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Sample records for cadmium zinc telluride

  1. Induced Positron Annihiliation Investigation of Cadmium Zinc Telluride Crystal Microstructures

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Akers

    2005-06-01

    Cadmium-Zinc-Telluride (CZT) crystals are used in semiconductor radiation detectors for the detection of x-ray and gamma radiation. However, production of detector grade crystals is difficult as small variations in compositional uniformity and primarily the zinc content can significantly affect the ability of the CZT crystal to function as a radiation detector. Currently there are no known nondestructive methods that can be used to identify detector grade crystals. The current test method is to fabricate and test the detector to determine if the crystal is sufficiently uniform and of the correct composition to be considered a detector grade crystal. Consequently, nondestructive detection methods are needed to identify detector grade crystals prior to the fabrication process. The purpose of this feasibility study was to perform a preliminary assessment of the ability of several new, nondestructive technologies based on Induced Positron Annihilation (IPA) to determine if detector grade CZT crystals can be identified. Results of measurements performed on specimens from Fisk University and EV Products, Inc. indicate that both the near surface Distributed Source Positron Annihilation (up to 3 mm penetration) and the volumetric Photon Induced Positron Annihilation methods may be suitable for determining CZT crystal quality. Further work on CZT crystals with a broader range of compositions and detector characteristics is needed to provide a well defined, calibrated, method for assessing CZT crystal quality.

  2. Properties of Nitrogen-Doped Zinc Telluride Films for Back Contact to Cadmium Telluride Photovoltaics

    Science.gov (United States)

    Shimpi, Tushar M.; Drayton, Jennifer; Swanson, Drew E.; Sampath, Walajabad S.

    2017-08-01

    Zinc telluride (ZnTe) films have been deposited onto uncoated glass superstrates by reactive radiofrequency (RF) sputtering with different amounts of nitrogen introduced into the process gas, and the structural and electronic transport properties of the resulting nitrogen-doped ZnTe (ZnTe:N) films characterized. Based on transmission and x-ray diffraction measurements, it was observed that the crystalline quality of the ZnTe:N films decreased with increasing nitrogen in the deposition process. The bulk carrier concentration of the ZnTe:N films determined from Hall-effect measurements showed a slight decrease at 4% nitrogen flow rate. The effect of ZnTe:N films as back contact to cadmium telluride (CdTe) solar cells was also investigated. ZnTe:N films were deposited before or after CdCl2 passivation on CdTe/CdS samples. Small-area devices were characterized for their electronic properties. Glancing-angle x-ray diffraction measurements and energy-dispersive spectroscopy analysis confirmed substantial loss of zinc from the samples where CdCl2 passivation was carried out after ZnTe:N film deposition.

  3. Characterization of large cadmium zinc telluride crystals grown by traveling heater method

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Iniewski, K.

    2008-01-01

    The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions/precipitates of these c......The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions...

  4. Evaluation of Fully 3-D Emission Mammotomography With a Compact Cadmium Zinc Telluride Detector

    OpenAIRE

    Brzymialkiewicz, Caryl N.; Tornai, Martin P.; McKinley, Randolph L.; Bowsher, James E.

    2005-01-01

    A compact, dedicated cadmium zinc telluride (CZT) gamma camera coupled with a fully three-dimensional (3-D) acquisition system may serve as a secondary diagnostic tool for volumetric molecular imaging of breast cancers, particularly in cases when mammographic findings are inconclusive. The developed emission mammotomography system comprises a medium field-of-view, quantized CZT detector and 3-D positioning gantry. The intrinsic energy resolution, sensitivity and spatial resolution of the dete...

  5. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L. [University of South Florida, Tampa, FL (United States)

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  6. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers

    OpenAIRE

    Zhenyu Zhang; Bo Wang; Ping Zhou; Renke Kang; Bi Zhang; Dongming Guo

    2016-01-01

    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5?nm and 4.7?nm are achieved for Ra and peak-to-valley (PV) v...

  7. Towards optimization of ACRT schedules applied to the gradient freeze growth of cadmium zinc telluride

    Science.gov (United States)

    Divecha, Mia S.; Derby, Jeffrey J.

    2017-12-01

    Historically, the melt growth of II-VI crystals has benefitted from the application of the accelerated crucible rotation technique (ACRT). Here, we employ a comprehensive numerical model to assess the impact of two ACRT schedules designed for a cadmium zinc telluride growth system per the classical recommendations of Capper and co-workers. The ;flow maximizing; ACRT schedule, with higher rotation, effectively mixes the solutal field in the melt but does not reduce supercooling adjacent to the growth interface. The ACRT schedule derived for stable Ekman flow, with lower rotation, proves more effective in reducing supercooling and promoting stable growth. These counterintuitive results highlight the need for more comprehensive studies on the optimization of ACRT schedules for specific growth systems and for desired growth outcomes.

  8. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers

    Science.gov (United States)

    Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Kang, Renke; Zhang, Bi; Guo, Dongming

    2016-01-01

    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm2, using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements. PMID:27225310

  9. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers.

    Science.gov (United States)

    Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Kang, Renke; Zhang, Bi; Guo, Dongming

    2016-05-26

    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm(2), using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements.

  10. Imaging of the thyroid and parathyroid using a cardiac cadmium zinc telluride camera: Phantom studies.

    Science.gov (United States)

    Miyazaki, Yosuke; Kato, Yasuhiro; Imoto, Akira; Fukuchi, Kazuki

    2017-11-10

    Purpose: Cadmium zinc telluride (CZT) detectors have recently been introduced to the field of clinical nuclear cardiology. However, the feasibility of using them for organs other than the heart remains unclear. The aim of this study was to evaluate the potential of a cardiac CZT camera to acquire thyroid and parathyroid images. We used custom-made phantoms and the currently available standard protocols for CZT, instead of a sodium-iodine scintillation (NaI) camera. Materials and Methods: Thyroid phantoms with or without parathyroid adenomas were made from agar using radiopharmaceuticals (99mTc or 123I) and imaged using CZT and NaI cameras. Using the CZT camera data, we prepared maximum intensity projection (MIP) images and planar equivalent (PE) images. Image counts were compared to those from the NaI camera, and the radioactivity of the phantoms was measured. For parathyroid imaging, three different protocols with the NaI camera were tested using MIP images. Results: For thyroid imaging, MIP could provide images as clear as those obtained from the NaI camera. The radioactivity and image counts correlated better for the PE images than the MIP images, especially for 123I images. We succeeded in obtaining clear parathyroid adenoma images from MIP images using all three protocols. Conclusion: A cardiac CZT camera can effectively perform qualitative and quantitative assessments of the thyroid and parathyroid organs. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  11. Low energy Ar+ ion irradiation induced surface modification in cadmium zinc telluride (CdZnTe)

    Science.gov (United States)

    Tripathi, J. K.; Harilal, S. S.; Hassanein, A.

    2014-09-01

    In this paper, we report on modifications in structural, stoichiometry, and optical properties of cadmium zinc telluride (CdZnTe) crystals due to 1 keV Ar+ ion irradiation as a function of ion fluence, using ion flux of 1.7 × 1017 ions cm-2 s-1. The CdZnTe crystals were irradiated at normal incidence, using fluence range of 8 × 1017-3 × 1019 ions cm-2. Atomic force microscopy studies show sequential change in surface structure as a function of ion fluence, from homogeneously populated nano-hole to micron sized holes on the entire CZT crystal surface. These holes are well geometrically defined and most of them are rectangular in shape. X-ray photoelectron spectroscopy studies show a reduction in Zn at % while Raman and photoluminescence studies show almost complete depletion of Te inclusions and slight red shifts, respectively, due to ion irradiations. Schottky diode radiation detectors fabricated from such defect free CZT crystals will show significantly higher energy resolution.

  12. Cadmium zinc telluride based infrared interferometry for X-ray detection

    Energy Technology Data Exchange (ETDEWEB)

    Lohstroh, A., E-mail: A.Lohstroh@surrey.ac.uk; Della Rocca, I. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Parsons, S. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); AWE Aldermaston, Reading RG7 4PR (United Kingdom); Langley, A.; Shenton-Taylor, C.; Blackie, D. [AWE Aldermaston, Reading RG7 4PR (United Kingdom)

    2015-02-09

    Cadmium Zinc Telluride (CZT) is a wide band gap semiconductor for room temperature radiation detection. The electro-optic Pockels effect of the material has been exploited in the past to study electric field non-uniformities and their consequence on conventional detector signals in CZT, by imaging the intensity distribution of infrared (IR) light transmitted through a device placed between crossed polarizers. Recently, quantitative monitoring of extremely high intensity neutron pulses through the change of transmitted IR intensity was demonstrated, offering the advantage to place sensitive electronics outside the measured radiation field. In this work, we demonstrate that X-ray intensity can be deduced directly from measuring the change in phase of 1550 nm laser light transmitted through a 7 × 7 × 2 mm{sup 3} CZT based Pockels cell in a simple Mach Zehnder interferometer. X-rays produced by a 50 kVp Mo X-ray tube incident on the CZT cathode surface placed at 7 mm distance cause a linearly increasing phase shift above 0.3 mA tube current, with 1.58 ± 0.02 rad per mA for an applied bias of 500 V across the 2 mm thick device. Pockels images confirm that the sample properties are in agreement with the literature, exhibiting electric field enhancement near the cathode under irradiation, which may cause the non-linearity at low X-ray tube anode current settings. The laser used to probe the X-ray intensity causes itself some space charge, whose spatial distribution does not seem to be exclusively determined by the incident laser position, i.e., charge carrier generation location, with respect to the electrodes.

  13. Evaluation of fully 3-D emission mammotomography with a compact cadmium zinc telluride detector.

    Science.gov (United States)

    Brzymialkiewicz, Caryl N; Tornai, Martin P; McKinley, Randolph L; Bowsher, James E

    2005-07-01

    A compact, dedicated cadmium zinc telluride (CZT) gamma camera coupled with a fully three-dimensional (3-D) acquisition system may serve as a secondary diagnostic tool for volumetric molecular imaging of breast cancers, particularly in cases when mammographic findings are inconclusive. The developed emission mammotomography system comprises a medium field-of-view, quantized CZT detector and 3-D positioning gantry. The intrinsic energy resolution, sensitivity and spatial resolution of the detector are evaluated with Tc-99m (140 keV) filled flood sources, capillary line sources, and a 3-D frequency-resolution phantom. To mimic realistic human pendant, uncompressed breast imaging, two different phantom shapes of an average sized breast, and three different lesion diameters are imaged to evaluate the system for 3-D mammotomography. Acquisition orbits not possible with conventional emission, or transmission, systems are designed to optimize the viewable breast volume while improving sampling of the breast and anterior chest wall. Complications in camera positioning about the patient necessitate a compromise in these two orbit design criteria. Image quality is evaluated with signal-to-noise ratios and contrasts of the lesions, both with and without additional torso phantom background. Reconstructed results indicate that 3-D mammotomography, incorporating a compact CZT detector, is a promising, dedicated breast imaging technique for visualization of tumors imaging parameters. Qualitatively, imaging breasts with realistic torso backgrounds (out-of-field activity) substantially alters image characteristics and breast morphology unless orbits which improve sampling are utilized. In practice, the sampling requirement may be less strict than initially anticipated.

  14. Crystal Growth, Characterization and Fabrication of Cadmium Zinc Telluride-based Nuclear Detectors

    Science.gov (United States)

    Krishna, Ramesh M.

    In today's world, nuclear radiation is seeing more and more use by humanity as time goes on. Nuclear power plants are being built to supply humanity's energy needs, nuclear medical imaging is becoming more popular for diagnosing cancer and other diseases, and control of weapons-grade nuclear materials is becoming more and more important for national security. All of these needs require high-performance nuclear radiation detectors which can accurately measure the type and amount of radiation being used. However, most current radiation detection materials available commercially require extensive cooling, or simply do not function adequately for high-energy gamma-ray emitting nuclear materials such as uranium and plutonium. One of the most promising semiconductor materials being considered to create a convenient, field-deployable nuclear detector is cadmium zinc telluride (CdZnTe, or CZT). CZT is a ternary semiconductor compound which can detect high-energy gamma-rays at room temperature. It offers high resistivity (≥ 1010 O-cm), a high band gap (1.55 eV), and good electron transport properties, all of which are required for a nuclear radiation detector. However, one significant issue with CZT is that there is considerable difficulty in growing large, homogeneous, defect-free single crystals of CZT. This significantly increases the cost of producing CZT detectors, making CZT less than ideal for mass-production. Furthermore, CZT suffers from poor hole transport properties, which creates significant problems when using it as a high-energy gamma-ray detector. In this dissertation, a comprehensive investigation is undertaken using a successful growth method for CZT developed at the University of South Carolina. This method, called the solvent-growth technique, reduces the complexity required to grow detector-grade CZT single crystals. It utilizes a lower growth temperature than traditional growth methods by using Te as a solvent, while maintaining the advantages of

  15. Bulk growth and surface characterization of epitaxy ready cadmium zinc telluride substrates for use in IR imaging applications

    Science.gov (United States)

    Flint, J. P.; Martinez, B.; Betz, T. E. M.; Mackenzie, J.; Kumar, F. J.; Burgess, L.

    2017-02-01

    Cadmium Zinc Telluride (Cd1-xZnxTe or CZT) is a compound semiconductor substrate material that has been used for infrared detector (IR) applications for many years. CZT is a perfect substrate for the epitaxial growth of Mercury Cadmium Telluride (Hg1-xCdxTe or MCT) epitaxial layers and remains the material of choice for many high performance IR detectors and focal plane arrays that are used to detect across wide IR spectral bands. Critical to the fabrication of high performance MCT IR detectors is a high quality starting CZT substrate, this being a key determinant of epitaxial layer crystallinity, defectivity and ultimately device electro-optical performance. In this work we report on a new source of substrates suitable for IR detector applications, grown using the Travelling Heater Method (THM). This proven method of crystal growth has been used to manufacture high quality IR specification CZT substrates where industry requirements for IR transmission, dislocations, tellurium precipitates and copper impurity levels have been met. Results will be presented for the chemo-mechanical (CMP) polishing of CZT substrates using production tool sets that are identical to those that are used to produce epitaxy-ready surface finishes on related IR compound semiconductor materials such as GaSb and InSb. We will also discuss the requirements to scale CZT substrate manufacture and how with a new III-V like approach to both CZT crystal growth and substrate polishing, we can move towards a more standardized product and one that can ultimately deliver a standard round CZT substrate, as is the case for competing IR materials such as GaSb, InSb and InP.

  16. Improved Sensitization of Zinc Oxide Nanorods by Cadmium Telluride Quantum Dots through Charge Induced Hydrophilic Surface Generation

    Directory of Open Access Journals (Sweden)

    Karthik Laxman

    2014-01-01

    Full Text Available This paper reports on UV-mediated enhancement in the sensitization of semiconductor quantum dots (QDs on zinc oxide (ZnO nanorods, improving the charge transfer efficiency across the QD-ZnO interface. The improvement was primarily due to the reduction in the interfacial resistance achieved via the incorporation of UV light induced surface defects on zinc oxide nanorods. The photoinduced defects were characterized by XPS, FTIR, and water contact angle measurements, which demonstrated an increase in the surface defects (oxygen vacancies in the ZnO crystal, leading to an increase in the active sites available for the QD attachment. As a proof of concept, a model cadmium telluride (CdTe QD solar cell was fabricated using the defect engineered ZnO photoelectrodes, which showed ∼10% increase in photovoltage and ∼66% improvement in the photocurrent compared to the defect-free photoelectrodes. The improvement in the photocurrent was mainly attributed to the enhancement in the charge transfer efficiency across the defect rich QD-ZnO interface, which was indicated by the higher quenching of the CdTe QD photoluminescence upon sensitization.

  17. Experimental Evaluation And Simulation Of Multi-pixel Cadmium-zinc-telluride Hard-x-ray Detectors

    CERN Document Server

    Gaskin, J A

    2004-01-01

    This dissertation describes the evaluation of many-pixel Cadmium-Zinc-Telluride (CdZnTe) hard-X-ray detectors for future use with the High Energy Replicated Optics (HERO) telescope being developed at Marshall Space Flight Center. The detector requirements for the HERO application are good energy resolution (sufficient to resolve cyclotron features and nuclear lines), spatial resolution of ∼200 μm, minimal charge loss of absorbed X rays, and minimal sensitivity to the background environment. This research concentrates on assessing the suitability of these detectors for the focus of HERO, and includes the development of a simulation of the physics involved in an X-ray-detector interaction, a study of the intrinsic material properties, measurements with prototype detectors such as the energy and spatial resolution, charge loss, and X-ray background reduction through 3-dimensional depth sensing. Two types of detectors were available for evaluation. The first type includes 1-mm and 2-mm thick 4 x 4 ...

  18. 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.)

  19. Influence of proton-pump inhibitors on stomach wall uptake of 99mTc-tetrofosmin in cadmium-zinc-telluride SPECT myocardial perfusion imaging.

    Science.gov (United States)

    Mouden, Mohamed; Rijkee, Karlijn S; Schreuder, Nanno; Timmer, Jorik R; Jager, Pieter L

    2015-02-01

    Proton-pump inhibitors (PPIs) induce potentially interfering stomach wall activity in single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) with technetium-99m ((99m)Tc)-sestamibi. However, no data are available for (99m)Tc-tetrofosmin. We assessed the influence of prolonged (>2 weeks) PPI use on the stomach wall uptake of (99m)Tc-tetrofosmin in patients referred for stress MPI with a cadmium-zinc-telluride-based SPECT camera and its relation with dyspepsia symptoms. Consecutive patients (n=127) underwent a 1-day adenosine stress-first SPECT-MPI with (99m)Tc-tetrofosmin, of whom 54 (43%) patients had been on PPIs for more than 2 weeks. Stomach wall activity was identified on stress SPECT using computed tomographic attenuation maps and was scored using a four-point grading scale into clinically relevant (scores 2 or 3) or nonrelevant (scores 0 or 1).Patients on PPIs had stomach wall uptake more frequently as compared with patients not using PPIs (22 vs. 7%, P=0.017). Dyspepsia was similar in both groups. Prolonged use of PPIs is associated with stomach wall uptake of (99m)Tc-tetrofosmin in stress cadmium-zinc-telluride-SPECT images. Gastric symptoms were not associated with stomach wall uptake.

  20. Investigating the effect of characteristic x-rays in cadmium zinc telluride detectors under breast computerized tomography operating conditions.

    Science.gov (United States)

    Glick, Stephen J; Didier, Clay

    2013-10-14

    A number of research groups have been investigating the use of dedicated breast computerized tomography (CT). Preliminary results have been encouraging, suggesting an improved visualization of masses on breast CT as compared to conventional mammography. Nonetheless, there are many challenges to overcome before breast CT can become a routine clinical reality. One potential improvement over current breast CT prototypes would be the use of photon counting detectors with cadmium zinc telluride (CZT) (or CdTe) semiconductor material. These detectors can operate at room temperature and provide high detection efficiency and the capability of multi-energy imaging; however, one factor in particular that limits image quality is the emission of characteristic x-rays. In this study, the degradative effects of characteristic x-rays are examined when using a CZT detector under breast CT operating conditions. Monte Carlo simulation software was used to evaluate the effect of characteristic x-rays and the detector element size on spatial and spectral resolution for a CZT detector used under breast CT operating conditions. In particular, lower kVp spectra and thinner CZT thicknesses were studied than that typically used with CZT based conventional CT detectors. In addition, the effect of characteristic x-rays on the accuracy of material decomposition in spectral CT imaging was explored. It was observed that when imaging with 50-60 kVp spectra, the x-ray transmission through CZT was very low for all detector thicknesses studied (0.5-3.0 mm), thus retaining dose efficiency. As expected, characteristic x-ray escape from the detector element of x-ray interaction increased with decreasing detector element size, approaching a 50% escape fraction for a 100 μm size detector element. The detector point spread function was observed to have only minor degradation with detector element size greater than 200 μm and lower kV settings. Characteristic x-rays produced increasing distortion

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

    Science.gov (United States)

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

    2013-02-01

    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 < 0.001). This larger extent was mainly observed in 50 obese patients who were in the (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.

  2. Investigation of the Internal Electric Field in Cadmium Zinc Telluride Detectors Using the Pockels Effect and the Analysis of Charge Transients

    Science.gov (United States)

    Groza, Michael; Krawczynski, Henic; Garson, Alfred, III; Martin, Jerrad W.; Lee, Kuen; Li, Qiang; Beilicke, Matthias; Cui, Yunlong; Buliga, Vladimir; Guo, Mingsheng; hide

    2010-01-01

    The Pockels electro-optic effect can be used to investigate the internal electric field in cadmium zinc telluride (CZT) single crystals that are used to fabricate room temperature x and gamma radiation detectors. An agreement is found between the electric field mapping obtained from Pockels effect images and the measurements of charge transients generated by alpha particles. The Pockels effect images of a CZT detector along two mutually perpendicular directions are used to optimize the detector response in a dual anode configuration, a device in which the symmetry of the internal electric field with respect to the anode strips is of critical importance. The Pockels effect is also used to map the electric field in a CZT detector with dual anodes and an attempt is made to find a correlation with the simulated electric potential in such detectors. Finally, the stress-induced birefringence effects seen in the Pockels images are presented and discussed.

  3. 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...

  4. Cadmium telluride quantum dots advances and applications

    CERN Document Server

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  5. 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.)

  6. Diagnostic accuracy of cadmium-zinc-telluride-based myocardial perfusion SPECT: impact of attenuation correction using a co-registered external computed tomography.

    Science.gov (United States)

    Caobelli, Federico; Akin, Muharrem; Thackeray, James T; Brunkhorst, Thomas; Widder, Julian; Berding, Georg; Burchert, Ina; Bauersachs, Johann; Bengel, Frank M

    2016-09-01

    Computed tomography (CT)-based attenuation correction (AC) improves the accuracy of standard myocardial perfusion SPECT. Most dedicated cadmium-zinc-telluride (CZT) SPECT cameras are not equipped with an integrated CT component. We aimed to determine the impact of AC on diagnostic performance of CZT SPECT using co-registration with an external low-dose CT. Sixty patients underwent CZT SPECT (GE Discovery 530c) with (99m)Tc-sestamibi at rest and following regadenoson stress. Using commercial software, SPECT images were co-registered with a low-dose CT acquired on a separate system (GE Discovery 670NMCT). Attenuation corrected and non-corrected (NC) images were reconstructed using an iterative algorithm. Accuracy was measured in 44 patients who had undergone invasive angiography within 6 months. Normalcy was compared in the remaining 16 patients who had a low pre-test likelihood (<5%) of coronary artery disease (CAD). Summed stress and rest scores were significantly lower in AC images (9 ± 8 vs. 13 ± 9 and 6 ± 7 vs. 10 ± 9, P = 0.01), while summed difference score did not differ. According to angiography, 38 patients had significant CAD in 71 vascular territories. Attenuation correction improved accuracy globally (P = 0.03) and in RCA territory (P = 0.008). Specificity improved both globally (100 vs. 40%, P < 0.05) and in each individual territory (LAD: 63 vs. 36%, LCX: 70 vs. 33%, RCA: 81 vs. 19%, P < 0.01). Normalcy was 100% for AC and 62.5% for NC images (P < 0.05). Attenuation correction with a co-registered external CT is feasible using CZT cameras and improves diagnostic accuracy mostly by improving specificity over uncorrected images. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  7. Prognostic Value of Myocardial Perfusion Imaging with a Cadmium-Zinc-Telluride SPECT Camera in Patients Suspected of Having Coronary Artery Disease.

    Science.gov (United States)

    Engbers, Elsemiek M; Timmer, Jorik R; Mouden, Mohamed; Knollema, Siert; Jager, Pieter L; Ottervanger, Jan Paul

    2017-09-01

    The prognostic value of myocardial perfusion imaging (MPI) with the cadmium-zinc-telluride (CZT) SPECT camera is not well established. Therefore, the aim of the current study was to evaluate the prognostic value of MPI performed with a CZT SPECT camera in a large cohort of patients suspected of having coronary artery disease. Methods: Consecutive symptomatic stable patients (n = 4,057) without a history of coronary artery disease underwent CZT SPECT MPI. During a median follow-up of 2.4 y (25th-75th percentile, 1.7-3.4), patients were monitored for primary (nonfatal myocardial infarction and cardiac mortality) and secondary outcomes (late revascularization [>90 d after scanning] and primary outcome). Results: Patients with normal perfusion demonstrated low annual event rates (primary outcome, 0.2%; secondary outcome, 0.6%). Annual event rates increased with the extent of abnormality of myocardial perfusion. In patients with small ischemic perfusion defects, annual event rates were 0.7% and 2.8% for the primary and secondary outcome, respectively. In patients with moderate or large ischemic perfusion defects, these event rates were 1.2% and 4.3%, respectively. After multivariate analysis, the risk for events was significantly associated with the extent of ischemia (hazard ratio for small ischemic defects: 2.2, 95% confidence interval [CI], 0.9-5.9 and 4.6, 95% CI, 2.8-7.6, for primary and secondary outcomes, respectively; hazard ratio for moderate or large ischemic defects: 4.0, 95% CI, 1.5-10.5 and 12.1, 95% CI, 7.2-20.2, for primary and secondary outcomes, respectively). Conclusion: Our findings show that MPI acquired with a CZT SPECT camera provides excellent prognostic information, with low event rates in patients with normal myocardial perfusion. In patients with abnormal SPECT MPI, the extent of abnormality is independently associated with an increased risk of events. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  8. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-01

    Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for Polycrystalline Thin-Film Research: Cadmium Telluride at the National Center for Photovoltaics.

  9. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2013-06-01

    This National Center for Photovoltaics sheet describes the capabilities of its polycrystalline thin-film research in the area of cadmium telluride. The scope and core competencies and capabilities are discussed.

  10. Recent developments in cadmium mercury telluride infrared detectors

    Science.gov (United States)

    Charlton, D. E.

    1982-09-01

    A II-VI compound, cadmium mercury telluride, has dominated recent advances in the detection of infrared radiation. Although the main application is in thermal imaging, other applications include instrumentation and guidance. In this paper we describe the history of the development of cadmium mercury telluride as a detector material, with emphasis on the importance of material parameters and the role of the material scientist. High purity material, free from defects and of good crystal quality, is needed in order to ensure good minority carrier lifetime. Because of the segregation of impurities during solidification, material produced by the Bridgman technique offers considerable advantages over material produced by cast recrystallize techniques. Detectors based on a principle established by C.T. Elliott of the RSRE, Malvern, have led to families of thermal imagers that produce near perfect imagery. These detectors incorporate signal processing in the element by providing the time delay and integration functions that are normally performed off the focal plane in conventional serial scanned systems. A particular requirement of these SPRITE detectors is for long minority carrier lifetime. This has called for improvements in both material and fabrication technology which have led to an advanced technology that has benefited all aspects of the manufacture of cadmium mercury telluride detectors. Near background limited performance will be described in both the 8-14 and the 3-5 μm atmospheric transmission bands. There is, however, more image blurring in the 3-5 μm band than occurs in the 8-14 μm band. The direction of present work is towards detectors combining cadmium mercury telluride elements with advanced integrated circuits to provide more complex signal processing in the focal plane. This has been driven by the need to improve the sensitivity of thermal imaging systems where the scan rates are too low to allow useful time delay and integration in SPRITE detectors

  11. Bis(3-methyl-2-pyridyl)ditelluride and pyridyl tellurolate complexes of zinc, cadmium, mercury: Synthesis, characterization and their conversion to metal telluride nanoparticles.

    Science.gov (United States)

    Kedarnath, G; Jain, Vimal K; Wadawale, Amey; Dey, Gautam K

    2009-10-21

    Treatment of an acetonitrile solution of metal chloride with bis(3-methyl-2-pyridyl)ditelluride, [Te(2)(pyMe)(2)], in the same solvent yielded complexes of composition [MCl(2){Te(2)(pyMe)(2)}] (M = Zn or Cd) whereas reactions of [MCl(2)(tmeda)] with NaTepyR (R = H or Me) gave tellurolate complexes of the general formula [M(TepyR)(2)] (M = Cd or Hg). When the cadmium complex [Cd(Tepy)(2)] was crystallized in the presence of excess tmeda, [Cd(Tepy)(2)(tmeda)] was formed exclusively. These complexes were characterized by elemental analyses, uv-vis, (1)H NMR data. The crystal structures of [ZnCl(2){Te(2)(pyMe)(2)}] and [Cd(Tepy)(2)(tmeda)] were established by single crystal X-ray diffraction. In the former zinc is coordinated to nitrogen atoms of the pyridyl group, while in the latter the coordination environment around tetrahedral cadmium is defined by the two neutral nitrogen atoms of tmeda, and two pyridyl tellurolate ligands. Thermal behavior of some of these complexes was studied by thermogravimetric analysis. Pyrolysis of [M(Tepy)(2)] in a furnace or in coordinating solvents such as hexadecylamine/tri-n-octylphosphine oxide (HDA/TOPO) at 350 and 160 degrees C, respectively gave MTe nanoparticles, which were characterized by uv-vis, photoluminiscence, XRD, EDAX and TEM.

  12. Detecting Triple-Vessel Disease with Cadmium Zinc Telluride-Based Single-Photon Emission Computed Tomography Using the Intensity Signal-to-Noise Ratio between Rest and Stress Studies

    Directory of Open Access Journals (Sweden)

    Yu-Hua Dean Fang

    2017-01-01

    Full Text Available The purpose of this study was to investigate if a novel parameter, the stress-to-rest ratio of the signal-to-noise ratio (RSNR obtained with a cadmium zinc telluride (CZT SPECT scanner, could be used to distinguish triple-vessel disease (TVD patients. Methods. One hundred and two patients with suspected coronary artery disease were retrospectively involved. Each subject underwent a Tl-201 SPECT scan and subsequent coronary angiography. Subjects were separated into TVD (n=41 and control (n=61 groups based on coronary angiography results using 50% as the stenosis cutoff. The RSNR was calculated by dividing the stress signal-to-noise ratio (SNR by the rest SNR. Summed scores were calculated using quantitative perfusion SPECT (QPS for all subjects. Results. The RSNR in the TVD group was found to be significantly lower than that in the control group (0.83 ± 0.15 and 1.06 ± 0.17, resp.; P<0.01. Receiver-operating characteristic (ROC analysis showed that RSNR can detect TVD more accurately than the summed difference score with higher sensitivity (85% versus 68%, higher specificity (90% versus 72%, and higher accuracy (88% versus 71%. Conclusion. The RSNR may serve as a useful index to assist the diagnosis of TVD when a fully automatic quantification method is used in CZT-based SPECT studies.

  13. Transient Response of Cadmium Telluride Modules to Light Exposure: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Deline, C.; del Cueto, J.; Albin, D. S.; Petersen, C.; Tyler, L.; TamizhMani, G.

    2011-07-01

    Commercial cadmium telluride (CdTe) photovoltaic (PV) modules from three different manufacturers were monitored for performance changes during indoor and outdoor light-exposure. Short-term transients in Voc were recorded on some modules, with characteristic times of ~1.1 hours. Outdoor performance data shows a similar drop in Voc after early morning light exposure. Preliminary analysis of FF changes show light-induced changes on multiple time scales, including a long time scale.

  14. 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, cadmium ... By conducting several trials optimization of the adsorption, reaction and rinsing time duration for CdTe thin film deposition was ... 3.1 Reaction mechanism. CdTe thin films were grown on micro ...

  15. Synthesis of ultra-long cadmium telluride nanotubes via combinational chemical transformation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kee-Ryung; Cho, Hong-Baek; Choa, Yong-Ho, E-mail: choa15@hanyang.ac.kr

    2017-03-01

    Synthesis of high-throughput cadmium telluride (CdTe) nanotubes with an ultra-long aspect ratio is presented via a combination process concept combined with electrospinning, electrodeposition, and cationic exchange reaction. Ultra-long sacrificial silver (Ag) nanofibers were synthesized by electrospinning involving two-step calcination, and were then electrodeposited to create silver telluride nanotubes. These nanotubes underwent cationic exchange reaction in cadmium nitrate tetrahydrate solution with the aid of a ligand, tributylphosphine (TBP). Analysis showed that ultra-long pure zinc blende CdTe nanotubes were obtained with controlled dimension and uniform morphology. The thermodynamic driving force induced by the coordination of methanol solvent and TBP attributed to overcome the kinetic barrier between Ag{sub 2}Te and CdTe nanotubes, facilitating the synthesis of CdTe nanotubes. This synthetic process involving a topotactic reaction route paves a way for high-throughput extended synthesis of new chalcogenide hollow nanotubes for application in photodetectors and solar cells. - Highlights: • High throughput synthetic route of hollow CdTe nanotubes with ultra-long aspect ratio. • Chemical combination of electrospinning, electrodeposition & cation exchange reaction. • Pure zinc blende CdTe by controlled dimension & structural variation of Ag nanofibers. • Potential for the high throughput synthesis of new exotic chalcogenide nanotubes.

  16. Megapixel mercury cadmium telluride focal plane arrays for infrared imaging out to 12 microns Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the fabrication of large format, long wave infrared (LWIR) mercury cadmium telluride (HgCdTe or MCT) detector arrays where the cutoff wavelength is...

  17. Theoretical study of bismuth-doped cadmium telluride

    Science.gov (United States)

    Menendez-Proupin, E.; Rios-Gonzalez, J. A.; Pena, J. L.

    Cadmium telluride heavily doped with bismuth has been proposed as an absorber with an intermediate band for solar cells. Increase in the photocurrent has been shown recently, although the overall cell efficiency has not improved. In this work, we study the electronic structure and the formation energies of the defects associated to bismuth impurities. We have performed electronic structure calculations within generalized density functional theory, using the exchange-correlation functional HSE(w) , where the range-separation parameter w has been tuned to reproduce the CdTe bandgap. Improving upon previous reports, we have included the spin-orbit interaction, which modifies the structure of the valence band and the energy levels of bismuth. We have found that interstitial Bi (Bii) tends to occupy Cd vacancies, cadmium substitution (BiCd) creates single donor level, while tellurium substitution (BiTe) is a shallow single acceptor. We investigate the interaction between these point defects and how can they be combined to create a partially filled intermediate band. Supported by FONDECYT Grant 1130437, CONACYT-SENER SUSTENTABILIDAD ENERGETICA/project CeMIE-Sol PY-207450/25 and PY-207450/26. JARG acknowledges CONACYT fellowship for research visit. Powered@NLHPC (ECM-02).

  18. (CdnTen) and Cadmium Zinc Telluride

    African Journals Online (AJOL)

    Bheema

    solar cells, integrated optics and electro-optics devices. Hence, there are different experimental and theoretical studies on this group using various techniques or methods. A number of theoretical and experimental attempts (Jianguang, 2009) have been made to determine the structure and properties of small CdnTen and ...

  19. 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.

  20. Brief review of cadmium telluride-based photovoltaic technologies

    Science.gov (United States)

    Başol, Bülent M.; McCandless, Brian

    2014-01-01

    Cadmium telluride (CdTe) is the most commercially successful thin-film photovoltaic technology. Development of CdTe as a solar cell material dates back to the early 1980s when ˜10% efficient devices were demonstrated. Implementation of better quality glass, more transparent conductive oxides, introduction of a high-resistivity transparent film under the CdS junction-partner, higher deposition temperatures, and improved Cl-treatment, doping, and contacting approaches yielded >16% efficient cells in the early 2000s. Around the same time period, use of a photoresist plug monolithic integration process facilitated the demonstration of the first 11% efficient module. The most dramatic advancements in CdTe device efficiencies were made during the 2013 to 2014 time frame when small-area cell conversion efficiency was raised to 20% range and a champion module efficiency of 17% was reported. CdTe technology is attractive in terms of its limited life-cycle greenhouse gas and heavy metal emissions, small carbon footprint, and short energy payback times. Limited Te availability is a challenge for the growth of this technology unless Te utilization rates are greatly enhanced along with device efficiencies.

  1. 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.

  2. zinc, chromium, cadmium

    African Journals Online (AJOL)

    2016-06-30

    Jun 30, 2016 ... determined with an Atomic Absorption Spectrophotometer, and the results showed significantly (P<0.05) lower concentrations of Zn ... toxic in moderate doses and is a potent antagonist of several essential minerals including calcium, iron, copper and zinc. (Lettow, 2004). ... MATERIALS AND METHODS.

  3. Prospects of novel front and back contacts for high efficiency cadmium telluride thin film solar cells from numerical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Matin, M.A. [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Electrical and Electronics Engineering, Chittagong University of Engineering and Technology (CUET), Chittagong (Bangladesh); Mannir Aliyu, M.; Quadery, Abrar H. [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Amin, Nowshad [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Center of Excellence for Research in Engineering Materials (CEREM), College of Engineering, King Saud University, Riyadh 11421 (Saudi Arabia)

    2010-09-15

    Cadmium telluride (CdTe) thin film solar cell has long been recognized as a leading photovoltaic candidate for its high efficiency and low cost. A numerical simulation has been performed using AMPS-1D simulator to explore the possibility of higher efficiency and stable CdS/CdTe cell among several cell structures with indium tin oxide (ITO) and cadmium stannate (Cd{sub 2}SnO{sub 4}) as front contact material, tin oxide (SnO{sub 2}), zinc oxide (ZnO) and zinc stannate (Zn{sub 2}SnO{sub 4}) as buffer layer, and silver (Ag) or antimony telluride (Sb{sub 2}Te{sub 3}) with molybdenum (Mo) or zinc telluride (ZnTe) with aluminium (Al) as back contact material. The cell structure ITO/i-ZnO/CdS/CdS{sub x}Te{sub 1-x}/CdTe/Ag has shown the best conversion efficiency of 16.9% (Voc=0.9 V, Jsc=26.35 mA/cm{sup 2}, FF=0.783). This analysis has shown that ITO as front contact material, ZnO as buffer layer and ZnTe or Sb{sub 2}Te{sub 3} back surface reflector (BSR) are suitable material system for high efficiency (>15%) and stable CdS/CdTe cells. The cell normalized efficiency linearly decreased at a temperature gradient of -0.25%/ C for ZnTe based cells, and at -0.40%/ C for other cells. (author)

  4. 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.

  5. One-Dimensional Fast Transient Simulator for Modeling Cadmium Sulfide/Cadmium Telluride Solar Cells

    Science.gov (United States)

    Guo, Da

    Solar energy, including solar heating, solar architecture, solar thermal electricity and solar photovoltaics, is one of the primary alternative energy sources to fossil fuel. Being one of the most important techniques, significant research has been conducted in solar cell efficiency improvement. Simulation of various structures and materials of solar cells provides a deeper understanding of device operation and ways to improve their efficiency. Over the last two decades, polycrystalline thin-film Cadmium-Sulfide and Cadmium-Telluride (CdS/CdTe) solar cells fabricated on glass substrates have been considered as one of the most promising candidate in the photovoltaic technologies, for their similar efficiency and low costs when compared to traditional silicon-based solar cells. In this work a fast one dimensional time-dependent/steady-state drift-diffusion simulator, accelerated by adaptive non-uniform mesh and automatic time-step control, for modeling solar cells has been developed and has been used to simulate a CdS/CdTe solar cell. These models are used to reproduce transients of carrier transport in response to step-function signals of different bias and varied light intensity. The time-step control models are also used to help convergence in steady-state simulations where constrained material constants, such as carrier lifetimes in the order of nanosecond and carrier mobility in the order of 100 cm2/Vs, must be applied.

  6. The effect of different annealing temperatures on tin and cadmium telluride phases obtained by a modified chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Anderson Fuzer [Departamento de Química, CCE, Universidade Federal do Espírito Santo, Campus Goiabeiras, 29075-910 Vitória, Espírito Santo (Brazil); Porto, Arilza de Oliveira, E-mail: arilzaporto@yahoo.com.br [Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Magela de Lima, Geraldo [Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Paniago, Roberto [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Ardisson, José Domingos [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Belo Horizonte, Minas Gerais (Brazil)

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ► Synthesis of cadmium and tin telluride. ► Chemical route to obtain pure crystalline cadmium and tin telluride. ► Effect of the annealing temperature on the crystalline phases. ► Removal of tin oxide as side product through thermal treatment. -- Abstract: In this work tin and cadmium telluride were prepared by a modification of a chemical route reported in the literature to obtain metallacycles formed by oxidative addition of tin-tellurium bonds to platinum (II). Through this procedure it was possible to obtain tin and cadmium telluride. X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the crystalline phases obtained as well as the presence of side products. In the case of tin telluride it was identified potassium chloride, metallic tellurium and tin oxide as contaminants. The tin oxidation states were also monitored by {sup 119}Sn Mössbauer spectroscopy. The annealing in hydrogen atmosphere was chosen as a strategy to reduce the tin oxide and promote its reaction with the excess of tellurium present in the medium. The evolution of this tin oxide phase was studied through the annealing of the sample at different temperatures. Cadmium telluride was obtained with high degree of purity (98.5% relative weight fraction) according to the Rietveld refinement of X-ray diffraction data. The modified procedure showed to be very effective to obtain amorphous tin and cadmium telluride and the annealing at 450 °C has proven to be useful to reduce the amount of oxide produced as side product.

  7. Influence of hydrogen on hydrogenated cadmium telluride optical spectra

    Energy Technology Data Exchange (ETDEWEB)

    Pociask, M.; Polit, J.; Sheregii, E.; Cebulski, J. [Institute of Physics, University of Rzeszow (Poland); Kisiel, A. [Institute of Physics, Jagiellonian University, Krakow (Poland); Mycielski, A. [Institute of Physics, PAS, Warszawa (Poland); Morgiel, J. [Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences, Krakow (Poland); Piccinini, M. [INFN-Laboratori Nazionali di Frascati (Italy); Dipartimento Scienze Geologiche, Universita Roma Tre, Rome (Italy); Marcelli, A.; Robouch, B.; Guidi, M.C. [INFN-Laboratori Nazionali di Frascati (Italy); Savchyn, V. [Ivan Franko Lviv National University (Ukraine); Izhnin, I.I. [Institute for Materials SRC ' ' Carat' ' , Lviv (Ukraine); Zajdel, P. [Institute of Fizyki, University of Silesia, 4 Uniwersytecka Str., 40-007 Katowice (Poland); Nucara, A. [Universita' di Roma La Sapienza, P. le Aldo Moro 1, Rome (Italy)

    2009-09-15

    The presence of oxygen impurity in semiconducting materials affects the electrical properties of crystals and significantly limits their application. To remove oxygen impurity, ultra-pure hydrogen is used while growing Te-containing crystals such as CdTe, CdZnTe, and ZnTe. The hydrogenation of CdTe crystals is a technological process that purifies the basic material from oxygen, mainly cadmium and tellurium oxide compounds incorporated in CdTe crystalline lattice. In the present work we analyses the deformations induced by hydrogen and oxygen atoms in CdTe crystals looking at their influence on the near fundamental band (NFB), middle infrared (MIR) and far infrared (FIR) reflectivity spectra as well as on cathodoluminescence (CL) spectra. Comparison of the hydrogenated CdTe phonon structure profiles confirms the presence of hydrogen atoms bounded inside the lattice. The possible localization of hydrogen and oxygen ions within the tetrahedron coordinated lattice is discussed in the framework of a model that shows a good agreement with recent NFB, MIR and FIR experiments carried out on hydrogenated CdTe crystals. Measured reflection spectra in the wavelength range 190-1400 nm (NFB) indicate the appearance in CdTe(H{sub M}) and CdTe(H{sub L}) of additional maxima at 966 nm related to the electron transitions from level about 0.2 eV above the valence band. The CL spectra confirmed existence of this electron level. We present a possible H{sub 2} alignment similar to the single H model i.e., over the face (at about 0.38 Aa). For this model the angle from the central atom to the H atoms is equal to 64 which is also close to the bonding angle of CdH{sub 2} (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. SUBSTITUTION OF CADMIUM CYANIDE ELECTROPLATING WITH ZINC CHLORIDE ELECTROPLATING

    Science.gov (United States)

    The study evaluated the zinc chloride electroplating process as a substitute for cadmium cyanide electroplating in the manufacture of industrial connectors and fittings at Aeroquip Corporation. The process substitution eliminates certain wastes, specifically cadmium and cyanide, ...

  9. Cadmium telluride quantum dots as pH-sensitive probes for tiopronin determination

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yunqing; Ye Chao; Zhu Zhenghui [Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing 210009 (China); Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Hu Yuzhu [Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing 210009 (China) and Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China)], E-mail: njhuyuzu@126.com

    2008-03-03

    The pH-sensitive cadmium telluride (CdTe) quantum dots (QDs) were used as proton probes for tiopronin determination. Based on the fluorescence quenching of CdTe QDs caused by tiopronin, a simple, rapid and specific quantitative method was proposed. Under the optimal conditions, the calibration plot of ln(F{sub 0}/F) with concentration of tiopronin was linear in the range of 0.15-20 {mu}g mL{sup -1}(0.92-122.5 {mu}mol L{sup -1}) with correlation coefficient of 0.998. The limit of detection (LOD) (3{sigma}/k) was 0.15 {mu}g mL{sup -1}(0.92 {mu}mol mL{sup -1}). The content of tiopronin in pharmaceutical tablet was determined by the proposed method and the result agreed with that obtained from the oxidation-reduction titration method and the claimed value.

  10. Atomic resolution on the (111 )B surface of mercury cadmium telluride by scanning tunneling microscopy

    Science.gov (United States)

    Zha, Fang-Xing; Hong, Feng; Pan, Bi-Cai; Wang, Yin; Shao, Jun; Shen, Xue-Chu

    2018-01-01

    The real-space atomic surface structure of mercury cadmium telluride was successfully achieved on the (111 )B surface of H g0.78C d0.22Te by ultrahigh-vacuum scanning tunneling microscopy (STM). The work casts light on the reconstructions of the (111 )B surface unraveling a (2 ×2 ) surface reconstruction induced by adatom adsorption of Cd. The other (2 ×2 ) surface reconstruction is clarified to be induced by the single Te vacancy, which is more stable than the reconstruction of multivacancies in contrast to the prevailing view. The simulated STM images are in good agreement with the experiments. We also observed an in situ morphology transition from the (1 ×1 ) structure to those (2 ×2 ) reconstructions, implying the stability of the reconstructions.

  11. A miniature cadmium telluride detector module for continuous monitoring of left-ventricular function.

    Science.gov (United States)

    Hoffer, P B; Berger, H J; Steidley, J; Brendel, A F; Gottschalk, A; Zaret, B L

    1981-02-01

    The authors describe a miniature cadmium telluride (CdTe) detector module for continuous monitoring of ventricular function using an equilibrium radionuclide blood-pool label. The detector and collimator are small, light, and suitable for direct attachment to the chest wall. Clinical studies in 18 patients using a prototype system demonstrated reasonably good correlation with left-ventricular ejection fractions (LVEF) determined by first-pass studies performed with a multicrystal scintillation camera (r = 0.74) and gated equilibrium studies performed with a computerized sodium iodide (Nal) probe (r = 0.76). The CdTe device may prove to be useful in patients in intensive and coronary care units as well as in ambulatory patients.

  12. 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.)

  13. A COMPARATIVE ANALYSIS OF SILICON AND CADMIUM TELLURIDE BASED SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    Amjad Al QASSEM

    2016-12-01

    Full Text Available A compartive analzsis of silicon solar cells and of those containing a CdTe thin film which are widely used in solar energetics, particullarilly, in photovoltaic modules fabrication, is brought in this paper. The silicon is largely used in solar cells fabrication due to the low cost of solar cells production related to the low cost of the semiconductor fabrication and to the advanced material processing technology, when at the same time cadmium telluride has the wide use due to the fact that its fundamental parameters can provide theoretically a high value of efficiency of solar energy conversion into electrical one of 30%. The structure and photoelectrical parameters of silicon solar cells and of those cotaining a thin cadmium telluride layer are considered.ANALIZA COMPARATIVĂ A CELULELOR SOLARE DIN SILICIU ŞI TELURURA DE CADMIUÎn lucrarea de faţă este prezentată analiza comparativă a celulelor solare fabricate din siliciu şi a celor cu strat subţire de CdTe, care sunt pe larg utilizate în energetica solară, în particular la producerea modulelor fotovoltaice. Siliciul este intens folosit în fabricarea celulelor solare datorită costului redus al materialului semiconductor şi tehnologiei avansate de procesare, pe când telurura de cadmiu are o utilizare tot mai largă care, datorită parametrilor fundamentali, poate asigura teoretic o valoare înaltă a eficienţei conversiei energiei solare în cea electrică de (30%. Sunt considerate structura şi parametrii fotoelectrici ai celulelor solare din siliciu şi ai celor cu strat subţire de telurură de cadmiu.

  14. 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.

  15. 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

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Patricia Richter

    2017-09-01

    Full Text Available 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.

  18. The relationship between maternal blood cadmium, zinc levels and ...

    African Journals Online (AJOL)

    The delivery of babies with low birth weight is a prognosis of neonatal mortality, morbidity and poor health outcomes later in life. This study evaluates the levels of cadmium, zinc and calculated cadmium/zinc ratio in non-occupationally exposed pregnant women at delivery and their relationship with birth weight of babies.

  19. Blocking contacts for N-type cadmium zinc telluride

    Science.gov (United States)

    Stahle, Carl M. (Inventor); Parker, Bradford H. (Inventor); Babu, Sachidananda R. (Inventor)

    2012-01-01

    A process for applying blocking contacts on an n-type CdZnTe specimen includes cleaning the CdZnTe specimen; etching the CdZnTe specimen; chemically surface treating the CdZnTe specimen; and depositing blocking metal on at least one of a cathode surface and an anode surface of the CdZnTe specimen.

  20. Cadmium-zinc telluride detector arrays for synchrotron radiation applications

    Science.gov (United States)

    Kakuno, Edson M.; Camarda, Giuseppe S.; Siddons, D. P.

    2004-01-01

    We have begun a program to develop CZT-based detectors optimized for Synchrotron Radiation (SR) applications. SR provides high brightness beams of hard x-rays, typically in the range 5-100keV. Below 10keV, Peltier-cooled silicon detector arrays can provide high throughput with good spectroscopic resolution. At higher energies, only cryo-cooled germanium detectors or scintillation counters are available. Neither are easily available in large arrays, and scintillation counters lack energy resolution. CZT offers a solution to both these problems. Our development has focused on surface preparation and contact definition technologies which minimize device leakage currents while allowing high-definition contact patterns suitable for SR applications. We have used SR also for diagnostic purposes in these developments, both for detector testing and material characterization. X-ray diffraction, Infrared microscopy and photoemission are all relevant SR-based tools which we are using in our work. As an example, we have observed that bromine remains attached to the CZT surface after chemical etching, and is remarkably persistent in the face of surface cleaning and argon ion sputtering, as revealed by photoemission spectroscopy and x-ray absorption spectroscopy.

  1. The Cadmium Zinc Telluride Imager on AstroSat

    Indian Academy of Sciences (India)

    V. Bhalerao

    2017-06-19

    Jun 19, 2017 ... Instrument data, processing pipelines and default products are discussed in section. 4. We conclude by giving brief information about in– orbit performance of the instrument in section 5. 2. Instrument configuration. The instrument consists of four identical independent quadrants A–D, to give design safety ...

  2. The Cadmium Zinc Telluride Imager on AstroSat

    Indian Academy of Sciences (India)

    Inter University Centre for Astronomy and Astrophysics, Pune 411 007, India. S. R. T. M. University, Nanded, 431 606, India. Tata Institute of Fundamental Research, Homi Babha Road, Mumbai 400 005, India. Vikram Sarabhai Space Centre, Thiruvananthapuram 695 022, India. Physical Research Laboratory, Ahmedabad ...

  3. Terahertz-field-induced second harmonic generation through Pockels effect in zinc telluride crystal.

    Science.gov (United States)

    Cornet, Marion; Degert, Jérôme; Abraham, Emmanuel; Freysz, Eric

    2014-10-15

    We report on the second harmonic generation (SHG) of a near-infrared pulse in a zinc telluride crystal through the Pockels effect induced by an intense terahertz pulse. The temporal and angular behaviors of the SHG have been measured and agree well with theoretical predictions. This phenomenon, so far overlooked, makes it possible to generate second harmonic through cascading of two second-order nonlinear phenomena in the near-infrared and terahertz ranges. We also show how this cascading process can be used to sample terahertz pulses.

  4. Physical properties of sublimated zinc telluride thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nazar Abbas, E-mail: nazar_abbas@comsats.edu.pk; Mahmood, Waqar

    2013-10-01

    Zinc telluride (ZnTe) thin films were fabricated by using closed space sublimation (CSS) technique on glass substrate under vacuum. Pre-fabricated ZnTe thin films were doped with silver (Ag) by ion exchange method. X-ray diffraction showed the preferred orientation (111) of ZnTe thin film with polycrystalline behavior. Scanning electron microscope images were taken to estimate the grain boundaries; energy dispersive X-ray results confirmed the Ag composition in doped-ZnTe samples. Electrical measurements were performed to determine the resistivity, mobility and carrier concentrations of un-doped thin films and Ag-doped samples. The electrical resistivity was of the order of 10{sup 6} Ω-cm before doping. Ag-doped ZnTe samples exhibits low resistivity of the order of 10{sup 3} Ω-cm along with a change in the carrier concentrations and mobility as well at room temperature. The angle resolved optical transmission data, taken by spectrophotometer, was used to find the optical properties before and after Ag doping. Energy band gap showed decreasing trend with increasing Ag doping time. - Highlights: • Zinc telluride thin films were grown by closed space sublimation technique. • Ag was doped, by ion exchange process. • Physical properties were investigated before and after doping.

  5. Two-color detector: Mercury-cadmium-telluride as a terahertz and infrared detector

    Energy Technology Data Exchange (ETDEWEB)

    Sizov, F.; Zabudsky, V.; Petryakov, V.; Golenkov, A.; Andreyeva, K.; Tsybrii, Z. [Institute of Semiconductor Physics, 03028 Kiev (Ukraine); Dvoretskii, S. [Institute of Semiconductor Physics of SB RAS, 630090 Novosibirsk (Russian Federation)

    2015-02-23

    In this paper, issues associated with the development of infrared (IR) and terahertz (THz) radiation detectors based on HgCdTe are discussed. Two-color un-cooled and cooled to 78 K narrow-gap mercury-cadmium-telluride semiconductor thin layers with antennas were considered both as sub-THz (sub-THz) direct detection bolometers and 3–10 μm IR photoconductors. The noise equivalent power (NEP) for one of the detectors studied at ν ≈ 140 GHz reaches NEP{sub 300 K} ≈ 4.5 × 10{sup −10} W/Hz{sup 1/2} and NEP{sub 78 K} ≈ 5 × 10{sup −9} W/Hz{sup 1/2}. The same detector used as an IR photoconductor showed the responsivity at temperatures T = 78 K and 300 K with signal-to-noise ratio S/N ≈ 750 and 50, respectively, under illumination by using IR monochromator and globar as a thermal source.

  6. 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.

  7. Directional solidification of mercury cadmium telluride during the second United States Microgravity Payload Mission (USMP-2)

    Energy Technology Data Exchange (ETDEWEB)

    Gillies, D.C.; Lehoczky, S.L.; Szofran, F.R.; Watring, D.A.; Alexander, H.A.; Jerman, G.A. [NASA Marshall Space Flight Center, Huntsville, AL (United States)

    1996-12-31

    As a solid solution semiconductor having a large separation between liquidus and solidus, mercury cadmium telluride (MCT) presents a formidable challenge to crystal growers desiring an alloy of high compositional uniformity. To avoid constitutional supercooling during Bridgman crystal growth it is necessary to solidify slowly in a high temperature gradient region. The necessary translation rate of less than 1 mm/hr results in a situation where fluid flow induced by gravity on earth is a significant factor in material transport. The Advanced Automated Directional Solidification Furnace (AADSF) is equipped to provide the stable thermal environment with a high gradient, and the required slow translation rate needed. Ground based experiments in AADSF show clearly the dominance of flow driven transport. The first flight of AADSF in low gravity on USMP-2 provided an opportunity to test theories of fluid flow in MCT and showed several solidification regimes which are very different from those observed on earth. Residual acceleration vectors in the orbiter during the mission were measured by the Orbital Acceleration Research Experiment (OARE), and correlated well with observed compositional differences in the samples.

  8. 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...

  9. 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%.

  10. Reproductive toxicity and gender differences induced by cadmium telluride quantum dots in an invertebrate model organism

    Science.gov (United States)

    Yan, Si-Qi; Xing, Rui; Zhou, Yan-Feng; Li, Kai-Le; Su, Yuan-Yuan; Qiu, Jian-Feng; Zhang, Yun-Hu; Zhang, Ke-Qin; He, Yao; Lu, Xiao-Ping; Xu, Shi-Qing

    2016-09-01

    Sexual glands are key sites affected by nanotoxicity, but there is no sensitive assay for measuring reproductive toxicity in animals. The aim of this study was to investigate the toxic effects of cadmium telluride quantum dots (CdTe-QDs) on gonads in a model organism, Bombyx mori. After dorsal vein injection of 0.32 nmol of CdTe-QDs per individual, the QDs passed through the outer membranes of gonads via the generation of ROS in the membranes of spermatocysts and ovarioles, as well as internal germ cells, thereby inducing early germ cell death or malformations via complex mechanisms related to apoptosis and autophagy through mitochondrial and lysosomal pathways. Histological observations of the gonads and quantitative analyses of germ cell development showed that the reproductive toxicity was characterized by obvious male sensitivity. Exposure to QDs in the early stage of males had severe adverse effects on the quantity and quality of sperm, which was the main reason for the occurrence of unfertilized eggs. Ala- or Gly-conjugated QDs could reduce the nanotoxicity of CdTe-QDs during germ cell development and fertilization of their offspring. The results demonstrate that males are preferable models for evaluating the reproductive toxicity of QDs in combined in vivo/in vitro investigations.

  11. Protective effect of zinc against cadmium toxicity on pregnant rats ...

    African Journals Online (AJOL)

    Protective effect of zinc against cadmium toxicity on pregnant rats and their fetuses at morphological, physiological and molecular level. Ashraf El-Sayed, Salem M Salem, Amany A El-Garhy, Zeinab A Rahman, Asmaa M Kandil ...

  12. Transfer and accumulation of lead, zinc, cadmium and copper in ...

    African Journals Online (AJOL)

    Transfer and accumulation of lead, zinc, cadmium and copper in plants growing in abandoned mining-district area. HK Chakroun, F Souissi, JL Bouchardon, R Souissi, J Moutte, O Faure, E Remon, S Abdeljaoued ...

  13. Influence of a front buffer layer on the performance of flexible Cadmium sulfide/Cadmium telluride solar cells

    Science.gov (United States)

    Mahabaduge, Hasitha Padmika

    Cadmium telluride (CdTe) solar cells have been developing as a promising candidate for large-scale application of photovoltaic energy conversion and have become the most commercially successful polycrystalline thin-film solar module material. In scaling up from small cells to large-area modules, inevitably non-uniformities across the large area will limit the performance of the large cell or module. The effects of these non-uniformities can be reduced by introducing a thin, high-resistivity transparent buffer layer between the conductive electrodes and the semiconductor diode. ZnO is explored in this dissertation as a high-resistivity transparent buffer layer for sputtered CdTe solar cells and efficiencies over 15% have been achieved on commercially available Pilkington TEC15M glass substrates. The highest open-circuit voltage of 0.858V achieved using the optimized ZnO buffer layer is among the best reported in the literature. The properties of ZnO:Al as a buffer are also investigated. We have shown that ZnO:Al can serve both as a transparent conducting oxide layer as well as a high-resistivity transparent layer for CdTe solar cells. ZnO:Al reactively sputtered with oxygen can give the necessary resistivities that allow it to be used as a high-resistivity transparent layer. Glass is the most common choice as the substrate for solar cells fabricated in the superstrate configuration due to its transparency and mechanical rigidity. However flexible substrates offer the advantages of light weight, high flexibility, ease of integrability and higher throughput through roll-to-roll processing over glass. This dissertation presents significant improvements made to flexible CdTe solar cells reporting an efficiency of 14% on clear KaptonRTM flexible polyimide substrates. Our efficiency of 14% is, to our knowledge, the best for any flexible CdTe cell reported in literature.

  14. High efficiency cadmium telluride and zinc telluride based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C. (Georgia Inst. of Tech., Atlanta, GA (United States))

    1992-10-01

    This report describes work to improve the basic understanding of CdTe and ZnTe alloys by growing and characterizing these films along with cell fabrication. The major objective was to develop wide-band-gap (1.6--1.8 eV) material for the top cell, along with compatible window material and transparent ohmic contacts, so that a cascade cell design can be optimized. Front-wall solar cells were fabricated with a glass/SnO{sub 2}/CdS window, where the CdS film is thin to maximize transmission and current. Wide-band-gap absorber films (E{sub g} = 1.75 eV) were grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) techniques, which provided excellent control for tailoring the film composition and properties. CdZnTe films were grown by both MBE and MOCVD. All the as-grown films were characterized by several techniques (surface photovoltage spectroscopy, Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS)) for composition, bulk uniformity, thickness, and film and interface quality. Front-wall-type solar cells were fabricated in collaboration with Ametek Materials Research Laboratory using CdTe and CdZnTe polycrystalline absorber films. The effects of processing on ternary film were studied by AES and XPS coupled with capacitance voltage and current voltage measurements as a function of temperature. Bias-dependent spectral response and electrical measurements were used to test some models in order to identify and quantify dominant loss mechanisms.

  15. A rapid and sensitive assay for determination of doxycycline using thioglycolic acid-capped cadmium telluride quantum dots

    Science.gov (United States)

    Tashkhourian, Javad; Absalan, Ghodratollah; Jafari, Marzieh; Zare, Saber

    2016-01-01

    A rapid, simple and inexpensive spectrofluorimetric sensor for determination of doxycycline based on its interaction with thioglycolic acid-capped cadmium telluride quantum dots (TGA/CdTe QDs) has been developed. Under the optimum experimental conditions, the sensor exhibited a fast response time of determination of doxycycline in a concentration range of 1.9 × 10-6-6.1 × 10-5 mol L-1 with a detection limit of 1.1 × 10-7 mol L-1. The sensor was applied for determination of doxycycline in honey and human serum samples.

  16. 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.

  17. Bulk Dissolution Rates of Cadmium and Bismuth Tellurides As a Function of pH, Temperature and Dissolved Oxygen.

    Science.gov (United States)

    Biver, Marc; Filella, Montserrat

    2016-05-03

    The toxicity of Cd being well established and that of Te suspected, the bulk, surface-normalized steady-state dissolution rates of two industrially important binary tellurides-polycrystalline cadmium and bismuth tellurides- were studied over the pH range 3-11, at various temperatures (25-70 °C) and dissolved oxygen concentrations (0-100% O2 in the gas phase). The behavior of both tellurides is strikingly different. The dissolution rates of CdTe monotonically decreased with increasing pH, the trend becoming more pronounced with increasing temperature. Activation energies were of the order of magnitude associated with surface controlled processes; they decreased with decreasing acidity. At pH 7, the CdTe dissolution rate increased linearly with dissolved oxygen. In anoxic solution, CdTe dissolved at a finite rate. In contrast, the dissolution rate of Bi2Te3 passed through a minimum at pH 5.3. The activation energy had a maximum in the rate minimum at pH 5.3 and fell below the threshold for diffusion control at pH 11. No oxygen dependence was detected. Bi2Te3 dissolves much more slowly than CdTe; from one to more than 3.5 orders of magnitude in the Bi2Te3 rate minimum. Both will readily dissolve under long-term landfill deposition conditions but comparatively slowly.

