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Sample records for antimony

  1. Antimony Toxicity

    Directory of Open Access Journals (Sweden)

    Shyam Sundar

    2010-12-01

    Full Text Available Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically.

  2. Pentavalent Antimonials: New Perspectives for Old Drugs

    OpenAIRE

    Ribeiro, Raul R.; Cynthia Demicheli; Frédéric Frézard

    2009-01-01

    Pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate, have been used for more than half a century in the therapy of the parasitic disease leishmaniasis. Even though antimonials are still the first-line drugs, they exhibit several limitations, including severe side effects, the need for daily parenteral administration and drug resistance. The molecular structure of antimonials, their metabolism and mechanism of action are still being investigated. Some recent stud...

  3. Pentavalent Antimonials: New Perspectives for Old Drugs

    Directory of Open Access Journals (Sweden)

    Raul R. Ribeiro

    2009-06-01

    Full Text Available Pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate, have been used for more than half a century in the therapy of the parasitic disease leishmaniasis. Even though antimonials are still the first-line drugs, they exhibit several limitations, including severe side effects, the need for daily parenteral administration and drug resistance. The molecular structure of antimonials, their metabolism and mechanism of action are still being investigated. Some recent studies suggest that pentavalent antimony acts as a prodrug that is converted to active and more toxic trivalent antimony. Other works support the direct involvement of pentavalent antimony. Recent data suggest that the biomolecules, thiols and ribonucleosides, may mediate the actions of these drugs. This review will summarize the progress to date on the chemistry and biochemistry of pentavalent antimony. It will also present the most recent works being done to improve antimonial chemotherapy. These works include the development of simple synthetic methods for pentavalent antimonials, liposome-based formulations for targeting the Leishmania parasites responsible for visceral leishmaniasis and cyclodextrin-based formulations to promote the oral delivery of antimony.

  4. FIRST REPORT ON OTOTOXICITY OF MEGLUMINE ANTIMONIATE

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Valete-Rosalino

    2014-09-01

    Full Text Available Introduction: Pentavalent antimonials are the first drug of choice in the treatment of tegumentary leishmaniasis. Data on ototoxicity related with such drugs is scarcely available in literature, leading us to develop a study on cochleovestibular functions. Case Report: A case of a tegumentary leishmaniasis patient, a 78-year-old man who presented a substantial increase in auditory threshold with tinnitus and severe rotatory dizziness during the treatment with meglumine antimoniate, is reported. These symptoms worsened in two weeks after treatment was interrupted. Conclusion: Dizziness and tinnitus had already been related to meglumine antimoniate. However, this is the first well documented case of cochlear-vestibular toxicity related to meglumine antimoniate.

  5. Antimony bioavailability in mine soils

    International Nuclear Information System (INIS)

    Antimony has low bioavailability in mining and smelting contaminated soils and bacterial biosensors are not suitable for its detection. - Five British former mining and smelting sites were investigated and found to have levels of total Sb of up to 700 mg kg-1, indicating high levels of contamination which could be potentially harmful. However, this level of Sb was found to be biologically unavailable over a wide range of pH values, indicating that Sb is relatively unreactive and immobile in the surface layers of the soil, remaining where it is deposited rather than leaching into lower horizons and contaminating ground water. Sb, sparingly soluble in water, was unavailable to the bacterial biosensors tested. The bioluminescence responses were correlated to levels of co-contaminants such as arsenic and copper, rather than to Sb concentrations. This suggests that soil contamination by Sb due to mining and smelting operations is not a severe risk to the environment or human health provided that it is present as immobile species and contaminated sites are not used for purposes which increase the threat of exposure to identified receptors. Co-contaminants such as arsenic and copper are more bioavailable and may therefore be seen as a more significant risk

  6. Perspectives of antimony compounds in oncology

    Institute of Scientific and Technical Information of China (English)

    Pankaj SHARMA; Diego PEREZ; Armando CABRERA; Nee ROSAS; Jose Luis ARIAS

    2008-01-01

    Antimony, a natural element that has been used as a drug for over more than 100 years, has remarkable therapeutic efficacy in patients with acute promyelocytic leukemia. This review focuses on recent advances in developing antimony anti- cancer agents with an emphasis on antimony coordination complexes, Sb (Ⅲ) and Sb (V). These complexes, which include many organometallic complexes, may provide a broader spectrum of antitumoral activity. They were compared with classical platinum anticancer drugs. The review covers the literature data pub- lished up to 2007. A number of antimonials with different antitumoral activities are known and have diverse applications, even though little research has been done on their possibilities. It might be feasible to develop more specific and effective inhibitors for phosphatase-targeted, anticancer therapeutics through the screen- ing of sodium stibogluconate (SSG) and potassium antimonyltartrate-related compounds, which are comprised of antimony conjugated to different organic moieties. For example, SSG appears to be a better inhibitor than suramin which is a compound known for its antineoplastic activity against several types of cancers.

  7. Preparation of nanosized antimony by mechanochemical reduction of antimony sulphide Sb2S3

    International Nuclear Information System (INIS)

    The preparation of nanosized antimony (grain size 19 nm) by high-energy milling of antimony sulphide Sb2S3 with elemental Fe as reducing element is reported. The mechanochemical reduction was performed in a planetary ball mill for 10-180 min. The process is rather straightforward with elemental antimony and iron sulphide (pyrrhotite-4H) being the only solid-state products. The process kinetics as described by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) magnetometry shows that most of the reduction is complete after 60 min of milling

  8. The Membrane Electrowinning Separation of Antimony from a Stibnite Concentrate

    Science.gov (United States)

    Yang, Jian-Guang; Yang, Sheng-Hai; Tang, Chao-Bo

    2010-06-01

    The main purpose of this study was to characterize and to extract antimony from a stibnite concentrate through electrowinning. This article reports an account of a study conducted on the optimization of the process parameters for antimony pentachloride circular leaching, purification, and electrowinning of antimony from antimony trichloride solution. The effect of electrowinning parameters, such as antimony and sodium chloride concentration in the catholyte, temperature, current density, polar distance, etc., on the voltage requirement and the current efficiency (CE) of antimony electrodeposition was explored. A maximum CE of more than 97 pct was attained with a catholyte composition of 70-g/L antimony, 25-g/L NaCl, 4.5-mol/L hydrogen ion concentration, with an anolyte composition of 40-g/L antimony trichloride at a temperature of 328 K (55 °C), a 4-cm polar distance, and a cathode current density of 200 A/m2. Under the optimized conditions, the CE was more than 97 pct, and a 99.98 pct antimony plate was obtained on the cathode. The chemical content analysis of the resulting anolyte was indicated to be 97 pct antimony pentachloride and 3 pct antimony trichloride, which could be recycled to leaching tank as the leaching agent.

  9. Synthesis and application of antimony pent(isooctyl thioglycollate)

    Institute of Scientific and Technical Information of China (English)

    LIU You-nian; LI Hong-bing; SHU Wan-gen; CHEN Qi-yuan

    2005-01-01

    A new type of thermal stabilizer, antimony pent(isooctyl thioglycollate)(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride(PVC). The results show that the thermal stability time is 52 min at 200 ℃ by heat-ageing oven test when adding 2.5% thermal stabilizer to PVC resin. Compared with antimony tris(isooctyl thiolycollate), the initial thermal stability of antimony pent(isooctyl thioglycollate) is better than that of antimony tris(isooctyl thioglycollate), while the long-term thermal stability time is shorter than that of antimony tris(isooctyl thioglycollate). Meanwhile, the synergism of antimony pent(isooctyl thioglycollate) with calcium stearate was studied, indicating that when the mass ratio of antimony pent(isooctyl thioglycollate) to calcium stearate is 2:1, the thermal stability time of PVC is 58 min.

  10. Novel methods for the encapsulation of meglumine antimoniate into liposomes

    Directory of Open Access Journals (Sweden)

    F. Frézard

    2000-07-01

    Full Text Available The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs. High encapsulation efficiencies (from 28 to 58% and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3 were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast, free meglumine antimoniate was found to be inefficient when administered at a comparable dose of antimony. This novel liposome-based meglumine antimoniate formulation appears to be promising as a pharmaceutical product for the treatment of visceral leishmaniasis.

  11. Microbial antimony biogeochemistry: Enzymes, regulation, and related metabolic pathways

    Science.gov (United States)

    Li, Jingxin; Qian Wang; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher; Wang, Gejiao

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.”

  12. Vacuum Evaporation Technology for Treating Antimony-Rich Anode Slime

    Science.gov (United States)

    Qiu, Keqiang; Lin, Deqiang; Yang, Xuelin

    2012-11-01

    A vacuum evaporation technology for treating antimony-rich anode slime was developed in this work. Experiments were carried out at temperatures from 873 K to 1073 K and residual gas pressures from 50 Pa to 600 Pa. During vacuum evaporation, silver from the antimony-rich anode slime was left behind in the distilland in a silver alloy containing antimony and lead, and antimony trioxide was evaporated. The experimental results showed that 92% by weight of antimony can be removed, and the silver content in the alloy was up to 12.84%. The antimony trioxide content in the distillate was more than 99.7%, and the distillate can be used directly as zero-grade antimony trioxide (China standard).

  13. In vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    International Nuclear Information System (INIS)

    Pentavalent antimony, as meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam), is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer studies have a potential in pharmaceutical development. The aim of this study was to obtain a radiotracer for antimony, with suitable physical and biological properties. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes 122 Sb and 124 Sb, with high radionuclidic purity and good specific activity. This compound showed the same antileishmanial activity as the native compound. The use of the radiotracers, easily created by neutron irradiation, could be an interesting tool to solve important questions in antimonial pharmacology. (author)

  14. In vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    Energy Technology Data Exchange (ETDEWEB)

    Borborema, Samanta Etel Treiger; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Lab. de Biologia Molecular]. E-mail: samanta@usp.br; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Centro de Radiofarmacia]. E-mail: jaosso@ipen.br; Andrade Junior, Heitor Franco de [Instituto de Medicina Tropical de Sao Paulo (IMT-SP), SP (Brazil). Lab. de Protozoologia]. E-mail:hfandrad@usp.br

    2005-10-15

    Pentavalent antimony, as meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam), is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer studies have a potential in pharmaceutical development. The aim of this study was to obtain a radiotracer for antimony, with suitable physical and biological properties. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes {sup 122} Sb and {sup 124} Sb, with high radionuclidic purity and good specific activity. This compound showed the same antileishmanial activity as the native compound. The use of the radiotracers, easily created by neutron irradiation, could be an interesting tool to solve important questions in antimonial pharmacology. (author)

  15. In Vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    OpenAIRE

    Samanta Etel Treiger Borborema; Heitor Franco de Andrade Junior; João Alberto Osso Junior; Nanci do Nascimento

    2005-01-01

    Pentavalent antimony, as meglumine antimoniate (Glucantime® ) or sodium stibogluconate (Pentostam® ), is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer...

  16. The exposure to and health effects of antimony

    DEFF Research Database (Denmark)

    Cooper, Ross G.; Harrison, Adrian Paul

    2009-01-01

    . Antimony toxicity is dependent on the exposure dose, duration, route (breathing, eating, drinking, or skin contact), other chemical exposures, age, sex, nutritional status, family traits, life style, and state of health. Chronic exposure to antimony in the air at levels of 9 mg/m3 may exacerbate irritation...

  17. The presence of antimony in various dental filling materials

    International Nuclear Information System (INIS)

    Antimony was determined in a number of non-metallic dental materials currently used for tooth restoration. The method applied was instrumental neutron activation analysis. The concentration of antimony in some of the brands tested was found to be as high as 900 fold that in the normal hard dental tissues. (author)

  18. Pharmacokinetic of antimony in mice with cutaneous Leishmaniasis

    International Nuclear Information System (INIS)

    Cutaneous Leishmaniasis (CL) remains a major world health problem, with about 1.5 million new cases each year. Caused by protozoa Leishmania, in South America, this infection can vary from a chronic skin ulcer, to an erosive mucosal disease and severe facial disfigurement. Pentavalent antimony (Sb+5) as sodium stibogluconate (Pentostam) or meglumine antimoniate (Glucantime) are main drugs for treating most forms of human leishmaniasis. For six decades, despite the recent developments, the effective therapy to cutaneous leishmaniasis has been based on long parenteral courses of such drugs, even though these are fairly costly, toxic and inconvenient to use, without adequate knowledge on their pharmacokinetics or mechanism of action. Pharmacokinetics studies could be based on bioactive traceable drugs, usually with radioactive isotopes, but antimony radioisotopes are unavailable commercially. Neutron irradiation is a powerful tool in the analysis of mineral content of samples, for antimony, there are at least two main isotopes that could be formed after neutron irradiation in nuclear reactor. The aim of the present study was to construct antimony salts with those radioisotopes to obtain tracers to compare the pharmacokinetic and the tissue distribution of neutron irradiated meglumine antimoniate in healthy and cutaneous leishmaniasis experimentally infected mice. Meglumine antimoniate, (Glucantime, Aventis, S.P, Brazil), was neutron irradiated inside the IEA-R1 nuclear reactor (IPEN/CNEN-SP), producing two radioisotopes 122Sb and 124Sb. Its biodistribution was verified in BALB/c mice experimentally infected with Leishmania (Leishmania) Amazonensis, which received a single intraperitoneal dose of the drug. At different times after injection, the tissues and blood were excised and activity measured in a NaI (Tl) scintillation counter. Compared with the healthy mice, experimentally infected mice had significantly lower maximum concentration of antimony and high uptake in

  19. Pharmacokinetic of antimony in mice with cutaneous Leishmaniasis

    Energy Technology Data Exchange (ETDEWEB)

    Borborema, Samanta E.T.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil). Lab. de Biologia Molecular]. E-mails: samanta@usp.br; nnascime@ipen.br; Andrade Junior, Heitor F. de [Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil). Lab. de Biologia Molecular; Instituto de Medicina Tropical de Sao Paulo, Sao Paulo, SP (Brazil); E-mail: hfandrad@usp.br; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil). Centro de Radiofarmacia]. E-mail: jaosso@ipen.br

    2007-07-01

    Cutaneous Leishmaniasis (CL) remains a major world health problem, with about 1.5 million new cases each year. Caused by protozoa Leishmania, in South America, this infection can vary from a chronic skin ulcer, to an erosive mucosal disease and severe facial disfigurement. Pentavalent antimony (Sb{sup +5}) as sodium stibogluconate (Pentostam) or meglumine antimoniate (Glucantime) are main drugs for treating most forms of human leishmaniasis. For six decades, despite the recent developments, the effective therapy to cutaneous leishmaniasis has been based on long parenteral courses of such drugs, even though these are fairly costly, toxic and inconvenient to use, without adequate knowledge on their pharmacokinetics or mechanism of action. Pharmacokinetics studies could be based on bioactive traceable drugs, usually with radioactive isotopes, but antimony radioisotopes are unavailable commercially. Neutron irradiation is a powerful tool in the analysis of mineral content of samples, for antimony, there are at least two main isotopes that could be formed after neutron irradiation in nuclear reactor. The aim of the present study was to construct antimony salts with those radioisotopes to obtain tracers to compare the pharmacokinetic and the tissue distribution of neutron irradiated meglumine antimoniate in healthy and cutaneous leishmaniasis experimentally infected mice. Meglumine antimoniate, (Glucantime, Aventis, S.P, Brazil), was neutron irradiated inside the IEA-R1 nuclear reactor (IPEN/CNEN-SP), producing two radioisotopes {sup 122}Sb and {sup 124}Sb. Its biodistribution was verified in BALB/c mice experimentally infected with Leishmania (Leishmania) Amazonensis, which received a single intraperitoneal dose of the drug. At different times after injection, the tissues and blood were excised and activity measured in a NaI (Tl) scintillation counter. Compared with the healthy mice, experimentally infected mice had significantly lower maximum concentration of antimony

  20. Separation of traffic related antimony compounds

    International Nuclear Information System (INIS)

    Complete text of publication follows. It is known that most of the brake pads contain Sb2S3 as lubricant to achieve better friction stability. Due to braking the brake lining crumbles away and its Sb content gets into the air. As a result of the temperature increase accompanying the braking a part of the antimony may oxidize to oxides, as Sb2O3 or even to the more stable form, Sb2O4. Since Sb2O3 more readily soluble than the others, its absorption from the lung so its environmental impact effect is more harmful. After a systematic investigation involving solubilization of the solid compounds, citric and tartaric acid as well as 6 mol/dm3 HCl were tested for leaching of trace antimony compounds from natural matrix. To prepare reference material related to these species, soil and activated charcoal was spiked in 10 μg/g concentration with all the three material (Sb2S3, Sb2O3,Sb2O4). separately. Recovery of the different forms was checked by graphite furnace atomic absorption spectrometric (GFAAS) analysis of the leachates. The soil was confirmed to oxidize the sulfide content while the activated charcoal was established to enrich antimony from HCl solution as ion association complex. It was concluded, that Sb2S3 is leached only in slight amount in 4 hours by 0.1-0.5 mol/dm3 citric acid, while leaching of Sb2O3 is quantitative. On the other side, it was proved that Sb2O3 as well as Sb2S3 traces are soluble in 6 HCl solution in 60 min, whilst Sb2O4 is not destroyed. So, the Sb2O3 and Sb2S3 content of a flying dust can be determined. The GFAAS temperature program had to be modified in order to be capable to analyze high organic matrix as citric or tartaric acid even in 0.5 mol/dm3 concentration. Concerning their decomposition temperature an additional step was inserted into the temperature program, pyrolysis on 300 and 400 deg C, respectively. The antimony concentration of the highly acidic leachates were determined by hydride generation GFAAS. The reproducibility of

  1. Reducing NOx emissions with antimony additive

    International Nuclear Information System (INIS)

    This paper describes improvement in a process for the catalytic cracking of a heavy hydrocarbon feed containing Ni and nitrogen compounds by contact with a circulating inventory of catalytic cracking catalyst to produce catalytically cracked products and spent catalyst. It comprises: Ni or Ni compounds and coke comprising nitrogen compounds, and wherein the spent catalyst is regenerated by contact with oxygen or an oxygen-containing gas in a catalyst regeneration zone operating at catalyst regeneration conditions to produce hot regenerated catalyst comprising Ni or Ni compounds which is recycled to catalytically crack the heavy feed and the catalyst regeneration zone produces a flue gas comprising CO, CO2 and oxides of nitrogen, NOx. The improvement comprises: adding to the circulating catalyst inventory CO combustion promoter in an amount equivalent to 0.01 to 50 wt ppm Pt to reduce the CO content of the flue gas and reducing the NOx content of the flue gas by adding to the circulating catalyst inventory a separate particle additive comprising antimony. The additive being added in an amount sufficient to reduce the production of NOx relative to operation without the additive, and wherein the additive comprises a compound of antimony which does not substantially passivate the Ni or Ni compounds present on the cracking catalyst, nor deactivate the CO combustion promoter

  2. Investigation into antimony mobility in sewage sludge fermentation.

    Science.gov (United States)

    Wehmeier, Silvia; Feldmann, Jörg

    2005-12-01

    Antimony is distributed in the environment in inorganic and organic species with different solubility and mobility characters. Here we investigate the transformation of antimony in view of biomethylation during sewage sludge fermentation as a case study for an anaerobic environment. Our approach was to identify if antimony methylation follows the Challenger pathway by using isotopically enriched antimonite (123Sb(v)). The antimony source was subjected to methylation in sewage sludge, an anaerobic dominant methanogenic Archaea community. The antimony species were determined in the gas phase using cryotrapping (CT)-GC-ICP-MS, and in the medium (sewage slude) by hydride generation (HG) prior CT-GC-ICP-MS. The determined 123/121Sb isotope ratios in the volatile trimethylstibine and non-volatile methylantimony species indicated that the methylation follows the proposed methylation pathway. With this approach we were able to quantify 123Sb incorporation into monomethyl-, dimethyl- and trimethylantimony, respectively. The incorporation decreased with further methylation from 91% to 82% and 73%. Volatilisation as trimethystibine was generally lower than 0.1%, however, up to 0.8% of added antimony was found methylated to methylantimony species and mainly accumulated in the cell. Moreover, antimony biomethylation was enhanced by stimulation of the anaerobic communities of methanogenic Archaea and sulfate reducing bacteria (SRB), with the methanogens showing a higher activity. PMID:16307071

  3. Structural and electrical characterization of zinc oxide doped with antimony

    Directory of Open Access Journals (Sweden)

    G. Juárez Díaz

    2014-08-01

    Full Text Available In this work we report the results of structural and electrical characterization realized on zinc oxide single crystal samples with (001 orientation, which were doped with antimony. Doping was carried out by antimony thermal diffusion at 1000 °C for periods of 1 and 2 hours under nitrogen environment from a solid source formed by antimony oxide. Electrical characterization by I-V curves and Hall effect shown an increase in acceptor concentration which demonstrates that doping is effective and create holes in zinc oxide samples.

  4. Nanometric Antimony Powder Synthesis by Activated Alkaline Hydride Reduction of Antimony Pentachloride

    International Nuclear Information System (INIS)

    A novel chemical reduction method using an activated alkaline hydride (LiH or NaH-t-BuONa) in tetrahydrofuran solvent has been applied to antimony salt reduction. X-ray diffraction and transmission electron microscopy studies have been carried out to characterize the morphology and structure of the materials. Alkali hydride nature influence has been proved. In both cases the process allows to prepare antimony particles in nanometer range from few nanometers to about 20nm which could be used as anodic materials for lithium-ion batteries. With lithium hydride well-crystallized particles inclined to agglomeration were observed whereas finely dispersed amorphous particles were pointing out after activated sodium hydride reduction

  5. Deposition of rod-shaped antimony sulfide thin films from single-source antimony thiosemicarbazone precursors

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jasmine B.; Sawant, Narayan V. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai - 400 098 (India); Garje, Shivram S., E-mail: ssgarje@chem.mu.ac.i [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai - 400 098 (India)

    2010-04-02

    Antimony sulfide thin films were deposited on glass substrates by aerosol assisted chemical vapour deposition technique using single source precursors, namely, antimony(III) thiosemicarbazones, SbCl{sub 3}(L) (L = thiosemicarbazones of thiophene-2-carboxaldehyde (1) and cinnamaldehyde (2)). The deposited films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and UV-visible spectroscopy in order to identify their phases, morphologies, compositions and optical properties respectively. These characterizations revealed that the films were comprised of rod-shaped particles of orthorhombic stibnite (Sb{sub 2}S{sub 3}) with a Sb:S stoichiometry of {approx} 1:1.3. The calculated optical band gap from UV-vis absorption spectrum is found to be 3.48 eV.

  6. Antimony mobility in Japanese agricultural soils and the factors affecting antimony sorption behavior

    International Nuclear Information System (INIS)

    The mobility of antimony (Sb) in Japanese agricultural soils was studied by radiotracer experiments using 124Sb tracer. The soil-solution distribution coefficients (K d) of Sb were measured for 110 soil samples. These K ds ranged from 1 to 2065 L kg-1; the geometric mean was 62 L kg-1 excluding one extremely high value, 2065 L kg-1. Experimental measurement of K d showed a decrease with both increasing pH and increasing phosphate concentration. The latter suggested that one aspect of the Sb sorption phenomena in Japanese soil was influenced by specific adsorption of anions such as phosphate. However, other aspects could not be explained by this specific adsorption mechanism, because only 20-40% of soil-sorbed Sb could be extracted by phosphate solution. - Antimony mobility in tested Japanese agricultural soils was generally low and was affected by pH and phosphate concentration

  7. Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer.

    Science.gov (United States)

    Kamada, T; Yamamoto, Y

    1977-05-01

    The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 mul, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water. PMID:18962096

  8. Antimony distribution and environmental mobility at an historic antimony smelter site, New Zealand

    International Nuclear Information System (INIS)

    A historic antimony smelter site at Endeavour Inlet, New Zealand has smelter residues with up to 17 wt.% antimony. Residues include coarse tailings (cm scale particles, poorly sorted), sand tailings (well sorted) and smelter slag (blocks up to 30 cm across). All of this material has oxidised to some degree over the ca. 100 years since the site was abandoned. Oxidation has resulted in acidification of the residues down to pH 2-5. Smelter slag contains pyrrhotite (FeS) and metallic antimony, and oxidation is restricted to surfaces only. The coarse tailings are the most oxidised, and few sulfide grains persist. Unoxidised sand tailings contain 10-20 vol.% stibnite (Sb2S3) containing up to 5% As, with subordinate arsenopyrite (FeAsS), and minor pyrite (FeS2). The sand tailings are variably oxidised on a scale of 2-10 cm, but original depositional layering is preserved during oxidation and formation of senarmontite (Sb2O3). Oxidation of sand tailings has resulted in localised mobility of both Sb and As on the cm scale, resulting in redistribution of these metalloids with iron oxyhydroxide around sand grain boundaries. Experiments demonstrate that Sb mobility decreases with time on a scale of days. Attenuation of both As and Sb occurs due to adsorption on to iron oxyhydroxides which are formed during oxidation of the smelter residues. There is no detectable loss of Sb or As from the smelter site into the adjacent river, <50 m away, which has elevated Sb (ca. 20 μg/l) and As (ca. 7 μg /l) from mineralised rocks upstream. Despite the high concentrations of Sb and As in the smelter residues, these metalloids are not being released into the environment. - High levels of antimony in primitive smelter soils remain largely immobile on the metre scale

  9. Tissue distribution of residual antimony in rats treated with multiple doses of meglumine antimoniate

    Directory of Open Access Journals (Sweden)

    Deise Riba Coelho

    2014-07-01

    Full Text Available Meglumine antimoniate (MA and sodium stibogluconate are pentavalent antimony (SbV drugs used since the mid-1940s. Notwithstanding the fact that they are first-choice drugs for the treatment of leishmaniases, there are gaps in our knowledge of their toxicological profile, mode of action and kinetics. Little is known about the distribution of antimony in tissues after SbV administration. In this study, we evaluated the Sb content of tissues from male rats 24 h and three weeks after a 21-day course of treatment with MA (300 mg SbV/kg body wt/d, subcutaneous. Sb concentrations in the blood and organs were determined by inductively coupled plasma-mass spectrometry. In rats, as with in humans, the Sb blood levels after MA dosing can be described by a two-compartment model with a fast (t1/2 = 0.6 h and a slow (t1/2 >> 24 h elimination phase. The spleen was the organ that accumulated the highest amount of Sb, while bone and thyroid ranked second in descending order of tissues according to Sb levels (spleen >> bone, thyroid, kidneys > liver, epididymis, lungs, adrenals > prostate > thymus, pancreas, heart, small intestines > skeletal muscle, testes, stomach > brain. The pathophysiological consequences of Sb accumulation in the thyroid and Sb speciation in the liver, thyroid, spleen and bone warrant further studies.

  10. How can we adapt to geological scarcity of antimony? Investigation of antimony's substitutability and of other measures to achieve a sustainable use

    NARCIS (Netherlands)

    Henckens, M.L.C.M.; Driessen, P.P.J.; Worrell, E.

    2016-01-01

    Abstract Antimony is an element that is applied in many useful applications for mankind. However, antimony resources are very scarce, when comparing the current extraction rates with the availability of antimony containing ores. From an inter-temporal sustainability perspective, current generations

  11. Cloud point extraction combined with electrothermal atomic absorption spectrometry for the speciation of antimony(III) and antimony(V) in food packaging materials

    International Nuclear Information System (INIS)

    A simple, sensitive method for the speciation of inorganic antimony by cloud point extraction combined with electrothermal atomic absorption spectrometry (ETAAS) is presented and evaluated. The method based on the fact that formation of a hydrophobic complex of antimony(III) with ammonium pyrrolidine dithiocarbamate (APDC) at pH 5.0 and subsequently the hydrophobic complex enter into surfactant-rich phase, whereas antimony(V) remained in aqueous solutions. Antimony(III) in surfactant-rich phase was analyzed by ETAAS after dilution by 0.2 mL nitric acid in methanol (0.1 M), and antimony(V) was calculated by subtracting antimony(III) from the total antimony after reducing antimony(V) to antimony(III) by L-cysteine. The main factors affecting the cloud point extraction, such as pH, concentration of APDC and Triton X-114, equilibrium temperature and incubation time, sample volume were investigated in detail. Under the optimum conditions, the detection limit (3σ) of the proposed method was 0.02 ng mL-1 for antimony(III), and the relative standard deviation was 7.8% (c = 1.0 ng mL-1, n = 7). The proposed method was successfully applied to speciation of inorganic antimony in the leaching solutions of different food packaging materials with satisfactory results.

  12. Cloud point extraction combined with electrothermal atomic absorption spectrometry for the speciation of antimony(III) and antimony(V) in food packaging materials.

    Science.gov (United States)

    Jiang, Xiuming; Wen, Shengping; Xiang, Guoqiang

    2010-03-15

    A simple, sensitive method for the speciation of inorganic antimony by cloud point extraction combined with electrothermal atomic absorption spectrometry (ETAAS) is presented and evaluated. The method based on the fact that formation of a hydrophobic complex of antimony(III) with ammonium pyrrolidine dithiocarbamate (APDC) at pH 5.0 and subsequently the hydrophobic complex enter into surfactant-rich phase, whereas antimony(V) remained in aqueous solutions. Antimony(III) in surfactant-rich phase was analyzed by ETAAS after dilution by 0.2 mL nitric acid in methanol (0.1M), and antimony(V) was calculated by subtracting antimony(III) from the total antimony after reducing antimony(V) to antimony(III) by l-cysteine. The main factors affecting the cloud point extraction, such as pH, concentration of APDC and Triton X-114, equilibrium temperature and incubation time, sample volume were investigated in detail. Under the optimum conditions, the detection limit (3 sigma) of the proposed method was 0.02 ng mL(-1) for antimony(III), and the relative standard deviation was 7.8% (c=1.0 ng mL(-1), n=7). The proposed method was successfully applied to speciation of inorganic antimony in the leaching solutions of different food packaging materials with satisfactory results. PMID:19853991

  13. Antimony distribution and environmental mobility at an historic antimony smelter site, New Zealand.

    Science.gov (United States)

    Wilson, N J; Craw, D; Hunter, K

    2004-05-01

    A historic antimony smelter site at Endeavour Inlet, New Zealand has smelter residues with up to 17 wt.% antimony. Residues include coarse tailings (cm scale particles, poorly sorted), sand tailings (well sorted) and smelter slag (blocks up to 30 cm across). All of this material has oxidised to some degree over the ca. 100 years since the site was abandoned. Oxidation has resulted in acidification of the residues down to pH 2-5. Smelter slag contains pyrrhotite (FeS) and metallic antimony, and oxidation is restricted to surfaces only. The coarse tailings are the most oxidised, and few sulfide grains persist. Unoxidised sand tailings contain 10-20 vol.% stibnite (Sb2S3) containing up to 5% As, with subordinate arsenopyrite (FeAsS), and minor pyrite (FeS2). The sand tailings are variably oxidised on a scale of 2-10 cm, but original depositional layering is preserved during oxidation and formation of senarmontite (Sb2O3). Oxidation of sand tailings has resulted in localised mobility of both Sb and As on the cm scale, resulting in redistribution of these metalloids with iron oxyhydroxide around sand grain boundaries. Experiments demonstrate that Sb mobility decreases with time on a scale of days. Attenuation of both As and Sb occurs due to adsorption on to iron oxyhydroxides which are formed during oxidation of the smelter residues. There is no detectable loss of Sb or As from the smelter site into the adjacent river, <50 m away, which has elevated Sb (ca. 20 microg/l) and As (ca. 7 microg/l) from mineralised rocks upstream. Despite the high concentrations of Sb and As in the smelter residues, these metalloids are not being released into the environment. PMID:14987811

  14. Heat-treated Saccharomyces cerevisiae for antimony speciation and antimony(III) preconcentration in water samples

    International Nuclear Information System (INIS)

    An analytical method was developed for antimony speciation and antimony(III) preconcentration in water samples. The method is based on the selective retention of Sb(III) by modified Saccharomyces cerevisiae in the presence of Sb(V). Heat, caustic and solvent pretreatments of the biomass were investigated to improve the kinetics and thermodynamics of Sb(III) uptake process at room temperature. Heating for 30 min at 80 deg. C was defined as the optimal treatment. Antimony accumulation by the cells was independent of pH (5-10) and ionic strength (0.01-0.1 mol L-1). 140 mg of yeast and 2 h of contact were necessary to ensure quantitative sequestration of Sb(III) up to 750 μg L-1. In these conditions, Sb(V) was not retained. Sb(V) was quantified in sorption supernatant by inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma optical emission spectrometry (ICP-OES). Sb(III) was determined after elution with 40 mmol L-1 thioglycolic acid at pH 10. A preconcentration factor close to nine was achieved for Sb(III) when 100 mL of sample was processed. After preconcentration, the detection limits for Sb(III) and Sb(V) were 2 and 5 ng L-1, respectively, using ICP-MS, 7 and 0.9 μg L-1 using ICP-OES. The proposed method was successfully applied to the determination of Sb(III) and Sb(V) in spiked river and mineral water samples. The relative standard deviations (n = 3) were in the 2-5% range at the tenth μg L-1 level and less than 10% at the lowest Sb(III) and Sb(V) tested concentration (0.1 μg L-1). Corrected recoveries were in all cases close to 100%

  15. Characterization of Antimony exchanged Hydrous Zirconium oxide

    International Nuclear Information System (INIS)

    Pentavalent 125Sb bearing species are persistent even after chemical treatment in low level liquid waste effluents. It was found that Hydrous Zirconium Oxide (HZO) had an efficiency better that 80% for Sb pick in a wide pH range of 1-13 for concentrations up to 150 mg/l. HZO coated on poly urethane foam was used in WMD Trombay for removal for 125Sb from waste effluent. The exchange capacity of HZO with 40% moisture content ranged between 0.7-0.9 meq/g for removal of Sb(V). In order to understand the mechanism of Sb uptake by HZO, freshly prepared HZO exchanged with trivalent and pentavalent Sb from aqueous solutions was characterized with FTIR and XRD. The FTIR analysis confirmed presence of surface hydroxyl groups. Sb exchanged HZO samples showed modification in characteristic frequencies of -OH group when compared with unexchanged HZO. The broadening of -OH stretching frequency at 3400 cm-1 in Sb exchanged HZO-B indicated of ingress of disorderliness or weakening of -OH bond. The spectral shift was towards lower frequencies indicating clustering of low frequency bonds around -OH groups and weakening of -O-H bond. This change in -OH profile shows it to be the site of exchange/sorption. The XRD analysis showed HZO to be amorphous. Both pentavalent and trivalent antimony was exchanged with HZO, heat treated at 600℃ and analysed with XRD. Hydrous Zirconium Oxide (Heated up to 600℃) had an X-Ray diffraction pattern identical to Aldrich make pure Zirconia (Monoclinic) (PCPDF-371484). Pentavalent Sb loaded HZO and trivalent Sb loaded HZO showed different crystalline structures on heat treatment. Sb(V) loaded HZO shows Orthorhombic structure (PCCPDF-371413) and Sb(III) exchanged Zirconia shows tetragonal structure (PCPDF-501089). Cubic Sb2O5 antimony oxide crystals were also detected in the sample. From the above analysis it could be understood that the surface hydroxyl group helped in sorption of Sb species. But this was not purely surface phenomenon. Sb after

  16. Noninferiority of Miltefosine Versus Meglumine Antimoniate for Cutaneous Leishmaniasis in Children

    OpenAIRE

    Rubiano, Luisa Consuelo; Miranda, María Consuelo; Muvdi Arenas, Sandra; Montero, Luz Mery; Rodríguez-Barraquer, Isabel; Garcerant, Daniel; Prager, Martín; Osorio, Lyda; Rojas, Maria Ximena; Pérez, Mauricio; Nicholls, Ruben Santiago; Gore Saravia, Nancy

    2012-01-01

    Background. Children have a lower response rate to antimonial drugs and higher elimination rate of antimony (Sb) than adults. Oral miltefosine has not been evaluated for pediatric cutaneous leishmaniasis.

  17. Martensite transformation in antimony implanted stainless steel

    International Nuclear Information System (INIS)

    The authors have used Rutherford backscattering analysis (RBS) and transmission electron microscopy (TEM) and diffraction to investigate austenitic stainless steel crystals implanted at room temperature with 80 keV Sb+ ions to a fluence of 5 x 1020 ions/m2, thus providing implantation with a heavy group V element. RBS channeling spectra from implanted crystals show a damage peak which approaches the height of the random level and therefore indicates a very high degree of disorder in the implanted layers. The distribution of the disorder extends to a depth 3-5 times the depth of the primary radiation damage. The Sb peaks under channeling as well as random conditions are indistinguishable, confirming that substitutionality during implantation is negligible. To establish the nature of the disorder which cannot be assessed from the RBS analysis alone, and in particular to assess whether an amorphous alloy is formed in the implanted layer as indicated from the RBS spectra, samples implanted under similar conditions were investigated in the TEM. Significant extra spots in the patterns can be ascribed to the presence of a radiation induced b.c.c. phase of martensitic origin. The result that a significant amount of martensite can be induced by antimony implantation seems to indicate that the main driving force for the transition is due to damage induced stress concentrations. (Auth.)

  18. Recovery of antimony-125 from tin-124 irradiated by neutrons

    International Nuclear Information System (INIS)

    Currently, antimony-125 is produced by recovery from tin-124 irradiated by neutrons in nuclear reactors. The radionuclide builds up following the pathway: Sn-124 (n,γ) → Sn-125 (β-) (9.6 days) → Sb-125 ((β-) (2.77 years) The cross-section of the (n,γ) reaction is low (0.2 barn), therefore tin metal enriched with tin-124 is used. It should be noted that the use of an enriched target decreases the build-up of other radionuclides as compared to the natural mixture of tin isotopes. Published data showed that ion exchange on anion exchangers is one of the most promising procedures of recovery of antimony-125 from irradiated tin-124. We irradiated tin metal enriched with tin-124 (approximately 96%). After cooling and storage, the specific activity was 5 μCi per g of metal. The irradiated sample was dissolved in concentrated hydrochloric acid containing hydrogen peroxide or bromine in order to convert tin to the tetravalent state and antimony to the pentavalent state. We used tin-119m as a mark for an express gamma-spectrometric determination of the distribution coefficients. We studied the separation of Sb-125 and tin on strongly basic (Dowex-50 and AV-17), moderately basic (AN-2FN), and weakly basic (AN-31) ion exchangers. Hydrochloric acid, a mixture of hydrochloric and hydrobromic acids, and nitric acid were used as the elutriating agents. The samples from chromatography were subjected to gamma-spectrometric analysis using Si(Li) and Ge(Li) semiconductor detectors. In experiments examining the separation on strongly basic anion exchangers, the attained decontamination factor for removal of tin from antimony-125 was approximately 104-105 in one cycle. In the experiments devoted to the separation on moderately basic and weakly basic anion exchangers, tin was eluted before antimony-125. This should improve reasonably the regeneration of the enriched tin samples. The most interesting and significant results were obtained in the study of separation of antimony-125

  19. Oral Delivery of Meglumine Antimoniate-β-Cyclodextrin Complex for Treatment of Leishmaniasis

    OpenAIRE

    Demicheli, Cynthia; Ochoa, Rosemary; da Silva, José B. B.; Falcão, Camila A. B.; Rossi-Bergmann, Bartira; Melo, Alan L.; Sinisterra, Ruben D.; Frézard, Frédéric

    2004-01-01

    The need for daily parenteral administration represents one of the most serious limitations in the clinical use of pentavalent antimonials against leishmaniasis. In this work, we investigated the ability of β-cyclodextrin to enhance the oral absorption of antimony and to promote the oral efficacy of meglumine antimoniate against experimental cutaneous leishmaniasis. The occurrence of interactions between β-cyclodextrin and meglumine antimoniate was demonstrated through the changes induced in ...

  20. The influence of pet containers on antimony concentration in bottled drinking water

    OpenAIRE

    Perić-Grujić Aleksandra A.; Radmanovac Aleksandar R.; Stojanov Aleksander M.; Pocajt Viktor V.; Ristić Mirjana Đ.

    2010-01-01

    Antimony trioxide (Sb2O3) is the most frequently used catalyst in the polyethylene terephthalate (PET) manufacture. As a result, antimony is incorporated into PET bottles at concentration level of 100-300 mg/kg. PET containers are used for drinking water and beverages, as well as food packaging and in the pharmaceutical industry. Thus, it is important to understand the factors that may influence the release of antimony from the catalysts into water and other products, since antimony is potent...

  1. The influence of pet containers on antimony concentration in bottled drinking water

    Directory of Open Access Journals (Sweden)

    Perić-Grujić Aleksandra A.

    2010-01-01

    Full Text Available Antimony trioxide (Sb2O3 is the most frequently used catalyst in the polyethylene terephthalate (PET manufacture. As a result, antimony is incorporated into PET bottles at concentration level of 100-300 mg/kg. PET containers are used for drinking water and beverages, as well as food packaging and in the pharmaceutical industry. Thus, it is important to understand the factors that may influence the release of antimony from the catalysts into water and other products, since antimony is potentially toxic trace element. In this paper, the antimony content in nine brands of bottled mineral and spring water from Serbia, and seven brands of bottled mineral and spring water from EU countries was analyzed. The measurements were conducted using the inductively coupled plasma-mass spectrometry (ICP-MS technique. In the all examined samples the antimony concentration was bellow the maximum contaminant level of 5 μg/L prescribed by the Serbian and EU regulations. Comparison of the content of antimony in PET bottled waters with the content of antimony in water bottled commercially in glass and the natural content of antimony in pristine groundwaters, provides explicit evidence of antimony leaching from PET containers. Since waters bottled in PET have much greater concentration ratio of Sb to Pb than corresponding pristine groundwaters, it can be assumed that bottled waters cannot be used as the relavant source for the study of the natural antimony content in groundwaters. There is a clear relation between the quality of water in bottles (composition, ion strength and antimony leaching rate. Moreover, while the rate of antimony leaching is slow at temperatures below 60 oC, at the temperature range of 60-80 oC antimony release occurs and reaches maximum contaminant level rapidly. As antimony can cause both acute and chronic health problems, factors that promote the increase of antimony concentration should be avoided.

  2. Antimony Doped Tin Oxide Thin Films: Co Gas Sensor

    Directory of Open Access Journals (Sweden)

    P.S. Joshi

    2011-01-01

    Full Text Available Tin dioxide (SnO2 serves as an important base material in a variety of resistive type gas sensors. The widespread applicability of this semicoducting oxide is related both to its range of conductance variability and to the fact that it responds to both oxidising and reducing gases. The antimony doped tin-oxide films were prepared by spray pyrolysis method. The as-deposited films are blackish in colour. Addition of antimony impurity showed little increase in the thickness. The X-ray diffraction pattern shows characteristic tin oxide peaks with tetragonal structure. As the doping concentration of antimony was increased, new peak corresponding to Sb was observed. The intensity of this peak found to be increased when the Sb concentration was increased from 0.01 % to the 1 % which indicates the antimony was incorporated into the tin oxide. For gas sensing studies ohmic contacts were preferred to ensure the changes in resistance of sensor is due to only adsorption of gas molecule. The graph of I-V shows a straight line in nature which indicates the ohmic contact. The sensitivity of the sensor for CO gas was tested. The sensitivity of antimony doped tin oxide found to be increased with increasing Sb concentration. The maximum sensitivity was observed for Sb = 1 % at a working temperature of 250 °C.

  3. Behavior of arsenic impurity at antimony electric precipitation

    International Nuclear Information System (INIS)

    In the paper the arsenic impurity electrochemical behavior and it purification from antimony by electric precipitation out of fluoride solutions was studied. For this the arsenic sample with mass 0.003-0.006 g has been irradiated at the WWR-SM nuclear reactor during 3-5 hour in the thermal neutron flux 1013 n/cm2 s, after 24 h keeping the sample has being dissolved in the concentrated nitric acid, and then it has been evaporated several times with distillation water addition up to wet precipitation state. It is shown, that arsenic impurity behavior character in the antimony electric precipitation out to fluoride electrolyte depends on the electrolyte content, electrolysis conditions, arsenic valency state in arsenic impurity existence in the five-valency state its joint electric reduction with antimony is practically not observing. In the case the arsenic being in three-valency state, it joint electric reduction with antimony is taking place. In this time the electrolytic antimony contents arsenic impurities less in dozen time than initial material

  4. Antimony Resistance in Leishmania, Focusing on Experimental Research

    Directory of Open Access Journals (Sweden)

    Fakhri Jeddi

    2011-01-01

    Full Text Available Leishmaniases are parasitic diseases that spread in many countries with a prevalence of 12 million cases. There are few available treatments and antimonials are still of major importance in the therapeutic strategies used in most endemic regions. However, resistance toward these compounds has recently emerged in areas where the replacement of these drugs is mainly limited by the cost of alternative molecules. In this paper, we reviewed the studies carried out on antimonial resistance in Leishmania. Several common limitations of these works are presented before prevalent approaches to evidence antimonial resistance are related. Afterwards, phenotypic determination of resistance is described, then confronted to clinical outcome. Finally, we detail molecular mechanisms and targets involved in resistance and already identified in vitro within selected mutant strains or in clinical isolates.

  5. Lattice dynamics of femtosecond laser-excited antimony

    Science.gov (United States)

    Abdel-Fattah, Mahmoud Hanafy; Bugayev, Aleksey; Elsayed-Ali, Hani E.

    2016-07-01

    Ultrafast electron diffraction is used to probe the lattice dynamics of femtosecond laser-excited antimony thin film. The temporal hierarchies of the intensity and position of diffraction orders are monitored. The femtosecond laser excitation of antimony film was found to lead to initial compression after the laser pulse, which gives way to tension vibrating at new equilibrium displacement. A damped harmonic oscillator model, in which the hot electron-blast force contributes to the driving force of oscillations in lattice spacing, is used to interpret the data. The electron-phonon energy-exchange rate and the electronic Grüneisen parameter were obtained.

  6. Self-standing nanoribbons of antimony selenide and antimony sulfide with well-defined size and band gap

    Energy Technology Data Exchange (ETDEWEB)

    Vadapoo, Rajasekarakumar; Krishnan, Sridevi; Yilmaz, Hulusi [Department of Physics, University of Puerto Rico, San Juan, PR 00936 (Puerto Rico); Marin, Carlos [Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States)

    2011-04-29

    Sub-10 nm semiconducting nanostructures are crucial for the realization of nanoscale devices. Fabrication of nanostructures at this scale with homogeneous properties is challenging. Using ab initio calculations, we show that self-standing ribbons of antimony selenide and antimony sulfide of width 1.1 nm exhibit well-defined bandgaps of 1.66 and 2.16 eV, respectively. Molecular dynamics studies show that these ribbons are stable at 500 K. The one-dimensional (1D) heterostructure of these nanoribbons (Sb{sub 2}Se{sub 3}/Sb{sub 2}S{sub 3}) along the [001] direction shows a straddling type behavior.

  7. Selective oxidation of propene on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony

    International Nuclear Information System (INIS)

    Propene + 1802 reactions have been studied in a static reaction system on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony. The [160] acrolein content of the total acrolein formed and the proportion of 160 in the oxygen of the carbon dioxide by-product have been determined. The results indicate that for each catalyst the lattice is the only direct source of the oxygen in the aldehyde, and that lattice and/or gas phase oxygen is used in carbon dioxide formation. Oxygen anion mobility appears to be greater in the molybdate catalyst than in the other two. (author)

  8. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B

    Science.gov (United States)

    Morizot, Gloria; Jouffroy, Romain; Faye, Albert; Chabert, Paul; Belhouari, Katia; Calin, Ruxandra; Charlier, Caroline; Miailhes, Patrick; Siriez, Jean-Yves; Mouri, Oussama; Yera, Hélène; Gilquin, Jacques; Tubiana, Roland; Lanternier, Fanny; Mamzer, Marie-France; Legendre, Christophe; Peyramond, Dominique; Caumes, Eric; Lortholary, Olivier; Buffet, Pierre

    2016-01-01

    We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure. PMID:26735920

  9. Vapor pressures of dimethylcadmium, trimethylbismuth, and tris(dimethylamino)antimony

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Fulem, Michal; Pangrác, Jiří; Hulicius, Eduard; Růžička, K.

    2013-01-01

    Roč. 360, Dec (2013), s. 106-110. ISSN 0378-3812 R&D Projects: GA ČR GA13-15286S; GA MŠk(CZ) LM2011026 Institutional support: RVO:68378271 Keywords : vapor pressure * dimethylcadmium * trimethylbismuth * tris(dimethylamino)antimony * sublimation and vaporization enthalpy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  10. Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes

    OpenAIRE

    Kathawa, J.; Fry, C; Thoennessen, M

    2012-01-01

    Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  11. Vacuum distillation of antimony-mercury gold containing concentrates

    International Nuclear Information System (INIS)

    Results of researches on vacuum distillation of mercury from gold containing antimony-mercury concentrates are considered in this article. It is shown that at vacuum of 20-50 mm Hg and temperature 300 deg C mercury is sublimated and gold remain in a cinder. (author)

  12. Antimony content of macrofungi from clean and polluted areas

    Czech Academy of Sciences Publication Activity Database

    Borovička, J.; Řanda, Zdeněk; Jelínek, E.

    2006-01-01

    Roč. 64, č. 11 (2006), s. 1837-1844. ISSN 0045-6535 Institutional research plan: CEZ:AV0Z10480505 Keywords : mushrooms * antimony pollution * bioaccumulation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.442, year: 2006

  13. Antimony and arsenic biogeochemistry in the East China Sea

    Science.gov (United States)

    Ren, Jing-Ling; Zhang, Xu-Zhou; Sun, You-Xu; Liu, Su-Mei; Huang, Daji; Zhang, Jing

    2016-02-01

    The biogeochemical cycles of the metalloid elements arsenic and antimony in the East China Sea (ECS), one of the most important marginal seas for western Pacific, were examined in May 2011. Dissolved inorganic arsenic (As(V) and As(III)) and antimony (Sb(V) and Sb(III)) species were determined by selective hydride generation-atomic fluorescence spectrometry (HG-AFS). Results show that total dissolved inorganic arsenic (TDIAs; [TDIAs]=[As(V)]+[As(III)]) were moderately depleted in the surface water and enriched in the deep water. Arsenite (As(III)) showed different vertical profiles with that of TDIAs, with significant surface enrichment in the middle shelf region where the concentrations of phosphate were extremely low. Speciation of dissolved arsenic was subtly controlled by the stoichiometric molar ratio of arsenate (As(V)) to phosphate. The average As(V)/P ratio for the ECS in spring 2011 was 10.8×10-3, which is higher than previous results and indicates the arsenate stress. The concentrations of total dissolved inorganic antimony (TDISb; [TDISb]=[Sb(V)]+[Sb(III)]) were high near the Changjiang Estuary and the coastal area of Hangzhou Bay and decreased moderately off the coast. TDISb displayed moderate conservative behavior in the ECS that confirms by the correlations with salinity and dissolved aluminum. Different with that of As(III), antimonite (Sb(III)) concentrations were extremely lower in the ECS, with relative higher concentration appeared at the bottom layer which indicates the contribution from sediment-water interface. A preliminary box model was established to estimate the water-mass balance and antimony budgets for the ECS. Compared with other areas in the world, the concentrations of dissolved inorganic arsenic and antimony in the ECS remain at natural levels.

  14. The determination of the thermodynamic activity of antimony in alpha-iron

    International Nuclear Information System (INIS)

    In this paper a method is suggested for determining the thermodynamic activity of antimony dissolved in alpha-iron, based on the study of antimony distribution between the two phases: liquid lead and solid iron. By this method, it was found that solid solutions of antimony in alpha-iron can be distinguished by positive divergences from the ideal state. Over a fairly wide range of concentrations, solutions of antimony in iron obey Henry's law. Special experiments on the distribution of antimony between lead and liquid iron showed that in the liquid state also the iron-antimony system is marked by positive divergences from the ideal state when small concentrations of antimony are present. The heat required for the solution of antimony in alpha-iron, and the excess partial molar entropy, were calculated from the activity temperature. The results were used for accurately locating the line showing the solubility limit of antimony in alpha-iron. Since alloys of antimony with iron were obtained by diffusion saturation and not by cooling from the liquid state, there was no liquefaction. Thus the lattice constant of the alloys and its relation to the alloy concentration could be reliably determined. The solubility limit established from X-ray data agrees with that obtained with Sb124. (author)

  15. In Vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    Directory of Open Access Journals (Sweden)

    Samanta Etel Treiger Borborema

    2005-10-01

    Full Text Available Pentavalent antimony, as meglumine antimoniate (Glucantime® or sodium stibogluconate (Pentostam® , is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer studies have a potential in pharmaceutical development. The aim of this study was to obtain a radiotracer for antimony, with suitable physical and biological properties. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes 122Sb and 124Sb, with high radionuclidic purity and good specific activity. This compound showed the same antileishmanial activity as the native compound. The use of the radiotracers, easily created by neutron irradiation, could be an interesting tool to solve important questions in antimonial pharmacology.Os antimoniais pentavalentes, como o antimoniato de meglumina (Glucantime® ou estibogluconato de sódio (Pentostam® , são o principal tratamento para a leishmaniose, um complexo de doenças causadas pelo protozoário parasita Leishmania, uma doença endêmica e negligenciada no Brasil. Apesar do seu uso clínico por mais de meio século, seu mecanismo de ação, toxicidade e dados de farmacocinética permanecem desconhecidos. Os métodos analíticos para determinação de antimônio em sistemas biológicos são complexos e apresentam baixa sensibilidade. Estudos utilizando radiotraçadores têm papel potencial no desenvolvimento farmacológico. O objetivo deste estudo foi desenvolver um radiotraçador de antimônio, com propriedades físicas e biológicas adequadas. O antimoniato de meglumina foi irradiado por nêutrons no reator nuclear IEA-R1, produzindo dois radioisótopos: 122

  16. States of antimony and tin atoms in lead chalcogenides

    International Nuclear Information System (INIS)

    It is shown by Mössbauer spectroscopy of the 119Sb(119mSn) isotope that impurity antimony atoms in PbS, PbSe, and PbTe lattices are distributed between cation and anion sublattices. In n-type samples, the greatest part of antimony is located in the anion sublattice; in hole ones, in the cation sublattice. The tin atoms formed as a result of radioactive decay of 119Sb (antisite state) are electrically inactive in the anion sub-lattice of PbS and PbSe, while, in the cation sublattice, they form donor U− centers. Electron exchange between the neutral and doubly ionized tin U− centers via the allowed band states is observed. The tin atoms formed after radioactive decay of 119Sb are electrically inactive in the anion and cation sublattices of PbTe.

  17. Resistance to Arsenic- and Antimony-Based Drugs

    OpenAIRE

    Milena Salerno; Arlette Garnier-Suillerot

    2003-01-01

    Organic arsenicals were the first antimicrobial agents specifically synthesized for the treatment of infectious diseases such as syphilis and sleeping sickness. For the treatment of diseases caused by trypanosomatid parasites, organic derivatives of arsenic and the related metalloid antimony are still the drugs of choice. Arsenic trioxide, As203, has been used for a long time in traditional Chinese medicines for treatment of various diseases, and it has recently been shown to be clinically ac...

  18. Crystallization of antimony orthotantalate and its physical properties

    International Nuclear Information System (INIS)

    Physicochemical conditions of monophase synthesis of antimony orthoniobate monocrystals in the system SbO3-Ta2O5-KHF2-H2O2-H2O were investigated. In the area of monophase synthesis of SbTaO4 monocrystals kinetic studies of its growth conditions for inoculation, depending on solvent concentration, temperature, pyroelectric properties of the monocrystal grown were studied and conclusion was made on their practical use

  19. Correlation of CsK2Sb photocathode lifetime with antimony thickness

    Energy Technology Data Exchange (ETDEWEB)

    Mamun, M. A. [Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, Virginia 23529, USA; The Applied Research Center, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA; Hernandez-Garcia, C. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA; Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA; Elmustafa, A. A. [Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, Virginia 23529, USA; The Applied Research Center, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA

    2015-06-01

    CsK2Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  20. Correlation of CsK{sub 2}Sb photocathode lifetime with antimony thickness

    Energy Technology Data Exchange (ETDEWEB)

    Mamun, M. A., E-mail: mmamu001@odu.edu; Elmustafa, A. A. [Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); The Applied Research Center, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Hernandez-Garcia, C.; Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2015-06-01

    CsK{sub 2}Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  1. Correlation of CsK2Sb photocathode lifetime with antimony thickness

    Directory of Open Access Journals (Sweden)

    M. A. Mamun

    2015-06-01

    Full Text Available CsK2Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  2. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    OpenAIRE

    Ye L.G.; Tang C.B.; Yang S.H.; Chen Y.M.; Zhang W.H.

    2015-01-01

    In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3...

