Articoli di riviste: "Tellurium"

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Muthu, Arjun, Daniella Sári, Aya Ferroudj, Hassan El-Ramady, Áron Béni, Khandsuren Badgar e József Prokisch. "Microbial-Based Biotechnology: Production and Evaluation of Selenium-Tellurium Nanoalloys". Applied Sciences 13, n. 21 (26 ottobre 2023): 11733. http://dx.doi.org/10.3390/app132111733.

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Using seleno-compounds and telluric compounds is a practical approach for developing solutions against drug-resistant bacterial infections and malignancies. It will accelerate the search for novel treatments or adjuvants for existing therapies. Selenium and tellurium nanospheres can be produced by lactic acid bacteria. The bacteria can differentiate the selenium and tellurium when the medium contains both selenite and tellurite. Therefore, our question in this study was the following: are they making alloys from the selenium and tellurium and what will be the composition, color, and shape of the nanoparticles? We used a simple microbial synthesis to produce nanoselenium, nanotellurium, and their alloys from sodium selenite and sodium tellurite using Lactobacillus casei. This bacterium produced red spherical amorphous elemental selenium nanospheres with a diameter of 206 ± 33 nm from selenite and amorphous black nanorods with a length of 176 ± 32 nm and a cross-section of 62 ± 13 nm from tellurite. If the initial medium contains a mixture of selenite and tellurite, the resulting nanoparticles will contain selenium and tellurium in the same ratios in the alloy as in the medium. This proves that Lactobacillus casei cannot distinguish between selenite and tellurite. The shape of the nanoparticles varies from spherical to rod-shaped, depending on the ratio of selenium and tellurium. The color of nanomaterials ranges from red to black, depending on the percentage of selenium and tellurium. These nanomaterials could be good candidates in the pharmaceutical industry due to their antipathogenic and anticarcinogenic properties.

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Aleksiichuk, О. Yu, V. S. Tkachishin, V. Ye Kondratyuk, О. M. Arustamyan e I. V. Dumka. "Poisoning from tellurium and its toxic compounds in industry". EMERGENCY MEDICINE 17, n. 6 (10 gennaio 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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Ollivier, Patrick R. L., Andrew S. Bahrou, Sarah Marcus, Talisha Cox, Thomas M. Church e Thomas E. Hanson. "Volatilization and Precipitation of Tellurium by Aerobic, Tellurite-Resistant Marine Microbes". Applied and Environmental Microbiology 74, n. 23 (10 ottobre 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., Jörg Jeske e Peter G. Jones. "Telluronium Salts Involving Hypervalent Tellurium-Tellurium Interactions". Phosphorus, Sulfur, and Silicon and the Related Elements 136, n. 1 (1 gennaio 1998): 305–8. http://dx.doi.org/10.1080/10426509808545956.

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Tanaka, Masayoshi, Atsushi Arakaki, Sarah S. Staniland e Tadashi Matsunaga. "Simultaneously Discrete Biomineralization of Magnetite and Tellurium Nanocrystals in Magnetotactic Bacteria". Applied and Environmental Microbiology 76, n. 16 (25 giugno 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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Presentato, Alessandro, Raymond J. Turner, Claudio C. Vásquez, Vladimir Yurkov e Davide Zannoni. "Tellurite-dependent blackening of bacteria emerges from the dark ages". Environmental Chemistry 16, n. 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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Jayasekera, S., IM Ritchie e J. Avraamides. "A Cyclic Voltammetric Study of the Dissolution of Tellurium". Australian Journal of Chemistry 47, n. 10 (1994): 1953. http://dx.doi.org/10.1071/ch9941953.

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A cyclic voltammetric study of the oxidation and reduction of elemental tellurium over the pH range 0-14 has been undertaken with tellurium disk electrodes which could be rotated. In both oxidation and reduction, the behaviour of tellurium is largely that expected from the predictions of the E-pH diagram for this element. Exceptions to this general principle were observed during the oxidation of tellurium at both low and high pH where it was found that tellurous acid was relatively quick to form and slow to dissolve; this led to a type of passivation behaviour. On the reduction side, the system behaved in a complex, fashion between pH 8 and 11 with both HTe - and Te22- being formed.

