Academic literature on the topic 'Bromure de Thorium'

Thorium is a naturally occurring radioactive metal belonging to the actinide group. It is found at low levels in water, soil, rocks, plants and animals. Thorium is used as a nuclear fuel in nuclear technology, and its compounds are used in industry, chemistry, mining, ceramic production and high-quality lens production. It also occurs naturally in different sources, including phosphate fertilizers used in agriculture. Its increasing role in the nuclear and defense industries poses a risk to human health as a result of occupational and accidental exposure. Thorium enters the body mainly through inhalation of contaminated dust. Studies conducted on workers have found that inhaling thorium dust will cause an increased the risk of developing lung diseases such as lung cancer. This study aimed to determine the cytotoxic effect of thorium on normal human lung fibroblast cells (MRC-5) exposed to thorium in vitro. For this purpose, MRC-5 cells were cultured in a 96-well plate (1x105 cells/well; 200 µl) containing 150 µM thorium (the stock solution was 1000 µg/ml in 5% HNO3). Cell viability (cytotoxicity status) was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, yellow tetrazole (MTT) analysis method after 48 h of incubation. As a result of the MTT test, cell viability was determined as %99.52 in cells treated with 150 μM thorium. Accordingly, it was concluded that 150 μM thorium is not cytotoxic on MRC-5 cells. However, in later studies, it was decided to examine the cytotoxic effect of thorium at higher doses

The 95% ethanol extract of Alfredia drooping Alfredia cernua (L.) Cass. (Asteraceae) aerial part exhibits pronounced antidepressant, nootropic and anxiolytic activity. The aim of the work was the qualitative and quantitative analysis of macro-, trace and ultra trace elements of the pharmacologically active extract of the aerial part of the plant. The study of the elemental composition of the extract was performed after ashing using instrumental neutron activation analysis with irradiation with thermal neutrons. The study found 26 elements, of which eight are (conditionally) essential, two macro elements and four trace elements. The obtained results indicate the prevalence of Alfredia cernua of calcium, zinc, sodium, strontium, bromine, as well as iron, barium, cobalt, chromium and lanthanum in the pharmacologically active extract. The extract concentrates a specific group of elements (zinc, cobalt, thorium, hafnium, bromine, chromium, lutetium, lanthanum, strontium, samarium) in comparison with the feedstock, which can be explained by the formation of strong organometallic compounds and chelate complexes. Macro-, trace and ultra trace elements can have a significant impact on metabolic processes, nervous, immune, endocrine, cardiovascular systems, they are an integral part of enzymes, give other biologically active substances an easily digestible form and potentiate their effects.

This article investigates the impact of geothermal water from the Cherkashinskaya No. 36-RG self-injection exploration well on ecosystem watercourses. The well was drilled in 1965 to investigate deposits of iodine-bromine water. This article presents estimations of the acceptable levels of radiation hazard content in the water and near-bottom sediments of gravity-flow hydrogeological wells. The radiation safety of working with these materials for personnel in geological exploration and national economic enterprises is also evaluated. The article provides information on the study of the natural radiation background, as well as results on the natural radioactivity of the bottom sediments and the volumetric radium content of the water. Natural radioactivity in the bottom sediments of potassium (40K) and thorium (232Th) is analyzed in this study. The relevance of this research originates from over fifty years of pollution by highly mineralised iodine-bromine water within the catchment area of one of Western Siberia's largest transboundary rivers, the Irtysh River. The Aremzyanka River is first-order tributary of the Irtysh River, and it receives water from a stream originating from exploration well No. 36-RG.

