Articles de revues : « Tellurio »

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Aleksiichuk, О. Yu, V. S. Tkachishin, V. Ye Kondratyuk, О. M. Arustamyan et I. V. Dumka. « Poisoning from tellurium and its toxic compounds in industry ». EMERGENCY MEDICINE 17, n^o 6 (10 janvier 2022) : 6–11. http://dx.doi.org/10.22141/2224-0586.17.6.2021.242321.

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Tellurium has been primarily used in the steel industry for the past 40 years. This material is used for the manufacture of solar cells, lasers, photoresistors, and counters of radioactive radiation. Cadmium tellurium batteries are the second most popular solar technology. Another important application of tellurium is in the manufacture of thermoelectric generators. In the metallurgical industry, tellurium is used as an additive to metals and alloys. Tellurium and its compounds enter the body mainly through the respiratory system, as well as through the mouth and skin. Penetration into the body through the respiratory tract causes nausea, bronchitis, and pneumonia. The tellurium compounds are restored to elementary tellurium or amenable to methylation (methyl telluride has a characteristic garlic odor; it is less toxic than tellurium) in the body. Tellurium is excreted through the kidneys and gastrointestinal tract. Methyl telluride is excreted from the body partially with exhaled air and with sweat. For the diagnosis of acute heavy metal poisoning, blood is mainly used. The use of updated algorithm-criteria for assessing the severity of clinical manifestations of systemic organ toxicity of poisons provides an appropriate level of diagnosis of disorders of vital body functions. Treatment of such patients should include antidote and symptomatic therapy depending on the severity of clinical manifestations. To prevent the development of telluric intoxication, first of all, it is necessary to apply maximum sealing and automation of production processes. It is also necessary to introduce ventilation in production facilities and to carry out preliminary and periodic medical examinations of workers without fail. The use of personal protective equipment is also required.

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Wang, Sharon Xuesong, Natasha Latouf, Peter Plavchan, Bryson Cale, Cullen Blake, Étienne Artigau, Carey M. Lisse, Jonathan Gagné, Jonathan Crass et Angelle Tanner. « Characterizing and Mitigating the Impact of Telluric Absorption in Precise Radial Velocities ». Astronomical Journal 164, n^o 5 (24 octobre 2022) : 211. http://dx.doi.org/10.3847/1538-3881/ac947a.

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Abstract Precise radial velocity (PRV) surveys are important for the search for Earth analogs around nearby bright stars, which induce a small stellar reflex motion with an RV amplitude of ∼10 cm s−1. Detecting such a small RV signal poses challenges to instrumentation, data analysis, and the precision of astrophysical models to mitigate stellar jitter. In this work, we investigate an important component in the PRV error budget—the spectral contamination from the Earth’s atmosphere (tellurics). We characterize the effects of telluric absorption on the RV precision and quantify its contribution to the RV error budget over time and across a wavelength range of 350 nm–2.5 μm. We use simulated solar spectra with telluric contamination injected, and we extract the RVs using two commonly adopted algorithms: dividing out a telluric model before performing cross-correlation or forward modeling the observed spectrum incorporating a telluric model. We assume various degrees of cleanness in removing the tellurics. We conclude that the RV errors caused by telluric absorption can be suppressed to close to or even below 1–10 cm s−1 in the blue optical region. At red through near-infrared wavelengths, however, the residuals of tellurics can induce an RV error on the meter-per-second level even under the most favorable assumptions for telluric removal, leading to significant systematic noise in the RV time series and periodograms. If the red-optical or near-infrared becomes critical in the mitigation of stellar activity, systematic errors from tellurics can be eliminated with a space mission such as EarthFinder.

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Ollivier, Patrick R. L., Andrew S. Bahrou, Sarah Marcus, Talisha Cox, Thomas M. Church et Thomas E. Hanson. « Volatilization and Precipitation of Tellurium by Aerobic, Tellurite-Resistant Marine Microbes ». Applied and Environmental Microbiology 74, n^o 23 (10 octobre 2008) : 7163–73. http://dx.doi.org/10.1128/aem.00733-08.

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ABSTRACT Microbial resistance to tellurite, an oxyanion of tellurium, is widespread in the biosphere, but the geochemical significance of this trait is poorly understood. As some tellurite resistance markers appear to mediate the formation of volatile tellurides, the potential contribution of tellurite-resistant microbial strains to trace element volatilization in salt marsh sediments was evaluated. Microbial strains were isolated aerobically on the basis of tellurite resistance and subsequently examined for their capacity to volatilize tellurium in pure cultures. The tellurite-resistant strains recovered were either yeasts related to marine isolates of Rhodotorula spp. or gram-positive bacteria related to marine strains within the family Bacillaceae based on rRNA gene sequence comparisons. Most strains produced volatile tellurides, primarily dimethyltelluride, though there was a wide range of the types and amounts of species produced. For example, the Rhodotorula spp. produced the greatest quantities and highest diversity of volatile tellurium compounds. All strains also produced methylated sulfur compounds, primarily dimethyldisulfide. Intracellular tellurium precipitates were a major product of tellurite metabolism in all strains tested, with nearly complete recovery of the tellurite initially provided to cultures as a precipitate. Different strains appeared to produce different shapes and sizes of tellurium containing nanostructures. These studies suggest that aerobic marine yeast and Bacillus spp. may play a greater role in trace element biogeochemistry than has been previously assumed, though additional work is needed to further define and quantify their specific contributions.

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du Mont, Wolf-W. « Die Reaktion von Tri-t-butylphosphan und Tri-t-butylarsan mit Selen und Tellur : Bildung inerter und labiler Chalkogenophosphorane und -arsorane / The Reaction of Tri-t-butylphosphane and Tri-t-butylarsane with Selenium and Tellurium : Formation of Inert and Labile Chalcogenophosphoranes and -arsoranes ». Zeitschrift für Naturforschung B 40, n^o 11 (1 novembre 1985) : 1453–56. http://dx.doi.org/10.1515/znb-1985-1106.

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The reactions of tri-t-butylphosphane 1 with selenium and tellurium proceed quantitatively with formation of seleno- and the telluro-tri-t-butylphosphorane. respectively (3, 4). Tri-t-butylarsane 2 reacts with selenium to give seleno-tri-t-butylarsorane (5), but no significant interaction is observed between 2 and elemental tellurium. 1H and 31P NMR spectra provide evidence for rapid tellurium transfer between telluro-tri-t-butylphosphorane (4) and tri-t-butylphosphane (1), tri-t-butylarsane (2) or tris(dimethylamino)phosphane. Selenium transfer between seleno-tri-t-butylarsorane (5) and tri-t-butylarsane (2) leads to 1H and 13C NMR line broadening. Vibrational spectra of t-Bu3E−Y (3: E = P, Y = Se; 4: E = P, Y = Te; 5: E = As, X = Se) indicate coupling of E−C and E−Y stretching vibrations in 3 and 4.

