Bibliografie tematiche / Bromine and iodine

Letteratura scientifica selezionata sul tema "Bromine and iodine"

Autore: Grafiati

Pubblicato: 1 giugno 2024

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Articoli di riviste sul tema "Bromine and iodine":

Gilfedder, B. S., M. Petri e H. Biester. "Iodine and bromine speciation in snow and the effect of orographically induced precipitation". Atmospheric Chemistry and Physics 7, n. 10 (21 maggio 2007): 2661–69. http://dx.doi.org/10.5194/acp-7-2661-2007.

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Abstract. Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting its distribution, speciation and transport are relatively unknown. The aim of this study was to determine the effect of orographically induced precipitation on iodine concentrations in snow and also to quantify the inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~840 m) from the northern Black Forest and were analysed by ion-chromatography - inductively coupled plasma mass spectrometry (IC-ICP-MS) for iodine and bromine species and trace metals (ICP-MS). All elements and species concentrations in snow showed significant (r2>0.65) exponential decrease relationships with altitude despite the short (5 km) horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l) over the 840 m height change. The results suggest that orographic lifting and subsequent precipitation has a major influence on iodine concentrations in snow. This orographically induced removal effect may be more important than lateral distance from the ocean in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements indicating that the iodine and bromine are internally mixed within the snow crystals. We also show that organically bound iodine is the dominant iodine species in snow (61–75%), followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max. of 32% organo-Br.

Gilfedder, B. S., M. Petri e H. Biester. "Iodine and Bromine speciation in snow and the effect of elevation". Atmospheric Chemistry and Physics Discussions 7, n. 1 (22 gennaio 2007): 995–1016. http://dx.doi.org/10.5194/acpd-7-995-2007.

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Abstract. Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting the distribution, speciation and transport of these elements are relatively unknown. The aim of this study was to determine the effect of orographic lifting on iodine concentrations and also quantify inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~800 m) from the northern Black Forest and were analysed (IC-ICP-MS) for iodine and bromine species and trace metals (ICP-MS). All elements and species showed a significant (r2>0.65) inverse relationship with altitude despite the short (5 km) horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l) over the 800 m height change. The results suggest that orographic lifting of cloud masses has a major influence on iodine levels in precipitation and is perhaps more important than lateral distances in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements. We also show that organically bound iodine is the dominant iodine species in snow (61–75%), followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max.~of 32% organo-Br.

Spolaor, A., P. Vallelonga, J. M. C. Plane, N. Kehrwald, J. Gabrieli, C. Varin, C. Turetta, G. Cozzi, C. Boutron e C. Barbante. "Halogen species record Antarctic sea ice extent over glacial-interglacial periods". Atmospheric Chemistry and Physics Discussions 13, n. 2 (12 febbraio 2013): 3881–913. http://dx.doi.org/10.5194/acpd-13-3881-2013.

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Abstract. Sea ice is an integral part of the Earth's climate system because it affects planetary albedo, sea surface salinity, and the atmosphere-ocean exchange of reactive gases and aerosols. Bromine and iodine chemistry is active at polar sea ice margins with the occurrence of bromine explosions and the biological production of organo-iodine from sea ice algae. Satellite measurements demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO) decrease over sea ice toward the Antarctic interior. Here we present speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice CorE) ice core (159°11' E, 72°49' S, 2315 m a.s.l.) spanning the last 215 ky. The Talos Dome ice core is located 250 km inland and is sensitive to marine air masses intruding onto the Antarctic Plateau. Talos Dome bromide (Br−) is positively correlated with temperature and negatively correlated with sodium (Na). Based on the Br−/Na seawater ratio, bromide is depleted in the ice during glacial periods and enriched during interglacial periods. Total iodine, consisting of iodide (I−) and iodate (IO3−), peaks during glacials with lower values during interglacial periods. Although IO3− is considered the most stable iodine species in the atmosphere it was only observed in the TALDICE record during glacial maxima. Sea ice dynamics are arguably the primary driver of halogen fluxes over glacial-interglacial timescales, by altering the distance between the sea ice edge and the Antarctic plateau and by altering the surface area of sea ice available to algal colonization. Based on our results we propose the use of both halogens for examining Antarctic variability of past sea ice extent.

Spolaor, A., P. Vallelonga, J. M. C. Plane, N. Kehrwald, J. Gabrieli, C. Varin, C. Turetta et al. "Halogen species record Antarctic sea ice extent over glacial–interglacial periods". Atmospheric Chemistry and Physics 13, n. 13 (12 luglio 2013): 6623–35. http://dx.doi.org/10.5194/acp-13-6623-2013.

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Abstract. Sea ice is an integral part of the earth's climate system because it affects planetary albedo, sea-surface salinity, and the atmosphere–ocean exchange of reactive gases and aerosols. Bromine and iodine chemistry is active at polar sea ice margins with the occurrence of bromine explosions and the biological production of organoiodine from sea ice algae. Satellite measurements demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO) decrease over sea ice toward the Antarctic interior. Here we present speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice CorE) ice core (159°11' E, 72°49' S; 2315 m a.s.l.) spanning the last 215 ky. The Talos Dome ice core is located 250 km inland and is sensitive to marine air masses intruding onto the Antarctic Plateau. Talos Dome bromide (Br−) is positively correlated with temperature and negatively correlated with sodium (Na). Based on the Br−/Na seawater ratio, bromide is depleted in the ice during glacial periods and enriched during interglacial periods. Total iodine, consisting of iodide (I−) and iodate (IO3−), peaks during glacials with lower values during interglacial periods. Although IO3− is considered the most stable iodine species in the atmosphere it was only observed in the TALDICE record during glacial maxima. Sea ice dynamics are arguably the primary driver of halogen fluxes over glacial–interglacial timescales, by altering the distance between the sea ice edge and the Antarctic plateau and by altering the surface area of sea ice available to algal colonization. Based on our results we propose the use of both halogens for examining Antarctic variability of past sea ice extent.

