High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

2015-01-01

Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films.

High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

International Nuclear Information System (INIS)

Lisco, F.; Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

2015-01-01

Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films

Carrier Transport, Recombination, and the Effects of Grain Boundaries in Polycrystalline Cadmium Telluride Thin Films for Photovoltaics

Science.gov (United States)

Tuteja, Mohit

Cadmium Telluride (CdTe), a chalcogenide semiconductor, is currently used as the absorber layer in one of the highest efficiency thin film solar cell technologies. Current efficiency records are over 22%. In 2011, CdTe solar cells accounted for 8% of all solar cells installed. This is because, in part, CdTe has a low degradation rate, high optical absorption coefficient, and high tolerance to intrinsic defects. Solar cells based on polycrystalline CdTe exhibit a higher short-circuit current, fill factor, and power conversion efficiency than their single crystal counterparts. This is despite the fact that polycrystalline CdTe devices exhibit lower open-circuit voltages. This is contrary to the observation for silicon and III-V semiconductors, where material defects cause a dramatic drop in device performance. For example, grain boundaries in covalently-bonded semiconductors (a) act as carrier recombination centers, and (b) lead to localized energy states, causing carrier trapping. Despite significant research to date, the mechanism responsible for the superior current collection properties of polycrystalline CdTe solar cells has not been conclusively answered. This dissertation focuses on the macro-scale electronic band structure, and micro scale electronic properties of grains and grain boundaries in device-grade CdTe thin films to answer this open question. My research utilized a variety of experimental techniques. Samples were obtained from leading groups fabricating the material and devices. A CdCl 2 anneal is commonly performed as part of this fabrication and its effects were also investigated. Photoluminescence (PL) spectroscopy was employed to study the band structure and defect states in CdTe polycrystals. Cadmium vacancy- and chlorine-related states lead to carrier recombination, as in CdTe films grown by other methods. Comparing polycrystalline and single crystal CdTe, showed that the key to explaining the improved performance of polycrystalline CdTe does

Cadmium telluride gamma-radiation detectors with a high energy resolution

International Nuclear Information System (INIS)

Alekseeva, L.A.; Dorogov, P.G.; Ivanov, V.I.; Khusainov, A.K.

1985-01-01

This paper considers the possibility of improving the energy resolution of cadmium telluride gamma-radiation detectors through the choice of the geometry and size of the sensitive region of the detector. The optimum ratio of the product of the mobility and lifetime for electrons to the same product for holes from the point of view of energy resolution is greater than or equal to 10 2 for a detector of spherical geometry and should be less than or equal to 10 for a cylindrical geometry and approximately 1 for a planar geometry. The optimum values of the major and minor radii of a spherical detector are calculated

Thin-Film Material Science and Processing | Materials Science | NREL

Science.gov (United States)

Thin-Film Material Science and Processing Thin-Film Material Science and Processing Photo of a , a prime example of this research is thin-film photovoltaics (PV). Thin films are important because cadmium telluride thin film, showing from top to bottom: glass, transparent conducting oxide (thin layer

Landfill waste and recycling: Use of a screening-level risk assessment tool for end-of-life cadmium telluride (CdTe) thin-film photovoltaic (PV) panels

International Nuclear Information System (INIS)

Cyrs, William D.; Avens, Heather J.; Capshaw, Zachary A.; Kingsbury, Robert A.; Sahmel, Jennifer; Tvermoes, Brooke E.

2014-01-01

Grid-connected solar photovoltaic (PV) power is currently one of the fastest growing power-generation technologies in the world. While PV technologies provide the environmental benefit of zero emissions during use, the use of heavy metals in thin-film PV cells raises important health and environmental concerns regarding the end-of-life disposal of PV panels. To date, there is no published quantitative assessment of the potential human health risk due to cadmium leaching from cadmium telluride (CdTe) PV panels disposed in a landfill. Thus, we used a screening-level risk assessment tool to estimate possible human health risk associated with disposal of CdTe panels into landfills. In addition, we conducted a literature review of potential cadmium release from the recycling process in order to contrast the potential health risks from PV panel disposal in landfills to those from PV panel recycling. Based on the results of our literature review, a meaningful risk comparison cannot be performed at this time. Based on the human health risk estimates generated for PV panel disposal, our assessment indicated that landfill disposal of CdTe panels does not pose a human health hazard at current production volumes, although our results pointed to the importance of CdTe PV panel end-of-life management. - Highlights: • Analysis of possible human health risk posed by disposal of CdTe panels into landfills. • Qualitative comparison of risks associated with landfill disposal and recycling of CdTe panels. • Landfill disposal of CdTe panels does not pose a human health hazard at current production volumes. • There could be potential risks associated with recycling if not properly managed. • Factors other than concerns over toxic substances will likely drive the decisions of how to manage end-of-life PV panels

Effect of Annealing on the Properties of Antimony Telluride Thin Films and Their Applications in CdTe Solar Cells

Directory of Open Access Journals (Sweden)

Zhouling Wang

2014-01-01

Full Text Available Antimony telluride alloy thin films were deposited at room temperature by using the vacuum coevaporation method. The films were annealed at different temperatures in N2 ambient, and then the compositional, structural, and electrical properties of antimony telluride thin films were characterized by X-ray fluorescence, X-ray diffraction, differential thermal analysis, and Hall measurements. The results indicate that single phase antimony telluride existed when the annealing temperature was higher than 488 K. All thin films exhibited p-type conductivity with high carrier concentrations. Cell performance was greatly improved when the antimony telluride thin films were used as the back contact layer for CdTe thin film solar cells. The dark current voltage and capacitance voltage measurements were performed to investigate the formation of the back contacts for the cells with or without Sb2Te3 buffer layers. CdTe solar cells with the buffer layers can reduce the series resistance and eliminate the reverse junction between CdTe and metal electrodes.

Mechanism of manganese (mono and di) telluride thin-film formation and properties

Science.gov (United States)

Sharma, Raj Kishore; Singh, Gurmeet; Shul, Yong Gun; Kim, Hansung

2007-03-01

Mechanistic studies on the electrocrystallization of manganese telluride (MnTe) thin film are reported using aqueous acidic solution containing MnSO 4 and TeO 2. Tartaric acid was used for the inhibition of hydrated manganese oxide anodic growth at counter electrode. A detailed study on the mechanistic aspect of electrochemical growth of MnTe using cyclic voltametry is carried out. Conditions for electrochemical growth of manganese mono and di telluride thin films have been reported using cyclic voltammetric scans for Mn 2+, Te 4+ and combined Mn 2+ and Te 4+. X-ray diffraction showed the formation of polycrystalline MnTe films with cubic, hexagonal and orthorhombic mixed phases. MnTe film morphology was studied using scanning electron microscope. Susceptibility and electrical characterization supports the anti-ferromagnetic behavior of the as-deposited MnTe thin film.

Radiation resistance of thin-film solar cells for space photovoltaic power

Science.gov (United States)

Woodyard, James R.; Landis, Geoffrey A.

1991-01-01

Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

KAUST Repository

Aktakka, Ethem Erkan

2013-10-01

This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning process using predeposition surface treatment methods for reduced TE-metal contact resistance. As a demonstration vehicle, a 2 × 2 mm2-sized integrated planar thermoelectric generator (TEG) is shown to harvest 0.7 μ W from 21-K temperature gradient. Transistor performance showed no significant change upon post-CMOS TEG integration, indicating, for the first time, the CMOS compatibility of the Bi2Te3 and Sb2Te3 thin films, which could be leveraged for realization of high-performance integrated micro-TE harvesters and coolers. © 2013 IEEE.

Characterization of nanocrystalline cadmium telluride thin films ...

Indian Academy of Sciences (India)

Unknown

tion method, successive ionic layer adsorption and reaction (SILAR), are described. For deposition of CdTe thin films ... By conducting several trials optimization of the adsorption, reaction and rinsing time duration for CdTe thin film .... The electrical resistivity of CdTe films was studied in air. Figure 3 shows the variation of log ...

Rapid long-wave infrared laser-induced breakdown spectroscopy measurements using a mercury-cadmium-telluride linear array detection system.

Science.gov (United States)

Yang, Clayton S-C; Brown, Eiei; Kumi-Barimah, Eric; Hommerich, Uwe; Jin, Feng; Jia, Yingqing; Trivedi, Sudhir; D'souza, Arvind I; Decuir, Eric A; Wijewarnasuriya, Priyalal S; Samuels, Alan C

2015-11-20

In this work, we develop a mercury-cadmium-telluride linear array detection system that is capable of rapidly capturing (∼1-5  s) a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared (LWIR) region (∼5.6-10  μm). Similar to the conventional UV-Vis LIBS, a broadband emission spectrum of condensed phase samples covering the whole 5.6-10 μm region can be acquired from just a single laser-induced microplasma or averaging a few single laser-induced microplasmas. Atomic and molecular signature emission spectra of solid inorganic and organic tablets and thin liquid films deposited on a rough asphalt surface are observed. This setup is capable of rapidly probing samples "as is" without the need of elaborate sample preparation and also offers the possibility of a simultaneous UV-Vis and LWIR LIBS measurement.

Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions

Science.gov (United States)

Ramos-Ruiz, Adriana; Wilkening, Jean V.; Field, James A.; Sierra-Alvarez, Reyes

2017-01-01

A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. PMID:28472709

Nanocrystalline CdTe thin films by electrochemical synthesis

Directory of Open Access Journals (Sweden)

Ramesh S. Kapadnis

2013-03-01

Full Text Available Cadmium telluride thin films were deposited onto different substrates as copper, Fluorine-doped tin oxide (FTO, Indium tin oxide (ITO, Aluminum and zinc at room temperature via electrochemical route. The morphology of the film shows the nanostructures on the deposited surface of the films and their growth in vertical direction. Different nanostructures developed on different substrates. The X-ray diffraction study reveals that the deposited films are nanocrystalline in nature. UV-Visible absorption spectrum shows the wide range of absorption in the visible region. Energy-dispersive spectroscopy confirms the formation of cadmium telluride.

Novel aspects of application of cadmium telluride quantum dots nanostructures in radiation oncology

Science.gov (United States)

Fazaeli, Yousef; Zare, Hakimeh; Karimi, Shokufeh; Rahighi, Reza; Feizi, Shahzad

2017-08-01

In the last two decades, quantum dots nanomaterials have garnered a great deal of scientific interest because of their unique properties. Quantum dots (QDs) are inorganic fluorescent nanocrystals in the size range between 1 and 20 nm. Due to their structural properties, they possess distinctive properties and behave in different way from crystals in macro scale, in many branches of human life. Cadmium telluride quantum dots (CdTe QDs) were labeled with 68Ga radio nuclide for fast in vivo targeting and coincidence imaging of tumors. Using instant paper chromatography, the physicochemical properties of the Cadmium telluride quantum dots labeled with 68Ga NPs (68Ga@ CdTe QDs) were found high enough stable in organic phases, e.g., a human serum, to be reliably used in bioapplications. In vivo biodistribution of the 68Ga@ CdTe QDs nanoconposite was investigated in rats bearing fibro sarcoma tumor after various post-injection periods of time. The 68Ga NPs exhibited a rapid as well as high tumor uptake in a very short period of time (less than 10 min), resulting in an efficient tumor targeting/imaging agent. Meantime, the low lipophilicity of the 68Ga NPs caused to their fast excretion throughout the body by kidneys (as also confirmed by the urinary tract). Because of the short half-life of 68Ga radionuclide, the 68Ga@ CdTe QDs with an excellent tumor targeting/imaging and fast washing out from the body can be suggested as one of the most effective and promising nanomaterials in nanotechnology-based cancer diagnosis and therapy.

The use of cadmium telluride γ spectrometers in monitoring activity deposited in nuclear power stations

International Nuclear Information System (INIS)

Jones, L.T.

1977-01-01

The ability to inspect and test key components and when necessary repair or replace them is a significant factor in the safety case submitted before consent is given for construction of a nuclear reactor. A knowledge of the probable rate of deposition and isotopic composition of radioactive contamination in these areas is necessary and since it is not always practicable to take samples away to the laboratory for analysis, direct gamma ray spectroscopy in the contaminated environment is sometimes used. The experience of direct monitoring with a cadmium telluride spectrometer in two such reactor situations is reported. In the first situation, a remotely cooled intrinsic Germanium spectrometer was used in equivalent positions and spectra from both systems are presented. The relative merits of the two systems are discussed. In the second situation, measurements were made in an environment at 70 deg C in radiation levels of 10Rh -1 . An improvised cooling system was used to maintain the Cadmium Telluride at about 20 deg C and Pile-up Rejection was used to enable count rates of about 10 5 s -1 to be handled. It is noted that the usually quoted detector parameters, resolution and crystal volume, are not necessarily the most important in practical spectrometry of mixed isotopes. As with germanium detectors, the most useful parameter is probably the Peak-to-Compton ratio

Cadmium zinc telluride as a mid-infrared variable retarder

Science.gov (United States)

FitzGerald, William; Taherion, Saeid; Kumar, F. Joseph; Giles, David; Hore, Dennis

2018-04-01

The electro-optic behavior of cadmium zinc telluride is examined in the mid-infrared region between 3 and 11 μm, for applied DC field strengths of up to 106 V/m. The measurements performed here include full characterization of the polarization state of the transmitted light by means of the Stokes vector. We demonstrate the suitability of this material for DC variable retarder applications such as those achieved by quarter- or half-wave retardation. A comparison of two different metallic coatings for electrodes, gold and indium, reveals important differences in performance that are attributed to the homogeneity of the field through the bulk of the crystal. We illustrate that, in the case of both metals, the same electro-optic coefficients are measured, but regions of higher and lower retardation result in significant depolarization in the case of gold. Such depolarization may adversely affect the contrast ratio in a light valve, or increase the voltage necessary for the operation of an arbitrary polarization state generator.

Study on thermal annealing of cadmium zinc telluride (CZT) crystals

International Nuclear Information System (INIS)

Yang, G.; Bolotnikov, A.E.; Fochuk, P.M.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.; Horace, J.; McCall, B.; Gul, R.; Xu, L.; Kopach, O.V.; James, R.B.

2010-01-01

Cadmium Zinc Telluride (CZT) has attracted increasing interest with its promising potential as a room-temperature nuclear-radiation-detector material. However, different defects in CZT crystals, especially Te inclusions and dislocations, can degrade the performance of CZT detectors. Post-growth annealing is a good approach potentially to eliminate the deleterious influence of these defects. At Brookhaven National Laboratory (BNL), we built up different facilities for investigating post-growth annealing of CZT. Here, we report our latest experimental results. Cd-vapor annealing reduces the density of Te inclusions, while large temperature gradient promotes the migration of small-size Te inclusions. Simultaneously, the annealing lowers the density of dislocations. However, only-Cd-vapor annealing decreases the resistivity, possibly reflecting the introduction of extra Cd in the lattice. Subsequent Te-vapor annealing is needed to ensure the recovery of the resistivity after removing the Te inclusions.

Novel aspects of application of cadmium telluride quantum dots nanostructures in radiation oncology

Energy Technology Data Exchange (ETDEWEB)

Fazaeli, Yousef; Feizi, Shahzad [Nuclear Science and Technology Research Institute (NSTRI), Radiation Application Research School, Karaj (Iran, Islamic Republic of); Zare, Hakimeh; Karimi, Shokufeh [Yazd University, Department of Physics, Yazd (Iran, Islamic Republic of); Rahighi, Reza [Sharif University of Technology, Department of Physics, Tehran (Iran, Islamic Republic of)

2017-08-15

In the last two decades, quantum dots nanomaterials have garnered a great deal of scientific interest because of their unique properties. Quantum dots (QDs) are inorganic fluorescent nanocrystals in the size range between 1 and 20 nm. Due to their structural properties, they possess distinctive properties and behave in different way from crystals in macro scale, in many branches of human life. Cadmium telluride quantum dots (CdTe QDs) were labeled with {sup 68}Ga radio nuclide for fast in vivo targeting and coincidence imaging of tumors. Using instant paper chromatography, the physicochemical properties of the Cadmium telluride quantum dots labeled with {sup 68}Ga NPs ({sup 68}Ga rate at CdTe QDs) were found high enough stable in organic phases, e.g., a human serum, to be reliably used in bioapplications. In vivo biodistribution of the {sup 68}Ga rate at CdTe QDs nanoconposite was investigated in rats bearing fibro sarcoma tumor after various post-injection periods of time. The {sup 68}Ga NPs exhibited a rapid as well as high tumor uptake in a very short period of time (less than 10 min), resulting in an efficient tumor targeting/imaging agent. Meantime, the low lipophilicity of the {sup 68}Ga NPs caused to their fast excretion throughout the body by kidneys (as also confirmed by the urinary tract). Because of the short half-life of {sup 68}Ga radionuclide, the {sup 68}Ga rate at CdTe QDs with an excellent tumor targeting/imaging and fast washing out from the body can be suggested as one of the most effective and promising nanomaterials in nanotechnology-based cancer diagnosis and therapy. (orig.)

A cadmium-zinc-telluride crystal array spectrometer

International Nuclear Information System (INIS)

McHugh, H. R.; Quam, W.; DeVore, T.; Vogle, R.; Weslowski, J.

2003-01-01

This paper describes a gamma detector employing an array of eight cadmium-zinc-telluride (CZT) crystals configured as a high resolution gamma ray spectrometer. This detector is part of a more complex instrument that identifies the isotope,displays this information, and records the gamma spectrum. Various alarms and other operator features are incorporated in this battery operated rugged instrument. The CZT detector is the key component of this instrument and will be described in detail in this paper. We have made extensive spectral measurements of the usual laboratory gamma sources, common medical isotopes, and various Special Nuclear Materials (SNM) with this detector. Some of these data will be presented as spectra. We will also present energy resolution and detection efficiency for the basic 8-crystal array. Additional data will also be presented for a 32-crystal array. The basic 8-crystal array development was completed two years ago, and the system electronic design has been imp roved recently. This has resulted in significantly improved noise performance. We expect to have a much smaller detector package, using 8 crystals, in a few months. This package will use flip-chip packaging to reduce the electronics physical size by a factor of 5

Precision timing detectors with cadmium-telluride sensor

Science.gov (United States)

Bornheim, A.; Pena, C.; Spiropulu, M.; Xie, S.; Zhang, Z.

2017-09-01

Precision timing detectors for high energy physics experiments with temporal resolutions of a few 10 ps are of pivotal importance to master the challenges posed by the highest energy particle accelerators such as the LHC. Calorimetric timing measurements have been a focus of recent research, enabled by exploiting the temporal coherence of electromagnetic showers. Scintillating crystals with high light yield as well as silicon sensors are viable sensitive materials for sampling calorimeters. Silicon sensors have very high efficiency for charged particles. However, their sensitivity to photons, which comprise a large fraction of the electromagnetic shower, is limited. To enhance the efficiency of detecting photons, materials with higher atomic numbers than silicon are preferable. In this paper we present test beam measurements with a Cadmium-Telluride (CdTe) sensor as the active element of a secondary emission calorimeter with focus on the timing performance of the detector. A Schottky type CdTe sensor with an active area of 1cm2 and a thickness of 1 mm is used in an arrangement with tungsten and lead absorbers. Measurements are performed with electron beams in the energy range from 2 GeV to 200 GeV. A timing resolution of 20 ps is achieved under the best conditions.

Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

International Nuclear Information System (INIS)

Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

2017-01-01

Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

Energy Technology Data Exchange (ETDEWEB)

Goto, Masahiro, E-mail: goto.masahiro@nims.go.jp [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sasaki, Michiko [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Xu, Yibin [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Materials Database Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhan, Tianzhuo [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Isoda, Yukihiro [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Shinohara, Yoshikazu [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

2017-06-15

Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

Thin-film solar cells

International Nuclear Information System (INIS)

Aberle, Armin G.

2009-01-01

The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and microcrystalline silicon films ('micromorph cells'). Significant thin-film PV production levels are also being set up for cadmium telluride and copper indium diselenide.

Preliminary uranium enrichment analysis results using cadmium zinc telluride detectors

International Nuclear Information System (INIS)

Lavietes, A.D.; McQuaid, J.H.; Paulus, T.J.

1995-01-01

Lawrence Livermore National Laboratory (LLNL) and EG ampersand G ORTEC have jointly developed a portable ambient-temperature detection system that can be used in a number of application scenarios. The detection system uses a planar cadmium zinc telluride (CZT) detector with custom-designed detector support electronics developed at LLNL and is based on the recently released MicroNOMAD multichannel analyzer (MCA) produced by ORTEC. Spectral analysis is performed using software developed at LLNL that was originally designed for use with high-purity germanium (HPGe) detector systems. In one application, the CZT detection system determines uranium enrichments ranging from less than 3% to over 75% to within accuracies of 20%. The analysis was performed using sample sizes of 200 g or larger and acquisition times of 30 min. The authors have demonstrated the capabilities of this system by analyzing the spectra gathered by the CZT detection system from uranium sources of several enrichments. These experiments demonstrate that current CZT detectors can, in some cases, approach performance criteria that were previously the exclusive domain of larger HPGe detector systems

Development of a cadmium telluride pixel detector for astrophysical applications

Science.gov (United States)

Miyasaka, Hiromasa; Harrison, Fiona A.; Cook, Walter R.; Mao, Peter H.; Rana, Vikram R.; Ishikawa, Shin-Nosuke; Ushio, Masayoshi; Aono, Hiroyuki; Watanabe, Shin; Sato, Goro; Kokubun, Motohide; Takahashi, Tadayuki

2009-08-01

We are developing imaging Cadmium Telluride (CdTe) pixel detectors optimized for astrophysical hard X-ray applications. Our hybrid detector consist of a CdTe crystal 1mm thick and 2cm × 2cm in area with segmented anode contacts directly bonded to a custom low-noise application specific integrated circuit (ASIC). The CdTe sensor, fabricated by ACRORAD (Okinawa, Japan), has Schottky blocking contacts on a 605 micron pitch in a 32 × 32 array, providing low leakage current and enabling readout of the anode side. The detector is bonded using epoxy-gold stud interconnects to a custom low noise, low power ASIC circuit developed by Caltech's Space Radiation Laboratory. We have achieved very good energy resolution over a wide energy range (0.62keV FWHM @ 60keV, 10.8keV FWHM @ 662keV). We observe polarization effects at room temperature, but they are suppressed if we operate the detector at or below 0°C degree. These detectors have potential application for future missions such as the International X-ray Observatory (IXO).

Heart imaging by cadmium telluride gamma camera European Program 'BIOMED' consortium

CERN Document Server

Scheiber, C; Chambron, J; Prat, V; Kazandjan, A; Jahnke, A; Matz, R; Thomas, S; Warren, S; Hage-Hali, M; Regal, R; Siffert, P; Karman, M

1999-01-01

Cadmium telluride semiconductor detectors (CdTe) operating at room temperature are attractive for medical imaging because of their good energy resolution providing excellent spatial and contrast resolution. The compactness of the detection system allows the building of small light camera heads which can be used for bedside imaging. A mobile pixellated gamma camera based on 2304 CdTe (pixel size: 3x3 mm, field of view: 15 cmx15 cm) has been designed for cardiac imaging. A dedicated 16-channel integrated circuit has also been designed. The acquisition hardware is fully programmable (DSP card, personal computer-based system). Analytical calculations have shown that a commercial parallel hole collimator will fit the efficiency/resolution requirements for cardiac applications. Monte-Carlo simulations predict that the Moire effect can be reduced by a 15 deg. tilt of the collimator with respect to the detector grid. A 16x16 CdTe module has been built for the preliminary physical tests. The energy resolution was 6.16...

Effect of electronic contribution on temperature-dependent thermal transport of antimony telluride thin film

Energy Technology Data Exchange (ETDEWEB)

Lee, Won-Yong; Park, No-Won [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Hong, Ji-Eun [Department of Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Yoon, Soon-Gil, E-mail: sgyoon@cnu.ac.kr [Department of Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Koh, Jung-Hyuk [School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Sang-Kwon, E-mail: sangkwonlee@cau.ac.kr [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2015-01-25

Highlights: • We investigated thermal transport of the antimony telluride thin films. • The contribution of the electronic thermal conductivity increased up to ∼77% at 300 K. • We theoretically analyze and explain the high contribution of electronic component. - Abstract: We study the theoretical and experimental characteristics of thermal transport of 100 nm and 500 nm-thick antimony telluride (Sb{sub 2}Te{sub 3}) thin films prepared by radio frequency magnetron sputtering. The thermal conductivity was measured at temperatures ranging from 20 to 300 K, using four-point-probe 3-ω method. Out-of-plane thermal conductivity of the Sb{sub 2}Te{sub 3} thin film was much lesser in comparison to the bulk material in the entire temperature range, confirming that the phonon- and electron-boundary scattering are enhanced in thin films. Moreover, we found that the contribution of the electronic thermal conductivity (κ{sub e}) in total thermal conductivity (κ) linearly increased up to ∼77% at 300 K with increasing temperature. We theoretically analyze and explain the high contribution of electronic component of thermal conductivity towards the total thermal conductivity of the film by a modified Callaway model. Further, we find the theoretical model predictions to correspond well with the experimental results.

Charge sharing and charge loss in a cadmium-zinc-telluride fine-pixel detector array

International Nuclear Information System (INIS)

Gaskin, J.A.; Sharma, D.P.; Ramsey, B.D.

2003-01-01

Because of its high atomic number, room temperature operation, low noise, and high spatial resolution a cadmium-zinc-telluride multi-pixel detector is ideal for hard X-ray astrophysical observation. As part of on-going research at MSFC to develop multi-pixel CdZnTe detectors for this purpose, we have measured charge sharing and charge loss for a 4x4 (750 μm pitch), 1 mm thick pixel array and modeled these results using a Monte-Carlo simulation. This model was then used to predict the amount of charge sharing for a much finer pixel array (with a 300 μm pitch). Future work will enable us to compare the simulated results for the finer array to measured values

Electro-Plating and Characterisation of CdTe Thin Films Using CdCl2 as the Cadmium Source

Directory of Open Access Journals (Sweden)

Nor A. Abdul-Manaf

2015-09-01

Full Text Available Cadmium telluride (CdTe thin films have been successfully prepared from an aqueous electrolyte bath containing cadmium chloride (CdCl2·H2O and tellurium dioxide (TeO2 using an electrodeposition technique. The structural, electrical, morphological and optical properties of these thin films have been characterised using X-ray diffraction (XRD, Raman spectroscopy, optical profilometry, DC current-voltage (I-V measurements, photoelectrochemical (PEC cell measurement, scanning electron microscopy (SEM, atomic force microscopy (AFM and UV-Vis spectrophotometry. It is observed that the best cathodic potential is 698 mV with respect to standard calomel electrode (SCE in a three electrode system. Structural analysis using XRD shows polycrystalline crystal structure in the as-deposited CdTe thin films and the peaks intensity increase after CdCl2 treatment. PEC cell measurements show the possibility of growing p-, i- and n-type CdTe layers by varying the growth potential during electrodeposition. The electrical resistivity of the as-deposited layers are in the order of 104 Ω·cm. SEM and AFM show that the CdCl2 treated samples are more roughness and have larger grain size when compared to CdTe grown by CdSO4 precursor. Results obtained from the optical absorption reveal that the bandgap of as-deposited CdTe (1.48–1.52 eV reduce to (1.45–1.49 eV after CdCl2 treatment. Full characterisation of this material is providing new information on crucial CdCl2 treatment of CdTe thin films due to its built-in CdCl2 treatment during the material growth. The work is progressing to fabricate solar cells with this material and compare with CdTe thin films grown by conventional sulphate precursors.

NREL Achieves Solar-Electric Record

Science.gov (United States)

Solar-Electric Record New Technology Could Spur Growth in Photovoltaic Panels For more information thin-film panels made from cadmium telluride. Benner said these and other plants may adopt all or part panels. Of the several materials that can be used for thin-film panels, cadmium telluride yields higher

Cadmium-Zinc-Telluride photon detector for epithermal neutron spectroscopy--pulse height response characterisation

International Nuclear Information System (INIS)

Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Bracco, A.; D'Angelo, A.; Gorini, G.; Imberti, S.; Senesi, R.; Rhodes, N.J.; Schooneveld, E.M.

2004-01-01

The Resonance Detector Spectrometer was recently revised for neutron spectroscopic studies in the eV energy region. In this technique one makes use of a photon detector to record the gamma emission from analyser foils used as neutron-gamma converters. The pulse-height response of a Cadmium-Zinc-Telluride photon detector to neutron capture emission from 238 U and 197 Au analyser foils was characterised in the neutron energy range 1-200 eV. The experiment was performed on the VESUVIO spectrometer at the ISIS neutron-pulsed source. A biparametric data acquisition, specifically developed for these measurements, allowed the simultaneous measurements of both the neutron time of flight and γ pulse-height spectra. Through the analysis of the γ pulse-height spectra the main components of the signal associated with resonant and non-resonant neutron absorption were identified. It was also shown that, in principle, energy discrimination can be used to improve the signal to background ratio of the neutron time-of-flight measurement

Investigation of the electrochemical deposition of thick layers of cadmium telluride

International Nuclear Information System (INIS)

Rousset, J.

2007-04-01

This research thesis deals with the problem of electrochemical deposition of thick layers of cadmium telluride (CdTe) meeting the requirements of high energy radiation detection. The author first recalls the physicochemical properties of CdTe and the basic principles of radiology. He details the different criteria which define a material for X ray detection. He describes the experimental conditions, the nature and preparation of substrates, and the different electrochemical systems used in this research. He studies the impact of the applied potential on the material properties, and compares previously obtained results available in the literature with those obtained in the chosen pool conditions. He discusses the synthesis of CdTe thick layers for which different methods are tested: static in potential, static in intensity, pulsed. The coatings obtained with a given potential and then with a given current are investigated. Finally, the influence of a thermal treatment in presence or absence of a sintering agent on the morphology, the chemical composition, and the crystalline and electric properties of the deposited material is discussed, and the results of the behaviour under X rays of a electrodeposited layer are presented

Measurement and Modeling of Blocking Contacts for Cadmium Telluride Gamma Ray Detectors

Energy Technology Data Exchange (ETDEWEB)

Beck, Patrick R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

2010-01-07

Gamma ray detectors are important in national security applications, medicine, and astronomy. Semiconductor materials with high density and atomic number, such as Cadmium Telluride (CdTe), offer a small device footprint, but their performance is limited by noise at room temperature; however, improved device design can decrease detector noise by reducing leakage current. This thesis characterizes and models two unique Schottky devices: one with an argon ion sputter etch before Schottky contact deposition and one without. Analysis of current versus voltage characteristics shows that thermionic emission alone does not describe these devices. This analysis points to reverse bias generation current or leakage through an inhomogeneous barrier. Modeling the devices in reverse bias with thermionic field emission and a leaky Schottky barrier yields good agreement with measurements. Also numerical modeling with a finite-element physics-based simulator suggests that reverse bias current is a combination of thermionic emission and generation. This thesis proposes further experiments to determine the correct model for reverse bias conduction. Understanding conduction mechanisms in these devices will help develop more reproducible contacts, reduce leakage current, and ultimately improve detector performance.

Trace analysis in cadmium telluride by heavy ion induced X-ray emission and by SIMS

International Nuclear Information System (INIS)

Scharager, C.; Stuck, R.; Siffert, P.; Cailleret, J.; Heitz, Ch.; Lagarde, G.; Tenorio, D.

1979-01-01

The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained

The state of the art of thin-film photovoltaics

International Nuclear Information System (INIS)

Surek, T.

1993-10-01

Thin-film photovoltaic technologies, based on materials such as amorphous or polycrystalline silicon, copper indium diselenide, cadmium telluride, and gallium arsenide, offer the potential for significantly reducing the cost of electricity generated by photovoltaics. The significant progress in the technologies, from the laboratory to the marketplace, is reviewed. The common concerns and questions raised about thin films are addressed. Based on the progress to date and the potential of these technologies, along with continuing investments by the private sector to commercialize the technologies, one can conclude that thin-film PV will provide a competitive alternative for large-scale power generation in the future

Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions.

Science.gov (United States)

Ramos-Ruiz, Adriana; Wilkening, Jean V; Field, James A; Sierra-Alvarez, Reyes

2017-08-15

A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1mgL -1 ), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005mgL -1 ). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of reaction times on structural, optical and luminescence properties of cadmium telluride nanoparticles prepared by wet-chemical process

Energy Technology Data Exchange (ETDEWEB)

Kiprotich, Sharon, E-mail: KiprotichS@qwa.ufs.ac.za [Department of Physics, University of the Free State (QwaQwa campus), Private Bag X-13, Phuthaditjhaba 9866 (South Africa); Dejene, Francis B.; Ungula, Jatani [Department of Physics, University of the Free State (QwaQwa campus), Private Bag X-13, Phuthaditjhaba 9866 (South Africa); Onani, Martin O. [Departments of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa)

2016-01-01

This paper explains one pot synthesis of type II water soluble L-cysteine capped cadmium telluride (CdTe) core shell quantum dots using cadmium acetate, potassium tellurite and L-cysteine as the starting materials. The reaction was carried out in a single three necked flask without nitrogen under reflux at 100 °C. Results from PL show a sharp absorption excitonic band edge of the CdTe core with respect to the core shell which loses its shoulder during the growth of the shell on the core. The PL spectra indicate a drastic shift in emission window of the core which is simultaneously accompanied by an increase in emission intensity. X-ray diffraction pattern confirms the formation of hexagonal phase for all samples. Some difference in absorption edges were observed due to varying synthesis time of CdTe NPs. The position of the absorption band is observed to shift towards the lower wavelength side for shorter durations of synthesis.

Progress and issues in polycrystalline thin-film PV technologies

Energy Technology Data Exchange (ETDEWEB)

Zweibel, K.; Ullal, H.S.; Roedern, B. von [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

Substantial progress has occurred in polycrystalline thin-film photovoltaic technologies in the past 18 months. However, the transition to first-time manufacturing is still under way, and technical problems continue. This paper focuses on the promise and the problems of the copper indium diselenide and cadmium telluride technologies, with an emphasis on continued R&D needs for the near-term transition to manufacturing and for next-generation improvements. In addition, it highlights the joint R&D efforts being performed in the U.S. Department of Energy/National Renewable Energy Laboratory Thin-Film Photovoltaic Partnership Program.

Current transport mechanisms in mercury cadmium telluride diode

Energy Technology Data Exchange (ETDEWEB)

Gopal, Vishnu, E-mail: vishnu-46@yahoo.com, E-mail: wdhu@mail.sitp.ac.cn [Institute of Defence Scientists and Technologists, CFEES Complex, Brig. S. K. Majumdar Marg, Delhi 110054 (India); Li, Qing; He, Jiale; Hu, Weida, E-mail: vishnu-46@yahoo.com, E-mail: wdhu@mail.sitp.ac.cn [National Lab for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); He, Kai; Lin, Chun [Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China)

2016-08-28

This paper reports the results of modelling of the current-voltage characteristics (I-V) of a planar mid-wave Mercury Cadmium Telluride photodiode in a gate controlled diode experiment. It is reported that the diode exhibits nearly ideal I-V characteristics under the optimum surface potential leading to the minimal surface leakage current. Deviations from the optimum surface potential lead to non ideal I–V characteristics, indicating a strong relationship between the ideality factor of the diode with its surface leakage current. Diode's I–V characteristics have been modelled over a range of gate voltages from −9 V to −2 V. This range of gate voltages includes accumulation, flat band, and depletion and inversion conditions below the gate structure of the diode. It is shown that the I–V characteristics of the diode can be very well described by (i) thermal diffusion current, (ii) ohmic shunt current, (iii) photo-current due to background illumination, and (iv) excess current that grows by the process of avalanche multiplication in the gate voltage range from −3 V to −5 V that corresponds to the optimum surface potential. Outside the optimum gate voltage range, the origin of the excess current of the diode is associated with its high surface leakage currents. It is reported that the ohmic shunt current model applies to small surface leakage currents. The higher surface leakage currents exhibit a nonlinear shunt behaviour. It is also shown that the observed zero-bias dynamic resistance of the diode over the entire gate voltage range is the sum of ohmic shunt resistance and estimated zero-bias dynamic resistance of the diode from its thermal saturation current.

Effect of Gallium Doping on the Characteristic Properties of Polycrystalline Cadmium Telluride Thin Film

Science.gov (United States)

Ojo, A. A.; Dharmadasa, I. M.

2017-08-01

Ga-doped CdTe polycrystalline thin films were successfully electrodeposited on glass/fluorine doped tin oxide substrates from aqueous electrolytes containing cadmium nitrate (Cd(NO3)2·4H2O) and tellurium oxide (TeO2). The effects of different Ga-doping concentrations on the CdTe:Ga coupled with different post-growth treatments were studied by analysing the structural, optical, morphological and electronic properties of the deposited layers using x-ray diffraction (XRD), ultraviolet-visible spectrophotometry, scanning electron microscopy, photoelectrochemical cell measurement and direct-current conductivity test respectively. XRD results show diminishing (111)C CdTe peak above 20 ppm Ga-doping and the appearance of (301)M GaTe diffraction above 50 ppm Ga-doping indicating the formation of two phases; CdTe and GaTe. Although, reductions in the absorption edge slopes were observed above 20 ppm Ga-doping for the as-deposited CdTe:Ga layer, no obvious influence on the energy gap of CdTe films with Ga-doping were detected. Morphologically, reductions in grain size were observed at 50 ppm Ga-doping and above with high pinhole density within the layer. For the as-deposited CdTe:Ga layers, conduction type change from n- to p- were observed at 50 ppm, while the n-type conductivity were retained after post-growth treatment. Highest conductivity was observed at 20 ppm Ga-doping of CdTe. These results are systematically reported in this paper.

Preparation and study of the properties of lead telluride and cadmium telluride diodes for use in nuclear spectrometry; Preparation et etude des proprietes de diodes au tellurure de plomb et au tellurure de cadmium en vue d'une utilisation en spectrometrie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Lancon, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

This work studies the possibility of using high atomic number compound semiconductors, like lead telluride and cadmium telluride as to realize nuclear radiation detectors, specially in gamma ray spectrometry because of their high absorption coefficient. The problems related to the preparation of binary compounds are exposed. Experiments on PbTe show the influence of the conditions of preparation on the electrical properties of the semiconductor which are greatly dependent on the stoichiometry of the compound. PbTe surface-barrier diodes were realized and have been used to study the surface properties of this semiconductor. These diodes cannot detect nuclear radiations because of the too weak resistivity of our material. Different types of devices made of Cd Te have been studied. One of these diodes has been used as an alpha particle detector. We explain the relative poor performances of that detector by the presence of lattice defects in Cd Te where charge carriers may recombine themselves. By analysing the properties of gold diffused Cd Te diodes we identified this defect, the cadmium vacancy, the presence of which is due to the deviation from stoichiometry during the preparation of the material. (author) [French] Ce travail etudie la possibilite d'utiliser des semiconducteurs composes d'elements a numero atomique eleve, tels que le tellurure de plomb et le tellurure de cadmium pour la realisation de detecteurs de rayonnements nucleaires, grace notamment a la section efficace de capture elevee qu'ils presentent vis-a-vis des rayons gamma. On souligne les problemes relatifs a la preparation des composes binaires. Les experiences realisees sur PbTe mettent en evidence l'influence des conditions de preparation sur les proprietes electriques du semiconducteur qui dependent fortement de la stoechiometrie du compose. Nous avons realise des diodes au PbTe a barriere de surface qui ont permis de preciser les proprietes de surface de ce semiconducteur. La trop faible

Derived reference doses for three compounds used in the photovoltaics industry: Copper indium diselenide, copper gallium diselenide, and cadmium telluride

Energy Technology Data Exchange (ETDEWEB)

Moskowitz, P.D.; Bernholc, N.; DePhillips, M.P.; Viren, J.

1995-07-06

Polycrystalline thin-film photovoltaic modules made from copper indium diselenide (CIS), copper gallium diselenide (CGS), and cadmium telluride (CdTe) arc nearing commercial development. A wide range of issues are being examined as these materials move from the laboratory to large-scale production facilities to ensure their commercial success. Issues of traditional interest include module efficiency, stability and cost. More recently, there is increased focus given to environmental, health and safety issues surrounding the commercialization of these same devices. An examination of the toxicological properties of these materials, and their chemical parents is fundamental to this discussion. Chemicals that can present large hazards to human health or the environment are regulated often more strictly than those that are less hazardous. Stricter control over how these materials are handled and disposed can increase the costs associated with the production and use of these modules dramatically. Similarly, public perception can be strongly influenced by the inherent biological hazard that these materials possess. Thus, this report: presents a brief background tutorial on how toxicological data are developed and used; overviews the toxicological data available for CIS, CGS and CdTe; develops ``reference doses`` for each of these compounds; compares the reference doses for these compounds with those of their parents; discusses the implications of these findings to photovoltaics industry.

Cadmium sulphide thin film for application in gamma radiation ...

African Journals Online (AJOL)

Cadmium Sulphide (CdS) thin film was prepared using pyrolytic spraying technique and then irradiated at varied gamma dosage. The CdS thin film absorption before gamma irradiation was 0.6497. Absorbed doses were computed using standard equation established for an integrating dosimeter. The plot of absorbed dose ...

Templated growth of cadmium zinc telluride (CZT) nanowires using pulsed-potentials in hot non-aqueous solution

International Nuclear Information System (INIS)

Gandhi, T.; Raja, K.S.; Misra, M.

2006-01-01

A single step non-aqueous electrodeposition of cadmium zinc telluride (CZT) nanowires on nanoporous TiO 2 substrate was investigated under pulsed-potential conditions. Propylene carbonate was used as the non-aqueous medium. Cyclic voltammogram studies were carried out to understand the growth mechanism of CZT. EDAX and XRD measurements indicated formation of a compound semiconductor with a stoichiometry of Cd 1-x Zn x Te, where x varied between 0.04 and 0.2. Variation of the pulsed-cathodic potentials could modulate the composition of the CZT. More negative cathodic potentials resulted in increased Zn content. The nanowires showed an electronic band gap of about 1.6 eV. Mott-Schottky analyses indicated p-type semiconductor properties of both as-deposited and annealed CZT materials. Increase in Zn content increased the charge carrier density. Annealing of the deposits resulted in lower charge carrier densities, in the order of 10 15 cm -3

Fluorescence Stability of Mercaptopropionic Acid Capped Cadmium Telluride Quantum Dots in Various Biochemical Buffers.

Science.gov (United States)

Borse, Vivek; Kashikar, Adisha; Srivastava, Rohit

2018-04-01

Quantum dots are the semiconductor nanocrystals having unique optical and electronic properties. Quantum dots are category of fluorescent labels utilized for biological tagging, biosensing, bioassays, bioimaging and in vivo imaging as they exhibit very small size, signal brightness, photostability, tuning of light emission range, longer photoluminescence decay time as compared to organic dyes. In this work, we have synthesized and characterized mercaptopropionic acid capped cadmium telluride quantum dots (MPA-CdTe QDs) using hydrothermal method. The study further reports fluorescence intensity stability of quantum dots suspended in different buffers of varying concentration (1-100 mM), stored at various photophysical conditions. Fluorescence intensity values were reduced with increase in buffer concentration. When the samples were stored at room temperature in ambient light condition the quantum dots suspended in different buffers lost the fluorescence intensity after day 15 (except TRIS II). Fluorescence intensity values were found stable for more than 30 days when the samples were stored in dark condition. Samples stored in refrigerator displayed modest fluorescence intensity even after 300 days of storage. Thus, storage of MPA-CdTe QDs in refrigerator may be the suitable choice to maintain its fluorescence stability for longer time for further application.

Cadmium telluride nanoparticles loaded on activated carbon as adsorbent for removal of sunset yellow

Science.gov (United States)

Ghaedi, M.; Hekmati Jah, A.; Khodadoust, S.; Sahraei, R.; Daneshfar, A.; Mihandoost, A.; Purkait, M. K.

2012-05-01

Adsorption is a promising technique for decolorization of effluents of textile dyeing industries but its application is limited due to requirement of high amounts of adsorbent required. The objective of this study was to assess the potential of cadmium telluride nanoparticles loaded onto activated carbon (CdTN-AC) for the removal of sunset yellow (SY) dye from aqueous solution. Adsorption studies were conducted in a batch mode varying solution pH, contact time, initial dye concentration, CdTN-AC dose, and temperature. In order to investigate the efficiency of SY adsorption on CdTN-AC, pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion kinetic models were studied. It was observed that the pseudo-second-order kinetic model fits better than other kinetic models with good correlation coefficient. Equilibrium data were fitted to the Langmuir model. Thermodynamic parameters such as enthalpy, entropy, activation energy, and sticking probability were also calculated. It was found that the sorption of SY onto CdTN-AC was spontaneous and endothermic in nature. The proposed adsorbent is applicable for SY removal from waste of real effluents including pea-shooter, orange drink and jelly banana with efficiency more than 97%.

Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

International Nuclear Information System (INIS)

Brunett, B.A.; Lund, J.C.; Van Scyoc, J.M.; Hilton, N.R.; Lee, E.Y.; James, R.B.

1999-01-01

The goal of this project was to utilize a novel device design to build a compact, high resolution, room temperature operated semiconductor gamma ray sensor. This sensor was constructed from a cadmium zinc telluride (CZT) crystal. It was able to both detect total radiation intensity and perform spectroscopy on the detected radiation. CZT detectors produced today have excellent electron charge carrier collection, but suffer from poor hole collection. For conventional gamma-ray spectrometers, both the electrons and holes must be collected with high efficiency to preserve energy resolution. The requirement to collect the hole carriers, which have relatively low lifetimes, limits the efficiency and performance of existing experimental devices. By implementing novel device designs such that the devices rely only on the electron signal for energy information, the sensitivity of the sensors for detecting radiation can be increased substantially. In this report the authors describe a project to develop a new type of electron-only CZT detector. They report on their successful efforts to design, implement and test these new radiation detectors. In addition to the design and construction of the sensors the authors also report, in considerable detail, on the electrical characteristics of the CZT crystals used to make their detectors

Niobium and zirconium telluride thin films prepared by sputtering

International Nuclear Information System (INIS)

Kassem, M.; Pailharey, D.; Mathey, Y.

2000-01-01

A versatile procedure of sputter deposition, well adapted for getting a large of Te/M ratios (with M = Zr or Nb), has led to the synthesis of several highly anisotropic zirconium and niobium poly tellurides in thin film form. Upon tuning the two key parameters of the process, i.e., the Te percentage in the target and the substrate temperature during the deposition, preparation of systems ranging from ZrTe 0 .72 to ZrTe 6 .7, on the one hand, and from NbTe 1 .28 to NbTe 7 .84, on the other, has been achieved. Besides their amorphous or crystalline (with or without preferential orientations) behavior and their relationship to known structural types, the most striking feature of these films is their large departure from the stoichiometry of the bulk Mte x reference compounds. This peculiarity, together with the possible changes of composition under annealing, are described and interpreted in terms of variable of Te and M atoms trapped or intercalated within the parent structures. (author)

Economic viability of thin-film tandem solar modules in the United States

Science.gov (United States)

Sofia, Sarah E.; Mailoa, Jonathan P.; Weiss, Dirk N.; Stanbery, Billy J.; Buonassisi, Tonio; Peters, I. Marius

2018-05-01

Tandem solar cells are more efficient but more expensive per unit area than established single-junction (SJ) solar cells. To understand when specific tandem architectures should be utilized, we evaluate the cost-effectiveness of different II-VI-based thin-film tandem solar cells and compare them to the SJ subcells. Levelized cost of electricity (LCOE) and energy yield are calculated for four technologies: industrial cadmium telluride and copper indium gallium selenide, and their hypothetical two-terminal (series-connected subcells) and four-terminal (electrically independent subcells) tandems, assuming record SJ quality subcells. Different climatic conditions and scales (residential and utility scale) are considered. We show that, for US residential systems with current balance-of-system costs, the four-terminal tandem has the lowest LCOE because of its superior energy yield, even though it has the highest US per watt (US W-1) module cost. For utility-scale systems, the lowest LCOE architecture is the cadmium telluride single junction, the lowest US W-1 module. The two-terminal tandem requires decreased subcell absorber costs to reach competitiveness over the four-terminal one.

Thin-film photovoltaic technology

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, R.N. [National Renewable Energy Laboratory, Golden, CO (United States)

2010-07-01

The high material and processing costs associated with single-crystal and polycrystalline silicon wafers that are commonly used in photovoltaic cells render these modules expensive. This presentation described thin-film solar cell technology as a promising alternative to silicon solar cell technology. Cadmium telluride (CdTe) thin films along with copper, indium, gallium, and selenium (CIGS) thin films have become the leaders in this field. Their large optical absorption coefficient can be attributed to a direct energy gap that allows the use of thin layers (1-2 {mu}m) of active material. The efficiency of thin-film solar cell devices based on CIGS is 20 per cent, compared to 16.7 per cent for thin-film solar cell devices based on CdTe. IBM recently reported an efficiency of 9.7 per cent for a new type of inorganic thin-film solar cell based on a Cu{sub 2}ZnSn(S, Se){sub 4} compound. The efficiency of an organic thin-film solar cell is 7.9 per cent. This presentation included a graph of PV device efficiencies and discussed technological advances in non-vacuum deposited, CIGS-based thin-film solar cells. 1 fig.

Study of a high-resolution, 3-D positioning cadmium zinc telluride detector for PET

Science.gov (United States)

Gu, Y; Matteson, J L; Skelton, R T; Deal, A C; Stephan, E A; Duttweiler, F; Gasaway, T M; Levin, C S

2011-01-01

This paper investigates the performance of 1 mm resolution Cadmium Zinc Telluride (CZT) detectors for positron emission tomography (PET) capable of positioning the 3-D coordinates of individual 511 keV photon interactions. The detectors comprise 40 mm × 40 mm × 5 mm monolithic CZT crystals that employ a novel cross-strip readout with interspersed steering electrodes to obtain high spatial and energy resolution. The study found a single anode FWHM energy resolution of 3.06±0.39% at 511 keV throughout most the detector volume. Improved resolution is expected with properly shielded front-end electronics. Measurements made using a collimated beam established the efficacy of the steering electrodes in facilitating enhanced charge collection across anodes, as well as a spatial resolution of 0.44±0.07 mm in the direction orthogonal to the electrode planes. Finally, measurements based on coincidence electronic collimation yielded a point spread function with 0.78±0.10 mm FWHM, demonstrating 1 mm spatial resolution capability transverse to the anodes – as expected from the 1 mm anode pitch. These findings indicate that the CZT-based detector concept has excellent performance and shows great promise for a high-resolution PET system. PMID:21335649

Study of a high-resolution, 3D positioning cadmium zinc telluride detector for PET.

Science.gov (United States)

Gu, Y; Matteson, J L; Skelton, R T; Deal, A C; Stephan, E A; Duttweiler, F; Gasaway, T M; Levin, C S

2011-03-21

This paper investigates the performance of 1 mm resolution cadmium zinc telluride (CZT) detectors for positron emission tomography (PET) capable of positioning the 3D coordinates of individual 511 keV photon interactions. The detectors comprise 40 mm × 40 mm × 5 mm monolithic CZT crystals that employ a novel cross-strip readout with interspersed steering electrodes to obtain high spatial and energy resolution. The study found a single anode FWHM energy resolution of 3.06 ± 0.39% at 511 keV throughout most of the detector volume. Improved resolution is expected with properly shielded front-end electronics. Measurements made using a collimated beam established the efficacy of the steering electrodes in facilitating enhanced charge collection across anodes, as well as a spatial resolution of 0.44 ± 0.07 mm in the direction orthogonal to the electrode planes. Finally, measurements based on coincidence electronic collimation yielded a point spread function with 0.78 ± 0.10 mm FWHM, demonstrating 1 mm spatial resolution capability transverse to the anodes-as expected from the 1 mm anode pitch. These findings indicate that the CZT-based detector concept has excellent performance and shows great promise for a high-resolution PET system.

Fabrication of thin cadmium cylinder coated with aluminum for neutron irradiation capsules

International Nuclear Information System (INIS)

Takeyama, Tomonori; Chiba, Masaaki

2001-03-01

In order to fabricate the irradiation capsule screened thermal neutron, a thin cadmium cylinder coated with aluminum was developed. The capsule is used for the fast neutron irradiation test. Requested specification of the cylinder are the thickness of 5.5 mm, the inner diameter of 23 mm, the length of 750 mm and the coated thickness of aluminum of 0.75 mm. Moreover, cadmium and aluminum adhere to each other. The cylinder was developed and fabricated by means of casting. The a new vacuum chamber in which solving and casting work is possible was fabricated to prevent cadmium oxidation and work safely from poison of cadmium. (author)

N-hydroxysuccinimide-mediated photoelectrooxidation of aliphatic alcohols based on cadmium telluride nanoparticles decorated graphene nanosheets

International Nuclear Information System (INIS)

Navaee, Aso; Salimi, Abdollah

2013-01-01

A simple nonenzymatic electrochemical protocol is proposed for the oxidation of aliphatic alcohols using formed N-hydroxysuccinimide (NHS) radical cation on the graphene nanosheets/L-cysteine/cadmium telluride quantum dot (QD) nanocomposite (GNs/Cys/CdTe) modified glassy carbon (GC) electrode. At first, graphene oxide (GO) is chemically synthesized from graphite after which Cys is covalently functionalized to GO through formation of amide bonds between carboxylic acid groups of GO and amine groups of Cys. The resulting GNs/Cys is used as a capping agent to synthesize CdTe QD nanoparticles. After the characterization of the as-made nanocomposite which confirmed the successful attachment of CdTe nanoparticles to the GNs, the ability of the GNs/Cys/CdTe modified GC electrode toward the nonenzymatic ethanol electrooxidation is examined in the presence of NHS as an effective mediating system. Our results revealed that the proposed system possess a good activity to NHS electrooxidation and subsequently, ethanol oxidation. Moreover, the GNs/Cys/CdTe modified electrode displayed a significant photoelectrocatalytic activity toward the ethanol oxidation upon illumination by visible light. The photoactive GNs/Cys/CdTe nanohybrid presented here showing favorable photoelectrochemical features for nonenzymatic aliphatic alcohols oxidation may hold great promise to the development of electrochemical sensors and biofuel cells

Investigation of the Electronic Properties of Cadmium Zinc Telluride (CZT) Detectors using a Nuclear Microprobe

International Nuclear Information System (INIS)

BRUNETT, BRUCE A.; DOYLE, BARNEY L.; JAMES, RALPH B.; VIZKELETHY, GYORGY; WALSH, DAVID S.