The productivity of barley Raushan 24.9-53.1 tons per hectare on the farm (SKHPK) them. Michurin, Vavozhsky district of the Udmurt Republic for 2013-2019 had a positive average correlation (r = 0,46) with the pH of the arable layer, a positive weak correlation with the content in the arable layer of mobile phosphorus (r = 0,26), exchange potassium (r = 0.12) and humus (r = 0,12). The crop of 2017, had more potassium, sulfur, phosphorus, magnesium, silicon, calcium, sodium, manganese, tin, iron, rubidium, strontium, barium, zirconium, copper, zinc, titanium, selenium, nickel, vanadium, gadolinium, lithium, germanium, cobalt, tungsten, beryllium, cadmium, than their content in the grain of the 2018 crop. In 2018, the yield was lower by 14,2 centner per hectare of the 2017 crop, and barley kernels contained more bromine, aluminum, boron, molybdenum, thorium, chromium, cerium, lanthanum, niobium, tantalum, gallium

Cationic surfactant, cetyldimethylethylammonium bromide (CDMEAB), sensitize the color reactions of Th(IV) and U(VI) with chrome azurol-S(CRAS). Formation of water soluble deeply colored ternary complexes of metal ions show large bathochromic shift. Same stoichiometric composition of ternary complexes with 1:2:4 molar ratio (M-CRAS-CDMEAB) have been observed for both the metal ions and are responsible for enhancement in molar absorptivities and sensitivities at shifted wavelength. The ternary complexes of thorium(IV) and uranium(VI) exhibit absorption maxima at 640 and 620 nm with molar absorptivities 85500 and 69600 L.mol-1.cm-2respectively. Beer’s law were obeyed in concentration range 0.12-0.185 ppm for Th(IV) and 0.13-0.162 ppm for U(VI) in presence of CDMEAB. Conditional formation constants and various analytical parameters have been evaluated and compared the results of binary and ternary complexes. Enhancement in the molar absorptivities in presence of CDMEAB clearly indicated the usefulness of these colored reactions for microdetermination.

Neutron activation analysis was used in this research to measure the concentrations of aluminum (Al), bromine (Br), chlorine (Cl), mercury (Hg), arsenic (As), and thorium (Th) in soil and saffron plants as well as their contamination, enrichment, and translocation rates. The edible part of the saffron showed a higher Hg concentration than the WHO/FAO-permitted level in the urban area. The soil was not intoxicated and contaminated by Al, As, and Th except in the urban areas, which were slightly polluted by As. The calculated contamination degree and pollution load index indicated that the soil was almost uncontaminated. The enrichment factors (EF) showed minimal enrichment levels of Al and Th and low As contamination, which may still increase due to human activities in the environment. The tested elements’ translocation abilities were also evaluated by the paired t-test statistical method and indexes of translocation, and it was found that Al, As, and Th can quickly relocate into different soil depths. Saffron was also evaluated as a very poor absorber of the elements studied. While Cl and Th can easily move from the saffron’s corm to its aerial parts, Al and Hg merely translocate from the corm to the petal. It was also found that Al, Cl, and Th can move between the petals and the thread.

AbstractIn this work, after on-line and in-situ solid phase extraction technique was used for the extraction and preconcentration of uranium and thorium from aqueous samples prior to inductively coupled plasma optical emission spectrometry (ICP-OES) determination. In this method, sodium hexafluorophosphate (as an ion-pairing agent) was added to the sample solution containing the cationic surfactant (dodecyltrimethylammonium bromide) and the complexing agent (dibenzoylmethane). A cloudy solution was formed as a result of formation of an ion pair between surfactant and hexafluorophosphate. The solid microparticles were passed through a microcolumn filter and the adsorbed microparticles were subsequently eluted with acid, which was directly introduced into the ICP-OES nebulizer. The main variables affecting the pre-concentration and determination steps of uranium and thorium were studied and optimized. Under the optimum conditions, the enhancement factors of 97 and 95 and the detection limits of 0.52 and 0.21 μg L

Propriétés comparatives structurales et de luminescence intrinsèque des matrices alpha et béta Thbr₄. Étude de la structure électronique par spectroscopie optique de l'ion u⁴ + dans la matrice alpha Thbr₄. Caractérisation de la fluorescence par excitation UV dans ces deux matrices. Étude de l'absorption UV. Interprétation. Les spectres d'absorption et d'émission de u⁴ + α [alpha]-Thbr₄ retirés entre 300 et 4,2 k ont permis d'indexer 30 niveaux de la configuration 5f(2)