  18. A far-infrared broadband (8.5-37 mu m) autocorrelator with sub-picosecond time resolution based on cadmium telluride

    NARCIS (Netherlands)

    Xu, J.; Knippels, G.M.H.; Oepts, D.; van der Meer, A. F. G.

    2001-01-01

    A background-free autocorrelator has been developed for measuring the duration of far-infrared laser pulses in the spectral range from 8.5 to 37 mum by using an 840-mum-long wedged cadmium telluride crystal as the second-harmonic generator. Typical intensity second-harmonic autocorrelation traces

  19. Copper, nickel, zinc, cadmium and lead contamination of soil at ...

    African Journals Online (AJOL)

    This paper discussed heavy metals such as coppper (Cu), nickel (Ni), zinc (Zn), cadmium (Cd) and lead (Pb) in the soil collected from three sites from the solid waste dumping ground at Kureepuzha, very close to Ashtamudi Lake. Also, control samples were collected and analyzed for the said heavy metals. The levels of all ...

  20. Production of high purity granular metals: cadmium, zinc, lead

    Directory of Open Access Journals (Sweden)

    Shcherban A. P.

    2017-04-01

    Full Text Available Cadmium, zinc and lead are constituent components of many semiconductor compounds. The obtained high purity distillates and ingots are large-size elements, which is not always convenient to use, and thus require additional grinding, which does not always allow maintaining the purity of the original materials. For the growth of semiconductor and scintillation single crystals it is advisable to use "friable" granular high-purity distillates, which can be processed without the risk of contamination. For example, the European low-background experiment LUCIFER required more than 20 kg of high-purity granulated zinc, which was agreed to be supplied by NSC KIPT. This task was then extended to cadmium and lead. Motivated by these tasks, the authors of this paper propose complex processes of deep refining of cadmium, zinc and lead by vacuum distillation. A device producing granules has been developed. The process of granulation of high-purity metals is explored. The purity of produced granules for cadmium and zinc is >99,9999, and >99,9995% for lead granules. To prevent oxidation of metal granules during exposition to air, chemical methods of surface passivation were used. Organic solvent based on dimethylformamide used as a coolant improves the resistance of granules to atmospheric corrosion during the granulation of high purity Cd, Zn and Pb.

  1. Operational speciation of lead, cadmium, and zinc in farmlands ...

    African Journals Online (AJOL)

    This study was undertaken to evaluate the geochemical fractions and risk potential of lead (Pb), cadmium (Cd) and zinc (Zn) in farmlands around a polluted goldmine in Dareta, northern Nigeria. The total heavy metal concentrations were obtained through a mixed acid digestion. A modified sequential extraction procedure ...

  2. Thermoelectric material comprising scandium doped zinc cadmium oxide

    DEFF Research Database (Denmark)

    2016-01-01

    There is presented a composition of scandium doped Zinc Cadmium Oxide with the general formula ZnzCdxScyO which the inventors have prepared, and for which material the inventors have made the insight that it is particularly advantageous as an n-type oxide material, such as particularly advantageous...

  3. Evaluation of some trace elements (zinc, chromium, cadmium and ...

    African Journals Online (AJOL)

    Throughout the world, tuberculosis (TB) infection is on the increase and it has remained one of the most important causes of death among adults in developing countries. This study evaluated the serum concentrations of some trace elements -Zinc (Zn), Manganese (Mn), Chromium (Cr) and Cadmium (Cd), in 100 blood ...

  4. Cadmium, lead and zinc contents of sporocarps of some ...

    African Journals Online (AJOL)

    Zinc, cadmium and lead concentrations were determined in sporocarps of Ganoderma applanatum (Pers.ex Wallr.), Ganoderma lucidum (Leys.) Fr., Heteroporus biennis (Bull.exFr.), Lycoperdon molle (Pers.: Pers), Lycoperdon pyriforme (Schaeff.ex Pers.), Peniophora incarnata (Fr.) Karst.syn, Pisolithus tinctorius (Mich.ex ...

  5. Monte Carlo and least-squares methods applied in unfolding of X-ray spectra measured with cadmium telluride detectors

    Energy Technology Data Exchange (ETDEWEB)

    Moralles, M. [Centro do Reator de Pesquisas, Instituto de Pesquisas Energeticas e Nucleares, Caixa Postal 11049, CEP 05422-970, Sao Paulo SP (Brazil)], E-mail: moralles@ipen.br; Bonifacio, D.A.B. [Centro do Reator de Pesquisas, Instituto de Pesquisas Energeticas e Nucleares, Caixa Postal 11049, CEP 05422-970, Sao Paulo SP (Brazil); Bottaro, M.; Pereira, M.A.G. [Instituto de Eletrotecnica e Energia, Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 1289, CEP 05508-010, Sao Paulo SP (Brazil)

    2007-09-21

    Spectra of calibration sources and X-ray beams were measured with a cadmium telluride (CdTe) detector. The response function of the detector was simulated using the GEANT4 Monte Carlo toolkit. Trapping of charge carriers were taken into account using the Hecht equation in the active zone of the CdTe crystal associated with a continuous function to produce drop of charge collection efficiency near the metallic contacts and borders. The rise time discrimination is approximated by a cut in the depth of the interaction relative to cathode and corrections that depend on the pulse amplitude. The least-squares method with truncation was employed to unfold X-ray spectra typically used in medical diagnostics and the results were compared with reference data.

  6. Monte Carlo and least-squares methods applied in unfolding of X-ray spectra measured with cadmium telluride detectors

    Science.gov (United States)

    Moralles, M.; Bonifácio, D. A. B.; Bottaro, M.; Pereira, M. A. G.

    2007-09-01

    Spectra of calibration sources and X-ray beams were measured with a cadmium telluride (CdTe) detector. The response function of the detector was simulated using the GEANT4 Monte Carlo toolkit. Trapping of charge carriers were taken into account using the Hecht equation in the active zone of the CdTe crystal associated with a continuous function to produce drop of charge collection efficiency near the metallic contacts and borders. The rise time discrimination is approximated by a cut in the depth of the interaction relative to cathode and corrections that depend on the pulse amplitude. The least-squares method with truncation was employed to unfold X-ray spectra typically used in medical diagnostics and the results were compared with reference data.

  7. 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

  8. Synthesis of mercaptosuccinic acid/MercaptoPolyhedral oligomeric silsesquioxane coated cadmium telluride quantum dots in cell labeling applications.

    Science.gov (United States)

    Ghaderi, Shirin; Ramesh, Bala; Seifalian, Alexander M

    2012-06-01

    An aqueous synthesis method to obtain highly luminescent cadmium telluride nanocrystals is described. We have shown water-soluble semi-conductor quantum dots with high photoluminescence quantum yield have great potential for biological applications. The spectral properties of these nanocrystals can be easily tuned according to their particle size to yield multicolours simultaneously by a single excitation light source. A stable precursor material sodium tellurite is utilised instead of the traditional oxygen sensitive NaHTe or H2Te as Te source. We have introduced mercaptosuccinic acid and propylisobutyl polyhedral oligomeric silsesquioxane nanoparticles as novel capping agents to stabilize the nanocrystals, synthesized in borate-citrate buffering system. Inclusion of propylisobutyl polyhedral oligomeric silsesquioxane nanoparticles in the capping procedure showed enhanced stability and biocompatibility. The presence of mercaptosuccinic acid/propylisobutyl polyhedral oligomeric silsesquioxane coatings was confirmed by Fourier Transform Infrared spectroscopy and average sizes of 2-5 nm by transmission electron microscopy measurements. The functionalized and targeted quantum dots detected cancer cell death on exposure to some anticancer drugs. Studies have indicated that apoptotic cells can activate signaling pathways in dendritic cells via ligation of surface receptors. Cells treated with specific class of pro-apototic drug such as anthracyclines mount an anti-tumour immune response when introduced into mice. Apoptotic cells may be immunogenic or non-immunogenic depending on the presence of calreticulin on the plasma membrane of dying tumour cells. Here the confocal microscopy showed localization of conjugated mercaptosuccinic acid/propylisobutyl polyhedral oligomeric silsesquioxane cadmium telluride quantum dots on MCF-7 cells when exposed to cadmium ions at 50 microM, compared to coated quantum dots. We have used cadmium ions as a model drug as certain anticancer

  9. Cadmium and zinc accumulation in soybean: A threat to food safety?

    Energy Technology Data Exchange (ETDEWEB)

    Shute, Tracy [Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada); Macfie, Sheila M. [Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada)]. E-mail: smacfie@uwo.ca

    2006-12-01

    A greenhouse study was conducted to quantify cadmium and zinc accumulated by soybean (Glycine max (L.) Merr.) when the metals were supplied separately and together. The highest dose of cadmium (100 mg/kg) reduced plant height and dry weight (down to 40% and 34% of control, respectively); the highest dose of zinc (2000 mg/kg) reduced plant height to 55% of control and dry weight to 70% of control. With both metals present, the plants were approximately the same size as those treated with cadmium only. The concentration of cadmium in the roots was unaffected by zinc. In other tissues, the effect of zinc on the accumulation of cadmium depended on the doses provided. At low doses, the addition of zinc reduced the concentration of cadmium in aboveground tissues to 40-50% of that found in plants exposed to cadmium only. However, when applied in high doses, the presence of zinc in cadmium-contaminated soils increased the uptake and accumulation of cadmium in aboveground tissues by up to 42%. In contrast, at high doses, the presence of cadmium in zinc-contaminated soil resulted in approximately 35% lower concentrations of zinc in all tissues. At a lower dose, cadmium had no effect on concentration of zinc in the plant tissues. The effects of high doses of one metal on the uptake of the other metal can be partially explained by the effects of one metal on the bioavailability of the other metal. In soils to which only one metal was added, bioavailable cadmium was 70-80% of the total cadmium, and bioavailable zinc was 50-70% of the total zinc. When both metals were added to the soil, 80-100% of the cadmium and 46-60% of the zinc were bioavailable. Concentrations of both metals were highest in root tissues (10-fold higher for cadmium, and up to 2-fold higher for zinc). Although relatively little cadmium was translocated to pods and seeds, the seeds of all plants (including those from control and zinc-treated plants) had concentrations of cadmium 3-4 times above the limit of 0

  10. The Protective Roles of Zinc and Magnesium in Cadmium-Induced Renal Toxicity in Male Wistar Rats

    National Research Council Canada - National Science Library

    Nasim Babaknejad; Ali Asghar Moshtaghie; Kahin Shahanipour; Somaye Bahrami

    2014-01-01

    .... Cadmium can cause dysfunction of different body organs. Zinc (Zn) and magnesium (Mg) supplementation can have protective effects against cadmium toxicity due to their antagonistic and antioxidants properties...

  11. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  12. Effects of Nano-zinc on Biochemical Parameters in Cadmium-Exposed Rats.

    Science.gov (United States)

    Hejazy, Marzie; Koohi, Mohammad Kazem

    2017-12-01

    Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn2+ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl2) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl2 (2-5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P nano-zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P nano-zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.

  13. 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

  14. A novel approach of chemical mechanical polishing using environment-friendly slurry for mercury cadmium telluride semiconductors

    Science.gov (United States)

    Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Guo, Dongming; Kang, Renke; Zhang, Bi

    2016-03-01

    A novel approach of chemical mechanical polishing (CMP) is developed for mercury cadmium telluride (HgCdTe or MCT) semiconductors. Firstly, fixed-abrasive lapping is used to machine the MCT wafers, and the lapping solution is deionized water. Secondly, the MCT wafers are polished using the developed CMP slurry. The CMP slurry consists of mainly SiO2 nanospheres, H2O2, and malic and citric acids, which are different from previous CMP slurries, in which corrosive and toxic chemical reagents are usually employed. Finally, the polished MCT wafers are cleaned and dried by deionized water and compressed air, respectively. The novel approach of CMP is environment-friendly. Surface roughness Ra, and peak-to-valley (PV) values of 0.45, and 4.74 nm are achieved, respectively on MCT wafers after CMP. The first and second passivating processes are observed in electrochemical measurements on MCT wafers. The fundamental mechanisms of CMP are proposed according to the X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Malic and citric acids dominate the first passivating process, and the CMP slurry governs the second process. Te4+3d peaks are absent after CMP induced by the developed CMP slurry, indicating the removing of oxidized films on MCT wafers, which is difficult to achieve using single H2O2 and malic and citric acids solutions.

  15. 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.

  16. Solid phase extraction of trace amounts of zinc and cadmium ions ...

    African Journals Online (AJOL)

    ... and determination of the zinc and cadmium ions in the water and food samples and satisfactory results were obtained. KEY WORDS: Solid phase extraction, Zinc determination, Cadmium determination, Preconcentration, Perlite. Bull. Chem. Soc. Ethiop. 2016, 30(2), 175-184. DOI: http://dx.doi.org/10.4314/bcse.v30i2.2 ...

  17. Surface passivation of high purity granular metals: zinc, cadmium, lead

    Directory of Open Access Journals (Sweden)

    Pirozhenko L. A.

    2017-10-01

    Full Text Available For the high purity metals (99.9999%, such as zinc, cadmium, and lead, which are widely used as initial components in growing semiconductor and scintillation crystals (CdTe, CdZnTe, ZnSe, (Cd, Zn, Pb WO4, (Cd, Zn, Pb MoO4 et al., it is very important to ensure reliable protection of the surface from oxidation and adsorption of impurities from the atmosphere. The specific features of surface passivation of high purity cadmium, lead and zinc are not sufficiently studied and require specific methodologies for further studies. The use of organic solutions in the schemes of chemical passivation of the investigated metals avoids hydrolysis of the obtained protective films. The use of organic solvents with pure cation and anion composition as the washing liquid prevents chemisorption of ions present in the conventionally used distilled water. This keeps the original purity of the granular metals. Novel compositions of etchants and etching scheme providing simultaneous polishing and passivation of high purity granular Zn, Cd and Pb are developed. Chemical passivation allows storing metals in the normal atmospheric conditions for more than half a year for Zn and Cd and up to 30 days for Pb without changing the state of the surface. The use of the glycerol-DMF solution in the processes for obtaining Pb granules provides self-passivation of metal surfaces and eliminates the additional chemical processing while maintaining the quality of corrosion protection.

  18. Levels of lead, cadmium and zinc in vegetables

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, G.; Haegglund, J.; Jorhem, L.

    1976-01-01

    The concentrations of lead, cadmium and zinc have been determined in 455 samples of fresh fruit, vegetables and mushrooms by dry ashing and atomic absorption spectrophotometry. The lead content in all samples was in the range < 0.001-0.288 mg/kg, the mean being 0.02 mg/kg. Leaf vegetables (lettuce and spinach) showed higher values, mean 0.04 mg/kg. The mean values of the cadmium content in fruit, green vegetables, potatoes and root vegetables were 0.003, 0.013, 0.016 and 0.038 mg/kg respectively. The zinc contents were in the ppm range. The ratio Zn/Cd was also determined in some samples. All values concern edible parts and are calculated on wet weight basis. The fruit and vegetables were estimated to constitute about 2 percent and 8 percent respectively of the provisional tolerable weekly intake of these metals recommended by an FAO/WHO Expert Committee.

  19. Inclusion free cadmium zinc tellurium and cadmium tellurium crystals and associated growth method

    Science.gov (United States)

    Bolotnikov, Aleskey E [South Setauket, NY; James, Ralph B [Ridge, NY

    2010-07-20

    The present disclosure provides systems and methods for crystal growth of cadmium zinc tellurium (CZT) and cadmium tellurium (CdTe) crystals with an inverted growth reactor chamber. The inverted growth reactor chamber enables growth of single, large, high purity CZT and CdTe crystals that can be used, for example, in X-ray and gamma detection, substrates for infrared detectors, or the like. The inverted growth reactor chamber enables reductions in the presence of Te inclusions, which are recognized as an important limiting factor in using CZT or CdTe as radiation detectors. The inverted growth reactor chamber can be utilized with existing crystal growth techniques such as the Bridgman crystal growth mechanism and the like. In an exemplary embodiment, the inverted growth reactor chamber is a U-shaped ampoule.

  20. Nuclear myocardial perfusion imaging with a cadmium-telluride semiconductor detector gamma camera in patients with acute myocardial infarction.

    Science.gov (United States)

    Fukushima, Yoshimitsu; Kumita, Shin-ichiro; Kawaguchi, Tsuneaki; Maruyama, Takatoshi; Kawasaki, Yoshiyuki; Shinkai, Yasuhiro

    2014-08-01

    Since myocardial perfusion imaging (MPI) with conventional sodium iodine (NaI) device has low spatial resolution, there have been some cases in which small structures such as non-transmural myocardial infarction could not be properly detected. The purpose of this study was to evaluate potential usefulness of cadmium-telluride (CdTe) semiconductor detector-based high spatial resolution gamma cameras in detecting myocardial infarction sites, especially non-transmural infarction. A total of 38 patients (mean age ± SD: 64 ± 21 year) who were clinically diagnosed with acute myocardial infarction were included. Twenty-eight cases of them were with ST segment elevation myocardial infarction (STEMI) and 10 cases with non-ST segment elevation myocardial infarction (NSTEMI). In all patients, myocardial perfusion single photon emission computed tomography images were acquired with Infinia (NaI device) and R1-M (CdTe device), and the images were compared concerning the detectability of acute myocardial infarction sites. The detection rates of the myocardial infarction site in cases with STEMI were 100% both by NaI and CdTe images. In cases with NSTEMI, detection rate by NaI images was 50%, while that of CdTe images was 100% (p = 0.033). The summed rest score (SRS) value derived from CdTe images was significantly higher than that from NaI images in cases with STEMI [NaI images: 12 (7-18) versus CdTe images: 14 (9-20)] (p cases with NSTEMI [NaI images: 2 (0-5) versus CdTe images: 6 (6-8)] (p = 0.006). These results indicate that MPI using CdTe-semiconductor device will provide a much more accurate assessment of acute myocardial infarction in comparison to current methods.

  1. 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.

  2. Determination of zinc, cadmium, lead and copper in wines by potentiometric stripping analysis.

    Science.gov (United States)

    Suturović, Z J; Marjanović, N J

    1998-02-01

    A method for determination of zinc, cadmium, lead and copper in wines by means of potentiometric stripping analysis (PSA) is described. Cadmium, lead and copper are determined directly, whereas the zinc determination is possible only after the wine samples decomposition. The results for five red and white Yugoslav wines are given. The content of zinc, cadmium, lead and copper in analyzed samples were in the range of 0.16-0.79, 0.010-0.045, 0.13-0.27 and 0.10-0.46 mg/l, respectively. The contents of the all analyzed metals were below the maximum ordered by the Yugoslav law.

  3. 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.

  4. Sorption Kinetics for the Removal of Cadmium and Zinc onto Palm Kernel Shell Based Activated Carbon

    Directory of Open Access Journals (Sweden)

    Muhammad Muhammad

    2010-12-01

    Full Text Available The kinetics and mechanism of cadmium and zinc adsorption on palm kernel shell based activated carbons (PKSAC have been studied. A series of batch laboratory studies were conducted in order to investigate the suitability of palm kernel shell based activated carbon (PKSAC for the removal of cadmium (cadmium ions and zinc (zinc ions from their aqueous solutions. All batch experiments were carried out at pH 7.0 and a constant temperature of 30+-1°C using an incubator shaker that operated at 150 rpm. The kinetics investigated includes the pseudo first order, the pseudo-second order and the intraparticle diffusion models. The pseudo-second order model correlate excellently the experimental data, suggesting that chemisorption processes could be the rate-limiting step. Keywords: adsorption, cadmium, kinetics, palm kernel shell, zinc

  5. Low serum zinc is associated with elevated risk of cadmium nephrotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yu-Sheng, E-mail: Lin.Yu-Sheng@epa.gov [National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC (United States); Ho, Wen-Chao [Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan (China); Caffrey, James L. [Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX (United States); Sonawane, Babasaheb [National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC (United States)

    2014-10-15

    Background: Despite animal evidence suggests that zinc modulates cadmium nephrotoxicity, limited human data are available. Objective: To test the hypothesis that low serum zinc concentrations may increase the risk of cadmium-mediated renal dysfunction in humans. Methods: Data from 1545 subjects aged 20 or older in the National Health and Nutrition Examination Survey (NHANES), 2011–2012 were analyzed. Renal function was defined as impaired when estimated glomerular filtration rate (eGFR) fell below 60 ml/min/1.73 m{sup 2} and/or the urinary albumin-to-creatinine ratio surpassed 2.5 in men and 3.5 mg/mmol in women. Results: Within the study cohort, 117 subjects had reduced eGFR and 214 had elevated urinary albumin. After adjusting for potential confounders, subjects with elevated blood cadmium (>0.53 μg/L) were more likely to have a reduced eGFR (odds ratio [OR]=2.21, 95% confidence interval [CI]: 1.09–4.50) and a higher urinary albumin (OR=2.04, 95% CI: 1.13–3.69) than their low cadmium (<0.18 μg/L) peers. In addition, for any given cadmium exposure, low serum zinc is associated with elevated risk of reduced eGFR (OR=3.38, 95% CI: 1.39–8.28). A similar increase in the odds ratio was observed between declining serum zinc and albuminuria but failed to reach statistical significance. Those with lower serum zinc/blood cadmium ratios were likewise at a greater risk of renal dysfunction (p<0.01). Conclusions: This study results suggest that low serum zinc concentrations are associated with an increased risk of cadmium nephrotoxicity. Elevated cadmium exposure is global public health issue and the assessment of zinc nutritional status may be an important covariate in determining its effective renal toxicity. - Highlights: • Blood cadmium was associated with increased risk of nephrotoxicity. • Low serum zinc may exacerbate risk of cadmium-mediated renal dysfunction. • Both zinc deficiency and elevated cadmium exposure are global public health issues.

  6. Single or combined cadmium and aluminum intoxication of mice liver and kidney with possible effect of zinc

    Directory of Open Access Journals (Sweden)

    Ahmed S. Ibraheem

    2016-10-01

    Full Text Available In this study, we planned to test toxic effects of cadmium, aluminum either alone or combined with each other on sensitive organs as kidney and liver. The cadmium alone decreased the animal’s body weight. Meanwhile, aluminum did not affect the changes in body weight of cadmium treated animals; adding the zinc significantly reduced the loss of body weight. Serum creatinine and urea were significantly lower in treated group than in control group. Cadmium aluminum or combination of them resulted in a significant increase in serum GPT and GOT activity. Zinc did not prevent the changes caused by aluminum, however, the changes resulted by cadmium intoxication were almost healed or ameliorated by zinc. Treating with Zn alone resulted in drastic effects on kidney tissues more than either cadmium or aluminum. Treating with cadmium or aluminum resulted in infiltration of the liver parenchyma with lymphocytes, fibrosis, micro vesicular steatosis of the hepatocytes for both and appearance of many phagocytic cells, pyknotic cells and vacuolation for cadmium. Combined cadmium and aluminum treatment resulted in less damage than cadmium alone with exception of fatty degeneration. Unexpectedly, zinc induced acute cell vacuolation and steatosis. Cadmium and aluminum combined together did not worsen the situation as expected but was less damaging than cadmium alone, which suggests a possible synergistic effect of combination. Meanwhile, zinc failed to protect kidney from aluminum intoxication, which strengthens the suggestion of two different pathways of cadmium and aluminum intoxication. This finding meant that cadmium is more hepatotoxic than aluminum.

  7. Effect of dietary zinc deficiency on the accumulation of cadmium and metallothionein in selected tissues of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Waalkes, M.P.

    1986-01-01

    The effect of continuous dietary zinc deficiency on the metabolism of the toxic heavy metal cadmium has not been widely studied. This investigation was designed to assess the effects of subadequate dietary zinc intake on the accumulation of dietary cadmium and on metallothionein (MT) and zinc concentrations in target organs of cadmium toxicity. Adult male Wistar rats (180-200 g) were allowed, ad libitum, diets either adequate (60 ppm) or deficient (7 ppm) in zinc for a total of 9 wk. The zinc-deficient diet resulted in an approximately 40% reduction in plasma zinc (assessed at 3, 6, and 9 wk) in the absence of overt signs of zinc deficiency (i.e., reduced weight gain, alopecia, etc.). Separate groups of rats were also maintained on zinc-defined diets for a total of 9 wk, but cadmium was added to the diet (0, 12.5, 25, 50, 100, and 200 ppm) a the end of wk 3 and maintained at that level throughout the remaining 6 wk of the study, when the rats were killed. The feeding of the zinc-deficient diet markedly enhanced the accumulation of cadmium in the liver, kidney, and testes. Hepatic, renal, and testicular zinc concentrations were not affected by suboptimal zinc intake alone. However, marked reductions in renal and testicular zinc concentrations were caused by zinc deficiency in concert with cadmium exposure. MT levels, when related to tissue cadmium concentrations, were elevated to a significantly lesser extent in the kidneys of zinc-deficient animals. These results indicate that marginal zinc deficiency markedly increases cadmium accumulation in various organs and reduces zinc content and MT induction in some organs.

  8. Solvent extraction of cadmium and zinc from sulphate solutions: Comparison of mechanical agitation and ultrasonic irradiation.

    Science.gov (United States)

    Daryabor, Mahboubeh; Ahmadi, Ali; Zilouei, Hamid

    2017-01-01

    This research was conducted to evaluate the potential of ultrasonic irradiation during the solvent extraction of metals, and comparing its efficiency with a mechanically stirred system (MSSX). The simultaneous extraction of zinc and cadmium from sulphate solutions was investigated by di-(2-ethylhexyl) phosphoric acid (D2EHPA) as an organic extractant which was diluted (20%) in kerosene at the organic: aqueous phase ratio of 1:1 and the temperature of 25°C. The influence of some critical parameters, including contact time, solution pH, ultrasonic power, and zinc/cadmium ratio were investigated on the extraction of the metals. Results show that D2EHPA selectively extract zinc rather than cadmium in both mechanically and ultrasonically mixed systems. It was also found that increase of ultrasonic power from 10 to 120W cause a small decrease in zinc extraction; while, at low and high levels of the induced power, cadmium extraction was significantly decreased. Results also show that maximum extraction amounts of zinc (88.7%) and cadmium (68.2%) by the MSSX system occurred at the pH of 3 and the contact times of 3 and 20min, respectively. Although capability of extraction in the ultrasonically assisted solvent extraction (USAX) system for both metals was higher, the selectivity was lower than that of MSSX system under different conditions especially in high zinc/cadmium ratios. It can be concluded that physical effects (i.e. mixing) inducing at low ultrasonic powers (below 60W) mainly results in increasing solvent extraction rate, while the chemical actions applied at the higher powers have a negative outcome on the extraction rate particularly for cadmium. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Characterization of metal contacts on and surfaces of cadmium zinc telluride

    CERN Document Server

    Bürger, A; Chattopadhyay, K; Shi, D; Morgan, S H; Collins, W E; James, R B

    1999-01-01

    In the past several years significant progress has been made in building a database of physical properties for detector quality Cd sub x Zn sub 1 sub - sub x Te (CZT) (x=0.1-0.2) crystal material. CZT's high efficiency combined with its room temperature operation make the material an excellent choice for imaging and spectroscopy in the 10-200 keV energy range. For detector grade material, superior crystallinity and high bulk resistivity are required. The surface preparation during the detector fabrication plays a vital role in determining the contact characteristics and the surface leakage current, which are often the dominant factors influencing its performance. This paper presents a surface and contact characterization study aimed at establishing the effects of the surface preparation steps prior to contacting (polishing and chemical etching), the choice of the metal and contact deposition technique, and the surface oxidation process. A photoconductivity mapping technique is used for studying the effects of...

  10. Ultrastructural study of the submandibular gland of the rat after 6-month exposure to cadmium and zinc in drinking water.

    Science.gov (United States)

    Dabrowska, E; Szynaka, B; Kulikowska-Karpińska, E

    2006-01-01

    Cadmium toxicity in the exposure of the general, professional and cigarette smoking populations has been well known. From the dental point of view, it is important to find out whether and how separate and joint exposures to cadmium and zinc affect the structure and function of the submandibular gland, which is the major saliva-releasing gland. Cadmium, a particularly active xenobiotic, damages cellular metabolism at the level of various enzymatic systems of the cell, which may disturb functioning of the salivary glands. Mutual interactions of cadmium and zinc suggest a protective role of zinc through the induction of metallothionein which inactivates cadmium effect. The aim of the study was to assess the ultrastructural picture of chosen cell organelles of the submandibular salivary gland of the rat exposed to cadmium and zinc. The study used 90 male Wistar rats, of the initial b.w. 150-180 g. The animals were exposed to cadmium and/or zinc for 6 months. Cadmium was received in aqueous solutions of cadmium chloride with drinking water at a concentration of 5 mg Cd/dm3 or 50 mg Cd/dm3. Zinc was also given in aqueous solutions of zinc chloride ad libitum at concentrations of 30 mg Zn/dm3 and 60 mg Zn/dm3. The ultrastructural changes in the mucous and serous cells of the submandibular salivary gland were most pronounced at cadmium concentration of 50 mg Cd/dm3 and were mainly observed in the cell nucleus, Golgi Apparatus and secretory granules of the salivary gland cells. 1. Exposure to cadmium induces ultrastructural changes in the submandibular gland, which are dose and time of exposure. 2. Exposure to zinc did not affect significantly the ultrastructural picture of cells of the submandibular gland. 3. Zinc administered together with cadmium reduces the intensity of ultrastructural changes in the submandibular gland.

  11. Kinetically controlled separation of cadmium(II) from zinc(II) with dithizone in the presence of nitrilotriacetic acid.

    Science.gov (United States)

    Itabashi, H; Yoshida, M; Kawamoto, H

    2001-11-01

    The extraction rates of cadmium(II) and zinc(II) with dithizone (H2dz) in the presence of nitrilotriacetic acid (NTA) were measured, and the possible kinetic separation of cadmium(II) from zinc(II) was investigated. Upon the addition of NTA, the difference in the extraction rate between cadmium(II) and zinc(II) became large. Based on the observed rate constant under the condition [NTA] = 1 x 10(-2) mol dm-3, [H2dz]org = 1 x 10(-3) mol dm-3, and pH = 7.0, the shaking time required for the quantitative separation of cadmium(II) from zinc(II) was calculated to be between 326 and 995 s. The experimental results agreed with the prediction, and the quantitative separation of cadmium(II) from zinc(II) was performed within the above-mentioned range of shaking times.

  12. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Longhua, E-mail: lhwu@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Pengjie [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yongming [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Yantai 264003 (China); Christie, Peter [Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom)

    2013-10-15

    Highlights: • Low Cu has no significant effect on Sedum plumbizincicola plant growth and Cd and Zn uptake. • Plant held Cu in unactive areas and insoluble forms as de-toxification mechanisms. • Influence of Cu on Zn and Cd uptake and translocation were different. • Cu accumulation in leaf veins may restrain Cd/Zn unloading to the leaves -- Abstract: Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5–50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola.

  13. Investigations of effects of magnesium, zinc and copper on cadmium excretion in rabbits

    Directory of Open Access Journals (Sweden)

    Bulat Zorica

    2012-01-01

    Full Text Available Cadmium (Cd is today one of the most significant metal poisons, both in the area of professional as well as of eco toxicology. In the organism, cadmium has a harmful effect on the kidneys, liver, bones, testicles, etc., and, based on evidence in humans that it causes lung carcinoma, it has been placed in the first group of carcinogens. In spite of numerous data in literature on the harmful effects of cadmium, the interactions between cadmium and bioelements as a significant mechanism for cadmium toxicity have still not been sufficiently explained. Since the data so far point to a positive effect of supplementation with certain bioelements regarding toxicity and cadmium content in the organism, the objective of this work was to investigate the effect of increased simultaneous intake of magnesium, zinc and copper on urinary elimination of cadmium in rabbits exposed to cadmium. Rabbits were divided into two groups: Cd group - for a period of 28 days the animals received per os 10 mg Cd/kg b.m/day and Cd+(Mg+Zn+Cu group - 10 mg Cd/kg b.m. + 40 mg Mg/kg b.m, 20 mg Zn/kg b.m. and 10 mg Cu/kg b.m/day. Daily urine was collected on days 0, 10, 15, 17, 19, 21, 23, 25, and 28 of the experiment. Following decomposition of urine samples with the help of concentrated HNO3 and HClO4 (4:1, the metal concentration was determined using the method of atomic absorption spectrophotometry. Supplementation with magnesium, zinc and copper did not result in significant changes in the elimination of cadmium through urine in animals poisoned with cadmium, in comparison with the animals that were administered only cadmium, while the concentration of all three applied bioelements in urine was significantly increased. It can be concluded that the simultaneous administration of increased doses of zinc, copper and magnesium does not have a positive effect on the elimination of cadmium in conditions when rabbits are poisoned with cadmium.

  14. Cigarette smoking, cadmium exposure, and zinc intake on obstructive lung disorder

    Directory of Open Access Journals (Sweden)

    Dowling Nicole

    2010-05-01

    Full Text Available Abstract Background and objective This study examined whether zinc intake was associated with lower risk of smoking-induced obstructive lung disorder through interplay with cadmium, one of major toxicants in cigarette smoke. Methods Data were obtained from a sample of 6,726 subjects aged 40+ from the Third National Health and Nutrition Examination Survey. The forced expiratory volume in 1 second (FEV1 and forced vital capacity (FVC were measured using spirometry. Gender-, ethnicity-, and age-specific equations were used to calculate the lower limit of normal (LLN to define obstructive lung disorder as: observed FEV1/FVC ratio and FEV1 below respective LLN. Zinc intake was assessed by questionnaire. Logistic regression analysis was applied to investigate the associations of interest. Results The analyses showed that an increased prevalence of obstructive lung disorder was observed among individuals with low zinc intake regardless of smoking status. The adjusted odds of lung disorder are approximately 1.9 times greater for subjects in the lowest zinc-intake tertile than those in the highest tertile (odds ratio = 1.89, 95% confidence interval = 1.22-2.93. The effect of smoking on lung function decreased considerably after adjusting for urinary cadmium. Protective association between the zinc-to-cadmium ratio (log-transformed and respiratory risk suggests that zinc may play a role in smoking-associated lung disorder by modifying the influence of cadmium. Conclusions While zinc intake is associated with lower risk of obstructive lung disorder, the role of smoking cession and/or prevention are likely to be more important given their far greater effect on respiratory risk. Future research is warranted to explore the mechanisms by which zinc could modify smoking-associated lung disease.

  15. [Bioaccumulation of cadmium and zinc in tomato (Lycopersicon esculentum L.)].

    Science.gov (United States)

    Sbartai, Hana; Djebar, Med Reda; Sbartai, Ibtissem; Berrabbah, Houria

    2012-09-01

    This work aims at evaluating the accumulation of cadmium (Cd) and zinc (Zn) (trace elements) in the organs of young tomato plants (Lycopersicon esculentum L. var. Rio Grande) and their effects on the rate of chlorophyll and enzyme activities involved in the antioxidant system: catalase (CAT), glutathion-S-transferase (GST) and peroxysase ascorbate (APX). Plants previously grown on a basic nutrient solution were undergoing treatment for 7 days, either by increasing concentrations of CdCl(2) or ZnSO(4) (0, 50, 100, 250, 500 μM) or by the combined concentrations of Cd and Zn (100/50, 100/100, 100/250, 100/500 μM). The results concerning the determination of metals in the various compartments of tomato plants as a function of increasing concentrations of Cd or Zn, suggest a greater accumulation of Cd and Zn in the roots compared to leaves. The combined treatment (Cd/Zn) interferes with the absorption of the two elements according to their concentrations in the culture medium. The presence of Zn at low concentrations (50 μM of Zn/100 μM Cd) has little influence on the accumulation of Cd in the roots and leaves, while the absorption of these two elements in the leaves increases and decreases in roots when their concentrations are equivalent (100/100 μM) compared to treatment alone. When the concentration of Zn is higher than that of Cd (500 μM of Zn/100 μM Cd) absorption of the latter is inhibited in the roots while increasing their translocation to the leaves. Meanwhile, the dosage of chlorophylls shows that they tend to decrease in a dose-dependent for both treatments (Cd or Cd/Zn), however, treatment with low concentrations of Zn (50 and 100 μM) stimulates chlorophyll synthesis. However, treatment with different concentrations of Cd seems to induce the activity of the enzymes studied (CAT, APX, GST). It is the same for treatment with different concentrations of Zn and this particularly for the highest concentrations. Finally, the combined treatment (Zn

  16. Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

    African Journals Online (AJOL)

    This study also evaluated the sublethal effects of cadmium, manganese, lead, zinc and iron in plasma samples utilising plasma electrolyte parameters as a biomarker using an albino mice model, M. musculus. Mice were subjected to sublethal concentrations of the selected heavy metals (1/10th of 96 hrLC50). Blood plasma ...

  17. To study the relationship between cadmium, zinc and mtDNA copy ...

    African Journals Online (AJOL)

    Objective: To examine the variation of cadmium (Cd), zinc (Zn) and mitochondrial DNA (mtDNA) copy number in prostate cancer (PCa) patients and their age match controls and correlations with clinicopathological parameters. Subjects and methods: This study was conducted between January 2012 and January 2015.

  18. Evaluations of Effective Factors on Efficiency Zinc Oxides Nanoparticles in Cadmium Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    MH Ehrampoush

    2014-09-01

    Results: The results indicated that the adsorption process is affected by different parameters such as initial pollutant concentrations, adsorbent dose, pH, and contact time and Cadmiumremoval efficiency increases with increasing adsorbent dose and reaction time and decreases with increasing initial concentration of Cadmium. Therefore, it is observed that by raising the initial Cadmium concentration, the adsorption rate increases. The maximum efficiency of adsorptionin pH=7amounted to 89.6%. Conclusion: It is concluded that Zinc Oxide nanoparticles have proper efficiency in removal of Cadmium from aqueous solutions and can be used in the treatment of wastewater that contains ion Cadmium. However, its efficiency is deeply dependent on ion strength and the interaction of other metals in wastewater.

  19. Uptake of Cadmium and Zinc from Synthetic Effluent by Water Hyacinth (Eichhornia crassipes

    Directory of Open Access Journals (Sweden)

    Hafidzatul Husna Mohamad

    2010-01-01

    Full Text Available In this study was conducted on aquatic plant; water hyacinth (Eichchornia crassipes which has been successfully utilized for the removal of cadmium (Cd and zinc (Zn from aqueous solutions. The overall metal uptake by the plant was dependent upon the concentration of the metal and the duration of exposure. In general, the metal content in plants increased with the increase in metal concentrations in solution and the metal accumulation in roots was always significantly higher than that in shoots for both metals in water hyacinth. Water hyacinth treated with 4 mg/L of cadmium accumulated the highest concentration metal in shoots (148 μg/g and roots (2006 μg/g and water hyacinth treated with solution containing 40 mg/L zinc accumulated the highest zinc concentration in shoots (1899 μg/g and roots (9646 μg/g.

  20. Investigation of quad-energy high-rate photon counting for X-ray computed tomography using a cadmium telluride detector.

    Science.gov (United States)

    Matsukiyo, Hiroshi; Sato, Eiichi; Oda, Yasuyuki; Yamaguchi, Satoshi; Sato, Yuichi; Hagiwara, Osahiko; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya

    2017-12-01

    To obtain four kinds of tomograms at four different X-ray energy ranges simultaneously, we have constructed a quad-energy (QE) X-ray photon counter with a cadmium telluride (CdTe) detector and four sets of comparators and microcomputers (MCs). X-ray photons are detected using the CdTe detector, and the event pulses produced using amplifiers are sent to four comparators simultaneously to regulate four threshold energies of 20, 33, 50 and 65keV. Using this counter, the energy ranges are 20-33, 33-50, 50-65 and 65-100keV; the maximum energy corresponds to the tube voltage. We performed QE computed tomography (QE-CT) at a tube voltage of 100kV. Using a 0.5-mm-diam lead pinhole, four tomograms were obtained simultaneously at four energy ranges. K-edge CT using iodine and gadolinium media was carried out utilizing two energy ranges of 33-50 and 50-65keV, respectively. At a tube voltage of 100kV and a current of 60 μA, the count rate was 15.2 kilocounts per second (kcps), and the minimum count rates after penetrating objects in QE-CT were regulated to approximately 2 kcps by the tube current. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Protective Effects of Long Term Administration of Zinc on Bone Metabolism Parameters in Male Wistar Rats Treated with Cadmium

    Directory of Open Access Journals (Sweden)

    Shiva Najafi

    2016-10-01

    Full Text Available Background Violent poisoning by cadmium in human is created through drinks or meals which have packed in the metallic tins with cadmium plating. The symptoms of variation in the mineral metabolism of bones are observed and different conditions maybe appeared. The toxic (poisonous effect due to cadmium can be neutralized by intervening zinc. This study has been designed to investigate the protective effects of zinc for reducing the poisonous effects due to cadmium on the metabolism in the parameters related to the bone in rat. Methods In this experimental study, 48 male rats of wistar species were distributed in eight experimental groups and tested in the investigative lab of Falavarjan university. These groups were received 0.5 cc physiological serum, 0.5 mg/kg Zinc, 0.5, 1, 2 mg/kg Cadmium respectively and some groups were included in those were taken all there cadmium and zinc concentrations synchronously. Blood samples were taken in a 60 days period and those factors related to the bone metabolism were measured. The data were analyzed by 2-ANOVA Ways, complementary tests through software SPSS 16. Results The results showed that 0.5, 1, 2 mg/kg doses cadmium chloride caused to increase alkaline Phosphatase, calcium, phosphorus, magnesium and decrease albumin as compared with control group. Also, synchronous usage of all three cadmium chloride concentrations with zinc cause to decrease alkaline phosphatase, calcium, phosphorus, magnesium and increase albumin concentration. In a word, the other bone parameters have been significant in different cadmium and zinc doses (P < 0.05. Conclusions Findings showed that zinc can play a protective role on the metabolism parameters related to bone against to poisoning caused by cadmium.

  3. DETERMINATION OF ZINC, CADMIUM, LEAD AND COPPER IN SAMPLES OF COFFEE

    Directory of Open Access Journals (Sweden)

    E. Yu. Kupchik

    2015-12-01

    Full Text Available The potential pollutants which can get to the body using food products were explored in this work. The content of heavy metals such as zinc, cadmium, lead and copper are determined in coffee by inversion voltammetry. Sample preparation of samples was performed by oxidizing mineralization of paint sample in nitrate acid. It is shown that the method of inversion voltammetry can be successfully applied for the determination of zinc, cadmium, lead and copper at their combined presence in coffee. It is established that lead and zinc contain in all investigated samples, most of them contain cadmium and copper. Based on the analysis of experimental data discovered that the content of lead and cadmium don’t exceed permissible limits. It is noted that the average number of heavy metals increases in the order: coffee drinks- a soluble coffee – coffee beans and Grinded – green coffee. However, for an objective assessment of hair dyes quality, it is recommended to use a separate identification on each of heavy metals.

  4. Mechanical Activation-Assisted Reductive Leaching of Cadmium from Zinc Neutral Leaching Residue Using Sulfur Dioxide

    Science.gov (United States)

    Zhang, Chun; Min, Xiaobo; Chai, Liyuan; Zhang, Jianqiang; Wang, Mi

    2015-12-01

    In this work, zinc neutral leaching residue was mechanically activated by ball-milling. The subsequent leaching behavior and kinetics of cadmium extraction in a mixed SO2-H2SO4 system were studied. Changes in the crystalline phase, lattice distortion, particle size and morphology, which were induced by mechanical activation, were also investigated. The activated samples showed different physicochemical characteristics, and cadmium extraction was found to be easier than for the un-activated samples. Under the same conditions, mechanical activation contributed to higher cadmium leaching. The cadmium extraction kinetics at 75-95°C was found to fit the shrinking core model. The raw neutral leaching residue, and the samples activated for 60 min and 120 min had a calculated activation energy of 65.02 kJ/mol, 59.45 kJ/mol and 53.46 kJ/mol, respectively. The leaching residue was characterized by ICP, XRD and SEM analysis. According to XRD analysis, the main phases in the residue were lead sulfate (PbSO4), zinc sulfide (ZnS) and cadmium sulfide (CdS).

  5. Cadmium telluride quantum dots cause oxidative stress leading to extrinsic and intrinsic apoptosis in hepatocellular carcinoma HepG2 cells.

    Science.gov (United States)

    Nguyen, Kathy C; Willmore, William G; Tayabali, Azam F

    2013-04-05

    The mechanisms of toxicity related to human hepatocellular carcinoma HepG2 cell exposures to cadmium telluride quantum dots (CdTe-QDs) were investigated. CdTe-QDs caused cytotoxicity in HepG2 cells in a dose- and time-dependent manner. Treated cells showed an increase in reactive oxygen species (ROS). Altered antioxidant levels were demonstrated by depletion of reduced glutathione (GSH), a decreased ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) and an increased NF-E2-related Factor 2 (Nrf2) activation. Enzyme assays showed that superoxide dismutase (SOD) activity was elevated whereas catalase (CAT) and glutathione-S-transferase (GST) activities were depressed. Further analyses revealed that CdTe-QD exposure resulted in apoptosis, indicated by changes in levels of caspase-3 activity, poly ADP-ribose polymerase (PARP) cleavage and phosphatidylserine externalization. Extrinsic apoptotic pathway markers such as Fas levels and caspase-8 activity increased as a result of CdTe-QD exposure. Involvement of the intrinsic/mitochondrial apoptotic pathway was indicated by decreased levels of B-cell lymphoma 2 (Bcl2) protein and mitochondrial cytochrome c, and by increased levels of mitochondrial Bcl-2-associated X protein (Bax) and cytosolic cytochrome c. Further, mitogen-activated protein kinases (MAPKs) such as c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinases (Erk1/2), and p38 were all activated. Our findings reveal that CdTe-QDs cause oxidative stress, interfere with antioxidant defenses and activate protein kinases, leading to apoptosis via both extrinsic and intrinsic pathways. Since the effects of CdTe-QDs on selected biomarkers were similar or greater compared to those of CdCl2 at equivalent concentrations of cadmium, the study suggests that the toxicity of CdTe-QDs arises from a combination of the effects of cadmium and ROS generated from the NPs. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  6. High cadmium / zinc ratio in cigarette smokers: potential implications ...

    African Journals Online (AJOL)

    Tobacco smoke may be one of the most common sources of cadmium (Cd) in the general population, particularly in the rising population of smokers in developing countries. Although a relationship between both cigarette smoking and environmental Cd contamination with prostate cancer exist, the mechanisms are unclear.

  7. CadA of Mesorhizobium metallidurans isolated from a zinc-rich mining soil is a P(IB-2)-type ATPase involved in cadmium and zinc resistance.

    Science.gov (United States)

    Maynaud, Geraldine; Brunel, Brigitte; Yashiro, Erika; Mergeay, Max; Cleyet-Marel, Jean-Claude; Le Quéré, Antoine

    2014-04-01

    Mesorhizobium metallidurans STM 2683(T) is a nitrogen-fixing bacterium that nodulates Anthyllis vulneraria in mine tailings highly contaminated in zinc, lead and cadmium. To study the mechanisms whereby this bacterium copes with metals, we functionally screened a cosmid genomic library of M. metallidurans for zinc or cadmium tolerance. A cosmid clone harbored a gene encoding P(IB)-type ATPase homologous to CadA that leads to cadmium and zinc resistance in Escherichia coli. The CadA protein structure presents one duplication of the two N-terminal metal binding domains (i.e. a heavy metal-associated domain followed by a histidine-rich domain) which allows specific binding to zinc and cadmium cations. A cadA-deleted strain of M. metallidurans failed to grow at high zinc concentrations (2 mM) and its growth was delayed at lower zinc concentrations. Expression studies using a transcriptional fusion of cadA promoter to gfp showed that cadA is specifically induced in a dose-dependent manner by zinc and cadmium in M. metallidurans in vitro conditions and into A. vulneraria nodules after Zn stress. Metal induction sensitivity was increased in the strain where cadA gene was deleted. This study identified cadA as a first mesorhizobial resistance determinant involved in detoxification of cadmium and zinc and which confers upon M. metallidurans greater capacity for coping with high zinc concentrations. This improves the knowledge of this bacterium for potential use as a symbiotic inoculant of Anthyllis in phytostabilization strategies of metal-rich sites. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  8. Adsorption and immobilisation of nickel, zinc and cadmium by goethite (. cap alpha. -FeOOH)

    Energy Technology Data Exchange (ETDEWEB)

    Gerth, J.; Bruemmer, G.

    1983-11-01

    The adsorption of nickel, zinc, and cadmium by geothite was studied at different metal concentrations of 0.5 and 5 ..mu..mole/g goethite, reaction times from 2 h to 42 days and temperatures between 5 and 35/sup 0/C. The metal amounts adsorbed strongly increase with pH in the range from 4 to 8. The specificity of the heavy metal adsorption by geothite is characterized by the pH of 50% sorption of the total metal content added (pH/sub 50/). Under the reaction conditions of these experiments pH/sub 50/-values of 4.9, 5.6, and 5.8 were found for zinc, nickel, and cadmium, respectively. The differences between the pH/sub 50/-values closely agree with the differences between the pH-values of the first hydrolysis constants of zinc, nickel, and cadmium, thus indicating that trace metal adsorption by the hydroxylated surfaces of iron oxides is strongly affected by the hydroxocomplex formation of trace metals. With increasing reaction time and temperature the adsorption of all three metals rises. Besides adsorption at the surface solid state diffusion is also observed which can probably be related to defective structures in the lattice of geothetite. Linear plots of the metal amount adsorbed versus the square root of time provide relative diffusion rates for nickel, zinc, and cadmium of 2.47, 1.00, and 0.31, respectively, at 20/sup 0/C and definite pH. These values show that the effect of diffusion on the binding of metals by geothite is increased in the order Cd

  9. Effects of Cadmium, Lead, Manganese, and Zinc at WHO Safe Limits ...

    African Journals Online (AJOL)

    In the present study, The in vitro availability of chloramphenicol was studied in the presence of lead (Pb), cadmium (Cd), manganese (Mn) and zinc (Zn) at 0.01, 0.003, 0.5 and 3 mg/L respectively corresponding to WHO safe limits in drinking water for each of the metals. The in vitro availability study was carried out in ...

  10. Survey of lead, cadmium, iron, copper and zinc in Kaşar cheese.

    Science.gov (United States)

    Yüzbaşi, N; Sezgin, E; Yildirim, M; Yildirim, Z

    2003-05-01

    Lead, cadmium, iron, copper and zinc contents of Kaşar cheese sold in the markets of Ankara, Turkey, were determined over 12 months. A total of 240 samples comprising 10 different brands were analysed. Graphite-furnace atomic absorption was employed for the determination of lead and cadmium, and flame atomic absorption for iron, copper and zinc. The mean (range) of the lead, cadmium, iron, copper and zinc content of the samples were 86 (10-421) microg kg(-1), 1.8 (0.3-8.3) microg kg(-1), 4.2 (1.0-14.1) mg kg(-1), 0.7 (0.3-1.6) mg kg(-1) and 37.7 (26.5-63.0) mg kg(-1), respectively. The samples in November, December and January contained higher amounts of lead than those in other months (p cheese producers (p 0.05). These findings suggested that some contamination occurred during milk production and/or manufacturing of cheese depending on the equipment used. For a consumption of 100 g Kaşar cheese, one would ingest approximately 8.6 microg (4% of the provisional tolerable daily intake, PTDI) of lead, 0.2 microg (0.3%) of cadmium, 0.4 mg (0.9%) of iron, 0.07 mg (2%) of copper and 3.8 mg (6%) of zinc. Therefore, it was concluded that Kaşar cheese is not a significant contributor to the intake of investigated heavy metals.

  11. Spectral analysis of the effects of 1.7 MeV electron irradiation on the current transfer characteristic of cadmium telluride solar cells.

    Science.gov (United States)

    Tian, Jin-Xiu; Zeng, Guang-Gen; He, Xu-Lin; Zhang, Jing-Quan; Wu, Li-Li; Li, Wei; Li, Bing; Wang, Wen-Wu; Feng, Liang-Huan

    2014-04-01

    The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystalline thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe : Cu/Ni have been studied. Light and dark I-V characteristics, dark C-V characteristics, quantum efficiency (QE), admittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF) and conversion efficiency (eta). It was explored to find out the effects of irradiation on the current transfer characteristic of solar cells combined with the dark current density (Jo), diode ideal factor (A), quantum efficiency, carrier concentration and the depletion layer width. The decline in short-circuit current was very large and the efficiency of solar cells decreased obviously after irradiation. Reverse saturation current density increased, which indicates that p-n junction characteristics of solar cells were damaged, and diode ideal factor was almost the same, so current transport mechanism of solar cells has not changed. Quantum efficiency curves proved that the damage of solar cells' p-n junction influenced the collection of photo-generated carriers. Irradiation made carrier concentration reduce to 40.6%. The analyses have shown that. A new defect was induced by electron irradiation, whose position is close to 0.58 eV above the valence band in the forbidden band, and capture cross section is 1.78 x 10(-16) cm2. These results indicate that irradiation influences the generation of photo-generated carriers, increases the risk of the carrier recombination and the reverse dark current, and eventually makes the short-circuit current of solar cells decay.

  12. Concentrations of lead, cadmium and zinc in the tissues of reproductive organs of men.

    Science.gov (United States)

    Oldereid, N B; Thomassen, Y; Attramadal, A; Olaisen, B; Purvis, K

    1993-11-01

    The concentrations of lead in blood and the concentrations of lead, cadmium and zinc in tissues were determined in various reproductive organs, liver and kidney removed at necropsy from 41 men who had died suddenly. None of the reproductive organs specifically accumulated lead and no significant correlation could be demonstrated between blood and organ concentrations or between concentrations and age, occupation or urban/rural background of the subject. Unlike lead, the tissue concentrations of cadmium increased with increasing age in all of the reproductive organs examined. Of these, the epididymides and seminal vesicles contained the highest concentrations. Whereas prostatic zinc also exhibited a significant age-dependent increase, the concentrations in the testes declined with age. The age-dependent increase in testicular cadmium did not become apparent until after the fourth decade, when any potentially deleterious impact on male fertility has less relevance. It is concluded that measurable amounts of lead and cadmium are present in all of the human reproductive organs but their organ and age distribution do not offer strong support for their involvement in the aetiology of male infertility or in the genesis of glandular neoplasms.

  13. Transport phenomena in the close-spaced sublimation deposition process for manufacture of large-area cadmium telluride photovoltaic panels: Modeling and optimization

    Science.gov (United States)

    Malhotra, C. P.

    With increasing national and global demand for energy and concerns about the effect of fossil fuels on global climate change, there is an increasing emphasis on the development and use of renewable sources of energy. Solar cells or photovoltaics constitute an important renewable energy technology but the major impediment to their widespread adoption has been their high initial cost. Although thin-film photovoltaic semiconductors such as cadmium sulfide-cadmium telluride (CdS/CdTe) can potentially be inexpensively manufactured using large area deposition techniques such as close-spaced sublimation (CSS), their low stability has prevented them from becoming an alternative to traditional polycrystalline silicon solar cells. A key factor affecting the stability of CdS/CdTe cells is the uniformity of deposition of the thin films. Currently no models exist that can relate the processing parameters in a CSS setup with the film deposition uniformity. Central to the development of these models is a fundamental understanding of the complex transport phenomena which constitute the deposition process which include coupled conduction and radiation as well as transition regime rarefied gas flow. This thesis is aimed at filling these knowledge gaps and thereby leading to the development of the relevant models. The specific process under consideration is the CSS setup developed by the Materials Engineering Group at the Colorado State University (CSU). Initially, a 3-D radiation-conduction model of a single processing station was developed using the commercial finite-element software ABAQUS and validated against data from steady-state experiments carried out at CSU. A simplified model was then optimized for maximizing the steady-state thermal uniformity within the substrate. It was inferred that contrary to traditional top and bottom infrared lamp heating, a lamp configuration that directs heat from the periphery of the sources towards the center results in the minimum temperature

  14. Reproduction and biochemical responses in Enchytraeus albidus (Oligochaeta) to zinc or cadmium exposures

    Energy Technology Data Exchange (ETDEWEB)

    Novais, Sara C., E-mail: sara.novais@ua.pt [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gomes, Susana I.L. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gravato, Carlos [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Guilhermino, Lucia [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); ICBAS-Instituto de Ciencias Biomedicas Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Porto (Portugal); De Coen, Wim [University of Antwerp, Department of Biology - E.B.T., Groenenborgerlaan 171 - U.7., B-2020 Antwerp (Belgium); Soares, Amadeu M.V.M.; Amorim, Monica J.B. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

    2011-07-15

    To better understand chemical modes of action, emphasis has been given to stress responses at lower levels of biological organization. Cholinesterases and antioxidant defenses are among the most used biomarkers due to their crucial role in the neurocholinergic transmission and in cell homeostasis preventing DNA damage, enzymatic inactivation and lipid peroxidation. The main goal of this study was to investigate the effects of zinc and cadmium on survival and reproduction of E. albidus and to assess metals oxidative stress potential and neurotoxic effects at concentrations that affected reproduction. Both metals affected the enchytraeids' survival and reproduction and induced significant changes in the antioxidant defenses as well as increased lipid peroxidation, indicating oxidative damage. This study demonstrates that determining effects at different levels of biological organization can give better information on the physiological responses of enchytraeids in metal contamination events and further unravel the mechanistic processes dealing with metal stress. - Highlights: > Zinc and cadmium influence the survival and reproduction of Enchytraeus albidus. > Oxidative stress and membrane damage occur at reproduction effect concentrations. > Glutathione seems to be important in the antioxidant defense against metals. > Time intervals (2, 4, 8 days) allowed following the evolution of oxidative events. - Zinc and cadmium cause oxidative stress and membrane damage in Enchytraeus albidus at reproduction effect concentrations.

  15. Alcohol vapor sensing by cadmium-doped zinc oxide thick films based chemical sensor

    Science.gov (United States)

    Zargar, R. A.; Arora, M.; Chackrabarti, S.; Ahmad, S.; Kumar, J.; Hafiz, A. K.

    2016-04-01

    Cadmium-doped zinc oxide nanoparticles were derived by simple chemical co-precipitation route using zinc acetate dihydrate and cadmium acetate dihydrate as precursor materials. The thick films were casted from chemical co-precipitation route prepared nanoparticles by economic facile screen printing method. The structural, morphological, optical and electrical properties of the film were characterized relevant to alcohol vapor sensing application by powder XRD, SEM, UV-VIS and DC conductivity techniques. The response and sensitivity of alcohol (ethanol) vapor sensor are obtained from the recovery curves at optimum working temperature range from 20∘C to 50∘C. The result shows that maximum sensitivity of the sensor is observed at 25∘C operating temperature. On varying alcohol vapor concentration, minor variation in resistance has been observed. The sensing mechanism of sensor has been described in terms of physical adsorption and chemical absorption of alcohol vapors on cadmium-doped zinc oxide film surface and inside film lattice network through weak hydrogen bonding, respectively.

  16. Interpretation of single and competitive adsorption of cadmium and zinc on activated carbon using monolayer and exclusive extended monolayer models.

    Science.gov (United States)

    Sellaoui, Lotfi; Dotto, Guilherme L; Lamine, Abdelmottaleb Ben; Erto, Alessandro

    2017-08-01

    In this work, a modeling analysis based on experimental tests of cadmium/zinc adsorption, in both single-compound and binary systems, was carried out. All the experimental tests were conducted at constant pH (around neutrality) and temperature (20 °C). The experimental results showed that the zinc adsorption capacity was higher than that of cadmium and it does not depend on cadmium presence in binary system. Conversely, cadmium adsorption is affected by zinc presence. In order to provide good understanding of the adsorption process, two statistical physics models were proposed. A monolayer and exclusive extended monolayer models were applied to interpret the single-compound and binary adsorption isotherms of zinc and cadmium on activated carbon. Based on these models, the modeling analysis demonstrated that zinc is dominant in solution and more favorably adsorbed on activated carbon surface. For instance, in single-compound systems, the number of ions bound per each receptor site was n (Zn2+) = 2.12 > n (Cd2+) = 0.98. Thus, the receptor sites of activated carbon are more selective for Zn2+ than for Cd2+. Moreover, the determination of adsorption energy through the adopted models confirmed that zinc is more favored for adsorption in single-compound system (adsorption energies equal to 12.12 and 7.12 kJ/mol for Zn and Cd, respectively) and its adsorption energy does not depend on the cadmium presence in binary system. Finally, the adsorption energy values suggested that single-compound and binary adsorption of zinc and cadmium is a physisorption.

  17. Zinc and cadmium accumulation among and within populations of the pseudometalophytic species Arrhenatherum elatius: Implications for phytoextraction

    Energy Technology Data Exchange (ETDEWEB)

    Deram, A. [Universite Droit et Sante de Lille - EA 2690, Institut Lillois d' Ingenierie de la Sante, 42, rue Ambroise Pare 59 120 Loos (France)]. E-mail: annabelle.deram@univ-lille2.fr; Denayer, F.-O. [Universite Droit et Sante de Lille - EA 2690, Institut Lillois d' Ingenierie de la Sante, 42, rue Ambroise Pare 59 120 Loos (France); Dubourgier, H.-C. [Eesti Maauelikool, Pollumajandus-ja keskkonnainstituut, Kreutzwaldi 64, Tartu 51 014 (Estonia); Douay, F. [Institut Superieur d' Agriculture, Laboratoire Sols et Environnement, 48, Boulevard Vauban 59 046 Lille (France); Petit, D. [Laboratoire de Genetique et Evolutions des Populations Vegetales, UPRESA-CNRS 8016, Bat SN2, Universite des Sciences et Technologies de Lille, Villeneuve d' Ascq, 59 655 France (France); Van Haluwyn, C. [Universite Droit et Sante de Lille - EA 2690, Departement de Botanique, Faculte des Sciences Pharmaceutiques et Biologiques, 3, rue du Professeur Laguesse, B.P. 83, F-59 006 Lille cedex (France)

    2007-01-01

    The purpose of this study was to investigate, under standard conditions, the bioaccumulation of zinc and cadmium in Arrhenatherum elatius, a perennial grass with a high biomass production. Nine populations of three different origins were tested: three metallicolous populations (mpop); three non-metallicolous populations (nmpop) and three populations developing on soils moderately metal polluted (medpop). We have found that bioaccumulation differs among these populations, with nmpop accumulating significantly more zinc (p < 0.0001) and cadmium (p < 0.0001) than mpop. Indeed, we have observed a concentration of 325 mg kg{sup -1} of zinc and 52 mg kg{sup -1} of cadmium in A. elatius shoots from mpop, whereas in nmpop, the concentration reached on average 524 mg kg{sup -1} zinc and 83 mg kg{sup -1} cadmium. In the same way, medpop accumulated as much zinc but more cadmium than nmpop. Moreover, the standard deviation of medpop was larger than the one for mpop and nmpop. Indeed, some A. elatius samples from medpop presented a high metal content whereas, others presented low concentrations in their shoots (ranging from 60 to 210 mg kg{sup -1} cadmium). Hence, these medpop exhibited a large variability among and within populations in accumulating zinc and cadmium in their shoots. Based on these results, the possibility of selecting A. elatius plants with the best accumulating capacity from medpop was proposed. We concluded that if the accumulation capacity is genetically controlled in A. elatius, this species fulfils this necessary condition for efficiently increasing species bioaccumulation by crossbreeding A. elatius plants with the higher accumulation capacity.

