• 제목/요약/키워드: tellurium

검색결과 71건 처리시간 0.02초

네모파 전압전류법에 의한 텔루륨(Ⅳ) 정량

  • 서무열;서무열;엄태윤;최인규
    • 대한화학회지
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    • 제38권7호
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    • pp.496-501
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    • 1994
  • Tellurium(Ⅳ)에 대한 네모파 전압전류법적 연구를 HMDE를 사용하여 염산 용액에서 수행하였다. 염산 용액중에서 Tellurium(Ⅳ)의 환원반응은 산에 의한 촉매반응의 특징을 나타내는 비가역적인 과정으로 진행됨을 알 수 있었다. 본 연구에서는 또한 네모파 전압전류법에 의한 Tellurium(Ⅳ)의 분석 조건 및 방해이온들에 대하여 검토하였다. 이 방법에 의한 Tellurium(Ⅳ)의 검출한계는 $4.2\;ppb (3.3{\tiems}10^{-8}M)$이었으며, 전극표면에서의 4.2 Tellurium(Ⅳ)의 양은 ${\Gamma}=(7.2{\pm}1.4){\times}10^{-11}\;mol\;cm^{-2}$이었다.

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Determination of Selenium and Tellurium by HG-AAS in Foods

  • Cha, Ki-Won;Park, Sang-Ho;Park, Kwang-Won
    • 분석과학
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    • 제8권4호
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    • pp.419-425
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    • 1995
  • A method has been investigated for the determination of selenium and tellurium in Ginseng, Ganoderma and Garlic using hydride generation atomic absorption spectrometry(HG-AAS). The concentration effects of hydrochloric acid and sodium tetrahydroborate on the hydride generation for the determination of selenium and tellurium were investigated. The method of sample decomposition was also investigated using various mineral acids, such as nitric, perchloric and sulfuric acid in the closed system, and foreign ion effects containing in the samples were studied. The calibration curves of selenium and tellurium were obtained in the range of 0~40 ppb. The detection limits(S/N=2) of selenium and tellurium are 0.1 and 0.2 ppb. Analytical data of selenium and tellurium in Garlic, Ganoderma and Ginseng are 289, 296 and 198 ng/g for selenium and 146, 127 and 110 ng/g for tellurium, respectively.

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랫드의 신경조직에 미치는 Tellurium의 독성에 관한 연구 (A Study on the Neurotoxic Effects of Tellurium on Murine Nervous System)

  • 김기석;정문호
    • 한국환경보건학회지
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    • 제24권3호
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    • pp.35-40
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    • 1998
  • This study was conducted to examine the pathological changes of rat peripheral nervous system during exposure to tellurium known to be a demyelinating agent by using teasing nerve fiber method and quantitative light microscopic analysis by image analyzer. The pellet containing 1.2% of tellurium were fed for 3, 5, 7, 9, 13 days to male wistar rats (21 days old) and then neurologic symptom and the feature of nerve fiber myelination were studied. From this study, following results were obtained. In 3 days treated group, it showed various neurologic symptom and teased nerve fiber showed slight irregularity of the myeline sheath. In 5 days and 7 days treated groups, it showed the segmental demyetination in larger size fiber and widening of nodes of ranvier. In 9 days and 13 days treated groups, the remyelinated fibers were observed and it was generally small in size. We consequently suggest that teasing nerve fiber method and quantitative analysis of nerve fiber were useful pathologic screening method of neurotoxicity of the peripheral nervous system.

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The Recovery of Tellurium from Copper Anode Slimes by Hydrometallurgical Processes

  • Lee, Churl-Kyoung;Rhee, Kang-In;Sohn, Hun-Joon
    • 자원리싸이클링
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    • 제6권3호
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    • pp.41-45
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    • 1997
  • The recovery of tellurium from Te-cement obtained during the processing of copper anode slimes was carried out by a series of hydrometallurgical processes, i.E. leaching Te-cement in NaOH solution, precipitation of impurities with the addition of ${Na}_{2}S$ followed by direct electrowinning of tellurium in NaOH solution. The optimum conditions for each process were determined and discussed in terms of various parameters associated with each step to maximize the recovery and purity of tellurium. The final purity of tellurium from electrownning in alkaline solution was found to be more than 99.9%.

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RF Sputtering 공정 법을 이용해 증착한 Te 기반 박막 및 박막 트랜지스터의 공정 변수에 따른 전기적 특성 평가 (Effect of Working Pressure Conditions during Sputtering on the Electrical Performance in Te Thin-Film Transistors)

  • 이규리;김현석
    • 한국전기전자재료학회논문지
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    • 제35권2호
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    • pp.190-193
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    • 2022
  • In this work, the effect of sputtering working pressure for the tellurium film and its thin-film transistor was investigated. The transfer characteristics of tellurium thin-film transistors were improved by increasing the working pressure during sputtering process. As increasing working pressure, physical and optical properties of Te films such as crystallinity, transmittance, and surface roughness were improved. Therefore, the improved transfer characteristics of Te thin-film transistors may originate from both improved interface properties between the silicon oxide gate dielectric layer and the tellurium active layer with an improved quality of Te film. In conclusion, the control of working pressure during sputtering would be important for obtaining high-performance tellurium-based thin film transistor

Gas Sensing Properties of Powder Prepared from Waste Thermoelectric Devices by Wet Reduction Process