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Kucharski, M., P. Madej, M. Wedrychowicz, T. Sak e W. Mróz. "Recovery of Tellurium From Sodium Carbonate Slag". Archives of Metallurgy and Materials 59, n. 1 (1 marzo 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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Bi, Congzhi, Tianyu Wu, Jingjing Shao, Pengtao Jing, Hai Xu, Jilian Xu, Wenxi Guo, Yufei Liu e Da Zhan. "Evolution of the Electronic Properties of Tellurium Crystals with Plasma Irradiation Treatment". Nanomaterials 14, n. 9 (25 aprile 2024): 750. http://dx.doi.org/10.3390/nano14090750.

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Tellurium exhibits exceptional intrinsic electronic properties. However, investigations into the modulation of tellurium’s electronic properties through physical modification are notably scarce. Here, we present a comprehensive study focused on the evolution of the electronic properties of tellurium crystal flakes under plasma irradiation treatment by employing conductive atomic force microscopy and Raman spectroscopy. The plasma-treated tellurium experienced a process of defect generation through lattice breaking. Prior to the degradation of electronic transport performance due to plasma irradiation treatment, we made a remarkable observation: in the low-energy region of hydrogen plasma-treated tellurium, a notable enhancement in conductivity was unexpectedly detected. The mechanism underlying this enhancement in electronic transport performance was thoroughly elucidated by comparing it with the electronic structure induced by argon plasma irradiation. This study not only fundamentally uncovers the effects of plasma irradiation on tellurium crystal flakes but also unearths an unprecedented trend of enhanced electronic transport performance at low irradiation energies when utilizing hydrogen plasma. This abnormal trend bears significant implications for guiding the prospective application of tellurium-based 2D materials in the realm of electronic devices.

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Nitsenko, A. V., V. N. Volodin, X. A. Linnik, F. Kh Tuleutay e N. M. Burabaeva. "Distillation recovery of tellurium from copper telluride in oxide forms". Izvestiya Vuzov. Tsvetnaya Metallurgiya (Universities' Proceedings Non-Ferrous Metallurgy) 28, n. 4 (18 agosto 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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Sarangi, Chinmaya Kumar, Abdul Rauf Sheik, Barsha Marandi, Vijetha Ponnam, Malay Kumar Ghosh, Kali Sanjay, Manickam Minakshi e Tondepu Subbaiah. "Recovery of Tellurium from Waste Anode Slime Containing High Copper and High Tellurium of Copper Refineries". Sustainability 15, n. 15 (3 agosto 2023): 11919. http://dx.doi.org/10.3390/su151511919.

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Tellurium is used in cadmium tellurium-based solar cells. Mercury cadmium telluride is used as a sensing material for thermal imaging devices. High-purity tellurium is used in alloys for electronic applications. It is one of the important raw materials for solar energy applications. It is used as an alloying element in the production of low-carbon steel and copper alloys. Tellurium catalysts are used chiefly for the oxidation of organic compounds and as vulcanizing/accelerating agents in the processing of rubber compounds. Even though several researchers tried to recover tellurium from different raw materials, there is no attempt to develop a process flow sheet to recover tellurium from waste anode slime having a high tellurium concentration. In this study, optimum conditions were developed to recover Te and Cu from anode slime with the composition Cu: 31.8%, Te: 24.7%, and As: 0.96%. The unit operations involved are leaching, purification, and electro winning. The optimum conditions for producing Te at a recovery of 90% are found to be roasting of anode slime at 450 °C without the addition of soda ash followed by leaching in 1 M NaOH at 10% pulp density for 2 h. The purity of Te metal achieved was up to 99.99%, which could provide a sustainable energy future. The major impurities of the tellurium are observed to be in the order: Se > Sb > As > Cu.

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Tsygankova, M. V., E. A. Perminova, M. T. Chukmanova e O. A. Raikina. "BISMUTH TELLURID WASTE PROCESSING". Fine Chemical Technologies 12, n. 1 (28 febbraio 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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Nuss, Philip. "Losses and environmental aspects of a byproduct metal: tellurium". Environmental Chemistry 16, n. 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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Mu, Yannan, Qian Li, Pin Lv, Yanli Chen, Dong Ding, Shi Su, Liying Zhou, Wuyou Fu e Haibin Yang. "Fabrication of NiTe films by transformed electrodeposited Te thin films on Ni foils and their electrical properties". RSC Adv. 4, n. 97 (2014): 54713–18. http://dx.doi.org/10.1039/c4ra11246f.