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Presentato, Alessandro, Raymond J. Turner, Claudio C. Vásquez, Vladimir Yurkov et Davide Zannoni. « Tellurite-dependent blackening of bacteria emerges from the dark ages ». Environmental Chemistry 16, n^o 4 (2019) : 266. http://dx.doi.org/10.1071/en18238.

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Environmental contextAlthough tellurium is a relatively rare element in the earth’s crust, its concentration in some niches can be naturally high owing to unique geology. Tellurium, as the oxyanion, is toxic to prokaryotes, and although prokaryotes have evolved resistance to tellurium, no universal mechanism exists. We review the interaction of tellurite with prokaryotes with a focus on those unique strains that thrive in environments naturally rich in tellurium. AbstractThe timeline of tellurite prokaryotic biology and biochemistry is now over 50 years long. Its start was in the clinical microbiology arena up to the 1970s. The 1980s saw the cloning of tellurite resistance determinants while from the 1990s through to the present, new strains were isolated and research into resistance mechanisms and biochemistry took place. The past 10 years have seen rising interest in more technological developments and considerable advancement in the understanding of the biochemical mechanisms of tellurite metabolism and biochemistry in several different prokaryotes. This research work has provided a list of genes and proteins and ideas about the fundamental metabolism of Te oxyanions. Yet the biomolecular mechanisms of the tellurite resistance determinants are far from established. Regardless, we have begun to see a new direction of Te biology beyond the clinical pathogen screening approaches, evolving into the biotechnology fields of bioremediation, bioconversion and bionanotechnologies and subsequent technovations. Knowledge on Te biology may still be lagging behind that of other chemical elements, but has moved beyond its dark ages and is now well into its renaissance.

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Zawadzka, Anna M., Ronald L. Crawford et Andrzej J. Paszczynski. « Pyridine-2,6-Bis(Thiocarboxylic Acid) Produced by Pseudomonas stutzeri KC Reduces and Precipitates Selenium and Tellurium Oxyanions ». Applied and Environmental Microbiology 72, n^o 5 (mai 2006) : 3119–29. http://dx.doi.org/10.1128/aem.72.5.3119-3129.2006.

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ABSTRACT The siderophore of Pseudomonas stutzeri KC, pyridine-2,6-bis(thiocarboxylic acid) (pdtc), is shown to detoxify selenium and tellurium oxyanions in bacterial cultures. A mechanism for pdtc's detoxification of tellurite and selenite is proposed. The mechanism is based upon determination using mass spectrometry and energy-dispersive X-ray spectrometry of the chemical structures of compounds formed during initial reactions of tellurite and selenite with pdtc. Selenite and tellurite are reduced by pdtc or its hydrolysis product H2S, forming zero-valent pdtc selenides and pdtc tellurides that precipitate from solution. These insoluble compounds then hydrolyze, releasing nanometer-sized particles of elemental selenium or tellurium. Electron microscopy studies showed both extracellular precipitation and internal deposition of these metalloids by bacterial cells. The precipitates formed with synthetic pdtc were similar to those formed in pdtc-producing cultures of P. stutzeri KC. Culture filtrates of P. stutzeri KC containing pdtc were also active in removing selenite and precipitating elemental selenium and tellurium. The pdtc-producing wild-type strain KC conferred higher tolerance against selenite and tellurite toxicity than a pdtc-negative mutant strain, CTN1. These observations support the hypothesis that pdtc not only functions as a siderophore but also is involved in an initial line of defense against toxicity from various metals and metalloids.

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Pugin, Benoit, Fabián A. Cornejo, Pablo Muñoz-Díaz, Claudia M. Muñoz-Villagrán, Joaquín I. Vargas-Pérez, Felipe A. Arenas et Claudio C. Vásquez. « Glutathione Reductase-Mediated Synthesis of Tellurium-Containing Nanostructures Exhibiting Antibacterial Properties ». Applied and Environmental Microbiology 80, n^o 22 (5 septembre 2014) : 7061–70. http://dx.doi.org/10.1128/aem.02207-14.

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ABSTRACTTellurium, a metalloid belonging to group 16 of the periodic table, displays very interesting physical and chemical properties and lately has attracted significant attention for its use in nanotechnology. In this context, the use of microorganisms for synthesizing nanostructures emerges as an eco-friendly and exciting approach compared to their chemical synthesis. To generate Te-containing nanostructures, bacteria enzymatically reduce tellurite to elemental tellurium. In this work, using a classic biochemical approach, we looked for a novel tellurite reductase from the Antarctic bacteriumPseudomonassp. strain BNF22 and used it to generate tellurium-containing nanostructures. A new tellurite reductase was identified as glutathione reductase, which was subsequently overproduced inEscherichia coli. The characterization of this enzyme showed that it is an NADPH-dependent tellurite reductase, with optimum reducing activity at 30°C and pH 9.0. Finally, the enzyme was able to generate Te-containing nanostructures, about 68 nm in size, which exhibit interesting antibacterial properties againstE. coli, with no apparent cytotoxicity against eukaryotic cells.

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Rosamilia, J. M., et B. Miller. « Voltammetric studies of tellurium film and hydrogen telluride formation in acidic tellurite solution ». Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 215, n^o 1-2 (décembre 1986) : 261–71. http://dx.doi.org/10.1016/0022-0728(86)87020-6.

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Mu, Yannan, Qian Li, Pin Lv, Yanli Chen, Dong Ding, Shi Su, Liying Zhou, Wuyou Fu et Haibin Yang. « Fabrication of NiTe films by transformed electrodeposited Te thin films on Ni foils and their electrical properties ». RSC Adv. 4, n^o 97 (2014) : 54713–18. http://dx.doi.org/10.1039/c4ra11246f.

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Tanaka, Masayoshi, Atsushi Arakaki, Sarah S. Staniland et Tadashi Matsunaga. « Simultaneously Discrete Biomineralization of Magnetite and Tellurium Nanocrystals in Magnetotactic Bacteria ». Applied and Environmental Microbiology 76, n^o 16 (25 juin 2010) : 5526–32. http://dx.doi.org/10.1128/aem.00589-10.

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ABSTRACT Magnetotactic bacteria synthesize intracellular magnetosomes comprising membrane-enveloped magnetite crystals within the cell which can be manipulated by a magnetic field. Here, we report the first example of tellurium uptake and crystallization within a magnetotactic bacterial strain, Magnetospirillum magneticum AMB-1. These bacteria independently crystallize tellurium and magnetite within the cell. This is also highly significant as tellurite (TeO3 2−), an oxyanion of tellurium, is harmful to both prokaryotes and eukaryotes. Additionally, due to its increasing use in high-technology products, tellurium is very precious and commercially desirable. The use of microorganisms to recover such molecules from polluted water has been considered as a promising bioremediation technique. However, cell recovery is a bottleneck in the development of this approach. Recently, using the magnetic property of magnetotactic bacteria and a cell surface modification technology, the magnetic recovery of Cd2+ adsorbed onto the cell surface was reported. Crystallization within the cell enables approximately 70 times more bioaccumulation of the pollutant per cell than cell surface adsorption, while utilizing successful recovery with a magnetic field. This fascinating dual crystallization of magnetite and tellurium by magnetotactic bacteria presents an ideal system for both bioremediation and magnetic recovery of tellurite.