Fin 2017, le stock d’uranium appauvri représentait 315 000 t en France tandis que celui de thorium équivalait à 8 600 t environ. Les quantités stockées continuent d’augmenter avec le risque de voir la matière radioactive requalifiée en déchet radioactif si ses perspectives de valorisation ne sont pas suffisamment établies. Ce travail de recherche vise à valoriser l’uranium appauvri et le thorium comme matériaux de stockage de la chaleur dans la perspective d’améliorer l’efficacité énergétique des réseaux de chaleur. Un mode de stockage de la chaleur par réaction chimique a été retenu. La plupart des matériaux font intervenir une réaction solide-gaz (H2O, CO2, NH3, SO2, O2). En première approche nous nous sommes plus spécifiquement intéressés au stockage de la chaleur par absorption d’eau. Les travaux ont été menés sur quatre systèmes UO3.xH2O (x = 0-2,25), AnL4.xH2O (An = U, Th ; L = Br, F ; x = 0-10), UO2F2.xH2O (x = 0-5), et An(SO4)2.xH2O (An = Th, U ; x = 0-9). Le fluorure d’uranium (IV), le bromure de thorium et le sulfate d’uranium (IV) ne sont pas adaptés au stockage de la chaleur par hydratation/déshydratation du fait de limites cinétiques ou de stabilité (décomposition thermique, oxydation). Les systèmes les plus prometteurs sont UO3-H2O, UO2F2-H2O et, dans une moindre mesure, Th(SO4)2-H2O. L’étude du diagramme de phases UO3-H2O par DVS a permis d’établir les domaines de formation de UO3.2H2O et d’UO3.0,8H2O et d’en déduire les conditions d’hydratation optimales en vue d’un cyclage UO3  UO3.2H2O. Le caractère cyclable de l’hydratation et de la déshydratation a été vérifié sur 5 à 10 cycles. Quelle que soit la forme du précurseur (poudre ou comprimé) et le mode d’hydratation choisi (air balayé ou statique), le taux d’hydratation tend à se stabiliser autour de 1,2-1,6 H2O/U. Le problème de transfert de masse reste le défi le plus important à relever pour ce système. Le système UO2F2-H2O tend à déliquescer à des taux d’humidité relative supérieurs à 85 %. En limitant l’humidité relative à cette valeur la réaction UO2F2  UO2F2.4,85H2O est reproduite sur trois cycles en moins de 21 h. Le système Th(SO4)2-H2O présente l’avantage d’être modulable : les températures de décomposition thermique et les énergies mises en jeu sont directement fonction du taux d’hydratation du sulfate de thorium (x = 2,33 ; 8 ou 9)
At the end of 2017, the stock of depleted uranium in France was estimated at 315 000 t, while the stock of thorium amounted to about 8 600 t. The quantities stored continue to increase with the risk that the radioactive material will be requalified as radioactive waste if its recovery prospects are not sufficiently established. This research work aims to valorize depleted uranium and thorium as heat storage materials with a perspective to improve the energy efficiency of heating networks. A method of heat storage by chemical reaction has been selected. Most materials involve a solid-gas reaction (H2O, CO2, NH3, SO2, O2). As a first approach, we were more specifically interested in heat storage by water absorption. Work was conducted on four systems UO3.xH2O (x = 0-2.25), AnL4.xH2O (An = U, Th ; L = Br, F ; x = 0-10), UO2F2.xH2O (x = 0-5), and An(SO4)2.xH2O (An = Th, U ; x = 0-9). Uranium (IV) fluoride, thorium bromide and uranium (IV) sulphate are not suitable for heat storage by hydration/dehydration due to kinetic limits or stability (thermal decomposition, oxidation). The most promising systems are UO3-H2O, UO2F2-H2O and, to a lesser extent, Th(SO4)2-H2O. The study of the UO3-H2O phase diagram by DVS made it possible to establish the formation domains of UO3.2H2O and UO3.0,8H2O and to deduce the optimal hydration conditions for a UO3  UO3.2H2O cycling. The cyclical nature of hydration and dehydration has been verified over 5 to 10 cycles. Whatever the form of the precursor (powder or tablet) and the hydration mode chosen (flow or static air), the hydration rate tends to stabilize around 1.2-1.6 H2O/U. The problem of mass transfer remains the most important challenge for this system. The UO2F2-H2O system tends to be deliquescent at relative humidity levels above 85%. By limiting the relative humidity to this value, the UO2F2  UO2F2.4.85H2O reaction is reproduced over three cycles in less than 21 hours. The Th(SO4)2-H2O system has the advantage of being modular: the thermal decomposition temperatures and energies involved are directly related to the hydration rate of thorium sulphate (x = 2.33 ; 8 or 9)