  3. Recent advances on antimony(III/V) compounds with potential activity against tumor cells.

    Science.gov (United States)

    Hadjikakou, S K; Ozturk, I I; Banti, C N; Kourkoumelis, N; Hadjiliadis, N

    2015-12-01

    Antimony one of the heavier pnictogens, has been in medical use against microbes and parasites as well. Antimony-based drugs have been prescribed against leishmaniasis since the parasitic transmission of the tropical disease was understood in the beginning of the 20th century. The activity of arsenic against visceral leishmaniasis led to the synthesis of an array of arsenic-containing parasitic agents, among them the less toxic pentavalent antimonials: Stibosan, Neostibosan, and Ureastibamine. Other antimony drugs followed: sodium stibogluconate (Pentostam) and melglumine antimoniate (Glucantim or Glucantime); both continue to be in use today despite their toxic side effects and increasing loss in potency due to the growing resistance of the parasite against antimony. Antimony compounds and their therapeutic potentials are under consideration from many research groups, while a number of early reviews recording advances of antimony biomedical applications are also available. However, there are only few reports on the screening for antitumor potential of antimony compounds. This review focuses upon results obtained on the anti-proliferative activity of antimony compounds in the past years. This survey shows that antimony(III/V) complexes containing various types of ligands such as thiones, thiosemicarbazones, dithiocarbamates, carboxylic acids, or ketones, nitrogen donor ligands, exhibit selectivity against a variety of cancer cells. The role of the ligand type of the complex is elucidated within this review. The complexes and their biological activity are already reported elsewhere. However quantitative structure-activity relationship (QSAR) modeling studies have been carried out and they are reported for the first time here. PMID:26092367

  4. Complexation of HSA with different forms of antimony (Sb): An application of fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Antimony (Sb) pollution has been of a great environmental concern in some areas in China. Sb enters human body via drinking water, inhalation and food chain, unavoidably interacts with human serum albumin (HSA) in blood plasma, and consequently does harm to human health. The harmful effects of Sb on human health depend on the Sb species and their binding ability to HSA. In the present study, binding of three forms of Sb with HSA was investigated by excitation-emission matrix (EEM) spectroscopy. All of antimony potassium tartrate, antimony trichloride and potassium pyroantimonate quenched fluorescence of HSA. Values of conditional stability constant Ka (×105/M) for Sb and HSA systems were 8.13–9.12 for antimony potassium tartrate, 2.51–4.27 for antimony trichloride and 3.63–9.77 for potassium pyroantimonate. The binding constant Kb (×104/M) values of HSA with antimony potassium tartrate, antimony trichloride and potassium pyroantimonate were 0.02–0.07, 3.55–5.01, and 0.07–1.08, respectively. There was one independent class of binding site for antimony trichloride towards HSA. There was more than one Sb binding site and negative cooperativity between multiple binding sites for potassium pyroantimonate and antimony potassium tartrate towards HSA. The binding ability of HSA to complex Sb followed the order: antimony trichloride>potassium pyroantimonate>antimony potassium tartrate. -- Highlights: ► The first study reporting interaction of Sb with HSA. ► Sb can effectively quench the fluorescence of HSA. ► The binding ability of HSA to Sb was dependent on the form of Sb. ► Binding differences indicate differences in toxicity of various forms Sb to human. ► HAS-Sb binding parameters are important for understanding toxicity of Sb

  5. Leishmania donovani isolates with antimony-resistant but not -sensitive phenotype inhibit sodium antimony gluconate-induced dendritic cell activation.

    Directory of Open Access Journals (Sweden)

    Arun Kumar Haldar

    2010-05-01

    Full Text Available The inability of sodium antimony gluconate (SAG-unresponsive kala-azar patients to clear Leishmania donovani (LD infection despite SAG therapy is partly due to an ill-defined immune-dysfunction. Since dendritic cells (DCs typically initiate anti-leishmanial immunity, a role for DCs in aberrant LD clearance was investigated. Accordingly, regulation of SAG-induced activation of murine DCs following infection with LD isolates exhibiting two distinct phenotypes such as antimony-resistant (Sb(RLD and antimony-sensitive (Sb(SLD was compared in vitro. Unlike Sb(SLD, infection of DCs with Sb(RLD induced more IL-10 production and inhibited SAG-induced secretion of proinflammatory cytokines, up-regulation of co-stimulatory molecules and leishmanicidal effects. Sb(RLD inhibited these effects of SAG by blocking activation of PI3K/AKT and NF-kappaB pathways. In contrast, Sb(SLD failed to block activation of SAG (20 microg/ml-induced PI3K/AKT pathway; which continued to stimulate NF-kappaB signaling, induce leishmanicidal effects and promote DC activation. Notably, prolonged incubation of DCs with Sb(SLD also inhibited SAG (20 microg/ml-induced activation of PI3K/AKT and NF-kappaB pathways and leishmanicidal effects, which was restored by increasing the dose of SAG to 40 microg/ml. In contrast, Sb(RLD inhibited these SAG-induced events regardless of duration of DC exposure to Sb(RLD or dose of SAG. Interestingly, the inhibitory effects of isogenic Sb(SLD expressing ATP-binding cassette (ABC transporter MRPA on SAG-induced leishmanicidal effects mimicked that of Sb(RLD to some extent, although antimony resistance in clinical LD isolates is known to be multifactorial. Furthermore, NF-kappaB was found to transcriptionally regulate expression of murine gammaglutamylcysteine synthetase heavy-chain (mgammaGCS(hc gene, presumably an important regulator of antimony resistance. Importantly, Sb(RLD but not Sb(SLD blocked SAG-induced mgammaGCS expression in DCs by

  6. Oxidation and mobilization of metallic antimony in aqueous systems with simulated groundwater

    Science.gov (United States)

    Ilgen, A. G.; Majs, F.; Barker, A. J.; Douglas, T. A.; Trainor, T. P.

    2014-05-01

    Antimony (Sb) is a contaminant of concern that can be present in elevated concentrations in shooting range soils due to mobilization from spent lead/antimony bullets. Antimony in shooting range soils has been observed as either metallic Sb(0) or as Sb(V) immobilized by iron (hydr)oxides. The absence of Sb(III) in soils is indicative of rapid Sb(III) oxidation to Sb(V) under surface soil conditions. However, the major controls on antimony oxidation and mobility are poorly understood. To better understand these controls we performed multiple batch experiments under oxic conditions to quantify the oxidation and dissolution of antimony in systems where Sb(0) is oxidized to Sb(III) and further to Sb(V). We also tested how variations in the aqueous matrix composition and the presence of metallic lead (Pb) affect the dissolution, solid phase speciation, and oxidation of antimony. We monitored changes in the aqueous antimony speciation using liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). To test which solid phases form as a result of Sb(0) oxidation, and therefore potentially limit the mobility of antimony in our studied systems, we characterized the partially oxidized Sb(0) powders by means of extended X-ray absorption fine structure (EXAFS) spectroscopy and powder X-ray diffraction (XRD).

  7. Tin dioxide sol-gel derived films doped with platinum and antimony deposited on porous silicon

    NARCIS (Netherlands)

    Savaniu, C.; Arnautu, A.; Cobianu, C.; Craciun, G.; Flueraru, C.; Zaharescu, M.; Parlog, C.; Paszti, F.; Berg, van den A.

    1999-01-01

    SnO2 sol-gel derived thin films doped simultaneously with Pt and Sb are obtained and reported for the first time. The Sn sources were tin(IV) ethoxide or tin(II) ethylhexanoate, while hexachloroplatinic acid (H2PtCl6) and antimony chloride (SbCl3) were used as platinum and antimony sources, respecti

  8. Comparison of modification with strontium and the refining with antimony in A 356 aluminium alloys

    International Nuclear Information System (INIS)

    Strontium and Antimony treated A356 aluminium alloy samples were metallographically characterized in the as cast and solution and aged conditions. Antimony treated alloy has shown slower spheroidizing kinetics of the Silicon particles during solution treatment, lower porosity level and higher tensile strength and elongation than Strontium treated one. (author)

  9. Leishmania donovani: an in vitro study of antimony-resistant amphotericin B-sensitive isolates

    DEFF Research Database (Denmark)

    Sharief, Abdalla Hassan; Gasim Khalil, Eltahir Awad; Theander, Thor G;

    2006-01-01

    Drug sensitivity of clinically antimony-unresponsive Leishmania donovani isolates from Eastern Sudan was evaluated in an in vitro culture system against sodium stibogluconate (Pentostam) and Amphotericin B. Eight isolates, six from antimony-resistant and two from clinically responsive patients were...

  10. Waste treatment as applied to the problem of recovery of antimony-125

    International Nuclear Information System (INIS)

    In the report we present the average radionuclide and chemical composition of processing solutions in various stages of treatment of spent nuclear fuel. The behavior of antimony-125 during sorption from these solutions was studied. A series of oxide and phosphate compounds was used as sorbents. The best results on recovery of antimony were reached on silica gel. A necessary condition for prolonged high-cycle operation of silica gel in actual practice is its rather complete regeneration. In this connection, we studied completeness of antimony desorption from various sorbents. The best results were obtained with aqueous hydrochloric and oxalic acids. Our study showed the possibility of recovery of antimony-125 from spent nuclear fuel wastes by adsorption on silica gel from processing solutions with subsequent desorption of the target product. In the average the yield of antimony-125 is 85%. (authors)

  11. Testing of antimony selective media for treatment of liquid radwaste

    International Nuclear Information System (INIS)

    Nuclear power plants have sought radiation source term reduction and reduced discharge of radioactive constituents for many years. In the case of pressurized water reactors (PWRs), the latter efforts have been directed toward capture and immobilization of recalcitrant (ubiquitous radionuclides with long half-lives) species such as Cs-134 and Cs-137 and Co-58 and Co-60. As these plants resolved, or at least mitigated, the problems with radiocesium and radio-cobalt, antimony radionuclides (Sb-122, Sb-124, and Sb-125) have become a primary concern in liquid liquid radwaste systems Graver Technologies developed a granular composite metal oxide media with good selectivity for radio-antimony. Initial laboratory data were collected using non-radioactive salts of antimony, cesium, and cobalt to judge efficacy of selective removal of antimony. Based on success of those trials, the media, designated Gravex GX187, was tested in partnership with Energy Solutions (nee Duratek) using actual liquid liquid radwaste in two PWR plants. One of these plants performed extensive slip-stream trials comparing the GX187 with strong base anion resins. With more than 2500 bed volumes of throughput, the GX187 outperformed the other competitors by reducing both Sb-124 and Sb-125 radionuclides below minimum detectable activity (MDA) with average decontamination factors (DF's) of 170, even when subjected to high levels of borate. Based on these favorable results, Energy Solutions installed the GX187 in a layered bed in their ALPS liquid radwaste processing system at this plant in August 2005. After one year of intermittent, batchwise operation including an outage, the GX187 processed more than 2.25 million liters (>600,000 gallons) of liquid liquid radwaste while reducing the Sb-125 activity to 2.9 E-08 Bq/L (DF=111) on average. This evaluation is ongoing and will continue at least until the fall 2006 outage at this plant. Concurrently, Graver developed a second generation antimony selective

  12. Behavior of ruthenium, cesium and antimony during simulated HLLW vitrification

    International Nuclear Information System (INIS)

    The behavior of ruthenium, cesium, and antimony during the vitrification of simulated high-level radioactive liquid wastes (HLLW) in a liquid fed melter was studied on a laboratory scale and on a semi-pilot scale. In the laboratory melter of a 2.5 kg capacity, a series of tests with the simulate traced with 103Ru, 134Cs and 124Sb, has shown that the Ru and Cs losses to the melter effluent are generally higher than 10% whereas the antimony losses remain lower than 0.4%. A wet purification system comprising in series, a dust scrubber, a condenser, an ejector venturi and an NOx washing column retains most of the activity present in the off-gas so that the release fractions for Ru at the absolute filter inlet ranges between 5.10-3 to 5.10-5% of the Ru fed, for Cs the corresponding release fraction ranges between 3.10-3 to 10-4% and for Sb the release fraction ranges between 1.7 10-4 to 1.7 10-5%. The same experiments were performed at a throughput of 1 to 2 1 h-1 of simulated solution in the semi-pilot scale unit RUFUS. The RUFUS unit comprises a glass melter with a 50 kg molten glass capacity and the wet purification train comprises in series a dust scrubber, a condenser, an ejector venturi and an NOx washing column. The tracer tests were restricted to 103Ru and 134Cs since the laboratory tests had shown that the antimony losses were very low. The results of the tests are presented

  13. Metabolism of antimony-124 in lactating dairy cows

    International Nuclear Information System (INIS)

    Lactating cows received oral and intravenous administrations of radioactive antimony (III) chloride to study its intestinal and urinary excretion, secretion into milk and organ distribution. Milk samples were taken twice a day and the milk, feces and urine assayed using gamma spectroscopy. Cows administered orally were sacrificed at 102 days and those injected intravenously at 70 days. Distribution of 124 Sb in the organs was determined at the time of sacrifice. Excretion of 124Sb occurs mainly via urine, little is secreted into milk. Highest organ concentrations are in the spleen, liver and bone. (U.K.)

  14. Electrostatically defined silicon quantum dots with counted antimony donor implants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M., E-mail: msingh@sandia.gov; Luhman, D. R.; Lilly, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87175 (United States); Pacheco, J. L.; Perry, D.; Garratt, E.; Ten Eyck, G.; Bishop, N. C.; Wendt, J. R.; Manginell, R. P.; Dominguez, J.; Pluym, T.; Bielejec, E.; Carroll, M. S. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2016-02-08

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.

  15. Electrostatically defined silicon quantum dots with counted antimony donor implants

    International Nuclear Information System (INIS)

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants

  16. Antimony implanted strained Si for nMOSFET applications

    OpenAIRE

    Zamani, Atieh

    2009-01-01

    Incorporation of implanted antimony (Sb) in strained-silicon (s-Si) formed on relaxed-SiGe virtual substrates (10 and 30% Ge) has been studied. The implantation doses were 5×1013- 5×1014 cm-2 with an energy of 20 keV. The activation of dopant was performed by an rapid thermal annealing (RTA) treatment at 700 and 800 °C for 30 sec. Projected range of this implantation is about 20 nm which was also confirmed by different techniques. The layers were analyzed in terms of strain relaxation, sheet ...

  17. Solubility behaviour of antimony(III) and antimony(V) solids in basic aqueous solutions at 300{sup o}C

    Energy Technology Data Exchange (ETDEWEB)

    Lemire, R.J.; Tosello, N.B.; Halliday, J.D

    1999-12-01

    The major contributions of the isotopes {sup 122}Sb and {sup 124}Sb to activity transport in a CANDU reactor primary heat transport system (HTS), have been associated with oxygen ingress during reactor shutdown. As part of a program to minimize the release and redeposition of these isotopes, the solubilities of antimony(III) and (V) oxides and salts have been measured in basic solutions at temperatures from 25 to 300{sup o}C. The results provide information on the charge and the stability as a function of temperature of antimony solution species and, hence, a guide to the trends in the temperature dependence of the solubilities of antimony solids. In solutions in which oxidation of antimony(III) to antimony(V) is minimized, the solubility of Sb{sub 2}O{sub 3} increases by about two orders of magnitude between 25 and 200{sup o}C, and then levels out or decreases slightly. At 250{sup o}C, in oxidizing solutions, Sb{sub 2}O{sub 5}{center_dot}xH{sub 2}O and simple sodium antimonate(V) were found to be unstable in sodium hydroxide solutions with respect to the solid, Na{sub 2{alpha}}[H(H{sub 2}O)]{sub 2-2{alpha}}Sb{sub 2}O{sub 6}, which has a pyrochlore structure. The solubility of this partially protonated sodium antimonate increases from 25 to 200{sup o}C and decreases at temperatures above 250{sup o}C. These solubility changes for the antimony (V) solids reflect changes in the stability of the anionic antimony solution species (SbO{sub 3}{sup -} or Sb(OH){sub 6}{sup -}), even though the compositions of antimony-containing solids in basic oxidizing solutions are strongly dependent on the cations and their aqueous phase concentrations. All solids used in the present experiments would be expected to generate total solution antimony concentrations {>=} 0.00005 mol{center_dot}dm{sup -3} in any neutral or basic aqueous solutions (assuming no added sodium salts). Therefore, under HTS conditions, precipitation of any antimony oxides or mixed oxides is unlikely. It cannot be

  18. Thermal decomposition kinetics of antimony oxychloride in air

    Institute of Scientific and Technical Information of China (English)

    阳卫军; 唐谟堂; 金胜明

    2002-01-01

    The DTA and XRD techniques were employed to study thermal decomposition mechanism of antimony oxychloride SbOCl in the air. The thermal decomposition reaction occurs in four steps, and the former three steps as: SbOCl(s)→Sb4O5Cl2(s)+SbCl3(g)→Sb8O11Cl2(s)+SbCl3(g)→Sb2O3(s)+SbCl3(g). The forth step is the oxidation of Sb2O3 by air, Sb2O3(s)+O2→Sb2O4(s). The activation energy and the order of the thermal decomposition reaction of antimony oxychloride in three steps presented in DTA curves were calculated according to Kinssinger methods from DTA curves. The values of activation energy and the order are respectively 91.97kJ/mol, 0.73 in the first step, 131.14kJ/mol, 0.63 in the second step and 146.94kJ/mol, 1.58 in the third step.

  19. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    Science.gov (United States)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  20. Antimony removal from the polyethylene terephthalate manufacture wastewater

    Directory of Open Access Journals (Sweden)

    Tomas Vengris

    2010-04-01

    Full Text Available In this study, antimony removal by coagulation from polyethylene terephthalate resin production wastewater of „Orion Global PET“ factory in Klaipėda city was investigated, with regard to the dependence of coagulant type and dosage, pH and presence of organics. FeCl3 ∙6H2O, FeSO4 ∙7H2O, AlCl3∙6H2O and TiCl4 salts were used as coagulants. Ti(IV and Fe(III revealed oneself to be the most effective coagulants. Antimony removal effectiveness is moderate and low using FeSO4 ∙7H2O and AlCl3∙6H2O coagulants, respectively. The addition of 10 mg dm-3 Ti(IV and 30 mg dm-3 Fe(III reduces by ~98% of the Sb, when the initial amount of Sb in wastewater is about 1200 mkg/l. The action of Fe(III is practically independent in the pH range 4-9, and that of Ti(IV slightly decreases in the same pH interval. The Sb amount in wastewater can be reduced to 13-20 mkg dm-3, while the initial Sb concentration is 1200 mkg dm-3. The presence of organic compounds in wastewater determines the reduction of Sb removal by coagulation.

  1. Antimony contamination and its effect on Trifolium plants

    Science.gov (United States)

    Corrales, Isabel; Barceló, Juan; Bech, Jaume; Poschenrieder, Charlotte

    2014-05-01

    Antimony is not an essential element and soil Sb contents usually are low.However, soil contamination by Sb has increased in the last years due to the human activities (combustion of fossil fuels, mining, waste incineration, smelting, shooting and road traffic). The main objective of this work was to study the effect of different concentrations of antimony (KSb(OH)6) in order to evaluate the effect on growth and Sb uptake on Trifolium pratense cv. Milvus and Trifolium repens. Our results show that Sb accumulated both in roots and shoots of clover without any negative effect on root growth, cellular viability and lipid peroxidation. This absence of toxicity sympthoms in clover plants could be very dangerous because Sb can be inadvertedly incorporated into the trophic chain causing toxic effects both in animals and humans. The absence of toxic effects on plants does not seem to be due to detoxification by phytochelatins because the use of the gamma-glutamylcysteine synthetase inhibitor, L-buthionine-[S,R]-sulphoximine (BSO) did not enhance Sb toxicity to plants. (Supported by the Spanish MICINN project BFU2010-14873)

  2. Segregation of antimony in InP in MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Weeke, Stefan

    2008-07-01

    In this work the segregation of antimony in indium phosphide in metal organic vapour phase epitaxy (MOVPE)was systematically investigated. Therefore phosphine stabilized InP surfaces were treated with tri-methyl-antimony (TMSb) in MOVPE. An antimony rich Sb/InP surface was established, showing a typical spectra for the antimonides observed in reflectance anisotropy spectroscopy (RAS).Adsorption and desorption of antimony are investigated, as well as the incorporation of Sb during overgrowth of the Sb/InP surface with InP. Therefore the growth parameters temperature, TMSb partial pressure and treatment time are varied and their influence investigated. The experiments are monitored in-situ with RAS, the achieved data is correlated with ex-situ characterisation such as X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS). It is shown that under treatment with TMSb a stable Sb/InP surface is formed within seconds, which does not change under further TMSb treatment. This process is rarely influenced by the TMSb partial pressure. On the contrary, the desorption of Sb is a very slow process. Two main processes can be distinguished: The desorption of excess Sb from the surface and the formation of the MOVPE prepared InP (2 x 1) surface. The reaction velocity of adsorption and desorption increases with temperature. Above a critical value the increase of TMSb partial pressure has no influence on the time for desorption. During overgrowth of the Sb/InP surface the opposite temperature dependence is observed: with increasing growth temperature the typical spectra for antimonides is observed longer. An analysis of the grown samples with XRD and SIMS showed the formation of an InPSb double quantum well. One layer is formed at the interface, the second one 50 nm-120 nm deep in the InP. The location of the 2nd InPSb layer can be correlated with the vanishing of the Sb signature in RAS. The distance between the quantum wells increases with growth temperature, until it

  3. Leaching Mechanism of Complicated Antimony-Lead Concentrate and Sulfur Formation in Slurry Electrolysis

    Institute of Scientific and Technical Information of China (English)

    WangChengyan; QiuDingfan; JiangPeihai

    2004-01-01

    Anodic reaction mechanism of complicated antimony-lead concentrate in slurry electrolysis was investigated by the anodic polarization curves determined under various conditions. The main reactions on the anode are the oxidations of FeCln(2-n) . Though the oxidation of jamesonite particle on the anode can occur during the whole process, it is less. With the help of mineralogy studies and relevant tests, the leaching reaction mechanism of jameson[to and gudmundite during slurry electrolysis was ascertained. Because of the oxidation reaction of FeCl3 produced by antimony-lead concentrate itself, the non-oxidation complex acid dissolution of jameson[re, the oxidation complex acid dissolution of gudmundite, and the oxidation of air carried by stirring, the leaching ratio of antimony reaches about 35% when HCl-NH4Cl solution is used to leach antimony-lead concentrate directly. So when the theoretical electric quantity is given to oxidation of antimony in slurry electrolysis, all of antimony, lead and iron containing in antimony-lead concentrate, are leached. The formation of sulfur is through the directly redox reaction of Fe3+ and jameson[re. The S2- in jamesonite is oxidized into S0 , and forms the crystals of sulfur again on the spot. The redox reaction of Fe3+ and H2S formed by non-oxidative acid dissolution of jamesonite is less.

  4. Behaviour of antimony during thermal treatment of Sb-rich halogenated waste

    International Nuclear Information System (INIS)

    Antimony compounds have a wide range of industrial applications, particularly as additives in flame retardants. To ensure environmentally friendly waste incineration of Sb-rich wastes, it is essential to strengthen the knowledge about the fate of antimony and the potential formation of harmful species. Investigations should be conducted particularly in relation with the main operational parameters controlling the process, chiefly temperature, residence time and air supply in the oven and in the post-combustion zone, prior final adapted cleaning of the flue-gas stream. Experimental studies focusing on antimony behaviour were undertaken through laboratory-scale thermal treatment at 850 deg. C and 1100 deg. C of a Sb-rich halogenated waste, originating from the sector of flame retardants formulation. The configuration of our laboratory experimental device allowed to achieve only low oxidative conditions in the waste bed, but high oxidative strength coupled with high temperature and sufficient gas residence time in the post-combustion zone, as prescribed during the incineration of hazardous wastes. Atomic absorption spectroscopy was used to assess the partition of antimony in the different compartments of the process. The oxidation degree of antimony in the gas-phase was determined by the use of electrochemical techniques, namely polarography coupled with anodic stripping voltamperometry. The partition of antimony between the residual ash and the gas-phase under moderate oxidative conditions in the waste bed was constant, whatever the temperature: the volatilization rate for antimony was ∼64%, while a ∼36% fraction remained in the residual bottom ashes. But interestingly, while at 850 oC, antimony was mainly present in the gas-phase at a +III oxidation degree, an increase in temperature of 250 oC favoured the presence of antimony to its highest oxidation degree +V in the flue-gas stream, a valence known to be involved in less toxic species.

  5. Antimony powder-modified carbon paste electrodes for electrochemical stripping determination of trace heavy metals

    International Nuclear Information System (INIS)

    Highlights: → New antimony powder-modified carbon paste electrode. → Combination of specific properties of carbon paste substrate and metallic antimony. → No requirement of using toxic antimony(III) salts. → Electrochemical stripping determination of trace heavy metals at ppb levels. → Anodic stripping voltammetric and stripping chronopotentiometric measurements. - Abstract: A new type of the antimony electrode based on a carbon paste bulk-modified with antimony powder (Sb-CPE) is presented for the determination of cadmium(II) and lead(II) ions at the microgram-per-liter concentration level, when using square-wave anodic stripping voltammetric or stripping chronopotentiometric protocol. The Sb-CPE was prepared by mixing fine antimony powder, carbon powder, and silicon oil, thus combining typical features of the carbon paste material with specific electrochemical properties of antimony. Key-operational parameters, including the amount of antimony powder in the carbon paste mixture, effect of the deposition potential and deposition time, were optimized and electroanalytical performance of the Sb-CPE in nondeaerated solution of 0.01 M hydrochloric acid (pH 2) was compared with related bismuth powder-modified carbon paste electrode (Bi-CPE) and with in situ prepared antimony film carbon paste electrode (SbF-CPE). The electrode of interest exhibited well-developed signals and highly linear calibration plots for both metal ions tested. In addition, favorable limits of detection were achieved; namely: 1.4 μg L-1 for Cd(II) and 0.9 μg L-1 for Pb(II). The applicability of the new electrode was demonstrated on the analysis of tap water (spiked sample). Besides voltammetric measurements, the Sb-CPE was preliminary tested also under chronopotentiometric stripping mode in deoxygenated solutions, revealing also an excellent electroanalytical performance.

  6. Structural and optical characterization of thermally evaporated bismuth and antimony films for photovoltaic applications

    Science.gov (United States)

    Srimathy, N.; Ruban Kumar, A.

    2016-05-01

    In this present study, the thin film of bismuth and antimony is coated by thermal evaporation system equipped with the inbuilt ultra high vacuum system. XRD analysis confirmed the rhombohedral structure of Bismuth and Antimony on the prepared film. The surface roughness and physical appearance is analyzed by Atomic force microscopy. The results of Raman Spectroscopy show the wave functions and the spectrum of electrons. The preparation technique and conditions strongly influence the crystalline structure and the phase composition of bismuth and antimony thin films. The electrical and optical properties for the prepared film are analyzed. The results show a great interest and promising applications in Photovoltaic devices.

  7. Varicella zoster virus reactivation during or immediately following treatment of tegumentary leishmaniasis with antimony compounds

    Directory of Open Access Journals (Sweden)

    Andrea Barbieri Barros

    2014-07-01

    Full Text Available Antimony compounds are the cornerstone treatments for tegumentary leishmaniasis. The reactivation of herpes virus is a side effect described in few reports. We conducted an observational study to describe the incidence of herpes zoster reactivation during treatment with antimony compounds. The global incidence of herpes zoster is approximately 2.5 cases per 1,000 persons per month (or 30 cases per 1,000 persons per year. The estimated incidence of herpes zoster in patients undergoing antimony therapy is higher than previously reported.

  8. Coordination- and Redox-Noninnocent Behavior of Ambiphilic Ligands Containing Antimony.

    Science.gov (United States)

    Jones, J Stuart; Gabbaï, François P

    2016-05-17

    Stimulated by applications in catalysis, the chemistry of ambiphilic ligands featuring both donor and acceptor functionalities has experienced substantial growth in the past several years. The unique opportunities in catalysis offered by ambiphilic ligands stem from the ability of their acceptor functionalities to play key roles via metal-ligand cooperation or modulation of the reactivity of the metal center. Ligands featuring group 13 centers, most notably boranes, as their acceptor functionalities have undoubtedly spearheaded these developments, with remarkable results having been achieved in catalytic hydrogenation and hydrosilylation. Motivated by these developments as well as by our fundamental interest in the chemistry of heavy group 15 elements, we became fascinated by the possibility of employing antimony centers as Lewis acids within ambiphilic ligands. The chemistry of antimony-based ligands, most often encountered as trivalent stibines, has historically been considered to mirror that of their lighter phosphorus-based congeners. There is growing evidence, however, that antimony-based ligands may display unique coordination behavior and reactivity. Additionally, despite the diverse Lewis acid and redox chemistry that antimony exhibits, there have been only limited efforts to explore this chemistry within the coordination sphere of a transition metal. By incorporation of antimony into the framework of polydentate ligands in order to enforce the main group metal-transition metal interaction, the effect of redox and coordination events at the antimony center on the structure, electronics, and reactivity of the metal complex may be investigated. This Account describes our group's continuing efforts to probe the coordination behavior, reactivity, and application of ambiphilic ligands incorporating antimony centers. Structural and theoretical studies have established that both Sb(III) and Sb(V) centers in polydentate ligands may act as Z-type ligands toward late

  9. Crystal structure and thermodynamic properties of potassium antimony tungsten oxide

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Aleksandr V., E-mail: knav@uic.nnov.ru [Nizhny Novgorod State University, Gagarin Prospekt 23/2, Nizhny Novgorod, 603950 (Russian Federation); Tananaev, Ivan G. [Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky prospect, Moscow GSP-1, 119991 (Russian Federation); Kuznetsova, Nataliya Yu.; Smirnova, Nataliya N.; Letyanina, Irene A.; Ladenkov, Igor V. [Nizhny Novgorod State University, Gagarin Prospekt 23/2, Nizhny Novgorod, 603950 (Russian Federation)

    2010-02-20

    In the present work potassium antimony tungsten oxide with pyrochlore structure is refined by the Rietveld method (space group Fd3m, Z = 8). The temperature dependences of heat capacity have been measured for the first time in the range from 7 to 370 K for this compound. The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity C{sub p}{sup o}(T), enthalpy H{sup o}(T) - H{sup o}(0), entropy S{sup o}(T) - S{sup o}(0) and Gibbs function G{sup o}(T) - H{sup o}(0), for the range from T {yields} 0 to 370 K. The differential scanning calorimetry was applied to measure the incongruent melting temperature of compound under study. The high-temperature X-ray diffraction was used for the determining thermal expansion coefficients.

  10. Atomistic mechanisms governing structural stability change of zinc antimony thermoelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaolong [Frontier Institute of Science and Technology, Xi' an Jiaotong University, Xi' an 710054 (China); Lin, Jianping, E-mail: jaredlin@163.com [School of Materials Science and Engineering, Xiamen University of Technology, Xiamen 361024 (China); Qiao, Guanjun [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, Zhao, E-mail: zwangzhao@gmail.com [Frontier Institute of Science and Technology, Xi' an Jiaotong University, Xi' an 710054 (China); State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-01-05

    The structural stability of thermoelectric materials is a subject of growing importance for their energy harvesting applications. Here, we study the microscopic mechanisms governing the structural stability change of zinc antimony at its working temperature, using molecular dynamics combined with experimental measurements of the electrical and thermal conductivity. Our results show that the temperature-dependence of the thermal and electrical transport coefficients is strongly correlated with a structural transition. This is found to be associated with a relaxation process, in which a group of Zn atoms migrates between interstitial sites. This atom migration gradually leads to a stabilizing structural transition of the entire crystal framework, and then results in a more stable crystal structure of β–Zn{sub 4}Sb{sub 3} at high temperature.

  11. Coherent and Incoherent Structural Dynamics in Laser-Excited Antimony

    CERN Document Server

    Waldecker, Lutz; Bertoni, Roman; Vasileiadis, Thomas; Garcia, Martin E; Zijlstra, Eeuwe S; Ernstorfer, Ralph

    2016-01-01

    We investigate the excitation of phonons in photoexcited antimony and demonstrate that the entire electron-lattice interactions, in particular coherent and incoherent electron-phonon coupling, can be probed simultaneously. Using femtosecond electron diffraction (FED) with high temporal resolution, we observe the coherent excitation of the fully symmetric \\Ag\\ optical phonon mode via the shift of the minimum of the atomic potential energy surface. Molecular dynamics simulations are performed to quantify the change in lattice potential and the associated real-space amplitude of the coherent atomic oscillations. In addition, our experimental configuration allows observing the energy transfer from electrons to phonons via incoherent electron-lattice scattering events. Applying a modified two-temperature model, the electron-phonon coupling is determined from the data as a function of electronic temperature.

  12. NEW THIO S2- ADDUCTS WITH ANTIMONY (III AND V HALIDE: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    HASSAN ALLOUCH

    2013-12-01

    Full Text Available Five new S2- adducts with SbIII and SbV halides have been synthesized and studied by infrared. Discrete structures have been suggested, the environment around the antimony being tetrahedral, trigonal bipyramidal or octahedral.

  13. Liquid-liquid extraction of arsenic, antimony, selenium and tellurium by zinc diethyldithiocarbamate

    International Nuclear Information System (INIS)

    The authors report the solvent extraction, oxidation, reduction, extraction in the presence of iron, and reextraction of arsenic, antimony, selenium and tellurium. These processes were studied using radioactive tracers. (G.T.H.)

  14. Antimonial drugs entrapped into phosphatidylserine liposomes: physicochemical evaluation and antileishmanial activity

    OpenAIRE

    Samanta Etel Treiger Borborema; João Alberto Osso Junior; Heitor Franco de Andrade Junior; Nanci do Nascimento

    2016-01-01

    Abstract: INTRODUCTION: Leishmaniasis is a disease caused by the protozoan Leishmania that resides mainly in mononuclear phagocytic system tissues. Pentavalent antimonials are the main treatment option, although these drugs have toxic side effects and high resistance rates. A potentially alternative and more effective therapeutic strategy is to use liposomes as carriers of the antileishmanial agents. The aims of this study were to develop antimonial drugs entrapped into phosphatidylserine l...

  15. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    Directory of Open Access Journals (Sweden)

    Ye L.G.

    2015-01-01

    Full Text Available In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3 begin endothermic reaction at 863K (590°C, and the reaction mainly form NaPb4(PO43 and NaPbPO4 below 1123K (850°C and above 1123K (850°C, respectively. Sb2O3 and NaPO3 start the reaction at 773K (500°C and generate an antimonic salt compound. The reaction product of the mixture of PbO, Sb2O3 and NaPO3 show that NaPO3 reacted with PbO prior when NaPO3 was insufficient, amorphous antimony glass will be generated only when NaPO3 was adequate. Single factor experiments were taken with NaNO3 as oxidizing agent under argon, effect of reaction time, reaction temperature and dosage of NaPO3 and NaNO3 on smelting results. The average content of lead in refined antimony was 0.05340% and 98.85% of lead were removed under optimal conditions; the content of lead in antimony have meet the requirements of commercial antimony.

  16. Electrochemical antimony removal from accumulator acid: Results from removal trials in laboratory cells

    International Nuclear Information System (INIS)

    Highlights: ► In non-divided cells, antimony did not deposit at cathode due to oxidation of Sb(III) at anode. ► Copper and graphite were found to be the most suitable electrode materials for antimony deposition. ► Sb species covering electrode lowers deposition efficiency with time. ► Thus, periodical renewal of cathode material is necessary. ► Calculated specific electroenergy consumption was relatively high. ► In contrast, absolute energy consumption was low due to small quantities of antimony removed. - Abstract: Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35 °C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L−1 and 2000 Wh L−1. In other experiments on substances with antimony contents up to 3500 mg L−1, the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results.

  17. Effect of Antimony, Phosphorous and Salinity on Growth, Root Membrane Permeability and Root Antimony, Iron and Zinc Concentration of Corn in Hydroponic Media

    OpenAIRE

    H. Barangizi; M. Afyuni; B. Rezaee

    2010-01-01

    Antimony (Sb) pollution has increased in recent years because of human activities and extensive usage of antimony compounds. To date, only a few researches have been conducted in this field in Iran. The purpose of this research is to determine fresh and dry weight, root permeability percentage and root concentration of Sb, Fe and Zn in the corn. This greenhouse research was performed in hydroponics. A factorial experiment (3 × 2 × 3) with three Sb concentrations (0, 6, 18 mgL-1), with and wit...

  18. Arsenic and Antimony Content in Soil and Plants from Baia Mare Area, Romania

    Directory of Open Access Journals (Sweden)

    Gabriela Oprea

    2010-01-01

    Full Text Available Problem statement: The objective of this research was to evaluate the degree of soil contamination with arsenic and antimony in Baia Mare, a nonferrous mining and metallurgical center located in the North West region of Romania. The soil in the area is affected by the emissions of powders containing metals from metallurgical factories. Previous studies indicated the soil contamination with copper, zinc, cadmium and lead, but there is few data about the actual level of soil pollution with arsenic and antimony. Approach: The soil samples were collected from 2 districts of Baia Mare: Ferneziu, which is located in the proximity of a lead smelter and Săsar district which is located along the Sasar River in the preferential direction of the wind over a metallurgical factory producing lead. As reference was considered Dura area located in a less polluted hilly area, in the west part of the town. Samples of soil and plants from the residential area of Ferneziu, Săsar and Dura districts were collected. The arsenic determination was carried out by inductively coupled plasma atomic emission spectrometry and the antimony determination by inductively coupled plasma mass spectrometry. Results: In Ferneziu area, the concentration of arsenic in soil ranged between 0.25 and 255 mg kg-1. In Săsar district the arsenic concentration in the soil ranged between 5.5 and 295 mg kg-1. Regarding antimony, in Ferneziu area the concentration ranged between 5.3 and 40.6 mg kg-1; while in Săsar, antimony soils concentrations vary in the range: 0.9-18.4. Arsenic and antimony concentrations in plants were low for almost of the samples, both in Ferneziu and Săsar area indicating a low mobility of these elements in the studied soils. Conclusion: This study indicated the soil pollution with arsenic both in Ferneziu district and in Săsar district. The soil pollution with antimony was found especially in Ferneziu district.

  19. The MRP1-mediated effluxes of arsenic and antimony do not require arsenic-glutathione and antimony-glutathione complex formation.

    Science.gov (United States)

    Salerno, Milena; Petroutsa, Maria; Garnier-Suillerot, Arlette

    2002-04-01

    Arsenic trioxide is an effective treatment for acute promyelocytic leukemia, but resistance to metalloid salts is found in humans. Using atomic absorption spectroscopy, we have measured the rate of uptake of arsenic trioxide and of antimony tartrate in GLC4 and GLC4/ADR cells overexpressing MRP1 and the rate of their MRP1-mediated effluxes as a function of the intracellular GSH concentration. In sensitive cells, after 1 h, a pseudosteady state is reached where intra- and extracellular concentrations of metalloid are the same. This precludes the formation, at short term, of complexes between arsenic or antimony with GSH. In resistant cells reduced intracellular accumulation of arsenic (or antimony), reflecting an increased rate of arsenic (or antimony) efflux from the cells, is observed. No efflux of the metalloid is observed in GSH depleted cells. The two metalloids and GSH are pumped out by MRP1 with the same efficiency. Moreover for the three compounds 50% of the efflux is inhibited by 2 microM MK571. This led us to suggest that As- and Sb-containing species could be cotransported with GSH. PMID:12018890

  20. Antimony distribution and mobility in topsoils and plants (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa) from polluted Sb-mining areas in Extremadura (Spain)

    International Nuclear Information System (INIS)

    A study about topsoil antimony distribution and mobility from the soils to the biomass has been afforded in three abandoned Sb mining areas located at Extremadura. Physico-chemical characteristics of the soils and total antimony levels were measured in soils and autochthonous plant species (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa). Comparison with corresponding values in reference areas isolated from the mining activities is discussed. Antimony mobility in the soils was estimated by measuring the water extractable fraction; low results were obtained for the three soil areas, with no statistical differences. Plant ability to accumulate antimony was estimated by use of plant accumulation coefficients (PAC). Seasonal (spring vs. autumn) effects on the antimony content in the plant species. Cytisus striatus from Mari Rosa mine presented antimony excluder characteristics, whereas Dittrichia viscosa specimens growing in San Antonio mine showed a significant antimony bioaccumulation. - Bioaccumulation of antimony in vegetal species growing in mining areas

  1. Antimony distribution and mobility in topsoils and plants (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa) from polluted Sb-mining areas in Extremadura (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Murciego, A. Murciego [Area de Cristalografia y Mineralogia, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain); Sanchez, A. Garcia [IRNA-CSIC, Departamento de Geoquimica Ambiental, Aptdo. 257, Salamanca (Spain); Gonzalez, M.A. Rodriguez [Area de Cristalografia y Mineralogia, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain); Gil, E. Pinilla [Departamento de Quimica Analitica y Electroquimica, Facultad de Ciencias, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain)]. E-mail: epinilla@unex.es; Gordillo, C. Toro [Departamento de Quimica Analitica y Electroquimica, Facultad de Ciencias, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain); Fernandez, J. Cabezas [Area de Ecologia, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain); Triguero, T. Buyolo [Area de Ecologia, Universidad de Extremadura, Avda. Elvas, s/n, E-06071 Badajoz (Spain)

    2007-01-15

    A study about topsoil antimony distribution and mobility from the soils to the biomass has been afforded in three abandoned Sb mining areas located at Extremadura. Physico-chemical characteristics of the soils and total antimony levels were measured in soils and autochthonous plant species (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa). Comparison with corresponding values in reference areas isolated from the mining activities is discussed. Antimony mobility in the soils was estimated by measuring the water extractable fraction; low results were obtained for the three soil areas, with no statistical differences. Plant ability to accumulate antimony was estimated by use of plant accumulation coefficients (PAC). Seasonal (spring vs. autumn) effects on the antimony content in the plant species. Cytisus striatus from Mari Rosa mine presented antimony excluder characteristics, whereas Dittrichia viscosa specimens growing in San Antonio mine showed a significant antimony bioaccumulation. - Bioaccumulation of antimony in vegetal species growing in mining areas.

  2. Determination of antimony by using tungsten trap atomic absorption spectrometry

    International Nuclear Information System (INIS)

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 deg. C. Following the preconcentration step, the trap is heated to 895 deg. C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH4 solutions, H2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l-1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17

  3. NEW ERBIUM DOPED ANTIMONY GLASSES FOR LASER AND GLASS AMPLIFICATION

    Directory of Open Access Journals (Sweden)

    B. Tioua

    2015-07-01

    Full Text Available Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses. In this poster will offer new doped erbium glasses synthesized in silicate crucibles were obtained in the combination Sb2O3-WO3-Na2O. Several properties are measured and correlated with glass compositions. The absorption spectral studies have been performed for erbium doped glasses. The intensities of various absorption bands of the doped glasses are measured and the Judd-Ofelt parameters have been computed. From the theory of Judd-Ofelt, various radiative properties, such as transition probability, branching ratio and radiative life time for various emission levels of these doped glasses have been determined and reported. These results confirm the ability of antimony glasses for glass amplification.

  4. Predictors of an unsatisfactory response to pentavalent antimony in the treatment of American visceral leishmaniasis

    Directory of Open Access Journals (Sweden)

    Santos Mácia A.

    2002-01-01

    Full Text Available Although treatment of visceral leishmaniasis with pentavalent antimony is usually successful, some patients require second-line drug therapy, most commonly with amphotericin B. To identify the clinical characteristics that predict an inadequate response to pentavalent antimony, a case-control study was undertaken in Teresina, Piaui, Brazil. Over a two-year period, there were 19 cases of VL in which the staff physicians of a hospital prescribed second-line therapy with amphotericin B after determining that treatment with pentavalent antimony had failed. The control group consisted of 97 patients that were successfully treated with pentavalent antimony. A chart review using univariate and multivariate analysis was performed. The cure rate was 90% with amphotericin B. The odds ratio for the prescription of amphotericin B was 10.2 for children less than one year old, compared with individuals aged over 10 years. Patients who presented coinfection had an OR of 7.1 while those on antibiotics had an OR of 2.8. These data support either undertaking a longer course of therapy with pentavalent antimony for children or using amphotericin B as a first-line agent for children and individuals with coinfections. It also suggests that chemoprophylaxis directed toward bacterial coinfection in small children with VL may be indicated.

  5. Copper-promoted cementation of antimony in hydrochloric acid system: A green protocol.

    Science.gov (United States)

    Wu, Lian-Kui; Li, Ying-Ying; Cao, Hua-Zhen; Zheng, Guo-Qu

    2015-12-15

    A new method of recovering antimony in hydrochloric acid system by cementation with copper powder was proposed and carried out at laboratory scale. Thermodynamic analysis and cyclic voltammetry test were conducted to study the cementation process. This is a novel antimony removal technology and quite meets the requirements of green chemistry. The main cement product Cu2Sb is a promising anodic material for lithium and sodium ion battery. And nearly all consumed copper powder are transformed into CuCl which is an important industrial material. The effect of reaction temperature, stoichiometric ratio of Cu to Sb(III), stirring rate and concentration of HCl on the cementation efficiency of antimony were investigated in detail. Optimized cementation condition is obtained at 60 °C for 120 min and stirring rate of 600 rpm with Cu/Sb(III) stoichiometric ratio of 6 in 3 mol L(-1) HCl. At this time, nearly all antimony can be removed by copper powder and the cementation efficiency is over 99%. The structure and morphologies of the cement products were characterized by X-ray diffraction and scanning electron microscopy, respectively. Results show that the reaction temperature has little influence on the morphology of the cement products which consist of particles with various sizes. The activation energy of the cementation antimony on copper is 37.75 kJ mol(-1), indicating a chemically controlled step. Inductively coupled plasma mass spectrometry results show that no stibine generates during the cementation process. PMID:26252996

  6. Determination of traces of uranium and thorium in antimony(III) oxide by ICP-MS

    International Nuclear Information System (INIS)

    Traces of uranium and thorium in antimony(III) oxide were determined by inductively coupled plasma mass spectrometry (ICP-MS). A method of vaporization as the halide was applied to the separation of the analytes from the antimony matrix. Because the above separation method is so simple, reduced of external contamination was expected. In the case of vaporization using hydrochloric acid, however, it was found that antimony trichloride ions overlapped thorium ion of 232 (m/z). To find the most suitable conditions for matrix separation, vaporization behaviors were studied by using different acidic solutions such as HBr, HBr-HClO4 and HBr-H2SO4. Neither HBr+HClO4 nor HBr+H2SO4 was able to reduce the antimony matrix down to an unaffected level on ICP-MS measurement. On the other hand, in the case of the vaporization using hydrobromic acid, almost all the antimony matrix was removed. Determination limits obtained by this method were 0.02 and 0.03 ng g-1 for uranium and thorium, respectively. (author)

  7. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation

    International Nuclear Information System (INIS)

    Highlights: • We have proposed a method to recover antimony from electronic plastics. • The most efficient acid solution was sodium hydrogen tartrate in dimethyl sulfoxide. • Gamma irradiation did not influence the antimony leaching ability. - Abstract: There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed

  8. Mixed Antimony(V Complexes with Different Sugars to Modulate the Oral Bioavailability of Pentavalent Antimonial Drugs

    Directory of Open Access Journals (Sweden)

    Weverson A. Ferreira

    2014-04-01

    Full Text Available Previous studies have shown that the association of the drug meglumine antimoniate (MA with β-cyclodextrin can improve its bioavailability by the oral route. In this work, ribose and maltose were investigated for their ability to form mixed or association complexes with MA, release MA and modulate the serum levels of Sb after oral administration in mice. Analysis of the MA/ribose composition by high performance liquid chromatography coupled to mass spectrometry (LCMS-IT-TOF revealed the presence of mixed meglumine-Sb-ribose and Sb-ribose complexes. Analysis of the MA/maltose composition suggested the formation of MA-maltose association compounds. Circular dichroism characterization of these compositions following dilution in water at 37 °C suggested a partial and slow dissociation of the association compounds. When the MA/ribose composition was administered orally and compared to MA, the serum concentration of Sb was significantly lower after 1 h and greater after 3 h. On the other hand, the MA/maltose composition showed similar serum Sb concentration after 1 h and higher level of Sb after 3 h, when compared to MA. In conclusion, the present study has demonstrated the formation of mixed or association complexes of MA with sugars, such as maltose and ribose, which promoted sustained serum level of Sb after oral administration.

  9. Anodic stripping voltammetry of antimony using gold nanoparticle-modified carbon screen-printed electrodes

    International Nuclear Information System (INIS)

    Carbon screen-printed electrodes (CSPE) modified with gold nanoparticles present an interesting alternative in the determination of antimony using differential pulse anodic stripping voltammetry. Metallic gold nanoparticles deposits have been obtained by direct electrochemical deposition. Scanning electron microscopy measurements show that the electrochemically synthesized gold nanoparticles are deposited in aggregated form. Any undue effects caused by the presence of foreign ions in the solution were also analyzed to ensure that common interferents in the determination of antimony by ASV. The detection limit for Sb(III) obtained was 9.44 x 10-10 M. In terms of reproducibility, the precision of the above mentioned method in %R.S.D. values was calculated at 2.69% (n = 10). The method was applied to determine levels of antimony in seawater samples and pharmaceutical preparations

  10. Response of cutaneous leishmaniasis (chiclero's ulcer) to treatment with meglumine antimoniate in Southeast Mexico.

    Science.gov (United States)

    Vargas-Gonzalez, A; Canto-Lara, S B; Damian-Centeno, A G; Andrade-Narvaez, F J

    1999-12-01

    Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is characterized by a predominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become chronic, causing destruction of the pinna and disfigurement. It is caused predominantly by Leishmania (L.) mexicana. Although pentavalent antimonials (Sb5+) are the mainstay of leishmanial therapy and have been used for more than 50 years, dosage regimens have been repeatedly modified and the best one has not been fully identified. The main purpose of the present study was to investigate the response of chiclero's ulcer to treatment with meglumine antimoniate. One hundred five patients were treated with meglumine antimoniate at a daily dose of 1 ampule per day (425 mg of Sb5+) until healing. The lesions healed after a mean of 25 days (range = 5-60 days). PMID:10674678

  11. Synthesis of barium mercaptides and application of antimony/barium mercaptides

    Institute of Scientific and Technical Information of China (English)

    瞿龙; 张露露; 舒万艮

    2001-01-01

    Mercaptoacetic acid, isooctyl thioglycolate and barium hydroxide used as start materials, barium bis (2-ethylhexyl thioglycolate) (Ba(2EHTG)2), barium thioglycolate (Ba(TG)) and barium bisthioglycolate (Ba(TG)2) were synthesized. Their optimum synthetic techniques were discussed, and some physicochemical data were reported. Infrared spectroscopy and elemental analysis methods were used to identify the structures. They were put into PVC plastic products together with antimony tris (2-ethylhexyl thioglycolate) (Sb(2EHTG)3) under the suitable compounding, and their heat stability to PVC was studied. It is shown that these barium mercaptides have remarkable synergisms with antimony mercaptides and the long-term stabilizing effect of organoantimony stabilizer can be effectively improved, reducing the amount of antimony compounds so as to avoid the decrease of its stabilizing effect.

  12. Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

    Institute of Scientific and Technical Information of China (English)

    YANG Ruiyan; MA Dongsheng; BAO Zhengyu; PAN Jiayong; CAO Shuanglin; XIA Fei

    2006-01-01

    The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the largest antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuangshan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2-0.4 m/a.

  13. Future trends of global atmospheric antimony emissions from anthropogenic activities until 2050

    Science.gov (United States)

    Zhou, Junrui; Tian, Hezhong; Zhu, Chuanyong; Hao, Jiming; Gao, Jiajia; Wang, Yong; Xue, Yifeng; Hua, Shenbin; Wang, Kun

    2015-11-01

    This paper presents the scenario forecast of global atmospheric antimony (Sb) emissions from anthropogenic activities till 2050. The projection scenarios are built based on the comprehensive global antimony emission inventory for the period 1995-2010 which is reported in our previous study. Three scenarios are set up to investigate the future changes of global antimony emissions as well as their source and region contribution characteristics. Trends of activity levels specified as 5 primary source categories are projected by combining the historical trend extrapolation with EIA International energy outlook 2013, while the source-specific dynamic emission factors are determined by applying transformed normal distribution functions. If no major changes in the efficiency of emission control are introduced and keep current air quality legislations (Current Legislation scenario), global antimony emissions will increase by a factor of 2 between 2010 and 2050. The largest increase in Sb emissions is projected from Asia due to large volume of nonferrous metals production and waste incineration. In case of enforcing the pollutant emission standards (Strengthened Control scenario), global antimony emissions in 2050 will stabilize with that of 2010. Moreover, we can anticipate further declines in Sb emissions for all continents with the best emission control performances (Maximum Feasible Technological Reduction scenario). Future antimony emissions from the top 10 largest emitting countries have also been calculated and source category contributions of increasing emissions of these countries present significant diversity. Furthermore, global emission projections in 2050 are distributed within a 1° × 1°latitude/longitude grid. East Asia, Western Europe and North America present remarkable differences in emission intensity under the three scenarios, which implies that source-and-country specific control measures are necessary to be implemented for abating Sb emissions from

  14. Co-doping with antimony to control phosphorous diffusion in germanium

    KAUST Repository

    Tahini, H. A.

    2013-02-15

    In germanium, phosphorous and antimony diffuse quickly and as such their transport must be controlled in order to design efficient n-typed doped regions. Here, density functional theory based calculations are used to predict the influence of double donor co-doping on the migration activation energies of vacancy-mediated diffusion processes. The migration energy barriers for phosphorous and antimony were found to be increased significantly when larger clusters involving two donor atoms and a vacancy were formed. These clusters are energetically stable and can lead to the formation of even larger clusters involving a number of donor atoms around a vacancy, thereby affecting the properties of devices.

  15. Studies on Thin Films of Antimony Vacuum Evaporated from a Knudsen-Type Source

    Directory of Open Access Journals (Sweden)

    K.L. Chaudhary

    2000-10-01

    Full Text Available A Knudsen-type evaporation source was used for the deposition of thin films of antimony to study their growth and microstructure under different rates of evaporation and substrate temperatures when vacuum evaporated onto air-cleaved KC1, mica, amorphous carbon and doped KCl substrates. The crystallisation of these films on exposure to an electron beam of moderate intensity inside the electron microscope was studied, and the orientations of the crystallised films wrt the substrate were established. It has been concluded that antimony films prepared by this source compare well with those prepared by other sources of vacuum evaporation.

  16. Diel variation of arsenic, molybdenum and antimony in a stream draining natural As geochemical anomaly

    Czech Academy of Sciences Publication Activity Database

    Drahota, P.; Nováková, B.; Matoušek, Tomáš; Mihaljevič, M.; Rohovec, Jan; Filippi, Michal

    2013-01-01

    Roč. 31, APR (2013), s. 84-93. ISSN 0883-2927 Institutional research plan: CEZ:AV0Z30130516 Institutional support: RVO:68081715 ; RVO:67985831 Keywords : arsenic * molybdenum * antimony * trace elements * diel cycle Subject RIV: CB - Analytical Chemistry, Separation; DD - Geochemistry (GLU-S) Impact factor: 2.021, year: 2013

  17. Differences in antimony and arsenic releases from lead smelter fly ash in soils

    Czech Academy of Sciences Publication Activity Database

    Ettler, V.; Mihaljevič, M.; Šebek, O.; Valigurova, R.; Klementová, Mariana

    2012-01-01

    Roč. 72, Supp. 4 (2012), s. 15-22. ISSN 0009-2819 Institutional research plan: CEZ:AV0Z40320502 Keywords : Antimony * Arsenic * Lead smelting * Fly ash * Soil * Mobility Subject RIV: CA - Inorganic Chemistry Impact factor: 1.351, year: 2012

  18. Transparent Conducting Films of Antimony-Doped Tin Oxide with Uniform Mesostructure Assembled from Preformed Nanocrystals

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rathouský, Jiří; Rasp, M.; Schütz, B.; Niederberger, M.; Fattakhova-Rohlfing, D.

    Vol. 1. Boca Raton : Taylor-Francis, 2010, s. 627-630. ISBN 978-1-4398-3401-5. - ( Nanotech 2010) R&D Projects: GA ČR GA104/08/0435 Institutional research plan: CEZ:AV0Z40400503 Keywords : antimony-doped tin oxide * mesoporous materials * nanoparticles * self-assembly Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Determination of barium and antimony in gun shot residues by neutron activation analysis

    International Nuclear Information System (INIS)

    The antimony contents on both hands of 7 persons before and after firing an automatic pistol were determined by instrumental neutron activation analysis. The gun shot residues were removed from hands by a 4% solution of cellulose acetate in acetone. The average content of antimony on both hands before firing obtained from 70 measurements (35 from each hand) was 0.040 ± 0.010 micro gram, whereas the average contents on the right and the left hands after 1 firing were 0.385 ± 0.036 and 0.144 ± 0.029 micro gram respectively. The ration of the antimony contents after 1 firing to the normal level (before firing) was 9.9 for the right and 3.6 for the left. No significant difference was observed between male and female, smoker and non-smoker. The antimony content after several firings was not much different from that of 1 firing and it reduced to the normal level within 2 days after firing. The barium contents before and after firing were studied from one person. Barium was precipitated as Ba SO4 before counting. An average contents of 0.936 ± 0.551 micro gram for both hands before firing, 4.092 ± 2.687 micro gram for the right hand and 1.363 ± 0.879 micro gram for the left hand after 1 firing were found

  20. Transparent Conducting Films of Antimony-Doped Tin Oxide with Uniform Mesostructure Assembled from Preformed Nanocrystals

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rasp, M.; Rathouský, Jiří; Schütz, B.; Niederberger, M.; Fattakhova-Rohlfing, D.