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Molina, Roberto C., Radhika Burra, José M. Pérez-Donoso, Alex O. Elías, Claudia Muñoz, Rebecca A. Montes, Thomas G. Chasteen et Claudio C. Vásquez. « Simple, Fast, and Sensitive Method for Quantification of Tellurite in Culture Media ». Applied and Environmental Microbiology 76, n^o 14 (4 juin 2010) : 4901–4. http://dx.doi.org/10.1128/aem.00598-10.

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ABSTRACT A fast, simple, and reliable chemical method for tellurite quantification is described. The procedure is based on the NaBH4-mediated reduction of TeO3 2− followed by the spectrophotometric determination of elemental tellurium in solution. The method is highly reproducible, is stable at different pH values, and exhibits linearity over a broad range of tellurite concentrations.

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Basnayake, Rukma S. T., Janet H. Bius, Osman M. Akpolat et Thomas G. Chasteen. « Production of dimethyl telluride and elemental tellurium by bacteria amended with tellurite or tellurate ». Applied Organometallic Chemistry 15, n^o 6 (2001) : 499–510. http://dx.doi.org/10.1002/aoc.186.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov et Galiya Ruzakhunova. « Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa ». Metals 12, n^o 10 (21 octobre 2022) : 1774. http://dx.doi.org/10.3390/met12101774.

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This paper presents the results of a study of phase transformations occurring in copper-telluride by-products during its processing of oxidation-distillate roasting at low pressure. The results show that copper telluride is oxidized through intermediate compounds to the most stable tellurate (Cu3TeO6) at low temperatures. The increase in the roasting temperature above 900 °C and the presence of an oxidizer favor the copper orthotellurate decomposition. Thus, the tellurium extraction rate is 90–93% at a temperature of 1000 °C, the oxidant flow rate is 2.2 × 10−2 m3/m2·s, and the roasting time is 60–90 min. One of the decomposition products is copper oxide alloy, which is the basis of the residue. The second product is tellurium in oxide form, which evaporates and then condenses in the cold zone of the condenser in crystalline form. The main constituent phase of the condensate is tellurium oxide (TeO2), which can be further processed during one operation to elemental chalcogen by thermal reduction or electrolytic method.

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Latouf, Natasha, Sharon Xuesong Wang, Bryson Cale et Peter Plavchan. « Characterizing and Mitigating Telluric Absorption in Precise Radial Velocities. II. A Study of an M2-type Star ». Astronomical Journal 164, n^o 5 (24 octobre 2022) : 212. http://dx.doi.org/10.3847/1538-3881/ac947b.

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Abstract Telluric absorption lines impact the measuring of precise radial velocities (RVs) from high-resolution ground-based spectrographs. In this paper, we simulate the dependence of this impact on stellar spectral type and extend the work of the first paper in this series, which studied a G-type star, to a synthetic M-dwarf star. We quantify the bias in precise RV measurements in the visible and near-infrared (NIR) from the presence of tellurics in a simulated set of observations. We find that M-dwarf RVs are more impacted by tellurics compared to G-type stars. Specifically, for an M-dwarf star, tellurics can induce RV errors of up to 16 cm s−1 in the red optical and in excess of 220 cm s−1 in the NIR. For a G dwarf, the comparable RV systematics are 3 cm s−1 in the red optical and 240 cm s−1 in the NIR. We attribute this relative increase for M-dwarf stars to the increased concordance in wavelength between telluric lines and stellar Doppler information content. We compare the results of our simulation to data collected for Barnard’s star from the iSHELL spectrograph at the NASA Infrared Telescope Facility. This study was conducted as a follow-up to the NASA probe mission concept study EarthFinder.

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Zhao, Jing, et Allan Pring. « Mineral Transformations in Gold–(Silver) Tellurides in the Presence of Fluids : Nature and Experiment ». Minerals 9, n^o 3 (9 mars 2019) : 167. http://dx.doi.org/10.3390/min9030167.

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Gold–(silver) telluride minerals constitute a major part of the gold endowment at a number of important deposits across the globe. A brief overview of the chemistry and structure of the main gold and silver telluride minerals is presented, focusing on the relationships between calaverite, krennerite, and sylvanite, which have overlapping compositions. These three minerals are replaced by gold–silver alloys when subjected to the actions of hydrothermal fluids under mild hydrothermal conditions (≤220 °C). An overview of the product textures, reaction mechanisms, and kinetics of the oxidative leaching of tellurium from gold–(silver) tellurides is presented. For calaverite and krennerite, the replacement reactions are relatively simple interface-coupled dissolution-reprecipitation reactions. In these reactions, the telluride minerals dissolve at the reaction interface and gold immediately precipitates and grows as gold filaments; the tellurium is oxidized to Te(IV) and is lost to the bulk solution. The replacement of sylvanite is more complex and involves two competing pathways leading to either a gold spongy alloy or a mixture of calaverite, hessite, and petzite. This work highlights the substantial progress that has been made in recent years towards understanding the mineralization processes of natural gold–(silver) telluride minerals and mustard gold under hydrothermal conditions. The results of these studies have potential implications for the industrial treatment of gold-bearing telluride minerals.

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Ottosson, Lars-Göran, Katarina Logg, Sebastian Ibstedt, Per Sunnerhagen, Mikael Käll, Anders Blomberg et Jonas Warringer. « Sulfate Assimilation Mediates Tellurite Reduction and Toxicity in Saccharomyces cerevisiae ». Eukaryotic Cell 9, n^o 10 (30 juillet 2010) : 1635–47. http://dx.doi.org/10.1128/ec.00078-10.

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ABSTRACT Despite a century of research and increasing environmental and human health concerns, the mechanistic basis of the toxicity of derivatives of the metalloid tellurium, Te, in particular the oxyanion tellurite, Te(IV), remains unsolved. Here, we provide an unbiased view of the mechanisms of tellurium metabolism in the yeast Saccharomyces cerevisiae by measuring deviations in Te-related traits of a complete collection of gene knockout mutants. Reduction of Te(IV) and intracellular accumulation as metallic tellurium strongly correlated with loss of cellular fitness, suggesting that Te(IV) reduction and toxicity are causally linked. The sulfate assimilation pathway upstream of Met17, in particular, the sulfite reductase and its cofactor siroheme, was shown to be central to tellurite toxicity and its reduction to elemental tellurium. Gene knockout mutants with altered Te(IV) tolerance also showed a similar deviation in tolerance to both selenite and, interestingly, selenomethionine, suggesting that the toxicity of these agents stems from a common mechanism. We also show that Te(IV) reduction and toxicity in yeast is partially mediated via a mitochondrial respiratory mechanism that does not encompass the generation of substantial oxidative stress. The results reported here represent a robust base from which to attack the mechanistic details of Te(IV) toxicity and reduction in a eukaryotic organism.

