Dissertations / Theses on the topic 'Barium sulfide'
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Цейтлин, Мусий Абрамович, and Валентина Федоровна Райко. "Математическое моделирование равновесного состава системы BaS–Ba(HS)₂–H₂S–H₂O." Thesis, Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/41241.
Full textA mathematical model describing the equilibrium composition of the BaS–Ba(HS)₂–H₂S–H₂О system is developed. Model allows, in particular, to calculate the pH of the solution, and was used to calculate the driving force for desorption of hydrogen sulfide in the process of obtaining barium carbonate.
Whyte, John Morrison. "Surfactant-inhibited barium sulphate nanoparticles for use in drilling fluids." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231876.
Full textPacary, Vincent. "Étude des procédés de décontamination des effluents liquides radioactifs par coprécipitation : de la modélisation à la conception de nouveaux procédés." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL057N/document.
Full textTo decontaminate liquid nuclear wastes, the coprecipitation process is the most commonly used in nuclear field because it can be applied to any type of aqueous effluents whatever their composition may be. This process deals with the in situ precipitation of solid particles to selectively remove one or more radioelements. The aim of this PhD work is to investigate phenomena which take place during the coprecipitation of a trace component. To reach this objective, we have proposed a new modelling of the coprecipitation mechanism. The originality of this new approach lies in the possibility to simulate the phenomenon in non equilibrium conditions and at the reactor scale. This modelling combined with the resolution of the population balance, enable to identify the influence of process parameters (flowrates, stirring speed…) on crystal size and ultimately on decontamination. To test this new modelling, simulations of the coprecipitation of strontium ions with barium sulphate have been performed in continuous and semibatch reactors. Thanks to these simulations, laws of the treatment efficiency variation as a function of several process parameters (mean residence time, stirring speed, BaSO4 concentration) have been determined and experimentally verified. This study leads to the determination of optimal treatment conditions. Three apparatus (recycling apparatus, fluidised bed and reactor/settling tank) providing these optimal conditions have been successfully tested and offered significant outlooks for the reduction of the volume of sludge produced by the process. Two new processes are patent pending
Yan, Luke, Rongrong Huang, Jian Xiao, Huiyun Xia, Min Chao, and Sven Wieβner. "Preparation and properties of a composite made by barium sulfate-containing polytetrafluoroethylene granular powder." Sage, 2016. https://tud.qucosa.de/id/qucosa%3A35550.
Full textQueiróz, Camila Ribeiro Gomide. "Padronização do contraste de Bário nas preparações para videofluoroscopia em bebês com disfagia." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/61/61132/tde-26052014-100340/.
Full textVideofluoroscopy (VDF) is considered a gold standard exam as an evaluation method for swallowing which requires that the patient ingests the Barium contrast in different consistencies so the oral and pharyngeal stages are evaluated with greater effectiveness. However, there is a difference between the viscosity of food with barium contrast for the VDF and thickened foods with the thickener, indicated subjectively in rehabilitation therapy. Therefore, the aim of this study was to standardize the amount of thickener to be added to infant formula in the following consistencies: nectar (N), honey (M) and (P) pudding in 2 environmental temperatures: (T1) and ranging from-40 degrees C to 44 C (T2); compare the average values of viscosities with seven brands of thickening agents most commonly used and available (E1, E2, E3, E4, E5, E6, E7) at temperatures T1 and T2; identify the minimal amount of barium contrast to be added to infant formula for good resolution in videofluoroscopy (50%, 25% and 12.5%), and elaborate a manual of food preparation to VFD in different consistencies (N, M, P) with Barium contrast. Seven brands of thickeners, an infant formula, and the average viscosity evaluated by Brookfield viscometer model DV-E, in two temperatures (above 40°C and environment) were used for standardization. Three dilutions (50%, 25% and 12.5%) of Barium contrast (Bariogel 100%) were used to evaluate the thickened milk by syringes into the VFD and the images obtained judged by two experienced speech language pathologists. Results revealed that the standardization of the amount of thickener to be added to infant formula to obtain the nectar, honey and pudding consistencies, in tested temperatures, varied according to the type of thickener, requiring the use of a manual for correct handling. Viscosity values decreased with increasing temperature, but the values were maintained within the range proposed by the American Dietetic Association (2002) regarding nectar, honey and pudding consistencies. Although the three tested quantities of Barium contrast have provided visible images, evaluated by the judges, those observed in dilutions of 25% and 50% were considered safer. It demanded tests in others situated in this range once in the dilution of 50% there was a change from nectar to honey consistency. A manual has been prepared for the guidance on the standardization of seven thickeners, in the three tested.