Prashanth, Nagaraj, Kanakapura Basavaiah, Sameer Abdulrahman, Nagaraju Rajendraprasad e Basavaiah Vinay. "Application of bromate-bromide mixture as a green brominating agent for the spectrophotometric determination of atenolol in pharmaceuticals". Chemical Industry and Chemical Engineering Quarterly 18, n. 1 (2012): 43–52. http://dx.doi.org/10.2298/ciceq110721045p.

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Two highly sensitive spectrophotometric methods are proposed for the quantification of atenolol (ATN) in pure drug as well as in pharmaceutical formulations. The methods are based on the bromination reaction of ATN with a known excess of bromate-bromide mixture in acid medium followed by the determination of unreacted bromine. The residual bromine is determined by its reaction with excess iodide and the liberated iodine (I3?) is either measured at 360 nm (method A) or reacted with starch followed by the measurement of the starch-iodine chromogen at 570 nm (method B). Under the optimum conditions, ATN could be assayed in the concentration ranges of 0.5-9.0 and 0.3-6.0?g mL-1 for method A and method B, respectively, with corresponding molar absorptivity values of 2.36?104 and 2.89?104 L/mol.cm. Sandell?s sensitivity values are found to be 0.0113 and 0.0092 ?g/cm2 for method A and method B, respectively. The proposed methods were successfully applied to the analysis of different commercial brands of pharmaceutical formulations and the results obtained by the proposed methods were in good agreement with those obtained using the reference method. The reliability of the methods was further ascertained by recovery studies using standard- addition method.

Abdel-Moety, Ezzat M., Abdel-Kader S. Ahmad e Mohie Sharaf El-Din. "Determination of Iodine Values of Lipids by Bromide Ion Selective Electrode". Journal of AOAC INTERNATIONAL 69, n. 1 (1 gennaio 1986): 67–69. http://dx.doi.org/10.1093/jaoac/69.1.67.

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Abstract A semimicro method for determination of iodine values of lipids is described. An accurately weighed smear of sample (10-20 mg) on a strip of ashless filter paper, 14 × 40 mm, is brominated with bromine vapors for about 5 min. Excess bromine adsorbed on the filter paper is allowed to sublime. Bromine absorbed by the sample is directly related to the degree of unsaturation. Paper with brominated sample is subjected to oxygen flask combustion in the presence of 2 mL 1M sodium hydroxide solution and 10 mL water as absorbing liquid. Bromide formed, which is equivalent to unsaturation, is determined by bromide ion selective electrode. Bromide ions can be also determined by gravimetry or by indirect argentometric titration. The results were statistically analyzed. The iodine values of some fatty acids and oils, determined by this technique, are in accord with those of some officially approved methods.

Spolaor, A., P. Vallelonga, J. Gabrieli, T. Martma, M. P. Björkman, E. Isaksson, G. Cozzi et al. "Seasonality of halogen deposition in polar snow and ice". Atmospheric Chemistry and Physics Discussions 14, n. 6 (25 marzo 2014): 8185–207. http://dx.doi.org/10.5194/acpd-14-8185-2014.

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Abstract. The atmospheric chemistry of iodine and bromine in polar regions is of interest due to the key role of halogens in many atmospheric processes, particularly tropospheric ozone destruction. Bromine is emitted from the open ocean but is enriched above first-year sea ice during springtime bromine explosion events, whereas iodine is emitted from biological communities hosted by sea ice. It has been previously demonstrated that bromine and iodine are present in Antarctic ice over glacial-interglacial cycles. Here we investigate seasonal variability of bromine and iodine in polar snow and ice, to evaluate their emission, transport and deposition in Antarctica and the Arctic and better understand potential links to sea ice. We find that bromine enrichment (relative to sea salt content) and iodine concentrations in polar ice do vary seasonally in Arctic snow and Antarctic ice and we relate such variability to satellite-based observations of tropospheric halogen concentrations. Peaks of bromine enrichment in Arctic snow and Antarctic ice occur in spring and summer, when sunlight is present. Iodine concentrations are largest in winter Antarctic ice strata, contrary to contemporary observations of summer maxima in iodine emissions.

Rybakova, Anastasiya V., Dmitry G. Kim, Elena I. Danilina, Olesya V. Sazhaeva, Marina A. Ezhikova e Mikhail I. Kodess. "HETEROCYCLIZATION OF 3-PROPARGYLSULFANYL-5 PHENYL-1,2,4-TRIAZINE: TANDEM REACTIONS WITH BROMINE LEADING TO NEW DERIVATIVES OF 7 PHENYL[1,3]THIAZOLO[3,2-B][1,2,4]TRIAZINIUM". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, n. 6 (12 maggio 2020): 19–24. http://dx.doi.org/10.6060/ivkkt.20206306.6102.

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Derivatives of 1,2,4-triazine-3-thione exhibit biological activity in a wide range. They have optoelectronic properties and can be used as synthons in synthesis of various pyridines by the Diels-Alder reaction. 1,2,4-Triazines are of the greatest interest, for organic synthesis in particular. In the present study we have established that the interaction of 3-propargylsulfanyl-5-phenyl-1,2,4-triazine, obtained by alkylation of 5-phenyl-2,3-dihydro-1,2,4-triazine-3-thione with 3-bromopropyne in acetone in the presence of triethylamine, with halogens leads to annelation of thiazole cycle. At that, [1,3]thiazolo[3,2-b][1,2,4]triazinium systems contain either endo- or exocyclic double bond in their structure, depending on the halogen type. By way of example, iodine acting on propargyl sulfide forms a dark precipitate of (3Z)-3-iodomethylene-7-phenyl-2,3-dihydro-[1,3]thiazolo[3,2-b][1,2,4]triazinium triiodide, the structure of which has been confirmed by 1H and 13C NMR spectroscopy, including two-dimensional 2D 1H-13C HSQC, HMBC and 1H-1H NOESY experiments. Treatment of the obtained triiodide by sodium iodide in acetone leads to synthesis of the corresponding monoiodide, which precipitates from the reaction mixture as a dark red precipitate. Reaction with bromine, as distinct from heterocyclization under iodine action, comprises an unusual cascade reaction including the stages of electrophile heterocyclization, bromine addition, and hydrogen bromide elimination, which leads to formation of 3-dibromomethyl-7-phenyl[1,3]thiazolo[3,2-b][1,2,4]triazinium bromide. It should be pointed out that the identifying feature of 3-propargylsulfanyl-5-phenyl-1,2,4-triazine heterocyclization under iodine and bromine action is the signal bias of the aromatic proton in a triazine ring towards weak field in the 1H NMR spectrum of the reaction products. This is presumably associated with formation of the positively charged nitrogen atom.