Fin 2017, le stock d’uranium appauvri représentait 315 000 t en France tandis que celui de thorium équivalait à 8 600 t environ. Les quantités stockées continuent d’augmenter avec le risque de voir la matière radioactive requalifiée en déchet radioactif si ses perspectives de valorisation ne sont pas suffisamment établies. Ce travail de recherche vise à valoriser l’uranium appauvri et le thorium comme matériaux de stockage de la chaleur dans la perspective d’améliorer l’efficacité énergétique des réseaux de chaleur. Un mode de stockage de la chaleur par réaction chimique a été retenu. La plupart des matériaux font intervenir une réaction solide-gaz (H2O, CO2, NH3, SO2, O2). En première approche nous nous sommes plus spécifiquement intéressés au stockage de la chaleur par absorption d’eau. Les travaux ont été menés sur quatre systèmes UO3.xH2O (x = 0-2,25), AnL4.xH2O (An = U, Th ; L = Br, F ; x = 0-10), UO2F2.xH2O (x = 0-5), et An(SO4)2.xH2O (An = Th, U ; x = 0-9). Le fluorure d’uranium (IV), le bromure de thorium et le sulfate d’uranium (IV) ne sont pas adaptés au stockage de la chaleur par hydratation/déshydratation du fait de limites cinétiques ou de stabilité (décomposition thermique, oxydation). Les systèmes les plus prometteurs sont UO3-H2O, UO2F2-H2O et, dans une moindre mesure, Th(SO4)2-H2O. L’étude du diagramme de phases UO3-H2O par DVS a permis d’établir les domaines de formation de UO3.2H2O et d’UO3.0,8H2O et d’en déduire les conditions d’hydratation optimales en vue d’un cyclage UO3  UO3.2H2O. Le caractère cyclable de l’hydratation et de la déshydratation a été vérifié sur 5 à 10 cycles. Quelle que soit la forme du précurseur (poudre ou comprimé) et le mode d’hydratation choisi (air balayé ou statique), le taux d’hydratation tend à se stabiliser autour de 1,2-1,6 H2O/U. Le problème de transfert de masse reste le défi le plus important à relever pour ce système. Le système UO2F2-H2O tend à déliquescer à des taux d’humidité relative supérieurs à 85 %. En limitant l’humidité relative à cette valeur la réaction UO2F2  UO2F2.4,85H2O est reproduite sur trois cycles en moins de 21 h. Le système Th(SO4)2-H2O présente l’avantage d’être modulable : les températures de décomposition thermique et les énergies mises en jeu sont directement fonction du taux d’hydratation du sulfate de thorium (x = 2,33 ; 8 ou 9)
At the end of 2017, the stock of depleted uranium in France was estimated at 315 000 t, while the stock of thorium amounted to about 8 600 t. The quantities stored continue to increase with the risk that the radioactive material will be requalified as radioactive waste if its recovery prospects are not sufficiently established. This research work aims to valorize depleted uranium and thorium as heat storage materials with a perspective to improve the energy efficiency of heating networks. A method of heat storage by chemical reaction has been selected. Most materials involve a solid-gas reaction (H2O, CO2, NH3, SO2, O2). As a first approach, we were more specifically interested in heat storage by water absorption. Work was conducted on four systems UO3.xH2O (x = 0-2.25), AnL4.xH2O (An = U, Th ; L = Br, F ; x = 0-10), UO2F2.xH2O (x = 0-5), and An(SO4)2.xH2O (An = Th, U ; x = 0-9). Uranium (IV) fluoride, thorium bromide and uranium (IV) sulphate are not suitable for heat storage by hydration/dehydration due to kinetic limits or stability (thermal decomposition, oxidation). The most promising systems are UO3-H2O, UO2F2-H2O and, to a lesser extent, Th(SO4)2-H2O. The study of the UO3-H2O phase diagram by DVS made it possible to establish the formation domains of UO3.2H2O and UO3.0,8H2O and to deduce the optimal hydration conditions for a UO3  UO3.2H2O cycling. The cyclical nature of hydration and dehydration has been verified over 5 to 10 cycles. Whatever the form of the precursor (powder or tablet) and the hydration mode chosen (flow or static air), the hydration rate tends to stabilize around 1.2-1.6 H2O/U. The problem of mass transfer remains the most important challenge for this system. The UO2F2-H2O system tends to be deliquescent at relative humidity levels above 85%. By limiting the relative humidity to this value, the UO2F2  UO2F2.4.85H2O reaction is reproduced over three cycles in less than 21 hours. The Th(SO4)2-H2O system has the advantage of being modular: the thermal decomposition temperatures and energies involved are directly related to the hydration rate of thorium sulphate (x = 2.33 ; 8 or 9)