1999-01-01

The electronic transport properties of Cadmium Zinc Telluride (CZT) determine the charge collection efficiency (i.e. the signal quality) of CZT detectors. These properties vary on both macroscopic and microscopic scale and depend on the presence of impurities and defects introduced during the crystal growth. Ion Beam Induced Charge Collection (IBICC) is a proven method to measure the charge collection efficiency. Using an ion microbeam, the charge collection efficiency can be mapped with submicron resolution, and the map of electronic properties (such as drift length) can be calculated from the measurement. A more sophisticated version of IBICC, the Time Resolved IBICC (TRIBICC) allows them to determine the mobility and the life time of the charge carriers by recording and analyzing the transient waveform of the detector signal. Furthermore, lateral IBICC and TRIBICC can provide information how the charge collection efficiency depends on the depth where the charge carriers are generated. This allows one to deduce information on the distribution of the electric field and transport properties of the charge carriers along the detector axis. IBICC and TRIBICC were used at the Sandia microbeam facility to image electronic properties of several CZT detectors. From the lateral TRIBICC measurement the electron and hole drift length profiles were calculated

Angular dependence of magnetization reversal in epitaxial chromium telluride thin films with perpendicular magnetic anisotropy

Energy Technology Data Exchange (ETDEWEB)

Pramanik, Tanmoy, E-mail: pramanik.tanmoy@utexas.edu; Roy, Anupam, E-mail: anupam@austin.utexas.edu; Dey, Rik, E-mail: rikdey@utexas.edu; Rai, Amritesh; Guchhait, Samaresh; Movva, Hema C.P.; Hsieh, Cheng-Chih; Banerjee, Sanjay K.

2017-09-01

Highlights: • Perpendicular magnetic anisotropy in epitaxial Cr{sub 2}Te{sub 3} has been investigated. • Presence of a relatively strong second order anisotropy contribution is observed. • Magnetization reversal is explained quantitatively using a 1D defect model. • Relative roles of nucleation and pinning in magnetization reversal are discussed. • Domain structures and switching process are visualized by micromagnetic simulation. - Abstract: We investigate magnetic anisotropy and magnetization reversal mechanism in chromium telluride thin films grown by molecular beam epitaxy. We report existence of strong perpendicular magnetic anisotropy in these thin films, along with a relatively strong second order anisotropy contribution. The angular variation of the switching field observed from the magnetoresistance measurement is explained quantitatively using a one-dimensional defect model. The model reveals the relative roles of nucleation and pinning in the magnetization reversal, depending on the applied field orientation. Micromagnetic simulations are performed to visualize the domain structure and switching process.

and Cadmium Zinc Telluride

African Journals Online (AJOL)

Bheema

INTRODUCTION. Semiconductor nanoparticles or Quantum Dots (QDs), in particular II-VI materials, have ... the study of structural, electronic transport and optical properties of Zn doped CdTe thin films, ...... Bhattacharya, S.K & Anjali, K. 2007.

Mercury-Cadmium-Telluride Focal Plane Array Performance Under Non-Standard Operating Conditions

Science.gov (United States)

Richardson, Brandon S.; Eastwood, Michael L.; Bruce, Carl F.; Green, Robert O.; Coles, J. B.

2011-01-01

This paper highlights a new technique that allows the Teledyne Scientific & Imaging LLC TCM6604A Mercury-Cadmium-Telluride (MCT) Focal Plane Array (FPA) to operate at room temperature. The Teledyne MCT FPA has been a standard in Imaging Spectroscopy since its creation in the 1980's. This FPA has been used in applications ranging from space instruments such as CRISM, M3 and ARTEMIS to airborne instruments such as MaRS and the Next Generation AVIRIS Instruments1. Precise focal plane alignment is always a challenge for such instruments. The current FPA alignment process results in multiple cold cycles requiring week-long durations, thereby increasing the risk and cost of a project. These alignment cycles are necessary because optimal alignment is approached incrementally and can only be measured with the FPA and Optics at standard operating conditions, requiring a cold instrument. Instruments using this FPA are normally cooled to temperatures below 150K for the MCT FPA to properly function. When the FPA is run at higher temperatures the dark current increases saturating the output. This paper covers the prospect of warm MCT FPA operation from a theoretical and experimental perspective. We discuss the empirical models and physical laws that govern MCT material properties and predict the optimal settings that will result in the best MCT PA performance at 300K. Theoretical results are then calculated for the proposed settings. We finally present the images and data obtained using the actual system with the warm MCT FPA settings. The paper concludes by emphasizing the strong positive correlation between the measured values and the theoretical results.

Study of CdTe and HgCdTe thin films obtained by electrochemical methods

International Nuclear Information System (INIS)

Guillen, C.

1990-01-01

Cadmium telluride polycrystalline thin films were fabricated on SnO 2 -coated glass substrates by potentiostatic electrodeposition and characterized by X-ray diffraction, energy dispersive X-ray analyses (EDAX), optical and electrical measurements. The films dseposited at potentials more positive than -0.65 V vs.SCE were p-type but those deposited at more negative potentials were n-type. All CdTe thin films showed a band-gap energy about 1.45 eV and a large absorption coeffici-ent (a=10 5 cm -1 ) above de band edge. The addition of even small amounts of mercury to the CdTe produces higuer conductivity values and lower band-gap energies. We have prepared HgCdTe thin films where the band-gap energies ranged between 0.93 and 0.88 eV depending on the ratio of mercury to cadmium. Heat treatment at 300 0 C increases the crystalline diameter and alter the composition of the electrodeposited films, a decrease of the resistivity values was also observed. (Author)

Optical characterisation of thin film cadmium oxide prepared by a ...

African Journals Online (AJOL)

The optical transmission spectra of transparent conducting cadmium oxide (CdO) thin films deposited by a modified reactive evaporation process onto glass substrates have been measured. The interference fringes were used to calculate the refractive index, thickness variation, average thickness and absorption coefficient ...

Pre-chemotherapy values for left and right ventricular volumes and ejection fraction by gated tomographic radionuclide angiography using a cadmium-zinc-telluride detector gamma camera

DEFF Research Database (Denmark)

Haarmark, Christian; Haase, Christine; Jensen, Maria Maj

2016-01-01

age and both left and right ventricular volumes in women (r = -0.4, P right end systolic ventricular volume in men (r = -0.3, P = .001). CONCLUSION: A set of reference values for cardiac evaluation prior to chemotherapy in cancer patients without other known cardiopulmonary......BACKGROUND: Estimation of left ventricular ejection fraction (LVEF) using equilibrium radionuclide angiography is an established method for assessment of left ventricular function. The purpose of this study was to establish normative data on left and right ventricular volumes and ejection fraction......, using cadmium-zinc-telluride SPECT camera. METHODS AND RESULTS: From routine assessments of left ventricular function in 1172 patients, we included 463 subjects (194 men and 269 women) without diabetes, previous potentially cardiotoxic chemotherapy, known cardiovascular or pulmonary disease. The lower...

Spectrometry of X-ray beams using Cadmium and Zinc Teluride detector

International Nuclear Information System (INIS)

Becker, Paulo Henriques Bastos

1997-06-01

Determination of X-ray spectra to be utilized for medical diagnostics is a complementary process to the development of procedures to be applied to the quality control of radiodiagnostics X-ray equipment. Until some years ago, that was only possible using Germanium or Silicon detectors. Both have an excellent resolution in this energy range, but present also some restrictions as there are high costs and the necessity of operating them at temperature of liquid Nitrogen, which is not always available at the measurement's place. Room temperature detectors like Cadmium Telluride and Mercury Iodine don't have these restrictions. They, however, have a lower resolution and incomplete collection of the charges produced by their interaction with radiation. With technological advance of crystal growth in general and new techniques like cooling the crystal with a Peltier cell and rise time discrimination circuits, today Cadmium Telluride detectors show a resolution very close to that from Germanium detectors. This work relates to the routine use of Cadmium and Zinc Telluride detectors for measuring X-ray spectra in loco of diagnostic X-ray units. It characterizes the properties of a commercially available detector and offers a model for stripping the measured pulse height distribution. It was also developed a collimator to allow the direct measurement of the beam. The model developed and the constructed set-up were applied to two X-ray tubes and the achieved spectra compared with some spectra available from the literature. (author)

Diagnostic performance of a novel cadmium-zinc-telluride gamma camera system assessed using fractional flow reserve.

Science.gov (United States)

Tanaka, Hirokazu; Chikamori, Taishiro; Tanaka, Nobuhiro; Hida, Satoshi; Igarashi, Yuko; Yamashita, Jun; Ogawa, Masashi; Shiba, Chie; Usui, Yasuhiro; Yamashina, Akira

2014-01-01

Although the novel cadmium-zinc-telluride (CZT) camera system provides excellent image quality, its diagnostic value using thallium-201 as assessed on coronary angiography (CAG) and fractional flow reserve (FFR) has not been validated. METHODS AND RESULTS: To evaluate the diagnostic accuracy of the CZT ultrafast camera system (Discovery NM 530c), 95 patients underwent stress thallium-201 single-photon emission computed tomography (SPECT) and then CAG within 3 months. Image acquisition was performed in the supine and prone positions after stress for 5 and 3 min, respectively, and in the supine position at rest for 10 min. Significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or a lesion with <90% and ≥50% stenosis and FFR ≤0.75. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 90%, 64%, and 78% for left anterior descending coronary artery stenosis, 78%, 84%, and 81% for left circumflex stenosis, and 83%, 47%, and 60% for right coronary artery (RCA) stenosis. The combination of prone and supine imaging had a higher specificity for RCA disease than supine imaging alone (65% vs. 47%), with an improvement in accuracy from 60% to 72%. Using thallium-201 with short acquisition time, combined with prone imaging, CZT SPECT had a high diagnostic yield in detecting significant coronary stenosis as assessed using FFR.

GEOLOGY OF THE FLORENCIA GOLD – TELLURIDE DEPOSIT (CAMAGÜEY, CUBA AND SOME METALLURGICAL CONSIDERATIONS

Directory of Open Access Journals (Sweden)

López K Jesús M.

2006-12-01

Full Text Available This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors.
It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones.

Growth of Bi doped cadmium zinc telluride single crystals by Bridgman oscillation method and its structural, optical, and electrical analyses

International Nuclear Information System (INIS)

Carcelen, V.; Rodriguez-Fernandez, J.; Dieguez, E.; Hidalgo, P.

2010-01-01

The II-VI compound semiconductor cadmium zinc telluride (CZT) is very useful for room temperature radiation detection applications. In the present research, we have successfully grown Bi doped CZT single crystals with two different zinc concentrations (8 and 14 at. %) by the Bridgman oscillation method, in which one experiment has been carried out with a platinum (Pt) tube as the ampoule support. Pt also acts as a cold finger and reduces the growth velocity and enhances crystalline perfection. The grown single crystals have been studied with different analysis methods. The stoichiometry was confirmed by energy dispersive by x-ray and inductively coupled plasma mass spectroscopy analyses and it was found there is no incorporation of impurities in the grown crystal. The presence of Cd and Te vacancies was determined by cathodoluminescence studies. Electrical properties were assessed by I-V analysis and indicated higher resistive value (8.53x10 8 Ω cm) for the crystal grown with higher zinc concentration (with Cd excess) compare to the other (3.71x10 5 Ω cm).

Phase transition of bismuth telluride thin films grown by MBE

DEFF Research Database (Denmark)

Fülöp, Attila; Song, Yuxin; Charpentier, Sophie

2014-01-01

A previously unreported phase transition between Bi2Te3 and Bi4Te3 in bismuth telluride grown by molecular beam epitaxy is recorded via XRD, AFM, and SIMS observations. This transition is found to be related to the Te/Bi beam equivalent pressure (BEP) ratio. BEP ratios below 17 favor the formation...

Preparation of cadmium-doped ZnO thin films by SILAR and their ...

Indian Academy of Sciences (India)

Cadmium-doped zinc oxide (Cd : ZnO) thin films were deposited from sodium zincate bath .... of complex ion on the substrate followed by reaction of the .... Intensity (a.u.). 0. 500 .... trum confirmed the presence of Zn, O and Cd elements in the.

Comparison of Cadmium-Zinc-Telluride semiconductor and Yttrium-Aluminum-Perovskite scintillator as photon detectors for epithermal neutron spectroscopy

International Nuclear Information System (INIS)

Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Gorini, G.; Imberti, S.; Perelli-Cippo, E.; Senesi, R.; Rhodes, N.; Schooneveld, E.M.

2006-01-01

The range of applications of epithermal neutron scattering experiments has been recently extended by the development of the Resonance Detector. In a Resonance Detector, resonant neutron absorption in an analyzer foil results in prompt emission of X- and γ-rays which are detected by a photon counter. Several combinations of analyzer foils and photon detectors have been studied and tested over the years and best results have been obtained with the combination of a natural uranium and (i) Cadmium-Zinc-Telluride (CZT) semiconductor (ii) Yttrium-Aluminum-Perovskite (YAP) scintillators. Here we compare the performance of the CZT semiconductor and YAP scintillator as Resonance Detector units. Two Resonance Detector prototypes made of natural uranium foil viewed by CZT and YAP were tested on the VESUVIO spectrometer at the ISIS spallation neutron source. The results show that both YAP and CZT can be used to detect epithermal neutrons in the energy range from 1 up to 66 eV. It was found that the signal-to-background ratio of the measurement can significantly be improved by raising the lower level discrimination threshold on the γ energy to about 600 keV. The advantages/disadvantages of the choice of a Resonance Detector based on YAP or CZT are discussed together with some potential applications

Studies of antimony telluride and copper telluride films electrodeposition from choline chloride containing ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Catrangiu, Adriana-Simona; Sin, Ion [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Prioteasa, Paula [INCDIE ICPE-Advanced Research, Splaiul Unirii 313, Bucharest (Romania); Cotarta, Adina [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Cojocaru, Anca, E-mail: a_cojocaru@chim.upb.ro [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Anicai, Liana [Center of Surface Science and Nanotechnology, University POLITEHNICA of Bucharest, Splaiul Independentei 313, Bucharest (Romania); Visan, Teodor [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania)

2016-07-29

Cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the deposition of antimony telluride or copper telluride from ionic liquid consisting in mixture of choline chloride with oxalic acid. In addition, the cathodic process during copper telluride formation was studied in the mixture of choline chloride with ethylene glycol. The results indicate that the Pt electrode is first covered with a Te layer, and then the more negative polarisation leads to the deposition of Sb{sub x}Te{sub y} or Cu{sub x}Te{sub y} semiconductor compounds. Thin films were deposited on copper and carbon steel at 60–70 °C and were characterised by scanning electron microscopy, energy X-ray dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Their stoichiometry depends on the bath composition and applied potential. EDS and XRD patterns indicate the possible synthesis of stoichiometric Sb{sub 2}Te{sub 3} phase and Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, and Cu{sub 2.8}Te{sub 2} phases, respectively, by controlling the ratio of ion concentrations in ionic liquid electrolytes and deposition potential. - Highlights: • Sb{sub x}Te{sub y} and Cu{sub x}Te{sub y} films electrodeposited from choline-chloride-based ionic liquids. • The stoichiometry of film depends on the bath composition and deposition potential. • Sb{sub 2}Te{sub 3}, Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, Cu{sub 2.8}Te{sub 2} phases were identified in X-ray diffraction patterns.

Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency.

Science.gov (United States)

Wen, Xixing; Chen, Chao; Lu, Shuaicheng; Li, Kanghua; Kondrotas, Rokas; Zhao, Yang; Chen, Wenhao; Gao, Liang; Wang, Chong; Zhang, Jun; Niu, Guangda; Tang, Jiang

2018-06-05

Antimony selenide is an emerging promising thin film photovoltaic material thanks to its binary composition, suitable bandgap, high absorption coefficient, inert grain boundaries and earth-abundant constituents. However, current devices produced from rapid thermal evaporation strategy suffer from low-quality film and unsatisfactory performance. Herein, we develop a vapor transport deposition technique to fabricate antimony selenide films, a technique that enables continuous and low-cost manufacturing of cadmium telluride solar cells. We improve the crystallinity of antimony selenide films and then successfully produce superstrate cadmium sulfide/antimony selenide solar cells with a certified power conversion efficiency of 7.6%, a net 2% improvement over previous 5.6% record of the same device configuration. We analyze the deep defects in antimony selenide solar cells, and find that the density of the dominant deep defects is reduced by one order of magnitude using vapor transport deposition process.

Spectroscopic, microscopic, and internal stress analysis in cadmium telluride grown by close-space sublimation

International Nuclear Information System (INIS)

Manciu, Felicia S.; Salazar, Jessica G.; Diaz, Aryzbe; Quinones, Stella A.

2015-01-01

High quality materials with excellent ordered structure are needed for developing photovoltaic and infrared devices. With this end in mind, the results of our research prove the importance of a detailed, comprehensive spectroscopic and microscopic analysis in assessing cadmium telluride (CdTe) characteristics. The goal of this work is to examine not only material crystallinity and morphology, but also induced stress in the deposit material. A uniform, selective growth of polycrystalline CdTe by close-space sublimation on patterned Si(111) and Si(211) substrates is demonstrated by scanning electron microscopy images. Besides good crystallinity of the samples, as revealed by both Raman scattering and Fourier transform infrared absorption investigations, the far-infrared transmission data also show the presence of surface optical phonon modes, which is direct evidence of confinement in such a material. The qualitative identification of the induced stress was achieved by performing confocal Raman mapping microscopy on sample surfaces and by monitoring the existence of the rock-salt and zinc-blende structural phases of CdTe, which were associated with strained and unstrained morphologies, respectively. Although the induced stress in the material is still largely due to the high lattice mismatch between CdTe and the Si substrate, the current results provide a direct visualization of its partial release through the relaxation effect at crystallite boundaries and of preferential growth directions of less strain. Our study, thus offers significant value for improvement of material properties, by targeting the needed adjustments in the growth processes. - Highlights: • Assessing the characteristics of CdTe deposited on patterned Si substrates • Proving the utility of confocal Raman microscopy in monitoring the induced stress • Confirming the partial stress release through the grain boundary relaxation effect • Demonstrating the phonon confinement effect in low

Surface modification of cadmium sulfide thin film honey comb nanostructures: Effect of in situ tin doping using chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Wilson, K.C., E-mail: wilsonphy@gmail.com [Department of Physics, Govt. Polytechnic College Kothamangalam, Chelad P O, Ernakulam, Kerala 686681 (India); Department of Physics, B. S. Abdur Rahman University, Vandaloor, Chennai, Tamilnadu 600048 (India); Basheer Ahamed, M. [Department of Physics, B. S. Abdur Rahman University, Vandaloor, Chennai, Tamilnadu 600048 (India)

2016-01-15

Graphical abstract: - Highlights: • Novel honey comb like cadmium sulfide thin film nanostructures prepared using chemical bath deposition on glass substrates. • Honey comb nanostructure found in two layers: an ultra thin film at bottom and well inter connected with walls of < 25 nm thick on top; hence maximum surface area possible for CdS nanostructure. • Shell size of the nanostructures and energy band gaps were controlled also an enhanced persistent conductivity observed on Sn doping. - Abstract: Even though nanostructures possess large surface to volume ratio compared to their thin film counterpart, the complicated procedure that demands for the deposition on a substrate kept them back foot in device fabrication techniques. In this work, a honey comb like cadmium sulfide (CdS) thin films nanostructure are deposited on glass substrates using simple chemical bath deposition technique at 65 °C. Energy band gaps, film thickness and shell size of the honey comb nanostructures are successfully controlled using tin (Sn) doping and number of shells per unit area is found to be maximum for 5% Sn doped (in the reaction mixture) sample. X-ray diffraction and optical absorption analysis showed that cadmium sulfide and cadmium hydroxide coexist in the samples. TEM measurements showed that CdS nanostructures are embedded in cadmium hydroxide just like “plum pudding”. Persistent photoconductivity measurements of the samples are also carried out. The decay constants found to be increased with increases in Sn doping.

Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

International Nuclear Information System (INIS)

James, R.B.; Lund, J.; Yoon, H.

1997-01-01

The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm 3 and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances

Growth and Characterization of (211)B Cadmium Telluride Buffer Layer Grown by Metal-organic Vapor Phase Epitaxy on Nanopatterned Silicon for Mercury Cadmium Telluride Based Infrared Detector Applications

Science.gov (United States)

Shintri, Shashidhar S.

Mercury cadmium telluride (MCT or Hg1-xCdxTe) grown by molecular beam epitaxy (MBE) is presently the material of choice for fabricating infrared (IR) detectors used in night vision based military applications. The focus of MCT epitaxy has gradually shifted since the last decade to using Si as the starting substrate since it offers several advantages. But the ˜19 % lattice mismatch between MCT and Si generates lots of crystal defects some of which degrade the performance of MCT devices. Hence thick CdTe films are used as buffer layers on Si to accommodate the defects. However, growth of high quality single crystal CdTe on Si is challenging and to date, the best MBE CdTe/Si reportedly has defects in the mid-105 cm -2 range. There is a critical need to reduce the defect levels by at least another order of magnitude, which is the main motivation behind the present work. The use of alternate growth technique called metal-organic vapor phase epitaxy (MOVPE) offers some advantages over MBE and in this work MOVPE has been employed to grow the various epitaxial films. In the first part of this work, conditions for obtaining high quality (211)B CdTe epitaxy on (211)Si were achieved, which also involved studying the effect of having additional intermediate buffer layers such as Ge and ZnTe and incorporation of in-situ thermal cyclic annealing (TCA) to reduce the dislocation density. A critical problem of Si cross-contamination due to 'memory effect' of different reactant species was minimized by introducing tertiarybutylArsine (TBAs) which resulted in As-passivation of (211)Si. The best 8-10 µm thick CdTe films on blanket (non-patterned) Si had dislocations around 3×105 cm-2, which are the best reported by MOVPE till date and comparable to the highest quality films available by MBE. In the second part of the work, nanopatterned (211)Si was used to study the effect of patterning on the crystal quality of epitaxial CdTe. In one such study, patterning of ˜20 nm holes in SiO2

Comparison of structural properties of thermally evaporated CdTe thin films on different substrates

International Nuclear Information System (INIS)

Tariq, G.H.; Anis-ur-Rehman, M.

2011-01-01

The direct energy band gap in the range of 1.5 eV and the high absorption coefficient (105 cm/sup -1/) makes Cadmium Telluride (CdTe) a suitable material for fabrication of thin film solar cells. Thin film solar cells based on CdTe (1 cm area) achieved efficiency of 15.6% on a laboratory scale. CdTe thin films were deposited by thermal evaporation technique under vacuum 2 X 10/sup -5/mbar on glass and stainless steel (SS) substrates. During deposition substrates temperature was kept same at 200 deg. C for all samples. The structural properties were determined by the X-ray Diffraction (XRD) patterns. All samples exhibit polycrystalline nature. Dependence of different structural parameters such as lattice parameter, micro strain, and grain size and dislocation density on thickness was studied. Also the influence of the different substrates on these parameters was investigated. The analysis showed that the preferential orientation of films was dependent on the substrate type. (author)

Investigations of portable cadmium telluride (CdTe(Cl)) detectors for clinical studies with radioactive indicators

International Nuclear Information System (INIS)

Bojsen, J.

1985-01-01

The combination of small, portable γ-radiation-sensitive Cadmium Telluride (CdTE(Cl)) crystal detectors and portable solid state data storage memories makes it feasible to extend the measuring period in a number of clinical investigations based on the use of various radioisotopes and external detection. Blood sampling can be avoided in some cases. Continuous ambulatory monitoring of relevant physiological parameters is practicable, e.g. kidney function (GFR), left ventricular ejection fraction, subcutaneous blood flow, muscle blood flow and insulin absorption in diabetic patients. In the present methodological study the applicability of the 133-Xe washout technique to subcutaneous (s.c.) adipose tissue blood flow (SBF) has been investigated and adapted to the use of CdTe(Cl) detectors attached to the skin surface for the measurement of local 133-Xe-disappearance rate constants (k). Physical characterization of CdTe(Cl) detectors as γ-sensitive devices has been performed, and adequate counting sensitivities were found without detector energy-resolution properties. The CdTe(Cl) detectors are therefore suitable for single indicator studies. The measuring geometry of CdTe(Cl) detectors was studied and compared with that of stationary Sodium Iodide (NaI(Tl)) detectors in both phantom and in vivo investigations. The spatial properties of CdTe(Cl) detectors could to some extent be adjusted by pulse height discrimination and lead collimation. When long-term measurements were complicated by for instance physical activity of the patients, the small CdTe(Cl) detectors in general showed equal or better performance than the heavy and voluminous NaI(Tl) detectors. The free movement of the ambulatory patient and the avoidance of cable connections to stationary data-collecting systems gave improved possibilities for measurements of the relevant parameters. From this point of view, portable CdTe(Cl) detectors must be considered an important advance for radioactivity studies in

Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

Energy Technology Data Exchange (ETDEWEB)

James, R.B.; Lund, J. [Sandia National Labs., Livermore, CA (United States); Yoon, H. [Sandia National Labs., Livermore, CA (United States)]|[Univ. of California, Los Angeles, CA (United States)] [and others

1997-09-01

The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm{sup 3} and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances.

Myocardial perfusion imaging with a cadmium zinc telluride-based gamma camera versus invasive fractional flow reserve

Energy Technology Data Exchange (ETDEWEB)

Mouden, Mohamed [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Ottervanger, Jan Paul; Timmer, Jorik R. [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Reiffers, Stoffer; Oostdijk, Ad H.J.; Jager, Pieter L. [Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Boer, Menko-Jan de [University Medical Centre Nijmegen, Department of Cardiology, Nijmegen (Netherlands)

2014-05-15

Recently introduced ultrafast cardiac SPECT cameras with cadmium zinc telluride-based (CZT) detectors may provide superior image quality allowing faster acquisition with reduced radiation doses. Although the level of concordance between conventional SPECT and invasive fractional flow reserve (FFR) measurement has been studied, that between FFR and CZT-based SPECT is not yet known. Therefore, we aimed to assess the level of concordance between CZT SPECT and FFR in a large patient group with stable coronary artery disease. Both invasive FFR and myocardial perfusion imaging with a CZT-based SPECT camera, using Tc-tetrofosmin as tracer, were performed in 100 patients with stable angina and intermediate grade stenosis on invasive coronary angiography. A cut-off value of <0.75 was used to define abnormal FFR. The mean age of the patients was 64 ± 11 years, and 64 % were men. SPECT demonstrated ischaemia in 31 % of the patients, and 20 % had FFR <0.75. The concordance between CZT SPECT and FFR was 73 % on a per-patient basis and 79 % on a per-vessel basis. Discordant findings were more often seen in older patients and were mainly (19 %) the result of ischaemic SPECT findings in patients with FFR ≥0.75, whereas only 8 % had an abnormal FFR without ischaemia as demonstrated by CZT SPECT. Only 20 - 30 % of patients with intermediate coronary stenoses had significant ischaemia as assessed by CZT SPECT or invasive FFR. CZT SPECT showed a modest degree of concordance with FFR, which is comparable with previous results with conventional SPECT. Further investigations are particularly necessary in patients with normal SPECT and abnormal FFR, especially to determine whether these patients should undergo revascularization. (orig.)

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

International Nuclear Information System (INIS)

Hernandez-Como, N.; Martinez-Landeros, V.; Mejia, I.; Aguirre-Tostado, F.S.; Nascimento, C.D.; Azevedo, G. de M; Krug, C.; Quevedo-Lopez, M.A.

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10 −1 to 10 4 Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10 19 to 10 13 cm −3 and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm 2 /V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10 19 to 10 13 cm −3 . • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied

Thermodynamics of post-growth annealing of cadmium zinc telluride nuclear radiation detectors

Science.gov (United States)

Adams, Aaron Lee

Nuclear Radiation Detectors are used for detecting, tracking, and identifying radioactive materials which emit high-energy gamma and X-rays. The use of Cadmium Zinc Telluride (CdZnTe) detectors is particularly attractive because of the detector's ability to operate at room temperature and measure the energy spectra of gamma-ray sources with a high resolution, typically less than 1% at 662 keV. While CdZnTe detectors are acceptable imperfections in the crystals limit their full market potential. One of the major imperfections are Tellurium inclusions generated during the crystal growth process by the retrograde solubility of Tellurium and Tellurium-rich melt trapped at the growth interface. Tellurium inclusions trap charge carriers generated by gamma and X-ray photons and thus reduce the portion of generated charge carriers that reach the electrodes for collection and conversion into a readable signal which is representative of the ionizing radiation's energy and intensity. One approach in resolving this problem is post-growth annealing which has the potential of removing the Tellurium inclusions and associated impurities. The goal of this project is to use experimental techniques to study the thermodynamics of Tellurium inclusion migration in post-growth annealing of CdZnTe nuclear detectors with the temperature gradient zone migration (TGZM) technique. Systematic experiments will be carried out to provide adequate thermodynamic data that will inform the engineering community of the optimum annealing parameters. Additionally, multivariable correlations that involve the Tellurium diffusion coefficient, annealing parameters, and CdZnTe properties will be analyzed. The experimental approach will involve systematic annealing experiments (in Cd vapor overpressure) on different sizes of CdZnTe crystals at varying temperature gradients ranging from 0 to 60°C/mm (used to migrate the Tellurium inclusion to one side of the crystal), and at annealing temperatures ranging

Electroplating of CdTe Thin Films from Cadmium Sulphate Precursor and Comparison of Layers Grown by 3-Electrode and 2-Electrode Systems

Directory of Open Access Journals (Sweden)

Imyhamy M. Dharmadasa

2017-01-01

Full Text Available Electrodeposition of CdTe thin films was carried out from the late 1970s using the cadmium sulphate precursor. The solar energy group at Sheffield Hallam University has carried out a comprehensive study of CdTe thin films electroplated using cadmium sulfate, cadmium nitrate and cadmium chloride precursors, in order to select the best electrolyte. Some of these results have been published elsewhere, and this manuscript presents the summary of the results obtained on CdTe layers grown from cadmium sulphate precursor. In addition, this research program has been exploring the ways of eliminating the reference electrode, since this is a possible source of detrimental impurities, such as K+ and Ag+ for CdS/CdTe solar cells. This paper compares the results obtained from CdTe layers grown by three-electrode (3E and two-electrode (2E systems for their material properties and performance in CdS/CdTe devices. Thin films were characterized using a wide range of analytical techniques for their structural, morphological, optical and electrical properties. These layers have also been used in device structures; glass/FTO/CdS/CdTe/Au and CdTe from both methods have produced solar cells to date with efficiencies in the region of 5%–13%. Comprehensive work carried out to date produced comparable and superior devices fabricated from materials grown using 2E system.

Modelling of illuminated current–voltage characteristics to evaluate leakage currents in long wavelength infrared mercury cadmium telluride photovoltaic detectors

International Nuclear Information System (INIS)

Gopal, Vishnu; Qiu, WeiCheng; Hu, Weida

2014-01-01

The current–voltage characteristics of long wavelength mercury cadmium telluride infrared detectors have been studied using a recently suggested method for modelling of illuminated photovoltaic detectors. Diodes fabricated on in-house grown arsenic and vacancy doped epitaxial layers were evaluated for their leakage currents. The thermal diffusion, generation–recombination (g-r), and ohmic currents were found as principal components of diode current besides a component of photocurrent due to illumination. In addition, both types of diodes exhibited an excess current component whose growth with the applied bias voltage did not match the expected growth of trap-assisted-tunnelling current. Instead, it was found to be the best described by an exponential function of the type, I excess  = I r0  + K 1 exp (K 2 V), where I r0 , K 1 , and K 2 are fitting parameters and V is the applied bias voltage. A study of the temperature dependence of the diode current components and the excess current provided the useful clues about the source of origin of excess current. It was found that the excess current in diodes fabricated on arsenic doped epitaxial layers has its origin in the source of ohmic shunt currents. Whereas, the source of excess current in diodes fabricated on vacancy doped epitaxial layers appeared to be the avalanche multiplication of photocurrent. The difference in the behaviour of two types of diodes has been attributed to the difference in the quality of epitaxial layers

Metastable Electrical Characteristics of Polycrystalline Thin-Film Photovoltaic Modules upon Exposure and Stabilization: Preprint

Energy Technology Data Exchange (ETDEWEB)

Deline, C. A.; del Cueto, J. A.; Albin, D. S.; Rummel, S. R.

2011-09-01

The significant features of a series of stabilization experiments conducted at the National Renewable Energy Laboratory (NREL) between May 2009 and the present are reported. These experiments evaluated a procedure to stabilize the measured performance of thin-film polycrystalline cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) thin-film photovoltaic (PV) modules. The current-voltage (I-V) characteristics of CdTe and CIGS thin-film PV devices and modules exhibit transitory changes in electrical performance after thermal exposure in the dark and/or bias and light exposures. We present the results of our case studies of module performance versus exposure: light-soaked at 65 degrees C; exposed in the dark under forward bias at 65 degrees C; and, finally, longer-term outdoor exposure. We find that stabilization can be achieved to varying degrees using either light-soaking or dark bias methods and that the existing IEC 61646 light-soaking interval may be appropriate for CdTe and CIGS modules with one caveat: it is likely that at least three exposure intervals are required for stabilization.

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Martinez-Landeros, V. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Mejia, I. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Nascimento, C.D.; Azevedo, G. de M; Krug, C. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91509-900 (Brazil); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States)

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10{sup −1} to 10{sup 4} Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10{sup 19} to 10{sup 13} cm{sup −3} and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm{sup 2}/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10{sup 19} to 10{sup 13} cm{sup −3}. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied.

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

Directory of Open Access Journals (Sweden)

Claudio Davet Gutiérrez-Lazos

2014-06-01

Full Text Available This work presents results of the optical and structural characterization of oleic acid-stabilized cadmium telluride nanocrystals (CdTe-NC synthesized by an organometallic route. After being cleaned, the CdTe-NC were dispersed in toluene to obtain an ink-like dispersion, which was drop-cast on glass substrate to deposit a thin film. The CdTe-NC colloidal dispersion as well as the CdTe drop-cast thin films were characterized with regard to the optical and structural properties. TEM analysis indicates that the CdTe-NC have a nearly spherical shape (3.5 nm as mean size. Electron diffraction and XRD diffraction analyses indicated the bulk-CdTe face-centered cubic structure for CdTe-NC. An additional diffraction line corresponding to the octahedral Cd3P2 was also detected as a secondary phase, which probably originates by reacting free cadmium ions with trioctylphosphine (the tellurium reducing agent. The Raman spectrum exhibits two broad bands centered at 141.6 and 162.3 cm−1, which could be associated to the TO and LO modes of cubic CdTe nanocrystals, respectively. Additional peaks located in the 222 to 324 cm−1 range, agree fairly well with the wavenumbers reported for TO modes of octahedral Cd3P2.

Physical vapor deposition of CdTe thin films at low temperature for solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Heisler, Christoph; Brueckner, Michael; Lind, Felix; Kraft, Christian; Reisloehner, Udo; Ronning, Carsten; Wesch, Werner [Institute of Solid State Physics, University of Jena, Max-Wien-Platz 1, D-07743 Jena (Germany)

2012-07-01

Cadmium telluride is successfully utilized as an absorber material for thin film solar cells. Industrial production makes use of high substrate temperatures for the deposition of CdTe absorber layers. However, in order to exploit flexible substrates and to simplify the manufacturing process, lower deposition temperatures are beneficial. Based on the phase diagram of CdTe, predictions on the stoichiometry of CdTe thin films grown at low substrate temperatures are made in this work. These predictions were verified experimentally using additional sources of Cd and Te during the deposition of the CdTe thin films at different substrate temperatures. The deposited layers were analyzed with energy-dispersive X-ray spectroscopy. In case of CdTe layers which were deposited at substrate temperatures lower than 200 C without usage of additional sources we found a non-stoichiometric growth of the CdTe layers. The application of the additional sources leads to a stoichiometric growth for substrate temperatures down to 100 C which is a significant reduction of the substrate temperature during deposition.

Inhibition of autophagy contributes to the toxicity of cadmium telluride quantum dots in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Fan J

2016-07-01

Full Text Available Junpeng Fan,1–4 Ming Shao,1–4 Lu Lai,3–5 Yi Liu,3–5 Zhixiong Xie1–4,6 1College of Life Sciences, Wuhan University, 2Hubei Provincial Cooperative Innovation Center of Industrial Fermentation,3State Key Laboratory of Virology, 4Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE, 5College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 6School of Life Science and Technology, Hubei Engineering University, Xiaogan, People’s Republic of China Abstract: Cadmium telluride quantum dots (CdTe QDs are used as near-infrared probes in biologic and medical applications, but their cytological effects and mechanism of potential toxicity are still unclear. In this study, we evaluated the toxicity of CdTe QDs of different sizes and investigated their mechanism of toxicity in the yeast Saccharomyces cerevisiae. A growth inhibition assay revealed that orange-emitting CdTe (O-CdTe QDs (half inhibitory concentration [IC50] =59.44±12.02 nmol/L were more toxic than green-emitting CdTe QDs (IC50 =186.61±19.74 nmol/L to S. cerevisiae. Further studies on toxicity mechanisms using a transmission electron microscope and green fluorescent protein tagged Atg8 processing assay revealed that O-CdTe QDs could partially inhibit autophagy at a late stage, which differs from the results reported in mammalian cells. Moreover, autophagy inhibited at a late stage by O-CdTe QDs could be partially recovered by enhancing autophagy with rapamycin (an autophagy activator, combined with an increased number of living cells. These results indicate that inhibition of autophagy acts as a toxicity mechanism of CdTe QDs in S. cerevisiae. This work reports a novel toxicity mechanism of CdTe QDs in yeast and provides valuable information on the effect of CdTe QDs on the processes of living cells. Keywords: CdTe quantum dots, Saccharomyces cerevisiae, toxicity, autophagy

Structural, optical, photoluminescence, dielectric and electrical ...

Indian Academy of Sciences (India)

The optical band gap of thin films was found to allow direct tran- sition with energy ... Cadmium telluride (CdTe) is an important group II–VI semi- ... Extensive research was done in the last two decades on CdTe ... 3.1 X-ray diffraction analysis.

Optoelectronic properties of cadmium sulfide thin films deposited by thermal evaporation technique

International Nuclear Information System (INIS)

Ali, N.; Iqbal, M.A.; Hussain, S.T.; Waris, M.; Munair, S.A.

2011-01-01

The substrate temperature in depositions of thin films plays a vital role in the characteristics of deposited films. We studied few characteristics of cadmium sulphide thin film deposited at different temperature (150 deg. C- 300 deg. C) on corning 7059 glass substrate. We measured transmittance, absorbance, band gap and reflectance via UV spectroscopy. It was found that the transmittance for 300 nm to 1100 nm was greater than 80%. The resistivity and mobility was calculated by Vander Pauw method which were 10-80 cm and 2-60 cm/sup 2/V/sup -1/S/sup -1/ respectively. The thermoelectric properties of the film were measured by hot and cold probe method which shows the N-type nature of the film. (author)

Long-Wave Infrared (LWIR) Molecular Laser-Induced Breakdown Spectroscopy (LIBS) Emissions of Thin Solid Explosive Powder Films Deposited on Aluminum Substrates.

Science.gov (United States)

Yang, Clayton S-C; Jin, Feng; Trivedi, Sudhir B; Brown, Ei E; Hommerich, Uwe; Tripathi, Ashish; Samuels, Alan C

2017-04-01

Thin solid films made of high nitro (NO 2 )/nitrate (NO 3 ) content explosives were deposited on sand-blasted aluminum substrates and then studied using a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared region (LWIR; ∼5.6-10 µm). Despite the similarities of their chemical compositions and structures, thin films of three commonly used explosives (RDX, HMX, and PETN) studied in this work can be rapidly identified in the ambient air by their molecular LIBS emission signatures in the LWIR region. A preliminary assessment of the detection limit for a thin film of RDX on aluminum appears to be much lower than 60 µg/cm 2 . This LWIR LIBS setup is capable of rapidly probing and charactering samples without the need for elaborate sample preparation and also offers the possibility of a simultaneous ultraviolet visible and LWIR LIBS measurement.

Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

Science.gov (United States)

Choudhary, Ritika; Chauhan, Rishi Pal

2017-07-01

The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

Health, safety and environmental risks from the operation of CdTe and CIS thin-film modules

International Nuclear Information System (INIS)

Steinberger, Hartmut

1998-01-01

This paper identifies the materials embedded in on a type of CIS (Copper indium diselenide) and four different types of CdTe (cadmium telluride) thin-film modules. It refers to the results of our outdoor leaching experiments on photovoltaic (PV) samples broken into small fragments. Estimations for modules accidents on the roof or in the garden of a residential house, e.g. leaching of hazardous materials into water or soil, are given. The outcomes of our estimations show some module materials released into water or oil during leaching accidents. In a worst-case scenario for CdTe modules the leached cadmium concentration in the collected water is estimated to be no higher than the German drinking water limit concentration. For the CIS module scenario the estimated leached element concentrations are about one to two orders of magnitude below the German drinking water limit concentration. For broken CIS and CdTe modules on the ground no critical increase of the natural element concentration is observed after leaching into the soil for 1 year. (Author)

Bulletin of Materials Science | News

Indian Academy of Sciences (India)

Effect of heat treatment on tensile behaviour of Ti–6Al–5Zr–0.5Mo–0.25Si alloy ... Microstructural characterization in diffusion bonded TiC–Al2O3/Cr18–Ni8 joint with ... Characterization of nanocrystalline cadmium telluride thin films grown by ...

Advanced Processing of CdTe- and CuInxGa1-xSe2-Based Solar Cells: Final Report: 18 April 1995 - 31 May 1998

International Nuclear Information System (INIS)

Jayapalan, A.; Tetali, B.; Ferekides, C.S.; Marinskiy, D.; Morel, D.L.; Lin, H.; Sankaranarayanan, H.; Bhatt, R.; Narayanaswamy, R.; Prabhakaran, R.; Marinskaya, S.; Zafar, S.

1999-01-01

This report summarizes work performed by the University of South Florida Department of Electrical Engineering under this subcontract. The Cadmium telluride(CdTe) portion of this project deals with the development of high-efficiency thin-filmed CdTe solar cells using fabrication techniques that are suitable for manufacturing environments

Cadmium sulfide thin films growth by chemical bath deposition

Science.gov (United States)

Hariech, S.; Aida, M. S.; Bougdira, J.; Belmahi, M.; Medjahdi, G.; Genève, D.; Attaf, N.; Rinnert, H.

2018-03-01

Cadmium sulfide (CdS) thin films have been prepared by a simple technique such as chemical bath deposition (CBD). A set of samples CdS were deposited on glass substrates by varying the bath temperature from 55 to 75 °C at fixed deposition time (25 min) in order to investigate the effect of deposition temperature on CdS films physical properties. The determination of growth activation energy suggests that at low temperature CdS film growth is governed by the release of Cd2+ ions in the solution. The structural characterization indicated that the CdS films structure is cubic or hexagonal with preferential orientation along the direction (111) or (002), respectively. The optical characterization indicated that the films have a fairly high transparency, which varies between 55% and 80% in the visible range of the optical spectrum, the refractive index varies from 1.85 to 2.5 and the optical gap value of which can reach 2.2 eV. It can be suggested that these properties make these films perfectly suitable for their use as window film in thin films based solar cells.

Cadmium Manganese Telluride (Cd1-xMnxTe): A potential material for room-temperature radiation detectors

Energy Technology Data Exchange (ETDEWEB)

Hossain, A.; Cui, Y.; Bolotnikov, A.; Camarda, G.; Yang, G.; Kim, K-H.; Gul, R.; Xu, L.; Li, L.; Mycielski, A.; and James, R.B.

2010-07-11

Cadmium Manganese Telluride (CdMnTe) recently emerged as a promising material for room-temperature X- and gamma-ray detectors. It offers several potential advantages over CdZnTe. Among them is its optimal tunable band gap ranging from 1.7-2.2 eV, and its relatively low (< 50%) content of Mn compared to that of Zn in CdZnTe that assures this favorable band-gap range. Another important asset is the segregation coefficient of Mn in CdTe that is approximately unity compared to 1.35 for Zn in CdZnTe, so ensuring the homogenous distribution of Mn throughout the ingot; hence, a large-volume stoichiometric yield is attained. However, some materials issues primarily related to the growth process impede the production of large, defect-free single crystals. The high bond-ionicity of CdMnTe entails a higher propensity to crystallize into a hexagonal structure rather than to adopt the expected zinc-blend structure, which is likely to generate twins in the crystals. In addition, bulk defects generate in the as-grown crystals due to the dearth of high-purity Mn, which yields a low-resistivity material. In this presentation, we report on our observations of such material defects in current CdMnTe materials, and our evaluation of its potential as an alternative detector material to the well-known CdZnTe detectors. We characterized the bulk defects of several indium- and vanadium-doped Cd1-xMnxTe crystals by using several advanced techniques, viz., micro-scale mapping, white-beam x-ray diffraction/reflection topography, and chemical etching. Thereafter, we fabricated some detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results indicate that CdMnTe materials could well prove to become a viable alternative in the near future.

Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols

International Nuclear Information System (INIS)

Verger, Antoine; Karcher, Gilles; Djaballah, Wassila; Fourquet, Nicolas; Rouzet, Francois; Le Guludec, Dominique; Koehl, Gregoire; Roch, Veronique; Imbert, Laetitia; Poussier, Sylvain; Fay, Renaud; Marie, Pierre-Yves

2013-01-01

The results of stress myocardial perfusion SPECT could be enhanced by new cadmium-zinc-telluride (CZT) cameras, although differences compared to the results with conventional Anger cameras remain poorly known for most study protocols. This study was aimed at comparing the results of CZT and Anger SPECT according to various study protocols while taking into account the influence of obesity. The study population, which was from three different institutions equipped with identical CZT cameras, comprised 276 patients referred for study using protocols involving 201 Tl (n = 120) or 99m Tc-sestamibi injected at low dose at stress ( 99m Tc-Low; stress/rest 1-day protocol; n = 110) or at high dose at stress ( 99m Tc-High; rest/stress 1-day or 2-day protocol; n = 46). Each Anger SPECT scan was followed by a high-speed CZT SPECT scan (2 to 4 min). Agreement rates between CZT and Anger SPECT were good irrespective of the study protocol (for abnormal SPECT, 201 Tl 92 %, 99m Tc-Low 86 %, 99m Tc-High 98 %), although quality scores were much higher for CZT SPECT with all study protocols. Overall correlations were high for the extent of myocardial infarction (r = 0.80) and a little lower for ischaemic areas (r = 0.72), the latter being larger on Anger SPECT (p 201 Tl or 99m Tc-Low group and in whom stress myocardial counts were particularly low with Anger SPECT (228 ± 101 kcounts) and dramatically enhanced with CZT SPECT (+279 ± 251 %). Concordance between the results of CZT and Anger SPECT is good regardless of study protocol and especially when excluding obese patients who have low-count Anger SPECT and for whom myocardial counts are dramatically enhanced on CZT SPECT. (orig.)

Study on analytical modelling approaches to the performance of thin film PV modules in sunny inland climates

International Nuclear Information System (INIS)

Torres-Ramírez, M.; Nofuentes, G.; Silva, J.P.; Silvestre, S.; Muñoz, J.V.

2014-01-01

This work is aimed at verifying that analytical modelling approaches may provide an estimation of the outdoor performance of TF (thin film) PV (photovoltaic) technologies in inland sites with sunny climates with adequate accuracy for engineering purposes. Osterwald's and constant fill factor methods were tried to model the maximum power delivered and the annual energy produced by PV modules corresponding to four TF PV technologies. Only calibrated electrical parameters at STC (standard test conditions), on-plane global irradiance and module temperature are required as inputs. A 12-month experimental campaign carried out in Madrid and Jaén (Spain) provided the necessary data. Modelled maximum power and annual energy values obtained through both methods were statistically compared to the experimental ones. In power terms, the RMSE (root mean square error) stays below 3.8% and 4.5% for CdTe (cadmium telluride) and CIGS (copper indium gallium selenide sulfide) PV modules, respectively, while RMSE exceeds 5.4% for a-Si (amorphous silicon) or a-Si:H/μc-Si PV modules. Regarding energy terms, errors lie below 4.0% in all cases. Thus, the methods tried may be used to model the outdoor behaviour of the a-Si, a-Si:H/μc-Si, CIGS and CdTe PV modules tested – ordered from the lowest to the highest accuracy obtained – in sites with similar spectral characteristics to those of the two sites considered. - Highlights: • Simple analytical methods to model the outdoor behaviour of thin film PV (photovoltaic) technologies. • 8 PV modules were deployed outdoors over a 12-month period in two sunny inland sites. • RMSE (root mean square error) values stay below 3.8% and 4.5% in CdTe (cadmium telluride) and CIGS (copper indium gallium selenide sulfide) PV modules. • Errors remain below 4.0% for all the PV modules and sites in energy terms. • Simple methods: suitable estimation of PV outdoor behaviour for engineering purposes

Structural, Optical, and Morphological Properties of the Cadmium Oxide Thin Film Taif S. Almaadhede

Directory of Open Access Journals (Sweden)

Taif S. Almaadhede

2018-04-01

Full Text Available Cadmium oxide nanoparticles CdO NPS has been prepared by laser ablation in ethanol at 600 pulses and 600 mJ as laser energy. The structural, optical, and morphological properties of the cadmium oxide CdO thin film deposited on a glass substrate have been studied. X-ray diffrac-tometer (XRD 6000, Shimadzu, X-ray, diffractometer with Cukα radiation at a wavelength of ( = 0.154056 nm was utilized to investigate the structural properties of CdO NPs. The optical absorption of colloidal CdO NPs was measured using a spectrophotometer (Cary, 100 cans plus, UV-Vis-NIR, Split Beam Optics, Dual detectors in the range of (200–900 nm. The morpholo-gy of the CdO NPs was investigated by using AFM (AA 3000 Scanning Probe Microscope. The thickness of the films was measured using ellipsometer (Angstrom sun Technologies Ins.

Mercury telluride as a zero-gap semiconductor

International Nuclear Information System (INIS)

Berchenko, N.N.; Pashkovskij, M.V.

1976-01-01

The paper presents a review of main properties of mercury telluride which is a representative of a new class of substances - gapless semiconductors. The causes leading to the appearance of a gapless state in mercury chalcogenides are considered; it is demonstrated that the main role in the formation of the inverse band structure belongs to relativistic corrections. The specific properties of mercury telluride are associated with the zero forbidden band, p-like nature of electron states of the conduction band and its nonparabolicity, resonance states of impurities and anomalies of dielectric permittivity. Conditions of forbidden band appearing in mercury telluride under the effect external factors are analyzed

Preparation and study of the properties of indium phosphide thin films impregnated with cadmium and zinc

International Nuclear Information System (INIS)

Moutinho, H.R.

1984-01-01

Indium phosphide thin films were deposited by vacuum evaporation of indium and phosphorous, using the three-temperature method. The effects of the introduction of cadmium and zinc, group II impurities, on the properties of these films were studied. The introduction of cadmium was achieved by coevaporation of this element during the film deposition. The introduction of zinc was done by diffusion of this element in intrinsic films. Analyses of these films were carried out by the study of the composition, morphology, structure, optical properties and electrical properties. The introduction of cadmium led to the reduction of grain size and increase in the bandgap and in certain cases, even change in morphology. Phases of CdP2 and β-CdP2 were detected and the resistivity increased by some orders of magnitude. The introduction of zinc did not change the morphology, crystalline structure and bandgap. However, a new energy level corresponding to the zinc acceptor level was found and the resistivity increased by some orders of magnitude. (Author) [pt

Selective and low temperature transition metal intercalation in layered tellurides

Science.gov (United States)

Yajima, Takeshi; Koshiko, Masaki; Zhang, Yaoqing; Oguchi, Tamio; Yu, Wen; Kato, Daichi; Kobayashi, Yoji; Orikasa, Yuki; Yamamoto, Takafumi; Uchimoto, Yoshiharu; Green, Mark A.; Kageyama, Hiroshi

2016-01-01

Layered materials embrace rich intercalation reactions to accommodate high concentrations of foreign species within their structures, and find many applications spanning from energy storage, ion exchange to secondary batteries. Light alkali metals are generally most easily intercalated due to their light mass, high charge/volume ratio and in many cases strong reducing properties. An evolving area of materials chemistry, however, is to capture metals selectively, which is of technological and environmental significance but rather unexplored. Here we show that the layered telluride T2PTe2 (T=Ti, Zr) displays exclusive insertion of transition metals (for example, Cd, Zn) as opposed to alkali cations, with tetrahedral coordination preference to tellurium. Interestingly, the intercalation reactions proceed in solid state and at surprisingly low temperatures (for example, 80 °C for cadmium in Ti2PTe2). The current method of controlling selectivity provides opportunities in the search for new materials for various applications that used to be possible only in a liquid. PMID:27966540

Preparation and characterization of ZnTe thin films by SILAR method

International Nuclear Information System (INIS)

Kale, S.S.; Mane, R.S.; Pathan, H.M.; Shaikh, A.V.; Joo, Oh-Shim; Han, Sung-Hwan

2007-01-01

Nanocrystalline zinc telluride (ZnTe) thin films were prepared by using successive ionic layer adsorption and reaction (SILAR) method from aqueous solutions of zinc sulfate and sodium telluride. The films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques. The synthesized ZnTe thin films were nanocrystalline with densely aggregated particles in nanometer scale and were free from the voids or cracks. The optical band gap energy of the film was found to be thickness dependent. The elemental chemical compositional stoichiometric analysis revealed good Zn:Te elemental ratio of 53:47

Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiupei, E-mail: xiupeiyang@163.com [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, Nanchong 637000 (China); College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China); Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan [College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China)

2015-06-15

Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH{sub 3}{sup +} moiety of doxorubicin and the −COO{sup −} moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum.

Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

International Nuclear Information System (INIS)

Yang, Xiupei; Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan

2015-01-01

Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH 3 + moiety of doxorubicin and the −COO − moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum

Occurency and aqueous processing of tellurides from Sonora (Mexico)

International Nuclear Information System (INIS)

Aguayo, S.; Perez, E.; Ecinas, M.A.

1996-01-01

Tellurium production is limited mainly to that obtained from the treatment of electrolyte muds from copper refineries. however, there are several other sources from which the precious metal tellurides are potentially attractive. This work presents a review of the main localitiesin Sonora (Mexico), where tellurides have been found. In addition, based upon the physical chemistry fundamentals for tellurium and precious metal tellurides, the aqueous extraction and recovery routes are discussed. (Author) 51 refs

Structural, electrical and optical studies of SILAR deposited cadmium oxide thin films: Annealing effect

International Nuclear Information System (INIS)

Salunkhe, R.R.; Dhawale, D.S.; Gujar, T.P.; Lokhande, C.D.

