a au cytosol. Nous avons constate que l'internalisation et le transport intracellulaire de l'immunotoxine sont gouvernes par l'anticorps porteur et que l'interiorisation de l'anticorps anti-t65 dans les lymphocytes t du sang peripherique est un processus rapide et conduit a une degradation massive dont les monocytes sont en grande partie responsables
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Dandrieux, Aurélia. "Etude expérimentale de l'efficacité des rideaux d'eau mobiles face à un rejet de gaz lourds (ammoniac, chlore)." Aix-Marseille 1, 2001. http://www.theses.fr/2001AIX11025.
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Le nombre d'accidents technologiques impliquant la dispersion atmosphérique de gaz toxique souligne l'importance de la connaissance de l'efficacité des méthodes de limitation des conséquences tels que les rideaux d'eau. La quantification de leur efficacité ainsi que la modélisation de leur influence sur un nuage de gaz toxique sont donc essentielles pour faciliter l'aide à la décision en cas de formation d'un nuage de gaz toxique. Dans ce but, des essais de dispersion atmosphérique de gaz toxiques (ammoniac et chlore), sur site, ont permis d'évaluer l'efficacité des rideaux d'eau mobiles, type queue de paon (rideau d'eau vertical ascendant), comme moyen de mitigation d'un nuage de gaz lourd. La lance queue de paon s'est avérée efficace à diluer un nuage d'ammoniac ou de chlore. Son efficacité dépend notamment de la distance de positionnement par rapport à la source, du débit en gaz ainsi que des conditions météorologiques (le vent essentiellement). La dispersion en présence de rideau d'eau a été modélisée selon différentes approches : le rideau d'eau a été assimilé à un obstacle imperméable à l'aide de modèles gaussiens modifiés, puis à un obstacle poreux à l'aide du modèle intégral GASTAR®. Les conclusions relatives à l'utilisation de ces modèles ont conduit à mettre au point un modèle novateur, le modèle des Sources Virtuelles Discontinues (SVD) permettant de prédire les concentrations en aval de la lance queue de paon. Le modèle SVD a été validé, avec de bons résultats, sur les essais expérimentaux de dispersion d'un panache d'ammoniac en présence de la lance queue de paon.
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Rinaldi, Gino. "An X- and Q-band electron paramagnetic resonance study of Mn²§+ in a single crystal of ammonium chloride-iodide in the temperature range 77--295 K." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ64048.pdf.
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Tanamati, Fábio Yomei [UNESP]. "Nitrogênio e potássio em cobertura na nutrição e produtividade do alho vernalizado livre de vírus e qualidade do alho minimamente processado." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/146744.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O alho é uma hortaliça utilizada como condimento e como planta medicinal. O Brasil é um importante produtor/consumidor desta hortaliça, entretanto a produção nacional é insuficiente e portanto importa de quase 60% do alho consumido. Práticas precisas de manejo na produção e pós-colheita precisas podem resultar em economia na produção, aumento da produtividade e qualidade. Entre as práticas de manejo destaca-se a fertilização destaca-se pela influência direta na produção do alho e constituir um dos principais itens do custo de produção. Após a colheita a deterioração do alho minimamente processado (produto com maior valor agregado) pode ser diminuída através do armazenamento em temperatura controlada e atmosfera modificada. Com o objetivo de avaliar e documentar as melhores fontes e doses de nitrogênio e fontes potássio, bem como o melhor método para o armazenamento do alho minimamente processado foram conduzidos três ensaios que serão apresentados em três capítulos, sendo o primeiro intitulado “Fontes de nitrogênio e potássio sob a produtividade e nutrição mineral do alho”, o segundo capítulo intitulado “Produtividade e nutrição mineral do alho sob diferentes doses de nitrogênio e fontes de potássio”, e o terceiro capítulo intitulado “Efeito de diferentes temperaturas e atmosfera modificada sob as características qualitativas do alho minimamente processado”. Concluiu- se a) Diferentes fontes de N e K podem ser combinadas para a obtenção de máxima produção de alho comercial, b) o teor de nutrientes do alho não é influenciado pelas fontes de N e K ao ponto de constituir um fator crítico à produtividade do alho, c) Recomenda-se a dose 80 kg ha -1 de N como forma de obtenção de máxima eficiência do fertilizante e produtiva do alho vernalizado livre de vírus cv. Caçador, d) Não houve diferenças significativas na produção do alho acima da dose 80 kg ha -1 de N, a partir desta dose, o acúmulo de nutrientes no bulbo, de forma geral, foi inferior nos tratamentos K2SO4, e) baixa temperatura e atmosfera modificada contribuem significativamente para a manutenção da qualidade do alho minimamente processado, f) embalagem a vácuo mantém uma atmosfera consistentes em uma maior gama de temperaturas, g) as atmosferas modificadas com alto teor de CO2 podem influenciar a diminuição do valor de L* durante o armazenamento, h) a pungência do alho é mais bem conservada em embalagens a vácuo.