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Breunig, Hans Joachim, et Ditmar Müller. « Reaktionen von Tetrapropyldibismutan mit Chalkogenen und Tetramethyldistiban / Reactions of Tetrapropyldibism uthane with Chalcogens and Tetramethyldistibane ». Zeitschrift für Naturforschung B 41, n^o 9 (1 septembre 1986) : 1129–32. http://dx.doi.org/10.1515/znb-1986-0912.

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Abstract Bis(dipropylbismuth)oxide, -sulfide, -selenide and -telluride are obtained by reactions of tetra propyldibismuthane with elem entaloxygen, sulfur, selenium or tellurium. Tetramethyldistibane and tetrapropyldibismuthane undergo an exchange reaction to give (dipropylbismuthino)-dimethylstibane.

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Pokhrel, Dipendra, Ebin Bastola, Adam B. Phillips, Michael J. Heben et Randy J. Ellingson. « Aspect ratio controlled synthesis of tellurium nanowires for photovoltaic applications ». Materials Advances 1, n^o 8 (2020) : 2721–28. http://dx.doi.org/10.1039/d0ma00394h.

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Here, we report an aspect ratio-controlled synthesis of tellurium (Te) nanowires (NWs) utilizing a hot injection colloidal method and demonstrate their use as a back buffer layer in cadmium telluride (CdTe) photovoltaics.

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Nitsenko, A. V., V. N. Volodin, X. A. Linnik, F. Kh Tuleutay et N. M. Burabaeva. « Distillation recovery of tellurium from copper telluride in oxide forms ». Izvestiya Vuzov. Tsvetnaya Metallurgiya (Universities' Proceedings Non-Ferrous Metallurgy) 28, n^o 4 (18 août 2022) : 45–54. http://dx.doi.org/10.17073/0021-3438-2022-4-45-54.

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The paper presents the results of studies into tellurium extraction from its compounds with copper in the form of oxides by the pyrometallurgical method. Commercial copper telluride of Kazakhmys Corporation LLP containing crystalline phases, wt.%: Cu7Te4 – 36.5; Cu5Te3 – 28.5; Cu2Te – 12.9; Cu2.5SO4(OH)3·2H2O – 16.2 and Cu3(SO4)(OH)4 – 6.0 was used as an object of research. The physical and chemical research and technology experiments showed the fundamental possibility of commercial copper telluride processing by oxidative distillation roasting with the extraction of tellurium into a separate product. Air oxygen was used as an oxidant. It was established that a pressure decrease in the range of 80–0.67 kPa at the same temperature entails an increase in the degree of tellurium extraction. However, the tellurium extraction degree (93.0–98.0 %) at all pressures (within 1 hour) acceptable from the technology point of view is achieved at 1100 °C. Increasing the exposure to 3 hours has a minor beneficial effect. Diffractometric studies of cinders from technology experiments showed a decrease in the content of copper oxides in the pressure range of 80–40 kPa and an increase in the Cu3TeO6 phase content. With a subsequent increase in rarefaction from 40 to 0.67 kPa, there is a noticeable decrease in the amount of cuprite and, as a consequence, a sharp increase in the amount of cuprous oxide. A slowdown in the increase of the copper tellurate volume was noted at pressures of 40–20 kPa, and a sharp drop in its content at pressures below 13.3 kPa. The derived condensate is a free-flowing mixture of crystalline phases of tellurium dioxide (67.7 %) and tellurium oxysulfate (32.3 %). This condensate is a middling product for further production of elemental tellurium.

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Arora, Swati, Vivek Jaimini, Subodh Srivastava et Y. K. Vijay. « Properties of Nanostructure Bismuth Telluride Thin Films Using Thermal Evaporation ». Journal of Nanotechnology 2017 (2017) : 1–4. http://dx.doi.org/10.1155/2017/4276506.

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Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te) and bismuth (Bi) were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show granular growth.

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Tsygankova, M. V., E. A. Perminova, M. T. Chukmanova et O. A. Raikina. « BISMUTH TELLURID WASTE PROCESSING ». Fine Chemical Technologies 12, n^o 1 (28 février 2017) : 39–44. http://dx.doi.org/10.32362/2410-6593-2017-12-1-39-44.

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The main stages of bismuth telluride processing comprising sintering with NaOH, leaching and precipitation were investigated. Bi2Te3 samples produced by "ADV Engineering" were used as starting compounds. The studies revealed regularities of tellurium behavior during the sintering of Bi2Te3 with NaOH and the resulting the solid residue leaching. It was noted that annealing at 350-450°C with NaOH transforms tellurium into Na2TeO3, which is an appropriate form for further dissolution and separation from bismuth. Increasing temperature results in Na2TeO3 oxidation and formation of the water-insoluble compound Na2TeO4. Thus, it decreases tellurium extraction degree during the leaching. It has been shown that increasing temperature from 8 to 25°C at the step of tellurium hydrolytic precipitation slightly affects the extraction degree, the value of which is 93.5-98.2%.

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Peng, Wanli, Yanqiu Wang, Yali Fu, Zixin Deng, Shuangjun Lin et Rubing Liang. « Characterization of the Tellurite-Resistance Properties and Identification of the Core Function Genes for Tellurite Resistance in Pseudomonas citronellolis SJTE-3 ». Microorganisms 10, n^o 1 (1 janvier 2022) : 95. http://dx.doi.org/10.3390/microorganisms10010095.

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Tellurite is highly toxic to bacteria and commonly used in the clinical screening for pathogens; it is speculated that there is a potential relationship between tellurite resistance and bacterial pathogenicity. Until now, the core function genes of tellurite resistance and their characteristics are still obscure. Pseudomonas citronellolis SJTE-3 was found able to resist high concentrations of tellurite (250 μg/mL) and formed vacuole-like tellurium nanostructures. The terZABCDE gene cluster located in the large plasmid pRBL16 endowed strain SJTE-3 with the tellurite resistance of high levels. Although the terC and terD genes were identified as the core function genes for tellurite reduction and resistance, the inhibition of cell growth was observed when they were used solely. Interestingly, co-expression of the terA gene or terZ gene could relieve the burden caused by the expression of the terCD genes and recover normal cell growth. TerC and TerD proteins commonly shared the conserved sequences and are widely distributed in many pathogenic bacteria, highly associated with the pathogenicity factors.

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Kucharski, M., P. Madej, M. Wedrychowicz, T. Sak et W. Mróz. « Recovery of Tellurium From Sodium Carbonate Slag ». Archives of Metallurgy and Materials 59, n^o 1 (1 mars 2014) : 51–57. http://dx.doi.org/10.2478/amm-2014-0009.