  18. Contamination of Soil, Water, Plant and Dust by Zinc, Lead and Cadmium in Southwest Isfahan

    Directory of Open Access Journals (Sweden)

    Nastaran Esmaeilpourfard

    2016-02-01

    Full Text Available Introduction Due to mining, considerable amounts of heavy metal bearing mineralsare scattered in the atmosphere in the form of dust and make the surrounding air, water and soils polluted.Runoff water movingfrom the mountainstowardsplains may also transport heavy metals from mines to the soils.One type ofpollutions is contamination withheavy metals.The purpose of the present research has been to investigate the effect of heavy metals of mine on soil, water, plant and dust pollution. Materials and Methods: Gushfil mine is located 3 kilometers southwest of Sepahanshahr, Isfahan. Soil profiles were dug 500 meters apart along three parallel transects, between east of Sepahanshahr and Gushfil mine. The profiles were described and samples were collected from their horizons. Ore, wells, plant and dust were sampled as well. Total concentrations of lead, zinc and cadmium were measured in the samples. To find the origin of polluted dust and soil, lead isotopes contents in the samples were measured and regressional relationships between the ratios of these contents were investigated. Results and Discussion Sepahanshahr soils are not contaminated by zinc, lead and cadmium, but within a distance of one to two kilometers from the Gushfil mine, the soils are polluted by zinc and lead. Cadmium contamination was not observed in the studied soils. In all of the soils, the heavy metals content varies downwards irregularly. The reason for this variation trend is that the studied soils are alluvial. In different periods of time, alluvium parent materials have been transported by runoff water from the lead and zinc mines towards the alluvial piedmont plain. The studied heavy metals have been distributed irregularly in different horizons of the soils that have been formed in these parent materials. Lead and cadmium concentrations of drinking water in the studied area are much higher than the maximum amount allowed by the World Health Organization. Cadmium content in

  19. 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.

  20. Cadmium Alternatives

    Science.gov (United States)

    2012-08-01

    using for commercial applications Other zinc alloys Zinc cobalt , tin zinc, zinc iron Passivation Cadmium, ZnNi, SnZn, ZnCo, ZnFe, and...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

  1. Can zinc supplementation ameliorate cadmium-induced alterations in the bioelement content in rabbits?

    Science.gov (United States)

    Bulat, Zorica; Đukić-Ćosić, Danijela; Antonijević, Biljana; Buha, Aleksandra; Bulat, Petar; Pavlović, Zoran; Matović, Vesna

    2017-03-01

    The study was designed to investigate the influence of zinc (Zn) supplementation on cadmium-induced alterations in zinc, copper (Cu), and magnesium (Mg) status in rabbits. For this purpose, the concentrations of cadmium (Cd), Zn, Cu, and Mg were estimated in the blood, liver, kidney, and bone. The rabbits were divided in a control group, a Cd group-animals intoxicated orally with Cd (10 mg kg-1 bw, as aqueous solution of Cd-chloride), and a Cd+Zn group-animals intoxicated with the same dose of Cd and co-treated with Zn (20 mg kg-1 bw, as aqueous solution of Zn-sulphate). Solutions were administered orally, every day for 28 days. Sample mineralisation was performed with concentrated nitric acid (HNO3) and perchloric acid (HClO4) (4:1) and metal concentrations were determined by atomic absorption spectrophotometry (AAS). Zinc supplementation improved some of Cd-induced disturbances in bioelement levels in the investigated tissues. Beneficial effects of Zn on Zn and Cu levels were observed in blood, as well as on the Cu kidney level. The calculated values for Cu/Zn, Mg/Zn, and Mg/Cu ratios in blood suggest that Zn co-treatment reduces Cd-induced changes in bioelement ratios in blood.

  2. 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.

  3. Sorption of cadmium and zinc from aqueous solutions by zeolite 4A, zeolite 13X and bentonite.

    Science.gov (United States)

    Purna Chandra Rao, G; Satyaveni, S; Ramesh, A; Seshaiah, K; Murthy, K S N; Choudary, N V

    2006-11-01

    The sorption and desorption of cadmium and zinc on zeolite 4A, zeolite 13X and bentonite has been studied using batch sorption studies. Parameters such as equilibrium time, effect of pH and sorbent dose were studied. The sorbents exhibited good sorption potential for cadmium and zinc with a peak value at pH 6.0 and 6.5, respectively. The sorption followed the Freundlich sorption model. More than 70% sorption occurred within 20 min and equilibrium was attained at around 90 min for the three sorbents. The metals sorption by zeolite 4A was higher than that by zeolite 13X and bentonite. The desorption studies were carried out using NaCl solution and the effect of NaCl concentration on desorption was also studied. Maximum desorption of 76% for cadmium and 80% for zinc occurred with 10% NaCl.

  4. Scandium-doped zinc cadmium oxide as a new stable n-type oxide thermoelectric material

    DEFF Research Database (Denmark)

    Han, Li; Christensen, Dennis Valbjørn; Bhowmik, Arghya

    2016-01-01

    Scandium-doped zinc cadmium oxide (Sc-doped ZnCdO) is proposed as a new n-type oxide thermoelectric material. The material is sintered in air to maintain the oxygen stoichiometry and avoid instability issues. The successful alloying of CdO with ZnO at a molar ratio of 1 : 9 significantly reduced...... is a good candidate for improving the overall conversion efficiencies in oxide thermoelectric modules. Meanwhile, Sc-doped ZnCdO is robust in air at high temperatures, whereas other n-type materials, such as Al-doped ZnO, will experience rapid degradation of their electrical conductivity and ZT....

  5. Evaluation of Cadmium, Lead and Zinc Content of Compost Produced in Babol Composting Plant

    Directory of Open Access Journals (Sweden)

    Fatemeh Asgharzadeh

    2014-03-01

    Full Text Available Background and purpose: The most important parameter is heavy metal contents in compost production technology. These heavy metals residue from substances like soap, detergents, cosmetics, packaging, leather and butteries are existed in municipal solid waste. The heavy metals can produce toxin for animal, human and plant. The aim of this research was study of produced compost quality based on heavy metals (Pb, Cd and Zn in Babol compost plant in 2012. Materials and Methods: The present research is a descriptive- cross sectional study in which was performed in six months. Total sample numbers (5 samples were randomly provided from final compost of Babol plant and then after extraction and filtration, the concentration of heavy metals like cadmium, lead and zinc was measured by atomic absorption spectrophotometer PG- 999. Results: In analyzed samples the maximum, minimum and average of cadmium in the final compost were 7.25, 0.47 and 1.9 mg/kg. The maximum, minimum and mean of lead were 239.2, 31.9 and 67.1 mg/kg; in zinc were 972.7, 483.5 and 603.7 mg/kg respectively. Conclusion: The concentration of heavy metals in Babol compost samples was under Iranian national and World Health Organization standards and could be used for different species of plants. However, the usability of compost depends on other parameters such as carbon to nitrogen and other components like glass, plastics and textiles.

  6. [Environmental concerns on geochemical mobility of lead, zinc and cadmium from zinc smelting areas: western Guizhou, China].

    Science.gov (United States)

    Lin, Wen-Jie; Xiao, Tang-Fu; Zhou, Wan-Chun; Ao, Zi-Qiang; Zhang, Jun-Fang

    2009-07-15

    Indigenous zinc smelting activity, widely spread in western Guizhou, China, had caused serious pollution of heavy metals of lead (Pb), zinc (Zn) and cadmium (Cd) in soil and water and posed risk to the local ecosystem. Geochemical distribution and mobility of Pb, Zn and Cd in soil, waste residue and waters were investigated in a small watershed in order to provide scientific base for the approach to pollution control and remediation. Concentrations of Pb, Zn and Cd in smelting residues averaged at 4 632 mg/kg, 8 968 mg/kg, and 58 mg/kg, respectively; whereas Pb 234 mg/kg, Zn 400 mg/kg and Cd 9.6 mg/kg in average in the soils around the smelting areas were measured. The sequential geochemical extraction test showed that Pb, Zn and Cd in the contaminated soils had high mobility and bioavailability for the metals, whereas smelting waste residues had lower mobility and bioavailability because their concentrations presented small percentages (all less than 0.2%) in the exchangeable fraction. Concentrations of Pb, Zn and Cd were high in the local stream water but low in groundwater. In the surface water, Pb, Zn and Cd were significantly concentrated in the suspended sediment. The results indicated that metal-rich erosion process of smelting residue and contaminated soil contributed to mobility of the metals into stream water.

  7. Polycrystalline Cadmium Telluride Photovoltaic Devices

    Science.gov (United States)

    Gessert, Timothy A.; Bonnet, Dieter

    2015-10-01

    The following sections are included: * Introduction * Brief history of CdTe PV devices * Initial attempts towards commercial modules * Review of present commercial industry/device designs * General CdTe material properties * Layer-specific process description for superstrate CdTe devices * Where is the junction? * Considerations for large-scale deployment * Conclusions * Acknowledgements * References

  8. Quaternary oxide halides of group 15 with zinc and cadmium; Quaternaere Oxidhalogenide der Gruppe 15 mit Zink und Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Rueck, Nadia

    2014-07-30

    The present thesis ''Quaternary oxide halides of group 15 with zinc and cadmium'' deals with the chemical class of oxide halides, which contain d-block element cations and pnicogens. Over the past few years compounds containing pnicogene cations are intensively investigated. The reason for this is the free electron pair of the Pn{sup 3+} cation, which is responsible for some interesting properties. Free electron pairs do not only impact the spatial structure of molecules but also the properties of materials. The object of this work was the synthesis and characterization of compounds containing Pn{sup 3+} cations with free electron pairs. Due to the structure-determining effect of these free electron pairs and in combination with halides it is possible to synthesize compounds with low-dimensional structures like chains and layers. In these compounds the structure is separated into halophilic and chalcophilic sub-structures, which are held together only by weak Van der Waals forces.

  9. Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

    DEFF Research Database (Denmark)

    Holm, P.E.; Christensen, T.H.

    1998-01-01

    Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... Cd L(-1) and 9 to 3600 mu g Zn L(-1), which were dominated by free metal ions as measured by an ion exchange-resin method. Annual leaching outflows were estimated from soil water concentrations to be 0.5-17 g Cd ha(-1) y(-1) and 9-3600 g Zn ha(-1) y(-1) per 100 mm of net percolation, corresponding...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...

  10. Protein Biochemistry and Expression Regulation of Cadmium/Zinc Pumping ATPases in the Hyperaccumulator Plants Arabidopsis halleri and Noccaea caerulescens

    Czech Academy of Sciences Publication Activity Database

    Mishra, S.; Mishra, Archana; Küpper, Hendrik

    2017-01-01

    Roč. 8, May 22 (2017), č. článku 835. ISSN 1664-462X R&D Projects: GA MŠk EF15_003/0000336 Institutional support: RVO:60077344 Keywords : cellular compartmentation * zinc homeostasis * cadmium * metal hyperaccumulator plants Subject RIV: CE - Biochemistry Impact factor: 4.298, year: 2016

  11. Factors that Affect the Content of Cadmium, Nickel, Copper and Zinc in Tissues of the Knee Joint.

    Science.gov (United States)

    Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Jakóbik-Kolon, Agata; Kluczka, Joanna; Babuśka-Roczniak, Magdalena

    2017-08-01

    Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).

  12. Cloning and occurrence of czrC, a gene conferring cadmium and zinc resistance in MRSA CC398 Isolates

    DEFF Research Database (Denmark)

    Cavaco, Lina; Hasman, Henrik; Stegger, Marc

    2010-01-01

    determinant, czrC, by PCR. The cloning of czrC confirmed that the zinc chloride and cadmium acetate MICs for isogenic constructs carrying this gene were increased compared to those for S. aureus RN4220. No difference in susceptibility to sodium arsenate, copper sulfate, or silver nitrate was observed. Seventy...

  13. Expression profiling reveals functionally redundant multiple-copy genes related to zinc, iron and cadmium responses in Brassica rapa

    NARCIS (Netherlands)

    Li, J.; Liu, B.; Cheng, F.; Wang, X.; Aarts, M.G.M.; Wu, J.

    2014-01-01

    Genes underlying environmental adaptability tend to be over-retained in polyploid plant species. Zinc deficiency (ZnD) and iron deficiency (FeD), excess Zn (ZnE) and cadmium exposure (CdE) are major environmental problems for crop cultivation, but little is known about the differential expression of

  14. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Comprehensive progress report, October 1, 1975--December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, R. H.

    1978-10-01

    Investigations were undertaken to elucidate the mode of transepithelial transport of potentially toxic metal ions across the gastrointestinal tract, with primary attention given to cadmium, zinc, and arsenic. In addition, the toxic effects of cadmium on the metabolism of vitamin D and calcium have been investigated in some detail. Several approaches have been taken, including studies on the localization of heavy metals in the intestinal mucosa, the effects of cadmium on various parameters of calcium metabolism, the modes of intestinal absorption of cadmium, arsenate, and zinc, and the interactions of heavy metals with each other and with calcium, phosphorus, and vitamin D. Details of these experiments are attached in the Comprehensive Progress Report.

  15. Simultaneous Measurement of Zinc, Copper, Lead and Cadmium in Baby Weaning Food and Powder Milk by DPASV.

    Science.gov (United States)

    Sadeghi, Naficeh; Oveisi, Mohammad Reza; Jannat, Behrooz; Hajimahmoodi, Mannan; Behfar, Abdolazim; Behzad, Masoomeh; Norouzi, Narges; Oveisi, Morvarid; Jannat, Behzad

    2014-01-01

    Apart from the breast milk, infant formula and baby weaning food have a special role in infant diet. Infants and young children are very susceptible to amount of trace elements. Copper and zinc are two elements that add in infant food. Lead and cadmium are heavy metals that enter to food chain unavoidably. DPASV is a benefit and applicable method for measurement of trace elements in food products. In this study, concentration of zinc, copper, lead and cadmium in four brands of baby food (rice and wheat based) and powder milk was analyzed with DPASV and polarograph set. Total Mean ± SE of zinc, copper, lead and cadmium in baby foods (n = 240) were 11.86 ± 1.474 mg/100g, 508.197 ± 83.154 μg/100g, 0.445 ± 0.006, 0.050 ± 0.005 mg/Kg respectively. Also these amount in powder milk (n = 240) were 3.621± 0.529 mg/100g, 403.822 ± 133.953 μg/100g, 0.007 ± 0.003, 0.060 ± 0.040 mg/Kg respectively. Zinc level in baby food type I was higher than lablled value (P = 0.030), but in other brands was not difference. Concentration of copper in all of samples was in labeled range (P > 0.05). In each four products, level of lead and cadmium were lower than the standard limit (P lead in baby food I, had difference versus other products. Concentration of zinc, camium in baby food type I, was higher than type II (P = 0.043, 0.001 respectively). Concentration of lead and cadmium in baby food type II, was higher than infant formulas, but are in standard limit.

  16. Zinc to cadmium replacement in the A. thaliana SUPERMAN Cys₂ His₂ zinc finger induces structural rearrangements of typical DNA base determinant positions.

    Science.gov (United States)

    Malgieri, Gaetano; Zaccaro, Laura; Leone, Marilisa; Bucci, Enrico; Esposito, Sabrina; Baglivo, Ilaria; Del Gatto, Annarita; Russo, Luigi; Scandurra, Roberto; Pedone, Paolo V; Fattorusso, Roberto; Isernia, Carla

    2011-11-01

    Among heavy metals, whose toxicity cause a steadily increasing of environmental pollution, cadmium is of special concern due to its relatively high mobility in soils and potential toxicity at low concentrations. Given their ubiquitous role, zinc fingers domains have been proposed as mediators for the toxic and carcinogenic effects exerted by xenobiotic metals. To verify the structural effects of zinc replacement by cadmium in zinc fingers, we have determined the high resolution structure of the single Cys₂ His₂ zinc finger of the Arabidopsis thaliana SUPERMAN protein (SUP37) complexed to the cadmium ion by means of UV-vis and NMR techniques. SUP37 is able to bind Cd(II), though with a dissociation constant higher than that measured for Zn(II). Cd-SUP37 retains the ββα fold but experiences a global structural rearrangement affecting both the relative orientation of the secondary structure elements and the position of side chains involved in DNA recognition: among them Ser17 side chain, which we show to be essential for DNA binding, experiences the largest displacement. 2011 Wiley Periodicals, Inc.

  17. Spatial Mapping of the Mobility-Lifetime (microtau) Production in Cadmium Zinc Telluride Nuclear Radiation Detectors Using Transport Imaging

    Science.gov (United States)

    2013-06-01

    its good electron transport. However, CdZnTe crystals are susceptible to growth defects such as grain boundaries, twin boundaries, and tellurium (Te...good electron transport. However, CdZnTe crystals are susceptible to growth defects such as grain boundaries, twin boundaries, and tellurium (Te...lifetime (left) or non-radiative lifetime (right). ..............63 Figure 49. Gettering of excess tellurium towards a point defect within the CdZnTe

  18. Development Of Position-sensitive Cadmium Zinc Telluride Detectors For High-energy X-ray Astrophysics

    CERN Document Server

    Slavis, K R

    2001-01-01

    This dissertation reports on the studies of an orthogonal cross-strip CdZnTe detector for high-energy X-ray (20–250 keV) astrophysics applications. The intrinsic three-dimensional detector response and the effectiveness of using various shielding techniques at balloon altitudes are investigated. This detector has great promise for use as the imaging detector of a large- area, coded-mask instrument in an all-sky high-energy X- ray survey or as the focal-plane detector for an X-ray focusing telescope (Constellation-X) for high throughput, high resolution X-ray spectroscopy (6–40 keV). The most recent hard X-ray all-sky survey was conducted by HEAO-1/A4 in 1978, and one has not been conducted since then due to performance limitations of available X-ray detector technology. The next generation instruments need to have sub-degree angular resolution, good sensitivity in the hard X-ray band (3σ sensitivity to sub- mCrab), and few keV energy resolution. This performance is demonstrated u...

  19. An XPS study of bromine in methanol etching and hydrogen peroxide passivation treatments for cadmium zinc telluride radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Babar, S.; Sellin, P.J.; Watts, J.F. [Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Baker, M.A., E-mail: M.Baker@surrey.ac.uk [Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer CdZnTe single crystal etched in bromine-in-methanol and passivated in H{sub 2}O{sub 2}. Black-Right-Pointing-Pointer XPS depth used to accurately determine enriched Te layer and TeO{sub 2} thickness. Black-Right-Pointing-Pointer For 0.2 and 2.0 (v/v) % bromine-in-methanol treatments, enriched Te layer thickness determined to be 1.3 and 1.8 nm, respectively. Black-Right-Pointing-Pointer After passivation in 30 wt.% H{sub 2}O{sub 2}, the oxide thickness varies between 1.0 and 1.25 nm depending on the calculation method. - Abstract: The performance of single crystal CdZnTe radiation detectors is dependent on both the bulk and the surface properties of the material. After single crystal fabrication and mechanical polishing, modification of the surface to remove damage and reduce the surface leakage current is generally achieved through chemical etching followed by a passivation treatment. In this work, CdZnTe single crystals have been chemically etched using a bromine in methanol (BM) treatment. The BM concentrations employed were 0.2 and 2.0 (v/v) % and exposure times varied between 5 and 120 s. Angle resolved XPS and sputter depth profiling has been employed to characterize the surfaces for the different exposure conditions. A Te rich surface layer was formed for all exposures and the layer thickness was found to be independent of exposure time. The enriched Te layer thickness was accurately determined by calibrating the sputter rate against a CdTe layer of known thickness. For BM concentrations of 0.2 (v/v) % and 2 (v/v) %, the Te layer thickness was determined to be 1.3 {+-} 0.2 and 1.8 {+-} 0.2 nm, respectively. The BM etched surfaces have subsequently been passivated in a 30 wt.% H{sub 2}O{sub 2} solution employing exposure time of 15 s. The oxide layer thickness has been calculated using two standard XPS methodologies, based on the Beer-Lambert expression. The TeO{sub 2} thickness calculated from ARXPS data are slightly higher than the thickness obtained by the simplified Beer-Lambert expression. For BM exposures of 30-120 s followed by a passivation treatment of 30 wt. % H{sub 2}O{sub 2} solution employing an exposure time 15 s, the ARXPS method gave an average TeO{sub 2} thickness value of 1.20 nm and the simplified Beer-Lambert expression gave an average thickness value of 0.99 nm.

  20. An XPS study of bromine in methanol etching and hydrogen peroxide passivation treatments for cadmium zinc telluride radiation detectors

    OpenAIRE

    Babar, S.; Sellin, PJ; Watts, JF; Baker, MA

    2013-01-01

    The performance of single crystal CdZnTe radiation detectors is dependent on both the bulk and the surface properties of the material. After single crystal fabrication and mechanical polishing, modification of the surface to remove damage and reduce the surface leakage current is generally achieved through chemical etching followed by a passivation treatment. In this work, CdZnTe single crystals have been chemically etched using a bromine in methanol (BM) treatment. The BM concentrations empl...

  1. Effect of Annealing On Thin Film Fabrication of Cadmium Zinc Telluride by Single-R.F. Magnetron Sputtering Unit

    OpenAIRE

    Dr. Monisha Chakraborty A,; Sugata Bhattacharyya

    2014-01-01

    In this work, formation of Cd1-xZnxTe thin films under various annealing-environments, created by layer by layer deposition of individual CdTe and ZnTe targets from a Single-R.F. Magnetron Sputtering unit is investigated. Structural and optical characterization results show that Vacuum Annealing is the best suitable for the formation of better Cd1-xZnxTe XRD peaks of higher intensities in comparison to Argon or Nitrogen-Annealing, for a bi-layered deposited CdTe and ZnTe film on glass substra...

  2. Gated tomographic radionuclide angiography using cadmium-zinc-telluride detector gamma camera; comparison to traditional gamma cameras

    DEFF Research Database (Denmark)

    Jensen, Maria Maj; Schmidt, Ulla; Huang, Chenxi

    2014-01-01

    PURPOSE: Estimation of left ventricular ejection fraction (LVEF) with equilibrium 99MTc-HSA equilibrium radionuclide angiography (MUGA) is frequently used for assessing cardiac function. The purpose of this study was to compare intra- and interobserver variation between three different gamma...

  3. Pyrolysis of Plants After Phytoremediation of Contaminated Soil with Lead, Cadmium and Zinc.

    Science.gov (United States)

    Özkan, Aysun; Günkaya, Zerrin; Banar, Müfide

    2016-03-01

    The aim of this study was to remediate lead (Pb), cadmium (Cd) and zinc (Zn) from contaminated soil and stabilize to pyrolysis solid product. To accomplish this, phytoremediation of soil contaminated with Pb, Cd and Zn by different plants (sunflower, corn and rape) was performed with and without ethylenediaminetetraacetic acid (EDTA). According to phytoremediation results, rape was the most effective plant with 72 %, 76 % and 77 % removal efficiency for Pb, Cd and Zn, respectively. Also, EDTA addition had no significant effect on translocation of the metals from roots to stems. According to pyrolysis results, Pb, Cd and Zn in the contaminated plants were stabilized in the ash/char fraction. In addition, the solid product can be safely landfilled as inert waste since its toxicity leaching value is lower than the limit values given in the Turkish Regulation on Landfilling of Wastes.

  4. Cadmium, copper, lead, and zinc in five toothed whale species of the Mediterranean Sea.

    Science.gov (United States)

    Frodello, J P; Marchand, B

    2001-01-01

    The cadmium, lead, copper, and zinc levels were measured in six organs (lung, liver, kidney, skin, muscle, and bone) from 18 specimens of toothed whales, belonging to five species, found stranded along the Corsican coast between November 1993 and December 1998. The five species examined were the bottlenose dolphin Tursiops truncatus, the common dolphin Delphinus delphis, the striped dolphin Stenella coeruleoalba, the pilot whale Globicephala melas, and the Risso's dolphin Grampus griseus. The values obtained demonstrate that there is a great variability in the accumulation of toxic metals. A comparison of the values with those obtained in other geographical regions also demonstrates an extensive variability in metal levels. The presence of metals in the stomach contents of three of the individuals studied shows that the food source is responsible for a significant input of pollutants to the whales. Measured pollutant levels in whales are thus the result of an accumulation occurring throughout the animal's life.

  5. Variability of cadmium, copper and zinc levels in molluscs and associated sediments from Chile.

    Science.gov (United States)

    De Gregori, I; Pinochet, H; Gras, N; Muñoz, L

    1996-01-01

    The concentrations of cadmium, copper and zinc in mussel and sediment samples collected together from eight different geographical coastal areas of Chile were determined. The mussels studied were 'Chorito Maico', 'Almejas' and 'Navajuelas Chilenas' (Perumytilus purpuratus, Semelle solida and Tagellus dombeii, respectively). Sampling was carried out in July and September 1992 and January and April 1993 (winter, spring, summer and autumn seasons in Chile, respectively). The metal levels in these mussels varied among species; there were several sites where the metal concentrations in molluscs approached or exceeded the criteria levels for Cd, Cu and Zn in shellfish products: 1, 10 and 50 ppm ww respectively, which are regarded as safe levels for human consumption. The results of metal levels in sediments showed two areas clearly polluted with Cu. Strong relationships between Cu concentrations in the three molluscs and sediments were found; weak correlations were observed for Zn in S. solida.

  6. Cadmium Testicular Toxicity in Male Wistar Rats: Protective Roles of Zinc and Magnesium.

    Science.gov (United States)

    Babaknejad, Nasim; Bahrami, Somaye; Moshtaghie, Ali Asghar; Nayeri, Hashem; Rajabi, Parvin; Iranpour, Farhad Golshan

    2017-12-14

    Cadmium (Cd) is a highly toxic element, which may cause toxicity to most organs in the body. Zinc (Zn) and magnesium (Mg) are essential minerals with probable benefits on Cd harmful effects. Finding an efficient and non-pathological treatment against Cd toxicity seems promising. Fifty adult rats were divided into ten experimental groups of five rats each. The Cd group was treated with 1 mg Cd/kg and the control group received 0.5 cm3 normal saline. The other eight groups received Zn (0.5 and 1.5 mg/kg) and Mg (0.5 and 1.5 mg/kg) either alone or in combination with 1 mg Cd/kg through IP injection for 3 weeks. Testis malondialdehyde (MDA), sperm parameters, and testis histopathology were investigated. Cd reduced sperm parameters and increased testis MDA. Moreover, Cd exposure caused a significant histological damage in testis of male rats. However, Zn or Mg treatment prevented and reversed Cd toxic alterations in testis. These findings suggest that co-administration of Zn or Mg could improve cadmium testicular toxicity in male Wistar rats.

  7. Concentration of cadmium, zinc and manganese in root, stalk and leaf of spinach and tomato in Hamedan

    Directory of Open Access Journals (Sweden)

    A. Ghobadi

    2016-11-01

    Full Text Available Heavy metals are considers as significant environment pollutants. Their entrance into food chain is a serious health hazard to humans. This study was conducted to determine the concentrations of Cadmium, Zinc and Manganese in root, stalk and leaf portions of spinach and tomato. For this reason, during 2014 in Hamedan city, 3 farms with 5 repetitions from each farm were sampled. Samples were subjected to acid-digestion and the concentrations of the elements were assayed by inductively coupled plasma (ICP. According to the results, the average concentrations of heavy metals in root, stalk and leaf of spinach was estimated at: cadmium, 0.14, 0.24, 0.34 mg/kg, zinc, 15.53, 24.82, 35 mg/kg and manganese, 26.59, 24.42, 45.38 mg/kg, respectively. The data for the tomato samples were: cadmium, 16.20, 24.42, 33.81 mg/kg, Zinc, 21.48, 39.74, 52.92 mg/kg and manganese, 26.60, 42.41, 61.90 mg/kg, respectively. The mean concentration of cadmium and manganese in spinach and tomato showed a significant difference with the WHO/FAO standard limit. However, in the case of zinc the difference was insignificant. It was concluded that in this experiment the spinach and tomato samples were polluted with higher concentration of cadmium and manganese than the approved limit of WHO/FAO and therefore was found risky for the consumers.

  8. Effect of oral cadmium administration to female rats during pregnancy on zinc, copper, and iron content in placenta, foetal liver, kidney, intestine, and brain

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, B.; Steibert, E.

    1985-02-01

    Cadmium chloride was administered in drinking water at a concentration of 50 ppm cadmium to female rats for 20 days of gestation. The foetuses were then removed from the uteri of the dams. Gestational exposure to oral cadmium resulted in decreased zinc, copper, iron, metallothionein, and thionein-bound zinc content in foetal liver as well as in reduced copper content in placenta and foetal intestine, brain and kidney. Subcellular fractionation of the foetal liver revealed decreased microsomal iron content. Pregnant rats exposed to oral cadmium revealed decreased serum zinc and iron concentration as well as reduced ceruloplasmin activity. The decreased zinc, copper, and iron content in foetal organs is suggested to be causally connected with the diminished availability of these metals in the maternal circulation.

  9. Fluorescence Properties of Fe2+- and Co2+-doped Hosts of CdMnTe Compositions as Potential Mid-Infrared Laser Materials

    Science.gov (United States)

    2011-09-01

    manganese telluride (CdMnTe or CMT), cadmium zinc telluride ( CdZnTe ), and zinc sulfur selenide (ZnSSe) chalcogenide crystals (1). Among the TM ions, Cr2...cadmium magnesium telluride CdS cadmium sulfide CdSe cadmium selenide CdTe cadmium telluride CdZnTe cadmium zinc telluride Co2+ divalent

  10. Cadmium ion in solution recovery by electro-chemical cementation on zinc powder in agitated reactor; Recuperation d'ions cadmium en solution par cementation electrochimique sur poudre de zinc en reacteur agite

    Energy Technology Data Exchange (ETDEWEB)

    Pham, N.T.; Aurousseau, M.; Bultel, Y.; Ozil, P. [Institut National Polytechnique de Grenoble, Lab. d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, UMR 5631, 38 - Saint Martin d' Heres (France)

    2001-07-01

    This document presents a study on the the reaction kinetic of cadmium cementation on zinc powder in agitated reactor. The results analysis and evaluation have been realized by the control of the Cd(II) level in the solution, by SAA determination for one hand and surface scanning electronic microscopy observation of zinc particle on the other hand. Other parameters as the agitation speed, the temperature and the initial rate of Cd(II) and Zn(II) have been studied. A simplified simulation allowed the experimental results analysis. (A.L.B.)

  11. Sonochemical synthesis and characterization of new seven coordinated zinc, cadmium and mercury nitrate complexes: New precursors for nanostructure metal oxides.

    Science.gov (United States)

    Jahromi, S Mojahedi; Montazerozohori, M; Masoudiasl, A; Houshyar, E; Joohari, S; White, J M

    2018-03-01

    The nitrate complexes of group 12 elements with a tridentate Schiff base ligand (L = (E)-N1-((E)-3- phenylallylidene)-N2-(2-((E)-((E)-3-phenylallylidene) amino)ethyl) ethane-1,2-diamine) were synthesized via sonochemical process and characterized by various physical and chemical methods. The structural analysis of the zinc nitrate complex by single crystal X-ray diffraction analysis shows that the central atom is seven-coordinated by three nitrogen atoms from the Schiff base ligand as well as four oxygen atoms from two different nitrate anions. The geometry around the metal center can be described as a distorted pentagonal bipyramid. The crystal packing analysis of zinc nitrate complex indicates that the intermolecular interactions related to nitrate groups plays the essential role in the orientation of supramolecular structure. Hirshfeld surfaces (HS) and their corresponding fingerprint plots (FP) have been also used for further investigation of crystal structure of zinc nitrate complex. Furthermore thermal analyses (TG/DTG) of three nanostructure complexes were carried out and discussed. Finally, direct thermolysis of zinc and cadmium nitrate complexes in air atmosphere led to the production of zinc and cadmium oxide nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Determination of zinc and cadmium with characterized Electrodes of carbon and polyurethane modified by a bismuth film

    Directory of Open Access Journals (Sweden)

    Jossy Karla Brasil Bernardelli

    2011-09-01

    Full Text Available This study aims to use electrodes modified with bismuth films for the determination of zinc and cadmium. The film was electrodeposited ex situ on a composite carbon electrode with polyurethane and 2% metallic bismuth (2BiE and on a carbon bar electrode (CBE. The electrodes were characterized by scanning electron microscopy and energy dispersive spectroscopy. Through differential pulse anodic stripping voltammetry, the electrodes 2BiE and CBE containing bismuth films showed a limit of detection (LOD of 5.56 × 10-5 and 3.07 × 10-5 g.L-1 for cadmium and 1.24 × 10-4 and 1.53 × 10-4 g.L-1 for zinc, respectively. The presence of a bismuth film increased the sensitivity of both electrodes.

  13. Concurrent reduction and distillation: an improved technique for the recovery and chemical refinement of the isotopes of cadmium and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Caudill, H.H.; McBride, L.E.; McDaniel, E.W.

    1982-01-01

    The Electromagnetic Isotope Separations Program of the Oak Ridge National Laboratory has been involved in the separation, chemical recovery, and refinement of the stable isotopes of cadmium and zinc since 1946. Traditionally, the chemical refinement procedures for these elements consisted of ion exchange separations using anion exchange resins followed by pH-controlled hydrogen sulfide precipitations. The procedures were quite time-consuming and made it difficult to remove trace quantities of sulfur which interferes in subsequent attempts to prepare rolled metal foils. As demands for /sup 113/Cd and /sup 68/Zn (a precursor for the production of the radiopharmaceutical /sup 67/Ga) increased, it became evident that a quicker, more efficient refinement procedure was needed. Details of an improved method, which employs concurrent hydrogen reduction and distillation in the recovery and refinement of isotopically enriched zinc, are described. Modifications of the procedure suitable for the refinement of cadmium isotopes are also described. 3 figures, 1 table.

  14. Determination of silver, bismuth, cadmium, copper, lead, and zinc in geologic materials by atomic absorption spectrometry with tricaprylylmethylammonium chloride

    Science.gov (United States)

    Viets, J.G.

    1978-01-01

    Interferences commonly encountered in the determination of silver, bismuth, cadmium, copper, lead, and zinc at crustal abundance levels are effectively eliminated using a rapid, sensitive, organic extraction technique. A potassium chlorate-hydrochloric acid digestion solubilizes the metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The six metals are selectively extracted into a 10% Aliquat 336-MIBK organic phase in the presence of ascorbic acid and potassium iodide. Metals in the organic extract are determined by flame atomic absorption spectrometry to the 0.02-ppm level for silver, cadmium, copper, and zinc and to the 0.2-ppm level for bismuth and lead with a maximum relative standard deviation of 18.8% for known reference samples. An additional hydrofluoric acid digestion may be used to determine metals substituted in the silicate lattice.

  15. Biomarker of chronic cadmium exposure in a population residing in the vicinity of a zinc producing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bratveit, Magne, E-mail: magne.bratveit@isf.uib.no [Department for Public Health and Primary Health Care, Occupational and Environmental Medicine, University of Bergen, Bergen (Norway); Uni Health, Bergen (Norway); Mageroy, Nils, E-mail: nils.mageroy@isf.uib.no [Uni Health, Bergen (Norway); Gundersen, Hilde, E-mail: hilde.gundersen@isf.uib.no [Department for Public Health and Primary Health Care, Occupational and Environmental Medicine, University of Bergen, Bergen (Norway); Vahter, Marie, E-mail: Marie.Vahter@ki.se [Division of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Moen, Bente E., E-mail: Bente.Moen@isf.uib.no [Department for Public Health and Primary Health Care, Occupational and Environmental Medicine, University of Bergen, Bergen (Norway)

    2011-09-15

    Measurements of cadmium (Cd) in air, soil and moss have shown elevated concentrations in residential areas close to a zinc smelter in Norway. This study aimed to evaluate whether men and women residing in the area with elevated Cd concentrations in air and soil had increased levels of Cd and microproteins in urine. An invitation to participate was mailed to 200 persons residing close to the zinc smelter and to 200 controls from an area more than 4 km away from the smelter. They were asked to complete a questionnaire, and to deliver a urine sample for analysis of cadmium (CdU), mercury (HgU), lead (PbU) and {alpha}1-microglobulin (ProteinHC). Two hundred and six participants (response rate 52%), between 19 and 88 years of age, were included. Results were analysed by multiple-adjusted linear and logistic regression. CdU was not significantly different between individuals in the two residence areas. Only ten individuals had CdU concentrations exceeding European Food Safety Authority (EFSA) critical value of 1 {mu}g/g creatinine, whereas 35 persons (22% of the women vs. 11% of the men) had CdU concentrations higher than 0.66 {mu}g/g creatinine, which EU suggested to be sufficiently protective for the general population. Smoking was the predominant contributing factor to values of elevated CdU. There was a tendency of higher CdU, although not statistically significant, amongst people regularly consuming fruit, berries and vegetables grown in their own garden near the smelter area. Home address in the polluted area was not a significant determinant. There was a positive correlation between CdU and ProteinHC in urine, but no significant difference was found for ProteinHC between residents from polluted area and controls. In spite of demonstrated industrial emissions of cadmium, the results do not indicate elevated cadmium exposure or kidney damage in the polluted area compared to the control area. - Highlights: {yields} Cadmium in air and soil is elevated in the

  16. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Spann, Nicole, E-mail: nicole.spann@web.de [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Aldridge, David C., E-mail: da113@cam.ac.uk [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Griffin, Julian L., E-mail: jlg40@mole.bio.cam.ac.uk [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom); Jones, Oliver A.H., E-mail: o.jones@gmail.com [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom)

    2011-10-15

    Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC-MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes

  17. The Protective Roles of Zinc and Magnesium in Cadmium-Induced Renal Toxicity in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Nasim Babaknejad

    2014-12-01

    Full Text Available Background: Cadmium (Cd is a heavy metal that has widespread use. It enters the food chain in different ways, including soil and water. Cadmium can cause dysfunction of different body organs. Zinc (Zn and magnesium (Mg supplementation can have protective effects against cadmium toxicity due to their antagonistic and antioxidants properties. This study examines the influence of supplemental Zn and Mg on Cd renal toxicity. Methods: Young male Wistar rats were divided into six groups of five. The Cd group received 1 mg Cd/kg and the control group received 0.5 mg/kg normal saline (i.p.. The other four groups were administered 1 mg/kg Cd+0.5 mg/kg Zn, 1 mg/kg Cd+1.5 mg/kg Zn, 1 mg/kg Cd+ 0.5 mg/kg Mg, and 1 mg/kg Cd+ 1.5 mg/kg Mg (i.p. for 21 days. Then, serum sodium, potassium, urea, creatinine, and protein levels were measured. Results: The results indicated that creatinine and protein levels decreased while urea, sodium, and potassium levels increased as a result of Cd exposure. Co-administered Cd and Zn and Mg decreased urea and increased sodium serum level in comparison to the cadmium group. Treatment by Mg, contrary to co-administered Cd and Zn, reduced serum protein level compared to the cadmium group. Compared to the cadmium treated group, Zn and Mg treatment enhanced serum creatinine level and reduced serum potassium level. Conclusion: The findings seem to suggest that zinc and magnesium compounds, due to their antagonistic and antioxidant activities, can protect Cd renal toxic effects in a dose-dependent manner.

  18. Application of anodic stripping voltammetry for zinc, copper, and cadmium quantification in the aqueous humor: implications of pseudoexfoliation syndrome.

    Science.gov (United States)

    Panteli, Vassiliki S; Kanellopoulou, Dimitra G; Gartaganis, Sotirios P; Koutsoukos, Petros G

    2009-12-01

    Anodic stripping voltammetric (ASV) procedure, using mercury film electrode, was optimized and applied to determine the concentrations of zinc, cadmium, and copper in the aqueous humor. Concentration levels as low as 1 ppb of the test metals was possible to be detected using short electrolysis times (120 s) and microquantities of aqueous humor (up to 35 μL). As a first application of the voltammetric analysis of trace metals in the aqueous humor, the role of the three selected trace elements in the pseudoexfoliation (PEX) syndrome was examined. Samples from aqueous humor were collected during cataract extraction from patients with and without PEX. The zinc and copper concentration levels in the aqueous humor did not show statistically significant difference in the study and control group. Cadmium was detected in a small number of samples, without however statistical differences between the two groups. ASV proved to be a highly precise and sensitive tool for the quantification of heavy metal ions in aqueous humor. Further studies may lead to useful conclusions for the role of zinc, copper, or cadmium in PEX syndrome.

  19. Bioavailability of arsenic, cadmium, iron and zinc in leafy vegetables amended with urban particulate matter suspension.

    Science.gov (United States)

    Tremlová, Jana; Száková, Jiřina; Sysalová, Jiřina; Tlustoš, Pavel

    2013-04-01

    Urban particulate matter (PM) can affect green plants either via deposition on the above-ground biomass, where the contaminants can penetrate the leaf surface, or indirectly via soil-root interaction. This experiment assessed the potential risk of PM-derived risk elements contained in vegetables. The bioavailable portions of arsenic (As), cadmium (Cd), iron (Fe), and zinc (Zn) in leafy vegetables amended by PM via soil and/or foliar application were investigated in a model pot experiment, in which lettuce and chard were cultivated. By using the physiologically based extraction test simulating in vitro human digestive processes in the stomach and small intestine, the bioavailable portions of toxic elements from PM-amended plant biomass were extracted. Extractable portions of elements by a simulated gastric solution from biomass decreased for lettuce in the order Zn > Cd > As > Fe; while for chard, the order was As > Zn > Cd > Fe. No significant effects of PM physical fractions or soil were observed. Although the bioavailable element portions in the PM samples were lower compared to plants, the bioavailable element contents in foliar PM-amended plant leaves exceeded the control and soil PM amendment levels, even after biomass washing. © 2012 Society of Chemical Industry.

  20. Cadmium restores in vitro splicing activity inhibited by zinc-depletion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myeong Jin; Ayaki, Hitoshi; Kitamura, Keiko; Nishio, Hisahide [Kobe University Graduate School of Medicine, Department of Public Health, Kobe (Japan); Goji, Junko [Hyogo College of Medicine, Department of Public Health, Hyogo (Japan)

    2006-10-15

    Zinc (Zn)-depletion inhibits the second step of RNA splicing, namely exon-ligation. To investigate the effects of cadmium (Cd) and other metal ions on RNA splicing inhibited by Zn-depletion, we measured in vitro splicing activities in the presence of these metals. Zn-depletion in the splicing reaction mixture was achieved by addition of a Zn-chelator, 1,10-phenanthroline. Cd(II) at 1, 5 and 10 {mu}M restored the splicing activity to 2, 24 and 72% of that in the control reaction mixture, while higher concentrations of Cd(II) decreased the splicing activity, and more than 50 {mu}M Cd(II) showed a complete absence of spliced products. Hg(II) also restored the splicing activity, albeit to a lesser extent, since 5 and 10 {mu}M Hg(II) restored the splicing activity to 3 and 4% of the control value. The other metal ions examined in this study, Co(II), Cu(II), Mg(II) and Mn(II), did not show any restoration of the splicing activity. We concluded that Cd(II) could restore the in vitro splicing activity inhibited by Zn-depletion, although higher concentrations of Cd(II) prevented progress of the RNA splicing reaction. These results suggest that Cd(II) has a bifunctional property regarding RNA splicing, and is stimulatory at low concentrations and inhibitory at high concentrations. (orig.)

  1. Protective Effects of Zinc Supplementation on Renal Toxicity in Rats Exposed to Cadmium

    Directory of Open Access Journals (Sweden)

    Morshedi

    2014-07-01

    Full Text Available Background Cadmium (Cd is a nonessential element with many industrial applications and is one of the most toxic pollutants in the environment. The ultimate goal of occupational health is prevention of health hazards on workplace; hence, is as a hazardous chemical contaminant in the workplace, Cd needs special attention. Objectives The object of this study was to determine the effect of ZnCl2 on Cd-induced nephrotoxicity in rats. Materials and Methods Adult male rats were given CdCl2 at doses of 0, 1, 2, and 3 mg/kg. Another series of rats were pretreated with 4 mg/kg of ZnCl2 30 minutes prior to administration of various doses of CdCl2. The experiment was repeated for seven consecutive days. Twenty-four hours after administering the latest dose, animals were sacrificed. Blood samples were analyzed for blood urea nitrogen (BUN and creatinine levels. Kidney tissues were excised for measuring malondialdehyde (MDA concentration. Results In contrast to the animals that received ZnCl2, CdCl2 induced a dose-dependent elevation in BUN, creatinine, and MDA in those without ZnCl2 pretreatment. Zinc chloride had significantly decreased all biochemical parameters and protected kidney cells against Cd-induced toxicity. Conclusions The results of this study supported the potential protective effects of ZnCl2 on rat kidney tissues against CdCl2 toxicity.

  2. Prevention of cadmium-induced sterility by zinc in the male rat.

    Science.gov (United States)

    Saksena, S; White, M J; Mertzlufft, J; Lau, I

    1983-05-01

    The potential of zinc (Zn) to antagonize the adverse effects of cadmium (Cd) on the male reproductive processes was studied. A significant reduction in the weights of the testis and epididymis, the testicular sperm population and oligospermia to azoospermia in the epididymis was recorded in rats treated once s.c. with 2 mg/kg Cd and sacrificed 20 days later. This was accompanied by a significantly reduced serum T and a loss of fertility. Administration of a single s.c. injection of Zn (80 mg/kg) did not alter significantly any of the reproductive parameters studied. On the other hand, Zn given 1/2 to 2 h after Cd resulted in partial recovery. Organ weights and sperm population in these groups were maintained and the fertility rate was 67% and 50% at 5 and 20 days as compared to 67% and 0% at corresponding period in Cd-exposed males. The protective effect diminished when Zn was given more than 2 h after Cd exposure. The most effective regimen of Zn therapy was an administration of a total dose of 80 mg/kg Zn given in 3 injections (15 mg/kg before, 50 mg/kg at the time and 15 mg/kg 2 h after Cd). The results provide evidence that Zn, if given before or within 2 h of Cd exposure, is capable of at least partially reversing its deleterious effects on spermatogenesis, steroidogenesis and fertility of the male rat.

  3. Lead, cadmium and zinc in mineral structure of deposits of the gallbladder in men and women

    Directory of Open Access Journals (Sweden)

    Jerzy Kwapuliński

    2012-11-01

    Full Text Available Introduction: The former studies have shown the presence of As and Sb in deposits of the gallbladder. The aim of studies: The aim of the studies was to define the level of accumulation of Pb, Cd, Zn in deposits of the gallbladder as supplementary biological test for exposure assessment in a long run. Materials and methods: Pb, Cd and Zn content was investigated with inductive coupled plasmaatomic emission spectrometry were deposits of the gallbladder in men and women living in the Silesia Region. Results: The change of these elements content was analyzed in connection with behavioral factors ( diet, alcohol, coffee, obesity and tobacco addiction of the gender. Attention was drawn to the probability of interaction of Pb, Cd, Zn with other elements during their accumulation in deposits of the gallbladder. It appeared that deposits of the gall bladder can be used as an additional biological test in individual exposure assessment to Pb, Cd and Zn. It was noted that the level of content of Pb, Zn and Cd in deposits of the gallbladder is impacted by behavioral factors (diet, alcohol, coffee, obesity tobacco addiction. A characteristic impact of the tobacco addiction on the rise in the content of lead, cadmium and zinc was demonstrated as well as significant role of the presence of these elements in the total environmental pollution in relevant living areas.

  4. Incubating rainbow trout in soft water increased their later sensitivity to cadmium and zinc

    Science.gov (United States)

    Mebane, Christopher A.; Hennessy, Daniel P.; Dillon, Frank S.

    2010-01-01

    Water hardness is well known to affect the toxicity of some metals; however, reports on the influence of hardness during incubation or acclimation on later toxicity to metals have been conflicting. We incubated rainbow trout (Oncorhynchus mykiss) near the confluence of two streams, one with soft water and one with very-soft water (average incubation hardnesses of about 21 and 11 mg/L as CaCO3, respectively). After developing to the swim-up stage, the fish were exposed for 96-h to a mixture of cadmium (Cd) and zinc (Zn) in water with a hardness of 27 mg/L as CaCO3. The fish incubated in the higher hardness water were about two times more resistant than the fish incubated in the extremely soft water. This difference was similar or greater than the difference that would have been predicted by criteria hardness equations had the fish been tested in the different acclimation waters. We think it is plausible that the energy demands for fish to maintain homeostasis in the lower hardness water make the fish more sensitive to metals that inhibit ionoregulation such as Cd and Zn. We suggest that if important decisions were to be based upon test results, assumptions of adequate hardness acclimation should be carefully considered and short acclimation periods avoided. If practical, incubating rainbow trout in the control waters to be tested may reduce uncertainties in the possible influences of differing rearing water hardness on the test results.

  5. Development of a thermodynamic model for zinc, lead and cadmium in saline solutions; Entwicklung eines thermodynamischen Modells fuer Zink, Blei und Cadmium in salinaren Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Sven

    2012-07-15

    Waters on aboveground and underground landfills often contain high concentrations of pollutants like zinc, lead and cadmium. Interactions between wastes and aqueous solutions could lead to a mobilisation of these elements. If their maximum solubilities are to be predicted by geochemical modelling a thermodynamic data base is needed. Due to the lack of experimental data such a data base could not be developed yet. In order to fill the gaps isopiestic as well as solubility measurements were made at 25 C. Furthermore the complex formation of zinc and cadmium was investigated and quantified by means of Raman spectrometry and evolving factor analysis. It could be proven that only complexes with two and four chlorine atoms achieve significant concentrations. On basis of these results and a critical evaluation of literature data a consistent thermodynamic data base for was developed for the calculation of activity coefficients and solubilities in the system Na, K, Mg, Ca, Zn, Cd, Cl, SO{sub 4}-H{sub 2}O at 298,15 K.

  6. Assessment of a sewage sludge treatment on cadmium, copper and zinc bioavailability in barley, ryegrass and earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, Agnes Y. [Sanexen Environmental Services Inc., 1471 Lionel-Boulet Boulevard, Varennes, Quebec J3X 1P7 (Canada)]. E-mail: arenoux@sanexen.com; Rocheleau, Sylvie [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Sarrazin, Manon [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Sunahara, Geoffrey I. [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada)]. E-mail: geoffrey.sunahara@cnrc-nrc.gc.ca; Blais, Jean-Francois [Institut national de la recherche scientifique (INRS-ETE), Centre Eau, Terre et Environnement, 490 rue de la Couronne street, Quebec, Quebec G1K 9A9 (Canada)]. E-mail: blaisjf@ete.inrs.ca

    2007-01-15

    The toxicity and bioavailability of metals were assessed to verify the efficiency of a new chemical leaching process (METIX-AC) to minimize the risk of metals found in municipal sewage sludge. For this purpose, sludge samples were spiked with cadmium, copper and/or zinc before being treated using METIX-AC. The sludge decontamination resulted in a removal of spiked metals (79-89%), in a decrease of the more labile fractions, and in a corresponding increase of the residual fraction. The toxicity observed after exposure of two plant species, barley (Hordeum vulgare) and ryegrass (Lolium perenne), and a terrestrial invertebrate, Eisenia andrei, to sludge-soil mixtures, disappeared after treatment, although the adverse effects were minor before treatment. The sludge treatment also significantly decreased the bioaccumulation of cadmium, copper, and zinc in the exposed species. For cadmium, maximum tissue concentrations of 0.45 {+-} 0.08 mg/kg in barley, 0.79 {+-} 0.27 mg/kg in ryegrass, and 21.82 {+-} 1.85 mg/kg in earthworm exposed to sludge before treatment decreased after treatment to values similar to those observed with negative controls. - Assessment of a sewage sludge treatment on metal bioavailability as measured by metal speciation, toxicity and bioaccumulation.

  7. Profiles of enzymatic activity in earthworms from zinc, lead and cadmium polluted areas near Olkusz (Poland).

    Science.gov (United States)

    Łaszczyca, Piotr; Augustyniak, Maria; Babczyńska, Agnieszka; Bednarska, Katarzyna; Kafel, Alina; Migula, Pawel; Wilczek, Grazyna; Witas, Ilona

    2004-09-01

    The aim of the study was to determine whether there are signs of adaptation of soil fauna to a gradient of heavy metal contamination. Earthworms Aporrectodea caliginosa, Lumbricus terrestris and Eisenia fetida were collected during the spring and summer of 2000 and 2001 from meadow sites situated between 2 and 32 km from the Bukowno-Olkusz complex of zinc-lead ore mines and smelters. The heavy metal content in the soil near smelters reaches 10,500 mg/kg (d.w.) for Zn, 2600 mg/kg for Pb and 81.9 mg/kg for Cd. The sites differ with respect to species composition of earthworm community, with A. caliginosa being dominant. Complete data was obtained only for A. caliginosa, since other species were not abundant at all investigated sites during the whole period of investigation. The body burdens of Zn, Pb, Cd and Cu in A. caliginosa reached 1500, 100, 220 and 10 microg/g, respectively, in the vicinity of the smelter (2-4 km), and decreased to 400, 2, 36 and 6 microg/g at the most distant site (32 km). Cadmium and lead content was significantly elevated in the whole body of L. terrestris collected at the site 2.5 km distant from the smelters when compared to more distant sites, while in E. fetida only the body burden of cadmium was elevated at the nearest site compared to the next site of transect. Activities of glutathione peroxidase (GPX; EC 1.11.1.9) against hydrogen peroxide (H2O2) or cumene hydroperoxide (cumOOH), glutathione reductase (GR; EC 1.6.4.2), glutathione S-transferase (GST; EC 2.5.1.18) and catalase (CAT; EC 1.11.1.6) were assayed in postmitochondrial supernatant obtained from whole body homogenates. Seasonal and annual variations of enzyme activity were reflected by higher GPX activity in the late summer of 2001 in comparison with the spring and summer of 2000. This may reflect severe drought in the spring and summer of 2000. The activity of both GPX isozymes, GR and GST in A. caliginosa and L. terrestris increased with increasing distance from the

  8. Uptake of lead, zinc, cadmium, and copper by the pulmonate mollusc, Helix aspersa Muller, and its relevance to the monitoring of heavy metal contamination of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Coughtrey, P.J.; Martin, M.H.

    1977-01-13

    The occurrence of lead, zinc, cadmium, and copper in individuals of Helix aspersa from two sites of varying degrees of contamination was studied. Zinc, cadmium, and copper were shown to increase in a linear fashion with animal weight. The rate of uptake for zinc and cadmium in particular was significantly greater at the more contaminated site. Statistical analysis of the data, using correlation and regression techniques, provided information on apparent intermetallic effects. It is concluded that because metal uptake and body weight show a positive linear relationship only the use of animals of similar weight and/or size can be used for monitoring purposes. Even then, different patterns of uptake into different organs and interactions between metal uptakes are such as to seriously question the use of Helix, and other molluscs, for monitoring purposes unless specific organs from comparably sized and/or aged animals are used.

  9. The interactive toxicity of cadmium, copper, and zinc to Ceriodaphnia dubia and rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Naddy, Rami B; Cohen, Adam S; Stubblefield, William A

    2015-04-01

    Traditionally, aquatic toxicity studies examine the toxicity of a single chemical to an organism. Organisms in nature, however, may be exposed to multiple toxicants. Given this is a more realistic exposure scenario in situ, the authors sought to understand the interactive toxicity of multiple metals to aquatic organisms. The authors performed a series of studies using equitoxic mixtures of cadmium, copper, and zinc to 2 aquatic organisms, rainbow trout (Oncorhynchus mykiss) and the waterflea, Ceriodaphnia dubia. Single metal toxicity tests were conducted to determine the acute median lethal concentration (LC50) values for O. mykiss and short-term, chronic median effective concentration (EC50) values for C. dubia. All 3 metals were then combined in equitoxic concentrations for subsequent mixture studies using a toxic unit (TU) approach (i.e., 1 TU = EC50 or LC50). For C. dubia, the mixture study showed greater-than-additive effects in hard water (TU-based EC50 = 0.74 TU), but less-than-additive effects in soft water (TU-based EC50 = 1.93 TU). The mixture effects for O. mykiss showed less-than-additive effects in both hard and soft waters, with TU-based LC50 values of 2.33 total TU and 2.22 total TU, respectively. These data are useful in helping understand metal mixture toxicity in aquatic systems and indicate that although in most situations the assumption of additivity of metal mixture toxicity is valid, under certain conditions it may not be sufficiently protective. © 2014 SETAC.

  10. Zinc supplementation protects against cadmium accumulation and cytotoxicity in Madin-Darby bovine kidney cells.

    Directory of Open Access Journals (Sweden)

    Ding Zhang

    Full Text Available Cadmium ions (Cd2+ have been reported to accumulate in bovine tissues, although Cd2+ cytotoxicity has not been investigated thoroughly in this species. Zinc ions (Zn2+ have been shown to antagonize the toxic effects of heavy metals such as Cd2+ in some systems. The present study investigated Cd2+ cytotoxicity in Madin-Darby bovine kidney (MDBK epithelial cells, and explored whether this was modified by Zn2+. Exposure to Cd2+ led to a dose- and time-dependent increase in apoptotic cell death, with increased intracellular levels of reactive oxygen species and mitochondrial damage. Zn2+ supplementation alleviated Cd2+-induced cytotoxicity and this protective effect was more obvious when cells were exposed to a lower concentration of Cd2+ (10 μM, as compared to 50 μM Cd2+. This indicated that high levels of Cd2+ accumulation might induce irreversible damage in bovine kidney cells. Metallothioneins (MTs are metal-binding proteins that play an essential role in heavy metal ion detoxification. We found that co-exposure to Zn2+ and Cd2+ synergistically enhanced RNA and protein expression of MT-1, MT-2, and the metal-regulatory transcription factor 1 in MDBK cells. Notably, addition of Zn2+ reduced the amounts of cytosolic Cd2+ detected following MDBK exposure to 10 μM Cd2+. These findings revealed a protective role of Zn2+ in counteracting Cd2+ uptake and toxicity in MDBK cells, indicating that this approach may provide a means to protect livestock from excessive Cd2+ accumulation.

  11. Larval aquatic insect responses to cadmium and zinc in experimental streams

    Science.gov (United States)

    Mebane, Christopher A.; Schmidt, Travis S.; Balistrieri, Laurie S.

    2017-01-01

    To evaluate the risks of metal mixture effects to natural stream communities under ecologically relevant conditions, the authors conducted 30-d tests with benthic macroinvertebrates exposed to cadmium (Cd) and zinc (Zn) in experimental streams. The simultaneous exposures were with Cd and Zn singly and with Cd+Zn mixtures at environmentally relevant ratios. The tests produced concentration–response patterns that for individual taxa were interpreted in the same manner as classic single-species toxicity tests and for community metrics such as taxa richness and mayfly (Ephemeroptera) abundance were interpreted in the same manner as with stream survey data. Effect concentrations from the experimental stream exposures were usually 2 to 3 orders of magnitude lower than those from classic single-species tests. Relative to a response addition model, which assumes that the joint toxicity of the mixtures can be predicted from the product of their responses to individual toxicants, the Cd+Zn mixtures generally showed slightly less than additive toxicity. The authors applied a modeling approach called Tox to explore the mixture toxicity results and to relate the experimental stream results to field data. The approach predicts the accumulation of toxicants (hydrogen, Cd, and Zn) on organisms using a 2-pKa bidentate model that defines interactions between dissolved cations and biological receptors (biotic ligands) and relates that accumulation through a logistic equation to biological response. The Tox modeling was able to predict Cd+Zn mixture responses from the single-metal exposures as well as responses from field data. The similarity of response patterns between the 30-d experimental stream tests and field data supports the environmental relevance of testing aquatic insects in experimental streams.

  12. Comparative study of responses in the brown algae Sargassum thunbergii to zinc and cadmium stress

    Science.gov (United States)

    Lü, Fang; Dind, Gang; Liu, Wei; Zhan, Dongmei; Wu, Haiyi; Guo, Wen

    2017-08-01

    Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to different concentrations (0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc (Zn) and cadmium (Cd) exposure separately were studied for 15 days in laboratory-controlled conditions. The results show that the specific growth rates increased slightly under the lower Zn concentration treatment (0.1 mg/L) at the first 5 d and then decreased gradually, which were significantly reduced with the exposure time in higher Zn concentrations and all Cd treatments compared to respective control, especially for 1.0 and 5.0 mg/L Cd. Chlorophyll a contents showed significant increase in 0.1 mg/L Zn treatment, whereas the gradually reduction were observed in the other three Zn treatments and all Cd treatments. The oxygen evolution rate and respiration rate presented distinct behavior in the Zn-treated samples, but both declined steadily with the exposure time in Cd treatments. The P/R value analyses showed similar variation patterns as chlorophyll a contents. Real-time PCR showed that lower Zn concentration (0.1 mg/L) increased mRNA expression of rbcL gene, whereas higher Zn concentrations and Cd reduced the rbcL expression. Taken together, these findings strongly indicate that Zn and Cd had different effects on S. thunbergii both at the physiological and gene transcription levels, the transcript level of photosynthesis-related gene rbcL can be used as an useful molecular marker of algal growth and environment impacts.

  13. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea.

    Science.gov (United States)

    Spann, Nicole; Aldridge, David C; Griffin, Julian L; Jones, Oliver A H

    2011-10-01

    The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes it more difficult to extrapolate laboratory results to the natural environment. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Preparation and thermal decomposition of copper(II, zinc(II and cadmium(II chelates with 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Crespi Marisa S.

    1999-01-01

    Full Text Available When the compounds are heated in an inert atmosphere it can be verified the consecutive partial sublimation, fusion, partial volatilization and partial thermal decomposition of the anhydrous complexes. When in an oxidating atmosphere the above process is only verified to Cu(II chelates. Anhydrous copper(II complexes present a monoclinic structure in the b form and the volatilized compound in a a form. Zinc(II and cadmium(II hydrated complexes are isomorphous and they present different cell dimensions from those reported previously.

  15. Accumulation of copper, zinc, cadmium and lead from two contaminated sediments by three marine invertebrates: a laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Ray, S.; McLeese, D.W.; Peterson, M.R.

    1981-03-01

    Animals from areas with contaminated sediments have been shown in some cases to contain high levels of trace metals. In other cases, the tissue levels of contaminants were relatively constant regardless of the metal contents of the sediments. The availability of sediment-bound metals to bottom-dwelling organisms has been the subject of a few studies. This study describes the uptake of copper, zinc, cadmium and lead from natural, highly contaminated sediments by three marine invertebrates: Nereis virens, Macoma balthica and Crangon septemspinosa.