Gatumel, Cendrine. "Précipitation du sulfate de baryum sous ultrasons : effets sur le micromélange et sur la nucléation." Toulouse, INPT, 1997. http://www.theses.fr/1997INPT033G.
Full textAoun, Montaha. "Étude cinétique par une nouvelle méthode de la précipitation du sulfate de baryum à partir de différentes solutions réactives et à stoechiométrie variable." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL095N.
Full textMessaoudene, Nafa. "Etude de la formation et de l'inhibition des dépôts de sulfate de baryum dans les champs pétroliers : application au champ algérien de Tin Fouyé Tabankort." Toulouse, INPT, 1990. http://www.theses.fr/1990INPT031G.
Full textLebeau, Fabian. "Conditionnement céramique des boues STE. Synthèse de BaTiO3 à partir de BaSO4 et TiO2. Propriétés physicochimiques : frittage, lixiviation, irradiation." Limoges, 1995. http://www.theses.fr/1995LIMO0049.
Full textZezulová, Anežka. "Vliv oxidu barnatého na tvorbu a vlastnosti portlandského slínku." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217077.
Full textKeller, Jana [Verfasser]. "Biokinetics and inhalation toxicity of cerium dioxide and barium sulfate nanoparticles after 1, 4, 13 and 52 weeks of exposure / Jana Keller." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/1078849315/34.
Full textLoza, Kateryna [Verfasser], and Matthias [Akademischer Betreuer] Epple. "Behavior of toxicologically relevant silver compounds and barium sulfate particles in complex media : from synthesis to biological investigations / Kateryna Loza. Betreuer: Matthias Epple." Duisburg, 2016. http://d-nb.info/1099910307/34.
Full textFaleh, El Mâti el. "Les mecanismes de synthese de l'apatite par activite bacterienne : role et comportement de quelques elements mineraux, application aux phosphates sedimentaires." Strasbourg 1, 1988. http://www.theses.fr/1988STR13038.
Full textSteyer, Christiane Verfasser], Kai [Akademischer Betreuer] [Sundmacher, Jürgen [Akademischer Betreuer] Tomas, and Michael [Akademischer Betreuer] Mangold. "Precipitation of barium sulfate in a semi-batch stirred tank reactor : influence of feeding policy on particle size and morphology / Christiane Steyer. Betreuer: Kai Sundmacher ; Jürgen Tomas ; Michael Mangold." Magdeburg : Universitätsbibliothek, 2012. http://d-nb.info/105391430X/34.
Full textDuncan-Chamberlin, Katherine V. "The Effect of Baffles and Entrance Ports on the Measured Reflectance of Diffuse and Specular Samples in the Integrating Sphere." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1430151078.
Full textGuevar, Célia. "Etude du couplage échange d’ions - coprécipitation avec des sorbants minéraux au Ba : application à la décontamination sélective en 90Sr d’effluents liquides radioactifs." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2017. http://www.theses.fr/2017ENCM0011.