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Abstract This study is devoted to tellurium recovery from sodium carbonate slag, formed in the fire refining process of crude silver. The slag was modified by silica additions and then reduced by carbon oxide. The degree of the slag modification was defined by the parameter kw: where:ni- the mole numbers of silica, sodium carbonate and sodium oxide. The compositions of the investigated slag determined by the parameter kw and the mole fraction of the tellurium oxide (xTeO2 ) are given in the following Table. The reduction of tellurium was very fast for all the investigated slags, which was manifested by an almost complete conversion of CO into CO2. Unfortunately, at the same time, a side reaction took place, and as a results sodium telluride was formed, which reported to the slag: (Na2O)slag + Te(g) + CO = (Na2Te)slag + CO2 The tellurium content in the reduced slag decreases as the parameter kw increases, and only the slag with the kw equal unity was suitable for the tellurium recovery in form of dusts, containing more than 76 wt-% tellurium.

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Boruk, S. D., K. S. Dremlyuzhenko, V. Z. Tsalyi, І. М. Yuriychuk, V. P. Kladko, A. Y. Gudimenko, O. A. Kapush, S. G. Dremlyuzhenko et S. I. Budzulyak. « Properties of Highly Dispersed Systems on The Base of Cadmium Telluride Obtained by Electrochemical Dispergation ». Фізика і хімія твердого тіла 18, n^o 3 (15 septembre 2017) : 338–41. http://dx.doi.org/10.15330/pcss.18.3.338-341.

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Physical and chemical properties of highly dispersed systems on the base of metallic (cadmium, tellurium) and semiconductor materials (cadmium telluride) obtained by the plasma-electrochemical method are studied. It is shown that obtained systems consist of particles of different sizes, and in some cases there are two polymorphic modifications of the systems.

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Maltman, Chris, et Vladimir Yurkov. « Extreme Environments and High-Level Bacterial Tellurite Resistance ». Microorganisms 7, n^o 12 (22 novembre 2019) : 601. http://dx.doi.org/10.3390/microorganisms7120601.

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Bacteria have long been known to possess resistance to the highly toxic oxyanion tellurite, most commonly though reduction to elemental tellurium. However, the majority of research has focused on the impact of this compound on microbes, namely E. coli, which have a very low level of resistance. Very little has been done regarding bacteria on the other end of the spectrum, with three to four orders of magnitude greater resistance than E. coli. With more focus on ecologically-friendly methods of pollutant removal, the use of bacteria for tellurite remediation, and possibly recovery, further highlights the importance of better understanding the effect on microbes, and approaches for resistance/reduction. The goal of this review is to compile current research on bacterial tellurite resistance, with a focus on high-level resistance by bacteria inhabiting extreme environments.

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Mao, Jun, Hangtian Zhu, Zhiwei Ding, Zihang Liu, Geethal Amila Gamage, Gang Chen et Zhifeng Ren. « High thermoelectric cooling performance of n-type Mg3Bi2-based materials ». Science 365, n^o 6452 (18 juillet 2019) : 495–98. http://dx.doi.org/10.1126/science.aax7792.

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Thermoelectric materials have a large Peltier effect, making them attractive for solid-state cooling applications. Bismuth telluride (Bi2Te3)–based alloys have remained the state-of-the-art room-temperature materials for many decades. However, cost partially limited wider use of thermoelectric cooling devices because of the large amounts of expensive tellurium required. We report n-type magnesium bismuthide (Mg3Bi2)–based materials with a peak figure of merit (ZT) of ~0.9 at 350 kelvin, which is comparable to the commercial bismuth telluride selenide (Bi2Te3–xSex) but much cheaper. A cooling device made of our material and p-type bismuth antimony telluride (Bi0.5Sb1.5Te3) has produced a large temperature difference of ~91 kelvin at the hot-side temperature of 350 kelvin. n-type Mg3Bi2-based materials are promising for thermoelectric cooling applications.

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Valková, Danka, Lenka Valkovičová, Silvia Vávrová, Elena Kováčová, Jozef Mravec et Ján Turňa. « The contribution of tellurite resistance genes to the fitness of Escherichia coli uropathogenic strains ». Open Life Sciences 2, n^o 2 (1 juin 2007) : 182–91. http://dx.doi.org/10.2478/s11535-007-0019-9.

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AbstractThe presence of tellurite resistance gene operons has been reported in several human pathogens despite the fact that tellurium, as well as its soluble salts, are both rare in nature and are no longer in use as antimicrobial agents. We have introduced the cloned terWZA-F genes from an uropathogenic Escherichia coli isolate into another clinical E. coli isolate that was shown to be ter-gene free. The presence of the introduced genes increased the level of potassium tellurite resistance, as well as the level of resistance to oxidative stress mediated by hydrogen peroxide; and prolonged the ability of particular strains to survive in macrophages. We therefore propose that the contribution of tellurite resistance genes to oxidative stress resistance in bacteria is at least one reason for their presence in the genomes of a broad range of pathogenic microorganisms.

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Alam, Mohammad Firoz, Saeed Alshahrani, Essam Alamir, Mohammad Abdurrhman Alhazmi, Tarique Anwer, Gyas Khan et Moni Sivakumar Sivagurunathan. « Zingerone ameliorates tellurium induced nephrotoxicity by abating elevated serum markers in the rats ». Environment Conservation Journal 21, n^o 1&2 (10 juin 2020) : 125–29. http://dx.doi.org/10.36953/ecj.2020.211214.

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The present study was designed to investigate the nephrotoxicity of tellurium (Sodium tellurite) in rats through evaluating the level of kidney functional marker enzymes and its treatment with Zingerone. Rats were divided into four groups, Group-A (control group), Group-B (tellurium treated group), Group-C (tellurium + Zingerone treatment group), and Group-D (Zingerone treatment alone) and each group have six animals. Tellurium was given in Group-B and Group-C at the dose of 8.3mg/kg bodyweight daily orally for 15 days, while Zingerone of 100mg/kg body weight was given in Group-C as pre- and post-treatment orally for 15days. Group-D was given alone Zingerone of 100mg/kg bodyweight; orally for 15 days. Results revealed that tellurium administration significantly (P<0.001) increased the serum markers (ALP, BUN, Uric Acid and Creatinine) in Group-B as a compared to Group-A while the treatment with Zingerone significantly (P<0.001) decreased these elevated serum markers in Group-C as comparison to Group-B. There were no changes observed in the positive control (Zingerone administered Group-D). Thus, the present finding confirmed that the Zingerone plays a potential role in reducing nephrotoxicity against tellurium by abating elevated serum markers in rats.

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Yang, Wei, Gang Wang, Qian Wang, Ping Dong, Huan Cao et Kai Zhang. « Comprehensive Recovery Technology for Te, Au, and Ag from a Telluride-Type Refractory Gold Mine ». Minerals 9, n^o 10 (30 septembre 2019) : 597. http://dx.doi.org/10.3390/min9100597.