    2010-01-01

    Roč. 6, č. 5 (2010), s. 633-637. ISSN 1613-6810 R&D Projects: GA ČR GA104/08/0435 Institutional research plan: CEZ:AV0Z40400503 Keywords : antimony-doped tin oxide * msoporous materials * nanoparticles Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 7.333, year: 2010

  1. Antimony production by carbothermic reduction of stibnite in the presence of lime

    Directory of Open Access Journals (Sweden)

    Padilla R.

    2014-01-01

    Full Text Available Experimental work on the carbothermic reduction of Sb2S3 in the presence of lime was carried out in the temperature range of 973 to 1123 K to produce antimony in an environmentally friendly manner. The results demonstrated the technical feasibility of producing antimony by this method without producing SO2 gas. Complete conversion of Sb2S3 was obtained at 1023 K in about 1000 seconds and at 1123 K in less than 250 seconds using stibnite-carbon-lime mixtures with molar ratios Sb2S3:CaO:C = 1:3:3. It was found that the reduction proceeds through the formation of an intermediate oxide SbO2, which is subsequently reduced by CO(g to yield antimony metal and CaS. The kinetics of the Sb2S3 reduction was analyzed by using the equation ln(1-X = -kt. The activation energy was 233 kJ mol-1 in the temperature range of 973 to 1123 K. This value would correspond to an antimony catalyzed carbon oxidation by CO2.

  2. Reaction products and corrosion of molybdenum electrode in glass melt containing antimony oxides and sodium sulfate

    Czech Academy of Sciences Publication Activity Database

    Matěj, J.; Langrová, Anna

    2012-01-01

    Roč. 56, č. 3 (2012), s. 280-285. ISSN 0862-5468 Institutional support: RVO:67985831 Keywords : antimony oxides * corrosion * glass melt * Molybdenum electrode * sulfate Subject RIV: DD - Geochemistry Impact factor: 0.418, year: 2012 http://www.ceramics-silikaty.cz/2012/pdf/2012_03_280.pdf

  3. On the segregation behavior of tin and antimony at grain boundaries of polycrystalline bcc iron

    Czech Academy of Sciences Publication Activity Database

    Lejček, Pavel; Šandera, P.; Horníková, J.; Pokluda, J.; Godec, M.

    2016-01-01

    Roč. 363, Feb (2016), 140-144. ISSN 0169-4332 R&D Projects: GA ČR GAP108/12/0144 Institutional support: RVO:68378271 Keywords : grain boundary segregation * tin * antimony * Fe based alloy * AES quantification Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014

  4. Synthesis of antimony tris(mercaptoethyl carboxylates) as thermal stabilizer for polyvinyl chloride

    Institute of Scientific and Technical Information of China (English)

    舒万艮; 刘又年; 陈启元

    2002-01-01

    A novel type of thermal stabilizers-antimony tris(mercaptoethyl carboxylates) (Sb(SCH2CH2OOCR) 3), was synthesized from carboxylic acid, antimony trioxide and 2-mercaptoethanol in two steps. The experimental results show that the molar ratio of carboxylic acid to antimony tris(2-hydroxyethyl mercaptide) is 1.2, when adding 0.6% tetra-n-butyl titanate as catalyst and xylene as isotropic solvent, heating and refluxing for about 2~4h. The thermal stability was measured by heat-aging oven test. The thermal stability time is about 8~40min(at 200℃) when adding 2% tetra-n-butyl titanate in polyvinyl chloride(PVC). Among these stabilizers, antimony tris(mercaptoethyl stearate) has best thermal stability. Its thermal stability is better than that of Ca-Zn complex and basic lead stabilizers, and equal to that of organotin. In addition, the stabilization mechanism of this kind of stabilizers for PVC was discussed briefly.

  5. Antimonial drugs entrapped into phosphatidylserine liposomes: physicochemical evaluation and antileishmanial activity

    Directory of Open Access Journals (Sweden)

    Samanta Etel Treiger Borborema

    2016-04-01

    Full Text Available Abstract: INTRODUCTION: Leishmaniasis is a disease caused by the protozoan Leishmania that resides mainly in mononuclear phagocytic system tissues. Pentavalent antimonials are the main treatment option, although these drugs have toxic side effects and high resistance rates. A potentially alternative and more effective therapeutic strategy is to use liposomes as carriers of the antileishmanial agents. The aims of this study were to develop antimonial drugs entrapped into phosphatidylserine liposomes and to analyze their biological and physicochemical characteristics. METHODS: Liposomes containing meglumine antimoniate (MA or pentavalent antimony salt (Sb were obtained through filter extrusion (FEL and characterized by transmission electron microscopy. Promastigotes of Leishmania infantum were incubated with the drugs and the viability was determined with a tetrazolium dye (MTT assay. The effects of these drugs against intracellular amastigotes were also evaluated by optical microscopy, and mammalian cytotoxicity was determined by an MTT assay. RESULTS: Liposomes had an average diameter of 162nm. MA-FEL showed inhibitory activity against intracellular L. infantum amastigotes, with a 50% inhibitory concentration (IC50 of 0.9μg/mL, whereas that of MA was 60μg/mL. Sb-FEL showed an IC50 value of 0.2μg/mL, whereas that of free Sb was 9μg/mL. MA-FEL and Sb-FEL had strong in vitro activity that was 63-fold and 39-fold more effective than their respective free drugs. MA-FEL tested at a ten-times higher concentration than Sb-FEL did not show cytotoxicity to mammalian cells, resulting in a higher selectivity index. CONCLUSIONS: Antimonial drug-containing liposomes are more effective against Leishmania-infected macrophages than the non-liposomal drugs.

  6. Extraction-radiochemical study of the ion-association complex of antimony (V) with tetrazolium violet and its thermal behavior

    International Nuclear Information System (INIS)

    The optimum conditions for extraction of ion-associated complexes (IAS) formed from the tetrazolium salt - tetrazolium violet and Sb(V) in hydrochloric acid medium have been studied. An isotope of antimony (125Sb) was used for determination of the recovery factor (R%) and distribution ratio (DSb). The thermal behavior of the antimony complex with tetrazole violet was studied using differential thermal and thermogravimetric analysis. (author) 12 refs.; 3 figs

  7. Electrodes modified with bismuth, antimony and tin precursor compounds for electrochemical stripping analysis of trace metals (a short review)

    OpenAIRE

    Lezi, Nikolitsa; Economou, Anastasios; Barek, Jiří

    2014-01-01

    Over the last decade, intensive research is being carried out towards the development of “green” electrochemical sensors. Bismuth, antimony and tin electrodes have been proposed as potential substitutes of mercury electrodes in electrochemical stripping analysis of trace metals. The main advantage of these metals as electrode materials is their lower toxicity compared to mercury. Among the different configuration of bismuth, antimony and tin electrodes, one of the most attractive inv...

  8. Electrodeposition of SnSbCu Alloy on Copper from an Electrolyte with Varied Content of Antimony Chloride

    Science.gov (United States)

    Valeeva, A. Kh.; Valeev, I. Sh.

    2015-10-01

    The microstructure and chemical composition of electrodeposited alloys of the SnSbCu system with varied concentration of antimony chloride in the electrolyte have been investigated. It is shown that during electrodeposition mechanical-mixture alloys are not formed, but rather intermetallic compounds. It is found that increasing the concentration of antimony chloride in the electrolyte leads to a decrease in the tin content and cracking of the coating.

  9. Investigation into properties of the mixture of perfluoro-2-methyl-bicyclo(4,4,0) decane with antimony fluoride

    International Nuclear Information System (INIS)

    State diagram was constructed for a binary system formed by antimony fluoride and perfluoro-2-methyl-bicyclo-(4,4,0)decane in the temperature range of -58 deg to +56 deg C. Temperature dependence of solubility and the differential molar heat of solubility of solid Sb F5 were determined. Above the melting point of antimony fluoride these components were found to form a system of two sparingly miscible liquids with upper critical dissolution temperature

  10. Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria.

    Science.gov (United States)

    Li, Yongchao; Hu, Xiaoxian; Ren, Bozhi

    2016-01-01

    The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb2S3 precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration. PMID:27148704

  11. Understanding the radiolabelling mechanism of 99mTc-antimony sulphide colloid

    International Nuclear Information System (INIS)

    The chemistry of antimony trisulphide colloid (ATC) was examined to elucidate the radiolabelling mechanism with 99mTcO4-. Ion exchange chromatography and atomic absorption spectrophotometry techniques determined ATC to be resistant to hydrolysis in 0.1 M hydrochloric acid (HCl) at 25 deg. C or 100 deg. C (>97% recovery, Sb3+ absent). Hydrogen sulphide gas detected did not participate in the mechanism, where antimony trisulphide and 99mTcO4- in HCl/100 deg. C yielded 96% 99mTc-product from a K2S-free formulation (versus 98% when K2S was present). 99mTcO4- was reduced >90% by DMSA or dithiothreitol under the same conditions, identifying involvement of thiol groups. Infrared analysis of Re-ATC showed S-O bonds, indicating excess thiol groups at the colloid surface were oxidised at the expense of 99mTcO4- reduction

  12. A facile and fast route to prepare antimony (Sb) nanostructures without additives

    KAUST Repository

    Shah, M.A.

    2011-12-01

    Herein, we report a safe, low cost and reproducible approach for the synthesis of antimony (Sb) nanostructures with most of them having prism like morphology and having well defined faces in the range of ∼70210 nm. The organics free approach is based on a reaction of antimony powder and pure water at ∼210 °C without using any harmful additives and amines. The XRD pattern confirmed the composition and crystallinity of the grown nanostructures. The reported method besides being organics free is economical, fast and free of pollution, which will make it suitable for large scale production. Furthermore, it is well expected that such a technique could be extended to prepare many other important metal and metal oxide nanostructures. The prospects of the process are bright and promising. © 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.

  13. Determination by neutron activation analysis of loss of arsenic, antimony, bromine and mercury during lyophilization

    International Nuclear Information System (INIS)

    Neutron activation analysis has been used to monitor the loss of arsenic, as dimethylarsinic acid, (CH3)2AsOOH, or as sodium arsenate (Na2HAsO4.7H2O), antimony (as potassium antimony, tartrate, KSbC4O7.1/2H2O) and bromine (as bromide ion) during lyophilization of acidified and neutral aqueous synthetic and environmental samples. Losses of Sb and As ranged from zero to 60%, while losses of bromine were constant (at 91%) in acidic solutions. The variable losses of As and Sb were due solely to the presence of and partial decomposition of the (CH3)2AsOOH. Electrochemical oxidation of Br- to Br2 is responsible for the high losses of bromine. In addition losses of mercury (as methylmercuric chloride) were 1O0% in both acidic and neutral aqueous synthetic samples during lyophilization. (author)

  14. Deciphering lead and cadmium stripping peaks for porous antimony deposited electrodes

    Directory of Open Access Journals (Sweden)

    Taimoor Aqeel Ahmad

    2016-06-01

    Full Text Available Cadmium and lead are generally taken as model heavy metal ions in water to scale the detection limit of various electrode sensors, using electrochemical sensing techniques. These ions interact with the electrochemically deposited antimony electrodes depending on the diffusion limitations. The phenomenon acts differently for the in-situ and ex-situ deposition as well as for porous and non-porous electrodes. A method has been adopted in this study to discourage the stripping and deposition of the working ions (antimony to understand the principle of heavy metal ion detection. X-ray photoelectron spectroscopy (XPS technique was used to establish the interaction between the working and dissolved ions. In addition to the distinct peaks for each analyte, researchers also observed a shoulder peak. A possible reason for the presence of this peak was provided. Different electrochemical tests were performed to ascertain the theory on the basis of the experimental observations.

  15. Antimony/Graphitic Carbon Composite Anode for High-Performance Sodium-Ion Batteries.

    Science.gov (United States)

    Zhao, Xin; Vail, Sean A; Lu, Yuhao; Song, Jie; Pan, Wei; Evans, David R; Lee, Jong-Jan

    2016-06-01

    Although the room-temperature rechargeable sodium-ion battery has emerged as an attractive alternative energy storage solution for large-scale deployment, major challenges toward practical sodium-ion battery technology remain including identification and engineering of anode materials that are both technologically feasible and economical. Herein, an antimony-based anode is developed by incorporating antimony into graphitic carbon matrices using low-cost materials and scalable processes. The composite anode exhibits excellent overall performance in terms of packing density, fast charge/discharge capability and cyclability, which is enabled by the conductive and compact graphitic network. A full cell design featuring this composite anode with a hexacyanometallate cathode achieves superior power output and low polarization, which offers the potential for realizing a high-performance, cost-effective sodium-ion battery. PMID:27172376

  16. Antimony segregation in stressed SiGe heterostructures grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    The effects of the growth temperature, composition, and elastic strains in separate layers on the segregation of antimony are studied experimentally for stressed SiGe structures grown by molecular beam epitaxy. It is established that the growth conditions and parameters of the structures exert an interrelated influence on the segregation of Sb: the degree of the influence of the composition and elastic stresses in the SiGe layers on Sb segregation depends on the growth temperature. It is shown that usage of a method previously proposed by us for the selective doping of silicon structures with consideration for the obtained dependences of Sb segregation on the growth conditions and parameters of the SiGe layers makes it possible to form SiGe structures selectively doped with antimony

  17. Synthesis, spectroscopic characterization and antibacterial activity of antimony(III) bis(dialkyldithiocarbamato)alkyldithiocarbonates.

    Science.gov (United States)

    Chauhan, H P S; Bakshi, Abhilasha; Bhatiya, Sumit

    2011-10-15

    Some mixed sulfur donor ligand complexes of antimony(III) of the general formula [(R(2)NCS(2))](2)SbS(2)COR' where R = CH(3), C(2)H(5) and R' = Me, Et, Pr(n), Pr(i), Bu(n) and Bu(i) have been synthesized by the reaction of antimony(III) bis(dialkyldithiocarbamate) chloride with potassium organodithiocarbonate in an equimolar ratio by stirring at room temperature in benzene/CS(2) mixture. These complexes have been characterized by physicochemical [elemental analysis, melting points and molecular weight determinations] and spectral [UV, IR, Far-IR, NMR ((1)H and (13)C), FAB(+) mass and powder X-ray diffraction] studies. Free ligands and synthesized complexes have also been screened against different bacterial strains and results obtained made it desirable to delineate a comparison between free ligands, standard drug used and synthesized complexes. PMID:21764366

  18. Measurement of aluminium, silicon, manganese, copper and antimony in slag, castings and white metal

    International Nuclear Information System (INIS)

    Chemical analysis of the slag showed 24.90% SiO2, 17.88% Al2O3, 0.75% F2O3, 46.4% CaO and 2.34% MgO. In the four cast metal samples the manganese concentration was 0.75%, 0.48%, 0.47% and 0.42%. The white metal contained 59.04% tin, 7.43% antimony, 22.55% lead and 7.08% copper. The slag, casting and white metal samples came from the Industrial Research Centre for Central Africa (CRIAC), having been provided originally by the Société Somkat of Lubumbashi which operates iron, bronze and aluminium foundries. The aluminium, silicon, manganese, copper and antimony concentrations were easily measured, without the need for chemical separation. (author)

  19. Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jiao [College of Chemistry and Material Science, Hebei Normal University, No. 20 Road East of 2nd Ring South, Yuhua District, Shijiazhuang, Hebei 050024 (China); Han, Zhangang, E-mail: hanzg116@yahoo.com.cn [College of Chemistry and Material Science, Hebei Normal University, No. 20 Road East of 2nd Ring South, Yuhua District, Shijiazhuang, Hebei 050024 (China); Zhang, Heng; Yu, Haitao [College of Chemistry and Material Science, Hebei Normal University, No. 20 Road East of 2nd Ring South, Yuhua District, Shijiazhuang, Hebei 050024 (China); Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn [College of Chemistry and Material Science, Hebei Normal University, No. 20 Road East of 2nd Ring South, Yuhua District, Shijiazhuang, Hebei 050024 (China)

    2012-10-15

    Three polyoxometalates consisting of bi-antimony capped Keggin-type clusters: [Cu(mbpy){sub 2}]{sub 2}[PMo{sub 12}O{sub 40}Sb{sub 2}]{center_dot}4H{sub 2}O (1), [Cu(mbpy){sub 2}][PMo{sub 12}O{sub 40}Sb{sub 2}] (2) and {l_brace}Cu(mbpy)[Cu(mbpy){sub 2}]{sub 2}{r_brace}[VMo{sub 8}V{sub 4}O{sub 40}Sb{sub 2}]{center_dot}2H{sub 2}O (3) (mbpy=4,4 Prime -dimethyl-2,2 Prime - dipyridyl in 1 and 2; 5,5 Prime -dimethyl-2,2 Prime -dipyridyl in 3) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. Single-crystal analysis revealed that all of three compounds are built upon bi-antimony capped Keggin-type polyoxoanions and Cu-mbpy cations. In 1-3, two Sb{sup III} centers located at the two opposite of anionic surface adopt fundamentally tetragonal pyramidal coordination geometry. Both compounds 1 and 2 consist of P-centered Keggin structure, while compound 3 presents a V-centered Keggin anion. The Keggin-type anions present different structural features: isolated cluster in 1 and Cu-ligand-supported cluster in 2 and 3. - Graphical abstract: Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters modified with Cu-ligand cations have been synthesized and characterized. Highlights: Black-Right-Pointing-Pointer Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters have been synthesized. Black-Right-Pointing-Pointer Two Sb{sup III} centers located at the two opposite of anionic surface adopt tetragonal pyramidal coordination geometry. Black-Right-Pointing-Pointer The anions present different structural features: isolated and Cu-ligand-supported cluster.

  20. Application of Hyphenated Techniques in Speciation Analysis of Arsenic, Antimony, and Thallium

    OpenAIRE

    Rajmund Michalski; Sebastian Szopa; Magdalena Jabłońska; Aleksandra Łyko

    2012-01-01

    Due to the fact that metals and metalloids have a strong impact on the environment, the methods of their determination and speciation have received special attention in recent years. Arsenic, antimony, and thallium are important examples of such toxic elements. Their speciation is especially important in the environmental and biomedical fields because of their toxicity, bioavailability, and reactivity. Recently, speciation analytics has been playing a unique role in the studies of biogeochemi...

  1. Metal corrosion studies with the fluorosulphonic acid-antimony pentafluoride superacid system

    International Nuclear Information System (INIS)

    Because of their rapid dissolution of many actinide metals and refractory oxides, superacids such as HSO3F/SbF5 have potential applications in actinide processing. However, material compatibility must first be addressed because of the highly corrosive nature of superacids. This paper describes the qualitative rates of attack of fluorosulphonic acid-antimony pentafluoride superacid on a variety of metal substrates relevant to nuclear processing

  2. Molybdenum-vanadium-antimony mixed oxide catalyst for isobutane partial oxidation synthesized using magneto hydrodynamic forces

    OpenAIRE

    Stuyven, Bernard; Emmerich, Jens; Eloy, Pierre; Van Humbeeck, Jan; Jacobs, Pierre; Kirschhock, Christine; Martens, Johan; Breynaert, Eric

    2014-01-01

    A peculiar effect was observed that the oxidation behavior of antimony oxide prepared in presence of a weak permanent magnetic field is changed. Reactivity of alpha-Sb2O3 (senarmontite) towards oxidation is significantly enhanced after recirculating its suspension in a magneto hydrodynamic (MHD) system. This inspired the MHD synthesis of a molybdenum-vanadiumantimony mixed oxide with superior catalytic activity for selective partial oxidation of isobutane. Traditionally these mixed oxides are...

  3. Temporal and spatial distribution of atmospheric antimony emission inventories from coal combustion in China

    International Nuclear Information System (INIS)

    A multiple-year inventory of atmospheric antimony (Sb) emissions from coal combustion in China for the period of 1980-2007 has been calculated for the first time. Specifically, the emission inventories of Sb from 30 provinces and 4 economic sectors (thermal power, industry, residential use, and others) are evaluated and analyzed in detail. It shows that the total Sb emissions released from coal combustion in China have increased from 133.19 t in 1980 to 546.67 t in 2007, at an annually average growth rate of 5.4%. The antimony emissions are largely emitted by industrial sector and thermal power generation sector, contributing 53.6% and 26.9% of the totals, respectively. At provincial level, the distribution of Sb emissions shows significant variation. Between 2005 and 2007, provinces always rank at the top five largest Sb emissions are: Guizhou, Hunan, Hebei, Shandong, and Anhui. - Highlights: → Atmospheric Sb emission inventory from coal in China during 1980-2007 is developed. → We included 1612 coal samples to determine the provincial mean Sb contents in coal. →Emission inventories of Sb from 30 provinces and 4 economic sectors are evaluated. → Total 546.67t Sb emissions in 2007 are mainly emitted from industrial sector. → There is significant variation for Sb distribution among different provinces. - A multiple-year inventory of atmospheric antimony emissions from coal combustion in China for the period of 1980-2007 has been calculated for the first time.

  4. Antimony in the Contaminated Site of El Triunfo, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Marmolejo-Rodríguez A. J.

    2013-04-01

    Full Text Available Antimony has properties similar to arsenic with some of its compounds toxic to humans. Therefore it is necessary to control the wastes accumulated by anthropogenic activities, such as mining, where it is in tailings to be released to the environment. According to the Environment Protection Agency, the maximum value in sediments is 11.2 mg Sb kg–1 and the Earth’s crust average is 0.2 mg Sb kg–1. In this semiarid area, the drainage basin El Carrizal is impacted with wastes of an abandoned gold mine at the Mining District El Triunfo (MD – ET which have tailings with 17,600 mg kg–1 of antimony. In the main dry river (arroyo, the Sb content is between 0.6 and 122 mg kg–1. This element is transported from the source throughout the fluvial basin to discharge into the Pacific Ocean. In the arroyo mouth we collected one sedimentary core and the sediment from dunes (28.6 – 45.7 and 6.43 – 7.74 mg Sb kg–1. This research concluded the antimony is enriched in this semiarid system, with Normalized Enrichment Factors severely enriched mainly in arroyo sediments close to the MD-ET

  5. Morphology and antimony segregation of spangles on batch hot-dip galvanized coatings

    International Nuclear Information System (INIS)

    Spangles produced by batch hot-dip galvanizing process have a rougher surface and a greater surface segregation of alloying element compared with those in continuous hot-dip galvanizing line (CGL), owing to the cooling rate of the former is much smaller than that of the later. Therefore, typical spangles on a batch hot-dipped Zn-0.05Al-0.2Sb alloy coating were investigated. The chemical, morphological characterization and identification of the phases on the spangles were examined by scanning electron microscopy (SEM), backscattered electron imaging (BSE), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). The results showed that the coating surface usually exhibited three kinds of spangles: shiny, feathery and dull spangle, of which extensively antimony surface segregation was detected. The nature of precipitate on the coating surface was identified as β-Sb3Zn4, The precipitated β-Sb3Zn4 particles distributed randomly on the shiny spangle surface, both β-Sb3Zn4 particles and dentritic segregation of antimony dispersed in the dendritic secondary arm spacings of the feathery spangle and on the whole dull spangle surface. The dentritic segregation of antimony and precipitation of Sb3Zn4 compound are discussed by a proposed model.

  6. Methylated arsenic and antimony species in suspended matter of the river Ruhr, Germany

    Directory of Open Access Journals (Sweden)

    L. Duester

    2008-04-01

    Full Text Available The methylated antimony and arsenic species content of sediments derived from a sedimentation bowl of the river Ruhr were monitored over a 12 month period. The most prevalent species detected were monomethylarsenic (MMAs and monomethylantimony (MMSb. The methylantimony and methylarsenic species concentration was found to be directly correlated to the winter spate. As the biological activity in the water body is generally low at this time of the year, it may be concluded that the concentration maxima in winter originated from the translocation of soil- and sediment particles to the river by heavy rains and the melting of snow. A second maximum in Spring/early Summer was observed for the methylarsenic species, and specifically the dimethylarsenic species (DMAs; this occurred in parallel to the algal bloom. A change in the methylarsenic speciation pattern was observed between April, May and June, with DMAs replacing MMAs as the dominant methylarsenic species. For methylated antimony species no seasonal variation in the species pattern was detected. Taken together these data strongly indicate a higher degree of transformation of arsenic compared to antimony in the Ruhr river system in spring and can be taken as a record for a biogeochemical different behaviour of these two elements which are often treated as equivalent in environmental studies.

  7. Studies in atomic-fluorescence spectroscopy-V The fluorescence characteristics and determination of antimony.

    Science.gov (United States)

    Dagnall, R M; Thompson, K C; West, T S

    1967-10-01

    Atomic-fluorescence of antimony may be generated in an air-propane flame by nebulizing aqueous solutions of antimony salts whilst irradiating the flame by means of a microwave-excited electrode-less discharge tube operating at 30 W. The strongest fluorescence is exhibited by the (4)S(11 2 ) --> (4)P(1 3 ) 2311 A resonance line and weaker signals are observed at the 2068 and 2176 A resonance lines and at four intercombination lines, at 2598, 2671, 2770 and 2878 A. A process of thermally assisted direct-line fluorescence is postulated to account for the otherwise inexplicable intensity of the 2598 A line emission. Atomic-fluorescence spectroscopy at 2176 A permits the determination of antimony in the range 0.1-120 ppm with a detection limit of 0.05 ppm. With the same equipment and source, the range of measurement for atomic-absorption was 6-120 ppm and the detection limit was 1 ppm. No interferences were observed from 100-fold molar amounts of Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, NH(4), Pb and Zn or from arsenate, chloride, nitrate, phosphate and sulphate. PMID:18960212

  8. Ultrasound- assisted emulsification microextraction for separation of trace amounts of antimony prior to FAAS determination

    International Nuclear Information System (INIS)

    We describe a simple and rapid method for the ultrasound-assisted microextraction of antimony using the solidified floating organic drop method. The effects of pH, type and volume of the extractant, time of sonication, amount of chelating agent, type and amount of surfactant were investigated and optimized. Bromopyrogollol red is acting as the chelating agent. Antimony(III) ion was extracted into finely dispersed droplets of undecanol after ion-pair formation with the water soluble chelator and the cationic detergent benzyldimethyltetradecylammonium chloride. Flame atomic absorption spectrometry was used for the detection. The resulting calibration is linear in the concentration range from 4. 0 to 900 ng mL-1 of Sb(III) with a correlation coefficient of 0. 9981. The enrichment factor is 67, the detection limit is 0. 62 ng mL-1, and the relative standard deviation is ±3. 6% (at 100 ng mL-1; for n = 10). The method was successfully applied to the determination of antimony in water samples. (author)

  9. Accumulation of antimony and other potentially toxic elements in plants around a former antimony mine located in the Ribes Valley (Eastern Pyrenees)

    Science.gov (United States)

    Bech, Jaume; Corrales, Isabel; Duran, Paola; Roca, Núria; Tume, Pedro; Barceló, Juan; Poschenrieder, Charlotte

    2010-05-01

    Soil contamination by antimony is of increasing environmental concern due to the use of this amphoterous p-block element in many industrial applications such as flame retardant, electronics, alloys, rubber and textile industries. However, little is still known about the response of plants to antimony. Here we report on the accumulation of antimony and other potentially toxic elements (mainly As, Pb and Cu) in plants growing around a former antimony mine in the ribes Valley located in the Eastern Pyrenees (424078E, 4686100N alt. 1145 m.a.s.l) that was operating approximately between the years 1870 to 1960. The ore mineral veins are included in quartz gangue. The main ores were: Sulphides: Stibnite (Sb2S3), Pyrite (FeS2), Sphalerite (ZnS), Arsenopyrite (FeAs), Galenite (PbS), Chalcopyrite (CuFeS2), Tetrahydrite (Cu5Sb2S3). Sulphosals: Boulangerite (5PbS•2Sb2S3), Jamesonite (4PbS•FeS•3Sb2S3), Zinckenite (6PbS•7Sb2S3), Plagionite (5PbS•4Sb2S3), Bournonite PbCu (Sb,As)S3, Pyrargirite (Ag3SbS3). Soil and plant samples were taken at five locations with different levels of Sb, As, and polymetallic contamination. Both pseudototal (aqua regia soluble) and extractable (EDTA) concentrations of metals from sites with low (sites 1 and 2), moderate (site 3 and 4) and high (sites 5 and 6) pollutant burdens were studied. The range of agua regia and EDTA values in mgkg-1 is as follows: Sb 8-2904 and 0.88-44; As: 33-16186 and 3.2-167; Pb: 79-4794 and 49-397; Cu: 66-712 and 48-56 mg•kg-1, respectively). While sites 1 to 4 had alkaline soil pH (7.4-8.7), sites 5 and 6 were acidic with values of 6 and 4.6, respectively. Different herbaceous plant species (Poa annua, Echium vulgare, Sonchus asper, Barbera verna among others) at the low and moderately polluted sites were able to efficiently restrict Sb and As transport to shoots showing average concentration ranges between 5.5 and 23 mg/kg As and 1.21 mg/kg and 4.9 mg/kg Sb. However, at the highly polluted acidic sites (5 and

  10. Comparison of oral itraconazole and intramuscular meglumine antimoniate in the treatment of cutaneous leishmaniasis

    International Nuclear Information System (INIS)

    To compare the efficacy and tolerability of oral itraconazole against intramuscular meglumine antimoniate in the treatment of Cutaneous Leishmaniasis (CL). Two hundred eligible and consenting patients of Cutaneous Leishmaniasis (CL) were divided in two groups with 100 patients in each. The number and location of the lesions were documented and clinical types of cutaneous leishmaniasis were noted. The diagnosis was confirmed by skin slit smear and histopathology of the lesional skin. Culture on Nicolle Novy MacNeal (NNN) medium and Leishmanin test was done in all patients. All the patients in both groups were subjected to complete blood picture, urine examination, serum urea and creatinine levels and ECG examination. One group was given itraconazole 100 mg twice daily orally for a duration of 6-8 weeks. The other group was given meglumine antimoniate 10 cc in the form of deep intramuscular injections for 15-30 days. The efficacy of the treatment was judged by clinical and parasitological response. Side effects of the agents were also noted during treatment. Out of 200 patients studied, 185 were males and 15 were females. The mean age of presentation was 30 + 6.6 years. Single lesion was seen in 132 (66%) subjects whereas 68 (34%) subjects had multiple lesions. Slit skin smears were positive in 50 (25%) of the patients. Skin biopsy yielded the presence of LT bodies in 150 (75%) subjects. The culture was positive in 102 (51%) cases. Leishmanin test was positive in 94% subjects. Seventy-five (75%) patients on itraconazole therapy showed complete clinical and parasitological cure in 4-8 weeks duration. A rise in ALT was seen in 12% subjects. Five (5%) subjects did not show any improvement till the end of therapy. Sixty-five (65%) subjects on meglumine antimoniate showed complete healing in 15-30 days. In 35 (35%) of the patients, the treatment had to be stopped due to intolerable side-effects. Four cases of lupoid leishmaniasis and 4 cases of sporotrichoid leishmaniasis

  11. Study on determination of antimony in environmental samples by nuclear technique neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Tassiane Cristina Gomes; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Full text: The Interest on determination of antimony in environmental samples has increased significantly in recent years due to the impact caused by human activities and their potential cumulative toxic at low concentrations, apart from not having known biological function. However, the quantification of antimony has interference problems due to low concentrations that hinder its analysis. Therefore becomes of great interest to establish adequate procedures for neutron activation analysis (NAA) to obtain reliable results in environmental samples. In this context, reference materials INCT-TL-1 Tea Leaves, INCT-MPH -2 Mixed Polish Herbs, CTA-VTL-2 Virginia Tobaco Leaves, White Cabbage BCR-679, IAEA 140/TM Seaweed (Focus sp), IAEA -SL-1 Lake Sediment and IAEA-336 Lichen, were selected for analysis and evaluation of results. Aliquots of these standard synthetic materials and antimony were irradiated in the nuclear research reactor IEA-R1 under thermal neutron flux of approximately 5 x 1012 cm{sup -2} s{sup -1} for a period of 8 or 16 hours. After appropriate decay time, the induced gamma activity of the irradiated samples and standard was measured using hyperpure Ge detector coupled to the digital spectrum analyzer DAS 1000, both from Canberra. The radioisotopes measured with gamma ray energies and the half-life were Sb-122 (E{gamma} = 564keV ; t1=2 = 2:7d) and Sb - 124 (E{gamma} = 1692keV; t1=2 60:2d). Antimony concentrations were calculated by the comparative method and the uncertainties of the results were estimated using statistical error of the sample and standard counts Results obtained in these analyses showed a good agreement with certified values and relative errors varying from 0.78 to 13.8%. The values of the standardized difference or Z-scores obtained were lower than 2, indicating that the obtained data were within the range of certified values at a significance level of 68%, demonstrating the suitability of the method used for determination of antimony

  12. Study on determination of antimony in environmental samples by nuclear technique neutron activation analysis

    International Nuclear Information System (INIS)

    Full text: The Interest on determination of antimony in environmental samples has increased significantly in recent years due to the impact caused by human activities and their potential cumulative toxic at low concentrations, apart from not having known biological function. However, the quantification of antimony has interference problems due to low concentrations that hinder its analysis. Therefore becomes of great interest to establish adequate procedures for neutron activation analysis (NAA) to obtain reliable results in environmental samples. In this context, reference materials INCT-TL-1 Tea Leaves, INCT-MPH -2 Mixed Polish Herbs, CTA-VTL-2 Virginia Tobaco Leaves, White Cabbage BCR-679, IAEA 140/TM Seaweed (Focus sp), IAEA -SL-1 Lake Sediment and IAEA-336 Lichen, were selected for analysis and evaluation of results. Aliquots of these standard synthetic materials and antimony were irradiated in the nuclear research reactor IEA-R1 under thermal neutron flux of approximately 5 x 1012 cm-2 s-1 for a period of 8 or 16 hours. After appropriate decay time, the induced gamma activity of the irradiated samples and standard was measured using hyperpure Ge detector coupled to the digital spectrum analyzer DAS 1000, both from Canberra. The radioisotopes measured with gamma ray energies and the half-life were Sb-122 (Eγ = 564keV ; t1=2 = 2:7d) and Sb - 124 (Eγ = 1692keV; t1=2 60:2d). Antimony concentrations were calculated by the comparative method and the uncertainties of the results were estimated using statistical error of the sample and standard counts Results obtained in these analyses showed a good agreement with certified values and relative errors varying from 0.78 to 13.8%. The values of the standardized difference or Z-scores obtained were lower than 2, indicating that the obtained data were within the range of certified values at a significance level of 68%, demonstrating the suitability of the method used for determination of antimony in this type sample

  13. Biodistribution of meglumine antimoniate in healthy and Leishmania (Leishmania infantum chagasi-infected BALB/c mice

    Directory of Open Access Journals (Sweden)

    Samanta Etel Treiger Borborema

    2013-08-01

    Full Text Available Pentavalent antimonials such as meglumine antimoniate (MA are the primary treatments for leishmaniasis, a complex disease caused by protozoan parasites of the genus Leishmania . Despite over 70 years of clinical use, their mechanisms of action, toxicity and pharmacokinetics have not been fully elucidated. Radiotracer studies performed on animals have the potential to play a major role in pharmaceutical development. The aims of this study were to prepare an antimony radiotracer by neutron irradiation of MA and to determine the biodistribution of MA in healthy and Leishmania (Leishmania infantum chagasi-infected mice. MA (Glucantime(r was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes, 122Sb and 124Sb, with high radionuclidic purity and good specific activity. This irradiated compound presented anti-leishmanial activity similar to that of non-irradiated MA in both in vitro and in vivo evaluations. In the biodistribution studies, healthy mice showed higher uptake of antimony in the liver than infected mice and elimination occurred primarily through biliary excretion, with a small proportion of the drug excreted by the kidneys. The serum kinetic curve was bi-exponential, with two compartments: the central compartment and another compartment associated with drug excretion. Radiotracers, which can be easily produced by neutron irradiation, were demonstrated to be an interesting tool for answering several questions regarding antimonial pharmacokinetics and chemotherapy.

  14. Development of an analytical method for antimony speciation in vegetables by HPLC-hydride generation-atomic fluorescence spectrometry.

    Science.gov (United States)

    Olivares, David; Bravo, Manuel; Feldmann, Jorg; Raab, Andrea; Neaman, Alexander; Quiroz, Waldo

    2012-01-01

    A new method for antimony speciation in terrestrial edible vegetables (spinach, onions, and carrots) was developed using HPLC with hydride generation-atomic fluorescence spectrometry. Mechanical agitation and ultrasound were tested as extraction techniques. Different extraction reagents were evaluated and optimal conditions were determined using experimental design methodology, where EDTA (10 mmol/L, pH 2.5) was selected because this chelate solution produced the highest extraction yield and exhibited the best compatibility with the mobile phase. The results demonstrated that EDTA prevents oxidation of Sb(III) to Sb(V) and maintains the stability of antimony species during the entire analytical process. The LOD and precision (RSD values obtained) for Sb(V), Sb(III), and trimethyl Sb(V) were 0.08, 0.07, and 0.9 microg/L and 5.0, 5.2, and 4.7%, respectively, for a 100 microL sample volume. The application of this method to real samples allowed extraction of 50% of total antimony content from spinach, while antimony extracted from carrots and onion samples ranged between 50 and 60 and 54 and 70%, respectively. Only Sb(V) was detected in three roots (onion and spinach) that represented 60-70% of the total antimony in the extracts. PMID:22970588

  15. Leachability of antimony from energy ashes. Total contents, leachability and remedial suggestions; Lakning av antimon fraan energiaskor. Totalhalter, lakbarhet samt foerslag till aatgaerder

    Energy Technology Data Exchange (ETDEWEB)

    Baeckstroem, Mattias [Oerebro Univ. (Sweden)

    2006-01-15

    In the current project total concentrations for antimony in 31 energy ashes have been compiled. The average concentration of antimony in boiler fly ash and grate boiler fly ash is 192 and 1,140 mg/kg, respectively. The corresponding antimony concentrations for boiler ashes and grate bottom ashes are 86,5 and 61,8 mg/kg, respectively. Multivariate calculations clearly pointed out waste as the major source for antimony in ashes. The difference between total antimony concentration in fly ash and bottom ash is greatest for grate boilers, in average 18 times higher in the fly ash. The difference for CFB/BFB-boilers is only slightly more than 2. However, based on amount, 75% of the total antimony inventory is recovered in the fly ashes for both CFB/BFB and grate boilers. Eleven (eight of which were bottom ashes) out of the 31 samples exceeded the guidelines for inert waste. It is clear that the higher ionic strength in the solutions from the fly ashes contribute to decrease the solubility for critical minerals retaining antimony. In addition, the fly ashes have considerably larger effective surface able to sorb trace elements. A clear and positive covariance was discovered between aluminium and antimony. Furthermore, it was noted that antimony showed no typical anionic behaviour despite the fact that it according to the geochemical calculations should be present as SbO{sub 3}{sup -}. At L/S 10, a maximum of 1% of the total antimony concentration is leached. This should be compared to chloride that had 94% of the total concentration leached at L/S 10. There was no correlation between the leached antimony concentrations and the total antimony concentrations. The sequential extractions also suggest a low leachability for antimony from the ashes. In average only 9,6% is released at pH 7, 7,3% at pH 5, 3,6% during reducing conditions and 3,2% during oxidising conditions. In total, only 24% of the total antimony concentrations is released during the four extraction steps. The

  16. Selective liquid-liquid extraction of antimony(III from hydrochloric acid media by N-n-octylaniline in xylene

    Directory of Open Access Journals (Sweden)

    M. A. ANUSE

    2004-04-01

    Full Text Available N-n-Octylaniline in xylene was used for the extraction separation of antimony(III from hydrochloric acid media. Antimony(III was extracted quantitatively with 10 mL 4 % N-n-octylaniline in xylene. It was stripped from the organic phase with 0.5 M ammonia and estimated photometrically by the iodide method. The effect of metal ion, acid, reagent concentration and various foreign ions was investigated. The method affords binary and ternary separation of antimony(III from tellurium(IV, selenium(IV, lead(II, bismuth(III, tin(IV, germanium(IV, copper(II, gold(III, iron(III and zinc(II. The method is applicable for the analysis of synthetic mixtures, alloys and semiconductor thin films. It is fast, accurate and precise.

  17. Synthesis, characterization and single crystal X-ray analysis of chlorobis(N,N-dimethyldithiocarbamato-S,S′antimony(III

    Directory of Open Access Journals (Sweden)

    H.P.S. Chauhan

    2015-07-01

    Full Text Available The title compound chlorobis(N,N-dimethyldithiocarbamato-S,S′antimony(III has been prepared in distilled acetonitrile and characterized by physicochemical [melting point and molecular weight determination, elemental analysis (C, H, N, S & Sb], spectral [FT–IR, far IR, NMR (1H & 13C] studies. The crystal and molecular structure was further confirmed using single crystal X-ray diffraction analysis which features a five-coordinate geometry for antimony(III within a ClS4 donor set. The distortion in the co-planarity of ClSbS3 evidences the stereochemical influence exerts by the lone pair of electrons on antimony(III. Two centrosymmetrically related molecule held together via C–H···Cl secondary interaction result in molecular aggregation of the compound.

  18. Pharmacokinetics and tissue distribution of Antimony after multiple intramuscular administrations in the Hamster

    International Nuclear Information System (INIS)

    The fate of pentavalent antimony (Sb) in different tissues in the body after intramuscular administration is of great interest for the future study of Sb therapy in different sitting. Pharmacokinetics and tissue distribution of antimony (Sb) were studied in the hamster after daily dose of sodium stibogluconate equivalent to 120 mg kg of Sb, administered intramuscularly for two weeks. Liver, spleen, heart, kidney and skin tissues were isolated after blood collection at the specified time. Antimony was measured in these tissues after suitable treatment, ashing and processing, by flame less atomic absorption spectrophotometry. The concentration of Sb time profile in blood showed a linear raid decline with elimination half life (tz1/2) of 1.7h. The concentration of drug (ug/gm) declined in a biphasic manner from almost all tissues. However, the concentrations of Sb were declined in slower fashion from the hamster tissues than from the blood. The maximum concentration of Sb was determined in the kidney tissues (3416+-631ug/gm) while the lowest concentration was in the spleen (209+-187ug/gm). The maximum concentration of Sb in the kidney (ug/gm) was more than 25 fold higher than that measured from blood (ug/ml). The AUC of Sb in the studied tissues was in this rank: kidney>liver>skin>spleen>heart>blood. Surprisingly, the heart, spleen and liver showed a similar t1/2 of 5.2-6.2h while the kidney and skin had a t1/2 of about 3h. Therefore, disposition of Sb seems to kinetically follow multicompartmental compartmental model. The kidneys got the highest concentration of drug which may lead to nephrotoxicity on long term therapy. (author)

  19. Lithium-antimony-lead liquid metal battery for grid-level energy storage

    Science.gov (United States)

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J.; Boysen, Dane A.; Bradwell, David J.; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R.

    2014-10-01

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this finding

  20. Development and pharmacokinetic of antimony encapsulated in liposomes of phosphatidylserine using radioisotopes in experimental leishmaniasis

    International Nuclear Information System (INIS)

    Leishmaniasis are a complex of parasitic diseases caused by intra macrophage protozoa of the genus Leishmania, and is fatal if left untreated. Pentavalent antimonials, though toxic and their mechanism of action being unclear, remain the first-line drugs for treatment. Effective therapy could be achieved by delivering antileishmanial drugs to these sites of infection. Liposomes are phospholipid vesicles that promote improvement in the efficacy and action of drugs in target cell. Liposomes are taken up by the cells of mononuclear phagocytic system (MPS). The purpose of this study was to develop a preparation of meglumine antimonate encapsulated in liposomes of phosphatidylserine and to study its pharmacokinetic in healthy mice to establish its metabolism and distribution. Quantitative analysis of antimony from liposomes demonstrated that Neutron Activation Analysis was the most sensitive technique with almost 100 % of accuracy. All liposome formulations presented a mean diameter size of 150 nm. The determination of IC50 in infected macrophage showed that liposome formulations were between 10 - 63 fold more effective than the free drug, indicating higher selectivity index. By fluorescence microscopy, an increased uptake of fluorescent-liposomes was seen in infected macrophages during short times of incubation compared with non-infected macrophages. Biodistribution studies showed that meglumine antimonate irradiated encapsulated in liposomes of phosphatidylserine promoted a targeting of antimony for MPS tissues and maintained high doses in organs for a prolonged period. In conclusion, these data suggest that meglumine antimonate encapsulated in liposomes showed higher effectiveness than the non-liposomal drug against Leishmania infection. The development of liposome formulations should be a new alternative for the chemotherapy of infection diseases, especially Leishmaniasis, as they are used to sustain and target pharmaceuticals to the local of infection. (author)

  1. The LABCG2 Transporter from the Protozoan Parasite Leishmania Is Involved in Antimony Resistance.

    Science.gov (United States)

    Perea, Ana; Manzano, José Ignacio; Castanys, Santiago; Gamarro, Francisco

    2016-06-01

    Treatment for leishmaniasis, which is caused by Leishmania protozoan parasites, currently relies on a reduced arsenal of drugs. However, the significant increase in the incidence of drug therapeutic failure and the growing resistance to first-line drugs like antimonials in some areas of Northern India and Nepal limit the control of this parasitic disease. Understanding the molecular mechanisms of resistance in Leishmania is now a matter of urgency to optimize drugs used and to identify novel drug targets to block or reverse resistant mechanisms. Some members of the family of ATP-binding cassette (ABC) transporters in Leishmania have been associated with drug resistance. In this study, we have focused our interest to characterize LABCG2's involvement in drug resistance in Leishmania. Leishmania major parasites overexpressing the ABC protein transporter LABCG2 were generated in order to assess how LABCG2 is involved in drug resistance. Assays of susceptibility to different leishmanicidal agents were carried out. Analysis of the drug resistance profile revealed that Leishmania parasites overexpressing LABCG2 were resistant to antimony, as they demonstrated a reduced accumulation of Sb(III) due to an increase in drug efflux. Additionally, LABCG2 was able to transport thiols in the presence of Sb(III) Biotinylation assays using parasites expressing LABCG2 fused with an N-terminal green fluorescent protein tag revealed that LABCG2 is partially localized in the plasma membrane; this supports data from previous studies which suggested that LABCG2 is localized in intracellular vesicles that fuse with the plasma membrane during exocytosis. In conclusion, Leishmania LABCG2 probably confers antimony resistance by sequestering metal-thiol conjugates within vesicles and through further exocytosis by means of the parasite's flagellar pocket. PMID:27021316

  2. Antimony film sensor for sensitive rare earth metal analysis in environmental samples.

    Science.gov (United States)

    Makombe, Martin; van der Horst, Charlton; Silwana, Bongiwe; Iwuoha, Emmanuel; Somerset, Vernon

    2016-07-01

    A sensor for the adsorptive stripping voltammetric determination of rare earth elements has been developed. The electrochemical procedure is based on the oxidation of the rare earth elements complexed with alizarin complexone at a glassy carbon electrode that was in situ modified with an antimony film, during an anodic scan from -0.2 V to 1.1 V (vs. Ag/AgCl) and deposition potential of -0.1 V (vs. Ag/AgCl). The factors influencing the adsorptive stripping capability were optimised, including the complexing agent concentration, plating concentration of antimony and deposition time. The detection of rare earth elements (La, Ce and Pr) were realised in 0.08 M sodium acetate (pH = 5.8) solution as supporting electrolyte, with 2 × 10(-6) M alizarin complexone and 1.0 mg L(-1) antimony solution. Under the optimised conditions, a deposition time of 360 s was obtained and a linear response was observed between 1 and 25 µg L(-1). The reproducibility of the voltammetric measurements was found to be within 5.0% RSD for 12 replicate measurements of cerium(III) concentration of 5 µg L(-1) using the same electrode surface. The detection limits obtained using stripping analysis was 0.06, 0.42 and 0.71 μg L(-1) for Ce(III), La(III) and Pr(III), respectively. The developed sensor has been successfully applied for the determination of cerium, lanthanum and praseodymium in municipal tap water samples. PMID:27065049

  3. Determination of PM10 deposition based on antimony flux to selected urban surfaces

    International Nuclear Information System (INIS)

    Deposition of PM10 particles to several types of urban surfaces was investigated within this study. Antimony was chosen as a tracer element to calculate dry deposition velocities for PM10, since antimony proved to be present almost exclusively in PM10 particles in ambient urban air. During 18 months, eight sampling sites in Berlin and Karlsruhe, two cities in Germany, were operated. PM10 concentrations and dry deposition were routinely sampled as two week averages. Additionally, leaf-samples were collected at three sites with tall vegetation. The obtained deposition velocities ranged from 0.8 to 1.3 cm s-1 at roadside sites and from 0.4 to 0.5 cm s-1 at the other sites. With reference to the whole canopy, additional deposition velocities of about 0.5 cm s-1 were obtained for leaf surfaces. As a consequence, it can be concluded that vegetation-covered areas beside streets show the highest potential to capture particles in urban areas. - Highlights: → Deposition velocities of PM10 were determined using Sb as a tracer element. → Dry PM10 deposition velocities ranged from 0.8 to 1.3 cm s-1 at roadside sites. → Dry PM10 deposition velocities ranged from 0.4 to 0.5 cm s-1 at other urban sites. → Additional deposition velocities of 0.5 cm s-1 were obtained for leaf surfaces. - Antimony is used as a tracer element to calculate dry deposition velocities of PM10 particles to selected urban surfaces.

  4. Separation of antimony from synthetic cloth. Application in forensic science using neutron activation analysis

    International Nuclear Information System (INIS)

    A simple ion-exchange separation procedure was developed for selective removal of antimony from synthetic cloth to facilitate determination of several trace elements frequently used to identify gunshot residues by neutron activation analysis. Radiotracers of Sb, Ba, Cu, Co, As, Zn, Hg and Ag were employed to optimize the developed procedure. The method involves the quantitative retention of the above elements, except of Sb, from 0.2M ammonium carbonate solution using Chelex 100 resin and subsequent quantitative elution of the elements of interest with 2M nitric acid for gamma-ray spectrometry. The procedure was tested by simulated gunshot residues. (author)

  5. Investigation of adsorption interaction of cadmium oxide with antimony (3) in alkaline solutions

    International Nuclear Information System (INIS)

    Adsorption processes on cadmium oxide in pure antimonite alkaline (KOH) solutions and in the presence of organic additions (sodium salt of carboxymethylcellulose, straw oil) have been studied. It is shown, that in the systems being studied, the chemosorptional interaction, leading to a sharp change in the adsorbent surface state is observed. It is established that the formation of a surface high-disperse cadmium oxide-antimony com ound on the cadmium oxide results in practically complete suppression of the cadmium oxide hydration process in aqueous solutions

  6. Polymorphism and properties of Bi{sub 2}WO{sub 6} doped with pentavalent antimony

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonova, E.P.; Belov, D.A. [M.V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Gagor, A.B.; Pietraszko, A.P. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-950 Wrocław (Poland); Alekseeva, O.A. [Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 119333 Moscow (Russian Federation); Voronkova, V.I., E-mail: voronk@polly.phys.msu.ru [M.V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation)

    2014-04-05

    Highlights: • The limit of Bi{sub 2}W{sub 1−x}Sb{sub x}O{sub 6−y} solid solutions is at x = 0.05. • Bi{sub 2}W{sub 1−x}Sb{sub x}O{sub 6−y} does not fully transform into high-temperature monoclinic phase. • Sb{sup 5+} has a weak effect on the temperatures of the ferroelectric transitions. • γ→γ{sup ‴} transition near 650 °C was observed as strong permittivity peak at 0.01–8 Hz. • The conductivity of Bi{sub 2}W{sub 0.96}Sb{sub 0.04}O{sub 6−y} at 800 °C reaches 0.02 S/cm. -- Abstract: Antimony-containing solid solutions isostructural with bismuth tungstate, Bi{sub 2}WO{sub 6}, have been prepared in air as polycrystalline samples by solid-state reactions and as single crystals by unseeded flux growth. The antimony in the solid solutions is in a pentavalent state and substitutes for tungsten in the structure of Bi{sub 2}WO{sub 6}. The Bi{sub 2}W{sub 1−x}Sb{sub x}O{sub 6−y} solid solutions have been shown to exist in the composition range 0 ⩽ x ⩽ 0.05. We have examined the effect of Sb{sup 5+} doping on the polymorphism and properties of Bi{sub 2}WO{sub 6}. In contrast to undoped Bi{sub 2}WO{sub 6}, antimony-substituted bismuth tungstate does not completely transform into its high-temperature, monoclinic phase at 960 °C and remains two-phase up to temperatures approaching its melting point. Antimony substitution for tungsten has a weak effect on the temperatures of the ferroelectric phase transitions. Heterovalent substitution of Sb{sup 5+} for W{sup 6+} is accompanied by the formation of extra oxygen vacancies and an increase in the electrical conductivity of the solid solutions by one to two orders of magnitude relative to undoped Bi{sub 2}WO{sub 6}.

  7. Influence of arsenic,antimony and cobalt impurities on the cathodic process in zinc electrowinning

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By means of an electrochemical study,the influence of arsenic,antimony and cobalt on cathodic polarization in the zinc electrowinning process,the associated kinetic equations and parameters,and the polarization mechanism have been studied.The results show that the experimental values of the kinetic parameters are in accord with the theoretical values in the ZnSO4/H2SO4 solution with a single impurity is added.In contrast,the charge transfer coefficient α is smaller than the theoretical value in the ZnSO4/H2SO4 solution when the three impurities are added together.

  8. Determination of arsenic, selenium and antimony by neutron activation analysis. Application to hair samples

    International Nuclear Information System (INIS)

    A fast rabbit system for instrumental activation analysis with reactor neutrons is described. Its use in the determination of selenium in hair is discussed. A survey is given of the correction factors which are inherent to the use of short-lived radionuclides. An alternative to INAA is NAA based on the separation of arsenic, selenium and antimony by hydride evaporation and adsorption to active carbon. Data for some Standard Reference Materials are given. This work was done under research contract 2440/RI/RB with the IAEA

  9. Impact of Biofield Treatment on Physical, Structural and Spectral Properties of Antimony Sulfide

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Antimony sulfide (Sb2S3) has gained extensive attention in solar cells due to their potential as a low-cost and earth abundant absorber material. In solar cell absorber, the optoelectrical properties such as energy band gap and absorption coefficient of Sb2S3play an important role, which have strong relationships with their crystal structure, lattice parameter and crystallite size. Hence in the present investigation, Sb2S3 powder samples were exposed to biofield treatment, and furthe...

  10. Novel antimony doped tin oxide/carbon aerogel as efficient electrocatalytic filtration membrane

    Science.gov (United States)

    Liu, Zhimeng; Zhu, Mengfu; Wang, Zheng; Wang, Hong; Deng, Cheng; Li, Kui

    2016-05-01

    A facile method was developed to prepare antimony doped tin oxide (Sb-SnO2)/carbon aerogel (CA) for use as an electrocatalytic filtration membrane. The preparation process included synthesis of a precursor sol, impregnation, and thermal decomposition. The Sb-SnO2, which was tetragonal in phase with an average crystallite size of 10.8 nm, was uniformly distributed on the CA surface and firmly attached via carbon-oxygen-tin chemical bonds. Preliminary filtration tests indicated that the Sb-SnO2/CA membrane had a high rate of total organic carbon removal for aqueous tetracycline owing to its high current efficiency and electrode stability.

  11. Electromagnetic absorption and shielding behavior of polyaniline-antimony oxide composites

    Science.gov (United States)

    Faisal, Muhammad; Khasim, Syed

    2013-02-01

    This work highlights the microwave absorption and electromagnetic interference (EMI) shielding properties of synthesized polyaniline (PAni)-antimony oxide (Sb2O3) composites in the 8-12 GHz (X-band) range. These composites showed absorption dominated EMI shielding effectiveness (EMI SEA) of -34 to -40 dB (> 99 % attenuation), indicating their shielding potential throughout the X-band. Our analyses reveal that the Sb2O3 particles in PAni matrix have key impact in determining the microwave absorption properties of the composites.