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Zawadzka, Anna M., Ronald L. Crawford e 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. 5 (maggio 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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Nitsenko, Alina, Xeniya Linnik, Valeriy Volodin, Farkhat Tuleutay, Nurila Burabaeva, Sergey Trebukhov e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 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 e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 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 e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 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 e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 2022): 1774. http://dx.doi.org/10.3390/met12101774.

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Abstract (sommario):

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 e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 2022): 1774. http://dx.doi.org/10.3390/met12101774.

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Abstract (sommario):

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 e Galiya Ruzakhunova. "Phase Transformations and Tellurium Recovery from Technical Copper Telluride by Oxidative-Distillate Roasting at 0.67 kPa". Metals 12, n. 10 (21 ottobre 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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22

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

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Abstract (sommario):

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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23

Ottosson, Lars-Göran, Katarina Logg, Sebastian Ibstedt, Per Sunnerhagen, Mikael Käll, Anders Blomberg e Jonas Warringer. "Sulfate Assimilation Mediates Tellurite Reduction and Toxicity in Saccharomyces cerevisiae". Eukaryotic Cell 9, n. 10 (30 luglio 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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24

Alam, Mohammad Firoz, Saeed Alshahrani, Essam Alamir, Mohammad Abdurrhman Alhazmi, Tarique Anwer, Gyas Khan e Moni Sivakumar Sivagurunathan. "Zingerone ameliorates tellurium induced nephrotoxicity by abating elevated serum markers in the rats". Environment Conservation Journal 21, n. 1&2 (10 giugno 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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25

Pugin, Benoit, Fabián A. Cornejo, Pablo Muñoz-Díaz, Claudia M. Muñoz-Villagrán, Joaquín I. Vargas-Pérez, Felipe A. Arenas e Claudio C. Vásquez. "Glutathione Reductase-Mediated Synthesis of Tellurium-Containing Nanostructures Exhibiting Antibacterial Properties". Applied and Environmental Microbiology 80, n. 22 (5 settembre 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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26

Yin, Jianzhao, Haoyu Yin, Yuhong Chao, Shoupu Xiang e Hongyun Shi. "Geology and geochemistry of the only independent tellurium deposit in the world". Naturalis Scientias 01, n. 01 (2024): 01–31. http://dx.doi.org/10.62252/nss.2024.1001.

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The article discusses both the regional and deposit geology including structure, strata, and igneous rocks, as well as the ore body and alteration of Dashuigou tellurium deposit at the Qinghai-Tibet Plateau, the only independent tellurium deposit in the world. There are over 30 minerals that make up the deposit‘s ore, including carbonates, silicates, oxides, sulfides including various tellurides and native element minerals. Euhedral, semi-euhedral, xenomorphic granular, metasomatic, metasomatic graphic, reaction rim, and solid solution separation are the main ore texture; while massive, vein/veinlet, stockwork, dissemination, breccia, and bird‘s-eye are the major ore structure of the deposit. Based on the ore structure, this deposit‘s ore can be divided into three categories: massive, veinlet-stockwork, and disseminated. The ores are further divided into eight subcategories in total based on the proportions of tellurium minerals, other sulfides, dolomite, quartz, and muscovite in it. Both geology and K-Ar isotope dating have confirmed that the pyritic (pyrrhotite + pyrite) vein and telluride vein are products of two different geological events that are far apart. The tellurium grade in the ores varies between 0.01% and 34.58%. All ores in this deposit are primary sulfide ores that have not been transformed by oxidation or weathering. Two paragenetic stages; namely, the pyritic stage and tellurium stage consisting of five sub-stages in total exist in the deposit. According to Laznicka‘s idea, the deposit‘s tonnage accumulation indices indicate that it is a super-large independent tellurium deposit.

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27

Zhou, Benyu, e François P. Gabbaï. "Redox-controlled chalcogen-bonding at tellurium: impact on Lewis acidity and chloride anion transport properties". Chemical Science 11, n. 28 (2020): 7495–500. http://dx.doi.org/10.1039/d0sc02872j.

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Abstract (sommario):

The oxidative alkylation of diorganotellurides enhances the chalcogen-bond donor properties of the tellurium center, an effect manifested in the enhanced chloride anion affinity and transport properties of the resulting telluronium cations.