On décrit la réalisation d'un spectromètre pulsé informatisé effectuée à partir d'un montage antérieur dont les performances ont été améliorées. Cette réalisation se situe dans la perspective de l'extension des possibilités de recherche du service de R. Q. N. Et s'intègre dans un ensemble informatisé assurant le traitement des données expérimentales et une automatisation des mesures. Le spectromètre réalisé est entièrement transistorisé et couvre une gamme de fréquences s'étendant de quelques centaines de kilohertz à 60 MHz. Les circuits sont à large bande à l'exception d'un circuit accordable réducteur de bande passante destiné à éviter la saturation du récepteur par le bruit aux gains élevés et du Circuit Oscillant principal. Il en résulte à ce niveau une réduction du nombre des réglages nécessaires et une simplification dans l'utilisation de l'ensemble. Les progrès réalisés concernent le taux de réjection de la porte analogique (> 60 db jusqu'à 80 MHz)- l'augmentation de la fréquence maximale de fonctionnement (80 MHz pour la porte et le récepteur, 60 MHz pour l'émetteur)- la puissance d'émission (100 W) et le temps de récupération du récepteur (15 µs en l'absence du Circuit Oscillant contenant l'échantillon. Ce spectromètre a été utilisé pour l'étude de la phase incommensurable de ThB4. Les études antérieures sur ce produit avaient été effectuées avec un spectromètre à superréaction dont les limitations pour l'étude de la forme des raies sont connues. Avec le spectromètre pulsé la nature de la raie de résonance large fournie par l'échantillon dans la phase incommensurable a été confirmée; dans la gamme de température étudiée dans ce travail (77-95K), la raie reste sensiblement symétrique (indiquant une modulation sinusoïdale simple de la structure cristalline). L'étude de T1 montre la forte relaxation nucléaire au voisinage de la transition de phase en relation avec les fluctuations associées à la condensation du "mode mou" responsable de la transition
We describe the realization of the radio-frequency sections of a pulsed and computerized N. Q. R. Spectrometer, the design of which is derived from a system existing at the Laboratory. The performances were improved and the design made with a view to increase the versatility of the N. Q. R. Research Group facilities. The all solid-state spectrometer can be operated from a few hundred hertz up to 60 MHz. Circuits are wide-band except for the tank circuit and a tunable pass-band circuit provided to reduce the amplified noise level; as a result adjustments when operating the system are minimized and phase shift problems are eliminated. The rejection ratio of the analogic gate is increased and still 60 db at 80 MHz. The transmitting power stage, also transistorized, can deliver one hundred watts up to 60 MHz time 15 µs. The receiver pass-band is 80 MHz and its recovery when the high-Q tank circuit is not connected. The spectrometer has been used for investigating the incommensurate phase of ß-ThBr4 below 96 K. As compared with previous measurements made with a SRO spectrometer of poor re­ solution as line shape studies are considered, this series of investigations brings new pieces of information about the actual shape of the broad bromine N. Q. R. Line observed in the incommensurate phase below 96 K. In the range of temperature investigated so far (77-96 K), the line remains quite symmetrical with respect to its center frequency suggesting that the modulation is of the sine plane wave type. Investigation of the relaxation time, T1, shows a strong relaxation near the phase transition temperature quite probably related to the soft mode condensation at the transition temperature