Mityusheva, T. P., e O. Ye Amosova. "Industrial brines of the Khoreyver depression of the Pech ora plate". Vestnik of Geosciences 8 (2021): 27–45. http://dx.doi.org/10.19110/geov.2021.8.3.

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We studied areal distribution of the Khoreyver depression and strontium and lithium-rich iodine-bromine and iodine-boron industrial brines in the hydrogeological section. We presented the potential of the territory for practical use of industrial sodium chloride and calcium-sodium underground brines in the maps of distribution of bromine, iodine, boron and strontium-lithium iodinebromine and iodine-boric industrial brines within three Paleozoic calcareous aquifers (O2–S–D1; D3–C1; C–P1). Separate areas with lithium-strontium iodine - bromine and iodine-boric standard quality brines are designated.

Spolaor, A., P. Vallelonga, J. Gabrieli, T. Martma, M. P. Björkman, E. Isaksson, G. Cozzi et al. "Seasonality of halogen deposition in polar snow and ice". Atmospheric Chemistry and Physics 14, n. 18 (16 settembre 2014): 9613–22. http://dx.doi.org/10.5194/acp-14-9613-2014.

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Abstract. The atmospheric chemistry of iodine and bromine in Polar regions is of interest due to the key role of halogens in many atmospheric processes, particularly tropospheric ozone destruction. Bromine is emitted from the open ocean but is enriched above first-year sea ice during springtime bromine explosion events, whereas iodine emission is attributed to biological communities in the open ocean and hosted by sea ice. It has been previously demonstrated that bromine and iodine are present in Antarctic ice over glacial–interglacial cycles. Here we investigate seasonal variability of bromine and iodine in polar snow and ice, to evaluate their emission, transport and deposition in Antarctica and the Arctic and better understand potential links to sea ice. We find that bromine and iodine concentrations and Br enrichment (relative to sea salt content) in polar ice do vary seasonally in Arctic snow and Antarctic ice. Although seasonal variability in halogen emission sources is recorded by satellite-based observations of tropospheric halogen concentrations, seasonal patterns observed in snowpack are likely also influenced by photolysis-driven processes. Peaks of bromine concentration and Br enrichment in Arctic snow and Antarctic ice occur in spring and summer, when sunlight is present. A secondary bromine peak, observed at the end of summer, is attributed to bromine deposition at the end of the polar day. Iodine concentrations are largest in winter Antarctic ice strata, contrary to contemporary observations of summer maxima in iodine emissions. These findings support previous observations of iodine peaks in winter snow strata attributed to the absence of sunlight-driven photolytic re-mobilisation of iodine from surface snow. Further investigation is required to confirm these proposed mechanisms explaining observations of halogens in polar snow and ice, and to evaluate the extent to which halogens may be applied as sea ice proxies.

Più fonti

Tesi sul tema "Bromine and iodine":

Cader, Mohamed Shah Roshan. "The intercalation of bromine- and iodine fluorosulfate derivatives in solutions of fluorosulfuric acid". Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/25853.

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The oxidative intercalation of halogen fluorosulfate derivatives such as I(SO₃F) ₃, Br(SO₃F)₃, BrSO₃F, K[I(SO₃F)₄] and K[Br(SO₃F)₄] from solutions in fluorosulfuric acid into graphite (SP-1 and to a lesser extent HOPG) is studied. In addition, the intercalation of solvated cations of the type I₂₊ and NO⁺ is included in this research as well. The results, supported by microanalysis, X-ray powder diffraction data, Raman frequency shifts, Solid state -¹⁹F-NMR spectroscopy and UV-visible optical spectra of the supernatant solutions support three different courses of the intercalation reactions: a) At very high intercalant concentrations (about a five fold excess over the stoichiometrically required quantity) Hal (SO₃F)₃ and the anion [Hal(SO₃F)₄], with Hal - I or Br, intercalate without noticeable solvent cointercalation. b) At intermediate concentrations, solvent intercalation is observed. c) When low intercalant concentrations are used, the only intercalate is found to be the solvent HSO₃F. In all the intercalation reactions except the NO⁺ (solv) promoted synthesis, first stage compounds are formed. These stage one GIC's with c-axis layer repeat distance I[sub c] - 8.0 A are found for the intercalants I₂₊(solv), I(SO₃F)₃, BrSO₃F and Br(SO₃F)₃ with compositions C₃₂SO₃F.₃HSO₃F.0-2I, C₂₂l(SO₃F)₃, C₁₁HSO₃F.0•5SO₃F.xBrSO₃F (x ≤ 0.025) and C[sub 26.8] Br.4SO₃F respectively. K[Hal(SO₃F)₄] (Hal - Br, I) in HSO₃F gave first stage products with formulae C₈₄Br.11•22SO₃F and C₈₆I.10-51SO₃F. The NO⁺ (solv) induced reaction leads to a stage two compound with I[sub c] - 10.6 A, and a general composition of C[sub n] x SO₃F-yHSO₃F is proposed for the product which is compositionally inhomogeneous. In addition, the basal plane electrical conductivity enhancements are measured for the graphite-I₂₊(solv) and graphite-I(SO₃F)₃systems employing a contactless radio frequency induction method.
Science, Faculty of
Chemistry, Department of
Graduate

Du, Toit Jacolene. "Effect of bromine and iodine in drinking water on the physiological parameters of broilers". Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/27559.