Garlic is used as a spice and as a medicinal plant, Brazil is an important producer/ consumer of this herb, however small domestic production stimulates import of about 60% the garlic consumed in this country. Management practices in the production and accurate post-harvest can result in savings in production and increasing in yield and quality. Among the management practices, fertilization is distinguished by its direct influence on the production of garlic and constitute one of the main cost items of production and postharvest deterioration of minimally processed garlic (product with higher added value) can be reduced by storing in controlled and modified atmosphere temperature. In order to assess and document the best sources and doses of nitrogen and potassium sources, as well as the more suitable storage method for fresh-peeled garlic we carried out three tests that will be presented in three chapters, the first entitled "Yield and mineral nutrition of vernalized virus free garlic in response to nitrogen and potassium sources topdressing" the second chapter entitled "Yield and mineral nutrition of garlic in response to nitrogen doses and potassium sources topdressing”, "Quality changes in fresh-peeled garlic cloves in relation to storage temperatures and modified atmospheres". From these assays we concluded that a) Different sources of N and K may be combined to obtain maximum production of commercial garlic, b) the garlic mineral content is not influenced by the sources of N and K to be considered a critical factor to garlic productivity, c) 80 kg ha -1 of N is the best way to obtain both maximum fertilizer efficiency and productive of virus free vernalizated garlic cultivar Caçador, d) from the dose 80 kg ha -1 , the lowest accumulation of nutrients in the bulb in SKO treatments suggests that potassium sulfate, alleviates possible effects of toxicity caused by excess NH4 + and reduces minerals export for bulb and thereby the ground, e) both low temperature and modified atmosphere significantly contribute to the maintenance of the quality of fresh-peeled garlic, f) vacuum packaging maintains an atmosphere consistent across a wider range of temperatures, g) modified atmospheres with high CO2 content can influence the decrease in L* value during storage, h) garlic pungency is better preserved in vacuum packaging.
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Moussa, Mariam. "Loading of dendrimer nanoparticles into layer-by-layer assembled Poly(diallyl dimethyl ammonium) chloride-(Poly(acrylic acid))n Multilayer Films : Particle Electrokinetics, Film Structure Dynamics and Elasticity." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0383/document.
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Une analyse détaillée des propriétés physico-chimiques des nanoparticules (NP) anthropogéniques est nécessaire pour comprendre à un niveau mécanistique leurs interactions/toxicité potentielle avec/envers les composants biotiques des systèmes aquatiques naturels. Une telle analyse est également requise pour réaliser une évaluation complète et une optimisation de la performance des méthodes d’(ultra)filtration développées pour circonscrire le relargage des NPs dans les milieux aquatiques. Dans ce contexte, l'objectif de cette thèse de doctorat était de déchiffrer les processus physico-chimiques fondamentaux régissant la capture de nanodendrimères carboxylés (PAMAM-COOH) - utilisés fréquemment dans des applications biomédicales – par des films multicouches du type (poly(diallyldiméthylammonium)chlorure-poly(acide acrylique))n ((PDADMAC-PAA)n) assemblés par déposition séquentielle des composantes polymériques cationique et anionique. À cette fin, une étude systématique des propriétés électrohydrodynamiques des NPs PAMAM-COOH a d'abord été effectuée en fonction du pH et de la concentration en sel monovalent du milieu. Sur la base de la théorie électrocinétique de particules molles ayant une fonctionnalité zwitterionique, il est démontré que les caractéristiques électriques interfaciales des NPs considérées sont déterminées à la fois par des contributions électrostatiques de surface et volumique des nanoparticules, lesquelles dependent de l’extension intraparticulaire de la double couche électrique. L’existence de ces deux types de contributions conduit à un changement remarquable de signe de la mobilité des NPs en modifiant la concentration du sel monovalent en solution et à une dépendance prononcé du point de zéro mobilité des NPs avec la concentration de l’électrolyte. En outre, une confrontation quantitative entre résultats expérimentaux et théorie souligne comment les modifications structurales des NPs induites par des changements de pH et de salinité affectent les caractéristiques électrocinétiques des dendrimères. Dans une deuxième partie, la structure, la morphologie et les propriétés mécaniques des films PDADMAC-PAA et leur évolution temporelle dans des conditions de vieillissement naturel ou après traitement thermique ont été déterminées par microscopie à force atomique (AFM) et analyses microspectroscopie Raman. Les résultats démontrent que les films multicouches PDADMAC-PAA de type exponentiel présentent des caractéristiques mécaniques et structurelles typiques de films polyélectrolytes multicouches à croissance linéaire. En particulier, leur relaxation lente vers un état d’équilibre est accélérée après traitement thermique à 60°C et se révèle être intimement liée à l'instabilité de domaines de films riches en PDADMAC, épuisés en eau (faits confirmés par la théorie de la fonctionnelle de la densité) et marqués par la présence de structures caractéristiques