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While extracting gold and silver from telluride-type gold deposits, it is beneficial to develop a comprehensive recovery technology for tellurium. In this paper, we report process mineralogy based on the backward processing technology and the low comprehensive utilization rate of typical telluride-type gold deposits in Xiaoqinling, China. The findings show that tellurium, gold, and silver are the most valuable elements in the ore fissures and gangue minerals and are encapsulated in metallic sulfur ore in the form of altaite, hessite, calaverite, antamokite and natural gold. The flotation method was innovatively applied in this study to comprehensively recover Te, Au and Ag. The results show that when the ore particle size was −0.074 mm (70%), the flotation pulp density was 33%, the pulp pH was 8, and the combined collector (isoamyl xanthate + ethyl thio- carbamate (1:1)) was 120 g/t, in the process involving one rough flotation step, two cleaning flotations and two scavenging flotations as well as a continuous 8 d industrial test, the recovery degree was stable and the average grades of Te, Au, and Ag were 241.61, 90.30, and 92.74 g/t with 95.42%, 97.28%, and 94.65% recovery rates, respectively; thus, excellent recovery degrees were obtained. Compared with the original flotation process, the recovery rates of Te, Au, and Ag were increased by 19.91%, 6.93%, and 5.67%, which boosted the effective enrichment of all valuable elements in the telluride-type gold mine and achieved technological progress.

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Calderón, Iván L., Alex O. Elías, Eugenia L. Fuentes, Gonzalo A. Pradenas, Miguel E. Castro, Felipe A. Arenas, José M. Pérez et Claudio C. Vásquez. « Tellurite-mediated disabling of [4Fe–4S] clusters of Escherichia coli dehydratases ». Microbiology 155, n^o 6 (1 juin 2009) : 1840–46. http://dx.doi.org/10.1099/mic.0.026260-0.

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The tellurium oxyanion tellurite is toxic for most organisms and it seems to alter a number of intracellular targets. In this work the toxic effects of tellurite upon Escherichia coli [4Fe–4S] cluster-containing dehydratases was studied. Reactive oxygen species (ROS)-sensitive fumarase A (FumA) and aconitase B (AcnB) as well as ROS-resistant fumarase C (FumC) and aconitase A (AcnA) were assayed in cell-free extracts from tellurite-exposed cells in both the presence and absence of oxygen. While over 90 % of FumA and AcnB activities were lost in the presence of oxygen, no enzyme inactivation was observed in anaerobiosis. This result was not dependent upon protein biosynthesis, as determined using translation-arrested cells. Enzyme activity of purified FumA and AcnB was inhibited when exposed to an in vitro superoxide-generating, tellurite-reducing system (ITRS). No inhibitory effect was observed when tellurite was omitted from the ITRS. In vivo and in vitro reconstitution experiments with tellurite-damaged FumA and AcnB suggested that tellurite effects involve [Fe–S] cluster disabling. In fact, after exposing FumA to ITRS, released ferrous ion from the enzyme was demonstrated by spectroscopic analysis using the specific Fe2+ chelator 2,2′-bipyridyl. Subsequent spectroscopic paramagnetic resonance analysis of FumA exposed to ITRS showed the characteristic signal of an oxidatively inactivated [3Fe–4S]+ cluster. These results suggest that tellurite inactivates enzymes of this kind via a superoxide-dependent disabling of their [4Fe–4S] catalytic clusters.

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Hathaway, Evan, Jiyang Chen, Roberto Gonzalez-Rodriguez, Yuankun Lin et Jingbiao Cui. « Raman study of silicon telluride nanoplates and their degradation ». Nanotechnology 33, n^o 26 (7 avril 2022) : 265703. http://dx.doi.org/10.1088/1361-6528/ac5c13.

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Abstract Silicon telluride (Si2Te3) has emerged as one of the many contenders for 2D materials ideal for the fabrication of atomically thin devices. Despite the progress which has been made in the electric and optical properties of silicon telluride, much work is still needed to better understand this material. We report here on the Raman study of Si2Te3 degradation under both annealing and in situ heating with a laser. Both processes caused pristine Si2Te3 to degrade into tellurium and silicon oxide in air in the absence of a protective coating. A previously unreported Raman peak at ∼140 cm−1 was observed from the degraded samples and is found to be associated with pure tellurium. This peak was previously unresolved with the peak at 144 cm−1 for pristine Si2Te3 in the literature and has been erroneously assigned as a signature Raman peak of pure Si2Te3, which has caused incorrect interpretations of experimental data. Our study has led to a fundamental understanding of the Raman peaks in Si2Te3, and helps resolve the inconsistent issues in the literature. This study is not only important for fundamental understanding but also vital for material characterization and applications.

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Nuss, Philip. « Losses and environmental aspects of a byproduct metal : tellurium ». Environmental Chemistry 16, n^o 4 (2019) : 243. http://dx.doi.org/10.1071/en18282.

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Environmental contextStudies involving modelling are increasingly being performed to better understand how technology-critical elements such as tellurium are transported and accumulated in man-made technological systems. The resulting ‘anthropogenic cycles’ provide estimates of current and anticipated future material releases to the environment, and their associated environmental implications. This information complements data on natural cycles in which the subsequent transport and fate of tellurium in the environment can be examined. AbstractGlobal demand for tellurium has greatly increased owing to its use in solar photovoltaics. Elevated levels of tellurium in the environment are now observed. Quantifying the losses from human usage into the environment requires a life-cycle wide examination of the anthropogenic tellurium cycle (in analogy to natural element cycles). Reviewing the current literature shows that tellurium losses to the environment might occur predominantly as mine tailings, in gas and dust and slag during processing, manufacturing losses, and in-use dissipation (situation in around 2010). Large amounts of cadmium telluride will become available by 2040 as photovoltaic modules currently in-use reach their end-of-life. This requires proper end-of-life management approaches to avoid dissipation to the environment. Because tellurium occurs together with other toxic metals, e.g. in the anode slime collected during copper production, examining the life-cycle wide environmental implication of tellurium production requires consideration of the various substances present in the feedstock as well as the energy and material requirements during production. Understanding the flows and stock dynamics of tellurium in the anthroposphere can inform environmental chemistry about current and future tellurium releases to the environment, and help to manage the element more wisely.

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Guzzo, Julie, et Michael S. Dubow. « A Novel Selenite- and Tellurite-Inducible Gene inEscherichia coli ». Applied and Environmental Microbiology 66, n^o 11 (1 novembre 2000) : 4972–78. http://dx.doi.org/10.1128/aem.66.11.4972-4978.2000.