2009-01-01

Successive ionic layer adsorption and reaction (SILAR) method has been successfully employed for the deposition of cadmium oxide (CdO) thin films. The films were annealed at 623 K for 2 h in an air and changes in the structural, electrical and optical properties were studied. From the X-ray diffraction patterns, it was found that after annealing, H 2 O vapors from as-deposited Cd(O 2 ) 0.88 (OH) 0.24 were removed and pure cubic cadmium oxide was obtained. The as-deposited film consists of nanocrystalline grains of average diameter about 20-30 nm with uniform coverage of the substrate surface, whereas for the annealed film randomly oriented morphology with slight increase in the crystallite size has been observed. The electrical resistivity showed the semiconducting nature with room temperature electrical resistivity decreased from 10 -2 to 10 -3 Ω cm after annealing. The decrease in the band gap energy from 3.3 to 2.7 eV was observed after the annealing

The digital structural analysis of cadmium selenide crystals by a method of ion beam thinning for high resolution electron microscopy

International Nuclear Information System (INIS)

Kanaya, Koichi; Baba, Norio; Naka, Michiaki; Kitagawa, Yukihisa; Suzuki, Kunio

1986-01-01

A digital processing method using a scanning densitometer system for structural analysis of electron micrographs was successfully applied to a study of cadmium selenide crystals, which were prepared by an argon-ion beam thinning method. Based on Fourier techniques for structural analysis from a computer-generated diffractogram, it was demonstrated that when cadmium selenide crystals were sufficiently thin to display the higher order diffraction spots at a high resolution approaching the atomic level, they constitute an alternative hexagonal lattice of imperfect wurtzite phase from a superposition of individual harmonic images by the enhanced scattering amplitude and corrected phase. From the structural analysis data, a Fourier synthetic lattice image was reconstructed, representing the precise location and three-dimensional arrangement of each of the atoms in the unit cell. Extensively enhanced lattice defect images of dislocations and stacking faults were also derived and shown graphically. (author)

Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols

Energy Technology Data Exchange (ETDEWEB)

Verger, Antoine; Karcher, Gilles [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Djaballah, Wassila [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Fourquet, Nicolas [Clinique Pasteur, Toulouse (France); Rouzet, Francois; Le Guludec, Dominique [AP-HP, Hopital Bichat, Department of Nuclear Medicine, Paris (France); INSERM U 773 Inserm and Denis Diderot University, Paris (France); Koehl, Gregoire; Roch, Veronique [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Imbert, Laetitia [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Centre Alexis Vautrin, Department of Radiotherapy, Vandoeuvre (France); Poussier, Sylvain [INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Fay, Renaud [INSERM, Centre d' Investigation Clinique CIC-P 9501, Nancy (France); Marie, Pierre-Yves [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); INSERM U961, Nancy (France); Hopital de Brabois, CHU-Nancy, Medecine Nucleaire, Vandoeuvre-les-Nancy (France)

2013-03-15

The results of stress myocardial perfusion SPECT could be enhanced by new cadmium-zinc-telluride (CZT) cameras, although differences compared to the results with conventional Anger cameras remain poorly known for most study protocols. This study was aimed at comparing the results of CZT and Anger SPECT according to various study protocols while taking into account the influence of obesity. The study population, which was from three different institutions equipped with identical CZT cameras, comprised 276 patients referred for study using protocols involving {sup 201}Tl (n = 120) or {sup 99m}Tc-sestamibi injected at low dose at stress ({sup 99m}Tc-Low; stress/rest 1-day protocol; n = 110) or at high dose at stress ({sup 99m}Tc-High; rest/stress 1-day or 2-day protocol; n = 46). Each Anger SPECT scan was followed by a high-speed CZT SPECT scan (2 to 4 min). Agreement rates between CZT and Anger SPECT were good irrespective of the study protocol (for abnormal SPECT, {sup 201}Tl 92 %, {sup 99m}Tc-Low 86 %, {sup 99m}Tc-High 98 %), although quality scores were much higher for CZT SPECT with all study protocols. Overall correlations were high for the extent of myocardial infarction (r = 0.80) and a little lower for ischaemic areas (r = 0.72), the latter being larger on Anger SPECT (p < 0.001). This larger extent was mainly observed in 50 obese patients who were in the {sup 201}Tl or {sup 99m}Tc-Low group and in whom stress myocardial counts were particularly low with Anger SPECT (228 {+-} 101 kcounts) and dramatically enhanced with CZT SPECT (+279 {+-} 251 %). Concordance between the results of CZT and Anger SPECT is good regardless of study protocol and especially when excluding obese patients who have low-count Anger SPECT and for whom myocardial counts are dramatically enhanced on CZT SPECT. (orig.)

Diagnostic Performance of a Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography System With Low-Dose Technetium-99m as Assessed by Fractional Flow Reserve.

Science.gov (United States)

Chikamori, Taishiro; Hida, Satoshi; Tanaka, Nobuhiro; Igarashi, Yuko; Yamashita, Jun; Shiba, Chie; Murata, Naotaka; Hoshino, Kou; Hokama, Yohei; Yamashina, Akira

2016-04-25

Although stress single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride (CZT) camera facilitates radiation dose reduction, only a few studies have evaluated its diagnostic accuracy in Japanese patients by applying fractional flow reserve (FFR) measurements. We prospectively evaluated 102 consecutive patients with suspected or known coronary artery disease with a low-dose stress/rest protocol ((99m)Tc radiotracer 185/370 MBq) using CZT SPECT. Within 3 months, coronary angiography was performed and a significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or as a lesion of <90% and ≥ 50% stenosis with FFR ≤0.80. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 86%, 75%, and 82% for left anterior descending artery stenosis, 76%, 81%, and 79% for left circumflex artery stenosis, and 87%, 92%, and 90% for right coronary artery stenosis. When limited to 92 intermediate stenotic lesions in which FFR was measured, stress SPECT showed 77% sensitivity, 91% specificity, and 84% accuracy, whereas the diagnostic value decreased to 52% sensitivity, 68% specificity, and 58% accuracy based only on visual estimation of ≥75% diameter narrowing. CZT SPECT demonstrated a good diagnostic yield in detecting hemodynamically significant coronary stenoses as assessed by FFR, even when using a low-dose (99m)Tc protocol with an effective dose ≤5 mSv. (Circ J 2016; 80: 1217-1224).

About thermo-electric properties of bismuth telluride doped by gadolinium

International Nuclear Information System (INIS)

Akperov, M.M.; Ismailov, Sh.S.; Shukyurova, A.A.

2004-01-01

Results of study of the Gd impurities effect on the bismuth telluride thermo-electric properties are presented. The experiment was carried out within the temperature range T=300-700 K. It is determined, that at temperature increase the energy level is appreciably closing up to bismuth telluride forbidden zone which makes up 0.16-0.24 eV. Such anomalous energy properties of gadolinium in telluride affect on material thermoelectric properties

Studies on focal alveolar bone healing with technetium (Tc)-99m labeled methylene diphosphonate and gold-collimated cadmium telluride probe

International Nuclear Information System (INIS)

Tsuchimochi, M.; Hosain, F.; Engelke, W.; Zeichner, S.J.; Ruttimann, U.E.; Webber, R.L.

1991-01-01

The benefit of using a collimator for a miniaturized cadmium telluride probe was evaluated by monitoring the bone-healing processes for 13 weeks after the induction of small iatrogenic alveolar bone lesions in one side of the mandible in beagles. Technetium (Tc)-99m labeled methylene diphosphonate (200 to 300 MBq, 5.1 to 8.1 mCi, in a solution of 0.5 to 1 ml, intravenously) was used as a bone-seeking radiopharmaceutical. The radioactivity over the bone lesion (L) and the contralateral normal site (C) in the mandible were measured between 1.5 and 2 hours after injection of the tracer, and the activity ratio L/C served as an index of relative bone uptake. A study of six dogs revealed that the healing response to a hemispheric bone defect of 2 mm diameter in the cortical bone could not be detected by an uncollimated probe, and in a repeated study in two dogs the use of a gold collimator (5 mm in diameter, 5 mm in length) did not increase the L/C ratio significantly. A second study in six dogs with 5 mm lesions showed that although systematic trends in the time courses of the L/C ratio obtained both with and without the collimator could be demonstrated, the L/C ratio of collimated versus uncollimated measurements was significantly (p less than 0.005) increased. In three of the latter six dogs, abscesses developed after 9 weeks, leading to a second increase (p less than 0.05) of the L/C ratio with collimation compared with the noninflammation group; without collimation no significant (p greater than 0.15) difference between the two groups could be demonstrated

Photosensitive space charge limited current in screen printed CdTe thin films

Science.gov (United States)

Vyas, C. U.; Pataniya, Pratik; Zankat, Chetan K.; Patel, Alkesh B.; Pathak, V. M.; Patel, K. D.; Solanki, G. K.

2018-05-01

Group II-VI Compounds have emerged out as most suitable in the class of photo sensitive material. They represent a strong position in terms of their applications in the field of detectors as well as photo voltaic devices. Cadmium telluride is the prime member of this Group, because of high acceptance of this material as active component in opto-electronic devices. In this paper we report preparation and characterization of CdTe thin films by using a most economical screen printing technique in association with sintering at 510°C temperature. Surface morphology and smoothness are prime parameters of any deposited to be used as an active region of devices. Thus, we studied of the screen printed thin film by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM) for this purpose. However, growth processes induced intrinsic defects in fabricated films work as charge traps and affect the conduction process significantly. So the conduction mechanism of deposited CdTe thin film is studied under dark as well as illuminated conditions. It is found that the deposited films showed the space charge limited conduction (SCLC) mechanism and hence various parameters of space charge limited conduction (SCLC) of CdTe film were evaluated and discussed and the photo responsive resistance is also presented in this paper.

Thermodynamics of gallium arsenide electrodeposition

International Nuclear Information System (INIS)

Perrault, G.G.

1986-01-01

Gallium Arsenide is well known as a very interesting compound for photoelectrical devices. Up to now, it has been prepared mostly by high temperature technology, and the authors considered that it might be of interest to set up an electrodeposition technique suitable to prepare thin layers of this compound. A reaction sequence similar to the one observed for Cadmium Sulfide or Cadmium Telluride could be considered. In these cases, the metal chalcogenide is obtained from the precipitation of the metal ions dissolved in the solutions by the reduction product of the metalloidic compound

Design study of a high-resolution breast-dedicated PET system built from cadmium zinc telluride detectors

International Nuclear Information System (INIS)

Peng Hao; Levin, Craig S

2010-01-01

We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The proposed system consists of two 4 cm thick 12 x 15 cm 2 area cadmium zinc telluride (CZT) panels with adjustable separation, which can be put in close proximity to the breast and/or axillary nodes. Unique characteristics distinguishing the proposed system from previous efforts in breast-dedicated PET instrumentation are the deployment of CZT detectors with superior spatial and energy resolution, using a cross-strip electrode readout scheme to enable 3D positioning of individual photon interaction coordinates in the CZT, which includes directly measured photon depth-of-interaction (DOI), and arranging the detector slabs edge-on with respect to incoming 511 keV photons for high photon sensitivity. The simulation results show that the proposed CZT dual-panel PET system is able to achieve superior performance in terms of photon sensitivity, noise equivalent count rate, spatial resolution and lesion visualization. The proposed system is expected to achieve ∼32% photon sensitivity for a point source at the center and a 4 cm panel separation. For a simplified breast phantom adjacent to heart and torso compartments, the peak noise equivalent count (NEC) rate is predicted to be ∼94.2 kcts s -1 (breast volume: 720 cm 3 and activity concentration: 3.7 kBq cm -3 ) for a ∼10% energy window around 511 keV and ∼8 ns coincidence time window. The system achieves 1 mm intrinsic spatial resolution anywhere between the two panels with a 4 cm panel separation if the detectors have DOI resolution less than 2 mm. For a 3 mm DOI resolution, the system exhibits excellent sphere resolution uniformity (σ rms /mean) ≤ 10%) across a 4 cm width FOV. Simulation results indicate that the system exhibits superior hot sphere visualization and is expected to visualize 2 mm diameter spheres with a 5:1 activity concentration ratio within

Fractal features of CdTe thin films grown by RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Hosseinpanahi, Fayegh, E-mail: f.hosseinpanahi@yahoo.com [Department of Physics, Payame Noor University, P.O. Box 19395-4697, Tehran (Iran, Islamic Republic of); Raoufi, Davood [Department of Physics, University of Bu Ali Sina, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Ranjbarghanei, Khadijeh [Department of Physics, Plasma Physics Research Center, Science & Research Branch Islamic Azad University, Tehran (Iran, Islamic Republic of); Karimi, Bayan [Department of Physics, Payame Noor University, P.O. Box 19395-4697, Tehran (Iran, Islamic Republic of); Babaei, Reza [Department of Physics, Plasma Physics Research Center, Science & Research Branch Islamic Azad University, Tehran (Iran, Islamic Republic of); Hasani, Ebrahim [Department of Physics, University of Bu Ali Sina, P.O. Box 65174, Hamedan (Iran, Islamic Republic of)

2015-12-01

Graphical abstract: - Highlights: • CdTe thin films were deposited on glass substrates by RF magnetron sputtering at room temperature with different deposition time 5, 10 and 15 min. • Nanostructure of CdTe layer indicates that CdTe films are polycrystalline and have zinc blende structure, irrespective of their deposition time. • Complexity and roughness of the CdTe films and strength of multifractality increase with increasing deposition time. • Detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe films have multifractal nature. - Abstract: Cadmium telluride (CdTe) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature (RT). The film deposition was performed for 5, 10, and 15 min at power of 30 W with a frequency of 13.56 MHz. The crystal structure of the prepared CdTe thin films was studied by X-ray diffraction (XRD) technique. XRD analyses indicate that the CdTe films are polycrystalline, having zinc blende structure of CdTe irrespective of their deposition time. All CdTe films showed a preferred orientation along (1 1 1) crystalline plane. The surface morphology characterization of the films was studied using atomic force microscopy (AFM). The quantitative AFM characterization shows that the RMS surface roughness of the prepared CdTe thin films increases with increasing the deposition time. The detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe thin films have multifractal nature. The complexity, roughness of the CdTe thin films and strength of the multifractality increase as deposition time increases.

Fractal features of CdTe thin films grown by RF magnetron sputtering

International Nuclear Information System (INIS)

Hosseinpanahi, Fayegh; Raoufi, Davood; Ranjbarghanei, Khadijeh; Karimi, Bayan; Babaei, Reza; Hasani, Ebrahim

2015-01-01

Graphical abstract: - Highlights: • CdTe thin films were deposited on glass substrates by RF magnetron sputtering at room temperature with different deposition time 5, 10 and 15 min. • Nanostructure of CdTe layer indicates that CdTe films are polycrystalline and have zinc blende structure, irrespective of their deposition time. • Complexity and roughness of the CdTe films and strength of multifractality increase with increasing deposition time. • Detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe films have multifractal nature. - Abstract: Cadmium telluride (CdTe) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature (RT). The film deposition was performed for 5, 10, and 15 min at power of 30 W with a frequency of 13.56 MHz. The crystal structure of the prepared CdTe thin films was studied by X-ray diffraction (XRD) technique. XRD analyses indicate that the CdTe films are polycrystalline, having zinc blende structure of CdTe irrespective of their deposition time. All CdTe films showed a preferred orientation along (1 1 1) crystalline plane. The surface morphology characterization of the films was studied using atomic force microscopy (AFM). The quantitative AFM characterization shows that the RMS surface roughness of the prepared CdTe thin films increases with increasing the deposition time. The detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe thin films have multifractal nature. The complexity, roughness of the CdTe thin films and strength of the multifractality increase as deposition time increases.

Demonstration of iodine K-edge imaging by use of an energy-discrimination X-ray computed tomography system with a cadmium telluride detector.

Science.gov (United States)

Abudurexiti, Abulajiang; Kameda, Masashi; Sato, Eiichi; Abderyim, Purkhet; Enomoto, Toshiyuki; Watanabe, Manabu; Hitomi, Keitaro; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Takahashi, Kiyomi; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2010-07-01

An energy-discrimination K-edge X-ray computed tomography (CT) system is useful for increasing the contrast resolution of a target region by utilizing contrast media. The CT system has a cadmium telluride (CdTe) detector, and a projection curve is obtained by linear scanning with use of the CdTe detector in conjunction with an X-stage. An object is rotated by a rotation step angle with use of a turntable between the linear scans. Thus, CT is carried out by repetition of the linear scanning and the rotation of an object. Penetrating X-ray photons from the object are detected by the CdTe detector, and event signals of X-ray photons are produced with use of charge-sensitive and shaping amplifiers. Both the photon energy and the energy width are selected by use of a multi-channel analyzer, and the number of photons is counted by a counter card. For performing energy discrimination, a low-dose-rate X-ray generator for photon counting was developed; the maximum tube voltage and the minimum tube current were 110 kV and 1.0 microA, respectively. In energy-discrimination CT, the tube voltage and the current were 60 kV and 20.0 microA, respectively, and the X-ray intensity was 0.735 microGy/s at 1.0 m from the source and with a tube voltage of 60 kV. Demonstration of enhanced iodine K-edge X-ray CT was carried out by selection of photons with energies just beyond the iodine K-edge energy of 33.2 keV.

NCPV preprints for the 2. world conference on photovoltaic solar energy conversion

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

The proceedings contain 26 papers arranged under the following topical sections: Silicon (3 papers); Thin-film PV technologies (11 papers): amorphous silicon, cadmium telluride, copper indium diselenide, and high efficiency devices; Module and BOS manufacturing (2 papers); Cell, module, and system testing (7 papers); and Market development (3 papers). Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

International Nuclear Information System (INIS)

Agostini, Denis; Marie, Pierre-Yves; Ben-Haim, Simona; Rouzet, Francois; Songy, Bernard; Giordano, Alessandro; Gimelli, Alessia; Hyafil, Fabien; Sciagra, Roberto; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H.J.A.; Lindner, Oliver

2016-01-01

The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

Energy Technology Data Exchange (ETDEWEB)

Agostini, Denis [CHU Caen and Normandy University, Department of Nuclear Medicine, Caen (France); Normandy University, Caen (France); Marie, Pierre-Yves [University of Lorraine, Faculty of Medicine, Nancyclotep Experimental Imaging Platform, Nancy (France); University of Lorraine, Faculty of Medicine, CHU Nancy, Department of Nuclear Medicine, Nancy (France); University of Lorraine, Faculty of Medicine, Nancy (France); Ben-Haim, Simona [University College London, University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Chaim Sheba Medical Center, Department of Nuclear Medicine, Ramat Gan (Israel); Rouzet, Francois [University Hospital of Paris-Bichat, UMR 1148, Inserm et Paris Diderot-Paris 7 University Paris, Department of Nuclear Medicine, Paris (France); UMR 1148, Inserm and Paris Diderot-Paris 7 University Paris, Paris (France); Songy, Bernard [Centre Cardiologique du Nord, Saint-Denis (France); Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of Sacred Heart, Largo A. Gemelli, Department of Bioimages and Radiological Sciences, Rome (Italy); Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Hyafil, Fabien [Bichat University Hospital, Assistance Publique - Hopitaux de Paris, UMR 1148, Inserm and Paris Diderot-Paris 7 University, Department of Nuclear Medicine, Paris (France); Sciagra, Roberto [University of Florence, Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, Florence (Italy); Bucerius, Jan [Maastricht University Medical Center, Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Verberne, Hein J. [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Slart, Riemer H.J.A. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Twente, Faculty of Science and Technology, Department of Biomedical Photonic Imaging, Enschede (Netherlands); Lindner, Oliver [Institute of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center NRW, Bad Oeynhausen (Germany); Collaboration: Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

2016-12-15

The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

Synthesis of cadmium tungstate films via sol-gel processing

Energy Technology Data Exchange (ETDEWEB)

Lennstrom, Kirk; Limmer, Steven J.; Cao Guozhong

2003-06-23

Cadmium tungstate is a scintillator material with excellent intrinsic photoluminescent properties. It is highly resistant to gamma radiation, has an almost non-existent afterglow and is highly efficient. Cadmium tungstate is also non-hydroscopic, unlike the more prevalent thallium-doped alkali halide scintillators. In order to create thin films of cadmium tungstate with precise stoichiometric control, a sol-gel processing technique has been applied to produce this material for the first time. In addition to lower processing temperatures, sol-gel-derived cadmium tungstate is cheaper and easier than other technologies, particularly for thin films. Furthermore, it has the potential to produce nanostructured materials with good optical quality. X-Ray diffraction results of sol-gel-derived materials fired at various temperatures imply crystallization of cadmium tungstate without the intermediate formation of either tungsten oxide or cadmium oxide. Scanning electron microscopy analysis shows the formation of nano-sized particles prior to heat treatment, which form meso-sized particles after the heat treatment. Photoluminesce analysis indicates emission of derived films at 480 nm, which agrees with other published data. Finally, the efficiency of derived films was approximately 6%{+-}1.8%.

Thin-film photovoltaic power generation offers decreasing greenhouse gas emissions and increasing environmental co-benefits in the long term.

Science.gov (United States)

Bergesen, Joseph D; Heath, Garvin A; Gibon, Thomas; Suh, Sangwon

2014-08-19

Thin-film photovoltaic (PV) technologies have improved significantly recently, and similar improvements are projected into the future, warranting reevaluation of the environmental implications of PV to update and inform policy decisions. By conducting a hybrid life cycle assessment using the most recent manufacturing data and technology roadmaps, we compare present and projected environmental, human health, and natural resource implications of electricity generated from two common thin-film PV technologies-copper indium gallium selenide (CIGS) and cadmium telluride (CdTe)-in the United States (U.S.) to those of the current U.S. electricity mix. We evaluate how the impacts of thin films can be reduced by likely cost-reducing technological changes: (1) module efficiency increases, (2) module dematerialization, (3) changes in upstream energy and materials production, and (4) end-of-life recycling of balance of system (BOS). Results show comparable environmental and resource impacts for CdTe and CIGS. Compared to the U.S. electricity mix in 2010, both perform at least 90% better in 7 of 12 and at least 50% better in 3 of 12 impact categories, with comparable land use, and increased metal depletion unless BOS recycling is ensured. Technological changes, particularly efficiency increases, contribute to 35-80% reductions in all impacts by 2030.

Tellurium self-diffusion and point defects in lead telluride

International Nuclear Information System (INIS)

Simirskij, Yu.N.; Firsova, L.P.

1982-01-01

Method of radioactive indicators was used to determine factors of tellurium self-diffusion in lead telluride with different deviation of the composition from stoichiometric in the range of enrichment by tellurium. It was found that at 973 K factors of tellurium self-diffusion in lead telluride depend slightly on the vapor pressure of tellurium equilibrium with solid phase

Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

Science.gov (United States)

Ganguly, Shreyashi; Zhou, Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

2011-12-01

Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2- xSb xTe 3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2- xSb xTe 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.

Effects of oxygen partial pressure, deposition temperature, and annealing on the optical response of CdS:O thin films as studied by spectroscopic ellipsometry

Energy Technology Data Exchange (ETDEWEB)

Junda, Maxwell M.; Grice, Corey R.; Subedi, Indra; Yan, Yanfa; Podraza, Nikolas J. [Department of Physics & Astronomy and The Wright Center for Photovoltaics Innovation & Commercialization, University of Toledo, Toledo, Ohio 43606 (United States)

2016-07-07

Ex-situ spectroscopic ellipsometry measurements are made on radio frequency magnetron sputtered oxygenated cadmium sulfide (CdS:O) thin films. Films are deposited onto glass substrates at room temperature and at 270 °C with varying oxygen to total gas flow ratios in the sputtering ambient. Ellipsometric spectra from 0.74 to 5.89 eV are collected before and after annealing at 607 °C to simulate the thermal processes during close-space sublimation of overlying cadmium telluride in that solar cell configuration. Complex dielectric function (ε = ε{sub 1} + iε{sub 2}) spectra are extracted for films as a function of oxygen gas flow ratio, deposition temperature, and post-deposition annealing using a parametric model accounting for critical point transitions and an Urbach tail for sub-band gap absorption. The results suggest an inverse relationship between degree of crystallinity and oxygen gas flow ratio, whereas annealing is shown to increase crystallinity in all samples. Direct band gap energies are determined from the parametric modeling of ε and linear extrapolations of the square of the absorption coefficient. As-deposited samples feature a range of band gap energies whereas annealing is shown to result in gap energies ranging only from 2.40 to 2.45 eV, which is close to typical band gaps for pure cadmium sulfide.

Scientific/Technical Report: Improvement in compensation and crystal growth of cadmium zinc telluride radiation detectors

International Nuclear Information System (INIS)

Kelvin G. Lynn; Kelly A. Jones

2007-01-01

Comparison of actual accomplishments with goals and objectives: (1) Growth of 12 ingots--Washington State University (WSU) more than met this goal for the project by growing 12 final ingots for the year. Nine of the twelve crystal growth ingots resolved gamma radiation at room temperature. The other three ingots where resistivity of ∼ 3 x 10 8 Ohm*cm for CG32a, CG36, and CG42 lower than expected, however none of these were tried with blocking contacts. All ingots were evaluated from tip to heel. In these three cases, the group III, dopant Aluminum (Al) was not detected to a level to compensate the Cd vacancies in the cadmium zinc telluride (CZT) thus the ingots were lower resistivity. The nine ingots that were successful radiation detectors averaged a bulk resistivity of 1.25 x 10 10 Ohm*cm and with a average μτ product for electrons of ∼ 2 x 10 -4 cm 2 /V with a 1/4 microsecond shaping time with samples ∼2 mm in thickness. (2) Attempt new compensations techniques--WSU also met this goal. Several doping schemes were attempted and investigated with various amounts of excess Tellurium added to the growth. The combination of Al and Erbium (Er) were first attempted for these ingots and subsequently CG34 was grown with Al, Er and Holmium. These compensation techniques produced radiation detectors and are currently under investigation. These growths were made with significant different doping levels to determine the affect of the dopants. CG43 was doped with Indium and Er. Indium was introduced instead of Al to determine if Indium is more soluble than Al for CZT and was less oxidized. This may decrease the amount of low resistivity ingots grown by doping with Indium instead of Al. (3) Grow large single crystals--Several changes in approach occurred in the crystal growth furnace. Steps were taken to maximize the crystal growth interface during growth by modifying liners, quartz, heat sinks, crucibles and various growth steps and temperature profiles. CG39 ingot

Emissions from photovoltaic life cycles.

Science.gov (United States)

Fthenakis, Vasilis M; Kim, Hyung Chul; Alsema, Erik

2008-03-15

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004-2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

Lead telluride with increased mechanical stability for cylindrical thermoelectric generators

International Nuclear Information System (INIS)

Schmitz, Andreas

2013-01-01

The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb 1-x Ca x Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while its thermoelectric properties

The direct determination, by differential pulse anodic-stripping voltammetry at the thin mercury-film electrode, of cadmium, lead and copper

International Nuclear Information System (INIS)

Lee, A.F.

1981-01-01

This report describes the development and application of a voltammetric procedure for the direct, simultaneous determination of cadmium, lead, and copper in three SAROC reference materials (carbonatite, magnesite, and quartz). The electrolyte was a mixture of 1 M ammonium chloride, 0,1 M citric acid, and 0,025 M ascorbic acid. No interferences were encountered from Fe(III), As(III), Sb(V), Tl(I), or In(III) at the concentrations present in the samples. Intermetallic interferences were eliminated by the use of thin mercury-film electrodes not less than 80nm thick. Limits of detection were determined by the degree to which the supporting electrolyte could be purified, and were estimated to be 10ng/g, 250ng/g, and 150ng/g for cadmium, lead, and copper respectively

Comparison of conventional and cadmium-zinc-telluride single-photon emission computed tomography for analysis of thallium-201 myocardial perfusion imaging: an exploratory study in normal databases for different ethnicities.

Science.gov (United States)

Ishihara, Masaru; Onoguchi, Masahisa; Taniguchi, Yasuyo; Shibutani, Takayuki

2017-12-01

The aim of this study was to clarify the differences in thallium-201-chloride (thallium-201) myocardial perfusion imaging (MPI) scans evaluated by conventional anger-type single-photon emission computed tomography (conventional SPECT) versus cadmium-zinc-telluride SPECT (CZT SPECT) imaging in normal databases for different ethnic groups. MPI scans from 81 consecutive Japanese patients were examined using conventional SPECT and CZT SPECT and analyzed with the pre-installed quantitative perfusion SPECT (QPS) software. We compared the summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for the two SPECT devices. For a normal MPI reference, we usually use Japanese databases for MPI created by the Japanese Society of Nuclear Medicine, which can be used with conventional SPECT but not with CZT SPECT. In this study, we used new Japanese normal databases constructed in our institution to compare conventional and CZT SPECT. Compared with conventional SPECT, CZT SPECT showed lower SSS (p < 0.001), SRS (p = 0.001), and SDS (p = 0.189) using the pre-installed SPECT database. In contrast, CZT SPECT showed no significant difference from conventional SPECT in QPS analysis using the normal databases from our institution. Myocardial perfusion analyses by CZT SPECT should be evaluated using normal databases based on the ethnic group being evaluated.

Cadmium colours: composition and properties

International Nuclear Information System (INIS)

Paulus, J.; Knuutinen, U.

2004-01-01

The composition and the properties of cadmium aquarelle colours are discussed. The examined colours were 24 different aquarelle cadmium colours from six different manufacturers. The colours ranged from light, bright yellows to dark, deep-red tones. The aim of this research was to find out if the pigments contain cadmium salts: sulphides and/or selenides. This information will help in choosing watercolours in conservation processes. Today, aquarelle colours not containing cadmium pigments are being sold as cadmium colours; thus their properties might be different from actual cadmium colours. The aim of the research was to verify that the colour samples contained cadmium pigments and to estimate their compositions and ageing properties. Element analyses were performed from colour samples using micro-chemical tests and X-ray fluorescence measurements. Thin-layer chromatography was used for analysing gum Arabic as a possible binding medium in the chosen colour samples. Through ageing tests, the resistance of the colour samples to the exposure to light, heat and humidity was studied. Visible-light spectroscopy was used in determining the hues and hue changes of the aquarelle colour samples. The spectrophotometer used the CIE L * a * b * tone colour measuring system. From the colour measurements the changes in the lightness/darkness, the redness, the yellowness and the saturation of the samples were examined. (orig.)

Looking for new market niches; Neue Nischen gesucht

Energy Technology Data Exchange (ETDEWEB)

Schwarzburger, Heiko

2013-05-15

The past year was difficult for the solar industry. The German government policy does not promote large-scale solar power plants anymore. The feed-in tariff was reduced for solar power plants less than 10 megawatts. Nevertheless, large-scale solar power plants are built. However, for example, the solar power plant Turnow II uses 230,000 thin-film modules from First Solar (Tempe, Arizona, USA) as well as 24 central inverters from SMA (Niestetal, Federal Republic of Germany). The investment volume amounts to 37 million Euro. Thin-film modules consisting of cadmium telluride and copper indium compound semiconductors make the race.

Effects of different annealing atmospheres on the properties of cadmium sulfide thin films

Energy Technology Data Exchange (ETDEWEB)

Yücel, E., E-mail: dr.ersinyucel@gmail.com [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Kahraman, S. [Department of Metallurgy and Material Engineering, Faculty of Technology, Mustafa Kemal University, 31034 Hatay (Turkey); Güder, H.S. [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey)

2015-08-15

Graphical abstract: The effects of different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values. - Highlights: • Compactness and smoothness of the films were enhanced after sulfur annealing. • Micro-strain values of some films were improved after sulfur annealing. • Dislocation density values of some films were improved after sulfur annealing. • Band gap values of the films were improved after sulfur annealing. - Abstract: Cadmium sulfide (CdS) thin films were prepared on glass substrates by using chemical bath deposition (CBD) technique. The effects of different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values. Compactness and smoothness of the films (especially for pH 10.5 and 11) enhanced after sulfur annealing. pH value of the precursor solution remarkably affected the roughness, uniformity and particle sizes of the films. Based on the analysis of X-ray diffraction (XRD) patterns of the films, micro-strain and dislocation density values of the sulfur-annealed films (pH 10.5 and 11) were found to be lower than those of air-annealed films. Air-annealed films (pH 10.5, 11 and 11.5) exhibited higher transmittance than sulfur-annealed films in the wavelength region of 550–800 nm. Optical band gap values of the films were found between 2.31 eV and 2.36 eV.

Viscoelastic optical nonlocality of doped cadmium oxide epsilon-near-zero thin films

Energy Technology Data Exchange (ETDEWEB)

Luk, Ting S.; De Ceglia, Domenico; Scalora, Michael; Vincenti, Maria A.; Campione, Salvatore; Kelley, Kyle; Maria, Jon-Paul; Keeler, Gordon A.

2017-08-01

Optical nonlocalities are elusive and hardly observable in traditional plasmonic materials like noble and alkali metals. Here we experimentally observe and theoretically model viscoelastic nonlocalities in the infrared optical response of a doped, cadmium oxide epsilon-near-zero thin film. The nonlocality is clearly detectable thanks to the low damping rate of conduction electrons and the virtual absence of interband transitions at infrared wavelengths. We describe the motion of conduction electrons using a hydrodynamic model for a viscoelastic fluid, and find excellent agreement with experimental results. The electrons’ elasticity blue-shifts the infrared plasmonic resonance associated with the main epsilon-near-zero mode, and triggers the onset of higher-order resonances due to the excitation of electron-pressure modes above the bulk plasma frequency. We also provide evidence of the existence of nonlocal damping, i.e., viscosity, in the motion of optically-excited conduction electrons using a combination of spectroscopic ellipsometry data and predictions based on the viscoelastic hydrodynamic model.

Electrodeposition of CdTe thin films onto n-Si(1 0 0): nucleation and growth mechanisms

International Nuclear Information System (INIS)

Gomez, H.; Henriquez, R.; Schrebler, R.; Cordova, R.; Ramirez, D.; Riveros, G.; Dalchiele, E.A.

2005-01-01

The mechanisms related to the initial stages of the nucleation and growth of cadmium telluride (CdTe) thin films on the rough face side of a (1 0 0) monocrystalline n-type silicon have been studied as a function of different potential steps that varied from an initial value of -0.200 V to values comprised between -0.515 and -0.600 V versus saturated calomel electrode (SCE). The analysis of the corresponding potentiostatic j/t transients suggests that the main phenomena involved at short times is the formation of a Te-Cd bi-layer (BL). For potentials below -0.540 V, the formation of this bi-layer can be considered independent of potential. At greater times, the mechanisms is controlled by two process: (i) progressive nucleation three dimensional charge transfer controlled growth (PN-3D) ct and (ii) progressive nucleation three dimensional diffusion controlled growth (PN-3D) diff , both giving account for the formation of conical and hemispherical nuclei, respectively. Ex situ AFM images of the surface seem to support these assumptions

(99m)Tc-MDP bone scintigraphy of the hand: comparing the use of novel cadmium zinc telluride (CZT) and routine NaI(Tl) detectors.

Science.gov (United States)

Koulikov, Victoria; Lerman, Hedva; Kesler, Mikhail; Even-Sapir, Einat

2015-12-01

Cadmium zinc telluride (CZT) solid-state detectors have been recently introduced in the field of nuclear medicine in cardiology and breast imaging. The aim of the current study was to evaluate the performance of the novel detectors (CZT) compared to that of the routine NaI(Tl) in bone scintigraphy. A dual-headed CZT-based camera dedicated originally to breast imaging has been used, and in view of the limited size of the detectors, the hands were chosen as the organ for assessment. This is a clinical study. Fifty-eight consecutive patients (total 116 hands) referred for bone scan for suspected hand pathology gave their informed consent to have two acquisitions, using the routine camera and the CZT-based camera. The latter was divided into full-dose full-acquisition time (FD CZT) and reduced-dose short-acquisition time (RD CZT) on CZT technology, so three image sets were available for analysis. Data analysis included comparing the detection of hot lesions and identification of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. A total of 69 hot lesions were detected on the CZT image sets; of these, 61 were identified as focal sites of uptake on NaI(Tl) data. On FD CZT data, 385 joints were identified compared to 168 on NaI(Tl) data (p < 0.001). There was no statistically significant difference in delineation of joints between FD and RD CZT data as the latter identified 383 joints. Bone scintigraphy using a CZT-based gamma camera is associated with improved lesion detection and anatomic definition. The superior physical characteristics of this technique raised a potential reduction in administered dose and/or acquisition time without compromising image quality.

Theoretical and Experimental Study on the Permittivity of CdTe in the Terahertz Band

Directory of Open Access Journals (Sweden)

Sun Wang

2018-02-01

Full Text Available The phonon dispersion spectrum, eigenvector, and lattice vibration frequency of cadmium telluride with a zinc blende structure have been investigated using the density functional theory, and the permittivity of cadmium telluride crystal is numerically calculated. The permittivity of the crystal is measured using the terahertz time-domain spectroscopy system. The experimental results are consistent with the theoretical calculations on the modified local density approximation, the general gradient approximation, and the modified general gradient approximation. Finally, the differences among the three approximate exchange correlation potentials indicate that in the terahertz region, the permittivity of cadmium telluride is dominantly contributed by the coupling between electron and phonon; however, the phonon frequencies of transverse wave and longitudinal wave were sensitive to electron density distribution.

Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

Science.gov (United States)

Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Park, Yeonjoon (Inventor); Lee, Kunik (Inventor)

2014-01-01

Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

Resource recovery from urban stock, the example of cadmium and tellurium from thin film module recycling

Energy Technology Data Exchange (ETDEWEB)

Simon, F.-G., E-mail: franz-georg.simon@bam.de [BAM Federal Institute for Materials Research and Testing, Division 4.3 Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205 Berlin (Germany); Holm, O.; Berger, W. [BAM Federal Institute for Materials Research and Testing, Division 4.3 Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205 Berlin (Germany)

2013-04-15

Highlights: ► The semiconductor layer on thin-film photovoltaic modules can be removed from the glass-plate by vacuum blast cleaning. ► The separation of blasting agent and semiconductor can be performed using flotation with a valuable yield of 55%. ► PV modules are a promising source for the recovery of tellurium in the future. - Abstract: Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources.

Resource recovery from urban stock, the example of cadmium and tellurium from thin film module recycling

International Nuclear Information System (INIS)

Simon, F.-G.; Holm, O.; Berger, W.

2013-01-01

Highlights: ► The semiconductor layer on thin-film photovoltaic modules can be removed from the glass-plate by vacuum blast cleaning. ► The separation of blasting agent and semiconductor can be performed using flotation with a valuable yield of 55%. ► PV modules are a promising source for the recovery of tellurium in the future. - Abstract: Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources

Defect characterization of CdTe thin films using a slow positron beam

International Nuclear Information System (INIS)

Neretina, S.; Grebennikov, D.; Mascher, P.; Hughes, R.A.; Weber, M.; Lynn, K.G.; Simpson, P.J.; Preston, J.S.

2007-01-01

Cadmium Telluride (CdTe) is the most well established II-VI compound largely due to its use as a photonic material. Existing applications, as well as those under consideration, are demanding increasingly stringent control of the material properties. The deposition of high quality thin films is of the utmost importance to such applications. In this regard, we present a report detailing the role of lattice mismatch in determining the film quality. Thin films were deposited on a wide variety of substrate materials using the pulsed laser deposition technique. Common to all substrates was the strong tendency towards the preferential alignment of CdTe's (111) planes parallel to the substrate's surface. X-ray diffraction analysis, however, revealed that the crystalline quality varied dramatically depending upon the substrate used with the best results yielding a single crystal film. This tendency also manifested itself in the surface morphology with higher structural perfection yielding smoother surfaces. Slow positron beam techniques revealed a strong correlation between the defect concentration and the degree of structural perfection. Simulations of the data using the POSTRAP 5 program were used to calculate the defect concentration in relative (atom -1 ) and absolute units and to determine the diffusion lengths of the positrons in the film. All of these characterization techniques point towards lattice mismatch as being the dominant mechanism in determining the quality of CdTe films. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Special features of self-compensation of halogen donor action in lead telluride

International Nuclear Information System (INIS)

Kajdanov, V.I.; Nemov, S.A.; Ravich, Yu.I.; Dereza, A.Yu.

1985-01-01

Specific features of self-compensation of halogen donor action in lead telluride are investigasted. Lead telluride samples with chlorine additions (with tellurium excess) and, besides, with bromine- and iodine additions were studied in order to reveal general regularities in alloyind with all halogen donor impurities. Experimental dependences of the difference between the electron and hole concentrations (n-p) in PbTe as a function of an amount of introduced halogen impurities (Ni) are presented for samples with a maximum compensation at 295 K. General features of the n-p=f(Ni) dependence are presented for all halogens. The hypothesis on the kinetic mechanism of increasing the efficiency of self-compensation of halogen donor action in lead telluride is suggested

solution growth and characterization of copper oxide thin films ...

African Journals Online (AJOL)

Thin films of copper oxide (CuO) were grown on glass slides by using the solution growth technique. Copper cloride (CuCl ) and potassium telluride (K T O ) were used. Buffer 2 2e 3 solution was used as complexing agent. The solid state properties and optical properties were obtained from characterization done using PYE ...

Cadmium-manganese oxide composite thin films: Synthesis, characterization and photoelectrochemical properties

Energy Technology Data Exchange (ETDEWEB)

Mansoor, M.A. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Faculty of Science, Kuala Lumpur 50603 (Malaysia); Ebadi, M. [Solar Energy Research Institute, University Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia); Mazhar, M., E-mail: mazhar42pk@yahoo.com [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Huang, N.M. [Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Faculty of Science, Kuala Lumpur 50603 (Malaysia); Mun, L.K.; Misran, M. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Basirun, W.J. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Institute of Nanotechnology and Catalysis (NanoCat), University Malaya, Kuala Lumpur 50603 (Malaysia)

2017-01-15

Ceramic composite CdO–Mn{sub 2}O{sub 3} thin films have been deposited on fluorine doped tin oxide (FTO) coated glass substrates by aerosol assisted chemical vapour deposition (AACVD) using a 1:1 mixture of cadmium complex, [Cd(dmae){sub 2}(OAc){sub 2}]·H{sub 2}O (1) (where dmae = 2-dimethylaminoethanolato and OAc = acetato), and diacetatomanganese (II). The phase purity, stoichiometry and thickness of the films were examined by X-ray diffraction (XRD), Fourier transformed infra-red (FTIR), Raman spectroscopy, field emission gun scanning electron microscopy (FEG-SEM), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy and profilometer. The FEG-SEM analysis illustrated that the morphology of the fabricated films was influenced by the type of solvent. The optical direct band gap of the film fabricated from THF solution was 1.95 eV. From the current–voltage characteristics it is evident that the CdO–Mn{sub 2}O{sub 3} composite semiconductor electrode exhibits n-type behaviour and the photocurrent density was found to be dependent on the deposition medium. The film deposited from THF solution displayed maximum photocurrent density of 4.80 mA cm{sup −2} at 0.65 V vs. Ag/AgCl/3 M KCl (∼1.23 V vs. RHE) in 0.5 M NaOH electrolyte. - Highlights: • Single crystal X-ray structure of [Cd(dmae){sub 2}(OAc){sub 2}]·H{sub 2}O (1). • CdO-Mn{sub 2}O{sub 3} composite photoanode thin films. • Optical band gap of CdO-Mn{sub 2}O{sub 3} photoanode. • Photoelectrochemical and EIS studies.

Sputtered indium-tin oxide/cadmium telluride junctions and cadmium telluride surfaces

International Nuclear Information System (INIS)

Courreges, F.G.; Fahrenbruch, A.L.; Bube, R.H.

1980-01-01

The properties of indium-tin oxide (ITO)/CdTe junction solar cells prepared by rf sputtering of ITO on P-doped CdTe single-crystal substrates have been investigated through measurements of the electrical and photovoltaic properties of ITO/CdTe and In/CdTe junctions, and of electron beam induced currents (EBIC) in ITO/CdTe junctions. In addition, surface properties of CdTe related to the sputtering process were investigated as a function of sputter etching and thermal oxidation using the techniques of surface photovoltage and photoluminescence. ITO/CdTe cells prepared by this sputtering method consist of an n + -ITO/n-CdTe/p-CdTe buried homojunction with about a 1-μm-thick n-type CdTe layer formed by heating of the surface of the CdTe during sputtering. Solar efficiencies up to 8% have been observed with V/sub 0c/=0.82 V and J/sub s/c=14.5 mA/cm 2 . The chief degradation mechanism involves a decrease in V/sub 0c/ with a transformation of the buried homojunction structure to an actual ITO/CdTe heterojunction

Property elucidation of vacuum-evaporated zinc telluride thin film ...

Indian Academy of Sciences (India)

J U Ahamed

2017-08-31

Aug 31, 2017 ... method for the deposition of ZnTe thin film as compared to other methods. ... the advantages and disadvantages of different deposition process, it was ... by a spiral resistance heater and the temperature was measured by a ...

Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide

International Nuclear Information System (INIS)

Danilova, M.G.; Sveshnikova, L.L.; Stavitskaya, T.A.; Repinskij, S.M.

1991-01-01

Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide was investigated. Dependences of change of PbTe dissolution rate on concentration of hydrogen peroxide and alkali in the solution were obtained. It is shown that dissolution rate of lead telluride is affected by dissolution rate of lead oxide, representing the product of ReTe dissolution. The obtained regularities can be explained by change of solution structure with increase of KOH concentration and by the state of hydrogen peroxide in the solution

Recent developments in materials and detectors for the infrared; Proceedings of the Meeting, Cannes, France, November 25, 26, 1985

Science.gov (United States)

Morten, F. D. (Editor); Seeley, John S. (Editor)

1986-01-01

The present conference on advancements in IR-sensitive materials and detector technologies employing them gives attention to thermal detectors, focal plane array processing detectors, novel detector designs, general properties of IR optics materials, and preparation methods for such materials. Specific topics encompass the fabrication of InSb MIS structures prepared by photochemical vapor deposition, IR heterodyne detectors employing cadmium mercury telluride, low microphony pyroelectric arrays, IR detection based on minority carrier extrusion, longwave reststrahl in IR crystals, and molecular beam techniques for optical thin film fabrication.

Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

International Nuclear Information System (INIS)

Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman

2016-01-01

polygon, total absorption remains approximately the same. However, the total absorption suffers significantly if the holes are triangle. The transmission spectra of incident light into the bottom subcell, and hence the absorption, change significantly for square and circle holes if the active materials change to cadmium selenide (CdSe) and cadmium telluride (CdTe) in the top and bottom subcells, respectively. Although the intermediate metal layer may induce electron-hole pair recombination due to surface defects, the short-circuit current density of an ultra-thin plasmonic solar cell with an intermediate metal layer with two-dimensional hole array is >9% of that of a structure without the intermediate metal layer.

Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

Energy Technology Data Exchange (ETDEWEB)

Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman, E-mail: anis@eee.buet.ac.bd [Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1205 (Bangladesh)

2016-05-21

polygon, total absorption remains approximately the same. However, the total absorption suffers significantly if the holes are triangle. The transmission spectra of incident light into the bottom subcell, and hence the absorption, change significantly for square and circle holes if the active materials change to cadmium selenide (CdSe) and cadmium telluride (CdTe) in the top and bottom subcells, respectively. Although the intermediate metal layer may induce electron-hole pair recombination due to surface defects, the short-circuit current density of an ultra-thin plasmonic solar cell with an intermediate metal layer with two-dimensional hole array is >9% of that of a structure without the intermediate metal layer.

Influences of the CdS nanoparticles grown strategies on CdTe nanorods array films: A comparison between successive ionic layer absorption and reaction and chemical bath deposition

International Nuclear Information System (INIS)

Wang, Jun; Zhou, Xiaoming; Lv, Pin; Yang, Lihua; Ding, Dong; Niu, Jiasheng; Liu, Li; Li, Xue; Fu, Wuyou; Yang, Haibin

2016-01-01

The cadmium sulfide (CdS) film is deposited on the surface of cadmium telluride (CdTe) nanorods (NRs) by two different methods, successive ionic layer adsorption and reaction (SILAR) and chemical bath deposition (CBD) techniques. The influence of the deposition parameters on the properties of the films is investigated. Compared to SILAR, CBD is a simple and time saving technique, which can ensure full coverage and better growth of CdS on the surface of CdTe NRs. The photovoltaic characteristics of CdS sensitized CdTe films are also investigated. It is found that the CdTe/CBD-CdS thin film demonstrates excellent photoelectrical properties, which is ascribed to the large absorption coefficient of the material, indicating the potential applications in solar cells.

Telluride School, Telluride, Colorado solar-energy-system performance evaluation, February 1982-April 1982

Energy Technology Data Exchange (ETDEWEB)

Welch, K.M.

1982-01-01

The Telluride School solar site is an elementary/junior-senior high school in Colorado with a passive/active hybrid solar energy system designed to supply 40% of the heating load. It is equipped with a 1428 square foot, double glazed Trombe wall, a 1392 square foot greenhouse with collection tube, and an auxiliary oil-fired boiler. Monthly performance data are tabulated for the overall system and for the Trombe wall, greenhouse, and greenhouse storage. System operation is illustrated by graphs of typical Trombe wall insolation and temperatures and typical greenhouse insolation and temperatures. (LEW)

High-temperature thermoelectric behavior of lead telluride

Indian Academy of Sciences (India)

The central problem in thermoelectric material research is the selection of ... temperature range (400–1000 K), and bismuth telluride-based materials .... parent from the results that band non-parabolicity has a significant effect on the .... M P Singh thankfully acknowledges financial assistance from the Council of Scien-.

Effect of annealing on the electrical, optical and structural properties of cadmium stannate thin films prepared by spray pyrolysis technique

International Nuclear Information System (INIS)

Kumaravel, R.; Krishnakumar, V.; Gokulakrishnan, V.; Ramamurthi, K.; Jeganathan, K.

2010-01-01

Polycrystalline thin films of cadmium stannate (Cd 2 SnO 4 ) were deposited by spray pyrolysis method on the Corning substrates at substrate temperature of 525 o C. Further, the films were annealed at 600 o C in vacuum for 30 min. These films were characterized for their structural, electrical and optical properties. The experimental results showed that the post-deposition annealing in vacuum has a significant influence on the properties of the films. The average grain size of the film was increased from 27.3 to 35.0 nm on heat treatment. The average optical transmittance in the visible region (500-850 nm) is decreased from 81.4% to 73.4% after annealing in vacuum. The minimum resistivity achieved in the present study for the vacuum annealed films is the lowest among the reported values for the Cd 2 SnO 4 thin films prepared by spray pyrolysis method.

Studies of crystalline CdZnTe radiation detectors and polycrystalline thin film CdTe for X-ray imaging applications

International Nuclear Information System (INIS)

Ede, Anthony

2001-01-01

The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and γ-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and experimental arrangement for this technique are described in detail with preliminary results from the fabricated films presented. Attention is then turned to the CdS/CdTe films that are produced commercially for the photovoltaic industry. In this case the crystalline nature, surface topography and optical properties are investigated. A conclusion examines the progress that has been made towards the development of a large area fiat panel digital imaging technique. (author)

Simultaneous determination of oxygen and cadmium in cadmium and cadmium compounds

International Nuclear Information System (INIS)

Imaeda, K.; Kuriki, T.; Ohsawa, K.; Ishii, Y.

1977-01-01

Cadmium and its compounds were analysed for oxygen and cadmium by a modification of the Schutze-Unterzaucher method. Oxygen in some compounds such as cadmium oxide, nitrate and sulphate could not be determined by the usual method. The method of adding carbon was employed for the determination of total oxygen. Total oxygen could be determined by the addition of 5 mg of carbon to a sample boat and heating at 950 0 . The determination was also carried out by addition of naphthalene (2 mg). It was found that the cadmium powder and cadmium flake used contained ca. 1 and 0.15% oxygen, respectively. Oxygen and cadmium in cadmium and its compounds were simultaneously determined by the addition of 2 mg of naphthalene. Cadmium was determined colorimetrically by use of glyoxal-bis-(2-hydroxyanil). Oxygen and cadmium in the samples could be determined simultaneously with an average error of -0.02 and -0.22%, respectively. (author)

Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

International Nuclear Information System (INIS)

Ganguly, Shreyashi; Zhou Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

2011-01-01

Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2−x Sb x Te 3 ) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2−x Sb x Te 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties. - Graphical abstract: PbTe nanoparticles introduced into p-type Bi 2 Te 3 by incipient wetness results in decreased lattice thermal conductivity, but also acts as an electronic dopant, resulting in an overall decrease in thermoelectric performance. Highlights: ► Composites of PbTe nanoparticles in Bi 2−x Sb x Te 3 were formed by incipient wetness. ► PbTe nanoparticles leads to decreased κ l , consistent with phonon scattering. ► PbTe nanoparticles lead to decreased S and ρ, due to increased carriers. ► Collateral doping from PbTe leads to decreased ZT with increasing concentration. ► Immiscible systems are preferred for improved ZT.

Process for obtaining oxygen doped zinc telluride monocrystals and scintillator crystals obtained by this process

International Nuclear Information System (INIS)

Schneider, Maurice; Moreau, Roland; D'Haenen, J.-P.; Merenda, Pierre.

1976-01-01

A process is described for obtaining oxygen doped zinc telluride monocrystals, for use as scintillator crystals for ionising radiation detectors. The following operations are carried out in succession: one or several zinc telluride crystals are introduced into a silica ampoule together with a ternary mixture of zinc tellurium and oxygen, as an oxide or hydroxide of these elements; the ampoule is pumped down to a high vacuum and sealed; the sealed ampoule containing the mixture and monocrystals is placed in a kiln and brought to a uniform temperature sufficient to make the mixture three-phased, depending on its composition; the zinc telluride crystalline compound remains solid; the ampoule is then tempered to bring it quickly back to ambient temperature [fr

Processing of semiconductors and thin film solar cells using electroplating

Science.gov (United States)

Madugu, Mohammad Lamido

The global need for a clean, sustainable and affordable source of energy has triggered extensive research especially in renewable energy sources. In this sector, photovoltaic has been identified as a cheapest, clean and reliable source of energy. It would be of interest to obtain photovoltaic material in thin film form by using simple and inexpensive semiconductor growth technique such as electroplating. Using this growth technique, four semiconductor materials were electroplated on glass/fluorine-doped tin oxide (FTO) substrate from aqueous electrolytes. These semiconductors are indium selenide (In[x]Sey), zinc sulphide (ZnS), cadmium sulphide (CdS) and cadmium telluride (CdTe). In[x]Se[y] and ZnS were incorporated as buffer layers while CdS and CdTe layers were utilised as window and absorber layers respectively. All materials were grown using two-electrode (2E) system except for CdTe which was grown using 3E and 2E systems for comparison. To fully optimise the growth conditions, the as-deposited and annealed layers from all the materials were characterised for their structural, morphological, optical, electrical and defects structures using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption (UV-Vis spectroscopy), photoelectrochemical (PEC) cell measurements, current-voltage (I-V), capacitance-voltage (C-V), DC electrical measurements, ultraviolet photoelectron spectroscopy (UPS) and photoluminescence (PL) techniques. Results show that InxSey and ZnS layers were amorphous in nature and exhibit both n-type and p-type in electrical conduction. CdS layers are n-type in electrical conduction and show hexagonal and cubic phases in both the as-deposited and after annealing process. CdTe layers show cubic phase structure with both n-type and p-type in electrical conduction. CdTe-based solar cell structures with a n-n heterojunction plus large Schottky barrier, as well as multi-layer graded

Solar-energy conversion by combined photovoltaic converters with CdTe and CuInSe2 base layers

International Nuclear Information System (INIS)

Khrypunov, G. S.; Sokol, E. I.; Yakimenko, Yu. I.; Meriuts, A. V.; Ivashuk, A. V.; Shelest, T. N.