en forme de ‘donuts’. Dans une dernière partie, des résultats préliminaires sont donnés pour la dépendance de l'élasticité des films multicouches PDADMAC-PAA avec la concentration en solution de nanodendrimères. Les résultats suggèrent que ces films multicouches complexes constituent une option prometteuse pour la capture et l'élimination de nanodendrimères carboxylés présents en milieux aqueuxA detailed analysis of the physicochemical properties of engineered nanoparticles (NPs) is required to understand on a mechanistic level their interactions/potential toxicity with/towards biotic components of fresh water systems. Such an analysis is further mandatory to achieve a comprehensive evaluation and optimisation of the performance of (ultra)filtration methods developed to prevent NPs release into aquatic media. Within this context, the aim of this PhD thesis was to decipher the basic physico-chemical processes governing the loading of carboxylated-poly(amidoamine) (PAMAM-COOH) nanodendrimers -commonly employed in biomedical applications- into layer-by-layer assembled (poly(diallyl dimethyl ammonium) chloride-poly(acrylic acid))n ((PDADMAC-PAA)n) multilayer films. For that purpose, a systematic investigation of the electrohydrodynamic properties of PAMAM-COOH NPs was first performed as a function of pH and monovalent salt concentration in solution. On the basis of advanced electrokinetic theory for soft particles with zwitterionic functionality, it is demonstrated that the interfacial electrostatic features of the considered NPs are determined both by surface and bulk particle contributions to an extent that depends on electrolyte concentration. This leads to a remarkable NPs mobility reversal with changing monovalent salt concentration and to a marked dependence of the point of zero NPs mobility on electrolyte content. In addition, confrontation between experiments and theory further highlights how pH- and salt-mediated modifications of the NP particle structure affect dendrimer electrokinetic features at large pH and/or low salt concentrations. In a second part, the structure, morphology and mechanical properties of PDADMAC-PAA films, and their evolution over time under natural aging conditions or after thermal treatment, were addressed from atomic force microscopy (AFM) and Raman microspectroscopy analyses. Results evidence that PDADMAC-PAA multilayer films of exponential type exhibit mechanical and structural features that are typical for polyelectrolyte multilayer films with linear growth. In particular, their slow relaxation to equilibrium is accelerated after heating treatment at 60°C and, in line with density functional theory computation, this relaxation dynamics is shown to be intimately connected to instability of film domains rich in PDADMAC, depleted in water and marked by the presence of characteristic donut-like structures. In a final part, the reported dependence of PDADMAC-PAA multilayer films elasticity on concentration of nanodendrimers in bulk solution suggests that these complex multilayer films constitute a promising option to be further investigated for the loading and removal of carboxylated nanodendrimers from aqueous environments
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Mary, Stéphane. "Préparation et vieillissement de catalyseurs supportés Ir/Al2O3 pour applications spatiales ; influence de la nature du gaz et de la teneur en chlore." Poitiers, 1999. http://www.theses.fr/1999POIT2289.
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Ce travail a trait a l'amelioration des performances du catalyseur ir/al 2o 3, utilise dans la propulsion spatiale. L'etude porte sur les phenomenes de vieillissement du catalyseur lors de son stockage. En effet il est apparu que celui-ci evolue au cours du temps au contact de l'atmosphere, perdant de la surface metallique, et favorisant une perte d'activite en decomposition catalytique de l'ammoniac. Lors de la preparation des catalyseurs, l'utilisation d'une solution h 2ircl 6 permet la fixation de chlore sur le support. Ce chlore est le siege de nombreux phenomenes. Il permet d'une part d'obtenir une plus grande surface metallique par la creation de sites piegeurs sur le support, mais il favorise aussi le vieillissement du catalyseur. Ainsi, au contact de la vapeur d'eau (humidite) ou de l'oxygene (air), il se forme des especes hydroxychlorees ou oxychlorees de surface responsable du frittage du catalyseur et donc de sa perte d'activite catalytique. La dechloration du support apres l'etape de preparation, permet de conserver l'effet benefique du chlore par la creation des sites de germination et inhibe la formation d'especes non metallique de surface permettant une meilleure stabilite du catalyseur vis a vis de l'atmosphere environnante.
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Fagundes, Agnes Afrodite Sumarelli Albuquerque. "Efeito da acidose metabólica crônica sobre a reatividade vascular da artéria carótida e função cardiorrespiratória de ratos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17137/tde-08112018-141134/.