  12. Effect of antimony incorporation on structural properties of CuInS{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ben Rabeh, M., E-mail: mohamedbenrabeh@yahoo.f [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia); Chaglabou, N., E-mail: nadia_chaglabou@yahoo.f [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia); Kanzari, M., E-mail: Mounir.Kanzari@ipeit.rnu.t [Laboratoire de Photovoltaique et Materiaux Semi-Conducteurs - ENIT BP 37, Le belvedere, 1002 Tunis (Tunisia)

    2010-02-15

    CuInS{sub 2} (CIS) single crystals doped with 1, 2, 3 and 4 atomic percent (at.%) of antimony (Sb) were grown by the horizontal Bridgman method. The effect of Sb doping on the structural properties of CIS crystal was studied by means of X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM) and PL measurements. X-ray diffraction data suggests that the doping of Sb in the CIS single crystals does not affect the tetragonal (chalcopyrite) crystal structure and exhibited a (1 1 2) preferred orientation. In addition, with increasing Sb concentration, the X-ray diffraction analysis show that Sb doped CIS crystals are more crystallized and the diffraction peaks of the CuInS{sub 2} phase were more pronounced in particular the (1 1 2) plane. EDAX study revealed that Sb atoms can occupy the indium site and/or occupying the sulfur site to make an acceptor. PL spectra of undoped and Sb doped CIS crystals show two emission peaks at 1.52 and 1.62 eV, respectively which decreased with increasing atomic percent antimony. Sb doped CIS crystals show p-type conductivity.

  13. Understanding the radiolabelling mechanism of {sup 99m}Tc-antimony sulphide colloid

    Energy Technology Data Exchange (ETDEWEB)

    Tsopelas, Chris E-mail: ctsopela@mail.rah.sa.gov.au

    2003-12-01

    The chemistry of antimony trisulphide colloid (ATC) was examined to elucidate the radiolabelling mechanism with {sup 99m}TcO{sub 4}{sup -}. Ion exchange chromatography and atomic absorption spectrophotometry techniques determined ATC to be resistant to hydrolysis in 0.1 M hydrochloric acid (HCl) at 25 deg. C or 100 deg. C (>97% recovery, Sb{sup 3+} absent). Hydrogen sulphide gas detected did not participate in the mechanism, where antimony trisulphide and {sup 99m}TcO{sub 4}{sup -} in HCl/100 deg. C yielded 96% {sup 99m}Tc-product from a K{sub 2}S-free formulation (versus 98% when K{sub 2}S was present). {sup 99m}TcO{sub 4}{sup -} was reduced >90% by DMSA or dithiothreitol under the same conditions, identifying involvement of thiol groups. Infrared analysis of Re-ATC showed S-O bonds, indicating excess thiol groups at the colloid surface were oxidised at the expense of {sup 99m}TcO{sub 4}{sup -} reduction.

  14. A Black Phosphate Conversion Coating on Steel Surface Using Antimony(III)-Tartrate as an Additive

    Science.gov (United States)

    Li, Feng; Wang, Guiping

    2016-05-01

    A novel black phosphate conversion coating was formed on steel surface through a Zn-Mn phosphating bath containing mainly ZnO, H3PO4, Mn(H2PO4)2, and Ca(NO3)2, where antimony(III)-tartrate was used as the blackening agent of phosphatization. The surface morphology and composition of the coating were characterized by scanning electron microscopy, energy dispersion spectroscopy, and x-ray photoelectron spectroscopy. Corrosion resistance of the coating was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy. The pH value of the solution had significant influence on the formation and corrosion resistance of the coating. The experimental results indicated that the Sb plays a vital role in the blackening of phosphate conversion coating. The optimal concentration of antimony(III)-tartrate in the phosphating bath used in this experiment was 1.0 g L-1, as higher values reduced the corrosion resistance of the coating. In addition, by saponification and oil seals, the corrosion duration of the black phosphate coating in a copper sulfate spot test can be as long as 20 min.

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

    International Nuclear Information System (INIS)

    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 (Sb2Te3) 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 Sb2Te3 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 (κe) 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

  16. Antimony retention and release from drained and waterlogged shooting range soil under field conditions.

    Science.gov (United States)

    Hockmann, Kerstin; Tandy, Susan; Lenz, Markus; Reiser, René; Conesa, Héctor M; Keller, Martin; Studer, Björn; Schulin, Rainer

    2015-09-01

    Many soils polluted by antimony (Sb) are subject to fluctuating waterlogging conditions; yet, little is known about how these affect the mobility of this toxic element under field conditions. Here, we compared Sb leaching from a calcareous shooting range soil under drained and waterlogged conditions using four large outdoor lysimeters. After monitoring the leachate samples taken at bi-weekly intervals for >1.5 years under drained conditions, two of the lysimeters were subjected to waterlogging with a water table fluctuating according to natural rainfall water infiltration. Antimony leachate concentrations under drained conditions showed a strong seasonal fluctuation between 110 μg L(-1) in summer and soil solution indicated that this decrease in Sb(V) concentrations was attributable to the reduction of Sb(V) to Sb(III) and the stronger sorption affinity of the latter to iron (Fe) (hydr)oxide phases. Our results demonstrate the importance of considering seasonal and waterlogging effects in the assessment of the risks from Sb-contaminated sites. PMID:25592464

  17. Phase effects on chemical behaviors of tin, antimony and tellurium fission products in aqueous solutions

    International Nuclear Information System (INIS)

    The oxidation states of tin, antimony and tellurium isotopes formed predominantly (>91%) by fission were investigated in aqueous solutions of 233U irradiated in a reactor. Results were corrected for the thermal reactions with the bulk radiolysis products using tracers for each element. In 0.4 M H2SO4 solutions containing 4.3 mM 233UO22+, 1.5 mM Te(IV) and 1.5 mM Te(VI), the fraction of Te(IV) is 98 +- 2% in the absence of oxygen and 92 +- 3% in the presence of oxygen. In frozen solutions of the same composition, the fraction of Te(IV) is 83 +- 2% in the absence of oxygen and 81 +- 3% in the presence of oxygen. Similar differences are also found in the case of the antimony isotopes in 0.4 M H2SO4 solutions and the tin isotopes in 1 M HCl solutions. For the interpretation of the differences, the reducing action of the species diffusing from the track of the fission fragments is considered. (author)

  18. Effect of indium and antimony doping in SnS single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chaki, Sunil H., E-mail: sunilchaki@yahoo.co.in; Chaudhary, Mahesh D.; Deshpande, M.P.

    2015-03-15

    Highlights: • Single crystals growth of pure SnS, indium doped SnS and antimony doped SnS by direct vapour transport (DVT) technique. • Doping of In and Sb occurred in SnS single crystals by cation replacement. • The replacement mechanism ascertained by EDAX, XRD and substantiated by Raman spectra analysis. • Dopants concentration affects the optical energy bandgap. • Doping influences electrical transport properties. - Abstract: Single crystals of pure SnS, indium (In) doped SnS and antimony (Sb) doped SnS were grown by direct vapour transport (DVT) technique. Two doping concentrations of 5% and 15% each were employed for both In and Sb dopants. Thus in total five samples were studied viz., pure SnS (S1), 5% In doped SnS (S2), 15% In doped SnS (S3), 5% Sb doped SnS (S4) and 15% Sb doped SnS (S5). The grown single crystal samples were characterized by evaluating their surface microstructure, stoichiometric composition, crystal structure, Raman spectroscopy, optical and electrical transport properties using appropriate techniques. The d.c. electrical resistivity and thermoelectric power variations with temperature showed semiconducting and p-type nature of the as-grown single crystal samples. The room temperature Hall Effect measurements further substantiated the semiconducting and p-type nature of the as-grown single crystal samples. The obtained results are deliberated in detail.

  19. The analysis of antimony species by using ESI-MS and HPLC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Lintschinger, J.; Schramel, O.; Kettrup, A. [GSF-Forschungszentrum fuer Umwelt und Gesundheit GmbH, Institut fuer Oekologische Chemie, Ingolstaedter Landstrasse 1, Gebaeude 22, D-85758 Neuherberg (Germany)

    1998-05-01

    A new method for the separation of organic antimony as trimethylantimony dichloride (TMSbCl{sub 2}) and inorganic Sb(V) and Sb(III) by using anion exchange high-performance liquid chromatography coupled with inductively-coupled plasma mass spectrometry (ICP-MS) is presented. In comparison with previous work the detection limits for both species were significantly decreased, down to 5 ngL{sup -1}, mainly by avoiding any contamination from the chromatographic device. Using an ultrasonic nebulizer (USN) improved the detection limits for inorganic Sb species, but was useless for the HPLC method due to problems in the recovery of the TMSbCl{sub 2}. Matrix interferences of the chromatographic determination were studied in detail and the method was applied to environmental samples assumed to contain organic antimony species. Additionally, the molecular structure of the TMSbCl{sub 2} in solution was studied by using electrospray-ionization mass spectrometry (ESI-MS) showing that this species occurs most probably as [TMSbOH]{sup +} in aqueous solutions. (orig.) With 7 figs., 2 tabs., 14 refs.

  20. Migration of antimony from PET containers into regulated EU food simulants.

    Science.gov (United States)

    Sánchez-Martínez, María; Pérez-Corona, Teresa; Cámara, Carmen; Madrid, Yolanda

    2013-11-15

    Antimony migration from polyethylene terephthalate (PET) containers into aqueous (distilled water, 3% acetic acid, 10% and 20% ethanol) and fatty food simulants (vegetable oil), as well as into vinegar, was studied. Test conditions were according to the recent European Regulation 10/2011 (EU, 2011). Sb migration was assayed by ICP-MS and HG-AFS. The results showed that Sb migration values ranged from 0.5 to 1.2μg Sb/l, which are far below the maximum permissible migration value for Sb, 40μg Sb/kg, (EU, Regulation 10/2011). Parameters as temperature and bottle re-use influence were studied. To assess toxicity, antimony speciation was performed by HPLC-ICP-MS and HG-AFS. While Sb(V) was the only species detected in aqueous simulants, an additional species (Sb-acetate complex) was measured in wine vinegar. Unlike most of the studies reported in the literature, migration tests were based on the application of the EU directive, which enables comparison and harmonisation of results. PMID:23790852

  1. Evaluation of antimony microparticles supported on biochar for application in the voltammetric determination of paraquat.

    Science.gov (United States)

    Gevaerd, Ava; de Oliveira, Paulo R; Mangrich, Antonio S; Bergamini, Márcio F; Marcolino-Junior, Luiz H

    2016-05-01

    This work describes the construction and application of carbon paste electrodes modified with biochar and antimony microparticles (SbBCPE) for voltammetric determination of paraquat using a simple and sensitive procedure based on voltammetric stripping analysis. Some parameters such as amount of biochar and antimony used in the composition of the carbon paste and instrumental parameters were examined in detail. Under optimized conditions, an analytical curve was obtained for paraquat determination employing SbBCPE, which showed a linear response ranging from 0.2 to 2.9μmolL(-1), with limit of detection and quantification of 34nmolL(-1) and 113nmolL(-1), respectively, after paraquat pre-concentration of 120s. The repeatability study presented a RSD=2.0% for 10 consecutive measurements using the same electrode surface and the reproducibility study showed a RSD=2.7% for measurements with 10 different electrode surfaces. The proposed sensor was successfully applied for paraquat determination in tap water and citric fruit juice spiked samples and good recoveries were obtained without any sample pre-treatment, showing its promising analytical performance. PMID:26952405

  2. High levels of antimony in dust from e-waste recycling in southeastern China

    International Nuclear Information System (INIS)

    Environmental contamination due to uncontrolled e-waste recycling is an emerging global issue. Antimony (Sb) is a toxic element used in semiconductor components and flame retardants for circuit board within electronic equipment. When e-waste is recycled, Sb is released and contaminates the surrounding environment; however, few studies have characterized the extent of this problem. In this study, we investigated Sb and arsenic (As) distributions in indoor dust from 13 e-waste recycling villages in Guiyu, Guangdong Province, southeastern China. Results revealed significantly elevated concentrations of Sb (6.1-232 mg/kg) in dust within all villages, which were 3.9-147 times higher than those from the non e-waste sites, indicating e-waste recycling was an important source of Sb pollution. On the contrary, As concentrations (5.4-17.7 mg/kg) in e-waste dusts were similar to reference values from the control sites. Therefore, dusts emitted from e-waste recycling may be characterized by high Sb/As ratios, which may help identify the contamination due to the e-waste recycling activities. - Highlights: → Antimony and arsenic concentrations in dust from e-waste recycling were investigated. → E-waste recycling is an important emerging source of Sb pollution. → Sb/As ratios may help identify the e-waste contamination.

  3. Contrasting distribution of trace elements between representative antimony deposits in southern China

    International Nuclear Information System (INIS)

    The Xuefeng uplifted belt and the neighboring Xikuangshan region of southern China is the largest antimony producing area in the world. The mineralizing solution which was responsible for the antimony deposition is considered to be derived mainly from deep crustal fluids during a large tectonic movement of the Jurassic time. We analyzed trace elements of ore minerals and fluid inclusions from this area by CSIRO's micro-PIXE to understand characteristics of the mineralizing solution. We selected three representative 'super-large' deposits, one in the Xikuangshan area and the others within the Xuefeng belt: (1) Xikuangshan (simple Sb) which is structurally controlled by large-scale transcrustal faults and fractures, and mainly hosted by limestone; (2) Wuxi (Sb-Au-W), embedded in slate and structurally controlled by large-scale faults and fractures; and (3) Banxi (simple Sb) which is hosted by slate and controlled by local fractures. Our preliminary result indicated that the trace element distribution is highly contrasting for these three deposits corresponding to each geologic setting. Our case study showed that being combined with field evidence, micro-PIXE can contribute to understand large tectonic movements and to establish an effective exploration model for super-large mineral deposits

  4. Structure and properties of antimony-doped lanthanum molybdate La2Mo2O9

    International Nuclear Information System (INIS)

    Polycrystalline samples of the composition La2Mo2−xSbxO9−y, where 0 ≤ x ≤ 0.05, were prepared by solid-phase synthesis. Single crystals of La2Mo1.96Sb0.04O8.17 were obtained by spontaneous crystallization from flux. The structure of the metastable βms phase of this compound was determined at room temperature by X-ray diffraction. It was found that the La, Mo, and O1 atoms are displaced from the threefold axis on which they are located in the high-temperature β phase. It was shown that molybdenum atoms in the crystal structure are partially replaced by antimony atoms, which are located on the threefold axis. In antimony-doped crystals, lanthanum atoms partially return to the site on the threefold axis and the coordination environment of molybdenum cations becomes more ordered, thus facilitating the stabilization of the cubic phase at room temperature. Calorimetric measurements (DSC) showed that the introduction of Sb as the dopant into the La2Mo2O9 structure leads to a decrease in the temperature of the α → β phase transition from 570 to 520°C and to the partial suppression of this transition. The temperature behavior of the conductivity confirms the DSC data. Thus, doping with Sb contributes to the stabilization of the cubic phase at room temperature.

  5. Organically complexed iron enhances bioavailability of antimony to maize (Zea mays) seedlings in organic soils.

    Science.gov (United States)

    Ptak, Corey; McBride, Murray

    2015-12-01

    Antimony (Sb) is a metalloid belonging to group 15 of the periodic table. Chemical similarities between arsenic (As) and Sb produce concerns about potential health effects of Sb and enrichment in the environment. Antimony is found in oxic environments predominately as an oxyanionic species, antimonite (Sb[OH](6-)). As a result of its net negative charge, Sb[OH](6-) was not initially predicted to have strong interactions with natural organic matter. Oxyanionic species could bind the negatively charged organic matter via a ternary complexation mechanism, in which cationic metals mediate the strong association between organic matter functional groups and oxyanions. However, these interactions are poorly understood in how they influence the bioavailability of oxyanionic contaminants to plants. Iron (Fe) additions to organic soils have been found to increase the number of organically complexed Fe sites suitable for Sb exchange, resulting in a reduced bioavailable fraction of Sb. The bioavailability of Sb to maize seedlings as a function of organically complexed Fe was examined using a greenhouse study. A significant increase in plant tissue Sb was observed as organically complexed Fe increased, which was not predicted by methods commonly used to assess bioavailable Sb. Extraction of soils with organic acids common to the maize rhizosphere suggested that organic acid exudation can readily mobilize Sb bound by organic Fe complexes. PMID:26076768

  6. Antimony isotopic composition in river waters affected by ancient mining activity.

    Science.gov (United States)

    Resongles, Eléonore; Freydier, Rémi; Casiot, Corinne; Viers, Jérôme; Chmeleff, Jérôme; Elbaz-Poulichet, Françoise

    2015-11-01

    In this study, antimony (Sb) isotopic composition was determined in natural water samples collected along two hydrosystems impacted by historical mining activities: the upper Orb River and the Gardon River watershed (SE, France). Antimony isotope ratio was measured by HG-MC-ICP-MS (Hydride Generation Multi-Collector Inductively Coupled Plasma Mass Spectrometer) after a preconcentration and purification step using a new thiol-cellulose powder (TCP) procedure. The external reproducibility obtained for δ(123)Sb measurements of our in-house Sb isotopic standard solution and a certified reference freshwater was 0.06‰ (2σ). Significant isotopic variations were evident in surface waters from the upper Orb River (-0.06‰≤δ(123)Sb≤+0.11‰) and from the Gardon River watershed (+0.27‰≤δ(123)Sb≤+0.83‰). In particular, streams that drained different former mining sites exploited for Sb or Pb-Zn exhibited contrasted Sb isotopic signature, that may be related to various biogeochemical processes occurring during Sb transfer from rocks, mine wastes and sediments to the water compartment. Nevertheless, Sb isotopic composition appeared to be stable along the Gardon River, which might be attributed to the conservative transport of Sb at distance from mine-impacted streams, due to the relative mobile behavior of Sb(V) in natural oxic waters. This study suggests that Sb isotopic composition could be a useful tool to track pollution sources and/or biogeochemical processes in hydrologic systems. PMID:26452900

  7. One-step synthesis of antimony-doped tin dioxide nanocrystallites and their property

    Institute of Scientific and Technical Information of China (English)

    ZHENG Min; WANG Bao

    2009-01-01

    Antimony-doped tin dioxide(ATO) nanoparticles with primary diameter in the range of 9-10 nm were rapidly synthesized via a novel combustion technique, starting with antimony trichloride and tin tetrachloride as metal sources and self-assembly compounds as fuels. The combustion phenomena and characteristics of products were controlled by assembling components in fuel compounds according to appropriate molar ratio. The as-synthesized products were characterized by XRD, SEM, TEM and XPS, respectively. The electrical conductivity was evaluated through measuring the antistatic property of polyester fiber treated by the as-synthesized products. The results show that a mild combustion phenomena without release of smoke can be taken on and perfect azury rutile ATO crystal with complete substitution can be formed rapidly under the appropriate synthetic conditions. The antistatic property of the polyester fiber treated by the as-synthesized ATO products is enhanced remarkably. The triboelectricity voltage below 1.0 kV, half life below 1.0 s and surface resistance below 1.0×106 Ω can be attained.

  8. Distributions and impact factors of antimony in topsoils and moss in Ny-Ålesund, Arctic

    International Nuclear Information System (INIS)

    The distribution of antimony (Sb) in topsoil and moss (Dicranum angustum) in disturbed and undisturbed areas, as well as coal and gangue, in Ny-Ålesund, Arctic was examined. Results show that the weathering of coal bed could not contribute to the increase of Sb concentrations in topsoil and moss in the study area. The distribution of Sb is partially associated with traffic and historical mining activities. The occurrence of the maximum Sb concentration is due to the contribution of human activities. In addition, the decrease of Sb content in topsoil near the coastline may be caused by the washing of seawater. Compared with topsoils, moss could be a useful tool for monitoring Sb in both highly and lightly polluted areas. - Highlights: ► We examined the distribution of antimony in topsoil and moss in Ny-Ålesund, Arctic. ► The distribution of Sb is associated with traffic and historical mining activities. ► The weathering of coal bed cannot lead to the Sb increase in the surface environment. ► The distribution of Sb in moss could reflect the accumulation of Sb pollution. ► Moss can be a useful tool for monitoring Sb in highly and lightly polluted areas. - The distribution of Sb in Ny-Ålesund is partially associated with traffic and historical mining activities, and moss can be a useful tool for monitoring Sb in both highly and lightly polluted areas.

  9. Determination of antimony in nail and hair by thermal neutron activation analysis

    International Nuclear Information System (INIS)

    The concentration of antimony in nail and hair was determined by thermal neutron activation analysis. Samples were collected from the workers of an antimony refinery, inhabitants near the refinery, and residents in control area. They were irradiated by Kyoto University 5000 kW Reactor for 1 h, and cooled for 30 to 100 days. After cooling, the concentration of Sb in nail and hair was estimated by measuring the intensity of γ-ray from 124Sb of the samples, then the samples were washed by 0.1 % aqueous solution of nonionic surface active agent in an ultrasonic cleaner. The γ-ray spectrometry was done again (after washing). The concentration of Sb in nail before washing was 730 ppm for the workers, 2.46 ppm for habitants near the refinery, and 0.19 ppm for the control; after washing, it became 230 ppm for the workers, 0.63 ppm for habitants, and 0.09 ppm for the control. The concentration of Sb in hair before and after washing was 222 ppm and 196 ppm for the workers, and 0.21 ppm and 0.15 ppm for the control, respectively. (author)

  10. Morphology-controlled growth of crystalline antimony sulfide via a refluxing polyol process

    Science.gov (United States)

    Zhang, Rui; Chen, Xiangying; Mo, Maosong; Wang, Zhenghua; Zhang, Meng; Liu, Xinyuan; Qian, Yitai

    2004-02-01

    By refluxing antimony trichloride (SbCl 3) and thiourea in various solvents at suitable reaction conditions, antimony sulfide (Sb 2S 3) crystallites with a diversity of well-defined morphologies were synthesized. Sb 2S 3 rods with the average diameter of 800 nm and the length of 7 μm, as well as microtubes with the average outer diameter of 1.2 μm, the average inner diameter of 800 nm and the length of 8 μm, were obtained in 1,2-propanediol at 180°C for 10 min. In contrast, a series of experiments under different conditions were carried out to investigate the influencing factors on the reaction. The as-synthesized products were characterized by powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscope and X-ray photoelectron spectra. The results indicate Sb 2S 3 crystals with different morphologies, including rod-like, tube-like, bowknot-like, flower-like, straw-bundled-like, taken under different experimental conditions. It is found that the reaction temperature, time, solvent and poly(vinyl pyrrolidone) (as a polymer capping reagent) play important roles in the formation of the final Sb 2S 3 crystallites with different morphologies. Also, the possible growth mechanism is discussed.

  11. Highly conducting nanosized monodispersed antimony-doped tin oxide particles synthesized via nanoaqueous sol-gel method

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rathouský, Jiří; Rasp, M.; Štefanić, G.; Günther, S.; Niederberger, M.; Fattakhova-Rohlfing, D.

    Vol. 1. Boca Raton : Taylor-Francis, 2010, s. 340-343. ISBN 978-1-4398-3401-5. - ( Nanotech 2010) R&D Projects: GA ČR GA104/08/0435 Institutional research plan: CEZ:AV0Z40400503 Keywords : antimony-doped tin oxide * TCO * nanoparticles Subject RIV: CF - Physical ; Theoretical Chemistry

  12. Ambulatory oesophageal pH monitoring : a comparison between antimony, ISFET, and glass pH electrodes

    NARCIS (Netherlands)

    Hemmink, Gerrit J. M.; Weusten, Bas L. A. M.; Oors, Jac; Bredenoord, Albert J.; Timmer, Robin; Smout, Andre J. P. M.

    2010-01-01

    Background and aim Ambulatory oesophageal pH-impedance monitoring is a widely used test to evaluate patients with reflux symptoms. Several types of pH electrodes are available: antimony, ion sensitive field effect transistor (ISFET), and glass electrodes. These pH electrodes have not been compared d

  13. Determination of antimony in environment samples by gas phase chemiluminescence detection following flow injection hydride generation and cryotrapping.

    Science.gov (United States)

    Ye, Yousheng; Sang, Jianchi; Ma, Hongbing; Tao, Guanhong

    2010-06-15

    A novel method for the determination of antimony in environmental samples was developed with gas phase chemiluminescence detection following flow injection hydride generation and cryotrapping. The stibine, generated from samples by borohydride reduction of antimony using flow injection technique, was separated by using a new gas-liquid separator, dried with an ice-salt cryogenic bath and concentrated in a glass U-tube immersed in liquid nitrogen. Re-vaporization of stibine based on its boiling point was achieved by allowing the tube to warm at room temperature. A gas phase chemiluminescence signal was produced during the ozonation of the hydride in a reflective chamber. Under optimal conditions, the proposed method was characterized by a wide linear calibration range from 1.0microgL(-1) to 10.0mgL(-1) with a detection limit of 0.18microgL(-1) (n=11). The relative standard deviation for 10.0microgL(-1) antimony was 3.56% (n=11) and the sampling rate was 15 samples h(-1). Blank signal was reduced by the purification of reagents and the interference from transition metal ions was eliminated by the addition of L-cysteine into samples. The method was applied to the determination of antimony in environmental samples with satisfactory results. PMID:20441930

  14. Comparative phytotoxicity of methylated and inorganic arsenic- and antimony species to Lemna minor, Wolffia arrhiza and Selenastrum capricornutum

    NARCIS (Netherlands)

    L. Duester; H.G. van der Geest; S. Moelleken; A.V. Hirner; K. Kueppers

    2011-01-01

    The alkylation of metalloids through the transfer of methyl groups is an important factor in the biogeochemical cycling of elements like arsenic and antimony. In the environment, many different organic and inorganic forms of these elements can therefore be found in soils, sediments or organisms. Stu

  15. A cloud point extraction for spectrophotometric determination of ultra- trace antimony without chelating agent in environmental and biological samples

    International Nuclear Information System (INIS)

    We report on a simple, sensitive and reliable method for the cloud point extraction of antimony (Sb) and its subsequent spectrophotometric detection. It is based on the color reaction of Sb (III) with iodide in acidic medium and subsequent micelle-mediated extraction of tetraiodoantimonate using a non-ionic surfactant in the absence of any chelating agent. The effects of reaction and extraction parameters were optimized. The calibration plot is linear in the range of 0.80-95 ng mL-1 of antimony in the sample solution, with a regression coefficient (r) of 0.9994 (for n=9). The detection limit (at SNR=3) is 0.23 ng mL-1, and the relative standard deviations at 10 and 70 ng mL-1 of antimony are 3.32 and 1.85 % (at n=8), respectively. The method compared favorably to other methods and was applied to determine antimony in seawater, anti-leishmania drug (glucantime), and human serum. (author)

  16. 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.

  17. The use of colloidal nano gold as an effective modifier for the determination of antimony, arsenic and lead by ETAAS

    International Nuclear Information System (INIS)

    Complete text of publication follows. Colloidal nano gold was prepared and used as a modifier for the determination of antimony, arsenic and lead by electrothermal atomic absorption spectrometry. The effects of pyrolysis and atomization temperature, the amounts of interferants and modifier on the sensitivities of antimony, arsenic and lead in the presence of modifier were investigated. In addition, the contribution of another modifying reagent Mg(NO3)2 mixed with colloidal nano gold was also investigated. The modifier allows the use of pyrolysis temperatures between 1200 deg C and 1300 deg C for antimony, arsenic and lead. In the presence of colloidal nano gold modifier, the tolerance limits of NaCl and Na2SO4 for the quantitative recoveries of antimony, arsenic and lead were investigated. After optimization of experimental conditions, the three elements were successfully determined in some model solutions containing some sulphate and chloride salts as well as in CRM water samples at 95% confidence level using pure aqueous standards. The effectiveness of modifier was compared with that of the mixed universal modifier (Mg+Pd).

  18. Determination of natural isotopic variation in antimony using inductively coupled plasma mass spectrometry for an uncertainty estimation of the standard atomic weight of antimony

    International Nuclear Information System (INIS)

    The isotopic variation of industrially produced antimony was estimated using multiple-collector inductively coupled plasma mass spectrometry. A reproducible 123Sb/121Sb ratio of ±0.004% (2 standard deviations) was routinely obtained using a Sn doping mass discrimination correction technique. Only a small isotopic variation of about 0.05% was observed among industrially important Sb materials (five commercially available reagents and two ore minerals). The degree of Sb isotopic variation to determine the uncertainty in Sb atomic weight can be reduced by this new analytical technique to 0.00025 compared to the currently accepted IUPAC isotopic variation determined by conventional mass spectrometry of ±0.001. Heavy isotope enrichment of Sb in a drainage water sample from a stibnite mining area was found. This heavy isotope enrichment tendency in an aqueous environment may be useful in detecting anthropogenic Sb input from industrial emission by the smelting process via air because Sb of anthropogenic origin will have lighter isotope enrichment features. (author)

  19. Spin dynamics of complex oxides, bismuth-antimony alloys, and bismuth chalcogenides

    Science.gov (United States)

    Sahin, Cuneyt

    The emerging field of spintronics relies on the manipulation of electron spin in order to use it in spin-based electronics. Such a paradigm change has to tackle several challenges including finding materials with sufficiently long spin lifetimes and materials which are efficient in generating pure spin currents. This thesis predicts that two types of material families could be a solution to the aforementioned challenges: complex oxides and bismuth based materials. We derived a general approach for constructing an effective spin-orbit Hamiltonian which is applicable to all nonmagnetic materials. This formalism is useful for calculating spin-dependent properties near an arbitrary point in momentum space. We also verified this formalism through comparisons with other approaches for III-V semiconductors, and its general applicability is illustrated by deriving the spin-orbit interaction and predicting spin lifetimes for strained strontium titanate (STO) and a two-dimensional electron gas in STO (such as at the LAO/STO interface). Our results suggest robust spin coherence and spin transport properties in STO related materials even at room temperature. In the second part of the study we calculated intrinsic spin Hall conductivities for bismuth-antimony (BISb) semimetals with strong spin-orbit couplings, from the Kubo formula and using Berry curvatures evaluated throughout the Brillouin zone from a tight-binding Hamiltonian. Nearly crossing bands with strong spin-orbit interaction generate giant spin Hall conductivities in these materials, ranging from 474 ((h/e)O--1cm--1) for bismuth to 96((h/e)O--1cm --1) for antimony; the value for bismuth is more than twice that of platinum. The large spin Hall conductivities persist for alloy compositions corresponding to a three-dimensional topological insulator state, such as Bi0.83Sb0.17. The spin Hall conductivity could be changed by a factor of 5 for doped Bi, or for Bi0.83Sb0.17, by changing the chemical potential by 0.5 e

  20. Antimony: a traffic-related element in the atmosphere of Buenos Aires, Argentina.

    Science.gov (United States)

    Gómez, Darío R; Fernanda Giné, María; Claudia Sánchez Bellato, Ana; Smichowski, Patricia

    2005-12-01

    Vehicular traffic is one of the main sources of antimony in highly populated urban areas like Buenos Aires where an overall traffic density of 1 500 000 vehicles per day (corresponding to 7500 vehicles km(-2)) is estimated. In this context, a study was undertaken to ascertain the levels of Sb and other traffic-related elements (TRE) in the atmosphere of this city. To this end, sixty-seven samples of PM-10 particulate matter were collected during eight days in nine representative sampling sites located downtown Buenos Aires and spread over an area of about 30 km2. The collection of particulate matter was performed on ash-free glass-fibre filters using high volume samplers with PM-10 sampling heads. A combination of aqua regia and perchloric acid was used for leaching metals from filters. The resulting solutions were evaporated and then diluted with 0.1 mol l(-1) HCl. Antimony was determined by inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) at ng g(-1) levels. Concentrations of Sb varied from 12.9 +/- 0.9 to 375 +/- 23 microg g(-1)(equivalent to 0.87 +/- 0.06 to 15.3 +/- 0.8 ng m(-3)). Statistical analysis was performed on the data set including the measured PM-10 mass and Sb concentrations for the monitored period. Correlations of Sb with other TRE namely, Cu and Mo were also assessed. The highest concentrations of Sb were detected at two sites (Hospital Alemán and Casa Rapallini) located in streets with traffic consisting mostly of passenger cars and showing a "stop-and-go" pattern in peak hours. Antimony levels in the Buenos Aires PM-10 are by far below the level of 0.5 mg m(-3)(for an 8 hour workday, 40 hour work week) set by the US Occupational Safety and Health Administration (OSHA) for occupational exposure. However, monitoring of Sb and other TRE should be carried out in a systematic fashion to detect the possibility of increases in from the present levels. PMID:16307067

  1. The electrical characterizations of selenium (Se) doped gallium antimony (GaSb) single crystal

    Science.gov (United States)

    Choudhari, Rashmi; Deshpande, Manisha; Maske, Dilip; Gadkari, Dattatray

    2016-05-01

    The growth of Se doped GaSb bulk crystal is carried out using Vertical directional solidification (VDS) technique. High purity Gallium and Antimony is taken as source material and selenium as doping material. From grown ingot substrate were obtained in wafer form using diamond cutter. The electrical characteristics such as Hall measurement is used to find the carrier concentration and mobility, while Van der pauw for measuring resistivity of the sample The GaSb:Se sample shows high resistivity and mobility. The grown crystal was detached from the ampoule wall with high crystal quality. The measured resistivity of GaSb:Se is 9.9×10-3ohm-cm, the mobility is 1464cm3/Vsec and carrier concentration is 5.08×1017 per cm3.

  2. Sequential solvent extraction for forms of antimony in five selected coals

    Science.gov (United States)

    Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

    2008-01-01

    Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

  3. Supermolecular template route to fabrication of well crystallized hollow antimony microspheres

    Institute of Scientific and Technical Information of China (English)

    GU Li; CHEN Shu-da; WEI Xiao-yan

    2006-01-01

    Hollow spheres of elemental antimony (Sb) with good crystallinity, high contrast and thin wall were prepared in the solutions of poly(ethylene glycol) (PEG) and oleic acid(OA) associations at the refluxed temperature. The complexes of Sb3+ with tartaric acid were used as precursors, which can avoid the hydrolysis of SbCl3 and the resulting impurity of products. The average diameter and thickness of the as-prepared hollow sphere are about 300 nm and less than 20 nm, respectively. The formation of hollow spheres depends on the template function of PEG and OA associations, which can be confirmed through the theoretical analysis and results of control experiments. The specific surface area reaches 34.669 m2/g.

  4. Surface morphology of crystalline antimony islands on graphite at room temperature

    International Nuclear Information System (INIS)

    Antimony islands of different shapes and dimensions were grown on highly oriented pyrolytic graphite (HOPG) at room temperature in ultrahigh vacuum. Three-dimensional (3D) spherical, 2D thin films and 1D nanorods of Sb on graphite were studied using in situ scanning tunnelling microscopy. Sb was evaporated in the form of Sb4, which interacts with HOPG weakly and exhibits a high surface mobility, resulting in preferential nucleation of 3D spherical islands at defect sites. Surface diffusion and aggregation lead to the formation of nanoparticles with various shapes and sizes. The shape and size of islands depend on growth parameters, i.e. flux and deposition time. The 3D and 2D structures of Sb on graphite have the same bulk crystalline rhombohedral (α-Sb) structure, but the 1D nanorods show a highly compressed structure different from the α-Sb lattice

  5. Novel antimony doped tin oxide/carbon aerogel as efficient electrocatalytic filtration membrane

    Directory of Open Access Journals (Sweden)

    Zhimeng Liu

    2016-05-01

    Full Text Available A facile method was developed to prepare antimony doped tin oxide (Sb-SnO2/carbon aerogel (CA for use as an electrocatalytic filtration membrane. The preparation process included synthesis of a precursor sol, impregnation, and thermal decomposition. The Sb-SnO2, which was tetragonal in phase with an average crystallite size of 10.8 nm, was uniformly distributed on the CA surface and firmly attached via carbon-oxygen-tin chemical bonds. Preliminary filtration tests indicated that the Sb-SnO2/CA membrane had a high rate of total organic carbon removal for aqueous tetracycline owing to its high current efficiency and electrode stability.

  6. Focused ion beam induced synthesis of a porous antimony nanowire network

    International Nuclear Information System (INIS)

    We present a focused ion beam-based approach for the synthesis of an antimony nanofiber network. The nanofibers, with a homogeneous distribution of diameters of about 25 nm and lengths up to several microns, are synthesized in a self-assembling process without any additional material source at room temperature. It is possible to recrystallize the as-grown amorphous nanofibers by moderate rapid thermal annealing at 473 K. These results have been verified by means of scanning electron microscopy, Auger electron spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and energy dispersive x-ray analysis. As this approach is not limited solely to the material discussed here, other substrates (e.g., GaSb and Ge) and ion sources should extend this method to other materials, which offers a great potential for future nanoscale devices and applications

  7. Novel fabrication of an electrochromic antimony-doped tin oxide film using a nanoparticle deposition system

    Science.gov (United States)

    Kim, Hyungsub; Park, Yunchan; Choi, Dahyun; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2016-07-01

    Novel deposition method of Antimony-doped tin oxide (ATO) thin films was introduced using a nanoparticle deposition system (NPDS) to fabricate an electrochromic (EC) device. NPDS is a dry deposition method that simplifies the ATO deposition process by eliminating the need for solvents or binders. In this study, an ATO EC layer was deposited using NPDS. The surface morphology and electrochemical and optical transmittance properties were characterized. The optical transmittance change in the ATO EC device was ∼35% over the wavelength range of 350-800 nm, and the cyclic transmittance was stable. The ATO film deposited using NPDS, exhibited a coloration efficiency of 15.5 cm2 C-1. Therefore, our results suggest that ATO EC devices can be fabricated using a simple, cost-effective NPDS, which allows nanoparticles to be deposited directly without pre- or post-processing.

  8. Microbial diversity and community structure in an antimony-rich tailings dump.

    Science.gov (United States)

    Xiao, Enzong; Krumins, Valdis; Dong, Yiran; Xiao, Tangfu; Ning, Zengping; Xiao, Qingxiang; Sun, Weimin

    2016-09-01

    To assess the impact of antimony (Sb) on microbial community structure, 12 samples were taken from an Sb tailings pile in Guizhou Province, Southwest China. All 12 samples exhibited elevated Sb concentrations, but the mobile and bioaccessible fractions were small in comparison to total Sb concentrations. Besides the geochemical analyses, microbial communities inhabiting the tailing samples were characterized to investigate the interplay between the microorganisms and environmental factors in mine tailings. In all samples, Proteobacteria and Actinobacteria were the most dominant phyla. At the genus level, Thiobacillus, Limnobacter, Nocardioides, Lysobacter, Phormidium, and Kaistobacter demonstrated relatively high abundances. The two most abundant genera, Thiobacillus and Limnobacter, are characterized as sulfur-oxidizing bacteria and thiosulfate-oxidizing bacteria, respectively, while the genus Lysobacter contains arsenic (As)-resistant bacteria. Canonical correspondence analysis (CCA) indicates that TOC and the sulfate to sulfide ratio strongly shaped the microbial communities, suggesting the influence of the environmental factors in the indigenous microbial communities. PMID:27188777

  9. Nuclear quadrupole resonance of iodine pentafluoride and its complexes with antimony pentafluoride

    International Nuclear Information System (INIS)

    The spectra of nuclear quadrupole resonance (NQR) have been obtained at 77 deg K for I127 and Sbsup(121,128) in the IF5, IF5xSbF5, IF5x2SbF5, CsIF6, and RbIF6 compounds. An agreement between quadrupole spectra and structural data have been observed. The results of studying IF5 by NQR, gamma resonance and microwave spectroscopy have been compared. It has been established that unshared electron pair of an iodine atom is stereochemically active which leads to a considerable distortion of octahedral symmetry of coordination polyhedron of the iodine atoms. The structure of complexes of iodine pentafluoride with antimony pentafluoride is given

  10. Distributions and impact factors of antimony in topsoils and moss in Ny-Ålesund, Arctic.

    Science.gov (United States)

    Jia, Nan; Sun, Liguang; He, Xin; You, Kehua; Zhou, Xin; Long, Nanye

    2012-12-01

    The distribution of antimony (Sb) in topsoil and moss (Dicranum angustum) in disturbed and undisturbed areas, as well as coal and gangue, in Ny-Ålesund, Arctic was examined. Results show that the weathering of coal bed could not contribute to the increase of Sb concentrations in topsoil and moss in the study area. The distribution of Sb is partially associated with traffic and historical mining activities. The occurrence of the maximum Sb concentration is due to the contribution of human activities. In addition, the decrease of Sb content in topsoil near the coastline may be caused by the washing of seawater. Compared with topsoils, moss could be a useful tool for monitoring Sb in both highly and lightly polluted areas. PMID:22885219

  11. A novel composite material based on antimony(III) oxide and amorphous silica

    Energy Technology Data Exchange (ETDEWEB)

    Zemnukhova, Ludmila A. [Institute of Chemistry, Far-Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok (Russian Federation); Panasenko, Alexander E., E-mail: panasenko@ich.dvo.ru [Institute of Chemistry, Far-Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok (Russian Federation)

    2013-05-01

    The composite material nSb₂O₃·mSiO₂·xH₂O was prepared by hydrolysis of SbCl₃ and Na₂SiO₃ in an aqueous medium. It has been shown that the composition of the material is influenced by the ratio of the initial components and the acidity of the reaction medium. The morphology of the material particles and its specific surface area have been determined. The thermal and optic properties were also investigated. - Graphical abstract: Novel composite material containing amorphous silica and crystal antimony(III) oxide has been synthesized by hydrolysis of SbCl₃ and Na₂SiO₃ in an aqueous medium. Highlights: • The composite material nSb₂O₃·mSiO₂·xH₂O was prepared in an aqueous medium. • The composition of the material is controllable by a synthesis conditions. • The morphology of the material and its optic properties have been determined.

  12. Evaluations of antimony and strontium interaction in an Al–Si–Cu–Zn die cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed, E-mail: saeedfarahany@gmail.com; Idris, Mohd Hasbullah; Ourdjini, Ali

    2014-05-01

    Graphical abstract: - Highlights: • Probable interactions between Sb and Sr in a complex Al–Si alloy were evaluated. • Sequence of addition did not affect thermal and microscopical characteristics. • Threshold ratio for the Sb and Sr interaction is proposed. - Abstract: The interaction between antimony and strontium in an ADC12 die casting alloy is investigated comprehensively by using a computer aided cooling curve thermal analysis coupled with microstructure inspection. The results of the thermal analysis show significant changes in Al–Si eutectic reaction based on different concentrations of Sb and Sr. Sb reduces the efficiency of Sr in modifying the eutectic Si. Based upon the data obtained in this study, the threshold Sr/Sb ratio should exceed about 0.5 in order to obtain fully modified structure. Moreover, a pre-eutectic reaction of Al{sub 2}Si{sub 2}Sr intermetallic was detected for high concentrations of Sr.

  13. Synthesis and optical properties of antimony oxide glasses doped with holmium trioxide

    Science.gov (United States)

    Raghunatha, S.; Eraiah, B.

    2016-05-01

    Holmium doped lithium-antimony-lead borate glasses having 1mol% AgNO3 with composition 50B2O3-20PbO-25Sb2O3-5Li2O have been prepared using single step melt quenching technique. The XRD spectrum confirms amorphous nature of glasses. The optical absorbance studies were carried out on these glasses. The optical direct band gap energies were found to be in the range of 3.10 eV to 3.31 eV and indirect band gap energies were found to be in the range of 2.28 eV to 3.00 eV. The refractive indexes have been calculated by using Lorentz-Lorenz formula and the calculated values in the range of 2.31 to 2.37.

  14. Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Sadananda Kumar, N., E-mail: sadanthara@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Surathkal, Thin Films Laboratory, Department of Physics (India)

    2015-07-15

    Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

  15. First-Principles Study of Antimony Doping Effects on the Iron-Based Superconductor CaFe(SbxAs1-x)2

    Science.gov (United States)

    Nagai, Yuki; Nakamura, Hiroki; Machida, Masahiko; Kuroki, Kazuhiko

    2015-09-01

    We study antimony doping effects on the iron-based superconductor CaFe(SbxAs1-x)2 by using the first-principles calculation. The calculations reveal that the substitution of a doped antimony atom into As of the chainlike As layers is more stable than that into FeAs layers. This prediction can be checked by experiments. Our results suggest that doping homologous elements into the chainlike As layers, which only exist in the novel 112 system, is responsible for rising up the critical temperature. We discuss antimony doping effects on the electronic structure. It is found that the calculated band structures with and without the antimony doping are similar to each other within our framework.

  16. First-principles study of antimony doping effects on the iron-based superconductor CaFe(SbxAs1−x)2

    International Nuclear Information System (INIS)

    We study antimony doping effects on the iron-based superconductor CaFe(SbxAs1−x)2 by using the first-principles calculation. The calculations reveal that the substitution of a doped antimony atom into As of the chainlike As layers is more stable than that into FeAs layers. This prediction can be checked by experiments. Our results suggest that doping homologous elements into the chainlike As layers, which only exist in the novel 112 system, is responsible for rising up the critical temperature. We discuss antimony doping effects on the electronic structure. It is found that the calculated band structures with and without the antimony doping are similar to each other within our framework. (author)

  17. Optical properties of Eu3+-doped antimony-oxide-based low phonon disordered matrices

    Science.gov (United States)

    Som, Tirtha; Karmakar, Basudeb

    2010-01-01

    A new series of monolithic Eu2O3-doped high antimony oxide (40-80 mol%) content disordered matrices (glasses) of low phonon energy (about 600 cm-1) in the K2O-B2O3-Sb2O3 (KBS) system was prepared by the melt-quench technique. Infrared reflection spectroscopy was used to establish the low phonon energy of the glasses. Amorphicity and devitrification of the glasses were confirmed by x-ray diffraction analysis. UV-vis absorption spectra of Eu3+ have been measured and the band positions have been justified with quantitative calculation of the nephelauxetic parameter and covalent bonding characteristics of the host. These Eu2O3-doped glasses upon excitation at 393 nm radiation exhibit six emission bands in the range 500-750 nm due to their low phonon energy. Of these, the magnetic dipole ^{5}\\mathrm {D}_{0} \\to {}^{7} \\mathrm {F_{1}} transition shows small Stark splitting while the electric dipole ^{5}\\mathrm {D}_{0} \\to {}^{7}\\mathrm {F}_{2} transition undergoes remarkable Stark splitting into two components. They have been explained by the crystal field effect. The Judd-Ofelt parameters, Ωt = 2,4,6, were also evaluated and the change of Ωt with the glass composition was correlated with the asymmetric effect at Eu3+ ion sites and the fundamental properties like covalent character and optical basicity. We are the first to report the spectroscopic properties of the Eu3+ ion in KBS low phonon antimony glasses.

  18. Impact of arsenic on uptake and bio-accumulation of antimony by arsenic hyperaccumulator Pteris vittata

    International Nuclear Information System (INIS)

    Individual uptake of As and Sb species in Pteris vittata have been investigated, but little information is available how uptake is affected if both metalloids are simultaneously present in different amounts. We investigated the uptake of antimony and its speciation in Pteris vittata cultivated in quartz substrate with, versus without, co-contamination with arsenic and a contaminated soil for 7 weeks. Applying HPLC-ICP-MS technique Sb(V), Sb(III), As(III), and As(V) could be identified as main species in aqueous extracts of roots and fronds with up to 230 mg kg−1 of total Sb in the roots. Adding increasing amounts of As to the quartz substrate resulted in increasing uptake of Sb. In contrast to As, which is readily transferred to the fronds, Sb is primarily accumulated in the roots with Sb(V) being the dominant species (>90% of Sb). The addition of As doesn't result in enhanced translocation of Sb into the fronds. Highlights: ► Antimonate is bioavailable to P. vittata grown for 7 weeks in different substrates. ► Antimony is primarily accumulated in the roots with Sb(V) being the dominant species. ► Sb(III) is present to a somewhat higher portion in the fronds than in the roots. ► Increasing amounts of As(V) in substrate resulted in increasing uptake of Sb(V). ► Addition of As is not accompanied by any alteration of Sb translocation to fronds. -- Roots of Pteris vittata cultivated under green-house conditioned in substrates containing antimonate accumulates Sb(V). This was promoted by As(V)

  19. Infrared-to-red upconversion luminescence in samarium-doped antimony glasses

    International Nuclear Information System (INIS)

    A new antimony-based glass system (K2O-B2O3-Sb2O3) having low phonon energy (about 600 cm-1) doped with Sm3+ ions has been developed. Infrared reflection spectroscopic (IRRS) studies have been employed to establish its low phonon energy. Ultraviolet-Visible-near infrared (UV-Vis-NIR) absorption and photoluminescence upconversion properties with the spectrochemistry of the 15K2O-15B2O3-70Sb2O3 (mol%) glasses have been studied doping with different concentrations (0.1-1.0 wt%) of Sm2O3. UV-Vis-NIR absorption band positions have been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 949 nm at room temperature. Three upconverted bands originating from the 4G5/2→6H5/2, 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions are found to be centered at 566 (green, weak), 602 (orange, weak) and 636 (red, remarkably strong) nm, respectively. These bands have been explained from the evaluation of the absorption, normal (downconversion) fluorescence and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET) and cross-relaxation (CR) mechanisms involving population of the metastable (storage) energy level (4G5/2) by multiphonon deexcitation effect. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in antimony glasses owing to their low phonon energy (602 cm-1, the main and highest intensity Sb-O-Sb stretching band) which is very close to that of fluoride glasses (500-600 cm-1)

  20. Quantitative HPLC-ICP-MS analysis of antimony redox speciation in complex sample matrices: new insights into the Sb-chemistry causing poor chromatographic recoveries

    OpenAIRE

    Hansen, Claus; Schmidt, Bjørn; Larsen, Erik Huusfeldt; Gammelgaard, Bente; Stürup, Stefan; Hansen, Helle Rüsz

    2011-01-01

    In solution antimony exists either in the pentavalent or trivalent oxidation state. As Sb(III) is more toxic than Sb(V), it is important to be able to perform a quantitative speciation analysis of Sb’s oxidation state. The most commonly applied chromatographic methods used for this redox speciation analysis do, however, often show a low chromatographic Sb recovery when samples of environmental or biological origin are analysed. In this study we explored basal chemistry of antimony and found t...

  1. Decreased antimony uptake and overexpression of genes of thiol metabolism are associated with drug resistance in a canine isolate of Leishmania infantum.

    Science.gov (United States)

    Gómez Pérez, Verónica; García-Hernandez, Raquel; Corpas-López, Victoriano; Tomás, Ana M; Martín-Sanchez, Joaquina; Castanys, Santiago; Gamarro, Francisco

    2016-08-01

    Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania infantum, is one of the most important zoonotic diseases affecting dogs and humans in the Mediterranean area. The presence of infected dogs as the main reservoir host of L. infantum is regarded as the most significant risk for potential human infection. We have studied the susceptibility profile to antimony and other anti-leishmania drugs (amphotericin B, miltefosine, paromomycin) in Leishmania infantum isolates extracted from a dog before and after two therapeutic interventions with meglumine antimoniate (subcutaneous Glucantime(®), 100 mg/kg/day for 28 days). After the therapeutic intervention, these parasites were significantly less susceptible to antimony than pretreatment isolate, presenting a resistance index of 6-fold to Sb(III) for promastigotes and >3-fold to Sb(III) and 3-fold to Sb(V) for intracellular amastigotes. The susceptibility profile of this resistant L. infantum line is related to a decreased antimony uptake due to lower aquaglyceroporin-1 expression levels. Additionally, other mechanisms including an increase in thiols and overexpression of enzymes involved in thiol metabolism, such as ornithine decarboxylase, trypanothione reductase, mitochondrial tryparedoxin and mitochondrial tryparedoxin peroxidase, could contribute to the resistance as antimony detoxification mechanisms. A major contribution of this study in a canine L. infantum isolate is to find an antimony-resistant mechanism similar to that previously described in other human clinical isolates. PMID:27317865

  2. Remediation of antimony-rich mine waters: Assessment of antimony removal and shifts in the microbial community of an onsite field-scale bioreactor.

    Science.gov (United States)

    Sun, Weimin; Xiao, Enzong; Kalin, Margarete; Krumins, Valdis; Dong, Yiran; Ning, Zengping; Liu, Tong; Sun, Min; Zhao, Yanlong; Wu, Shiliang; Mao, Jianzhong; Xiao, Tangfu

    2016-08-01

    An on-site field-scale bioreactor for passive treatment of antimony (Sb) contamination was installed downstream of an active Sb mine in Southwest China, and operated for one year (including a six month monitoring period). This bioreactor consisted of five treatment units, including one pre-aerobic cell, two aerobic cells, and two microaerobic cells. With the aerobic cells inoculated with indigenous mine water microflora, the bioreactor removed more than 90% of total soluble Sb and 80% of soluble antimonite (Sb(III)). An increase in pH and decrease of oxidation-reduction potential (Eh) was also observed along the flow direction. High-throughput sequencing of the small subunit ribosomal RNA (SSU rRNA) gene variable (V4) region revealed that taxonomically diverse microbial communities developed in the bioreactor. Metal (loid)-oxidizing bacteria including Ferrovum, Thiomonas, Gallionella, and Leptospirillum, were highly enriched in the bioreactor cells where the highest total Sb and Sb(III) removal occurred. Canonical correspondence analysis (CCA) indicated that a suite of in situ physicochemical parameters including pH and Eh were substantially correlated with the overall microbial communities. Based on an UPGMA (Unweighted Pair Group Method with Arithmetic Mean) tree and PCoA (Principal Coordinates Analysis), the microbial composition of each cell was distinct, indicating these in situ physicochemical parameters had an effect in shaping the indigenous microbial communities. Overall, this study was the first to employ a field-scale bioreactor to treat Sb-rich mine water onsite and, moreover, the findings suggest the feasibility of the bioreactor in removing elevated Sb from mine waters. PMID:27208755

  3. Sodium Antimony Gluconate Induces Generation of Reactive Oxygen Species and Nitric Oxide via Phosphoinositide 3-Kinase and Mitogen-Activated Protein Kinase Activation in Leishmania donovani-Infected Macrophages

    OpenAIRE

    Mookerjee Basu, Jayati; Mookerjee, Ananda; Sen, Prosenjit; Bhaumik, Suniti; Sen, Pradip; Banerjee, Subha; Naskar, Ksudiram; Choudhuri, Soumitra K.; Saha, Bhaskar; Raha, Sanghamitra; Roy, Syamal

    2006-01-01

    Pentavalent antimony complexes, such as sodium stibogluconate and sodium antimony gluconate (SAG), are still the first choice for chemotherapy against various forms of leishmaniasis, including visceral leishmaniasis, or kala-azar. Although the requirement of a somewhat functional immune system for the antileishmanial action of antimony was reported previously, the cellular and molecular mechanism of action of SAG was not clear. Herein, we show that SAG induces extracellular signal-regulated k...

  4. Cyanide and antimony thermodynamic database for the aqueous species and solids for the EPA-MINTEQ geochemical code

    Energy Technology Data Exchange (ETDEWEB)

    Sehmel, G.A.

    1989-05-01

    Thermodynamic data for aqueous species and solids that contain cyanide and antimony were tabulated from several commonly accepted, published sources of thermodynamic data and recent journal article. The review does not include gases or organic complexes of either antimony or cyanide, nor does the review include the sulfur compounds of cyanide. The basic thermodynamic data, ..delta..G/sub f,298//sup o/, ..delta..H/sub f,298//sup o/, and S/sub f//sup o/ values, were chosen to represent each solid phase and aqueous species for which data were available in the appropriate standard state. From these data the equilibrium constants (log K/sub r,298//sup o/) and enthalpies of reaction (..delta..H/sub r,298//sup o/) at 298 K (25/degree/C) were calculated for reactions involving the formation of these aqueous species and solids from the basic components. 34 refs., 14 tabs.

  5. Cyanide and antimony thermodynamic database for the aqueous species and solids for the EPA-MINTEQ geochemical code

    International Nuclear Information System (INIS)

    Thermodynamic data for aqueous species and solids that contain cyanide and antimony were tabulated from several commonly accepted, published sources of thermodynamic data and recent journal article. The review does not include gases or organic complexes of either antimony or cyanide, nor does the review include the sulfur compounds of cyanide. The basic thermodynamic data, ΔG/sub f,298//sup o/, ΔH/sub f,298//sup o/, and S/sub f//sup o/ values, were chosen to represent each solid phase and aqueous species for which data were available in the appropriate standard state. From these data the equilibrium constants (log K/sub r,298//sup o/) and enthalpies of reaction (ΔH/sub r,298//sup o/) at 298 K (25/degree/C) were calculated for reactions involving the formation of these aqueous species and solids from the basic components. 34 refs., 14 tabs

  6. Interest of lymphoscintigraphy with 99sup(m)Tc-labelled antimony sulfide in the arms after breast carcinoma treatment

    International Nuclear Information System (INIS)

    2 mCi of antimony sulfide colloid labelled with sup(99m)Tc were injected subcutaneously between the digits in 25 patients with postoperative lymphoedema of the arm for breast carcinoma. The two arms are examined successively, the normal one being used as control. The lymphoscintigraphy is realised with a gamma camera during an hour. The information obtained is threefoled; on the peripheral block's importance, the place where the lymphatic flow is stopped, and the presence in 40% of patients of axillary lymph nodes. The diminution of the lymphatic flow is not in correlation with the lymphoedema's importance. Lymphoscintigraphy with sup(99m)Tc antimony sulfide colloid is a simple examination but some side effects may occur. In 7 patients, post-injection lymphangitis was observed, with favorable evolution under antibiotic treatment. The lymphoscintigraphy can give some interesting information on the evolution of treated lymphoedema

  7. Antimony incorporation in InAs quantum dots grown on GaAs substrate by molecular beam epitaxy

    Science.gov (United States)

    Rihani, J.; Sallet, V.; Christophe, H. J.; Oueslati, M.; Chtourou, R.