2014-01-01

The possibility of the combined use of bifacial thin-film solar cells based on CdTe and frontal solar cells with a CuInSe 2 base layer in tandem structures is experimentally confirmed. It is found that, for the use of bifacial solar cells based on cadmium telluride in a tandem structure, the optimal thickness of their base layer should be 1 μm. The gain in the efficiency of the tandem structure, compared with an individual CuInSe 2 -based solar cell, is 1.8% in the case of series-connected solar cells and 1.3%, for parallel-connected

Technical evaluation of Solar Cells, Inc., CdTe module and array at NREL

Energy Technology Data Exchange (ETDEWEB)

Kroposki, B.; Strand, T.; Hansen, R. [National Renewable Energy Lab., Golden, CO (United States); Powell, R.; Sasala, R. [Solar Cells, Inc., Toledo, OH (United States)

1996-05-01

The Engineering and Technology Validation Team at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of polycrystalline thin-film photovoltaic (PV) modules and arrays. This paper focuses on the technical evaluation of Solar Cells, Inc., (SCI) cadmium telluride (CdTe) module and array performance by attempting to correlate individual module and array performance. This is done by examining the performance and stability of the modules and array over a period of more than one year. Temperature coefficients for module and array parameters (P{sub max}, V{sub oc}, V{sub max}, I{sub sc}, I{sub max}) are also calculated.

The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

Energy Technology Data Exchange (ETDEWEB)

Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing, E-mail: libing70@126.com; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

2016-01-01

Graphical abstract: - Highlights: • The large-area CdTe film has been prepared by PVD under the pressure of 0.9 kPa. • The as-prepared CdTe thin film processes excellent photovoltaic properties. • This technique is suitable for depositing large-area CdTe thin film. • The 14.6% champion efficiency CdS/CdTe cell has been achieved. - Abstract: The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O{sub 2} pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm{sup 2}. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O{sub 2} flow. Through this method, the compact and uniform CdTe film (30 × 40 cm{sup 2}) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm{sup 2}) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (J{sub sc}) of the cell is 26.9 mA/cm{sup 2}, open circuit voltage (V{sub oc}) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

The effect of annealing on structural, optical and photosensitive properties of electrodeposited cadmium selenide thin films

Directory of Open Access Journals (Sweden)

Somnath Mahato

2017-06-01

Full Text Available Cadmium selenide (CdSe thin films have been deposited on indium tin oxide coated glass substrate by simple electrodeposition method. X-ray Diffraction (XRD studies identify that the as-deposited CdSe films are highly oriented to [002] direction and they belong to nanocrystalline hexagonal phase. The films are changed to polycrystalline structure after annealing in air for temperatures up to 450 °C and begin to degrade afterwards with the occurrence of oxidation and porosity. CdSe completely ceases to exist at higher annealing temperatures. CdSe films exhibit a maximum absorbance in the violet to blue-green region of an optical spectrum. The absorbance increases while the band gap decreases with increasing annealing temperature. Surface morphology also shows that the increase of the annealing temperature caused the grain growth. In addition, a number of distinct crystals is formed on top of the film surface. Electrical characteristics show that the films are photosensitive with a maximum sensitivity at 350 °C.

Doping of germanium telluride with bismuth tellurides

International Nuclear Information System (INIS)

Abrikosov, N.Kh.; Karpinskij, O.G.; Makalatiya, T.Sh.; Shelimova, L.E.

1981-01-01

Effect of germanium telluride doping with bismuth fellurides (Bi 2 Te 3 ; BiTe; Bi 2 Te) on phase transition temperature, lattice parameters and electrophysical properties of alloys is studied. It is shown that in alloys of GeTe-Bi 2 Te 3 (BiTe)(Bi 2 Te) cross sections solid solution of GeTe with Bi 2 Te 3 , characterized by deviation from stoichiometry, and germanium in the second phase the quantity of which increases during the transition from GeTe-Bi 2 Te 3 cross section to GeTe-Bi 2 Te are in equilibrium. Lower values of holes concentration and of electric conductivity and higher values of thermo e.m.f. coefficient in comparison with alloys of GeTe-Bi 2 Te 3 cross section with the same bismuth content are characterized for GeTe-Bi 2 Te cross section alloys. It is shown that in the range of GeTe-base solid solution the α→γ phase transformation which runs trough the two-phase region (α→γ) is observed with tellurium content increase. Extension of α-phase existence region widens with the bismuth content increase. Peculiarities of interatomic interaction in GeTe-base solid solutions with isovalent and heterovalent cation substitution are considered [ru

Structural and optoelectronic properties of β-In{sub 2}S{sub 3} thin films to Be applied on cadmium reduced solar cells

Energy Technology Data Exchange (ETDEWEB)

Galarza Gutierrez, Uziel; Albor Aguilera, Maria Lourdes de; Hernandez Vasquez, Cesar; Aguilar Hernandez, Jorge R.; Remolina Millan, Aduljay [Instituto Politecnico Nacional - ESFM, Dept. de Fisica, U.P.A.L.M., Zacatenco (Mexico); Flores Marquez, Jose M. [Instituto Politecnico Nacional - ESIQIE, Dept. Metalurgia y Mat., U.P.A.L.M., Zacatenco (Mexico); Gonzalez Trujillo, Miguel A. [Instituto Politecnico Nacional - ESCOM, Dept. de Ciencias Basicas, U.P.A.L.M., Zacatenco (Mexico); Jimenez Olarte, Daniel [Instituto Politecnico Nacional - ESIME, SEPI, U.P.A.L.M., Zacatenco (Mexico)

2018-02-15

In{sub 2}S{sub 3} thin films are prepared by chemical bath deposition (CBD) technique to be applied as buffer layer in CdTe solar cells. CdTe photovoltaic devices are developed using In{sub 2}S{sub 3} as ''standard buffer layer'' in order to reduce the CdS thickness used as window material. It is important to examine potential thin films in a prospective life cycle study, focusing on direct costs, resource availability, and environmental impacts. Open and closed CBD system influence on the In{sub 2}S{sub 3} physical properties is analyzed. Stable tetragonal β-In{sub 2}S{sub 3} phase was confirmed by X-ray diffraction. Electrical properties were determined by four-point probe technique obtaining a resistivity value of 10{sup 2} Ω cm. CdTe solar cells performance was studied by measuring J-V characteristics and spectral quantum efficiencies. These results reveal In{sub 2}S{sub 3} thin films as buffer layer reduce the cadmium quantity used in solar cells manufacture and improve their current collection in blue wavelength region (300-500 nm). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Use of a Soluble Anode in Electrodeposition of Thick Bismuth Telluride Layers

Science.gov (United States)

Maas, M.; Diliberto, S.; de Vaulx, C.; Azzouz, K.; Boulanger, C.

2014-10-01

Integration of thermoelectric devices within an automotive heat exchanger could enable conversion of lost heat into electrical energy, contributing to improved total output from the engine. For this purpose, synthesis of thick bismuth telluride (Bi2Te3) films is required. Bismuth telluride has been produced by an electrochemical method in nitric acid with a sacrificial bismuth telluride anode as the source of cations. The binary layer grows on the working electrode while the counter-electrode, a Bi2Te3 disk obtained by high frequency melting, is oxidized to BiIII and TeIV. This process leads to auto-regeneration of the solution without modification of its composition. The thickness of films deposited by use of the Bi2Te3 anode was approximately 10 times that without. To demonstrate the utility of a soluble anode in electrochemical deposition, we report characterization of the composition and morphology of the films obtained under different experimental conditions. Perfectly dense and regular Bi2Te3 films (˜400 μm) with low internal stress and uniform composition across the cross-section were prepared. Their thermoelectric properties were assessed.

Cadmium carcinogenesis

International Nuclear Information System (INIS)

Waalkes, Michael P.

2003-01-01

Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis

Cadmium carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Waalkes, Michael P

2003-12-10

Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis.

with palladium (ii)

African Journals Online (AJOL)

Mgina

Mercury telluride is an important semi conductor with application in infra-red detection (Charlon 1982, Mullin & Irrine. 1985). Photolysis of mixture of the organometallic compounds RHgTeR and. RCdTeR can produce mercury cadmium telluride. Haris and Nissan (1987) prepared. (t-butyl)HgTe(t-butyl) and demonstrated that.

Microstructure evolution in pulsed laser deposited epitaxial Ge-Sb-Te chalcogenide thin films

Energy Technology Data Exchange (ETDEWEB)

Ross, Ulrich; Lotnyk, Andriy, E-mail: andriy.lotnyk@iom-leipzig.de; Thelander, Erik; Rauschenbach, Bernd

2016-08-15

The thin film deposition and structure of highly oriented telluride compounds is of particular interest for phase-change applications in next-generation non-volatile memory such as heterostructure designs, as well as for the investigation of novel optical, thermoelectric and ferroelectric properties in layered telluride compounds. In this work, epitaxial Ge-Sb-Te thin films were successfully produced by pulsed laser deposition on silicon with and without amorphous SiO{sub x} interlayer at elevated process temperatures from a Ge{sub 2}Sb{sub 2}Te{sub 5} target. Aberration-corrected high-resolution scanning transmission electron microscopy (STEM) imaging reveals a distinct interface configuration of the trigonal phase connected by a quasi van der Waals gap (vacancy) to the Sb/Te-passivated single crystalline Si substrate, yet also an intermediate textured growth regime in which the substrate symmetry is only weakly coupled to the thin film orientation, as well as strong deviation of composition at high deposition temperatures. Textured growth of Ge-Sb-Te thin film was also observed on SiO{sub x}/Si substrate with no evidence of an intermediate Sb/Te surface layer on top of an SiO{sub x} layer. In addition, particular defect structures formed by local reorganization of the stacking sequence across the vacancy gap are observed and appear to be intrinsic to these van der Waals-layered compounds. Theoretical image simulations of preferred stacking sequences can be matched to individual building blocks in the Ge-Sb-Te grain. - Highlights: • Atomic-resolution Cs-corrected STEM imaging of PLD deposited Ge-Sb-Te thin films. • Changing of overall composition with increasing deposition temperature. • Direct imaging of surface passivation Sb/Te layer at the Ge-Sb-Te/Si(111) interface. • The Sb/Te passivation layer is not a prerequisite for highly oriented growth of Ge-Sb-Te thin films.

Influence of pH of spray solution on optoelectronic properties of cadmium oxide thin films

International Nuclear Information System (INIS)

Hodlur, R. M.; Rabinal, M. K.

2015-01-01

Highly conducting transparent cadmium oxide thin films were prepared by the conventional spray pyrolysis technique. The pH of the spray solution is varied by adding ammonia/hydrochloric acid. The effect of pH on the morphology, crystallinity and optoelectronic properties of these films is studied. The structural analysis showed all the films in the cubic phase. For the films with pH < 7 (acidic condition), the preferred orientation is along the (111) direction and for those with pH >7 (alkaline condition), the preferred orientation is along the (200) direction. A lowest resistivity of 9.9 × 10 −4 Ω·cm (with carrier concentration = 5.1 × 10 20 cm −3 , mobility = 12.4 cm 2 /(V·s)) is observed for pH ≈ 12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70%. Thus, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of the spray solution without compromising the optical transparency. (paper)

Cadmium and Cadmium/Zinc Ratios and Tobacco-Related Morbidities

Science.gov (United States)

Richter, Patricia; Faroon, Obaid; Pappas, R. Steven

2017-01-01

Metals are one of five major categories of carcinogenic or toxic constituents in tobacco and tobacco smoke. Cadmium is highly volatile and a higher percentage of the total tobacco cadmium content is efficiently transferred to mainstream tobacco smoke than many other toxic metals in tobacco. Inhaled cadmium bioaccumulates in the lungs and is distributed beyond the lungs to other tissues, with a total body biological half-life of one to two decades. Chronic cadmium exposure through tobacco use elevates blood and urine cadmium concentrations. Cadmium is a carcinogen, and an inducer of proinflammatory immune responses. Elevated exposure to cadmium is associated with reduced pulmonary function, obstructive lung disease, bronchogenic carcinoma, cardiovascular diseases including myocardial infarction, peripheral arterial disease, prostate cancer, cervical cancer, pancreatic cancer, and various oral pathologies. Cadmium and zinc have a toxicologically inverse relationship. Zinc is an essential element and is reportedly antagonistic to some manifestations of cadmium toxicity. This review summarizes associations between blood, urine, and tissue cadmium concentrations with emphasis on cadmium exposure due to tobacco use and several disease states. Available data about zinc and cadmium/zinc ratios and tobacco-related diseases is summarized from studies reporting smoking status. Collectively, data suggest that blood, urine, and tissue cadmium and cadmium/zinc ratios are often significantly different between smokers and nonsmokers and they are also different in smokers for several diseases and cancers. Additional biomonitoring data such as blood or serum and urine zinc and cadmium levels and cadmium/zinc ratios in smokers may provide further insight into the development and progression of diseases of the lung, cardiovascular system, and possibly other organs. PMID:28961214

Cadmium and Cadmium/Zinc Ratios and Tobacco-Related Morbidities.

Science.gov (United States)

Richter, Patricia; Faroon, Obaid; Pappas, R Steven

2017-09-29

Metals are one of five major categories of carcinogenic or toxic constituents in tobacco and tobacco smoke. Cadmium is highly volatile and a higher percentage of the total tobacco cadmium content is efficiently transferred to mainstream tobacco smoke than many other toxic metals in tobacco. Inhaled cadmium bioaccumulates in the lungs and is distributed beyond the lungs to other tissues, with a total body biological half-life of one to two decades. Chronic cadmium exposure through tobacco use elevates blood and urine cadmium concentrations. Cadmium is a carcinogen, and an inducer of proinflammatory immune responses. Elevated exposure to cadmium is associated with reduced pulmonary function, obstructive lung disease, bronchogenic carcinoma, cardiovascular diseases including myocardial infarction, peripheral arterial disease, prostate cancer, cervical cancer, pancreatic cancer, and various oral pathologies. Cadmium and zinc have a toxicologically inverse relationship. Zinc is an essential element and is reportedly antagonistic to some manifestations of cadmium toxicity. This review summarizes associations between blood, urine, and tissue cadmium concentrations with emphasis on cadmium exposure due to tobacco use and several disease states. Available data about zinc and cadmium/zinc ratios and tobacco-related diseases is summarized from studies reporting smoking status. Collectively, data suggest that blood, urine, and tissue cadmium and cadmium/zinc ratios are often significantly different between smokers and nonsmokers and they are also different in smokers for several diseases and cancers. Additional biomonitoring data such as blood or serum and urine zinc and cadmium levels and cadmium/zinc ratios in smokers may provide further insight into the development and progression of diseases of the lung, cardiovascular system, and possibly other organs.

Molecular precursors for the phase-change material germanium-antimony-telluride, Ge{sub 2}Sb{sub 2}Te{sub 5} (GST)

Energy Technology Data Exchange (ETDEWEB)

Harmgarth, Nicole; Zoerner, Florian; Engelhardt, Felix; Edelmann, Frank T. [Chemisches Institut, Otto-von-Guericke-Universitaet Magdeburg (Germany); Liebing, Phil [Laboratorium fuer Anorganische Chemie, ETH Zuerich (Switzerland); Burte, Edmund P.; Silinskas, Mindaugas [Institut fuer Mikro- und Sensorsysteme, Otto-von-Guericke-Universitaet Magdeburg (Germany)

2017-10-04

This review provides an overview of the precursor chemistry that has been developed around the phase-change material germanium-antimony-telluride, Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). Thin films of GST can be deposited by employing either chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques. In both cases, the success of the layer deposition crucially depends on the proper choice of suitable molecular precursors. Previously reported processes mainly relied on simple alkoxides, alkyls, amides and halides of germanium, antimony, and tellurium. More sophisticated precursor design provided a number of promising new aziridinides and guanidinates. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Dependence of electrical and optical properties of sol-gel prepared undoped cadmium oxide thin films on annealing temperature

International Nuclear Information System (INIS)

Santos-Cruz, J.; Torres-Delgado, G.; Castanedo-Perez, R.; Jimenez-Sandoval, S.; Jimenez-Sandoval, O.; Zuniga-Romero, C.I.; Marquez Marin, J.; Zelaya-Angel, O.

2005-01-01

The effect of the annealing temperature (T a ) on the optical, electrical and structural properties of the undoped cadmium oxide (CdO) thin films obtained by the sol-gel method, using a simple precursor solution, was studied. All the CdO films annealed in the range from 200 to 450 deg. C are polycrystalline with (111) preferential orientation and present high optical transmission > 85% for wavelengths above 500 nm. The resistivity decreases as T a increases until it reaches a value of 6 x 10 -4 Ω cm for T a 350 deg. C. For higher temperatures the resistivity experiences a slight increase. Images obtained by atomic force microscopy show an evident incremental change of the aggregate size (clusters of grains) as T a increases. The grain size also increases when T a increases as observed in data calculated from X-ray measurements

Simulation of core-level binding energy shifts in germanium-doped lead telluride crystals

International Nuclear Information System (INIS)

Zyubin, A.S.; Dedyulin, S.N.; Yashina, L.V.; Shtanov, V.I.

2007-01-01

To simulate the changes in core-level binding energies in germanium-doped lead telluride, cluster calculations of the changes in the electrostatic potential at the corresponding centers have been performed. Different locations of the Ge atom in the crystal bulk have been considered: near vacancies, near another dopant site, and near the surface. For calculating the potential in the clusters that model the bulk and the surface of the lead telluride crystal (c-PbTe), the electron density obtained in the framework of the Hartree-Fock and hybrid density functional theory (DFT) methods has been used [ru

Supply risks associated with CdTe and CIGS thin-film photovoltaics

International Nuclear Information System (INIS)

Helbig, Christoph; Bradshaw, Alex M.; Kolotzek, Christoph; Thorenz, Andrea; Tuma, Axel

2016-01-01

Highlights: • Supply risks associated with thin film photovoltaic technologies are considered. • Eleven supply risk indicators are used to evaluate Cd, Te, Cu, In, Ga, Se and Mo. • Indicator weighting based on peer assessment and an Analytic Hierarchy Process. • Various possibilities for the aggregation of elemental supply risks discussed. • Aggregated results show a marginally lower supply risk for CdTe than for CIGS. - Abstract: As a result of the global warming potential of fossil fuels there has been a rapid growth in the installation of photovoltaic generating capacity in the last decade. While this market is dominated by crystalline silicon, thin-film photovoltaics are still expected to make a substantial contribution to global electricity supply in future, due both to lower production costs and to recent increases in conversion efficiency. At present, cadmium telluride (CdTe) and copper-indium-gallium diselenide (CuIn_xGa_1_−_xSe_2) seem to be the most promising materials and currently have a share of ≈9% of the photovoltaic market. An expected stronger market penetration by these thin-film technologies raises the question as to the supply risks associated with the constituent elements. Against this background, we report here a semi-quantitative, relative assessment of mid- to long-term supply risk associated with the elements Cd, Te, Cu, In, Ga, Se and Mo. In this approach, the supply risk is measured using 11 indicators in the four categories “Risk of Supply Reduction”, “Risk of Demand Increase”, “Concentration Risk” and “Political Risk”. In a second step, the single indicator values, which are derived from publicly accessible databases, are weighted relative to each other specifically for the case of thin film photovoltaics. For this purpose, a survey among colleagues and an Analytic Hierarchy Process (AHP) approach are used, in order to obtain a relative, element-specific value for the supply risk. The aggregation of these

Optoelectronic properties of R-F magnetron sputtered Cadmium Tin Oxide (Cd2SnO4) thin films for CdS/CdTe thin film solar cell applications

International Nuclear Information System (INIS)

Jeyadheepan, K.; Thamilselvan, M.; Kim, Kyunghae; Yi, Junsin; Sanjeeviraja, C.

2015-01-01

Highlights: • Characterization of “as-prepared” Cd 2 SnO 4 thin films ideal for thin film solar cells. • Lowest value of resistivity with high mobility attained for the as-prepared Cd 2 SnO 4 films. • Maximum transmittance of 93% in the visible range for the as-prepared films. • Effect of substrate temperature on the scattering mechanism of TCO. - Abstract: The influence of substrate temperature on the microstructural behavior, optical, electrical properties and on the scattering mechanism of charge carriers were studied for the as-prepared radio-frequency (R-F) magnetron sputtered Cadmium Tin Oxide (Cd 2 SnO 4 ) thin films. Films prepared at the substrate temperature of 300 °C were found to be polycrystalline in nature with preferential orientation along (3 1 1) plane. Well pronounced Moss–Burstein shift, in the transmittance spectra with dispersions in the optical band gap from 3.07 to 3.30 eV, was observed at substrate temperatures between 25 and 300 °C. Optical property of high visible transmittance was retained by the films. Analysis of the electrical properties on the prepared crystalline Cd 2 SnO 4 films showed a calculated resistivity of 10 −3 –10 −4 Ω cm, with n-type carrier density in the range of 10 19 –10 20 cm −3 and the charge carrier mobility in the range of 63–30 cm 2 /V s. The effects of structural, compositional and optical properties on the scattering mechanism of charge carrier are elaborated and reported to be an experimental evidence for the theoretical predictions. The results revealed the essential DC electrical conduction behavior, which is ideal for the fabrication of Cd 2 SnO 4 -based CdS/CdTe thin film solar cells

Cadmium telluride quantum dots induce apoptosis in human breast cancer cell lines.

Science.gov (United States)

Naderi, Saeed; Zare, Hakimeh; Taghavinia, Nima; Irajizad, Azam; Aghaei, Mahmoud; Panjehpour, Mojtaba

2018-05-01

Semiconductor quantum dots (QDs), especially those containing cadmium, have undergone marked improvements and are now widely used nanomaterials in applicable biological fields. However, great concerns exist regarding their toxicity in biomedical applications. Because of the lack of sufficient data regarding the toxicity mechanism of QDs, this study aimed to evaluate the cytotoxicity of three types of QDs: CdTe QDs, high yield CdTe QDs, and CdTe/CdS core/shell QDs on two human breast cancer cell lines MDA-MB468 and MCF-7. The breast cancer cells were treated with different concentrations of QDs, and cell viability was evaluated via MTT assay. Hoechst staining was applied for observation of morphological changes due to apoptosis. Apoptotic DNA fragmentation was visualized by the agarose gel electrophoresis assay. Flow cytometric annexin V/propidium iodide (PI) measurement was used for apoptosis detection. A significant decrease in cell viability was observed after QDs treatment ( p < 0.05). Apoptotic bodies and chromatin condensation was observed by Hoechst staining. DNA fragmentation assay demonstrated a DNA ladder profile in the exposed cells and also annexin V/PI flow cytometry confirmed apoptosis in a dose-dependent manner. Our results revealed that CdTe, high yield CdTe, and CdTe/CdS core/shell QDs induce apoptosis in breast cancer cell lines in a dose-dependent manner. This study would help realizing the underlying cytotoxicity mechanism, at least partly, of CdTe QDs and may provide information for the development of nanotoxicology and safe use of biological applications of QDs.

Characterization of CdZnTe ambient temperature detectors

International Nuclear Information System (INIS)

Lavietes, A.

1994-09-01

A great deal of interest has been generated in the use of cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) detectors for ambient temperature detection of radionuclides. The addition of zinc to CdTe provides several benefits that enhance the materials operational characteristics at ambient temperature. Recent movement in the industry is to produce larger volume detectors using CdZnTe without much known about the effects of larger geometry on performance. The purpose of this study is to get an idea of the relationship of detector performance to both area and thickness variations

CdTe/CZT under high flux irradiation

International Nuclear Information System (INIS)

Strassburg, Matthias; Schroeter, Christian; Hackenschmied, Peter

2011-01-01

Direct converting quantum counting detectors based on cadmium telluride and cadmium zinc telluride have been investigated with respect to their properties under intense X-ray irradiation. To derive a detailed picture of the performance of such detectors, the influence of the electric field, the detector thickness, the temperature and the intensity of the X-ray irradiation was studied. The results are discussed in terms of the ''polarization'' phenomenon, a reduction of the electric field strength inside the detector due to immobile charge carriers accumulating during irradiation. Furthermore, the impact of Te-inclusions and -precipitates is presented.

Diagnostic Genesis Features of Au-Ag Selenide-Telluride Mineralization of Western Java Deposits

Directory of Open Access Journals (Sweden)

Euis Tintin Yuningsih

2016-01-01

Full Text Available DOI: 10.17014/ijog.3.1.67-76The ore mineralogy of the westernmost part of West Java such as Pongkor, Cibaliung, Cikidang, Cikotok, and Cirotan are characterized by the dominance of silver-arsenic-antimony sulfosalt with silver selenides and rarely tellurides over the argentite, whereas the eastern part of West Java including Arinem and Cineam deposits are dominated by silver-gold tellurides. Mineralogy of Se-type deposits at Pongkor, Cikidang, Cibaliung, Cisungsang, and Cirotan and Te-type deposits at Arinem and Cineam shows their different geochemical characteristics. Mineralogical and geochemical differences can be explained by variation of physico-chemical conditions that existed during gold-silver deposition by applying the phase relation among sulfide, telluride, and selenide mineral association in the deposits. The relative values of ƒSe2(g, ƒTe(g, and ƒS2(g control the actual presence of selenide or telluride minerals within the West Java deposits, which also depend on their concentrations in the hydrothermal fluid. Even though the concentration of selenium in the hydrothermal fluid of Te-type deposits might have been similar or even higher than that in the Se-type, early substitution of selenium in the sulfide minerals prevents its concentration in the hydrothermal fluid to the levels for precipitating selenide minerals. Therefore, early sulfide mineral deposition from reduction fluids will not increase the ƒSe2(g/ƒS2(g ratio to form selenide minerals in Te-type deposits of Arinem and Cineam, other than selenium-bearing sulfide mineral such as Se-bearing galena or Se-bearing pyrargyrite-proustite.

Technical and economic opportunities for CdTe PV at the turn of the millennium

International Nuclear Information System (INIS)

Meyers, Peter V.; Albright, Scot P.

2000-01-01

A variety of issues face the photovoltaic (PV) industry in order to meet a market penetration goal of more than gigawatt per year in worldwide sales before the year 2020. Although the PV market is dominated by silicon-based technology, it is not reasonable to project installed system prices of below $1.50/W in the next 5 or even 20 years without including the impact of polycrystalline thin films. Polycrystalline thin-film technologies, including cadmium telluride (CdTe)-based technologies, are a viable option for enabling lower costs, more rapid market expansion, and gigawatt/yr annual sales. A number of issues must be resolved in order to demonstrate a competitive price of energy to the customer in the range of the $0.11-0.16/kWh. (Author)

Development of planar waveguides in zinc telluride

International Nuclear Information System (INIS)

Valette, Serge

1977-02-01

Zinc telluride (ZnTe) is one of the most attractive semi-conductors for monolithic integrated optics. In this study, the general characteristics of the planar optical waveguides achieved by implantation of light ions in ZnTe are investigated. Different aspects of prism-coupling and coherent light guiding have been taken up theoretically and experimentally. Some assumptions about the physical origin of these structures are discussed in order to explain all these results and the weak losses which have been measured. [fr

Deposition of antimony telluride thin film by ECALE

Institute of Scientific and Technical Information of China (English)

GAO; Xianhui; YANG; Junyou; ZHU; Wen; HOU; Jie; BAO; Siqian; FAN; Xi'an; DUAN; Xingkai

2006-01-01

The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.

Photovoltaic power. Industries and market

International Nuclear Information System (INIS)

Muller, J.C.

2007-01-01

Photovoltaic conversion should become competitive with respect to other power generation sources before the second half of the 21. century. This article treats first of the different solar cell technologies (monocrystalline and polycrystalline silicon, thin film silicon, cadmium telluride-based materials, copper-indium selenide-based materials, multi-spectral cells, organic cells) with respect to their conversion efficiency, production and energy cost, and environmental impact. A second part describes the solar cells market, its growth with respect to the different applications (isolated sites, decentralized generation, power plants). A third part deals with the perspectives of photovoltaic conversion with respect to the advance in the development of new cell materials. (J.S.)

Iron telluride nanorods-based system for the detection of total mercury in blood

Energy Technology Data Exchange (ETDEWEB)

Roy, Prathik; Lin, Zong-Hong [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Liang, Chi-Te [Department of Physics, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Chang, Huan-Tsung, E-mail: changht@ntu.edu.tw [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China)

2012-12-15

Graphical abstract: Elucidation of the detection of mercury using iron telluride nanorods (FeTe NRs), and dose-response curve for varying concentrations of Hg{sup 2+}. Highlights: Black-Right-Pointing-Pointer Iron telluride nanorods (FeTe NRs) are prepared from tellurium nanowires (Te NWs). Black-Right-Pointing-Pointer Mercury telluride nanorods (HgTe NRs) form by cation exchange reaction of FeTe NRs. Black-Right-Pointing-Pointer Fe{sup 2+} ions released catalyze the oxidation of ABTS by H{sub 2}O{sub 2}. Black-Right-Pointing-Pointer Mercury is effectively determined in blood with an LOD of 1.31 nM at S/N ratio 3. - Abstract: We have developed a simple, colorimetric iron telluride (FeTe) nanorods (NRs) based system for the detection of mercury, mainly based on the cation exchange reaction between FeTe NRs and Hg{sup 2+}. FeTe NRs (length, 105 {+-} 21 nm) react with Hg{sup 2+} to form HgTe NRs (length, 112 {+-} 26 nm) and consequently release Fe{sup 2+} ions that catalyzes the oxidation between a peroxidase substrate 2,2 Prime -azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and H{sub 2}O{sub 2}. The concentration of Fe{sup 2+} and thereby Hg{sup 2+} can be determined by measuring the absorbance of the ABTS oxidized product at 418 nm. This approach allows the detection of Hg{sup 2+}, with a limit of detection of 1.31 nM at a signal-to-noise ratio 3 and a linear range 5-100 nM (R{sup 2} = 0.99). The low-cost, simple, sensitive, and reproducible assay has been validated for the detection of Hg{sup 2+} in a blood sample (SRM 955c), with the result being in good agreement with that provided by National Institute of Standards and Technology.

The effect of thermal annealing on the optical band gap of cadmium sulphide thin films, prepared by the chemical bath deposition technique

International Nuclear Information System (INIS)

Ampong, F. K.; Boakye, F.; Asare Donkor, N. K.

2010-01-01

Cadmium sulphide thin films have been prepared by the chemical bath deposition technique (ph 11, 70 degree centigrade). Two different sets of films were prepared under varied conditions and concentrations of their ions sources (Cd 2+ from cadmium nitrate, S 2- from thiourea) and Na 2 EDTA as a complexing agent. A UV mini-Schimazu UV-VIS Spectrophotometer was used to determine the optical absorbance of the films as a function of wavelength at room temperature over the wavelength range 200 - 600 nm. The samples were then thermally annealed for thirty minutes, at temperatures of 100 degree centigrade, and 200 degree centigrade, after which the absorbance of the films were again recorded. The band gap values obtained for the sample with 0.5 M CdS as deposited, annealed at 100 degree centigrade and 200 degree centigrade were 2.1 eV, 2.2 eV and 2.3 eV respectively. Whilst the values obtained for the sample 0.15 CdS as deposited, annealed at 100 degree centigrade and annealed at 200 degree centigrade were 2.0 eV, 2.01 eV and 2.02 eV respectively. The increase in band gap with annealing temperature might be attributed to the improvement in crystallinity in the films. (au)

Effect of the cadmium ion source on the structural and optical properties of chemical bath deposited CdS thin films

Science.gov (United States)

Rami, M.; Benamar, E.; Fahoume, M.; Chraibi, F.; Ennaoui, A.

1999-06-01

The chemical bath deposition (CBD) technique has been successfully used to deposit cadmium sulphide from cadmium chloride and cadmium acetate as the cadmium ion source and thiourea as the sulphur source on both glass microscope slide and indium tin oxide coated glass substrates. Various properties of the films such as surface morphology, crystallinity, optical properties and resistivitiy have been investigated. XRD patterns reveal that the CdS films deposited from cadmium chloride have an hexagonal structure. Their preferential orientation changes from (002) to (100) with the thermal annealing. Films deposited from cadmium acetate are amorphous but improve their crystallinity with annealing. SEM analysis shows that the grains of the as deposited films are randomly shaped and appear to be bigger in the case of the CdS prepared from cadmium chloride. The optical transmission of the layers are in the 70-80 % range for wavelength above the band gap absorption which makes them more appropriate as window material in heterojunction solar cells.

Effect of the cadmium ion source on the structural and optical properties of chemical bath deposited CdS thin films

Energy Technology Data Exchange (ETDEWEB)

Rami, M.; Benamar, E.; Fahoume, M.; Chraibi, F.; Ennaoui, A. [University Mohamed V, Laboratory of Materials Physics, Dept., Faculty of Sciences, Rabat (Morocco)

1999-06-01

The chemical bath deposition (CBD) technique has been successfully used to deposit cadmium sulphide from cadmium chloride and cadmium acetate as the cadmium ion source and thiourea as the sulphur source on both glass microscope slide and indium tin oxide coated glass substrates. Various properties of the films such as surface morphology, crystallinity, optical properties and resistivity have been investigated. XRD patterns reveal that the CdS films deposited from cadmium chloride have an hexagonal structure. Their preferential orientation changes from (002) to (100) with the thermal annealing. Films deposited from cadmium acetate are amorphous but improve their crystallinity with annealing. SEM analysis shows that the grains of the as deposited films are randomly shaped and appear to be bigger in the case of the CdS prepared from cadmium chloride. The optical transmission of the layers are in the 70-80% range for wavelength above the band gap absorption which makes them more appropriate as window material in heterojunction solar cells. (authors)

Effect of the cadmium chloride treatment on RF sputtered Cd{sub 0.6}Zn{sub 0.4}Te films for application in multijunction solar cells

Energy Technology Data Exchange (ETDEWEB)

Shimpi, Tushar M., E-mail: mechanical.tushar@gmail.com; Kephart, Jason M.; Swanson, Drew E.; Munshi, Amit H.; Sampath, Walajabad S. [Department of Mechanical Engineering, Colorado State University, 1320 Campus Delivery, Fort Collins, Colorado 80523 (United States); Abbas, A.; Walls, John M. [CREST (Centre for Renewable Energy Systems and Technology), Loughborough University, Loughborough LE11 3TU (United Kingdom)

2016-09-15

Single phase Cd{sub 0.6}Zn{sub 0.4}Te (CdZnTe) films of 1 μm thickness were deposited by radio frequency planar magnetron sputter deposition on commercial soda lime glass samples coated with fluorine-doped tin oxide and cadmium sulphide (CdS). The stack was then treated with cadmium chloride (CdCl{sub 2}) at different temperatures using a constant treatment time. The effect of the CdCl{sub 2} treatment was studied using optical, materials, and electrical characterization of the samples and compared with the as-deposited CdZnTe film with the same stack configuration. The band gap deduced from Tauc plots on the as-deposited CdZnTe thin film was 1.72 eV. The deposited film had good crystalline quality with a preferred orientation along the {111} plane. After the CdCl{sub 2} treatment, the absorption edge shifted toward longer wavelength region and new peaks corresponding to cadmium telluride (CdTe) emerged in the x-ray diffraction pattern. This suggested loss of zinc after the CdCl{sub 2} treatment. The cross sectional transmission electron microscope images of the sample treated at 400 °C and the energy dispersive elemental maps revealed the absence of chlorine along the grain boundaries of CdZnTe and residual CdTe. The presence of chlorine in the CdTe devices plays a vital role in drastically improving the device performance which was not observed in CdZnTe samples treated with CdCl{sub 2}. The loss of zinc from the surface and incomplete recrystallization of the grains together with the presence of high densities of stacking faults were observed. The surface images using scanning electron microscopy showed that the morphology of the grains changed from small spherical shape to large grains formed due to the fusion of small grains with distinct grain boundaries visible at the higher CdCl{sub 2} treatment temperatures. The absence of chlorine along the grain boundaries, incomplete recrystallization and distinct grain boundaries is understood to cause the poor

Feasibility of preparing patterned molybdenum coatings on bismuth telluride thermoelectric modules.

Energy Technology Data Exchange (ETDEWEB)

Sarobol, Pylin; Hall, Aaron Christopher; Miller, Stephen Samuel; Knight, Marlene E.; LePage, William S.; Sobczak, Catherine Elizabeth.; Wesolowski, Daniel Edward

2013-09-01

Molybdenum electrical interconnects for thermoelectric modules were produced by air plasma spraying a 30%CE%BCm size molybdenum powder through a laser-cut Kapton tape mask. Initial feasibility demonstrations showed that the molybdenum coating exhibited excellent feature and spacing retention (~170%CE%BCm), adhered to bismuth-telluride, and exhibited electrical conductivity appropriate for use as a thermoelectric module interconnect. A design of experiments approach was used to optimize air plasma spray process conditions to produce a molybdenum coating with low electrical resistivity. Finally, a molybdenum coating was successfully produced on a fullscale thermoelectric module. After the addition of a final titanium/gold layer deposited on top of the molybdenum coating, the full scale module exhibited an electrical resistivity of 128%CE%A9, approaching the theoretical resistivity value for the 6mm module leg of 112%CE%A9. Importantly, air plasma sprayed molybdenum did not show significant chemical reaction with bismuth-telluride substrate at the coating/substrate interface. The molybdenum coating microstructure consisted of lamellar splats containing columnar grains. Air plasma sprayed molybdenum embedded deeply (several microns) into the bismuth-telluride substrate, leading to good adhesion between the coating and the substrate. Clusters of round pores (and cracks radiating from the pores) were found immediately beneath the molybdenum coating. These pores are believed to result from tellurium vaporization during the spray process where the molten molybdenum droplets (2623%C2%B0C) transferred their heat of solidification to the substrate at the moment of impact. Substrate cooling during the molybdenum deposition process was recommended to mitigate tellurium vaporization in future studies.

Effects of various deposition times and RF powers on CdTe thin film growth using magnetron sputtering

Science.gov (United States)

Ghorannevis, Z.; Akbarnejad, E.; Ghoranneviss, M.

2016-09-01

Cadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio frequency (RF) magnetron sputtering system onto a glass substrate. To improve the properties of the CdTe film, effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer were used to study the structural, morphological and optical properties of the CdTe samples grown at different experimental conditions, respectively. Our results suggest that film properties strongly depend on the experimental parameters and by optimizing these parameters, it is possible to tune the desired structural, morphological and optical properties. From XRD data, it is found that increasing the deposition time and RF power leads to increasing the crystallinity as well as the crystal sizes of the grown film, and all the films represent zinc blende cubic structure. Roughness values given from AFM images suggest increasing the roughness of the CdTe films by increasing the RF power and deposition times. Finally, optical investigations reveal increasing the film band gaps by increasing the RF power and the deposition time.

Lead telluride with increased mechanical stability for cylindrical thermoelectric generators; Bleitellurid mit erhoehter mechanischer Stabilitaet fuer zylindrische thermoelektrische Generatoren

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Andreas

2013-04-30

The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb{sub 1-x}Ca{sub x}Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while its thermoelectric

Lead telluride with increased mechanical stability for cylindrical thermoelectric generators; Bleitellurid mit erhoehter mechanischer Stabilitaet fuer zylindrische thermoelektrische Generatoren

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Andreas

2013-04-30

The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb{sub 1-x}Ca{sub x}Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while

Time-dependent toxicity of cadmium telluride quantum dots on liver and kidneys in mice: histopathological changes with elevated free cadmium ions and hydroxyl radicals

Directory of Open Access Journals (Sweden)

Wang M

2016-05-01

Full Text Available Mengmeng Wang,1,2,* Jilong Wang,1,2,* Hubo Sun,1,2 Sihai Han,3 Shuai Feng,1 Lu Shi,1 Peijun Meng,1,2 Jiayi Li,1,2 Peili Huang,1,2 Zhiwei Sun1,2 1Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, 2Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 3College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, People’s Republic of China *These authors contributed equally to this work Abstract: A complete understanding of the toxicological behavior of quantum dots (QDs in vivo is of great importance and a prerequisite for their application in humans. In contrast with the numerous cytotoxicity studies investigating QDs, only a few in vivo studies of QDs have been reported, and the issue remains controversial. Our study aimed to understand QD-mediated toxicity across different time points and to explore the roles of free cadmium ions (Cd2+ and hydroxyl radicals (·OH in tissue damage. Male ICR mice were administered a single intravenous dose (1.5 µmol/kg of CdTe QDs, and liver and kidney function and morphology were subsequently examined at 1, 7, 14, and 28 days. Furthermore, ·OH production in the tissue was quantified by trapping ·OH with salicylic acid (SA as 2,3-dihydroxybenzoic acid (DHBA and detecting it using a high-performance liquid chromatography fluorescence method. We used the induction of tissue metallothionein levels and 2,3-DHBA:SA ratios as markers for elevated Cd2+ from the degradation of QDs and ·OH generation in the tissue, respectively. Our experimental results revealed that the QD-induced histopathological changes were time-dependent with elevated Cd2+ and ·OH, and could recover after a period of time. The Cd2+ and ·OH exhibited delayed effects in terms of histopathological abnormalities. Histological assessments performed at multiple time points might facilitate the evaluation of the biological safety of

Isolation, identification and cadmium adsorption of a high cadmium ...

African Journals Online (AJOL)

GREGORY

2010-09-27

Sep 27, 2010 ... 1School of Minerals Processing and Bioengineering, Central South University, Changsha, ... Cadmium is a non-essential ... (1994) reported that cadmium might interact ... uptake of cadmium, lead and mercury (Svecova et al.,.

Kelvin probe studies of cesium telluride photocathode for AWA photoinjector

Energy Technology Data Exchange (ETDEWEB)

Wisniewski, Eric E., E-mail: ewisniew@anl.gov [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Velazquez, Daniel [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Yusof, Zikri, E-mail: zyusof@hawk.iit.edu [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Spentzouris, Linda; Terry, Jeff [Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Sarkar, Tapash J. [Rice University, 6100 Main, Houston, TX 77005 (United States); Harkay, Katherine [Accelerator Science Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States)

2013-05-21

Cesium telluride is an important photocathode as an electron source for particle accelerators. It has a relatively high quantum efficiency (>1%), is sufficiently robust in a photoinjector, and has a long lifetime. This photocathode is grown in-house for a new Argonne Wakefield Accelerator (AWA) beamline to produce high charge per bunch (≈50nC) in a long bunch train. Here, we present a study of the work function of cesium telluride photocathode using the Kelvin probe technique. The study includes an investigation of the correlation between the quantum efficiency and the work function, the effect of photocathode aging, the effect of UV exposure on the work function, and the evolution of the work function during and after photocathode rejuvenation via heating. -- Highlights: ► The correlation between Quantum Efficiency (QE) and work function. ► How QE and work function evolve together. ► Rejuvenation of the photocathode via heating and the effect on work function. ► The effects on the work function due to exposure to UV light.

Optimization of material/device parameters of CdTe photovoltaic for solar cells applications

Science.gov (United States)

Wijewarnasuriya, Priyalal S.

2016-05-01

Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cell applications due to its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single-junction solar cell. The high absorption coefficient allows films as thin as 2.5 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 20% have been produced with poly-CdTe materials. This paper examines n/p heterostructure device architecture. The performance limitations related to doping concentrations, minority carrier lifetimes, absorber layer thickness, and surface recombination velocities at the back and front interfaces is assessed. Ultimately, the paper explores device architectures of poly- CdTe and crystalline CdTe to achieve performance comparable to gallium arsenide (GaAs).

Recent status and prospects of the EU-funded ALPINE project

Science.gov (United States)

Selleri, Stefano; Cucinotta, Annamaria; Poli, Federica; Coscelli, Enrico; Passaro, Davide; Leick, Lasse; Hernandez, Yves; Bermudez, Veronica; Zibik, Evgeny; Lichtenstein, Norbert; Lotter, Erwin; Bosio, Alessio; Polverini, Davide

2011-03-01

The ALPINE project is developing innovative fiber lasers for the scribing of new thin film photovoltaic modules with the aims to push forward the European research and development of fiber laser systems and solar energy exploitation. The fiber lasers will be based on photonic crystal fibers, which are characterized by unusual and interesting light guiding properties exploited to deliver high power with excellent beam quality and high resonator stability and efficiency, and will be applied to substitute mechanical scribing steps in the photovoltaic module production. In addition, new photovoltaic thin film technologies is applied, which is based on cadmium telluride and copper indium diselenide materials. With a potential conversion efficiency just below that of crystalline silicon, these new material approaches are ready to enter the market with low manufacturing costs for immediate economic or environment impact.

The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

International Nuclear Information System (INIS)

Apelblat, Alexander; Korin, Eli

2007-01-01

Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems

The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

Energy Technology Data Exchange (ETDEWEB)

Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Korin, Eli [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

2007-07-15

Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems.

Enhanced thermoelectric properties of bismuth telluride-organic hybrid films via graphene doping

International Nuclear Information System (INIS)

Rahman, Airul Azha Abd; Umar, Akrajas Ali; Salleh, Muhamad Mat; Chen, Xiaomei; Oyama, Munetaka

2016-01-01

The thermoelectric properties of graphene-doped bismuth telluride-PEDOT:PSS-glycerol (hybrid) films were investigated. Prior to the study, p-type and n-type hybrid films were prepared by doping the PEDOT:PSS-glycerol with the p- and n-type bismuth telluride. Graphene-doped hybrid films were prepared by adding graphene particles of concentration ranging from 0.02 to 0.1 wt% into the hybrid films. Films of graphene-doped hybrid system were then prepared on a glass substrate using a spin-coating technique. It was found that the electrical conductivity of the hybrid films increases with the increasing of the graphene-dopant concentration and optimum at 0.08 wt% for both p- and n-type films, namely 400 and 195 S/cm, respectively. Further increasing in the concentration caused a decreasing in the electrical conductivity. Analysis of the thermoelectric properties of the films obtained that the p-type film exhibited significant improvement in its thermoelectric properties, where the thermoelectric properties increased with the increasing of the doping concentration. Meanwhile, for the case of n-type film, graphene doping showed a negative effect to the thermoelectrical properties, where the thermoelectric properties decreased with the increasing of doping concentration. Seebeck coefficient (and power factor) for optimum p-type and n-type hybrid thin films, i.e., doped with 0.08 wt% of graphene, is 20 μV/K (and 160 μW m -1 K -2 ) and 10 μV/K (and 19.5 μW m -1 K -2 ), respectively. The obtained electrical conductivity and thermoelectric properties of graphene-doped hybrid film are interestingly several orders higher than the pristine hybrid films. A thermocouple device fabricated utilizing the p- and n-type graphene-doped hybrid films can generate an electric voltage as high as 2.2 mV under a temperature difference between the hot-side and the cold-side terminal as only low as 55 K. This is equivalent to the output power as high as 24.2 nW (for output load as high as 50

[Investigation of urinary cadmium reference of general population in two rural high background areas of soil cadmium and non-cadmium-polluted in China].

Science.gov (United States)

Han, Jingxiu; Li, Qiujuan; Yao, Dancheng; Zheng, Jiangang; Zhang, Wenli; Shang, Qi

2014-09-01

To study the reference of urinary. cadmium of the general population in rural high background areas of soil cadmium and non-cadmium contaminated in China. In rural high background areas of soil cadmium and non-cadmium contaminated, randomly selected non-occupational-cadmium exposed population 1134 people (male 519, female 615) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr 3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P,95 ) of urinary cadmium after correction by urinary Cr. Female median urinary cadmium was significantly higher than men, male smokers median urinary cadmium was significantly higher than male non-smokers (P 30 year-old. According to gender, and 15 -30, 30 years old, analysis the upper limit of cadmium in urine. The 95% upper limit of urinary cadmium of 30 year-old female (12.24 microg/gCr) was significantly higher than other populations ( population exceeded the upper limit (5 microg/gCr) of the occupational cadmium poisoning diagnostic criteria in China (GBZ 17-2002). In the two rural high background areas of soil cadmium and non-cadmium polluted , urinary cadmium reference of non-cadmium-occupational-exposed male is <9.0 microg/gCr, and female <13.0 microg/gCr.

Effects of chemical intermixing on electrical and thermal contact conductances at metallized bismuth and antimony telluride interfaces

Energy Technology Data Exchange (ETDEWEB)

Devender,; Mehta, Rutvik J.; Ramanath, Ganpati, E-mail: Ramanath@rpi.edu [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lofgreen, Kelly; Mahajan, Ravi [Intel Corporation, Assembly Test and Technology Development, Chandler, Arizona 85226 (United States); Yamaguchi, Masashi [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Borca-Tasciuc, Theodorian [Department of Mechanical Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2015-03-15

Tailoring electrical and thermal contact conductivities (Σ{sub c} and Γ{sub c}) across metallized pnictogen chalcogenide interfaces is key for realizing efficient thermoelectric devices. The authors report that Cu, Ni, Ti, and Ta diffusion and interfacial telluride formation with n-Bi{sub 2}Te{sub 3} and p-Sb{sub 2}Te{sub 3} influence both Σ{sub c} and Γ{sub c}. Cu metallization yields the highest Γ{sub c} and the lowest Σ{sub c}, correlating with maximal metal diffusion and copper telluride formation. Ni diffuses less and yields the highest Σ{sub c} with Sb{sub 2}Te{sub 3} due to p-type nickel telluride formation, which diminishes Σ{sub c} improvement with n-Bi{sub 2}Te{sub 3} interfaces. Ta and Ti contacts yield the lowest properties similar to that in Ni-metallized structures. These correlations between interfacial diffusion and phase formation on electronic and thermal transport properties will be important for devising suitable metallization for thermoelectric devices.

Magnetic Field Enhanced Superconductivity in Epitaxial Thin Film WTe2.

Science.gov (United States)

Asaba, Tomoya; Wang, Yongjie; Li, Gang; Xiang, Ziji; Tinsman, Colin; Chen, Lu; Zhou, Shangnan; Zhao, Songrui; Laleyan, David; Li, Yi; Mi, Zetian; Li, Lu

2018-04-25

In conventional superconductors an external magnetic field generally suppresses superconductivity. This results from a simple thermodynamic competition of the superconducting and magnetic free energies. In this study, we report the unconventional features in the superconducting epitaxial thin film tungsten telluride (WTe 2 ). Measuring the electrical transport properties of Molecular Beam Epitaxy (MBE) grown WTe 2 thin films with a high precision rotation stage, we map the upper critical field H c2 at different temperatures T. We observe the superconducting transition temperature T c is enhanced by in-plane magnetic fields. The upper critical field H c2 is observed to establish an unconventional non-monotonic dependence on temperature. We suggest that this unconventional feature is due to the lifting of inversion symmetry, which leads to the enhancement of H c2 in Ising superconductors.

Boron-doped cadmium oxide composite structures and their electrochemical measurements

Energy Technology Data Exchange (ETDEWEB)

Lokhande, B.J., E-mail: bjlokhande@yahoo.com [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Ambare, R.C. [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Mane, R.S. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606 (India); Bharadwaj, S.R. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2013-08-01

Graphical abstract: Conducting nano-fibrous 3% boron doped cadmium oxide thin films were prepared by SILAR and its super capacitive properties were studied. - Highlights: • Samples are of nanofibrous nature. • All samples shows pseudocapacitive behavior. • 3% B doped CdO shows good specific capacitance. • 3% B doped CdO shows maximum 74.93% efficiency at 14 mA/cm{sup 2}. • 3% B doped CdO shows 0.8 Ω internal resistance. - Abstract: Boron-doped and undoped cadmium oxide composite nanostructures in thin film form were prepared onto stainless steel substrates by a successive ionic layer adsorption and reaction method using aqueous solutions of cadmium nitrate, boric acid and 1% H{sub 2}O{sub 2}. As-deposited films were annealed at 623 K for 1 h. The X-ray diffraction study shows crystalline behavior for both doped and undoped films with a porous topography and nano-wires type architecture, as observed in SEM image. Wettability test confirms the hydrophilic surface with 58° contact angle value. Estimated band gap energy is around 1.9 eV. Electrochemical behavior of the deposited films is attempted in 1 M KOH electrolyte using cyclic voltammetry (CV), electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. Maximum values of the specific capacitance, specific energy and specific power obtained for 3% B doped CdO film at 2 mV/s scan rate are 20.05 F/g, 1.22 Wh/kg and 3.25 kW/kg, respectively.

Dynamic of cadmium accumulation in the internal organs of rats after exposure to cadmium chloride and cadmium sulphide nanoparticules of various sizes

Directory of Open Access Journals (Sweden)

Apykhtina O.L.

2017-06-01

Full Text Available The article presents the results of study of cadmium accumulation in the internal organs of Wistar rats after prolonged intraperitoneal administration of cadmium chloride and cadmium sulphide nanoparticles of 4-6 nm and 9-11 nm in size in a dose of 0.08 mg /kg/day calculated as cadmium. Toxic effects were evaluated after 30 injections (1.5 months, 60 injections (3 months, and 1.5 months after the exposure has been ceased. The results of the study showed that the most intensive accumulation of cadmium was observed in the kidneys and liver of experimental animals, which is due to the peculiarities of the toxicokinetics and the route of administration of cadmium compounds. In the kidneys, spleen and thymus of animals exposed to cadmium sulphide nanoparticles, a greater concentration of cadmium than in the organs of animals exposed to cadmium chloride was found. Cadmium accumulated more intensively in the spleen after exposure to larger nanoparticles, than in the kidneys and thymus. In the liver, heart, aorta and brain significant accumulation was observed after cadmium chloride exposure.

Cadmium and renal cancer

International Nuclear Information System (INIS)

Il'yasova, Dora; Schwartz, Gary G.