Full textThis thesis concerns the treatment of radioactive wastewaters, specifically 90Sr containing highly saline effluents.Two types of Ba2+ containing ion exchange materials were examined as possible Sr sorbents: a barium titanate and a barium zeolite LTA. The extractants originality lies in its double extraction mechanism. Firstly, the majority of the Sr present in the solution is removed via ion exchange with the Ba present in the sorbent. A secondary process then sees the now free Ba precipitate onto the sorbents surface as BaSO4. The effluent itself is the sulfate source. This precipitation reaction initiates a second coprecipitation reaction with the remaining Sr. Strontium coprecipitation with barium sulfate is crucial to leading to a high strontium selectivity in the presence of calcium. This thesis outlines a mechanistic and comparative study which will hopefully open the way to the development of new strontium selective sorbents.The barium zeolite, which is more efficient (higher capacity and selectivity) than the barium titanate for treatment of saline effluents, was evaluated for use in industrial type processes (stirred reactor and column). Experiments conducted with variable supersaturation or molar ratio [SO4]/[Ba] allowed us to identify optimal conditions for the use of barium zeolite powders in batch type stirred reactor. These results demonstrate the potential of this material to replace the current coprecipitation process in stirred reactors, which is carried out in effluent treatment plants. Barium zeolite beads were also evaluated for effluent treatment in a column type continuous process. Ion diffusion kinetics in the material were shown to be limiting for this continuous process. The material shaping has still to be optimized.Keywords: decontamination, strontium, selectivity, ion exchange, titanate, zeolite LTA, coprecipitation, barium sulfate
Missous, Omar. "Contribution à l'étude du phénomène de luminescence par stimulation optique dans le sulfure de magnésium dopé cerium, samarium en vue d'une utilisation en dosimétrie." Montpellier 2, 1992. http://www.theses.fr/1992MON20021.
Full textAL-NEAMI, KADOM ANAM. "Mesure des sections efficaces de production des rayons x : :(l) des elements ::(56)ba, ::(57)la, ::(58)ce par des protons de 1 mev-3,5 mev." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13172.
Full textLarsson, Emanuel. "Evaluation of the Dual-Modal usage of contrast agents by means of Synchrotron X-ray Computed Microtomography and Magnetic Resonance Imaging using Macrophages loaded with Barium Sulfate and Gadolinium Nanoparticles for Detection and Monitoring in Animal Disease Models." Doctoral thesis, Linköpings universitet, Molekylär ytfysik och nanovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-122607.
Full textAl-Sharaa, Marwan. "Etude géochimique et métallogénique des minéralisations (U-Ba) du nord du massif des Palanges (Aveyron, France)." Paris 6, 1986. http://www.theses.fr/1986PA066381.
Full textBose, Sweta. "Dissolution Kinetics of Sulfate Minerals: Linking Environmental Significance of Mineral-Water Interface Reactions to the Retention of Aqueous CrO42- in Natural Waters." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1207285064.
Full textRivera, Santillan Rosa Elva. "Flottation ionique des cations métalliques par les collecteurs à longue chaîne : Application aux ions BA**(2+) et GA**(3+)." Nancy 1, 1987. http://www.theses.fr/1987NAN10241.
Full textBernasconi, Pascal. "Flottation ionique : Analyse des mécanismes pour les tensio-actifs, application à la purification de solutions uranifères." Nancy 1, 1986. http://www.theses.fr/1986NAN10117.
Full textShende, Aniket Vishwanath. "Dissolution of Barite Scale using Chelating Agents." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10964.
Full textWANG, BING-HAO, and 王秉豪. "Study of the Mechanical Properties of Polystyrene/Barium sulfate/Styrene-butadiene-styrene Copolymer Blends." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/4tmc38.
Full text萬能科技大學
材料科學與工程研究所在職專班
105
In this study, Polystyrene (PS) / barium sulfate (BaSO4) / styrene-butadiene-styrene copolymer (SBS) composites were prepared by melt compounding and mixed with barium sulphate in different content.The mixture was kneaded at a temperature of 180-260 ℃ through a twin-screw extruder. The samples were prepared by injection molding and tested according to ASTM standards. We examined mechanical and physical properties of different compounding. We discussed melt index analysis, tensile property test, flexural strength test, impact strength, the results revealed the use of barium sulfate (BaSO4) can the processing required flow index can be adjusted by the ratio. Adjustment of BaSO4 / SBS proportions can obtain different mechanical properties of the materials. In accordance with different needs, such as the tensile properties of good circumstances can choose PS / SBS 5% of its BaSO4 addition of 10-20%, bending strength of good circumstances can choose PS / BaSO4 / SBS ratio of 45/50 / 5, good impact strength can be used in the case of PS / SBS 10% of its BaSO4 can choose to add 10-30%, so the compounding can be adjusted according to different requirements in response to the need of material industry.
Αθανασόπουλος, Ευάγγελος. "Καθαλατώσεις θειικού βαρίου : σχηματισμός και παρεμπόδιση με την [sic] χρήση φωσφονικών αλάτων." Thesis, 2014. http://hdl.handle.net/10889/8348.