    2008-01-01

    We have grown InAs(Sb) quantum dots (QDs) on GaAs (0 0 1) substrates by molecular beam epitaxy (MBE) using two different antimony exposures ( ΦSb). Atomic force microscopy (AFM) and photoluminescence (PL) spectroscopy were carried out to investigate the dot size evolution as function of the incorporated antimony content in InAs/GaAs QDs material. Anomalous asymmetric-band feature was observed in room temperature photoluminescence (RTPL) spectra of the investigated QD samples grown at relatively high temperature (490 °C). From the temperature-dependent PL measurements, it was found that the asymmetric-band feature is associated with the ground-states transitions from QDs with bimodal size distribution. The analysis of the pump power dependent PL spectra allows us to suggest a type II band lineup for the InAsSb/GaAs QDs materials system.

  8. Co-administration of glycyrrhizic acid with the antileishmanial drug sodium antimony gluconate (SAG) cures SAG-resistant visceral leishmaniasis.

    Science.gov (United States)

    Bhattacharjee, Amrita; Majumder, Saikat; Majumdar, Suchandra Bhattacharyya; Choudhuri, Soumitra Kumar; Roy, Syamal; Majumdar, Subrata

    2015-03-01

    Since there are very few affordable antileishmanial drugs available, antimonial resistance has crippled antileishmanial therapy, thereby emphasising the need for development of novel therapeutic strategies. This study aimed to evaluate the antileishmanial role of combined therapy with sodium antimony gluconate (SAG) and the triterpenoid glycyrrhizic acid (GA) against infection with SAG-resistant Leishmania (GE1F8R). Combination therapy with GA and SAG successfully limited infection with SAG-resistant Leishmania in a synergistic manner (fractional inhibitory concentration index resistant Leishmania and co-treated with GA and SAG exhibited a significant reduction in hepatic and splenic parasite burden. In probing the mechanism, it was observed that GA treatment suppressed the expression and efflux activity of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1), two host ABC transporters responsible for antimony efflux from host cells infected with SAG-resistant parasites. This suppression correlated with greater intracellular antimony retention during SAG therapy both in vitro and in vivo, which was reflected in the reduced parasite load. Furthermore, co-administration of GA and SAG induced a shift in the cytokine balance towards a Th1 phenotype by augmenting pro-inflammatory cytokines (such as IL-12, IFNγ and TNFα) and inducing nitric oxide generation in GE1F8R-infected macrophages as well as GE1F8R-infected mice. This study aims to provide an affordable leishmanicidal alternative to expensive antileishmanial drugs such as miltefosine and amphotericin B. Furthermore, this report explores the role of GA as a resistance modulator in MRP1- and P-gp-overexpressing conditions. PMID:25600891

  9. The Potential Impact of Biofield Energy Treatment on the Atomic and Physical Properties of Antimony Tin Oxide Nanopowder

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Antimony tin oxide (ATO) is known for its high thermal conductivity, optical transmittance, and wide energy band gap, which makes it a promising material for the display devices, solar cells, and chemical sensor industries. The present study was undertaken to evaluate the effect of biofield energy treatment on the atomic and physical properties of ATO nanopowder. The ATO nanopowder was divided into two parts: control and treated. The treated part was subjected to Mr. Trivedi’s biofield ...

  10. The influence of remelting on the properties of AlSi6Cu4 alloy modified by antimony

    OpenAIRE

    D. Medlen; D. Bolibruchova

    2012-01-01

    The paper deals with the problem of multiple remelting influence on AlSi6Cu4 alloy modified by antimony on chosen mechanical characteristics, microstructure and gas content. This foundry alloy is used mostly in automotive industry. Foundry Aluminum-Silicon alloys are also used in number of industrial weight sensitive applications because of their low weight and very good castability and good mechanical properties. Modifiers are usually added to molten aluminum-silicon alloys to refine the eut...

  11. EFFECT OF GRAIN BOUNDARY SEGREGATION OF ANTIMONY ON RELAXATION AT GRAIN BOUNDARIES IN SILICON-IRON ALLOYS

    OpenAIRE

    Iwasaki, Y.; Fujimoto, K

    1981-01-01

    A sharp grain boundary peak appears in both 2 and 3% silicon-iron alloys due to a substitutional solute of silicon. This peak is highly sensitive to the segregation of the third element of antimony and, contrary to orthodox solute peaks in binary and ternary alloys, largely decreases in magnitude on heating after a segregation treatment. The subsequent measurement on cooling returns the peak to the ordinary magnitude. As a function of annealing time at a temperature of segregation, the height...

  12. Exploring screen printing technology on thermoelectric energy harvesting with printing copper-nickel and bismuth-antimony thermocouples

    OpenAIRE

    Cao, Zhuo; Koukharenko, Elena; Torah, R; Beeby, SP

    2013-01-01

    This paper reports the fabrication and testing of copper (Cu) - nickel (Ni) and bismuth (Bi) - antimony (Sb) based thermocouples fabricated using screen printing technology. The transport properties of the printed thermoelectric material were measured in room temperature while the Seebeck voltage and power output of the printed thermocouples were tested under a variety temperature gradient. Initial thermoelectric materials have been integrated in inks and then deposited on substrate by the si...

  13. Potentiometric stripping analysis of antimony based on carbon paste electrode modified with hexathia crown ether and rice husk

    International Nuclear Information System (INIS)

    Highlights: → Potentiometric stripping analysis (PSA) employed for the determination of antimony. → Hexathia-18C6 and rice husk modified carbon paste electrode developed for the analysis. → Lowest detection limit obtained for the determination of Sb(III) using PSA. → Analysis of Sb in pharmaceutical formulations, human hair, blood serum, urine and sea water. → Rice husk used as a modifier for the first time in electrochemistry. - Abstract: An electrochemical method based on potentiometric stripping analysis (PSA) employing a hexathia 18C6 (HT18C6) and rice husk (RH) modified carbon paste electrode (HT18C6-RH-CPE) has been proposed for the subnanomolar determination of antimony. The characterization of the electrode surface has been carried out by means of scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and chronocoulometry. By employing HT18C6-RH-CPE, a 12-fold enhancement in the PSA signal (dt/dE) was observed as compared to plain carbon paste electrode (PCPE). Under the optimized conditions, dt/dE (s V-1) was proportional to the Sb(III) concentration in the range of 1.42 x 10-8 to 6.89 x 10-11 M (r = 0.9944) with the detection limit (S/N = 3) of 2.11 x 10-11 M. The practical analytical utilities of the modified electrode were demonstrated by the determination of antimony in pharmaceutical formulations, human hair, sea water, urine and blood serum samples. The prepared modified electrode showed several advantages, such as simple preparation method, high sensitivity, very low detection limit and excellent reproducibility. Moreover, the results obtained for antimony analysis in commercial and real samples using HT18C6-RH-CPE and those obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES) are in agreement at the 95% confidence level.

  14. Potentiometric stripping analysis of antimony based on carbon paste electrode modified with hexathia crown ether and rice husk

    Energy Technology Data Exchange (ETDEWEB)

    Gadhari, Nayan S.; Sanghavi, Bankim J. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Srivastava, Ashwini K., E-mail: aksrivastava@chem.mu.ac.in [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India)

    2011-10-03

    Highlights: {yields} Potentiometric stripping analysis (PSA) employed for the determination of antimony. {yields} Hexathia-18C6 and rice husk modified carbon paste electrode developed for the analysis. {yields} Lowest detection limit obtained for the determination of Sb(III) using PSA. {yields} Analysis of Sb in pharmaceutical formulations, human hair, blood serum, urine and sea water. {yields} Rice husk used as a modifier for the first time in electrochemistry. - Abstract: An electrochemical method based on potentiometric stripping analysis (PSA) employing a hexathia 18C6 (HT18C6) and rice husk (RH) modified carbon paste electrode (HT18C6-RH-CPE) has been proposed for the subnanomolar determination of antimony. The characterization of the electrode surface has been carried out by means of scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and chronocoulometry. By employing HT18C6-RH-CPE, a 12-fold enhancement in the PSA signal (dt/dE) was observed as compared to plain carbon paste electrode (PCPE). Under the optimized conditions, dt/dE (s V{sup -1}) was proportional to the Sb(III) concentration in the range of 1.42 x 10{sup -8} to 6.89 x 10{sup -11} M (r = 0.9944) with the detection limit (S/N = 3) of 2.11 x 10{sup -11} M. The practical analytical utilities of the modified electrode were demonstrated by the determination of antimony in pharmaceutical formulations, human hair, sea water, urine and blood serum samples. The prepared modified electrode showed several advantages, such as simple preparation method, high sensitivity, very low detection limit and excellent reproducibility. Moreover, the results obtained for antimony analysis in commercial and real samples using HT18C6-RH-CPE and those obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES) are in agreement at the 95% confidence level.

  15. Separation of Lead from Crude Antimony by Pyro-Refining Process with NaPO3 Addition

    Science.gov (United States)

    Ye, Longgang; Hu, Yuejie; Xia, Zhimei; Chen, Yongming

    2016-06-01

    The main purpose of this study was to separate lead from crude antimony through an oxidation pyro-refining process and by using sodium metaphosphate as a lead elimination reagent. The process parameters that will affect the refining results were optimized experimentally under controlled conditions, such as the sodium metaphosphate charging dosage, the refining temperature and duration, and the air flow rate, to determine their effect on the lead content in refined antimony and the lead removal rate. A minimum lead content of 0.0522 wt.% and a 98.6% lead removal rate were obtained under the following optimal conditions: W_{{{NaPO}_{{3}} }} = 15% W Sb (where W represents weight), a refining temperature of 800°C, a refining time of 30 min, and an air flow rate of 3 L/min. X-ray diffractometry and scanning electron microscopy showed that high-purity antimony was obtained. The smelting operation is free from smoke or ammonia pollution when using monobasic sodium phosphate or ammonium dihydrogen phosphate as the lead elimination reagent. However, this refining process can also remove a certain amount of sulfur, cobalt, and silicon simultaneously, and smelting results also suggest that sodium metaphosphate can be used as a potential lead elimination reagent for bismuth and copper refining.

  16. Evaluation of potential dietary toxicity of heavy metals in some common Nigerian beverages: A look at antimony, tin and mercury

    Directory of Open Access Journals (Sweden)

    I.I. Roberts

    2011-11-01

    Full Text Available There is currently little information on the composition of heavy metals in beverages imported and locally produced in Nigeria. The study quantitatively determined the composition of antimony (Sb, tin (Sn and mercury (Hg in 50 different beverage samples and evaluated the extent of violation of guideline values. Analysis of the beverage samples for the presence of Sb, Sn, and Hg was carried out using an atomic absorption spectrophotometer (AAS 929. The mean values detected for mercury, tin and antimony (±SE in fruit juices and soft drinks were 2.39±0.25, 3.66±0.22 and 0.49±0.048 μg/l; 2.93±0.34, 3.60±0.46 and 0.49±0.10 μg/l in dairy drinks and 0.94±0.02, 4.34±0.48 and 0.48±0.05 μg/l in bottled water samples respectively. While antimony detected in all products was below guideline values, mercury and tin were above the acceptable levels established by the World Health Organization, United States Environmental Protection Agency and European Union in most samples tested.

  17. Distribution, speciation and availability of antimony (Sb) in soils and terrestrial plants from an active Sb mining area

    International Nuclear Information System (INIS)

    Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg-1), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg-1), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg-1) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH)6]2, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content. - Highlights: → Antimony (Sb) in soils from an active Sb mining area is highly bioavailable. → Sb occurs mainly as Sb(V) in Sb mining impacted soils and plants. → Sb solubility in Sb mining impacted soils is governed by Ca[Sb(OH)6]2. → Citric acid extractable Sb in plants and bioavailable Sb in soils are strongly correlated. - Antimony (Sb) in soils from an active Sb mining area is highly bioavailable and controlled by the solubility of calcium antimonate.

  18. Distribution, speciation and availability of antimony (Sb) in soils and terrestrial plants from an active Sb mining area

    Energy Technology Data Exchange (ETDEWEB)

    Okkenhaug, Gudny, E-mail: go@ngi.no [Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, P.O. Box 5003, N-1432 As (Norway); Norwegian Geotechnical Institute, P.O. Box 3930, Ullevaal Stadion, NO-0806 Oslo (Norway); Zhu Yongguan [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Luo Lei [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Lei Ming [College of Resource and Environment, Hunan Agricultural University, Changsha 410128 (China); Li Xi [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Mulder, Jan [Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, P.O. Box 5003, N-1432 As (Norway)

    2011-10-15

    Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg{sup -1}), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg{sup -1}), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg{sup -1}) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH){sub 6}]{sub 2}, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content. - Highlights: > Antimony (Sb) in soils from an active Sb mining area is highly bioavailable. > Sb occurs mainly as Sb(V) in Sb mining impacted soils and plants. > Sb solubility in Sb mining impacted soils is governed by Ca[Sb(OH){sub 6}]{sub 2}. > Citric acid extractable Sb in plants and bioavailable Sb in soils are strongly correlated. - Antimony (Sb) in soils from an active Sb mining area is highly bioavailable and controlled by the solubility of calcium antimonate.

  19. Precipitation of antimony from the solution of sodium thioantimonite by air oxidation in the presence of catalytic agents

    Institute of Scientific and Technical Information of China (English)

    杨天足; 赖琼琳; 唐建军; 楚广

    2002-01-01

    The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassium permanganate, phenol, 1,2-dihydroxybenzene and their combination on the oxidation of sodium thioantimonite were investigated. A pilot test was carried out. The results show that the respective use of sodium tartrate, cupric sulfate, potassium permanganate, phenol and 1,2-dihydroxybenzene have little catalytic effect on the oxidation of sodium thioantimonite. However there exists obvious catalytic oxidation by the combination of 0.25 g/L 1,2-dihydroxybenzene, 0.5 g/L potassium permanganate and 1.0 g/L phenol. Moreover, high blast intensity, the increase of temperature and NaOH concentration favor the oxidation of antimony. The oxidation process of antimony has such advantages as quick reaction and low operation costs. The results of the pilot test are consistent with those of laboratory experiments.

  20. Preparation of antimony sulfide semiconductor nanoparticles by pulsed laser ablation in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ren-De, E-mail: son003@sekisui.com [Research & Development Institute, High Performance Plastics Company, Sekisui Chemical Co., Ltd. 2-1 Hyakuyama, Shimamoto-Cho, Mishima-Gun, Osaka, 618-0021 (Japan); Tsuji, Takeshi [Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu-Cho, Matsue, 690-8504 (Japan)

    2015-09-01

    Highlights: • Pulsed laser ablation in liquid (LAL) was applied to prepare antimony sulfide nanoparticles (Sb{sub 2}S{sub 3} NPs). • Sb{sub 2}S{sub 3} NPs with a stoichiometric composition were successfully prepared by LAL in water without using any surfactants or capping agents. • Thus-prepared Sb{sub 2}S{sub 3} NPs showed low-temperature crystallization and melting at a temperature low as 200 °C. • The NPs-coated Sb{sub 2}S{sub 3} thin film showed comparable semiconductor properties (carrier mobility and carrier density) to the vacuum deposited one. • Byproducts such as CS{sub 2}, CH{sub 4} and CO were detected by GC-MS analysis when LAL was performed in organic solvent. • The LAL-induced decomposition mechanism of Sb{sub 2}S{sub 3} and organic solvents was discussed based on the GC-MS results. - Abstract: In this paper, we report on the synthesis of antimony sulfide (Sb{sub 2}S{sub 3}) semiconductor nanoparticles by pulsed laser ablation in liquid without using any surfactants or capping agents. Different results were obtained in water and organic solvents. In the case of water, Sb{sub 2}S{sub 3} nanoparticles with chemical compositions of stoichiometry were successfully prepared when laser irradiation was performed under the condition with the dissolved oxygen removed by argon gas bubbling. It was shown that thus-obtained Sb{sub 2}S{sub 3} nanoparticles exhibit features of not only low-temperature crystallization but also low-temperature melting at a temperature as low as 200 °C. Nanoparticle-coated Sb{sub 2}S{sub 3} thin films were found to show good visible light absorption and satisfying semiconductor properties (i.e., carrier mobility and density), which are essential for photovoltaic application. On the other hand, in the case of organic solvents (e.g., acetone, ethanol), such unexpected byproducts as CS{sub 2}, CO and CH{sub 4} were detected from the reaction system by GC-MS analysis, which suggests that both Sb{sub 2}S{sub 3} and organic

  1. Efficient green and red fluorescence upconversion in erbium doped new low phonon antimony glasses

    Science.gov (United States)

    Som, Tirtha; Karmakar, Basudeb

    2009-02-01

    New K 2O-B 2O 3-Sb 2O 3 (KBS) glass system having low phonon energy (about 600 cm -1) doped with Er 3+ ions has been developed. Infrared reflection spectroscopic (IRRS) studies have been employed to establish its low phonon energy. Ultraviolet-visible-near infrared (UV-vis-NIR) absorption and photoluminescence upconversion properties with special emphasis on the spectrochemistry of the 15K 2O-15B 2O 3-70Sb 2O 3 (mol%) glass have been studied doping with different concentrations (0.1-1.0 wt%) of Er 2O 3. UV-vis-NIR absorption band positions have been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 798 nm at room temperature. Three upconverted bands originating from the 2H 11/2 → 4I 15/2, 4S 3/2 → 4I 15/2 and 4F 9/2 → 4I 15/2 transitions are found to be centered at 522 (green, very weak), 536 (green, medium) and 645 (red, strong) nm, respectively. These bands have been explained from the evaluation of the absorption, normal (down conversion) fluorescence and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET), cooperative energy transfer (CET) and cross relaxation (CR) mechanisms involving population of the metastable (storage) energy levels ( 2H 11/2, 4S 3/2 and 4F 9/2) by effects of multiphonon deexcitation and thermal population. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in antimony glasses owing to their high intense low phonon energy (602 cm -1) which is very close to that of fluoride glasses (500-600 cm -1). We are the first to report the upconversion fluorescence of Er 3+ ions in KBS antimony glasses.

  2. Infrared-to-red upconversion luminescence in samarium-doped antimony glasses

    Energy Technology Data Exchange (ETDEWEB)

    Som, Tirtha [Glass Technology Laboratory, Glass Division, Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700 032 (India); Karmakar, Basudeb [Glass Technology Laboratory, Glass Division, Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700 032 (India)], E-mail: basudebk@cgcri.res.in

    2008-12-15

    A new antimony-based glass system (K{sub 2}O-B{sub 2}O{sub 3}-Sb{sub 2}O{sub 3}) having low phonon energy (about 600 cm{sup -1}) doped with Sm{sup 3+} ions has been developed. Infrared reflection spectroscopic (IRRS) studies have been employed to establish its low phonon energy. Ultraviolet-Visible-near infrared (UV-Vis-NIR) absorption and photoluminescence upconversion properties with the spectrochemistry of the 15K{sub 2}O-15B{sub 2}O{sub 3}-70Sb{sub 2}O{sub 3} (mol%) glasses have been studied doping with different concentrations (0.1-1.0 wt%) of Sm{sub 2}O{sub 3}. UV-Vis-NIR absorption band positions have been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 949 nm at room temperature. Three upconverted bands originating from the {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 5/2}, {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 7/2} and {sup 4}G{sub 5/2}{yields}{sup 6}H{sub 9/2} transitions are found to be centered at 566 (green, weak), 602 (orange, weak) and 636 (red, remarkably strong) nm, respectively. These bands have been explained from the evaluation of the absorption, normal (downconversion) fluorescence and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET) and cross-relaxation (CR) mechanisms involving population of the metastable (storage) energy level ({sup 4}G{sub 5/2}) by multiphonon deexcitation effect. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in antimony glasses owing to their low phonon energy (602 cm{sup -1}, the main and highest intensity Sb-O-Sb stretching band) which is very close to that of fluoride glasses (500-600 cm{sup -1})

  3. A study on low cost-high conducting fluorine and antimony-doped tin oxide thin films

    International Nuclear Information System (INIS)

    Thin films of undoped, fluorine- and antimony-doped tin oxide on glass at 400 deg. C was prepared by spray pyrolysis technique. Tin chloride (SnCl2), ammonium fluoride (NH4F), and antimony trichloride (SbCl3) were used as source for tin (Sn), fluorine (F), and antimony (Sb), respectively. To ensure the control of solution concentration on growth rate, fluorine-doped tin oxide (SnO2:F) thin films were first prepared with different amount of tin precursor, in the range of 5-12g, which has resulted in deposition of films with different thickness values. The optimum amount of tin precursor found from this study (11g) was fixed constant for preparing SnO2 films with different doping levels of F and Sb. From the X-ray diffraction analyses, it is understood that the preferred orientation of SnO2:F films is dependent on their thickness and the solution concentration. The variation in the solution concentration and orientation of the films was reflected in their morphology as examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM studies showed that the variation in the solution concentration lead to different grain shapes for different orientations. The AFM study showed that the RMS roughness of undoped films reduced considerably from 86 to 24nm due to fluorine doping (15wt.%), whereas the antimony doping (2wt.%) has no significance effect on RMS roughness (93nm). The electrical properties of the films were examined by a Hall measurements setup in van der Pauw configuration. A minimum sheet resistance of 1.75 and 2.17Ω/ were obtained for F and Sb doped films, respectively. From the optical studies, it is found that the transmittance of undoped films increased from 42% to a maximum 85% on 30wt.% fluorine doping, whereas that has been decreased to a minimum of 12% on 4wt.% antimony doping (800nm). A discussion on the effect of type of dopants and their concentration on the structural, electrical and optical properties of the SnO2 film have

  4. Development of a MSFIA system for sequential determination of antimony, arsenic and selenium using hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    de Santana, Fernanda A; Portugal, Lindomar A; Serra, Antonio M; Ferrer, Laura; Cerdà, Víctor; Ferreira, Sergio L C

    2016-08-15

    This paper proposed a multisyringe flow injection analysis (MSFIA) system for antimony, arsenic and selenium determination in peanut samples by hydride generation atomic fluorescence spectrometry (HG-AFS). The optimization step of the hydride generation was performed using a two-level full factorial design involving the parameters: hydrochloric acid, sodium tetrahydroborate and potassium iodide concentrations. So, using the chemical conditions optimized, this method allows the determination of these elements employing the external calibration technique using aqueous standards with limits of detection and quantification of 0.04 and 0.14µgL(-1) for antimony, 0.04 and 0.14µgL(-1) for arsenic and 0.14 and 0.37µgL(-1) for selenium, respectively. Additionally, the effect of vanadium, chromium, cobalt, nickel, zinc, copper, iron and molybdenum on the generation of chemical vapour was also studied. The precision expressed as relative standard deviation varied from 1.2 to 3.6% for antimony, 1.8-3.9% for arsenic and 1.8-2% for selenium. The accuracy for arsenic and selenium was confirmed using the certified peach leaves reference material SRM 1547 produced by National Institute of Standard and Technology. The proposed method showed 45 injection throughput (h(-1)) using 1.6mL sample volume for each element, 0.8mL NaBH4 0.5% (w/v) containing NaOH 0.05% (w/v), 0.8mL HCl 5M and 0.4mL KI 14% (w/v) containing L-ascorbic acid 2.5% (w/v). The method was applied to the determination of antimony, arsenic and selenium in peanut samples, which were firstly lyophilized and afterward digested using microwave assisted radiation. Six samples were analyzed and the contents of the elements found were: 28.7-41.3µgkg(-1) for arsenic, 86.4-480.1µgkg(-1) for selenium and 32.6-52.4µgkg(-1) for antimony. Addition/recovery tests were also performed to confirm the method accuracy for the three elements. PMID:27260431

  5. Partitioning geochemistry of arsenic and antimony, El Tatio Geyser Field, Chile

    International Nuclear Information System (INIS)

    The abundance of As and Sb in aqueous, mineral and biological reservoirs was examined at El Tatio Geyser Field, a unique hydrothermal basin located in the Atacama Desert region of Chile. Here the concentration of total As and Sb in hydrothermal springs and discharge streams are the highest reported for a natural surface water, and the geyser basin represents a significant source of toxic elements for downstream users across Region II, Chile. The geyser waters are near neutral Na:Cl type with ∼0.45 and 0.021 mmol L-1 total As and Sb, respectively, primarily in the reduced (III) redox state at the discharge with progressive oxidation downstream. The ferric oxyhydroxides associated with the microbial mats and some mineral precipitates accumulate substantial As that was identified as arsenate by XAS analysis (>10 wt% in the mats). This As is easily mobilized by anion exchange or mild dissolution of the HFO, and the ubiquitous microbial mats represent a significant reservoir of As in this system. Antimony, in contrast, is not associated with the mineral ferric oxides or the biomats, but is substantially enriched in the silica matrix of the geyserite precipitates, up to 2 wt% as Sb2O3. Understanding the mobility and partitioning behavior of these metalloids is critical for understanding their eventual impact on regional water management.

  6. Suppression of the vapor-liquid-solid growth of silicon nanowires by antimony addition.

    Science.gov (United States)

    Nimmatoori, Pramod; Zhang, Qi; Dickey, Elizabeth C; Redwing, Joan M

    2009-01-14

    The effect of Sb addition on the growth rate and structural properties of Si nanowires synthesized by vapor-liquid-solid growth was investigated. The nanowire growth rate was reduced by an order of magnitude following the addition of a low concentration pulse of trimethylantimony (TMSb) to the gas phase during growth. Transmission electron microscopy analysis revealed that the wires had a thick amorphous coating ( approximately 8 nm) around the catalyst particle and a distorted catalyst shape. Energy-dispersive x-ray spectroscopy showed the presence of trace amounts of Sb in the amorphous coating around the catalyst and at the catalyst-wire interface. Antimony was also found to be incorporated in the Si nanowires with a peak in the Sb concentration measured at the initial point where the TMSb pulse was added to the gas stream. The significant reduction in wire growth rate was attributed to Sb segregation at the vapor-liquid and liquid-solid interfaces which results in a change in interfacial energies and a reduction in the rate of Si incorporation at these interfaces. PMID:19417276

  7. Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

    Science.gov (United States)

    Suehiro, Satoshi; Horita, Keisuke; Yuasa, Masayoshi; Tanaka, Tooru; Fujita, Katsuhiko; Ishiwata, Yoichi; Shimanoe, Kengo; Kida, Tetsuya

    2015-08-17

    The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells. PMID:26237216

  8. Assessment and distribution of antimony in soils around three coal mines, Anhui, China

    Science.gov (United States)

    Qi, C.; Liu, Gaisheng; Kang, Y.; Lam, P.K.S.; Chou, C.

    2011-01-01

    Thirty-three soil samples were collected from the Luling, Liuer, and Zhangji coal mines in the Huaibei and Huainan areas of Anhui Province, China. The samples were analyzed for antimony (Sb) by inductively coupled plasmaoptical emission spectrometry (ICP-OES) method. The average Sb content in the 33 samples was 4 mg kg-1, which is lower than in coals from this region (6.2 mg kg-1). More than 75% of the soils sampled showed a significant degree of Sb pollution (enrichment factors [EFs] 5-20). The soils collected near the gob pile and coal preparation plant were higher in Sb content than those collected from residential areas near the mines. The gob pile and tailings from the preparation plant were high in mineral matter content and high in Sb. They are the sources of Sb pollution in surface soils in the vicinity of coal mines. The spatial dispersion of Sb in surface soil in the mine region shows that Sb pollution could reach out as far as 350 m into the local environment conditions. Crops in rice paddies may adsorb some Sb and reduce the Sb content in soils from paddyfields. Vertical distribution of Sb in two soil profiles indicates that Sb is normally relatively immobile in soils. ?? 2011 Air & Waste Management Association.

  9. Antimony nanoparticles anchored in three-dimensional carbon network as promising sodium-ion battery anode

    Science.gov (United States)

    Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang

    2016-02-01

    A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next "beyond lithium" battery generation.

  10. Antimony uptake, translocation and speciation in rice plants exposed to antimonite and antimonate.

    Science.gov (United States)

    Ren, Jing-Hua; Ma, Lena Q; Sun, Hong-Jie; Cai, Fei; Luo, Jun

    2014-03-15

    Antimony (Sb) accumulation in rice is a potential threat to human health, but its uptake mechanisms are unclear. A hydroponic experiment was conducted to investigate uptake, translocation, speciation and subcellular distribution of Sb in rice plants exposed to antimonite (SbIII) and antimonate (SbV) at 0.2, 1.0 or 5.0 mg/L for 4h. More Sb was accumulated in iron plaque than in the plant, with both the roots (~10-12 times) and Fe plaque (~28-54 times) sequestering more SbIII than SbV. The presence of iron plaque decreased uptake of both SbV and SbIII. SbIII uptake kinetics fitted better to the Michaelis-Menten function than SbV. Antimonate (56 to 98%) was the predominant form in rice plant with little methylated species being detected using HPLC-ICP-MS. Cell walls accumulated more Sb than organelles and cytosol, which were considered as the first barrier against Sb entering into cells. Sb transformation and subcellular distribution can help to understand the metabolic mechanisms of Sb in rice. PMID:24419289

  11. A new method for antimony speciation in plant biomass and nutrient media using anion exchange cartridge.

    Science.gov (United States)

    Tisarum, Rujira; Ren, Jing-Hua; Dong, Xiaoling; Chen, Hao; Lessl, Jason T; Ma, Lena Q

    2015-11-01

    A selective separation method based on anion exchange cartridge was developed to determine antimony (Sb) speciation in biological matrices by graphite furnace atomic absorption spectrophotometry (GFAAS). The selectivity of the cartridge towards antimonite [Sb(III)] and antimonate [Sb(V)] reversed in the presence of deionized (DI) water and 2mM citric acid. While Sb(V) was retained by the cartridge in DI water, Sb(III) was retained in citric acid media. At pH 6, Sb(III) and Sb(V) formed Sb(III)- and Sb(V)-citrate complexes, but the cartridge had higher affinity towards the Sb(III)-citrate complex. Separation of Sb(III) was tested at various concentrations in fresh and spent growth media and plant tissues. Our results showed that cartridge-based Sb speciation was successful in plant tissues, which was confirmed by HPLC-ICP-MS. The cartridge retained Sb(III) and showed 92-104% Sb(V) recovery from arsenic hyperaccumulator Pteris vittata roots treated with Sb(III) and Sb(V). The cartridge procedure is an effective alternative for Sb speciation, offering low cost, reproducible results, and simple Sb analysis using GFAAS. PMID:26452943

  12. Antimony release from contaminated mine soils and its migration in four typical soils using lysimeter experiments.

    Science.gov (United States)

    Shangguan, Yu-Xian; Zhao, Long; Qin, Yusheng; Hou, Hong; Zhang, Naiming

    2016-11-01

    Antimony (Sb) can pose great risks to the environment in mining and smelting areas. The migration of Sb in contaminated mine soil was studied using lysimeter experiments. The exchangeable concentration of soil Sb decreased with artificial leaching. The concentrations of Sb retained in the subsoil layers (5-25cm deep) were the highest for Isohumosol and Ferrosol and the lowest for Sandy soil. The Sb concentrations in soil solutions decreased with soil depth, and were adequately simulated using a logarithmic function. The Sb migration pattern in Sandy soil was markedly different from the patterns in the other soils which suggested that Sb may be transported in soil colloids. Environmental factors such as water content, soil temperature, and oxidation-reduction potential of the soil had different effects on Sb migration in Sandy soil and Primosol. The high Fe and Mn contents in Ferrosol and Isohumosol significantly decreased the mobility of Sb in these soils. The Na and Sb concentrations in soils used in the experiments positively correlated with each other (PPrimosol>Isohumosol>Ferrosol, and we concluded that the Sb mobility in the soils also decreased in that order. PMID:27395817

  13. Enhanced hematite water electrolysis using a 3D antimony-doped tin oxide electrode.

    Science.gov (United States)

    Moir, Jonathon; Soheilnia, Navid; O'Brien, Paul; Jelle, Abdinoor; Grozea, Claudia M; Faulkner, Daniel; Helander, Michael G; Ozin, Geoffrey A

    2013-05-28

    We present herein an example of nanocrystalline antimony-doped tin oxide (nc-ATO) disordered macroporous "inverse opal" 3D electrodes as efficient charge-collecting support structures for the electrolysis of water using a hematite surface catalyst. The 3D macroporous structures were created via templating of polystyrene spheres, followed by infiltration of the desired precursor solution and annealing at high temperature. Using cyclic voltammetry and electrochemical impedance spectroscopy, it was determined that the use of this 3D transparent conducting oxide with a hematite surface catalyst allowed for a 7-fold increase in active surface area for water splitting with respect to its 2D planar counterpart. This ratio of surface areas was evaluated based on the presence of oxidized trap states on the hematite surface, as determined from the equivalent circuit analysis of the Nyquist plots. Furthermore, the presence of nc-ATO 2D and 3D "underlayer" structures with hematite deposited on top resulted in decreased charge transfer resistances and an increase in the number of available active surface sites at the semiconductor-liquid junction when compared to hematite films lacking any nc-ATO substructures. Finally, absorption, transmission, and reflectance spectra of all of the tested films were measured, suggesting the feasibility of using 3D disordered structures in photoelectrochemical reactions, due to the high absorption of photons by the surface catalyst material and trapping of light within the structure. PMID:23581965

  14. Spark Plasma Sintering and Densification Mechanisms of Antimony-Doped Tin Oxide Nanoceramics

    Directory of Open Access Journals (Sweden)

    Junyan Wu

    2013-01-01

    Full Text Available Densification of antimony-doped tin oxide (ATO ceramics without sintering aids is very difficult, due to the volatilization of SnO2, formation of deleterious phases above 1000°C, and poor sintering ability of ATO particles. In this paper, monodispersed ATO nanoparticles were synthesized via sol-gel method, and then ATO nanoceramics with high density were prepared by spark plasma sintering (SPS technology using the as-synthesized ATO nanoparticles without the addition of sintering aids. The effect of Sb doping content on the densification was investigated, and the densification mechanisms were explored. The results suggest that ATO nanoparticles derived from sol-gel method show good crystallinity with a crystal size of 5–20 nm and Sb is incorporated into the SnO2 crystal structure. When the SPS sintering temperature is 1000°C and the Sb doping content is 5 at.%, the density of ATO nanoceramics reaches a maximum value of 99.2%. Densification mechanisms are explored in detail.

  15. Leaching of Antimony (Sb)from Municipal Solid Waste Incineration (MSWI) Residues

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Inga

    2004-07-01

    The mobility of antimony (Sb) in municipal solid waste incineration (MSWI) residues often exceeds the limit values stipulated by the European Union. As an ash treatment by washing is conceivable, this work investigated the Sb release from Swedish bottom ash and fly ash when mixed with water. The leaching experiments revealed the factors significantly (a = 0.05) affecting Sb release from the ashes. The following factors were investigated: Liquid to solid ratio (L/S), time, pH, carbonation (treatment with CO{sub 2}), ultrasonics and temperature. The data were evaluated using multiple linear regression (MLR). The impact of the factors could be quantified. The maximum Sb release calculated was 13 mg/kg DM for bottom ash and 51 mg/kg DM for fly ash. The derived models explained the observed data well. Nevertheless, the calculated values were subject to a high uncertainty. For bottom ash, a lowering of the Sb total content of approximately 22% could be achieved. If this also involves a sufficient lowering of the Sb mobility to meet EU limit values could not yet be assessed. Chemical equilibrium calculations were performed to explain the empirical results. However, no solid phases controlling Sb release from the ashes could be identified.

  16. Controlled n-doping in chemical vapour deposition grown graphene by antimony

    International Nuclear Information System (INIS)

    We have studied the effects of antimony (Sb) doping on graphene grown by chemical vapour deposition without any significant change in its electrical properties. By increasing the metal thickness from 1 to 5 nm, we found a shift in the wave numbers of Raman G and two-dimensional (2D) peaks consistent with n-doping and a change in the Fermi level of the graphene into the conduction band. The relative intensity of the D peak to the G peak did not show a significant change and that of the 2D peak to the G peak remained at a large enough number as a function of metal thickness, implying little degradation by the metal dopants. Transport measurements also confirm the n-doping of graphene through a shift of Dirac point in the transfer characteristics and the quality preservation with little changes in mobility. We also report on the formation of a p–n junction by metal doping on selected areas of the graphene and their electrical properties with transfer characteristics and Hall measurements. (paper)

  17. Evaluation of atmospheric inputs as possible sources of antimony in pregnant women from urban areas.

    Science.gov (United States)

    Fort, Marta; Grimalt, Joan O; Querol, Xavier; Casas, Maribel; Sunyer, Jordi

    2016-02-15

    Antimony and copper are common components of brake linings. The occurrence of these two metals in urban atmospheric aerosols has been related to vehicular use. Urine samples (n=466) taken during the 32nd week of pregnancy were analyzed for Sb and Cu in pregnant women from an urban area (Sabadell, Catalonia, Spain). The geometric mean levels were 0.28 and 13 μg/g creatinine, respectively. Positive significant associations between urine concentrations of Sb and seasonality, intensity of physical exercise, working activities and traffic intensity at their home streets were observed. Cu showed the same trends but without statistical significance. In both cases, the estimated dietary ingestion of these two metals was larger than the inhalation inputs but the difference was much higher for Cu than for Sb. While Sb has no dietary role, Cu is an essential element which is also incorporated into humans through diet. The results suggest that inhalation of atmospheric particles may also constitute a source of Sb in pregnant women and general population of urban areas. PMID:26657384

  18. Partitioning geochemistry of arsenic and antimony, El Tatio Geyser Field, Chile

    Energy Technology Data Exchange (ETDEWEB)

    Landrum, J.T. [Department of Geological Sciences, The University of Texas, Austin, TX 78759 (United States); Bennett, P.C., E-mail: pbennett@mail.utexas.edu [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States); Engel, A.S. [Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 (United States); Alsina, M.A.; Pasten, P.A. [Departamento de Ingenieria Hidraulica y Ambiental, Pontificia Universidad Catolica de Chile, Santiago (Chile); Milliken, K. [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States)

    2009-04-15

    The abundance of As and Sb in aqueous, mineral and biological reservoirs was examined at El Tatio Geyser Field, a unique hydrothermal basin located in the Atacama Desert region of Chile. Here the concentration of total As and Sb in hydrothermal springs and discharge streams are the highest reported for a natural surface water, and the geyser basin represents a significant source of toxic elements for downstream users across Region II, Chile. The geyser waters are near neutral Na:Cl type with {approx}0.45 and 0.021 mmol L{sup -1} total As and Sb, respectively, primarily in the reduced (III) redox state at the discharge with progressive oxidation downstream. The ferric oxyhydroxides associated with the microbial mats and some mineral precipitates accumulate substantial As that was identified as arsenate by XAS analysis (>10 wt% in the mats). This As is easily mobilized by anion exchange or mild dissolution of the HFO, and the ubiquitous microbial mats represent a significant reservoir of As in this system. Antimony, in contrast, is not associated with the mineral ferric oxides or the biomats, but is substantially enriched in the silica matrix of the geyserite precipitates, up to 2 wt% as Sb{sub 2}O{sub 3}. Understanding the mobility and partitioning behavior of these metalloids is critical for understanding their eventual impact on regional water management.

  19. Comparison of arsenic and antimony biogeochemical behavior in water, soil and tailings from Xikuangshan, China.

    Science.gov (United States)

    Fu, Zhiyou; Wu, Fengchang; Mo, Changli; Deng, Qiujing; Meng, Wei; Giesy, John P

    2016-01-01

    Although similar geochemical behaviors of arsenic (As) and antimony (Sb) in the environment has been assumed and widely reported, growing evidence suggests the two elements cannot, under some conditions, be assumed to behave similarly. In this four-year study (samples collected in each year), comparative investigation of the biogeochemistry of As and Sb in water/fish, soil/vegetable, tailings/plant samples were carried out at the world's largest active Sb mine area (Xikuangshan, China). Depending on duration the tailings had been stacked, significant differences in spatial distributions between As and Sb were found, and these were associated with change in pH over time. Bio-accumulation factors (BAFs) of As were approximately 10-fold greater than those of Sb in fish/water, plant/tailing, and vegetable/soil systems. Sb had higher BAF in non-fatty tissues such as gills of fishes and shells of crabs. BAFs of Sb in vegetable/soil exhibited insignificantly, but different from As, positive correlation with pH in soil. PMID:26356182

  20. DFT Study on the Carrier Concentration and Temperature-Dependent Thermoelectric Properties of Antimony Selenide

    Directory of Open Access Journals (Sweden)

    Aditya Jayaraman

    2016-01-01

    Full Text Available We present the thermoelectric properties of Antimony Selenide (Sb2Se3 obtained using first principles calculations. We investigated the electronic band structure using the FP-LAPW method within the sphere of the density functional theory. Thermoelectric properties were calculated using BoltzTrap code using the constant relaxation time (τ approximation at three different temperatures 300 K, 600 K, and 800 K. Seebeck coefficient (S was found to decrease with increasing temperature, electrical conductivity (σ/τ was almost constant in the entire temperature range, and electronic thermal conductivity (κ/τ increased with increasing temperature. With increase in temperature S decreased from 1870 μV/K (at 300 K to 719 μV/K (at 800 K, electronic thermal conductivity increased from 1.56 × 1015 W/m K s (at 300 K to 3.92 × 1015 W/m K s (at 800 K, and electrical conductivity decreased from 22 × 1019/Ω m s (at 300 K to 20 × 1019/Ω m s (at 800 K. The thermoelectric properties were also calculated for different hole concentrations and the optimum concentration for a good thermoelectric performance over a large range of temperatures (from 300 K to 1000 K was found for hole concentration around 1019 cm−3.

  1. Validation of methodology and uncertainty assessment of antimony determination in environmental materials using Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Antimony is an element found in low concentrations in the environment. However, its determination has attracted great interest because of the knowledge of its toxicity and increasing application. Neutron activation analysis (NAA) is a suitable method for the determination of several elements in different types, but in case of Sb, the analysis presents some difficulties due to spectral interferences. The objective of this research was to validate the method of NAA and uncertainty assessment for Sb determination in environmental samples. The experimental procedure consisted of irradiating twelve certified reference samples of different kind of matrices. The samples were irradiated in the nuclear research reactor IEA R1 IPEN/CNEN/SP followed by measurement of induced radioactivity, using a hyperpure germanium detector coupled to a gamma ray spectrometry. The radioisotopes 122Sb and 124Sb were measured and the Sb concentrations with their respective uncertainties were obtained by the comparative method. Relative errors and values of Z scores were calculated to evaluate the accuracy of the results for Sb determination in certified reference materials. The evaluation of the components that contribute to uncertainty measurement of the Sb concentration, showed that the major uncertainty contribution is due to statistical counting. The results also indicated that the uncertainty value of the combined standard uncertainty depends on the radioisotope measured and the decay time used for counting. (author)

  2. Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

    Science.gov (United States)

    Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

    2016-03-01

    Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

  3. Gold and Antimony Mixed Flotation on a Micrite Gold Antimony ore in Guizhou%贵州某泥晶灰岩型含锑金矿金锑混浮试验

    Institute of Scientific and Technical Information of China (English)

    石贵明; 周意超

    2015-01-01

    贵州某泥晶灰岩型含锑金矿石为块状构造,金属矿物主要为黄铁矿、针铁矿,含量小于1%,非金属矿物以方解石为主,另有少量石英、有机质等;金含量为6.04 g/t,显微镜下未见自然金粒,74.34%的金赋存在硫化矿中,游离金仅占总金的7.14%;硅酸盐、碳酸盐包裹金分别占11.96%和6.56%;锑主要以辉锑矿的形式存在。为高效、低成本回收矿石中的金、锑,对混合浮选工艺进行了试验研究。结果表明,在一段磨矿细度为-0.074 mm占71%的情况下1粗2扫混浮、尾矿再磨细度为-0.074 mm占92.7%的情况下再1粗2扫混浮、两粗精矿合并后3次精选、中矿顺序返回流程处理,最终获得了金品位为47.60 g/t、锑品位为9.81%、金回收率为76.68%、锑回收率为85.22%的金锑混合精矿,金锑混浮效果较理想。尾矿中金的回收及金锑分离工艺研究将另文介绍。%The micrite type antimony-containing gold ore in Guizhou is in blocky construction. Its metallic minerals are mainly pyrite and goethite,with content of less than 1%. Non-metallic minerals are calcite,and few of quartz,organic matter, etc. It contains gold of 6. 04 g/t,and natural gold grains were not seen in microscope,74. 34% of the gold occurred in sulfide ore,free gold accounted for only 7. 14%,wrapped gold in silicate and carbonate accounted for 11. 96% and 6. 56% respective-ly. Antimony mainly existed in the form of stibnite. Bulk flotation process was studied to make high efficient recovery of gold and antimony at low costs. The results indicated that,at the grinding fineness of 71% passing 0. 074 mm,through one roughing and two scavenging bulk flotation,one roughing and two scavenging bulk flotation after regrinding the tailings to 92. 7% passing 0. 074 mm,three cleaning flotation for the two mixed rough concentrate,and then middles back to the flow-sheet in turn,rough gold-antimony concentrate with gold grade of 47. 60 g

  4. Quantitative HPLC-ICP-MS analysis of antimony redox speciation in complex sample matrices: new insights into the Sb-chemistry causing poor chromatographic recoveries

    DEFF Research Database (Denmark)

    Hansen, Claus; Schmidt, Bjørn; Larsen, Erik Huusfeldt;

    2011-01-01

    low chromatographic recoveries. A combination of HPLC-ICP-MS, AFFF-ICP-MS and spinfiltration was applied for analysis of model compounds and biological samples. Quantitative chromatographic Sb redox speciation analysis was possible by acidic hydrolysis of the antimony polymers prior to analysis......In solution antimony exists either in the pentavalent or trivalent oxidation state. As Sb(III) is more toxic than Sb(V), it is important to be able to perform a quantitative speciation analysis of Sb’s oxidation state. The most commonly applied chromatographic methods used for this redox speciation...... analysis do, however, often show a low chromatographic Sb recovery when samples of environmental or biological origin are analysed. In this study we explored basal chemistry of antimony and found that formation of macromolecules, presumably oligomeric and polymeric Sb(V) species, is the primary cause of...

  5. Changes induced by gamma radiation in nanocomposites based on copper II and antimony sulfides in commercial poly(methyl methacrylate) matrix

    International Nuclear Information System (INIS)

    Poly (methyl methacrylate) (PMMA) is a polymer with wide application in the manufacture of medical devices that is exposed to gamma irradiation. Currently the use of composite materials has been disseminated and PMMA is an excellent polymer matrix to package various materials. This study aimed to analyze the changes induced by gamma irradiation (25 kGy) on the properties of PMMA nanocomposites with nanoparticles of copper II sulfide (250nm-900nm) and antimony sulfite (300-500 nm). The nanoparticles were added to the polymer in different concentrations and synthesized by ultrasonic irradiation from the corresponding chlorides with thioacetamide. Viscometric results showed a good radioprotective effect of nanoparticles of copper and antimony. It was found a good protection of nanoparticles on PMMA matrix in the concentration of 0.3% wt. The protections of 75% and 50% were calculated for nanoparticles of antimony and copper II, respectively. (author)

  6. Cobalt doped antimony oxide nano-particles based chemical sensor and photo-catalyst for environmental pollutants

    International Nuclear Information System (INIS)

    Graphical abstract: A dichloromethane chemical sensor using cobalt antimony oxides has been fabricated. This sensor showed high sensitivity and will be a useful candidate for environmental and health monitoring. Also it showed high photo-catalytic activity and can be a good candidate as a photo-catalyst for organic hazardous materials. Highlights: ► Reusable chemical sensor. ► Green environmental and eco-friendly chemi-sensor. ► High sensitivity. ► Good candidate for environmental and health monitoring. - Abstract: Cobalt doped antimony oxide nano-particles (NPs) have been synthesized by hydrothermal process and structurally characterized by utilizing X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transforms infrared spectrophotometer (FT-IR) which revealed that the synthesized cobalt antimony oxides (CoSb2O6) are well crystalline nano-particles with an average particles size of 26 ± 10 nm. UV–visible absorption spectra (∼286 nm) were used to investigate the optical properties of CoSb2O6. The chemical sensing of CoSb2O6 NPs have been primarily investigated by I–V technique, where dichloromethane is used as a model compound. The analytical performance of dichloromethane chemical sensor exhibits high sensitivity (1.2432 μA cm−2 mM−1) and a large linear dynamic range (1.0 μM–0.01 M) in short response time (10 s). The photo catalytic activity of the synthesized CoSb2O6 nano-particles was evaluated by degradation of acridine orange (AO), which degraded 58.37% in 200 min. These results indicate that CoSb2O6 nano-particles can play an excellent research impact in the environmental field.

  7. Cobalt doped antimony oxide nano-particles based chemical sensor and photo-catalyst for environmental pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Jamal, Aslam [Centre for Advanced Materials and Nano-Engineering (CAMNE) and Department of Chemistry, Faculty of Sciences and Arts, Najran University, P. O. Box 1988, Najran 11001 (Saudi Arabia); Rahman, Mohammed M. [Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Khan, Sher Bahadar, E-mail: drkhanmarwat@gmail.com [Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Faisal, Mohd. [Centre for Advanced Materials and Nano-Engineering (CAMNE) and Department of Chemistry, Faculty of Sciences and Arts, Najran University, P. O. Box 1988, Najran 11001 (Saudi Arabia); Akhtar, Kalsoom [Division of Nano Sciences and Department of Chemistry, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Rub, Malik Abdul; Asiri, Abdullah M.; Al-Youbi, Abdulrahman O. [Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia)

    2012-11-15

    Graphical abstract: A dichloromethane chemical sensor using cobalt antimony oxides has been fabricated. This sensor showed high sensitivity and will be a useful candidate for environmental and health monitoring. Also it showed high photo-catalytic activity and can be a good candidate as a photo-catalyst for organic hazardous materials. Highlights: Black-Right-Pointing-Pointer Reusable chemical sensor. Black-Right-Pointing-Pointer Green environmental and eco-friendly chemi-sensor. Black-Right-Pointing-Pointer High sensitivity. Black-Right-Pointing-Pointer Good candidate for environmental and health monitoring. - Abstract: Cobalt doped antimony oxide nano-particles (NPs) have been synthesized by hydrothermal process and structurally characterized by utilizing X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transforms infrared spectrophotometer (FT-IR) which revealed that the synthesized cobalt antimony oxides (CoSb{sub 2}O{sub 6}) are well crystalline nano-particles with an average particles size of 26 {+-} 10 nm. UV-visible absorption spectra ({approx}286 nm) were used to investigate the optical properties of CoSb{sub 2}O{sub 6}. The chemical sensing of CoSb{sub 2}O{sub 6} NPs have been primarily investigated by I-V technique, where dichloromethane is used as a model compound. The analytical performance of dichloromethane chemical sensor exhibits high sensitivity (1.2432 {mu}A cm{sup -2} mM{sup -1}) and a large linear dynamic range (1.0 {mu}M-0.01 M) in short response time (10 s). The photo catalytic activity of the synthesized CoSb{sub 2}O{sub 6} nano-particles was evaluated by degradation of acridine orange (AO), which degraded 58.37% in 200 min. These results indicate that CoSb{sub 2}O{sub 6} nano-particles can play an excellent research impact in the environmental field.

  8. Clinical and Parasitological Features of Patients with American Cutaneous Leishmaniasis that Did Not Respond to Treatment with Meglumine Antimoniate

    Science.gov (United States)

    Robayo, Marta L.; Lopez, Myriam C.; Daza, Carlos D.; Bedoya, Angela; Mariño, Maria L.; Saavedra, Carlos H.

    2016-01-01

    Background American cutaneous leishmaniasis (ACL) is a complicated disease producing about 67.000 new cases per year. The severity of the disease depends on the parasite species; however in the vast majority of cases species confirmation is not feasible. WHO suggestion for ACL produced by Leishmania braziliensis, as first line treatment, are pentavalent antimonial derivatives (Glucantime or Sodium Stibogluconate) under systemic administration. According to different authors, pentavalent antimonial derivatives as treatment for ACL show a healing rate of about 75% and reasons for treatment failure are not well known. Methods In order to characterise the clinical and parasitological features of patients with ACL that did not respond to Glucantime, a cross-sectional observational study was carried out in a cohort of 43 patients recruited in three of the Colombian Army National reference centers for complicated ACL. Clinical and paraclinical examination, and epidemiological and geographic information were recorded for each patient. Parasitological, histopathological and PCR infection confirmation were performed. Glucantime IC50 and in vitro infectivity for the isolated parasites were estimated. Results Predominant infecting Leishmania species corresponds to L. braziliensis (95.4%) and 35% of the parasites isolated showed a significant decrease in in vitro Glucanatime susceptibility associated with previous administration of the medicament. Lesion size and in vitro infectivity of the parasite are negatively correlated with decline in Glucantime susceptibility (Spearman: r = (-)0,548 and r = (-)0,726; respectively). Conclusion A negative correlation between lesion size and parasite resistance is documented. L. braziliensis was found as the main parasite species associated to lesion of patients that underwent treatment failure or relapse. The indication of a second round of treatment in therapeutic failure of ACL, produced by L. braziliensis, with pentavalent antimonial

  9. Characterization of circulating lymphocyte subpopulations in canine leishmaniasis throughout treatment with antimonials and allopurinol.

    Science.gov (United States)

    Miranda, Sonia; Martorell, Susanna; Costa, Manuela; Ferrer, Lluis; Ramis, Antonio

    2007-03-31

    Canine leishmaniasis (CL) is a systemic parasitic disease with a wide variability of response to specific therapy: the majority of patients apparently improve with treatment, some of them respond but later relapse, and few of them do not respond at all. It has been demonstrated that the immune response plays a key role in the development and outcome of Leishmania infection in the dog and in the response to the treatment, although this response is not well understood. Some authors have suggested that ill dogs show a reduction in the percentage of circulating CD4+ lymphocytes and in the CD4+/CD8+ ratio, both of which normalize after treatment and clinical recovery. The present paper discusses the variation of the different lymphocyte subpopulations (CD3, CD4, CD8, CD21) of peripheral blood mononuclear cells (PBMC) in 28 dogs diagnosed with CL and submitted to conventional treatment with meglumine antimoniate (Glucantime) for 1 month and with allopurinol (Zyloric) for 1 year, in order to evaluate the usefulness of these parameters as indicators of the immunological condition of the ill animals and of the prognosis of their evolution during the treatment. It is concluded that circulating lymphocyte subpopulations are similar in dogs with leishmaniasis and in healthy dogs and that there is no correlation between the clinical status or response to therapy and the values of the counts of the different lymphocyte subpopulations. Therefore, the percentage of different lymphocyte subpopulations cannot be used as a parameter to predict the evolution of an individual patient in a clinical context. PMID:17110042

  10. Radiation-induced reactions of antimony and tellurium compounds in sulfuric acid solutions

    International Nuclear Information System (INIS)

    In deaerated 0.4 M H2SO4 solutions containing both Sb(III) and Sb(V), Sb(III) was oxidized to Sb(V) and Sb(V) was reduced to Sb(III) by γ rays. The initial yield of reduction G/sub i/(Sb(V) → Sb(III)) increased linearly with the ratio [Sb(V)]0/[Sb(III)]0, that of oxidation G/sub i/(Sb(III) → Sb(V)) increased with increasing G/sub i/(Sb(V) → Sb(III)), and the overall yield of oxidation G/sub i/(Sb(V)) = G/sub i/(Sb(III) → Sb(V)) - G/sub i/(Sb(V) → Sb(III)) was constant and equivalent to the primary yield of hydrogen g/sub H2/ = 1/2(g/sub OH/ - g/sub H/) + g/sub H2O2/. A possible mechanism of γ-ray-induced reactions in deaerated solutions was proposed in which Sb(III) was reduced by H and oxidized by OH, Sb(II) was oxidized by H2O2, and Sb(IV), and the disproportionation of Sb(IV) to Sb(III) and Sb(V) followed. In the presence of Sb(V), reduction of Sb(V) by H gives the same stoichiometry. The results on Te(IV) and Te(VI) in 0.02 M H2SO4 solutions support a similar sequence to that of the antimony system, in which the unstable valence states Te(III) and Te(V) play an important part

  11. Semimetal-semiconductor transitions in bismuth-antimony films and nanowires induced by size quantization

    International Nuclear Information System (INIS)

    In this paper we present the experimental results of an investigation of the electrical transport, thermoelectrical properties, the Shubnikov de Haas oscillations of Bi1-xSbx films (0 < x < 0.04) grown by the vacuum thermal evaporation and nanowires prepared by a modified Ulitovsky - Teilor technique. The results of the X-ray diffraction indicate that the trigonal axes were perpendicular to the film plane and the single Bi-2at%Sb nanowires with the diameter 100-1000 nm were represented by single crystals in a glass capillary with (1011) orientation along the wire axis. The investigations of the Shubnikov de Haas oscillations on Bi-2at%Sb wires with d > 600 nm show that overlapping of L and T bands was twice smaller than that in pure Bi. The temperature dependences of thin semimetallic Bi-3at%Sb films and Bi-2at%Sb wires show a semiconducting behavior. The semimetal semiconductor transition induced by the quantum confinement effect is observed in semimetal Bi1-xSbx films and nanowires at the diameters up to five times greater than those in the pure Bi. That experimental fact, on the one hand, will allow observing the display quantum confinement effect at higher temperatures on nanowires of the same diameters, and, on the other hand, will allows separating effects connected with the surface state and the quantum size effects. In addition, the thermoelectric properties and thermoelectric efficiency of bismuth-antimony wires are considered and a possibility to use them in thermoelectric converters of energy is discussed. (authors)

  12. Contamination of bottled waters with antimony leaching from polyethylene terephthalate (PET) increases upon storage.

    Science.gov (United States)

    Shotyk, William; Krachler, Michael

    2007-03-01

    Antimony concentrations were determined in 132 brands of bottled water from 28 countries. Two of the brands were at or above the maximum allowable Sb concentration for drinking water in Japan (2 microg/L). Elevated concentrations of Sb in bottled waters are due mainly to the Sb2O3 used as the catalyst in the manufacture of polyethylene terephthalate (PET(E)). The leaching of Sb from PET(E) bottles shows variable reactivity. In 14 brands of bottled water from Canada, Sb concentrations increased on average 19% during 6 months storage at room temperature, but 48 brands of water from 11 European countries increased on average 90% under identical conditions. A mineral water from France in PET(E), purchased in Germany, yielded 725 ng/L when first tested, but 1510 ng/L when it was stored for 6 months at room temperature; the same brand of water, purchased in Hong Kong, yielded 1990 ng/L Sb. Pristine groundwater containing 1.7+/-0.4 ng/L Sb (n = 6) yielded 26.6+/-2.3 ng/L Sb (n = 3) after storage in PET(E) bottles from Canada for 6 months versus 281+/-38 ng/L Sb (n = 3) in PET(E) bottles from Germany. Tap water bottled commercially in PET(E) in December 2005 contained 450+/-56 ng/L Sb (n = 3) versus 70.3+/-0.3 ng/L Sb (n = 3) when sampled from a household faucet in the same village (Bammental, Germany), and 25.7+/-1.5 ng/L Sb (n = 3) from a local artesian flow. PMID:17396641

  13. EPR, optical absorption and luminescence studies of Cr3+-doped antimony phosphate glasses

    Science.gov (United States)

    De Vicente, F. S.; Santos, F. A.; Simões, B. S.; Dias, S. T.; Siu Li, M.