2005-01-01

Background: Rates of renal cancer have increased steadily during the past two decades, and these increases are not explicable solely by advances in imaging modalities. Cadmium, a widespread environmental pollutant, is a carcinogen that accumulates in the kidney cortex and is a cause of end-stage renal disease. Several observations suggest that cadmium may be a cause of renal cancer. Methods: We performed a systematic review of the literature on cadmium and renal cancer using MEDLINE for the years 1966-2003. We reviewed seven epidemiological and eleven clinical studies. Results: Despite different methodologies, three large epidemiologic studies indicate that occupational exposure to cadmium is associated with increased risk renal cancer, with odds ratios varying from 1.2 to 5.0. Six of seven studies that compared the cadmium content of kidneys from patients with kidney cancer to that of patients without kidney cancer found lower concentrations of cadmium in renal cancer tissues. Conclusions: Exposure to cadmium appears to be associated with renal cancer, although this conclusion is tempered by the inability of studies to assess cumulative cadmium exposure from all sources including smoking and diet. The paradoxical findings of lower cadmium content in kidney tissues from patients with renal cancer may be caused by dilution of cadmium in rapidly dividing cells. This and other methodological problems limit the interpretation of studies of cadmium in clinical samples. Whether cadmium is a cause of renal cancer may be answered more definitively by future studies that employ biomarkers of cadmium exposure, such as cadmium levels in blood and urine

Studies on voltammetric determination of cadmium in samples containing native and digested proteins

Energy Technology Data Exchange (ETDEWEB)

Drozd, Marcin; Pietrzak, Mariusz, E-mail: mariusz@ch.pw.edu.pl; Malinowska, Elżbieta

2014-03-01

Highlights: • Proteins exhibit diverse impact on the DPASV cadmium signals. • Proteins subjected to HNO{sub 3} introduce less interference, than the native ones. • Optimal amount of SDS depends on the kind of protein. • Presence of thiolated coating agents of QDs do not influence the analysis. - Abstract: This work focuses on determination of cadmium ions using anodic stripping voltammetry (ASV) on thin film mercury electrode in conditions corresponding to those obtained after digestion of cadmium-based quantum dots and their conjugates. It presents the impact of selected proteins, including potential receptors and surface blocking agents on the voltammetric determination of cadmium. Experiments regarding elimination of interferences related to proteins presence using sodium dodecyl sulfate (SDS) are also shown. Effect of SDS on selected analytical parameters and simplicity of analyses carried out was investigated in the framework of current studies. The significant differences of influence among tested proteins on ASV cadmium determination, as well as the variability in SDS effectiveness as the antifouling agent were observed and explained. This work is especially important for those, who design new bioassays and biosensors with a use of quantum dots as electrochemical labels, as it shows what problems may arise from presence of native and digested proteins in tested samples.

Improvement of cadmium phytoremediation after soil inoculation with a cadmium-resistant Micrococcus sp.

Science.gov (United States)

Sangthong, Chirawee; Setkit, Kunchaya; Prapagdee, Benjaphorn

2016-01-01

Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L.

Thin-film-based CdTe photovoltaic module characterization: measurements and energy prediction improvement.

Science.gov (United States)

Lay-Ekuakille, A; Arnesano, A; Vergallo, P

2013-01-01

Photovoltaic characterization is a topic of major interest in the field of renewable energy. Monocrystalline and polycrystalline modules are mostly used and, hence characterized since many laboratories have data of them. Conversely, cadmium telluride (CdTe), as thin-film module are, in some circumstances, difficult to be used for energy prediction. This work covers outdoor testing of photovoltaic modules, in particular that regarding CdTe ones. The scope is to obtain temperature coefficients that best predict the energy production. A First Solar (K-275) module has been used for the purposes of this research. Outdoor characterizations were performed at Department of Innovation Engineering, University of Salento, Lecce, Italy. The location of Lecce city represents a typical site in the South Italy. The module was exposed outdoor and tested under clear sky conditions as well as under cloudy sky ones. During testing, the global-inclined irradiance varied between 0 and 1500 W/m(2). About 37,000 I-V characteristics were acquired, allowing to process temperature coefficients as a function of irradiance and ambient temperature. The module was characterized by measuring the full temperature-irradiance matrix in the range from 50 to 1300 W/m(2) and from -1 to 40 W/m(2) from October 2011 to February 2012. Afterwards, the module energy output, under real conditions, was calculated with the "matrix method" of SUPSI-ISAAC and the results were compared with the five months energy output data of the same module measured with the outdoor energy yield facility in Lecce.

Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

International Nuclear Information System (INIS)

Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

1993-01-01

The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

Determination of the mean inner potential of cadmium telluride via electron holography

Science.gov (United States)

Cassidy, C.; Dhar, A.; Shintake, T.

2017-04-01

Mean inner potential is a fundamental material parameter in solid state physics and electron microscopy and has been experimentally measured in CdTe, a technologically important semiconductor. As a first step, the inelastic mean free path for electron scattering in CdTe was determined, using electron energy loss spectroscopy, to enable precise thickness mapping of thin CdTe lamellae. The obtained value was λi(CdTe, 300 kV) = 192 ± 10 nm. This value is relatively large, given the high density of the material, and is discussed in the text. Next, electron diffraction and specimen tilting were employed to identify weakly diffracting lattice orientations, to enable the straightforward measurement of the electron phase shift. Finally, electron holography was utilized to quantitatively map the phase shift experienced by electron waves passing through a CdTe crystal, with several different propagation vectors. Utilization of both thickness and phase data allowed computation of mean inner potential as V0 (CdTe) = 14.0 ± 0.9 V, within the range of previous theoretical estimates.

XAFS studies of nickel-doped lead telluride

International Nuclear Information System (INIS)

Radisavljevic, Ivana; Novakovic, Nikola; Ivanovic, Nenad; Romcevic, Nebojsa; Manasijevic, Miodrag; Mahnke, Heinz-Eberhard

2009-01-01

The problem of impurities and defect states in lead telluride-based semiconductors is of crucial importance for their practical applications. X-ray absorption fine structure (XAFS) techniques are capable to address some of the key issues regarding impurities position, their valent state, as well as the local structural changes of the host lattice in the immediate surrounding of the impurity atoms. In this paper we present the results of the Ni K-absorption edge XAFS studies of Ni-doped PbTe at different temperatures. Analysis of near edge and extended XAFS regions of the measured spectra provided information about exact local environment and lattice ordering around Ni atoms.

Cadmium accumulation by Axonopus compressus (Sw.) P. Beauv and Cyperus rotundas Linn growing in cadmium solution and cadmium-zinc contaminated soil

OpenAIRE

Paitip Thiravetyan; Vibol Sao; Woranan Nakbanpote

2007-01-01

This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass) and Axonopus compressus (Sw.) P. Beauv (Carpetgrass) for cadmium removal from cadmium solution andcadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increasedwith the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with...

Trace analysis of lead and cadmium in seafoods by differential pulse anodic stripping voltametry

International Nuclear Information System (INIS)

Sumera, F.C.; Verceluz, F.P.; Kapauan, P.A.

1979-01-01

A method for the simultaneous determination of cadmium and lead in seafoods is described. The sample is dry ashed in a muffle furnace elevating the temperature gradually up to 500 0 C. The ashed sample is treated with concentrated nitric acid, dried on a heating plate and returned to the muffle furnace for further heating. The treated ash is then dissolved in 1 N HCL acetate buffer and citric acid are added and the pH adjusted to 3.6-4. The resulting solution is analyzed for lead and cadmium by differential pulse anodic stripping voltametry (DPASV) using a wax-impregnated graphite thin film electrode. The average recoveries of 0.4 of cadmium and lead added to 5 fish samples were 97% and 99% respectively. The standard deviations, on a homogenized shark sample for lead and cadmium analysis were 6.7 ppb and 12.3 ppb, respectively, and the relative standard deviations were 21.0% and 15.5% respectively. Studies on instrumental parameters involved in the DPASV step of analysis and methods of measuring peak current signals were also made. (author)

Morphology, microstructure, and magnetic properties of ordered large-pore mesoporous cadmium ferrite thin film spin glasses.

Science.gov (United States)

Reitz, Christian; Suchomski, Christian; Chakravadhanula, Venkata Sai Kiran; Djerdj, Igor; Jagličić, Zvonko; Brezesinski, Torsten

2013-04-01

Herein, we report the synthesis, microstructure, and magnetic properties of cadmium ferrite (CdFe2O4) thin films with both an ordered cubic network of 18 nm diameter pores and single-phase spinel grains averaging 13 nm in diameter. These mesoporous materials were produced through facile polymer templating of hydrated nitrate salt precursors. Both the morphology and the microstructure, including cation site occupancy and electronic bonding configuration, were analyzed in detail by electron microscopy, grazing incidence small-angle X-ray scattering, Raman and X-ray photoelectron spectroscopy, and N2-physisorption. The obtained data demonstrate that the network of pores is retained up to annealing temperatures as high as 650 °C--the onset of crystallization is at ϑ = (590 ± 10) °C. Furthermore, they show that the polymer-templated samples exhibit a "partially" inverted spinel structure with inversion parameter λ = 0.40 ± 0.02. This differs from microcrystalline CdFe2O4 which shows virtually no inversion. Magnetic susceptibility studies reveal ferrimagnetic spin coupling below 147 K and further point to the likelihood of glassy behavior at low temperature (T(f) ≈ 60 K). In addition, analysis of room temperature magnetization data indicates the presence of sub-10 nm diameter superparamagnetic clusters in an otherwise paramagnetic environment.

Cadmium accumulation by Axonopus compressus (Sw. P. Beauv and Cyperus rotundas Linn growing in cadmium solution and cadmium-zinc contaminated soil

Directory of Open Access Journals (Sweden)

Paitip Thiravetyan

2007-05-01

Full Text Available This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass and Axonopus compressus (Sw. P. Beauv (Carpetgrass for cadmium removal from cadmium solution andcadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increasedwith the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with Cd-contaminated zinc silicate residue (65% Si, 19% Ca, 2% Zn, 1% Mg and 0.03% Cd at the ratio of 50:50 (w/wfor 30 days showed that C. rotundas Linn accumulated cadmium in root and shoot to 2,178 and 1,144 mg kg-1 dry weight, respectively. A. compressus (Sw. P. Beauv accumulated cadmium in root and shoot to 1,965and 669 mg kg-1 dry weight, respectively. Scanning electron microscope connected to energy-dispersive X-ray spectroscopy suggested that the mechanism of cadmium accumulation by both grasses involved thecadmium precipitation in the stable form of cadmium silicate, which indicated that C. rotundas Linn and A. compressus (Sw. P. Beauv could be grown to prevent soil erosion and to remediate cadmium-contaminatedsoil.

Analysis of MCNP simulated gamma spectra of CdTe detectors for boron neutron capture therapy.

Science.gov (United States)

Winkler, Alexander; Koivunoro, Hanna; Savolainen, Sauli

2017-06-01

The next step in the boron neutron capture therapy (BNCT) is the real time imaging of the boron concentration in healthy and tumor tissue. Monte Carlo simulations are employed to predict the detector response required to realize single-photon emission computed tomography in BNCT, but have failed to correctly resemble measured data for cadmium telluride detectors. In this study we have tested the gamma production cross-section data tables of commonly used libraries in the Monte Carlo code MCNP in comparison to measurements. The cross section data table TENDL-2008-ACE is reproducing measured data best, whilst the commonly used ENDL92 and other studied libraries do not include correct tables for the gamma production from the cadmium neutron capture reaction that is occurring inside the detector. Furthermore, we have discussed the size of the annihilation peaks of spectra obtained by cadmium telluride and germanium detectors. Copyright © 2017 Elsevier Ltd. All rights reserved.

A study on dependence of the structural, optical and electrical properties of cadmium lead sulphide thin films on Cd/Pb ratio

Energy Technology Data Exchange (ETDEWEB)

Nair, Sinitha B., E-mail: sinithanair@gmail.com, E-mail: anithakklm@gmail.com; Abraham, Anitha, E-mail: sinithanair@gmail.com, E-mail: anithakklm@gmail.com; Philip, Rachel Reena, E-mail: reenatara@rediffmail.com [Thin film research Lab, U.C. College, Aluva, Kerala (India); Pradeep, B., E-mail: bp@cusat.ac.in [Solid State Physics Laboratory, Cochin University of science and Technology, Cochin (India); Shripathi, T., E-mail: shri@csr.res.in, E-mail: vganesancsr@gmail.com; Ganesan, V., E-mail: shri@csr.res.in, E-mail: vganesancsr@gmail.com [UGC-DAE CSR, Khandwa Road, Indore, 452001, Madhya Pradesh (India)

2014-10-15

Cadmium Lead Sulphide thin films with systematic variation in Cd/Pb ratio are prepared at 333K by CBD, adjusting the reagent-molarity, deposition time and pH. XRD exhibits crystalline-amorphous transition as Cd% exceeds Pb%. AFM shows agglomeration of crystallites of size ∼50±5 nm. EDAX assess the composition whereas XPS ascertains the ternary formation, with binding energies of Pb4f{sub 7/2} and 4f{sub 5/2}, Cd3d{sub 5/2} and 3d{sub 3/2} and S2p at 137.03, 141.606, 404.667, 412.133 and 160.218 eV respectively. The optical absorption spectra reveal the variance in the direct allowed band gaps, from 1.57eV to 2.42 eV as Cd/Pb ratio increases from 0.2 to 2.7, suggesting possibility of band gap engineering in the n-type films.

Thermoluminescent properties of nanocrystalline ZnTe thin films: Structural and morphological studies

Science.gov (United States)

Rajpal, Shashikant; Kumar, S. R.

2018-04-01

Zinc Telluride (ZnTe) is a binary II-VI direct band gap semiconducting material with cubic structure and having potential applications in different opto-electronic devices. Here we investigated the effects of annealing on the thermoluminescence (TL) of ZnTe thin films. A nanocrystalline ZnTe thin film was successfully electrodeposited on nickel substrate and the effect of annealing on structural, morphological, and optical properties were studied. The TL emission spectrum of as deposited sample is weakly emissive in UV region at ∼328 nm. The variation in the annealing temperature results into sharp increase in emission intensity at ∼328 nm along with appearance of a new peak at ∼437 nm in visible region. Thus, the deposited nanocrystalline ZnTe thin films exhibited excellent thermoluminescent properties upon annealing. Furthermore, the influence of annealing (annealed at 400 °C) on the solid state of ZnTe were also studied by XRD, SEM, EDS, AFM. It is observed that ZnTe thin film annealed at 400 °C after deposition provide a smooth and flat texture suited for optoelectronic applications.

Cadmium, an environmental poison

Energy Technology Data Exchange (ETDEWEB)

Oestergaard, A K

1974-04-15

In recent years, industrial employment of cadmium has increased considerably. Cadmium is now present in the environment and has caused acute and chronic poisoning. Inhalation of cadmium vapor or dust causes pulmonary damage while the kidney is the critical organ in absorption of cadmium. The element accumulates in the kidney and causes tubular damage or 200 ppm in the renal cortex. In animal experiments, cadmium may cause raised blood pressure, sterility and malignant tumors. On account of the pronounced tendency of cadmium to accumulate and its toxicity, it is important to trace sources and to reduce exposure of the population. 62 references.

Cadmium and the kidney.

OpenAIRE

Friberg, L

1984-01-01

The paper is a review of certain aspects of importance of cadmium and the kidney regarding the assessment of risks and understanding of mechanisms of action. The review discusses the following topics: history and etiology of cadmium-induced kidney dysfunction and related disorders; cadmium metabolism, metallothionein and kidney dysfunction; cadmium in urine as indicator of body burden, exposure and kidney dysfunction; cadmium levels in kidney and liver as indicators of kidney dysfunction; cha...

Cadmium

NARCIS (Netherlands)

Meulenbelt, Jan

2017-01-01

Together with zinc and mercury, cadmium belongs to group IIb of the periodic table. It can be found in rocks, soil, water, coal, zinc ore, lead ore, and copper ore. In the environment, cadmium is present predominantly as the oxide or as the chloride, sulfide, or sulfate salt. It has no recognizable

Insights into cadmium diffusion mechanisms in two-stage diffusion profiles in solar-grade Cu(In,Ga)Se2 thin films

International Nuclear Information System (INIS)

Biderman, N. J.; Sundaramoorthy, R.; Haldar, Pradeep; Novak, Steven W.; Lloyd, J. R.

2015-01-01

Cadmium diffusion experiments were performed on polished copper indium gallium diselenide (Cu(In,Ga)Se 2 or CIGS) samples with resulting cadmium diffusion profiles measured by time-of-flight secondary ion mass spectroscopy. Experiments done in the annealing temperature range between 275 °C and 425 °C reveal two-stage cadmium diffusion profiles which may be indicative of multiple diffusion mechanisms. Each stage can be described by the standard solutions of Fick's second law. The slower cadmium diffusion in the first stage can be described by the Arrhenius equation D 1  = 3 × 10 −4  exp (− 1.53 eV/k B T) cm 2  s −1 , possibly representing vacancy-meditated diffusion. The faster second-stage diffusion coefficients determined in these experiments match the previously reported cadmium diffusion Arrhenius equation of D 2  = 4.8 × 10 −4  exp (−1.04 eV/k B T) cm 2  s −1 , suggesting an interstitial-based mechanism

Flux of Cadmium through Euphausiids

International Nuclear Information System (INIS)

Benayoun, G.; Fowler, S.W.; Oregioni, B.

1976-01-01

Flux of the heavy metal cadmium through the euphausiid Meganyctiphanes norvegica was examined. Radiotracer experiments showed that cadmium can be accumulated either directly from water or through the food chain. When comparing equilibrium cadmium concentration factors based on stable element measurements with those obtained from radiotracer experiments, it is evident that exchange between cadmium in the water and that in euphausiid tissue is a relatively slow process, indicating that, in the long term, ingestion of cadmium will probably be the more important route for the accumulation of this metal. Approximately 10% of cadmium ingested by euphausiids was incorporated into internal tissues when the food source was radioactive Artemia. After 1 month cadmium, accumulated directly from water, was found to be most concentrated in the viscera with lesser amounts in eyes, exoskeleton and muscle, respectively. Use of a simple model, based on the assumption that cadmium taken in by the organism must equal cadmium released plus that accumulated in tissue, allowed assessment of the relative importance of various metabolic parameters in controlling the cadmium flux through euphausiids. Fecal pellets, due to their relatively high rate of production and high cadmium content, accounted for 84% of the total cadmium flux through M. norvegica. Comparisons of stable cadmium concentrations in natural euphausiid food and the organism's resultant fecal pellets indicate that the cadmium concentration in ingested material was increased nearly 5-fold during its passage through the euphausiid. From comparisons of all routes by which cadmium can be released from M. norvegica to the water column, it is concluded that fecal pellet deposition represents the principal mechanism effecting the downward vertical transport of cadmium by this species. (author)

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

Energy Technology Data Exchange (ETDEWEB)

Braga, A., E-mail: antonio.braga@iit.it [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Baratto, C. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Bontempi, E. [INSTM and Chemistry for Technologies Laboratory, University of Brescia, Via Branze 28, 25133 Brescia (Italy); Colombi, P. [Centro Coating C.S.M.T. Gestione S.c.a.r.l., Via Branze, 45 25123 Brescia (Italy); Sberveglieri, G. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy)

2014-03-31

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO{sub 2}) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T{sub avg} ≥ 90%) along with competitive sheet resistance (R{sub sheet} ≤ 15 Ω/sq), while a very thin layer of TiO{sub 2} (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO{sub 2} transparent front contact by sputtering. • Very thin TiO{sub 2} buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells.

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

International Nuclear Information System (INIS)

Braga, A.; Baratto, C.; Bontempi, E.; Colombi, P.; Sberveglieri, G.

2014-01-01

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO 2 ) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T avg ≥ 90%) along with competitive sheet resistance (R sheet ≤ 15 Ω/sq), while a very thin layer of TiO 2 (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO 2 transparent front contact by sputtering. • Very thin TiO 2 buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells

Calcium enhances cadmium tolerance and decreases cadmium ...

African Journals Online (AJOL)

We aimed at characterizing mechanisms controlling cadmium accumulation in lettuce, which is a food crop showing one of the highest capacities to accumulate this toxic compound. In this study, plants from three lettuce varieties were grown for eight days on media supplemented or not with cadmium (15 μM CdCl2) and ...

Production of CdTe Semiconductor Thin Films by Electrodeposition Technique for Solar Cell Applications

Directory of Open Access Journals (Sweden)

Ahmet PEKSÖZ

2016-08-01

Full Text Available Electro-deposited cadmium tellurite (CuTe thin film was grown onto ITO-coated glass substrate for 120 seconds at the room temperature and a constant cathodic potential of -0.85 V. Deposition solution was prepared from cadmium chloride (CdCl2, sodium tellurite (Na2TeO3 and pure water. The pH value of the deposition solution was adjusted to 2.0 by adding HCl. The EDX analysis shows that the film has 52% Cd and 48% Te elemental compositions. Film thickness was found to be 140 nm. The CdTe thin film exhibits p-type semiconductor character, and has an energy bandgap of 1.47 eV. 

Alberi Validates New Theory, Sheds Light on Semiconductors | News | NREL

Science.gov (United States)

(cadmium telluride), and GaN (gallium nitride), which are used for cell phones, solar panels, and LED suppressing defects with light, which may allow higher efficiencies in solar panels, greater lifespan for LED

Cathodoluminescence and ion implantation of cadmium sulphide/cuprous sulphide solar cells

Energy Technology Data Exchange (ETDEWEB)

Glew, R W; Bryant, F J

1975-10-01

By the use of implantation with copper ions or oxygen ions of 50 keV energy, changes in the cathodoluminescence emission spectrum from cadmium sulfide/cuprous sulfide thin film manufactured solar cells have been correlated with changes in the phases of the cuprous sulfide layer. Thus, monitoring the relative intensities of cathodoluminescence emission bands affords a method of assessing the cuprous sulfide layer and possibly predicting the performance of the cells.

Magneto-photoconductivity of three dimensional topological insulator bismuth telluride

Science.gov (United States)

Cao, Bingchen; Eginligil, Mustafa; Yu, Ting

2018-03-01

Magnetic field dependence of the photocurrent in a 3D topological insulator is studied. Among the 3D topological insulators bismuth telluride has unique hexagonal warping and spin texture which has been studied by photoemission, scanning tunnelling microscopy and transport. Here, we report on low temperature magneto-photoconductivity, up to 7 T, of two metallic bismuth telluride topological insulator samples with 68 and 110 nm thicknesses excited by 2.33 eV photon energy along the magnetic field perpendicular to the sample plane. At 4 K, both samples exhibit negative magneto-photoconductance below 4 T, which is as a result of weak-antilocalization of Dirac fermions similar to the previous observations in electrical transport. However the thinner sample shows positive magneto-photoconductance above 4 T. This can be attributed to the coupling of surface states. On the other hand, the thicker sample shows no positive magneto-photoconductance up to 7 T since there is only one surface state at play. By fitting the magneto-photoconductivity data of the thicker sample to the localization formula, we obtain weak antilocalization behaviour at 4, 10, and 20 K, as expected; however, weak localization behaviour at 30 K, which is a sign of surface states masked by bulk states. Also, from the temperature dependence of phase coherence length bulk carrier-carrier interaction is identified separately from the surface states. Therefore, it is possible to distinguish surface states by magneto-photoconductivity at low temperature, even in metallic samples.

Impacting Innovation and Commercialization: NREL's Partnering Facilities

Science.gov (United States)

pioneer cadmium telluride (CdTe) solar panels with industry. DOE recognized the lab's role, and NREL's deposits uniform layers of semiconductor material for solar panels, won a 2003 R&D100 Award and was

Application of CdTe for the NeXT mission

International Nuclear Information System (INIS)

Takahashi, Tadayuki; Nakazawa, Kazuhiro; Watanabe, Shin; Sato, Goro; Mitani, Takefumi; Tanaka, Takaaki; Oonuki, Kousuke; Tamura, Ken'ichi; Tajima, Hiroyasu; Kamae, Tuneyoshi; Madejski, Greg; Nomachi, Masaharu; Fukazawa, Yasushi; Makishima, Kazuo; Kokubun, Motohide; Terada, Yukikatsu; Kataoka, Jun; Tashiro, Makoto

2005-01-01

Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and γ-ray detection. The high-atomic number of the materials (Z Cd =48,Z Te =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (E g =1.5eV) allows to operate the detector at room temperature. Based on recent achievements in high-resolution CdTe detectors, in the technology of ASICs and in bump-bonding, we have proposed the novel hard X-ray and γ-ray detectors for the NeXT mission in Japan. The high-energy response of the super mirror onboard NeXT will enable us to perform the first sensitive imaging observations up to 80keV. The focal plane detector, which combines a fully depleted X-ray CCD and a pixellated CdTe detector, will provide spectra and images in the wide energy range from 0.5 to 80keV. In the soft γ-ray band up to ∼ 1MeV, a narrow field-of-view Compton γ-ray telescope utilizing several tens of layers of thin Si or CdTe detector will provide precise spectra with much higher sensitivity than present instruments. The continuum sensitivity will reach several x10 -8 photons -1 keV -1 cm -2 in the hard X-ray region and a few x10 -7 photons -1 keV -1 cm -2 in the soft γ-ray region

Effects of cadmium electrode properties on nickel-cadmium cell performance

International Nuclear Information System (INIS)

Zimmerman, A.H.

1986-01-01

Tests have been conducted on a number of nickel-cadmium cells that have exhibited a variety of performance problems, ranging from high voltages and pressures during overcharge to low capacity. The performance problems that have been specifically linked to the cadmium electrode are primarily related to two areas, poor sinter and the buildup of excessive pressure during overcharge. A number of specific nickel-cadmium cell and cadmium electrode characterists have been studied in this work to determine what the effects of poor sinter are, and to determine what factors are important in causing excessive pressures during overcharge in cells that otherwise appear normal. Several of the tests appear suitable for screening cells and electrodes for such problems

Optimization of CZT Detectors with Sub-mm Pixel Pitches Project

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop and optimize 0.5 cm thick Cadmium Zinc Telluride (CZT) detectors with very small pixel pitches, i.e. 350 micron and 600 micron. The proposed...

Chemical Bath Deposition and Characterization of CdS layer for CZTS Thin Film Solar Cell

OpenAIRE

Kamal, Tasnim; Parvez, Sheikh; Matin, Rummana; Bashar, Mohammad Shahriar; Hossain, Tasnia; Sarwar, Hasan; Rashid, Mohammad Junaebur

2016-01-01

CZTS is a new type of an absorber and abundant materials for thin film solar cells (TFSC). Cadmium sulfide (CdS) is the n-type buffer layer of it with band gap of 2.42 eV. Cadmium sulfide (CdS) buffer layer of CZTS solar cell was deposited on soda-lime glass substrates by the Chemical Bath Deposition(CBD) method, using anhydrous Cadmium chloride(CdCl_2) and Thiourea (CS(NH_2)_2). Deposition of CdS using CBD is based on the slow release of Cd^ ions and S^ ions in an alkaline bath which is achi...

Solid-state cadmium telluride radiation detector

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, Yoji; Kitamoto, Hisashi; Hosomatsu, Haruo

1984-09-01

The growth of CdTe single crystal and its application to CdTe detector array was studied for X-ray computed tomography (XCT) equipment. A p-type CdTe single crystal with 10/sup 4/ ohm.cm specific resistivity was grown in a quartz ampoule under vapor pressure control of Cd in a vertical Bridgman furnace. An 18-element detector array was fabricated with this single crystal. The detector was operated with no bias and the sensitivity was confirmed to be between 2.8 x 10/sup -12/ and 14 x 10/sup -12/ A.h/(R.mm/sup 2/). Commercial CdTe single crystal was used to manufacture as 560-element detector array for XCT. Results show that CdTe detector is sensitive, linear and has high resolution.

Molecular basis of cadmium toxicity

Energy Technology Data Exchange (ETDEWEB)

Nath, R; Prasad, R; Palinal, V K; Chopra, R K

1984-01-01

Cadmium has been shown to manifest its toxicity in human and animals by mainly accumulating in almost all of the organs. The kidney is the main target organ where it is concentrated mainly in the cortex. Environmental exposure of cadmium occurs via food, occupational industries, terrestrial and aquatic ecosystem. At molecular level, cadmium interferes with the utilization of essential metals e.g. Ca, Zn, Se, Cr and Fe and deficiencies of these essential metals including protein and vitamins, exaggerate cadmium toxicity, due to its increased absorption through the gut and greater retention in different organs as metallothionein (Cd-Mt). Cadmium transport, across the intestinal and renal brush border membrane vesicles, is carrier mediated and it competes with zinc and calcium. It has been postulated that cadmium shares the same transport system. Cadmium inhibits protein synthesis, carbohydrate metabolism and drug metabolizing enzymes in liver of animals. Chronic environmental exposure of cadmium produces hypertension in experimental animals. Functional changes accompanying cadmium nephropathy include low molecular weight proteinuria which is of tubular origin associated with excess excretion of proteins such as beta 2 microglobulin, metallothionein and high molecular weight proteinuria of glomerular origin (excretion of proteins such as albumin IgG, transferrin etc.). Recent data has shown that metallothionein is more nephrotoxic to animals. Cadmium is also toxic to central nervous system. It causes an alterations of cellular functions in lungs. Cadmium affects both humoral and cell mediated immune response in animals. Cadmium induces metallothionein in liver and kidney but under certain nutritional deficiencies like protein-calorie malnutrition and calcium deficiency, enhanced induction and greater accumulation of cadmium metallothionein has been observed.

Cadmium-containing waste and recycling possibilities

International Nuclear Information System (INIS)

Wiegand, V.; Rauhut, A.

1981-01-01

To begin with, the processes of cadmium production from zinc ores in smelting plants or from intermediates of other metal works are described. A considerable amount of the cadmium is obtained in the recycling process in zinc, lead, and copper works. The way of the cadmium-containing intermediaries, processing, enrichment, and disposal of cadmium waste are described. Uses of cadmium and its compounds are mentioned, and cadmium consumption in the years 1973-1977 in West Germany is presented in a table. Further chapters discuss the production and the way of waste during production and processing of cadmium-containing products, the problem of cadmium in household refuse and waste incineration plants, and the problem of cadmium emissions. (IHOE) [de

Tailoring and optimization of optical properties of CdO thin films for gas sensing applications

Science.gov (United States)

Rajput, Jeevitesh K.; Pathak, Trilok K.; Kumar, V.; Swart, H. C.; Purohit, L. P.

2018-04-01

Cadmium oxide (CdO) thin films have been deposited onto glass substrates using different molar concentrations (0.2 M, 0.5 M and 0.8 M) of cadmium acetate precursor solutions using a sol-gel spin coating technique. The structural, morphological, optical and electrical results are presented. X-ray diffraction patterns indicated that the CdO films of different molarity have a stable cubic structure with a (111) preferred orientation at low molar concentration. Scanning electron microscopy images revealed that the films adopted a rectangular to cauliflower like morphology. The optical transmittance of the thin films was observed in the range 200-800 nm and it was found that the 0.2 M CdO thin films showed about 83% transmission in the visible region. The optical band gap energy of the thin films was found to vary from 2.10 to 3.30 eV with the increase in molar concentration of the solution. The electrical resistance of the 0.5 M thin film was found to be 1.56 kΩ. The oxygen sensing response was observed between 20-33% in the low temperature range (32-200 °C).

Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure

Energy Technology Data Exchange (ETDEWEB)

King, L.M. [ARS USDA, Germplasm and Gamete Physiology Lab., Beltsville, MD (United States); Anderson, M.B. [Dept. of Anatomy, Tulane Univ. School of Medicine, New Orleans, LA (United States); Sikka, S.C. [Dept. of Urology, Tulane Univ. School of Medicine, New Orleans, LA (United States); George, W.J. [Dept. of Pharmacology, Tulane Univ. School of Medicine, New Orleans, LA (United States)

1998-10-01

The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 {mu}mol/kg CdCl{sub 2}). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 {mu}mol/kg ZnAc), given 24 h prior to 20 {mu}mol/kg CdCl{sub 2} administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible

Strain effect on the heat transport properties of bismuth telluride nanofilms with a hole

Science.gov (United States)

Fang, Te-Hua; Chang, Win-Jin; Wang, Kuan-Yu; Huang, Chao-Chun

2018-06-01

We investigated the mechanical behavior of bismuth telluride nanofilms with holes by using an equilibrium molecular dynamics (MD) approach. The holes had diameters of 20, 30, 40, and 50 Å. The thermal conductivity values of the nanofilms were calculated under different strains at different temperatures using a nonequilibrium MD simulation. The simulation revealed that the thermal conductivity of a bismuth telluride nanofilm with a hole decreases with an increase in hole diameter at different strains. For a film with a perfect structure at 300 K, a 48% reduction (from 0.33 to 0.17 W/m K) in the thermal conductivity was observed at a 7% tensile strain. In addition, the thermal conductivity increased by approximately 39% (from 0.33 to 0.46 W/m K) at a 7% compressive strain. A very low value (0.11 W/m K) of thermal conductivity is obtained for the nanofilm with a hole diameter of 50 Å at a 7% tensile strain at 300 K.

Possible bicollinear nematic state with monoclinic lattice distortions in iron telluride compounds

Energy Technology Data Exchange (ETDEWEB)

Bishop, Christopher B. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Herbrych, Jacek W. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dagotto, Elbio R. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moreo, Adriana [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-07-15

Here, iron telluride (FeTe) is known to display bicollinear magnetic order at low temperatures together with a monoclinic lattice distortion. Because the bicollinear order can involve two different wave vectors (π/2,π/2) and (π/2,–π/2), symmetry considerations allow for the possible stabilization of a nematic state with short-range bicollinear order coupled to monoclinic lattice distortions at a T_S higher than the temperature T_N where long-range bicollinear order fully develops. As a concrete example, the three-orbital spin-fermion model for iron telluride is studied with an additional coupling ˜λ₁₂ between the monoclinic lattice strain and an orbital-nematic order parameter with B_2g symmetry. Monte Carlo simulations show that with increasing ˜λ₁₂ the first-order transition characteristic of FeTe splits and bicollinear nematicity is stabilized in a (narrow) temperature range. In this new regime, the lattice is monoclinically distorted and short-range spin and orbital order breaks rotational invariance. A discussion of possible realizations of this exotic state is provided.

Cadmium in Sweden - environmental risks

Energy Technology Data Exchange (ETDEWEB)

Parkman, H; Iverfeldt, Aa [Swedish Environmental Research Inst. (Sweden); Borg, H; Lithner, G [Stockholm Univ. (Sweden). Inst. for Applied Environmental Research

1998-03-01

This report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buffering capacity, severely affected by acidification. In addition, the low salinity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soils is mobilized at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish environment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricultural soils, and fresh-waters in Sweden are enhanced compared to `back-ground concentrations`, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bio-available `free` cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. 90 refs, 23 figs, 2 tabs. With 3 page summary in Swedish

Insights into cadmium diffusion mechanisms in two-stage diffusion profiles in solar-grade Cu(In,Ga)Se{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

Biderman, N. J.; Sundaramoorthy, R.; Haldar, Pradeep [Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York 12203 (United States); U.S. Photovoltaic Manufacturing Consortium, Albany, New York 12203 (United States); Novak, Steven W.; Lloyd, J. R. [Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York 12203 (United States)

2015-12-07

Cadmium diffusion experiments were performed on polished copper indium gallium diselenide (Cu(In,Ga)Se{sub 2} or CIGS) samples with resulting cadmium diffusion profiles measured by time-of-flight secondary ion mass spectroscopy. Experiments done in the annealing temperature range between 275 °C and 425 °C reveal two-stage cadmium diffusion profiles which may be indicative of multiple diffusion mechanisms. Each stage can be described by the standard solutions of Fick's second law. The slower cadmium diffusion in the first stage can be described by the Arrhenius equation D{sub 1} = 3 × 10{sup −4} exp (− 1.53 eV/k{sub B}T) cm{sup 2} s{sup −1}, possibly representing vacancy-meditated diffusion. The faster second-stage diffusion coefficients determined in these experiments match the previously reported cadmium diffusion Arrhenius equation of D{sub 2} = 4.8 × 10{sup −4} exp (−1.04 eV/k{sub B}T) cm{sup 2} s{sup −1}, suggesting an interstitial-based mechanism.

Determination of cadmium selenide nonstoichiometry

International Nuclear Information System (INIS)

Brezhnev, V.Yu.; Kharif, Ya.L.; Kovtunenko, P.V.

1986-01-01

Physicochemical method of determination of cadmium selenide nonstoichiometry is developed. The method nature consists in the fact, that under definite conditions dissolved cadmium is extracted from crystals to a vapor phase and then is determined in it using the photocolorimetric method. Cadmium solubility in CdSe crystal is calculated from known CdSe mass and amount of separated cadmium. The lower boundary of determined contents constitutes 1x10 -5 % mol at sample of cadmium selenide 10 g

Reduced Graphene Oxide-Cadmium Zinc Sulfide Nanocomposite with Controlled Band Gap for Large-Area Thin-Film Optoelectronic Device Application

Science.gov (United States)

Ibrahim, Sk; Chakraborty, Koushik; Pal, Tanusri; Ghosh, Surajit

2017-12-01

Herein, we report the one pot single step solvothermal synthesis of reduced grapheme oxide-cadmium zinc sulfide (RGO-Cd0.5Zn0.5S) composite. The reduction in graphene oxide (GO), synthesis of Cd0.5Zn0.5S (mentioned as CdZnS in the text) nanorod and decoration of CdZnS nanorods onto RGO sheet were done simultaneously. The structural, morphological and optical properties were studied thoroughly by different techniques, such as XRD, TEM, UV-Vis and PL. The PL intensity of CdZnS nanorods quenches significantly after the attachment of RGO, which confirms photoinduced charge transformation from CdZnS nanorods to RGO sheet through the interface of RGO-CdZnS. An excellent photocurrent generation in RGO-CdZnS thin-film device has been observed under simulated solar light irradiation. The photocurrent as well as photosensitivity increases linearly with the solar light intensity for all the composites. Our study establishes that the synergistic effect of RGO and CdZnS in the composite is capable of getting promising applications in the field of optoelectronic devising.

Relation between dietary cadmium intake and biomarkers of cadmium exposure in premenopausal women accounting for body iron stores

Directory of Open Access Journals (Sweden)

Julin Bettina

2011-12-01

Full Text Available Abstract Background Cadmium is a widespread environmental pollutant with adverse effects on kidneys and bone, but with insufficiently elucidated public health consequences such as risk of end-stage renal diseases, fractures and cancer. Urinary cadmium is considered a valid biomarker of lifetime kidney accumulation from overall cadmium exposure and thus used in the assessment of cadmium-induced health effects. We aimed to assess the relationship between dietary cadmium intake assessed by analyses of duplicate food portions and cadmium concentrations in urine and blood, taking the toxicokinetics of cadmium into consideration. Methods In a sample of 57 non-smoking Swedish women aged 20-50 years, we assessed Pearson's correlation coefficients between: 1 Dietary intake of cadmium assessed by analyses of cadmium in duplicate food portions collected during four consecutive days and cadmium concentrations in urine, 2 Partial correlations between the duplicate food portions and urinary and blood cadmium concentrations, respectively, and 3 Model-predicted urinary cadmium concentration predicted from the dietary intake using a one-compartment toxicokinetic model (with individual data on age, weight and gastrointestinal cadmium absorption and urinary cadmium concentration. Results The mean concentration of cadmium in urine was 0.18 (+/- s.d.0.12 μg/g creatinine and the model-predicted urinary cadmium concentration was 0.19 (+/- s.d.0.15 μg/g creatinine. The partial Pearson correlations between analyzed dietary cadmium intake and urinary cadmium or blood concentrations were r = 0.43 and 0.42, respectively. The correlation between diet and urinary cadmium increased to r = 0.54 when using a one-compartment model with individual gastrointestinal cadmium absorption coefficients based on the women's iron status. Conclusions Our results indicate that measured dietary cadmium intake can reasonably well predict biomarkers of both long-term kidney accumulation

[Investigation of urinary cadmium characteristics of the general population in three non-cadmium-polluted rural areas in China].

Science.gov (United States)

Han, Jingxiu; Hu, Ji; Sun, Hong; Jing, Qiqing; Wang, Xiaofeng; Lou, Xiaoming; Ding, Zhen; Chen, Xiaodong; Zhang, Wenli; Shang, Qi

2014-11-01

To investigate the characteristics of urinary cadmium of the non-occupational-cadmium-exposed population in non-cadmium contaminated rural area in China. Randomly selected non-occupational cadmium exposed population 2548 people (male 1290, female 1258) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr 3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P95) of urinary cadmium after correction by urinary Cr. Urinary cadmium increased with age and showed an upward trend. The urinary cadmium of the population of ≥ 30 years old was significantly higher than that of populations (China (GB Z17-2002). The urinary cadmium reference value of non-occupational-cadmium-exposed populations is China, but for smoking women over 30 year-old it needs more research to explore.

Phenomenon of ''self-cleaning'' of crystals

International Nuclear Information System (INIS)

Matveev, O.A.; Arkad'eva, E.N.; Goncharov, L.A.

1975-01-01

Crystals of germanium and cadmium telluride have been produced having the characteristics corresponding to the low content of electrically active impurities and crystal defects. The crystals have been grown under conditions of an equilibrium diffusion-concentration interaction of the impurities and crystal defects, with the donor alloying and controlling the acceptors concentration. These crystals have been studied with the help of the mass-spectral analysis, the Hall effect, photoelectroscopy, spectral photoconductivity and losses of collection of a charge from an ionizing particle on gamma-detectors fabricated of the crystals. Herein the doped composition of the crystals has been determined, the concentrations of the shallow and deep acceptors and donors have been measured separately, the life-times of the electrons and holes have been measured, the energetic position and the concentration of the carrier capture levels have been determined. The crystals grown possess all the characteristic features of rather pure crystals. The results of the mass-spectral analysis have shown that in the cadmium telluride crystals the impurities are present within 10 14 to 10 17 cm -3 . Therefore, a deep ''self-refining'' of the crystal takes place, which proceeds by means of deactivation of the electrically active centers with their associating into electrically inactive complexes. Thus a fact of the deep ''self-refining'' of germanium- and cadmium telluride crystals is stated. It is presumed that such a ''self-refining'' can actually proceed practically in all the crystals

Chemical bath deposition of CdS thin films doped with Zn and Cu

Indian Academy of Sciences (India)

Abstract. Zn- and Cu-doped CdS thin films were deposited onto glass substrates by the chemical bath technique. ... Cadmium sulfide; chemical bath deposition; doping; optical window. 1. ..... at low temperature (10 K), finding similar trends than.

Miniature gamma-ray camera for tumor localization

International Nuclear Information System (INIS)

Lund, J.C.; Olsen, R.W.; James, R.B.; Cross, E.

1997-08-01

The overall goal of this LDRD project was to develop technology for a miniature gamma-ray camera for use in nuclear medicine. The camera will meet a need of the medical community for an improved means to image radio-pharmaceuticals in the body. In addition, this technology-with only slight modifications-should prove useful in applications requiring the monitoring and verification of special nuclear materials (SNMs). Utilization of the good energy resolution of mercuric iodide and cadmium zinc telluride detectors provides a means for rejecting scattered gamma-rays and improving the isotopic selectivity in gamma-ray images. The first year of this project involved fabrication and testing of a monolithic mercuric iodide and cadmium zinc telluride detector arrays and appropriate collimators/apertures. The second year of the program involved integration of the front-end detector module, pulse processing electronics, computer, software, and display

Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

Directory of Open Access Journals (Sweden)

Dian Siswanto

2013-05-01

Full Text Available The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N, Cd soils (Cds, and Cd soils each amended with 1% w/w of coir pith (CP, coir pith modified with sodium hydroxide (CPm and corncob (CC under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatments under high cadmium contaminated soil followed the order: Cds > CPm ≥ CP ≥ CC. These transpirations directly influenced cadmium accumulation in shoots and husks of rice plants. The CC and CP seemed to work to reduce the cadmium uptake by rice plants indicated by accumulated cadmium in the husk that were 2.47 and 7.38 mg Cd kg-1 dry weight, respectively. Overall, transpiration tended to drive cadmium accumulation in plants for rice grown in high cadmium contaminated soil. The more that plants uptake cadmium, the lower cadmium that remains in the soil.

Zinc and cadmium monosalicylates

International Nuclear Information System (INIS)

Kharitonov, Yu.Ya.; Tujebakhova, Z.K.

1984-01-01

Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC 6 H 4 COOH (H 2 Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC 6 H 4 COO) and products of their thepmal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure

Physical properties and characterization of Ag doped CdS thin films

International Nuclear Information System (INIS)

Shah, N.A.; Nazir, A.; Mahmood, W.; Syed, W.A.A.; Butt, S.; Ali, Z.; Maqsood, A.

2012-01-01

Highlights: ► CdS thin films were grown. ► By ion exchange, Ag was doped. ► Physical properties were investigated. - Abstract: Thin films of cadmium sulfide with very well defined preferential orientation and relatively high absorption coefficient were fabricated by thermal evaporation technique. The research is focused to the fabrication and characterization of the compositional data of CdS thin films obtained by using X-ray diffraction, scanning electron microscope along with energy dispersive X-ray spectroscopy. The optical properties were studied by using a UV-VIS-NIR spectrophotometer. The effects of silver-doping by ion exchange process on the properties of as-deposited CdS thin films have been investigated.

Cadmium in blood and hypertension

Energy Technology Data Exchange (ETDEWEB)

Eum, Ki-Do; Lee, Mi-Sun [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of); Paek, Domyung [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of)], E-mail: paekdm@snu.ac.kr

2008-12-15

Objectives:: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods:: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results:: The mean blood cadmium level was 1.67 {mu}g/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 {mu}g/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose-response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions:: Cadmium exposures at the current level may have increased the blood pressure of Korean general population.

Cadmium in blood and hypertension

International Nuclear Information System (INIS)

Eum, Ki-Do; Lee, Mi-Sun; Paek, Domyung

2008-01-01

Objectives:: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods:: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results:: The mean blood cadmium level was 1.67 μg/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 μg/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose-response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions:: Cadmium exposures at the current level may have increased the blood pressure of Korean general population

Effect of increasing tellurium content on the electronic and optical properties of cadmium selenide telluride alloys CdSe{sub 1-x}Te{sub x}: An ab initio study

Energy Technology Data Exchange (ETDEWEB)

Reshak, Ali Hussain, E-mail: maalidph@yahoo.co.uk [Institute of Physical Biology-South Bohemia University, Nove Hrady 37333 (Czech Republic); School of Material Engineering, Malaysia University of Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis (Malaysia); Kityk, I.V. [Electrical Engineering Department, Technical University of Czestochowa, Al. Armii Krajowej 17/19, Czestochowa (Poland); Khenata, R. [Laboratoire de Physique Quantique et de Modelisation Mathematique de la Matiere (LPQ3 M), universite de Mascara, Mascara 29000 (Algeria); Department of Physics and Astronomy, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Auluck, S. [National Physical Laboratory Dr. K S Krishnan Marg, New Delhi 110012 (India)

2011-06-16

Highlights: > Theoretical study of effect of vary Te content on band structure, density of states, linear and nonlinear optical susceptibilities of CdSe{sub 1-x}Te{sub x}. > Increasing Te content leads to a decrease in the energy band gap. > Significant enhancement of the electronic properties as a function of tellurium concentration - Abstract: An all electron full potential linearized augmented plane wave method, within a framework of GGA (EV-GGA) approach, has been used for an ab initio theoretical study of the effect of increasing tellurium content on the band structure, density of states, and the spectral features of the linear and nonlinear optical susceptibilities of the cadmium-selenide-telluride ternary alloys CdSe{sub 1-x}Te{sub x} (x = 0.0, 0.25, 0.5, 0.75 and 1.0). Our calculations show that increasing Te content leads to a decrease in the energy band gap. We find that the band gaps are 0.95 (1.76), 0.89 (1.65), 0.83 (1.56), 0.79 (1.44) and 0.76 (1.31) eV for x = 0.0, 0.25, 0.5, 0.75 and 1.0 in the cubic structure. As these alloys are known to have a wurtzite structure for x less than 0.25, the energy gaps are 0.8 (1.6) eV and 0.7 (1.55) eV for the wurtzite structure (x = 0.0, 0.25) for the GGA (EV-GGA) exchange correlation potentials. This reduction in the energy gaps enhances the functionality of the CdSe{sub 1-x}Te{sub x} alloys, at least for these concentrations, leading to an increase in the effective second-order susceptibility coefficients from 16.75 pm/V (CdSe) to 18.85 pm/V (CdSe{sub 0.75}Te{sub 0.25}), 27.23 pm/V (CdSe{sub 0.5}Te{sub 0.5}), 32.25 pm/V (CdSe{sub 0.25}Te{sub 0.75}), and 37.70 pm/V (CdTe) for the cubic structure and from 12.65 pm/V (CdSe) to 21.11 pm/V (CdSe{sub 0.75}Te{sub 0.25}) in the wurtzite structure. We find a nonlinear relationship between the absorption/emission energies and composition, and a significant enhancement of the electronic properties as a function of tellurium concentration. This variation will help in

Cadmium induces cadmium-tolerant gene expression in the filamentous fungus Trichoderma harzianum.

Science.gov (United States)

Cacciola, Santa O; Puglisi, Ivana; Faedda, Roberto; Sanzaro, Vincenzo; Pane, Antonella; Lo Piero, Angela R; Evoli, Maria; Petrone, Goffredo

2015-11-01

The filamentous fungus Trichoderma harzianum, strain IMI 393899, was able to grow in the presence of the heavy metals cadmium and mercury. The main objective of this research was to study the molecular mechanisms underlying the tolerance of the fungus T. harzianum to cadmium. The suppression subtractive hybridization (SSH) method was used for the characterization of the genes of T. harzianum implicated in cadmium tolerance compared with those expressed in the response to the stress induced by mercury. Finally, the effects of cadmium exposure were also validated by measuring the expression levels of the putative genes coding for a glucose transporter, a plasma membrane ATPase, a Cd(2+)/Zn(2+) transporter protein and a two-component system sensor histidine kinase YcbA, by real-time-PCR. By using the aforementioned SSH strategy, it was possible to identify 108 differentially expressed genes of the strain IMI 393899 of T. harzianum grown in a mineral substrate with the addition of cadmium. The expressed sequence tags identified by SSH technique were encoding different genes that may be involved in different biological processes, including those associated to primary and secondary metabolism, intracellular transport, transcription factors, cell defence, signal transduction, DNA metabolism, cell growth and protein synthesis. Finally, the results show that in the mechanism of tolerance to cadmium a possible signal transduction pathway could activate a Cd(2+)/Zn(2+) transporter protein and/or a plasma membrane ATPase that could be involved in the compartmentalization of cadmium inside the cell.

The determination, by differential pulse anodic-stripping voltammetry at the thin mercury-film electrode, of cadmium and thallium in six NIMROC reference materials

International Nuclear Information System (INIS)

Lee, A.F.

1981-01-01

A previously reported procedure has been extended to include the determination of thallium. In samples where thallium occurred in the presence of relatively high concentrations of cadmium, the stripping peak for cadmium was first suppressed with non-ionic surface-active agent, Triton X-100. Cadmium and thallium were determined directly in six NIMROC reference materials without interference from iron(III), in a reducing electrolyte, which is also a complexing agent, consisting of 1 M ammonium chloride, 0,1 M citric acid, and 0,025 M ascorbic acid. Interelement interferences were eliminated by the use of a mercury-film electrode of adequate thickness. The limits of detection for cadmium were 10ng/g and those for thallium 20ng/g

Effects of cadmium and mycorrhizal fungi on growth, fitness, and cadmium accumulation in flax (Linum usitatissimum; Linaceae).

Science.gov (United States)

Hancock, Laura M S; Ernst, Charlotte L; Charneskie, Rebecca; Ruane, Lauren G

2012-09-01

Agricultural soils have become contaminated with a variety of heavy metals, including cadmium. The degree to which soil contaminants affect plants may depend on symbiotic relationships between plant roots and soil microorganisms. We examined (1) whether mycorrhizal fungi counteract the potentially negative effects of cadmium on the growth and fitness of flax (Linum usitatissimum) and (2) whether mycorrhizal fungi affect the accumulation of cadmium within plant parts. Two flax cultivars (Linott and Omega) were grown in three soil cadmium environments (0, 5, and 15 ppm). Within each cadmium environment, plants were grown in either the presence or absence of mycorrhizal fungi. Upon senescence, we measured growth and fitness and quantified the concentration of cadmium within plants. Soil cadmium significantly decreased plant fitness, but did not affect plant growth. Mycorrhizal fungi, which were able to colonize roots of plants growing in all cadmium levels, significantly increased plant growth and fitness. Although mycorrhizal fungi counteracted the negative effects of cadmium on fruit and seed production, they also enhanced the concentration of cadmium within roots, fruits, and seeds. The degree to which soil cadmium affects plant fitness and the accumulation of cadmium within plants depended on the ability of plants to form symbiotic relationships with mycorrhizal fungi. The use of mycorrhizal fungi in contaminated agricultural soils may offset the negative effects of metals on the quantity of seeds produced, but exacerbate the accumulation of these metals in our food supply.

High Throughput Manufacturing of Thin-Film CdTe Photovoltaic Materials; Final Subcontract Report, 16 November 1993-31 December 1998

International Nuclear Information System (INIS)

Sandwisch, D.W.

1999-01-01

This report describes work performed by Solar Cells, Inc. (SCI), during this Photovoltaic Manufacturing Technology (PVMaT) subcontract. Cadmium telluride (CdTe) is recognized as one of the leading materials for low-cost photovoltaic modules. SCI has developed this technology and is preparing to scale its pilot production capabilities to a multi-megawatt level. This four-phase PVMaT subcontract supports these efforts. The work was related to product definition, process definition, equipment engineering, and support programs development. In the area of product definition and demonstration, two products were specified and demonstrated-a grid-connected, frameless, high-voltage product that incorporates a pigtail potting design and a remote low-voltage product that may be framed and may incorporate a junction box. SCI produced a 60.3-W thin-film CdTe module with total-area efficiency of 8.4%; SCI also improved module pass rate on the interim qualification test protocol from less than 20% to 100% as a result of work related to the subcontract. In the manufacturing process definition area, the multi-megawatt manufacturing process was defined, several of the key processes were demonstrated, and the process was refined and proven on a 100-kW pilot line that now operates as a 250-kW line. In the area of multi-megawatt manufacturing-line conceptual design review, SCI completed a conceptual layout of the multi-megawatt lines. The layout models the manufacturing line and predicts manufacturing costs. SCI projected an optimized capacity, two-shift/day operation of greater than 25 MW at a manufacturing cost of below$1.00/W

High Throughput Manufacturing of Thin-Film CdTe Photovoltaic Materials; Final Subcontract Report, 16 November 1993-31 December 1998

Energy Technology Data Exchange (ETDEWEB)

Sandwisch, D. W. (Solar Cells, Inc.)

1999-09-02

This report describes work performed by Solar Cells, Inc. (SCI), during this Photovoltaic Manufacturing Technology (PVMaT) subcontract. Cadmium telluride (CdTe) is recognized as one of the leading materials for low-cost photovoltaic modules. SCI has developed this technology and is preparing to scale its pilot production capabilities to a multi-megawatt level. This four-phase PVMaT subcontract supports these efforts. The work was related to product definition, process definition, equipment engineering, and support programs development. In the area of product definition and demonstration, two products were specified and demonstrated-a grid-connected, frameless, high-voltage product that incorporates a pigtail potting design and a remote low-voltage product that may be framed and may incorporate a junction box. SCI produced a 60.3-W thin-film CdTe module with total-area efficiency of 8.4%; SCI also improved module pass rate on the interim qualification test protocol from less than 20% to 100% as a result of work related to the subcontract. In the manufacturing process definition area, the multi-megawatt manufacturing process was defined, several of the key processes were demonstrated, and the process was refined and proven on a 100-kW pilot line that now operates as a 250-kW line. In the area of multi-megawatt manufacturing-line conceptual design review, SCI completed a conceptual layout of the multi-megawatt lines. The layout models the manufacturing line and predicts manufacturing costs. SCI projected an optimized capacity, two-shift/day operation of greater than 25 MW at a manufacturing cost of below $1.00/W.