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28

Breunig, Hans Joachim, e Ditmar Müller. "Reaktionen von Tetrapropyldibismutan mit Chalkogenen und Tetramethyldistiban / Reactions of Tetrapropyldibism uthane with Chalcogens and Tetramethyldistibane". Zeitschrift für Naturforschung B 41, n. 9 (1 settembre 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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29

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

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Abstract (sommario):

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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30

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

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Abstract (sommario):

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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31

Lu, Yongwei, Xiaobo Zhao, Chunji Xue, Bakhtiar Nurtaev, Yiwei Shi, Yangtao Liu e Shukhrat Shukurov. "Telluride Mineralogy of the Kochbulak Epithermal Gold Deposit, Tien Shan, Eastern Uzbekistan". Minerals 14, n. 7 (22 luglio 2024): 730. http://dx.doi.org/10.3390/min14070730.

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Abstract (sommario):

The Kochbulak gold deposit is situated on the northern slope of the Kurama range of eastern Uzbekistan and is one of the largest Tellurium-rich epithermal gold deposits in the world. Based on a detailed field and petrological investigation, three stages of mineralization can be classified, including, from early to late, quartz–pyrite vein stage, quartz–telluride–sulfide–sulphosalt–native gold stage, and pyrite–chalcopyrite vein stage. Abundant tellurides, including tellurobismuthite, rucklidgeite, tetradymite, altaite, volynskite, and hessite, have been well recognized in the second (main) mineralization stage. Based on the mineral assemblages and petrogenetic occurrence, the sequence of tellurides in the second mineralization stage can be approximately identified as altaite+calaverite+native tellurium, calaverite+native gold, Bi-telluride (e.g., tellurobismuthite and rucklidgeite)+petzite+native gold, Ag-Bi telluride (e.g., volynskite), and Ag-telluride (e.g., hessite)+native gold. By depicting the Log ƒ(Te2)-Log ƒ(S2) relationship diagram of the Kochbulak gold deposit under 250 °C and 200 °C, the Log ƒ(S2) value ranges from −14.7 to −8.6 and from −16.7 to −10.9, respectively, with Log ƒ(Te2) value varies from −12.3 to −7.8 under 250 °C and ranges from −13.8 to −11.2 under 200 °C.

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32

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

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33

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

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Abstract (sommario):

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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34

Burabaeva, Nurila, Valeriy Volodin, Sergey Trebukhov, Alina Nitsenko e Xeniya Linnik. "On the Distillation Separation of Aluminum–Tellurium System Melts under Equilibrium Condition". Metals 12, n. 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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35

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

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36

Filella, Montserrat, Clemens Reimann, Marc Biver, Ilia Rodushkin e Katerina Rodushkina. "Tellurium in the environment: current knowledge and identification of gaps". Environmental Chemistry 16, n. 4 (2019): 215. http://dx.doi.org/10.1071/en18229.

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Abstract (sommario):

Environmental contextTellurium, a chemical element increasingly being used in new technologies, is an emerging contaminant. Our understanding of tellurium’s environmental behaviour, however, is poor, with critical knowledge gaps such as its distribution in the various environmental compartments and the environmental fluxes associated with mining, usage and disposal. Significant progress in these areas requires the development of robust analytical methods that are sufficiently sensitive to provide data at environmentally relevant concentrations. AbstractTellurium has recently become a ‘technology-critical element’ increasingly used in new applications. Thus, potential environmental impacts need to be evaluated. This, in turn, requires knowledge of its typical concentrations in the environment along with better understanding of the chemical processes governing its environmental behaviour. We evaluate the current situation of our understanding of tellurium in the environment and identify the areas where improvements in measurement technology are most needed. The comprehensive evaluation of published data described in this study shows that values for tellurium concentrations in the different environmental compartments are scarce, particularly in the case of natural waters where reliable estimates of tellurium concentrations in seawater and freshwater cannot even be produced. Data in air are even less abundant than for natural water. Concentration data do exist for soils suggesting a predominant geological origin. Some urban soil surveys and lake sediment data close to tellurium contamination sources point to possible effects on the element’s distribution as a result of human activity; long-range atmospheric transport remains to be proved. Current knowledge about tellurium behaviour in the environment is strongly hindered by analytical difficulties, with insufficiently low analytical detection limits being the main limitation. For instance, ‘dissolved’ concentrations are well below current analytical capabilities in natural water and often require pre-concentration procedures that, for the moment, do not provide consistent results; solid samples require complex mineralisation procedures that often exclude tellurium from routine multielement studies. In general, the use of available measuring techniques is far from straightforward and needs particular expertise. Overcoming the current analytical limitations is essential to be able to progress in the field.