  16. Extraction and isolation of the salidroside-type metabolite from zinc (Zn) and cadmium (Cd) hyperaccumulator Sedum alfredii Hance*

    Science.gov (United States)

    Xing, Yan; Peng, Hong-yun; Li, Xia; Zhang, Meng-xi; Gao, Ling-ling; Yang, Xiao-e

    2012-01-01

    The active metabolite in the post-harvested biomass of zinc (Zn) and cadmium (Cd) hyperaccumulator Sedum alfredii Hance from phytoextraction is of great interest in China. The current study demonstrates that a salidroside-type metabolite can be yielded from the Zn/Cd hyperaccumulator S. alfredii biomass by means of sonication/ethanol extraction and macroporous resin column (AB-8 type) isolation. The concentrations of Zn and Cd in the salidroside-type metabolite were below the limitation of the national standards. PMID:23024051

  17. Antibiotic resistance of cadmium- and zinc-tolerant strains of Klebsilla (Aerobacter) aerogenes growing in glucose-limited chemostats

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, A.W.; Dean, A.C.R.

    1976-01-01

    Cadmium and zinc resistant strains derived from K. aerogenes NCIB 418 by serial subculture in a minimal medium containing gradually increasing concentrations of the appropriate metal ions, but never previously exposed to antibiotics, exhibited multiple antibiotic resistance. Both strains were especially resistant to streptomycin, and Zn/sup 2 +/-resistant organisms were more resistant than Cd/sup 2 +/-resistant organisms to this antibiotic and to nalidixic acid but not to gentamycin or chloramphenicol. Growth rate effects on antibiotic action were eliminated by chemostat culture at the same dilution rate before exposure to the antibiotics. The possible ecological significance of the results is pointed out since both metals occur as environmental pollutants.

  18. Cadmium Contamination and Health Assessment in Frog Microhyla fissipes Living Downstream of Zinc Mining Area in Thailand

    Directory of Open Access Journals (Sweden)

    Jirarach Kitana

    2015-01-01

    Full Text Available In Mae Sot District, Tak Province, Thailand, concerns have been raised over cadmium contamination, potentially due to zinc mining activities. Although there is no report of acute toxicity on animals in this area, the impact of long-term environmental exposure to cadmium on their health are of attention. Water and sediment samples collected from two field sites (low-Cd and high-Cd sites in Mae Sot during 2008 were analyzed by GFAAS. Year round cadmium contamination in water ranged from 0.0015-0.002 mg/L in low-Cd site to 0.0019-0.0023 mg/L in high-Cd site, while higher levels were found in sediment ranged from 0.1013-0.2206 mg/kg in low-Cd site to 2.9260-3.2888 mg/kg in high-Cd site. Microhyla fissipes was collected from each habitat in 2-month interval during wet season. Detectable level of cadmium residue was found only in the frog collected from high-Cd habitat. Gravimetric analysis showed that hepatosomatic indices were significantly higher in high-Cd habitat. Histopathology showed several similar alterations in the liver, however higher number of melanomacrophage center was found in high-Cd habitat. Renosomatic indices and kidney tissue alterations were not significantly different between two sites. Reproductive health in term of gonadosomatic indices (GSI was not significantly different between male frogs from both habitats. But in the females living in high-Cd habitat, significantly lower GSI were observed. The results indicate that exposure to environmentally relevant dose of cadmium may interfere with the frog health. Using the frog as a sentinel species in this study suggests an important implication for overall health of animals/human in this area.

  19. Cadmium, copper, iron, and zinc concentrations in kidneys of grey wolves, Canis lupus, from Alaska, Idaho, Montana (USA) and the Northwest Territories (Canada).

    Science.gov (United States)

    Hoffmann, S R; Blunck, S A; Petersen, K N; Jones, E M; Koval, J C; Misek, R; Frick, J A; Cluff, H D; Sime, C A; McNay, M; Beckman, K B; Atkinson, M W; Drew, M; Collinge, M D; Bangs, E E; Harper, R G

    2010-11-01

    Cadmium, copper, iron, and zinc levels were measured in the kidneys of 115 grey wolves (Canis lupus) from Idaho, Montana and Alaska (United States), and from the Northwest Territories (Canada). No significant differences in the levels of iron or copper were observed between locations, but wolf kidneys from more northern locations had significantly higher cadmium levels (Alaska > Northwest Territories > Montana ≈ Idaho), and wolves from Alaska showed significantly higher zinc than other locations. Additionally, female wolves in Alaska had higher iron levels than males, and adult wolves in Montana had higher copper levels than subadults.

  20. Plasma clearance of cadmium and zinc in non-acclimated and metal-acclimated trout

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, M. Jasim; Grosell, M.; McDonald, D.G.; Wood, C.M

    2003-08-20

    Adult rainbow trout were pre-exposed to a sublethal concentration of waterborne cadmium (Cd, 26.7 nmol/l) or waterborne zinc (Zn, 2294 nmol/l) for 30 days to induce acclimation. A single dose of radiolabeled Cd (64.4 nmol/kg) or Zn (183.8 nmol/kg) was injected into the vascular system of non-acclimated and Cd- or Zn-acclimated trout through indwelling arterial catheters. Subsequently, repetitive blood samples over 10 h and terminal tissue samples (liver, heart, bile, stomach, intestine, kidney, gills, muscle, and spleen) were taken to characterize the effect of metal acclimation on clearance kinetics in vivo. Plasma clearance of Cd in Cd-acclimated fish (0.726{+-}0.015 and 0.477{+-}0.012 ml/min per kg for total and newly accumulated Cd, respectively), was faster than that in non-acclimated trout (0.493{+-}0.013 and 0.394{+-}0.009 ml/min per kg). Unlike plasma Cd, the levels of Cd in red blood cells (RBCs) were 1.2-2.2 times higher in Cd-acclimated fish than in non-acclimated fish. At 10 h post-injection, the liver accumulated the highest proportion ({approx}22%) of the injected Cd dose in both non-acclimated and Cd-acclimated fish but did not account for the difference in plasma levels of Cd between two groups. Plasma clearance of Zn ({approx}0.23 ml/min per kg for new Zn) was substantially lower than Cd clearance. Pre-acclimation to waterborne Zn reduced the new Zn levels in RBCs, but did not affect the clearance of Zn from blood plasma or tissue burdens of Zn in fish. Bile concentrations of both Cd and Zn were elevated in acclimated fish, but total bile burden accounted for <1% of the injected metal dose. The results suggest that the detoxification process of injected plasma Cd is stimulated by pre-acclimation to waterborne Cd, and that Zn levels are homeostatically controlled in both non-acclimated and acclimated trout.

  1. Proteomic responses of oceanic Synechococcus WH8102 to phosphate and zinc scarcity and cadmium additions

    Directory of Open Access Journals (Sweden)

    Alysia eCox

    2013-12-01

    Full Text Available Synechococcus sp. WH 8102 is a motile marine cyanobacterium isolated originally from the Sargasso Sea. To test the response of this organism to cadmium (Cd -generally considered a toxin- cultures were grown in a matrix of high and low zinc (Zn and phosphate (PO43- and were then exposed to an addition of 4.4 pM free Cd2+ at mid-log phase and harvested after 24 h. Whereas Zn and PO43- had little effect on overall growth rates, in the final 24 h of the experiment three growth effects were noticed: i low PO43- treatments showed increased growth rates relative to high PO43- treatments, ii the Zn/high PO43- treatment appeared to enter stationary phase, and iii Cd increased growth rates further in both the low PO43- and Zn treatments. Global proteomic analysis revealed that: i Zn appeared to be critical to the PO43- response in this organism, ii bacterial metallothionein (SmtA appears correlated with PO43- stress-associated proteins, iii Cd has the greatest influence on the proteome at low PO43- and Zn, iv Zn buffered the effects of Cd, and v in the presence of both replete PO43- and added Cd the proteome showed little response to the presence of Zn. Similar trends in alkaline phosphate (ALP and SmtA suggest the possibility of a Zn supply system to provide Zn to ALP that involves SmtA. In addition, proteome results were consistent with a previous transcriptome study of PO43- stress (with replete Zn in this organism, including the greater relative abundance of ALP (PhoA, ABC phosphate binding protein (PstS and other proteins. Yet with no Zn in this proteome experiment the PO43- response was quite different including the greater relative abundance of five hypothetical proteins with no increase in PhoA or PstS, suggesting that Zn nutritional levels are connected to the PO43- response in this cyanobacterium. Alternate ALP PhoX (Ca was found to be a low abundance protein, suggesting that PhoA (Zn, Mg may be more environmentally relevant than PhoX.

  2. 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).

  3. Effects of long-term exposure of gelatinated and non-gelatinated cadmium telluride quantum dots on differentiated PC12 cells

    Directory of Open Access Journals (Sweden)

    Prasad Babu R

    2012-01-01

    Full Text Available 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.

  4. Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G.; Dorman, Rebecca A.; Brumbaugh, William G.; Mebane, Christopher A.; Kunz, James L.; Hardesty, Douglas K.

    2014-01-01

    Chronic toxicity of cadmium, copper, lead, or zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was evaluated in water-only exposures started with newly hatched larvae or approximately 1-mo-old juveniles. The 20% effect concentration (EC20) for cadmium from the sturgeon tests was higher than the EC20 from the trout tests, whereas the EC20 for copper, lead, or zinc for the sturgeon were lower than those EC20s for the trout. When the EC20s from the present study were included in compiled toxicity databases for all freshwater species, species mean chronic value for white sturgeon was in a relatively low percentile of the species sensitivity distribution for copper (9th percentile) and in the middle percentile for cadmium (55th percentile), zinc (40th percentile), or lead (50th percentile). However, the species mean chronic value for rainbow trout was in a high percentile for copper, lead, and zinc (∼68th–82nd percentile), but in a low percentile for cadmium (23rd percentile). The trout EC20s for each of the 4 metals and the sturgeon EC20s for cadmium or lead were above US Environmental Protection Agency chronic ambient water quality criteria (AWQC) or Washington State chronic water quality standards (WQS), whereas the sturgeon EC20s for copper or zinc were approximately equal to or below the chronic AWQC and WQS. In addition, acute 50% effect concentrations (EC50s) for copper obtained in the first 4 d of the chronic sturgeon test were below the final acute value used to derive acute AWQC and below acute WQS for copper.

  5. Crystal structure of Helicobacter pylori neutrophil-activating protein with a di-nuclear ferroxidase center in a zinc or cadmium-bound form

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Hideshi, E-mail: h-yokoya@u-shizuoka-ken.ac.jp [School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Tsuruta, Osamu; Akao, Naoya; Fujii, Satoshi [School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Structures of a metal-bound Helicobacter pylori neutrophil-activating protein were determined. Black-Right-Pointing-Pointer Two zinc ions were tetrahedrally coordinated by ferroxidase center (FOC) residues. Black-Right-Pointing-Pointer Two cadmium ions were coordinated in a trigonal-bipyramidal and octahedral manner. Black-Right-Pointing-Pointer The second metal ion was more weakly coordinated than the first at the FOC. Black-Right-Pointing-Pointer A zinc ion was found in one negatively-charged pore suitable as an ion path. -- Abstract: Helicobacter pylori neutrophil-activating protein (HP-NAP) is a Dps-like iron storage protein forming a dodecameric shell, and promotes adhesion of neutrophils to endothelial cells. The crystal structure of HP-NAP in a Zn{sup 2+}- or Cd{sup 2+}-bound form reveals the binding of two zinc or two cadmium ions and their bridged water molecule at the ferroxidase center (FOC). The two zinc ions are coordinated in a tetrahedral manner to the conserved residues among HP-NAP and Dps proteins. The two cadmium ions are coordinated in a trigonal-bipyramidal and distorted octahedral manner. In both structures, the second ion is more weakly coordinated than the first. Another zinc ion is found inside of the negatively-charged threefold-related pore, which is suitable for metal ions to pass through.

  6. SIGNIFICATION BIOLOGIQUE DES TENEURS EN PLOMB, CADMIUM, ZINC ET CUIVRE DANS LA LAINE DE MOUTON DE LA RACE OULED DJELLAL

    OpenAIRE

    F Z MEHENNAOUI-AFRI; M F KADI; S AMRI; Mehennaoui, S

    2001-01-01

    Les teneurs en plomb, cadmium, zinc et cuivre ont été déterminées dans la laine lavée et la laine non lavée de mouton de la race Ouled Djellal par spectrophotométrie d’absorption atomique avec ou  sans flamme. Les concentrations en plomb dans la laine non lavée sont toujours supérieures à celles de la laine lavée quels que soient le prélèvement et la région d’étude. Les taux en plomb déterminés varient entre 0,2 et 2,3 ppm et entre 0,8 et 11 ppm respectivement pour la laine lavée et la laine ...

  7. Kinetics of the synthesis of ultradisperse cadmium and zinc oxide-like powders in a plasma-solution system

    Science.gov (United States)

    Smirnova, K. V.; Shutov, D. A.; Rybkin, V. V.; Ivanov, A. N.; Gromov, M. V.

    2017-11-01

    The action of the DC glow discharge on the cadmium and zinc nitrates water solution in the absence of additional reagents and without electrodes-solution contact was shown to result in the production of the solids in the liquid phase. The atmospheric pressure direct current discharge was excited in the ambient air by applying a high direct voltage to two pointed titanium electrodes placed above liquid anode and liquid cathode in the H-shaped cell. The discharge current was varied in the range of 30-70 mA and the initional solutions concentrations were 5 mM. The kinetics of particles formation was studied using turbidimetry and nephelometry methods.

  8. Increasing cadmium and zinc levels in wild common eiders breeding along Canada's remote northern coastline

    Energy Technology Data Exchange (ETDEWEB)

    Mallory, Mark L., E-mail: mark.mallory@acadiau.ca [Biology Department, Acadia University, Wolfville, Nova Scotia B4P 2R6 (Canada); Braune, Birgit M. [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario K1A 0H3 (Canada); Robertson, Gregory J. [Environment Canada, Wildlife Research Division, 6 Bruce Street, Mount Pearl, Newfoundland and Labrador A1N 4T3 (Canada); Gilchrist, H. Grant [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario K1A 0H3 (Canada); Mallory, Conor D. [Chemistry Department, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Forbes, Mark R. [Biology Department, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Wells, Regina [Environment Canada, Canadian Wildlife Service, 512 Lahr Boulevard, Happy Valley-Goose Bay, Newfoundland and Labrador A0P 1C0 (Canada)

    2014-04-01

    The common eider (Somateria mollissima) is an abundant sea duck breeding around the circumpolar Arctic, and is an important component of subsistence and sport harvest in some regions. We determined hepatic cadmium (Cd) and zinc (Zn) concentrations in the livers of breeding females sampled during three time periods including 1992/3, 2001/2 and 2008 at three sites spanning 53.7°N–75.8°N in the eastern Canadian Arctic. At all sites, concentrations of both Cd and Zn increased ∼ 300% over this time period. The reasons for this rapid increase in concentrations are unclear. - Highlights: • Cd and Zn analyzed in common eider (Somateria mollissima) liver tissue in Canadian Arctic from sites spanning 3000 km. • ∼ 300% increase in concentrations observed over ∼ 20 years • Levels of both elements considered high and near levels thought to pose concerns for wildlife health.

  9. Determination of arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc in geological materials by atomic-absorption spectrometry

    Science.gov (United States)

    Viets, J.G.; O'Leary, R. M.; Clark, Robert J.

    1984-01-01

    Arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc are very useful elements in geochemical exploration. In the proposed method, geological samples are fused with potassium pyrosulphate and the fusate is dissolved in a solution of hydrochloric acid, ascorbic acid and potassium iodide. When this solution is shaken with a 10% V/V Aliquat 336 - isobutyl methyl ketone organic phase, the nine elements of interest are selectively partitioned in the organic phase. All nine elements can then be determined in the organic phase using flame atomic-absorption spectrometry. The method is rapid and allows the determination of Ag and Cd at levels down to 0.1 p.p.m., Cu, Mo, and Zn down to 0.5 p.p.m., Pb, Bi and Sb down to 1 p.p.m. and As down to 5 p.p.m. in geological materials.

  10. Growth mechanism, dielectric, elastic and thermal properties of zinc cadmium thiocyanate crystal as a potential piezoelectric crystal

    Science.gov (United States)

    Lü, Yadong; Liu, Xitao; Wang, Xinqiang; Gao, Zeliang; Yin, Xin; Yuan, Kangkang; Xu, Chonghe; Wang, Lin; Zhang, Guanghui; Zhu, Luyi; Xu, Dong

    2017-10-01

    Bulk single crystals of zinc cadmium thiocyanate, ZnCd(SCN)4 (ZCTC) with dimensions of 51 × 15 × 12 and 28 × 13 × 12 mm3 have been obtained. Growth habits were investigated, two-dimensional nucleation growth mechanism and crystal twinning defect were observed from the as-grown crystals. The thermal diffusivities were measured, and then thermal conductivities were calculated with values decreasing from 1.3683 to 0.8739 Wṡm-1ṡK-1 and 0.8496 to 0.5356 Wṡm-1ṡK-1 as the temperature increasing from 303 to 423 K, along the a- and c-directions, respectively. The relative dielectric constants and elastic compliance constants at room temperature were determined. Meanwhile, first-principles calculation was used to calculate elastic constants.

  11. Determination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Quentin Hurdebise

    2015-04-01

    Full Text Available Zinc, lead and cadmium are metallic trace elements (MTEs that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this work is to evaluate the applicability of biosensors as tools able to provide data about the bioavailability of such MTEs in contaminated soils. Here, we tested the genetically-engineered strain Escherichia coli pPZntAgfp as a biosensor applicable to the detection of zinc, lead and cadmium by the biosynthesis of green fluorescent protein (GFP accumulating inside the cells. Flow cytometry was used to investigate the fluorescence induced by the MTEs. A curvilinear response to zinc between 0 and 25 mg/L and another curvilinear response to cadmium between 0 and 1.5 mg/L were highlighted in liquid media, while lead did not produce exploitable results. The response relating to a Zn2+/Cd2+ ratio of 10 was further investigated. In these conditions, E. coli pPZntAgfp responded to cadmium only. Several contaminated soils with a Zn2+/Cd2+ ratio of 10 were analyzed with the biosensor, and the metallic concentrations were also measured by atomic absorption spectroscopy. Our results showed that E. coli pPZntAgfp could be used as a monitoring tool for contaminated soils being processed.

  12. Adaptive and cross-protective responses against cadmium and zinc toxicity in cadmium-resistant bacterium isolated from a zinc mine

    Directory of Open Access Journals (Sweden)

    Benjaphorn Prapagdee

    2009-12-01

    Full Text Available Cadmium (Cd is a major environmental hazard, which usually is detected in its ionic form of Cd2+. It also causes adverse toxic effects on human health and other living organisms. Cd-resistant bacteria were isolated from Cd-contaminated soils. One isolate, TAK1, was highly resistance level to Cd toxicity. TAK1 was isolated from soil contaminated with a high Cd concentration (204.1 mg.kg-1. The result of 16S rDNA sequence analysis found that the TAK1 showed the similarity to Ralstonia sp. Physiological adaptive and cross-protective responses to Cd and Zn killing were investigated in Ralstonia sp.TAK1. Exposure to a low concentration of Cd induced adaptive resistance to higher concentrations of Cd. In addition, pretreatment of Ralstonia sp.TAK1 with an inducing concentration of Cd conferred cross-protective response against subsequent exposure to the lethal concentrations of Zn. The induced adaptive and cross-protective response Ralstonia sp.TAK1 required newly synthesized protein(s. Cd-induced adaptive and cross-protective responses against Cd and Zn toxicity are the important mechanisms used by Ralstonia sp.TAK1 to survive in the heavy metal contaminated environments. These findings might lead to the use of Ralstonia sp.TAK1 for microbial based remediation in Cd and Zn-contaminated soils.

  13. The Role of Blood Lead, Cadmium, Zinc and Copper in Development and Severity of Acne Vulgaris in a Nigerian Population.

    Science.gov (United States)

    Ikaraoha, C I; Mbadiwe, N C; Anyanwu, C J; Odekhian, J; Nwadike, C N; Amah, H C

    2017-04-01

    Acne vulgaris is a very common skin disorder affecting human beings. There is a paucity of report on the role of heavy metals-lead (Pb) and cadmium (Cd)-globally, and trace metals-zinc (Zn) and copper (Cd)-particularly in Nigeria in the development/severity of acne vulgaris. This study is aimed to determine the blood levels of some heavy metals-cadmium and lead-and trace metals-zinc and copper-in acne vulgaris sufferers in a Nigerian population. Venous blood samples were collected from a total number of 90 non-obese female subjects consisting of 30 mild, 30 moderate and 30 severe acne vulgaris sufferers for blood Cd, Pb, Cu and Zn determination. They were age-matched with 60 females without acne vulgaris who served as the control subjects. Acne sufferers had significantly higher blood Cd and Pb (P = 0.0143 and P = 0.0001 respectively) and non-significantly different blood levels of Cu and Zn (P = 0.910 and P = 0.2140 respectively) compared to controls. There were significant progressive increases in blood levels of Cd and Pb (P = 0.0330 and P = 0.0001 respectively) and non-significant differences in the mean blood level of Cu and Zn (P = 0.1821 and P = 0.2728 respectively) from mild to moderate and severe acne vulgaris sufferers. Increases in blood Cd and Pb may play critical roles in the pathogenesis/severity of acne vulgaris, while Cu and Zn seem to play less significant roles in the development of this disorder in this environment.

  14. Optical, crystalline perfection and mechanical studies on unidirectional grown bis(thiourea) cadmium zinc chloride single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Uthrakumar, R. [Department of Physics, Loyola College, Sterling Road, Nungambakkam, Chennai-600 034, Tamilnadu (India); Department of Physics, Sri Muthukumaran Institute of Technology, Chennai-600 069 (India); Vesta, C. [Department of Physics, SDNB Vaishnav College, Chennai-600 044 (India); Bhagavannarayana, G. [CGC Section, National Physical Laboratory, New Delhi-110 012 (India); Robert, R. [Department of Physics, Government Arts College, Krishnagiri-635 001 (India); Jerome Das, S., E-mail: sjeromedas2004@yahoo.com [Department of Physics, Loyola College, Sterling Road, Nungambakkam, Chennai-600 034, Tamilnadu (India)

    2011-02-03

    Research highlights: > Growth of bulk and optically clear single crystal of bis(thiourea) cadmium zinc chloride was successfully grown from aqueous solution by utilizing unidirectional crystal growth method. The title material belongs to orthorhombic crystal system with space group P2{sub 1}2{sub 1}2{sub 1}. The grown single crystal was free from structural grain boundaries with the FWHM value of the diffraction curve as 14 arc s. The optical transmission analysis indicates that BTCZC has a wide transparency window in the visible region with a lower cutoff wavelength at 250 nm. Hardness parameters have been calculated for the grown crystal. The dielectric studies reveal that BTCZC has low dielectric constant with fewer defects, and hence this crystal can be used as a potential material for optical applications. - Abstract: Optically transparent and bulk single crystal of bis(thiourea) cadmium zinc chloride was successfully grown by unidirectional crystal growth technique. The quality of the crystal was examined by high-resolution X-ray diffraction analysis. The cell parameters and the crystallinity of the grown crystal were estimated by the single-crystal and powder X-ray diffraction analyses, respectively. Optical transmittance of the crystal was recorded using the UV-vis-NIR spectrophotometer. The optical band gap and optical constant of the material were calculated by using transmission spectrum. Microhardness measurements were made for the grown crystal using Vicker's microhardness tester. The dielectric loss and dielectric constant measurements as a function of frequency and temperature were measured for the grown crystal.

  15. Influence of chronic cadmium exposure on the tissue distribution of copper and zinc and oxidative stress parameters in rats.

    Science.gov (United States)

    Erdem, Onur; Yazihan, Nuray; Kocak, Mehtap Kacar; Sayal, Ahmet; Akcil, Ethem

    2016-08-01

    The aim of this study was to investigate the effect of oral cadmium (Cd) intoxication on the antioxidant response and its relationship with essential bioelements like copper (Cu) and zinc (Zn). The experimental group was chronically exposed to Cd daily for 8 weeks via consumption of water containing 15 ppm cadmium chloride. Cu, Zn, and Cd concentrations and oxidative stress parameters were analyzed in liver, kidney, and heart tissues. Exposure to Cd led to a significant decrease in the activities of superoxide dismutase in all considered samples while a significant increase in the activity of glutathione peroxidase except for the kidney. We found a significant increase in malondialdehyde concentration in the tissues except for heart. Also oral administration of Cd caused a significant reduction of Zn and Cu in the tissues. Our results allow us to hypothesize that higher Cd concentration in the tissues causes oxidative stress by increasing malondialdehyde as a means of altering antioxidant defense system and deterioration of bioelements in rat liver, kidney, and heart. In addition, further studies are needed to explain the effect of long-term, low-dose exposure to Cd on distribution of bioelements and its relationship with oxidative stress. © The Author(s) 2015.

  16. Interaction of cadmium and zinc in biological samples of smokers and chewing tobacco female mouth cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Wadhwa, Sham Kumar, E-mail: wadhwashamkumar@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Naveed, E-mail: tgkazi@yahoo.com [Liaquat University of Medical and Health Sciences, Jamshoro 76080 (Pakistan); Kandhro, Ghulam Abbas [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jamil Ahmed, E-mail: jab_mughal@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Qadir, E-mail: aqshah07@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kolachi, Nida Fatima [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Arain, Muhammad Balal, E-mail: bilal_ku2004@yahoo.com [Department of Mathematics and Basic Sciences, NED University of Engineering and Technology, Karachi 75270 (Pakistan)

    2010-04-15

    Epidemiologic studies suggest that zinc (Zn) deficiency and high accumulation of cadmium (Cd) may be associated with increased risk of cancer. The incidence of mouth cancer has increased among females, who possess habits of chewing tobacco with gradients (areca nut and betel quid) and smoking tobacco in Pakistan. In present study, we measured the concentration of Cd and Zn in 96 mouth cancer patients (MCPs) and 110 female controls/referents (67 smoker and chewing tobacco), while 43 have none of smoking and chewing tobacco habits, belongs to different cities of Pakistan. Both controls and patients have same age group (ranged 35-65 years), socio-economic status, localities and dietary habits. The Zn and Cd were determined by flame/graphite furnace atomic absorption spectrophotometer, prior to microwave assisted acid digestion method. The Cd/Zn ratio in both biological samples was also calculated. The results of this study showed that the mean value of Zn was lower, while the mean concentration of Cd was higher in the blood and scalp hair samples of MCPs as compared to control subjects (p < 0.001). The controls chewing and smoking tobacco have high level of Cd in both biological samples as compared to those have not smoking or chewing tobacco (p < 0.012). The Cd/Zn ratio was higher in MCPs than control subjects. This study is compelling evidence in support of positive associations between cadmium, cigarette smoking, deficiency of Zn and cancer risk.

  17. Exposure of cultured human proximal tubular cells to cadmium, mercury, zinc and bismuth: toxicity and metallothionein induction.

    Science.gov (United States)

    Rodilla, V; Miles, A T; Jenner, W; Hawksworth, G M

    1998-08-14

    The kidney, in particular the proximal convoluted tubule, is a major target site for the toxic effects of various metals. However, little is known about the early effects of these metals after acute exposure in man. In the present study we have evaluated the toxicity of several inorganic metal compounds (CdCl2, HgCl2, ZnCl2, and Bi(NO3)3) and the induction of metallothionein by these compounds in cultured human proximal tubular (HPT) cells for up to 4 days. The results showed that bismuth was not toxic even at the highest dose (100 microM) used, while zinc, cadmium and mercury exhibited varying degrees of toxicity, zinc being the least toxic and mercury the most potent. A significant degree of interindividual variation between the different isolates used in these experiments was also observed. All metals used in the present study induced MT, as revealed by immunocytochemistry. All metals showed maximal induction between 1 and 3 days after treatment. Although a certain amount of constitutive MT was present in the cultures, the intensity of the staining varied with time in culture and between the different isolates studied. No correlation could be made between the intensity of the staining in control cultures (indicating total amount of constitutive MT) and the susceptibility of a given isolate to metal toxicity. Furthermore, no correlation could be made between metal-induced MT and the susceptibility of a given isolate to that particular metal.

  18. Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: Implication for human health

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.T.; Liao, B.; Lan, C.Y. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, Guangdong (China); Qiu, J.W. [Deparment of Biology, Hong Kong Baptist University, Kowloon, Hong Kong (China); Shu, W.S. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, Guangdong (China)], E-mail: shuws@mail.sysu.edu.cn

    2007-12-15

    Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies.

  19. An Investigation of Electrodeposited Alloys and Pure Metals as Substitutes for Zinc and Cadmium for Protective Finishes for Steel Parts of Aircraft

    Science.gov (United States)

    1947-11-30

    me^suremf-nts were made. 5692 93 SABLE 14. INITIAL AM?- 24-HOUR DINAMIC POTENTIAL AMD CORROSION CURREM IV.TA FOR CAST ZINC-INDIUM AND CADMIUM...243 (1920) 2. "A Textbook of Metallurgy", G. Tamraan, pp. 329-34-5, Chemical Catalog Co., N. Y. (1925) 3. " Structure of Alloys Deposited by...Electrolysis - II Copper-Zinc Alloys", E. Raub and D. Krause. Z. Electrochem., J50, 91 (1944) Met. Abst.. 12, 217 (1946) 4. "The Structure of the Galvanic

  20. Dispersive liquid-liquid microextraction for the simultaneous separation of trace amounts of zinc and cadmium ions in water samples prior to flame atomic absorption spectrometry determination

    Directory of Open Access Journals (Sweden)

    Sayed Zia Mohammadi

    2012-01-01

    Full Text Available In the proposed method, carbon tetrachloride and ethanol were used as extraction and dispersive solvents. Several factors that may be affected on the extraction process, such as extraction solvent, disperser solvent, the volume of extraction and disperser solvent, pH of the aqueous solution and extraction time were optimized. Under the optimal conditions, linearity was maintained between 1.0 ng mL-1 to 1.5 mg mL-1 for zinc and 1.0 ng mL-1 to 0.4 mg mL-1 for cadmium. The proposed method has been applied for determination of trace amount of zinc and cadmium in standard and water samples with satisfactory results.

  1. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Inês C. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Mesquita, Raquel B.R. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto (Portugal); Rangel, António O.S.S., E-mail: arangel@porto.ucp.pt [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal)

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60–160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11–21 for the metal ions. A LOD of 0.23 μg L{sup −1} for cadmium, 2.39 μg L{sup −1} for zinc, and 0.11 μg L{sup −1} for copper and a sampling rate of 12, 13, and 15 h{sup −1} for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples. - Highlights: • Multi-parametric determination of cadmium, zinc, and copper at the μg L{sup −1} level. • In-line metal ions preconcentration using NTA resin. • Minimization of matrix interferences by performing solid phase spectrometry in a SI-LOV platform. • Successful application to metal ions determination in freshwaters.

  2. Survey of heavy metal pollution (copper, lead, zinc, cadmium, iron and manganese) in drinking water resources of Nurabad city, Lorestan, Iran 2013

    OpenAIRE

    GHodratolah Shams Khorramabadi; Abdolah Dargahi; Lila Tabandeh; Hatam Godini; Parvin Mostafaee

    2016-01-01

    Background: Healthy water passes through the pipelines from supply resources to consuming places in which passing from these stages may cause some cases of contamination like heavy metal contamination. Therefore, the aim of this study was to evaluate the contamination of heavy metals (copper, lead, zinc, cadmium, iron, and manganese) in water resources of Nurabad city of Lorestan in 2013. Materials and Methods: In this cross-sectional study, samples were collected from 7 wells of drinking...

  3. Simultaneous determination of traces amounts of cadmium, zinc, and cobalt based on UV-Vis spectrometry combined with wavelength selection and partial least squares regression.

    Science.gov (United States)

    Xu, Deng; Fan, Wei; Lv, Huiying; Liang, Yizeng; Shan, Yang; Li, Gaoyang; Yang, Zhenyu; Yu, Ling

    2014-04-05

    The use of wavelength selection before partial least squares regression (PLSR) for simultaneous determination of divalent metal ions, cadmium, zinc and cobalt by UV-Vis spectrometry was investigated in this paper. The number of wavelengths selected by competitive adaptive reweighted sampling (CARS) for cadmium, zinc, and cobalt were 21, 13 and 7, respectively, from the 916 original wavelength points. The analytical system was based on the formation of the complexes with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) in surfactant media. Compared with the results of full spectra calibration, the root mean squared error of prediction (RMSEP) reduced to 0.0110, 0.0098 and 0.0031 for cadmium, zinc and cobalt, respectively. Moreover, by using the selective wavelengths instead of the 916 original wavelengths, the latent variables of PLS models reduced to 3, 3 and 4. The results indicated that the PLS model established by selected wavelength could be used for simultaneous determination of divalent metal ions. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters.

    Science.gov (United States)

    Santos, Inês C; Mesquita, Raquel B R; Rangel, António O S S

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60-160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11-21 for the metal ions. A LOD of 0.23 μg L(-1) for cadmium, 2.39 μg L(-1) for zinc, and 0.11 μg L(-1) for copper and a sampling rate of 12, 13, and 15 h(-1) for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. 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

  6. Distribution of Zinc and Cadmium in Tissues of Giant Reed (Arundo Donax L.: Sequential Extraction - Radiometric Study

    Directory of Open Access Journals (Sweden)

    Richveisová Barbora Micháleková

    2014-06-01

    Full Text Available Heavy metals are taken up by the vascular plant root system from water solutions in cationic forms. Subsequently, during both short and long distance transport to other plant tissues, cation forms are incorporated to many bioorganic compounds differing in stability, ionic character and physico-chemical properties such as solubility in lipid structures and mobility across cell membrane systems. Many sequential and single step extraction methods have been elaborated for characterization of the role of individual components of plant cells components in transport and detoxication of heavy metals. In our study, dry biomass of giant reed (Arundo donax L. grown in hydroponic media spiked with 65ZnCl2 and 109CdCl2 was treated with dithizone solutions as complexing ligand in order to convert free Zn2+ and Cd2+ ions to corresponding dithizonates. Treatment with dithizone showed that up to 67 % of the total plant Cd and 56 % of the total plant Zn were transformed to dithizonate complexes extracted with chloroform. Extraction of biomass with Folch reagent showed that up to 48 % of the total root cadmium and up to 18 % of the total shoot cadmium is bound in lipid fraction. Zinc was not found in lipid fraction of root and shoot. Derivatization of the dried root and shoot lipid fraction by dithizone showed that two third of Cd in root and practically all Cd in shoot lipid fraction could be transformed to Cd-dithizonate. Methods of biomass treating with complexing ligands and a method of sequential extraction procedures with non-polar organic solvents and radiotracer methodology seem to be useful methods for the study of metal speciation and distribution in vascular plants

  7. Effects of zinc and cadmium interactions on root morphology and metal translocation in a hyperaccumulating species under hydroponic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Li Tingqiang, E-mail: litq@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe; Lu Lingli [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029 (China); Islam, Ejazul [Nuclear Institute of Agriculture, Tandojam, 48800 Hyderabad (Pakistan); He Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, Florida 34945 (United States)

    2009-09-30

    Effects of zinc (Zn) and cadmium (Cd) interactions on root morphology and metal translocation in the hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of S. alfredii were investigated under hydroponic conditions. Specific root lengths (SRL), specific root surface areas (SRA) and specific root volumes (SRV) of the HE increased significantly when plant were treated with 500 {mu}M Zn or 100 {mu}M Cd + 500 {mu}M Zn, whereas these root parameters were significantly decreased for the NHE when plant were treated with 100 {mu}M Cd, 500 {mu}M Zn or 100 {mu}M Cd + 500 {mu}M Zn. SRL and SRA of the HE were mainly constituted by roots with diameter between 0.2-0.4 mm (diameter class 3 and 4) which were significantly increased in treatment of 500 {mu}M Zn or 100 {mu}M Cd + 500 {mu}M Zn, whereas in the NHE, metal treatments caused a significant decrease in SRL and SRA of the finest diameter class root (diameter between 0.1-0.3 mm). The HE of S. alfredii could maintain a fine, widely branched root system under contaminated conditions compared with the NHE. Relative root growth, net Cd uptake and translocation rate in the HE were significantly increased by adding 500 {mu}M Zn, as compared with the second growth period, where 100 {mu}M Cd was supplied alone. Cadmium and Zn concentrations in the shoots of the HE were 12-16 times and 22-27 times higher than those of the NHE under 100 {mu}M Cd + 500 {mu}M Zn combined treatment. These results indicate strong positive interactions of Zn and Cd occurred in the HE under 100 {mu}M Cd + 500 {mu}M Zn treatment and Cd uptake and translocation was enhanced by adding 500 {mu}M Zn.

  8. Clean hydrometallurgical route to recover zinc, silver, lead, copper, cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy.

    Science.gov (United States)

    Ju, Shaohua; Zhang, Yifei; Zhang, Yi; Xue, Peiyi; Wang, Yihui

    2011-08-30

    A hydrometallurgical process for treating the hazardous jarosite residue from zinc hydrometallurgy was proposed, for not only detoxifying the residue, but also recovering the contained valuable metal components. The jarosite was initially activated and decomposed by sintering at 650°C for 1h. The sintered residue was leached in 6mol L(-1) aqueous NH(4)Cl solution at 105°C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. During reduction with Zn powder, more than 93% of Pb, Cu, Ag and Cd can be simultaneously recovered. Then the NH(4)Cl leaching residue were leached again in 30wt% aqueous NaOH solution for 1h at 160°C, and about 94% of As and 73% of Si were removed from the residue. The final residue was almost completely detoxified, and contains about 55wt% Fe, which can be used as an iron concentration. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Accumulation of heavy metals (cadmium, zinc, and copper) from smelter in forest ecosystems and their uptakes by Shiitake mushroom (Lentinus edodes (Berk) Sing. ) and Nameko mushroom (Pholiota glutinosa Kawamura) through polluted bed logs

    Energy Technology Data Exchange (ETDEWEB)

    Nishimoto, T.; Fujita, K.; Furukawa, H.; Yoshimoto, M.

    1977-12-01

    Mushrooms cultivated on sawdust medium which had been innoculated with heavy metals accumulated the metals increasingly in stems, pileus, gill and spores, in that order. There were strain differences, in accumulation, and highest concentration was found in the first-born fruit body. At 2 ppm, cadmium did not affect yield of the fruiting body. At 20 ppm, however, yield was seriously reduced. Species differences in absorption capacity for heavy metals were noted. Seasonal variations in cadmium and copper accumulation were noted, along with zinc. Cadmium concentration in fruiting bodies increased with increase of cadmium concentration in the growth substrate. 23 figures, 16 tables.

  10. Potential Influence of Selenium, Copper, Zinc and Cadmium on L-Thyroxine Substitution in Patients with Hashimoto Thyroiditis and Hypothyroidism.

    Science.gov (United States)

    Rasic-Milutinovic, Z; Jovanovic, D; Bogdanovic, G; Trifunovic, J; Mutic, J

    2017-02-01

    Background: Besides genetic factors, it is known that some trace elements, as Selenium, Copper, and Zinc are essential for thyroid gland fuction and thyroid hormone metabolism. Moreover, there were some metals effect that suggested patterns associated with overt thyroid disease. Aim of study: Hashimoto thyroiditis (HT), chronic autoimune inflamation of thyroid gland with cosequtive hipothyroidism, is common disease in Serbia, and we thought it is worthwile to explore potential effects of essential and toxic metals and metalloides on thyroid function and ability to restore euthyroid status of them. Results: This cross-sectional, case-control, study investigated the status of essential elements (Selenium,Copper,and Zinc) and toxic metals and metalloides (Al, Cr, Mn, Co, As, Cd, Sb, Ba, Be, Pb and Ni) from the blood of 22 female, patients with Hashimoto thyroiditis and overt hypothyroidism, and compared it with those of 55 female healthy persons. We tried to establish the presence of any correlation between previous mentioned elements and thyroid function in hypothyroid patients and healthy participants. Conclusions: The results of our study suggested that the blood concentration of essential trace elements, especially the ratio of Copper, and Selenium may influence directly thyroid function in patients with HT and overt hypothyroidism.Thus, our findings may have implication to life-long substitution therapy in terms of l-thyroxine dose reduction. Furthermore, for the first time, our study shown potential toxic effect of Cadmium on thyroid function in HT patients, which may implicate the dose of l-thyroxine substitution. © Georg Thieme Verlag KG Stuttgart · New York.

  11. New CZT cardiac cameras and myocardial perfusion imaging with thallium 201; Nouvelles cameras cardiaques a semi-conducteur cadmium -zinc- telluride (CZT) et scintigraphies myocardiques au thallium 201

    Energy Technology Data Exchange (ETDEWEB)

    Songy, B. [Service de medecine et imagerie nucleaire, centre cardiologique du Nord (CCN), 93 - Saint-Denis (France)

    2010-08-15

    Myocardial perfusion imaging is widely used for management of coronary artery disease. However, it suffers from technical limitations. New cardiac cameras using CZT detectors are now available and increase spatial (x2) and energy (x2) resolutions and photons sensitivity (x5). We describe here the General Electric Discovery NM 530c new camera and summarize the validation studies with technetium agents and with thallium 201, protocols to reduce doses, ultrafast protocols and perspectives offered with this new technology. (author)

  12. Zinc

    Science.gov (United States)

    ... can function properly. Full-term newborns that are underweight.. Most research suggests that taking zinc supplements during ... infant. However, adding zinc to nutritional supplementation for underweight, full-term infants in developing countries seems to ...

  13. Uptake, Accumulation and Excretion by Corophium volutator(Crustacea: Amphipoda) of Zinc, Cadmium and Cobalt Added to Sewage Sludge

    Science.gov (United States)

    Burgos, M. Galay; Rainbow, P. S.

    1998-11-01

    Zinc, cadmium and cobalt associated with digested sewage sludge are available to the benthic deposit-feeding amphipodCorophium volutator(Pallas). Accumulation by the amphipod of radioactively labelled metals adsorbed onto a 5% sludge-sediment mixture increased with time of exposure up to 15 days, but irregularly so as pulses of labelled metal were excreted into faecal pellets. The three labelled metals were accumulated and excreted apparently almost synchronously by individual amphipods, although great variability between different individuals was found. This intraspecific variability could not be attributed to differences between male and female amphipods. Net accumulation of labelled metals from the sludge increased with increased labelled metal concentration in the sludge, but not with time beyond an initial period of 15-30 days. It is proposed that the metal excretion patterns might reflect the breakdown of epithelial cells of the ventral caeca following a cell cycle, releasing accumulated stores of detoxified metals into the gut lumen and out of the body through faeces.

  14. The contribution of ecdysis to the fate of copper, zinc and cadmium in grass shrimp, Palaemonetes pugio holthius

    Energy Technology Data Exchange (ETDEWEB)

    Keteles, K.A.; Fleeger, J.W. [Louisiana State Univ., Dept. of Biological Sciences, Baton Rouge, LA (United States)

    2001-07-01

    Depuration through ecdysis by grass shrimp, Palaemonetes pugio, was examined by exposure to a sublethal mixture of copper, zinc and cadmium for 72 h, followed by placement in uncontaminated water to molt. Percent eliminated with the exuviae varied for each metal; of the total intermolt body burden, 11% Cu, 18% Zn and 26% Cd was associated with the exuviae. Cu concentrations of intermolt exoskeletons were significantly higher than of the exuviae of post-ecdysis shrimp suggesting that Cu contained in the exoskeleton was reabsorbed before molting. Exuvial Cd concentration was not significantly different than the concentration of the intermolt exoskeleton, suggesting that most Cd in the exoskeleton was depurated with the exuviae. Although Zn whole-body burdens were lower after a molt, Zn losses were most likely due to excretion because exuvial concentrations were significantly lower than in the intermolt exoskeleton. Cu, Cd and Zn concentrations in exuvaie shed in metal-enriched water were significantly higher due to adsorption than exuvaie produced in uncontaminated water. (Author)

  15. Phytosiderophores determine thresholds for iron and zinc accumulation in biofortified rice endosperm while inhibiting the accumulation of cadmium.

    Science.gov (United States)

    Banakar, Raviraj; Alvarez Fernandez, Ana; Díaz-Benito, Pablo; Abadia, Javier; Capell, Teresa; Christou, Paul

    2017-10-13

    Nicotianamine (NA) and 2'-deoxymugenic acid (DMA) are metal-chelating ligands that promote the accumulation of metals in rice endosperm, but it is unclear how these phytosiderophores regulate the levels of different metals and limit their accumulation. In this study, transgenic rice plants producing high levels of NA and DMA accumulated up to 4-fold more iron (Fe) and 2-fold more zinc (Zn) in the endosperm compared with wild-type plants. The distribution of Fe and Zn in vegetative tissues suggested that both metals are sequestered as a buffering mechanism to avoid overloading the seeds. The buffering mechanism involves the modulation of genes encoding metal transporters in the roots and aboveground vegetative tissues. As well as accumulating more Fe and Zn, the endosperm of the transgenic plants accumulated less cadmium (Cd), suggesting that higher levels of Fe and Zn competitively inhibit Cd accumulation. Our data show that although there is a strict upper limit for Fe (~22.5 µg g-1 dry weight) and Zn (~84 µg g-1 dry weight) accumulation in the endosperm, the careful selection of strategies to increase endosperm loading with essential minerals can also limit the accumulation of toxic metals such as Cd, thus further increasing the nutritional value of rice. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Developing acute-to-chronic toxicity ratios for lead, cadmium, and zinc using rainbow trout, a mayfly, and a midge

    Science.gov (United States)

    Mebane, C.A.; Hennessy, D.P.; Dillon, F.S.

    2008-01-01

    In order to estimate acute-to-chronic toxicity ratios (ACRs) relevant to a coldwater stream community, we exposed rainbow trout (Oncorhynchus mykiss) to cadmium (Cd), lead (Pb), and zinc (Zn) in 96-h acute and 60+ day early-life stage (ELS) exposures. We also tested the acute and sublethal responses of a mayfly (Baetis tricaudatus) and a midge (Chironomus dilutus, formerly C. tentans) with Pb. We examine the statistical interpretation of test endpoints and the acute-to-chronic ratio concept. Increasing the number of control replicates by 2 to 3x decreased the minimum detectable differences by almost half. Pb ACR estimates mostly increased with increasing acute resistance of the organisms (rainbow trout ACRs choice of test endpoint and statistical analysis influenced ACR estimates by up to a factor of four. When calculated using the geometric means of the no- and lowest-observed effect concentrations, ACRs with rainbow trout and Cd were 0.6 and 0.95; Zn about 1.0; and for Pb 3.3 and 11. The comparable Pb ACRs for the mayfly and Chironomus were 5.2 and 51 respectively. Our rainbow trout ACRs with Pb were about 5-20x lower than earlier reports with salmonids. We suggest discounting previous ACR results that used larger and older fish in their acute tests. ?? 2007 GovernmentEmployee: U.S. Geological Survey.

  17. Direct Determination of Zinc, Cadmium, Lead, Copper Metal in Tap Water of Delhi (India by Anodic Stripping Voltammetry Technique

    Directory of Open Access Journals (Sweden)

    Raj J.

    2013-04-01

    Full Text Available Salts of Zinc, Cadmium, Lead and Copper are taken incidentally or accidently and has become of great toxicological importance having toxic effect. In the present study direct determination of Zn, Cd, Pb and Cu metal was carried out from tap water of Delhi (India using differential pulse anodic stripping Voltammeter (DPASV at Hanging mercury dropping electrode (HMDE.Determination of Zn, Cd, Pb, Cu was done using Ammonium acetate buffer (pH 4.6 with a sweep rate (scan rate of 59.5 mV/s and pulse amplitude 50mV by HMDE by standard addition method. The solution was stirred during pre-electrolysis at -1150mV (vs. Ag/AgCl for 90 seconds and the potential was scanned from -1150V to +100V (vs..Ag/AgCl. As a result the minimum level of Zn, Cd, Pb, Cu was Zero and the concentration observed in the tap water sample of Delhi (India was determined as 0.174 mg/L-1, 0.001 mg/L-1, 0.002 mg/L-1, 0.011 mg/L-1 respectively.

  18. Effects of Cadmium and Zinc on the Gamete Viability, Fertilization, and Embryonic Development of Tripneustes gratilla (Linnaeus

    Directory of Open Access Journals (Sweden)

    Ivan Patrick B. Tualla

    2016-01-01

    Full Text Available Heavy metals are frequently reported for their mutagenic and teratogenic effects on benthic organisms. Thus, this study aimed to determine the toxicity of cadmium (Cd and zinc (Zn in the gametes of T. gratilla and to compare its fertilization and embryonic development under the highest nongametotoxic concentrations of these heavy metals. Gamete viability of T. gratilla under CdCl2 and ZnSO4 treatments was assayed through resazurin reduction test (RRT and was confirmed through gamete morphology assay. ZnSO4 was more toxic to T. gratilla gametes than CdCl2 and egg cells were more sensitive to both than the sperm cells. Higher concentrations of CdCl2 and ZnSO4 induced gamete apoptosis and necrosis while highest nongametotoxic concentrations were determined at 1 × 10−3 M and 1 × 10−4 M, respectively, and were used in an in vitro fertilization and embryonic development experiment. ZnSO4 treatment inhibited fertilization more than CdCl2 and yielded more deformed embryos, while both induced abnormalities and hindered further embryonic development. This study gives the first report on the specific concentrations of Cd and Zn that are toxic to T. gratilla gametes and has confirmed the teratogenic effects of these heavy metals.

  19. Zinc and/or cadmium accumulation in Gynura pseudochina (L.) DC. studied in vitro and the effect on crude protein

    Science.gov (United States)

    Panitlertumpai, Natthawoot; Nakbanpote, Woranan; Sangdee, Aphidech; Thumanu, Kanjana; Nakai, Izumi; Hokura, Akiko

    2013-03-01

    Gynura pseudochina (L.) DC. is a zinc (Zn)/cadmium (Cd) hyperaccumulative plant. The aim of this study was to examine the tolerance of G. pseudochina (L.) DC. for Zn and/or Cd accumulation and protein expression. An in vitro tissue culture system was used to control the environment and effects of the microorganisms. Treatments with higher Zn and Cd concentrations increased chlorosis and the accumulation of metals in the root and shoot. Cd treatment at low levels induced the growth of the plant, and the translocation factor was high. A dual treatment with Cd and Zn decreased the metals' toxicity and demonstrated the plant's proclivity to accumulate Cd. The SDS-PAGE and FT-IR analyses showed the effect of the metals' toxicity on protein expression and secondary structure. Moreover, using XAFS techniques, it was demonstrated that treatment with a high Zn concentration (100 mg l-1) resulted in tetrahedral coordination with mixed S/O ligation in the protein extract as compared with Znsbnd O coordination in the protein extract from the control plant cultured in the presence of trace levels of Zn (0.04 mg l-1). This research suggested that G. pseudochina (L.) DC. had properties to tolerate a high Zn and Cd concentration, related to the sulphur proteins.

  20. Expression profiling reveals functionally redundant multiple-copy genes related to zinc, iron and cadmium responses in Brassica rapa.

    Science.gov (United States)

    Li, Jimeng; Liu, Bo; Cheng, Feng; Wang, Xiaowu; Aarts, Mark G M; Wu, Jian

    2014-07-01

    Genes underlying environmental adaptability tend to be over-retained in polyploid plant species. Zinc deficiency (ZnD) and iron deficiency (FeD), excess Zn (ZnE) and cadmium exposure (CdE) are major environmental problems for crop cultivation, but little is known about the differential expression of duplicated genes upon these stress conditions. Applying Tag-Seq technology to leaves of Brassica rapa grown under FeD, ZnD, ZnE or CdE conditions, with normal conditions as a control, we examined global gene expression changes and compared the expression patterns of multiple paralogs. We identified 812, 543, 331 and 447 differentially expressed genes under FeD, ZnD, ZnE and CdE conditions, respectively, in B. rapa leaves. Genes involved in regulatory networks centered on the transcription factors bHLH038 or bHLH100 were differentially expressed under (ZnE-induced) FeD. Further analysis revealed that genes associated with Zn, Fe and Cd responses tended to be over-retained in the B. rapa genome. Most of these multiple-copy genes showed the same direction of expression change under stress conditions. We conclude that the duplicated genes involved in trace element responses in B. rapa are functionally redundant, making the regulatory network more complex in B. rapa than in Arabidopsis thaliana. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  1. Copper, cadmium, and zinc concentrations in aquatic food chains from the Upper Sacramento River (California) and selected tributaries

    Science.gov (United States)

    Saiki, M.K.; Castleberry, D. T.; May, T. W.; Martin, B.A.; Bullard, F. N.

    1995-01-01

    Metals enter the Upper Sacramento River above Redding, California, primarily through Spring Creek, a tributary that receives acid-mine drainage from a US EPA Superfund site known locally as Iron Mountain Mine. Waterweed (Elodea canadensis) and aquatic insects (midge larvae, Chironomidae; and mayfly nymphs, Ephemeroptera) from the Sacramento River downstream from Spring Creek contained much higher concentrations of copper (Cu), cadmium (Cd), and zinc (Zn) than did similar taxa from nearby reference tributaries not exposed to acid-mine drainage. Aquatic insects from the Sacramento River contained especially high maximum concentrations of Cu (200 mg/kg dry weight in midge larvae), Cd (23 mg/kg dry weight in mayfly nymphs), and Zn (1,700 mg/kg dry weight in mayfly nymphs). Although not always statistically significant, whole-body concentrations of Cu, Cd, and Zn in fishes (threespine stickleback, Gasterosteus aculeatus; Sacramento sucker, Catostomus occidentalis; Sacramento squawfish, Ptychocheilus grandis; and chinook salmon, Oncorhynchus tshawytasch) from the Sacramento River were generally higher than in fishes from the reference tributaries.

  2. 29 CFR 1910.1027 - Cadmium.

    Science.gov (United States)

    2010-07-01

    ... battery Plate making, plate preparation 50 All other processes 15 Zinc/Cadmium refining* Cadmium refining... as an airborne concentration of cadmium of 2.5 micrograms per cubic meter of air (2.5 µg/m3... air cadmium level to which an employee is exposed means the exposure to airborne cadmium that would...

  3. Radioactive zinc ( sup 65 Zn), zinc, cadmium, and mercury in the Pacific Hake, Merluccius productus (Ayres), off the West Coast of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, J.R.

    1974-06-01

    The Pacific Hake, Merluccius productus (Ayers) was used to monitor the waters off Puget Sound and the West Coast of the US for zinc(Zn), cadmium(Cd), mercury(Hg) and {sup 65}Zn. The Columbia River is not the source of Zn, Cd or Hg contamination, but is the source of {sup 65}Zn, with the concentration in the Hake reflecting the position of the Columbia River plume. Zn and Cd accumulation in the Hake were fit to the equation Y=B{sub 1}+B{sub 2}e{sup B}{sub 3}X where Y is the concentration of the element and X is the length or weight of the fish. Biological attributes were assigned to the other parameters as follows: B{sub 1} is the asymptotic value for Zn or Cd at chemical maturity; B{sub 2} is the location of the curve with respect to the length or weight of the fish; and B{sub 3} is a constant pertaining to the rate of change of Zn or Cd. Although Zn, Cd and Hg are all Group 2B elements, only the concentrations of Zn and Cd were correlated for all locations; Hg concentrations varied as a function of location. Zn and Cd concentrations increase with fish size and approach an asymptotic value at maturity, while Hg concentrations were linear and the slope is a function of sampling location. Zn and Cd levels are regulated in the adult, while Hg continues to increase with age. It may be significant that the age distribution of fish caught commercially coincides with the maximum concentration of Zn and Cd. 195 refs., 30 figs., 10 tabs. (MHB)

  4. Zinc(II) and Cadmium(II) coordination polymers constructed from phenylenediacetate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Sezer, Güneş Günay [Vocational School of Health Services, Bartın University, Bartın (Turkey); Department of Chemistry, Eskişehir Osmangazi University, Eskişehir (Turkey); Yeşilel, Okan Zafer; Erer, Hakan [Department of Chemistry, Eskişehir Osmangazi University, Eskişehir (Turkey); Şahin, Onur [Scientific and Technological Research Application Center, Sinop University, Sinop (Turkey)

    2016-01-15

    ABSTRACT: A series of new coordination polymers {[Zn(μ-opda)(μ-bpa)]·2H_2O}{sub n} (1), [Zn(μ{sub 3}-ppda)(μ-bpa)]{sub n} (2), [Cd(μ{sub 3}-ppda)(μ-bpa)]{sub n} (3), [Cd(μ{sub 3}-mpda)(μ-bpa)]{sub n} (4) and [Cd(μ{sub 3}-mpda)(μ-bipy)]{sub n} (5), (o/m/ppda=1,2/1,3/1,4-phenylenediacetate, bpa=1,2-bi(4-pyridyl)ethane, bipy=4,4′-bipyridine) were synthesized. Their structures were characterized by elemental analysis, IR spectroscopy, single-crystal and powder X-ray diffraction. Furthermore, the effect of metal sources (zinc acetate and zinc oxide) and acidity of the solution on the structure of the coordination polymers was discussed for complexes 1 and 5, respectively. The single-crystal X-ray crystallographic studies revealed that complexes 1, 3, 4 and 5 are uninodal (4)-connected 2D frameworks and display sql topology with the point symbol of (4{sup 4}.6{sup 2}). Complex 2 is 3D coordination polymer and exhibits pcu topology with the point symbol of (4{sup 12}.6{sup 3}). In addition, the luminescent properties and thermal behavior of all complexes were also investigated. - Graphical abstract: Scheme 1. Topologies of Coordination Polymers Reported in This Paper.

  5. [Recovery of zinc ion and cadmium ion with hollow fiber membrane extraction].

    Science.gov (United States)

    Wang, Y; Luo, G; Wang, Y; Wu, Z; Dai, Y

    2001-09-01

    The efficiency of hollow fiber membrane solvent extraction for the system of Meaq/bis(2-ethylhexyl) phosphate in heptane(Me = Cd2+, Zn2+) was studied for wastewater treatment and hydrometallurgy. It was found that the two phases velocity, the initial concentration and the pH value of the aqueous phase greatly influenced the extraction ratio. For very dilute solution with concentration lower than 500 mg/L, the mass transfer resistance was mainly in aqueous phase. When the aqueous phase concentration was relative higher than that of dilute solution, all the individual mass transfer resistances would not be ignored. For the concentrated solution, the mass transfer in the organic phase and the diffusion in membrane pores controlled the transport process. In the back extraction, the mass transfer resistance lied in the organic phase and the diffusion in membrane pores. The experimental results showed that it was possible that the extraction percentage achieved 90% when the metal ion concentration was lower than 400 mg/L. When the cadmium concentration was lower than 200 mg/L, its concentration can decrease 2 orders by extraction in a single-pass flow mode. The values of (HTU)w were between 15 cm and 30 cm, which was much lower than those of traditional extraction columns. The results indicated that membrane extraction with hollow fiber modules could efficiently remove or recover metal ions in the aqueous phases.

  6. Plant architecture, auxin homeostasis and phenol content in Arabidopsis thaliana grown in cadmium- and zinc-enriched media.

    Science.gov (United States)

    Sofo, Adriano; Bochicchio, Rocco; Amato, Mariana; Rendina, Nunzia; Vitti, Antonella; Nuzzaci, Maria; Altamura, Maria Maddalena; Falasca, Giuseppina; Rovere, Federica Della; Scopa, Antonio

    2017-09-01

    A screening strategy using micropropagation glass tubes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium (Cd) and zinc (Zn) at the concentration of 10-20μM and 100-200μM, respectively. Metal concentrations in plant shoots and roots were measured by quadrupole inductively coupled plasma mass spectrometry. After 21days from germination, all plants in the tubes were scanned at high resolution and the root systems analyzed. The localization of indole-3-acetic acid (IAA) in the primary root and lateral root apices was monitored using DR5:GUS, LAX3:GUS and AUX1:GUS Arabidopsis transgenic lines. Total phenol content in leaves was measured spectrophotometrically. Shoot and root dry weight and leaf area did not change in Zn-exposed plants and significantly decreased in Cd-exposed plants, compared to control plants. Cadmium induced a reduction of root length, of mean number of roots and of total root surface. Both Cd- and Zn-exposed plants showed a reduced specific root length. This morphological behavior, together with an observed increase in root diameter in metal-exposed plants could be interpreted as compensatory growth, and the observed thicker roots could act as a barrier to protect root from the metals. In comparison with the apical localization of the IAA signal in the control plants, Zn generally reinforced the intensity of IAA signal, without affecting its localization. In Cd-exposed plants, IAA localization remained apical but weaker compared to control plants. Total phenols decreased in plants exposed to Zn and Cd. Therefore, we propose that the remodelling of the root architecture and the production of some secondary metabolites, such as IAA and phenols could be two responses of plants subjected to metal stress. This knowledge can open the way to future phytoremediation strategies of contaminated sites

  7. Changes in selenium, zinc, copper and cadmium contents in human milk during the time when selenium has been supplemented to fertilizers in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Kantola, M. [Dept. of Chemistry, Univ. of Kuopio, Kuopio (Finland); Vartiainen, T. [Div. of Environmental Health, National Public Health Inst., Kuopio (Finland); Univ. of Kuopio, Dept. of Environmental Sciences, Kuopio (Finland)

    2001-07-01

    Sodium selenate has been supplemented to all agricultural fertilizers used in Finland since 1984. We followed the changes in selenium, cadmium, zinc and copper content in Finnish human milk between the years 1987 and 1993-1995. A total of 257 milk samples was collected, four weeks after delivery, in two areas: In Helsinki, an urban area, and in Kuopio, a rural area, where elevated copper concentrations have been found in the bedrock. Direct atomic absorption spectrophotometric methods without digestion were used for the analyses. The dependence of trace element content on study time, living area, smoking habits, fish eating frequency, and parity of mothers was studied by analysis of covariance. Inter-element correlations and correlations with mother's age and fat content in milk were studied by partial correlation. Significant increases were observed in mean selenium (16.4 {mu}g/l and 18.9 {mu}g/l, p < 0.001) and in fat contents (3.4% and 4.0%, p < 0.001), whereas significant decreases were seen in mean zinc (3.00 mg/l and 1.47 mg/l, p < 0.001), copper (0.52 mg/l and 0.43 mg/l, p < 0.001) and cadmium contents (0.095 {mu}g/l and 0.062 {mu}g/l, p < 0.01). In 1987, zinc had a positive correlation with copper and fat. Copper correlated inversely with the mothers' age. In 1993-1995, selenium correlated positively with copper, and zinc correlated inversely with mothers' age. Mothers living area had an effect on copper content in milk. Our results confirm that selenium supplementation to fertilizers in Finland has increased the selenium level in human maternal milk and most likely it also has an effect on the zinc and copper concentrations in maternal milk. (orig.)

  8. Copper, Manganese, Zinc, and Cadmium in Tea Leaves of Different Types and Origin.

    Science.gov (United States)

    Podwika, W; Kleszcz, K; Krośniak, M; Zagrodzki, P

    2017-09-02

    Concentrations of selected metals (Cu, Mn, Zn, Cd) in tea leaves were investigated. Samples included black, green, and other (red, white, yellow, and oolong) teas. They were purchased on a local market but they covered different countries of origin. Beverages like yerba mate, rooibos, and fruit teas were also included in the discussion. Metal determinations were performed using atomic absorption spectrometry. In black teas, Mn/Cd ratio was found to be significantly higher (48,091 ± 35,436) vs. green (21,319 ± 16,396) or other teas (15,692 ± 8393), while Cd concentration was lower (31.4 ± 18.3 μg/kg) vs. other teas 67.0 (67.0 ± 24.4). Moreover, Zn/Cu and Cu/Cd ratios were, respectively, lower (1.1 ± 0.2 vs. 2.2 ± 0.5) and higher (1086 ± 978 vs. 261 ± 128) when comparing black teas with other teas. Intake of each metal from drinking tea was estimated based on the extraction levels reported by other authors. Contributions to recommended daily intake for Cu, Mn, and Zn were estimated based on the recommendations of international authorities. Except for manganese, tea is not a major dietary source of the studied elements. From the total number of 27 samples, three have shown exceeded cadmium level, according to local regulations.