Donor impurity self-compensation by neutral complexes in bismuth doped lead telluride

International Nuclear Information System (INIS)

Ravich, Yu.I.; Nemov, S.A.; Proshin, V.I.

1994-01-01

Self-compensation is calculated of impurity doping action in semiconductors of the A 4 B 6 type by neutral complexes, consisting of a vacancy and two impurity atoms. Complexes entropy is estimated and the thermodynamic potential is minimized in the concentration of single two-charge vacancies and complexes. Calculation results are compared with experimental data, obtained when lead telluride doping by bismuth. Account for complex formation improves agreement theory with experiment. 4 refs., 1 fig

Cadmium Alternatives

Science.gov (United States)

2012-08-01

carcinogenic, leachable Trivalent and non- chrome passivates generally struggle with conductivity Major Differences in Trivalent vs. Hexavalent Passivates...for Change Cadmium passivated with hexavalent chromium has been in use for many decades Cadmium is toxic, and is classified as a priority...Executive Orders 13514 & 13423 DoD initiatives – Young memo (April 2009) DFAR restricting use of hexavalent chromium Allows the use of hexavalent

Chemical synthesis of porous web-structured CdS thin films for photosensor applications

Energy Technology Data Exchange (ETDEWEB)

Gosavi, S.R., E-mail: srgosavi.taloda@gmail.com [C. H. C. Arts, S. G. P. Commerce, and B. B. J. P. Science College, Taloda, Dist., Nandurbar 425413, M. S. (India); Nikam, C.P. [B.S.S.P.M.S. Arts, Commerce and Science College, Songir, Dist., Dhule 424309, M. S. (India); Shelke, A.R.; Patil, A.M. [Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India); Ryu, S.-W. [Department of Physics, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Bhat, J.S. [Department of Physics, Karnatak University, Dharwad 580003 (India); Deshpande, N.G., E-mail: nicedeshpande@yahoo.co.in [Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India)

2015-06-15

The photo-activity of chemically deposited cadmium sulphide (CdS) thin film has been studied. The simple chemical route nucleates the CdS films with size up to the mean free path of the electron. Growth Kinematics of crystalline hexagonal CdS phase in the thin film form was monitored using X-ray diffraction. The time limitation set for the formation of the amorphous/nano-crystalline material is 40 and 60 min. Thereafter enhancement of the crystalline orientation along the desired plane was identified. Web-like porous structured surface morphology of CdS thin film over the entire area is observed. With decrease in synthesis time, increase of band gap energy i.e., a blue spectral shift was seen. The activation energy of CdS thin film at low and high temperature region was examined. It is considered that this activation energy corresponds to the donor levels associated with shallow traps or surface states of CdS thin film. The photo-electrochemical performance of CdS thin films in polysulphide electrolyte showed diode-like characteristics. Exposure of light on the CdS electrode increases the photocurrent. This suggests the possibility of production of free carriers via excited ions and also the light harvesting mechanism due to porous web-structured morphology. These studies hint that the obtained CdS films can work as a photosensor. - Highlights: • Photoactivity of chemically synthesized cadmium sulphide (CdS) thin films was studied. • Web-like porous structured surface morphology of CdS thin film over the entire area was observed. • Blue spectral shift with lowering of the synthesis time suggests films can act as a window layer over the absorber layer. • Porous web-structured CdS thin films can be useful in light harvesting.

Chemical synthesis of porous web-structured CdS thin films for photosensor applications

International Nuclear Information System (INIS)

Gosavi, S.R.; Nikam, C.P.; Shelke, A.R.; Patil, A.M.; Ryu, S.-W.; Bhat, J.S.; Deshpande, N.G.

2015-01-01

The photo-activity of chemically deposited cadmium sulphide (CdS) thin film has been studied. The simple chemical route nucleates the CdS films with size up to the mean free path of the electron. Growth Kinematics of crystalline hexagonal CdS phase in the thin film form was monitored using X-ray diffraction. The time limitation set for the formation of the amorphous/nano-crystalline material is 40 and 60 min. Thereafter enhancement of the crystalline orientation along the desired plane was identified. Web-like porous structured surface morphology of CdS thin film over the entire area is observed. With decrease in synthesis time, increase of band gap energy i.e., a blue spectral shift was seen. The activation energy of CdS thin film at low and high temperature region was examined. It is considered that this activation energy corresponds to the donor levels associated with shallow traps or surface states of CdS thin film. The photo-electrochemical performance of CdS thin films in polysulphide electrolyte showed diode-like characteristics. Exposure of light on the CdS electrode increases the photocurrent. This suggests the possibility of production of free carriers via excited ions and also the light harvesting mechanism due to porous web-structured morphology. These studies hint that the obtained CdS films can work as a photosensor. - Highlights: • Photoactivity of chemically synthesized cadmium sulphide (CdS) thin films was studied. • Web-like porous structured surface morphology of CdS thin film over the entire area was observed. • Blue spectral shift with lowering of the synthesis time suggests films can act as a window layer over the absorber layer. • Porous web-structured CdS thin films can be useful in light harvesting

Cadmium exposure in the Swedish environment

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

This report gives a thorough description of cadmium in the Swedish environment. It comprises three parts: Cadmium in Sweden - environmental risks;, Cadmium in goods - contribution to environmental exposure;, and Cadmium in fertilizers, soil, crops and foods - the Swedish situation. Separate abstracts have been prepared for all three parts

Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi_2Te_3) single crystals for thermoelectric applications

International Nuclear Information System (INIS)

Krishna, Anuj; Vijayan, N.; Singh, Budhendra; Thukral, Kanika; Maurya, K.K.

2016-01-01

High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi_2Te_3) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

An in-situ chemical reaction deposition of nanosized wurtzite CdS thin films

International Nuclear Information System (INIS)

Chu Juan; Jin Zhengguo; Cai Shu; Yang Jingxia; Hong Zhanglian

2012-01-01

Nanocrystalline CdS thin films were deposited on glass substrates by an ammonia-free in-situ chemical reaction synthesis technique using cadmium cationic precursor solid films as reaction source and sodium sulfide based solutions as anionic reaction medium. Effects of ethanolamine addition to the cadmium cationic precursor solid films, deposition cycle numbers and annealing treatments in Ar atmosphere on structure, morphology, chemical composition and optical properties of the resultant films were investigated by X-ray diffraction, field emission scanning electron microscope, energy dispersive X-ray analysis and UV–Vis spectra measurements. The results show that CdS thin films deposited by the in-situ chemical reaction synthesis have wurtzite structure with (002) plane preferential orientation and crystallite size is in the range of 16 nm–19 nm. The growth of film thickness is almost constant with deposition cycle numbers and about 96 nm per cycle.

Annealing effects on room temperature thermoelectric performance of p-type thermally evaporated Bi-Sb-Te thin films

Science.gov (United States)

Singh, Sukhdeep; Singh, Janpreet; Tripathi, S. K.

2018-05-01

Bismuth antimony telluride (Bi-Sb-Te) compounds have been investigated for the past many decades for thermoelectric (TE) power generation and cooling purpose. We synthesized this compound with a stoichiometry Bi1.2Sb0.8Te3 through melt cool technique and thin films of as synthesized material were deposited by thermal evaporation. The prime focus of the present work is to study the influence of annealing temperature on the room temperature (RT) power factor of thin films. Electrical conductivity and Seebeck coefficient were studied and power factors were calculated which showed a peak value at 323 K. The compounds performance is comparable to some very efficient Bi-Sb-Te reported stoichiometries at RT scale. The values observed show that material has an enormous potential for energy production at ambient temperature scales.

Effects of Different Dietary Cadmium Levels on Growth and Tissue Cadmium Content in Juvenile Parrotfish,

Directory of Open Access Journals (Sweden)

Okorie E. Okorie

2014-01-01

Full Text Available This feeding trial was carried out to evaluate the effects of different dietary cadmium levels on growth and tissue cadmium content in juvenile parrotfish, Oplegnathus fasciatus, using cadmium chloride (CdCl2 as the cadmium source. Fifteen fish averaging 5.5±0.06 g (mean±SD were randomly distributed into each of twenty one rectangular fiber tanks of 30 L capacity. Each tank was then randomly assigned to one of three replicates of seven diets containing 0.30 (C0, 21.0 (C21, 40.7 (C41, 83.5 (C83, 162 (C162, 1,387 (C1,387 and 2,743 (C2,743 mg cadmium/kg diet. At the end of sixteen weeks of feeding trial, weight gain (WG, specific growth rate (SGR and feed efficiency (FE of fish fed C21 were significantly higher than those of fish fed C83, C162, C1,387 and C2,743 (p<0.05. Weight gain, SGR and FE of fish fed C0, C21 and C41 were significantly higher than those of fish fed C162, C1,387 and C2,743. Protein efficiency ratio of fish fed C0, C21 and C41 were significantly higher than those of fish fed C1,387 and C2,743. Average survival of fish fed C0, C21, C41 and C162 were significantly higher than that of fish fed C2,743. Tissue cadmium concentrations increased with cadmium content of diets. Cadmium accumulated the most in liver, followed by gill and then muscle. Muscle, gill and liver cadmium concentrations of fish fed C0, C21, C41 and C83 were significantly lower than those of fish fed C162, C1,387 and C2,743. Based on the ANOVA results of growth performance and tissue cadmium concentrations the safe dietary cadmium level could be lower than 40.7 mg Cd/kg diet while the toxic level could be higher than 162 mg Cd/kg diet.

On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

International Nuclear Information System (INIS)

Chattopadhyay, P.; Karim, B.; Guha Roy, S.

2013-01-01

The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material

On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

Science.gov (United States)

Chattopadhyay, P.; Karim, B.; Guha Roy, S.

2013-12-01

The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material.

Cadmium plating replacements

Energy Technology Data Exchange (ETDEWEB)

Nelson, M.J.; Groshart, E.C.

1995-03-01

The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

Mechanisms of cadmium induced genomic instability

Energy Technology Data Exchange (ETDEWEB)

Filipic, Metka, E-mail: metka.filipic@nib.si [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Ljubljana (Slovenia)

2012-05-01

Cadmium is an ubiquitous environmental contaminant that represents hazard to humans and wildlife. It is found in the air, soil and water and, due to its extremely long half-life, accumulates in plants and animals. The main source of cadmium exposure for non-smoking human population is food. Cadmium is primarily toxic to the kidney, but has been also classified as carcinogenic to humans by several regulatory agencies. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Cadmium dose not induce direct DNA damage, however it induces increase in reactive oxygen species (ROS) formation, which in turn induce DNA damage and can also interfere with cell signalling. More important seems to be cadmium interaction with DNA repair mechanisms, cell cycle checkpoints and apoptosis as well as with epigenetic mechanisms of gene expression control. Cadmium mediated inhibition of DNA repair mechanisms and apoptosis leads to accumulation of cells with unrepaired DNA damage, which in turn increases the mutation rate and thus genomic instability. This increases the probability of developing not only cancer but also other diseases associated with genomic instability. In the in vitro experiments cadmium induced effects leading to genomic instability have been observed at low concentrations that were comparable to those observed in target organs and tissues of humans that were non-occupationally exposed to cadmium. Therefore, further studies aiming to clarify the relevance of these observations for human health risks due to cadmium exposure are needed.

Mechanisms of cadmium induced genomic instability

International Nuclear Information System (INIS)

Filipič, Metka

2012-01-01

Cadmium is an ubiquitous environmental contaminant that represents hazard to humans and wildlife. It is found in the air, soil and water and, due to its extremely long half-life, accumulates in plants and animals. The main source of cadmium exposure for non-smoking human population is food. Cadmium is primarily toxic to the kidney, but has been also classified as carcinogenic to humans by several regulatory agencies. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Cadmium dose not induce direct DNA damage, however it induces increase in reactive oxygen species (ROS) formation, which in turn induce DNA damage and can also interfere with cell signalling. More important seems to be cadmium interaction with DNA repair mechanisms, cell cycle checkpoints and apoptosis as well as with epigenetic mechanisms of gene expression control. Cadmium mediated inhibition of DNA repair mechanisms and apoptosis leads to accumulation of cells with unrepaired DNA damage, which in turn increases the mutation rate and thus genomic instability. This increases the probability of developing not only cancer but also other diseases associated with genomic instability. In the in vitro experiments cadmium induced effects leading to genomic instability have been observed at low concentrations that were comparable to those observed in target organs and tissues of humans that were non-occupationally exposed to cadmium. Therefore, further studies aiming to clarify the relevance of these observations for human health risks due to cadmium exposure are needed.

Structure impact on the thermal and electronic properties of bismuth telluride by ab-initio and molecular dynamics calculations

International Nuclear Information System (INIS)

Termentzidis, K; Pokropivny, A; Xiong, S-Y; Chumakov, Y; Volz, S; Woda, M; Cortona, P

2012-01-01

We use molecular dynamics and ab-initio methods to predict the thermal and electronic properties of new materials with high figures of merit. The simulated systems are bulk bismuth tellurides with antisite and vacancy defects. Optimizations of the materials under investigation are performed by the SIESTA code for subsequent calculations of force constants, electronic properties, and Seebeck coefficients. The prediction of the thermal conductivity is made by Non-Equilibrium Molecular Dynamics (NEMD) using the LAMMPS code. The thermal conductivity of bulk bismuth telluride with different stoichiometry and with a number of substitution defects is calculated. We have found that the thermal conductivity can be decreased by 60% by introducing vacancy defects. The calculated thermal conductivities for the different structures are compared with the available experimental and theoretical results.

Structural and surface morphological studies of long chain fatty acid thin films deposited by Langmuir-Blodgett technique

Energy Technology Data Exchange (ETDEWEB)

Das, Nayan Mani, E-mail: nayanmanidas3@gmail.com [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Roy, Dhrubojyoti [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Gupta, Mukul [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India); Gupta, P.S. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

2012-12-15

In the present work we aim to study the structural and surface morphological characteristics of divalent cation (cadmium ion, Cd{sup 2+}) induced thin mono- to multilayer films of fatty acids such as arachidic acid and stearic acid prepared by the Langmuir-Blodgett (LB) technique. These ultra thin films of various numbers of layers were studied by X-ray diffraction (XRD), X-ray reflectivity (XRR) and Atomic Force Microscopy (AFM). In this specific Y-type deposition, it was found that as the individual layer thickness increases, the corresponding layer by layer interfacial electron density of the thin films decreases. Since the fatty acid chain tries to maintain its minimum value of cross-sectional area, tilting occurs with respect to its nearest neighbor. The tilt angle calculated for 9 layers of cadmium arachidate (CdA{sub 2}) and cadmium stearate (CdSt{sub 2}) are 18 Degree-Sign and 19.5 Degree-Sign , respectively. An asymmetric air gap of thickness {approx}3 A was also seen between the tail parts of 2 molecular chains. The RMS roughness and average height factors calculated through AFM studies show non-uniform surface morphology of both CdA{sub 2} and CdSt{sub 2}, although the calculated topographic variations were found to have more irregularity in case of CdSt{sub 2} than in case of CdA{sub 2}.

Microbolometer spectrometer: applications and technology

NARCIS (Netherlands)

Leijtens, J.A.P.; Court, A.J.; Hoegee, J.

2004-01-01

Current Thermal Infra Red (7.14μm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. Now due to the increased performance of uncooled microbolometer arrays, the next generation of instruments can be designed without cryogenic cooling. TNO

Microbolometer spectrometer opens hoist of new applications

NARCIS (Netherlands)

Leijtens, J.A.P.; Smorenburg, C.; Escudero, I.; Boslooper, E.C.; Visser, H.; Helden, W.A. van; Breussin, F.N.

2004-01-01

Current Thermal infra red ( 7..14μm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. This causes the instruments to be bulky, power hungry and expensive. For systems that have medium NETD (Noise Equivalent Temperature Difference)

Cadmium in the biofuel system

International Nuclear Information System (INIS)

Aabyhammar, T.; Fahlin, M.; Holmroos, S.

1993-12-01

Removal of biofuel depletes the soil of important nutrients. Investigations are being made of possibilities to return most of these nutrients by spreading the ashes remaining after combustion in the forest or on field. Return of ashes implies that both beneficial and harmful substances are returned. This study has been conducted to illustrate that the return of cadmium implies the greatest risk for negative influences. The occurrence, utilization, emissions and effects of cadmium are discussed. The behaviour of cadmium in soil is discussed in detail. Flows and quantities of cadmium in Swedish society are reviewed. Flows and quantities of both total and plant available cadmium in the entire forest and arable areas of Sweden are given. A scenario for a bioenergy system of max 100 TWh is discussed. The cadmium flow in different biofuels and forest raw products, and anticipated amounts of ashes and cadmium concentrations, are calculated. Power production from biofuels is surveyed. Possibilities to clean ashes have been examined in laboratory experiments. Ashes and trace elements occurring as a result of the gasification of biofuels are reviewed. Strategies for handling ashes are discussed. Proposals on continued inputs in both the biological and technical sciences are made. 146 refs, 23 figs, 38 tabs

Time-dependent toxicity of cadmium telluride quantum dots on liver and kidneys in mice: histopathological changes with elevated free cadmium ions and hydroxyl radicals.

Science.gov (United States)

Wang, Mengmeng; Wang, Jilong; Sun, Hubo; Han, Sihai; Feng, Shuai; Shi, Lu; Meng, Peijun; Li, Jiayi; Huang, Peili; Sun, Zhiwei

2016-01-01

A complete understanding of the toxicological behavior of quantum dots (QDs) in vivo is of great importance and a prerequisite for their application in humans. In contrast with the numerous cytotoxicity studies investigating QDs, only a few in vivo studies of QDs have been reported, and the issue remains controversial. Our study aimed to understand QD-mediated toxicity across different time points and to explore the roles of free cadmium ions (Cd(2+)) and hydroxyl radicals (·OH) in tissue damage. Male ICR mice were administered a single intravenous dose (1.5 µmol/kg) of CdTe QDs, and liver and kidney function and morphology were subsequently examined at 1, 7, 14, and 28 days. Furthermore, ·OH production in the tissue was quantified by trapping · OH with salicylic acid (SA) as 2,3-dihydroxybenzoic acid (DHBA) and detecting it using a high-performance liquid chromatography fluorescence method. We used the induction of tissue metallothionein levels and 2,3-DHBA:SA ratios as markers for elevated Cd(2+) from the degradation of QDs and ·OH generation in the tissue, respectively. Our experimental results revealed that the QD-induced histopathological changes were time-dependent with elevated Cd(2+) and ·OH, and could recover after a period of time. The Cd(2+) and ·OH exhibited delayed effects in terms of histopathological abnormalities. Histological assessments performed at multiple time points might facilitate the evaluation of the biological safety of QDs.

Solar Spectral and Module Temperature Influence on the Outdoor Performance of Thin Film PV Modules Deployed on a Sunny Inland Site

Directory of Open Access Journals (Sweden)

G. Nofuentes

2013-01-01

Full Text Available This work aims at analysing the influence of both module temperature and solar spectrum distribution on the outdoor performance of the following thin film technologies: hydrogenated amorphous silicon (a-Si:H, cadmium telluride (CdTe, copper indium gallium selenide sulfide (CIGS, and hydrogenated amorphous silicon/hydrogenated microcrystalline silicon hetero-junction (a-Si:H/μc-Si:H. A 12-month experimental campaign carried out in a sunny inland site in which a module of each one of these technologies was tested and measured outdoors has provided the necessary empirical data. Results show that module temperature exerts a limited influence on the performance of the tested a-Si:H, CdTe, and a-Si:H/μc-Si:H modules. In contrast, the outdoor behaviour of the CIGS module is the most affected by its temperature. Blue-rich spectra enhance the outdoor behaviour of the a-Si:H and a-Si:H/μc-Si:H modules while it is the other way round for the CIGS module. However, the CdTe specimen shows little sensitivity to the solar spectrum distribution. Anyway, spectral effects are scarcely relevant on an annual basis, ranging from gains for the CIGS module (1.5% to losses for the a-Si:H module (1.0%. However, the seasonal impact of the spectrum shape is more noticeable in these two materials; indeed, spectral issues may cause performance gains or losses of up to some 4% when winter and summer periods are considered.

Uptake and distribution of cadmium in corn

International Nuclear Information System (INIS)

Peel, J.W.; Vetter, R.J.; Christian, J.E.; Kessler, W.V.; McFee, W.W.

1978-01-01

The uptake and distribution of cadmium in corn (Zea mays) treated at various time intervals after planting and sampled at various times after treatment were measured. Cadmium was found to accumulate in all parts sampled. As shown in field studies, stems and leaves generally concentrated more cadmium than did husks, cobs, kernels, silks, or tassels. Samples of stems and leaves from corn treated 23 days after planting and sampled 5 days later exhibited higher concentrations of cadmium than samples taken 25, 45, 65, or 85 days after treatment. Concentrations generally decreased with time. Greenhouse studies showed that corn exposed to cadmium for the longest period of time accumulated the greatest total cadmium. The highest cadmium concentrations were found in the base or lowest leaves sampled 45 days after planting; this suggests a useful technique for quick screening corn crops for cadmium pollution

Biological indicators of cadmium exposure and toxicity

Energy Technology Data Exchange (ETDEWEB)

Shaikh, Z A; Smith, L M

1986-01-01

The increasing environmental and occupational exposure of populations to cadmium creates the need for biological indicators of cadmium exposure and toxicity. The advantages and disadvantages of monitoring blood cadmium, urinary, fecal, hair, and tissue cadmium, serum creatine, beta 2-microglobulin, alpha 1-anti-trypsin and other proteins, and urinary amino acids, enzymes, total proteins, glucose, beta 2-microglobulin, retinol-binding protein, lysozyme, and metallothionein are discussed. It is concluded that urinary cadmium, metallothionein and beta 2-microglubulin may be used together to assess cadmium exposure and toxicity. 66 references.

Studies on Cd1Se0.6Te0.4 Thin Films by Spectroscopic and Diffractometer Characterization

Directory of Open Access Journals (Sweden)

Cliff Orori Mosiori

2017-09-01

Full Text Available Cadmium selenide tellurium is a compound containing cadmium, tellurium and selenium elements forming a combined solid. Hall measurements suggest that it is an n-type semiconductor. Related optical studies indicate that is transparent to infra-red radiation. Structural studies clearly show that it has a wurtzite, sphalerite crystalline forms. Cadmium is a toxic heavy metal, and selenium is only toxic in large amounts or doses. By this toxicity, cadmium selenide is a known to be carcinogen to humans; however, this does not stop investigating it for optoelectronic applications. Current research has narrowed down to investigating cadmium selenide when in the form of nanoparticles. Cadmium selenide finds applications has found applications in opto-electronic devices like laser diodes, biomedical imaging, nano-sensing, high-efficiency solar cells and thin-film transistors. By chemical bath deposition, Cd1Se0.6Te0.4 thin films were grown onto glass. Tellurium was gradually introduced as an impurity and its crystalline structure and optical properties were investigated by XRD and UV-VIS spectroscopy. The main Cd1Se0.6Te0.4/glass characteristics were correlated with the conditions of growing and post-growth treatment and it was found out that films were homogeneous films with controllable thickness onto the glass substrate and suitable for n-type “sandwich” heterostructures applications. Comparison of the intensities of equivalent reflexions provided a test for the internal consistency of the measurements. Equivalent reflexions in two specimens differed on average by 1.4 % and 0.6% from the mean measured intensity, attesting to the high internal consistency of measurements from extended-face crystals. By comparison from data obtained from all samples showed their average deviation from the mean to be 0.9 %.

Direct examination of cadmium bonding in rat tissues dosed with mine wastes and cadmium-containing solutions

International Nuclear Information System (INIS)

Diacomanolis, V.; Ng, J. C.; Sadler, R.; Harris, H. H.; Nomura, M.; Noller, B. N.

2010-01-01

Direct examination by XANES and EXAFS of metal bonding in tissue can be demonstrated by examining cadmium uptake and bonding in animal tissue maintained at cryogenic temperatures. XANES at the K-edge of cadmium were collected at the Photon Factory Advanced Ring (PF-AR), NW10A beam line at KEK-Tsukuba-Japan. Rats fed with 1g mine waste containing 8-400 mg/kg cadmium per 200g body weight (b.w.) or dosed by oral gavage with either cadmium chloride solution alone (at 6 mg/kg b.w.) or in combination with other salts (As, Cu or Zn), 5 days/week for 6 weeks, had 0.1-7.5 and 8-86 mg/kg cadmium in the liver or kidney, respectively. Rats given intraperitoneally (ip) or intravenously (iv) 1-4 times with 1 mg/kg b.w. cadmium solution had 30-120 mg/kg cadmium in the liver or kidney. Tissues from rats were kept and transferred at cryogenic temperature and XANES were recorded at 20 K. The spectra for rat liver samples suggested conjugation of cadmium with glutathione or association with the sulfide bond (Cd-S) of proteins and peptides. EXAFS of rat liver fed by Cd and Zn solutions showed that Cd was clearly bound to S ligands with an inter-atomic distance of 2.54 A ring for Cd-S that was similar to cadmium sulfide with an inter-atomic distance of 2.52 A ring for Cd-S. Liver or kidney of rats fed with mine wastes did not give an edge in the XANES spectra indicating little uptake of cadmium by the animals. Longer and higher dosing regimen may be required in order to observe the same Cd-S bond in the rat tissue from mine wastes, including confirmation by EXAFS.

Electrochemical Studies of Lead Telluride Behavior in Acidic Nitrate Solutions

Directory of Open Access Journals (Sweden)

Rudnik E.

2015-04-01

Full Text Available Electrochemistry of lead telluride stationary electrode was studied in nitric acid solutions of pH 1.5-3.0. E-pH diagram for Pb-Te-H2O system was calculated. Results of cyclic voltammetry of Pb, Te and PbTe were discussed in correlation with thermodynamic predictions. Anodic dissolution of PbTe electrode at potential approx. -100÷50 mV (SCE resulted in tellurium formation, while above 300 mV TeO2 was mainly produced. The latter could dissolve to HTeO+2 under acidic electrolyte, but it was inhibited by increased pH of the bath.

Cadmium toxcity in the pregnant rat

International Nuclear Information System (INIS)

Martin, P.G.; Hitchcock, B.B.; King, J.F.

1978-01-01

Iron-deficient and normal pregnant rats were assigned to groups that either received a dose of cadmium (0.025, 0.050, or 0.100 mmole) plus 8 μCi of /sup 115m/Cd on day 18 of gestation or served as a nondosed group. Animals were either sacrificed 3 days after the dosing or allowed to litter (nondosed and 0.100 mmole cadmium groups only); pups and dams were sacrificed at 14 days of age. Viability of iron-deficient dams and fetuses and pups from iron-deficient dams was affected by the 0.100 mmole cadmium dose to a greater degree than was that in comparable normal animals. Although calculated amounts of cadmium deposited in the dam's liver, kidney, blood, tibia, and fetuses were greater in iron-deficient than in normal animals at all doses, differences were not significant except in the amount of cadmium accumulated in the placenta at the highest cadmium doses. Total deposition in the placentas/litter was similar for normal and iron-deficient groups at each dose level. The decreased viability may have been due to the dam's decreased food intake; blockage of nutrients, especially minerals, by cadmium--protein complexes in the placenta; or hormonal interruptions of pregnancy by steroid--cadmium complexes

Cadmium - a case of mistaken identity

Energy Technology Data Exchange (ETDEWEB)

Taylor, D

1984-05-01

New evidence is presented which describes the impact of cadmium in the environment. Cadmium is a persistent material, although its compounds may undergo a range of chemical changes in the environment. In soluble form cadmium and its compounds are toxic at relatively low concentrations to aquatic animals although their bioconcentrations in such animals is in general low, and there is no evidence of biomagnification. In insoluble form cadmium and its compounds are relatively non-toxic to aquatic animals and are unlikely to be bioconcentrated. As such, cadmium is similar to most other heavy metals. Recent studies indicate that cadmium is not implicated in Itai-Itai disease and does not appear to cause hypertension or cancer. In addition, the accepted critical level in the kidney may have been underestimated. Thus, the hazard to man appears to be considerably less than the original estimates. In view of these data, there seems little justification in treating cadmium in any way differently from the other metals and hence no reason for retaining it on the Black List of the international conventions. 19 references.

Compton imaging with the PorGamRays spectrometer

Energy Technology Data Exchange (ETDEWEB)

Judson, D.S., E-mail: dsj@ns.ph.liv.ac.uk [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Boston, A.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Coleman-Smith, P.J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Cullen, D.M. [Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom); Hardie, A. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Harkness, L.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Jones, L.L. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Jones, M. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Lazarus, I. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Nolan, P.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Pucknell, V. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Rigby, S.V. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Seller, P. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Scraggs, D.P. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Slee, M.; Sweeney, A. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom)

2011-10-01

The PorGamRays project aims to develop a portable gamma-ray detection system with both spectroscopic and imaging capabilities. The system is designed around a stack of thin Cadmium Zinc Telluride (CZT) detectors. The imaging capability utilises the Compton camera principle. Each detector is segmented into 100 pixels which are read out through custom designed Application Specific Integrated Circuits (ASICs). This device has potential applications in the security, decommissioning and medical fields. This work focuses on the near-field imaging performance of a lab-based demonstrator consisting of two pixelated CZT detectors, each of which is bonded to a NUCAM II ASIC. Measurements have been made with point {sup 133}Ba and {sup 57}Co sources located {approx}35mm from the surface of the scattering detector. Position resolution of {approx}20mm FWHM in the x and y planes is demonstrated.

Structural studies on Langmuir-Blodgett ultra-thin films on tin (IV) stearate using X-ray diffraction technique

International Nuclear Information System (INIS)

Mohamad Deraman; Muhamad Mat Salleh; Mohd Ali Sulaiman; Mohd Ali Sufi

1991-01-01

X-ray diffraction measurements were carried out on Langmuir-Blodgett (LB) ultra-thin films of tin (IV) stearate for different numbers of layers. The structural information such as interplanar spacing, unit cells spacing, molecular length and orientation of molecular chains were obtained from the diffraction data. This information is discussed and compared with that previously published for LB ultra-thin films of manganese stearate and cadmium stearate

Applications of CdTe to nuclear medicine. Final report

International Nuclear Information System (INIS)

Entine, G.

1985-01-01

Uses of cadmium telluride (CdTe) nuclear detectors in medicine are briefly described. They include surgical probes and a system for measuring cerebral blood flow in the intensive care unit. Other uses include nuclear dentistry, x-ray exposure control, cardiology, diabetes, and the testing of new pharmaceuticals

Teresa Barnes, Ph.D. | NREL

Science.gov (United States)

graduate student. She came to NREL as a postdoctoral researcher to continue working on transparent conducting oxides and began working on carbon nanotube and metal nanowire transparent contacts. She is currently a senior scientist at NREL working on cadmium telluride (CdTe) solar cells. Her research interests

Health hazards of environmental cadmium pollution

Energy Technology Data Exchange (ETDEWEB)

Nordberg, G F

1974-01-01

Cadmium, a metal widely used in industrial processes, has been recognized to be a highly toxic and dangerous environmental pollutant. In this study the author describes the sources and occurrence of cadmium, and the intake by human beings. He states that present standards for daily intake do not allow sufficient safety margins. The fate and known effects of cadmium in human beings are summarized; some effects associated with cadmium are renal (kidney) damage, anemia, hypertension, and liver damage. Cadmium was identified as the main cause of the Itai-Itai disease in Japan, and epidemiological studies from various areas of Japan are presented. 64 references, 9 figures, 5 tables.

Effects of Long-term exposure of Gelatinated and Non-gelatinated Cadmium Telluride Quantum Dots on Differentiated PC12 cells

LENUS (Irish Health Repository)

Prasad, Babu R

2012-01-20

Abstract Background The inherent toxicity of unmodified Quantum Dots (QDs) is a major hindrance to their use in biological applications. To make them more potent as neuroprosthetic and neurotherapeutic agents, thioglycolic acid (TGA) capped CdTe QDs, were coated with a gelatine layer and investigated in this study with differentiated pheochromocytoma 12 (PC12) cells. The QD - cell interactions were investigated after incubation periods of up to 17 days by MTT and APOTOX-Glo Triplex assays along with using confocal microscopy. Results Long term exposure (up to 17 days) to gelatinated TGA-capped CdTe QDs of PC12 cells in the course of differentiation and after neurites were grown resulted in dramatically reduced cytotoxicity compared to non-gelatinated TGA-capped CdTe QDs. Conclusion The toxicity mechanism of QDs was identified as caspase-mediated apoptosis as a result of cadmium leaking from the core of QDs. It was therefore concluded that the gelatine capping on the surface of QDs acts as a barrier towards the leaking of toxic ions from the core QDs in the long term (up to 17 days).

CdZnTe and CdTe materials for X-ray and gamma ray radiation detector applications

International Nuclear Information System (INIS)

Szeles, Csaba

2004-01-01

Good detection efficiency and high energy-resolution make Cadmium Zinc Telluride (CdZnTe) and Cadmium Telluride (CdTe) detectors attractive in many room temperature X-ray and gamma-ray detection applications such as medical and industrial imaging, industrial gauging and non-destructive testing, security and monitoring, nuclear safeguards and non-proliferation, and astrophysics. Advancement of the crystal growth and device fabrication technologies and the reduction of bulk, interface and surface defects in the devices are crucial for the widespread practical deployment of Cd 1-x Zn x Te-based detector technology. Here we review the effects of bulk, interface and surface defects on charge transport, charge transport uniformity and device performance and the progress in the crystal growth and device fabrication technologies aiming at reducing the concentration of harmful defects and improving Cd 1-x Zn x Te detector performance. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Cadmium removal by Lemna minor and Spirodela polyrhiza.

Science.gov (United States)

Chaudhuri, Devaleena; Majumder, Arunabha; Misra, Amal K; Bandyopadhyay, Kaushik

2014-01-01

The present study investigates the ability of two genus of duckweed (Lemna minor and Spirodela polyrhiza) to phytoremediate cadmium from aqueous solution. Duckweed was exposed to six different cadmium concentrations, such as, 0.5,1.0,1.5, 2.0, 2.5, and 3.0 mg/L and the experiment was continued for 22 days. Water samples were collected periodically for estimation of residual cadmium content in aqueous solution. At the end of treatment period plant samples were collected and accumulated cadmium content was measured. Cadmium toxicity was observed through relative growth factor and changes in chlorophyll content Experimental results showed that Lemna minor and Spirodela polyrhiza were capable of removing 42-78% and 52-75% cadmium from media depending upon initial cadmium concentrations. Cadmium was removed following pseudo second order kinetic model Maximum cadmium accumulation in Lemna minor was 4734.56 mg/kg at 2 mg/L initial cadmium concentration and 7711.00 mg/kg in Spirodela polyrhiza at 3 mg/L initial cadmium concentration at the end of treatment period. Conversely in both cases maximum bioconcentration factor obtained at lowest initial cadmium concentrations, i.e., 0.5 mg/L, were 3295.61 and 4752.00 for Lemna minor and Spirodela polyrhiza respectively. The present study revealed that both Lemna minor and Spirodela polyrhiza was potential cadmium accumulator.

Cadmium Exposure is Associated with the Prevalence of Dyslipidemia

Directory of Open Access Journals (Sweden)

Zhou Zhou

2016-11-01

Full Text Available Background: Cadmium is a widespread environmental and occupational pollutant that accumulates in human body with a biological half-life exceeding 10 years. Cadmium exposure has been demonstrated to increase rates of cardiovascular diseases. Whether occupational cadmium exposure is associated with the increase in the prevalence of dyslipidemia and hence contributes to the risk of cardiovascular diseases is still equivocal. To test the hypothesis that exposure to cadmium is related to the prevalence of dyslipidemia, we examined the associations between blood cadmium concentration and the prevalence of dyslipidemia in workers occupationally exposed to cadmium in China. Methods: A cross-sectional survey on demographic data, blood cadmium level and lipid profile in cadmium exposed workers from seven cadmium smelting factories in central and southwestern China was conducted. We measured blood cadmium concentration and lipid components of 1489 cadmium exposed workers. The prevalence of dyslipidemia was compared across blood cadmium quartiles. Associations between the blood cadmium concentrations and the prevalence of dyslipidemia were assessed using confounder adjusted linear and logistic regressions. Results: The blood cadmium concentration was 3.61±0.84µg/L ( mean ±SD. The prevalence of dyslipidemia in this occupational population was 66.3%. Mean blood cadmium concentration of workers with dyslipedemia was significantly higher than that of workers without dyslipidemia (p Conclusion: Elevated blood cadmium concentration is associated with prevalence of dyslipidemia. Cadmium exposure could alter lipid metabolism in humans. It is imperative to control cadmium exposure of occupational population in cadmium related industries and reduce adverse health effects.

Dietary cadmium and enteropathy in the Japanese quail: histochemical and ultrastructural studies

Energy Technology Data Exchange (ETDEWEB)

Richardson, M.E.; Fox, M.R.S.

1974-01-01

Cadmium was fed to young Japanese quail, at a level of 75 mg. per kg. of diet, from hatching to 4 weeks of age. Cadmium produced gross, microscopic, and ultrastructural lesions in the proximal small intestine of these quail, similar to those occurring in human malabsorption syndromes, celiac disease, nontropical sprue, and tropical sprue. The small intestines of the quail were dilated and thin walled. Villi were short and thick and had a dense cellular infiltrate in the lamina propria. The striated border was thin but stained for neutral mucopolysaccharides, as did the normal border. Some villi were covered with stratified epithelial cells. Hypertrophy and hyperplasia of goblet were seen, but the mucin stained for weakly acidic mucopolysaccharides, as did the normal cells. At the ultrastructural level, microvilli of both absorptive and goblet cells were markedly shortened, particularly near the tips of the villi. Absorptive cells were atrophic, and there was s diminution of the usual cellular organelles. Granular cisternae were long and tortuous, mitochondria were dense and small, and large lysosome-like bodies and large lipid droplets accumulated in the cytoplasm, but there was a decrease in the normal small, pale and dark lipid droplets. The cellular infiltrate of the lamina propria included groups of plasma cells with dilated cisternae. There were large, irregular, electron-dense bodies in the endothelium of large veins and degeneration of some nerve plexuses in the muscularis propria. 31 references, 21 figures.

Fabrication of CdS/CdTe-Based Thin Film Solar Cells Using an Electrochemical Technique

Directory of Open Access Journals (Sweden)

I. M. Dharmadasa

2014-06-01

Full Text Available Thin film solar cells based on cadmium telluride (CdTe are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n → p or p → n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV effect as well as making use of IR photons from the surroundings when fully optimised.

Cadmium Exposure is Associated with the Prevalence of Dyslipidemia.

Science.gov (United States)

Zhou, Zhou; Lu, Yong-Hui; Pi, Hui-Feng; Gao, Peng; Li, Min; Zhang, Lei; Pei, Li-Ping; Mei, Xiang; Liu, Lin; Zhao, Qi; Qin, Qi-Zhong; Chen, Yu; Jiang, Yue-Ming; Zhang, Zhao-Hui; Yu, Zheng-Ping

2016-01-01

Cadmium is a widespread environmental and occupational pollutant that accumulates in human body with a biological half-life exceeding 10 years. Cadmium exposure has been demonstrated to increase rates of cardiovascular diseases. Whether occupational cadmium exposure is associated with the increase in the prevalence of dyslipidemia and hence contributes to the risk of cardiovascular diseases is still equivocal. To test the hypothesis that exposure to cadmium is related to the prevalence of dyslipidemia, we examined the associations between blood cadmium concentration and the prevalence of dyslipidemia in workers occupationally exposed to cadmium in China. A cross-sectional survey on demographic data, blood cadmium level and lipid profile in cadmium exposed workers from seven cadmium smelting factories in central and southwestern China was conducted. We measured blood cadmium concentration and lipid components of 1489 cadmium exposed workers. The prevalence of dyslipidemia was compared across blood cadmium quartiles. Associations between the blood cadmium concentrations and the prevalence of dyslipidemia were assessed using confounder adjusted linear and logistic regressions. The blood cadmium concentration was 3.61±0.84µg/L ( mean ±SD). The prevalence of dyslipidemia in this occupational population was 66.3%. Mean blood cadmium concentration of workers with dyslipedemia was significantly higher than that of workers without dyslipidemia (p dyslipidemia increased dose-dependently with elevations in blood cadmium concentrations (p for trend dyslipidemia across the increasing blood cadmium quartiles were 1.21(1.16-1.55), 1.56(1.11-1.87), 1.79(1.26-2.25) respectively (referencing to 1.00; p for trend dyslipidemia remained unchanged (all p for trend dyslipidemia. Cadmium exposure could alter lipid metabolism in humans. It is imperative to control cadmium exposure of occupational population in cadmium related industries and reduce adverse health effects. © 2016 The

Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi{sub 2}Te{sub 3}) single crystals for thermoelectric applications

Energy Technology Data Exchange (ETDEWEB)

Krishna, Anuj [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Singh, Budhendra [TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN), University of Aveiro, 3810-193 Aveiro (Portugal); Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Maurya, K.K. [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

2016-03-07

High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi{sub 2}Te{sub 3}) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

On 28th September 2015, India launched its first astronomical space observatory AstroSat, successfully. AstroSat carried five astronomy payloads, namely, (i) Cadmium Zinc Telluride Imager (CZTI), (ii) Large Area X-ray Proportional Counter (LAXPC), (iii) Soft X-ray Telescope (SXT), (iv) Ultra Violet Imaging Telescope (UVIT) ...

Minimizing Patient-Specific Tracer Dose in Myocardial Perfusion Imaging Using CZT SPECT

NARCIS (Netherlands)

van Dijk, Joris David; Jager, Pieter L.; Ottervanger, Jan Paul; Slump, Cornelis H.; de Boer, Jaep; Oostdijk, Adrianus H.J.; van Dalen, Jorn A.

Myocardial perfusion imaging (MPI) with SPECT is widely adopted in clinical practice but is associated with a relatively high radiation dose. The aim of this study was to determine the minimum product of tracer dose and scan time that will maintain diagnostic value for cadmium zinc telluride (CZT)

Fabrication of Thermoelectric Sensor and Cooling Devices Based on Elaborated Bismuth-Telluride Alloy Thin Films

Directory of Open Access Journals (Sweden)

Abdellah Boulouz

2014-01-01

Full Text Available The principal motivation of this work is the development and realization of smart cooling and sensors devices based on the elaborated and characterized semiconducting thermoelectric thin film materials. For the first time, the details design of our sensor and the principal results are published. Fabrication and characterization of Bi/Sb/Te (BST semiconducting thin films have been successfully investigated. The best values of Seebeck coefficient (α(T at room temperature for Bi2Te3, and (Bi1−xSbx2Te3 with x = 0.77 are found to be −220 µV/K and +240 µV/K, respectively. Fabrication and evaluation of performance devices are reported. 2.60°C of cooling of only one Peltier module device for an optimal current of Iopt=2.50 mA is obtained. The values of temperature measured by infrared camera, by simulation, and those measured by the integrated and external thermocouple are reported. A sensitivity of the sensors of 5 mV Torr−1 mW−1 for the pressure sensor has been found with a response time of about 600 ms.

Reviews of the environmental effects of pollutants: IV. Cadmium

International Nuclear Information System (INIS)

Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

1978-06-01

This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 μg per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels

Reviews of the environmental effects of pollutants: IV. Cadmium

Energy Technology Data Exchange (ETDEWEB)

Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

1978-06-01

This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 ..mu..g per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels.

Cadmium-induced fetal toxicity in the rat

International Nuclear Information System (INIS)

Levin, A.A.

1980-01-01

Cadmium, a heavy metal environment contaminant, induces fetal death and placental necrosis in the Wistar rat. This study investigated fetal, maternal, and placental responses to cadmium intoxication. Subcutaneous injection of CdCl 2 to dams on day 18 of pregnancy produced a high incidence of fetal death (75%) and placental necrosis. Death in the fetus was produced despite limited fetal accumulations of cadmium. Distribution studies using 109 Cd-labeled CdCl 2 demonstrated that less than 0.1% of the injected dose was associated with the fetus. To determine if fetuses were sensitive to these low levels of cadmium, direct injections of CdCl 2 into fetuses were performed in utero. Direct injections produced fetal accumulations 8-fold greater than those following maternal injections. The 8-fold greater fetal accumulations following direct injection were associated with only a 12% fetal mortality compared to the 75% mortality following maternal injections. The data indicated that the fetal toxicity of cadmium following maternal injections was not the result of direct effects of cadmium on the fetus. In conclusion, cadmium-induced fetal death was not the result of direct effects of cadmium on the fetus but may have been induced by placental cellular injury resulting from high accumulations of cadmium in the placenta. A vascular response to placental injury, leading to decreased utero-placental bood flow and cadmium-induced alterations in trophoblastic function, resulted in fetal death

Cadmium in Salix. A study to show the capacity of Salix to remove cadmium from farmland

International Nuclear Information System (INIS)

Oestman, G.

1994-01-01

The aim of this report has been to show the ability of Salix to take up cadmium and how the uptake varies between different types of soil. The information that the results are based on has been obtained from analyses of soil and Salix. The samples were taken at five sites in the district around Lake Maelaren. Two or three stands were taken at each place. The factors studied were the pH, the organic matter content, and the concentration of cadmium in the soil. Salix has a good ability, relative to other crops, to remove cadmium from arable land. The cadmium uptake is 35 times higher with Salix than with straw or energy grass. Salix uptake of cadmium varies between 3 and 14% of the cadmium content in the soil that is accessible to plants. The present annual increase of cadmium in arable land is 1 g/ha, whereas the removal in a Salix plantation is 21 g Cd/ha, yr at an annual growth of 10 tonnes DM. If the Cd uptake is the same each year, then a total of 420 g Cd/ha is removed when Salix is grown over a 20-year period. This is a very large part of the topsoil's total cadmium content, which is 550 g/ha on average in Sweden. The investigation reveals no clear relationship between the Cd concentration in Salix and the concentration of Cd in the soil, the organic matter content or the pH. 22 refs, 4 figs, 2 tabs

Use of cadmium in solution in the EL 4 reactor moderator irreversible fixing of cadmium on the metallic surfaces; Utilisation du cadmium en solution dans le moderateur du reacteur EL 4 - fixation irreversible du cadmium sur les surfaces metalliques

Energy Technology Data Exchange (ETDEWEB)

Croix, O; Paoli, O; Lecomte, J; Dolle, L; Gallic, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In the framework of research into the poisoning of the EL-4 reactor by cadmium sulphate, measurements have been made by two different methods of the residual amounts of cadmium liable to be fixed irreversibly on the surfaces in contact with the heavy water. A marked influence of the pH has been noticed. The mechanism of the irreversible fixing is compatible with the hypothesis of an ion-exchange in the surface oxide layer. In a sufficiently wide range of pH the cadmium thus fixed causes very little residual poisoning. The stability of the cadmium sulphate solutions is however rather low in the conditions of poisoning. (authors) [French] Dans le cadre des etudes sur l'empoisonnement du reacteur EL-4 par le sulfate de cadmium, les quantites residuelles de cadmium susceptibles de se fixer irreversiblement sur les parois que mouillerait l'eau lourde, ont ete mesurees experimentalement par deux methodes differentes. On observe une influence nette du pH. Le mecanisme de la fixation irreversible est compatible avec l'hypothese d'un echange d'ions dans la pellicule d'oxyde superficielle. Dans des limites suffisamment larges de pH, la cadmium ainsi fixe n'occasionne pas d'empoisonnement residuel important. La stabilite des solutions de sulfate de cadmium dans les conditions de l'empoisonnement est cependant mediocre. (auteurs)

Cadmium incorporation by the marine copepod Pseudodiaptomus coronatus

International Nuclear Information System (INIS)

Sick, L.V.; Baptist, G.J.

1979-01-01

Pseudodiaptomus coronatus, after exposure to phytoplankton and cadmium in concentrations like those in temperate, coastal environments, incorporated 109 Cd at higher rates from ambient water than from phytoplankton food. When ambient stable cadmium concentrations were increased from 0.03 to 1.00 μg.liter -1 , cadmium concentration by phytoplankton cells increased and the rate of cell ingestion by P. coronatus decreased. This inverse relation between the accumulation of cadmium in phytoplankton cells and the animal's ingestion rate resulted in relatively small net increases in the cadmium accumulated from phytoplankton by copepods. Rates of stable cadmium ingestion for P. coronatus ranged from 0.18 to 0.38 ng.mg animal dry wt -1 .h -1 , depending on the initial algal cell density and the ambient cadmium concentration. For cadmium concentrations of 0.03 to 1.00 μg.liter -1 , percentage assimilation efficiencies ranged from 13.20 to 68.40. Both rates of cadmium ingestion and assimilation efficiencies were higher than published values for carnivorous zooplankton

Electric-field modulation of ferromagnetism in hexagonal chromium telluride thin film

International Nuclear Information System (INIS)

Akiyama, Ryota; Oikawa, Haruyoshi; Yamawaki, Kazuma; Kuroda, Shinji

2014-01-01

We report the electric-field modulation of magnetism of a hexagonal Cr 1-δ Te thin film. A gate voltage V G is ap-plied in the field effect capacitor (FEC) structure consisting of electric double-layer capacitor (EDLC) of an ion liquid and a 2nm-thick Cr 1-δ Te layer grown by molecular beam epitaxy (MBE) and the magnetization of the layer is directly measured using a superconducting quantum interference device (SQUID) magnetometer in the both configurations with magnetic fields perpendicular or parallel to the film plane. As a result, we observe a clear change in the magnetization vs. magnetic field (M-H) curves by applying VG at a low temperature of 15 K in the perpendicular field configuration; the magnetization increases and the coercivity decreases by applying either positive or negative gate voltage. When the temperature is increased up to 160K, slightly lower than the Curie temperature, or the magnetization was measured in the in-plane field configuration, the magnetization increases similarly by applying either positive or negative gate voltage, but the amount of the increase becomes much smaller. A possible mechanism of the electric-field modulation is discussed in relation to the Cr vacancies in the Cr 1-δ Te layer. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Electric-field modulation of ferromagnetism in hexagonal chromium telluride thin film

Energy Technology Data Exchange (ETDEWEB)

Akiyama, Ryota; Oikawa, Haruyoshi; Yamawaki, Kazuma; Kuroda, Shinji [Institute of Materials Science, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan)

2014-07-15

We report the electric-field modulation of magnetism of a hexagonal Cr{sub 1-δ}Te thin film. A gate voltage V{sub G} is ap-plied in the field effect capacitor (FEC) structure consisting of electric double-layer capacitor (EDLC) of an ion liquid and a 2nm-thick Cr{sub 1-δ}Te layer grown by molecular beam epitaxy (MBE) and the magnetization of the layer is directly measured using a superconducting quantum interference device (SQUID) magnetometer in the both configurations with magnetic fields perpendicular or parallel to the film plane. As a result, we observe a clear change in the magnetization vs. magnetic field (M-H) curves by applying VG at a low temperature of 15 K in the perpendicular field configuration; the magnetization increases and the coercivity decreases by applying either positive or negative gate voltage. When the temperature is increased up to 160K, slightly lower than the Curie temperature, or the magnetization was measured in the in-plane field configuration, the magnetization increases similarly by applying either positive or negative gate voltage, but the amount of the increase becomes much smaller. A possible mechanism of the electric-field modulation is discussed in relation to the Cr vacancies in the Cr{sub 1-δ}Te layer. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Diffusive gradient in thin films technique for assessment of cadmium and copper bioaccessibility to radish (Raphanus sativus)

Czech Academy of Sciences Publication Activity Database

Dočekalová, H.; Škarpa, P.; Dočekal, Bohumil

2015-01-01

Roč. 134, March (2015), s. 153-157 ISSN 0039-9140 R&D Projects: GA ČR GAP503/10/2002 Institutional support: RVO:68081715 Keywords : radish * cadmium * copper * DGT technique * bioaccesibility Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.035, year: 2015

An association between urinary cadmium and urinary stone disease in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

International Nuclear Information System (INIS)

Swaddiwudhipong, Witaya; Mahasakpan, Pranee; Limpatanachote, Pisit; Krintratun, Somyot

2011-01-01

Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: → Excessive calciuria is the major risk of urinary stone formation. → We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. → The rate of urinary stones increases with increasing urinary cadmium. → Urinary calcium excretion increases with increasing urinary cadmium. → Elevated calciuria induced by cadmium may increase the risk of urinary stones.

Preparation and characterization of pulsed laser deposited CdTe thin films at higher FTO substrate temperature and in Ar + O{sub 2} atmosphere

Energy Technology Data Exchange (ETDEWEB)

Ding, Chao; Ming, Zhenxun [College of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Li, Bing, E-mail: libing70@126.com [College of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Feng, Lianghuan [College of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Wu, Judy [Department of Physics and Astronomy, Kansas University, Lawrence 66045 (United States)

2013-06-20

Highlights: • CdTe films were deposited by PLD at high substrate temperatures (400 °C, 550 °C). • CdTe films were achieved under the atmosphere (1.2 Torr) of Ar mixed with O{sub 2}. • Deposited CdTe films were cubic phase and had strong (1 0 0) preferred orientation. • Scanning electron microscope (SEM) showed an average grain size of 0.3–0.6 μm. • The ultra-thin film (CdS/PLD-CdTe) solar cell with efficiency of 6.68% was made. -- Abstract: Pulsed laser deposition (PLD) is one of the promising techniques for depositing cadmium telluride (CdTe) thin films. It has been reported that PLD CdTe thin films were almost deposited at the lower substrate temperatures (<300 °C) under vacuum conditions. However, the poor crystallinity of CdTe films prepared in this way renders them not conducive to the preparation of high-efficiency CdTe solar cells. To obtain high-efficiency solar cell devices, better crystallinity and more suitable grain size are needed, which requires the CdTe layer to be deposited by PLD at high substrate temperatures (>400 °C). In this paper, CdTe layers were deposited by PLD (KrF, λ = 248 nm, 10 Hz) at different higher substrate temperatures (T{sub s}). Excellent performance of CdTe films was achieved at higher substrate temperatures (400 °C, 550 °C) under an atmosphere of Ar mixed with O{sub 2} (1.2 Torr). X-ray diffraction analysis confirmed the formation of CdTe cubic phase with a strong (1 0 0) preferential orientation at all substrates temperatures on 60 mJ laser energy. The optical properties of CdTe were investigated, and the band gaps of CdTe films were 1.51 eV and 1.49 eV at substrate temperatures of 400 °C and 550 °C, respectively. Scanning electron microscopy (SEM) showed an average grain size of 0.3–0.6 μm. Thus, under these conditions of the atmosphere of Ar + O{sub 2} (15 Torr) and at the relatively high T{sub s} (500 °C), an thin-film (FTO/PLD-CdS (100 nm)/PLD-CdTe (∼1.5 μm)/HgTe: Cu/Ag) solar cell with an

Characterization of nanostructured photosensitive cadmium sulphide thin films grown by SILAR deposition technique

International Nuclear Information System (INIS)

Ubale, A.U.; Bargal, A.N.