    2014-12-01

    Antimony phosphate glasses (SbPO) doped with 3 and 6 mol% of Cr3+ were studied by Electron Paramagnetic Resonance (EPR), UV-VIS optical absorption and luminescence spectroscopy. The EPR spectra of Cr3+-doped glasses showed two principal resonance signals with effective g values at g = 5.11 and g = 1.97. UV-VIS optical absorption spectra of SbPO:Cr3+ presented four characteristics bands at 457, 641, 675, and 705 nm related to the transitions from 4A2(F) to 4T1(F), 4T2(F), 2T1(G), and 2E(G), respectively, of Cr3+ ions in octahedral symmetry. Optical absorption spectra of SbPO:Cr3+ allowed evaluating the crystalline field Dq, Racah parameters (B and C) and Dq/B. The calculated value of Dq/B = 2.48 indicates that Cr3+ ions in SbPO glasses are in strong ligand field sites. The optical band gap for SbPO and SbPO:Cr3+ were evaluated from the UV optical absorption edges. Luminescence measurements of pure and Cr3+-doped glasses excited with 350 nm revealed weak emission bands from 400 to 600 nm due to the 3P1 → 1S0 electronic transition from Sb3+ ions. Cr3+-doped glasses excited with 415 nm presented Cr3+ characteristic luminescence spectra composed by two broad bands, one band centered at 645 nm (2E → 4A2) and another intense band from 700 to 850 nm (4T2 → 4A2).

  14. Metagenomic approach reveals variation of microbes with arsenic and antimony metabolism genes from highly contaminated soil.

    Directory of Open Access Journals (Sweden)

    Jinming Luo

    Full Text Available Microbes have great potential for arsenic (As and antimony (Sb bioremediation in heavily contaminated soil because they have the ability to biotransform As and Sb to species that have less toxicity or are more easily removed. In this study, we integrated a metagenomic method with physicochemical characterization to elucidate the composition of microbial community and functional genes (related to As and Sb in a high As (range from 34.11 to 821.23 mg kg-1 and Sb (range from 226.67 to 3923.07 mg kg-1 contaminated mine field. Metagenomic analysis revealed that microbes from 18 phyla were present in the 5 samples of soil contaminated with high As and Sb. Moreover, redundancy analysis (RDA of the relationship between the 18 phyla and the concentration of As and Sb demonstrated that 5 phyla of microbes, i.e. Actinobacteria, Firmicutes, Nitrospirae, Tenericutes and Gemmatimonadetes were positively correlated with As and Sb concentration. The distribution, diversity and abundance of functional genes (including arsC, arrA, aioA, arsB and ACR3 were much higher for the samples containing higher As and Sb concentrations. Based on correlation analysis, the results showed a positive relationship between arsC-like (R2 = 0.871 and aioA-like (R2 = 0.675 gene abundance and As concentration, and indicated that intracellular As(V reduction and As(III oxidation could be the dominant As detoxification mechanism enabling the microbes to survive in the environment. This study provides a direct and reliable reference on the diversity of microbial community and functional genes in an extremely high concentration As- and Sb-contaminated environment.

  15. Green and red fluorescence upconversion in neodymium-doped low phonon antimony glasses

    International Nuclear Information System (INIS)

    A new K2O-B2O3-Sb2O3 (KBS) glass system having low phonon energy (about 600 cm-1) doped with Nd3+ ions has been developed. Infrared reflection spectroscopic (IRRS) studies have been employed to establish its low phonon energy. Ultraviolet-visible-near infrared (UV-vis-NIR) absorption and photoluminescence upconversion properties with special emphasis on the spectrochemistry of the 15K2O-15B2O3-70Sb2O3 (mol%) glass have been studied doping with different concentrations (0.1-1.0 wt%) of Nd2O3. UV-vis-NIR absorption band positions have been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 805 nm at room temperature. Two upconverted bands originating from the 4G7/2 → 4I9/2 and 4G7/2 → 4I13/2 transitions are found to be centered at 540 nm (green, medium) and 650 nm (red, strong), respectively. These bands have been explained from the evaluation of the absorption and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET), cooperative energy transfer (CET) and cross-relaxation (CR) mechanisms involving population of the metastable (storage) energy level (4G7/2) by effects of multiphonon deexcitation and thermal population. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in antimony glasses owing to their low phonon energy (602 cm-1, the main and highest intensity Sb-O-Sb stretching band) which is very close to that of fluoride glasses (500-600 cm-1).

  16. Effect of external energy on atomic, crystalline and powder characteristics of antimony and bismuth powders

    Indian Academy of Sciences (India)

    Vikram V Dabhade; Rama Mohan R Tallapragada; Mahendra Kumar Trivedi

    2009-10-01

    Next to atoms and molecules the powders are the smallest state of matter available in high purities and large quantities. The effect of any external energy on the shape, morphology and structure can thus be studied with relative ease. The present investigation deals with the effect of a non-contact external energy on the powders of antimony and bismuth. The characteristics of powders treated by external energy are compared with the as received powders (control). The average particle sizes, 50 and 99, the sizes below which 99% of the particles are present showed significant increase and decrease indicating that the energy had caused deformation and fracture as if the powders have been subjected to high energy milling. To be able to understand the reasons for these changes the powders are characterized by techniques such as X-ray diffraction (XRD), surface area determination (BET), thermal analytical techniques such as DTA–DTG, DSC–TGA and SDTA and scanning electron microscopy (SEM). The treated powder samples exhibited remarkable changes in the powder characteristics at all structural levels starting from polycrystalline particles, through single crystal to atoms. The external energy had changed the lattice parameters of the unit cell which in turn changed the crystallite size and density. The lattice parameters are then used to compute the weight and effective nuclear charge of the atom which showed significant variation. It is speculated that the external energy is acting on the nucleus through some reversible weak interaction of larger cross section causing changes in the proton to neutron ratios. Thus the effect is felt by all the atoms, and hence the unit cell, single crystal grain and grain boundaries. The stresses generated in turn may have caused deformation or fracture of the weak interfaces such as the crystallite and grain boundaries.

  17. The influence of remelting on the properties of AlSi6Cu4 alloy modified by antimony

    Directory of Open Access Journals (Sweden)

    D. Medlen

    2012-01-01

    Full Text Available The paper deals with the problem of multiple remelting influence on AlSi6Cu4 alloy modified by antimony on chosen mechanical characteristics, microstructure and gas content. This foundry alloy is used mostly in automotive industry. Foundry Aluminum-Silicon alloys are also used in number of industrial weight sensitive applications because of their low weight and very good castability and good mechanical properties. Modifiers are usually added to molten aluminum-silicon alloys to refine the eutectic phase particle shape and improve the mechanical properties of the final cast products and Al-Si alloys cast properties.

  18. Flow analysis-hydride generation-gas phase derivative molecular absorption spectrophotometric determination of antimony in antileishmanial drugs

    Directory of Open Access Journals (Sweden)

    Máximo Gallignani

    2009-01-01

    Full Text Available In the present work, the development of a method based on the coupling of flow analysis (FA, hydride generation (HG, and derivative molecular absorption spectrophotometry (D-EAM in gas phase (GP, is described in order to determine total antimony in antileishmanial products. Second derivative order (D²224nm of the absorption spectrum (190 - 300 nm is utilized as measurement criterion. Each one of the parameters involved in the development of the proposed method was examined and optimized. The utilization of the EAM in GP as detection system in a continuous mode instead of atomic absorption spectrometry represents the great potential of the analytic proposal.

  19. Influence of antimony on the mechanical properties and gas content of alloy AlSi6Cu4

    OpenAIRE

    D. Medlen; D. Bolibruchova

    2011-01-01

    Aluminium alloys based on Al-Si are used in automotive and aerospace industries. AlSi6Cu4 alloy is used the complicated castings, whichmust comply high strength requirements. Strength characteristics can also be affected by the modifiers: Na, Sr, Sb. In the li terature ismentioned, that AlSi6Cu4 modified by sodium and strontium has negative effect - increases of the gas absorption. Modification of AlSi6Cu4 alloy by antimony, is still not mentioned in the literature. The article gives the effe...

  20. First-principle study of antimony doping effects on the iron-based superconductor CaFe(Sb$_{x}$As$_{1-x}$)$_{2}$

    OpenAIRE

    Nagai, Yuki; Nakamura, Hiroki; Machida, Masahiko; Kuroki, Kazuhiko

    2015-01-01

    We study antimony doping effects in the iron-based superconductor CaFe(Sb$_{x}$As$_{1-x}$)$_{2}$ by using the first-principle calculation. The calculations reveal that the substitution of the doped antimony atom into As of the chainlike As layers is more stable than that in FeAs layers. This prediction can be checked by experiments. Our results suggest that doping homologous elements into the chainlike As layers existing only in novel 112 system is responsible for rising up the critical tempe...

  1. Determination of Antimony (III in Real Samples by Anodic Stripping Voltammetry Using a Mercury Film Screen-Printed Electrode

    Directory of Open Access Journals (Sweden)

    Olga Domínguez-Renedo

    2009-01-01

    Full Text Available This paper describes a procedure for the determination of antimony (III by differential pulse anodic stripping voltammetry using a mercury film screen-printed electrode as the working electrode. The procedure has been optimized using experimental design methodology. Under these conditions, in terms of Residual Standard Deviation (RSD, the repeatability (3.81 % and the reproducibility (5.07 % of the constructed electrodes were both analyzed. The detection limit for Sb (III was calculated at a value of 1.27×10–8 M. The linear range obtained was between 0.99 × 10–8 – 8.26 × 10–8 M. An analysis of possible effects due to the presence of foreign ions in the solution was performed and the procedure was successfully applied to the determination of antimony levels in pharmaceutical preparations and sea water samples.

  2. Nutritional status in patients with cutaneous leishmaniasis and a study of the effects of zinc supplementation together with antimony treatment

    Directory of Open Access Journals (Sweden)

    Miguel Guzman-Rivero

    2014-11-01

    Full Text Available Background: The role of micronutrient status for the incidence and clinical course of cutaneous leishmaniasis is not much studied. Still zinc supplementation in leishmaniasis has shown some effect on the clinical recovery, but the evidence in humans is limited. Objective: To compare biochemical nutritional status in cutaneous leishmaniasis patients with that in controls and to study the effects of zinc supplementation for 60 days. Design: Twenty-nine patients with cutaneous leishmaniasis were treated with antimony for 20 days. Fourteen of them got 45 mg zinc daily and 15 of them got placebo. Biomarkers of nutritional and inflammatory status and changes in size and characteristics of skin lesions were measured. Results: The level of transferrin receptor was higher in patients than in controls but otherwise no differences in nutritional status were found between patients and controls. No significant effects of zinc supplementation on the clinical recovery were observed as assessed by lesion area reduction and characteristics or on biochemical parameters. Conclusions: It is concluded that nutritional status was essentially unaffected in cutaneous leishmaniasis and that oral zinc supplementation administered together with intramuscular injection of antimony had no additional clinical benefit.

  3. Treatment of air pollution control residues with iron rich waste sulfuric acid: does it work for antimony (Sb)?

    Science.gov (United States)

    Okkenhaug, Gudny; Breedveld, Gijs D; Kirkeng, Terje; Lægreid, Marit; Mæhlum, Trond; Mulder, Jan

    2013-03-15

    Antimony (Sb) in air pollution control (APC) residues from municipal solid waste incineration has gained increased focus due to strict Sb leaching limits set by the EU landfill directive. Here we study the chemical speciation and solubility of Sb at the APC treatment facility NOAH Langøya (Norway), where iron (Fe)-rich sulfuric acid (∼3.6M, 2.3% Fe(II)), a waste product from the industrial extraction of ilmenite, is used for neutralization. Antimony in water extracts of untreated APC residues occurred exclusively as pentavalent antimonate, even at low pH and Eh values. The Sb solubility increased substantially at pHettringite (at alkaline pH) or calcium (Ca)-antimonate. Treated APC residues, stored anoxically in the laboratory, simulating the conditions at the NOAH Langøya landfill, gave rise to decreasing concentrations of Sb in porewater, occurring exclusively as Sb(V). Concentrations of Sb decreased from 87-918μgL(-1) (day 3) to 18-69μgL(-1) (day 600). We hypothesize that an initial sorption of Sb to Fe(II)-Fe(III) hydroxides (green rust) and eventually precipitation of Ca- and Fe-antimonates (tripuhyite; FeSbO4) occurred. We conclude that Fe-rich, sulfuric acid waste is efficient to immobilize Sb in APC residues from waste incineration. PMID:23465722

  4. Complement activation-related pseudoallergy in dogs following intravenous administration of a liposomal formulation of meglumine antimoniate

    Directory of Open Access Journals (Sweden)

    Raul R. Ribeiro

    2013-08-01

    Full Text Available The increasing use of nanotechnologies in advanced therapies has allowed the observation of specific adverse reactions related to nanostructures. The toxicity of a novel liposome formulation of meglumine antimoniate in dogs with visceral leishmaniasis after single dose has been investigated. Groups of 12 animals received by the intravenous route a single dose of liposomal meglumine antimoniate (group I [GI], 6.5 mg Sb/kg, empty liposomes (GII or isotonic saline (GIII. Evaluation of hematological and biochemical parameters showed no significant changes 4 days after administration. No undesired effects were registered in the GIII. However, adverse reactions were observed in 67.7% of dogs from both groups that received liposomal formulations. The side effects began moments after bolus administration and disappeared during the first 15 minutes after treatment. Prostation, sialorrhea and defecation were the most frequent clinical signs, registered in 33.3% and 41.6 % of animals from the groups GI and GII, respectively. Tachypnea, mydriasis, miosis, vomiting and cyanosis were also registered in both groups. The adverse reactions observed in this study were attributed to the activation of the complement system by lipid vesicles in a phenomenon known as Complement Activation-Related Pseudoallergy (CARPA. The influence of the physical-chemical characteristics of liposomal formulation in the triggering of CARPA is discussed.

  5. Detection of pathogenic bacteria in skin lesions of patients with chiclero's ulcer: reluctant response to antimonial treatment

    Directory of Open Access Journals (Sweden)

    Isaac-Márquez Angélica Patricia

    2003-01-01

    Full Text Available We investigated the bacterial flora present in skin lesions of patients with chiclero's ulcer from the Yucatan peninsula of Mexico using conventional culture methods (11 patients, and an immunocolorimetric detection of pathogenic Streptococcus pyogenes (15 patients. Prevalence of bacteria isolated by culture methods was 90.9% (10/11. We cultured, from chiclero's ulcers (60%, pathogenic bacterial such as Staphylococcus aureus (20%, S. pyogenes (1.6%, Pseudomonas aeruginosa (1.6%, Morganella morganii (1.6%, and opportunist pathogenic bacteria such as Klebsiella spp. (20.0%, Enterobacter spp. (20%, and Enterococcus spp. (20%. We also cultured coagulase-negative staphylococci in 40% (4/10 of the remaining patients. Micrococcus spp. and coagulase-negative staphylococci constituted the bacterial genuses more frequently isolated in the normal skin of patients with chiclero's ulcer and healthy individuals used as controls. We also undertook another study to find out the presence of S. pyogenes by an immunocolorimetric assay. This study indicated that 60% (9/15 of the ulcerated lesions, but not normal controls, were contaminated with S. pyogenes. Importantly, individuals with purulent secretion and holding concomitant infections with S. pyogenes, S. aureus, P. aeruginosa, M. morganii, and E. durans took longer to heal Leishmania (L. mexicana infections treated with antimonial drugs. Our results suggest the need to eliminate bacterial purulent infections, by antibiotic treatment, before starting antimonial administration to patients with chiclero's ulcer.

  6. Effect of germanium pre-amorphization on solid-phase epitaxial regrowth of antimony and arsenic ion-implanted silicon

    International Nuclear Information System (INIS)

    Shallow, low-resistive n+/p junction was investigated for sub 100-nm metal-oxide-semiconductor field-effect transistors (MOSFETs) using antimony and arsenic ion-implantation and low-temperature rapid thermal annealing-increased gate leakage current due to high-permittivity gate dielectric crystallization during high-temperature source and drain dopant activation imposes low temperature annealing for next generation devices. In contrast to arsenic implanted junctions, Sb-doped specimens showed shallower junction depth, lower sheet resistance and leakage current at low temperature processing (600 deg. C). In addition, Ge pre-amorphization prior to As-implant was used to fully amorphize Si for ideal solid-phase epitaxial regrowth. Pre-amorphized As-doped samples did not result in highly activated junctions at low temperature. Pre-amorphized Sb-doped junctions did not regrow in acceptable annealing time. The results indicated the superiority of antimony to arsenic as a dopant for ultra-shallow and low-resistive source and drain extensions. Arsenic will not be a proper candidate because of higher sheet resistance as a consequence of presence of inactive As-vacancy clusters and higher leakage current for devices that should be fabricated at low temperature with implementing of high-κ dielectric metal-electrode gate stack in next generation MOSFETs

  7. The presence and leachability of antimony in different wastes and waste handling facilities in Norway.

    Science.gov (United States)

    Okkenhaug, G; Almås, Å R; Morin, N; Hale, S E; Arp, H P H

    2015-11-01

    The environmental behaviour of antimony (Sb) is gathering attention due to its increasingly extensive use in various products, particularly in plastics. Because of this it may be expected that plastic waste is an emission source for Sb in the environment. This study presents a comprehensive field investigation of Sb concentrations in diverse types of waste from waste handling facilities in Norway. The wastes included waste electrical and electronic equipment (WEEE), glass, vehicle fluff, combustibles, bottom ash, fly ash and digested sludge. The highest solid Sb concentrations were found in WEEE and vehicle plastic (from 1238 to 1715 mg kg(-1)) and vehicle fluff (from 34 to 4565 mg kg(-1)). The type of acid used to digest the diverse solid waste materials was also tested. It was found that HNO3:HCl extraction gave substantially lower, non-quantitative yields compared to HNO3:HF. The highest water-leachable concentration for wastes when mixed with water at a 1 : 10 ratio were observed for plastic (from 0.6 to 2.0 mg kg(-1)) and bottom ash (from 0.4 to 0.8 mg kg(-1)). For all of the considered waste fractions, Sb(v) was the dominant species in the leachates, even though Sb(iii) as Sb2O3 is mainly used in plastics and other products, indicating rapid oxidation in water. This study also presents for the first time a comparison of Sb concentrations in leachate at waste handling facilities using both active grab samples and DGT passive samples. Grab samples target the total suspended Sb, whereas DGT targets the sum of free- and other chemically labile species. The grab sample concentrations (from 0.5 to 50 μg L(-1)) were lower than the predicted no-effect concentration (PNEC) of 113 μg L(-1). The DGT concentrations were substantially lower (from 0.05 to 9.93 μg L(-1)) than the grab samples, indicating much of the Sb is present in a non-available colloidal form. In addition, air samples were taken from the chimney and areas within combustible waste incinerators, as

  8. Correlation models between environmental factors and bacterial resistance to antimony and copper.

    Directory of Open Access Journals (Sweden)

    Zunji Shi

    Full Text Available Antimony (Sb and copper (Cu are toxic heavy metals that are associated with a wide variety of minerals. Sb(III-oxidizing bacteria that convert the toxic Sb(III to the less toxic Sb(V are potentially useful for environmental Sb bioremediation. A total of 125 culturable Sb(III/Cu(II-resistant bacteria from 11 different types of mining soils were isolated. Four strains identified as Arthrobacter, Acinetobacter and Janibacter exhibited notably high minimum inhibitory concentrations (MICs for Sb(III (>10 mM,making them the most highly Sb(III-resistant bacteria to date. Thirty-six strains were able to oxidize Sb(III, including Pseudomonas-, Comamonas-, Acinetobacter-, Sphingopyxis-, Paracoccus- Aminobacter-, Arthrobacter-, Bacillus-, Janibacter- and Variovorax-like isolates. Canonical correspondence analysis (CCA revealed that the soil concentrations of Sb and Cu were the most obvious environmental factors affecting the culturable bacterial population structures. Stepwise linear regression was used to create two predictive models for the correlation between soil characteristics and the bacterial Sb(III or Cu(II resistance. The concentrations of Sb and Cu in the soil was the significant factors affecting the bacterial Sb(III resistance, whereas the concentrations of S and P in the soil greatly affected the bacterial Cu(II resistance. The two stepwise linear regression models that we derived are as follows: MIC(Sb(III=606.605+0.14533 x C(Sb+0.4128 x C(Cu and MIC((Cu(II=58.3844+0.02119 x C(S+0.00199 x CP [where the MIC(Sb(III and MIC(Cu(II represent the average bacterial MIC for the metal of each soil (μM, and the C(Sb, C(Cu, C(S and C(P represent concentrations for Sb, Cu, S and P (mg/kg in soil, respectively, p<0.01]. The stepwise linear regression models we developed suggest that metals as well as other soil physicochemical parameters can contribute to bacterial resistance to metals.

  9. Growth, photosynthesis, and defense mechanism of antimony (Sb)-contaminated Boehmeria nivea L.

    Science.gov (United States)

    Chai, Li-Yuan; Mubarak, Hussani; Yang, Zhi-Hui; Yong, Wang; Tang, Chong-Jian; Mirza, Nosheen

    2016-04-01

    Ramie (Boehmeria nivea L.) is the oldest cash fiber crop in China and is widely grown in antimony (Sb) mining areas. To evaluate the extent of Sb resistance and tolerance, the growth, tolerance index (TI), Sb content in plant parts and in Hoagland solution, bioaccumulation factor (BF), photosynthesis, and physiological changes in Sb-contaminated B. nivea (20, 40, 80, and 200 mg L(-1) Sb) grown hydroponically were investigated. The Sb tolerance and resistance of ramie were clearly revealed by growth inhibition, a TI between 13 and 99 %, non-significant changes in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (photosystem II (PSII)) and single-photon avalanche diode (SPAD) value, a significant increase in Sb in plant parts, BF >1, and an increase in catalase (CAT) and malondialdehyde (MDA) at 200 mg L(-1) Sb. Under increasing Sb stress, nearly the same non-significant decline in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (PSII), relative quantum yield of photosystem II (φPSII), and photochemical quenching (qP), except for F v /F m at 20 mg L(-1) Sb, were recorded. SPAD values for chlorophyll under Sb stress showed an increasing trend, except for a slight decrease, i.e., continuous increase in MDA, superoxide dismutase (SOD), peroxidase (POD), and CAT activities were suppressed under Sb addition up to 40 mg L(-1) Sb and the addition of Sb enhanced enzyme production at 80 and 200 mg L(-1) Sb. A continuous decrease in SOD, POD, and CAT up to 40 mg L(-1) Sb and enhancements at ≥80 mg L(-1), along with the continuous enhancement of MDA activity and inhibited biomass production, clearly reveal the roles of these enzymes in detoxifying Sb stress and the defense mechanism of ramie at 80 mg L(-1) Sb. Thus, B. nivea constitutes a promising candidate for Sb phytoremediation at mining sites. PMID:26711292

  10. Green and red fluorescence upconversion in neodymium-doped low phonon antimony glasses

    Energy Technology Data Exchange (ETDEWEB)

    Som, Tirtha [Glass Technology Laboratory, Central Glass and Ceramic Research Institute (Council of Scientific and Industrial Research), 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Karmakar, Basudeb [Glass Technology Laboratory, Central Glass and Ceramic Research Institute (Council of Scientific and Industrial Research), 196 Raja S.C. Mullick Road, Kolkata 700032 (India)], E-mail: basudebk@cgcri.res.in

    2009-05-12

    A new K{sub 2}O-B{sub 2}O{sub 3}-Sb{sub 2}O{sub 3} (KBS) glass system having low phonon energy (about 600 cm{sup -1}) doped with Nd{sup 3+} ions has been developed. Infrared reflection spectroscopic (IRRS) studies have been employed to establish its low phonon energy. Ultraviolet-visible-near infrared (UV-vis-NIR) absorption and photoluminescence upconversion properties with special emphasis on the spectrochemistry of the 15K{sub 2}O-15B{sub 2}O{sub 3}-70Sb{sub 2}O{sub 3} (mol%) glass have been studied doping with different concentrations (0.1-1.0 wt%) of Nd{sub 2}O{sub 3}. UV-vis-NIR absorption band positions have been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 805 nm at room temperature. Two upconverted bands originating from the {sup 4}G{sub 7/2} {yields} {sup 4}I{sub 9/2} and {sup 4}G{sub 7/2} {yields} {sup 4}I{sub 13/2} transitions are found to be centered at 540 nm (green, medium) and 650 nm (red, strong), respectively. These bands have been explained from the evaluation of the absorption and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET), cooperative energy transfer (CET) and cross-relaxation (CR) mechanisms involving population of the metastable (storage) energy level ({sup 4}G{sub 7/2}) by effects of multiphonon deexcitation and thermal population. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in antimony glasses owing to their low phonon energy (602 cm{sup -1}, the main and highest intensity Sb-O-Sb stretching band) which is very close to that of fluoride glasses (500-600 cm{sup -1})

  11. Novel organo-colloidal synthesis, optical properties, and structural analysis of antimony sesquioxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Validzic, Ivana Lj., E-mail: validzic@vinca.rs; Abazovic, Nadica D.; Mitric, Miodrag [University of Belgrade, ' Vinca' Institute of Nuclear Sciences (Serbia); Lalic, Milan V. [Universidade Federal de Sergipe, Departamento de Fisica (Brazil); Popovic, Zoran S. [University of Belgrade, ' Vinca' Institute of Nuclear Sciences (Serbia); Vukajlovic, Filip R. [' Vinca' Institute of Nuclear Sciences (Serbia)

    2013-01-15

    We report the novel colloidal syntheses in organic media of antimony sesquioxide ( Sb{sub 2}O{sub 3} ) spherical nanoparticles (30-250 nm) and octahedron micro- and nanocrystals (100nm - 4{mu}) depending on the synthetic method conditions. It is observed that small differences in the synthetic procedure cause large differences in the very changeable morphology. The structure of Sb{sub 2}O{sub 3} powders was refined down to the R-factors of 9.57, 7.44, 9.19, 9.78, and 8.30 %. The refinement showed that Sb{sub 2}O{sub 3} powder belongs to the cubic crystal type with space group Fd 3-bar m (No. 227). The values of estimated standard deviations, as well as reliability factors, confirmed that the structure of Sb{sub 2}O{sub 3} was well refined. Ultraviolet and visible (UV-Vis) absorption spectroscopy and diffuse reflectance measurements (DRS) reveal that the optical band gap energies found for the Sb{sub 2}O{sub 3} octahedrons and nanoparticles, micro- and nanocrystals, respectively, are quite independent of the synthetic method conditions and synthesized morphology and is found to be between 4.1-4.4 eV. No peaks in both photoluminescence (PL) emission and excitation spectra have been observed for a broad spectral range, typical for this material. In order to discriminate between conflicting experimental results concerning the band gap energy of this compound, we investigated theoretically the electronic structure and optical properties of one of the cubic sesquioxide Sb{sub 2}O{sub 3} samples synthesized here. This has been done on the basis of density functional theory (DFT) with the generalized gradient approximation (GGA) and improved version of exchange potential suggested recently by Tran and Blaha (TB-mBJ). The main characteristic of the calculated TB-mBJ electronic structure is the significant improvement of the band gap value, which is in perfect agreement with our experimental measurements. The real and imaginary parts of the dielectric tensor are also

  12. Real-world emission factors for antimony and other brake wear related trace elements: size-segregated values for light and heavy duty vehicles.

    Science.gov (United States)

    Bukowiecki, Nicolas; Lienemann, Peter; Hill, Matthias; Figi, Renato; Richard, Agnes; Furger, Markus; Rickers, Karen; Falkenberg, Gerald; Zhao, Yongjing; Cliff, Steven S; Prevot, Andre S H; Baltensperger, Urs; Buchmann, Brigitte; Gehrig, Robert

    2009-11-01

    Hourly trace element measurements were performed in an urban street canyon and next to an interurban freeway in Switzerland during more than one month each, deploying a rotating drum impactor (RDI) and subsequent sample analysis by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). Antimony and other brake wear associated elements were detected in three particle size ranges (2.5-10, 1-2.5, and 0.1-1 microm). The hourly measurements revealed that the effect of resuspended road dust has to be taken into account for the calculation of vehicle emission factors. Individual values for light and heavy duty vehicles were obtained for stop-and-go traffic in the urban street canyon. Mass based brake wear emissions were predominantly found in the coarse particle fraction. For antimony, determined emission factors were 11 +/- 7 and 86 +/- 42 microg km(-1) vehicle(-1) for light and heavy duty vehicles, respectively. Antimony emissions along the interurban freeway with free-flowing traffic were significantly lower. Relative patterns for brake wear related elements were very similar for both considered locations. Beside vehicle type specific brake wear emissions, road dust resuspension was found to be a dominant contributor of antimony in the street canyon. PMID:19924925

  13. Synthesis and Properties of Light-tolerant Organic Antimony%耐光型有机锑的合成及其性能研究

    Institute of Scientific and Technical Information of China (English)

    高勇; 韩永和; 李建丰; 袁余斌; 王爱红

    2014-01-01

    硫醇锑稳定剂由于其耐紫外光性能很差,在存储、运输和使用方面受到很大的限制。为解决这一问题,试探性以三氯化锑和巯基酯为原料,引入抗紫外线活性基团TBP-1(2,4-二羟基二苯甲酮),合成了“晒不黑”的有机锑热稳定剂。用红外光谱对产品结构进行了确认,光敏性实验表明其7周内不变色;静态热稳定性实验结果表明其与硫醇锑热稳定剂相当。%Because of its poor ultraviolet resistance , the storage , transportation and use of antimony mercaptide stabilizer was greatly limited.In order to solve this problem , a kind of synthesized organic antimony thermal stabilizer was prepared, which was light -tolerant with antimony trichloride , isooctyl thioglycollat as raw materials and TBP -1(2,4-dihydroxybenzophenone ) , with an anti-ultraviolet agent added in.The light-tolerant performance and thermal stability of product tested showed that the color of organic antimony as -synthesized was unchangeable when under the impact of direct sunlight for 7 weeks by infrared spectroscopy spectrum that was confirmed for structure of product , and the static experimental results showed that the thermal stability was nearly equivalent to antimony mercaptide.

  14. The chemistry and behaviour of antimony in the soil environment with comparisons to arsenic: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Susan C., E-mail: swilso24@une.edu.a [School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 (Australia); Lockwood, Peter V., E-mail: peter.lockwood@une.edu.a [School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 (Australia); Ashley, Paul M., E-mail: pashley@une.edu.a [School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 (Australia); Tighe, Matthew, E-mail: mtighe2@une.edu.a [School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 (Australia)

    2010-05-15

    This article provides a critical review of the environmental chemistry of inorganic antimony (Sb) in soils, comparing and contrasting findings with those of arsenic (As). Characteristics of the Sb soil system are reviewed, with an emphasis on speciation, sorption and phase associations, identifying differences between Sb and As behaviour. Knowledge gaps in environmentally relevant Sb data for soils are identified and discussed in terms of the limitations this imposes on understanding the fate, behaviour and risks associated with Sb in environmental soil systems, with particular reference to mobility and bioavailability. - A critical and comparative review of Sb and As chemistry and associations in soil systems identifies research directions needed for better understanding of risks.

  15. Photoelectron imaging as a probe of the repulsive Coulomb barrier in the photodetachment of antimony tartrate dianions

    Science.gov (United States)

    West, Christopher W.; Bull, James N.; Woods, David A.; Verlet, Jan R. R.

    2016-02-01

    A photoelectron imaging study of the text-book antimony tartrate dianion is presented. The vertical and adiabatic detachment energies are determined to be 2.5 ± 0.1 eV and 2.1 ± 0.2 eV, respectively. The photoelectron spectra exhibit a typical cut-off due to the presence of the repulsive Coulomb barrier (RCB) and the photoelectron images are highly anisotropic. Using a simple model for the RCB combined with classical molecular dynamics simulations, the photoelectron images were calculated and compared with experiment. Very good overall agreement between the simulations and experiments was achieved when the photodetachment occurs along a specific molecular axis.

  16. Improving the photoluminescence properties of self-assembled InAs surface quantum dots by incorporation of antimony

    International Nuclear Information System (INIS)

    This study investigates the effects of surfactant and segregation from InAs surface quantum dots (SQDs) by incorporating antimony (Sb) into the QD layers. The Sb surfactant effect extends planar growth and suppresses dot formation. Incorporating Sb can reduce the density of SQDs by more than two orders of magnitude. Photoluminescence (PL) reveals enhancement in the optical properties of InAs SQDs as the Sb beam equivalent pressure (BEP) increases. This improvement is caused by the segregation of Sb on the surface of SQDs, which reduces non-radiative recombination and suppresses carrier loss. The dark line at the SQDs surface in the transmission electron microscopic image suggests that the incorporated Sb probably segregates close to the surface of the SQDs. These results indicate a marked Sb segregation effect that can be exploited to improve the surface-sensitive properties of SQDs for biological sensing.

  17. Pb-Sb and Pb-Sb-Bi sulfosalts and associated sulphides from Dubrava antimony deposit, Nizke Tatry Mts

    International Nuclear Information System (INIS)

    A sulfosalt study was carried out on an antimony deposit Dubrava in Western Carpathians, Slovakia. Quartz-sulphide veins are hosted by Variscan crystalline complex built by granitoid rocks with lenticular bodies of amphibolite gneisses and migmatites. Pb-Sb sulfosalts are constituents of Sb ores and occur together with stibnite, sphalerite, pyrite and other sulphides. Among the sulfosalts, identified by X-ray micro-analyses, the most abundant one is zinckenite. Other phases are chemically close to plagionite, robinsonite, heteromorphite, semseyite and boulangerite. Sulfosalts richter in Bi accompany later tetrahedrite, bournonite and chalcostibite. These include tintinaite (kobellite homologous series) and Bi zinckenite. Intermediate phases between stibnite and bismuthinite, referred to as horobetsuite, are also common. (authors)

  18. Conjugative plasmid in Corynebacterium flaccumfaciens subsp. oortii that confers resistance to arsenite, arsenate, and antimony(III)

    Energy Technology Data Exchange (ETDEWEB)

    Hendrick, C.A.; Haskins, W.P.; Vidaver, A.K.

    1984-07-01

    Gene transfer systems for phytopathogenic corynebacteria have not been reported previously. In this paper a conjugative 46-megadalton plasmid (pDG101) found in Corynebacterium flaccumfaciens subsp. oorii CO101 is described that mediates resistance to arsenite, arsenate, and antimony(III). Transfer of the plasmid from CO101 to four other strains from the C. flaccumfaciens group occurred between cells immobilized on nitrocellulose filters or on agar surfaces. Transconjugant strains expressed the same levels of metal resistance as the donor strain and were able to act as donor strains in subsequent matings. The physical presence of the plasmid was detected by agarose gel electrophoresis. Arsenite-sensitive derivatives of the donor and transconjugant strains were obtained after heat treatment; these were cured of pDG101.

  19. Antimony orthophosphate glasses with large nonlinear refractive indices, low two-photon absorption coefficients, and ultrafast response

    International Nuclear Information System (INIS)

    Antimony glasses based on the composition Sb2O3-SbPO4 were prepared and characterized. The samples present high refractive index, good transmission from 380 to 2000 nm, and high thermal stability. The nonlinear refractive index, n2, of the samples was studied using the optical Kerr shutter technique at 800 nm. The third-order correlation signals between pump and probe pulses indicate ultrafast response (2 was observed by adding lead oxide to the Sb2O3-SbPO4 composition. Large values of n2≅10-14 cm2/W and negligible two-photon absorption coefficients (smaller than 0.01 cm/GW) were determined for all samples. The glass compositions studied present appropriate figure-of-merit for all-optical switching applications

  20. Fabrication of superhydrophobic and heat-insulating antimony doped tin oxide/polyurethane films by cast replica micromolding.

    Science.gov (United States)

    Feng, Jie; Huang, Baoyuan; Zhong, Mingqiang

    2009-08-01

    A novel process for fabricating superhydrophobic and heat-insulating polymeric nanocomposite films was developed. Briefly, antimony doped tin oxide (ATO) nanoparticles that commonly endow coats heat-insulating and transparent functions were mixed into commercial waterborne polyurethane (WPU) suspensions to obtain ATO/WPU suspensions, which were then cast onto poly(dimethylsiloxane) (PDMS) stamps replicated from fresh lotus leaves. After being dried and peeled off from stamps, ATO/PU films with superhydrophobic surface and heat-insulating property were created, while PU films without ATO only showed high hydrophobicity. Scanning electron microscopy (SEM) imaging showed the surface of ATO/PU superhydrophobic films had unique micro- and nano-structures similar with those on the lotus leaf. On the contrary, no obvious nano-structures were found on the surface of pure PU films, demonstrating mixing functional nanoparticles into polymers is a necessary and feasible step in creating superhydrophobic and functional films by replica molding method. PMID:19394955

  1. Effects of Antimony Doping on Cu(In1-x,Gax)Se2 Thin Films and Solar Cells

    Science.gov (United States)

    Yatsushiro, Yuta; Nakakoba, Hiroya; Mise, Takahiro; Kobayashi, Taizo; Nakada, Tokio

    2012-10-01

    The effects of antimony (Sb) doping into Cu(In1-x,Gax)Se2 (CIGS) thin films and solar cells have been investigated. 10-50-nm-thick Sb thin layers were deposited onto Mo-coated sodalime glass (SLG) and SiOx-coated SLG substrates by vacuum evaporation. CIGS thin films were then deposited by a three-stage process at substrate temperatures of 450-550 °C. The grain growth of CIGS thin films was enhanced, and the open-circuit voltage and hence the conversion efficiency improved with the Sb doping when the SLG substrates were used. However, little or no effect was observed when the alkali barrier SiOx layer was deposited on SLG substrates. As a result, we found that Sb doping is beneficial for improving the cell performance when sodium exists simultaneously in CIGS layers.

  2. Antimony (SbIII) reduces growth, declines photosynthesis, and modifies leaf tissue anatomy in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Vaculík, Marek; Mrázová, Anna; Lux, Alexander

    2015-12-01

    The role of antimony (Sb)--a non-essential trace metalloid--in physiological processes running in crops is still poorly understood. Present paper describes the effect of Sb tartrate (SbIII) on growth, Sb uptake, photosynthesis, photosynthetic pigments, and leaf tissue organization in young sunflower plants grown in hydroponics. We found that growth of below- and aboveground part was reduced with increasing concentration of Sb in the medium. Although Sb was mostly taken up by sunflower roots and only small part (1-2%) was translocated to the shoots, decline in photosynthesis, transpiration, and decreased content of photosynthetic pigments were observed. This indicates that despite relatively low mobility of Sb in root-shoot system, Sb in shoot noticeably modifies physiological status and reduced plant growth. Additionally, leaf anatomical changes indicated that Sb reduced the size of intercellular spaces and made leaf tissue more compact. PMID:26194244

  3. The chemistry and behaviour of antimony in the soil environment with comparisons to arsenic: A critical review

    International Nuclear Information System (INIS)

    This article provides a critical review of the environmental chemistry of inorganic antimony (Sb) in soils, comparing and contrasting findings with those of arsenic (As). Characteristics of the Sb soil system are reviewed, with an emphasis on speciation, sorption and phase associations, identifying differences between Sb and As behaviour. Knowledge gaps in environmentally relevant Sb data for soils are identified and discussed in terms of the limitations this imposes on understanding the fate, behaviour and risks associated with Sb in environmental soil systems, with particular reference to mobility and bioavailability. - A critical and comparative review of Sb and As chemistry and associations in soil systems identifies research directions needed for better understanding of risks.

  4. Synthesis and characterization of nanostructured Mn(II) doped antimony-tin oxide (ATO) films on glass

    International Nuclear Information System (INIS)

    Sol–gel Mn(II) doped antimony tin oxide films were developed with precursor of atomic ratio range, Sn:Sb:Mn = 68–72:23–25:9–3. The X-ray diffraction patterns depict tetragonal cassiterite phase of SnO2. Transmission electron microscopy images suggest the nanostructured form of the doped materials. The increase in crystallite size with Mn(II) concentration is reflected by the larger band gap values (4.61–4.73 eV) arising from the excitonic transitions which also respond to PL emissions. Hall effect measurements show that the carrier concentration increases but mobility decreases for Mn(II) doping. Room temperature ferromagnetism with different saturation magnetic moments (Ms) has been observed for all dopant concentrations, 3–9 at%.

  5. Novel antimony-silicate material Quasar-n for the removal of radionuclides from acidic decontamination liquids - 16157

    International Nuclear Information System (INIS)

    Novel antimony silicate material, commercially available from PQ Corporation (previously Ineos Silicas) is highly selective for the removal of several key radionuclides (Co-60, Sr-90, Cs-137, Pu-236 and Am-241) from acidic and neutral nuclear waste effluents. The paper will summarise most the key results that have been obtained in the previous studies of the material. In addition, new test results on the removal Co-60, Sr-90, Cs-137 and Am-241 from acid media are reported. Static batch experiments and column experiments show that Am can be removed efficiently from nitric and oxalic acid, indicating that Quasar is suitable e.g. for the purification of acidic decontamination solutions. (authors)

  6. lVIICROSTRUCTURE AND EUTECTIC MORPHOLOGY OF AL-12.5°/o Si ALLOY REFINED WITH ANTIMONY

    Directory of Open Access Journals (Sweden)

    Funda Kahraman

    2007-01-01

    Full Text Available Modification of Al-Si cast alloys can be achieved in two different ways, namely by additions of certain eleınents orwith rapid cooling rate. Modifications of the Al-Si al1oys are carried out extensivcly in industry to improve themechanical properties, particularly ductility. In this study, the effects of antiınony addition.s and growth rate on theınicrostructure and eutectic morphology on the directionally solidified Al- 1 2.5°/o Si cutectic all oy has beeninvestigated. The results showed that antimony can be identified as a grain refıner. Over modification occurs in Al-12.5 °/oSi alloy when modifier is present in the amount of 1 %Sb results in AISb compound.

  7. Enhanced Removal of Arsenic and Antimony in the Mining Site by Calcined γ-Fe2O3/Layered Double Hydroxide Nanocomposite

    Science.gov (United States)

    Lee, Sang-Ho; Choi, Heechul; Kim, Kyoung-Woong

    2016-04-01

    Arsenic (As) and Antimony (Sb) have been recognized as harmful contaminants in aquatic environment due to its high toxicity and carcinogenicity. Especially, the contamination of arsenic in the mining areas is considered as a serious emerging environmental issue in Korea. Due to the hazardous effect of arsenic, the United States Environmental Protection Agency (US EPA) regulated maximum contamination level of arsenic to 10 μg/L in drinking water. The harmful effect on human health by excessive intake of antimony was also reported by previous studies, and severe contamination level (100 - 7,000 μg/L) of antimony reported in surface and groundwater of abandoned mining area in China and Slovakia. Therefore, US EPA regulated maximum contaminants level of antimony in drinking water to 6 μg/L. In order to remove anionic contaminants in drinking water, various type of nanomaterials have been developed. Layered double hydroxide (LDH) is the artificial anionic clay that is based on the layered structure of positively charged brucite-like layers with interlayers of anions. The LDH is one of the promising nanomaterials for the removal of anionic contaminants because it has high selectivity for arsenic, phosphate, chromium and antimony. However, the biggest problem of LDH for wastewater treatment is that the particles cannot be easily separated after the removal of contaminants. In this study, magnetic nanoparticles (γ-Fe2O3) supported LDH nanocomposite (γ-Fe2O3/LDH) was investigated to enhance magnetic particle recovery and removal efficiency for arsenic and antimony. The calcined γ-Fe2O3/LDH nanocomposites synthesized by co-precipitation method, and the crystallographic properties of maghemite (γ-Fe2O3) and layered structure of LDH were confirmed by X-ray diffraction. The nano-sized γ-Fe2O3 (30 to 50 nm) was stably attached on the surface of LDH (100 to 150 nm) and O1s spectrum by X-ray photoelectron spectroscopy (XPS) explained that there are both physical and

  8. Growth and Characterization of Co-Doped Fluorine and Antimony in Tin Oxide Thin Films Obtained by Ultrasonic Spray Pyrolysis

    Science.gov (United States)

    Gaewdang, Thitinai; Wongcharoen, Ngamnit

    Fluorine (F)-doped, antimony (Sb)-doped, fluorine and antimony co-doped tin oxide (SnO2) thin films were prepared by ultrasonic spray pyrolysis technique using SnCl2, NH4F and SbCl3 as precursors of Sn, F and Sb elements respectively. F and Sb doping concentrations carried out from 1 to 20 wt% and 1 to 4 wt% in F-doped and Sb-doped SnO2 films respectively. In F and Sb co-doped SnO2 films, the proportions of F and Sb to Sn in starting solution were 15 and 2 wt% respectively. XRD patterns showed that the preferred orientation of SnO2:F, SnO2:Sb and SnO2:F, Sb is dependent on the doping concentration. The variation of doping concentration and preferred orientation of the films was reflected in their morphology as investigated by SEM. The electrical properties of the films were performed by Hall effect measurements in van der Pauw configuration. The minimum resistivity values of SnO2:F and SnO2:Sb were found in the films doped with 15 wt% of F and 2 wt% of Sb. However, The minimum of resistivity value of F and Sb co-doped SnO2 films is not better than neither the one of F-doped nor the one of Sb-doped SnO2 films. The optical transmission of SnO2:F films was found to increase with increasing in F doping concentration. Whereas the optical transmission of SnO2:Sb was found to decrease with increasing in Sb concentration. The F and Sb co-doped SnO2 films annealed in three different conditions at 500°C show the lower transmission values than the value obtained in the as-prepared SnO2:F, Sb films.

  9. One-step synthesis and properties of monolithic photoluminescent ruby colored cuprous oxide antimony oxide glass nanocomposites

    International Nuclear Information System (INIS)

    Research highlights: → Single-step synthesis of Cu2O, CuySb2-x(O,OH)6-7 (y ≤ 2, x ≤ 1) and Cu nanocrystals co-doped novel antimony oxide glass hybrid nanocomposites. → Yellow and orange colored nanocomposites shows size-controlled band gap shift of Cu2O. → Red nanocomposite exhibits surface plasmon resonance band due to metallic Cu. → They exhibit broad deep-red photoluminescence emission under various UV excitation wavelengths. - Abstract: Cuprous oxide (Cu2O) antimony glass (K2O-B2O3-Sb2O3) monolithic nanocomposites having brilliant yellow to ruby red color have been synthesized by a single-step melt-quench technique involving in situ thermochemical reduction of Cu2+ (CuO) by the reducing glass matrix without using any external reducing agent. The X-ray diffraction (XRD), infrared transmission and reflection spectra, and selected area electron diffraction analysis support the reduction of Cu2+ to Cu+ with the formation of Cu2O nanoclusters along with CuySb2-x(O,OH)6-7 (y ≤ 2, x ≤ 1) nanocrystalline phases while Cu0 nanoclusters are formed at very high Cu concentration. The UV-vis spectra of the yellow and orange colored nanocomposites show size-controlled band gap shift of the semiconductor (Cu2O) nanocrystallites embedded in the glasses while the red nanocomposite exhibits surface plasmon resonance band at 529 nm due to metallic Cu. Transmission electron microscopic image advocates the formation of nanocystallites (5-42 nm). Photoluminescence emission studies show broad red emission band around 626 nm under various excitation wavelengths from 210 to 270 nm.

  10. Fabrication and excellent conductive performance of antimony-doped tin oxide-coated diatomite with porous structure

    Energy Technology Data Exchange (ETDEWEB)

    Du Yucheng, E-mail: ychengdu@bjut.edu.cn [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Yan Jing; Meng Qi; Wang Jinshu [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Dai Hongxing, E-mail: hxdai@bjut.edu.cn [Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

    2012-04-16

    Graphical abstract: Antimony-doped tin oxide (ATO)-coated diatomite with porous structures are fabricated using the co-precipitation method. The porous ATO-coated diatomite material shows excellent conductive performance. Highlights: Black-Right-Pointing-Pointer Sb-doped SnO{sub 2} (ATO)-coated diatomite materials with porous structures are prepared. Black-Right-Pointing-Pointer Sn/Sb ratio, ATO coating amount, pH value, and temperature influence resistivity. Black-Right-Pointing-Pointer Porous ATO-coated diatomite materials show excellent conductive performance. Black-Right-Pointing-Pointer The lowest resistivity of the porous ATO-coated diatomite sample is 10 {Omega} cm. - Abstract: Diatomite materials coated with antimony-doped tin oxide (ATO) were prepared by the co-precipitation method, and characterized by means of the techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, X-ray fluorescence spectroscopy, and N{sub 2} adsorption-desorption measurement. It was shown that the coated ATO possessed a tetragonal rutile crystal structure, and the ATO-coated diatomite materials had a multi-pore (micro- meso-, and macropores) architecture. The porous ATO-coated diatomite materials exhibited excellent electrical conductive behaviors. The best conductive performance (volume resistivity = 10 {Omega} cm) was achieved for the sample that was prepared under the conditions of Sn/Sb molar ratio = 5.2, Sn/Sb coating amount = 45 wt%, pH = 1.0, and reaction temperature = 50 Degree-Sign C. Such a conductive porous material is useful for the applications in physical and chemical fields.

  11. Synthesis and characterization of a novel mesoporous silica funtionalized whith [1,5 bis (di-2-pyridyl) methylene thiocarbohydrazide] and its application as enrichment sorbent for determination of antimony by FI-HG-ETAAS

    OpenAIRE

    Siles Cordero, María Teresa; López Guerrero, María del Mar; Vereda Alonso, Elisa Isabel; García de Torres, Amparo; Cano Pavón, José Manuel

    2014-01-01

    Antimony is an element of environmental concern due to its toxicity and biological effects and is therefore considered as a priority pollutant by the US Environmental Protection Agency (EPA). Dissolved antimony is present in seawater at very low concentration levels, typical concentrations of Sb in unpolluted water samples are less than 1 µg L-1. Since the concentration of this element in water is very low, high sensitive analytical techniques are required, The system is based on retent...

  12. Highly active and stable Pt electrocatalysts promoted by antimony-doped SnO2 supports for oxygen reduction reactions

    DEFF Research Database (Denmark)

    Yin, Min; Xu, Junyuan; Li, Qingfeng; Jensen, Jens Oluf; Huang, Yunjie; Cleemann, Lars Nilausen; Bjerrum, Niels J.; Xing, Wei

    2014-01-01

    composite supports, which limited the mass activity of the supported catalysts. When the ATO composites were used as supports, the Pt/C-ATO catalysts showed significantly enhanced catalytic activity and durability for the ORR, attributable to the high ECSA and modified electronic structure of Pt by the ATO......Alternative composite supports for platinum catalysts were synthesized from antimony doped tin dioxide (ATO) nanoparticles. In the range of the antimony content from 0 to 11mol%, the highest electrical conductivity of 1.1Scm-1 at 130°C was obtained for the 5mol% Sb ATO, from which composite...... supports composed of oxides and carbon and supported platinum catalysts were prepared. Using the pure oxide support, the Pt/ATO catalyst displayed superior specific activity and stability for the oxygen reduction reactions (ORRs). Low surface area of ATO caused poor dispersion of Pt particles compared to...

  13. Promoting the Hydrosilylation of Benzaldehyde by Using a Dicationic Antimony-Based Lewis Acid: Evidence for the Double Electrophilic Activation of the Carbonyl Substrate.

    Science.gov (United States)

    Hirai, Masato; Cho, Junsang; Gabbaï, François P

    2016-05-01

    The concomitant activation of carbonyl substrates by two Lewis acids has been investigated by using [1,2-(Ph2 MeSb)2 C6 H4 ](2+) ([1](2+) ), an antimony-based bidentate Lewis acid obtained by methylation of the corresponding distibine. Unlike the simple stibonium cation [Ph3 MeSb](+) , dication [1](2+) efficiently catalyzes the hydrosilylation of benzaldehyde under mild conditions. The catalytic activity of this dication is correlated to its ability to doubly activate the carbonyl functionality of the organic substrate. This view is supported by the isolation of [1-μ2 -DMF][OTf]2 , an adduct, in which the DMF oxygen atom bridges the two antimony centers. PMID:26934491

  14. Antimoniais empregados no tratamento da leishmaniose: estado da arte Antimonials employed in the treatment of leishmaniaisis: the state of the art

    OpenAIRE

    Susanne Rath; Luciano Augusto Trivelin; Talitha Rebecca Imbrunito; Daniela Maria Tomazela; Marcelo Nunes de Jesús; Percy Calvo Marzal; Heitor Franco de Andrade Junior; André Gustavo Tempone

    2003-01-01

    Antimony preparations are the drugs of choice for the treatment of leishmaniasis over 90 years, a disease that currently affects 12 million people worldwide. Its introduction was based on 19th century concepts of therapeutic effects of metal salts as arsenicals and other metals, most of them abandoned due to toxic effects or better drugs. In the last three decades, there was a great improvement in the knowledge of cell biology and immunology of those infections, but chemotherapy has not been ...

  15. Arsenic and antimony determination in refined and unrefined table salts by means of hydride generation atomic absorption spectrometry--comparison of sample decomposition and determination methods

    OpenAIRE

    AKSUNER, Nur; TİRTOM, Vedia Nüket; HENDEN, Emür

    2011-01-01

    An evaluation was made of different digestion methods for the determination of arsenic and antimony in table salt samples prior to hydride generation atomic absorption spectrometric analysis. Microwave acid digestion, classical wet digestion, dry ashing, and fusion were applied to the decomposition of salt samples and optimum conditions were investigated. Samples were decomposed by changing heating time, digestion techniques, and the amount and composition of acid, and then the concen...

  16. Decreased antimony uptake and overexpression of genes of thiol metabolism are associated with drug resistance in a canine isolate of Leishmania infantum

    OpenAIRE

    Verónica Gómez Pérez; Raquel García-Hernandez; Victoriano Corpas-López; Tomás, Ana M.; Joaquina Martín-Sanchez; Santiago Castanys; Francisco Gamarro

    2016-01-01

    Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania infantum, is one of the most important zoonotic diseases affecting dogs and humans in the Mediterranean area. The presence of infected dogs as the main reservoir host of L. infantum is regarded as the most significant risk for potential human infection. We have studied the susceptibility profile to antimony and other anti-leishmania drugs (amphotericin B, miltefosine, paromomycin) in Leishmania infantum isolates extracted...