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Assessment of a significant number of water samples across South Africa by Casey and Meyer over a number of years, revealed that high concentrations (30- 32 mg/L) of bromine (Br) occur naturally within groundwater in South Africa, hence a potentially hazardous chemical constituent (PHCC). Br, the only liquid non-metallic element, is ubiquitous and an abundant trace element, but it has not been conclusively shown to perform essential functions in plants, micro organisms or animals (NRC, 2005). The recommended limit (maximum limit for no risk) for Br in drinking water was set at 1 mg/L by Kempster et al. (1980); Casey and Meyer (2001) recommend the relevant safety guideline for Br to be 0.01 mg/L. The aim of this project was to establish the effect of Br and iodine (I) in drinking water on the physiological parameters of broilers. This will contribute to verifying and refining water quality guidelines. The effect of six treatments administered as sodium bromide (NaBr) and potassium iodide (KI): 0 mg Br/L and 0 mg I/L; 1 mg Br/L; 1mg Br/L and 0.7 mg I/L; 0.7 mg I/L; 3 mg Br/L; 3 mg Br/L and 0.7 mg I/L, in the drinking water of 540 mixed Ross broiler chickens was investigated. The trial ran over a 42-day growth period from Day 1 post-hatching where mortalities, water and feed intakes were recorded daily. Chickens were weighed weekly and slaughtered at 4 and 6 weeks of age. Blood samples were taken before slaughter and free T3 and T4 hormone levels were quantified. Thyroid gland, liver and kidney samples were analysed for Br and I quantity. The different treatments of Br, irrespective of I, significantly decreased water intake (P=0.0232) and feed intake (P=0.0035) over the 42 days. The overall interaction of Br and I had no significant effect on water (P=0.0928) and feed (P=0.9593) intakes thus I did have an effective ameliorating effect on Br. FCR, weight gain and mortalities were not significantly affected by Br intake. This was also found for free T3 and T4 hormone levels. Br had an overall effect on the thyroid gland (P=0.0457), liver (P=0.0025) and kidney (P=0.0032) with accumulation of the PHCC within these three organs. It was apparent that 1 and 3 mg Br/L water administered to broilers or ingestion rates of 1.59 and 4.44 mg Br/L per bird per day, over a production period of 42 days did affect the production parameters of the birds sub-clinically. Another derivation to refine the water quality guidelines was that the administration of 0.7 mg I/L water or ingestion rates of 1.1 mg I/L per bird per day did alleviate the severe detrimental effect of the high PHCC. The 3 mg Br/L guideline is thus not too restrictive. Further research exposing the animals for a longer time period (exceeding 42 days) and exposing mature animals (producing nutritional products for human consumption) to these treatments would assist in quantifying these results.
Dissertation (MSc(Agric))--University of Pretoria, 2011.
Animal and Wildlife Sciences
unrestricted

Rauhut, Christian Bernhard. "Preparation of Functionalized Organomagnesium Reagents by ortho-Magnesiation, Sulfoxide-, Iodine- and Bromine-Magnesium Exchange Reactions". Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-95656.

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García, de la Concepción María Belén. "Novel Halogen(I) Reagents in the C-sp3- and Csp3-Bond Functionalization". Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/663299.

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En el treball presentat en aquesta tesi es mostren els desenvolupaments importants realitzats sobre l’ús de reactius d'halogen(I), específicament en la funcionalització d’enllaços C(sp2)-H i C(sp3)-H mitjançant reactius de iode(I) i brom(I). El present manuscrit està dividit en tres apartats principals: 1-Reactius de iode(I) per la difuncionalització d’alquens. 2- Aminació oxidativa d'enllaços C-(sp3)-H de tetrahidrocarbazoles. 3-Aplicació de reactius de iode(I) o catàlisi de brom en la síntesi formal de (±)-aspidospermidina. En la primera secció sobre la difuncionalització d'alquens, hem presentat la síntesi general, aïllament i caracterització de nous reactius de iode(I) amb fórmula R4N[I(O2CAr)2]. Aquests compostos posseeixen alta estabilitat davant l’exposició a l'aire i la humitat. El nostre interès radica en l'exploració de reaccions promogudes per iode electrofílic cap a una iodooxigenació de derivats d’estirè. En la segona secció, s'ha dut a terme una exploració sobre l'ús del reactiu de Varvoglis PhI(NPhth)2. Aquest es va utilitzar per a la síntesi de reactius de iode(I) i brom(I) amb lligands de ftalimida. Com l’aminació de tetrahidrocarbazoles en la posició 4 no s’ha explorat fins al moment, desenvolupem una metodologia innovadora per dur a terme l’aminación oxidativa en C(sp3)-H de derivats de tetrahidrocarbazol, utilitzant reactiu de iode(I) o catàlisi de brom. Finalment, en el tercer capítol volíem demostrar la versatilitat i el rendiment dels reactius d'halògens descrits en el capítol anterior per a la síntesi de (±)-aspidospermidina.
El trabajo presentado en esta tesis representa algunos desarrollos importantes en reactivos de halógeno(I), concretamente hacia la funcionalización de los enlaces C(sp2)-H y C(sp3)-H a través de reactivos de yodo(I) y bromo(I). El presente manuscrito está dividido en tres partes principales: 1- Reactivos de yodo(I) para la difuncionalización del alquenos. 2- Aminación oxidativa de enlaces C-(sp3)-H de tetrahidrocarbazoles 3- Aplicación de reactivos de yodo(I) o catálisis de bromo hacía la síntesis formal de (±)-aspidospermidina. En la primera sección sobre la difuncionalización de alquenos, hemos presentado una síntesis general, aislamiento y caracterización de varios reactivos de yodo(I) con la fórmula R4N[I(O2CAr)2]. Estos compuestos poseen alta estabilidad ante el aire y la humedad. Nuestro interés radica en la exploración de reacciones promovidas por yodo electrófilo hacia la yodooxigenación con derivados de estireno. En la segunda sección, se ha llevado a cabo una exploración del uso del reactivo de Varvoglis PhI(NPhth)2. Este reactivo se usó para la síntesis de reactivos de yodo(I) y bromo(I) con ligandos de ftalimida. Como la aminación de tetrahidrocarbazolas en la posición 4 no se ha sido explorada hasta el momento, se. llevó a cabo el desarrollo de una metodología innovadora para dar lugar a una aminación oxidativa en C(sp3) con derivados de tetrahidrocarbazol, usando reactivo de yodo(I) o catálisis de bromo. Finalmente, en el tercer capítulo queríamos demostrar la versatilidad y el rendimiento de los reactivos de halógenos descritos en el capítulo anterior para dar lugar a la síntesis de un compuesto natural, tal como (±)-aspidospermidina.
The work presented in this thesis represents some major developments in halogen(I) reagents, specifically towards the functionalization of C(sp2)-H and C(sp3)-H bonds through iodine(I)- and bromine(I)-reagents. The present manuscript is divided into three principal parts: 1- Iodine(I) reagents for vicinal alkene difunctionalization 2- Oxidative amination of C-(sp3)-H bonds of tetrahydrocarbazoles 3- Application of iodine(I) reagent or bromine catalysis to the formal synthesis of (±)-aspidospermidine. In the first section on alkene difunctionalization, we have presented a general synthesis, isolation and characterization of several novel iodine(I) reagents with the formula R4N[I(O2CAr)2]. These compounds exhibit high air and moisture stability. We were interested in the exploration of reactions promoted by electro-philic iodine towards a vicinal iodooxy-genation of styrene derivatives. In the second section an exploration of the use of Varvoglis reagent PhI(NPhth)2 has been carried out. This reagent was used to the synthesis of iodine(I) and bromine(I) reagents with phthalimide ligands to stabilize the electrophilic halogen center. As oxidative amination of tetrahydrocarbazoles in position 4 has not been explored so far, we developed an innovative methodology to carryout the C(sp3) oxidative amination of tetrahydrocarbazole derivatives using iodi-ne(I) reagent or bromine catalysis. Finally, in the third chapter we wanted to demonstrate the versatility and performance of halogen reagents described in the previous chapter, which were used in the synthesis of (±)-aspidospermidine.