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37

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

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38

Boruk, S. D., K. S. Dremlyuzhenko, V. Z. Tsalyi, І. М. Yuriychuk, V. P. Kladko, A. Y. Gudimenko, O. A. Kapush, S. G. Dremlyuzhenko e 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. 3 (15 settembre 2017): 338–41. http://dx.doi.org/10.15330/pcss.18.3.338-341.

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Abstract (sommario):

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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39

Maronchuk, I. I., D. D. Sanikovich, E. V. Davydova e N. Yu Tabachkova. "Cadmium telluride for high-efficiency solar cells". Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering 26, n. 1 (14 aprile 2023): 17–25. http://dx.doi.org/10.17073/1609-3577-2023-1-17-25.

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Abstract (sommario):

Problems of the synthesis of cadmium telluride powders having required purity and grain size distribution for high-efficiency solar cells have been analyzed. A test batch of powders has been synthesized and used for the manufacture and study of thin-film solar cell specimens exhibiting parameters compliant with the best worldwide standards. The phase composition of the powders has been studied using X-ray diffraction. Structural analysis and elemental composition measurements have been carried out using electron microscopy. The effect of free tellurium phase in the powders on the endurance of devices manufactured from the powder has been described. We show that excess tellurium in the film specimens whose atoms are predominantly localized along grain boundaries may cause temporal degradation of the electrical properties of the manufactured solar cells due to changes in the parameters of the crystalline structure of the cadmium telluride phase which are caused in turn by changes in the stoichiometric composition of the material. Structural studies of the film specimens have not revealed differences in the film structure before and after endurance tests. A new cadmium telluride powder process route has been developed, proven and tested taking into account the advantages and drawbacks of the previously used process and experiments confirming the correctness of the technical solutions chosen have been conducted.

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40

Maronchuk, Igor I., Daria D. Sanikovich, Elena V. Davydova e Nataliya Yu Tabachkova. "Cadmium telluride for high-efficiency solar cells". Modern Electronic Materials 9, n. 1 (31 marzo 2023): 9–14. http://dx.doi.org/10.3897/j.moem.9.1.103598.

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Abstract (sommario):

Problems of the synthesis of cadmium telluride powders having required purity and grain size distribution for high-efficiency solar cells have been analyzed. A test batch of powders has been synthesized and used for the manufacture and study of thin-film solar cell specimens exhibiting parameters compliant with the best worldwide standards. The phase composition of the powders has been studied using X-ray diffraction. Structural analysis and elemental composition measurements have been carried out using electron microscopy. The effect of free tellurium phase in the powders on the endurance of devices manufactured from the powder has been described. We show that excess tellurium in the film specimens whose atoms are predominantly localized along grain boundaries may cause temporal degradation of the electrical properties of the manufactured solar cells due to changes in the parameters of the crystalline structure of the cadmium telluride phase which are caused in turn by changes in the stoichiometric composition of the material. Structural studies of the film specimens have not revealed differences in the film structure before and after endurance tests. A new cadmium telluride powder process route has been developed, proven and tested taking into account the advantages and drawbacks of the previously used process and experiments confirming the correctness of the technical solutions chosen have been conducted.

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41

Arora, Swati, Vivek Jaimini, Subodh Srivastava e 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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Abstract (sommario):

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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42

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

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Abstract (sommario):

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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43

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

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Abstract (sommario):

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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44

Angermaier, Klaus, e Hubert Schmidbaur. "Preparation and Structure of Poly(gold)telluronium Salts". Zeitschrift für Naturforschung B 51, n. 6 (1 giugno 1996): 879–82. http://dx.doi.org/10.1515/znb-1996-0619.

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Abstract (sommario):

Abstract Tris[(triphenylphosphine)gold(I)]telluronium tetrafluoroborate (1) was prepared from the corresponding oxonium salt and bis(t-butyldimethylsilyl)tellurium in dichloromethane at -78°C. The product forms yellow crystals, thermally stable to 125°C. It was identified by standard analytical and spectroscopic techniques, including a single crystal X-ray diffraction study. In the crystal lattice, the cations form tellurium-capped triangles of gold, which are associated into dimers through short intermolecular Au -Au contacts, resembling those in the corresponding sulfur and selenium compounds. - The reaction of (t-BuMe2Si)2Te with four equivalents of [(Ph3P)Au]BF4 in tetrahydrofuran at -78°C gives a tetranuclear compound, {[(Ph3P)Au]4Te}2+ 2 BF4- (2) which differs from 1 in its analytical and spectroscopic data. Its structure could not be determined, but it is assumed that the dications have a square pyramidal geometry

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45

Sudarsan, K. G., e S. N. Dindi. "Kinetic and Mechanistic Aspects of Redox Reactions of Tellurium(Iv) and Tellurium(Vi)". Progress in Reaction Kinetics and Mechanism 27, n. 3 (settembre 2002): 127–63. http://dx.doi.org/10.3184/007967402103165379.