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Introdução: Os distúrbios ácido-base são comuns na prática médica e podem variar desde uma acidose ou alcalose simples até um distúrbio misto complexo e potencialmente fatal. Em situação de acidose ou alcalose, a permeabilidade iônica e as funções enzimáticas celulares se alteram, acarretando disfunção de diversos órgãos e sistemas. A acidose metabólica (MA), uma condição clínica comum, é causada por uma diminuição no pH do sangue e na concentração de bicarbonato. Pode ocorrer agudamente, com duração de algumas horas a um dia, ou como uma condição crônica, quando o pH normal não pode ser totalmente restaurado. Acidose, como um tipo dominante de distúrbio ácido-base, atualmente, é considerada um fator causador de disfunções cardiovasculares. Poucas pesquisas sobre o efeito da acidose metabólica crônica na função cardíaca, in vivo, estão disponíveis. Assim, é de grande interesse estudar a contratilidade cardíaca in vivo e as mudanças elétricas em resposta a acidose metabólica, além da reatividade vascular em artérias de animais acidóticos. Objetivos: O objetivo do presente estudo foi demonstrar os efeitos da acidose metabólica crônica (AMC) induzida pela administração de cloreto de amônio sobre a função cardiovascular e respiratória, assim como os possíveis mecanismos envolvidos. Metodologia: A AMC foi induzida em ratos Wistar pela substituição de água por uma solução do cloreto de amônio 0,50M ad libitum acrescido de 0,02M por gavagem, durante dez dias. Após dez dias os animais foram agrupados para as demais análises. Foi avaliada a reatividade vascular, frente a diversas drogas vasoativas (Acetilcolina, Fenilefrina, Angiotensina II, Endotelina-1 e ionóforo de cálcio - A23137) utilizando a metodologia de banho de órgão isolado. Algumas curvas dose-resposta foram realizadas na presença de L-NAME. Também foi avaliada a função cardíaca, através do ecocardiograma para pequenos animais, analisando os seguintes parâmetros: débito cardíaco, frequência cardíaca, volume sistólico e encurtamento sistólico e diastólico. A função respiratória foi analisada porResumo pletismografia de corpo inteiro e os parâmetros analisados foram ventilação, volume corrente e frequência respiratória. Além das análises principais citadas acima, foram realizadas também, dosagem de óxido nítrico, análise histológica de rins e dosagens de parâmetros associados a função renal (ureia e creatinina). Resultados: A acidose metabólica crônica (1) potencializou o relaxamento induzido pelo ionóforo de cálcio de maneira dependente do óxido nítrico e não foram observadas alterações para os demais agonistas testados; (2) reduziu o débito cardíaco e volume sistólico, sem alteração na frequência cardíaca; (3) reduziu os níveis de nitrito e nitrato plasmático; (4) aumentou a ventilação e o volume corrente, sem alterações na frequência respiratória e (5) não foram observadas alterações na ureia e creatinina e morfologia dos rins. Conclusão: A acidose metabólica promoveu alterações na reatividade vascular, na função cardíaca e na ventilação pulmonar.Introduction: Acid-base disorders are common in medical practice and can range from simple acidosis or alkalosis to a complex and potentially fatal disorder. In a situation of acidosis or alkalosis, the ionic permeability and the cellular enzymatic functions can change, leading to dysfunction of several organs and systems. Metabolic acidosis (MA), a common clinical condition, is caused by a decrease in blood pH and bicarbonate concentration. It can occur acutely, lasting from a few hours to a day, or as a chronic condition, when normal pH cannot be fully restored. Acidosis, as a dominant type of acid-base disorder, is currently considered a factor causing cardiovascular dysfunction. Few researches on the effect of chronic metabolic acidosis on cardiac function, in vivo, are available. Thus, it is of great interest to study cardiac contractility in vivo and electrical changes in response to metabolic acidosis, in addition to vascular reactivity in arteries from acidotic animals. Aim: The aim of the present study was to demonstrate the effects of chronic metabolic acidosis (CMA) induced by the administration of ammonium chloride on cardiovascular and respiratory function, as well as the possible mechanisms involved. Methods: CMA was induced in Wistar rats by replacing water by solution of ammonium chloride 0.50M ad libitum plus 0.02M per gavage, for ten days. After ten days the animals were grouped for the remaining analyzes. Vascular reactivity was evaluated for several vasoactive drugs (Acetylcholine, Phenylephrine, Angiotensin II, Endothelin-1 and calcium ionophore - A23137) using the isolated organ chamber methodology. Some dose-response curves were performed in the presence of L-NAME. Cardiac function was also evaluated through echocardiogram for small animals, analyzing the following parameters: cardiac output, heart rate, systolic volume and systolic and diastolic shortening. The respiratory function was analyzed by plethysmography of the whole body and the parameters analyzed were ventilation, tidal volume and respiratory rate. In addition to the main analyzes mentioned above, nitric oxide analysis, photomiographs of kidneys and urea and creatinine analysis for renal function evaluation, were also performed. Results:Abstract Chronic metabolic acidosis (1) potentiated calcium ionophore-induced relaxation in a nitric oxide-dependent manner and with no changes for the other agonists tested; (2) reduced cardiac output and systolic volume, with no change in heart rate; (3) reduced nitrite and plasma nitrate levels; (4) increased ventilation and tidal volume without changes in respiratory rate and (5) no changes were observed in urea and creatinine and morphology of the kidneys. Conclusion: Metabolic acidosis promoted changes in vascular reactivity, cardiac function and pulmonary ventilation.
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Bezerra, Raquel Pedrosa. "Influência do tempo de alimentação e da intensidade luminosa no cultivo de \'Spirulina platensis\' sob alimentação com cloreto de amônio." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/9/9134/tde-15122006-124231/.