Hay, Timothy Deane. "MAX-DOAS measurements of bromine explosion events in McMurdo Sound, Antarctica". Thesis, University of Canterbury. Physics and Astronomy, 2010. http://hdl.handle.net/10092/5394.

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Reactive halogen species (RHS) are responsible for ozone depletion and oxidation of gaseous elemental mercury and dimethyl sulphide in the polar boundary layer, but the sources and mechanisms controlling their catalytic reaction cycles are still not completely understood. To further investigate these processes, ground– based Multi–Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of boundary layer BrO and IO were made from a portable instrument platform in McMurdo Sound during the Antarctic spring of 2006 and 2007. Measurements of surface ozone, temperature, pressure, humidity, and wind speed and direction were also made, along with fourteen tethersonde soundings and the collection of snow samples for mercury analysis. A spherical multiple scattering Monte Carlo radiative transfer model (RTM) was developed for the simulation of box-air-mass-factors (box-AMFs), which are used to determine the weighting functions and forward model differential slant column densities (DSCDs) required for optimal estimation. The RTM employed the backward adjoint simulation technique for the fast calculation of box-AMFs for specific solar zenith angles (SZA) and MAX-DOAS measurement geometries. Rayleigh and Henyey-Greenstein scattering, ground topography and reflection, refraction, and molecular absorption by multiple species were included. Radiance and box-AMF simulations for MAX-DOAS measurements were compared with nine other RTMs and showed good agreement. A maximum a posteriori (MAP) optimal estimation algorithm was developed to retrieve trace gas concentration profiles from the DSCDs derived from the DOAS analysis of the measured absorption spectra. The retrieval algorithm was validated by performing an inversion of artificial DSCDs, simulated from known NO2 profiles. Profiles with a maximum concentration near the ground were generally well reproduced, but the retrieval of elevated layers was less accurate. Retrieved partial vertical column densities (VCDs) were similar to the known values, and investigation of the averaging kernels indicated that these were the most reliable retrieval product. NO₂ profiles were also retrieved from measurements made at an NO₂ measurement and profiling intercomparison campaign in Cabauw, Netherlands in July 2009. Boundary layer BrO was observed on several days throughout both measurement periods in McMurdo Sound, with a maximum retrieved surface mixing ratio of 14.4±0.3 ppt. The median partial VCDs up to 3km were 9.7±0.07 x 10¹² molec cm ⁻ in 2007, with a maximum of 2.3±0.07 x 10¹³ molec cm⁻², and 7.4±0.06 x 10¹² molec cm⁻² in 2006, with a maximum of 1.05 ± 0.07 x 1013 molec cm⁻². The median mixing ratio of 7.5±0.5 ppt for 2007 was significantly higher than the median of 5.2±0.5 ppt observed in 2006, which may be related to the more extensive first year sea ice in 2007. These values are consistent with, though lower than estimated boundary layer BrO concentrations at other polar coastal sites. Four out of five observed partial ozone depletion events (ODEs) occurred during strong winds and blowing snow, while BrO was present in the boundary layer in both stormy and calm conditions, consistent with the activation of RHS in these two weather extremes. Air mass back trajectories, modelled using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, indicated that the events were locally produced rather than transported from other sea ice zones. Boundary layer IO mixing ratios of 0.5–2.5±0.2 ppt were observed on several days. These values are low compared to measurements at Halley and Neumayer Stations, as well as mid-latitudes. Significantly higher total mercury concentrations observed in 2007 may be related to the higher boundary layer BrO concentrations, but further measurements are required to verify this.