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ABSTRACT Selenium is both an essential and a toxic trace element, and the range of concentrations between the two is extremely narrow. Although tellurium is not essential and is only rarely found in the environment, it is considered to be extremely toxic. Several hypotheses have been proposed to account for the toxic effects of selenite and tellurite. However, these potential mechanisms have yet to be fully substantiated. Through screening of an Escherichia coli luxABtranscriptional gene fusion library, we identified a clone whose luminescence increased in the presence of increasing concentrations of sodium selenite or sodium tellurite. Cloning and sequencing of theluxAB junction revealed that the fusion had occurred in a previously uncharacterized open reading frame, termed o393or yhfC, which we have now designated gutS, for gene up-regulated by tellurite and selenite. Transcription fromgutS in the presence of selenite or tellurite was confirmed by RNA dot blot analysis. In vivo expression of the GutS polypeptide, using the pET expression system, revealed a polypeptide of approximately 43 kDa, in good agreement with its predicted molecular mass. Although the function of GutS remains to be elucidated, homology searches as well as protein motif and secondary-structure analyses have provided clues which may implicate GutS in transport in response to selenite and tellurite.

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Langeveld, Adam B., Nikku Madhusudhan, Samuel H. C. Cabot et Simon T. Hodgkin. « Assessing telluric correction methods for Na detections with high-resolution exoplanet transmission spectroscopy ». Monthly Notices of the Royal Astronomical Society 502, n^o 3 (16 janvier 2021) : 4392–404. http://dx.doi.org/10.1093/mnras/stab134.

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ABSTRACT Using high-resolution ground-based transmission spectroscopy to probe exoplanetary atmospheres is difficult due to the inherent telluric contamination from absorption in Earth’s atmosphere. A variety of methods have previously been used to remove telluric features in the optical regime and calculate the planetary transmission spectrum. In this paper we present and compare two such methods, specifically focusing on Na detections using high-resolution optical transmission spectra: (1) calculating the telluric absorption empirically based on the airmass and (2) using a model of the Earth’s transmission spectrum. We test these methods on the transmission spectrum of the hot Jupiter HD 189733 b using archival data obtained with the HARPS spectrograph during three transits. Using models for Centre-to-Limb Variation and the Rossiter–McLaughlin effect, spurious signals which are imprinted within the transmission spectrum are reduced. We find that correcting tellurics with an atmospheric model of the Earth is more robust and produces consistent results when applied to data from different nights with changing atmospheric conditions. We confirm the detection of sodium in the atmosphere of HD 189733 b, with doublet line contrasts of $-0.64 \pm 0.07~{{\ \rm per\ cent}}$ (D2) and $-0.53 \pm 0.07~{{\ \rm per\ cent}}$ (D1). The average line contrast corresponds to an effective photosphere in the Na line located around 1.13 Rp. We also confirm an overall blueshift of the line centroids corresponding to net atmospheric eastward winds with a speed of 1.8 ± 1.2 km s−1. Our study highlights the importance of accurate telluric removal for consistent and reliable characterization of exoplanetary atmospheres using high-resolution transmission spectroscopy.

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Shamsuddin, M., A. Nasar et V. B. Tare. « Electrical conductivity of tellurium deficient cadmium telluride ». Journal of Applied Physics 74, n^o 10 (15 novembre 1993) : 6208–11. http://dx.doi.org/10.1063/1.355190.

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Yao, Hong-Bin, Xiao-Bo Li, Si-Yuan Ai et Shu-Hong Yu. « Hydrazine-cadmium tellurite hybrid microcrystals : An efficient precursor to porous cadmium telluride and tellurium architectures through its thermal decomposition ». Nano Research 3, n^o 2 (février 2010) : 81–91. http://dx.doi.org/10.1007/s12274-010-1011-7.

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Mikulski, Stanisław Z. « The Occurrence of Tellurium and Bismuth in the Gold-Bearing Polymetallic Sulfide Ores in the Sudetes (Sw Poland) ». Gospodarka Surowcami Mineralnymi 30, n^o 2 (1 juin 2014) : 15–33. http://dx.doi.org/10.2478/gospo-2014-0019.

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Streszczenie W artykule szczegółowo scharakteryzowano pod względem mineralogicznym i geochemicznym występowanie telluru i bizmutu w złotonośnych siarczkowych rudach polimctalicznych z zarzu- conych złóż (Złoty Stok, Czarnów, Radzimowicc i Radomicc) oraz punktu mineralizacji (Bardo Śląskie) w Sudetach. Tellur jest zaliczany do pierwiastków krytycznych, a jego rola stale wzrasta. Na rynkach światowych popyt na tellur znacznie przewyższa jego podaż zc względu na coraz większe wykorzystanie np. w produkcji paneli słonecznych czy nośników informacji. Maksymalne kon- centracje telluru około 150 ppm stwierdzono w rudach arscnopirytowo-chalkopirytowych w Ra- dzimowicach, a najwyższe koncentracje bizmutu (ok. 0,5%) w rudach siarczkowych w Czarnowie. W pozostałych obszarach koncentracje Tc są na poziomic od kilku do kilkudziesięciu ppm, a w przy- padku Bi od kilkudziesięciu do kilkuset ppm. Zawartości tc znacznie przewyższają klarki tych metali w skorupie ziemskiej. Wśród zidentyfikowanych minerałów telluru w Radzimowicach i Czarnowie dominują tcllurki Ag (hessyt) oraz w Bardzie Śląskim tcllurki Bi (hcdlcyit i tcllurobismutyt). Tcllurki występują głównie w postaci mikro-wrostków w minerałach siarczkowych w paragcnczic z mi- nerałami Au, Ag i Bi. Minerały bizmutu rozpoznano we wszystkich zbadanych miejscach i re- prezentowane są głównie przez bizmut rodzimy i wtórny minerał bizmutu -bismutynit. Tellur i bizmut wykazują przeważnie silną korelacje (cc>0,6) z Au, Ag i Pb. Krystalizacja głównych minerałów Bi i Tc nastąpiła w zakresie temperatur średnich (300 to 200°C) w dwóch etapach. Pierwszy związany głównie z krystalizacją tcllurków Bi w strefach kontaktowo-mctasomatycznych wokół waryscyjskich intmzji granitoidowych (Czarnów i Bardo Śląskie) i drugi - związany z krystalizacją tcllurków Ag w procesach cpitcrmalnych wokół intruzji porfirowych (Radzimowicc). Bi i Tc odgrywały donośną rolę w procesie wytrącania złota z roztworów hydrotcrmalnych. Pierwiastki tc mają znaczenie mctalogcnicznc i wskaźnikowe przy poszukiwaniach złota.

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Bradley, Jonathan. « (Invited) Rare-Earth-Doped Tellurium Oxide Light Emitting Nanophotonic Devices ». ECS Meeting Abstracts MA2022-01, n^o 20 (7 juillet 2022) : 1092. http://dx.doi.org/10.1149/ma2022-01201092mtgabs.