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A Cianobactéria Spirulina platensis representa uma fonte de proteínas e ácidos graxos que a tornam importante como suplemento alimentar. A fonte de nitrogênio é um nutriente que exerce influência em seu metabolismo. Neste trabalho, observou-se o crescimento de S. platensis e a composição da biomassa obtida, com a utilização de cloreto de amônio como fonte de nitrogênio por processo descontínuo alimentado. Com a utilização de planejamento fatorial, foi realizado o estudo do tempo de alimentação do cloreto de amônio e da intensidade luminosa no cultivo da S. platensis. Os resultados foram avaliados com auxílio da metodologia de superfície de resposta. Menores teores de proteínas e lipídios na biomassa final foram encontrados nos cultivos submetidos a maiores intensidades luminosas. A condição ótima calculada, obtida pela análise estatística, para a obtenção da concentração celular máxima (Xm) e fator de conversão de nitrogênio em células (YX/N) foi encontrada no cultivo sob intensidade luminosa de 13 klux e tempo de alimentação de 17,2 dias. Nessas condições foram obtidos Xm igual 1771 ± 2,3 mg/L e YX/N igual a 5,7 ± 0,17 mg/mg, 3,4% e 4,0% menores que os valores máximos estimados pelo modelo matemático, respectivamente. Maiores produtividades foram obtidas nos cultivos submetidos a maiores intensidades luminosas e menores tempos de alimentação.Cyanobacterium Spirulina platensis represents a protein and fatty acid source that becomes it important as food supplement. The nitrogen source is a nutrient that influences in its metabolism. In this work, it was observed the S. platensis growth and biomass composition using ammonium chloride as nitrogen source in fed-batch process. Using factorial experimental design, it was carried out the study of the ammonium chloride feeding time and light intensity in the S. platensis culture. The results were evaluated by response surface methodology (RSM). Lower protein and lipids contents were found in cell cultures cultivated at higher light intensity. The predictive optimal condition, obtained by statistic analysis, for maximum cellular concentration (Xm) and nitrogen-cell conversion factor (YX/N) was obtained in the culture grown at 13 klux and feeding time of 17.2 days. In these conditions, Xm of 1771 ± 2.3 mg/L and YX/N of 5.7 ± 0.17 mg/mg were obtained. These values are 3.4 % and 4.0 % lower than that ones predicted by mathematical model, respectively. Higher productivities were observed in the culture grown at higher intensity light and lower feeding time.
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Rerhrhaye, Amal. "Contribution à l'étude de divers couples frigorigènes : Application à la réfrigération solaire photothermique." Nancy 1, 1986. http://www.theses.fr/1986NAN10093.
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Détermination du profil annuel de l'irradiation globale dans plusieurs sites de climat aride, en vue de la production de froid. Étude des propriétés physico-chimiques de trois couples frigorigènes : CACL::(2)-NH::(3), BACL::(2)-NH::(3), MGCL::(2)-NH::(3). Détermination du couple le plus adapté à la production de froid dans les zones tropicales. Présentation des résultats expérimentaux du fonctionnement d'un réfrigérateur solaire photothermique de capacité de 380 L installé à Madagascar
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Rogers, Jennifer J. "Assessment of Mussel Declines in the Clinch and North Fork Holston Rivers Using Histological Evaluations of Vital Organs." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/63925.
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The Clinch River (CR) and North Fork Holston River (NFHR) contain some of the most diverse freshwater mussel assemblages in the United States; however, both rivers are experiencing declines in mussel populations. The first component of this study used histological evaluations and water quality data to determine whether mussels were negatively impacted in the CR zone of decline (ZD) and to inform future management of freshwater mussels in the river. In the 91 kilometer (km) section from Carbo, Virginia (CRKM 431) downstream to Speers Ferry, Virginia (CRKM 340), referred to as the ZD, mussel density decreased >90% from 1979 to 2014 at key sites such as Semones Island (CRKM 378.3) and Pendleton Island (CRKM 364.2). Laboratory propagated mussels were placed in cages in the river for one year from June 2012 to May 2013 at four sites within the ZD and four sites in reaches where mussel populations remain stable or are increasing, a zone of stability (ZS). The survival, growth and histological results indicated that there are continuing impacts to mussels in the ZD. Research investigating impacts to the ZD and methods to improve water quality in this zone are needed.
The laboratory component of this study examined sublethal effects of potassium (K+), chloride (Cl-), and un-ionized ammonia (NH3-N) on mussel tissues at concentrations relevant to those found in the NFHR. Historical industrial activities at Saltville, Virginia, as well as continued pollution of the NFHR from chemical waste ponds at this location, are believed to be significant contributors to mussel declines. Contaminant seepages from the waste ponds that include Cl-, K+, and NH3-N have been shown to be toxic to adult and juvenile mussels.
A three-month laboratory study was conducted to assess impacts to organ tissues (gills, digestive glands, kidneys, and gonads) of adult Villosa iris exposed to environmentally relevant concentrations of K+ (4 and 8 mg/L), Cl- (230 and 705 mg/L), and NH3-N (0.014 and 0.15 mg/L) using histological evaluations. No detectable differences were observed among the histological endpoints from mussels held in treatments and control (p>0.05). The study design was modified and repeated
using increased concentrations of K+ (8, 16, and 32 mg/L) and Cl- (705, 1410, and 2820 mg/L) for a two-month exposure period. Due to issues with maintaining NH3-N in mussel holding chambers, the second study did not the second study did not include NH3-N exposures. Control mussels in both studies had a higher abundance of lipofuscin in kidneys and degraded cytoplasm in the digestive gland diverticula compared to baseline mussels, indicating that captivity influenced mussel tissues. Future studies are needed to more thoroughly address these captivity effects. Both survival and histological data in the second test showed a significant negative effect of the increased concentrations of Cl- and K+, which were representative of those found at some sites in the NFHR downstream of Saltville, Virginia.Master of Science
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Bezerra, Roseane Madeira. "Níveis de cloro para codornas japonesas (Coturnix coturnix japonica) nas fases de crescimento e produção." reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/19047.