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Abstract (sommario):

Many kinetic and mechanistic studies are reported on the direct and transition metal ion catalysed oxidation of tellurium(IV) with oxidants like persulphate, periodate, chromium(VI), hexacyanoferrate(III), cerium(IV), manganese(III), cobalt(III) etc. Similar studies on the reduction of tellurium(VI) by different reductants are much fewer. An attempt has been made to discuss in brief up-to-date information available on the nature of tellurium(IV) and tellurium(VI) species as well as kinetic and mechanistic studies on the direct and catalysed oxidation and reduction reactions of tellurium(IV) and tellurium(VI) respectively. The majority of reactions concerned with the oxidation of tellurium(IV) to tellurium(VI) seems to prefer a complementary path to a non-complementary one, in accordance with Schaffer's principle of equivalent change.

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Guo, Ya Fei, Nan Zhang, Dong Chan Li, Fa Mang Tang e Tian Long Deng. "Tellurium Recovery from the Unique Tellurium Ores". Advanced Materials Research 549 (luglio 2012): 1060–63. http://dx.doi.org/10.4028/www.scientific.net/amr.549.1060.

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Generally, along with the rapid economic development in our country, the requirement of mineral resource is gradually increasing. Compared with the traditional metallurgy, the biohydrometallurgy has the merit of light damage of environment, low cost, and a few investments, and then it can treat with very low-grade ores even industrial disposals. Since the discovery of scattered elemental tellurium deposit in China, the development and utilization of this unique independent tellurium ores were studied. In this paper, firstly, the progresses on tellurium recovery process from the unique tellurium ores were summarized, and then, the experimental results on bioleaching in our lab were presented.

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Champarnaud-Mesjard, J. C., P. Thomas, S. Blanchandin, M. Dutreilh e B. Frit. "Tellurium crystal chemistry in some new tellurite compunds". Acta Crystallographica Section A Foundations of Crystallography 56, s1 (25 agosto 2000): s431. http://dx.doi.org/10.1107/s0108767300028907.

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Illing, Kurt-Hermann. "Tellurium". Zeitschrift für Klassische Homöopathie 18, n. 01 (2 aprile 2007): 21–22. http://dx.doi.org/10.1055/s-2006-937607.

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49

DITTMER, DONALD C. "TELLURIUM". Chemical & Engineering News 81, n. 36 (8 settembre 2003): 128. http://dx.doi.org/10.1021/cen-v081n036.p128.

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McLemore, V. T. "Tellurium resources in New Mexico". New Mexico Geology 38, n. 1 (2016): 1–16. http://dx.doi.org/10.58799/nmg-v38n1.1.

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Tellurium (Te) is one of the least abundant elements in the crust and tends to form minerals associated with gold, silver, bismuth, copper, lead, and zinc sulfide deposits. There are no primary tellurium mines in the world; most tellurium production comes from the anode slimes generated in metal refining, primarily from copper porphyry deposits. Tellurium is used as an alloying agent in iron and steel, as catalysts, and in the chemical industry. However, future demand and production could increase because tellurium is progressively used in thin film cadmium-tellurium solar panels and some electronic devices. In New Mexico, anomalous amounts of tellurium are found associated with porphyry copper deposits, as well as with gold-silver vein deposits, but were not considered important exploration targets in the past. The only tellurium production from New Mexico has been from the Lone Pine deposit (Wilcox district) in the Mogollon Mountains, where approximately 5 tons of tellurium ore were produced. Gold-tellurides are found with gold, silver, pyrite, and fluorite in fracture-filling veins in rhyolite at Lone Pine, with reported assays as much as 5,000 ppm Te. Tellurium-bearing deposits also are found in the Organ Mountains, Sylvanite, Tierra Blanca, Grandview Canyon, and Hillsboro districts. Additional detailed sampling and geologic mapping are required of the New Mexico deposits to fully understand the mineralogy and economic potential of tellurium.

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