Full textBarium sulfate is a crystalline solid encountered as mineral and precipitated in numerous applications from analytical chemistry to the of fire resistant paints up to the oil industry to avoid the pressure increase during the drilling. However, in oil industry form deposits which are difficult to remove due to the low solubility. The removal of barium sulfate scale deposits is not possible through the use of common acids, because the solubility of this salt does not change significantly with increasing acid concentration. Moreover the use of mineral acids result in the severe corrosion of the metal parts of the equipment involved (pipes, water storage reservoir). Alternative descaling and scale prevention techniques have been desighed and are widely applied. In these techniques, a number of compounds have been used which, when added at very low concentrations in scale prone aquatic media result in the inhibition or cancellation of the formation of barium sulfate scale deposits. In these compounds which include poly-phosphonates or polyelectrolytes with sulfonated or carboxyl functional groups, have shown impressive results. The issue of structure of the additive molecules both in solution but most important upon adsorption on the surface of the nuclei of the crystalline deposit forming under the favorable friving force created by the solution supersaturation, is very important for obtaining a better understanding of the factors underlying the efficiency of inhibition of inorganic scale formation. In the present work, we investigate the kinetics of precipitation of barium sulfate from supersaturated solutions both in the absence and in presence of additives was investigated. The kinetics of crystal growth were investigated using the seeded growth techiwue at sustained supersaturation. The molar ratio of total barium : sulfate (Ba:SO4) in the supersaturated solutions was 1:1 and all experiments were done at 25oC in the absence and presence of additives. The width of the metastable zone for the barium sulfate system was determined from spontaneous precipitation experiments involving unstable supersaturated solutions with the “free drift” technique. From the dependence of the inhibition times preceding precipitation on the solution supersaturation and using the classical nucleation theory (CNT) models the surface energy of the precipitated phase was estimated. The kinetics of crystallization of barium sulfate were investigated in stable supersaturated solutions which were seeded with well-aged and characterized barium sulfate crystals prepared from slow mixing of equimolar barium chloride and sodium sulfate solutions. The molar ratio Ba:SO4 was in these experiments 1:1. The rates of crystal growth were measured at conditions of constant supersaturation using a specific conductivity probe, which through the synchronized burettes of an automatic titrator triggered the addition of equimolar barium chloride and sodium sulfate solutions. The added titrants had the appropriate composition to compensate for the respective quantities transferred to the solid phase forming. The rate of titrants addition yieleded the rates of crystal growth at the respective conditions. The measured crystal growth rates showed parabolic dependence on the solution supersaturation suggesting the prevalence of a surface diffusion controlled mechanism. Moreover, the independence of the measured crystal growth rates (moles precipitated per unit time and seed crystals surface area) on the mass of the seed crystals. Confirmed that crystal growth took place exclusively on the seed crystals. The effect of the presence of benzene-1,3,5-triyltris phosphonic acid (BTP) and amino-tris(methylenephosphonic) acid (AMP) in the supersaturated solutions on the rates of crystal growth of barium sulfate was investigated by measurements of the respective crystal growth rates at sustained supersaturation as in the additives free solutions. The main structural difference of the two molecules tested is that the former has a flat conformation because of the aromatic ring while the latter has a significantly higher freedom of motion. The presence of the test additives in the supersaturated solutions had a significant effect on the solubility of barium sulfate. The modified solubilities were calculated from measurements of the concentrations of free Ba2+ and SO42- ions concentrations and solution supersaturations were calculated accordingly. The presence of the test additives resulted in the significant reduction of the respective crystal growth rates. The presence of AMP in the ssupersaturated solutions caused reduction of the crystal growth rates as high as 90% at 30 ppm. BTP was efficient as well in inhibiting barium sulfate crystallization. However, it was found that rates were reduced by more than 50% at concentrations as low as 10 ppm and high concentrations in the range of 50 ppm. At intermediate concentration (20-30 ppm) the efficiency of BTP in the reduction of crystal growth of barium sulfate was significantly lower. AMP inhibited barium sulfate scale not only at alkaline pH (pH=9,5) values and at acidic values (pH=3,6). At pH=3,6 and for AMP conentrations of 30 ppm the rates of crystal growth of barium sulfate were reduced by 70% with respect to the values in its absence.