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BEZERRA, Roseane Madeira. Níveis de cloro para codornas japonesas (Coturnix coturnix japonica) nas fases de crescimento e produção. 2010. 64 f. : Dissertação (Mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Zootecnia, Programa de Pós-Graduação em Zootecnia. Fortaleza-CE, 2010.Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-08-10T13:32:30Z No. of bitstreams: 1 2010_dis_rmbezerra.pdf: 314058 bytes, checksum: 7b30479bbaf907c17b54b3a8a3526f71 (MD5)
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In order to evaluate the effects of chlorine levels in the diet of growing and production of Japanese quails were conducted two experiments in which we assessed the levels of 0.07, 0.12, 0.17, 0.22, 0.27 and 0.32% chlorine. In the first experiment (growing phase), 384 quail on a day-old distributed in a completely randomized design with six treatments of eight replicates of eight birds each. According to the results for the period from 1 to 42 days, with the addition of chlorine level in the diet linearly increased feed intake (g/bird) and weight gain (g/bird) and a linear decrease in the ratio of consumption water/feed intake and excreta moisture. However, feed conversion (g/g), water intake (ml/bird/day), the digestibility of dry matter (CDMS), nitrogen (CDN) and gross energy (GEDC) and the values of metabolizable energy (AME) and apparent nitrogen corrected (AME) of feed were not affected by the level of chlorine still in testing, we found that chlorine levels received by the quails in the growing phase did not significantly affect the performance of phase posture. In the second experiment, 288 quail with seventeen weeks of age were distributed in a completely randomized design with six treatments, eight replicates and six birds per experimental unit. Chlorine levels did not significantly influence feed intake (g/bird/day), water consumption (ml/bird/day), the percentage of stance (%), egg weight (g), the mass of egg (g/bird/day), feed conversion (g/g), the moisture of excreta, the digestibility of dry matter (CDMS), nitrogen (CDN) and gross energy (GEDC), the metabolizable energy apparent (AME) and corrected apparent (AME), Haugh Units, the percentages of albumen, yolk and shell. However, the specific gravity increased linearly with the addition of chlorine in the feed. Considering the results, we can recommend diets for Japanese quails in the growing phase (1 to 42 days) and production made with corn and soybean meal can contain chlorine levels up to 0.32% subject to the parameters performance and egg quality
Com o objetivo de avaliar os efeitos dos níveis de cloro da ração nas fases de crescimento e produção de codornas japonesas foram realizados dois experimentos, nos quais, foram avaliados os níveis de 0,07; 0,12; 0,17; 0,22; 0,27 e 0,32% de cloro. No primeiro experimento (fase de crescimento), 384 codornas com um dia de idade distribuídas em um delineamento inteiramente casualizado, com seis tratamentos de oito repetições de oito aves cada. Conforme os resultados, no período de 1 a 42 dias, com o acréscimo do nível de cloro na ração houve aumento linear no consumo de ração (g/ave) e no ganho de peso (g/ave) e redução linear na relação consumo de água/consumo de ração e na umidade das excretas. Entretanto, a conversão alimentar (g/g), a ingestão de água (ml/ave/dia), os coeficientes de digestibilidade da matéria seca (CDMS), do nitrogênio (CDN) e da energia bruta (CDEB) e os valores de energia metabolizável aparente (EMA) e aparente corrigida para nitrogênio (EMAn) das rações não foram influenciados pelo nível de cloro Ainda nesse ensaio, observou-se que os níveis de cloro recebido pelas codornas na fase de crescimento não afetaram significativamente o desempenho da fase de postura. No segundo experimento, 288 codornas com dezessete semanas de idade foram distribuídas em um delineamento inteiramente casualizado, com seis tratamentos, oito repetições e seis aves por unidade experimental. Os níveis de cloro não influenciaram significativamente o consumo de ração (g/ave/dia), o consumo de água (ml/ave/dia), a percentagem de postura (%), o peso do ovo (g), a massa de ovo (g/ave/dia), a conversão alimentar (g/g), a umidade das excretas, os coeficientes de digestibilidade da matéria seca (CDMS), nitrogênio (CDN) e energia bruta (CDEB), os valores de energia metabolizável aparente (EMA) e aparente corrigida (EMAn), as Unidades Haugh, as percentagens de albúmen, gema e casca. Entretanto, a gravidade específica aumentou linearmente com o acréscimo de cloro na ração. Considerando os resultados, podese recomendar que as rações para codornas japonesas na fase de crescimento (1 a 42 dias) e de produção formuladas com milho e farelo de soja podem conter níveis de cloro de até 0,32% sem prejuízo para os parâmetros de desempenho e qualidade dos ovos.
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Demoliner, Fernanda. "Formação de biofilme e perfil de resistência antimicrobiana e a sanitizantes de isolados de Pseudomonas spp e Listeria spp. de corte de carne de frango e bubalino." Universidade Federal de Pelotas, 2015. http://repositorio.ufpel.edu.br:8080/handle/prefix/3884.