  • So, Hyeongsub;Im, Dong-Ha;Jung, Hyunsung;Lee, Kun-Jae
    • 한국세라믹학회지
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    • 제55권1호
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    • pp.90-93
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    • 2018
  • In this study, n-type $Bi_2Te_3$ in thermoelectric scrap is recovered through a wet reduction process. The recovered powder (tellurium) is grafted onto gas sensor in a new application that is not a thermoelectric device. Bismuth-rich powder is prepared by adding hydrazine when pH of the solution is brought to 13 using NaOH. The pH of the filtered solution was reduced using $HNO_3$, and then hydrazine was added to perform the re-reduction reaction. The tellurium-rich powder can be obtained through this reaction. The elemental analysis for these powders is confirmed by energy dispersive X-ray spectroscopy (EDS) analysis ; the successful separation of bismuth and tellurium is confirmed. Separated tellurium powder is mixed with DMF solvent and ethyl cellulose binder to confirm gas sensing properties. The tellurium paste was exposed in $NO_x$ atmosphere and exhibited a rapid reaction rate and recovery rate of less than 3 minutes for the gas.

Experimental assessment for the photon shielding features of silicone rubber reinforced by tellurium borate oxides

  • M. Elsafi;Heba jamal ALasali;Aljawhara H. Almuqrin;K.G. Mahmoud;M.I. Sayyed
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2166-2171
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    • 2023
  • In the present study, six silicone rubber doped by tellurium borate oxides were fabricated using the casting method. The densities of the fabricated silicon rubber-doped by tellurium borate oxides samples were measured using the Archimedes Method. Moreover, the linear attenuation coefficient of silicone rubber doped tellurium borate oxides samples was evaluated experimentally using the hyper pure germanium, and the recorded linear attenuation coefficient values were affirmed using the theoretical Phy-X program. The experimental measurements were performed using the narrow beam transmission method with radioactive isotopes Am-241, Cs-137, and Co-60 with energies of 59, 661, 1173, and 1332 keV. The linear attenuation coefficient values showed an enhancement by 4.73 times, 1.20 time, 1.17, time, and 1.17 time, respectively at gamma photon energies of 59, 661, 1173, and 1332 keV, when the TeO2 concentration increased in the fabricated composites from 0 to 50 wt%. The enhancement of the linear attenuation coefficient values has a positive effect on the transmission rate values where the half-value thickness and transmission rate were decreased accompanied by an increase in the RPE.

Tellurium 기반 휘발성 문턱 스위칭 및 고집적 메모리용 선택소자 응용 연구 (Advanced Tellurium-Based Threshold Switching Devices for High-Density Memory Arrays)

  • 김승환;김창환;허남욱;서준기
    • 한국전기전자재료학회논문지
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    • 제36권6호
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    • pp.547-555
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    • 2023
  • High-density crossbar arrays based on storage class memory (SCM) are ideally suited to handle an exponential increase in data storage and processing as a central hardware unit in the era of AI-based technologies. To achieve this, selector devices are required to be co-integrated with SCM to address the sneak-path current issue that indispensably arises in such crossbar-type architecture. In this perspective, we first summarize the current state of tellurium-based threshold-switching devices and recent advances in the material, processing, and device aspects. We thoroughly review the physicochemical properties of elemental tellurium (Te) and representative binary tellurides, their tailored deposition techniques, and operating mechanisms when implemented in two-terminal threshold switching devices. Lastly, we discuss the promising research direction of Te-based selectors and possible issues that need to be considered in advance.

Te를 이용한 상온 동작형 NO2 센서 제작 및 감응 특성 (Room temperature operating nitrogen dioxide sensor based tellurium thin films)

  • 신한재;송갑득;주병수;손명호;이덕동
    • 센서학회지
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    • 제16권2호
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    • pp.91-96
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    • 2007
  • The characteristic of tellurium thin films was studied for detecting nitrogen dioxide gas at room temperature. The film was deposited on $Al_{2}O_{3}$ substrate by using thermal evaporator. The subsequent process was heat treatment by several conditions. (temperature, flowed gases) Surface and grain boundary was investigated using SEM. The results showed that resistance of the tellurium film decreases reversibly in the presence of nitrogen dioxide. The sensitivity of this device depends on the gas concentration and detect lower concentrations less than 10 ppm.

Sandwich Intermediate Sitting-atop Complexation between Free Base meso-tetraarylporphyrins and Tellurium(IV) chloride

  • Dehghani, Hossein;Bakhshayesh, Sara;Shaterian, Maryam;Motamedi, Leila
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.815-818
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    • 2010
  • Free base meso-tetraarylporphyrins ($H_2T(X)PP$) react with tellurium(IV) chloride ($TeCl_4$) in mild conditions for formation sandwich intermediate sitting-atop (i-SAT) complexes, [$TeCl_4(H_2T(X)PP)_2$]. $^1H$ NMR, $^{13}C$ NMR, UV-vis, FT-IR and elemental analysis were used for characterization of the products. In the proposed structure of the i-SAT complexes, four pyrroles of each porphyrin ring are tilted alternatively up and down and this appropriates suitable orientation of lone pairs of two pyrrolenine nitrogens for electron donation to a tellurium center. $^1H$ NMR and FT-IR results showed that in the produced complex, hydrogen atoms of porphyrin macrocycles remained on the pyrrole nitrogens.