  17. Antimony determination in seawater and pore water of marine sediments by means of coprecipitation with Mg(OH)2 and atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The study of biogeochemical cycling of trace elements in inshore marine environment is of basic importance in order to understand the long-term distribution of both conventional and radioactive pollutants among the ecosystem components. Antimony is of radio- ecological interest, and its determination in some environmental matrices (seawater, pore water, biota) is always difficult from the analytical point of view. A quick method for antimony determination in seawater and interstitial water of marine sediments, by coprecipitation with Mg(OH)2 and subsequent atomic absorption measurement, is reported. Coprecipitation recovery (about 80% in optimal conditions) was evaluated using both radiotracers and the addition of known amounts of stable element, and turned out to depend on several parameters (percentage of precipitated Mg as compared to the natural content in seawater, ageing of Mg(OH)2, concomitant Fe and Mn concentrations, etc.). The total standard deviation of the proposed method is about 10%. The variance analysis showed that about 90% of total variance is due to the preconcentration procedure (sample handling and random contaminations) and only about 10% is due to the instrumental measurement. The results of antimony determinations in seawater and pore water of marine sediments collected at Montalto di Castro (Central Mediterranean Sea) are presented and discussed

  18. Mobility and chemical fate of arsenic and antimony in water and sediments of Sarouq River catchment, Takab geothermal field, northwest Iran.

    Science.gov (United States)

    Sharifi, Reza; Moore, Farid; Keshavarzi, Behnam

    2016-04-01

    Arsenic (As) and antimony (Sb) concentrations in water and sediments were determined along flow paths in the Sarouq River, Zarshuran and Agh Darreh streams. The results indicate high As and Sb concentrations in water and sediment samples. Raman spectroscopy shows hematite (α-Fe2O3), goethite [α-FeO(OH)] and lepidocrocite [γ-FeO(OH)] in sediment samples. Calculated saturation indices (SI) indicate oversaturation with respect to amorphous Fe(OH)3 for all samples, but undersaturation with respect to Al and Mn mineral and amorphous phases. Therefore, ferric oxides and hydroxides are assumed to be principal mineral phases for arsenic and antimony attenuation by adsorption/co-precipitation processes. The considerable difference between As and Sb concentration in sediment is due to strong adsorption of As(V) into the solid phase. Also, lower affinity of Sb(V) for mineral surfaces suggests a greater potential for aqueous transport. The adsorption of arsenic and antimony was examined using the Freundlich adsorption isotherm to determine their distribution model in water-sediment system and its compatibility with the existing theoretical model. The results showed that the adsorption behavior of both elements complies with the Freundlich adsorption isotherm. PMID:26820974

  19. Synthesis and properties of crystalline thin film of antimony trioxide on the Si(1 0 0) substrate

    International Nuclear Information System (INIS)

    Highlights: • Formation of crystalline phase of Sb2O3 on Si(1 0 0) is demonstrated. • STM and STS characterizations of the grown Sb2O3 film are presented. • STS results elucidate the band gap of Sb2O3. • Ab initio calculations reveal energetically favored Sb2O3 surface structures. - Abstract: Atomic-scale understanding and processing of the surface and interface properties of antimony trioxide (Sb2O3) are essential to the development of nanoscale Sb2O3 materials for various applications, such as photocatalysts, transparent conducting oxides, optical coatings, dielectric films, and fire retardants. Lack of atomically well-defined, crystalline Sb2O3 templates has however hindered atomic resolution characterization of the Sb2O3 properties. We report the preparation of crystalline Sb2O3 thin films on the Si(1 0 0) substrate with a simple process by oxidizing Sb-covered Si(1 0 0) in proper conditions. Physical properties of the synthesized films have been elucidated by low-energy electron diffraction, scanning tunneling microscopy and spectroscopy, and ab initio calculations. The spectroscopic results show that the band gap of Sb2O3 is 3.6 eV around the gamma point (i.e. Γ). Calculations reveal energetically favored Sb2O3(1 0 0) surface structures. The findings open a new path for the atomic-scale research of Sb2O3

  20. Synchronous Improvement of Dispersibility and Electrical Property of Antimony Doped Tin Oxide Nanoparticles Processed by Polyvinyl Alcohol

    Science.gov (United States)

    Liu, Shimin; Wen, Bin; Jiang, Weiwei; Liu, Chaoqian; Ding, Wanyu; Wang, Nan; Chai, Weiping

    2015-08-01

    Antimony doped tin oxide (ATO) nanoparticles were prepared by wet chemical coprecipitation method with different contents of polyvinyl alcohol (PVA) dispersant. The prepared ATO nanoparticles have been characterized by means of XRD, SEM, HRTEM, SAED, EDS, bulk density and electrical resistivity measurement. Results indicated that the approach functionalized by PVA dispersant enables a synchronous improvement of two important properties namely the dispersibility and electrical conductivity due to the mechanism of avoiding the formation of agglomeration of nanoparticles, which could be regarded as primary factors for the enhanced electron transfer of powders: The surface area over which are crucial for the interfacial arrangement and electron charge scattering/transfer processes. The bulk density and electrical resistivity decreased to a minimum of 0.90 g/cm3 and 1.44 Ωṡcm at PVA dispersant content of 5%, and increased rapidly at higher PVA contents. The prepared ATO nanoparticles can serve as a kind of effective conductive filler in insulating species such as plastics, textile and rubber.

  1. Lithium intercalation in sputter deposited antimony-doped tin oxide thin films: Evidence from electrochemical and optical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Montero, J., E-mail: jose.montero@angstrom.uu.se; Granqvist, C. G.; Niklasson, G. A. [Department of Engineering Sciences, The A°ngström Laboratory, Uppsala University, P.O. Box 534, SE-751 21 Uppsala (Sweden); Guillén, C.; Herrero, J. [Department of Energy, Ciemat, Avda. Complutense 40, Ed. 42, E-28040 Madrid (Spain)

    2014-04-21

    Transparent conducting oxides are used as transparent electrical contacts in a variety of applications, including in electrochromic smart windows. In the present work, we performed a study of transparent conducting antimony-doped tin oxide (ATO) thin films by chronopotentiometry in a Li{sup +}-containing electrolyte. The open circuit potential vs. Li was used to investigate ATO band lineups, such as those of the Fermi level and the ionization potential, as well as the dependence of these lineups on the preparation conditions for ATO. Evidence was found for Li{sup +} intercalation when a current pulse was set in a way so as to drive ions from the electrolyte into the ATO lattice. Galvanostatic intermittent titration was then applied to determine the lithium diffusion coefficient within the ATO lattice. The electrochemical density of states of the conducting oxide was studied by means of the transient voltage recorded during the chronopotentiometry experiments. These measurements were possible because, as Li{sup +} intercalation took place, charge compensating electrons filled the lowest part of the conduction band in ATO. Furthermore, the charge insertion modified the optical properties of ATO according to the Drude model.

  2. Antimony segregation in Ge and formation of n-type selectively doped Ge films in molecular beam epitaxy

    International Nuclear Information System (INIS)

    Antimony segregation in Ge(001) films grown by molecular beam epitaxy was studied. A quantitative dependence of the Sb segregation ratio in Ge on growth temperature was revealed experimentally and modeled theoretically taking into account both the terrace-mediated and step-edge-mediated segregation mechanisms. A nearly 5-orders-of-magnitude increase in the Sb segregation ratio in a relatively small temperature range of 180–350 °C was obtained, which allowed to form Ge:Sb doped layers with abrupt boundaries and high crystalline quality using the temperature switching method that was proposed earlier for Si-based structures. This technique was employed for fabrication of different kinds of n-type Ge structures which can be useful for practical applications like heavily doped n+-Ge films or δ-doped layers. Estimation of the doping profiles sharpness yielded the values of 2–5 nm per decade for the concentration gradient at the leading edge and 2–3 nm for the full-width-half-maximum of the Ge:Sb δ-layers. Electrical characterization of grown Ge:Sb structures revealed nearly full electrical activation of Sb atoms and the two-dimensional nature of charge carrier transport in δ-layers

  3. Profiling microbial community in a watershed heavily contaminated by an active antimony (Sb) mine in Southwest China.

    Science.gov (United States)

    Sun, Weimin; Xiao, Enzong; Dong, Yiran; Tang, Song; Krumins, Valdis; Ning, Zengping; Sun, Min; Zhao, Yanlong; Wu, Shiliang; Xiao, Tangfu

    2016-04-15

    Located in Southwest China, the Chahe watershed has been severely contaminated by upstream active antimony (Sb) mines. The extremely high concentrations of Sb make the Chahe watershed an excellent model to elucidate the response of indigenous microbial activities within a severe Sb-contaminated environment. In this study, water and surface sediments from six locations in the Chahe watershed with different levels of Sb contamination were analyzed. Illumina sequencing of 16S rRNA amplicons revealed more than 40 phyla from the domain Bacteria and 2 phyla from the domain Archaea. Sequences assigned to the genera Flavobacterium, Sulfuricurvum, Halomonas, Shewanella, Lactobacillus, Acinetobacter, and Geobacter demonstrated high relative abundances in all sequencing libraries. Spearman's rank correlations indicated that a number of microbial phylotypes were positively correlated with different speciation of Sb, suggesting potential roles of these phylotypes in microbial Sb cycling. Canonical correspondence analysis further demonstrated that geochemical parameters, including water temperature, pH, total Fe, sulfate, aqueous Sb, and Eh, significantly structured the overall microbial community in Chahe watershed samples. Our findings offer a direct and reliable reference to the diversity of microbial communities in the presence of extremely high Sb concentrations, and may have potential implications for in situ bioremediation strategies of Sb contaminated sites. PMID:26820933

  4. A novel voltammetric sensor based on carbon nanotubes and nanoparticles of antimony tin oxide for the determination of ractopamine.

    Science.gov (United States)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-02-01

    An electrochemical sensor was prepared by the modification of a glassy carbon electrode (GCE) with carbon nanotubes (CNTs) and nanoparticles of antimony tin oxide (ATO). The surface layer was characterized by scanning electronmicroscopy (SEM), energy dispersive X-ray diffraction method (EDX) and ATR FT-IR spectroscopy. The proposed electrode was assessed in respect to the electro-oxidation of ractopamine. Compared with a bare GCE and a GCE electrode modified with CNTs, the ATONPs/CNTs/GCE exhibited a great catalytic activity towards the oxidation of ractopamine with a well-defined anodic peak at 600 mV. The current response was linear with the concentration of ractopamine over the range from 10 to 240 nM with a detection limit of 3.3 nM. The proposed electrode enabled the selective determination of ractopamine in the presence of high concentrations of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The proposed electrode was successfully applied for the determination of ractopamine in feed and urine samples. The sensitive and selective determination of ractopamine makes the developed method of great interest for monitoring its therapeutic use and doping control purposes. PMID:26652385

  5. Effect of Vanadium and Titanium substitution over an antimony-based mixed oxide catalysts for propane ammoxidation to acrylonitrile

    International Nuclear Information System (INIS)

    Antimony (Sb) oxide is known to be the active phase for the ammoxidation of propane to acrylonitrile (ACN). The influenced of V and/ or Ti on the physicochemical properties of Sb-based mixed oxide catalysts were studied using catalysts prepared by slurry method. The dried precursor was calcined in air at 350-600 degree Celsius for a total of 10 h. The active phases in Sb-promoted catalysts were determined using X-ray Diffraction (XRD) while the changes in microstructure of these catalysts were studied using physical adsorption of nitrogen gas. The catalytic activities of these catalysts were tested in a fixed-bed reactor with online GC at 420 degree Celsius with reaction feed (% v) of 5.8:7:17.4 for propane, ammonia and oxygen, respectively. Results show that promotional of Sb with V and/ or Ti has an effect on the chemical environment of the Sb-mixed oxide catalysts, leading to differences in catalytic activity of these catalysts. (author)

  6. Quadrupole coupling constants and isomeric Moessbauer shifts for halogen-containing gold, platinum, niobium, tantalum and antimony compounds

    International Nuclear Information System (INIS)

    We have analyzed by means of Density functional theory calculations the nuclear quadrupole coupling constants of a range of gold, antimony, platinum, niobium and tantalum compounds. The geometrical parameters and halogen nuclear quadrupole coupling constants obtained by these calculations substantially corresponded to the data of microwave and nuclear quadrupole resonance spectroscopy. An analysis of the quality of the calculations that employ pseudo-potentials and all-electron basis sets for the halogen compounds was carried out. The zero order regular approximation (ZORA) method is shown to be a viable alternative for the calculation of halogen coupling constants in molecules. In addition, the ZORA model, in contrast to the pseudo-potential model, leads to realistic values of all metal nuclear quadrupole coupling constants. From Klopman's approach, it follows that the relationship between the electrostatic bonding and covalent depends on the nature of the central atom. The results on Moessbauer chemical shifts are also in a good agreement with the coordination number of the central atom.

  7. Quantitative study of the effect of deposition temperature on antimony incorporation in InAs/InAsSb superlattices

    Science.gov (United States)

    Haugan, H. J.; Mahalingam, K.; Szmulowicz, F.; Brown, G. J.

    2016-02-01

    InAs/InAsSb superlattices (SLs) are being actively explored for infrared detector applications owing to their superior carrier lifetimes. However, antimony (Sb) segregation during growth can alter the properties of the grown material. In this study, using X-ray energy dispersive spectrometry, authors quantify the compositional profile of individual layers and establish epitaxial parameters for high-quality InAs/InAsSb SL materials. Epitaxial conditions are determined for a nominal 7.7 nm InAs/3.5 nm InAs0.7Sb0.3 SL structure tailored for an approximately 6 μm response at 150 K. Since the growth of mixed anion alloys is complicated by the potential reaction of As2 with Sb surfaces, authors varied the deposition temperature (Tg) in order to control As2 surface reactions on Sb surfaces. Authors find that Sb incorporation is suppressed by 21%, with the increase of Tg from 395 to 440 °C. This incorporation likely stems from Sb surface segregation during InAsSb layer growth that is driven by the As-Sb exchange mechanism, which can lead to significant compositional and dimensional deviations from the intended design.

  8. Development of a non-chromatographic method for the speciation analysis of inorganic antimony in mushroom samples by hydride generation atomic fluorescence spectrometry

    Science.gov (United States)

    Sousa Ferreira, Hadla; Costa Ferreira, Sergio Luis; Cervera, M. Luisa; de la Guardia, Miguel

    2009-06-01

    A simple and sensitive method has been developed for the direct determination of toxic species of antimony in mushroom samples by hydride generation atomic fluorescence spectrometry (HG AFS). The determination of Sb(III) and Sb(V) was based on the efficiency of hydride generation employing NaBH 4, with and without a previous KI reduction, using proportional equations corresponding to the two different measurement conditions. The extraction efficiency of total antimony and the stability of Sb(III) and Sb(V) in different extraction media (nitric, sulfuric, hydrochloric, acetic acid, methanol and ethanol) were evaluated. Results demonstrated that, based on the extraction yield and the stability of extracts, 0.5 mol L - 1 H 2SO 4 proved to be the best extracting solution for the speciation analysis of antimony in mushroom samples. The limits of detection of the developed methodology were 0.6 and 1.1 ng g - 1 for Sb(III) and Sb(V), respectively. The relative standard derivation was 3.8% (14.7 ng g - 1 ) for Sb(V) and 5.1% (4.6 ng g - 1 ) for Sb(III). The recovery values obtained for Sb(III) and Sb(V) varied from 94 to 106% and from 98 to 105%, respectively. The method has been applied to determine Sb(III), Sb(V) and total Sb in five different mushroom samples; the Sb(III) content varied from 4.6 to 11.4 ng g - 1 and Sb(V) from 14.7 to 21.2 ng g - 1 . The accuracy of the method was confirmed by the analysis of a certified reference material of tomato leaves.

  9. STUDY ON THE REMOVAL OF ANTIMONY FOR PRODUCING SODIUM STANNATE BY TIN SLAG%锡渣生产锡酸钠中除锑的研究

    Institute of Scientific and Technical Information of China (English)

    卢丹艳

    2012-01-01

    利用生产硫酸亚锡、氯化亚锡、锡:扮的含锡废料生产锡酸钠,生产成本低,但在这过程中需要除去的杂质也相对比较多。文章对除锑的工艺参数和条件进行了研究,重点探讨了除锑温度、除锑时间、除锑后溶液静置沉降时间等因素对锑效果的影响。结果表明,采用该工艺,Sb的脱除率为95.3%,产品质量符合Sn-42等级标准。%waste material that contains tin and can be used for producing Stannous sulfate, Stannous chloride and Tin powder is use for producing Sodium stannate. The cost of production may stay at a relative low level. But It needs to get rid of More impurities, Relatively speaking .In this paper, the process parameters and conditions of the removal of Antimony are studied. The factors such as the temperature and time of the removal of Antimony and time of sedimentation time of the Solution are discussed, which have an influence on the removal of Antimony. It is shown that, using this technology, removal rate of Sb is 95.3%, and the Product quality is In accordance with the grading standard of Sn 42.

  10. Facilitated extracellular electron transfer of Shewanella loihica PV-4 by antimony-doped tin oxide nanoparticles as active microelectrodes

    Science.gov (United States)

    Zhang, Xiaojian; Liu, Huan; Wang, Jinrong; Ren, Guangyuan; Xie, Beizhen; Liu, Hong; Zhu, Ying; Jiang, Lei

    2015-11-01

    Dissimilatory metal reducing bacteria are capable of extracellular electron transfer (EET) to insoluble metal oxides as external electron acceptors for their anaerobic respiration, which is recognized as an important energy-conversion process in natural and engineered environments, such as in mineral cycling, bioremediation, and microbial fuel/electrolysis cells. However, the low EET efficiency remains one of the major bottlenecks for its practical application. We report firstly that the microbial current generated by Shewanella loihica PV-4 (S. loihica PV-4) could be greatly improved that is up to ca. 115 fold, by adding antimony-doped tin oxide (ATO) nanoparticles in the electrochemical reactor. The results demonstrate that the biocompatible, electrically conductive ATO nanoparticles acted as active microelectrodes could facilitate the formation of a cells/ATO composite biofilm and the reduction of the outer membrane c-type cytochromes (OM c-Cyts) that are beneficial for the electron transfer from cells to electrode. Meanwhile, a synergistic effect between the participation of OM c-Cyts and the accelerated EET mediated by cell-secreted flavins may play an important role for the enhanced current generation in the presence of ATO nanoparticles. Moreover, it is worth noting that the TCA cycle in S. loihica PV-4 cells is activated by adding ATO nanoparticles, even if the potential is poised at +0.2 V, thereby also improving the EET process. The results presented here may provide a simple and effective strategy to boost the EET of S. loihica PV-4 cells, which is conducive to providing potential applications in bioelectrochemical systems.Dissimilatory metal reducing bacteria are capable of extracellular electron transfer (EET) to insoluble metal oxides as external electron acceptors for their anaerobic respiration, which is recognized as an important energy-conversion process in natural and engineered environments, such as in mineral cycling, bioremediation, and

  11. Eficácia do sulfato de aminosidine na leishmaniose visceral grave, resistente ao tratamento com antimonial pentavalente

    Directory of Open Access Journals (Sweden)

    Cleudson Castro

    1995-09-01

    Full Text Available Descreve-se um caso de calazar grave resistente a dez cursos de antimonial petitavalente (glucantime à base de 20mg de Sb5/kg/dia, que respondeu favoravelmente ao sulfato de aminosidine intramuscular na dose de 20mg/kg/dia por 20 dias, repetido após 20 dias. O parasitismo esplénico passou de 50 parasitos por campo a 3 parasitos em 10 campos logo após a primeira série de sulfato de aminosidine, tornando-se negativo depois de sete meses. A melhora clínica foi imediata, com redução gradual da hepatoesplenomegalia, e desaparecimento 26 meses após. Neste período aumentou 13 kg. Após o uso de aminosidine a reação de Monténégro tornou-se positiva e as células mononucleares responderam quando estimuladas com antígenos de leishmânia.A grave kala-azar infection in a 14 years old boy is described. The leishmanial infection failed to respond to ten interrupted courses of glucantime of variable duration (14-56 days at a dose of 20mg Sb5/kg/day. However a favorable response ocurred to intramuscular aminosidine sulphate (20mg/kg/day for 20 days. This same regimen was repeated 20 days later. After the first treatment splenic puncture parasite density fell from 50 amastigotes per oil immersion field to 3 amastigotes in 10 fields. A further splenic puncture 7 months after treatment was negative. The marked hepatoesplenomegaly gradually resolved over 26 months follow up and he gained 13 kilogramas in weight. After aminosidine sulphate therapy his Montenegro reaction become positive and his lymphocytes responded to leishmania antigens.

  12. Migration and leaching risk of extraneous antimony in three representative soils of China: lysimeter and batch experiments.

    Science.gov (United States)

    Hou, H; Yao, N; Li, J N; Wei, Y; Zhao, L; Zhang, J; Li, F S

    2013-11-01

    Antimony (Sb) distribution, solubility and mobility onto natural soils of China were studied in lysimeter and batch experiments as a function of physicochemical properties of the soil. An outdoor lysimeter experiment investigated the leaching and migration of Sb in the soils with Sb-polluted topsoil and unpolluted subsoil over a 5month period. Soil solutions were collected by suction cups installed at different depth of lysimeters, and leachates were regularly collected and analyzed for Sb concentrations. The majority of the added Sb was retained in the topsoil layers, but small portions were moved to the sub-layers. Sb concentrations in the soil solutions and leachates ranged from 0-755.5 (6.38±54 on average) μg l(-1) and 0-0.45 (smaller than the detection limit) μg l(-1) respectively, indicating the low solubility of Sb in the soils. Batch experiments were performed in order to determine the sorption capacity and the partition coefficient (Kd). Freundlich isotherm described properly the equilibrium experimental data and results show that the Kd values for Primosol, Isohumosol, Ferrosol equal to 22.5, 87.8, 704 L kg(-1), respectively. These results showed the strong capacity of the soils to retain Sb, and prevent it being leached down the profile. The mobilizable Sb was in the order: Primosol>Isohumosol>Ferrosol. Sb migration in the soils was mainly associated with the exchangeable, carbonate-bound, and metal-organic complex-bound fractions. Health risk assessment indicates that Sb leaching from Ferrosol will not harm to human health through groundwater under the test conditions, while it has certain health risks from the Isohumosol and Primosol. PMID:23931906

  13. Correlating microbial community profiles with geochemical conditions in a watershed heavily contaminated by an antimony tailing pond.

    Science.gov (United States)

    Xiao, Enzong; Krumins, Valdis; Tang, Song; Xiao, Tangfu; Ning, Zengping; Lan, Xiaolong; Sun, Weimin

    2016-08-01

    Mining activities have introduced various pollutants to surrounding aquatic and terrestrial environments, causing adverse impacts to the environment. Indigenous microbial communities are responsible for the biogeochemical cycling of pollutants in diverse environments, indicating the potential for bioremediation of such pollutants. Antimony (Sb) has been extensively mined in China and Sb contamination in mining areas has been frequently encountered. To date, however, the microbial composition and structure in response to Sb contamination has remained overlooked. Sb and As frequently co-occur in sulfide-rich ores, and co-contamination of Sb and As is observed in some mining areas. We characterized, for the first time, the microbial community profiles and their responses to Sb and As pollution from a watershed heavily contaminated by Sb tailing pond in Southwest China. The indigenous microbial communities were profiled by high-throughput sequencing from 16 sediment samples (535,390 valid reads). The comprehensive geochemical data (specifically, physical-chemical properties and different Sb and As extraction fractions) were obtained from river water and sediments at different depths as well. Canonical correspondence analysis (CCA) demonstrated that a suite of in situ geochemical and physical factors significantly structured the overall microbial community compositions. Further, we found significant correlations between individual phylotypes (bacterial genera) and the geochemical fractions of Sb and As by Spearman rank correlation. A number of taxonomic groups were positively correlated with the Sb and As extractable fractions and various Sb and As species in sediment, suggesting potential roles of these phylotypes in Sb biogeochemical cycling. PMID:27182975

  14. Synthesis and properties of crystalline thin film of antimony trioxide on the Si(1 0 0) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yasir, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kuzmin, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Punkkinen, M.P.J.; Mäkelä, J.; Tuominen, M.; Dahl, J. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Laukkanen, P., E-mail: pekka.laukkanen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kokko, K. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

    2015-09-15

    Highlights: • Formation of crystalline phase of Sb{sub 2}O{sub 3} on Si(1 0 0) is demonstrated. • STM and STS characterizations of the grown Sb{sub 2}O{sub 3} film are presented. • STS results elucidate the band gap of Sb{sub 2}O{sub 3}. • Ab initio calculations reveal energetically favored Sb{sub 2}O{sub 3} surface structures. - Abstract: Atomic-scale understanding and processing of the surface and interface properties of antimony trioxide (Sb{sub 2}O{sub 3}) are essential to the development of nanoscale Sb{sub 2}O{sub 3} materials for various applications, such as photocatalysts, transparent conducting oxides, optical coatings, dielectric films, and fire retardants. Lack of atomically well-defined, crystalline Sb{sub 2}O{sub 3} templates has however hindered atomic resolution characterization of the Sb{sub 2}O{sub 3} properties. We report the preparation of crystalline Sb{sub 2}O{sub 3} thin films on the Si(1 0 0) substrate with a simple process by oxidizing Sb-covered Si(1 0 0) in proper conditions. Physical properties of the synthesized films have been elucidated by low-energy electron diffraction, scanning tunneling microscopy and spectroscopy, and ab initio calculations. The spectroscopic results show that the band gap of Sb{sub 2}O{sub 3} is 3.6 eV around the gamma point (i.e. Γ). Calculations reveal energetically favored Sb{sub 2}O{sub 3}(1 0 0) surface structures. The findings open a new path for the atomic-scale research of Sb{sub 2}O{sub 3}.

  15. Imipramine is an orally active drug against both antimony sensitive and resistant Leishmania donovani clinical isolates in experimental infection.

    Directory of Open Access Journals (Sweden)

    Sandip Mukherjee

    Full Text Available BACKGROUND: In an endeavor to find an orally active and affordable antileishmanial drug, we tested the efficacy of a cationic amphiphilic drug, imipramine, commonly used for the treatment of depression in humans. The only available orally active antileishmanial drug is miltefosine with long half life and teratogenic potential limits patient compliance. Thus there is a genuine need for an orally active antileishmanial drug. Previously it was shown that imipramine, a tricyclic antidepressant alters the protonmotive force in promastigotes, but its in vivo efficacy was not reported. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that the drug is highly active against antimony sensitive and resistant Leishmania donovani in both promastigotes and intracellular amastigotes and in LD infected hamster model. The drug was found to decrease the mitochondrial transmembrane potential of Leishmania donovani (LD promastigotes and purified amastigotes after 8 h of treatment, whereas miltefosine effected only a marginal change even after 24 h. The drug restores defective antigen presenting ability of the parasitized macrophages. The status of the host protective factors TNF α, IFN γ and iNOS activity increased with the concomitant decrease in IL 10 and TGF β level in imipramine treated infected hamsters and evolution of matured sterile hepatic granuloma. The 10-day therapeutic window as a monotherapy, showing about 90% clearance of organ parasites in infected hamsters regardless of their SSG sensitivity. CONCLUSIONS: This study showed that imipramine possibly qualifies for a new use of an old drug and can be used as an effective orally active drug for the treatment of Kala-azar.

  16. New and rapid access to synthesis of novel polysubstituted imidazoles using antimony trichloride and stannous chloride dihydrate as effective and reusable catalysts

    Indian Academy of Sciences (India)

    Leyla Poorali; Bahador Karami; Khalil Eskandari; Mahboobeh Azizi

    2013-05-01

    In this work, new, efficient and environmentally adapted synthesis of polysubstituted imidazoles in one-pot is repoted. The multicomponent reaction of various aldehydes, benzil, aliphatic and aromatic primary amines and ammonium acetate under solvent-free condition is explained. The highly efficient role of antimony trichloride and stannous chloride dihydrate as catalyst in this synthesis was shown and their effects on the reaction process were studied. By this advantage, several polysubstituted imidazoles as pharmaceutical important molecules can be prepared in high yield and high purity. This method is a very easy and rapid for the synthesis of imidazole derivatives.

  17. Effect of antimony substitution for niobium on the crystal structure, piezoelectric and dielectric properties of (K0.5Na0.5)NbO3 ceramics

    DEFF Research Database (Denmark)

    Mgbemere, H E; Schneider, G A; Stegk, Tobias

    2010-01-01

    The effect of antimony (Sb) substitution for niobium (Nb) on potassium sodium niobate (KNN) ceramic was investigated with respect to the densification behaviour at different sintering temperatures, microstructure and electrical properties. A small amount of Sb5+ was added while simultaneously......+ substituted is increased, the structure of the ceramic transformed from orthorhombic to pseudo-cubic which led to slight shrinkage in the unit cell volume. Microstructural examination revealed that above 10 mol%, a second phase (K2NaSb3O9) was formed which segregated mainly to the grain boundary while the...

  18. Comparative study on the corrosion behavior of the cold rolled and hot rolled low-alloy steels containing copper and antimony in flue gas desulfurization environment

    Science.gov (United States)

    Park, S. A.; Kim, J. G.; He, Y. S.; Shin, K. S.; Yoon, J. B.

    2014-12-01

    The correlation between the corrosion and microstructual characteristics of cold rolled and hot rolled low-alloy steels containing copper and antimony was established. The corrosion behavior of the specimens used in flue gas desulfurization systems was examined by electrochemical and weight loss measurements in an aggressive solution of 16.9 vol % H2SO4 + 0.35 vol % HCl at 60°C, pH 0.3. It has been shown that the corrosion rate of hot rolled steel is lower than that of cold rolled steel. The corrosion rate of cold rolled steel was increased by grain refinement, inclusion formation, and preferred grain orientation.

  19. Preparation and Characterization of Antimony Doped Tin Oxide Thin Films Synthesized by Co-Evaporation of Sn and Sb using Plasma Assisted Thermal Evaporation

    Directory of Open Access Journals (Sweden)

    C. Jariwala

    2013-05-01

    Full Text Available Tin oxide (SnO2 thin films are having promising properties such as high visible transmittance and low electric resistivity, makes them very important transparent conductor in a variety of optoelectronics devices. Further, doping with pentavalent impurity such as Antimony (Sb enhances its conductivity considerably. In order to study the effect of Antimony doping, Antimony doped tin oxide (SnO2 : Sb thin films have been prepared by the co-evaporation of Sn and Sb using Plasma Assisted Thermal Evaporation (PATE in oxygen (O2 partial pressure at various doping level from 4% to 25%. The influence of various Sb doping levels on the compositional, electrical, optical and structural properties have been investigated using Energy Dispersive X-ray (EDX spectroscopy, Ultraviolet-Visible (UV-VIS transmission spectroscopy, four-probe resistivity measurement and X-ray Diffraction (XRD, respectively. EDX studies confirmed the different Sb doping levels in the grown films from 4 % to 25 %, while electrical resistivity is obtained in range of 0.36 to 9.5 Ohmcm using four-probe setup for 4 % to 25 % Sb doping levels. Transmittance spectra measured in UV-VIS range for Sb doped films show reduction in an average transmittance in respect to increase in Sb doping levels in the grown films. Whereas, XRD analysis reveals that higher Sb doping of 25 % induce the precipitation of antimony oxide (Sb2O3 phase and its precipitation suppressed the growth of SnO2 peaks as well as responsible for reduction in conductivity and transparency. The best electrical resistivity of optimized SnO2 : Sb (5 % is 0.36 Ohmcm without deteriorating the high (~ 80 % average transmittance in the wavelength region 300-800 nm in comparison to undoped SnO2 film (6.57 Ohmcm , confirm the usefulness of SnO2 : Sb (5 % films for device applications.

  20. Design of a Flow-Through Voltammetric Sensor Based on an Antimony-Modified Silver Electrode for Determining Lithol Rubine B in Cosmetics

    OpenAIRE

    Wang Lai-Hao; Huang Shu-Juan

    2011-01-01

    Lithol Rubine B (LRB; the disodium salt of 3-hydroxy-4-[(4-methyl-2-sulfophenyl) azo]-2-naphthalenecarboxylic acid) was detected using high-performance liquid chromatography with an electrochemical (antimony film on silver) detector (HPLC-ECD). For direct current (DC) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 μg/mL was found. The detection limit of our method was approximately 2.0 ng/mL. An...

  1. Double blind, randomized controlled trial, to evaluate the effectiveness of a controlled nitric oxide releasing patch versus meglumine antimoniate in the treatment of cutaneous leishmaniasis [NCT00317629

    Directory of Open Access Journals (Sweden)

    Silva Federico A

    2006-05-01

    Full Text Available Abstract Background Cutaneous Leishmaniasis is a worldwide disease, endemic in 88 countries, that has shown an increasing incidence over the last two decades. So far, pentavalent antimony compounds have been considered the treatment of choice, with a percentage of cure of about 85%. However, the high efficacy of these drugs is counteracted by their many disadvantages and adverse events. Previous studies have shown nitric oxide to be a potential alternative treatment when administered topically with no serious adverse events. However, due to the unstable nitric oxide release, the topical donors needed to be applied frequently, making the adherence to the treatment difficult. The electrospinning technique has allowed the production of a multilayer transdermal patch that produces a continuous and stable nitric oxide release. The main objective of this study is to evaluate this novel nitric oxide topical donor for the treatment of cutaneous leishmaniasis. Methods and design A double-blind, randomized, double-masked, placebo-controlled clinical trial, including 620 patients from endemic areas for Leishmaniasis in Colombia was designed to investigate whether this patch is as effective as meglumine antimoniate for the treatment of cutaneous leishmaniasis but with less adverse events. Subjects with ulcers characteristic of cutaneous leishmaniasis will be medically evaluated and laboratory tests and parasitological confirmation performed. After checking the inclusion/exclusion criteria, the patients will be randomly assigned to one of two groups. During 20 days Group 1 will receive simultaneously meglumine antimoniate and placebo of nitric oxide patches while Group 2 will receive placebo of meglumine antimoniate and active nitric oxide patches. During the treatment visits, the medications will be daily administered and the presence of adverse events assessed. During the follow-up, the research group will visit the patients at days 21, 45, 90 and 180. The

  2. Antimony (Sb) sorption studies on zircaloy, carbon steel (CS) and magnetite coated CS (MCS) surfaces in aqueous medium at pH 10.2 and 280℃

    International Nuclear Information System (INIS)

    Antimony sorption studies on zircaloy, CS and magnetite coated carbon steel (MCS) at primary heat transport temperature (290℃) of pressurised heavy water reactor (PHWR) are of direct relevance in investigating Sb activity problem faced in Indian PHWRs. Sb impregnated PHT pump carbon bearing releases Sb to reactor core. This Sb activates, and redeposit on out-of-core surfaces and results in exposure and apparent high decontamination factors. This Sb is not amenable to normal decantation. The form and state of deposited Sb is not yet fully known. This works attempts for this

  3. Effect of the antimony thin-film deposition sequence on copper-silicon interdiffusion: Vpliv zaporedja nanosa tankih plasti antimona na interdifuzijo baker-silicij:

    OpenAIRE

    Chaouki, Benazzouz; Fouzia, Zekkar; Mahfoud, Benkerri; Mokhtar, Boudissa; Mounir, Reffas; Nasser, Menni

    2012-01-01

    In this work we present a study of the effect of an antimony layer on the interdiffusion and formation of copper silicides while inverting the sequence of Cu and Sb deposition on Si(111) substrates. Thermal evaporation was used to deposit Cu/Sb and Sb/Cu bilayers on a Si(111) substrate heated at 100 °C, without breaking the vacuum. XRD and RBS analysis showed, for samples heat treated at 200 °C and 400 °C, a segregation of the three elements (i.e., Cu, Sb and Si) to the surface and diffusion ...

  4. Surface morphologies and properties of pure and antimony-doped tin oxide films derived by sol-gel dip-coating processing

    International Nuclear Information System (INIS)

    A simple laboratory technique for the routine preparation of antimony-doped tin oxide (ATO) on float glass substrates (25 mm x 76 mm x 1 mm) was described. As-prepared thin films were dried at temperature of 100 ± 5 deg. C and annealed at temperatures of 400-550 deg. C. Microstructural and morphological analyses of as-prepared films were performed at different conditions. The evolution of grain size and the morphologies of ATO films were analyzed by means of atom force microscopy (AFM) and digital microscope. The studies suggested that higher Sb-doped level and higher annealing temperature led to a decrease in the surface roughness of the deposited films. The XRD patterns revealed that as-prepared ATO films were in the crystallization of a tetragonal rutile structure of SnO2 with highly (1 1 0) preferred orientation. Their optical properties were analyzed by U-3310 spectrophotometer. The transmission of the ATO thin films was obtained as high as 80-90% in visible region, but decreased substantially in IR region. The sheet resistance of the investigated thin films was determined by four-probe method, showing that it was about 85-100 Ω □-1which decreased with the increase of antimony-doped concentration

  5. Ultra-low carrier concentration and surface-dominant transport in antimony-doped Bi2Se3 topological insulator nanoribbons

    KAUST Repository

    Hong, Seung Sae

    2012-03-27

    A topological insulator is the state of quantum matter possessing gapless spin-locking surface states across the bulk band gap, which has created new opportunities from novel electronics to energy conversion. However, the large concentration of bulk residual carriers has been a major challenge for revealing the property of the topological surface state by electron transport measurements. Here we report the surface-state-dominant transport in antimony-doped, zinc oxide-encapsulated Bi2Se3 nanoribbons with suppressed bulk electron concentration. In the nanoribbon with sub-10-nm thickness protected by a zinc oxide layer, we position the Fermi levels of the top and bottom surfaces near the Dirac point by electrostatic gating, achieving extremely low two-dimensional carrier concentration of 2×10 11cm-2. The zinc oxide-capped, antimony-doped Bi 2Se3 nanostructures provide an attractive materials platform to study fundamental physics in topological insulators, as well as future applications. © 2012 Macmillan Publishers Limited. All rights reserved.

  6. Stability studies of arsenic, selenium, antimony and tellurium species in water, urine, fish and soil extracts using HPLC/ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, T.; Prange, A.; Neidhart, B. [GKSS Research Centre, Geesthacht (Germany). Inst. of Physical and Chemical Analysis; Dannecker, W. [Hamburg Univ. (Germany). Inst. fuer Anorganische und Angewandte Chemie

    2000-10-01

    The stability of arsenic, selenium, antimony and tellurium species in water and urine (NIST SRM 2670n) as well as in extracts of fish and soil certified reference materials (DORM-2 and NIST SRM 2710) has been investigated. Stability studies were carried out with As(III), As(V), arsenobetaine, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), Se(IV), Se(VI), selenomethionine, Sb(III), Sb(V) and Te(VI). Speciation analysis was performed by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Best storage of aqueous mixtures of the examined species was achieved at 3 C whereas at -20 C species transformation especially of selenomethionine and Sb(V) took place and a new selenium species appeared within a period of 30 days. Losses and species transformations during extraction processes were investigated. Extraction of the spiked fish material with methanol/water led to partial conversion of Sb(III), Sb(V) and selenomethionine to two new antimony and one new selenium species. The other arsenic, selenium and tellurium species were almost quantitatively extracted. For soil spiked with MMA, PAA, Se(IV) and Sb(III), recoveries after extraction with water and sulfuric acid (0.01 mol/L) were below 20%. (orig.)

  7. Antimony(v) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes.

    Science.gov (United States)

    Arias Ugarte, Renzo; Devarajan, Deepa; Mushinski, Ryan M; Hudnall, Todd W

    2016-07-01

    1-Diphenylphosphinonaphthyl-8-triphenylstibonium triflate ([][OTf]) was prepared in excellent yield by treating 1-lithio-8-diphenylphosphinonaphthalene with dibromotriphenylstiborane followed by halide abstraction with AgOTf. This antimony(v) cation was found to be stable toward oxygen and water, and exhibited exceptional Lewis acidity. The Lewis acidity of [][OTf] was exploited in the catalytic reductive coupling of a variety of aldehydes into symmetric ethers of type in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes () when aldehydes with 2 α-hydrogen atoms were used. Finally, [][OTf] catalyzed the cyclotrimerization of aliphatic and aromatic aldehydes to afford the industrially-useful 1,3,5 trioxanes () in good yields, and with great selectivity. This phosphine-stibonium motif represents one of the first catalytic systems of its kind that is able to catalyze these reactions with aldehydes in a controlled, efficient manner. The mechanism of these processes has been explored both experimentally and theoretically. In all cases the Lewis acidic nature of the antimony(v) cation was found to promote these reactions. PMID:27326797

  8. Annealing effects on structural, electrical and optical properties of antimony-tinoxide thin films deposited by sol gel dip coating technique

    Energy Technology Data Exchange (ETDEWEB)

    Lekshmy, S. Sujatha, E-mail: jolly2jolly@gmail.com; Anitha, V. S., E-mail: jolly2jolly@gmail.com; Berlin, I. John, E-mail: jolly2jolly@gmail.com; Joy, K., E-mail: jolly2jolly@gmail.com [Thin film Laboratory, Post Graduate and Research Department of Physics, Mar Ivanios College, Thiruvananthapuram 695 015 (India)

    2014-01-28

    Antimony-doped tin dioxide possess interesting physical and chemical properties. These properties have a wide range of applications such as catalysis and optoelectronic devices. In the present study, antimony-doped tin oxide (SnO2:Sb) thin films were deposited on the quartz substrates by sol-gel dip coating technique. The films were annealed at temperatures 350°C, 550°C and 850°C in air for 2 hours. The structure and surface morphologies were observed by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). XRD patterns shows tetragonal structure for the SnO2:Sb films annealed at different temperatures. Crystallite size increased from 6 to 14 nm as annealing temperature increased from 350°C to 850°C. SEM studies reveals crack free and smooth surface for all the films. The grains are found to be homogenously distributed for films annealed at higher temperature. The electrical conductivity of the films annealed at 350°C and 550°C decreased and increased for the films annealed at 850°C. The optical properties of the films were investigated in the UV-visible-NIR region (200-900 nm) using UV spectra. The transmittance of the films decreased for films annealed at higher temperature. The optical energy band gap values (4.13 eV-4.83 eV) increased with the increase in annealing temperature.

  9. Surface morphologies and properties of pure and antimony-doped tin oxide films derived by sol-gel dip-coating processing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daoli [Department of Electronic Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road Hongshan District, Wuhan City Hubei Province 430074 (China)]. E-mail: zhang_daoli@mail.hust.edu.cn; Tao Liang [Department of Electronic Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road Hongshan District, Wuhan City Hubei Province 430074 (China); Deng Zhibing [Department of Electronic Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road Hongshan District, Wuhan City Hubei Province 430074 (China); Zhang Jianbing [Department of Electronic Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road Hongshan District, Wuhan City Hubei Province 430074 (China); Chen Liangyan [Department of Electronic Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road Hongshan District, Wuhan City Hubei Province 430074 (China)

    2006-12-10

    A simple laboratory technique for the routine preparation of antimony-doped tin oxide (ATO) on float glass substrates (25 mm x 76 mm x 1 mm) was described. As-prepared thin films were dried at temperature of 100 {+-} 5 deg. C and annealed at temperatures of 400-550 deg. C. Microstructural and morphological analyses of as-prepared films were performed at different conditions. The evolution of grain size and the morphologies of ATO films were analyzed by means of atom force microscopy (AFM) and digital microscope. The studies suggested that higher Sb-doped level and higher annealing temperature led to a decrease in the surface roughness of the deposited films. The XRD patterns revealed that as-prepared ATO films were in the crystallization of a tetragonal rutile structure of SnO{sub 2} with highly (1 1 0) preferred orientation. Their optical properties were analyzed by U-3310 spectrophotometer. The transmission of the ATO thin films was obtained as high as 80-90% in visible region, but decreased substantially in IR region. The sheet resistance of the investigated thin films was determined by four-probe method, showing that it was about 85-100 {omega} {open_square}{sup -1}which decreased with the increase of antimony-doped concentration.

  10. Oral bioavailability of arsenic, antimony and a selection of metals in ashes; Oral biotillgaenglighet av arsenik, antimon och ett urval av metaller i askor

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Christel; Bendz, David; Jones, Celia

    2008-06-15

    In an earlier study, financed by Varmeforsk, 'Q4-238 Environmental guidelines for reuse of ash in civil engineering applications', the total content of arsenic and lead was shown to determine whether or not reuse of some of the ashes in construction work is feasible. The model used to calculate the guidelines uses the total concentration of metals to evaluate the health risks resulting from exposure to the ashes. The use of total concentration can lead to overly conservative risk assessments if a significant fraction of the total metal content is not bioavailable. Better precision in the risk assessment can be given by the use of the bioavailable fraction of arsenic and lead in the model. As a result, ashes which are rejected on the basis of total metal concentration may be acceptable for use in engineering construction when the assessment is based on the bioavailable fraction. The purpose of the study was to (i) compile information on the oral bioavailability of arsenic, antimony and a selection of metals in ashes and similar materials, and on in vitro methods for determination of oral bioavailability, and (ii) experimentally estimate oral bioavailability of arsenic, antimony and some metals in a selection of ashes by analysis of the gastrointestinal bioaccessibility of these elements. The investigated elements were antimony, arsenic, lead, cadmium, copper, chromium, nickel and zinc. In the literature study performed within the project a number of static and dynamic in vitro methods simulating gastrointestinal processes of contaminants were compiled. The methods include one or several segments, i.e. mouth, stomach and intestine. Among the compiled methods, the RIVM (Rijksinstituut voor volksgesundheid en milieu) in vitro method was used in the experimental part of the project. The advantages with the method was that: the method to a high degree mimicked the human gastrointestinal processes (the method included three segments mouth, stomach, and intestine

  11. Direct determination of arsenic and antimony in naphtha by electrothermal atomic absorption spectrometry with microemulsion sample introduction and iridium permanent modifier

    Energy Technology Data Exchange (ETDEWEB)

    Cassella, Ricardo J. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, 24020-007, Niteroi/RJ (Brazil); Barbosa, Bruno Alberto R.S.; Santelli, Ricardo E. [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, 24020-007, Niteroi/RJ (Brazil); Rangel, Alessandra T. [PETROBRAS, CENPES, PDEDS/QM, Rio de Janeiro (Brazil)

    2004-05-01

    This paper reports the determination of arsenic and antimony in naphtha by employing electrothermal atomic absorption spectrometry (ETAAS) as the analytical technique. In order to promote the direct determination of the analytes in the very volatile naphtha, the formation of a microemulsion with different surfactants (Triton X-100 and Brij-35) and different chemical modification strategies were tested. The results indicated that Triton X-100 is the best emulsification agent for naphtha in both As and Sb determination when it is employed at a concentration of 1% w/v in the microemulsion. Under these conditions, the microemulsion was stabile for at least 2 h. By using Brij-35 it was possible to achieve good stability only in the first 15 min. Among all chemical modification approaches investigated (Ir permanent modifier, W-Ir permanent modifier, and Pd modifier), the Ir permanent modifier provided better sensitivity for both analytes and allowed a higher pyrolysis temperature, which decreased the background signals at lower levels. Under the best conditions established in this work, an RSD of 4.6% (20 {mu}g L{sup -1}) and a detection limit of 2.7 {mu}g L{sup -1} were observed for arsenic. For antimony, an RSD of 4.0% (20 {mu}g L{sup -1}) and a detection limit of 2.5 {mu}g L{sup -1} were obtained. The accuracy of the procedure was assessed by analyzing spiked samples of naphtha from different origins. (orig.)

  12. Investigation on spread and risk factors of tuberculosis in antimony miners%锑矿工结核病传播及危险因素调查

    Institute of Scientific and Technical Information of China (English)

    陈开森; 刘涛; 林瑞瑞; 罗涛; 杨崇广

    2015-01-01

    Objective To explore the infection rate of tuberculosis ( TB) and its risk factors in antimony miners .Methods With cluster sampling method , the strains identification and drug sensitive test were performed in Mycobacterium tuberculosis ( MTB) of 263 TB patients in antimony miners .The method of 12 sites mycobacterial interspersed repetitive unit and variable number of tandem repeat wre used to determine the genetic type of MTB .Risk factors of TB spread were assessed by chi-square test.Results The TB infection rate in antimony miners was 9.8%(472/4 831);among 263 TB cases, 175 cases were found clustered the clustering rate was 66.5%, the least estimated recent TB spread rate was 53.2%.High TB spread rate was found in the antimony miners with failed treatment , length of service longer than 10 years , multidrug-resistant bacterial strains , and positive sputum smear .Conclusion The MTB of antimony miners showed the clustering feature and the bacterial strains had strong toxicity and higher spreading rate .The major risk factors affecting TB spread were therapeutic effect , length of service , drug resistant bacterial strain and sputum smear result .%目的 了解锑矿工肺结核感染率及感染的危险因素. 方法 采用整群抽样方法,对263例锑矿工肺结核患者进行结核分枝杆菌的菌株鉴定和药敏试验. 基因分型采用12位点结核分枝杆菌散在分布重复单元和多位点串联重复序列;采用X2检验评估结核传播的危险因素. 结果 锑矿工肺结核的感染率为9.8%(472/4 831); 纳入研究的263例患者中,175例成簇,成簇率为66 .5%,近期传播率最低估计值为53 .2%. 治疗失败、工龄大于10年、菌株多重耐药及痰涂片阳性的锑矿工肺结核传播率较高. 结论 锑矿工结核分枝杆菌具有成簇性,其菌株毒力更强、传播率高,治疗效果、矿龄、菌株耐药性及痰涂片结果是影响肺结核传播的重要危险因素.

  13. An evaluation of the migration of antimony from polyethylene terephthalate (PET) plastic used for bottled drinking water.

    Science.gov (United States)

    Chapa-Martínez, C A; Hinojosa-Reyes, L; Hernández-Ramírez, A; Ruiz-Ruiz, E; Maya-Treviño, L; Guzmán-Mar, J L

    2016-09-15

    The leaching of antimony (Sb) from polyethylene terephthalate (PET) bottling material was assessed in twelve brands of bottled water purchased in Mexican supermarkets by atomic fluorescence spectrometry with a hydride generation system (HG-AFS). Dowex® 1X8-100 ion-exchange resin was used to preconcentrate trace amounts of Sb in water samples. Migration experiments from the PET bottle material were performed in water according to the following storage conditions: 1) temperature (25 and 75°C), 2) pH (3 and 7) and 3) exposure time (5 and 15days), using ultrapure water as a simulant for liquid foods. The test conditions were studied by a 2(3) factorial experimental design. The Sb concentration measured in the PET packaging materials varied between 73.0 and 111.3mg/kg. The Sb concentration (0.28-2.30μg/L) in all of the PET bottled drinking water samples examined at the initial stage of the study was below the maximum contaminant level of 5μg/L prescribed by European Union (EU) regulations. The parameters studied (pH, temperature, and storage time) significantly affected the release of Sb, with temperature having the highest positive significant effect within the studied experimental domain. The highest Sb concentration leached from PET containers was in water samples at pH7 stored at 75°C for a period of 5days. The extent of Sb leaching from the PET ingredients for different brands of drinking water can differ by as much as one order of magnitude in experiments conducted under the worst-case conditions. The chronic daily intake (CDI) caused by the release of Sb in one brand exceeded the Environmental Protection Agency (USEPA) regulated CDI value of 400ng/kg/day, with values of 514.3 and 566.2ng/kg/day for adults and children. Thus, the appropriate selection of the polymer used for the production of PET bottles seems to ensure low Sb levels in water samples. PMID:27192700

  14. Spatial distribution of antimony and arsenic levels in Manadas Creek, an urban tributary of the Rio Grande in Laredo, Texas.

    Science.gov (United States)

    Baeza, Marcia; Ren, Jianhong; Krishnamurthy, Sushma; Vaughan, Thomas C

    2010-02-01

    The Rio Grande and its tributaries represent a critical water source for both the human population and the ecological resources of the Rio Grande drainage basin. Manadas Creek, an urban tributary of the Rio Grande, is located in an industrialized area of Laredo, Texas, where warehouses, a major railroad, and a decommissioned antimony (Sb) smelter are located. Previous studies have found that the creek water is contaminated with heavy metals such as Sb and arsenic (As). However, data on the metal distribution in this creek are very limited. Herein, water and sediment core samples were collected from six sites along the creek in February, April, and May 2008. Samples were analyzed for dissolved and total metals in water, total metals in sediments, and available (soluble-exchangeable, surface adsorbed, and organically bound) fractions of metals associated with the sediments. Results show that concentrations of Sb in the water and sediment samples were significantly lower at the upstream control site compared to the two sites located near the decommissioned smelter. Decreasing levels of Sb were found at the sites located downstream. The As levels in the sediment remained constant at different depths, whereas Sb varied significantly. A high level, 420 mg/kg, of sediment Sb was found at the maximum sediment depth of 35.0 cm sampled. In addition, 65.7-76.9% Sb and 80.3-85.6% As were in their residual form, 15.0-22.5% Sb and 6.2-11.4% As were bound to organic matter, and the remaining As and Sb were in the soluble and surface adsorbed fractions. Pearson correlation analyses indicated that the distribution of Sb was only moderately correlated to iron and nickel in the sediment and its correlation with the sediment properties measured was insignificant. Cluster analyses only grouped the two Sb isotopes together for the sediments collected in May, indicating that sources other than natural occurrence were associated with Sb. The high level of sediment Sb observed indicates

  15. Arsenic and Antimony Removal from Drinking Water by Point-of-Entry Reverse Osmosis Coupled with Dual Plumbing Distribution - U.S. EPA Demonstration Project at Carmel Elementary School in Carmel, ME -Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed for and the results obtained from the arsenic and antimony removal treatment technology demonstration project at the Carmel Elementary School (CES) in Carmel, ME. An innovative approach of employing point of entry (POE) reverse osmo...

  16. New antimony(III) halide complexes with dithiocarbamate ligands derived from thiuram degradation: The effect of the molecule's close contacts on in vitro cytotoxic activity.

    Science.gov (United States)

    Urgut, O S; Ozturk, I I; Banti, C N; Kourkoumelis, N; Manoli, M; Tasiopoulos, A J; Hadjikakou, S K

    2016-01-01

    Antimony(III) halide complexes of the formulae {[SbBr(Me2DTC)2]n} (1), {[SbI(Me2DTC)2]n} (2) and {[(Me2DTC)2Sb(μ2-I)Sb(Me2DTC)2](+).I3(-)} (3) (Me2DTC = dimethyldithiocarbomate) were synthesized from SbX3, (X = Br or I) and tetramethylthiuram monosulfide (Me4tms) or tetramethylthiuram disulfide (Me4tds). The complexes were characterized by melting point (m.p.), elemental analysis (e.a.), Fourier-transform Infra-Red (FT-IR), Fourier-transform Raman (FT-Raman), Nuclear Magnetic Resonance ((1)H,(13)C-NMR) spectroscopy and Thermogravimetric-Differential Thermal Analysis (TG-DTA). Crystal structures of complexes 1-3 were determined with single crystal X-ray diffraction analysis. Complexes 1 and 2 are polymers with distorted square pyramidal (SP) geometry in each monomeric unit, whereas complex 3 is ionic, containing an iodonium linkage Sb-I(+)-Sb and an I3(-) counter anion; to the best of our knowledge, this is the first ionic antimony(III) iodide complex. The in vitro cytotoxic activity of 1-3 against human adenocarcinoma cells: breast (MCF-7) and cervix (HeLa) cells and non-cancerous cells: MRC-5 (normal human fetal lung fibroblast cells) was evaluated with trypan blue (TB) and sulforhodamine B (SRB) assays. Among antimony(III) compounds with sulfur containing ligand, those of dithiocarbamates exhibit significant cytotoxic activity. Hirshfeld surface volumes were analyzed to clarify the nature of the intermolecular interactions by the 2D fingerprint plot. Molecules with lower H-all atoms inter-molecular interactions exhibit the higher activity against MCF-7 cells. The in vivo genotoxicity of 1-3 was evaluated by the mean of Allium cepa test. Alterations in the mitotic index values due to the chromosomal aberrations were observed in the case of complexes 2 and 3. Since, no such alteration is caused by 1, it makes this compound candidate for further study as potential drug. PMID:26478326

  17. Long wavelength gallium indium nitrogen arsenide and gallium-indium-nitrogen-arsenic-antimony lasers on gallium arsenide

    Science.gov (United States)

    Ha, Wonill

    The boom in fiber optic communications has created a high demand for much lower cost lasers in the 1.3--1.6 mum wavelength range for both low cost vertical-cavity surface-emitting lasers (VCSELs) and high-power Raman pumps. This has led to the introduction of dilute nitrogen into GaInAs to reduce the bandgap sufficiently, resulting in a new long wavelength material grown on GaAs. This new material will provide a new platform for low cost and high-speed directly-modulated lasers that are essential for the rapid expansion of optical wide area networks, metro area networks, and local area networks. The requirements for these lasers are a broad operating temperature range (-10 to 90°C) and moderate output power (˜10 mW) in the fundamental mode. There is also a growing interest in higher power lasers, at similar wavelengths, as pumps for Raman amplifiers to expand the available bandwidth and increase power budgets. Research has shown that GaInNAs can be coherently lattice matched to GaAs while providing the proper bandgap energy. These GaAs-based lasers with dilute N can take advantage of the well-developed GaAs processing techniques and superior distributed Bragg reflector mirror technology for VCSELs. This thesis presents new structures utilizing GaNAs barriers and a new quantum well material, GaInNAsSb, to achieve long-wavelength optical emission in post-annealed material. This increase is accompanied by a blue-shift in the bandgap energy. As a result, the distinct challenge of this material system is to achieve high quality material with sufficiently long wavelength emission. Introduction of nitrogen into the barriers reduces the blue-shift of luminescence by suppressing nitrogen out-diffusion from the quantum wells and decreasing carrier confinement in the quantum wells. We utilize antimony, both incorporated into the crystal and used as a surfactant, to enable higher indium incorporation. GaNAs or GaNAsSb barriers also reduce the overall strain of the active

  18. 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.