Ishita, Keisuke. "Design, Synthesis and Evaluation of Carborane and Thiazole Derivatives". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1510937794366855.

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Zielcke, Johannes [Verfasser], e Ulrich [Akademischer Betreuer] Platt. "Observations of reactive bromine, iodine and chlorine species in the Arctic and Antarctic with Differential Optical Absorption Spectroscopy / Johannes Zielcke ; Betreuer: Ulrich Platt". Heidelberg : Universitätsbibliothek Heidelberg, 2015. http://d-nb.info/1180499611/34.

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Lövgren, Robin. "Four-component DFT calculations of phosphorescence parameters". Thesis, Linköping University, Computational Physics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19180.

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Oscillator strengths and transition energies are calculated for several mono-substitutes of benzene and naphthalene molecules. The substituents investigated are chlorine, bromine and iodine. Calculations for these molecules are presented, at the Hartree-Fock and DFT level of theory. The functional used in DFT is CAM-B3LYP.

Cartwright, Julia Ann. "Noble gas components in Martian meteorites". Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/noble-gas-components-in-martian-meteorites(4ed4e430-096d-43a8-964a-c367ab7b2f45).html.

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This thesis focuses on the analysis of heavy noble gases (argon, krypton and xenon) and halogens (chlorine, bromine and iodine) in Martian meteorites. In the absence of a sample-return mission, Martian meteorite analysis is essential for establishing evidence for an active fluid system, evaluating the potential for life and understanding the formation and evolution of Mars. Noble gas analysis has multiple applications for Martian meteorite study, as described in this thesis. The noble gas isotopic signatures of Earth’s atmosphere, Martian atmosphere and Martian interior are sufficiently different that they can be distinguished through noble gas analysis. Analysis of bulk and mineral separates of shergottites showed that Martian atmospheric Xe was distributed evenly amongst samples, whilst terrestrially weathered samples contained elevated concentrations of terrestrial atmospheric Xe. Both atmospheric components were introduced by weathering. Shock redistribution is responsible for the distribution of Martian atmosphere into more retentive sites. Crustal contamination may be responsible for the presence or absence of detectable 129Xe from the Martian atmosphere. Halogen abundances can be determined as an extension of the Ar-Ar dating technique. As the halogen system on Earth acts as a tracer for important fluid related processes, Martian halogen abundances in meteorites may provide a tracer for the Martian fluid system. Analysis of bulk and mineral separates of nakhlites showed that halogens are distributed amongst minor phases and clear variation of Br/Cl and I/Cl ratios was observed amongst samples. Elevated I concentrations in low temperature releases of finds NWA 998 and MIL 03346 are consistent with terrestrial contamination. Analysis of Nakhla, (a meteorite fall), showed a trend of elevated Br/Cl and I/Cl ratios in crush and low temperature releases, consistent with Br/Cl ratios observed in Martian rocks, soils and weathering products. In contrast, high temperature releases had lower I/Cl and Br/Cl ratios, which are broadly comparable to the terrestrial mantle. This trend may represent mixing of hydrothermal fluids (low Br/Cl and I/Cl) and surface brines (high Br/Cl and I/Cl). An impact-induced hydrothermal system may provide a mechanism for mixing of both fluid types. The crystallisation ages of nakhlite meteorites were determined using the Ar-Ar dating technique. The apparent ages measured were similar to previous Ar-Ar analysis, and older than reported for other chronometers. Previously unrecognised components were observed, including evidence for a trapped hydrous fluid. This Cl-rich component showed strong correlation with 40Ar and had 40Ar/36Ar and 40Ar/129XeXS ratios consistent with Martian atmosphere. As this component was released during crush and low temperature analysis, fluid inclusions formed by percolation of brines from the Martian surface are likely hosts. Both finds showed clear evidence of a trapped component with 40Ar/36Ar ratios similar to either terrestrial atmosphere or the Martian interior. A further component observed in olivine phases had low 40Ar/36Ar ratios, and likely formed by the release of 36Ar formed by cosmic-ray spallation reactions on iron.

Widdifield, Cory. "Multinuclear Solid-State Magnetic Resonance Studies on ‘Exotic’ Quadrupolar Nuclei: Acquisition Methods, High-Order Effects, Quantum Chemical Computations, and NMR Crystallography". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20722.

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This dissertation attempts to extend the classes of halogen-containing systems which may be studied using solid-state nuclear magnetic resonance (SSNMR). As line shape broadening due to the quadrupolar interaction (QI) scales inversely with the applied field, high-field magnet technology is indispensable for this research. Combining advanced radiofrequency pulse sequences with high-field wideline data acquisition allowed for the collection of very broad SSNMR signals of all quadrupolar halogen nuclei (i.e., 35/37Cl, 79/81Br and 127I) within a reasonable amount of experimental time. The initial systems for study were of the MX2 variety (M = Mg, Ca, Sr, Ba; X = Cl, Br, I). In total, 9 anhydrous compounds were tested. The effects of hydrate formation were tested on 7 additional compounds. Systematic trends in the observed δiso values (and to a lesser extent, Ω and CQ) were found to be diagnostic of the extent of hydration in these materials. Resolving power was successfully tested using SrBr2, which possesses 4 magnetically unique sites. The composition of CaBr2•xH2O was convincingly determined using SSNMR data and the hydration trends noted above. The sensitivity of the QI to the local bonding environment (e.g., bond distance changes of less than 0.05 Å) was used to refine (when coupled with gauge-including projector augmented-wave density functional theory (GIPAW DFT) quantum chemical computations) the structure of MgBr2, and was used to correct prior NMR data for CaCl2 (earlier accounts had been performed upon a CaCl2 hydrate). During NMR data analysis of certain iodine-containing materials, it was found that standard fitting software (which uses perturbation theory) could not reproduce the observations. Proper analysis required the use of exact simulation software and allowed for the observation of high-order quadrupole-induced effects (HOQIE). This motivated further studies using rhenium-185/187 nuclei, where it was expected that HOQIE would be more dramatic. The observed rhenium SSNMR spectra possessed additional fine structure that had never been observed before experimentally, nor would be expected from currently-available perturbation theory analysis software. Lastly, preliminary results are shown where 127I SSNMR is used to study important supramolecular systems, and the composition of the popular synthetic reagent ‘GaI’ is elucidated.