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Tellurium oxide is a promising material for passive, nonlinear and rare-earth-doped active photonic devices because of its high transparency, high refractive index, high nonlinearity and unique structure allowing for high rare-earth solubility. In this talk I present on our recent progress on tellurite glass on-chip light emitting nanophotonic devices. Low-loss passive devices including high-Q-factor microdisks and microring resonators will be discussed. In addition, rare-earth-doped active devices, including erbium-doped and thulium-doped waveguide amplifiers and microlasers will be presented. Using similar structures, we demonstrate nonlinear light emission via four-wave-mixing, supercontinuum generation and third harmonic generation. These tellurium oxide integrated nanophotonic devices are highly promising for compact and low-cost passive, active and nonlinear photonic integrated circuits for applications in communications, computing, and sensing.

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Lisogorskyi, M., H. R. A. Jones, F. Feng, R. P. Butler et S. Vogt. « Exploring the robustness of Keplerian signals to the removal of active and telluric features ». Monthly Notices of the Royal Astronomical Society 500, n^o 1 (22 octobre 2020) : 548–57. http://dx.doi.org/10.1093/mnras/staa3180.

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ABSTRACT We examine the influence of activity- and telluric-induced radial velocity (RV) signals on high-resolution spectra taken with an iodine absorption cell. We exclude 2-$\mathring{\rm A}$ spectral chunks containing active and telluric lines based on the well-characterized K1V star α Centauri B and illustrate the method on Epsilon Eridani – an active K2V star with a long-period, low-amplitude planetary signal. After removal of the activity- and telluric-sensitive parts of the spectrum from the RV calculation, the significance of the planetary signal is increased and the stellar rotation signal disappears. In order to assess the robustness of the procedure, we perform Monte Carlo simulations based on removing random chunks of the spectrum. Simulations confirm that the removal of lines impacted by activity and tellurics provides a method for checking the robustness of a given Keplerian signal. We also test the approach on HD 40979, which is an active F8V star with a large-amplitude planetary signal. Our Monte Carlo simulations reveal that the significance of the Keplerian signal in the F star is much more sensitive to wavelength. Unlike the K star, the removal of active lines from the F star greatly reduces the RV precision. In this case, our removal of a K star active line from an F star does not a provide a simple useful diagnostic because it has far less RV information and heavily relies on the strong active lines.

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Alshehria, A. M., El Sayed Yousefa, A. A. Alshahrania, Akram Ibrahima, Nafis Ahmada et V. R. Bhardwajb. « Differential Nonlinear Absorption of an Elliptically Polarized Femtosecond Vortex Beam in Tellurite Glass-=SUP=-*-=/SUP=- ». Журнал технической физики 128, n^o 8 (2020) : 1178. http://dx.doi.org/10.21883/os.2020.08.49718.293-19.

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We present differential nonlinear absorption of an elliptically polarized femtosecond laser vortex beam carrying an angular momentum of l = -1 in tellurite glass. Transmission measurements were utilized to measure the nonlinear absorption of the glass on a shot-by-shot basis, and to investigate the modification threshold for the beam. Additionally, the effect of pulse energy on the polarization ellipse was investigated. The results revealed a reduction in the ellipticity as the incident pulse energy was increased. Non-rotation of the ellipsoid indicated that there is no change in the third order nonlinear susceptibility (chi(3)) of the telluride glass upon irradiation by the femtosecond beam. The transmission of multiple pulses through the same spot revealed that although an effect was evident for the first ten pulses, the subsequent pulses had no effect. The transmission of a complete cycle of increasing and decreasing pulse energies revealed no hysteresis of the femtosecond laser vortex beam in tellurite glass in contrast to that reported for Gaussian beams in silica glass. Keywords: vortex beam, tellurite glass, nonlinear absorption.

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Burabaeva, Nurila, Valeriy Volodin, Sergey Trebukhov, Alina Nitsenko et Xeniya Linnik. « On the Distillation Separation of Aluminum–Tellurium System Melts under Equilibrium Condition ». Metals 12, n^o 12 (29 novembre 2022) : 2059. http://dx.doi.org/10.3390/met12122059.

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The problem to purify secondary aluminum raw materials from tellurium can be solved by the distillation method based on phase diagrams with liquid and vapor coexistence fields. Similar diagrams can be generated based on the vapor pressure values of the components. In this regard, the vapor pressure values of tellurium and aluminum telluride were determined by the boiling point method. The aluminum vapor pressure values are found by integration of the Gibbs-Duhem equation. The boundaries of the system vapor-liquid equilibrium fields for the Al-Te system at 101.32 kPa and 6.67 kPa were calculated based on the vapor pressure values of the components. The following conclusion can be made from the consideration of the position of the liquid and vapor coexistence field boundaries under atmospheric pressure and in a vacuum. Aluminum can be quite completely purified from Al2Te3 and Te by distillation in a vacuum in one operation at temperatures above 1273 K. Tellurium will be in a complete vapor state under these conditions—above the boiling line in the Al2Te3-Te system.

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Hojniak-Thyssen, Sandra, Michał Szczepaniak, Lechosław Latos-Grażyński et Ewa Pacholska-Dudziak. « A flexible expanded heterocorrole : Tellura[22]porphyrin(6.1.1.0) ». Journal of Porphyrins and Phthalocyanines 23, n^o 11n12 (décembre 2019) : 1470–77. http://dx.doi.org/10.1142/s1088424619501621.

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An expanded heterocorrole, meso-tetraaryl-tellura[22]porphyrin(6.1.1.0), containing a bipyrrole moiety and a six-carbon long link, has been synthesized. The reaction path proceeds through a controlled acid-promoted extrusion of one tellurium atom from meso-aryl-26,28-ditellurasapphyrin, leading to a structure where one tellurophene ring of the substrate is replaced by a bridging acyclic four-carbon unit. This aromatic porphyrin-annulene hybrid is conformationally flexible in solution, on account of the C4 unit adopting two different configurations: trans–cis–trans or all-trans. Studies of the dynamic behavior of tellura[22]porphyrin(6.1.1.0) in solution were performed by means of 1H and 125Te NMR spectroscopy. The X-ray structure of the all-trans form with trapezoid macrocyclic skeleton is also presented.

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Liu, Jian-Wei, Jie Xu, Hai-Wei Liang, Kai Wang et Shu-Hong Yu. « Macroscale Ordered Ultrathin Telluride Nanowire Films, and Tellurium/Telluride Hetero-Nanowire Films ». Angewandte Chemie 124, n^o 30 (27 juin 2012) : 7538–43. http://dx.doi.org/10.1002/ange.201201608.

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Liu, Jian-Wei, Jie Xu, Hai-Wei Liang, Kai Wang et Shu-Hong Yu. « Macroscale Ordered Ultrathin Telluride Nanowire Films, and Tellurium/Telluride Hetero-Nanowire Films ». Angewandte Chemie International Edition 51, n^o 30 (27 juin 2012) : 7420–25. http://dx.doi.org/10.1002/anie.201201608.

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