  9. Relationship between the level of zinc, lead, cadmium, nickel and chromium in hair of people with diabetes

    Directory of Open Access Journals (Sweden)

    Tadayon F.

    2014-07-01

    Full Text Available It has long been believed that some metals possess many adverse health effects. Recently, certain elements have been identified as essential trace elements that play an important role in the genesis and progression of several diseases. Some toxic metals have also been shown to be elevated in biological samples of diabetes mellitus patients. The status of trace elements in diabetes patients is also influenced by their diet, drugs administered and, to a large extent, by environmental factors. Pollutants due to the presence of toxic metals in environment not only enter the body by breading, water, and foodstuff accumulates in hair, but they could be adsorbed directly on the hair from environment. The aim of present study was to investigate the relationship between the level of zinc, lead, cadmium, nickel and chromium in hair samples of diabetic women from Tehran (Iran. The study population consisted of 100 women between 30 to 70 years of age from Tehran. The hair samples were washed with 1% (w/v (DDTC, 0.1M HCL and deionized water. Afterwards, the hair sample dried in oven at 70° C for 5 hours and then digested the next day. Dry ashing digestion procedure was carried out. The concentration of elements was measured by means of an atomic absorption spectrophotometer. The statistical analysis confirmed that mean concentrations of lead and nickel did not differ significantly from the control group. The results of this study showed that the mean values of Cr and Zn were significantly decreased in scalp hair samples of diabetic patients as compared to control subjects. Hair Cd level was significantly higher in type 2 diabetic patients. Values of Pearson correlation coefficient showed positive correlation between these elements.

  10. Sensitivity of mottled sculpins (Cottus bairdi) and rainbow trout (Onchorhynchus mykiss) to acute and chronic toxicity of cadmium, copper, and zinc

    Science.gov (United States)

    Besser, John M.; Mebane, Christopher A.; Mount, David R.; Ivey, Chris D.; Kunz, James L.; Greer, I. Eugene; May, Thomas W.; Ingersoll, Christopher G.

    2007-01-01

    Studies of fish communities of streams draining mining areas suggest that sculpins (Cottus spp.) may be more sensitive than salmonids to adverse effects of metals. We compared the toxicity of zinc, copper, and cadmium to mottled sculpin (C. bairdi) and rainbow trout (Onchorhynchus mykiss) in laboratory toxicity tests. Acute (96-h) and early life-stage chronic (21- or 28-d) toxicity tests were conducted with rainbow trout and with mottled sculpins from populations in Minnesota and Missouri, USA, in diluted well water (hardness = 100 mg/L as CaCO3). Acute and chronic toxicity of metals to newly hatched and swim-up stages of mottled sculpins differed between the two source populations. Differences between populations were greatest for copper, with chronic toxicity values (ChV = geometric mean of lowest-observed-effect concentration and no-observed-effect concentration) of 4.4 μg/L for Missouri sculpins and 37 μg/L for Minnesota sculpins. Cadmium toxicity followed a similar trend, but differences between sculpin populations were less marked, with ChVs of 1.1 μg/L (Missouri) and 1.9 μg/L (Minnesota). Conversely, zinc was more toxic to Minnesota sculpins (ChV = 75 μg/L) than Missouri sculpins (chronic ChV = 219 μg/L). Species-average acute and chronic toxicity values for mottled sculpins were similar to or lower than those for rainbow trout and indicated that mottled sculpins were among the most sensitive aquatic species to toxicity of all three metals. Our results indicate that current acute and chronic water quality criteria for cadmium, copper, and zinc adequately protect rainbow trout but may not adequately protect some populations of mottled sculpins. Proposed water quality criteria for copper based on the biotic ligand model would be protective of both sculpin populations tested.

  11. Sensitivity of mottled sculpins (Cottus bairdi) and rainbow trout (Onchorhynchus mykiss) to acute and chronic toxicity of cadmium, copper, and zinc.

    Science.gov (United States)

    Besser, John M; Mebane, Christopher A; Mount, David R; Ivey, Chris D; Kunz, James L; Greer, I Eugene; May, Thomas W; Ingersoll, Christopher G

    2007-08-01

    Studies of fish communities of streams draining mining areas suggest that sculpins (Cottus spp.) may be more sensitive than salmonids to adverse effects of metals. We compared the toxicity of zinc, copper, and cadmium to mottled sculpin (C. bairdi) and rainbow trout (Onchorhynchus mykiss) in laboratory toxicity tests. Acute (96-h) and early life-stage chronic (21- or 28-d) toxicity tests were conducted with rainbow trout and with mottled sculpins from populations in Minnesota and Missouri, USA, in diluted well water (hardness = 100 mg/L as CaCO3). Acute and chronic toxicity of metals to newly hatched and swim-up stages of mottled sculpins differed between the two source populations. Differences between populations were greatest for copper, with chronic toxicity values (ChV = geometric mean of lowest-observed-effect concentration and no-observed-effect concentration) of 4.4 microg/L for Missouri sculpins and 37 microg/L for Minnesota sculpins. Cadmium toxicity followed a similar trend, but differences between sculpin populations were less marked, with ChVs of 1.1 microg/L (Missouri) and 1.9 microg/L (Minnesota). Conversely, zinc was more toxic to Minnesota sculpins (ChV = 75 microg/L) than Missouri sculpins (chronic ChV = 219 microg/L). Species-average acute and chronic toxicity values for mottled sculpins were similar to or lower than those for rainbow trout and indicated that mottled sculpins were among the most sensitive aquatic species to toxicity of all three metals. Our results indicate that current acute and chronic water quality criteria for cadmium, copper, and zinc adequately protect rainbow trout but may not adequately protect some populations of mottled sculpins. Proposed water quality criteria for copper based on the biotic ligand model would be protective of both sculpin populations tested.

  12. Subcellular interactions of dietary cadmium, copper and zinc in rainbow trout (Oncorhynchus mykiss)

    Energy Technology Data Exchange (ETDEWEB)

    Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3 (Canada); MacPhail, Ruth [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3 (Canada)

    2011-10-15

    Highlights: Interactions of Cu, Cd and Zn were studied at the subcellular level in rainbow trout. Metals accumulated in the liver were predominantly metabolically active. Cd, Cu and Zn exhibited both competitive and cooperative interactions. The metal-metal interactions altered subcellular metals partitioning. - Abstract: Interactions of Cu, Cd and Zn were studied at the subcellular level in juvenile rainbow trout (Oncorhynchus mykiss) fed diets containing ({mu}g/g) 500 Cu, 1000 Zn and 500 Cd singly and as a ternary mixture for 28 days. Livers were harvested and submitted to differential centrifugation to isolate components of metabolically active metal pool (MAP: heat-denaturable proteins (HDP), organelles, nuclei) and metabolically detoxified metal pool (MDP: heat stable proteins (HSP), NaOH-resistant granules). Results indicated that Cd accumulation was enhanced in all the subcellular compartments, albeit at different time points, in fish exposed to the metals mixture relative to those exposed to Cd alone, whereas Cu alone exposure increased Cd partitioning. Exposure to the metals mixture reduced (HDP) and enhanced (HSP, nuclei and granules) Cu accumulation while exposure to Zn alone enhanced Cu concentration in all the fractions analyzed without altering proportional distribution in MAP and MDP. Although subcellular Zn accumulation was less pronounced than that of either Cu or Cd, concentrations of Zn were enhanced in HDP, nuclei and granules from fish exposed to the metals mixture relative to those exposed to Zn alone. Cadmium alone exposure mobilized Zn and Cu from the nuclei and increased Zn accumulation in organelles and Cu in granules, while Cu alone exposure stimulated Zn accumulation in HSP, HDP and organelles. Interestingly, Cd alone exposure increased the partitioning of the three metals in MDP indicative of enhanced detoxification. Generally the accumulated metals were predominantly metabolically active: Cd, 67-83%; Cu, 68-79% and Zn, 60-76%. Taken

  13. Calcium, zinc and vitamin E ameliorate cadmium-induced renal oxidative damage in albino Wistar rats

    Directory of Open Access Journals (Sweden)

    Pradeepkiran Jangampalli Adi

    2016-01-01

    Full Text Available This study was aimed to examine the protective effects of supplementation with calcium + zinc (Ca + Zn or vitamin E (Vit-E on Cd-induced renal oxidative damage. Young albino Wistar rats (180 ± 10 g (n = 6 control rats, Cd, Cd + Ca + Zn, and Cd + Vit-E experimental groups and the experimental period was 30 days. Rats were exposed to Cd (20 mg/kg body weight alone treated as Cd treated group and the absence or presence of Ca + Zn (2 mg/kg each or Vit-E (20 mg/kg body weight supplementation treated as two separate groups. The activities of the stress marker enzymes superoxide dismutase (SOD, catalase (CAT, glutathione reductase (GR, glutathione peroxidase (GPx, glutathione-S-transferase (GST and lipid peroxidase (LPx were determined in renal mitochondrial fractions of experimental rats. We observed quantitative changes in SOD isoenzymatic patterns by non-denaturing PAGE analysis, and quantified band densities. These results showed that Cd exposure leads to decreases in SOD, CAT, GR, and GPx activities and a concomitant increase in LPx and GST activities. Ca + Zn and Vit-E administration with Cd significantly reversed Cd-induced perturbations in oxidative stress marker enzymes. However, Vit-E showed more inhibitory activity against Cd than did Ca + Zn, and it protected against Cd-induced nephrotoxicity.

  14. Acute and chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    Science.gov (United States)

    Ingersoll, Christopher G.; Contributions by Wang, Ning; Calfee, Robin D.; Beahan, Erinn; Brumbaugh, William G.; Dorman, Rebecca A.; Hardesty, Doug K.; Kunz, James L.; Little, Edward E.; Mebane, Christopher A.; Puglis, Holly J.

    2014-01-01

    White sturgeon (Acipenser transmontanus) are experiencing poor recruitment in the trans boundary reach of the upper Columbia River in eastern Washington State. Limited toxicity data indicated that early life stages of white sturgeon are sensitive to metals. In acute 4-day (d) exposures with larval white sturgeon, previous studies have reported that the 4-day median lethal concentrations (LC50) based on biotic ligand model (BLM) normalization for copper were below the U.S. Environmental Protection Agency national recommended acute water-quality criterion. In previously published chronic 66-d exposures starting with newly fertilized eggs of white sturgeon, 20-percent lethal effect concentrations (LC20s) for copper, cadmium, or zinc generally were within a factor of two of the chronic values of the most sensitive fish species in the databases of the U.S. Environmental Protection Agency water-quality criteria (WQC) for the three metals. However, there were some uncertainties in the chronic exposures previously performed with white sturgeon, including (1) low control survival (37 percent), (2) more control fish tested in each replicate compared to other treatments, (3) limited replication of treatments (n=2), (4) lack of reported growth data (such as dry weight), and (5) wide dilution factors for exposure concentrations (6- to 8-fold dilutions). The U.S. Environmental Protection Agency concluded that additional studies are needed to generate more toxicity data to better define lethal and sublethal toxicity thresholds for metals for white sturgeon. The objective of the study was to further evaluate the acute and chronic toxicity of cadmium, copper, lead, or zinc to early life stages of white sturgeon in water-only exposures. Toxicity tests also were performed with commonly tested rainbow trout (Oncorhynchus mykiss) under similar test conditions to determine the relative sensitivity between white sturgeon and rainbow trout to these metals. Toxicity data generated from

  15. Synthesis, Crystal Structure, and Luminescent Properties of New Zinc(II and Cadmium(II Metal-Organic Frameworks Based on Flexible Bis(imidazol-1-ylalkane Ligands

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    Marina Barsukova

    2016-10-01

    Full Text Available New metal-organic frameworks (MOFs based on zinc and cadmium ions, terephthalic acid, and flexible ligands 1,5-bis(imidazol-1-ylpentane or 1,6-bis(imidazol-1-ylhexane were prepared and characterized by X-ray diffraction, thermorgavimetric analysis and IR spectroscopy. The imidazolyl ligands were prepared by a new robust procedure involving the reaction between imidazole and 1,5-dibromopentane or 1,6-dibromohexane in a superbasic medium (KOH in DMSO. MOFs based on 1,5-bis(imidazol-1-ylpentane had diamond topology (dia and are triply interpenetrated. Ligands with longer spacer 1,6-bis(imidazol-1-ylhexane, terephthalate ions and zinc(II ions formed five-fold interpenetrated metal-organic framework also with dia topology, while cadmium(II ions with the same ligands formed eight-connected uninodal net with a very rare self-penetrated topological type ilc and a point symbol 424.5.63. The influence of the chemical composition of MOFs on their photoluminescent properties is investigated and discussed in detail.

  16. [Effects of intercropping Sedum plumbizincicola and Apium graceolens on the soil chemical and microbiological properties under the contamination of zinc and cadmium from sewage sludge application].

    Science.gov (United States)

    Nai, Feng-Jiao; Wu, Long-Hua; Liu, Hong-Yan; Ren, Jing; Liu, Wu-Xing; Luo, Yong-Ming

    2013-05-01

    Taking the vegetable soil with zinc- and cadmium contamination from a long-term sewage sludge application as the object, a pot experiment was conducted to study the remediation effect of Sedum plumbizincicola and Apium graceolens under continuous monoculture and intercropping. With the remediation time increased, both S. plumbizincicola and A. graceolens under monoculture grew poorly, but S. plumbizincicola under intercropping grew well. Under intercropping, the soil organic matter, total N, extractable N, and total P contents decreased significantly while the soil extractable K content had a significant increase, the counts of soil bacteria and fungi increased by 7.9 and 18.4 times and 3.7 and 4.3 times, respectively, but the soil urease and catalase activities remained unchanged, as compared with those under A. graceolens and S. plumbizincicola monoculture. The BIOLOG ECO micro-plates also showed that the carbon sources utilization level and the functional diversity index of soil microbial communities were higher under intercropping than under monoculture, and the concentrations of soil zinc and cadmium under intercropping decreased by 5.8% and 50.0%, respectively, with the decrements being significantly higher than those under monoculture. It was suggested that soil microbial effect could be one of the important factors affecting plant growth.

  17. Determination of mercury, cadmium, lead, zinc, selenium and iron by ICP-OES in mushroom samples from around thermal power plant in Muğla, Turkey.

    Science.gov (United States)

    Kula, Ibrahim; Solak, M Halil; Uğurlu, Mehmet; Işıloğlu, Mustafa; Arslan, Yasin

    2011-09-01

    Scleroderma verrucosum, Stropharia coronilla, Lactarius deterrimus, Chroogomphus rutilus, Russula delica, Laccaria laccata, Clitocybe odora var. alba, Lyophyllum decastes, Coprinus comatus, Helvella leucomelaena, Melanoleuca cognata, Melanoleuca cognata, Paxina acetabulum, Clitocybe vermicularis, Sarcosphaera crassa, Rhizopogon roseolu and Thelephora caryophyllea were collected from different localities in Muğla-Yatağan region of Turkey. Their trace metals concentrations were determined by ICPOES after microwave digestion. The results were 0.37 ± 0.01-5.28 ± 0.21 for cadmium, 467 ± 19-3,280 ± 131 for iron, 0.69 ± 0.03-9.15 ± 0.37 for lead, 18.70 ± 0.75-67.10 ± 2.68 for selenium, 75 ± 3-213 ± 8 for zinc and 0.15 ± 0.01-0.55 ± 0.01 for mercury (as μg/g). The detection limits for ICPOES were found as 0.25 for Cadmium, 0.2 for iron, 0.1 for lead, 0.5 for selenium, 0.2 for zinc and 0.03 for mercury (as mg L(-1)). The Relatively Standard Deviations (R.S.D.) were found below 4.0%. The accuracy of procedure was confirmed by certified reference material.

  18. Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III Oxide

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    Zuzana Koudelkova

    2017-08-01

    Full Text Available In this study, the preparation and electrochemical application of a chromium(III oxide modified carbon paste electrode (Cr-CPE and a screen printed electrode (SPE, made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L−1 for Zn(II, 3 and 10 µg·L−1 for Cd(II, 3 and 10 µg·L−1 for Pb(II, 3 and 10 µg·L−1 for Cu(II, and 3 and 10 µg·L−1 for Ag(I, respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L−1 for Zn(II, 25 µg·L−1 for Cd(II, 3 µg·L−1 for Pb(II and 3 µg·L−1 for Cu(II. Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

  19. Subcellular partitioning of cadmium and zinc in mealworm beetle (Tenebrio molitor) larvae exposed to metal-contaminated flour.

    Science.gov (United States)

    Bednarska, Agnieszka J; Świątek, Zuzanna

    2016-11-01

    By studying the internal compartmentalization of metals in different subcellular fractions we are able to better understand the mechanisms of metal accumulation in organisms and the transfer of metals through trophic chains. We investigated the internal compartmentalization of cadmium (Cd) and zinc (Zn) in mealworm beetle (Tenebrio molitor) larvae by breeding them in flour contaminated with either Cd at 100, 300 and 600mgkg(-1), or Zn at 1000 and 2000mgkg(-1). We separated the cellular components of the larvae into 3 fractions: the S1 or cytosolic fraction containing organelles, heat-sensitive and heat-stable proteins, the S2 or cellular debris fraction and the G or metal-rich granule fraction. The concentration of Cd and Zn in each fraction was measured at 0, 7, 14 and 21 days of being fed the flour. The concentration of Cd in the flour affected the concentration of Cd measured in each larval subcellular fraction (p≤0.0001), while the concentration of Zn in the flour only affected the Zn concentration in the S2 and G fractions (p≤0.02). Both Cd and Zn concentrations in mealworms remained relatively constant during the exposure (days 7, 14 and 21) in all three fractions, but the Cd concentrations were much higher than those found in larvae before the exposure (day 0). The concentration of Cd in the flour, however, did not affect the percentage of Cd in the S1 fraction. The contribution of Cd in the G fraction to the total Cd amount was similar (30-40%) in all Cd treatments. The percentage of Zn in all three fractions was not affected by the concentration of Zn in the flour and the relative contributions of each subcellular fraction to the total burden of Zn remained generally constant for both control and treated larvae. In general, larvae sequestered approximately 30% of Cd and Zn in the S1 fraction, which is important for the transport of metals to higher trophic levels in a food web. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Cytotoxic effects of cadmium and zinc co-exposure in PC12 cells and the underlying mechanism.

    Science.gov (United States)

    Rahman, Md Mostafizur; Ukiana, Junki; Uson-Lopez, Rachael; Sikder, Md Tajuddin; Saito, Takeshi; Kurasaki, Masaaki

    2017-05-01

    Cadmium (Cd(2+)) is a well studied inducer of cellular necrosis and apoptosis. Zinc (Zn(2+)) is known to inhibit apoptosis induced by toxicants including Cd(2+) both in vitro and in vivo. The mechanism of Zn(2+)-mediated protection from Cd(2+)-induced cytotoxicity is not established. In this study, we aimed to understand the effects of Zn(2+) on Cd(2+)-induced cytotoxicity and apoptosis using PC12 cells. Cell viability and DNA fragmentation assays in PC12 cells exposed to Cd(2+) and/or Zn(2+) revealed that Cd(2+) (5 and 10 μmol/L) alone induced significant cell death, and co-exposure to Zn(2+) (5, 10, and 100 μmol/L) for 48 h had a protective effect. Assessment of intracellular free sulfhydryl levels and lactate dehydrogenase activity suggested that Cd(2+) (10 μmol/L) induced oxidative stress and disrupted cell membrane integrity. Addition of Zn(2+) (10 and 100 μmol/L) reduced Cd(2+)-mediated cytotoxicity. Changes in expression of the apoptotic factors Bax, Bcl-2, Bcl-x, and cytochrome c were measured via western blot and expression of caspase 9 was detected via reverse transcriptase polymerase chain reaction. Western blots showed that Zn(2+) (10 and 100 μmol/L) suppressed Cd(2+)-induced apoptosis (10 μmol/L) by reducing cytochrome c release into the cytosol, and downregulating the proapoptotic protein, Bax. In addition, expression of caspase 9 was lower in Cd(2+) (5 μmol/L)-treated PC12 cells when co-treated with Zn(2+) (2 and 5 μmol/L). These findings suggest that the effective inhibition of Cd(2+)-induced apoptosis in PC12 cells by Zn(2+) might be due to suppression of mitochondrial apoptosis pathway and inhibition of Cd(2+)-induced production of reactive oxygen species. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Expression of metallothionein of freshwater crab (Sinopotamon henanense) in Escherichia coli enhances tolerance and accumulation of zinc, copper and cadmium.

    Science.gov (United States)

    He, Yongji; Ma, Wenli; Li, Yingjun; Liu, Jinping; Jing, Weixin; Wang, Lan

    2014-01-01

    Metallothioneins (MTs) are ubiquitous metal-binding, cysteine-rich, small proteins and play a major role in metal homeostasis and/or detoxification in all organisms. In a previous study, a novel full length MT gene was isolated from the freshwater crab (Sinopotamon henanense), a species widely distributed in Shanxi and Henan Provinces, China. In this report, the gene for the crab MT was inserted into a PET-28a-6His-SUMO vector and recombinant soluble MT was over-expressed as fusions with SUMO in Escherichia coli. The recombinant fusion protein was purified by affinity chromatography and its biochemical properties were analyzed. In addition, on the basis of constructing SUMO-MT, two mutants, namely SUMO-MTt1 and SUMO-MTt2, were constructed to change the primary structure of SUMO-MT using site-directed mutagenesis techniques with the amino acid substitutions D3C and S37C in order to increase metal-binding capacity of MT. E. coli cells expressing SUMO-MT and these single-mutant proteins exhibited enhanced metal tolerance and higher accumulation of metal ions than control cells. The results showed that the bioaccumulation and tolerance of Zn(2+), Cu(2+) and Cd(2+) in these strains followed the decreasing order of SUMO-MTt1 > SUMO-MTt2 > SUMO-MT. E. coli cells have low tolerance and high accumulation towards cadmium compared to zinc and copper. These results show that the MT of S. henanense could enhance tolerance and accumulation of metal ions. Moreover, we were able to create a novel protein based on the crab MT to bind metal ions at high density and with high affinity. Therefore, SUMO-MT and its mutants can provide potential candidates for heavy metal bioremediation. This study could help further elucidate the mechanism of how the crab detoxifies heavy metals and provide a scientific basis for environment bioremediation of heavy metal pollution using the over-expression of the crab MT and mutant proteins.

  2. Hafnium germanium telluride

    Science.gov (United States)

    Jang, Gyung-Joo; Yun, Hoseop

    2008-01-01

    The title hafnium germanium telluride, HfGeTe4, has been synthesized by the use of a halide flux and structurally characterized by X-ray diffraction. HfGeTe4 is isostructural with stoichiometric ZrGeTe4 and the Hf site in this compound is also fully occupied. The crystal structure of HfGeTe4 adopts a two-dimensional layered structure, each layer being composed of two unique one-dimensional chains of face-sharing Hf-centered bicapped trigonal prisms and corner-sharing Ge-centered tetra­hedra. These layers stack on top of each other to complete the three-dimensional structure with undulating van der Waals gaps. PMID:21202163

  3. Hafnium germanium telluride

    Directory of Open Access Journals (Sweden)

    Hoseop Yun

    2008-05-01

    Full Text Available The title hafnium germanium telluride, HfGeTe4, has been synthesized by the use of a halide flux and structurally characterized by X-ray diffraction. HfGeTe4 is isostructural with stoichiometric ZrGeTe4 and the Hf site in this compound is also fully occupied. The crystal structure of HfGeTe4 adopts a two-dimensional layered structure, each layer being composed of two unique one-dimensional chains of face-sharing Hf-centered bicapped trigonal prisms and corner-sharing Ge-centered tetrahedra. These layers stack on top of each other to complete the three-dimensional structure with undulating van der Waals gaps.

  4. Transcriptional up-regulation of genes involved in photosynthesis of the Zn/Cd hyperaccumulator Sedum alfredii in response to zinc and cadmium.

    Science.gov (United States)

    Tang, Lu; Yao, Aijun; Ming Yuan; Tang, Yetao; Liu, Jian; Liu, Xi; Qiu, Rongliang

    2016-12-01

    Zinc (Zn) and cadmium (Cd) are two closely related chemical elements with very different biological roles in photosynthesis. Zinc plays unique biochemical functions in photosynthesis. Previous studies suggested that in some Zn/Cd hyperaccumulators, many steps in photosynthesis may be Cd tolerant or even Cd stimulated. Using RNA-seq data, we found not only that Cd and Zn both up-regulated the CA1 gene, which encodes a β class carbonic anhydrase (CA) in chloroplasts, but that a large number of other Zn up-regulated genes in the photosynthetic pathway were also significantly up-regulated by Cd in leaves of the Zn/Cd hyperaccumulator Sedum alfredii. These genes also include chloroplast genes involved in transcription and translation (rps18 and rps14), electron transport and ATP synthesis (atpF and ccsA), Photosystem II (PSBI, PSBM, PSBK, PSBZ/YCF9, PSBO-1, PSBQ, LHCB1.1, LHCB1.4, LHCB2.1, LHCB4.3 and LHCB6) and Photosystem I (PSAE-1, PSAF, PSAH2, LHCA1 and LHCA4). Cadmium and Zn also up-regulated the VAR1 gene, which encodes the ATP-dependent zinc metalloprotease FTSH 5 (a member of the FtsH family), and the DAG gene, which influences chloroplast differentiation and plastid development, and the CP29 gene, which supports RNA processing in chloroplasts and has a potential role in signal-dependent co-regulation of chloroplast genes. Further morphological parameters (dry biomass, cross-sectional thickness, chloroplast size, chlorophyll content) and chlorophyll fluorescence parameters confirmed that leaf photosynthesis of S. alfredii responded to Cd much as it did to Zn, which will contribute to our understanding of the positive effects of Zn and Cd on growth of this plant. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. The synthesis and characterization of complexes of zinc(II, cadmium(II, platinum(II and palladium(II with potassium 3-dithiocarboxy-3-aza-5-aminopentanoate

    Directory of Open Access Journals (Sweden)

    SRECKO TRIFUNOVIC

    2004-02-01

    Full Text Available Complexes of zinc(II, cadmium(II, platinum(II and palladium(II with a new polydentate dithiocarbamate ligand, 3-dithiocarboxy-3-aza-5-aminopentanoate (daap-, of the type M(daap2·nH2O (M = Zn(II, Cd(II, n = 2, or M = Pt(II, Pd(II, n = 0, have been prepared and characterized by elemental analysis, IR and UV/VIS spectroscopy, as well as magnetic measurements. The spectra of the complexes suggest a bidentate coordination of the daap- ligand to the metal ions via the sulfur atoms of the deprotonated dithiocarbamato group. The fact that under the same experimental conditions its S-methyl ester does not form complexes could be taken as proof of the suggested coordination mode.

  6. Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

    Science.gov (United States)

    Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

    1987-01-01

    Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

  7. Survey of heavy metal pollution (copper, lead, zinc, cadmium, iron and manganese in drinking water resources of Nurabad city, Lorestan, Iran 2013

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    GHodratolah Shams Khorramabadi

    2016-09-01

    Full Text Available Background: Healthy water passes through the pipelines from supply resources to consuming places in which passing from these stages may cause some cases of contamination like heavy metal contamination. Therefore, the aim of this study was to evaluate the contamination of heavy metals (copper, lead, zinc, cadmium, iron, and manganese in water resources of Nurabad city of Lorestan in 2013. Materials and Methods: In this cross-sectional study, samples were collected from 7 wells of drinking water and 2 water storage tanks during 6 months in Nurabad. So that, heavy metal parameters such as copper, lead, zinc, cadmium, iron, and manganese were measured using an atomic absorption device and also electrical conductivity, sulfate, chloride and total dissolved solids were also measured in accordance with standard methods. Results: Results indicated that the concentration of studied metals in water sources was lower than the national standards and World Health Organization standard, and in the water supply system the concentration of some metals was more than standard level. Moreover, the results showed that the concentration of studied heavy metals were more in winter than in autumn. Conclusion: Generally, in the water resources of Nurabad city the concentration of studied heavy metals was lower than the national standards and World Health Organization standard and there are not problems for water consumers. However, due to public health and the presence of a high concentration of these metals in the distribution supply, the heavy metal concentration in drinking water of this region should be monitored regularly by responsible organizations.

  8. Cadmium, manganese, iron, zinc and magnesium content of bean plants (Phaseolus vulgaris L. ) in relation to the duration and the amount of cadmium supply

    Energy Technology Data Exchange (ETDEWEB)

    Barcelo, J.; Poschenrieder, C.; Cabot, C.

    1985-01-01

    In a long term experiment on bean plants, the effect of different cadmium concentrations on the growth and the content of Cd, Fe, Mn, Zn and Mg was studied during the total growth period. Cd treated and non-treated plants clearly exhibit differences in their growth and their nutrient content. There are clear differences between early and late Cd effects. In spite of a decrease of the magnesium content in most of the Cd treated plants, the values almost always stay above 1% and do not seem to be deficient. The results are discussed with the final conclusion, that the negative effect of Cd on the chlorophyll content observed in former studies, seems due to Mn deficiency rather than to the decrease of the Mg content.

  9. THE CONTENT OF ZINC, LEAD AND CADMIUM IN BAY BOLETE (XEROCOMUS BADIUS (FR. E. COLLECTED FROM A STRONGLY POLLUTED FOREST COMPLEX

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    Marek Pająk

    2016-09-01

    Full Text Available The research was carried out in the Świerklaniec Forest District, the Brynica sub-district, which is located in the immediate vicinity of a metallurgical plant, a zinc mine named Huta Cynku "Miasteczko Śląskie" (HCMŚ. In autumn 2008, in the area in question, 31 permanent trial plots were established, aligned within a regular net of squares, with dimensions of 1500×1500 m. The trial plots were located to the north-east and to the east of the emitter (the HCMŚ zinc mine, accordingly with the direction of prevailing winds. In September 2013, and September and October 2014, sporocarps of bay bolete (Xerocomus badius (Fr. E. were collected from the trial plots. The analyses performed for the material gathered covered a determination of heavy metal content in mushrooms (Zn, Pb and Cd, using a method of inductively coupled plasma atomic emission spectroscopy ICP-AES. This paper aimed to establish the accumulation levels of selected heavy metals (Zn, Pb and Cd in bay bolete growing in forests of the Brynica sub-district, in the Świerklaniec Forest District, and the correlation between their content in soil and in the mushrooms under scrutiny. The analyses revealed that the contamination degree in the investigated species was extremely high. The content of toxic elements in bay bolete significantly exceeded the acceptable standards referring to the maximum content of heavy metals in mushrooms, which was particularly true for cadmium.

  10. The cobalt, zinc, and cadmium efflux system CzcABC from Alcaligenes eutrophus functions as a cation-proton antiporter in Escherichia coli.

    Science.gov (United States)

    Nies, D H

    1995-05-01

    The function of the CzcABC protein complex, which mediates resistance to Co2+, Zn2+, and Cd2+ in Alcaligenes eutrophus by cation efflux, was investigated by using everted membrane vesicles of Escherichia coli and an acridine orange fluorescence quenching assay. Since metal cation uptake could not be measured with inside-out membrane vesicles prepared from A. eutrophus and since available E. coli strains did not express the Czc-mediated resistance to cobalt, zinc, and cadmium salts, mutants of E. coli which exhibited a Czc-dependent increase in heavy metal resistance were isolated. E. coli mutant strain EC351 constitutively accumulated Co2+, Zn2+, and Cd2+. In the presence of Czc, net uptake of these heavy metal cations was reduced to the wild-type level. Inside-out vesicles prepared from E. coli EC351 cells displayed a Czc-dependent uptake of Co2+, Zn2+, and Cd2+ and a cation-triggered acridine orange fluorescence increase. The czc-encoded protein complex CzcABC was shown to be a zinc-proton antiporter.

  11. Expression of the Znt1 zinc transporter from the metal hyperaccumulator noccaea caerulescens confers enhanced zinc and cadmium tolerance and accumulation to arabidopsis thaliana

    NARCIS (Netherlands)

    Lin, Ya Fen; Hassan, Zeshan; Talukdar, S.; Schat, Henk; Aarts, Mark G.M.

    2016-01-01

    Prompt regulation of transition metal transporters is crucial for plant zinc homeostasis. NcZNT1 is one of such transporters, found in the metal hyperaccumulator Brassicaceae species Noccaea caerulescens. It is orthologous to AtZIP4 from Arabidopsis thaliana, an important actor in Zn homeostasis.

  12. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Zinc-Finger Transcription Factor ZAT6 Positively Regulates Cadmium Tolerance through the Glutathione-Dependent Pathway in Arabidopsis1[OPEN

    Science.gov (United States)

    Chen, Jian; Yan, Xingxing; Liu, Yunlei; Wang, Ren; Fan, Tingting; Ren, Yongbing; Tang, Xiaofeng; Xiao, Fangming

    2016-01-01

    Cadmium (Cd) is an environmental pollutant with high toxicity to animals and plants. It has been established that the glutathione (GSH)-dependent phytochelatin (PC) synthesis pathway is one of the most important mechanisms contributing to Cd accumulation and tolerance in plants. However, the transcription factors involved in regulating GSH-dependent PC synthesis pathway remain largely unknown. Here, we identified an Arabidopsis (Arabidopsis thaliana) Cd-resistant mutant xcd2-D (XVE system-induced cadmium-tolerance2) using a forward genetics approach. The mutant gene underlying xcd2-D mutation was revealed to encode a known zinc-finger transcription factor, ZAT6. Transgenic plants overexpressing ZAT6 showed significant increase of Cd tolerance, whereas loss of function of ZAT6 led to decreased Cd tolerance. Increased Cd accumulation and tolerance in ZAT6-overexpressing lines was GSH dependent and associated with Cd-activated synthesis of PC, which was correlated with coordinated activation of PC-synthesis related gene expression. By contrast, loss of function of ZAT6 reduced Cd accumulation and tolerance, which was accompanied by abolished PC synthesis and gene expression. Further analysis revealed that ZAT6 positively regulates the transcription of GSH1, GSH2, PCS1, and PCS2, but ZAT6 is capable of specifically binding to GSH1 promoter in vivo. Consistently, overexpression of GSH1 has been shown to restore Cd sensitivity in the zat6-1 mutant, suggesting that GSH1 is a key target of ZAT6. Taken together, our data provide evidence that ZAT6 coordinately activates PC synthesis-related gene expression and directly targets GSH1 to positively regulate Cd accumulation and tolerance in Arabidopsis. PMID:26983992

  14. Cadmium tolerance and accumulation of Elsholtzia argyi origining from a zinc/lead mining site - a hydroponics experiment.

    Science.gov (United States)

    Li, Siliang; Wang, Fengping; Ru, Mei; Ni, Wuzhong

    2014-01-01

    In this study, a hydroponics experiment was conducted to investigate the characteristics of Cd tolerance and accumulation of Elsholtzia argyi natively growing on the soil with high levels of heavy metals in a Zn/Pb mining site. Seedlings of E. argyi grown for 4 weeks and then were treated with 0(CK), 5,10,15, 20, 25, 30, 40, 50,100 umM Cd for 21 days. Each treatment had three replications. No visual toxic symptoms on shoots of E. argyi were observed at Cd level < or = 50 muM. The results indicated that the dry biomass of each tissue and the whole plants of the treatments with < or =40 umM cadmium were similar to that of the control, implying that E. argyi was a cadmium tolerant plant. The results also showed that the shoot Cd concentration significantly (P < 0.05) increased with the increase in the Cd level in nutrient solution. The shoot Cd concentration of the treatment with 40 umM Cd was as high as 237.9 mg kg(-1), which was higher than 100 mg kg(-1), normally used as the threshold concentration for identifying the Cd hyperaccumulating plant. It could be concluded that E. argyi was a Cd tolerant and accumulating plant species.

  15. In vitro effects of simultaneous exposure to platinum and cadmium on the activity of antioxidant enzymes and DNA damage and potential protective effects of selenium and zinc.

    Science.gov (United States)

    Tariba, Blanka; Živković, Tanja; Gajski, Goran; Gerić, Marko; Gluščić, Valentina; Garaj-Vrhovac, Vera; Peraica, Maja; Pizent, Alica

    2017-04-01

    Circulating platinum (Pt) is detectable in the blood of Pt-treated cancer patients for over a decade after the treatment. Prolonged exposure to Pt, in combination with adverse compounds from nutrition and lifestyle, such as cadmium (Cd), could increase the risk from second cancers. The aim of this study was to investigate the effects of simultaneous exposure to Cd- and Pt-compounds on oxidative and DNA damage and the possible protective effects of zinc (Zn) and selenium (Se). The aqueous solutions of PtCl 4 , CdCl 2  ×   H 2 O, ZnCl 2 and Na 2 SeO 3 were added, alone or in combination, to whole blood and isolated erythrocytes to produce the final concentrations of 2000 μg/L of Pt, 8 μg/L of Cd, 100 μg/L of Se, and 1000 μg/L of Zn. The activity of copper, zinc-superoxide dismutase, glutathione peroxidase and glutathione in whole blood was determined after 1 h exposure in in vitro conditions. The induction of DNA strand-breaks in human peripheral blood leukocytes was determined with the alkaline comet assay after 24 h exposure. Exposure to Pt and/or Cd decreased the activities of antioxidant enzymes and elevated DNA damage compared to control. A statistically significant change in the activity of both enzymes and in the induction of DNA strand-breaks was observed in the cells treated with Pt + Cd combination, while the addition of Se and/or Zn resulted in partial recovery of these effects. The results indicate that combined exposure to Pt and Cd could disrupt antioxidant protection of the organism and increase DNA damage, whereas Se and Zn could partially ameliorate these harmful effects.

  16. Effects of tire rubber ash and zinc sulfate on crop productivity and cadmium accumulation in five rice cultivars under field conditions.

    Science.gov (United States)

    Fahad, Shah; Hussain, Saddam; Khan, Fahad; Wu, Chao; Saud, Shah; Hassan, Shah; Ahmad, Naeem; Gang, Deng; Ullah, Abid; Huang, Jianliang

    2015-08-01

    Cadmium (Cd) is among the most widespread and toxic heavy metals becoming a severe threat to humans. A field study was conducted to examine the role of various zinc (Zn) fertilization treatments and cultivars on crop productivity and Zn and Cd concentrations in brown rice and rice straw. The Zn fertilization treatments included an unfertilized control, foliar applied Zn sulfate (ZnSO4) at panicle initiation stage, foliar applied ZnSO4 at milky stage, soil application of rubber ash, and soil-applied ZnSO4, while five rice cultivars were Swat-1, Shadab, Shua-92, Swat-2, and Sada Hayat. All the Zn fertilization treatments resulted in significantly higher number of panicles, number of spikelets per panicles, spikelet fertility, 1,000-grain weight, grain yield, brown rice and rice straw Zn concentrations, and significantly lower Cd concentrations. Soil application of rubber ash remained the best among all Zn fertilization treatments as it resulted in 73% higher grain yield and reduced Cd concentration by 51% as compared with control. Variations were also apparent among cultivars, and Shua-92 and Swat-2 performed better in terms of all studied attributes as compared with other cultivars. Conclusively, cultivar selection and Zn application are effective strategies to improve rice grain yield as well as quality. Rubber ash appeared a viable source of Zn having the ability to increase yield along with reducing Cd accumulation.

  17. 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.

  18. Bioaccumulation of mercury, cadmium, zinc, chromium, and lead in muscle, liver, and spleen tissues of a large commercially valuable catfish species from Brazil

    Directory of Open Access Journals (Sweden)

    Fábio P. Arantes

    2016-03-01

    Full Text Available The increasing amounts of heavy metals entering aquatic environments can result in high accumulation levels of these contaminants in fish and their consumers, which pose a serious risk to ecosystems and human health. We investigated the concentrations of mercury (Hg, cadmium (Cd, zinc (Zn, chromium (Cr, and lead (Pb in muscle, liver, and spleen tissues of Pseudoplatystoma corruscans specimens collected from two sites on the Paraopeba River, Brazil. The level of heavy metals concentrations in the tissues was often higher in viscera (i.e. liver and spleen than in muscle, and thus, the viscera should not be considered for human consumption. Correlations between metal concentrations and fish size were not significant. Although the levels of muscle bioaccumulation of Hg, Cd, Zn, Cr, and Pb, generally do not exceed the safe levels for human consumption, the constant presence of heavy metals in concentrations near those limits considered safe for human consumption, is a reason for concern, and populations who constantly consume fish from polluted rivers should be warned. Our findings also indicate that in a river network where certain areas are connected to other areas with high rates of environmental pollutants, people should be cautious about the regular consumption of fish, even when the fish consumed are caught in stretches of the basin where contamination levels are considered low, since many of the freshwater fish with high commercial value, such as the catfish surubim, are migratory.

  19. NMR-based metabolomic investigations on the differential responses in adductor muscles from two pedigrees of Manila clam Ruditapes philippinarum to Cadmium and Zinc.

    Science.gov (United States)

    Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Yu, Junbao

    2011-01-01

    Manila clam Ruditapes philippinarum is one of the most important economic species in shellfishery in China due to its wide geographic distribution and high tolerance to environmental changes (e.g., salinity, temperature). In addition, Manila clam is a good biomonitor/bioindicator in "Mussel Watch Programs" and marine environmental toxicology. However, there are several pedigrees of R. philippinarum distributed in the marine environment in China. No attention has been paid to the biological differences between various pedigrees of Manila clams, which may introduce undesirable biological variation in toxicology studies. In this study, we applied NMR-based metabolomics to detect the biological differences in two main pedigrees (White and Zebra) of R. philippinarum and their differential responses to heavy metal exposures (Cadmium and Zinc) using adductor muscle as a target tissue to define one sensitive pedigree of R. philippinarum as biomonitor for heavy metals. Our results indicated that there were significant metabolic differences in adductor muscle tissues between White and Zebra clams, including higher levels of alanine, glutamine, hypotaurine, phosphocholine and homarine in White clam muscles and higher levels of branched chain amino acids (valine, leucine and isoleucine), succinate and 4-aminobutyrate in Zebra clam muscles, respectively. Differential metabolic responses to heavy metals between White and Zebra clams were also found. Overall, we concluded that White pedigree of clam could be a preferable bioindicator/biomonitor in marine toxicology studies and for marine heavy metals based on the relatively high sensitivity to heavy metals.

  20. NMR-Based Metabolomic Investigations on the Differential Responses in Adductor Muscles from Two Pedigrees of Manila Clam Ruditapes philippinarum to Cadmium and Zinc

    Science.gov (United States)

    Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Yu, Junbao

    2011-01-01

    Manila clam Ruditapes philippinarum is one of the most important economic species in shellfishery in China due to its wide geographic distribution and high tolerance to environmental changes (e.g., salinity, temperature). In addition, Manila clam is a good biomonitor/bioindicator in “Mussel Watch Programs” and marine environmental toxicology. However, there are several pedigrees of R. philippinarum distributed in the marine environment in China. No attention has been paid to the biological differences between various pedigrees of Manila clams, which may introduce undesirable biological variation in toxicology studies. In this study, we applied NMR-based metabolomics to detect the biological differences in two main pedigrees (White and Zebra) of R. philippinarum and their differential responses to heavy metal exposures (Cadmium and Zinc) using adductor muscle as a target tissue to define one sensitive pedigree of R. philippinarum as biomonitor for heavy metals. Our results indicated that there were significant metabolic differences in adductor muscle tissues between White and Zebra clams, including higher levels of alanine, glutamine, hypotaurine, phosphocholine and homarine in White clam muscles and higher levels of branched chain amino acids (valine, leucine and isoleucine), succinate and 4-aminobutyrate in Zebra clam muscles, respectively. Differential metabolic responses to heavy metals between White and Zebra clams were also found. Overall, we concluded that White pedigree of clam could be a preferable bioindicator/biomonitor in marine toxicology studies and for marine heavy metals based on the relatively high sensitivity to heavy metals. PMID:22131959

  1. Separation and Pre-concentration of Cadmium, Copper, Lead, Nickel and Zinc by Solid-Liquid Extraction of their Cocrystallized Naphthalene Dithizone Chelate in Saline Matrices

    Directory of Open Access Journals (Sweden)

    Costa Antônio C. Spínola

    2002-01-01

    Full Text Available A procedure for separation and pre-concentration of trace amounts of cadmium, copper, lead, nickel, and zinc in brine samples has been proposed. It is based on the adsorption of metal ions onto dithizone co-crystallized with microcrystalline naphthalene, in the pH range 8.5-9.1. Nitric acid is used to back-extract the cations from the solid phase, which are measured by ICP-OES. Various parameters, such as the effect of pH, stirring time, and amounts of solid phase, have been studied in detail, to optimize the conditions for the determination of trace amounts of Cd, Cu, Pb, Ni and Zn in synthetic brine samples. The limits of detection values expressed in mug L-1 are 44 (Zn, 11 (Ni, 30 (Cd, 47 (Pb and 11 (Cu. The precision of the procedure was determined by running 10 replicate samples, each one containing 250 mug L-1 of each element and the relative standard deviations were 2.71 % (Cd, 2.15 % (Cu, 1.53 % (Pb, 2.47 % (Ni, and 2.78 % (Zn. The accuracy of the procedure was confirmed by applying the analyte additions method and the results indicated that quantitative recoveries (superscript three 95 % were obtained.

  2. Selective sorption of lead, cadmium and zinc ions by a polymeric cation exchanger containing nano-Zr(HPO3S)2.

    Science.gov (United States)

    Zhang, Qingrui; Pan, Bingcai; Pan, Bingjun; Zhang, Weiming; Jia, Kun; Zhang, Quanxing

    2008-06-01

    A novel polymeric hybrid sorbent, namely ZrPS-001, was fabricated for enhanced sorption of heavy metal ions by impregnating Zr(HPO3S)2 (i.e., ZrPS) nanoparticles within a porous polymeric cation exchanger D-001. The immobilized negatively charged groups bound to the polymeric matrix D-001 would result in preconcentration and permeation enhancement of target metal ions prior to sequestration, and ZrPS nanoparticles are expected to sequester heavy metals selectively through an ion-exchange process. Highly effective sequestration of lead, cadmium, and zinc ions from aqueous solution can be achieved by ZrPS-001 even in the presence of competing calcium ion at concentration several orders of magnitude greater than the target species. The exhausted ZrPS-001 beads are amenable to regeneration with 6 M HCI solution for repeated use without any significant capacity loss. Fixed-bed column treatment of simulated waters containing heavy metals at high or trace levels was also performed. The content of heavy metals in treated effluent approached or met the WHO drinking water standard.

  3. Uptake of Cadmium, Copper, Lead, and Zinc from Sediments by an Aquatic Macrophyte and by Terrestrial Arthropods in a Freshwater Wetland Ecosystem.

    Science.gov (United States)

    Kim, Heung-Tae; Kim, Jae Geun

    2016-08-01

    The objective of this study was to investigate trace-metal [cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn)] biotransference and biomagnification in terrestrial biota at different trophic levels (primary producer-top predator) of a wetland ecosystem. We investigated whether metal concentrations in the sediment are reflected in terrestrial arthropods and aquatic plants. We sampled the floating-leaved plant Trapa japonica; its species-specific primary consumer, the leaf beetle Galerucella nipponensis; and two predatory arthropods (the water strider Gerris sp. and the wolf spider Arctosa sp.) from three wetlands with different sedimentary metal concentrations. The δ(13)C and δ(15)N signatures in the trophic link between the plants and the leaf beetles supported the specificity of their feeding relationship. The stable isotope signatures indicate that the leaf beetle could be an important link in the trophic transfer of the metals. Transference factors (TFs) were Cu and Zn had TF >1 for all biota, and the concentrations were positively correlated with the trophic levels. Thus, there may be Cu and Zn biomagnification in the arthropods. We noted TF 1 among the arthropods. Therefore, Cd is probably not biomagnified between T. japonica and G. nipponensis, but it might be biomagnified in the arthropods. The metal burden in terrestrial arthropods may also be influenced by uptake from the sediment by aquatic plants.

  4. The effect of binary mixtures of zinc, copper, cadmium, and nickel on the growth of the freshwater diatom Navicula pelliculosa and comparison with mixture toxicity model predictions.

    Science.gov (United States)

    Nagai, Takashi; De Schamphelaere, Karel A C

    2016-11-01

    The authors investigated the effect of binary mixtures of zinc (Zn), copper (Cu), cadmium (Cd), and nickel (Ni) on the growth of a freshwater diatom, Navicula pelliculosa. A 7 × 7 full factorial experimental design (49 combinations in total) was used to test each binary metal mixture. A 3-d fluorescence microplate toxicity assay was used to test each combination. Mixture effects were predicted by concentration addition and independent action models based on a single-metal concentration-response relationship between the relative growth rate and the calculated free metal ion activity. Although the concentration addition model predicted the observed mixture toxicity significantly better than the independent action model for the Zn-Cu mixture, the independent action model predicted the observed mixture toxicity significantly better than the concentration addition model for the Cd-Zn, Cd-Ni, and Cd-Cu mixtures. For the Zn-Ni and Cu-Ni mixtures, it was unclear which of the 2 models was better. Statistical analysis concerning antagonistic/synergistic interactions showed that the concentration addition model is generally conservative (with the Zn-Ni mixture being the sole exception), indicating that the concentration addition model would be useful as a method for a conservative first-tier screening-level risk analysis of metal mixtures. Environ Toxicol Chem 2016;35:2765-2773. © 2016 SETAC. © 2016 SETAC.

  5. Effect of Magnesium Supplementation on the Distribution Patterns of Zinc, Copper, and Magnesium in Rabbits Exposed to Prolonged Cadmium Intoxication

    Directory of Open Access Journals (Sweden)

    Zorica Bulat

    2012-01-01

    Full Text Available The present study is designed to investigate whether magnesium (Mg supplementation may prevent Cd-induced alterations in zinc (Zn, copper (Cu, and magnesium (Mg status in rabbits. For this purpose, the concentrations of Zn, Cu, and Mg were estimated in blood, urine, and organs (brain, heart, lungs, liver, kidney, spleen, pancreas, skeletal muscle, and bone of rabbits given Cd (10 mg/kg b.w. and rabbits cotreated with Mg (40 mg/kg b.w. orally, as aqueous solutions of Cd chloride and Mg acetate every day for 4 weeks. Samples were mineralized with conc. HNO3 and HClO4 (4:1 and metals concentrations were determined by atomic absorption spectrophotometry (AAS. Magnesium supplementation succeeded to overcome Cd-induced disbalance of investigated bioelements. Beneficial effects of Mg were observed on Zn levels in blood and urine, on Cu levels in urine, and on Mg levels in blood. Magnesium pretreatment also managed to counteract or reduce all Cd-induced changes in levels of Cu and Mg in organs, while it did not exert this effect on Zn levels. These findings suggest that enhanced dietary Mg intake during Cd exposure can have at least partly beneficial effect on Cd-induced alterations in homeostasis of zinc, copper, and magnesium.

  6. Effect of magnesium supplementation on the distribution patterns of zinc, copper, and magnesium in rabbits exposed to prolonged cadmium intoxication.

    Science.gov (United States)

    Bulat, Zorica; Dukić-Ćosić, Danijela; Antonijević, Biljana; Bulat, Petar; Vujanović, Dragana; Buha, Aleksandra; Matović, Vesna

    2012-01-01

    The present study is designed to investigate whether magnesium (Mg) supplementation may prevent Cd-induced alterations in zinc (Zn), copper (Cu), and magnesium (Mg) status in rabbits. For this purpose, the concentrations of Zn, Cu, and Mg were estimated in blood, urine, and organs (brain, heart, lungs, liver, kidney, spleen, pancreas, skeletal muscle, and bone) of rabbits given Cd (10 mg/kg b.w.) and rabbits cotreated with Mg (40 mg/kg b.w.) orally, as aqueous solutions of Cd chloride and Mg acetate every day for 4 weeks. Samples were mineralized with conc. HNO₃ and HClO₄ (4:1) and metals concentrations were determined by atomic absorption spectrophotometry (AAS). Magnesium supplementation succeeded to overcome Cd-induced disbalance of investigated bioelements. Beneficial effects of Mg were observed on Zn levels in blood and urine, on Cu levels in urine, and on Mg levels in blood. Magnesium pretreatment also managed to counteract or reduce all Cd-induced changes in levels of Cu and Mg in organs, while it did not exert this effect on Zn levels. These findings suggest that enhanced dietary Mg intake during Cd exposure can have at least partly beneficial effect on Cd-induced alterations in homeostasis of zinc, copper, and magnesium.

  7. Some effects of copper, cobalt, cadmium, zinc, nickel, and chromium on growth and mineral element concentration in chrysanthemum

    Energy Technology Data Exchange (ETDEWEB)

    Patel, P.M.; Wallace, A.; Mueller, R.T.

    1976-09-01

    Different levels of Cu, Co, Cd, Zn, Ni, and Cr (10/sup -6/, 10/sup -5/, and 10/sup -4/M) were studied in a glasshouse to evaluate effects on the yield and interactions among heavy metals in chrysanthemum (Chrysanthemum morifolium Ramat. cv. Bright Golden Anne). A 70 percent growth reduction was observed at the highest level (10/sup -4/M) of Cd, Cu, and Cr. The same level of Co, Ni, and Zn depressed growth 45, 45, and 21 percent, respectively. Added Cd in solution had the greatest effect on growth depression at ,,10/sup -5/M. Copper, Co, Cd, Zn, Ni, and Cr concentrations in leaves, stems, and roots were increased with their rate of application in nutrient solution. Most Cu, Co, Cd, Ni, and Cr were associated with roots, followed by leaves and stems. No gradient from root to shoot was observed with Zn. Root to stem metal ratios were in the following order: Cr greater than Co greater than Cd greater than Ni greater than Cu greater than Zn. Cadmium decreased Mn concentration in leaves, stems, and roots, and increased Zn concentration in leaves. Other interactions were also noted.

  8. Food-chain transfer of cadmium and zinc from contaminated Urtica dioica to Helix aspersa and Lumbricus terrestris.

    Science.gov (United States)

    Sinnett, Danielle E; Hodson, Mark E; Hutchings, Tony R

    2009-08-01

    The present study examines the potential of Urtica dioica as an ecologically relevant species for use in ecotoxicological testing. It is prevalent in degraded ecosystems and is a food source for invertebrates. Urtica dioica grown in hydroponic solutions containing from less than 0.003 to 5.7 mg Cd/L or from 0.02 to 41.9 mg Zn/L accumulated metals resulting in leaf tissue concentrations in the range of 0.10 to 24.9 mg Cd/kg or 22.5 to 2,772.0 mg Zn/kg. No toxicological effects were apparent except at the highest concentrations tested, suggesting that this species may be an important pathway for transfer of metals to primary plant consumers. Helix aspersa and Lumbricus terrestris were fed the Cd- and Zn-rich leaves of U. dioica for six and four weeks, respectively. Cadmium and Zn body load increased with increasing metal concentration in the leaves (p aspersa and 1:0.002 to 1:3.9 for Cd and 1:0.2 to 1:8.8 for Zn in L. terrestris. Helix aspersa Cd and Zn tissue concentrations (15.5 and 1,220.2 mg/kg, respectively) were approximately threefold those in L. terrestris when both species were fed nettle leaves with concentrations of approximately 23 mg Cd/kg and 3,400 mg Zn/kg. Models demonstrate that L. terrestris Cd tissue concentrations (r2 = 0.74, p aspersa Zn tissue concentrations (r(2) = 0.69, p < 0.001) can be estimated from concentrations of Cd and Zn within the leaves of U. dioica and suggest that reasonably reproducible results can be obtained using these species for ecotoxicological testing.

  9. Bioavailability of cadmium, copper, mercury, lead, and zinc in subtropical coastal lagoons from the southeast Gulf of California using mangrove oysters (Crassostrea corteziensis and Crassostrea palmula).

    Science.gov (United States)

    Páez-Osuna, Federico; Osuna-Martínez, Carmen C

    2015-02-01

    Cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) were assessed in the edible tissues of Crassrotrea corteziensis oysters collected during the rainy and dry seasons in 27 sites from 8 coastal lagoons of the southeast Gulf of California. In addition, C. palmula oysters were sampled at 9 sites from the same mangrove roots where C. corteziensis oysters were collected. Metal analyses were performed by flame atomic absorption spectrophotometry (Cd, Cu, and Zn), graphite furnace (Pb), and cold vapor detection (Hg). The obtained mean levels were (µg g(-1) dry weight) as follows: Cd 6.05 ± 2.77, Cu 60.0 ± 33.4, Hg 0.38 ± 0.17, Pb 1.11 ± 0.63, and Zn 777 ± 528 µg g(-1). For all metals except Hg, the concentrations were greater during dry season than during rainy seasons. The high levels, particularly that for Cd, were related to upwelling along the eastern Gulf of California. High Hg levels in the rainy season were associated with the transport of materials from the watershed to the lagoon. Shrimp farming, agriculture, and other sources were considered as potential sources to explain the differences in metal bioavailability in the 8 lagoons. The mean concentrations of Cd (Santa María-La Reforma lagoon), Cu [San Ignacio-Navachiste-El Macapule (SINM), Urías (URI), and Altata-Ensenada del Pabellón lagoons], and zinc (Zn) (URI, Santa María-Ohuira-Topolobampo, El Colorado, and SINM lagoons) during the dry season were greater than the maximum permissible limits. C. palmula collected in 8 sites where they were present simultaneously with C. corteziensis had consistently greater metal levels than C. corteziensis, but correlation analyses showed a high and significant (P < 0.05) correlation between metal concentrations in both species. The correlation equations obtained are useful where the same species is not distributed and is necessary to compare results from distinct regions.

  10. Bioaccumulation of Cadmium and Lead in Rodent Species from the Region of Lead-Zinc Smelting Factory – Plovdiv (South Bulgaria

    Directory of Open Access Journals (Sweden)

    Hristo A. Dimitrov

    2016-06-01

    Full Text Available The levels of the toxic metals, Cd and Pb, were measured in liver of yellow-necked mouse (Apodemus flavicollis Melchior, 1834, Mediterranean mouse (Mus macedonicus Petrov & Ružić, 1983 and common vole (Microtus arvalis Pallas, 1778 from the vicinity of Plovdiv (South Bulgaria, where the lead-zinc smelting factory is the main source of pollution. The study was carried out at three sites located along a pollution gradient. An unpolluted region, the Strandzha Natural Park was used as a background region. MANOVA analysis revealed significant differences by species (F=9.61, p=0.003, site (F=24.12, p=0.0001 and exposure (F=3.79, P=0.013 effects. Significant increase of Pb and Cd bioaccumulation was found along the pollution gradient. Cd and Pb mean concentrations were highest at the site closest to the smelter and decreased with increasing the distance from them. The bioaccumulation of Pb was significant highest in the individuals of the yellow-necked mouse, followed by Mediterranean mice and common voles, whereas the common voles accumulated more Cd in comparison with the yellow-necked-, and Mediterranean mice. However, there is little evidence of adverse cadmium-mediated effects in yellow-necked- and Mediterranean mice and this species may be tolerant to Cd exposure. High Cd concentrations in body organs may simply reflect an ability to store the metal in a nontoxic, metallothionein-bound state. Liver Pb and Cd concentration did not differ significantly among sexes.

  11. Characterization and identification of the sources of chromium, zinc, lead, cadmium, nickel, manganese and iron in PM10 particulates at the two sites of Kolkata, India.

    Science.gov (United States)

    Karar, Kakoli; Gupta, A K; Kumar, Animesh; Biswas, Arun Kanti

    2006-09-01

    Monitoring of ambient PM10 (particulate matter which passes through a size selective impactor inlet with a 50% efficiency cut-off at 10 microm aerodynamic diameter) has been done at residential (Kasba) and industrial (Cossipore) sites of an urban region of Kolkata during November 2003 to November 2004. These sites were selected depending on the dominant anthropogenic activities. Metal constituents of atmospheric PM10 deposited on glass fibre filter paper were estimated using Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Chromium (Cr), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn) and iron (Fe) are the seven toxic trace metals quantified from the measured PM10 concentrations. The 24 h average concentrations of Cr, Zn, Pb, Cd, Ni, Mn and Fe from ninety PM10 particulate samples of Kolkata were found to be 6.9, 506.1, 79.1, 3.3, 7.4, 2.4 and 103.6 ng/m3, respectively. The 24 h average PM10 concentration exceeded national ambient air quality standard (NAAQS) as specified by central pollution control board, India at both residential (Kasba) and industrial (Cossipore) areas with mean concentration of 140.1 and 196.6 microg/m3, respectively. A simultaneous meteorology study was performed to assess the influence of air masses by wind speed, wind direction, rainfall, relative humidity and temperature. The measured toxic trace metals generally showed inverse relationship with wind speed, relative humidity and temperature. Factor analysis, a receptor modeling technique has been used for identification of the possible sources contributing to the PM10. Varimax rotated factor analysis identified four possible sources of measured trace metals comprising solid waste dumping, vehicular traffic with the influence of road dust, road dust and soil dust at residential site (Kasba), while vehicular traffic with the influence of soil dust, road dust, galvanizing and electroplating industry, and tanning industry at industrial site (Cossipore).

  12. Green manure and long-term fertilization effects on soil zinc and cadmium availability and uptake by wheat (Triticum aestivum L.) at different growth stages.

    Science.gov (United States)

    Grüter, Roman; Costerousse, Benjamin; Bertoni, Angelina; Mayer, Jochen; Thonar, Cécile; Frossard, Emmanuel; Schulin, Rainer; Tandy, Susan

    2017-12-01

    Zinc (Zn) deficiency in human populations depending on cereals as a main source of Zn is a global malnutrition problem. In this field study, we investigated the potential of green manure application to increase soil Zn availability and wheat grain Zn concentrations (biofortification) on a Luvisol with different long-term fertilizer management. We also studied cadmium (Cd), as wheat is a major contributor of this undesired non-essential element to human diets. Clover (Trifolium alexandrinum L.), mustard (Sinapis alba L.) or no green manure was grown on field plots which had been managed with farmyard manure or mineral fertilizers for 65years in Switzerland. After green manure incorporation into the soil, spring wheat (Triticum aestivum L.) was grown on all plots. The "diffusive gradients in thin films" (DGT) method and DTPA extraction were used to compare soil Zn and Cd availability among the treatments. In contrast to mustard, clover increased soil mineral nitrogen concentrations and wheat biomass; however, neither increased grain Zn concentrations. DGT-available Zn and Cd increased temporarily after both farmyard manure and mineral nitrogen fertilizer application. Higher DTPA-extractable soil Zn and Cd, lower wheat grain yields, but higher grain Zn concentrations were obtained with farmyard manure compared to mineral fertilizers, independent of the green manure treatment. Farmyard manure added Zn, Cd and organic matter that increased the soil binding capacity for Zn and Cd. The decomposition of clover residues caused higher wheat grain yields, but only marginally lower grain Zn concentrations. The absence of a stronger dilution of grain Zn was probably due to organic acid and nitrogen release from decomposing clover, which facilitated Zn uptake by wheat. The study revealed that both long- and short-term field management with organic matter alters soil Zn and Cd concentrations but that the long-term effects dominate their uptake by wheat, in Zn sufficient soil

  13. Synchrotron-based X-Ray Spectroscopy Studies for Redox-based Remediation of Lead, Zinc, and Cadmium in Mine Waste Materials.