Più fonti

Libri sul tema "Bromine and iodine":

Neilson, Alasdair H., a cura di. Organic Bromine and Iodine Compounds. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-37055-0.

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Gaier, James R. Stability of bromine, iodine monochloride, copper (II) chloride, and nickel (II) chloride intercalated pitch-based graphite fibers. [Washington, DC]: National Aeronautics and Space Administration, 1987.

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Schaumann, E., J. Hartung, P. Margaretha, K. M. Roy, H. Ulrich, W. D. Pfeiffer, R. Göttlich et al. Chlorine, Bromine, and Iodine. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00000.

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Neilson, Alasdair H. Organic Bromine and Iodine Compounds. Springer Berlin Heidelberg, 2010.

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Knapp, Brian. Chlorine, Fluorine, Bromine and Iodine (Elements). Atlantic Europe Publishing Co Ltd, 1996.

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Roza, Greg. Halogen Elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Rosen Publishing Group, 2010.

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Neilson, Alasdair H. Organic Bromine and Iodine Compounds (Handbook of Environmental Chemistry). Springer, 2003.

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Lindman, B., e S. Forsen. Chlorine, Bromine and Iodine NMR: Physico-Chemical and Biological Applications. Springer, 2012.

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A method to remove intercalates from bromine and iodine intercalated carbon fibers. [Washington, DC]: National Aeronautics and Space Administration, 1993.

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The World Market for Fluorine, Bromine, and Iodine: A 2004 Global Trade Perspective. Icon Group International, Inc., 2005.

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Più fonti

Capitoli di libri sul tema "Bromine and iodine":

Predel, B. "Br - I (Bromine - Iodine)". In B - Ba … Cu - Zr, 124. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-540-44756-6_80.

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Härtinger, S. "Iodine Transfer from Organic or Organometallic Iodides". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00541.

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Troll, T. "Generation of Electrophilic Bromine by In Situ Oxidation of Bromide". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00436.

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Margaretha, P. "Substitution of Bromine". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00053.

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Hartung, J. "Bromination with Bromine". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00281.

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Pfeiffer, W. D. "Reaction with Bromine". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00391.

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Braun, M. "Substitution of Iodine". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00304.

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Braun, M. "Preparation from Sulfides and Cyanogen Bromide or from Selenides and Bromine". In Chlorine, Bromine, and Iodine, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-035-00346.

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"Chlorine, Bromine, and Iodine". In Category 5, Compounds with One Saturated Carbon Heteroatom Bond, a cura di Schaumann. Stuttgart: Georg Thieme Verlag, 2007. http://dx.doi.org/10.1055/sos-sd-035-00001.

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Aitken, R. A. "Of Bromine or Iodine". In Five-Membered Hetarenes with Three or More Heteroatoms, 1. Georg Thieme Verlag KG, 2004. http://dx.doi.org/10.1055/sos-sd-013-01336.

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Atti di convegni sul tema "Bromine and iodine":

Smalins, Edgars, Uldis Gross, Peter Spietz e Arnolds Ubelis. "Iodine and bromine resonance lamps in atmospheric research". In SPIE Proceedings, a cura di Janis Spigulis, Janis Teteris, Maris Ozolinsh e Andrejs Lusis. SPIE, 2003. http://dx.doi.org/10.1117/12.517005.

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Nguyen, Bich Phuong, Trang Thi Thu Nguyen, Juran Kim, Hye Ri Jung, Seokhyun Yoon e Wiilam Jo. "Influence of iodine-to-bromine ratio on electrical properties of lead-free Sn halide perovskite solar cells". In 2nd Asia-Pacific Hybrid and Organic Photovoltaics. Valencia: Fundació Scito, 2017. http://dx.doi.org/10.29363/nanoge.ap-hopv.2018.023.

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Ouvaroff, A. A., I. A. Butko e N. A. Litova. "Physico-chemical properties and ecological aspect of crystalline iron (III) orthovanadate, iron (III), copper (II) and lead (II) metavanadate". In III All-Russian Scientific Conference with International Participation "Science, technology, society: Environmental engineering for sustainable development of territories". Krasnoyarsk Science and Technology City Hall, 2022. http://dx.doi.org/10.47813/nto.3.2022.6.125-136.

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Abstract (sommario):

In the work, iron (III) orthovanadate, iron (III), copper (II) and lead (II) metavanadates were obtained, the ratio of the obtained substances to concentrated acids – sulfuric, hydrochloric, nitric and orthophosphoric, alkalis, aqueous solutions of chlorine, bromine and iodine, some chalcogens, aluminum and magnesium oxides was studied. Melting temperatures, densities of crystalline substances, solubility in water have been experimentally determined. IR spectroscopic analysis of compounds by the method of disturbed total internal reflection was carried out for the first time. Based on the data obtained, conclusions are drawn about the structure and chemical properties of substances, as well as the most dangerous compounds obtained by interacting with acids, alkalis and halogens.

Kopylov, I. S. "HYDROGEOCHEMICAL INDICATORS OF THE HYPERGENESIS ZONE OF THE TUNGUSSKA BASIN AND THEIR OIL-GEOLOGICAL SIGNIFICANCE". In Проблемы минералогии, петрографии и металлогении. Научные чтения памяти П. Н. Чирвинского. ПЕРМСКИЙ ГОСУДАРСТВЕННЫЙ НАЦИОНАЛЬНЫЙ ИССЛЕДОВАТЕЛЬСКИЙ УНИВЕРСИТЕТ, 2022. http://dx.doi.org/10.17072/chirvinsky.2022.14.