2010-01-01

This paper reports the preparation of photosensitive nanostructured CdS thin films by successive ionic layer adsorption and reaction (SILAR) method at room temperature. To obtain good quality CdS thin films, preparative conditions such as concentration of cationic and anionic precursors, adsorption and rinsing time durations etc. are optimized. The structural, optical and electrical characterizations of the as-deposited and annealed CdS thin films were carried out using X-ray diffraction, scanning electron microscopy, optical absorption and electrical resistivity methods. The photoconductivity studies showed that the annealed films are more than that photosensitive. The TEP measurement shows that deposited films are of n-type. (author)

Cadmium induced changes in cell organelles: An ultrastructural study using cadmium sensitive and resistant muntjac fibroblast cell lines

Energy Technology Data Exchange (ETDEWEB)

Ord, M.J.; Chibber, R.; Bouffler, S.D.

1988-09-01

A detailed electron microscopy study of cadmium sensitive and resistant muntjac fibroblast cell lines has identified a wide range of intracellular damage following exposure to cadmium. Damaged organelles included cell membrane, mitochondria, Golgi cisternae and tubular network, chromatin, nucleoli, microfilaments and ribosomes. Although cell membrane damage was generally the earliest indication of adverse cadmium action, particularly with continuous cadmium exposures, cells could tolerate extensive membrane loss. Mitochondrial distortion and some damage to Golgi was also tolerated. The turning point at which cadmium became lethal was generally marked by a cascade of events which included damage to both nuclear and cytoplasmic components. These results for fibroblasts are discussed and compared with damage reported in other types of cells.

Molecular and cellular mechanisms of cadmium carcinogenesis

International Nuclear Information System (INIS)

Waisberg, Michael; Joseph, Pius; Hale, Beverley; Beyersmann, Detmar

2003-01-01

Cadmium is a heavy metal, which is widely used in industry, affecting human health through occupational and environmental exposure. In mammals, it exerts multiple toxic effects and has been classified as a human carcinogen by the International Agency for Research on Cancer. Cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Cd 2+ does not catalyze Fenton-type reactions because it does not accept or donate electrons under physiological conditions, and it is only weakly genotoxic. Hence, indirect mechanisms are implicated in the carcinogenicity of cadmium. In this review multiple mechanisms are discussed, such as modulation of gene expression and signal transduction, interference with enzymes of the cellular antioxidant system and generation of reactive oxygen species (ROS), inhibition of DNA repair and DNA methylation, role in apoptosis and disruption of E-cadherin-mediated cell-cell adhesion. Cadmium affects both gene transcription and translation. The major mechanisms of gene induction by cadmium known so far are modulation of cellular signal transduction pathways by enhancement of protein phosphorylation and activation of transcription and translation factors. Cadmium interferes with antioxidant defense mechanisms and stimulates the production of reactive oxygen species, which may act as signaling molecules in the induction of gene expression and apoptosis. The inhibition of DNA repair processes by cadmium represents a mechanism by which cadmium enhances the genotoxicity of other agents and may contribute to the tumor initiation by this metal. The disruption of E-cadherin-mediated cell-cell adhesion by cadmium probably further stimulates the development of tumors. It becomes clear that there exist multiple mechanisms which contribute to the carcinogenicity of cadmium, although the relative weights of these contributions are difficult to estimate

Cadmium in the bioenergy system - a synthesis

International Nuclear Information System (INIS)

Ahlfont, K.

1997-12-01

Cadmium is a toxic metal without any known positive biological effects. Both emissions and atmospheric deposition of cadmium have decreased radically in Sweden during recent years. In Sweden, about 150 tonnes of cadmium was supplied to the technosphere in 1990, mostly originating from NiCd batteries. More than 100 tonnes of cadmium accumulated in the technosphere. Mankind takes up cadmium from water, food and particulate atmospheric pollution. Even small amounts may be injurious in the long-term since the half-life in the kidneys is 30 years. Cadmium in biofuel and ashes are generally a cause of discussion. Ashes from biofuel constitute a nutrient resource that should be returned to the soil. A possible risk with spreading ashes is the spreading of heavy metals, and then foremost cadmium, which is among the heavy metals that forest soils are considered to tolerate the least. Several studies on cadmium in the bioenergy system have been made, both within the Research Programme for Recycling of Wood-ash, and within Vattenfall's Bioenergy Project. The present report is intended to provide a picture of the current state of knowledge and to review plans for the future With a 3 page summary in English. 51 refs, 1 fig, 3 tabs

Association of urinary cadmium and myocardial infarction

International Nuclear Information System (INIS)

Everett, Charles J.; Frithsen, Ivar L.

2008-01-01

We conducted a cross-sectional analysis of individuals 45-79 years old in the National Health and Nutrition Examination Survey III (1988-1994) (NHANES III). Myocardial infarction was determined by electrocardiogram (ECG). Our sample included 4912 participants, which when weighted represented 52,234,055 Americans. We performed adjusted logistic regressions with the Framingham risk score, pack-years of smoking, race-ethnicity, and family history of heart attack, and diabetes as covariates. Urinary cadmium ≥0.88 μg/g creatinine had an odds ratio of 1.86 (95% CI 1.26-2.75) compared to urinary cadmium <0.43 μg/g creatinine. This result supports the hypothesis that cadmium is associated with coronary heart disease. When logistic regressions were done by gender, women, but not men, showed a significant association of urinary cadmium with myocardial infarction. Women with urinary cadmium ≥0.88 μg/g creatinine had an odds ratio of 1.80 (95% CI 1.06-3.04) compared to urinary cadmium <0.43 μg/g creatinine. When the analysis was restricted to never smokers (N=2187) urinary cadmium ≥0.88 μg/g creatinine had an odds ratio of 1.85 (95% CI 1.10-3.14) compared to urinary cadmium <0.43 μg/g creatinine

Cadmium action in synapses in the brain

International Nuclear Information System (INIS)

Minami, Akira; Takeda, Atsushi; Nishibaba, Daisuke; Tekefuta, Sachiyo; Oku, Naoto

2001-01-01

Chronic exposure to cadmium causes central nervous system disorders, e.g., olfactory dysfunction. To clarify cadmium toxicity in synaptic neurotransmission in the brain, the movement and action of cadmium in the synapses was examined using in vivo microdialysis. One and 24 h after injection of 109 CdCl 2 into the amygdala of rats, 109 Cd release into the extracellular space was facilitated by stimulation with high K + , suggesting that cadmium taken up in amygdalar neurons is released into the synaptic clefts in a calcium- and impulse-dependent manner. To examine the action of cadmium in the synapses, the amygdala was perfused with artificial cerebrospinal fluid containing 10-30 μM CdCl 2 . The release of excitatory neurotransmitters, i.e., glutamate and aspartate, into the extracellular space was decreased during perfusion with cadmium, while the release of inhibitory neurotransmitters, i.e., glycine and γ-amino butyric acid (GABA), into the extracellular space was increased during the period. These results suggest that cadmium released from the amygdalar neuron terminals affects the degree and balance of excitation-inhibition in synaptic neurotransmission. (author)

Distribution of cadmium between calcium carbonate and solution, 2

International Nuclear Information System (INIS)

Kitano, Yasushi; Kanamori, Nobuko; Fujiyoshi, Ryoko

1978-01-01

The distribution coefficient of cadmium between calcite and solution has been measured in the calcium bicarbonate solution containing cadmium and chloride ions, which forms complexes with cadmium ions. It has been confirmed experimentally that cadmium carbonate is present as a solid solution between calcitic calcium carbonate and cadmium carbonate in the carbonate precipitate formed in the solution system. However, the constant value of the thermodynamic distribution coefficient of cadmium between calcite and solution has not been obtained experimentally in the calcium bicarbonate solution containing cadmium and chloride ions. It may have been caused by the very specific behavior of cadmium ions, but the exact reason remains unsolved and must be studied. (Kobatake, H.)

Correlations of urinary cadmium with hypertension and diabetes in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

Energy Technology Data Exchange (ETDEWEB)

Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Limpatanachote, Pisit; Krintratun, Somyot [Department of Internal Medicine, Mae Sot General Hospital, Tak (Thailand)

2010-08-15

Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4{+-}2.3 {mu}g/g creatinine) was significantly greater than that for men (2.0{+-}2.2 {mu}g/g creatinine). Hypertension was presented in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.

Correlations of urinary cadmium with hypertension and diabetes in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

International Nuclear Information System (INIS)

Swaddiwudhipong, Witaya; Mahasakpan, Pranee; Limpatanachote, Pisit; Krintratun, Somyot

2010-01-01

Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4±2.3 μg/g creatinine) was significantly greater than that for men (2.0±2.2 μg/g creatinine). Hypertension was presented in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.

Novel Cadmium Resistance Determinant in Listeria monocytogenes.

Science.gov (United States)

Parsons, Cameron; Lee, Sangmi; Jayeola, Victor; Kathariou, Sophia

2017-03-01

Listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables Listeria to tolerate exposure to cadmium is the cadAC efflux system, with CadA being a P-type ATPase. Three different cadA genes (designated cadA1 to cadA3 ) were previously characterized in L. monocytogenes A novel putative cadmium resistance gene ( cadA4 ) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized cadA4 in L. monocytogenes strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in cadA4 The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette ( cadA4C ), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with cadA4C Cadmium exposure induced cadA4 expression, even at noninhibitory levels. Virulence assessments in the Galleria mellonella model suggested that a functional cadA4 suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that cadA4 inactivation reduced biofilm formation. These data not only confirm cadA4 as a novel cadmium resistance determinant in L. monocytogenes but also provide evidence for roles in virulence and biofilm formation. IMPORTANCE Listeria monocytogenes is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of Listeria in the environment are the abilities to persist in biofilms, grow in the cold, and

Processing and characterization of new oxy-sulfo-telluride glasses in the Ge-Sb-Te-S-O system

International Nuclear Information System (INIS)

Smith, C.; Jackson, J.; Petit, L.; Rivero-Baleine, C.; Richardson, K.

2010-01-01

New oxy-sulfo-telluride glasses have been prepared in the Ge-Sb-Te-S-O system employing a two-step melting process which involves the processing of a chalcogenide glass (ChG) and subsequent melting with TeO 2 or Sb 2 O 3 . The progressive incorporation of O at the expense of S was found to increase the density and the glass transition temperature and to decrease the molar volume of the investigated oxy-sulfo-telluride glasses. We also observed a shift of the vis-NIR cut-off wavelength to longer wavelength probably due to changes in Sb coordination within the glass matrix and overall matrix polarizability. Using Raman spectroscopy, correlations have been shown between the formation of Ge- and Sb-based oxysulfide structural units and the S/O ratio. Lastly, two glasses with similar composition (Ge 20 Sb 6 S 64 Te 3 O 7 ) processed by melting the Ge 23 Sb 7 S 70 glass with TeO 2 or the Ge 23 Sb 2 S 72 Te 4 glass with Sb 2 O 3 were found to have slightly different physical, thermal, optical and structural properties. These changes are thought to result mainly from the higher moisture content and sensitivity of the TeO 2 starting materials as compared to that of the Sb 2 O 3 . - Graphical abstract: In this paper, we discuss our most recent findings on the processing and characterization of new ChG glasses prepared with small levels of Te, melted either with TeO 2 or Sb 2 O 3 powders. We explain how these new oxy-sulfo-telluride glasses are prepared and we correlate the physical, thermal and optical properties of the investigated glasses to the structure changes induced by the addition of oxygen in the Ge-Sb-S-Te glass network.

Modelling of cadmium fluxes on energy crop land

International Nuclear Information System (INIS)

Palm, V.

1992-04-01

The flux of cadmium on energy crop land is investigated. Three mechanisms are accounted for; Uptake by plant, transport with water, and sorption to soil. Sorption is described with Freundlich isotherms. The system is simulated mathematically in order to estimate the sensitivity and importance of different parameters on the cadmium flow and sorption. The water flux through the soil and the uptake by plants are simulated with a hydrological model, SOIL. The simulated time period is two years. The parameters describing root distribution and evaporation due to crop are taken from measurements on energy crop (Salix). The resulting water flux, water content in the soil profile and the water uptake into roots, for each day and soil compartment, are used in the cadmium sorption simulation. In the cadmium sorption simulation the flux and equilibrium chemistry of cadmium is calculated. It is shown that the amount of cadmium that accumulates in the plant, and the depth to which the applied cadmium reaches depends strongly on the constants in the sorption isotherm. With an application of 10 mg Cd/m 2 in the given range of Freundlich equations, the simulations gave a plant uptake of between 0 and 30 % of the applied cadmium in two years. At higher concentrations, where cadmium sorption can be described by nonlinear isotherms, more cadmium is present in soil water and is generally more bioavailable. 25 refs

CdS thin films prepared by continuous wave Nd:YAG laser

Science.gov (United States)

Wang, H.; Tenpas, Eric W.; Vuong, Khanh D.; Williams, James A.; Schuesselbauer, E.; Bernstein, R.; Fagan, J. G.; Wang, Xing W.

1995-08-01

We report new results on continuous wave Nd:YAG laser deposition of cadmium sulfide thin films. Substrates were soda-lime silicate glass, silica glass, silicon, and copper coated formvar sheets. As deposited films were mixtures of cubic and hexagonal phases, with two different grain sizes. As revealed by SEM micrographs, films had smooth surface morphology. As revealed by TEM analysis, grain sizes were extremely small.

Zinc-induced protection against cadmium

Energy Technology Data Exchange (ETDEWEB)

Early, J.L.; Schnell, R.C.

1978-02-01

Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. Essy Samuel. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. N. Vagshette. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

First ever full size CdTE luminescent down-shifting module

NARCIS (Netherlands)

Ross, D.; Alonso-Alvarez, D.; Fritsche, J.; Bauer, M.; Debije, M.G.; Fifield, R.M.; Richards, B.S.

2012-01-01

For the first time a luminescent down-shifting (LDS) layer has been applied to a full size PV module to improve its short-wavelength response. An average 4.3% relative increase in the short-circuit current density (JSC) was recorded for the Calyxo cadmium telluride (CdTe) modules after the best LDS

Large silver-cadmium technology program

Science.gov (United States)

Charlip, S.; Lerner, S.

1971-01-01

The effects of varying cell design on operation factors on the electrochemical performance of sealed, silver-cadmium cells were determined. A factorial experiment was conducted for all test cells constructed with organic separators. Three operating factors were evaluated: temperature, depth of discharge, and charge rate. The six construction factors considered were separator, absorber, electrolyte quantity, cadmium electrode type, cadmium-to-silver ratio, and auxiliary electrode. Test cells of 4 ampere-hour capacity were fabricated and cycled. The best performing cells, on a 94 minute orbit, at 40% depth of discharge, were those containing silver-treated fibrous sausage casings as the separator, and Teflon-ated, pressed cadmium electrodes. Cycling data of cells with inorganic separators (Astroset) are given. Best performance was shown by cells with nonwoven nylon absorbers. Rigid inorganic separators provided the best barrier to silver migration.

Environmental costs of photovoltaics

International Nuclear Information System (INIS)

Hill, R.; Baumann, A.E.

1993-01-01

Photovoltaic (PV) systems are almost entirely benign in operation, and potential environmental hazards occur at the production and disposal stages. There are well established methods of monitoring and controlling potential hazards caused by the semiconductor materials used in PV modules such as silicon, copper indium diselenide and cadmium telluride. The main environmental hazards of photovoltaics are connected to the production processes. These processes require an input of energy, and this energy is derived from the standard fuel mix of the nation in which production takes place. The production of PV systems therefore has associated with it, emissions of greenhouse and acidic gases. However, as the new thin film PV technologies come into production, and the scale of production increases, the energy input to PV systems will decrease considerably, with consequent reduction in carbon dioxide emissions, to levels below that of other electricity generating technologies. (Author)

Formation of solid solutions on the boundary of zinc oxidezinc telluride heterojunction

International Nuclear Information System (INIS)

Tsurkan, A.E.; Buzhor, L.V.

1987-01-01

Distribution of ZnO x Te 1-x alloy composition on the interface of zinc oxide-zinc telluride heterojunction depending on the production conditions is investigated. A regularity in the formation of an extended area with constant alloy composition is detected. The regularity is explained by the fact that electric Peltier field conditioned by contact of two heterogeneous semiconductors participates in the solid solution formation process. Peltier field levels off the composition at the end length section. So, a possibility of creating a section with the assigned minor thickness alloy constant composition controlled in the interface of heterojunction occurs

Immunochromatographic assay of cadmium levels in oysters.

Science.gov (United States)

Nishi, Kosuke; Kim, In-Hae; Itai, Takaaki; Sugahara, Takuya; Takeyama, Haruko; Ohkawa, Hideo

2012-08-15

Oysters are one of foodstuffs containing a relatively high amount of cadmium. Here we report on establishment of an immunochromatographic assay (ICA) method of cadmium levels in oysters. Cadmium was extracted with 0.l mol L(-1) HCl from oysters and cleaned up from other metals by the use of an anion-exchange column. The behavior of five metals Mn, Fe, Cu, Zn, and Cd was monitored at each step of extraction and clean-up procedure for the ICA method in an inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The results revealed that a simple extraction method with the HCl solution was efficient enough to extract almost all of cadmium from oysters. Clean-up with an anion-exchange column presented almost no loss of cadmium adsorbed on the column and an efficient removal of metals other than cadmium. When a spiked recovery test was performed in the ICA method, the recovery ranged from 98% to 112% with relative standard deviations between 5.9% and 9.2%. The measured values of cadmium in various oyster samples in the ICA method were favorably correlated with those in ICP-MS analysis (r(2)=0.97). Overall results indicate that the ICA method established in the present study is an adequate and reliable detection method for cadmium levels in oysters. Copyright © 2012 Elsevier B.V. All rights reserved.

Cadmium action in synapses in the brain

Energy Technology Data Exchange (ETDEWEB)

Minami, Akira; Takeda, Atsushi; Nishibaba, Daisuke; Tekefuta, Sachiyo; Oku, Naoto [Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka (Japan)

2001-05-01

Chronic exposure to cadmium causes central nervous system disorders, e.g., olfactory dysfunction. To clarify cadmium toxicity in synaptic neurotransmission in the brain, the movement and action of cadmium in the synapses was examined using in vivo microdialysis. One and 24 h after injection of {sup 109}CdCl{sub 2} into the amygdala of rats, {sup 109}Cd release into the extracellular space was facilitated by stimulation with high K{sup +}, suggesting that cadmium taken up in amygdalar neurons is released into the synaptic clefts in a calcium- and impulse-dependent manner. To examine the action of cadmium in the synapses, the amygdala was perfused with artificial cerebrospinal fluid containing 10-30 {mu}M CdCl{sub 2}. The release of excitatory neurotransmitters, i.e., glutamate and aspartate, into the extracellular space was decreased during perfusion with cadmium, while the release of inhibitory neurotransmitters, i.e., glycine and {gamma}-amino butyric acid (GABA), into the extracellular space was increased during the period. These results suggest that cadmium released from the amygdalar neuron terminals affects the degree and balance of excitation-inhibition in synaptic neurotransmission. (author)

Simultaneous Automatic Electrochemical Detection of Zinc, Cadmium, Copper and Lead Ions in Environmental Samples Using a Thin-Film Mercury Electrode and an Artificial Neural Network

Directory of Open Access Journals (Sweden)

Jiri Kudr

2014-12-01

Full Text Available In this study a device for automatic electrochemical analysis was designed. A three electrodes detection system was attached to a positioning device, which enabled us to move the electrode system from one well to another of a microtitre plate. Disposable carbon tip electrodes were used for Cd(II, Cu(II and Pb(II ion quantification, while Zn(II did not give signal in this electrode configuration. In order to detect all mentioned heavy metals simultaneously, thin-film mercury electrodes (TFME were fabricated by electrodeposition of mercury on the surface of carbon tips. In comparison with bare electrodes the TMFEs had lower detection limits and better sensitivity. In addition to pure aqueous heavy metal solutions, the assay was also performed on mineralized rock samples, artificial blood plasma samples and samples of chicken embryo organs treated with cadmium. An artificial neural network was created to evaluate the concentrations of the mentioned heavy metals correctly in mixture samples and an excellent fit was observed (R2 = 0.9933.

Critical review of animal carcinogenesis by cadmium and its inorganic compounds

International Nuclear Information System (INIS)

Maximilien, R.; Dero, B.

1990-01-01

Animal carcinogenic biassays relative to 6 inorganic cadmium substances (cadmium metal, cadmium oxide, cadmium sulfide, cadmium sulfate, cadmium chloride and cadmium acetate) are reviewed (speciation). Critical evaluation of literature data on carcinogenicity has been performed by making reference to E.C. guidelines of good laboratory practice. There are few data on routes relevant for human risk assessment: experiments on inhalation demonstrate lung carcinogenicity of cadmium oxide, cadmium sulfide, cadmium sulfate and cadmium chloride in rats but not in mice nor in hamsters; no carcinogenic effects of cadmium compounds are observed following oral administration. For routes of less or no relevance for human risk assessment, some results are clearly positive: subcutaneous injection induces cancers in situ (various cadmium compounds), testicular tumours (cadmium sulfate and cadmium chloride) and prostatic tumours (cadmium chloride) but such effects are not observed using relevant malignancies in rats. With respect to other no relevant routes (intraperitoneal, intrarenal...) tumours are incidentally produced in situ, but not in remote organs. Numerous studies fail to demonstrate cadmium carcinogenicity, but methodologically acceptable negative ones are very limited in number. Accordingly strain dependent effects and dose effect relationship could not be thoroughly assessed

Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

Energy Technology Data Exchange (ETDEWEB)

Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

1985-02-01

Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

International Nuclear Information System (INIS)

Koparanova, N.; Simov, S.

1985-01-01

Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more. (author)

Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

Energy Technology Data Exchange (ETDEWEB)

Wu Fuzhong [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Yang Wanqin, E-mail: scyangwq@163.com [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Zhang Jian; Zhou Liqiang [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China)

2010-05-15

To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 {+-} 19.22 and 576.75 {+-} 40.55 {mu}g cadmium per plant with 110.77 {+-} 12.68 and 202.54 {+-} 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

Remediation of cadmium by Indian mustard (Brassica juncea L. from cadmium contaminated soil: a phytoextraction study

Directory of Open Access Journals (Sweden)

Rajeev Kumar Bhadkariya

2014-05-01

Full Text Available Cadmium is a toxic metal for living organisms and an environmental contaminant. Soils in many parts of the world are slightly too moderately contaminated by Cd due to long term use and disposal of Cd-contaminated wastes. Cost effective technologies are needed to remove cadmium from the contaminated sites. Soil phytoextraction is engineering based, low cost and socially accepted developing technology that uses plants to clean up contaminants in soils. This technology can be adopted as a remediation of cadmium from Cd-contaminated soils with the help of Brassica juncea plant. The objective of this work was to evaluate the cadmium (Cd accumulate and the tolerance of Brassica juncea. The Cd accumulates in all parts of plants (roots, stems and leaves. It was found that accumulating efficiency increased with the increase in the concentration of applied cadmium metal solution. Maximum accumulation of cadmium was found in roots than stem and leaves. Phytoextraction coefficient and translocation factor were highest to show the validity of the Brassica juncea species for hyperaccumulation of the Cd metal. These results suggested that Brassica juncea has a high ability to tolerate and accumulate Cd, so it might be a promising plant to be used for phytoextraction of Cd contaminated soil. DOI: http://dx.doi.org/10.3126/ije.v3i2.10533 International Journal of the Environment Vol.3(2 2014: 229-237

Influence of protein deficiency on cadmium toxicity in rats

Energy Technology Data Exchange (ETDEWEB)

Tewari, P C; Jain, V K; Ashquin, M; Tandon, S K

1986-07-01

The effects of a low protein diet on the body uptake and retention of cadmium, levels of essential trace elements, and cadmium-induced biochemical alterations in liver and kidneys of the rat were investigated. Low dietary protein disturbs cadmium induced alterations in carbohydrate metabolism, essential trace elements metabolism and offsets the hepatic and renal process of cadmium detoxification. Protein malnutrition enhances the susceptibility to cadmium intoxication.

Cadmium-related mortality and long-term secular trends in the cadmium body burden of an environmentally exposed population.

Science.gov (United States)

Nawrot, Tim S; Van Hecke, Etienne; Thijs, Lutgarde; Richart, Tom; Kuznetsova, Tatiana; Jin, Yu; Vangronsveld, Jaco; Roels, Harry A; Staessen, Jan A

2008-12-01

Few population studies have reported on the long-term changes in the internal cadmium dose and simultaneously occurring mortality. We monitored blood cadmium (BCd), 24-hr urinary cadmium (UCd), and mortality in an environmentally exposed population. Starting from 1985, we followed BCd (until 2003), UCd (until 1996), and mortality (until 2007) among 476 and 480 subjects, randomly recruited from low- exposure areas (LEA) and high-exposure areas (HEA). The last cadmium-producing plant in the HEA closed in 2002. From 1985-1989 to 1991-1996, BCd decreased by 40.3% and 18.9% in the LEA and HEA, respectively (p fashion without threshold.

Bioavailability of cadmium from linseed and cocoa

DEFF Research Database (Denmark)

Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data...

Phytoremediation of cadmium and nickel by Spirodela polyrhiza

International Nuclear Information System (INIS)

Chaudhuri, Devaleena; Goswami, Chandrima; Chatterjee, Sumon; Majumder, Arunabha; Mishra, A.K.; Bandyopadhyay, Kaushik

2011-01-01

Heavy metal pollution in surface and groundwater has considerably increased in the last few years. It is essential to have an effective removal mechanism of these toxic metals. Current research includes the need to develop environment friendly and cost effective technologies for removing heavy metals from water. In several studies cadmium and nickel have been considerably removed using phytoremediation. The removal efficiency of cadmium and nickel by Spirodela polyrhiza, common duckweed has been examined in the present study for 3 different concentrations of cadmium (1, 2 and 3 mg/L) and nickel (4, 5 and 6 mg/L). Two sets of experiments for cadmium and nickel were conducted separately. Effect of metal toxicity on Spirodela polyrhiza was evaluated in terms of relative growth factor and cadmium was found to be more toxic than nickel. Under experimental condition BCF value for cadmium removal was more than >1000 in all the 3 concentrations of cadmium. But the BCF value was found to be more than > 1000 only when input nickel concentration was 4 mg/L during phytoremediation process. Experimental results suggest that Spirodela polyrhiza has the potential of accumulating cadmium and nickel from aqueous solution at lower metal concentration. (author)

29 CFR 1926.1127 - Cadmium.

Science.gov (United States)

2010-07-01

... occupational exposure to cadmium as follows: (1) Reassess the employee's work practices and personal hygiene... employee's work practices and personal hygiene; the employee's respirator use, if any; the employee's...; assuring that all employees exposed to air cadmium levels above the PEL wear appropriate personal...

A confocal laser scanning microscopic study on thermoresponsive

Indian Academy of Sciences (India)

Monodisperse poly(N -isopropylacrylamide) (PNIPAM) particles loaded with cadmium telluride (CdTe) quantum dots (QDs) of two different sizes (4.7 nm and 5.6 nm) were synthesized in aqueous medium by bonding the capping agent on the quantum dots to the amide groups of PNIPAM and incubating the samples at 45° ...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. S. V. Vadawale. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna ...

Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A & B in workers exposed to cadmium at cadmium plating

Directory of Open Access Journals (Sweden)

Rajan BK

2007-07-01

Full Text Available Abstract Objective The present study was carried out to determine the effect of cadmium exposure on Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B in workers exposed at cadmium plating. Methods 50 subjects using cadmium during cadmium plating formed the study group. An equal number of age-sex matched subjects working in administrative section formed the control group. Urinary cadmium levels were determined by using a flameless atomic absorption spectrophotometer. Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B were determined by using spectrophotmetric method. Results A significant increase of urinary total N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B profiles were noted in study as compared to controls. The levels of urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B profiles were positively and significantly correlated with cadmium levels in urine. Multiple regression analysis was used to assess the effect of urinary cadmium or life style confounding factors (age, BMI, smoking and alcohol consumption on urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B. The analysis showed that the study subjects who had urine cadmium levels greater than 5 μg/g of creatinine, work duration >15 years, smoking and body mass index variables were significantly associated with urinary total N-acetyl-beta -D-glucosaminidase but not on isoenzymes A&B. Conclusion The results presented in this study shows that the increased levels of urinary N-acetyl-beta -D-glucosaminidase observed in cadmium-exposed workers could be used as biomarkers for suggesting preventive measure.

Polymer-coated compliant receivers for intact laser-induced forward transfer of thin films: experimental results and modelling

Science.gov (United States)

Feinaeugle, Matthias; Horak, Peter; Sones, Collin L.; Lippert, Thomas; Eason, Rob W.

2014-09-01

In this study, we investigate both experimentally and numerically laser-induced forward transfer (LIFT) of thin films to determine the role of a thin polymer layer coating the receiver with the aim of modifying the rate of deceleration and reduction of material stress preventing intact material transfer. A numerical model of the impact phase during LIFT shows that such a layer reduces the modelled stress. The evolution of stress within the transferred deposit and the substrate as a function of the thickness of the polymer layer, the transfer velocity and the elastic properties of the polymer are evaluated. The functionality of the polymer layer is verified experimentally by LIFT printing intact 1- m-thick bismuth telluride films and polymeric light-emitting diode pads onto a layer of 12-m-thick polydimethylsiloxane and 50-nm-thick poly(3,4-ethylenedioxythiophene) blended with poly(styrenesulfonate) (PEDOT:PSS), respectively. Furthermore, it is demonstrated experimentally that the introduction of such a compliant layer improves adhesion between the deposit and its substrate.

Response of Saccharomyces cerevisiae to cadmium stress

International Nuclear Information System (INIS)

Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C.; Rosa, Carlos Augusto

2009-01-01

The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K + and Na + ) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

Response of Saccharomyces cerevisiae to cadmium stress

Energy Technology Data Exchange (ETDEWEB)

Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

2009-07-01

The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

Epidemiological approach to cadmium pollution in Japan

Energy Technology Data Exchange (ETDEWEB)

Shigematsu, I.

1984-04-01

The study of health problems due to cadmium pollution in Japan originated from an endemic episode of Itai-itai disease in a rural area in north-central Japan after World War II. The disease was defined as osteomalacia with tubular changes in the kidney and considered to be associated with excess intake of cadmium. This episode motivated the Japanese Government to conduct health examinations on the general population in cadmium-polluted and non-polluted areas throughout the country since 1969. Although Itai-itai disease-like bone changes were rarely found, these studies revealed a higher prevalence of renal tubular dysfunction among elderly people in the cadmium-polluted areas. No significant difference was noted in cancer mortality, but mortality from cardiovascular diseases and all causes tended to be lower in cadmium-polluted areas. Clinical and pathological studies in man as well as experiments on primates have recently been made to elucidate the pathogenesis of Itai-itai disease and the health effects of cadmium. The lack of knowledge on the ecological and biological complex of cadmium resulted in the impediment of studies on this problem. The lesson from this experience is that basic research is essential for promoting the study of pollutants such as heavy metals, though pollution problems usually require urgent solutions.

Sources of cadmium exposure among healthy premenopausal women

Energy Technology Data Exchange (ETDEWEB)

Adams, Scott V., E-mail: sadams@fhcrc.org [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Newcomb, Polly A. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Shafer, Martin M. [Environmental Chemistry and Technology Program, University of Wisconsin and Wisconsin State Laboratory of Hygiene, Madison, WI (United States); Atkinson, Charlotte [Department of Oral and Dental Science, Bristol Dental School, Bristol (United Kingdom); Bowles, Erin J. Aiello [Group Health Research Institute, Seattle, WA (United States); Newton, Katherine M. [Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Group Health Research Institute, Seattle, WA (United States); Lampe, Johanna W. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States)

2011-04-01

Background: Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women. Methods: In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity. Results: Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 {mu}g/g (95% confidence interval (CI): 0.38-0.48 {mu}g/g) and 0.30 {mu}g/g (0.27-0.33 {mu}g/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 {mu}g/g (95% CI: 0.06-0.15 {mu}g/g) higher among women who consumed any tofu than among those who consumed none. Conclusions: Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration. - Research highlights: {yields

Sources of cadmium exposure among healthy premenopausal women

International Nuclear Information System (INIS)

Adams, Scott V.; Newcomb, Polly A.; Shafer, Martin M.; Atkinson, Charlotte; Bowles, Erin J. Aiello; Newton, Katherine M.; Lampe, Johanna W.

2011-01-01

Background: Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women. Methods: In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity. Results: Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 μg/g (95% confidence interval (CI): 0.38-0.48 μg/g) and 0.30 μg/g (0.27-0.33 μg/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 μg/g (95% CI: 0.06-0.15 μg/g) higher among women who consumed any tofu than among those who consumed none. Conclusions: Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration. - Research highlights: →Urine cadmium, usual

Separation of cadmium from solutions containing high concentration of zinc ions

International Nuclear Information System (INIS)

Sharma, K.D.; Bhutani, A.K.; Parvathisem, P.

1984-01-01

In hydrometallurgical process of extracting cadmium as a byproduct, zinc dust is added for separation of cadmium as cadimum sponge. High amounts of zinc are quite often noticed in the cadmium electrolyte subjected for electrowinning of the metal. This leads to poor quality of cadmium deposit and lower current efficiencies. Study of cadmium sponge cementation process revealed that zinc dust may be added to an acidic cadmium solution for precipitation of cadmium sponge without neutralization of the free acidity present in the system. This fact is utilized for obtaining a high cadmium sponge with 75-80 per cent cadmium and 5-10 per cent zinc with 98 per cent recovery of cadmium from the solution as sponge. The suggested process is confirmed in a cadmium production plant producing 11.0 MT of cadmium per month. (author)

Characterization inconsistencies in CdTe and CZT gamma-ray detectors

International Nuclear Information System (INIS)

Lavietes, A.D.; McQuaid, J.H.

1994-10-01

In the past few years, significant developments in cadmium telluride (CdTe) and cadmium zinc telluride (CZT) semiconductor materials have taken place with respect to both quality and yield. Many of the more recent developments have occurred in the area of CZT crystal growth. This has resulted in an explosion of interest in the use of these materials in ambient temperature gamma-ray detectors. Most, if not all, of the manufacturers of CdTe and CZT have acquired government funding to continue research in development and applications, indicating the importance of these improvements in material quality. We have examined many detectors, along with the accompanying manufacturer's data, and it has become apparent that a clear standard does not exist by which each manufacturer characterizes the performance of their material. Result is a wide variety of performance claims that have no basis for comparison and normally cannot be readily reproduced. This paper first supports our observations and then proposes a standard that all manufacturers and users of these materials may use for characterization

Fuel conditioning facility electrorefiner cadmium vapor trap operation

International Nuclear Information System (INIS)

Vaden, D. E.

1998-01-01

Processing sodium-bonded spent nuclear fuel at the Fuel Conditioning Facility at Argonne National Laboratory-West involves an electrometallurgical process employing a molten LiCl-KCl salt covering a pool of molten cadmium. Previous research has shown that the cadmium dissolves in the salt as a gas, diffuses through the salt layer and vaporizes at the salt surface. This cadmium vapor condenses on cool surfaces, causing equipment operation and handling problems. Using a cadmium vapor trap to condense the cadmium vapors and reflux them back to the electrorefiner has mitigated equipment problems and improved electrorefiner operations

Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413 512, Maharashtra (India)

2012-12-05

Highlights: Black-Right-Pointing-Pointer Simple and inexpensive method to dope trivalent Fe in CdSe thin films. Black-Right-Pointing-Pointer Fe doped CdSe thin films are highly photosensitive. Black-Right-Pointing-Pointer AFM analysis shows uniform deposition of film over the entire substrate surface. Black-Right-Pointing-Pointer The band gap energy decreases from 1.74 to 1.65 eV with Fe doping. Black-Right-Pointing-Pointer Film resistivity decreases to 6.76 Multiplication-Sign 10{sup 4} {Omega}-cm with Fe doping in CdSe thin films. - Abstract: Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14-0.19 eV at low temperature and 0.27-0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

CdS thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A.; Krishnan, B.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Shaji, S.

2015-01-01

Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties

CdS thin films prepared by laser assisted chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

2015-05-01

Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

International Nuclear Information System (INIS)

Wu Fuzhong; Yang Wanqin; Zhang Jian; Zhou Liqiang

2010-01-01

To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 ± 19.22 and 576.75 ± 40.55 μg cadmium per plant with 110.77 ± 12.68 and 202.54 ± 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

Prospects and performance limitations for Cu-Zn-Sn-S-Se photovoltaic technology.

Science.gov (United States)

Mitzi, David B; Gunawan, Oki; Todorov, Teodor K; Barkhouse, D Aaron R

2013-08-13

While cadmium telluride and copper-indium-gallium-sulfide-selenide (CIGSSe) solar cells have either already surpassed (for CdTe) or reached (for CIGSSe) the 1 GW yr⁻¹ production level, highlighting the promise of these rapidly growing thin-film technologies, reliance on the heavy metal cadmium and scarce elements indium and tellurium has prompted concern about scalability towards the terawatt level. Despite recent advances in structurally related copper-zinc-tin-sulfide-selenide (CZTSSe) absorbers, in which indium from CIGSSe is replaced with more plentiful and lower cost zinc and tin, there is still a sizeable performance gap between the kesterite CZTSSe and the more mature CdTe and CIGSSe technologies. This review will discuss recent progress in the CZTSSe field, especially focusing on a direct comparison with analogous higher performing CIGSSe to probe the performance bottlenecks in Earth-abundant kesterite devices. Key limitations in the current generation of CZTSSe devices include a shortfall in open circuit voltage relative to the absorber band gap and secondarily a high series resistance, which contributes to a lower device fill factor. Understanding and addressing these performance issues should yield closer performance parity between CZTSSe and CdTe/CIGSSe absorbers and hopefully facilitate a successful launch of commercialization for the kesterite-based technology.

Effect of thallium impurity on hole scattering in lead telluride

International Nuclear Information System (INIS)

Kajdanov, V.I.; Nemov, S.A.

1981-01-01

Hole mobility in PbTe monocrystalline specimens in the temperature range from 4.2 to 300 K has been investigated. Detected is a sharp increase in scattering cross section of light and heavy holes in the specimens having the Hall hole concentration p approximately (5+-9)x10 19 cm -3 explained by resonant scattering into a band of quasilocal states of thallium located lower than the ceiling of heavy carrier zone by 0.01+-0.01 eV. Very large differences in resonant scattering of current carriers into the quasilocal states of In and Tl in PbTe result from the inertial polarizability of a crystal. The same mechanism is used to explain long-lived relaxation of zone electron concentration in lead telluride and Pbsub(1-x)Snsub(x)Te doped with indium [ru

Cadmium verification measurements of HFIR shroud assembly 22

International Nuclear Information System (INIS)

Chapman, J.A.; Schultz, F.J.

1994-04-01

This report discusses radiation-based nondestructive examination methods which have been used to successfully verify the presence of cadmium in High Flux Isotope Reactor (HFIR) spent-fuel shroud assembly number 22 (SA22). These measurements show, in part, that SA22 is certified to meet the criticality safety specifications for a proposed reconfiguration of the HFIR spent-fuel storage array. Measurement of the unique 558.6-keV gamma-ray from neutron radiative capture on cadmium provided conclusive evidence for the presence of cadmium in the outer shroud of the assembly. Cadmium verification in the center post and outer shroud was performed by measuring the degree of neutron transmission in SA22 relative to two calibration shroud assemblies. Each measurement was performed at a single location on the center post and outer shroud. These measurements do not provide information on the spatial distribution or uniformity of cadmium within an assembly. Separate measurements using analog and digital radiography were performed to (a) globally map the continuity of cadmium internal mass, and (b) locally determine the thickness of cadmium. Radiography results will be reported elsewhere. The measurements reported here should not be used to infer the thickness of cadmium in either the center post or outer shroud of an assembly

Quantum dot solar cell

International Nuclear Information System (INIS)

Ahamefula, U.C.; Sulaiman, M.Y.; Sopian, K.; Ibarahim, Z.; Ibrahim, N.; Alghoul, M.A.; Haw, L.C.; Yahya, M.; Amin, N.; Mat, S.; Ruslan, M.H.

2009-01-01

Full text: The much awaited desire of replacing fossil fuel with photovoltaic will remain a fairy tale if the myriad of issues facing solar cell development are marginalized. Foremost in the list is the issue of cost. Silicon has reached a stage where its use on large scale can no longer be lavishly depended upon. The demand for high grade silicon from the microelectronics and solar industries has soared leading to scarcity. New approach has to be sought. Notable is the increased attention on thin films such as cadmium telluride, copper indium gallium diselenide, amorphous silicon, and the not so thin non-crystalline family of silicon. While efforts to address the issues of stability, toxicity and efficiency of these systems are ongoing, another novel approach is quietly making its appearance - quantum dots. Quantum dots seem to be promising candidates for solar cells because of the opportunity to manipulate their energy levels allowing absorption of a wider solar spectrum. Utilization of minute quantity of these nano structures is enough to bring the cost of solar cell down and to ascertain sustainable supply of useful material. The paper outlines the progress that has been made on quantum dot solar cells. (author)

Liquid scintillation counting analysis of cadmium-109

International Nuclear Information System (INIS)

Robinson, M.K.; Barfuss, D.W.

1991-01-01

Recently the authors have used radiolabled cadmium-109 to measure the transport of inorganic cadmium in renal proximal tubules. An anomaly discovered in the liquid scintillation counting analysis of Cd-109 which is not attributable to normal decay; it consists of a significant decrease in the measured count rate of small amounts of sample. The objective is to determine whether the buffer solution used in the membrane transport studies is causing precipitation of the cadmium or whether cadmium is being adsorbed by the glass. It was important to determine whether the procedure could be modified to correct this problem. The problem does not appear to be related to the use of the buffer or to adsorption of Cd onto glass. Correction based on using triated L-glucose in all of these experiments and calculating a correction factor for the concentration of cadmium

Effects of diethyldithiocarbamate on the toxicokinetics of cadmium chloride in mice

DEFF Research Database (Denmark)

Andersen, O; Nielsen, J B

1989-01-01

Diethyldithiocarbamate (DDC) efficiently alleviates the acute toxicity of injected cadmium chloride, but enhances the acute toxicity of orally administered cadmium chloride. Further, DDC induces extensive changes in organ distribution of cadmium, and mobilizes aged cadmium depots. The present study...... investigates effects of DDC on the toxicokinetics of cadmium at lower doses of cadmium than those used in previous studies. During single exposure to subtoxic oral doses of cadmium chloride DDC enhanced intestinal cadmium absorption, both after intraperitoneal and oral administration of DDC. In such acute...... exposure experiments orally administered DDC only slightly changed the relative organ distribution of absorbed cadmium, while intraperitoneal administration of DDC induced extensive changes in organ preference of absorbed cadmium. The relative hepatic and testicular deposition was reduced, while...

Manufacturing and Morphological Analysis of Composite Material of Polystyrene Nanospheres/Cadmium Metal Nanoparticles

Directory of Open Access Journals (Sweden)

Pratama Jujur Wibawa

2013-03-01

Full Text Available A very simple nanocomposite material has been in-situ manufactured from an aqueous polystyrene nanospheres dispersion and cadmium (Cd metal nanoparticles. The manufacturing was performed by using a high frequency of 40 kHz ultrasonic (US agitation for 45 minute at atmospheric pressure and at room temperature 20 oC. No chemical reducing agent and surfactant added in this manufacturing technique due to the US could reduce Cd2+ ions of cadmium nitrate tetrahydrate to Cd atomic metals nanoparticles whereas water molecules could act as a pseudo stabilizer for the manufactured material. A thin film was manufactured from aqueous colloidal nanocomposite material of Polystyrene nanospheres/Cd metal nanoparticles (PSNs/CdMNp fabricated on a hydrophilic silicon wafer. The thin film was then characterized by a JEOL-FESEM for its surface morphology characteristic and by ATR-FTIR spectrometry for its molecular change investigation. It could be clearly observed that surface morphology of the thin film material was not significantly changed under 633 nm wavelength continuous laser radiation exposure for 20 minute. In addition, its ATR-FTIR spectra of wave number peaks around 3400 cm-1 have been totally disappeared under the laser exposure whereas that at around 699 cm-1 and 668 cm-1 have not been significantly changed. The first phenomenon indicated that the hydrogen bond existed in PSNs/CdMNp material was collapsed by the laser exposure. The second phenomena indicated that the PSNs phenyl ring moiety was not totally destroyed under the laser exposure. It was suspected due to the existence of Cd nanoparticles covered throughout the spherical surface of PSNs/CdMNp material particles. Therefore a nice model of material structure of the mentioned PSNs/CdMNp nanocomposite material could be suggested in this research. It could be concluded that this research have been performed since the material structure model of the manufactured PSNs/CdMNp nanocomposite could be

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Astrophysics and Astronomy. P. Priya. Articles written in Journal of Astrophysics and Astronomy. Volume 38 Issue 2 June 2017 pp 31 Review Article. The Cadmium Zinc Telluride Imager on AstroSat · V. Bhalerao D. Bhattacharya A. Vibhute P. Pawar A. R. Rao M. K. Hingar Rakesh Khanna A. P. K. ...

Cadmium affects the social behaviour of rainbow trout, Oncorhynchus mykiss

International Nuclear Information System (INIS)

Sloman, Katherine A.; Scott, Graham R.; Diao Zhongyu; Rouleau, Claude; Wood, Chris M.; McDonald, D. Gord

2003-01-01

The present study investigated both the effects of cadmium on the social interactions of rainbow trout and the differential accumulation of waterborne cadmium among social ranks of fish. Fish exposed to waterborne cadmium concentrations of 2 μg l -1 for 24 h, followed by a 1, 2 or 3 day depuration period in clean water, had a decreased ability to compete with non-exposed fish. However, the competitive ability of exposed fish given a 5 day depuration period was not significantly impaired. Cadmium accumulated in the olfactory apparatus of fish exposed to waterborne cadmium for 24 h and decreased significantly only after 5 days depuration in clean water. Among groups of ten fish held in stream tanks, where all fish were exposed to cadmium, there were significant effects on social behaviour and growth rate. Dominance hierarchies formed faster among fish exposed to cadmium than among control fish, and overall growth rates were higher in the cadmium treatment. In groups of ten fish, social status also affected tissue accumulation of cadmium during waterborne exposure, with dominant fish accumulating more cadmium at the gill. In conclusion, exposure to low levels of cadmium, affects the social behaviour of fish, in part due to accumulation in the olfactory apparatus, and dominant fish accumulate more gill cadmium than subordinates during chronic waterborne exposure

Cadmium in milk and mammary gland in rats and mice

International Nuclear Information System (INIS)

Petersson Grawe, K.; Oskarsson, A.

2000-01-01

The purpose of the present investigation was to study the uptake of cadmium in mammary tissue, effects on milk secretion and composition, and lactational transport of cadmium to the sucklings. Cadmium exposure during lactation resulted in retention of cadmium in the mammary tissue in mice and rats. The uptake of cadmium in the mammary tissue was rapid, as shown in lactating mice by whole-body autoradiography 4 h after an intravenous injection of a tracer dose of 109 CdCl 2 . Retention of cadmium in kidneys of suckling pups was observed in the autoradiograms at 7 days after exposure of the dams. Lactating rats were intravenously infused with 109 CdCl 2 in 0.9% saline via osmotic minipumps from day 3 to day 16 after parturition. The cadmium dose given was 0, 8.8, 62 and 300 μg Cd/kg body wt. per day. Plasma and milk were collected at day 10 and 16 after parturition. Plasma cadmium levels in dams increased from day 10 to day 16. Cadmium levels were higher in milk than in plasma, with milk/plasma ratios varying from 2 to 6. Zinc levels in milk were positively correlated to cadmium levels in milk (r 2 =0.26; P=0.03). In milk, 109 Cd was distributed in fat (46-52%), casein fraction (40-46%), and whey fraction (6-8%). There was a high correlation between cadmium concentrations in pups' kidney and cadmium concentrations in dam's milk (r 2 =0.98; P 109 Cd was bound to metallothionein in mammary tissue. The fraction of radiolabelled cadmium bound to metallothionein increased in a dose-dependent manner in both the liver (88-98%) and mammary tissue (57-80%). The present results indicate a low transfer of cadmium to the suckling pup, which might be due to binding of cadmium to metallothionein in the mammary tissue. However, during the susceptible developmental period even a low cadmium exposure may be of concern. (orig.)

Effects of Aluminium Sulfate on Cadmium Accumulation in Rice

International Nuclear Information System (INIS)

Khamvarn, Vararas; Boontanon, Narin; Prapagdee, Benjaphorn; Kumsopa, Acharaporn; Boonsirichai, Kanokporn

2011-06-01

Full text: Cadmium accumulation in Pathum Thani 1 and Suphan Buri 60 rice cultivars was investigated upon treatment with aluminium sulfate as a precipitant. Rice was grown hydroponically in a medium containing 4 ppm cadmium nitrate with or without 4 ppm aluminium sulfate. Root, stem with leaves and grain samples were collected and analyzed for cadmium content using atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy. Without the addition of aluminium sulfate, Pathum Thani 1 and Suphan Buri 60 accumulated 24.71∫ 3.14 ppm and 34.43 ∫ 4.51 ppm (dry weight of whole plant) of cadmium, respectively. With aluminium sulfate, cadmium accumulation increased to 40.66 ∫ 2.47 ppm and 62.94 ∫ 10.69 ppm, respectively. The addition of aluminium sulfate to the planting medium did not reduce cadmium accumulation but caused the rice to accumulate more cadmium especially in the shoots and grains. This observation might serve as the basis for future research on the management of agricultural areas that are contaminated with cadmium and aluminium

Biological monitoring results for cadmium exposed workers.

Science.gov (United States)

McDiarmid, M A; Freeman, C S; Grossman, E A; Martonik, J

1996-11-01

As part of a settlement agreement with the Occupational Safety and Health Administration (OSHA) involving exposure to cadmium (Cd), a battery production facility provided medical surveillance data to OSHA for review. Measurements of cadmium in blood, cadmium in urine, and beta 2-microglobulin in urine were obtained for more than 100 workers over an 18-month period. Some airborne Cd exposure data were also made available. Two subpopulations of this cohort were of primary interest in evaluating compliance with the medical surveillance provisions of the Cadmium Standard. These were a group of 16 workers medically removed from cadmium exposure due to elevations in some biological parameter, and a group of platemakers. Platemaking had presented a particularly high exposure opportunity and had recently undergone engineering interventions to minimize exposure. The effect on three biological monitoring parameters of medical removal protection in the first group and engineering controls in platemakers is reported. Results reveal that both medical removal from cadmium exposures and exposure abatement through the use of engineering and work practice controls generally result in declines in biological monitoring parameters of exposed workers. Implications for the success of interventions are discussed.

Environmental exposure to cadmium and renal function of elderly women living in cadmium-polluted areas of West-Germany

Energy Technology Data Exchange (ETDEWEB)

Ewers, U.; Brockhaus, A.; Dolgner, R.; Freier, I.; Jermann, E.; Hahn, R.; Schlipkoeter, H.W.; Bernard, A.

1985-12-01

An epidemiological study was carried out to assess whether or not environmental pollution by cadmium as found in cadmium-polluted areas of the Federal Republic auf Germany is associated with an increased prevalence of biological signs of kidney dysfunction in population groups non-occupationally exposed to heavy metals. The study was run in two industrial areas known to be highly polluted by cadmium and other toxic heavy metals, viz. Stolberg and Duisburg. Duesseldorf was selected as a reference area. As a study population we selected 65- and 66-year-old women who had spent the major part of their lives in one of these areas. The average levels of cadmium in blood and urine showed significant differences in exposure to cadmium in the order Stolberg > Duisburg > Duesseldorf. Serum creatinine levels were, on average, significantly higher in the Stolberg group than in the Duisburg and Duesseldorf groups. With respect to other biological findings (total proteinuria, tubular proteinuria, albuminuria, aminoaciduria, phosphaturia, serum complement) no significant differences between the study populations were noted. It cannot be excluded, however, that in the Stolberg group there is a synergism of ageing and cadmium with respect to the age related decline of the glomerular filtration rate.

Effect of pregnancy on cadmium-treated rats

Energy Technology Data Exchange (ETDEWEB)

Takizama, Y. (Akita Univ. School of Medicine, Japan); Nakamura, I.; Kurayama, R.; Hirasawa, F.; Kawai, K.

1982-01-01

It is well known that itai-itai disease with the osteopathy is broken out among multiparas, 40 years of age and up Japanese residents. In this paper we described an experimental study of effect of pregnancy on cadmium treated rats. Female mature rats were administered drinking water containing 50 and 200 ppm cadmium as CdCl/sub 2/. During 180 days of the experiment, three times of pregnancy were succesful, though slight depression of body weight gain was noticed in the 200 ppm group. The cadmium was accumulated in the kidneys, liver and bone proportionally to the amount of cadmium administered. No significant change was recognized in serum calcium, phosphorus and alkaline phosphatase levels after 180 days. Though cadmium 200 ppm treated rats showed slight histological lesions in the proximal convoluted tubules of the kidney, there appeared to be no osteomalacia including excess formation of osteoid tissue.

Cadmium speciation and accumulation in periphyton in a small stream with dynamic concentration variations

Energy Technology Data Exchange (ETDEWEB)

Bradac, Philippe [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); ETH, Swiss Federal Institute of Technology, Department of Environmental Sciences, CH-8092 Zurich (Switzerland); Wagner, Bettina; Kistler, David; Traber, Jacqueline; Behra, Renata [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); Sigg, Laura, E-mail: laura.sigg@eawag.c [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); ETH, Swiss Federal Institute of Technology, Department of Environmental Sciences, CH-8092 Zurich (Switzerland)

2010-03-15

Accumulation of cadmium in periphyton was investigated under field conditions while Cd concentration and speciation were dynamically varying in a small stream during rain events. Speciation in water was determined in situ by diffusion gradient in thin-films (DGT) and by modeling of complexation with fulvic acids. During the rain events, dissolved Cd concentrations increased from 0.17 nM to 0.27-0.36 nM, and 70-97% were DGT-labile. Cd content in periphyton closely followed Cd concentrations in water, despite higher concentrations of Zn and Mn, and may be controlled by either free or DGT-labile Cd concentrations. Decrease of Cd content in periphyton after the rain events was slower than the decrease of Cd concentration in water. Concentrations of Zn, Mn, Cu, Pb and Fe in periphyton also followed the dynamic variations of metal concentrations in water. Repeated exposure of periphyton to elevated dissolved Cd may lead to Cd accumulation. - Cadmium accumulation in periphyton was examined in a small stream during rain events in relation to Cd speciation.