    Science.gov (United States)

    Karna, Ranju R; Hettiarachchi, Ganga M; Newville, Matthew; Sun, ChengJun; Ma, Qing

    2016-11-01

    Several studies have examined the effect of submergence on the mobility of metals present in mine waste materials. This study examines the effect of organic carbon (OC) and sulfur (S) additions and submergence time on redox-induced biogeochemical transformations of lead (Pb), zinc (Zn), and cadmium (Cd) present in mine waste materials collected from the Tri-State mining district located in southeastern Kansas, southwestern Missouri, and northeastern Oklahoma. A completely randomized design, with a two-way treatment structure, was used for conducting a series of column experiments. Two replicates were used for each treatment combination. Effluent samples were collected at several time points, and soil samples were collected at the end of each column experiment. Because these samples are highly heterogeneous, we used a variety of synchrotron-based techniques to identify Pb, Zn, and Cd speciation at both micro- and bulk-scale. Spectroscopic analysis results from the study revealed that the addition of OC, with and without S, promoted metal-sulfide formation, whereas metal carbonates dominated in the nonamended flooded materials and in mine waste materials only amended with S. Therefore, the synergistic effect of OC and S may be more promising for managing mine waste materials disposed of in flooded subsidence mine pits instead of individual S or OC treatments. The mechanistic understanding gained in this study is also relevant for remediation of waste materials using natural or constructed wetland systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Potential risks of copper, zinc, and cadmium pollution due to pig manure application in a soil-rice system under intensive farming: a case study of Nanhu, China.

    Science.gov (United States)

    Shi, Jiachun; Yu, Xiulin; Zhang, Mingkui; Lu, Shenggao; Wu, Weihong; Wu, Jianjun; Xu, Jianming

    2011-01-01

    Heavy metal (copper [Cu], zinc [Zn], and cadmium [Cd]) pollution of soils from pig manures in soil-rice ( L.) systems under intensive farming was investigated, taking Nanhu, China, as the case study area. Two hundred pig manures and 154 rice straws, brown rice samples, and corresponding surface soil (0-15 cm) samples were collected in paddy fields from 150 farms in 16 major villages within the study area. The mean Cu and Zn concentrations in pig manures consistently exceeded the related standard. About 44 and 60% of soil samples exceed the Chinese Soil Cu and Cd Environmental Quality Standards, respectively. The concentration of Cu, Zn, and Cd in brown rice did not exceed the Chinese Food Hygiene Standard. There was a significant positive correlation between total Cu and Zn contents in soil and application rate of pig manures. Strong correlation was observed between the extractable Cu, Zn, and Cd in soil and the Cu, Zn, and Cd contents in the brown rice. The spatial distribution maps of Cu and Zn concentrations in brown rice, straw, and extractable soil Cu and Zn concentration also showed similar geographical trends. Further analyses on heavy metals loading flux and accumulation rates from pig manure applied suggested that Cu and Cd contents in soil currently have already exceeded the maximum permissible limit, and Zn, if still at current manure application rates, will reach the ceiling concentration limits in 9 yr. This study assists in understanding the risk of heavy metals accumulating from pig manure applications to agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Effects of chronic waterborne cadmium and zinc interactions on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Driessnack, Melissa K; Jamwal, Ankur; Niyogi, Som

    2017-06-01

    The present study was designed to evaluate the interactive effects of chronic waterborne cadmium (Cd) and zinc (Zn) on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas). Trios (1 male: 2 female; n=6-7) of fish were exposed for 21 days to: (i) control (no added Cd or Zn), (ii) waterborne Cd (7µg/L), (iii) waterborne Zn (170µg/L), and (iv) Cd and Zn in mixture (7 and 170µg/L, respectively). Exposure to Cd or Zn alone did not elicit any significant effect on reproductive output (cumulative egg production) relative to the control, however exposure to Cd and Zn in mixture resulted in a ~50% decrease in fish fecundity. Plasma estradiol in females was reduced by Cd and Zn exposures, both individually and in mixture, with the maximum reduction in the metal mixture exposure. The expression of hepatic estrogen receptor genes (ER-α and ER-β) in females was affected by exposure to Zn, alone and in mixture with Cd, but not to Cd alone, whereas hepatic vitellogenin gene expression was downregulated across all treatments. Increased follicular atresia in the ovary was also recorded, but only in fish exposed to Cd and Zn in mixture. The interactions of Cd and Zn in mixture decreased Cd accumulation in tissues (gill and liver), however no reciprocal reduction in tissue Zn accumulation was observed. In addition, the expression of the hepatic metallothionein gene was upregulated following exposure to Zn, alone and in combination with Cd, with no additive effects in the latter treatment. Overall, our findings suggest that chronic exposure to waterborne Cd and Zn in mixture may induce additive reproductive toxicity, essentially by disrupting estrogen-mediated functions in fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

    Science.gov (United States)

    Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

    2009-01-01

    Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained indicate that blood sampling could provide reasonably accurate and precise estimates of fillet Pb, Co, and Cd concentrations that would be suitable for identifying contaminated sites and for monitoring, but some fillet sampling might be necessary at contaminated sites for establishing consumption advisories. ?? 2009 US Government.

  17. Cadmium, lead, and zinc mobility and plant uptake in a mine soil amended with sugarcane straw biochar.

    Science.gov (United States)

    Puga, A P; Abreu, C A; Melo, L C A; Paz-Ferreiro, J; Beesley, L

    2015-11-01

    Accumulation of heavy metals in unconsolidated soils can prove toxic to proximal environments, if measures are not taken to stabilize soils. One way to minimize the toxicity of metals in soils is the use of materials capable of immobilizing these contaminants by sorption. Biochar (BC) can retain large amounts of heavy metals due to, among other characteristics, its large surface area. In the current experiment, sugarcane-straw-derived biochar, produced at 700 °C, was applied to a heavy-metal-contaminated mine soil at 1.5, 3.0, and 5.0% (w/w). Jack bean and Mucuna aterrima were grown in pots containing a mine contaminated soil and soil mixed with BC. Pore water was sampled to assess the effects of biochar on zinc solubility, while soils were analyzed by DTPA extraction to confirm available metal concentrations. The application of BC decreased the available concentrations of Cd, Pb, and Zn in the mine contaminated soil leading to a consistent reduction in the concentration of Zn in the pore water. Amendment with BC reduced plant uptake of Cd, Pb, and Zn with the jack bean uptaking higher amounts of Cd and Pb than M. aterrima. This study indicates that biochar application during mine soil remediation could reduce plant concentrations of heavy metals. Coupled with this, symptoms of heavy metal toxicity were absent only in plants growing in pots amended with biochar. The reduction in metal bioavailability and other modifications to the substrate induced by the application of biochar may be beneficial to the establishment of a green cover on top of mine soil to aid remediation and reduce risks.

  18. Tolerance to cadmium hepatotoxicity by metallothionein and zinc: in vivo and in vitro studies with MT-null mice.

    Science.gov (United States)

    Coyle, P; Niezing, G; Shelton, T L; Philcox, J C; Rofe, A M

    2000-09-07

    The protective role of metallothionein (MT) in Cd-mediated hepatotoxicity was investigated in vivo and in vitro. Following injection of Cd (2 mg/kg, intraperitoneal or subcutaneous) hepatoxicity was significantly greater at 20 h in metallothionein-null (MT-/-) mice, compared with controls (MT+/+). The decrease in the blood and liver glucose concentrations correlated with the extent of hepatotoxicity, with blood glucose 43% lower in MT-/- mice. Zinc (50 microM) and/or Dex (1 microM) were used in hepatocyte cultures to raise MT 2-5-fold. When Cd at 10 microM was co-treated with Zn and/or Dex, lactate dehydrogenase (LD) leakage in the MT+/+ and MT-/- hepatocytes was reduced only when Zn was present. Cellular glutathione (GSH) was the same in control MT+/+ and MT-/- cultures and was uninfluenced by Zn and Dex. After treatment with 5 and 10 microM Cd, GSH levels were lower in MT-/- than MT+/+ hepatocytes in the control and Dex groups. Higher GSH concentrations were maintained in Zn co-treated cultures from both genotypes, indicating that the superior protective effect of Zn may in part derive from its influence on cellular GSH. Pre-treatment with Zn and/or Dex provided no further protection than co-treatment. Tolerance to brief (15 min) Cd exposure was also investigated in the presence of MT inducers including progesterone (100 microM). Zn, Dex and progesterone treated hepatocytes had less LD leakage than controls with Zn giving the greatest protection (LD leakage 18% of controls at 100 microM Cd). Zn pre-treated cells had higher cytosolic/particulate ratios of Cd. These findings demonstrate that MT protects primary cultures of mouse hepatocytes from short-term exposure to Cd. Zn enhances the protection through MT and non-MT mechanisms.

  19. Assessment of exposure to soils contaminated with lead, cadmium, and arsenic near a zinc smelter, Cassiopée Study, France, 2008.

    Science.gov (United States)

    Durand, Cécile; Sauthier, Nicolas; Schwoebel, Valérie

    2015-06-01

    After 150 years of industrial activity, significant pollution of surface soils in private gardens and locally produced vegetables with lead, cadmium, and arsenic has recently been observed in Viviez (Southern France). A public health intervention was conducted in 2008 to identify individual health risks of Viviez inhabitants and to analyze their environmental exposure to these pollutants. Children and pregnant women in Viviez were screened for lead poisoning. Urinary cadmium testing was proposed to all inhabitants. Those with urinary cadmium levels over 1 μg/g creatinine were then tested for kidney damage. Urinary cadmium and arsenic levels were compared between participants with non-occupational exposure from Viviez and Montbazens, a nearby town not exposed to these two pollutants, in order to identify environmental factors contributing to impregnation. No case of lead poisoning was detected in Viviez, but 23 % of adults had urinary cadmium over 1 μg/g creatinine, 14 % of whom having markers of kidney damage. Viviez adults had higher levels of urinary cadmium, and to a lesser extent, higher levels of urinary arsenic than those from Montbazens. Consumption of local produce (vegetables and animals) and length of residence in Viviez were associated with higher urinary cadmium levels, independently of known confounding factors, suggesting persisting environmental exposure to contaminated soil. To conclude, health risks related to cadmium exposure were identified in the Viviez population living on contaminated soils. Lead and arsenic exposure did not pose health concerns. Interventions were proposed to reduce exposure and limit health consequences.

  20. Mechanisms of antimony interstitial penetration into cadmium telluride crystals

    CERN Document Server

    Nikonyuk, E S; Zakharuk, Z I; Fochuk, P M; Rarenko, A I

    2001-01-01

    The results of electrophysical investigations of CdTe crystals, grown by Bridgman method and doped with Sb impurity in concentrations for 10 sup 1 sup 7 -3 x 10 sup 1 sup 9 cm sup - sup 3 are presented. The analysis of the temperature dependence of Hall coefficient, current carrier mobility and photoconductivity at intrinsic excitation for samples taken from different parts of ingots allows to conclude, that Sb sub T sub e , Sb sub C sub d centers and (Sb sub T sub e Sb sub C sub d) associated appear in CdTe crystal during its doping by antimony impurity. The hole conductivity in doped crystals is controlled by A sub 3 (Sb sub T sub e) acceptors, their density not exceeding 5 x 10 sup 1 sup 6 cm sup - sup 3 , and is essentially less than the real impurity content. The ionization energy of A sub 3 acceptors is (0.28 +- 0.01) eV. In non-equilibrium conditions these acceptors play the role of adhesion centers for holes (at high temperatures) and the slow recombination centers for electrons (at low temperatures)

  1. Cadmium telluride nanocrystals as luminescent sensitizers in flow analysis.

    Science.gov (United States)

    Fortes, Paula R; Frigerio, Christian; Silvestre, Cristina I C; Santos, João L M; Lima, José L F C; Zagatto, Elias A G

    2011-06-15

    A fully automated multipumping flow system (MPFS) using water-soluble CdTe quantum dots (QD) as sensitizers is proposed for the chemiluminometric determination of the anti-diabetic drugs gliclazide and glipizide in pharmaceutical formulations. The nanocrystals acted as enhancers of the weak CL emission produced upon oxidation of sulphite by Ce(IV) in acidic medium, thus improving sensitivity and expanding the dynamical analytical concentration range. By interacting with the QD, the two analytes prevented their sensitizing effect yielding a chemiluminescence quenching of the Ce(IV)-SO(3)(2-)CdTe QD system. The pulsed flow inherent to MPFS assured a fast and efficient mixing of all solutions inside the flow cell, circumventing the need for a reaction coil and facilitating the monitoring of the short-lived generated chemiluminescent species. QD crystal size, concentration and spectral region for measurement were investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Photoluminescence Excitation Spectroscopy Characterization of Cadmium Telluride Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Moore, James E.; Wang, Xufeng; Grubbs, Elizabeth K.; Drayton, Jennifer; Johnston, Steve; Levi, Dean; Lundstrom, Mark S.; Bermel, Peter

    2016-11-21

    The use of steady-state photoluminescence spectroscopy as a contactless characterization tool, suitable for inline optical characterization, has been previously demonstrated for high efficiency solar cells such as GaAs. In this paper, we demonstrate the use of PLE characterization on a thin film CdS/CdTe np heterojunction solar cell, and compare the results to measured EQE and I-V data. In contrast to previous work on high-quality GaAs, the PLE and EQE spectra do not match closely here. We still find, however, that reliable material parameters can be extracted from the PLE measurements. We also provide a physical explanation of the limits defining the cases when the PLE and EQE spectra may be expected to match.

  3. Back contact formation in thin cadmium telluride solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haedrich, M., E-mail: mathias.haedrich@uni-jena.de; Heisler, C.; Reisloehner, U.; Kraft, C.; Metzner, H.

    2011-08-31

    We present a model describing the undesired roll-over which is a well-known phenomenon in the current-voltage characteristics of CdTe solar cells. Therein, the roll-over is ascribed to a Schottky barrier at the back contact which is effective as a reverse diode. The formation of this barrier is investigated depending on the CdTe absorber thickness as well as on the employed back contact metal. Computer simulations of the energy band diagram reveal that the back contact barrier can be reduced and even eliminated for sufficiently thin absorbers. The reason is the spatial overlap between the space-charge regions of the p-n heterojunction with the one of the back contact. This behaviour correlates with experimental current-voltage data of solar cells with a simple gold back contact. In the latter, the roll-over is considerable for absorbers with 3 to 5 {mu}m thickness, diminishes when the absorber thickness is reduced and finally vanishes when the absorber thickness is approximately 1 {mu}m. The investigations show that thickness reduction can be employed in order to suppress the roll-over phenomenon in CdTe solar cells.

  4. Theoretical Investigation of Point Defects of Mercury Cadmium Telluride.

    Science.gov (United States)

    1985-11-01

    Mitonneau, and A. Mircea, Electron ’Lett. 13, 192(1977). v 26. D. E. Holmes, R. T. Chen, K. R. Elliott, C. G. Kirkpatrick , and P. W. Yu, IEEE Trans. MMT-30...alloys," Phys. Rev. 156, 809(1967). 19.B. Velicky, S. Kirkpatrick , and H. Ehrenreich, "Single-site approximations in the electronic theory of simple...Solid State Phys. 5, p.258, 1957, edited by F. Sietz and D. Turnbull. 20. H. A. Bethe and E.E. Salpeter, ’Quantum Mechanics of one and two- electron

  5. A portable cadmium telluride multidetector probe for cardiac function monitoring

    CERN Document Server

    Arntz, Y; Dumitresco, B; Eclancher, B; Prat, V

    1999-01-01

    A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) wh...

  6. Modeling Mercury Cadmium Telluride (HgCdTe) Photodiodes

    Science.gov (United States)

    2009-11-01

    composition for Hg1–xCdxTe and CdZnTe substrates, with the lattice constant for a variety of III-V compounds (5). Cd0.96Zn0.04Te is a good match for a wide...composition for Hg1–xCdxTe and CdZnTe substrates, with the lattice constant for a variety of III-V compounds (5). Cd0.96Zn0.04Te is a good match for a

  7. A portable cadmium telluride multidetector probe for cardiac function monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Arntz, Y.; Chambron, J.; Dumitresco, B.; Eclancher, B. E-mail: eclan@alsace.u-strasbg.fr; Prat, V

    1999-06-01

    A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) which well depicted the filling and ejection of the cardiac beats, allowing to compare the clinically relevant parameters of the cardiac performance, proportional variables of the stroke volume (SV), ejection fraction (EF) and ventricular flow-rate with the known absolute values programmed on the model. The portable system is now in operation for clinical assessment of cardiac patients.

  8. Electrochemical sensors for the simultaneous determination of zinc, cadmium and lead using a Nafion/ionic liquid/graphene composite modified screen-printed carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Chaiyo, Sudkate [Electrochemistry and Optical Spectroscopy Research Unit (EOSRU), Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok (Thailand); Mehmeti, Eda [Institute of Chemistry, Department of Analytical Chemistry, Karl-Franzens University, Universitätsplatz 1, Graz A-8010 (Austria); Žagar, Kristina [Department for Nanostructured Materials, Jozef Stefan Institute, Ljubljana (Slovenia); Siangproh, Weena, E-mail: weena@swu.ac.th [Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Wattana, Bangkok (Thailand); Chailapakul, Orawon, E-mail: corawon@chula.ac.th [Electrochemistry and Optical Spectroscopy Research Unit (EOSRU), Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok (Thailand); Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Patumwan, Bangkok (Thailand); Kalcher, Kurt, E-mail: kurt.kalcher@uni-graz.at [Institute of Chemistry, Department of Analytical Chemistry, Karl-Franzens University, Universitätsplatz 1, Graz A-8010 (Austria)

    2016-04-28

    A simple, low cost, and highly sensitive electrochemical sensor, based on a Nafion/ionic liquid/graphene composite modified screen-printed carbon electrode (N/IL/G/SPCE) was developed to determine zinc (Zn(II)), cadmium (Cd(II)), and lead (Pb(II)) simultaneously. This disposable electrode shows excellent conductivity and fast electron transfer kinetics. By in situ plating with a bismuth film (BiF), the developed electrode exhibited well-defined and separate peaks for Zn(II), Cd(II), and Pb(II) by square wave anodic stripping voltammetry (SWASV). Analytical characteristics of the BiF/N/IL/G/SPCE were explored with calibration curves which were found to be linear for Zn(II), Cd(II), and Pb(II) concentrations over the range from 0.1 to 100.0 ng L{sup −1}. With an accumulation period of 120 s detection limits of 0.09 ng mL{sup −1}, 0.06 ng L{sup −1} and 0.08 ng L{sup −1} were obtained for Zn(II), Cd(II) and Pb(II), respectively using the BiF/N/IL/G/SPCE sensor, calculated as 3σ value of the blank. In addition, the developed electrode displayed a good repeatability and reproducibility. The interference from other common ions associated with Zn(II), Cd(II) and Pb(II) detection could be effectively avoided. Finally, the proposed analytical procedure was applied to detect the trace metal ions in drinking water samples with satisfactory results which demonstrates the suitability of the BiF/N/IL/G/SPCE to detect heavy metals in water samples and the results agreed well with those obtained by inductively coupled plasma mass spectrometry. - Highlights: • Nafion/ionic liquid/graphene composite modified electrode was fabricated. • Simultaneous determination of Zn, Cd and Pb in real samples was studied. • Zn, Cd and Pb could be sensitively measured as low as 90, 60 and 80 pg mL{sup −1}.

  9. Protective effect of zinc supplementation against cadmium-induced oxidative stress and the RANK/RANKL/OPG system imbalance in the bone tissue of rats

    Energy Technology Data Exchange (ETDEWEB)

    Brzóska, Malgorzata M., E-mail: Malgorzata.Brzoska@umb.edu.pl; Rogalska, Joanna

    2013-10-01

    It was investigated whether protective influence of zinc (Zn) against cadmium (Cd)-induced disorders in bone metabolism may be related to its antioxidative properties and impact on the receptor activator of nuclear factor (NF)-κΒ (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system. Numerous indices of oxidative/antioxidative status, and Cd and Zn were determined in the distal femur of the rats administered Zn (30 and 60 mg/l) or/and Cd (5 and 50 mg/l) for 6 months. Soluble RANKL (sRANKL) and OPG were measured in the bone and serum. Zn supplementation importantly protected from Cd-induced oxidative stress preventing protein, DNA, and lipid oxidation in the bone. Moreover, Zn protected from the Cd-induced increase in sRANKL concentration and the sRANKL/OPG ratio, and decrease in OPG concentration in the bone and serum. Numerous correlations were noted between indices of the oxidative/antioxidative bone status, concentrations of sRANKL and OPG in the bone and serum, as well as the bone concentrations of Zn and Cd, and previously reported by us in these animals (Brzóska et al., 2007) indices of bone turnover and bone mineral density. The results allow us to conclude that the ability of Zn to prevent from oxidative stress and the RANK/RANKL/OPG system imbalance may be implicated in the mechanisms of its protective impact against Cd-induced bone damage. This paper is the first report from an in vivo study providing evidence that beneficial Zn impact on the skeleton under exposure to Cd is related to the improvement of the bone tissue oxidative/antioxidative status and mediating the RANK/RANKL/OPG system. - Highlights: • Cd induces oxidative stress in the bone tissue. • Cd disturbs bone metabolism via disorder of the RANK/RANKL/OPG system balance. • Zn supplementation protects from Cd-induced oxidative stress in the bone tissue. • Zn protects from the RANK/RANKL/OPG system imbalance caused by Cd in the bone tissue. • Enhanced Zn intake protects from Cd

  10. Recovery of zinc and cadmium from spent batteries using Cyphos IL 102 via solvent extraction route and synthesis of Zn and Cd oxide nanoparticles.

    Science.gov (United States)

    Singh, Rashmi; Mahandra, Harshit; Gupta, Bina

    2017-09-01

    The overall aim of this study is to separate and recover zinc and cadmium from spent batteries. For this purpose Cyphos IL 102 diluted in toluene was employed for the extraction and recovery of Zn and Cd from Zn-C and Ni-Cd batteries leach liquor. The influence of extractant concentration for the leach liquors of Zn-C (0.01-0.05mol/L) and Ni-Cd (0.04-0.20mol/L) batteries has been investigated. Composition of the leach liquor obtained from Zn-C/Ni-Cd spent batteries is Zn - 2.18g/L, Mn - 4.59g/L, Fe - 4.0×10-3g/L, Ni - 0.2×10-3g/L/Cd - 4.28g/L, Ni - 0.896×10-1g/L, Fe - 0.148g/L, Co - 3.77×10-3g/L, respectively. Two stage counter current extraction at A/O 1:1 and 3:2 with 0.04mol/L and 0.2mol/L Cyphos IL 102 for Zn and Cd, respectively provide more than 99.0% extraction of both the metal ions with almost negligible extraction of associated metal ions. A stripping efficiency of around 99.0% for Zn and Cd was obtained at O/A 1:1 using 1.0mol/L HNO3 in two and three counter current stages, respectively. ZnO and CdO were also synthesized using the loaded organic phase and characterized using XRD, FE-SEM and EDX techniques. XRD peaks of ZnO and CdO correspond to zincite and monteponite, respectively. The average particle size was ∼27.0nm and ∼37.0nm for ZnO and CdO, respectively. The EDX analysis of ZnO and CdO shows almost 1:1 atomic percentage. Copyright © 2017. Published by Elsevier Ltd.

  11. Acute toxicity of copper, lead, cadmium, and zinc to early life stages of white sturgeon (Acipenser transmontanus) in laboratory and Columbia River water.

    Science.gov (United States)

    Vardy, David W; Santore, Robert; Ryan, Adam; Giesy, John P; Hecker, Markus

    2014-01-01

    Populations of white sturgeon (Acipenser transmontanus) are in decline in North America. This is attributed, primarily, to poor recruitment, and white sturgeon are listed as threatened or endangered in several parts of British Columbia, Canada, and the United States. In the Columbia River, effects of metals have been hypothesized as possible contributing factors. Previous work has demonstrated that early life stage white sturgeon are particularly sensitive to certain metals, and concerns over the level of protectiveness of water quality standards are justified. Here we report results from acute (96-h) toxicity tests for copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) from parallel studies that were conducted in laboratory water and in the field with Columbia River water. Water effect ratios (WERs) and sensitivity parameters (i.e., median lethal accumulations, or LA50s) were calculated to assess relative bioavailability of these metals in Columbia River water compared to laboratory water, and to elucidate possible differences in sensitivity of early life stage white sturgeon to the same concentrations of metals when tested in the different water sources. For Cu and Pb, white sturgeon toxicity tests were initiated at two life stages, 8 and 40 days post-hatch (dph), and median lethal concentrations (LC50s) ranged between 9-25 μg Cu/L and 177-1,556 μg Pb/L. LC50s for 8 dph white sturgeon exposed to Cd in laboratory water and river water were 14.5 and 72 μg/L, respectively. Exposure of 8 dph white sturgeon to Zn in laboratory and river water resulted in LC50s of 150 and 625 μg/L, respectively. Threshold concentrations were consistently less in laboratory water compared with river water, and as a result, WERs were greater than 1 in all cases. In addition, LA50s were consistently greater in river water exposures compared with laboratory exposures in all paired tests. These results, in combination with results from the biotic ligand model, suggest that the observed

  12. Soil zinc and cadmium availability and uptake by wheat (Triticum aestivum L.) as affected by long-term organic matter management

    Science.gov (United States)

    Grüter, Roman; Costerousse, Benjamin; Mayer, Jochen; Mäder, Paul; Thonar, Cécile; Frossard, Emmanuel; Schulin, Rainer; Tandy, Susan

    2017-04-01

    Zinc (Zn) deficiency is a widespread problem in human mineral nutrition. It is mainly caused by imbalanced diets with low contents of bioavailable Zn. This is in particular a problem in populations depending on cereals such as wheat (Triticum aestivum L.) as a major source of this essential micronutrient element. Increasing Zn concentrations in wheat grains (biofortification) is therefore an important challenge. At the same time, increased uptake of the toxic heavy metal cadmium (Cd) must be prevented. Agronomic practises influence soil properties such as pH and soil organic carbon and thus also have an indirect effect on phytoavailable soil Zn and Cd concentrations and the uptake of these metals by wheat in addition to direct inputs with fertilizers and other amendments. This study investigated the effects of long-term organic matter management on the phytoavailability of soil Zn and Cd and their uptake by wheat on plots of two Swiss long-term field trials. In one trial (DOK), a farming system comparison trial established in 1978, we compared plots under conventional management with mineral fertilization either in combination or not with farmyard manure application to plots under biodynamic organic management and control plots with no fertilizer application. In the second trial (ZOFE), established in 1949, we compared different fertilizer regimes on conventionally managed plots, including plots with application of mineral fertilizers only, farmyard manure, or compost and control plots with no fertilizer application. Soil physico-chemical and biological properties were determined at the beginning of the growing season. Soil Zn and Cd availabilities were assessed by the Diffusive Gradients in Thin Films (DGT) method and by DTPA extraction before and after wheat cultivation. Additionally, various wheat yield components and element concentrations in shoots and grains were measured at harvest. In the ZOFE trial, soil Zn and Cd concentrations were lowest in the mineral

  13. Teor de zinco, cádmio e chumbo em plantas de arroz em solos incubados com resíduo siderúrgico Contents of zinc, cadmium and lead in rice plants in soils incubated with slag

    Directory of Open Access Journals (Sweden)

    André F. M. de Andrade

    2010-10-01

    grown in Fluvic Entisol had the highest dry matter production and higher zinc accumulation, but smaller accumulation of cadmium, while the ones in the Typic soil showed the lowest dry matter production, lower accumulation of zinc, but higher lead and cadmium accumulation. The DTPA extractor was subjected to high and significant correlations with the concentrations of lead, cadmium and zinc in roots and shoots and, with the total amount accumulated in plants, showed as a good indicator of the bioavailability of these three metals. According to the characteristics presented in the soils studied and the phytotoxic concentrations of lead and cadmium found in plants grown in PVA, the use of this residue as a source of zinc for rice cultivation is not recommended.

  14. Determination of particle mass deposition according to Bergerhoff; Performance characteristics of the measurement of particle mass deposition and its portions of lead, cadmium, zinc and thallium. Bestimmung des Staubniederschlags nach Bergerhoff; Verfahrenskenngroessen fuer die Messung des Staubniederschlags und seiner Anteile an Blei, Cadmium, Zink und Thallium

    Energy Technology Data Exchange (ETDEWEB)

    Gehrig, R. (Eidgenoessische Materialpruefungs- und Forschungsanstalt, Duebendorf (Switzerland). Abt. fuer Luftfremdstoffe); Faesi, C. (Eidgenoessische Materialpruefungs- und Forschungsanstalt, Duebendorf (Switzerland). Abt. fuer Luftfremdstoffe); Hofer, P. (Eidgenoessische Materialpruefungs- und Forschungsanstalt, Duebendorf (Switzerland). Abt. fuer Luftfremdstoffe)

    1993-05-01

    The requirements concerning quality assurance have increased considerably in the field of immission control. Well founded values for detection limits and confidence limits have to be given. Based on the statistical analysis of long term data series of deposition measurements of particle mass (Berghoff method), lead, cadmium, zinc and thallium performance characteristics were established for very differently polluted sites. The resulting detection limits as well as confidence limits are low enough for a reliable control of the respective immission limit values. It is further shown that the use of plastic buckets instead of the glass buckets required by the VDI guideline or the addition of a protecting agent to avoid freezing does not affect the measurements significantly. (orig.)

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

    Indian Academy of Sciences (India)

    Author Affiliations. J U AHAMED1 N P BEGUM1 M N I KHAN2. Department of Applied Physics, Electronics and Communication Engineering, University of Chittagong, Chittagong 4331, Bangladesh; Materials Science Division, Atomic Energy Center, Dhaka, Bangladesh ...

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

    Indian Academy of Sciences (India)

    J U Ahamed

    2017-08-31

    Aug 31, 2017 ... J U AHAMED1,*, N P BEGUM1 and M N I KHAN2. 1 Department of Applied Physics, Electronics and Communication Engineering, University of Chittagong,. Chittagong 4331, Bangladesh ..... between 0 (disorder) and 1 (fully ordered), the subscript s refers to the super lattice peak and the subscript f refers to.

  17. Dislocation Etching Solutions for Mercury Cadmium Selenide

    Science.gov (United States)

    2014-09-01

    mercury cadmium telluride (Hg1–xCdxTe) for infrared (IR) sensor applications, but etch pit density ( EPD ) measurements are required to measure...dislocations that affect device performance. No EPD solutions have been reported for Hg1–xCdxSe, and standard EPD solutions for Hg1–xCdxTe have proved...ineffective. Thus, a new etching solution is required for EPD measurements of Hg1–xCdxSe. Samples were etched in various solutions and the resulting pits

  18. Three zinc(II) and cadmium(II) complexes containing 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole and polynitrile ligands: synthesis, molecular and supramolecular structures, and photoluminescence properties.

    Science.gov (United States)

    Setifi, Zouaoui; Zambon, Daniel; Setifi, Fatima; El-Ghozzi, Malika; Mahiou, Rachid; Glidewell, Christopher

    2017-09-01

    Three photoluminescent complexes containing either ZnII or CdII have been synthesized and their structures determined. Bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2N1,N5]bis(dicyanamido-κN1)zinc(II), [Zn(C12H10N6)2(C2N3)2], (I), bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2N1,N5]bis(dicyanamido-κN1)cadmium(II), [Cd(C12H10N6)2(C2N3)2], (II), and bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2N1,N5]bis(tricyanomethanido-κN1)cadmium(II), [Cd(C12H10N6)2(C4N3)2], (III), all crystallize in the space group P-1, with the metal centres lying on centres of inversion, but neither analogues (I) and (II) nor CdII complexes (II) and (III) are isomorphous. A combination of N-H...N and C-H...N hydrogen bonds and π-π stacking interactions generates three-dimensional framework structures in (I) and (II), and a sheet structure in (III). The photoluminescence spectra of (I)-(III) indicate that the energies of the π-π* transitions in the coordinated triazole ligand are modified by minor changes of the ligand geometry associated with coordination to the metal centres.

  19. Long-term (1992-2004) record of lead, cadmium, and zinc air contamination in Warsaw, Poland: Determination by chemical analysis of moss bags and leaves of Crimean linden

    Energy Technology Data Exchange (ETDEWEB)

    Dmuchowski, Wojciech, E-mail: dmuchowski@ob.neostrada.p [Botanical Garden-Center for Conservation of Biological Diversity, Polish Academy of Sciences, 2 Prawdziwka St., 02-973 Warszawa (Poland); Warsaw University of Life Sciences-SGGW, Faculty of Agriculture and Biology, 159 Nowoursynowska St., 02-776 Warszawa (Poland); Bytnerowicz, Andrzej [US Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)

    2009-12-15

    Between 1992 and 2004, air contamination with lead (Pb), cadmium (Cd), and zinc (Zn) in Warsaw, Poland, was monitored annually with moss (Sphagnum fallax) bags on a network of 230 sites covering the entire city. During the study the highest contamination was near the Warszawa Steel Mill, northwestern Warsaw. Lead concentrations in moss bags decreased in time, while those of Cd and Zn did not show clear trends. Between 1994 and 2004, Pb, Cd, and Zn were also monitored in the Crimean linden (Tilia Euchlora) foliage along the main city avenue and in a northwestern warsaw park. Lead concentrations decreased more near the avenue than in the park, indicating that the phasing-out of leaded gasoline had a major effect on reduced Pb contamination in Warsaw. At the same time, foliar concentrations of Cd and Zn in both areas decreased much less. - Between 1992 and 2004, concentrations of Pb decreased, while those of Cd and Zn remained little changed in moss bags and linden foliage exposed to ambient air in Warsaw, Poland.

  20. Toxicity of cadmium to the developing lung

    Energy Technology Data Exchange (ETDEWEB)

    Daston, G.P.

    1981-01-01

    The effects of cadmium on the developing lung and pulmonary surfactant were studied. Pregnant rats received subcutaneous injections of cadmium chloride on days 12 to 15 of gestation and were sacrificed throughout late gestation. The treatment resulted in high embryonic mortality and growth regardation. Fetal lung weight was reduced 20 to 30% due to hypoplasia, as the number of lung cells (DNA/lung) but not cell size (protein/cell) was lowered. The ultrastructural development of alveolar epithelium was altered; cytodifferentiation was delayed; and the cytoplasmic inclusions which contain pulmonary surfactant, were reduced in the term fetus. Accumulation of phosphatidylcholine (PC), the major component of pulmonary surfactant, was diminished in the lungs of treated fetuses. The immediate cause of this lowered accumulation was a decreased rate of synthesis of PC from choline. Carbohydrates probably represent a major source of PC precursors and are present in large quantities in the fetal lung as glycogen. The pulmonary glycogen content of cadmium-exposed fetuses was diminished. It is postulated that this is a reason for the lowered rate of PC synthesis. Maternally administered cadmium did not pass through the placenta; thus, the mechanism of fetotoxicity was indirect. Maternal cadmium exposure did result in lowered fetal zinc levels. Coadministration of zinc with cadmium raised fetal zinc concentration to control values and alleviated all fetotoxicity. Fetal zinc deficiency is a possible mechanism for the toxic effects on the developing lung. Several dams were allowed to give birth and their offspring were observed for respiratory problems. Cadmium treatment delayed parturition by about a day. Symptoms of respiratory distress syndrome (RDS) were observed in 11% of the treated neonates. All but one of these individuals died and had lungs with hyaline membranes. This is the only known case of an environmental agent causing neonatal RDS.

  1. Solid phase extraction of lead, cadmium and zinc on biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer and their determination in water and food samples.

    Science.gov (United States)

    Tuzen, Mustafa; Sahiner, Samet; Hazer, Baki

    2016-11-01

    A new biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer was used as adsorbent for the sensitive and selective separation, preconcentration and determination of Pb(II), Cd(II) and Zn(II) by using atomic absorption spectrometry. Diethyl dithiocarbamate was used as chelating reagent. Analytical parameters such as pH, eluent type and its volume, flow rates of sample solution, ligand amount, sample volume were optimized. Effects of some cations, anions and transition metal ions were also investigated. Enrichment factor and relative standard deviation were found to be 100 and 3%, respectively. The limits of detection based on three times standard deviation of blanks (N=21) were found 1.05μgL(-1) for Pb(II), 0.42μgL(-1) for Cd(II) and 0.13μgL(-1) for Zn(II). Limits of quantification (10s, N=21) were found 3.47μgL(-1) for Pb(II), 1.39μgL(-1) for Cd(II) and 0.43μgL(-1) for Zn(II). Accuracy evaluation of the method was confirmed with analyses of certified reference materials (NIST SRM 1515 Apple leaves, IAEA 336 Lichen, GBW 07605 Tea). Optimized method was applied to tap water and food samples after microwave digestion method. Cadmium and lead values in some samples were found higher than legal limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

    Science.gov (United States)

    Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; Ma, Yibing

    2014-01-01

    To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

  3. Hydrothermal syntheses, crystal structures and luminescence properties of zinc(II) and cadmium(II) coordination polymers based on bifunctional 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Na; Guo, Hui-Lin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Song, Juan; Xu, Bing; Yang, Meng-Lin; Dong, Fa-Xin; Xue, Gang-Lin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2013-02-15

    Five new coordination polymers, [Zn{sub 2}(ctpy){sub 2}Cl{sub 2}]{sub n} (1), [Zn{sub 2}(ctpy){sub 2}(ox)(H{sub 2}O){sub 2}]{sub n} (2), [Zn{sub 2}(ctpy)(3-btc)(H{sub 2}O)]{sub n}{center_dot}0.5nH{sub 2}O (3), [Cd(ctpy){sub 2}(H{sub 2}O)]{sub n} (4), [Cd{sub 4}(ctpy){sub 2}(2-btc){sub 2}(H{sub 2}O){sub 2}]{sub n}{center_dot}2nH{sub 2}O (5), (Hctpy=3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid, H{sub 2}ox=oxalic acid, H{sub 3}(3-btc)=1,3,5-benzenetricarboxylic acid, H{sub 3}(2-btc)=1,2,4-benzenetricarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1-2 are a one-dimensional chain with weak interactions to form 3D supramolecular structures. Compound 3 is a 4-nodal 3D topology framework comprised of binuclear zinc units and (ctpy){sup -} anions. Compound 4 shows two dimensional net. Compound 5 is a (4,5,6)-connected framework with {l_brace}4{sup 4}{center_dot}6{sup 2}{r_brace}{l_brace}4{sup 6}{center_dot}6{sup 4}{r_brace}{sub 2}{l_brace}4{sup 9}{center_dot}6{sup 6}{r_brace} topology. In addition, the thermal stabilities and photoluminescence properties of 1-5 were also studied in the solid state. - Graphical abstract: Five new Zn/Cd compounds with 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid were prepared. The photoluminescence and thermal stabilities properties of 1-5 were investigated in the solid state. Highlights: Black-Right-Pointing-Pointer Five new zinc/cadmium metal-organic frameworks have been hydrothermal synthesized. Black-Right-Pointing-Pointer The structural variation is attributed to the diverse metal ions and auxiliary ligand. Black-Right-Pointing-Pointer Compounds 1-5 exhibit 1D ring chain, 2D layer and 3D open-framework, respectively. Black-Right-Pointing-Pointer These compounds exhibit strong solid state luminescence emission at room temperature.

  4. The study and comparison of heavy metals concentration (Nickel, Lead, Cadmium and Zinc in the muscle of Otolithes ruber, Parastromateus niger, Scomberomorus commerson and Sphyraena jello from Chabahar area in summer

    Directory of Open Access Journals (Sweden)

    E. Shahri

    2017-07-01

    Full Text Available The heavy metals are from the pollutants which create too much problems in aquatic ecosystems for aquatics and human. This study was done concentration of heavy metals Nickle, Cadmium, Lead  and  Zinc and risk assessment in the muscle of Otolithes ruber, Parastromateus niger, Scomberomorus commerson and Sphyraena jello in 2013. Ninety six  samples of fishes was prepared of coastal and marine from the Chabahar, Iran. Metals were extracted from the tissues using wet Digestion method and concentration of the heavy metals were measured by Atomic Absorption Spectrophotometer Younglin AAS8020. Concentration of Cd was in Parastromateus niger (0.0450 mg Kg-1 higher than other species. Also, the lowest Concentration of this element was in Otolithes ruber and Scomberomorus commerson (0.0150 mg Kg-1. Concentration of Pb was in Sphyraena jello (0.0125 mg Kg-1 lower than other species. Concentration of Ni was in Sphyraena jello (4.1800 mg Kg-1 higher than other species. Also, the lowest Concentration of this element was in Scomberomorus commerson (0.0150 mg Kg-1. Concentration of Zn was in Sphyraena jello (0.5450 mg Kg-1 higher than other species. Also, the lowest Concentration of this element was in Scomberomorus commerson (0.0150 mg Kg-1. Concentration of Cd, Pb and Zn was lower than comparison of FAO, WHO, UKMAFF, NHMRC and FDA. Concentration of Ni was higher than comparison ofGlobal Standards. According to the results, the amount of heavy metals in muscle of fishes in the study not take any risks for human consumption.

  5. Development and evaluation of hexaplex PCR for rapid detection of methicillin, cadmium/zinc and antiseptic-resistant staphylococci, with simultaneous identification of PVL-positive and -negative Staphylococcus aureus and coagulase negative staphylococci.

    Science.gov (United States)

    Panda, Sasmita; Kar, Sarita; Choudhury, Ranginee; Sharma, Savitri; Singh, Durg V

    2014-03-01

    We developed a multiplex PCR to detect the presence of methicillin- (mecA), cadmium/zinc-(czrC) and antiseptic-resistant (qacA/B) staphylococci and to identify Panton-Valentine leukocidin (PVL)-positive and -negative Staphylococcus aureus and coagulase-negative staphylococci (CoNS) from infected and healthy eyes. The assay was validated on 177 staphylococci comprising of 55 each of S. aureus and CoNS isolated from infected eyes and five S. aureus and 62 CoNS isolated from healthy eyes and nine direct ocular samples. Nine direct ocular samples for in situ testing consisted of corneal scrapings (4), conjunctiva swabs (2) and others (3). Multiplex PCR result was correlated with genotype data obtained with single PCR and dot-blot assay. The control strains that were positive in multiplex PCR for 16S rRNA, nuc, mecA, pvl, czrC and qacA/B genes were also positive in the dot-blot assay. The specificity of amplified genes obtained with reference strains was further confirmed by DNA sequencing. The single step-hexaplex PCR method can be used for rapid detection of mecA, nuc, pvl, czrC and qacA/B genes in staphylococci with simultaneous identification of PVL-positive and -negative S. aureus and CoNS from a variety of ocular samples. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Neutronographic investigations of lattice dynamics of mercury telluride

    Energy Technology Data Exchange (ETDEWEB)

    Kepa, H.; Giebultowicz, T. (Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej)

    1981-01-01

    The lattice dynamics of mercury telluride was investigated. The relation of acustics phonons dispersion was studied by neutron diffraction. The measurements of the relation were performed and the results are presented.

  7. Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

    Directory of Open Access Journals (Sweden)

    Bo Li

    Full Text Available To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

  8. 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.

  9. Zinco, chumbo e cádmio em plantas de arroz (Oryza Sativa L. cultivadas em solo após adição de resíduo siderúrgico Zinc, lead and cadmium influence in rice plants (Oryza Sativa L. cultivated in soil with addition of siderurgical residue

    Directory of Open Access Journals (Sweden)

    André Fernão Martins de Andrade

    2008-10-01

    Full Text Available Os efeitos da aplicação de resíduo siderúrgico, proveniente da concentração de zinco em lama de altos-fornos siderúrgicos, como fonte de zinco para plantas de arroz (Oryza Sativa L. BRS Curinga e a toxicidade devida ao cádmio e ao chumbo no resíduo, foram estudados em experimento de casa de vegetação. O material de solo usado foi proveniente do horizonte A e B de um Latossolo Vermelho-Amarelo e do horizonte A de um Neossolo Flúvico, coletados no município de Pinheiral, Estado do Rio de Janeiro. Foram aplicadas quatro doses de resíduo (94; 281; 844 e 2531kg ha-1. Foi determinado o teor de zinco, cádmio e chumbo na raiz e na parte aérea das plantas de arroz. As plantas crescidas no horizonte A do Neossolo Flúvico apresentaram a maior produção de matéria seca e a maior acumulação de zinco e a menor de cádmio. As plantas de arroz desenvolvidas no horizonte B do Latossolo apresentaram a menor produção de matéria seca, menor acumulação de zinco e a maior de chumbo, enquanto que as cultivadas no horizonte A do Latossolo apresentaram a mais elevada produção de matéria seca dos três substratos utilizados. O zinco e o chumbo concentraram-se, principalmente, nas raízes das plantas, e o cádmio se concentrou na parte aérea. Pelas características apresentadas nos solos estudados e pelas concentrações fitotóxicas do chumbo e do cádmio encontradas nas plantas desenvolvidas sobre o horizonte B do Latossolo, não é recomendável a utilização desse resíduo como fonte de zinco para a cultura do arroz.The effects of application of siderurgical residue, originated from the zinc concentration in siderurgical high-ovens mud, as supply of zinc for rice plants (Oryza Sativa L. and the toxicity due to cadmium and lead from the residue, were studied in a greenhouse experiment.The period of the experiment was from April of 2005 to March of 2006. The soil materials were from the A and B horizons of a Yellow - Red Oxisol, and the A

  10. Cadmium concentrations in the testes, sperm, and spermatids of mice subjected to long-term cadmium chloride exposure.

    Science.gov (United States)

    Bench, G; Corzett, M H; Martinelli, R; Balhorn, R

    1999-01-01

    Exposures to cadmium have been reported to reduce male fertility and there are several hypotheses that suggest how reduced male fertility may result from incorporation of cadmium into sperm chromatin. The purpose of this study was to determine whether mice subjected to long-term intraperitoneal cadmium exposure incorporated cadmium into their sperm chromatin. Male mice were exposed to 0.1 mg/kg body weight cadmium in the form of CdCl2 via intraperitoneal injection once per week for 4, 10, 26, and 52 weeks and then sacrificed. The cadmium contents of the liver, testes, pooled sperm, and pooled spermatids from dosed and control animals were determined by atomic absorption spectroscopy. Cadmium and zinc contents in individual sperm and spermatid heads were determined by particle-induced x-ray emission. Atomic absorption spectroscopy revealed that although cadmium accumulated in the liver and testes, cadmium was not detected in pooled sperm or spermatid samples down to minimum detectable limits of 0.02 microg/g dry weight. Particle-induced x-ray emission analyses did not show the presence of cadmium in any sperm or spermatid head down to minimum detectable limits of 15 microg/g dry weight. Particle-induced x-ray emission analyses also demonstrated that phosphorus, sulfur, and zinc concentrations in individual sperm and spermatid heads were not altered by exposure to CdCl2. Because cadmium was not incorporated into sperm chromatin at levels above 0.02 microg/g dry weight, the data cast doubt on hypotheses that suggest that reduced male fertility may result from incorporation of cadmium into sperm chromatin.

  11. 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.

  12. Effect of replacement of "zinc finger" zinc on estrogen receptor DNA interactions.

    Science.gov (United States)

    Predki, P F; Sarkar, B

    1992-03-25

    Exposure of bovine estrogen receptor to the metal chelators EDTA and 1,10-phenanthroline results in a loss of nonspecific DNA binding, presumably because of the removal of "zinc finger" zinc. Nonspecific DNA binding, as measured by a DNA-cellulose binding assay, can be restored by dialysis of the aporeceptor against buffer containing zinc, cadmium, and cobalt but not with buffer containing copper or nickel. More detailed studies were carried out using a bacterially expressed polypeptide encompassing the DNA binding domain of the human estrogen receptor. Apopolypeptide fails to bind DNA specifically, as measured by mobility shift assay using a consensus estrogen response element hexamer containing oligonucleotide, but DNA binding was restored by dialysis of the apopolypeptide against buffer containing zinc, cadmium, and cobalt but not with buffer containing copper or nickel. Dissociation constants of zinc- and cadmium-reconstituted polypeptide for the estrogen response element hexamer (66 and 48 nM, respectively) are virtually indistinguishable from native polypeptide (Kd = 48 nM) whereas cobalt-reconstituted polypeptide has a lower affinity (Kd = 720 nM). However, native, zinc-, cadmium-, and cobalt-reconstituted polypeptides gave identical results in a methylation interference assay. Competition experiments with zinc and copper or nickel suggest that copper and nickel are able to bind to zinc finger residues but do so nonproductively. The relative affinities copper greater than cadmium greater than zinc greater than cobalt greater than nickel for the polypeptide were determined by a zinc blot competition assay. The ability of cadmium and cobalt to substitute for zinc in the zinc fingers demonstrates a structural "flexibility" in the DNA binding domain as each of these metals has slightly different ionic radii. On the other hand, subtle differences in DNA binding affinity and/or specificity could exist, which may not be detectable here. Also, the ability of metals

  13. Zinc poisoning

    Science.gov (United States)

    ... in many things, including: Compounds used to make paint, rubber, dyes, wood preservatives, and ointments Rust prevention coatings Vitamin and mineral supplements Zinc chloride Zinc oxide (relatively nonharmful) Zinc ...

  14. Improvement of the Thermoelectric Figure-of-Merit of a Doped Telluride Nanocomposite by Combining Phonon Scattering with Grain Boundary-Modifying Zn-Containing Nanostructures

    Science.gov (United States)

    Rowe, Michael P.; Zhou, Li Qin; Banerjee, Debasish; Zhang, Minjuan

    2015-01-01

    Recovery of waste heat from internal combustion engines is one strategy for meeting the ever increasing demand for more fuel efficient-automobiles. Thermoelectric materials are capable of this, by solid-state conversion of thermal to electrical energy, but the efficiency of this energy conversion requires improvement. In this work the thermoelectric figure of merit ( ZT) was improved by combining phonon scattering with grain boundary modification in a bismuth antimony telluride nanocomposite material with zinc antimony grain boundaries and zinc oxide nanoparticle inclusions. The advantage of including these zinc nanostructures is discussed. By reducing thermal conductivity while increasing the power factor, ZT was been increased from 0.6 to 1.1.

  15. 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...

  16. Living with wildfire in Telluride Fire Protection District, Colorado

    Science.gov (United States)

    James R. Meldrum; Lilia C. Falk; Jamie Gomez; Christopher M. Barth; Hannah Brenkert-Smith; Travis Warziniack; Patricia A. Champ

    2017-01-01

    Residents in the wildland-urban interface can play an important role in reducing wildfires’ negative effects by performing wildfire risk mitigation on their properties. This report offers insight into the wildfire risk mitigation activities and related considerations such as attitudes, experiences, and concern about wildfire, for residents of the Telluride Fire...

  17. Effect of a new condensation product on electrodeposition of zinc ...

    Indian Academy of Sciences (India)

    TECS

    properties (Baldwin and Smith 1996). However, due to their high toxicity and hydrogen embrittlement properties, alternate coatings to cadmium are being actively explored. (Ashur et al 1996; Safranck 1997; Basker Veeraraghavan et al 2003). The most commonly used sacrificial coating is zinc and its alloys. Zinc by virtue of ...

  18. Cadmium determination in urine by atomic absorption spectrometry as a screening test in industrial medicine

    Science.gov (United States)

    Lehnert, G.; Klavis, G.; Schaller, K. H.; Haas, T.

    1969-01-01

    Lehnert, G., Klavis, G., Schaller, K. H., and Haas, T. (1969).Brit. J. industr. Med.,26, 156-158. Cadmium determination in urine by atomic absorption spectrometry as a screening test in industrial medicine. Cadmium was determined by atomic absorption spectrometry in the urine and serum of 18 workers exposed to cadmium dust and fume in a zinc smelting plant. In all cases the concentrations of cadmium in the serum were within the normal range, but those in the urine were elevated. The elevated urine concentrations showed that the exposed group had taken up more cadmium than normal, although they showed no clinical symptoms of cadmium poisoning. Analysis of urine for cadmium is therefore of value in preventive medicine, and should be used for periodic check-ups on those occupationally exposed. PMID:5780108

  19. Cadmium sulfide membranes

    Science.gov (United States)

    Spanhel, Lubomir; Anderson, Marc A.

    1991-10-22

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  20. 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 following a chemical dipping technique called successive ion layer adsorption and ... SILAR; Cd:ZnO thin film; X-ray line broadening; SEM; optical bandgap. 1. Introduction. Zinc oxide possesses a unique position among semiconduct-.

  1. Adsorption of Acetic Acid, Cadmium ions, Lead ions and Iodine ...

    African Journals Online (AJOL)

    Michael Horsfall

    pesticides, as plant nutrients and as a constituent of waste products. These heavy metals may include cadmium, zinc ... effluent might contain non-biodegradable matter, toxic heavy metals, organic matter and also might ..... (2003) Wastewater Engineering Treatment and. Reuse, 4th Edition, Tata McGraw-Hill Publishing.

  2. Human seminal plasma cadmium: comparison with fertility and smoking habits.

    Science.gov (United States)

    Saaranen, M; Kantola, M; Saarikoski, S; Vanha-Perttula, T

    1989-01-01

    Cadmium, selenium and zinc were determined in seminal plasma and serum of 64 men by atomic absorption spectrometry (AAS). The mean (+/- SD) cadmium concentrations in seminal plasma and serum were 0.22 +/- 0.22 micrograms and 0.28 +/- 0.10 micrograms, respectively, but they did not correlate with each other. Smokers (n = 31) had significantly (p less than 0.01) higher serum cadmium concentrations than non-smokers (n = 31). Also seminal plasma cadmium in smokers was elevated, but a significant difference to non-smokers was only found if more than 20 cigarettes were consumed daily. No differences were found in semen quality and fertility between smokers and non-smokers. The seminal plasma cadmium had no correlation to selenium or zinc which, however, displayed a positive correlation (r = 0.852, p less than 0.001) to each other. It is concluded that smoking increases the exposure to cadmium. Although no obvious reproductive suppression was observed, heavy smoking may possibly enhance toxic effects in men under other detrimental exposures.

  3. Thermoelectric Micro-Refrigerator Based on Bismuth/Antimony Telluride

    Science.gov (United States)

    Dang, Linh Tuan; Dang, Tung Huu; Nguyen, Thao Thi Thu; Nguyen, Thuat Tran; Nguyen, Hue Minh; Nguyen, Tuyen Viet; Nguyen, Hung Quoc

    2017-06-01

    Thermoelectric micro-coolers based on bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) are important in many practical applications thanks to their compactness and fluid-free circulation. In this paper, we studied thermoelectric properties of bismuth/antimony telluride (Bi/SbTe) thin films prepared by the thermal co-evaporation method, which yielded among the best thermoelectric quality. Different co-evaporation conditions such as deposition flux ratio of materials and substrate temperature during deposition were investigated to optimize the thermoelectric figure␣of merit of these materials. Micron-size refrigerators were designed and fabricated using standard lithography and etching technique. A three-layer structure was introduced, including a p-type layer, an n-type layer and an aluminum layer. Next to the main cooler, a pair of smaller Bi/SbTe junctions was used as a thermocouple to directly measure electron temperature of the main device. Etching properties of the thermoelectric materials were investigated and optimized to support the fabrication process of the micro-refrigerator. We discuss our results and address possible applications.

  4. Next Generation Semiconductor-Based Radiation Detectors Using Cadmium Magnesium Telluride

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, Sudhir B [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Kutcher, Susan W [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Palsoz, Witold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Berding, Martha [SRI International, Menlo Park, CA (United States); Burger, Arnold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States)

    2014-11-17

    The primary objective of Phase I was to perform extensive studies on the purification, crystal growth and annealing procedures of CdMgTe to gain a clear understanding of the basic material properties to enable production of detector material with performance comparable to that of CdZnTe. Brimrose utilized prior experience in the growth and processing of II-VI crystals and produced high purity material and good quality single crystals of CdMgTe. Processing techniques for these crystals including annealing, mechanical and chemical polishing, surface passivation and electrode fabrication were developed. Techniques to characterize pertinent electronic characteristics were developed and gamma ray detectors were fabricated. Feasibility of the development of comprehensive defect modeling in this new class of material was demonstrated by our partner research institute SRI International, to compliment the experimental work. We successfully produced a CdMgTe detector that showed 662 keV gamma response with energy resolution of 3.4% (FWHM) at room temperature, without any additional signal correction. These results are comparable to existing CdZnTe (CZT) technology using the same detector size and testing conditions. We have successfully demonstrated detection of gamma-radiation from various isotopes/sources, using CdMgTe thus clearly proving the feasibility that CdMgTe is an excellent, low-cost alternative to CdZnTe.

  5. Density Functional Study of Electronic and Structural Properties of Gold-Cadmium Selenide/Telluride Nanoclusters

    Directory of Open Access Journals (Sweden)

    Shimeles T. Bulbula

    2015-01-01

    gold electrodes decrease as cluster size increases, whereas the binding energy shows a reverse relationship with the cluster size. However, a few clusters show special properties like AuCd2Se3 and AuCd2Te3 clusters.

  6. Thin film cadmium telluride charged particle sensors for large area neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J. W.; Smith, L.; Calkins, J.; Mejia, I.; Cantley, K. D.; Chapman, R. A.; Quevedo-Lopez, M.; Gnade, B., E-mail: gnade@utdallas.edu [Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Kunnen, G. R.; Allee, D. R. [Flexible Display Center, Arizona State University, Phoenix, Arizona 85284 (United States); Sastré-Hernández, J.; Contreras-Puente, G. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Mexico City 07738 (Mexico); Mendoza-Pérez, R. [Universidad Autónoma de la Ciudad de México, Mexico City 09790 (Mexico)

    2014-09-15

    Thin film semiconductor neutron detectors are an attractive candidate to replace {sup 3}He neutron detectors, due to the possibility of low cost manufacturing and the potential for large areas. Polycrystalline CdTe is found to be an excellent material for thin film charged particle detectors—an integral component of a thin film neutron detector. The devices presented here are characterized in terms of their response to alpha and gamma radiation. Individual alpha particles are detected with an intrinsic efficiency of >80%, while the devices are largely insensitive to gamma rays, which is desirable so that the detector does not give false positive counts from gamma rays. The capacitance-voltage behavior of the devices is studied and correlated to the response due to alpha radiation. When coupled with a boron-based neutron converting material, the CdTe detectors are capable of detecting thermal neutrons.

  7. Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.

    2011-07-01

    It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, in-line tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.

  8. Superstrate and substrate type cadmium telluride solar cells and monolithic integration of photovoltaic modules

    Science.gov (United States)

    Matulionis, Ilvydas

    This dissertation describes the fabrication of polycrystalline CdTe-based solar cells and monolithic integration of photovoltaic devices into modules using laser scribing. We have improved the efficiency of sputtered superstrate type CdTe solar cells, including devices with unconventionally thin absorber, built world-record efficiency substrate type CdTe solar cells, observed effects related to interfacial layers, and investigated the use of 7 different types of lasers for scribing of materials used for CdTe and CuInGaSe2 solar cells. We have fabricated CdTe/CdS solar cells using magnetron sputtering with conversion efficiencies of 12.5%. As the thickness of CdTe is reduced to less than 1 mum, devices still maintain efficiencies near 10%. Thinning of the CdTe layer would make manufacturing of solar modules more economical. We have built inverted (substrate) configuration CdTe solar cells with state-of-the-art efficiencies of 7.8%. We find that tellurium and sulfur interdiffusion is strongly inhibited in substrate type cells due to the fact that the CdS is grown on fully formed CdTe grains. We have optimized a sputtering process for aluminum-doped ZnO, achieved a resistivity of 5 x 10-4 O-cm, and fabricated 5.8% efficient substrate type CdTe solar cells with the ZnO:Al top contact. We have researched the effect of a high resistivity (HR) layer between the CdS and a transparent conducting oxide. Cells with the HR layer maintain higher efficiencies as the thickness of the CdS is reduced to 60 nm and less. We have investigated the use of 7 different types of lasers for scribing of the polycrystalline materials used for CdTe and CuIn(Ga)Se2 (CIGS) thin-film solar cells. The lasers included four different Nd:YAG (532 and 1064 nm), a Cu vapor (511 and 578 nm) and two excimers (308 and 248 nm). Pulse durations ranged from 0.1 to 250 ns. We find that most wavelength and pulse duration combinations work well for the thin-film materials. ZnO should be scribed with an ultraviolet wavelength laser. We have achieved best results for CIGS on Mo with longer pulse durations (250 ns). Ridges along the edges of scribe lines can be eliminated by adjustment of focus conditions.

  9. Processing, Fabrication and Characterization of Advanced Target Sensors Using Mercury Cadmium Telluride (MCT)

    Science.gov (United States)

    2010-09-01

    from the Si lattice parameter to the HgCdTe lattice parameter while still maintaining high quality crystalline material. In summary, a thin ZnTe ...MCT film had to be removed, standard PR such as AZ5214 cannot be used because of the selectivity issues. There will be substantial erosion of the

  10. Feasibility of a Hand-Held Integrating Dosimeter Using a Cadmium Telluride Detector

    Science.gov (United States)

    1986-09-26

    and photons (in the X-ray and gamma ray energy span). Electronic dosimeters developed for nuclear reactor appli- cations are not satisfactory for...also be added the man-made component due to any nuclear reactors or thermoelectric generators on board the spacecraft. In all cases found in the open...no [with flat (with linear (ft) (R/hr) extrap .] extrap .] extrap .] 19 0.0012 0.00338 0.00451 0.00585 13 0.0026 0.00698 0.00924 0.0121 9 0.0055 0.0148

  11. An ultrasensitive method for the determination of melamine using cadmium telluride quantum dots as fluorescence probes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiafei; Li, Jin; Kuang, Huiyan; Feng, Lei; Yi, Shoujun; Xia, Xiaodong; Huang, Haowen [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, Hunan University of Science and Technology, Xiangtan 411201 (China); Chen, Yong; Tang, Chunran [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Zeng, Yunlong, E-mail: yunlongzeng1955@126.com [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, Hunan University of Science and Technology, Xiangtan 411201 (China); State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2013-11-13

    Graphical abstract: Melamine takes place of the TGA on the surface of TGA-CdTe QDs with negative charge to form melamine coated QDs changing the surface charge of the QDs, resulting the fluorescence quenched as the QDs aggregation occurred by electrostatic attraction of the two opposite charged nanocrystals. -- Highlights: •An ultrasensitive and selective method for the determination of melamine was developed at pH 11.0. •The selectivity of the method was improved. •The sensitivity of the method enhanced obviously as the CdTe QDs have higher QYs at pH 11. •The sensitivity and linear range for the analysis are size dependent using QDs PL probes. •Melamine takes the place of TGA resulting fluorescence quenched of QDs. -- Abstract: An ultrasensitive and simple method for the determination of melamine was developed based on the fluorescence quenching of thioglycolic acid (TGA) capped CdTe quantum dots (QDs) at pH 11.0. In strong alkaline aqueous solution, the selectivity of the method has been greatly improved due to most heavy metal ions show no interference as they are in the precipitation form or in their anion form. Furthermore, CdTe quantum dots have higher quantum yields at higher pH. The method has a wider concentration range and lower detection limit. The influence factors on the determination of melamine were investigated and the optimum conditions were determined. Under optimum conditions, the fluorescence intensity change of TGA coated CdTe quantum dots was linearly proportional to melamine over a concentration range from 1.0 × 10{sup −11} to 1.0 × 10{sup −5} mol L{sup −1} with a correlation coefficient of 0.9943 and a detection limit of 5 × 10{sup −12} mol L{sup −1}. The mechanism of fluorescence quenching of the QDs has been proposed based on the infrared spectroscopy information and electrophoresis experiments in presence of melamine under alkaline condition. The proposed method was employed to detect trace melamine in milk powder and pet feeds with satisfactory results.