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Geochemical and hydrogeological oil and gas exploration was carried out in the west of the Siberian platform in the basin of the river Podkamennaya Tun-guska, where 6 thousand groundwater sources and streams have been studied. The main informative hydrogeochemical indicators in the Tunguska basin in the upper hydrodynamic zone are: the type of water, the nature of mineralization, the content of chlorides, sulfates, bromine, iodine, some organic substances and microelements, as well as an indicator of water metamorphization. 150 hydrogeochemical anomalies associated mainly with geodynamic active zones have been established. In general, all the studied hydrogeochemical indicators indicate a good closure of deep horizons and a favorable environment for the preservation of deposits in the depths of local positive structures.

Motte-Tollet, F., M. J. Hubin-Franskin, J. Delwiche e P. Morin. "Relaxation processes following excitation and ionization of the iodine 4d and bromine 3d core electrons in C2H5I and C2H4IBr". In Synchrotron radiation and dynamic phenomena. AIP, 1992. http://dx.doi.org/10.1063/1.42546.

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Roy, Ajit K., Lalit Savalia, Narendra Kothapalli e Raghunandan Karamcheti. "Mechanical Properties and Cracking Behavior of High-Temperature Heat-Exchanger Materials". In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71781.

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The structural materials selected for high-temperature heat-exchanger applications are expected to withstand very severe operating conditions including elevated temperatures and aggressive chemical species during hydrogen generation using nuclear power. Three different cycles namely sulfur-iodine, calcium-bromine and high temperature electrolysis have been identified for hydrogen generation. Three different structural materials namely Alloy C-22, Alloy C-276 and Waspaloy have been tested to evaluate their high-temperature tensile properties and stress corrosion cracking (SCC) resistance in an acidic solution. The data indicate that all three alloys are capable of maintaining appreciably high tensile strength upto a temperature of 600°C. The results of SCC testing indicate that all three materials are highly resistant to cracking in an acidic solution retaining much of their ductility and time to failure in the tested environment. Fractographic evaluation by scanning electron microscopy revealed dimple microstructure indicating significant ductility in all three alloys.

Khorramshahi, Fatemeh, Navid Ghazizadeh, Ioannis Kymissis e Arash Takshi. "Laser engraving method to fabricate iodide and bromide-based perovskite photosensors". In Organic and Hybrid Sensors and Bioelectronics XIII, a cura di Ruth Shinar, Ioannis Kymissis e Emil J. List-Kratochvil. SPIE, 2020. http://dx.doi.org/10.1117/12.2568258.

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Andrianov, A. V., A. N. Aleshin, A. O. Zakhar'in e L. B. Matyushkin. "Terahertz Optical Characteristics of Organometallic Lead-Iodide (Bromide) Perovskites and Cesium Lead Halide Nanocrystals". In 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2018). IEEE, 2018. http://dx.doi.org/10.1109/irmmw-thz.2018.8509947.

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Unz, Ronald J., Donna M. Rogers, Charles Jones, Jay P. McCown e Charles A. Waggoner. "Use of Lanthanum Bromide Detectors to Augment Site Surveys for Depleted Uranium". In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59169.

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Abstract (sommario):

A variety of systems have now been described for use in surveying sites for anthropogenic radiological contamination. Virtually all of these include use of sodium iodide detectors and register detection data with global positioning satellite data. This paper demonstrates how lanthanum bromide detectors can be used to augment existing field surveys in a manner to reduce uncertainty in areas of low count rates and to discriminate between depleted uranium and naturally occurring uranium. The survey system described is equipped with large (20 × 20 × 100 cm) sodium iodide (Alpha Spectra) and 7.5 × 7.5 cm lanthanum bromide (Saint Gobain) detectors. Additional radiological detection equipment (DigiBase) was obtained from ORTEC with survey data collected in the List Mode. Data collected in surveys were then used to generate digital maps using GeoSoft’s Oasis Montaj. Software has been developed to automatically identify areas of increased count rates using user-defined thresholds. This software can collect the count data for the masked area and generate a composite spectrum that can be compared to a reference spectrum believed to represent an uncontaminated area. Ratios of counts attributed to protactinium-234m (Pa-234m) are compared to counts attributed to Bismuth-214 (Bi-214) for both the composite filed survey spectrum and the reference spectrum. Soil samples have been collected from selected sites over a range of soil and geology types for the purpose of collecting data comparing high purity germanium (HPGe) detector and lanthanum bromide (LaBr) detector spectra. These samples have come from areas believed to be devoid of depleted uranium contamination and from areas expected to have higher concentrations of naturally occurring uranium. A library of HPGe and LaBr spectra have been collected comparing: (1) background soil samples with, (2) spectra from the same samples that have been doped with half the remediation threshold activity of depleted uranium, and (3) the remediation threshold activity of depleted uranium. Ratios of the Pa-234m:Bi-214 for both HPGe and LaBr detectors are provided in this paper. This process can be repeated for any site of interest. Background soil samples can be obtained prior to surveying and an equivalent library of spectral ratios generated. Field data from three different sites will be used to show how LaBr detectors can be effectively used as an infield HPGe surrogate for rapid discrimination between DU contamination and areas of high naturally occurring uranium. Areas of maps of questionable contamination are selected and composite LaBr spectra are generated along with Pa-234m:Bi-214 ratio. This is compared to library data to determine the approximate activity of DU present. All areas suspected of DU contamination can also be selected and excluded from the remainder of map data. A composite spectrum from the areas believed to be uncontaminated can be generated and spectral ratios compared library data for clearance purposes.

Zheng, X. G., H. Kuriyaki e K. Hirakawa. "Simple synthesis of YBa/sub 2/Cu/sub 4/O/sub 8/ using copper iodide and bromide". In International Conference on Science and Technology of Synthetic Metals. IEEE, 1994. http://dx.doi.org/10.1109/stsm.1994.835864.

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