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A adesão e formação de biofilmes de micro-organismos a superfícies de equipamentos e utensílios no processamento de alimentos resulta em grave problema para a indústria, pois atua como fonte de contaminação do alimento, por serem mais resistentes a ação de sanitizantes e antimicrobianos. O objetivo deste trabalho foi avaliar a capacidade de Pseudomonas spp. e Listeria spp., provenientes de cortes de carnes de frango e de búfalo de frigoríficos e do comércio varejista da região sul do Rio Grande do Sul, de formar biofilmes em superfície de placas de poliestireno e aço inoxidável, bem como verificar a resistência destes a sanificantes e a antimicrobianos. Foram utilizados 69 isolados bacterianos provenientes de cortes de carnes de frango e de búfalo, sendo 19 de espécies de Listeria e 50 de Pseudomonas spp. Os isolados foram avaliados quanto à formação de biofilme em microplacas de poliestireno e em corpos de prova de aço inoxidável. Os isolados formadores de biofilme em aço inoxidável foram testados quanto à ação de sanitizantes: cloro orgânico e quaternário de amônio (200 ppm) e submetidos ao teste de resistência antimicrobiana. A formação biofilme em microplacas de poliestireno foi de 73,7 % para isolados de Listeria spp. e de 32 % para isolados de Pseudomonas spp. Todos os isolados de Listeria spp. e 72% dos isolados de Pseudomonas spp. formaram biofilmes em corpos de prova de aço inoxidável. O quaternário de amônio foi mais eficaz que o cloro orgânico na redução de biofilme de Listeria spp. e Pseudomonas spp. Os isolados pertencentes ao gênero Listeria apresentaram maior resistência à penicilina (94,7 %), à clindamicina (84,2 %), à oxacilina (73,7 %) e à cefepime (57,9 %), sendo que 94,7 % foram resistentes a dois ou mais antimicrobianos. Meropenem foi o antimicrobano menos efetivo para Pseudomonas spp. Também foram encontrados 84% dos isolados de Pseudomonas spp. multirresistentes a antimicrobianos. Conclui-se que os isolados provenientes de cortes de carnes de frango e de bubalino foram formadores de biofilme em poliestireno e aço inoxidável e apresentaram resistência a antimicrobianos, o que confere riscos a saúde do consumidor.
The adhesion and microorganisms biofilm formation on surfaces of equipment and utensilsin food processingresults inserious problem for the industry because it actsas a source of contamination are less resistant to sanitizers and antimicrobial action. The objective of this study was to evaluate the ability of Pseudomonas spp. and Listeria spp. present in chicken and buffalo meat, to form biofilms on the surface of polystyrene plates and stainless steel as well as verify their resistance to sanitizers and antimicrobials. Sixty nine bacterial isolates were used, 19 species of Listeria and 50 species of Pseudomonas spp. The isolates were evaluated to their biofilm formation capacity in polystyrene microplates and stainless steel. Isolated stainless steel biofilm formers were tested for sanitizing action of organic chlorine and quaternary ammonium (200 ppm) and submitted antimicrobial resistance testing. The ability to form biofilmon polystyrene microplates was 73,7 % in isolates of Listeria spp. and 32 % for Pseudomonas spp. All isolates of Listeria spp. and 72 % of Pseudomonas spp. showed the ability to form biofilm on stainless steel specimens. The sanitizing organic chlorine and quaternary ammonium were effective to reduce Listeria spp. and Pseudomonas spp. biofilm formation in stainless steel. Quaternary ammonium was more effective than organic chlorine to reduce Listeria spp. biofilm formation from buffalo meat. Isolates belonging to the Listeria generous showed greater resistance to penicillin (94.7 %), clindamycin (84.2 %), oxacillin (73.7 %) and cefepime (57.9 %), and 94.7 % were resistant to two or more antimicrobial. Meropenem was the less effective antimicroban of or Pseudomonas spp. It was also found that 84 % of isolates of Pseudomonas spp. were multirresistentes to antimicrobianos. The isolates from chicken meat cuts and buffalo were biofilm-forming polystyrene and stainless steel and were resistant to antimicrobials, which gives risk to consumer health.
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Allam, Lévi. "Etude de la diffusion unidimensionnelle dans les chaines finies : application au tmmc-cd." Toulouse 3, 1987. http://www.theses.fr/1987TOU30063.
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Etude rpe de (ch::(3))::(4) nmn::(1-x) cd::(x) cl::(5) entre 20 et 300 k, pour x = 0,02; 0,08 et 0,2; mesure des temps de relaxation spin-reseau. Mise en evidence de variations importantes en fonction de la composition. Interpretation des resultats au moyen du formalisme de la fonction memoire et d'un modele de la fonction de correlation de spins des chaines finies
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Lorenz, Tom. "Recycling Seltener Erden aus Permanentmagneten und Leuchtstoffabfällen mittels Feststoffchlorierung." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-237116.
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Die 17 Elemente der Seltenen Erden sind Bestandteil vieler Hochtechnologieprodukte, wie Elektromotoren, Spezialgläsern oder Katalysatoren, dennoch liegt die Recyclingrate aus End-of-Life-Produkten derzeit unter 1 %. Mit der Feststoffchlorierung wurde im Rahmen dieser Arbeit eine chemikalien- und kostensparende Methode für den Aufschluss Seltener Erden aus Leuchtstoff- und Magnetabfällen untersucht. Dabei wurden die gemahlenen Edukte mit NH4Cl vermischt und anschließend im Drehrohrofen erhitzt. Durch thermische Zersetzung des NH4Cl wird HCl- und NH3-Gas freigesetzt. Ersteres überführt die Seltenen Erden in die wasserlöslichen Metallchloride, während der NH3 im Prozess als Lösung in 5N-Reinheit anfiel. Die Seltenerdausbeuten lagen je nach Ausgangsstoff zwischen 83,9 und 99,9 %. Die Optimierung der Feststoffchlorierung erfolgte anhand statistischer Versuchspläne, wodurch neue, überraschende Erkenntnisse im Hinblick auf Reaktionsverläufe, Selektivitäten und Prozessführung gewonnen werden konnten.