  12. Analytical bond-order potential for the cadmium telluride binary system

    Science.gov (United States)

    Ward, D. K.; Zhou, X. W.; Wong, B. M.; Doty, F. P.; Zimmerman, J. A.

    2012-03-01

    CdTe and Cd1-xZnxTe are the leading semiconductor compounds for both photovoltaic and radiation detection applications. The performance of these materials is sensitive to the presence of atomic-scale defects in the structures. To enable accurate studies of these defects using modern atomistic simulation technologies, we have developed a high-fidelity analytical bond-order potential for the CdTe system. This potential incorporates primary (σ) and secondary (π) bonding and the valence dependence of the heteroatom interactions. The functional forms of the potential are directly derived from quantum-mechanical tight-binding theory under the condition that the first two and first four levels of the expanded Green's function for the σ- and π-bond orders, respectively, are retained. The potential parameters are optimized using iteration cycles that include first-fitting properties of a variety of elemental and compound configurations (with coordination varying from 1 to 12) including small clusters, bulk lattices, defects, and surfaces, and then checking crystalline growth through vapor deposition simulations. It is demonstrated that this CdTe bond-order potential gives structural and property trends close to those seen in experiments and quantum-mechanical calculations and provides a good description of melting temperature, defect characteristics, and surface reconstructions of the CdTe compound. Most importantly, this potential captures the crystalline growth of the ground-state structures for Cd, Te, and CdTe phases in vapor deposition simulations.

  13. Disponibilidade, acúmulo e toxidez de cádmio e zinco em milho cultivado em solo contaminado Cadmium and zinc availability, accumulation and toxicity in maize grown in a contaminated soil

    Directory of Open Access Journals (Sweden)

    Karina Patrícia Vieira da Cunha

    2008-06-01

    ção das paredes celulares da epiderme e colênquima, do tecido vascular e da endoderme foi associado a níveis críticos tóxicos de Cd e de Zn no solo.A greenhouse experiment was carried out to evaluate: (a the soil Cd and Zn availability to maize plants with and without liming, using the DTPA, EDTA, Mehlich-1, and Mehlich-3 extractants; (b The effect of Cd and Zn doses on plant growth and metal accumulation in maize; and (c toxicity symptoms and anatomical changes in leaves and roots exposed to Cd and zinc. Maize was grown for 30 days in soil contaminated with either Cd (0, 1, 3, 5, 10, 20 mg kg-1 or Zn (0, 10, 30, 50, 100, 150 mg kg-1. Highly significant correlations were found between all extractants tested and metal plant contents. The metal addition to soil reduced biomass production and increased Cd and Zn plant contents. The critical toxicity value for Cd in soil varied from 8.7 to 13.1 mg kg-1, whereas for Zn this value lied between 74.1 to 110.7 mg kg-1, depending on liming and extractant type. Interveinal and marginal chlorosis together with necrosis in the leaf apex and along the margins were observed for Zn treatments. On the other hand, leaf chlorosis, shriveling and curling were the most common symptoms in cadmium-damaged plants. Increased cell wall lignification in vascular tissues, epidermis, collenchyma, and endoderm cells were associated to critical toxicity values of Cd and Zn in soil.

  14. 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

  15. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals

    CERN Document Server

    Tu, Renyong; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; De Trizio, Luca; Manna, Liberato

    2016-01-01

    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e. with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2- xTe particles could be more easily deformed to match the anion framework of t...

  16. 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.

  17. 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...

  18. High Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk Alloys.

    Science.gov (United States)

    Poudel, B.; Hao, Q.; Ma, Y.; Minnich, A.; Muto, A.; Lan, Y. C.; Yu, B.; Yan, X.; Wang, D. Z.; Vashaee, D.; Chen, X. Y.; Dresselhaus, M. S.; Chen, G.; Ren, Z. F.

    2008-03-01

    Bismuth Telluride and its alloys are best thermoelectric materials for near room temperature applications like refrigeration and waste heat recovery. We have been pursuing an approach of random nanostructures in bulk to improve ZT of these materials. Here we report that ZT values of these random nanostructured materials were improved significantly over the state-of-the-art values. Experimental data coupled with microstructure studies and modeling shows that the ZT improvement mainly comes from a lower thermal conductivity because of the increased phonon scattering by defects and grain boundaries. Significantly improved power generation and cooling data produced from these samples confirmed the high ZT values.

  19. Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland

    DEFF Research Database (Denmark)

    Sonne-Hansen, C; Dietz, R; Leifsson, P S

    2002-01-01

    of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined...... or osteodystrophy. This might be explained by the composition of the ringed seals diet, which contains high levels of vitamin D, calcium, phosphorus, zinc, selenium and protein. These elements are all likely to counteract cadmium-induced damage. It is speculated that ringed seal are not particularly vulnerable......The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose...

  20. Mechanisms of cadmium carcinogenicity in the gastrointestinal tract.

    Science.gov (United States)

    Bishak, Yaser Khaje; Payahoo, Laleh; Osatdrahimi, Alireza; Nourazarian, Alireza

    2015-01-01

    Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer- related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

  1. Modeling the Growth of Aluminum Gallium Nitride ((Al)GaN) Films Grown on Aluminum Nitride (AlN) Substrates

    Science.gov (United States)

    2011-03-01

    cadmium zinc telluride ( CdZnTe or CZT) on Si using a superlattice (SL) in which the SL layers had different compositions (10). We found that the...Abbreviations, and Acronyms (Al)GaN aluminum gallium arsenide AlN aluminum nitride ARL U.S. Army Research Laboratory CdZnTe or CZT cadmium zinc

  2. Cadmium-induced olfactory dysfunction in rainbow trout: Effects of binary and quaternary metal mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Dew, William A. [Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4 (Canada); Department of Biology, Trent University, Peterborough, Ontario K9 J 7B8 (Canada); Veldhoen, Nik; Carew, Amanda C.; Helbing, Caren C. [Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8 P 5C2 Canada (Canada); Pyle, Greg G., E-mail: gregory.pyle@uleth.ca [Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4 (Canada)

    2016-03-15

    Highlights: • Cadmium impairs the olfactory response of rainbow trout. • Nickel and zinc, but not copper, protect against Cd-induced olfactory dysfunction. • Calcium, sodium, and magnesium also protect against the effect of cadmium. • Protection from cadmium is most likely not due to metallothionein expression. - Abstract: A functioning olfactory response is essential for fish to be able to undertake essential behaviors. The majority of work investigating the effects of metals on the olfactory response of fish has focused on single-metal exposures. In this study we exposed rainbow trout to cadmium, copper, nickel, zinc, or a mixture of these four metals at or below the current Canadian Council of Ministers of the Environment guidelines for the protection of aquatic life. Measurement of olfactory acuity using an electro-olfactogram demonstrated that cadmium causes significant impairment of the entire olfactory system, while the other three metals or the mixture of all four metals did not. Binary mixtures with cadmium and each of the other metals demonstrated that nickel and zinc, but not copper, protect against cadmium-induced olfactory dysfunction. Testing was done to determine if the protection from cadmium-induced olfactory dysfunction could be explained by binding competition between cadmium and the other metals at the cell surface, or if the protection could be explained by an up-regulation of an intracellular detoxification pathway, namely metallothionein. This study is the first to measure the effects of binary and quaternary metal mixtures on the olfactory response of fish, something that will aid in future assessments of the effects of metals on the environment.

  3. Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans

    Directory of Open Access Journals (Sweden)

    Yona J. Essig

    2016-02-01

    Full Text Available Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS, an enzyme involved in the biosynthesis of phytochelatins (PCs, plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1 is transcriptionally non-responsive to a chronic (48 h insult of high levels of zinc (500 μM or acute (3 h exposures to high levels of cadmium (300 μM. However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748 knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans.

  4. Optical Properties and Surface Morphology of Zinc Telluride Thin Films Prepared by Stacked Elemental Layer Method

    Directory of Open Access Journals (Sweden)

    Subramani SHANMUGAN

    2012-06-01

    Full Text Available ZnTe thin films were prepared by Stacking of elemental (Zn and Te layers (SEL followed by inert gas annealing. The optical parameters were calculated from the transmission spectra. The bandgap of the annealed samples was found between 1.95 eV and 2.06 eV. The change in film thickness after annealing was observed using cross sectional SEM image of the annealed samples. The surface morphology of the annealed Te/Zn stack was also analyzed and observed as very smooth, compact and dense surface. The prepared film was Zn rich evidenced by EDAX. The observed result encourages in pursuing the SEL method for the preparation of compound semiconductor from II-VI group materials.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1908

  5. Calcium enhances cadmium tolerance and decreases cadmium ...

    African Journals Online (AJOL)

    These results suggest that cadmium uptake in lettuce plants is negatively associated with the presence of calcium in the culture medium, maybe due to a competition between these two cations for binding and absorption sites in roots. In conclusion, the results suggest that fertilization with Ca2+ appears to be a promising ...

  6. 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.

  7. Induction of c-myc and c-jun proto-oncogene expression in rat L6 myoblasts by cadmium is inhibited by zinc preinduction of the metallothionein gene

    Energy Technology Data Exchange (ETDEWEB)

    Abshire, M.K.; Buzard, G.S.; Shiraishi, Noriyuki; Waalkers, M.P. [National Cancer Institute, Fredrick, MD (United States)

    1996-07-01

    Certain proto-oncogenes transfer growth regulatory signals from the cell surface to the nucleus. These genes often show activation soon after cells are exposed to mitogenic stimulation but can also be activated as a nonmitogenic stress response. Cadmium (Cd) is a carcinogenic metal in humans and rodents and, though its mechanism of action is unknown, it could involve activation of such proto-oncogenes. Metallothionein (MT), a metal-inducible protein that binds Cd, can protect against many aspects of Cd toxicity, including genotoxicity and possibly carcinogenesis. Thus, the effects of Cd on expression of c-myc and c-jun in rat L6 myoblasts, and the effect of preactivation of the MT gene by Zn treatment on such oncogene expression, were studied. MT protein levels were measured using oligonucleotide hybridization and standardized to {beta}-actin levels. Cd (5 {mu}M CdCl{sub 2}, 0-30 h) stimulated both c-myc and c-jun mRNA expression. An initial peak of activation of c-myc expression occurred 2 h after initiation of Cd exposure, and levels remained elevated throughout the assessment period. Zn pretreatment markedly reduced the activation of c-myc expression by Cd compared to cells not receiving Zn pretreatment. Cd treatment increased c-jun mRNA levels by up to 3.5-fold. Again, Zn pretreatment markedly reduced. 10 refs., 8 figs.

  8. Surfactant-directed synthesis of branched bismuth telluride/sulfide core/shell nanorods.

    Science.gov (United States)

    Purkayastha, Arup; Yan, Qingyu; Raghuveer, Makala S; Gandhi, Darshan D; Li, Huafang; Liu, Zhong W; Ramanujan, Raju V; Borca-Tasciuc, Theodorian; Ramanath, Ganapathiraman

    2008-07-17

    Branched core/shell bismuth telluride/bismuth sulfide nanorod heterostructures are prepared by using a biomimetic surfactant, L-glutathionic acid. Trigonal nanocrystals of bismuth telluride are encapsulated by nanoscopic shells of orthorhombic bismuth sulfide. Crystallographic twinning causes shell branching. Such heteronanostructures are attractive for thermoelectric power generation and cooling applications. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. SOLID PHASE EXTRACTION OF TRACE AMOUNTS OF ZINC AND ...

    African Journals Online (AJOL)

    ABSTRACT. A novel method using a packed column with perlite as a new sorbent has been developed for preconcentration of trace amounts of zinc and cadmium prior to their determination by flame atomic absorption spectrometry. Several factors that may be affected on the solid phase extraction (SPE) process, such as ...

  10. Rhizopus stolonifer mediated biosynthesis of biocompatible cadmium chalcogenide quantum dots.

    Science.gov (United States)

    Mareeswari, P; Brijitta, J; Harikrishna Etti, S; Meganathan, C; Kaliaraj, Gobi Saravanan

    2016-12-01

    We report an efficient method to biosynthesize biocompatible cadmium telluride and cadmium sulphide quantum dots from the fungus Rhizopus stolonifer. The suspension of the quantum dots exhibited purple and greenish-blue luminescence respectively upon UV light illumination. Photoluminescence spectroscopy, X-ray diffraction, and transmission electron microscopy confirms the formation of the quantum dots. From the photoluminescence spectrum the emission maxima is found to be 424 and 476nm respectively. The X-ray diffraction of the quantum dots matches with results reported in literature. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for cell viability evaluation carried out on 3-days transfer, inoculum 3×10(5) cells, embryonic fibroblast cells lines shows that more than 80% of the cells are viable even after 48h, indicating the biocompatible nature of the quantum dots. A good contrast in imaging has been obtained upon incorporating the quantum dots in human breast adenocarcinoma Michigan Cancer Foundation-7 cell lines. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Bioaccumulation of copper, zinc, cadmium and lead by Bacillus sp., Bacillus cereus, Bacillus sphaericus and Bacillus subtilis Bioacumulação de cobre, zinco, cádmio e chumbo por Bacillus sp., Bacillus cereus, Bacillus sphaericus e Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Augusto da Costa

    2001-03-01

    Full Text Available This work presents some results on the use of microbes from the genus Bacillus for uptake of cadmium, zinc, copper and lead ions. Maximum copper bioaccumulations were 5.6 mol/g biomass for B. sphaericus, 5.9 mol/g biomass for B. cereus and B. subtilis, and 6.4 mol/g biomass for Bacillus sp. Maximum zinc bioaccumulations were 4.3 mol/g biomass for B. sphaericus, 4.6 mol/g biomass for B. cereus, 4.8 mol/g biomass for Bacillus sp. and 5.0 mol/g biomass for B. subtilis. Maximum cadmium bioaccumulations were 8.0 mol/g biomass for B. cereus, 9.5 mol/g biomass for B. subtilis, 10.8 mol/g biomass for Bacillus sp. and 11.8 mol/g biomass for B. sphaericus. Maximum lead biomaccumulations were 0.7 mol/g biomass for B. sphaericus, 1.1 mol/g biomass for B. cereus, 1.4 mol/g biomass for Bacillus sp. and 1.8 mol/g biomass for B. subtilis. The different Bacillus strains tested presented distinct uptake capacities, and the best results were obtained for B. subtilis and B. cereus.Este trabalho apresenta resultados de acumulação dos íons metálicos cádmio, zinco, cobre e chumbo por bactérias do gênero Bacillus. A bioacumulação máxima de cobre foi 5,6 mol/g biomassa para B. sphaericus, 5,9 mol/g biomassa para B. cereus e B. subtilis, e 6,4 mol/g biomassa para Bacillus sp.. A bioacumulação máxima de zinco foi 4,3 mol/g biomassa para B. sphaericus, 4,6 mol/g biomassa para B. cereus, 4,8 mol/g biomassa para Bacillus sp. e 5,0 mol/g biomassa para B. subtilis. A bioacumulação máxima de cádmio foi 8,0 mol/g biomassa para B. cereus, 9,5 mol/g biomassa para B. subtilis, 10,8 mol/g biomassa para Bacillus sp. e 11,8 mol/g biomassa para B. sphaericus. A bioacumulação máxima de chumbo foi 0,7 mol/g biomassa para B. sphaericus, 1,1 mol/g biomassa para B. cereus, 1,4 mol/g biomassa para Bacillus sp. e 1,8 mol/g biomassa para B. subtilis. As distintas linhagens de Bacillus testadas apresentaram variáveis capacidades de carregamento de íons metálicos, sendo os

  12. Construction of new iodide selective electrodes based on bis(trans-cinnamaldehyde)1,3-propanediimine(L) zinc(II) chloride [ZnLCl{sub 2}] and bis(trans-cinnamaldehyde) 1,3-propanediimine(L) cadmium(II) chloride [CdLCl{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, M., E-mail: m_ghaedi@mail.yu.ac.ir; Montazerozohori, M.; Mousavi, A.; Khodadoust, S.; Mansouri, M.

    2012-04-01

    New plasticized PVC membranes iodide selective electrodes have been prepared by incorporating bis(trans-cinnamaldehyde)1,3-propanediimine zinc(II) chloride [ZnLCl2] and bis(trans-cinnamaldehyde) 1,3-propandiimine cadmium(II) chloride [CdLCl2] on the surface of graphite disk electrodes. At optimum value of variables the proposed electrodes have selective response to iodide with respect to a number of inorganic and organic anions with near-Nernstian slopes of - 60 {+-} 1.9 and - 58.5 {+-} 1.9 mV/decade of iodide concentration over the range 1.0 Multiplication-Sign 10{sup -6}-1.0 Multiplication-Sign 10{sup -1} M with detection limits of 4.0 Multiplication-Sign 10{sup -7} and 3.0 Multiplication-Sign 10{sup -7} M for the electrodes based on [ZnLCl{sub 2}] and [CdLCl{sub 2}], respectively. The electrodes based on both ionophores have response times of about (6 s), with stable reproducible response during 2 months, while their responses is independent of pH over the range 2.5-10.5. The proposed electrodes successfully have been applied for evaluation of iodide ion content in real samples with complicated matrices including water and pharmaceutical samples. - Highlights: Black-Right-Pointing-Pointer New ionophores have been synthesized for the first time in our laboratory. Black-Right-Pointing-Pointer The ionophores were made from inexpensive materials. Black-Right-Pointing-Pointer These Schiff bases synthesized for Zn{sup +2}, Cd{sup +2} ions.

  13. Sensitivity to cadmium-induced genotoxicity in rat testicular cells is associated with minimal expression of the metallothionein gene.

    Science.gov (United States)

    Shiraishi, N; Hochadel, J F; Coogan, T P; Koropatnick, J; Waalkes, M P

    1995-02-01

    Cadmium is a carcinogenic metal. Although the mechanism of tumor induction is unknown, DNA/metal interactions may be involved. Metallothionein can protect against cadmium toxicity in our previous work it was shown to reduce cadmium genotoxicity in cultured cells. To extend these results, the genotoxicity of cadmium was studied in R2C cells, a rat testicular Leydig cell line. The R2C cells were very sensitive to cadmium-induced single-strand DNA damage (SSD), as measured by alkaline elution. SSD occurred in R2C cells after treatment with 25 and 50 microM CdCl2 for 2 hr. Prior work showed other cells required much higher levels of cadmium (approximately 500 microM) to induce genotoxicity. The genotoxic levels of cadmium (25-50 microM) were not cytotoxic in R2C cells as assessed by a metabolic activity (MTT) assay. Pretreatment of R2C cells with a low cadmium dose (2 microM, 24 hr) had no effect on cadmium-induced SSD, in contrast to prior work in other cells where such pretreatments reduced SSD through metallothionein gene activation. In fact, cadmium or zinc treatments resulted in little or no increase in metallothionein gene expression in R2C cells as determined by Northern blot analysis for metallothionein mRNA using cDNA or oligonucleotide probes and radioimmunoassay for metallothionein protein production. Basal metallothionein mRNA was essentially nondetectable. Induction of a cadmium-binding protein in R2C cells did occur, as determined by Cd-heme assay, but did not induce tolerance to SSD. In vivo, the Leydig cell is a target for cadmium carcinogenicity and its cadmium-binding protein is thought not to be a true metallothionein. These results indicate that R2C cells are sensitive to cadmium-induced genotoxicity and that this sensitivity is associated with minimal expression of the metallothionein gene.

  14. Regional modeling of cadmium leaching to groundwater in the Kempen region, The Netherlands

    Science.gov (United States)

    van der Grift, B.; Rozemeijer, J. C.; Griffioen, J.

    2003-04-01

    Sandy soils in the border area of Belgium and the Netherlands (the Kempen region), are heavily contaminated with cadmium and zinc by atmospheric deposition from nearby smelters. Leaching of heavy metals from the topsoil is a major risk for groundwater contamination. The sandy soils in the Kempen area are vulnerable for leaching due to the acidifying conditions in these soils. Regional modeling of groundwater contamination by leaching of cadmium from soils in a diffusely polluted area is the subject of this study. An attempt has been made to model the present and predict the future concentrations of cadmium in shallow groundwater and the metal binding processes in the unsaturated zone in the total Kempen area. Leaching of cadmium is spatially highly variable. It depends on the soil type, the groundwater depth and cadmium input concentrations. In the Kempen area, the heavy metal load to the soil is controlled mostly by atmospheric deposition and the net rainwater infiltration. The atmospheric deposition of cadmium decreases strongly with the distance from the zinc smelters. In the mid-seventies, a change in production processes caused a sharp decline of cadmium emission. There is no temporal or spatial data available about the (historic) atmospheric deposition of cadmium covering the total Kempen region. Therefore, the atmospheric deposition of cadmium was reconstructed from the analyzed cadmium content in forest soil samples. Forest soil samples were chosen because the cadmium contents in these soils are not influenced by the use of manure, (lime) fertilizers and sewage sludge. For 13 locations with varying distances from the smelters the historic atmospheric deposition of cadmium was calculated by iteration with the analyzed cadmium content in the soil. Cadmium adsorption coefficients (K_F) for the individual locations, which are needed for these calculations, were derived with existing meta-models as a function of soil properties like pH, organic matter and clay

  15. Crystal structure of (4,4′-bipyridyl-κNbis[N-(2-hydroxyethyl-N-isopropyldithiocarbamato-κ2S,S′]zinc(II–4,4′-bipyridyl (2/1 and its isostructural cadmium(II analogue

    Directory of Open Access Journals (Sweden)

    Yee Seng Tan

    2017-11-01

    Full Text Available The title structures, [M(C6H12NOS22(C10H8N2]·0.5C10H8N2, for M = Zn, (I, and Cd, (II, feature terminally bound 4,4′-bipyridyl ligands and non-coordinating 4,4′-bipyridyl molecules, with the latter disposed about a centre of inversion. The coordination geometry about the metal atom is defined by two non-symmetrically chelating dithiocarbamate ligands and a pyridyl N atom. The NS4 donor sets are distorted but, approximate to trigonal bipyramidal in each case. In the crystal, hydroxy-O—H...O(hydroxy and hydroxy-O—H...N(pyridyl hydrogen bonds between the zinc-containing molecules lead to a supramolecular layer parallel to (100. The three-dimensional architecture arises as the layers are linked via methine-C—H...S, pyridyl-C—H...O(hydroxy and π–π [inter-centroid distance between coordinated pyridyl rings = 3.6246 (18 Å] interactions. Channels along the c-axis direction are occupied by the non-coordinating 4,4′-bipyridine molecules, which are held in place by C—H...π(chelate ring contacts.

  16. Cadmium analysis using field deployable nano-band electrode system and its removal using electrocoagulation

    Science.gov (United States)

    Guttula, Mallikarjuna Murthy

    Cadmium (Cd) is an extremely toxic metal commonly found in industrial workplaces. Major industrial releases of Cd stem from waste streams, leaching of landfills, and from a variety of operations that involve cadmium or zinc. Particularly, cadmium can be released to drinking water from the corrosion of some galvanized plumbing and water main pipe materials. The United State Environmental Protection Agency (USEPA) has set the Maximum Contaminant Level (MCL) for cadmium at 5 ppb. Long term exposure of cadmium above the MCL results in kidney, liver, bone and blood damage. An accurate and rapid measurement of cadmium in the field remains a technical challenge. In this work, a relatively new method of a Nano-Band Electrode system using anodic stripping voltammetry was optimized by changing deposition potential, electrolyte, and plating time. We efficiently used Electrocoagulation remove cadmium from wastewater and obtained a removal efficiency of +/-99%. Removal mechanism of cadmium in electrocoagulation was also proposed with the help of X-ray Diffraction (XRD), Attenuated Total Reflection - Fourier Transform Infra Red Spectroscopy (ATR-FTIR), and Scanning Electron Microscopy and Energy Dispersive Spectrometer (SEM-EDS).

  17. Regional modeling of cadmium leaching to groundwater in the Kempen region, The Netherlands

    NARCIS (Netherlands)

    van der Grift, B.|info:eu-repo/dai/nl/373433484; Rozemeijer, J. C.|info:eu-repo/dai/nl/304838403; Griffioen, J.|info:eu-repo/dai/nl/091129265

    2003-01-01

    Sandy soils in the border area of Belgium and the Netherlands (the Kempen region), are heavily contaminated with cadmium and zinc by atmospheric deposition from nearby smelters. Leaching of heavy metals from the topsoil is a major risk for groundwater contamination. The sandy soils in the Kempen

  18. Cadmium may impair prostate function as measured by Prostate Specific Antigen in semen

    DEFF Research Database (Denmark)

    Andreucci, Alessandro; Mocevic, Emina; Jönsson, Bo A

    2015-01-01

    We investigated the association between cadmium in blood and the concentration of the prostate specific antigen (PSA) in semen, including the modifying effects of zinc or the CAG polymorphism in the androgen receptor (AR). Blood and semen samples were collected from 504 partners of pregnant women...

  19. Mechanical properties of thermoelectric lanthanum telluride from quantum mechanics

    Science.gov (United States)

    Li, Guodong; Aydemir, Umut; Wood, Max; Goddard, William A., III; Zhai, Pengcheng; Zhang, Qingjie; Snyder, G. Jeffrey

    2017-07-01

    Lanthanum telluride (La3Te4) is an n-type high-performance thermoelectric material in the high temperature range, but its mechanical properties remain unknown. Since we want robust mechanical properties for their integration into industrial applications, we report here quantum mechanics (QM) simulations to determine the ideal strength and deformation mechanisms of La3Te4 under pure shear deformations. Among all plausible shear deformation paths, we find that shearing along the (0 0 1)/text{1} 0 0> slip system has the lowest ideal shear strength of 0.99 GPa, making it the most likely slip system to be activated under pressure. We find that the long range La-Te ionic interactions play the predominant role in resisting shear deformation. To enhance the mechanical strength, we suggest improving the long ionic La-Te bond stiffness to strengthen the ionic La-Te framework in La3Te4 by a defect-engineering strategy, such as partial substitution of La by Ce or Pr having isotypic crystal structures. This work provides the fundamental information to understand the intrinsic mechanics of La3Te4.

  20. Chemical synthesis and supercapacitive properties of lanthanum telluride thin film.

    Science.gov (United States)

    Patil, S J; Lokhande, A C; Lee, D-W; Kim, J H; Lokhande, C D

    2017-03-15

    Lanthanum telluride (La2Te3) thin films are synthesized via a successive ionic layer adsorption and reaction (SILAR) method. The crystal structure, surface morphology and surface wettability properties are investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and contact angle goniometer techniques, respectively. The La2Te3 material exhibits a specific surface area of 51m2g-1 determined by Brunauer-Emmett-Teller (BET) method. La2Te3 thin film electrode has a hydrophilic surface which consists of interconnected pine leaf-like flaky arrays that affect the performance of the supercapacitor. The supercapacitive performance of La2Te3 film electrode is evaluated in 1M LiClO4/PC electrolyte using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy techniques. La2Te3 film electrode exhibits a specific capacitance of 194Fg-1 at a scan rate of 5mVs-1 and stored energy density of 60Whkg-1 with delivering power density of 7.22kWkg-1. La2Te3 film electrode showed capacitive retention of 82% over 1000cycles at a scan rate of 100mVs-1. Further, flexible La2Te3|LiClO4-PVA|La2Te3 supercapacitor cell is fabricated. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Process dependent thermoelectric properties of EDTA assisted bismuth telluride

    Energy Technology Data Exchange (ETDEWEB)

    Kulsi, Chiranjit; Banerjee, Dipali, E-mail: dipalibanerjeebesu@gmail.com [Department of Physics, Indian Institute of Engineering Science and Technology, Shibpur, Howrah-711103, West Bengal (India); Kargupta, Kajari [Chemical Engineering Department, Jadavpur University, Kolkata-700032, West Bengal (India)

    2016-04-13

    Comparison between the structure and thermoelectric properties of EDTA (Ethylene-diamine-tetra-acetic acid) assisted bismuth telluride prepared by electrochemical deposition and hydrothermal route is reported in the present work. The prepared samples have been structurally characterized by high resolution X-ray diffraction spectra (HRXRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopic images (HRTEM). Crystallite size and strain have been determined from Williamson-Hall plot of XRD which is in conformity with TEM images. Measurement of transport properties show sample in the pellet form (S{sub 1}) prepared via hydrothermal route has higher value of thermoelectric power (S) than the electrodeposited film (S{sub 2}). But due to a substantial increase in the electrical conductivity (σ) of the film (S{sub 2}) over the pellet (S{sub 1}), the power factor and the figure of merit is higher for sample S{sub 2} than the sample S{sub 1} at room temperature.

  2. Enhancement of the thermoelectric performance of oxygen substituted bismuth telluride

    Science.gov (United States)

    Van Quang, Tran; Kim, Miyoung

    2017-12-01

    We carried out first-principles calculations based on density functional theory and the semi-classical Boltzmann transport theory to study the effect of oxygen substitution on the electronic structure and thermoelectric properties of bismuth telluride. The newly formed compound, Bi2O2Te, is found to be a narrow bandgap semiconductor with the bandgap of Eg = 0.13 eV. The presence of a flat band close to the valence band maximum gives rise to a steep slope of density of states near Fermi energy, leading to a significant enhancement of the Seebeck coefficient. As a result, the thermoelectric power factor of Bi2O2Te is significantly improved by controlling the carrier concentration, and the maximum power factor increased with temperature. Assuming the experiment-thermal conductivity, Bi2O2Te exhibits a high figure of merit of ZT ˜1.27 around 600 K for the p-type doping, which matches or exceeds ZT of the state-of-the-art thermoelectric materials in this temperature range. This suggests that Bi2O2Te with p-type doping is a new promising material for use in the moderate-temperature thermoelectric energy conversion.

  3. Inverting polar domains via electrical pulsing in metallic germanium telluride

    Science.gov (United States)

    Nukala, Pavan; Ren, Mingliang; Agarwal, Rahul; Berger, Jacob; Liu, Gerui; Johnson, A. T. Charlie; Agarwal, Ritesh

    2017-04-01

    Germanium telluride (GeTe) is both polar and metallic, an unusual combination of properties in any material system. The large concentration of free-carriers in GeTe precludes the coupling of external electric field with internal polarization, rendering it ineffective for conventional ferroelectric applications and polarization switching. Here we investigate alternate ways of coupling the polar domains in GeTe to external electrical stimuli through optical second harmonic generation polarimetry and in situ TEM electrical testing on single-crystalline GeTe nanowires. We show that anti-phase boundaries, created from current pulses (heat shocks), invert the polarization of selective domains resulting in reorganization of certain 71o domain boundaries into 109o boundaries. These boundaries subsequently interact and evolve with the partial dislocations, which migrate from domain to domain with the carrier-wind force (electrical current). This work suggests that current pulses and carrier-wind force could be external stimuli for domain engineering in ferroelectrics with significant current leakage.

  4. Toxicity of cadmium to grapevine

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, D.; Ruehl, E.; Alleweldt, G.

    1985-01-01

    Cuttings of the cv. Riesling were cultivated in nutrient solutions with different amounts of cadmium. Cadmium inhibited the growth of shoot and of leaf area and produced chlorosis, necroses and leaf deformations. Old leaves showed no symptoms at all, but with high cadmium levels leaf fall occurred. The threshold of cadmium damage was beneath a level of 0.1 ppm Cd of the nutrient solution. The dry matter production of the plants was reduced by cadmium: 0.66 mg Cd/l of nutrient solution caused an inhibition of 50%. Cadmium reduced the chlorophyll content of the leaves. The transport of iron from roots to leaves was inhibited nearly completely by medium to high levels of cadmium (1.0, 3.0, 10.0 ppm). Iron was accumulated in the roots. Thus cadmium may have caused an iron deficiency chlorosis in grapevines. The uptake of cadmium showed a clear dependence on the amount of cadmium in the nutrient solution. Within the plants, decreasing amounts of cadmium were found following the pattern roots - stem - leaves.

  5. Distribution and speciation of cadmium in the terrestrial snail, Helix aspersa

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, M.; Jackson, A.; Nickless, G.; Roberts, D.J.

    1979-11-01

    Cadmium is taken up by terrestrial snails living in an environment with a relatively high cadmium concentration. The metal becomes bound to protein with a molecular weight of approximately 22,000 daltons. This cadmium-protein complex concentrates in the digestive gland and is present in a form which is soluble in water, (though difficult to extract efficiently). That no efficient excretion mechanism exists for this soluble complex implies that it cannot traverse the cell wall. The failure to observe a metal-free M2 strongly suggests that formation of M2 is induced by metal insult rather than M2 being naturally present to guard against an increase in zinc and cadmium uptake.

  6. Near Infrared Quantum Cutting Luminescence of Er3+/Tm3+ Ion Pairs in a Telluride Glass.

    Science.gov (United States)

    Chen, Xiaobo; Li, Song; Hu, Lili; Wang, Kezhi; Zhao, Guoying; He, Lizhu; Liu, Jinying; Yu, Chunlei; Tao, Jingfu; Lin, Wei; Yang, Guojian; Salamo, Gregory J

    2017-05-16

    The multiphoton near-infrared, quantum cutting luminescence in Er3+/Tm3+ co-doped telluride glass was studied. We found that the near-infrared 1800-nm luminescence intensity of (A) Er3+(8%)Tm3+(0.5%):telluride glass was approximately 4.4 to 19.5 times larger than that of (B) Tm3+(0.5%):telluride glass, and approximately 5.0 times larger than that of (C) Er3+(0.5%):telluride glass. Additionally, the infrared excitation spectra of the 1800 nm luminescence, as well as the visible excitation spectra of the 522 nm and 652 nm luminescence, of (A) Er3+(8%)Tm3+(0.5%):telluride glass are very similar to those of Er3+ ions in (C) Er3+(0.5%):telluride glass, with respect to the shapes of their excitation spectral waveforms and peak wavelengths. Moreover, we found that there is a strong spectral overlap and energy transfer between the infrared luminescence of Er3+ donor ions and the infrared absorption of Tm3+ acceptor ions. The efficiency of this energy transfer {4I13/2(Er3+) → 4I15/2(Er3+), 3H6(Tm3+) → 3F4(Tm3+)} between the Er3+ and Tm3+ ions is approximately 69.8%. Therefore, we can conclude that the observed behaviour is an interesting multiphoton, near-infrared, quantum cutting luminescence phenomenon that occurs in novel Er3+-Tm3+ ion pairs. These findings are significant for the development of next-generation environmentally friendly germanium solar cells, and near-to-mid infrared (1.8-2.0 μm) lasers pumped by GaN light emitting diodes.

  7. Blood and urine cadmium and bioelements profile in nickel-cadmium battery workers in Serbia.

    Science.gov (United States)

    Bulat, Z Plamenac; Dukic-Cosic, D; Dokic, M; Bulat, P; Matovic, V

    2009-03-01

    Although cadmium (Cd) is extensively used for nickel-cadmium battery production, few recent reports are available on the effect of this toxic metal on the imbalance of biometals in occupational exposure. The current study was carried out to determine the Cd level and its effect on the content of bioelements: zinc, cooper, magnesium, and iron in blood and urine of workers exposed to Cd during nickel-cadmium battery production. beta(2)-microglobulins (beta(2)-MG), as indicators of kidney damage, were determined in urine.The study group comprised 32 male nickel-cadmium battery workers, and the control group had 15 male construction workers with no history of Cd exposure. Levels of Cd and bioelements were determined in blood and urine by atomic absorption spectrophotometry.Cd concentration in blood of exposed workers was around 10 microg/L and in urine ranged from 1.93 to 8.76 microg/g creatinine (cr). Urine Cd concentration was significantly higher in exposed workers than in the controls, although no statistical difference in beta(2)-MG content was observed in urine between the two groups. Blood Zn and Mg level were significantly reduced and urine Zn level was increased in Cd-exposed group when compared with controls.The mean Cd concentrations in blood and urine did not exceed the recommended reference values of 10 microg/L in blood and 10 microg/g cr in urine. Cd exposure resulted in disturbances of Zn in blood and urine and Mg in blood but had no effect on Cu and Fe content in biological fluids.

  8. Fabrication of Nanovoid-Imbedded Bismuth Telluride with Low Dimensional System

    Science.gov (United States)

    Chu, Sang-Hyon (Inventor); Choi, Sang H. (Inventor); Kim, Jae-Woo (Inventor); Park, Yeonjoon (Inventor); Elliott, James R. (Inventor); King, Glen C. (Inventor); Stoakley, Diane M. (Inventor)

    2013-01-01

    A new fabrication method for nanovoids-imbedded bismuth telluride (Bi--Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi--Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

  9. Telluride glasses with far-infrared transmission up to 35 μm

    Science.gov (United States)

    Le Coq, David; Cui, Shuo; Boussard-Plédel, Catherine; Masselin, Pascal; Bychkov, Eugène; Bureau, Bruno

    2017-10-01

    Telluride glasses are very attractive due to their unique infrared transparency window compared to other chalcogenide glasses. The extension of their infrared transmission by changing the composition appears to be very challenging. Glasses in the (GeTe4)100-x(AgI)x system, with 5 ≤ x ≤ 30 have been synthesized using the melt-quenching method. The effect of the addition of silver iodide is a widening of the infrared transparency range up to 35 μm that is much larger than for any other chalcogenide glass families. Moreover, the moulding of these telluride glasses is also achievable without affecting the optical properties.

  10. Cadmium-109 and methyl mercury-203 metabolism, tissue distribution, and secretion into milk of cows

    Energy Technology Data Exchange (ETDEWEB)

    Neathery, M.W.; Miller, W.J.; Gentry, R.P.; Stake, P.E.; Blackmon, D.M.

    1974-01-01

    Metabolism of cadmium-109 and methyl mercury-203 was studied in six lactating Jersey cows for 14 days following single tracer oral doses. Most of the cadmium-109 was excreted in feces with only .05% in urine. When the cows were killed 14 to 16 days after dosing, kidney and liver had highest cadmium-109. About .75% of the cadmium-109 was retained in the body with 34% of this in gastrointestinal tract and contents, 32% in liver, and 10% in kidney. In fetal tissues highest cadmium-109 was in kidney, tibia, and liver whereas fetal liver had highest methyl mercury-203. Apparent methyl mercury-203 absorption was 59% with 1.1% in urine. Highest concentration was in kidney, followed by liver, skeletal muscles, heart, smooth muscle, spleen, lung, brain, ovaries, and pancreas. Of total body mercury-203, muscle had about 72% and liver 7%. In 14 days, only .17% of mercury-203 dose was secreted into milk. Cadmium-109 in milk was below detectable limits of .00008% of the dose/day. Feed of cattle kept for meat should be protected from methyl mercury, at least near slaughter. Milk is protected from methyl mercury. In sharp contrast to zinc, little of the ingested cadmium appears in muscle or milk. 31 references, 3 figures, 4 tables.

  11. Zinc in diet

    Science.gov (United States)

    ... cell growth, wound healing, and the breakdown of carbohydrates . Zinc is also needed for the senses of smell and taste. During pregnancy, infancy, and childhood the body needs zinc to grow and develop properly. Zinc also ...

  12. Zinc Fertilization Effects on Seed Cadmium Accumulation in Oilseed and Grain Crops Grown on North Dakota Soils Efecto de la Fertilización con Zinc en la Acumulación de Cadmio en Semillas Oleaginosas y Cereales producidos en Suelos de Dakota del Norte

    Directory of Open Access Journals (Sweden)

    Gonzalo A Rojas-Cifuentes

    2012-03-01

    Full Text Available The Cd concentration in the seed of crops depends on various soil factors including parent material, texture, pH, soil redox, and salinity. Cadmium accumulation also varies among crop species and cultivars within a species. Cadmium and Zn may have either an antagonistic or a synergistic effect on plant uptake that can be influenced by the soil Cd and Zn concentrations. The objective was to determine the effect of Zn fertilizer additions on the seed Cd of nine crops commonly grown in North Dakota, USA. Studies were conducted at five North Dakota locations representing different soil series during 1994 and 1995. In Experiment 1, nine crops common in North Dakota were grown with and without the addition of 25 kg ha-1 Zn fertilizer. Among crops evaluated, the greatest seed Cd accumulation occurred in flax (Linum usitatissimum L. followed by sunflower (Helianthus annuus L., soybean (Glycine max [L.] Merr., and durum wheat (Triticum turgidum L. var. durum. In Experiment 2, two durum wheats and one flax cultivar were grown under three Zn treatments of 0, 5, and 25 kg ha-1. In Experiment again flax had the higher seed Cd level compared with the two durum varieties. Based on the results from both studies, addition of Zn fertilizer did not consistently reduce seed Cd content, and even when statistically significant, the level of reduction was small and not likely to impact marketability of Cd accumulating crops such as flax, sunflower, soybean, and durum.La concentración de Cd en semillas depende de varios factores, tanto del suelo como de la planta. Cadmio y Zn pueden tener efectos antagónicos o sinérgicos en la absorción de la planta dependiendo de las concentraciones de Cd y Zn existentes en el suelo. El objetivo de este estudio fue determinar el efecto de la fertilización con Zn en la acumulación de Cd en la semilla de diversos cultivos comúnmente producidos en Dakota del Norte, EE.UU. Dos estudios fueron realizados en cinco localidades en

  13. 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.

  14. Cadmium hazard in silver brazing.

    Science.gov (United States)

    Gan, S L; Tan, S H; Pinnagoda, J; Tan, K T

    1995-03-01

    This study evaluates the usage of cadmium-containing silver brazing alloys in Singapore and the potential cadmium hazard from its use. Of the 137 factories which responded to the survey questionnaire, only 28 (20.4%) carried out brazing. Of these, only 7 factories used cadmium-containing filler alloys. One hundred and six out of 123 workers from one of these factories had cadmium-in-blood concentrations exceeding 10 mcg/l. Thirty-one (29.2%) of the workers with excessive cadmium absorption had urinary beta-2 microglobulin levels exceeding 28 mcg/g creat. Workers in the other factories who were intermittently exposed had cadmium-in-blood concentrations of 10 mcg/l and below.

  15. 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

  16. Earthworm Lumbricus rubellus MT-2: Metal Binding and Protein Folding of a True Cadmium-MT

    Directory of Open Access Journals (Sweden)

    Gregory R. Kowald

    2016-01-01

    Full Text Available Earthworms express, as most animals, metallothioneins (MTs—small, cysteine-rich proteins that bind d10 metal ions (Zn(II, Cd(II, or Cu(I in clusters. Three MT homologues are known for Lumbricus rubellus, the common red earthworm, one of which, wMT-2, is strongly induced by exposure of worms to cadmium. This study concerns composition, metal binding affinity and metal-dependent protein folding of wMT-2 expressed recombinantly and purified in the presence of Cd(II and Zn(II. Crucially, whilst a single Cd7wMT-2 species was isolated from wMT-2-expressing E. coli cultures supplemented with Cd(II, expressions in the presence of Zn(II yielded mixtures. The average affinities of wMT-2 determined for either Cd(II or Zn(II are both within normal ranges for MTs; hence, differential behaviour cannot be explained on the basis of overall affinity. Therefore, the protein folding properties of Cd- and Zn-wMT-2 were compared by 1H NMR spectroscopy. This comparison revealed that the protein fold is better defined in the presence of cadmium than in the presence of zinc. These differences in folding and dynamics may be at the root of the differential behaviour of the cadmium- and zinc-bound protein in vitro, and may ultimately also help in distinguishing zinc and cadmium in the earthworm in vivo.

  17. Speciation of Dissolved Cadmium

    DEFF Research Database (Denmark)

    Holm, Peter Engelund; Andersen, Sjur; Christensen, Thomas Højlund

    1995-01-01

    Equilibrium dialysis and ion exchange methods, as well as computer calculations (GEOCHEM), were applied for speciation of dissolved cadmium (Cd) in test solutions and leachate samples. The leachate samples originated from soil, compost, landfill waste and industrial waste. The ion exchange (IE...... leachates showed different Cd speciation patterns as expected. Some leachates were dominated by free divalent Cd (1-70%), some by inorganic complexes (1-87%), and some by organic complexes (7-98%)....

  18. Electrodeposition of bismuth telluride thermoelectric films from a nonaqueous electrolyte using ethylene glycol

    NARCIS (Netherlands)

    Nguyen, H.P.; Wu, M.; Su, J.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

    2012-01-01

    Ethylene glycol was studied as an electrolyte for the electrodeposition of thermoelectric bismuth telluride films by cyclic voltammetry, rotating ring disk electrode and electrochemical quartz crystal microbalance (EQCM). The reduction of both Bi3+ and Te4+ ions proceeds in one step without the

  19. Structural Engineering of Vacancy Defected Bismuth Tellurides for Thermo-electric Applications

    Directory of Open Access Journals (Sweden)

    Chumakov Y.

    2012-10-01

    Full Text Available Molecular Dynamics and ab-initio simulations are used to find the most stable stoichiometries of Bismuth Tellurides with vacancy defects. The interest is to decrease the thermal conductivity of these compounds a key point to achieve high figure of merits. A reduction of 70% of the thermal conductivity is observed with Te vacancies of only 5%.

  20. Cadmium flows and emissions from CdTe PV: future expectations

    Energy Technology Data Exchange (ETDEWEB)

    Raugei, Marco, E-mail: marco.raugei@esci.e [Environmental Management Research Group (GiGa), International Trade Business School (ESCI), Pompeu Fabra University, Barcelona 08003 (Spain); Fthenakis, Vasilis [Brookhaven National Laboratory, Upton, NY 11973, USA, and Columbia University, New York, NY 10027 (United States)

    2010-09-15

    Cadmium telluride photovoltaic (CdTe PV) technology is growing rapidly, and already represents the largest contributor to non-silicon based photovoltaics worldwide. We assessed the extent to which CdTe PV will play a notable role in the Cd use and emission flows in the future, and whether it will be environmentally beneficial or detrimental. Our results show that while CdTe PV may account for a large percentage of future global Cd demand, its role in terms of Cd sequestration may be beneficial. We calculated that its potential contribution to yearly global Cd emissions to air and water may well be orders-of-magnitude lower than the respective current Cd emissions rates in Europe.

  1. Cadmium flows and emissions from CdTe PV. Future expectations

    Energy Technology Data Exchange (ETDEWEB)

    Raugei, Marco [Environmental Management Research Group (GiGa), International Trade Business School (ESCI), Pompeu Fabra University, Barcelona 08003 (Spain); Fthenakis, Vasilis [Brookhaven National Laboratory, Upton, NY 11973, USA, and Columbia University, New York, NY 10027 (United States)

    2010-09-15

    Cadmium telluride photovoltaic (CdTe PV) technology is growing rapidly, and already represents the largest contributor to non-silicon based photovoltaics worldwide. We assessed the extent to which CdTe PV will play a notable role in the Cd use and emission flows in the future, and whether it will be environmentally beneficial or detrimental. Our results show that while CdTe PV may account for a large percentage of future global Cd demand, its role in terms of Cd sequestration may be beneficial. We calculated that its potential contribution to yearly global Cd emissions to air and water may well be orders-of-magnitude lower than the respective current Cd emissions rates in Europe. (author)

  2. Seebeck and figure of merit enhancement in nanostructured antimony telluride by antisite defect suppression through sulfur doping.

    Science.gov (United States)

    Mehta, Rutvik J; Zhang, Yanliang; Zhu, Hong; Parker, David S; Belley, Matthew; Singh, David J; Ramprasad, Ramamurthy; Borca-Tasciuc, Theodorian; Ramanath, Ganpati

    2012-09-12

    Antimony telluride has a low thermoelectric figure of merit (ZT antimony antisite defects. Here, we mitigate this key problem by suppressing antisite defect formation using subatomic percent sulfur doping. The resultant 10-25% higher α in bulk nanocrystalline antimony telluride leads to ZT ∼ 0.95 at 423 K, which is superior to the best non-nanostructured antimony telluride alloys. Density functional theory calculations indicate that sulfur increases the antisite formation activation energy and presage further improvements leading to ZT ∼ 2 through optimized doping. Our findings are promising for designing novel thermoelectric materials for refrigeration, waste heat recovery, and solar thermal applications.

  3. Micro-Raman and UV-VIS Studies of 100 MeV Ni4+ Irradiated Cadmium Telluride Thin Films

    OpenAIRE

    Neelam Pahwa; A.D. Yadav; Dubey, S.K.; Patel, A. P.

    2011-01-01

    CdTe thin films grown by thermal evaporation on quartz substrates were irradiated with Swift (100 MeV) Ni 4 + ions for fluences in the range 1.0 × 1011 - 1.0 × 1013 cm – 2. The modification in the structure and optical properties has been studied as a function of ion fluence using Micro-Raman spectroscopy and UV-VIS spectroscopy. In Micro Raman spectrum, weak LO and TO modes of CdTe and A1 & E modes of Te were observed with blue shift which was found to increase with increase in fluence. Inte...

  4. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Michael David [Iowa State Univ., Ames, IA (United States)

    2001-05-01

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn,Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  5. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Michael David [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn, Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  6. Time-dependent changes in copper indium gallium (di)selenide and cadmium telluride photovoltaic modules due to outdoor exposure

    Science.gov (United States)

    Choi, Sungwoo; Sato, Ritsuko; Ishii, Tetsuyuki; Chiba, Yasuo; Masuda, Atsushi

    2017-08-01

    The performance of photovoltaic (PV) modules deteriorates with time due to outdoor exposure. We investigated the time-dependent changes in PV modules and evaluated the amount of power generated during their lifetime. Once a year, the exposed modules were removed and measured under standard test conditions using a solar simulator. Their outputs were measured indoors and normalized to nominal values. In addition, the relationship between the indoor measurement and the energy yield for thin-film PV modules will be reported. In CIGS PV modules, the normalized maximum power (P MAX) and performance ratio (PR) differ with the type of module. The P MAX and PR of CdTe PV modules significantly decrease after outdoor exposure for three years. These results help to determine the characteristics of the time-dependent changes in the P MAX of PV modules due to outdoor exposure.

  7. Polycrystalline thin film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report, 20 March 1995--19 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J U; Mao, D [Colorado School of Mines, Golden, CO (United States)

    1997-04-01

    The objective of this project is to develop improved processes for fabricating CdTe/CdS polycrystalline thin-film solar cells. Researchers used electrodeposition to form CdTe; electrodeposition is a non-vacuum, low-cost technique that is attractive for economic, large-scale production. During the past year, research and development efforts focused on several steps that are most critical to the fabricating high-efficiency CdTe solar cells. These include the optimization of the CdTe electrodeposition process, the effect of pretreatment of CdS substrates, the post-deposition annealing of CdTe, and back-contact formation using Cu-doped ZnTe. Systematic investigations of these processing steps have led to a better understanding and improved performance of the CdTe-based cells. Researchers studied the structural properties of chemical-bath-deposited CdS thin films and their growth mechanisms by investigating CdS samples prepared at different deposition times; investigated the effect of CdCl{sub 2} treatment of CdS films on the photovoltaic performance of CdTe solar cells; studied Cu-doped ZnTe as a promising material for forming stable, low-resistance contacts to the p-type CdTe; and investigated the effect of CdTe and CdS thickness on the photovoltaic performance of the resulting cells. As a result of their systematic investigation and optimization of the processing conditions, researchers improved the efficiency of CdTe/CdS cells using ZnTe back-contact and electrodeposited CdTe. The best CdTe/CdS cell exhibited a V{sub oc} of 0.778 V, a J{sub sc} of 22.4 mA/cm{sup 2}, a FF of 74%, and an efficiency of 12.9% (verified at NREL). In terms of individual parameters, researchers obtained a V{sub oc} over 0.8 V and a FF of 76% on other cells.

  8. Chronic exposure of sheep to a zinc smelter in Peru.

    Science.gov (United States)

    Reif, J S; Ameghino, E; Aaronson, M J

    1989-06-01

    Liver levels of arsenic, cadmium, copper, lead, manganese, and zinc were assessed in adult female sheep living in the vicinity of a zinc smelter in Peru. The study was conducted on a large sheep-raising cooperative divided into seven management units, operated under a standardized husbandry system. Soil samples were analyzed for the same metals at varying distances from the smelter. A gradient of concentration of heavy metals in soil was found between 1 and 56 km from the smelter. Soil concentrations for all metals except manganese decreased significantly with increasing distance from the smelter. The strongest correlations were found for copper, lead, and zinc (P less than 0.001). Topographic features and prevailing wind direction appeared to play a role in the dispersion of pollutants. Liver samples were obtained from 153 sheep on five units of the cooperative. The centers of the units sampled were between 13 and 56 km from the smelter. Hepatic concentrations of arsenic, lead, manganese, and zinc decreased significantly with increasing distance from the smelter. Liver arsenic and liver zinc were significantly related to soil concentrations. Liver levels of arsenic, cadmium, lead, and manganese in sheep from the cooperative were significantly higher than those detected in control sheep from southern Peru. Sheep populations may serve as biological monitors for heavy metal accumulation and environmental carcinogenesis.

  9. 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.

  10. Transfer and accumulation of lead, zinc, cadmium and copper in ...

    African Journals Online (AJOL)

    TUOYO

    3National Institute of Research and Physico-chemical Analysis, Technopol of Sidi Thabet, Tunis, Tunisia. ... The chemical analysis of plants: ... MATERIALS AND METHODS. Site characteristics. The district of Jebel Hallouf Sidi Bouaouane, a Pb-Zn-mining area abandoned since 1986, is located in the North-West of Tunisia.

  11. Infrared Spectroscopy of Divalent Zinc and Cadmium Crown Ether Systems

    NARCIS (Netherlands)

    Cooper, T. E.; Carl, D. R.; Oomens, J.; Steill, J. D.; Armentrout, P. B.

    2011-01-01

    The gas-phase structures of transition-metal dication (Zn2+ and Cd2+) complexes with varying sized crown ethers, 12-crown-4 (12c4), 15-crown-5 (15c5), and 18-crown-6 (18c6), are investigated using infrared multiple photon dissociation (IRMPD) spectroscopy and quantum mechanical calculations. The

  12. Genotoxicity and oxidative stress induced by cadmium and zinc in ...

    African Journals Online (AJOL)

    Planarian Dugesia dorotocephala collected in the Ignacio Ramirez reservoir, México, adapted to laboratory conditions, and exposed to the metals in a controlled system was used. Initially, LC50 at 96 h of exposure was determined and the result obtained were 0.69 mg/L for Cd, 11.99 mg/L for Zn, 10.28 mg/L for mix 1, and ...

  13. Cadmium, lead, copper and zinc in breast milk in Poland.

    Science.gov (United States)

    Winiarska-Mieczan, Anna

    2014-01-01

    Mother's milk is the fundamental food for infants. It contains proteins, fat, carbohydrates and essential metals which are necessary to ensure correct functioning of the organism. Unfortunately, breast milk is a potential source of toxic metals, which are dangerous for a baby. In Poland, previous research concerning the content of metals in breast milk was very scarce or its results were unavailable. The present study aimed at assessing the content of Cd, Pb, Cu and Zn in human breast milk, as well as estimating the mean weekly intake of these metals by breast-fed infants from Poland. The average concentrations of Cd, Pb, Cu and Zn were 2.114 μg/l, 6.331 μg/l, 0.137 mg/l and 1.623 mg/l, respectively. The admissible levels of supply of these toxic metals has not been exceeded, but their contents were high, particularly in 6-month-old infants (nearly 85 % TWI for Cd and nearly 70 % BMDL₀₁ for Pb). The daily intake of Cu and Zn did not fully satisfy the infant's requirements determined by Polish standards and WHO recommendations. Since the lifestyle of lactating women has a direct influence on the content of these elements in breast milk, women should be educated in this respect with particular focus on eliminating tobacco smoking, both by breastfeeding mothers and by their direct environment.

  14. Genotoxicity and oxidative stress induced by cadmium and zinc in ...

    African Journals Online (AJOL)

    Dr Madrigal

    2Laboratorio de Genética, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. 3Instituto de Ciencias de la Salud, Universidad Autónoma de Hidalgo. 4Facultad de Química, Universidad Autónoma del Estado de México, México. Accepted 19 June, 2013. This study sought to determine the DNA damage, ...

  15. OPERATIONAL SPECIATION OF LEAD, CADMIUM, AND ZINC IN ...

    African Journals Online (AJOL)

    IBUKUN

    Anthropogenic activities such as agricultural and industrial waste materials (Abdu et al., 2011) mining/smelting/electroplating activities (Liu et al., 2007) have been reported as major source of heavy metal pollution. Metals in the soil environment undergo an array of biogeochemical processes at reactive natural surfaces, ...

  16. Enhanced phyto-extraction of cadmium and zinc using rapeseed

    Energy Technology Data Exchange (ETDEWEB)

    Ghani, M.; Slycken, S.V.; Meers, E.; Tack, F.M.G. [Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent University, Ghent (Belgium); Naz, F. [National Insect Museum, National Agricultural Research Centre, Islamabad (Pakistan); Ali, S. [Agriculture Department, University of Haripur, Haripur (Pakistan)

    2013-07-01

    In a green house pot experiment, the effects of three amendments, sulphur (S), ammonium sulphate ((NH{sub 4}){sub 2}SO{sub 4}) and ethylenediaminetetracetic acid (EDTA) were tested for phyto-extraction of Cd and Zn by rapeseed (Brassica napus L.). Elemental sulphur was applied as 20.00, 60.00, and 120.00 mg.kg{sup -1} soil. EDTA was tested at a dose of 585.00 mg.kg{sup -1} soil, and (NH{sub 4}){sub 2}SO{sub 4}) at a rate of 0.23 mg.kg{sup -1} soil. All treatments received a base fertilization (Hogland) before sowing. Plants were harvested after 51 days of growth and shoot dry matter and soil samples were analysed for metal contents. All amendments caused a significant increase in Cd and Zn contents in plant shoots of all treatments than control treatment. Further, EDTA was most effective for extraction metals concentrations in shoot biomass but the plants showed significant signs of toxicity and yield were severely depressed. The addition of sulfur favorably influenced plant biomass production. The fertilized ammonium sulfate treatment resulted in the highest phyto-extraction of Cd and Zn and the amounts of these metals accumulated in plant shoot exceeded by a factor of 4 and 3 respectively. Finally, Brassica napus could be used for soil remediation keeping its other uses which will make the contaminated site income generating source for the farmers. (authors)

  17. Chemical Fractionation of Lead, Copper, Zinc and Cadmium in Soils ...

    African Journals Online (AJOL)

    Knowledge of the mobility and bioavailability of heavy metals in soils is necessary for the design of remediation processes and the establishment of environmental guidelines for heavy metal pollution. Single extractions were used to fractionate four heavy metals (Pb, Zn, Cu and Cd) from a total of fifty-four roadside soil ...

  18. Protective effect of zinc against cadmium toxicity on pregnant rats ...

    African Journals Online (AJOL)

    ZINO

    2013-04-17

    IARC, 1993). In the Earth's crust,. Cd has an average concentration of about 0.1 to 0.2 mg kg. −1. (Ursínyová and Hladíková, 2000; Lalor, 2008), contaminating the air, food and water, and so increasing the routes of exposure to ...

  19. OPERATIONAL SPECIATION OF LEAD, CADMIUM, AND ZINC IN ...

    African Journals Online (AJOL)

    IBUKUN

    To assess the level of heavy metal pollution of the soils of the farmlands; and. 3. To evaluate the potential risk of heavy metal transfer to human as a result of mobility of Pb, Cd, and Zn. MATERIALS AND METHODS. Study area and sampling strategy. The soils for the study were collected from Dareta village, northern Nigeria.

  20. High cadmium / zinc ratio in cigarette smokers: potential implications ...

    African Journals Online (AJOL)

    ... impaired DNA repair, P53 expression, angiogenic effect of Cu and impaired vitamin A metabolism. These converge in the risk of the carcinogenic process, suggesting high Cd: Zn ratio as the critical determinant of the risk of prostate cancer in smokers and possibly a biomarker of susceptibility to this environmental disease ...

  1. Cadmium and zinc sensitivity and tolerance in Klebsiella (aerobacter) aerogenes

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, A.W.; Dean, A.C.R.

    1976-01-01

    The resistance of strains of K. aerogenes NCIB 418 'trained' to Cd/sup 2 +/ or Zn/sup 2 +/ in liquid medium is graded to the training concentration. Training to Cd/sup 2 +/ increased the sensitivity to Zn/sup 2 +/ but training to Zn/sup 2 +/ reduced the sensitivity to Cd/sup 2 +/. The trained organisms, particularly those trained to Cd/sup 2 +/, grow slowly in medium containing the metals and the growth rates after 20 and 200 subcultures were not significantly different. The survival of untrained organisms on Cd/sup 2 +/ agar decreased progressively as the Cd/sup 2 +/ concentration was increased, but a threshold concentration of Zn/sup 2 +/ was necessary before any decrease set in. Very low concentrations of Zn/sup 2 +/ potentiated the lethal action of Cd/sup 2 +/ and vice versa, whereas chelating the metal ions with citrate, aspartate or gluconate eliminated it. Nutrient-limitation, as might occur in natural environments, also had a profound effect. Mg/sup 2 +/-limited organisms were particularly resistant to both metals whereas glucose-, NH/sub 4//sup +/ and PO/sub 4//sup 3 -/-limited organisms were very sensitive to Cd/sup 2 +/, and glucose- and K/sup +/-limited organisms to Zn/sup 2 +/.