Cadmium speciation and accumulation in periphyton in a small stream with dynamic concentration variations

International Nuclear Information System (INIS)

Bradac, Philippe; Wagner, Bettina; Kistler, David; Traber, Jacqueline; Behra, Renata; Sigg, Laura

2010-01-01

Accumulation of cadmium in periphyton was investigated under field conditions while Cd concentration and speciation were dynamically varying in a small stream during rain events. Speciation in water was determined in situ by diffusion gradient in thin-films (DGT) and by modeling of complexation with fulvic acids. During the rain events, dissolved Cd concentrations increased from 0.17 nM to 0.27-0.36 nM, and 70-97% were DGT-labile. Cd content in periphyton closely followed Cd concentrations in water, despite higher concentrations of Zn and Mn, and may be controlled by either free or DGT-labile Cd concentrations. Decrease of Cd content in periphyton after the rain events was slower than the decrease of Cd concentration in water. Concentrations of Zn, Mn, Cu, Pb and Fe in periphyton also followed the dynamic variations of metal concentrations in water. Repeated exposure of periphyton to elevated dissolved Cd may lead to Cd accumulation. - Cadmium accumulation in periphyton was examined in a small stream during rain events in relation to Cd speciation.

Mechanisms of component diffusion in mercury cadmium telluride

International Nuclear Information System (INIS)

Tang, M.S.; Stevenson, D.A.

1989-01-01

The component diffusion coefficients for the Hg/sub 0.8/Cd/sub 0.2/Te (MCT) system are measured using radioactive tracers. Multiple branches are observed in the tracer diffusion profiles which are related to fast and slow-diffusing components. Diffusion models for each component are proposed based on the defect chemistry of MCT, a calculation of the thermodynamic factor, and the relationship between component diffusion coefficients and the interdiffusion coefficients for pseudobinary systems. The model provides insight into the thermodynamic properties of the system, the mechanisms for diffusion, and the practical application of tracer diffusion data to interdiffusion and p-to-n conversion by Hg annealing

Acceptors in cadmium telluride. Identification and electronic structure

International Nuclear Information System (INIS)

Molva, E.

1983-11-01

It is shown that electronic properties of CdTe are determined by impurities more than by intrinsic defects like vacancies or interstitials in Cd or Te contrary to classical theories. These results are based on annealing, diffusion, implantation and electron irradiation at 4 K. Centers appearing in treated samples are accurately identified by photoluminescence, cathodoluminescence infra-red absorption, electrical measurements and magneto-optic properties. Acceptors identified are Li, Na, Cu, Ag and Au impurities in Cd and N, P and As in Te. Energy levels of all acceptors and fine structure of excitons are determined [fr

The Cadmium Zinc Telluride Imager on AstroSat

Indian Academy of Sciences (India)

V. Bhalerao

2017-06-19

Jun 19, 2017 ... which act as the interface to the satellite. The overall dimensions of ... plate affixed on a side to dissipate heat and provide a cold bias for maintaining ... patterns, with some repeats, were placed in the form of a 4 × 4 matrix to ...

Cadmium Telluride and Grain Boundaries: A Preliminary Study

Science.gov (United States)

Liao, Michael Evan

The efficacy of the CdCl2 treatment on polycrystalline CdTe-based solar cells was discovered over a quarter of a century ago; and yet, the exact mechanism of this treatment is still not fully understood to this day. In fact, the lack of understanding stems from a debate on the exact role of grain boundaries in CdCl2-treated CdTe solar cells. Some hypothesize that the CdCl2-treatment causes grain boundaries to become beneficial to solar cell performance while others disagree and claim that the treatment simply mitigates the harmful effects of grain boundaries via passivation. A future goal of this project is to determine which, if either, hypothesis is correct by direct wafer bonding single crystalline CdTe. Direct wafer bonding of single crystalline materials would create only one grain boundary at the bonded interface. This approach allows the orientation and surface chemistry of interfaces to be controlled in order to study the chemistry of grain boundaries methodically. However, before any direct wafer bonding can be done, a preliminary study of single crystalline CdTe is necessary. High-quality direct wafer bonding can only be achieved if the surfaces of each wafer satisfy certain requirements. Additionally, analyzing single crystalline CdTe materials prior to bonding is crucial in order to make any insightful connections between results found from direct bonding of single crystalline CdTe and what is observed in polycrystalline CdTe. First, the surface of an (001) CdTe layer epitaxially grown on an (001) InSb substrate is studied using atomic force microscopy. Stacking faults on the CdTe surface are observed and the thickness of the grown CdTe epilayer is calculated by considering the interplanar angles between the (001) and (111) crystallographic planes as well as the dimensions of the stacking faults. While the stacking faults will inhibit successful wafer bonding, the roughness of the regions outside the stacking faults is 0.9 nm, which is an acceptable roughness for direct wafer bonding. High resolution x-ray diffraction is used to study the strain of the CdTe epilayer at the epilayer-substrate interface by generating reciprocal space maps of the (004), (115), and (335) crystallographic planes. It is found that CdTe grown on an (001) InSb substrate at a low growth temperature exhibits nearly 0% relaxation. As a result, the in-plane lattice parameter of the CdTe layer is maximally strained to match the smaller lattice parameter of the InSb substrate. Consequently, the CdTe lattice is tetragonally strained normal to the substrate surface, which causes the out-of-plane lattice parameter of CdTe to be larger than its intrinsic value. Lastly, a CdCl2-treated CdTe-CdS (p-type CdTe on n-type CdS) solar cell structure is simulated using a semiconductor-heterojunction simulation program. In literature, it has been reported that chlorine atoms from the treatment segregate along grain boundaries in polycrystalline CdTe and cause the formation of local p-n junctions by inverting the grain boundaries to n-type. The simulated structure includes one grain and 2 grain boundaries. The grain/bulk CdTe material is p-type while the grain boundaries are made to be n-type with varying doping concentrations. Both the conduction band and valence band energy exhibit downward sloping from the CdTe surface to the CdTe-CdS interface. This structure assumes that the grain boundaries are parallel to the CdTe-CdS interface. While these simulations do not prove the existence of the local type-inversion hypothesis, they do entertain a novel possibility for future devices fabrication methods.

The melt-growth and characterization of cadmium telluride

International Nuclear Information System (INIS)

Mullin, J.B.; Straughan, B.W.

1977-01-01

Developments in the melt-growth of CdTe are reviewed particularly with respect to techniques for controlling the dissociation pressure. The potential merits of Pressure Balancing are considered together with the results of a preliminary LEC growth investigation. The characterization, dislocations, precipitates, impurities and impurity defects-together with a discussion on their origin, and experience and suggestions for their elimination or control

Accumulation of cadmium in livers and kidneys in Greenlanders

International Nuclear Information System (INIS)

Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth; Hansen, Jens C.; Riget, Frank

2006-01-01

In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 μg/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 μg/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 μg/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low

Accumulation of cadmium in livers and kidneys in Greenlanders

Energy Technology Data Exchange (ETDEWEB)

Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Mulvad, Gert [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Hansen, Jens C. [Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2006-12-15

In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 {mu}g/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 {mu}g/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 {mu}g/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low.

Coprecipitation of cadmium with calcite

International Nuclear Information System (INIS)

Fujino, Osamu; Kumagai, Tetsu; Shigematsu, Tsunenobu; Matsui, Masakazu

1976-01-01

The distribution of cadmium between precipitates of calcite and saturated aqueous solution was measured at 25 0 C to understand the distribution of cadmium in the bivalves. Calcite was precipitated from calcium bicarbonate solution by the gradual release of carbon dioxide. The cadmium ions were coprecipitated in calcite, obeying the logarithmic distribution law. The apparent distribution coefficient was decreased as α, α'-dipyridyl increased, but the true distribution coefficient was found to be an almost constant value, 560. This value is fairly close to the ratio of solubility product constants K sub(calcite)/K sub(CdCO 3 ), 890. This suggests that the deviation of the present solid solution from ideality is not very large. (auth.)

Tiny optical fiber temperature sensor based on temperature-dependent refractive index of zinc telluride film

Science.gov (United States)

Bian, Qiang; Song, Zhangqi; Song, Dongyu; Zhang, Xueliang; Li, Bingsheng; Yu, Yang; Chen, Yuzhong

2018-03-01

The temperature-dependent refractive index of zinc telluride film can be used to develop a tiny, low cost and film-coated optical fiber temperature sensor. Pulse reference-based compensation technique is used to largely reduce the background noise which makes it possible to detect the minor reflectivity change of the film in different temperatures. The temperature sensitivity is 0.0034dB/° and the background noise is measured to be 0.0005dB, so the resolution can achieve 0.2°.

Effect of composition on SILAR deposited CdxZn1-xS thin films

Science.gov (United States)

Ashith V., K.; Gowrish Rao, K.

2018-04-01

In the group of II-VI compound semiconductor, cadmium zinc sulphide (CdxZn1-xS) thin films have broad application in photovoltaic, optoelectronic devices etc. For heterojunction aspects, CdxZn1-xS thin film can be used as heterojunction partner for CdTe as the absorber layer. In this work, CdZnS thin films prepared on glass substrates by Successive Ion Layer Adsorption and Reaction (SILAR) method by varying the composition. The XRD patterns of deposited films showed polycrystalline with the hexagonal phase. The crystallite size of the films was estimated from W-H plot. The bond length of the film varied w.r.to the composition of the CdxZn1-xS films. The urbach energy of the films was calcualted from absorbance data.

Formation of CdS thin films in a chemical bath environment under the action of an external magnetic field

International Nuclear Information System (INIS)

Vaskes-Luna, Kh.G.; Zekhe, A.; Nhukhil'o-Garsiya, M.P.; Starostenko, O.

2000-01-01

The effect of external magnetic field on obtaining thin CdS films on glass sub layers through the method of chemical deposition from the cadmium chloride aqueous solution is studied. The intensity and direction of the magnetic field during deposition obviously affect the number of physical properties of polycrystalline films: thickness, grain size and optical quality. The films characteristics are studied through an atomic-power microscope, light absorption spectroscopy and conductometry in darkness. The results obtained are interpreted on the basis of notions on the cadmium and sulfur specific interaction in the chemical bath with a magnetic field [ru

Chlorination leaching of cadmium

International Nuclear Information System (INIS)

Lach, E.; Pajak, I.; Bojanowska, A.

1978-01-01

The results of the investigations on chlorination leaching of cadmium from dust coming from dry dust collector of sinter belt, that is leaching with water saturated with gaseous chlorine and leaching with solutions of ammonium chloride and sodium chloride were given. The optimum conditions for these processes were established. It was found, that the method of leaching in the presence of gaseous chlorine is more effective, as it allows to report into the solution over 90% cadmium contained in dust. Owing to technical difficulties, environmental protection and safety conditions more advantageous seems to be the use as leaching agent of the ammonium chloride solutions. When applying 20% NH 4 Cl and temperature of 60 0 C, the time of 2 hours and the ratio of solid to liquid of 1:5, 70% cadmium contained in the dust can be reported into the solution. (auth.)

Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52 MeV

OpenAIRE

Ditrói, F.; Takács, S.; Haba, H.; Komori, Y.; Aikawa, M.

2016-01-01

Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2 MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. Th...

Synthesis of cadmium chalcogenide nanotubes at room temperature

KAUST Repository

Pan, Jun; Qian, Yitai

2012-01-01

Cadmium chalcogenide (CdE, E=S, Se, Te) polycrystalline nanotubes have been synthesized from precursor of CdS/cadmium thiolate complex at room temperature. The precursor was hydrothermally synthesized at 180 °C using thioglycolic acid (TGA) and cadmium acetate as starting materials. The transformation from the rod-like precursor of CdS/cadmium thiolate complex to CdS, CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S 2-, Se 2- and Te 2-, respectively. The nanotube diameter can be controlled from 150 to 400 nm related to the dimension of templates. The XRD patterns show the cadmium chalcogenide nanotubes all corresponding to face-centered cubic structure. © 2012 Elsevier B.V. All rights reserved.

Synthesis of cadmium chalcogenide nanotubes at room temperature

KAUST Repository

Pan, Jun

2012-10-01

Cadmium chalcogenide (CdE, E=S, Se, Te) polycrystalline nanotubes have been synthesized from precursor of CdS/cadmium thiolate complex at room temperature. The precursor was hydrothermally synthesized at 180 °C using thioglycolic acid (TGA) and cadmium acetate as starting materials. The transformation from the rod-like precursor of CdS/cadmium thiolate complex to CdS, CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S 2-, Se 2- and Te 2-, respectively. The nanotube diameter can be controlled from 150 to 400 nm related to the dimension of templates. The XRD patterns show the cadmium chalcogenide nanotubes all corresponding to face-centered cubic structure. © 2012 Elsevier B.V. All rights reserved.

Polycrystalline CdTe solar cells on elastic substrates

International Nuclear Information System (INIS)

Sibinski, M.; Lisik, Z.

2007-01-01

The presented article is a report on progress in photovoltaic devices and material processing. A cadmium telluride solar cell as one of the most attractive option for thin-film polycrystalline cell constructions is presented. All typical manufacturing steps of this device, including recrystallisation and junction activation are explained. A new potential field of application for this kind of device - the BIPV (Building Integrated Photovoltaic) is named and discussed. All possible configuration options for this application, according to material properties and exploitation demands are considered. The experimental part of the presented paper is focused on practical implementation of the high - temperature polymer foil as the substrate of the newly designed device by the help of ICSVT (Isothermal Close Space Vapour Transport) technique. The evaluation of the polyester and polyamide foils according to the ICSVT/CSS manufacturing process parameters is described and discussed. A final conclusion on practical verification of these materials is also given. (authors)

Cadmium inhibits neurogenesis in zebrafish embryonic brain development

Energy Technology Data Exchange (ETDEWEB)

Chow, Elly Suk Hen [Division of Biology, California Institute of Technology, 1200 California Boulevard, Pasadena, CA 91125 (United States); Hui, Michelle Nga Yu; Lin Chunchi [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Cheng Shukhan [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)], E-mail: bhcheng@cityu.edu.hk

2008-05-01

Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum. Cadmium-treated embryos also have fewer differentiated neurons and glia in the facial sensory ganglia as indicated by decreased zn-12 expression. Also, a lower transcription level of neurogenic genes, ngn1 and neuroD, is observed in neurons. Our data suggest that cadmium-induced neurotoxicity can be caused by impaired neurogenesis, resulting in markedly reduced neuronal differentiation and axonogenesis.

Cadmium inhibits neurogenesis in zebrafish embryonic brain development

International Nuclear Information System (INIS)

Chow, Elly Suk Hen; Hui, Michelle Nga Yu; Lin Chunchi; Cheng Shukhan

2008-01-01

Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum. Cadmium-treated embryos also have fewer differentiated neurons and glia in the facial sensory ganglia as indicated by decreased zn-12 expression. Also, a lower transcription level of neurogenic genes, ngn1 and neuroD, is observed in neurons. Our data suggest that cadmium-induced neurotoxicity can be caused by impaired neurogenesis, resulting in markedly reduced neuronal differentiation and axonogenesis

Modification of cadmium pigments for colouring of polyolefins

International Nuclear Information System (INIS)

Kalinskaya, T.V.; Livshits, I.M.

1976-01-01

Modification conditions are studied of cadmium pigments, obtained by different methods, aliphatic acids(C 5 , C 8 and C 17 ). It is found, that cadmium pigments can adsorb acids with the number of atoms of carbon not less than 8. Stearic acid adsorption on lemon cadmium pigment taken as an example has shown the efficiency of pigment modification influence on its dispersancy in non-polar medium. Modification of yellow cadmium pigments of stearic acid makes possible to obtain pigment output forms ensuring a good particle distribution during polyolefine colouring

Effects of substrate temperature and post-deposition anneal on properties of evaporated cadmium telluride films

International Nuclear Information System (INIS)

Bacaksiz, E.; Basol, B.M.; Altunbas, M.; Novruzov, V.; Yanmaz, E.; Nezir, S.

2007-01-01

The effects of substrate temperature and post-deposition heat treatment steps on the morphology, structural, optical and electrical properties of thin film CdTe layers grown by vacuum evaporation were investigated. Scanning electron microscopy and X-ray diffraction (XRD) techniques were employed to study the structural changes. It was observed that the grain sizes and morphologies of as-deposited layers were similar for substrate temperatures of - 173 deg. C and - 73 deg. C. However, CdTe films produced at a substrate temperature of 27 deg. C had substantially larger grain size and clearly facetted morphology. Annealing at 200-400 deg. C in air did not cause any appreciable grain growth in any of the films irrespective of their growth temperature. However, annealing at 400 deg. C reduced faceting in all cases and initiated fusing between grains. XRD studies showed that this behavior after annealing at 400 deg. C coincided with an onset of a degree of randomization in the originally strong (111) texture of the as-grown layers. Optical band gap measurements showed sharpening of the band-edge upon annealing at 400 deg. C and a band gap value in the range of 1.46-1.49 eV. Resistivity measurements indicated that annealing at 400 deg. C in air forms a highly resistive compensated CdTe film. All results point to 400 deg. C to be a critical annealing temperature at which optical, structural and electrical properties of CdTe layers start to change

First operation of cesium telluride photocathodes in the TTF injector RF gun

CERN Document Server

Sertore, D; Flöttmann, K; Stephan, F; Zapfe, K; Michelato, P

2000-01-01

During the run 1998/1999 a new injector based on a laser-driven RF gun was brought in operation at the TESLA Test Facility (TTF) linac at DESY, in order to produce the beam structure and quality required either by TeV collider and SASE FEL experiments. High quantum efficiency cesium telluride photocathodes, prepared at Milano and transferred to DESY, have been successfully operated in the RF gun. A bunch charge of 50 nC, only limited by space charge effects, was achieved. The photocathodes have shown an operative lifetime of several months. A new cathode surface finishing has showed a promising decrease of the photocathode dark current. Measurements of dark current, quantum efficiency and lifetime are reported.

Cadmium release from a reprocessing electrorefiner falling over

Energy Technology Data Exchange (ETDEWEB)

Solbrig, Charles W., E-mail: Charles.solbrig@inl.gov [Batelle Energy Alliance, Idaho National Laboratory, PO Box 2528, Idaho Falls, ID 83404 (United States); Pope, Chad L. [Batelle Energy Alliance, Idaho National Laboratory, PO Box 2528, Idaho Falls, ID 83404 (United States)

2013-02-15

Highlights: ► We model an accident in a nuclear fuel processing facility caused by an earthquake. ► The earthquake causes the argon cell to breach and the electrorefiner to tip over. ► Cadmium is spilled and a cathode falls on the cadmium and starts to burn. ► Cadmium can be transported to people in the building, the site, and the public. ► The results show negligible doses to all persons except in one low probability case. -- Abstract: The possible biological consequences of a release of cadmium due to a design basis earthquake in the Idaho Nuclear Laboratory's nuclear fuel reprocessing cell are evaluated. The facility is designed to withstand the design basis earthquake except for some non-seismically qualified feedthroughs. The earthquake is hypothesized to breach these feedthroughs (allowing air into the argon atmosphere processing cell) and cause the MK-IV electrorefiner (ER) in the cell to tip over or split and spill its contents of fission product laden salt and cadmium. In addition, the uranium dendrite product cathode is assumed to fall on the cadmium and burn. The heat from the burning cathode results in release of cadmium vapor into the cell atmosphere. Ingestion and inhalation of a sufficient concentration of cadmium for a critical time period can cause irreversible health effects or death. The release of the small quantity of fission products, analyzed elsewhere, results in negligible doses. Analysis reported here shows there is no danger to the general public by the cadmium release or to on-site workers except in one low probability case. This one case requires a fivefold failure where the safety exhaust system fails just after the 4% oxygen concentration combustion limit in the cell is reached. Failure of the SES allows oscillatory inflow and outflow (and hence cadmium outflow) from the cell due to gravity. The dose to a worker in the basement exceeds the mortality limit in this one event if the worker does not leave the basement.

Cadmium release from a reprocessing electrorefiner falling over

International Nuclear Information System (INIS)

Solbrig, Charles W.; Pope, Chad L.

2013-01-01

Highlights: ► We model an accident in a nuclear fuel processing facility caused by an earthquake. ► The earthquake causes the argon cell to breach and the electrorefiner to tip over. ► Cadmium is spilled and a cathode falls on the cadmium and starts to burn. ► Cadmium can be transported to people in the building, the site, and the public. ► The results show negligible doses to all persons except in one low probability case. -- Abstract: The possible biological consequences of a release of cadmium due to a design basis earthquake in the Idaho Nuclear Laboratory's nuclear fuel reprocessing cell are evaluated. The facility is designed to withstand the design basis earthquake except for some non-seismically qualified feedthroughs. The earthquake is hypothesized to breach these feedthroughs (allowing air into the argon atmosphere processing cell) and cause the MK-IV electrorefiner (ER) in the cell to tip over or split and spill its contents of fission product laden salt and cadmium. In addition, the uranium dendrite product cathode is assumed to fall on the cadmium and burn. The heat from the burning cathode results in release of cadmium vapor into the cell atmosphere. Ingestion and inhalation of a sufficient concentration of cadmium for a critical time period can cause irreversible health effects or death. The release of the small quantity of fission products, analyzed elsewhere, results in negligible doses. Analysis reported here shows there is no danger to the general public by the cadmium release or to on-site workers except in one low probability case. This one case requires a fivefold failure where the safety exhaust system fails just after the 4% oxygen concentration combustion limit in the cell is reached. Failure of the SES allows oscillatory inflow and outflow (and hence cadmium outflow) from the cell due to gravity. The dose to a worker in the basement exceeds the mortality limit in this one event if the worker does not leave the basement

Blood cadmium by race/hispanic origin: The role of smoking

Energy Technology Data Exchange (ETDEWEB)

Aoki, Yutaka, E-mail: yaoki@cdc.gov [Centers for Disease Control and Prevention, National Center for Health Statistics, Division of Health and Nutrition Examination Surveys, 3311 Toledo Rd, Hyattsville, MD 20782 (United States); Yee, Jennifer [Centers for Disease Control and Prevention, National Center for Health Statistics, Division of Health and Nutrition Examination Surveys, 3311 Toledo Rd, Hyattsville, MD 20782 (United States); Centers for Disease Control and Prevention, Center for Surveillance, Epidemiology, and Laboratory Services, Division of Scientific Education and Professional Development, Epidemiology Elective Program, MS E-92, 1600 Clifton Rd, NE, Atlanta, GA 30329 (United States); Georgetown University Medical Center, Department of Family Medicine, 4000 Reservoir Road, N.W., Washington D.C 20057 (United States); Mortensen, Mary E. [Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Laboratory Sciences, MS F-20, 4770 Buford Highway, Atlanta, GA 30341 (United States)

2017-05-15

Background: There have been increasing concerns over health effects of low level exposure to cadmium, especially those on bones and kidneys. Objective: To explore how age-adjusted geometric means of blood cadmium in adults varied by race/Hispanic origin, sex, and smoking status among U.S. adults and the extent to which the difference in blood cadmium by race/Hispanic origin and sex may be explained by intensity of smoking, a known major source of cadmium exposure. Methods: Our sample included 7,368 adults from National Health and Nutrition Examination Survey (NHANES) 2011–2014. With direct age adjustment, geometric means of blood cadmium and number of cigarettes smoked per day were estimated for subgroups defined by race/Hispanic origin, smoking status, and sex using interval regression, which allows mean estimation in the presence of left- and right-censoring. Results: Among never and former smoking men and women, blood cadmium tended to be higher for non-Hispanic Asian adults than adults of other race/Hispanic origin. Among current smokers, who generally had higher blood cadmium than never and former smokers, non-Hispanic white, black, and Asian adults had similarly elevated blood cadmium compared to Hispanic adults. A separate analysis revealed that non-Hispanic white adults tended to have the highest smoking intensity regardless of sex, than adults of the other race/Hispanic origin groups. Conclusions: The observed pattern provided evidence for smoking as a major source of cadmium exposure, yet factors other than smoking also appeared to contribute to higher blood cadmium of non-Hispanic Asian adults. - Highlights: • Among never and former smoking adults, Asians have the highest blood cadmium. • White adults tend to have the highest smoking intensity, but not blood cadmium. • Women overall have higher levels of blood cadmium than men regardless of smoking. • Non-smoking sources of exposure likely contribute to Asians’ higher blood cadmium.

Blood cadmium by race/hispanic origin: The role of smoking

International Nuclear Information System (INIS)

Aoki, Yutaka; Yee, Jennifer; Mortensen, Mary E.

2017-01-01

Background: There have been increasing concerns over health effects of low level exposure to cadmium, especially those on bones and kidneys. Objective: To explore how age-adjusted geometric means of blood cadmium in adults varied by race/Hispanic origin, sex, and smoking status among U.S. adults and the extent to which the difference in blood cadmium by race/Hispanic origin and sex may be explained by intensity of smoking, a known major source of cadmium exposure. Methods: Our sample included 7,368 adults from National Health and Nutrition Examination Survey (NHANES) 2011–2014. With direct age adjustment, geometric means of blood cadmium and number of cigarettes smoked per day were estimated for subgroups defined by race/Hispanic origin, smoking status, and sex using interval regression, which allows mean estimation in the presence of left- and right-censoring. Results: Among never and former smoking men and women, blood cadmium tended to be higher for non-Hispanic Asian adults than adults of other race/Hispanic origin. Among current smokers, who generally had higher blood cadmium than never and former smokers, non-Hispanic white, black, and Asian adults had similarly elevated blood cadmium compared to Hispanic adults. A separate analysis revealed that non-Hispanic white adults tended to have the highest smoking intensity regardless of sex, than adults of the other race/Hispanic origin groups. Conclusions: The observed pattern provided evidence for smoking as a major source of cadmium exposure, yet factors other than smoking also appeared to contribute to higher blood cadmium of non-Hispanic Asian adults. - Highlights: • Among never and former smoking adults, Asians have the highest blood cadmium. • White adults tend to have the highest smoking intensity, but not blood cadmium. • Women overall have higher levels of blood cadmium than men regardless of smoking. • Non-smoking sources of exposure likely contribute to Asians’ higher blood cadmium.

Oral cadmium chloride intoxication in mice

DEFF Research Database (Denmark)

Andersen, O; Nielsen, J B; Svendsen, P

1988-01-01

Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect...

Lead and cadmium content of spices

Energy Technology Data Exchange (ETDEWEB)

Bielig, H J; Dreyer, H; Askar, A

1977-02-02

The lead and cadmium content of various spices was determined by flameless atomic absorption (AAS). With the exception of one sample, the lead content was lower than 5 ppm, averaging a value of 2,2 ppm Pb. Thus, the maximum permissible level of 5 ppm Pb as recommended by different DIN standards, is not exceeded. The cadmium content was - except for one sample - lower than 0,5 ppm averaging a value of 0,23 ppm Cd. It can be assumed, that by spicing our dishes, the ingestion of lead and cadmium stays at a low level.

Cadmium decontamination using in-house resin

International Nuclear Information System (INIS)

Pal, Sangita; Thalor, K.L; Prabhakar, S.; Srivastava, V.K.; Goswami, J.L.; Tewari, P.K.; Dhanpal, Pranav; Goswami, J.L.

2010-01-01

A selective and strong in-house chelator has been studied w.r.t. basic parameters like concentration, time, and elution. De-contamination of cadmium, mercury, chromium, lead etc by using high uptake values fro cadmium ions proves its selectivity with high elution ratio ensures further decontamination of run-off water during natural calamities. In three step cascade use the concentration of original cadmium solution (500 ppm) decocted to safe disposable attribute. This polymeric ligand exchanger displayed outlet effluent concentration to 1 ppm and less than 200 ppb when treated for inlet feed concentration of 50 ppm and 500 ppm respectively. (author)

New process to discharge negative cadmium electrodes for Ni/Cd batteries

International Nuclear Information System (INIS)

Stiker, B.; Vignaud, R.

1984-01-01

The new process relates to the chemical oxidation (whether partial or total) of cadmium metal negative electrodes, as used in alkaline nickel-cadmium or silver-cadmium batteries. This process concerns all cadmium electrodes but more particularly the electrodeposited cadmium electrode developed by the company LES PILES WONDER and described in this publication

Technology support for initiation of high-throughput processing of thin-film CdTe PV modules. Phase 3 final technical report, 14 March 1997--1 April 1998

Energy Technology Data Exchange (ETDEWEB)

Powell, R.C.; Dorer, G.L.; Jayamaha, U.; Hanak, J.J. [Solar Cells, Inc., Toledo, OH (United States)

1998-09-01

Thin-film PV devices based on cadmium telluride have been identified as one of the candidates for high-performance, low-cost source of renewable electrical energy. Roadblocks to their becoming a part of the booming PV market growth have been a low rate of production and high manufacturing cost caused by several rate-limiting process steps. Solar Cells Inc. has focused on the development of manufacturing processes that will lead to high volume and low-cost manufacturing of solar cells and on increasing the performance of the present product. The process research in Phase 3 was concentrated on further refinement of a newly developed vapor transport deposition (VTD) process and its implementation into the manufacturing line. This development included subsystems for glass substrate transport, continuous feed of source materials, generation of source vapors, and uniform deposition of the semiconductor layers. As a result of this R and D effort, the VTD process has now achieved a status in which linear coating speeds in excess of 8 ft/min have been achieved for the semiconductor, equal to about two modules per minute, or 144 kW per 24 hour day. The process has been implemented in a production line, which is capable of round-the-clock continuous production of coated substrates 120 cm x 60 cm in size at a rate of 1 module every four minutes, equal to 18 kW/day. Currently the system cycle time is limited by the rate of glass introduction into the system and glass heating, but not by the rate of the semiconductor deposition. A new SCI record efficiency of 14.1% has been achieved for the cells.

Optical properties of Cd Se thin films obtained by pyrolytic dew

International Nuclear Information System (INIS)

Perez G, A.M.; Tepantlan, C.S.; Renero C, F.

2006-01-01

In this paper the optical properties of Cd Se thin films obtained by spray pyrolysis are presented. The films are prepared by Sodium Seleno sulphate (Na 2 SSeO 3 ) and Cadmium Chloride (CdC 12 ) mixing in aqueous environment. Optical parameters of the films (refractive index, absorption coefficient and optical ban gap) were calculated from transmittance spectra. The obtained values of the optical ban gap are compared with the result obtained by other deposition method. (Author)

Calcium enhances cadmium tolerance and decreases cadmium ...

African Journals Online (AJOL)

Yomi

2012-04-26

Apr 26, 2012 ... concentrations alleviated the toxic effect of cadmium on the growth and water status of lettuce plants. The three lettuce varieties ... electroplating, in batteries, in electrical conductors, in the manufacture of alloys ..... Handbook on the Toxicology of Metals, Third edition, Salt Lake City, UT: Acad. Press. Österås ...

Synthesis and Characterization of Mercaptoacetic Acid Capped Cadmium Sulphide Quantum Dots.

Science.gov (United States)

Wageh, S; Maize, Mai; Donia, A M; Al-Ghamdi, Ahmed A; Umar, Ahmad

2015-12-01

This paper reports the facile synthesis and detailed characterization of mercaptoacetic acid capped cadmium sulphide (CdS) quantum dots using various cadmium precursors. The mercaptoacetic acid capped CdS quantum dots were prepared by facile and simple wet chemical method and characterized by several techniques such as energy dispersive spectroscopy (EDS), X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, UV-vis. spectroscopy, photoluminescence spectroscopy, high-resolution transmission microscopy (HRTEM) and thremogravimetric analysis. The EDS studies revealed that the prepared quantum dots possess higher atomic percentage of sulfur compared to cadmium due to the coordination of thiolate to the quantum dots surfaces. The X-ray and absorption analyses exhibited that the size of quantum dots prepared by cadmium acetate is larger than the quantum dots prepared by cadmium chloride and cadmium nitrate. The increase in size can be attributed to the low stability constant of cadmium acetate in comparison with cadmium chloride and cadmium nitrate. The FTIR and thermogravimetric analysis showed that the nature of capping molecule on the surface of quantum dots are different depending on the cadmium precursors which affect the emission from CdS quantum dots. Photoemission spectroscopy revealed that the emission of quantum dots prepared by cadmium acetate has high intensity band edge emission along with low intensity trapping state emission. However the CdS quantum dots prepared by cadmium chloride and cadmium nitrate produced only trapping state emissions.

USSR and Eastern Europe Scientific Abstracts, Physics and Mathematics, Number 34

Science.gov (United States)

1977-04-27

USSR UDC 621.315.592 ANOMALOUS PHOTOCONDUCTIVITY AND DARK CONDUCTIVITY OF SEMI-INSULATING CADMIUM TELLURIDE Leningrad FIZIKA I TEKHNIKA...conductivity activation energy of CdTe. The temperature characteristic of the dark conductivity, measured within the ohmic range of the current...A. V., Joint Institute for Nuclear Research [Abstract] The purpose of this theoretical paper is to show that the quark -parton modification offers

Cadmium uptake in oyster isognomon alatus under laboratory condition

International Nuclear Information System (INIS)

Katayon Saed; Ahmad Ismail; Missri Kusnan; Hishamuddin Omar

1999-01-01

The uptake of cadmium in Flat tree oyster Isognomon alatus was investigated under controlled laboratory conditions for two weeks. Oysters were exposed to 100 μg 1'-1 cadmium and the accumulation of cadmium in the tissues was measured for every two days. Soft tissues of oyster were digested in concentrated acid and cadmium concentrations were determined by using Atomic Absorption Spectrophotometer. The accumulation of cadmium in the soft tissues of oysters was increased during the first six days from 0.73 μg g- 1 to 10.77 μg g'-1, and remaining constant for four days at average level of 10.96 μg g'-1. The Cl concentrations was increased to 32.70 μg g'-1 until the end of experiment. There was no sign of cadmium accumulation approaching saturation for the period of exposure. (author)

New compositions of cadmium selenium nanoparticles and dye molecules with cyclodextrin inclusion complexes

International Nuclear Information System (INIS)

Asimov, M.M.; Anufrik, S.S.; Tarkovsky, V.V.; Sazonko, H.H.

2013-01-01

Spectroscopic properties of new heterogeneous multicolor compositions based on cadmium selenium (CdSe/ZnS) nano crystal and inclusion complexes of dye molecule with cyclodextrin are presented. Spectral fluorescence of proposed compositions investigated in thin films. Signals from multicolor fluorescence of proposing compositions may be combined to definite spectral codes that could be used for tracking or verification of different objects. Calibration bar of signal within spectral codes guarantee high reliability in practical application of proposed multicolor compositions. Express analysis the size of nanoparticles during their synthesis and purification by spectroscopic methods is suggested. Application of Cyclodextrin molecules as target delivery systems is considered. (authors)

Effect of cadmium on myocardial contractility and calcium fluxes

International Nuclear Information System (INIS)

Pilati, C.F.

1979-01-01

The effect of cadmium on myocardial mechanical performance and calcium fluxes was studied in kitten isometric papillary muscles and in isovolumic Langendorff-perfused rabbit hearts. Therefore, it is concluded that cadmium-induced decreases in contractility are not primarily the result of cadmium interference with ATP metabolic processes. Furthermore, these results imply that cadmium causes no structural alterations of the contractile proteins. These data suggest that cadmium may be competing with the calcium needed for excitation-contraction coupling. During experiments using radioisotopic calcium, a statistically significant cellular influx of calcium was observed following the onset of 100 μM Cd ++ perfusion of isolated, Langendorff-prepared rabbit hearts

Cadmium chronic administration to lactating ewes. Reproductive performance, cadmium tissue accumulation and placental transfer

Energy Technology Data Exchange (ETDEWEB)

Floris, B.; Bomboi, G.; Sechi, P.; Marongiu, M. L. [Sassari Univ., Sassari (Italy). Dipt. di Biologia Animale; Pirino, S. [Sassari Univ., Sassari (Italy). Ist. di Patologia Generale, Anatomia Patologica e Clinica Ostetrico-chirurgica Veterinaria

2000-12-01

20 lactating ewes were allotted to two groups: 10 subjects received orally 100 mg/day of CdCl{sub 2} for 108 consecutive days, and the remaining 10 acted as control. Reproductive performance in ewes and cadmium tissue accumulation, both in ewes and their lambs, were investigated. The results showed that in ewes: 1) the regular cadmium intestinal intake negatively influences all reproductive parameters; 2) cadmium is particularly accumulated in kidney and liver, bur also in mammary gland, although at distinctly lower level; 3) chronic administration does not increase cadmium placental transfer in lactating pregnant subjects. [Italian] 20 pecore in lattazione sono state suddivise in 2 gruppi: 10 soggetti ricevettero per os 100 mg/giorno di CdCl{sub 2} per 108 giorni consecutivi, e i restanti 10 funsero da controllo. Sono stati studiati i parametri riproduttivi delle pecore e l'accumulo di cadmio nei tessuti, sia delle pecore che dei loro agnelli. I risultati hanno mostrato che negli ovini: 1) il regolare assorbimento intestinale di cadmio influenza negativamente tutti i parametri riproduttivi; 2) il cadmio viene accumulato principalmente nei reni e nel fegato, ma anche dalla ghiandola mammaria, sebbene in misura nettamente inferiore; 3) la somministrazione cronica di cadmio nei soggetti gravidi non incrementa il suo passaggio transplacentare.

Cadmium Exposure is Associated with the Prevalence of Dyslipidemia

OpenAIRE

Zhou Zhou; Yong-hui Lu; Hui-feng Pi; Peng Gao; Min Li; Lei Zhang; Li-ping Pei; Xiang Mei; Lin Liu; Qi Zhao; Qi-Zhong Qin; Yu Chen; Yue-ming Jiang; Zhao-hui Zhang; Zheng-ping Yu

2016-01-01

Background: Cadmium is a widespread environmental and occupational pollutant that accumulates in human body with a biological half-life exceeding 10 years. Cadmium exposure has been demonstrated to increase rates of cardiovascular diseases. Whether occupational cadmium exposure is associated with the increase in the prevalence of dyslipidemia and hence contributes to the risk of cardiovascular diseases is still equivocal. To test the hypothesis that exposure to cadmium is related to the preva...

Stabilization of cadmium electrode properties when introducing surfactants

International Nuclear Information System (INIS)

Alekseeva, M.E.; Mansurov, F.Kh.; Nikol'skij, V.A.

1995-01-01

The results of tests of both separate cadmium electrodes and silver-cadmium accumulators, depending on introduction of surfactants (polyethylene oxide - PO - and its derivatives), have been considered. The influence of PO on the course of electrochemical reaction on cadmium is pronounced in facilitation of anodic process. In case of PO introduction in the amount of 1 % instead of sodium lignosulfonate (2 %) into accumulators with silver-cadmium electrodes, the electrode potential is stabilized, while the accumulator capacity increases. The time period of the accumulation maintenance in the charged state increases 2-3 fold (1-1,5 years). 5 refs.; 4 figs.; 2 tabs

Cadmium exposure and health risks: Recent findings

Energy Technology Data Exchange (ETDEWEB)

Elinder, C.G. [Huddinge Hospital (Sweden). Dept. of Renal Medicine; Jaerup, L. [Stockholm City Council (Sweden). Dept. of Environmental Health

1996-08-01

Environmental and/or occupational exposure to cadmium give rise to a tubular kidney dysfunction which may proceed to more generalized renal damage and bone disease if exposure has been high and prolonged. Recent scientific work shows that early renal effects develop at lower levels of exposure than previously anticipated. Previous risk assessments for cadmium were mainly based on studies on healthy male workers. The general population, however, also include particularly susceptible groups such as elderly and individuals with illnesses (e.g. diabetes) that may predispose to cadmium-induced health effects. A significant proportion of the general population displays early signs of toxicity already at urinary cadmium concentrations around 3 nmol mmol{sup -1} creatinine. In addition to early tubular effects, cadmium may exert direct or indirect effects on mineral metabolism and the mineralization of the skeleton at relatively low levels of exposure. This may have important health implications, as poor and easily fractured bone is a major problem among the elderly in all industrialized countries. 41 refs, 4 figs

An experimental study of the retention of zinc, zinc-cadmium mixture and zinc-65 in the presence of cadmium in Anguilla anguilla (L.)

International Nuclear Information System (INIS)

Pally, Monique; Foulquier, Luc

1976-07-01

Zinc uptake was studied in eels in fresh water, using stable zinc, a zinc-cadmium mixture, and zinc 65 in the presence of small amounts of cadmium. The zinc content in the eel began to increase after 45 days only, and reached approximately 85 ppm after 76 days in water initially containing 5ppm of zinc. At the conclusion of the experiment (76 days), the body organs could be classified in decreasing order in zinc content (in ppm): kidneys (152), skeleton (133), skin (129), muscles (89), head (80), gills (78), digestive tract (77), liver (63) spleen-heart-air bladder (32), and mucus (15). A comparison of experimental results obtained with the zinc-cadmium mixture and cadmium alone showed that zinc decreased the cadmium content of all organs except the gills. The presence of cadmium in water did not inhibit zinc uptake. As cadmium content in water increased, then zinc content in the digestive tract and the kidneys decreased and in all cases remained lower than when zinc alone was present. In the presence of cadmium the percentage of zinc in the kidneys was always lower than the value obtained for zinc alone, and that of the digestive tract did not increase. Contamination of eels treated with 18 and 50ppb of cadmium for 29 days, then contaminated by zinc-65 (5μCi/l) while maintaining the same low cadmium content, showed no significant difference in zinc 65 uptake in the two groups. The same applied to the body organs, and particularly the digestive tract and kidneys, where the highest activity levels were observed. By weight, muscles represented approximately 30% of the total contamination after 45 days [fr

Polarographic studies on the nature of cadmium in scallop, oyster, and lobster

Energy Technology Data Exchange (ETDEWEB)

Chou, C L; Uthe, J F; Zook, E G

1978-04-01

Free and bound forms of cadmium were determined in raw shellfish by use of differential pulse polarography and atomic absorption spectrophotometry. Free cadmium is defined by its polarographic peak potential of -0.62 +- 0.02 V (saturated calomel electrode) in solvent washed ammonium sulfate extracts. Bound cadmium was determined by subtracting the free cadmium from the total cadmium present in the meat. Both scallop (various species) and American lobster (Homarus americanus) muscle tissues contain no free cadmium. Oyster (various species), on the other hand, had a considerable percentage (approximately 50%) of its total cadmium present as free cadmium, a phenomena as yet unexplained. The detection limit for free cadmium is approximately 0.05 ..mu..g/g raw tissue.

Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

Science.gov (United States)

Goodman, Samuel M.; Noh, Hyunwoo; Singh, Vivek; Cha, Jennifer N.; Nagpal, Prashant

2015-02-01

Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers.

Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

Energy Technology Data Exchange (ETDEWEB)

Goodman, Samuel M.; Singh, Vivek [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Noh, Hyunwoo [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering Program and Department of Nanoengineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, California 92093 (United States); Cha, Jennifer N. [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering Program and Department of Nanoengineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, California 92093 (United States); Materials Science and Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Nagpal, Prashant, E-mail: pnagpal@colorado.edu [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Renewable and Sustainable Energy Institute, University of Colorado Boulder, 2445 Kittredge Loop, Boulder, Colorado 80309 (United States)

2015-02-23

Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers.

Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

International Nuclear Information System (INIS)

Goodman, Samuel M.; Singh, Vivek; Noh, Hyunwoo; Cha, Jennifer N.; Nagpal, Prashant

2015-01-01

Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers

Diaroyl Tellurides: Synthesis, Structure and NBO Analysis of (2-MeOC6H4CO2Te – Comparison with Its Sulfur and Selenium Isologues. The First Observation of [MgBr][R(C=TeO] Salts

Directory of Open Access Journals (Sweden)

Fumio Ando

2009-07-01

Full Text Available A series of aromatic diacyl tellurides were prepared in moderate to good yields by the reactions of sodium orpotassium arenecarbotelluroates with acyl chlorides in acetonitrile. X-ray structure analyses and theoretical calculations of 2-methoxybenzoic anhydride and bis(2-methoxybenzoyl sulfide, selenide and telluride were carried out. The two 2-MeOC6H4CO moieties of bis(2-methoxybenzoyl telluride are nearly planar and the two methoxy oxygen atoms intramolecularly coordinate to the central tellurium atom from both side of C(11-Te(11-C(22 plane. In contrast, the oxygen and sulfur isologues (2-MeOC6H4CO2E (E = O, S, show that one of the two methoxy oxygen atoms contacts with the oxygen atom of the carbonyl group connected to the same benzene ring. The structure of di(2-methoxybenzoyl selenide which was obtained by MO calculation resembles that of tellurium isologues rather than the corresponding oxygen and sulfur isologues. The reactions of di(aroyl tellurides with Grignard reagents lead to the formation of tellurocarboxylato magnesium complexes [MgBr][R(C=TeO].

Cadmium affects retinogenesis during zebrafish embryonic development

International Nuclear Information System (INIS)

Hen Chow, Elly Suk; Yu Hui, Michelle Nga; Cheng, Chi Wa; Cheng, Shuk Han

2009-01-01

Ocular malformations are commonly observed in embryos of aquatic species after exposure to toxicants. Using zebrafish embryos as the model organism, we showed that cadmium exposure from sphere stage (4 hpf) to end of segmentation stage (24 hpf) induced microphthalmia in cadmium-treated embryos. Embryos with eye defects were then assessed for visual abilities. Cadmium-exposed embryos were behaviorally blind, showing hyperpigmentation and loss of camouflage response to light. We investigated the cellular basis of the formation of the small eyes phenotype and the induction of blindness by studying retina development and retinotectal projections. Retinal progenitors were found in cadmium-treated embryos albeit in smaller numbers. The number of retinal ganglion cells (RGC), the first class of retinal cells to differentiate during retinogenesis, was reduced, while photoreceptor cells, the last batch of retinal neurons to differentiate, were absent. Cadmium also affected the propagation of neurons in neurogenic waves. The neurons remained in the ventronasal area and failed to spread across the retina. Drastically reduced RGC axons and disrupted optic stalk showed that the optic nerves did not extend from the retina beyond the chiasm into the tectum. Our data suggested that impairment in neuronal differentiation of the retina, disruption in RGC axon formation and absence of cone photoreceptors were the causes of microphthalmia and visual impairment in cadmium-treated embryos

Human health effects of exposure to cadmium

Energy Technology Data Exchange (ETDEWEB)

Hallenbeck, W.H.

1986-01-01

The health effects of human exposure to cadmium are discussed with emphases on intake, absorption, body burden, and excretion; osteomalacia in Japan; hypertension; and proteinuria, emphysema, osteomalacia, and cancer in workers. Elevated blood pressure has not been observed as a result of excessive exposures to cadmium in Japan or the workplace. Renal tubular dysfunction and consequent proteinuria is generally accepted as the main effect following long-term, low-level exposure to cadmium. Studies of workers show that proteinuria may develop after the first year of exposure or many years after the last exposure. Proteinuria and deterioration of renal function may continue even after cessation of exposure. The immediate health significance of low-level proteinuria is still under debate. However, there is evidence that long-term renal tubular dysfunction may lead to abnormalities of calcium metabolism and osteomalacia. The few autopsy and cross-sectional studies of workers do not permit conclusions to be drawn regarding the relationship between cadmium exposure and emphysema. Retrospective and historical-prospective studies are needed to settle this important question. No conclusive evidence has been published regarding cadmium-induced cancer in humans. However, there is sufficient evidence to regard cadmium as a suspect renal and prostate carcinogen. Because of equivocal results and the absence of dose-response relationships, the studies reviewed should be used with caution in making regulatory decisions and low-dose risk assessments. 62 references.

Human health effects of exposure to cadmium

Energy Technology Data Exchange (ETDEWEB)

Hallenbeck, W.H.

1984-02-15

The health effects of human exposure to cadmium are discussed with emphasis on intake, absorption, body burden, and excretion; osteomalacia in Japan; hypertension; and proteinuria, emphysema, osteomalacia, and cancer in workers. Elevated blood pressure has not been observed as a result of excessive exposures to cadmium in Japan or the workplace. Renal tubular dysfunction and consequent proteinuria is generally accepted as the main effect following long-term, low-level exposure to cadmium. Studies of workers show that proteinuria may develop after the first year of exposure or many years after the last exposure. Proteinuria and deterioration of renal function may continue even after cessation of exposure. The immediate health significance of low-level proteinuria is still under debate. However, there is evidence that long-term renal tubular dysfunction may lead to abnormalities of calcium metabolism and osteomalacia. The few autopsy and cross-sectional studies of workers do not permit conclusions to be drawn regarding the relationship between cadmium exposure and emphysema. Retrospective and historical-prospective studies are needed to settle this important question. No conclusive evidence has been published regarding cadmium-induced cancer in humans. However, there is sufficient evidence to regard cadmium as a suspect renal and prostate carcinogen. Because of equivocal results and the absence of dose-response relationships, the studies reviewed should be used with caution in making regulatory decisions and low-dose risk assessments.

[Physiological response and bioaccumulation of Panax notoginseng to cadmium under hydroponic].

Science.gov (United States)

Li, Zi-wei; Yang, Ye; Cui, Xiu-ming; Liao, Pei-ran; Ge, Jin; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui

2015-08-01

The physiological response and bioaccumulation of 2-year-old Panax notoginseng to cadmium stress was investigated under a hydroponic experiment with different cadmium concentrations (0, 2.5, 5, 10 μmol · L(-1)). Result showed that low concentration (2.5 μmol · L(-1)) of cadmium could stimulate the activities of SOD, POD, APX in P. notoginseng, while high concentration (10 μmol · L(-1)) treatment made activities of antioxidant enzyme descended obviously. But, no matter how high the concentration of cadmium was, the activities of CAT were inhibited. The Pn, Tr, Gs in P. notoginseng decreased gradually with the increase of cadmium concentration, however Ci showed a trend from rise to decline. The enrichment coefficients of different parts in P. notoginseng ranked in the order of hair root > root > rhizome > leaf > stem, and all enrichment coefficients decreased with the increase of concentration of cadmium treatments; while the cadmium content in different parts of P. notoginseng and the transport coefficients rose. To sum up, cadmium could affect antioxidant enzyme system and photosynthetic system of P. notoginseng; P. notoginseng had the ability of cadmium enrichment, so we should plant it in suitable place reduce for reducing the absorption of cadmium; and choose medicinal parts properly to lessen cadmium intake.

Cadmium exposure induces hematuria in Korean adults

Energy Technology Data Exchange (ETDEWEB)

Han, Seung Seok [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Myounghee, E-mail: dkkim73@gmail.com [Department of Dental Hygiene, College of Health Science, Eulji University, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Su Mi [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jung Pyo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Sejoong [Department of Internal Medicine, Seoul National University Bundang Hospital, Gyeonggi-do 463-707 (Korea, Republic of); Joo, Kwon Wook [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lim, Chun Soo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Yon Su; Kim, Dong Ki [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

2013-07-15

Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

A study on complex formation of cadmium(II) ions, 8

International Nuclear Information System (INIS)

Matsui, Haruo; Hirabayashi, Yoshihiro

1984-01-01

In the potentiometric titration of the solution containing a cadmium(II) ion and an amino acid, white precipitates often appear in the test solution, and they disturb the emf measurements. Such precipitates were formes in the solutions, pH ranging 7.5--8.5, during the course of titrations of the test solutions containing cadmium(II) ion and amino acid such as glycine, α-alanine. 2-aminobutanoic acid, 3-aminobutanoic acid, 4-aminobutanoic acid, 2-aminopentanoic acid, 5-aminopentanoic acid, 2-aminohexanoic acid, 6-aminohexanoic acid, aspartic acid, glutamic acid, asparagine, or glutamine. The identification of the precipitates obtained from the solutions containing cadmium(II) ion and L-aspartic acid, 4-aminobutanoic acid, or 6-aminohexanoic acid were carried out by both of elemental analysis and the infrared spectroscopy. These results indicated that the precipitate obtained from the solution containing cadmium(II) ion and L-aspartic acid was 1:1 cadmium(II)-L-aspartic acid complex and did not contain any cadmium(II) hydroxide, and other two precipitates were mostly cadmium(II) hydroxide and contained a little cadmium(II)-amino acid complexes. (author)

Modeling cadmium in the feed chain and cattle organs

NARCIS (Netherlands)

Fels-Klerx, van der H.J.; Romkens, P.F.A.M.; Franz, E.; Raamsdonk, van L.W.D.

2011-01-01

The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH,

Effect of cadmium on electron and energy transfer reactions in corn mitochondria

Energy Technology Data Exchange (ETDEWEB)

Miller, R J; Bittell, J E; Koeppe, D E

1973-01-01

The effects of cadmium on isolated corn shoot mitochondria were determined. In the absence of phosphate cadmium stimulated the oxidation of exogenous NADH optimally at 0.025 mM, but was inhibitory at 0.1 mM and above. The presence of phosphate negated the cadmium stimulation of exogenous NADH oxidation and permitted inhibitions only at higher cadmium concentrations. Succinate or malate + pyruvate oxidation in the absence of phosphate was inhibited to a greater extent by cadmium than when phosphate was present. ADP/O and respiratory control ratios were reduced by cadmium but generally were less sensitive to cadmium than state 4 or minus phosphate respiration. The data suggest that the site of cadmium effect is likely to be early in electron transport. Cadmium had a pronounced effect on mitochondrial swelling under either passive or active conditions. When succinate or exogenous NADH were being oxidized swelling occurred at 0.05 mM cadmium, but with malate + pyruvate the cadmium concentration had to exceed 1.0 mM. Phosphate (2 mM) prevented the swelling. Dithiothreitol, a SH group protector, prevented any effect of cadmium on swelling or respiration which suggests that sulfhydryl groups are likely involved in the cadmium-membrane interaction.

Electro-spark machining of cadmium antimonide

International Nuclear Information System (INIS)

Ivanovskij, V.N.; Stepakhina, K.A.

1975-01-01

Experimental data on electrical erosion of the semiconductor material (cadmium antimonide) alloyed with tellurium are given. The potentialisies and expediency of using the electric-spark method of cutting cadmium antimonide ingots with the resistivity of 1 ohm is discussed. Cutting has been carried out in distilled water and in the air

Cadmium Removal from Aqueous Solutions by Ground Pine Cone

Directory of Open Access Journals (Sweden)

H Izanloo, S Nasseri

2005-01-01

Full Text Available A study on the removal of cadmium ions from aqueous solutions by pine cone was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were obtained. The influence of different experimental parameters such as contact time, initial concentration of cadmium, pine cone mass and particle size, and temperature on the kinetics of cadmium removal was studied. Results showed that the main parameters that played an important role in removal phenomenon were initial cadmium concentration, particle size and pine cone mass. The necessary time to reach equilibrium was between 4 and 7 hours based on the initial concentration of cadmium. The capacity of cadmium adsorption at equilibrium increased with the decrease of pine cone particle size. The capacity of cadmium adsorption at equilibrium by pine cone increased with the quantity of pine cone introduced (1–4 g/L. Temperature in the range of 20-30°C showed a restricted effect on the removal kinetics (13.56 mg/g at 20°C and a low capacity of adsorption about 11.48 mg/g at 30°C. The process followed pseudo second-order kinetics. The cadmium uptake of pine cone was quantitatively evaluated using adsorption isotherms. Results indicated that the Langmuir model gave a better fit to the experimental data in comparison with the Freundlich equation.