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Atifi, Abdelghani el. "Application des composés d'insertion du graphite au stockage chimique de l'énergie thermique." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0072.
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Etude de l'action de l'ammoniac sur les composes d'insertion graphite-chlorures metalliques. Suivie de la reaction in sistu en temps reel par diffraction des neutrons. Formation de microcristallites d'ammoniacates au sein du reseau cristallin du graphite. Avantage de cette texture par rapport a l'ammoniacate seul en vue de son application aux procedes de conversion thermochimique de l'energie. L'etude cinetique des reactions mises en jeu
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Oliveira, Carlos Rafaell Correia de. "Ingestão de bicarbonato de sódio e cloreto de amônio e seus efeitos sobre o ritmo de prova, desempenho e equilíbrio ácido-base em um teste contrarrelógio de ciclismo de 4km." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/39/39132/tde-25082016-133341/.
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Nós determinamos a influência da alcalose e acidose metabólica induzida sobre o ritmo de prova, gasto energético e desempenho durante um teste contrarrelógio de ciclismo de 4 km (TCR). Após um estudo preliminar (N=7) determinando as doses ótimas de cloreto de amônio (NH4Cl), bicarbonato de sódio (NaHCO3) e placebo (carbonato de cálcio, CaCO3), 11 ciclistas amadores realizaram um TCR de 4 km 100 min após ingerirem 0,15 g·kg-1 de NH4Cl, 0,3 g·kg-1 de NaHCO3 ou 0,15 g·kg-1 de CaCO3 (desenho de medidas repetidas, contrabalançado e duplo-cego). Comparado com placebo, a ingestão de NaHCO3 resultou em uma alcalose sanguínea pré-exercício (pH: + 0,06 ± 0,04, [HCO3-]: + 4,7 ± 2,6 mmol?L-1, excess de base: + 4,6 ± 2,4 mmol?L-1, P<0,05), enquanto que o NH4Cl resultou em uma acidose sanguínea (pH: - 0,05 ± 0,04, [HCO3-]: - 5,5 ± 2,9 mmol?L-1, excesso de base: - 5,3 ± 2,5 mmol?L-1, P<0.05), com essas diferenças permanecendo durante todo o teste. Apesar de nenhum desconforto gastrointestinal severo, os participantes adotaram um ritmo de prova significativamente mais conservador em NH4Cl comparado com placebo e NaHCO3, que foi acompanhado por uma redução na taxa de gasto energético anaeróbio (~ -14 %, P<0,05) e menor trabalho anaeróbio total (~ -13 %, P<0,05). Consequentemente, o desempenho foi prejudicado em NH4Cl (~ -7 %) comparado com as demais condições (P<0,05). O lactato plasmático, VCO2 e a PetCO2 foram menores e a VE/VCO2 maior durante o TCR em acidose do que em placebo e alcalose (P<0,05). Entretanto, não houve diferença para essas variáveis entre placebo e NaHCO3 (P<0,05). A acidose metabólica induzida diminuiu o ritmo de prova e o metabolismo anaeróbio, além de prejudicar o desempenho durante um TCR de 4 km, independente de desconforto gastrointestinalWe determined the influence of induced metabolic alkalosis and metabolic acidosis on pacing, energy expenditure and performance during a 4-km cycling time trial (TT). After a preliminary study (N=7) determining the optimal ammonium chloride (NH4Cl), sodium bicarbonate (NaHCO3), and placebo (calcium carbonate, CaCO3) doses, 11 amateur cyclists performed a 4-km TT 100 min after ingesting either 0.15 g·kg-1 of body mass of NH4Cl, 0.3 g·kg-1 of NaHCO3 or 0.15 g·kg-1 of CaCO3 (double-blind, counterbalanced and repeated-measures design). Compared with placebo, the NaHCO3 ingestion resulted in a pre exercise blood alkalosis (pH: +0.06 ± 0.04, [HCO3-]: +4.7 ± 2.6 mmol?L-1, base excess: +4.6 ± 2.4 mmol?L-1, P<0.05), while NH4Cl resulted in a blood acidosis (pH: -0.05 ± 0.04, [HCO3-]: -5.5 ± 2.9 mmol?L-1, base excess: -5.3 ± 2.5 mmol?L-1, P<0.05), with these differences remaining throughout the trial. Despite no gastrointestinal distress, participants adopted a significant more conservative pacing in NH4Cl compared with placebo and NaHCO3, which was accompanied by a reduced anaerobic energy expenditure rate (~ -14 %, P<0.05) and lower total anaerobic work (~ -13 %, P<0.05). Consequently, the performance was less in NH4Cl (~ -7 %) compared with other conditions (P<0.05). Plasma lactate, VCO2 and PetCO2 were lower and the VE/VCO2 higher during the TT in acidosis than in placebo and alkalosis (P<0.05). However, there was no difference for these variables between placebo and NaHCO3 (P>0.05). Induced metabolic acidosis slows pacing, decreases anaerobic metabolism and impairs performance during a 4-km TT, independent of gastrointestinal distress