  2. Zinc and infant nutrition.

    Science.gov (United States)

    Ackland, M Leigh; Michalczyk, Agnes A

    2016-12-01

    Zinc is essential for a wide variety of cellular processes in all cells. It is a critical dietary nutrient, particularly in the early stages of life. In the early neonatal period, adequate sources of zinc can be obtained from breast milk. In rare circumstances, the mammary gland produces zinc deficient milk that is potentially lethal for exclusively breast-fed infants. This can be overcome by zinc supplementation to the infant. Alterations to key zinc transporters provide insights into the mechanisms of cellular zinc homeostasis. The bioavailability of zinc in food depends on the presence of constituents that may complex zinc. In many countries, zinc deficiency is a major health issue due to poor nourishment. Young children are particularly affected. Zinc deficiency can impair immune function and contributes to the global burden of infectious diseases including diarrhoea, pneumonia and malaria. Furthermore, zinc deficiency may extend its influence across generations by inducing epigenetic effects that alter the expression of genes. This review discusses the significance of adequate zinc nutrition in infants, factors that influence zinc nutrition, the consequences of zinc deficiency, including its contribution to the global burden of disease, and addresses some of the knowledge gaps in zinc biology. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. 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

  4. Indium telluride nanotubes: Solvothermal synthesis, growth mechanism, and properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liyan [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yan, Shancheng, E-mail: yansc@njupt.edu.cn [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China); Lu, Tao; Shi, Yi; Wang, Jianyu [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yang, Fan [School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China)

    2014-03-15

    hydrogen storage, compared with the nanowires. The nanotube device also has a broad light detection range from 300 nm to 1100 nm, covering the UV–visible–NIR region. This good performance of In{sub 2}Te{sub 3} nanotubes may enable significant advancements of new photodetection and photosensing applications. Highlights: • The In{sub 2}Te{sub 3} nanotube device also has a broad light detection range from 300 nm to 1100 nm. • The nanotube is 137.85 m{sup 2} g{sup −1}, which makes it suitable for gas sensing and hydrogen storage. • A possible growth mechanism of the indium telluride nanotubes was proposed. • In addition, no In{sub 2}Te{sub 3} nanotubes have been reported until now.

  5. Function of a novel cadmium-induced yodA protein in Escherichia coli.

    Science.gov (United States)

    Stojnev, Tatjana; Harichová, Jana; Ferianc, Peter; Nyström, Thomas

    2007-08-01

    Cells of Escherichia coli increase greatly the synthesis of a small primarily cytoplasmic protein as soon as the cell growth rate falls below the maximal growth rate supported by cadmium exposure, after which the mature product is exported to the periplasm. This protein was previously identified as the product of the E. coli yodA open reading frame. We now report the isolation of an E. coli mutant defective in YodA synthesis because of insertional inactivation of the corresponding gene. In experiments to test the ability of both the wild-type and yodA mutant E. coli cells to bind cadmium, we have used gamma-labeled [(109)Cd]. Whereas the wild-type E. coli strain was able to bind metal, the yodA mutant strain failed to do so. In addition, analysis of such a mutant demonstrated that it grows at a rate distinguishable from that of the isogenic parent in the presence of cadmium ions. However, challenging cells with hydrogen peroxide and additional metals such as zinc, copper, cobalt, and nickel did not significantly affect the growth rate of the mutant. This growth phenotype was found to be the result of the loss of its ability to bind cadmium. These results suggest that the role of YodA protein might be to decrease the concentration level of cadmium ions in E. coli cells during cadmium stress by its ability to bind heavy metal.

  6. Phytomass of beans and grain production as affected by zinc, copper and cadmium doses and bentonite application Fitomassa e produção do feijão afetadas pelas doses de zinco, cobre e cádmio e aplicação de bentonita

    Directory of Open Access Journals (Sweden)

    Gilvanise A. Tito

    2011-07-01

    Full Text Available The objective of this study was to determine the effect of zinc, copper and cadmium on phytomass and grain production and to evaluate indirectly the adsorbent effect of bentonite clay by determining the accumulation of these heavy metals in bean plants. The study consisted of three separate experiments (one for each cation with the application of three doses of bentonite (0, 30 and 60 t ha-1 in pots containing separately 50 mg of Zn; Cu and Cd kg-1 of soil, with three replicates. Thus, each experiment consisted of 9 experimental units. In each one, a bean plant was cultivated and after 65 days, samples of leaves, stems, roots and grains were collected. Afterwards, the samples were dried, weighed, grinded and the concentrations of Zn, Cu and Cd were determined. The phytomass of leaves of the plant growing on the soil with Zn, the Zn concentration in the whole plant and the Cd concentration in the leaves, stem and grains were significantly influenced by the bentonite application. Zn and Cd concentration in leaves, stem and grains decreased with the application of bentonite, indicating a positive effect of the clay application to the soil on the adsorption of these metals, decreasing the availability for plants. Zn was the most accumulated element in the plant, followed by Cd and Cu. The Zn, Cu and Cd accumulation in the plant obeyed the following sequence: stem > leaves > grains > roots; roots > stem > grains > leaves; roots > stem > leaves > grains, respectively.Objetivou-se, com este trabalho, estudar o efeito do cobre, zinco e cádmio em fitomassa e produção de grãos e avaliar indiretamente o efeito adsorvente da argila bentonita, determinando o acúmulo de metais pesados em plantas de feijão. O estudo consistiu de três experimentos separados (um para cada cátion, com a aplicação de três doses de bentonita (0, 30 e 60 t ha-1 em vasos contendo, separadamente, 50 mg de Zn, 50 mg de Cu e 50 mg de Cd kg-1 de solo, com três repeti

  7. 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....... Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered...... DDC increased cadmium-induced acute mortality and testicular necrosis, and it enhanced cadmium-induced reduction of intestinal motility and increased the whole-body retention of cadmium, indicating increased intestinal cadmium absorption. Also, DDC changed the organ distribution of absorbed cadmium...

  8. Method of capturing or trapping zinc using zinc getter materials

    Energy Technology Data Exchange (ETDEWEB)

    Hunyadi Murph, Simona E.; Korinko, Paul S.

    2017-07-11

    A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

  9. Functional analysis of zinc hyperaccumulation related genes of Noccaea (Thlaspi) caerulescens for phytoremediation purposes

    NARCIS (Netherlands)

    Hassan, Z.

    2013-01-01

    Zinc (Zn) and cadmium (Cd) are toxic metals that can cause serious soil contamination when present in excess. Especially Cd exposure is a threat to human health. Plants can potentially be used to clean-up the Zn- and/or Cd-contaminated soils in a technology called “Phytoremediation”. Two

  10. Cadmium immobilization by hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Smičiklas Ivana D.

    2003-01-01

    Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

  11. Cadmium colours: composition and properties

    Science.gov (United States)

    Paulus, J.; Knuutinen, U.

    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.

  12. Testing Cadmium-Free Coatings

    Science.gov (United States)

    2011-08-30

    Metallic Platings • Zinc (Zn) • Nickel (Ni) • Zinc Nickel (ZnNi) • Tin Zinc (SnZn) “ Paint -like” Coatings • Zinc-Rich • Magnesium-Rich • Zinc Aluminum-Rich...None of these match all properties of Cd 6 OPSEC approved for public release Fastener Coating Issues Cont’d Siloxane/Polysiloxane  Silicate ...Polymer-based Zirconium-based These passivation chemistries do not match all properties of Cr6+ Either paint adhesion is reduced Or Corrosion protection

  13. Cadmium in goods - contribution to environmental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bergbaeck, B.; Jonsson, Arne [Kalmar Univ. (Sweden). Dept. of Natural Science

    1998-03-01

    The total amount of Cd used in Sweden since 1940 is approximately 5000 tonnes, including alloys, fertilizers and impurities in zinc. The stock of Cd in goods in the Swedish anthroposphere is dominated by NiCd-batteries. However, when one considers the degree of exposure to corrosion, Cd stabilizers are dominant. Emissions of Cd from industrial plants and other point sources have been historically important. However, these point source emissions must be seen in relation to the increasingly significant fugitive `consumption emissions`, from the use and/or end-use of various goods. In this study, methods of reconstructing the flows of cadmium (Cd) and estimating the emissions over time are discussed. This is done through studies of the development of production, technology, trade and the longevity of metals in Swedish society. This last part in the chain will form the `consumption emissions` calculated from emission factors giving the proportion of the cadmium content in goods that eventually will reach the environment. The main accumulation of metals in the anthroposphere occurs in urban areas where the influx of metals is greatest. Urban areas probably represent `hot spots` as far as this type of environmental impact is concerned. Extreme Cd concentrations in surface sediments in central Stockholm indicate an ongoing release of Cd from the anthroposphere. The sources are so far unknown, i.e. this Cd flow to the biosphere cannot be explained in terms of deposition or emissions from point sources. Approximately 40 tonnes of Cd in goods are exposed to corrosion in varying degrees. This stock is dominated by Cd in stabilizers and pigments, and as impurities in Zn 15 refs, 2 figs, 8 tabs

  14. Ab initio lattice dynamics and thermochemistry of layered bismuth telluride (Bi2Te3).

    Science.gov (United States)

    Zurhelle, Alexander F; Deringer, Volker L; Stoffel, Ralf P; Dronskowski, Richard

    2016-03-23

    We present density-functional theory calculations of the lattice dynamics of bismuth telluride, yielding force constants, mean-square displacements and partial densities of phonon states which corroborate and complement previous nuclear inelastic scattering experiments. From these data, we derive an element- and energy-resolved view of the vibrational anharmonicity, quantified by the macroscopic Grüneisen parameter γ which results in 1.56. Finally, we calculate thermochemical properties in the quasiharmonic approximation, especially the heat capacity at constant pressure and the enthalpy of formation for bismuth telluride; the latter arrives at ΔHf (Bi2Te3)  =  -102 kJ mol(-1) at 298 K.

  15. 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.

  16. Process for fabricating polycrystalline semiconductor thin-film solar cells, and cells produced thereby

    Science.gov (United States)

    Wu, Xuanzhi; Sheldon, Peter

    2000-01-01

    A novel, simplified method for fabricating a thin-film semiconductor heterojunction photovoltaic device includes initial steps of depositing a layer of cadmium stannate and a layer of zinc stannate on a transparent substrate, both by radio frequency sputtering at ambient temperature, followed by the depositing of dissimilar layers of semiconductors such as cadmium sulfide and cadmium telluride, and heat treatment to convert the cadmium stannate to a substantially single-phase material of a spinel crystal structure. Preferably, the cadmium sulfide layer is also deposited by radio frequency sputtering at ambient temperature, and the cadmium telluride layer is deposited by close space sublimation at an elevated temperature effective to convert the amorphous cadmium stannate to the polycrystalline cadmium stannate with single-phase spinel structure.

  17. Exfoliation and characterization of bismuth telluride atomic quintuples and quasi-two-dimensional crystals.

    Science.gov (United States)

    Teweldebrhan, Desalegne; Goyal, Vivek; Balandin, Alexander A

    2010-04-14

    Bismuth telluride (Bi(2)Te(3)) and its alloys are the best bulk thermoelectric materials known today. In addition, stacked quasi-two-dimensional (2D) layers of Bi(2)Te(3) were recently identified as promising topological insulators. In this Letter we describe a method for "graphene-inspired" exfoliation of crystalline bismuth telluride films with a thickness of a few atoms. The atomically thin films were suspended across trenches in Si/SiO(2) substrates, and subjected to detail material characterization, which included atomic force microscopy and micro-Raman spectroscopy. The presence of the van der Waals gaps allowed us to disassemble Bi(2)Te(3) crystal into its quintuple building blocks-five monatomic sheets-consisting of Te((1))-Bi-Te((2))-Bi-Te((1)). By altering the thickness and sequence of atomic planes, we were able to create "designer" nonstoichiometric quasi-2D crystalline films, change their composition and doping, the type of charge carriers as well as other properties. The exfoliated quintuples and ultrathin films have low thermal conductivity, high electrical conductivity, and enhanced thermoelectric properties. The obtained results pave the way for producing stacks of crystalline bismuth telluride quantum wells with the strong spatial confinement of charge carriers and acoustic phonons, beneficial for thermoelectric devices. The developed technology for producing free-standing quasi-2D layers of Te((1))-Bi-Te((2))-Bi-Te((1)) creates an impetus for investigation of the topological insulators and their possible practical applications.

  18. Synthesis and Characterization of Antimony Telluride for Thermoelectric and Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Zybała R.

    2017-06-01

    Full Text Available Antimony telluride (Sb2Te3 is an intermetallic compound crystallizing in a hexagonal lattice with R-3m space group. It creates a c lose packed structure of an ABCABC type. As intrinsic semiconductor characterized by excellent electrical properties, Sb2Te3 is widely used as a low-temperature thermoelectric material. At the same time, due to unusual properties (strictly connected with the structure, antimony telluride exhibits nonlinear optical properties, including saturable absorption. Nanostructurization, elemental doping and possibilities of synthesis Sb2Te3 in various forms (polycrystalline, single crystal or thin film are the most promising methods for improving thermoelectric properties of Sb2Te3. Applications of Sb2Te3 in optical devices (e.g. nonlinear modulator, in particular saturable absorbers for ultrafast lasers are also interesting. The antimony telluride in form of bulk polycrystals and layers for thermoelectric and optoelectronic applications respectively were used. For optical applications thin layers of the material were formed and studied. Synthesis and structural characterization of Sb2Te3 were also presented here. The anisotropy (packed structure and its influence on thermoelectric properties have been performed. Furthermore, preparation and characterization of Sb2Te3 thin films for optical uses have been also made.

  19. 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.

  20. Zinc oxide overdose

    Science.gov (United States)

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used to prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of these ...

  1. Zinc oxyfluoride transparent conductor

    Science.gov (United States)

    Gordon, Roy G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  2. Accumulation and tolerance characteristics of cadmium in a halophytic Cd-hyperaccumulator, Arthrocnemum macrostachyum

    Energy Technology Data Exchange (ETDEWEB)

    Redondo-Gomez, Susana, E-mail: susana@us.es [Departamento de Biologia Vegetal y Ecologia, Facultad de Biologia, Universidad de Sevilla, Apartado 1095, 41080 Sevilla (Spain); Mateos-Naranjo, Enrique; Andrades-Moreno, Luis [Departamento de Biologia Vegetal y Ecologia, Facultad de Biologia, Universidad de Sevilla, Apartado 1095, 41080 Sevilla (Spain)

    2010-12-15

    The potential of the extreme halophyte Arthrocnemum macrostachyum was examined to determine its tolerance and ability to accumulate cadmium for phytoremediation purposes. A glasshouse experiment was designed to investigate the effect of cadmium from 0 to 1.35 mmol l{sup -1} on the growth and the photosynthetic apparatus of A. macrostachyum by measuring chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. We also determined ash, cadmium, calcium, copper, iron, manganese, magnesium, phosphorous, sodium, and zinc concentrations, and C/N ratio. A. macrostachyum demonstrated hypertolerance to cadmium stress; it did not show phytotoxicity at shoot concentration as high as 70 mg kg{sup -1}. The bioaccumulator factors exceeded the critical value (1.0) for all Cd treatments, and the transport factors indicated that this species has higher ability to transfer Cd from roots to shoots at lower Cd concentrations. At 1.35 mmol l{sup -1} Cd A. macrostachyum showed 25% biomass reduction after a month of treatment. Long-term effects of cadmium on the growth were mainly determined by variations in net photosynthetic rate (P{sub N}). Reductions in P{sub N} could be accounted by higher dark respiration and lower pigment concentrations. Finally, A. macrostachyum has the basic characteristics of a Cd-hyperaccumulator and may be useful for restoring Cd-contaminated sites.

  3. Activation of methanogenesis by cadmium in the marine archaeon Methanosarcina acetivorans.

    Directory of Open Access Journals (Sweden)

    Elizabeth Lira-Silva

    Full Text Available Methanosarcina acetivorans was cultured in the presence of CdCl(2 to determine the metal effect on cell growth and biogas production. With methanol as substrate, cell growth and methane synthesis were not altered by cadmium, whereas with acetate, cadmium slightly increased both, growth and methane rate synthesis. In cultures metabolically active, incubations for short-term (minutes with 10 µM total cadmium increased the methanogenesis rate by 6 and 9 folds in methanol- and acetate-grown cells, respectively. Cobalt and zinc but not copper or iron also activated the methane production rate. Methanogenic carbonic anhydrase and acetate kinase were directly activated by cadmium. Indeed, cells cultured in 100 µM total cadmium removed 41-69% of the heavy metal from the culture and accumulated 231-539 nmol Cd/mg cell protein. This is the first report showing that (i Cd(2+ has an activating effect on methanogenesis, a biotechnological relevant process in the bio-fuels field; and (ii a methanogenic archaea is able to remove a heavy metal from aquatic environments.

  4. Preliminary Results from Small-Pixel CdZnTe and CdTe Arrays

    Science.gov (United States)

    Ramsey, B. D.; Sharma, D. P.; Meisner, J.; Austin, R. A.

    1999-01-01

    We have evaluated 2 small-pixel (0.75 mm) Cadmium-Zinc-Telluride arrays, and one Cadmium-Telluride array, all fabricated for MSFC by Metorex (Finland) and Baltic Science Institute (Riga, Latvia). Each array was optimized for operating temperature and collection bias. It was then exposed to Cadmium-109 and Iron-55 laboratory isotopes, to measure the energy resolution for each pixel and was then scanned with a finely-collimated x-ray beam, of width 50 micron, to examine pixel to pixel and inter-pixel charge collections efficiency. Preliminary results from these array tests will be presented.

  5. Salinity and zinc application effects on phytoavailability of cadmium and zinc

    NARCIS (Netherlands)

    Khoshgoftar, A.H.; Shariatmadari, H.; Karimian, N.; Kalbasi, M.; Zee, van der S.E.A.T.M.; Parker, D.R.

    2004-01-01

    Salinity and Zn deficiency in soils are two factors that may change the phytoavailability of Zn and Cd. The aim of this study was to determine the effects of salinity and Zn application on soil Cd and Zn solubility and their concentration in wheat shoots. A greenhouse experiment with wheat (Triticum

  6. Cadmium uptake by plants

    Energy Technology Data Exchange (ETDEWEB)

    Haghiri, F.

    1973-01-01

    Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cd toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.

  7. 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 ...... or crushed linseed nor the intake of cocoa and chocolate....

  8. Comparative study of graphene nanosheet- and multiwall carbon nanotube-based electrochemical sensor for the sensitive detection of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lidong; Fu, Xiaochen; Liu, Huan; Li, Jincheng; Song, Yi, E-mail: wuld@cafs.ac.cn

    2014-12-03

    Graphical abstract: Schematic diagram of nanographene-based sensor detection of cadmium ions by stripping analysis. - Highlights: • A nanocomposite based on nanographene and Nafion is used as a platform for cadmium detection. • The performance of the nanographene-based sensor was compared with that of MWCNT. • It indicated that the nanographene-based sensor possessed significant advantages over MWCNT. • The nanographene-based sensor proved to be a reliable tool for rapid detection of cadmium. - Abstract: A novel nanocomposite was obtained through the controlled surface modification of graphene nanosheets (nanographene) with Nafion by ultrasonic oscillation. The composite was used as an ultrasensitive platform for the detection of cadmium ions (Cd{sup 2+}) by differential pulse anodic stripping voltammetry (DPASV) analysis. The performance of the nanographene-based sensor was systematically compared with that of a multiwall carbon nanotube (MWCNT)-modified sensor. The results indicate that the nanographene-based sensor exhibits significant advantages over the MWCNT-based sensor in terms of repeatability, sensitivity and limit of detection (LOD). The nanographene-based sensor displayed superior analytical performance over a linear range of Cd{sup 2+} concentrations from 0.25 μg L{sup −1} to 5 μg L{sup −1}, with a LOD of 3.5 ng L{sup −1}. This sensor was also used to systematically screen for 6 types of chemicals, including sodium salts, magnesium salts and zinc salts. It was observed that the sensor could successfully differentiate cadmium ions from interferents (magnesium salts, zinc salts, etc.). The nanographene-based sensor was also demonstrated to be a promising and reliable tool for the rapid detection of cadmium existing in tap water and for the rapid on-site analysis of critical pollution levels of cadmium.

  9. 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.

  10. 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

  11. Effects of spark plasma sintering conditions on the anisotropic thermoelectric properties of bismuth antimony telluride

    DEFF Research Database (Denmark)

    Han, Li; Hegelund Spangsdorf, Steeven; Van Nong, Ngo

    2016-01-01

    Bismuth antimony telluride (BixSb2-xTe3, 0.4 semiconductor materials for near-room-temperature thermoelectric power generation. In this work, p-type Bi0.4Sb1.6Te3 samples were prepared under various conditions (temperature, holding time, and ramp......-rate) using spark plasma sintering (SPS). The effects of SPS conditions on the anisotropic thermoelectric properties and microstructure evolutions were systematically investigated. The change of sintering temperature showed stronger influence than other sintering parameters to the resulting thermoelectric...

  12. Synthesis and structure of undoped and indium-doped thermoelectric lead telluride nanoparticles

    OpenAIRE

    Kadel, Kamal; Kumari, Latha; Wang, Xuewen; Li, Wenzhi; Huang, Jian Yu; Provencio, Paula Polyak

    2014-01-01

    Undoped and indium (In)-doped lead telluride (PbTe) nanostructures were synthesized via solvothermal/hydrothermal route. The crystalline structure of the as-prepared undoped and In-doped PbTe samples was examined by X-ray diffraction (XRD) which indicated the formation of face-centered single-phase cubic crystal. A first principle calculation on indium doping shows that the indium atoms are more likely to replace lead (Pb) rather than to take the interstitial sites. Laser-induced breakdown sp...

  13. Removal of cadmium from acidic phosphatic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Frankenfeld, K.; Brodt, P.; Eich, G.; Ruschke, P.

    1985-01-08

    The invention is concerned with a process of removing cadmium from acid, especially P/sub 2/O/sub 5/-containing solutions by liquid/liquid extraction with the aid of alkyl amine salts that are dissolved in an inert, organic solvent. The cadmium ions are removed from the acid, aqueous phase and are enriched in the organic phase. The cadmium-containing organic phase, subsequently, is re-extracted with an aqueous salt solution, with the cadmium ions migrating from the organic phase into the aqueous phase. The process is particularly suitable for extracting cadmium from concentrated, highly acid aqueous solutions.

  14. Zinc and Chlamydia trachomatis

    Energy Technology Data Exchange (ETDEWEB)

    Sugarman, B.; Epps, L.R.

    1985-07-01

    Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remained constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.

  15. Magnesium supplements affect selected cadmium toxic actions and uptake of repeated doses of cadmium

    Directory of Open Access Journals (Sweden)

    Grosicki Andrzej

    2015-12-01

    Full Text Available The importance of magnesium supplements on organ retention of cadmium and allometric parameters after repeated exposure to cadmium chloride were studied in male Wistar rats. Magnesium chloride was given via drinking water (500 mg Mg/L to rats exposed intragastrically to cadmium chloride (labelled with cadmium 109 at a daily dose corresponding to 25 mg/kg diet for 7, 14, 21, and 28 d. Supplements of magnesium temporarily decreased cadmium retention in the duodenum and liver. No significant differences in cadmium retention were evidenced in the kidneys and testicles. The supplements of magnesium also retain more of the body weight gains and restore the relative liver and testicle weight in rats intoxicated with cadmium. Comparison of the present results with earlier reports suggests a relationship between doses of magnesium and cadmium; higher doses of cadmium need more magnesium to overcome toxic action of the heavy metal.

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

    African Journals Online (AJOL)

    GREGORY

    2010-09-27

    Sep 27, 2010 ... P. chrysosporium was used to biosorp cadmium (II), lead (II), copper (II) and the adsorption capacities reached 23.04, 69.77 and 20.33mg/g dry biomass, respectively (Say et al. 2001). The maximum experimental biosorption capacities for entrapped live and dead fungal mycelia of L. sajur-caju were found ...

  17. Functional characterization of a cadmium resistance operon in Staphylococcus aureus ATCC12600: CadC does not function as a repressor.

    Science.gov (United States)

    Hoogewerf, Arlene J; Dyk, Lisa A Van; Buit, Tyler S; Roukema, David; Resseguie, Emily; Plaisier, Christina; Le, Nga; Heeringa, Lee; Griend, Douglas A Vander

    2015-02-01

    Sequencing of a cadmium resistance operon from a Staphylococcus aureus ATCC12600 plasmid revealed that it is identical to a cadCA operon found in MRSA strains. Compared to plasmid-cured and cadC-mutant strains, cadC-positive ATCC12600 cells had increased resistance to cadmium (1 mg ml(-1) cadmium sulfate) and zinc (4 mg ml(-1) zinc sulfate), but not to other metal ions. After growth in media containing 20 µg ml(-1) cadmium sulfate, cadC-mutant cells contained more intracellular cadmium than cadC-positive ATCC12600 cells, suggesting that cadC absence results in impaired cadmium efflux. Electrophoretic mobility shift assays were performed with CadC proteins encoded by the S. aureus ATCC12600 plasmid and by the cadC gene of pI258, which is known to act as a transcriptional repressor and shares only 47% protein sequence identity with ATCC12600 CadC. Mobility shifts occurred when pI258 CadC protein was incubated with the promoter DNA-regions from the pI258 and S. aureus ATCC12600 cadCA operons, but did not occur with S. aureus ATCC12600 CadC protein, indicating that the ATCC12600 CadC protein does not interact with promoter region DNA. This cadCA operon, found in MRSA strains and previously functionally uncharacterized, increases resistance to cadmium and zinc by an efflux mechanism, and CadC does not function as a transcriptional repressor. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. [Zinc and chronic enteropathies].

    Science.gov (United States)

    Giorgi, P L; Catassi, C; Guerrieri, A

    1984-01-01

    In recent years the nutritional importance of zinc has been well established; its deficiency and its symptoms have also been recognized in humans. Furthermore, Acrodermatitis Enteropathica has been isolated, a rare but severe disease, of which skin lesions, chronic diarrhoea and recurring infections are the main symptoms. The disease is related to the malfunctioning of intestinal absorption of zinc and can be treated by administering pharmacological doses of zinc orally. Good dietary sources of zinc are meat, fish and, to a less extent, human milk. The amount of zinc absorbed in the small intestine is influenced by other nutrients: some compounds inhibit this process (dietary fiber, phytate) while others (picolinic acid, citric acid), referred to as Zn-binding ligands (ZnBL) facilitate it. Citric acid is thought to be the ligand which accounts for the high level of bioavailability of zinc in human milk. zinc absorption occurs throughout the small intestine, not only in the prossimal tract (duodenum and jejunum) but also in the distal tract (ileum). Diarrhoea is one of the clinical manifestations of zinc deficiency, thus many illnesses distinguished by chronic diarrhoea entail a bad absorption of zinc. In fact, in some cases of chronic enteropathies in infants, like coeliac disease and seldom cystic fibrosis, a deficiency of zinc has been isolated. Some of the symptoms of Crohn's disease, like retarded growth and hypogonadism, have been related to hypozinchemia which is present in this illness. Finally, it is possible that some of the dietary treatments frequently used for persistent post-enteritis diarrhoea (i.e. cow's milk exclusion, abuse and misuse of dietary fiber like carrot and carub powder, use of soy formula) can constitute a scarce supply of zinc and therefore could promote the persistency of diarrhoea itself.

  19. Zinc Detoxification: A Functional Genomics and Transcriptomics Analysis in Drosophila melanogaster Cultured Cells

    Directory of Open Access Journals (Sweden)

    Stephanie E. Mohr

    2018-02-01

    Full Text Available Cells require some metals, such as zinc and manganese, but excess levels of these metals can be toxic. As a result, cells have evolved complex mechanisms for maintaining metal homeostasis and surviving metal intoxication. Here, we present the results of a large-scale functional genomic screen in Drosophila cultured cells for modifiers of zinc chloride toxicity, together with transcriptomics data for wild-type or genetically zinc-sensitized cells challenged with mild zinc chloride supplementation. Altogether, we identified 47 genes for which knockdown conferred sensitivity or resistance to toxic zinc or manganese chloride treatment, and >1800 putative zinc-responsive genes. Analysis of the ‘omics data points to the relevance of ion transporters, glutathione (GSH-related factors, and conserved disease-associated genes in zinc detoxification. Specific genes identified in the zinc screen include orthologs of human disease-associated genes CTNS, PTPRN (also known as IA-2, and ATP13A2 (also known as PARK9. We show that knockdown of red dog mine (rdog; CG11897, a candidate zinc detoxification gene encoding an ABCC-type transporter family protein related to yeast cadmium factor (YCF1, confers sensitivity to zinc intoxication in cultured cells, and that rdog is transcriptionally upregulated in response to zinc stress. As there are many links between the biology of zinc and other metals and human health, the ‘omics data sets presented here provide a resource that will allow researchers to explore metal biology in the context of diverse health-relevant processes.

  20. A field investigation of the relationship between zinc and acid volatile sulfide concentrations in freshwater sediments

    Science.gov (United States)

    Ankley, Gerald T.; Liber, Karsten; Call, Daniel J.; Markee, Thomas P.; Canfield, Timothy J.; Ingersoll, Christopher G.

    1996-01-01

    Understanding relationships between cationic metals such as cadmium, copper, nickel, lead and zinc, and amorphous iron sulfides, measured as acid volatile sulfide (AVS), is key to predicting metal bioavailability and toxicity insediments. The objective of the present study was to assess seasonal and spatial variations of AVS in freshwater sediments contaminated with zinc. Sediments were sampled from three streams with varying levels of zinc contamination at two different times, March and June of 1995, representing cold- and warm-weather situations. Interstitial (pore) water concentrations of zinc, and solid phase concentrations of AVS and zinc were measured in surficial and deep sediment horizons. Toxicity tests (10-d) with the amphipodHyalella azteca were conducted using intact cores. Sediment zinc concentrations from six sites within the primary test stream differed by about five-fold, and also varied seasonally. Acid volatile sulfide concentrations were generally lower than those of zinc, and pore water zinc concentrations typically were elevated. There was a positive correlation between solid-phase AVS and zinc concentrations, suggesting that the system was dominated by zinc, as opposed to iron sulfides. In contrast to expectations arising from some studies of seasonal variations of AVS in iron-dominated systems, AVS concentrations were smaller in June than in March. However, this was likely due to a major storm event and associated sediment scouring before the June sampling, rather than to seasonal processes related to variations in temperature and dissolved oxygen. Based upon an indirect analysis of depth variations in AVS, there was some indication that zinc sulfide might be less prone to oxidation than iron sulfide. There was a strong correlation between toxicity of the sediment samples toH. azteca and interstitial water concentrations of zinc; however, the possible contribution of other contaminants to sediment toxicity cannot be dismissed.

  1. Mineralogy of telluride-bearing epithermal ores in the Kassiteres-Sappes area, western Thrace, Greece

    Science.gov (United States)

    Voudouris, P.; Tarkian, M.; Arikas, K.

    2006-05-01

    The Kassiteres-Sappes district represents a multi-centered, porphyry-epithermal system developed during the Oligocene to Miocene at a composite calc-alkaline to high-K calc-alkaline volcanic edifice. Precious and base metal mineralization postdates the emplacement of dacite and rhyolite porphyries and is partly superimposed on earlier microdiorite-related porphyry-style mineralization exposed at the Koryfes Hill prospect. A second mineralized porphyry-type system genetically related to a dacite porphyry body developed near the St Demetrios deposit. Tellurides occur mainly at the St Barbara prospect and the St Demetrios deposit. Based on petrographic, electron microprobe, and scanning electron microscope analyses, hessite, petzite, sylvanite, altaite, stützite and native tellurium occur in the St Barbara prospect. These tellurium-bearing minerals are hosted in intermediate-sulfidation type veins and accompanied by pyrite, chalcopyrite, tetrahedrite-group minerals, galena and native gold/electrum. The St Demetrios mineralization includes hessite, altaite, stützite, and tetradymite in close spatial relation to a high-sulfidation assemblage composed of enargite, chalcopyrite, goldfieldite, and native gold. Tellurides were deposited at logfTe2 values of -8.5 to -7.1 and logfS2 values of -10.7 to -7.9 (275 °C). The ore systems are characterized by Au, Ag, Te, Bi, and Mo, which suggests a magmatic contribution to the mineralizing fluids. Ore-forming components were likely derived from both the dacite and rhyolite porphyries.

  2. 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.

  3. Solvothermal synthesis and thermoelectric property of undoped and indium doped lead telluride nanoparticles

    Science.gov (United States)

    Kadel, Kamal; Li, Wenzhi

    2013-03-01

    Undoped and indium (In) doped lead telluride (PbTe) nanostructures were synthesized via solvothermal/hydrothermal route. The crystallinity of the as-prepared un-doped and In-doped PbTe sample were examined by X-ray diffraction (XRD) which indicated the formation of face centered single phase cubic PbTe. Lattice constant calculation from XRD pattern revealed the formation of un-doped and In-doped PbTe crystals with almost similar size. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) examinations indicated that undoped and In-doped PbTe nanostructures were mostly cubically shaped and highly crystalline. The effect of the synthesis temperature on the structure and morphology of undoped PbTe was also investigated; it was found that the particle size increased with the synthesis temperature. Thermoelectric property of as-synthesized lead telluride sample was also investigated. This work is supported by the National Science Foundation under the grant DMR- 0548061.

  4. Joining of Half-Heusler and Bismuth Tellurides for Segmented Thermoelectric Generators

    DEFF Research Database (Denmark)

    Ngan, Pham Hoang; Han, Li; Christensen, Dennis Valbjørn

    2018-01-01

    -Heusler alloys p-type Hf0.5Zr0.5CoSn0.2Sb0.8 and n-type Ti0.6Hf0.4NiSn. A two-step process was introduced to join the half-Heusler to the bismuth tellurides to form a segmented structure which was then characterized for its thermoelectric and structural properties. The output power generation was characterized......Segmented generators where the p- or n-type legs are formed by joining materials in series enables each material to operate in their most efficient temperature range. Here, we have fabricated and characterized segmented thermoelectric p- and n-type legs based on bismuth tellurides and half...... under various hot side temperatures up to 873 K with the cold side fixed at 323 K. The stability of the joints was also investigated under heat treatment and thermal cycling. Under working temperatures from 323 K to 873 K, the obtained p-type segmented legs could deliver a power density of 0.3 W cm−2...

  5. Metallothionein in the ovaries of laying hens exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Shin; Okabe, Masashi; Kurasaki, Masaaki; Kojima, Yutaka [Hokkaido Univ., Sapporo (Japan)

    1996-03-29

    The prescence of metallothionein (MT) and its mRMA in the ovaries of laying hens is reported. In laying hens injected with cadmium (Cd), Cd accumulated in the follicle walls of the ovaries not in the follicle yolks. In the follicle walls, (Cd, Zn)-MT and its mRNA were found. This indicates that MT bound to Cd is biosynthesized in the follicle walls. We suggest that MT might play a role in sequestering Cd. On the other hand, zinc (Zn) was found in the follicle walls and yolks in the Cd-treated laying hens. The relationship between Zn and (Cd,Zn)-MT is also discussed. 27 refs., 3 fig., 2 tab.

  6. Molecular basis for the effects of zinc deficiency on spermatogenesis: An experimental study in the Sprague-dawley rat model

    Directory of Open Access Journals (Sweden)

    Alexander E Omu

    2015-01-01

    Full Text Available Introduction: The objective of this study is to investigate the molecular mechanisms underlying the effects of zinc deficiency on spermatogenesis in the Sprague-Dawley (SD rat. Materials and Methods: Three groups of eight adult male SD rats were maintained for 4 weeks on a normal diet as control, zinc deficient diet and zinc deficient diet with zinc supplementation of 28 mg zinc/kg body weight respectively. Using standard techniques, the following parameters were compared between the three groups of experimental animals at the end of 4 weeks: (a Serum zinc, magnesium (Mg, copper (Cu, selenium (Se and cadmium (Cd, (b serum sex hormones, malondialdehyde (MDA, superoxide dismutase (SOD and glutathione peroxidase (GPX, (c interleukin-4 (IL-4, tumor necrosis factor-alpha (TNF-α, Bcl-2, Bax and caspase-3 expression in the testes, (d assessment of apoptosis of testicular cells using electron microscopy and (e testicular volume and histology using the orchidometer and Johnsen score, respectively. Results: The zinc deficient group showed a reduction of testicular volume, serum concentrations of Zn, Cu, Se, Mg, SOD, GPX, IL-4, Bcl-2 and testosterone (P < 0.05, as well as increased levels of serum Cd, MDA and tissue TNF-α, Bax, caspase-3 and apoptosis of the germ cells (P < 0.05 compared with control and zinc supplementation groups. Conclusion: Zinc deficiency is associated with impaired spermatogenesis because of reduced testosterone production, increased oxidative stress and apoptosis. These findings suggest that zinc has a role in male reproduction.

  7. Dual-functional aniline-assisted wet-chemical synthesis of bismuth telluride nanoplatelets and their thermoelectric performance

    Science.gov (United States)

    Li, Changcun; Kong, Fangfang; Liu, Congcong; Liu, Huixuan; Hu, Yongjing; Wang, Tongzhou; Xu, Jingkun; Jiang, Fengxing

    2017-06-01

    The wet-chemical approach is of great significance for the synthesis of two-dimensional (2D) bismuth telluride nanoplatelets as a potential thermoelectric (TE) material. Herein, we proposed a simple and effective solution method with the assistance of aniline for the fabrication of bismuth telluride nanoplatelets at a low temperature of 100 °C. The choice of aniline with its dual function avoided the simultaneous use of a capping regent and a toxic reductant. The as-synthesized nanoplatelets have a large size of more than 900 × 500 nm2 and a small thickness of 15.4 nm. The growth of bismuth telluride nanoplatelets are related to the Bi/Te ratio of precursors indicating that a larger content of the Bi precursor is more conducive to the formation of 2D nanoplatelets. The bismuth telluride nanoplatelets pressed into a pellet show a smaller electrical resistivity (˜6.5 × 10-3 Ω · m) and a larger Seebeck coefficient (-135 μV K-1), as well as a lower thermal conductivity (0.27 W m-1 K-1) than those of nanoparticles. The next goal is to further reduce the electrical resistivity and optimize the TE performance by disposing of the residual reactant of aniline adsorbed on the surface of the nanoplatelets.

  8. 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.

  9. Facile preparation of carbon wrapped copper telluride nanowires as high performance anodes for sodium and lithium ion batteries

    Science.gov (United States)

    Yu, Hong; Yang, Jun; Geng, Hongbo; Chao Li, Cheng

    2017-04-01

    Uniform carbon wrapped copper telluride nanowires were successfully prepared by using an in situ conversion reaction. The length of these nanowires is up to several micrometers and the width is around 30-40 nm. The unique one dimensional structure and the presence of conformal carbon coating of copper telluride greatly accommodate the large volumetric changes during cycling, significantly increase the electrical conductivity and reduce charge transfer resistance. The copper telluride nanowires show promising performance in a lithium ion battery with a discharge capacity of 130.2 mA h g-1 at a high current density of 6.0 A g-1 (26.74 C) and a stable cycling performance of 673.3 mA h g-1 during the 60th cycle at 100 mA g-1. When evaluated as anode material for a sodium ion battery, the copper telluride nanowires deliver a reversible capacity of 68.1 mA h g-1 at 1.0 A g-1 (˜4.46 C) and have a high capacity retention of 177.5 mA h g-1 during the 500th cycle at 100 mA g-1.

  10. The effect of heavy metal accumulation on metallothionein content in selected tissues of bank voles and yellow-necked mice caught near a steelworks and zinc smelter.

    Science.gov (United States)

    Damek-Poprawa, Monika

    2002-01-01

    The effect of cadmium, zinc, and copper accumulation on metallothionein content in the selected tissues of bank voles and yellow-necked mice trapped near the Sendzimir Steelworks in Krakow and the zinc smelter in Bukowno were analysed. The Borecka Forest was chosen as a control area. The highest cadmium concentration, 32.98 microg g(-1) dry weight, was detected in the kidneys of the bank voles caught in the Bukowno area. Zinc and copper concentrations in the tissues did not exceed the critical values. Metallothionein content in the liver and kidneys was associated with heavy metal accumulation in the tissues. The highest content of sulphydryl groups was detected in the livers of the bank voles trapped within the neighbourhood of the zinc smelter in Bukowno. The highest level of disulphide bonds was found in the kidneys of the bank voles from the same area.

  11. 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.

  12. Survey of mercury, cadmium and lead content of household batteries.

    Science.gov (United States)

    Recknagel, Sebastian; Radant, Hendrik; Kohlmeyer, Regina

    2014-01-01

    The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline-manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc-carbon batteries, on average, contained the highest levels. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Role of mineral nutrition in minimizing cadmium accumulation by plants.

    Science.gov (United States)

    Sarwar, Nadeem; Malhi, Sukhdev S; Zia, Munir Hussain; Naeem, Asif; Bibi, Sadia; Farid, Ghulam

    2010-04-30

    Cadmium (Cd) is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of great concern regarding its entry into the food chain. Cadmium enters into the soil-plant environment mainly through anthropogenic activities. Compounds of Cd are more soluble than other heavy metals, so it is more available and readily taken up by plants and accumulates in different edible plant parts through which it enters the food chain. A number of approaches are being used to minimize the entry of Cd into the food chain. Proper plant nutrition is one of the good strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain. Plant nutrients play a very important role in developing plant tolerance to Cd toxicity and thus, low Cd accumulation in different plant parts. In this report, the role of some macronutrients (nitrogen, phosphorus, sulfur and calcium), micronutrients (zinc, iron and manganese), and silicon (a beneficial nutrient) has been discussed in detail as to how these nutrients play their role in decreasing Cd uptake and accumulation in crop plants.

  14. Comparative study of graphene nanosheet- and multiwall carbon nanotube-based electrochemical sensor for the sensitive detection of cadmium.

    Science.gov (United States)

    Wu, Lidong; Fu, Xiaochen; Liu, Huan; Li, Jincheng; Song, Yi

    2014-12-03

    A novel nanocomposite was obtained through the controlled surface modification of graphene nanosheets (nanographene) with Nafion by ultrasonic oscillation. The composite was used as an ultrasensitive platform for the detection of cadmium ions (Cd(2+)) by differential pulse anodic stripping voltammetry (DPASV) analysis. The performance of the nanographene-based sensor was systematically compared with that of a multiwall carbon nanotube (MWCNT)-modified sensor. The results indicate that the nanographene-based sensor exhibits significant advantages over the MWCNT-based sensor in terms of repeatability, sensitivity and limit of detection (LOD). The nanographene-based sensor displayed superior analytical performance over a linear range of Cd(2+) concentrations from 0.25μgL(-1) to 5μgL(-1), with a LOD of 3.5ngL(-1). This sensor was also used to systematically screen for 6 types of chemicals, including sodium salts, magnesium salts and zinc salts. It was observed that the sensor could successfully differentiate cadmium ions from interferents (magnesium salts, zinc salts, etc.). The nanographene-based sensor was also demonstrated to be a promising and reliable tool for the rapid detection of cadmium existing in tap water and for the rapid on-site analysis of critical pollution levels of cadmium. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Pancreatitis in wild zinc-poisoned waterfowl

    Science.gov (United States)

    Sileo, Louis; Beyer, W. Nelson; Mateo, Rafael

    2003-01-01

    Four waterfowl were collected in the TriState Mining District (Oklahoma, Kansas and Missouri, USA), an area known to be contaminated with lead, cadmium and zinc (Zn). They were part of a larger group of 20 waterfowl collected to determine the exposure of birds to metal contamination at the site. The four waterfowl (three Branta canadensis, one Anas platyrhynchos) had mild to severe degenerative abnormalities of the exocrine pancreas, as well as tissue (pancreas, liver) concentrations of Zn that were considered toxic. The mildest condition was characterized by generalized atrophy of exocrine cells that exhibited cytoplasmic vacuoles and a relative lack of zymogen. The most severe condition was characterized by acini with distended lumens and hyperplastic exocrine tissue that completely lacked zymogen; these acini were widely separated by immature fibrous tissue. Because the lesions were nearly identical to the lesions reported in chickens and captive waterfowl that had been poisoned with ingested Zn, and because the concentrations of Zn in the pancreas and liver of the four birds were consistent with the concentrations measured in Zn-poisoned birds, we concluded that these waterfowl were poisoned by Zn. This may be the first reported case of zinc poisoning in free-ranging wild birds poisoned by environmental Zn.

  16. Exploring zinc coordination in novel zinc battery electrolytes.

    Science.gov (United States)

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2014-06-14

    The coordination of zinc ions by tetraglyme has been investigated here to support the development of novel electrolytes for rechargeable zinc batteries. Zn(2+) reduction is electrochemically reversible from tetraglyme. The spectroscopic data, molar conductivity and thermal behavior as a function of zinc composition, between mole ratios [80 : 20] and [50 : 50] [tetraglyme : zinc chloride], all suggest that strong interactions take place between chloro-zinc complexes and tetraglyme. Varying the concentration of zinc chloride produces a range of zinc-chloro species (ZnClx)(2-x) in solution, which hinder full interaction between the zinc ion and tetraglyme. Both the [70 : 30] and [50 : 50] mixtures are promising electrolyte candidates for reversible zinc batteries, such as the zinc-air device.

  17. Cadmium content of plants as affected by soil cadmium concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  18. Luminescence-based whole-cell-sensing systems for cadmium and lead using genetically engineered bacteria.

    Science.gov (United States)

    Shetty, Ranjit S; Deo, Sapna K; Shah, Puja; Sun, Yan; Rosen, Barry P; Daunert, Sylvia

    2003-05-01

    Whole-cell-based sensing systems that respond to cadmium and lead ions have been designed and developed using genetically engineered bacteria. These systems take advantage of the ability of certain bacteria to survive in environments polluted with cadmium and lead ions. The bacteria used in this investigation have been genetically engineered to produce reporter proteins in response to the toxic ions. This was achieved by modifying a strain of Escherichia colito harbor plasmids pYSC1 and pYS2/pYSG1. In these dual-plasmid-based sensing systems, the expression of the reporters beta-galactosidase and red-shifted green fluorescent protein (rs-GFP) was controlled by CadC, the regulatory protein of the cad operon. Regulation of the expression of the reporter proteins is related to the amount of cadmium and lead ions employed to induce the bacteria. The bacterial sensing systems were found to respond to cadmium, lead, and zinc ions, and had no significant response to nickel, copper, manganese, and cobalt.

  19. Relations between liver cadmium, cumulative exposure, and renal function in cadmium alloy workers.

    OpenAIRE

    Mason, H. J.; Davison, A G; Wright, A. L.; Guthrie, C J; Fayers, P M; Venables, K M; Smith, N J; Chettle, D R; Franklin, D M; Scott, M. C.

    1988-01-01

    Detailed biochemical investigations of renal function were made on 75 male workers exposed to cadmium and an equal number of referents matched for age, sex, and employment status. The exposed group consisted of current and retired workers who had been employed in the manufacture of copper-cadmium alloy at a single factory in the United Kingdom for periods of up to 39 years and for whom cumulative cadmium exposure indices could be calculated. In vivo measurements of liver and kidney cadmium bu...

  20. Cadmium resistance in Drosophila: a small cadmium binding substance

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, K.B.; Williams, M.W.; Richter, L.J.; Holt, S.E.; Hook, G.J.; Knoop, S.M.; Sloop, F.V.; Faust, J.B.

    1985-01-01

    A small cadmium-binding substance (CdBS) has been observed in adult Drosophila melanogaster that were raised for their entire growth cycle on a diet that contained 0.15 mM CdCl/sub 2/. Induction of CdBS was observed in strains that differed widely in their sensitivity of CdCl/sub 2/. This report describes the induction of CdBS and some of its characteristics. 17 refs., 4 figs., 1 tab.

  1. [Effects of cadmium on testis function].

    Science.gov (United States)

    Martynowicz, Helena; Skoczyńska, Anna; Karczmarek-Wdowiak, Beata; Andrzejak, Ryszard

    2005-01-01

    The deterioration of male fertility, reported in numerous epidemiological studies over past decades, can be connected with growing exposure to environmental toxins. Heavy metals, especially cadmium, is widely spread and extremely toxic. The mechanisms of cadmium toxic effects vary and involve the damage of vascular endothelium, intracellular junctions, germ cells, Leydig and Sertoli cells. Cadmium can increase activity of reactive oxygen species and induce changes in activity of enzymatic systems and inflammatory reactions. The morphological changes caused by cadmium included the necrosis of seminiferous tubiles and interstitial edema. This metal can reduce testosterone synthesis at various levels and deteriorate spermatogenesis. Cadmium is also acknowledged carcinogen with confirmed mutagenic and genotoxic activity. Increasing environmental exposure to cadmium, currently existing occupational exposure and the prevalence of tobacco smoking results in constant increase in the number of diagnosed fertility impairments.

  2. Could cadmium be responsible for some of the neurological signs and symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

    Science.gov (United States)

    Pacini, Stefania; Fiore, Maria G; Magherini, Stefano; Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco

    2012-09-01

    -exposed healthy controls, exposed non-ME/CFS subjects, un-exposed ME/CFS patients and exposed ME/CFS patients. If our hypothesis is demonstrated correct, the consequences could affect prevention, early diagnosis, and treatment of ME/CFS. Implications in early diagnosis could entail the evaluation of symptoms typical of ME/CFS in cadmium-exposed subjects as well as the search for signs of exposure to cadmium in subjects diagnosed with ME/CFS. Nutritional supplementation of magnesium and zinc could then be considered, since these elements have been proposed in the prophylaxis and therapy of cadmium exposure, and magnesium was demonstrated effective on ME/CFS patients' symptom profiles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Semen quality and reproductive endocrine function with regard to blood cadmium in Croatian male subjects.

    Science.gov (United States)

    Jurasović, Jasna; Cvitković, Petar; Pizent, Alica; Colak, Bozo; Telisman, Spomenka

    2004-12-01

    In 123 Croatian men with no occupational exposure to metals, the influence of cadmium on reproductive parameters was examined after adjusting for age, smoking, alcohol, and biomarkers of lead, copper, zinc, and selenium. The following variables were measured: blood cadmium (BCd), blood lead (BPb), activity of delta-aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin, serum copper (SCu), serum zinc (SZn), serum selenium (SSe), activity of glutathione peroxidase (GPx) in blood, testis size, semen quality (including sperm concentration, motility, viability, and morphology), indicators in seminal fluid (the lactate dehydrogenase isoenzyme LDH-C4, fructose, zinc, acid phosphatase, and citric acid), and hormones in serum (follicle-stimulating hormone--FSH, luteinizing hormone, prolactin, testosterone, and estradiol). The median and range BCd values were 2.94 (0.49-11.93) microg/L in 61 smokers and 0.59 (0.20-3.71) microg/L in 62 nonsmokers (p metals, and other potential confounders when assessing the influence of a particular metal on reproductive function in men, is emphasized.

  4. Pd-BISMUTHOTELLURIDES and Other Tellurides from Some Cu-Ni-PGE Deposits, Eastern Desert, Egypt

    Science.gov (United States)

    Helmy, H. M.

    2003-04-01

    Pd-bismuthotellurides and other tellurides are described from three Cu-Ni-PGE deposits in the Eastern Desert, Egypt: Abu Swayl, Genina Gharbia, Gabbro Akarem. The deposits are hosted in Late Precambrian mafic-ultramafic rocks and have different geologic histories. The Abu Swayel deposit occurs in conformable, lens-like mafic-ultramafic rocks in metasediments. Mineralization and host rocks are metamorphosed (amphibolite facies; 550-650ºC, 4-5 kbar) and syn-metamorphically sheared. Metamorphism and associated fluid regimes resulted in remobilization and transport of Cu-sulfides and PGE, and development of hydrosilicates. Michenerite, merenskyite, Pd-Bi-melonite, (NiPdBi)Te2, melonite, hessite, altaite and joséite-B occur as inclusions in mobilized sulfides and along cracks in garnet and plagioclase. The Genina Gharbia and Gabbro Akarem deposits are hosted in concentrically zoned, Alaskan-type, complexes; neither is metamorphosed. At Genina Gharbia, ore forms either disseminations in peridotite or massive patches in hornblende-pyroxenite in the vicinity of metasediments. Important petrographic features are a dominance of hornblende, biotite and chlorapatite and alteration of plagioclase to epidote. Disseminated and network sulfide ores are dominated by po, pn, cp and minor py; accessories are cobaltite, molybdenite and valleriite. Sulfide textures and host rock petrography suggest a prolonged late-magmatic hydrothermal event. Michenerite, merenskyite, Pd-Bi-melonite, altaite, hessite, tsumoite and native-Te are mainly present at sulfide-silicate contacts. The Gabbro Akarem deposit is hosted in dunite pipes where net-textured and massive sulfides are associated with spinel and Cr-magnetite. Michenerite, merenskyite, Pd-Bi-melonite and hessite occur mainly as inclusions in sulfides. Typical magmatic textures indicate the limited role of late- and post-magmatic hydrothermal processes. Different geological history of the different deposits enables examination of the

  5. Talitrid amphipods (Crustacea) as biomonitors for copper and zinc

    Science.gov (United States)

    Rainbow, P. S.; Moore, P. G.; Watson, D.

    1989-06-01

    Data are presented on the copper and zinc concentrations of four talitrid amphipod species (standard dry weight 10 mg), i.e. Orchestia gammarellus (Pallas), O. mediterranea Costa, Talitrus saltator Montagu and Talorchestia deshayesii (Audouin), from 31 sites in S.W. Scotland, N. Wales and S.W. England. More limited data are also presented for cadmium in O. gammarellus (three sites) and T. deshayesii (one site). In S.W. Scotland, copper concentrations were raised significantly in O. gammarellus from Whithorn and Auchencairn (Solway) and Loch Long and Holy Loch (Clyde). In S.W. England, copper concentrations were highest at Restronguet Creek, Torpoint and Gannel (Cornwall). Samples of O. gammarellus from Islay (inner Hebrides) taken adjacent to the effluent outfalls of local whisky distilleries fell into two groups based on copper concentrations (presumably derived from copper stills), the higher copper levels deriving from the more productive distilleries. High copper levels were found in T. saltator and Tal. deshayesii from Dulas Bay (Wales). Zinc levels in O. gammarellus were high in Holy Loch and Auchencairn (Scotland), Gannel and Torpoint (England) but extremely elevated (as was Zn in O. mediterranea) at Restronguet Creek. Zinc was also high in T. saltator from Dulas Bay (Wales), but not in Tal. deshayesii. Cadmium levels in O. gammarellus from Kilve (Bristol Channel) were much raised. These differences (a) conform with expectations of elevated bioavailability of these metals from well researched areas (S.W. England & N. Wales), and (b) identify hitherto unappreciated areas of enrichment in S.W. Scotland. Orchestia gammarellus is put forward as a suitable biomonitor for copper and zinc in British coastal waters.

  6. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  7. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  8. Electrodialytic Removal of Cadmium from Straw Ash

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne

    1999-01-01

    A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days of remed......A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days...

  9. Interplay of calcium and cadmium in mediating cadmium toxicity.

    Science.gov (United States)

    Choong, Grace; Liu, Ying; Templeton, Douglas M

    2014-03-25

    The environmentally important toxic metal, cadmium, exists as the Cd(2+) ion in biological systems, and in this state structurally resembles Ca(2+). Thus, although cadmium exerts a broad range of adverse actions on cells by virtue of its propensity to bind to protein thiol groups, it is now well appreciated that Cd(2+) participates in a number of Ca(2+)-dependent pathways, attributable to its actions as a Ca(2+) mimetic, with a central role for calmodulin, and the Ca(2+)/calmodlin-dependent protein kinase II (CaMK-II) that mediates effects on cytoskeletal dynamics and apoptotic cell death. Cadmium interacts with receptors and ion channels on the cell surface, and with the intracellular estrogen receptor where it binds competitively to residues shared by Ca(2+). It increases cytosolic [Ca(2+)] through several mechanisms, but also decreases transcript levels of some Ca(2+)-transporter genes. It initiates mitochondrial apoptotic pathways, and activates calpains, contributing to mitochondria-independent apoptosis. However, the recent discovery of the role CaMK-II plays in Cd(2+)-induced cell death, and subsequent implication of CaMK-II in Cd(2+)-dependent alterations of cytoskeletal dynamics, has opened a new area of mechanistic cadmium toxicology that is a focus of this review. Calmodulin is necessary for induction of apoptosis by several agents, yet induction of apoptosis by Cd(2+) is prevented by CaMK-II block, and Ca(2+)-dependent phosphorylation of CaMK-II has been linked to increased Cd(2+)-dependent apoptosis. Calmodulin antagonism suppresses Cd(2+)-induced phosphorylation of Erk1/2 and the Akt survival pathway. The involvement of CaMK-II in the effects of Cd(2+) on cell morphology, and particularly the actin cytoskeleton, is profound, favouring actin depolymerization, disrupting focal adhesions, and directing phosphorylated FAK into a cellular membrane. CaMK-II is also implicated in effects of Cd(2+) on microtubules and cadherin junctions. A key question for

  10. Solvothermal synthesis and thermoelectric properties of indium telluride nanostring-cluster hierarchical structures

    Directory of Open Access Journals (Sweden)

    Zhang Haiqian

    2011-01-01

    Full Text Available Abstract A simple solvothermal approach has been developed to successfully synthesize n-type α-In2Te3 thermoelectric nanomaterials. The nanostring-cluster hierarchical structures were prepared using In(NO33 and Na2TeO3 as the reactants in a mixed solvent of ethylenediamine and ethylene glycol at 200°C for 24 h. A diffusion-limited reaction mechanism was proposed to explain the formation of the hierarchical structures. The Seebeck coefficient of the bulk pellet pressed by the obtained samples exhibits 43% enhancement over that of the corresponding thin film at room temperature. The electrical conductivity of the bulk pellet is one to four orders of magnitude higher than that of the corresponding thin film or p-type bulk sample. The synthetic route can be applied to obtain other low-dimensional semiconducting telluride nanostructures. PACS: 65.80.-g, 68.35.bg, 68.35.bt

  11. Solvothermal synthesis and thermoelectric properties of indium telluride nanostring-cluster hierarchical structures

    Science.gov (United States)

    Tai, Guo'an; Miao, Chunyang; Wang, Yubo; Bai, Yunrui; Zhang, Haiqian; Guo, Wanlin

    2011-12-01

    A simple solvothermal approach has been developed to successfully synthesize n-type α-In2Te3 thermoelectric nanomaterials. The nanostring-cluster hierarchical structures were prepared using In(NO3)3 and Na2TeO3 as the reactants in a mixed solvent of ethylenediamine and ethylene glycol at 200°C for 24 h. A diffusion-limited reaction mechanism was proposed to explain the formation of the hierarchical structures. The Seebeck coefficient of the bulk pellet pressed by the obtained samples exhibits 43% enhancement over that of the corresponding thin film at room temperature. The electrical conductivity of the bulk pellet is one to four orders of magnitude higher than that of the corresponding thin film or p-type bulk sample. The synthetic route can be applied to obtain other low-dimensional semiconducting telluride nanostructures. PACS: 65.80.-g, 68.35.bg, 68.35.bt

  12. Synthesis and structure of undoped and indium-doped thermoelectric lead telluride nanoparticles

    Science.gov (United States)

    Kadel, Kamal; Kumari, Latha; Wang, Xuewen; Li, Wenzhi; Huang, Jian Yu; Provencio, Paula Polyak

    2014-05-01

    Undoped and indium (In)-doped lead telluride (PbTe) nanostructures were synthesized via solvothermal/hydrothermal route. The crystalline structure of the as-prepared undoped and In-doped PbTe samples was examined by X-ray diffraction (XRD) which indicated the formation of face-centered single-phase cubic crystal. A first principle calculation on indium doping shows that the indium atoms are more likely to replace lead (Pb) rather than to take the interstitial sites. Laser-induced breakdown spectroscopy (LIBS) analysis confirms that indium is incorporated into the PbTe matrix of the indium-doped PbTe samples. The effects of surfactant and synthesis temperature on the structure and morphology of the undoped PbTe were also investigated; it was found that PbTe nanostructures synthesized with the addition of surfactants exhibited uniform shapes and their size increased with the synthesis temperature.

  13. 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.

  14. An additive approach to low temperature zero pressure sintering of bismuth antimony telluride thermoelectric materials

    Science.gov (United States)

    Catlin, Glenn C.; Tripathi, Rajesh; Nunes, Geoffrey; Lynch, Philip B.; Jones, Howard D.; Schmitt, Devin C.

    2017-03-01

    This paper presents an additive-based approach to the formulation of thermoelectric materials suitable for screen printing. Such printing processes are a likely route to such thermoelectric applications as micro-generators for wireless sensor networks and medical devices, but require the development of materials that can be sintered at ambient pressure and low temperatures. Using a rapid screening process, we identify the eutectic combination of antimony and tellurium as an additive for bismuth-antimony-telluride that enables good thermoelectric performance without a high pressure step. An optimized composite of 15 weight percent Sb7.5Te92.5 in Bi0.5Sb1.5Te3 is scaled up and formulated into a screen-printable paste. Samples fabricated from this paste achieve a thermoelectric figure of merit (ZT) of 0.74 using a maximum processing temperature of 748 K and a total thermal processing budget of 12 K-hours.

  15. Joining of Half-Heusler and Bismuth Tellurides for Segmented Thermoelectric Generators

    Science.gov (United States)

    Ngan, Pham Hoang; Han, Li; Christensen, Dennis Valbjørn

    2018-01-01

    Segmented generators where the p- or n-type legs are formed by joining materials in series enables each material to operate in their most efficient temperature range. Here, we have fabricated and characterized segmented thermoelectric p- and n-type legs based on bismuth tellurides and half-Heusler alloys p-type Hf0.5Zr0.5CoSn0.2Sb0.8 and n-type Ti0.6Hf0.4NiSn. A two-step process was introduced to join the half-Heusler to the bismuth tellurides to form a segmented structure which was then characterized for its thermoelectric and structural properties. The output power generation was characterized under various hot side temperatures up to 873 K with the cold side fixed at 323 K. The stability of the joints was also investigated under heat treatment and thermal cycling. Under working temperatures from 323 K to 873 K, the obtained p-type segmented legs could deliver a power density of 0.3 W cm-2 and maximum voltage of 115 mV. With the same condition, the power density and the maximum voltage generated by n-type segmented leg were 0.25 W cm-2 and 102 mV. The area-specific contact resistances of the p- and n-type legs were 50 μΩ cm2 and 35 μΩ cm2, respectively. The output performance of each leg was ˜ 95% after 6 cycles from 323 K to 873 K.

  16. Zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  17. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Y. K. Arora. 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 ...

  18. 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 ...

  19. The zinc bromine battery

    Energy Technology Data Exchange (ETDEWEB)

    Jonshagen, B. [ZBB (Australia) Ltd., West Perth, WA (Australia)

    1996-12-31

    The Zinc Bromine Battery electrolyte is essentially zinc bromide salt dissolved in water. Unlike the lead acid and most other batteries, the Zinc Bromine Battery uses electrodes that cannot and do not take part in the reactions but merely serve as substrates for the reactions. There is therefore no loss of performance, as in most re-chargeable batteries, from repeated cycling which causes electrode material deterioration. When the Zinc Bromine Battery is completely discharged all the metal zinc plated on the negative electrodes is dissolved in the electrolyte and again produced the next time the batter is charged. In the discharged state the battery can be shorted and left that way indefinitely. This paper presents an overview of large scale Zinc Bromine battery systems that are currently being commercialized as an economically attractive alternative to utility upgrades. Also outlined is how the battery can improve the viability of renewable energy and reduce diesel use in isolated grids and remote power installations. (author). 11 figs., 2 refs.

  20. Evaluation of metallothionein formation as a proxy for zinc absorption in an in vitro digestion/caco-2 cell culture model

    Science.gov (United States)

    Caco-2 cell metallothionein (MT) formation was studied to determine if MT could be used as a proxy for zinc (Zn) absorption in a cell culture model. MT intracellular concentration was determined by using a cadmium/hemoglobin affinity assay. Cellular Zn uptake was determined in acid digests (5% HNO3)...