  19. Antimony doped tin oxides and their composites with tin pyrophosphates as catalyst supports for oxygen evolution reaction in proton exchange membrane water electrolysis

    DEFF Research Database (Denmark)

    Xu, Junyuan; Li, Qingfeng; Hansen, Martin Kalmar;

    2012-01-01

    based on tin pyrophosphates as the catalyst support. The materials showed an overall conductivity of 0.57 S cm−1 at 130 °C under the water vapor atmosphere with a contribution of the proton conduction. Using this composite support, iridium oxide nanoparticle catalysts were prepared and characterized in......Proton exchange membrane water electrolysers operating at typically 80 °C or at further elevated temperatures suffer from insufficient catalyst activity and durability. In this work, antimony doped tin oxide nanoparticles were synthesized and further doped with an inorganic proton conducting phase...... sulfuric and phosphoric acid electrolytes, showing much enhanced catalytic activity. Electrolyzer tests were conducted at both 80 °C with an Aquivion™ membrane and at 130 °C with a phosphoric acid doped Aquivion™ membrane. Significant improvement in the anodic kinetics was achieved on the composite...

  20. Antimony, Arsenic and Chromium Speciation Studies in Biała Przemsza River (Upper Silesia, Poland) Water by HPLC-ICP-MS

    OpenAIRE

    Magdalena Jabłońska-Czapla

    2015-01-01

    In this paper the total concentration of As, Cr, Sb, pH and the red-ox potential of water and sediment samples of the Biała Przemsza River were determined. The arsenic (AB, MMA, DMA, As(III), As(V)), chromium (Cr(III), Cr(VI)) and antimony (Sb(III), Sb(V)) forms were studied by HPLC-ICP-MS. Ions were successfully separated on Hamilton PRP-X100: (AB, MMA, DMA, As(III), As(V)), Dionex Ion Pac AS-7 (Sb(III), Sb(V)) and Dionex IonPac AG7 columns: Cr(III), Cr(VI) with LOD 0.16 μg/L, 0.08 μg/L, ...

  1. Progress report on neutron beam experiments in Thailand: effects of antimony substitutions on the critical temperature of Bi-Pb-Sr-Ca-Cu-O compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sangariyavanich, A.; Ampornrat, P. [Office of Atomic Energy for Peace, Bangkok (Thailand)

    1998-10-01

    Effects of systematic substitutions of antimony for bismuth in Bi{sub 1.8-x}Pb{sub 0.2}Sb{sub x}Sr{sub 2}Ca{sub 3}Cu{sub 4}O{sub 10} have been investigated. Fabrication of the specimens has been performed by solid state reaction in air. The samples were sintered between 820degC - 843degC for 65 hours and subsequently quenched in liquid nitrogen. The critical temperatures of most specimens as determined by standard four-probe technique was higher than 100 K. Phase identification by X-ray diffraction technique indicated that `2223` and `2234` were the predominant phases in these samples. (author)

  2. Behavior of antimony isotopes in the primary coolant of WWER-1000-type nuclear reactors in NPP Kozloduy during operation and shutdown

    Energy Technology Data Exchange (ETDEWEB)

    Dobrevski, Ivan D.; Zaharieva, Neli N. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. for Nuclear Research and Nuclear Energy; Minkova, Katia F.; Gerchev, Nikolay B. [Kozloduy Nuclear Power Plant, Kozloduy (Bulgaria). Dept. of Chemistry and Radiochemistry

    2009-05-15

    This paper focuses on the behavior of the antimony isotopes {sup 122}Sb and {sup 124}Sb in the coolant of the WWER reactors in the nuclear power plant Kozloduy (Bulgaria) during operation and shutdown. It is concluded that the chemical properties of their actual precursor, the isotope {sup 121}Sb, determine the behavior of {sup 122}Sb and {sup 124}Sb during operation, load fluctuations, and shutdown as well as during the reactor coolant purification process. It is supposed that differences between the reactor bulk and the core fuel cladding surface chemistry as well as the presence of sub-cooled nucleate boiling at the fuel cladding may create conditions under which a local oxidizing environment may come into existence. (orig.)

  3. Comparison of the native antimony-bearing Paiting gold deposit, Guizhou Province, China, with Carlin-type gold deposits, Nevada, USA

    Science.gov (United States)

    Xie, Zhuo-Jun; Xia, Yong; Cline, Jean S.; Yan, Bao-Wen; Wang, Ze-Peng; Tan, Qin-Ping; Wei, Dong-Tian

    2016-03-01

    The Paiting gold deposit, Guizhou Province, China, has been regarded as a Carlin-type gold deposit by several researchers. Alteration and ore-related minerals from the Paiting deposit were examined, and results were compared with the Cortez Hills Carlin-type gold deposit, Nevada, USA. Similarities include the structural and stratigraphic controls on the orebodies in both deposits and the occurrence of invisible gold ionically bound in arsenian pyrite. Significant differences include the following: (1) The gold-bearing mineral in Nevada is arsenian pyrite. However, gold-bearing minerals in the Paiting deposit include arsenopyrite, arsenian pyrite, and trace pyrrhotite. Also, euhedral or subhedral gold-bearing arsenian pyrite at Paiting contains significantly less As, Cu, and Hg than gold-bearing pyrite from Nevada. (2) Alteration in the Paiting deposit displays significantly less decarbonatization. Instead, dolomite precipitation, which has not been described in Nevada deposits, is associated with deposition of gold-bearing sulfide minerals. (3) Stibnite and minor native antimony typify Paiting late-ore-stage minerals, whereas in Nevada, realgar, orpiment, and calcite are common late-ore-stage minerals. Precipitation of native antimony in the Paiting deposit reflects the evolution of a late-ore fluid with unusually low sulfur and oxygen fugacities. Some characteristics of the Paiting gold deposit, including formation of ore-stage dolomite and precipitation from CO2-rich ore fluids at temperatures in excess of 250 °C, are more typical of orogenic deposits than Nevada Carlin deposits. The presence of similarities in the Paiting deposit to both Carlin type and orogenic deposits is consistent with formation conditions intermediate to those typical of Carlin type and orogenic systems.

  4. Antimony, Arsenic and Chromium Speciation Studies in Biała Przemsza River (Upper Silesia, Poland) Water by HPLC-ICP-MS.

    Science.gov (United States)

    Jabłońska-Czapla, Magdalena

    2015-05-01

    In this paper the total concentration of As, Cr, Sb, pH and the red-ox potential of water and sediment samples of the Biała Przemsza River were determined. The arsenic (AB, MMA, DMA, As(III), As(V)), chromium (Cr(III), Cr(VI)) and antimony (Sb(III), Sb(V)) forms were studied by HPLC-ICP-MS. Ions were successfully separated on Hamilton PRP-X100: (AB, MMA, DMA, As(III), As(V)), Dionex Ion Pac AS-7 (Sb(III), Sb(V)) and Dionex IonPac AG7 columns: Cr(III), Cr(VI) with LOD 0.16 μg/L, 0.08 μg/L, 0.09 μg/L, 0.012 μg/L, 0.08 μg/L, 0.12 μg/L, 0.009 μg/L, 0.012 μg/L, 0.19 μg/L, 0.37 μg/L, respectively. The simplified BCR three-step sequential chemical extraction was performed on the bottom sediment samples. The samples were collected monthly, between April and December 2014, at five sampling points. Large contents of manganese, lead, cadmium and zinc were found in the Biała Przemsza River water. In December 2014, the lead content in the bottom sediment in Sławków was nearly 6000 mg/kg. In the river water, only the inorganic arsenic speciation forms were found. Sb(V), As(V) and Cr(III) were dominant. Studies have shown that arsenic, antimony and chromium were mainly bound to oxides, organic matter and sulphides in the bottom sediments. PMID:25941843

  5. Antimony, Arsenic and Chromium Speciation Studies in Biała Przemsza River (Upper Silesia, Poland Water by HPLC-ICP-MS

    Directory of Open Access Journals (Sweden)

    Magdalena Jabłońska-Czapla

    2015-04-01

    Full Text Available In this paper the total concentration of As, Cr, Sb, pH and the red-ox potential of water and sediment samples of the Biała Przemsza River were determined. The arsenic (AB, MMA, DMA, As(III, As(V, chromium (Cr(III, Cr(VI and antimony (Sb(III, Sb(V forms were studied by HPLC-ICP-MS. Ions were successfully separated on Hamilton PRP-X100: (AB, MMA, DMA, As(III, As(V, Dionex Ion Pac AS-7 (Sb(III, Sb(V and Dionex IonPac AG7 columns: Cr(III, Cr(VI with LOD 0.16 μg/L, 0.08 μg/L, 0.09 μg/L, 0.012 μg/L, 0.08 μg/L, 0.12 μg/L, 0.009 μg/L, 0.012 μg/L, 0.19 μg/L, 0.37 μg/L, respectively. The simplified BCR three-step sequential chemical extraction was performed on the bottom sediment samples. The samples were collected monthly, between April and December 2014, at five sampling points. Large contents of manganese, lead, cadmium and zinc were found in the Biała Przemsza River water. In December 2014, the lead content in the bottom sediment in Sławków was nearly 6000 mg/kg. In the river water, only the inorganic arsenic speciation forms were found. Sb(V, As(V and Cr(III were dominant. Studies have shown that arsenic, antimony and chromium were mainly bound to oxides, organic matter and sulphides in the bottom sediments.

  6. Evaluation of organelle changes in promastigotes of unresponsive leishmania tropica to meglumine antimoniate in comparison with sensitive and standard isolates by electron microscopy

    Directory of Open Access Journals (Sweden)

    Mitra Bahreini

    2015-01-01

    Full Text Available Background: The control of leishmaniasis faces serious challenges because of resistance to the first-line antimonial drugs. We aimed to evaluate the differences in organelle changes of cultivated promastigotes obtained from skin lesions of sensitive and unresponsive isolates to meglumine antimoniate (Glucantime by electron microscopy. Material and Methods: This study was done in Bam city, southeastern Iran, in which the incidence of disease has sharply increased since the earthquake in 2003. The samples were taken from 66 patients who were referred to the cutaneous leishmaniasis (CL treatment center in Bam. A questionnaire was completed for each individual, recording their demographic characteristics and CL status. The scraping smears provided from the edge of active lesions with sterile blades were fixed with methanol, stained by Giemsa, and examined under a compound light microscope for amastigote form simultaneously. To prepare the specimens for transmission electron imaging, promastigotes were centrifuged and resuspened. Results: Transmission electron microscopic study of the cultivated promastigotes revealed that there were alterations in the organelles and structures of sensitive isolates compared with unresponsive and standard ones. Organelles and structures such as mitochondria, kinetoplast, microtubules, cytoplasmic vacuoles, plasma membrane and vesicles were studied. The alterations such as disintegration of kinetoplast into thin filaments and condensation of kinetoplast DNA core, changes in size, number and location of vesicles and microtubules were observed. We noted intense cytoplasmic vacuolization, and considerable swelling of mitochondria. Conclusion: The significance and relevance of these changes might help understand drug resistance patterns and help localize the best target site for inactivating the organism.

  7. Evaluation of a Possible Synergistic Effect of Meglumine Antimoniate with Paromomycin, Miltefosine or Allopurinol on in Vitro Susceptibility of Leishmania tropica Resistant Isolate

    Directory of Open Access Journals (Sweden)

    Tahereh Rezaei Riabi

    2013-09-01

    Full Text Available Background: Pentavalent antimonials are still the first choice treatment for leishma­niasis, but with low efficacy and resistance is emerging. In the present study, the effect of meglumine antimoniate (MA, Glucantime combined with paromomy­cin, miltefosine or allopurinol on in vitro susceptibility of Leishmania tropica resistant isolate was evaluated.Method: The drugs were obtained from commercial sources and diluents of each drug in medium were prepared on the day of experiment. J774 A.1 murine macrophage cell lines were attached to the cultured on slide and incubated at 37 0C with 5% CO2 for 24 h. Then the stationary phase promastigotes were added to the cells and after 4 hrs of incubation different concentrations of MA, paromomycin, miltefosine or allopurinol were added and incubated for an additional of 72 h. Then the slides were dried and fixed with methanol, stained by Giemsa and studied under a light microscope. Drug activity was evaluated by assessing the macrophage infection rate and the number of amastigotes per infected macrophage was done by examin­ing 100 macrophages. The experiment was done in triplicates.Result: Various concentrations of MA along with paromomycin, miltefosine or allopurinol significantly inhibited (P<0.01 the proliferation of L. tropica amastigote stage in the macrophage cell line as compared with MA alone or positive control.Conclusion: Combination of Glucantime with paromomycin, miltefosine or allopuri­nol showed a synergistic effect on the clinical isolate of L. tropica in vitro. Use of combination therapy is a new hope and a logical basis for therapy of the pa­tients with cutaneous leishmaniasis. Further investigations are needed to evaluate the therapeutic effects of these drugs on the CL patients.

  8. Implementation of thermal processes for feedstock recycling of bromine and antimony, with energy recovery, from plastics waste of electrical and electronic equipment (WEEE). Phase 1. Literature survey/status update, evaluation, and ranking of combustion, gasification, and pyrolysis based technologies

    Energy Technology Data Exchange (ETDEWEB)

    Boerrigter, H. [ECN Biomass, Petten (Netherlands)

    2000-11-01

    The bromine industry wants to process plastic Waste from Electrical and Electronic Equipment (WEEE), containing brominated flame retardants (BFRs), to recycle bromine, antimony, and other valuable metals, with energy recovery for sustainable production and closing the bromine loop at the End-of-Life. The motivation to perform the underlying study was that insufficient detailed information was available regarding the technical and economical feasibility of processing of WEEE with thermal processes (i.e. combustion, gasification, and pyrolysis-based technologies). The objective of the study was to make an inventory of available processes and evaluate them based on the following six criteria:Energy efficiency, Bromine and Antimony recovery, Emissions (legislation permits), General quality of residues/secondary products, Operational experience, and Profit expectations (ROI). 57 refs.

  9. Normal coordinate analysis and quantum chemical study of tris(-fluorophenyl)antimony di(-phenylglycinate) [(-FC6H4)3Sb(O2CCH2NHC6H5)2

    Indian Academy of Sciences (India)

    Tanveer Hasan; P K Singh; K Singhal; P Raj; Neeraj Misra

    2007-10-01

    A complete normal coordinate analysis was performed by two different methods: a classical Wilson's G-F matrix method and the semi-empirical molecular orbital PM3 method, for a five coordinate tris(-fluorophenyl)antimony di( -phenylglycinate) [(-FC6H4)3Sb(O2CCH2NHC6H5)2], known to be an in vitro antitumour molecule.

  10. Highly efficient synthesis of dimethyl ether from syngas over the admixed catalyst of CuO-ZnO-Al2O3 and antimony oxide modified HZSM-5 zeolite

    International Nuclear Information System (INIS)

    A series of HZSM-5 zeolites modified with various contents of antimony oxide (0-30 wt.%) were prepared by solid state ion reaction at 500 deg. C, and the acidities of the resulted materials were characterized by temperature-programmed desorption of NH3. The direct synthesis of dimethyl ether (DME) from syngas was carried out over the admixed catalysts of an industrial CuO-ZnO-Al2O3 methanol synthesis catalyst and the parent and antimony oxide modified HZSM-5 zeolites under pressurized fixed-bed continuous flow conditions. The results indicated that modification of HZSM-5 with suitable amount of antimony oxide significantly decreased the selectivity for undesired byproducts like hydrocarbons and carbon dioxide from 9.3% and 32.4% to less than 1% and 28%, respectively, so the selectivity for DME was enhanced greatly from 55% to 69% under temperature of 260 deg. C, pressure of 4 MPa and gas hourly space velocity of 1500 mL h-1 gcat-1. The decrease in the formation of hydrocarbons and carbon dioxide can be attributed to the significant decline in the amount of strong acid sites of the HZSM-5 zeolite induced by antimony oxide modification. Additionally, the influences of the operating parameters on the performance of the most efficient catalyst were also investigated. The results showed that high reaction temperature and high gas hourly space velocity resulted in both lower carbon monoxide conversion and lower dimethyl ether selectivity, so they should be no higher than 280 deg. C and 3000 mL h-1 gcat-1, respectively.

  11. Structural consideration of antimony pentafluoride deposited on metal oxides (SiO2, Al2O3, and SiO2-Al2O3) by X-ray absorption (EXAFS/XANES) spectroscopy

    International Nuclear Information System (INIS)

    Using EXAFS/XANES, the structural environments of antimony pentafluoride deposited on SiO2, Al2O3, and SiO2-Al2O3 oxides are investigated to generate strong acid sites on the oxides. Sb-ligand bond lengths for SbF5 deposited on the oxides vary depending on the type of oxide. 31 refs., 6 figs., 2 tabs

  12. Combined effect of strontium modifier and antimony refiner on texture and growth mode of eutectic phase in an Al-11Si-2Cu-0.8Zn-0.6Fe cast alloy

    Science.gov (United States)

    Farahany, Saeed; Ourdjini, Ali; Hekmat-Ardakan, Alireza

    2015-12-01

    Results of electron back-scattered diffraction and transmission electron microscopy studies reveal that the orientation of aluminium in the eutectic phase is different from the surrounding aluminium dendrites and that twin spacing of eutectic silicon increased significantly due to the interaction between strontium and antimony. In addition, the formation of ternary Mg2Sb2Sr intermetallic compound that precedes the eutectic reaction was proposed to be responsible for interaction.

  13. PREPARATION AND CHARACTERIZATION OF ANTIMONY DOPED TIN OXIDE NANOPARTICLES%纳米锑掺杂氧化锡的制备及表征

    Institute of Scientific and Technical Information of China (English)

    龚圣; 陈泽成; 唐富龙; 皮丕辉; 文秀芳; 郑大锋; 程江; 杨卓如

    2009-01-01

    SnCl4·5H2O and SbCl3 were used as the initial materials to prepare antimony-doped tin oxide (ATO) nanoparticles by sol-gel method combined with the supercritical fluid drying technique. The microstructure and doping mechanism of the precursor and the ATO particles were investigated by simultaneous thermogravimetry-differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The effect of the drying method and the annealing temperature on the morphology, size, dispersion and crystallinity of particles were also investigated. The mechanism of the super-critical CO2 fluid drying on the precursor alcogels was discussed. The results show that the doped ATO particles with a soft agglomer-ate and a tetragonal phase structure in the size range of 15-30 nm could be obtained.%以无机盐SnCl4·5H2O和SbCl3为初始原料,以乙醇作为溶剂,采用溶胶-凝胶法结合超临界流体干燥(supercritical fluid drying,SCFD)技术制备了纳米锑掺杂氧化锡(antimony doped tin oxide.ATO)粉体.通过热重-差示扫描热分析、X射线衍射、扫描电子显微镜、透射电镜,对前驱体粒子以及ATO粒子的结构进行了分析.探讨了热处理温度、前驱体千燥方式对前驱体以及纳米粒子的形貌、粒径、分散性、晶型、结晶度的影响,并讨论了SCFD技术干燥前驱体的机理.结果表明:采用溶胶-凝胶法结合超临界CO2干燥技术,在给定的反应条件下,能够制得疏松的、良好掺杂的四方型结构的纳米ATO粒子,粒径约15~30nm,分散性好.

  14. Effects of Antimony on Microstructure and Mechanical Properties of A356 Alloy%Sb变质A356合金的组织与力学性能

    Institute of Scientific and Technical Information of China (English)

    申玉彬; 王明星; 刘志勇; 刘忠侠; 宋天福

    2012-01-01

    The modification of antimony (Sb) on eutectic Si phase in A356 aluminum-silicon alloy and the effects of rare earth (RE) on the modification efficiency of antimony were investigated, and effects of the strontium (Sr) on A356 alloy were analyzed comparatively. The tensile and fatigue properties of the Sb, Sb+RE or Sr modified A356 alloys were also analyzed comparatively. The results show that Sb can refine the eutectic silicon phases in A356 alloy significantly from plate-like into fine fibrous structure. , However, the modification efficiency of Sb is.lower than Sr. The modification effects can be improved obviously in Sb modified A356 aluminum-silicon alloy with the addition of a little RE, decreasing of Sb content for achieving the desirable modification efficiency. The tensile properties of the Sb or Sb + RE modified A356 alloys are lower than those of the Sr modified alloy, however, the fatigue properties are superior to that of the Sr modified alloy, which may be attributed to the higher compactness and less casting defects in Sb or Sb+RE modified alloys compared with the Sr modified alloy.%研究了Sb对A356合金中共晶Si相的变质作用及RE对Sb变质作用的影响,并且与Sr变质合金进行了比较,对Sb、Sb+RE以及Sr变质A356合金的拉伸及疲劳性能进行了对比.结果表明,Sb的A356合金变质使共晶Si相由粗大的板片状转化为细小的纤维状,但变质效果不如Sr;用Sb变质处理时,加入少量的RE,可明显改善Sh的变质效果,降低获得最佳变质效果的Sb含量;合金变质的力学性能不如Sr变质合金,但疲劳性能明显优于Sr变质合金.其原因可能与Sb或Sb+RE变质合金的致密性较Sr变质合金高、铸造缺陷较Sr变质合金少有关.

  15. Investigation of strontium and uranium sorption onto zirconium-antimony oxide/polyacrylonitrile (Zr-Sb oxide/PAN) composite using experimental design

    International Nuclear Information System (INIS)

    Highlights: • We model Sr2+ and UO22+ sorption onto Zr-Sb oxide/PAN composite. • Central composite design was separately employed for Sr2+ and UO22+ sorption. • The model F values indicate that both models are statistically significant. • All of the single factors were determined as significant for the sorption of Sr2+ and UO22+. • Zr-Sb oxide/PAN can be used effectively for Sr2+ and UO22+ removal from acidic solutions. - Abstract: A study on the sorption of strontium (Sr2+) and uranium (UO22+) onto zirconium-antimony oxide/PAN (Zr-Sb oxide/PAN) composite was conducted. The zirconium-antimony oxide was synthesized and was then turned into composite spheres by mixing it with polyacrylonitrile (PAN). The single and combined effects of independent variables such as initial pH, temperature, initial ion concentration and contact time on the sorption of Sr2+ and UO22+ were separately analyzed using response surface methodology (RSM). Central composite design (CCD) was separately employed for Sr2+ and UO22+ sorption. Analysis of variance (ANOVA) revealed that all of the single effects found statistically significant on the sorption of Sr2+ and UO22+. Probability F-values (F = 2.45 × 10−08 and F = 9.63 × 10−12 for Sr2+ and UO22+, respectively) and correlation coefficients (R2 = 0.96 for Sr2+ and R2 = 0.98 for UO22+) indicate that both models fit the experimental data well. At optimum sorption conditions Sr2+ and UO22+ sorption capacities of the composite were found as 39.78 and 60.66 mg/g, respectively. Sorption isotherm data pointed out that Langmuir model is more suitable for the Sr2+ sorption, whereas the sorption of UO22+ was correlated well with the Langmuir and Freundlich models. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° indicate that Sr2+ and UO22+ sorption processes are endothermic and spontaneous

  16. A study on antimony determination in environmental samples by neutron activation analysis: validation of the methodology and determination of the uncertainty of the measurement

    International Nuclear Information System (INIS)

    Antimony is an element found in low concentrations in the environment. However, its determination has attracted great interest due to the knowledge of its toxicity and increasing application in industry. The determination of antimony has been a challenge for researchers since this element is found in low concentrations which make its analysis a difficult task. Therefore, although neutron activation analysis (NAA) is an appropriate method for the determination of various elements in different types of matrix, in the case of Sb its analysis presents some difficulties, mainly due to spectral interferences. The objective of this research was to validate the NAA method for Sb determination in environmental samples. To establish appropriate conditions for Sb determinations, preliminary assays were carried out for further analysis of certified reference materials (CRM). The experimental procedure was to irradiate samples with a synthetic Sb standard for a period of 8 or 16 hours in the IEA-R1 nuclear research reactor, followed by gamma ray spectrometry. The quantification of Sb was performed by measuring the radioactive isotopes of 122Sb and '124Sb. The results of preliminary assays indicated the presence of Sb in Whatman no 40 filter paper used in the preparation of the synthetic standard, but at very low concentrations, which could be considered negligible. In the case of the plastic material used in bags for the sample irradiation, it should be chosen carefully, because depending on the thickness, they may contain Sb. The analyses of the stability of the diluted Sb standard solution showed no change in the Sb concentration within eight months after its preparation. Results obtained in the analysis of certified reference materials indicated the interference of 76As and also of 134Cs and 152Eu in the Sb determinations by measuring '122Sb, due to the proximity of the gamma ray energies. The high activity of '24Na can also mask the peak of 122Sb hindering its detection

  17. Surface plasmon resonance in nano-gold antimony glass-ceramic dichroic nanocomposites: One-step synthesis and enhanced fluorescence application

    International Nuclear Information System (INIS)

    A single-step melt-quench in situ thermochemical reduction technique has been used to synthesize a new series of Auo nanoparticles embedded antimony glass-ceramic (K2O-B2O3-Sb2O3-ZnO) dichroic nanocomposites. X-ray and selected area electron diffractions manifest growth of Auo nanoparticles along (2 0 0) planes. The particle sizes obtained from X-ray diffraction patterns are found to vary in the range 4-21 nm. Dichroic behavior is attributed to the elliptical shape gold nanoparticles having aspect ratio 1.2, as observed from the transmission electron microscopy (TEM) images. The Auo nanoparticles exhibit surface plasmon resonance band (SPR) around 600 nm, which experiences red-shifts with increasing Au concentration. These nanocomposites when co-doped with Sm2O3 and excited at 949 nm, exhibit 2-fold intensification of 636 nm red emission transition (4G5/2 → 6H9/2) due to SPR induced local field enhancement of Auo nanoparticles and are promising materials for display applications.

  18. Sources, migration and transformation of antimony contamination in the water environment of Xikuangshan, China: Evidence from geochemical and stable isotope (S, Sr) signatures.

    Science.gov (United States)

    Wen, Bing; Zhou, Jianwei; Zhou, Aiguo; Liu, Cunfu; Xie, Lina

    2016-11-01

    The Xikuangshan (XKS) mine in central China is the largest antimony (Sb) mine in the world. The mining activity has seriously contaminated the waters in the area. To determine the sources, migration and transformation of Sb contamination, 32 samples from groundwater (aquifer water), surface water and mine water were collected for water chemistry, trace element and SSO4 and Sr stable isotope analyses. The results showed that the groundwater and surface water were in an oxidized environment. The SSO4 and Sr isotope compositions in the water indicated that dissolved Sb and SO4(2) originated from sulfide mineral (Sb2S3) oxidation, whereas radiogenic Sr may have been sourced from silicified limestone and stibnite in the Shetianqiao aquifer. Furthermore, a positive correlation between δ(34)SSO4 and δ(87)Sr values revealed that the Sr, S and Sb in the waters had a common contamination source, i.e., silicified limestone and stibnite, whereas the Sr, S and Sb in rock and ore were sourced from Proterozoic basement clastics. The analysis also indicated that the isotope composition of dissolved SO4(2-) had been influenced by slight bacterial SO4 reduction in the Magunao aquifer. Mining or rock collapse may have caused Shetianqiao aquifer water to contaminate the Magunao aquifer water via mixing. This study has demonstrated that the stable isotopes of (34)SSO4 and (87)Sr, combined with hydrochemical methods, are effective in tracking the sources, migration and transformation of Sb contamination. PMID:27341112

  19. Ion-exchange separation of radioiodine and its application to production of 124I by alpha particle induced reactions on antimony

    International Nuclear Information System (INIS)

    The basic parameters related to radiochemical separation of iodine from tellurium and antimony by anion-exchange chromatography using the resin Amberlyst A26 were studied. The separation yield of 124I amounted to 96% and the decontamination factor from 121Te and 122Sb was > 104. The method was applied to the production of 124I via the 123Sb(α, 3n) reaction. In an irradiation of 110 mg of natSb2O3 (thickness ∝0.08 g/cm2) with 38 MeV α-particles at 1.2 μA beam current for 4 h, corresponding to the beam energy range of Eα = 37 → 27 MeV, the batch yield of 124I obtained was 12.42 MBq and the 125I and 126I impurities amounted to 3.8% and 0.7%, respectively. The experimental batch yield of 124I amounted to 80% of the theoretically calculated value but the level of the radionuclidic impurities were in agreement with the theoretical values. About 96% of the radioiodine was in the form of iodide and the inactive impurities (Te, Sb, Sn) were below the permissible level. Due to the relatively high level of radionuclidic impurity the 124I produced would possibly be useful only for restricted local consumption or for animal experiments.

  20. Structural, electrical, and optical properties of antimony-doped tin oxide films prepared at room temperature by radio frequency magnetron sputtering for transparent electrodes

    International Nuclear Information System (INIS)

    Antimony-doped tin oxide (ATO) films were prepared on 7059 Corning glass substrate by the radio frequency (rf) magnetron sputtering method using SnO2 target mixed with Sb of 6 wt % at room temperature. The working pressure was varied from 0.67 to 2 Pa in steps of 0.67 Pa, and the rf power was varied from 100 to 175 W in steps of 25 W at room temperature. The thickness of the deposited ATO films was about 150 nm. X-ray diffraction (XRD) measurements showed the ATO films to be crystallized with a strong (101) preferred orientation as the rf power is increased. The spectra revealed that the deposited films were polycrystalline, retaining the tetragonal structure. The grain size was estimated from the XRD spectra using the Scherrer equation and found to decrease with a decrease in the working pressure and an increase in the rf power, while the surface roughness was observed to be smoothened. The ATO film that was deposited at a working pressure of 0.67 Pa with rf power of 175 W showed the lowest resistivity of 8.6x10-3 Ω cm, and the optical transmittance was 86.5% in the visible wavelength range from 400 to 800 nm.

  1. Ion-exchange separation of radioiodine and its application to production of {sup 124}I by alpha particle induced reactions on antimony

    Energy Technology Data Exchange (ETDEWEB)

    Shuza Uddin, Md. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Medizin, INM-5: Nuklearchemie; Atomic Energy Research Establishment, Inst. of Nuclear Science and Technology, Dhaka (Bangladesh); Qaim, Seyed M.; Spahn, Ingo; Spellerberg, Stefan; Scholten, Bernhard; Coenen, Heinz H. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Medizin, INM-5: Nuklearchemie; Hermanne, Alex [Vrije Univ. Brussel (Belgium). Cyclotron Lab.; Hossain, Syed Mohammod [Atomic Energy Research Establishment, Inst. of Nuclear Science and Technology, Dhaka (Bangladesh)

    2015-07-01

    The basic parameters related to radiochemical separation of iodine from tellurium and antimony by anion-exchange chromatography using the resin Amberlyst A26 were studied. The separation yield of {sup 124}I amounted to 96% and the decontamination factor from {sup 121}Te and {sup 122}Sb was > 10{sup 4}. The method was applied to the production of {sup 124}I via the {sup 123}Sb(α, 3n) reaction. In an irradiation of 110 mg of {sup nat}Sb{sub 2}O{sub 3} (thickness ∝0.08 g/cm{sup 2}) with 38 MeV α-particles at 1.2 μA beam current for 4 h, corresponding to the beam energy range of E{sub α} = 37 → 27 MeV, the batch yield of {sup 124}I obtained was 12.42 MBq and the {sup 125}I and {sup 126}I impurities amounted to 3.8% and 0.7%, respectively. The experimental batch yield of {sup 124}I amounted to 80% of the theoretically calculated value but the level of the radionuclidic impurities were in agreement with the theoretical values. About 96% of the radioiodine was in the form of iodide and the inactive impurities (Te, Sb, Sn) were below the permissible level. Due to the relatively high level of radionuclidic impurity the {sup 124}I produced would possibly be useful only for restricted local consumption or for animal experiments.

  2. Low-voltage antimony-doped SnO2 nanowire transparent transistors gated by microporous SiO2-based proton conductors

    Institute of Scientific and Technical Information of China (English)

    Xuan Rui-Jie; Liu Hui-Xuan

    2012-01-01

    A battery drivable low-voltage transparent lightly antimony(Sb)-doped SnO2 nanowire electric-double-layer (EDL)field-effect transistor (FET) is fabricated on an ITO glass substrate at room temperature.An ultralow operation voltage of 1 V is obtained on account of an untralarge specific gate capacitance (~ 2.14 μF/cm2) directly bound up with mobile ions-induced EDL (sandwiched between the top and bottom electrodes) effect.The transparent FET shows excellent electric characteristics with a field-effect mobility of 54.43 cm2/V.s,current on/off ration of 2 × 104,and subthreshold gate voltage swing (S =dVgs/d(logIds)) of 140 mV/decade.The threshold voltage Vth (0.1 V) is estimated which indicates that the SnO2 namowire transistor operates in an n-type enhanced mode.Such a low-voltage transparent nanowire transistor gated by a microporous SiO2-based solid electrolyte is very promising for battery-powered portable nanoscale sensors.

  3. Investigation of upconversion luminescence in Yb3+/Tm3+/Ho3+ triply doped antimony-germanate glass and double-clad optical fiber

    Science.gov (United States)

    Zmojda, Jacek; Kochanowicz, Marcin; Miluski, Piotr; Righini, Giancarlo C.; Ferrari, Maurizio; Dorosz, Dominik

    2016-08-01

    The optical properties of novel antimony-germanate glass and optical fiber co-doped with Yb3+/Tm3+/Ho3+ ions were presented. White light luminescence in glass was observed as a result of energy transfer with upconversion between donor (Yb3+) and acceptors (Tm3+, Ho3+) ions under 976 nm excitation. The double-clad optical fiber with off-set core co-doped with Yb2O3/Tm2O3/Ho2O3 system was fabricated using a modified rod-in-tube technique. In glass co-doped with 0.5 mol%Yb2O3/0.1 mol%Tm2O3/0.2 mol%Ho2O3 the spectral distribution of three luminescence bands (478, 545 and 660 nm) corresponds to x = 0.35 and y = 0.32 CIE coordinates. In comparison to glass the optical fiber emission are located in the green region (CIE, x = 0.37, y = 0.49).

  4. Enhanced separation efficiency of photoinduced charges for antimony-doped tin oxide (Sb-SnO2)/TiO2 heterojunction semiconductors with varied Sb doping concentration

    International Nuclear Information System (INIS)

    In this paper, antimony-doped tin oxide (Sb-SnO2) nanoparticles were synthesized with varied Sb doping concentration, and the Sb-SnO2/TiO2 heterojunction semiconductors were prepared with Sb-SnO2 and TiO2. The separation efficiency of photoinduced charges was characterized with surface photovoltage (SPV) technique. Compared with Sb-SnO2 and TiO2, Sb-SnO2/TiO2 presents an enhanced separation efficiency of photoinduced charges, and the SPV enhancements were estimated to be 1.40, 1.43, and 1.99 for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. To understand the enhancement, the band structure of Sb-SnO2 and TiO2 in the heterojunction semiconductor was determined, and the conduction band offsets (CBO) between Sb-SnO2 and TiO2 were estimated to be 0.56, 0.64, and 0.98 eV for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. These results indicate that the separation efficiency enhancement is resulting from the energy level matching, and the increase of enhancement is due to the rising of CBO

  5. Enhanced separation efficiency of photoinduced charges for antimony-doped tin oxide (Sb-SnO2)/TiO2 heterojunction semiconductors with varied Sb doping concentration

    Science.gov (United States)

    Zhang, Zhen-Long; Ma, Wen-Hai; Mao, Yan-Li

    2014-09-01

    In this paper, antimony-doped tin oxide (Sb-SnO2) nanoparticles were synthesized with varied Sb doping concentration, and the Sb-SnO2/TiO2 heterojunction semiconductors were prepared with Sb-SnO2 and TiO2. The separation efficiency of photoinduced charges was characterized with surface photovoltage (SPV) technique. Compared with Sb-SnO2 and TiO2, Sb-SnO2/TiO2 presents an enhanced separation efficiency of photoinduced charges, and the SPV enhancements were estimated to be 1.40, 1.43, and 1.99 for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. To understand the enhancement, the band structure of Sb-SnO2 and TiO2 in the heterojunction semiconductor was determined, and the conduction band offsets (CBO) between Sb-SnO2 and TiO2 were estimated to be 0.56, 0.64, and 0.98 eV for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. These results indicate that the separation efficiency enhancement is resulting from the energy level matching, and the increase of enhancement is due to the rising of CBO.

  6. (Vapor + Liquid) Equilibrium (VLE) for Binary Lead-Antimony System in Vacuum Distillation: New Data and Modeling Using Nonrandom Two-Liquid (NRTL) Model

    Science.gov (United States)

    Xu, Junjie; Kong, Lingxin; Xu, Baoqiang; Yang, Bin; You, Yanjun; Xu, Shuai; Zhou, Yuezhen; Li, Yifu; Liu, Dachun

    2016-09-01

    In this work, new experimental vapor-liquid equilibrium (VLE) data of lead-antimony alloy (Pb-Sb alloy) in vacuum distillation are reported. The activity coefficients of components of Pb-Sb alloy were calculated by using the NRTL model. The calculated average relative deviations were ±0.1425 and ±0.2433 pct, and the average standard deviations were ±0.0009 and ±0.0007, respectively, for Pb and Sb. The VLE phase diagrams, such as the temperature composition ( T- x) and pressure composition ( P-x) diagrams of Pb-Sb alloy in vacuum distillation were predicted based on the NRTL model and VLE theory. The predicted results are consistent with the new experimental data indicating that VLE phase diagrams obtained by this method are reliable. The VLE phase diagrams of alloys will provide an effective and intuitive way for the technical design and realization of recycling and separation processes. The VLE data may be used in separation processes design, and the thermodynamic properties as the key parameters in specific applications.

  7. Antimony-Supported Cu4I4 Cuboid with Short Cu-Cu Bonds: Structural Premise for Near-Infrared Thermoluminescence.

    Science.gov (United States)

    Taylor, William V; Soto, Ulysses H; Lynch, Vincent M; Rose, Michael J

    2016-04-01

    Herein we report the synthesis, temperature-dependent X-ray structures (100, 150, 200, 250, 273, and 300 K), and solid-state emissive properties of the antimony-copper(I)-iodo cluster [Cu4(I)4(Sb(i)Pr3)4] (1), supported by the trialkylantimony donor Sb(i)Pr3. Overall, 1 exhibits a distorted cuboidal structure, wherein a twisting of the "cube" generates an interconnected Cu4 tetrahedron, as well as long Cu-I and Cu-Sb bonds [e.g., 2.707(2) and 2.571(2) Å]; in the 100 K X-ray structure, the Cu-Cu bonds are quite short [2.761(3) Å]. Solid-state emission spectra of 1 were obtained over a range of temperatures (163-298 K), wherein 1 exhibits only a low-energy emission feature centered near 700 nm (λEm = 711 nm, fwhm = 150 nm, and λEx = 390 nm). Because 1 contains no aryl units, the emission spectrum (and absorption) can be unambiguously attributed to the Cu4I4 core [no L (pnictogen ligand) component]. The luminescence is sharply attenuated upon warming from 150 to 200 K. An overlaid plot of the emissive properties of 1 and its Cu-Cu bond distances [2.761(3)-2.836(4) Å] reveal that ∼2.80 Å represents a critical crossing point for low-energy thermoluminescence in Cu4-based clusters. PMID:27010917

  8. Vortex-assisted surfactant-enhanced emulsification microextraction based on solidification of floating organic drop followed by electrothermal atomic absorption spectrometry for speciation of antimony (ΙΙΙ, V).

    Science.gov (United States)

    Eftekhari, Mohammad; Chamsaz, Mahmoud; Arbab-Zavar, Mohammad Hossein; Eftekhari, Ali

    2015-01-01

    Vortex-assisted surfactant-enhanced emulsification microextraction based on solidification of floating organic drop (VASEME-SFO) was used for preconcentration and speciation of antimony (ΙΙΙ, V) followed by electrothermal atomic absorption spectrometry (ETAAS). In this procedure, Triton X-114 was used as emulsifier and 1-undecanol was used as extraction solvent. This method is based on the complexation of Sb(ΙΙΙ) with dithizone (as complexing agent) at pH 2 and extraction of the resulting hydrophobic complex into the extraction solvent (1-undecanol) with vortex-assisted liquid phase microextraction, whereas Sb(V) remained in solution. Sb(ΙΙΙ) in extraction solvent was directly analyzed by ETAAS after dilution with ethanol, and Sb(V) was calculated by subtracting Sb(ΙΙΙ) from the total antimony after reducing Sb(V) to Sb(ΙΙΙ) by L-cysteine. Under the optimized condition, the calibration curve was linear in the range of 0.4-8 μg L(-1) of Sb(ΙΙΙ) with a correlation coefficient of 0.9995. The detection limit based on three times of the standard deviation of the blank (n = 8) was 0.09 μg L(-1). The validation and the recovery of the proposed method were performed by the analysis of a certified reference material and spike method. The obtained results were in very good agreements with certified values. The proposed method was successfully applied for the determination of antimony species at trace levels in different water samples. PMID:25404541

  9. Development and pharmacokinetic of antimony encapsulated in liposomes of phosphatidylserine using radioisotopes in experimental leishmaniasis; Desenvolvimento e farmacocinetica de antimonio encapsulado em lipossomas de fosfatidilserina utilizando radioisotopos em leishmaniose experimental

    Energy Technology Data Exchange (ETDEWEB)

    Borborema, Samanta Etel Treiger

    2010-07-01

    Leishmaniasis are a complex of parasitic diseases caused by intra macrophage protozoa of the genus Leishmania, and is fatal if left untreated. Pentavalent antimonials, though toxic and their mechanism of action being unclear, remain the first-line drugs for treatment. Effective therapy could be achieved by delivering antileishmanial drugs to these sites of infection. Liposomes are phospholipid vesicles that promote improvement in the efficacy and action of drugs in target cell. Liposomes are taken up by the cells of mononuclear phagocytic system (MPS). The purpose of this study was to develop a preparation of meglumine antimonate encapsulated in liposomes of phosphatidylserine and to study its pharmacokinetic in healthy mice to establish its metabolism and distribution. Quantitative analysis of antimony from liposomes demonstrated that Neutron Activation Analysis was the most sensitive technique with almost 100 % of accuracy. All liposome formulations presented a mean diameter size of 150 nm. The determination of IC{sub 50} in infected macrophage showed that liposome formulations were between 10 - 63 fold more effective than the free drug, indicating higher selectivity index. By fluorescence microscopy, an increased uptake of fluorescent-liposomes was seen in infected macrophages during short times of incubation compared with non-infected macrophages. Biodistribution studies showed that meglumine antimonate irradiated encapsulated in liposomes of phosphatidylserine promoted a targeting of antimony for MPS tissues and maintained high doses in organs for a prolonged period. In conclusion, these data suggest that meglumine antimonate encapsulated in liposomes showed higher effectiveness than the non-liposomal drug against Leishmania infection. The development of liposome formulations should be a new alternative for the chemotherapy of infection diseases, especially Leishmaniasis, as they are used to sustain and target pharmaceuticals to the local of infection. (author)

  10. Syntheses and characterization of one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs)

    Energy Technology Data Exchange (ETDEWEB)

    Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

    2015-01-15

    Three new isostructural quaternary antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) have been synthesized by using alkali metal thiosulfate flux and structurally characterized by X-ray diffraction. Their structures contain A{sup +} ions around the [Sb{sub 2}Sn{sub 3}S{sub 10}]{sup 2−} chains, which are built from SbS{sub 3} pyramids, SnS{sub 6} octahedra and SnS{sub 4} tetrahedra. Raman and Mössbauer spectroscopic measurements corroborate the oxidation states and coordination environments of Sb(III) and Sn(IV). All three compounds are wide band gap semiconductors. Potassium compound undergoes partial exchange with strontium, cadmium and lead ions. - Graphical abstract: Syntheses, crystal structure, spectroscopic and partial ion-exchange studies of new one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) are described. - Highlights: • Syntheses of new alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs). • Wide band gap semiconductors with one-dimensional structure. • Topotactic partial exchange of K{sup +} ions of K{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} with Sr{sup 2+}, Cd{sup 2+} and Pb{sup 2+} ions.

  11. Antimony (Sb) and lead (Pb) in contaminated shooting range soils: Sb and Pb mobility and immobilization by iron based sorbents, a field study.

    Science.gov (United States)

    Okkenhaug, Gudny; Grasshorn Gebhardt, Karl-Alexander; Amstaetter, Katja; Lassen Bue, Helga; Herzel, Hannes; Mariussen, Espen; Rossebø Almås, Åsgeir; Cornelissen, Gerard; Breedveld, Gijs D; Rasmussen, Grete; Mulder, Jan

    2016-04-15

    Small-arm shooting ranges often receive a significant input of lead (Pb), copper (Cu) and antimony (Sb) from ammunition. The goal of the present study was to investigate the mobility, distribution and speciation of Pb and Sb pollution under field conditions in both untreated and sorbent-amended shooting range soil. Elevated Sb (19-349μgL(-1)) and Pb (7-1495μgPbL(-1)) concentrations in the porewater of untreated soil over the four-year test period indicated a long-term Sb and Pb source to the adjacent environment in the absence of remedial measures. Mixing ferric oxyhydroxide powder (CFH-12) (2%) together with limestone (1%) into the soil resulted in an average decrease of Sb and Pb porewater concentrations of 66% and 97%, respectively. A similar reduction was achieved by adding 2% zerovalent iron (Fe°) to the soil. The remediation effect was stable over the four-year experimental period indicating no remobilization. Water- and 1M NH4NO3-extractable levels of Sb and Pb in field soil samples indicated significant immobilization by both treatments (89-90% for Sb and 89-99% for Pb). Results from sequential extraction analysis indicate fixation of Sb and Pb in less accessible fractions like amorphous iron oxides or even more crystalline and residual mineral phases, respectively. This work shows that amendment with Fe-based sorbents can be an effective method to reduce the mobility of metals both in cationic and anionic form in polluted shooting range soil. PMID:26799225

  12. Failure of antimony trioxide to induce micronuclei or chromosomal aberrations in rat bone-marrow after sub-chronic oral dosing.

    Science.gov (United States)

    Kirkland, David; Whitwell, James; Deyo, James; Serex, Tessa

    2007-03-01

    Antimony trioxide (Sb2O3, CAS 1309-64-4) is widely used as a flame retardant synergist in a number of household products, as a fining agent in glass manufacture, and as a catalyst in the manufacture of various types of polyester plastics. It does not induce point mutations in bacteria or mammalian cells, but is able to induce chromosomal aberrations (CA) in cultured cells in vitro. Although no CA or micronuclei (MN) have been induced after acute oral dosing of mice, repeated oral dosing for 14 or 21 days resulted in increased CA in one report, but did not result in increased MN in another. In order to further investigate its in vivo genotoxicity, Sb2O3 was dosed orally to groups of rats for 21 days at 250, 500 and 1000 mg/kg day. There were no clinical signs of toxicity in the Sb2O3-exposed animals except for some reductions in body-weight gain in the top dose group. Toxicokinetic measurements in a separate study confirmed bone-marrow exposure, and at higher levels than would have been achieved by single oral dosing. Large numbers of cells were scored for CA (600 metaphases/sex group) and MN (12,000 PCE/sex group) but frequencies of CA or MN in Sb2O3-treated rats were very similar to controls, and not biologically or statistically different, at all doses. These results provide further indication that Sb2O3 is not genotoxic to the bone marrow of rodents after 21 days of oral administration at high doses close to the maximum tolerated dose. PMID:17174592

  13. The chromosomal arsenic resistance genes of Thiobacillus ferrooxidans have an unusual arrangement and confer increased arsenic and antimony resistance to Escherichia coli.

    Science.gov (United States)

    Butcher, B G; Deane, S M; Rawlings, D E

    2000-05-01

    The chromosomal arsenic resistance genes of the acidophilic, chemolithoautotrophic, biomining bacterium Thiobacillus ferrooxidans were cloned and sequenced. Homologues of four arsenic resistance genes, arsB, arsC, arsH, and a putative arsR gene, were identified. The T. ferrooxidans arsB (arsenite export) and arsC (arsenate reductase) gene products were functional when they were cloned in an Escherichia coli ars deletion mutant and conferred increased resistance to arsenite, arsenate, and antimony. Therefore, despite the fact that the ars genes originated from an obligately acidophilic bacterium, they were functional in E. coli. Although T. ferrooxidans is gram negative, its ArsC was more closely related to the ArsC molecules of gram-positive bacteria. Furthermore, a functional trxA (thioredoxin) gene was required for ArsC-mediated arsenate resistance in E. coli; this finding confirmed the gram-positive ArsC-like status of this resistance and indicated that the division of ArsC molecules based on Gram staining results is artificial. Although arsH was expressed in an E. coli-derived in vitro transcription-translation system, ArsH was not required for and did not enhance arsenic resistance in E. coli. The T. ferrooxidans ars genes were arranged in an unusual manner, and the putative arsR and arsC genes and the arsBH genes were translated in opposite directions. This divergent orientation was conserved in the four T. ferrooxidans strains investigated. PMID:10788346

  14. People with diabetes, respiratory, liver or mental disorders, higher urinary antimony, bisphenol A, or pesticides had higher food insecurity: USA NHANES, 2005-2006.

    Science.gov (United States)

    Shiue, Ivy

    2016-01-01

    This study was aimed to examine the prevalence of food insecurity and what social, health, and environmental characteristics could constitute such situation in a national and population-based setting. Data was retrieved from the National Health and Nutrition Examination Survey, 2005-2006. Information on demographics, lifestyle factors, self-reported ever medical conditions in the past and self-reported food security conditions in the last 12 months calculated on the household level was obtained by household interview. Bloods and urines (subsample) were collected at the interview as well. Only adults aged 20 years and above (n = 4979) were included for statistical analysis in the present study. Chi-square test, t test, and survey-weighted logistic regression modeling were performed. Three thousand eight hundred thirty-four (77.9%) people were with full food security, 466 (9.5%) people were with marginal food security and 624 (12.7%) people were with low or very low food security. Being younger, having higher ratios of family income to poverty thresholds (due to low level of education or lack of financial support), having prior asthma, arthritis, chronic bronchitis, depression, diabetes, eczema, emphysema or liver problems, having higher levels of serum cotinine, urinary antimony, bisphenol A, pesticides, or having lower levels of urinary Benzophenone-3 were associated with food insecurity. In addition to socioeconomic and smoking conditions, evidence on people with several prior health conditions and being exposed to environmental chemicals and food insecurity is further provided. Future social, health and environmental policy, and programs protecting people from food insecurity by considering both health and environmental factors mentioned above would be suggested. PMID:26517997

  15. 三氧化二锑纳米粒子的形貌控制合成%Synthesis of Shape Controllable Antimony Trioxide Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    赵淑贤

    2015-01-01

    文章通过机械搅拌下,把三氯化锑乙醇溶液直接滴加到壬基苯酚聚氧乙烷(50)醚(TX-50)溶液中,得到了形貌较好、长20μm左右的带束状Sb2 O3纳米材料。通过X射线能谱( EDS),X射线衍射谱( XRD)和扫描电镜( SEM)对材料的结构和形貌进行了表征,研究了反应温度、氨水浓度、表面活性剂对三氧化二锑纳米粒子形貌和纯度的影响。相对于商品Sb2 O3,阻燃性能有所提高。%The belt-bundle Sb2 O3 nanoparticles were synthesized by adding dropwise the antimony butter etha⁃nol solution into the Nonylphenol polyethylene oxide ethane (50) ether aqueous solution(TX-50) with stirring. The effects of reaction temperature, ammonia concentration and surfactant on the morphology and purity of nanopar⁃ticles were studied respectively. The purity, crystal structure and morphology were characterized by energy disper⁃sive X-ray spectroscopy( EDS)、X-ray diffraction( XRD) and scanning electron microscopy ( SEM) . The flame re⁃tardant property of synthesized Sb2 O3 was improved compared with commercial grade Sb2 O3 .

  16. DNA cleavage, antimicrobial studies and a DFT-based QSAR study of new antimony(III) complexes as glutathione reductase inhibitor.

    Science.gov (United States)

    Tunç, Turgay; Koç, Yasemin; Açık, Leyla; Karacan, Mehmet Sayım; Karacan, Nurcan

    2015-02-01

    New antimony(III) complexes, [Sb(2-aminopyridine)2Cl3] (1a), [Sb(2-aminopyridine)2Br3] (1b), [Sb(5-methyl-2-aminopyridine)2Cl3] (2a), [Sb(5-methyl-2-aminopyridine)2Br3] (2b), [Sb(2-aminopyrimidine)2Cl3] (3a), [Sb(2-aminopyrimidine)2Br3] (3b), [Sb(4,6-dimethoxy-2-aminopyrimidine)2Cl3] (4a), [Sb(4,6-dimethoxy-2-aminopyrimidine)2Br3] (4b), [Sb(2-amino-1,3,5-triazine)2Cl3] (5a), [Sb(2-amino-1,3,5-triazine)2Br3] (5b), [Sb(2-guanidinobenzimidazole) Cl3] (6a), [Sb(2-guanidinobenzimidazole)Br3] (6b) [Sb(2- benzyl-2-thiopseudeourea)2Cl3] (7a) and [Sb(2- benzyl-2-thiopseudeourea)2Br3] (7b) were synthesized. Their structures were characterized by elemental analysis, molecular conductivity, FT-IR, (1)H NMR, LC-MS techniques. Glutathione reductase inhibitor activity, antimicrobial activity and DNA cleavage studies of the complexes were determined. The geometrical structures of the complexes were optimized by DFT/B3LYP method with LANL2DZ as basis set. Calculation results indicated that the equilibrium geometries of all complexes have square pyramidal shape. About 350 molecular descriptors (constitutional, topological, geometrical, electrostatic and quantum chemical parameters) of the complexes were calculated by DFT/B3LYP/LANL2DZ method with CODESSA software. Calculated molecular parameters were correlated to glutathione reductase inhibitory activity values (pIC50) of all complexes by Best Multi-Linear Regression (BMLR) method. Obtained two-parameter QSAR equation shows that increase in "maximum partial charge for a H atom" and decrease in HOMO-LUMO gap would be favorable for the glutathione reductase inhibitory activity. PMID:25459701

  17. In-situ growth of antimony sulfide in carbon nanoparticle matrix: Enhanced electrocatalytic activity as counter electrode in dye-sensitized solar cells

    Science.gov (United States)

    Sun, Panpan; Zhang, Ming; Ai, Changzhi; Wu, Zhixin; Lu, Shuang; Zhang, Xintong; Huang, Niu; Sun, Yihua; Sun, Xiaohua

    2016-07-01

    Considering the undesirable electrocatalytic activity toward I-/I3- redox system of prinstine antimony sulfide (Sb2S3) fabricated with the existing conditions, a mesoporous carbon nanoparticle film (CNP) is introduced here for in-situ growth of Sb2S3 to construct a Sb2S3@CNP hybrid catalyst. Based on a Sb-thiourea precursor solution, in-situ growth of Sb2S3 can be achieved via solution deposition (denoted as Sb2S3@CNP-S) as well as atmospheric pressure thermal evaporation (denoted as Sb2S3@CNP-T) in CNP matrix. Structural characterizations indicate that Sb2S3 particles have well dispersed in the pores of CNP matrix. Because of the introduction of porous and conductive CNP matrix to support Sb2S3, the hybrid catalyst exhibits lower charge transfer resistance at the catalyst/electrolyte interface and higher electrocatalytic activity. When used as counter electrode (CE) for dye-sensitized solar cells (DSSCs), devices using Sb2S3@CNP hybrid catalyst as CE produce fill factor of 67.6% and 66.3%, which is significantly higher than that using pristine Sb2S3 fabricated in our previous work (52.8%). Finally, the corresponding power conversion efficiencies reach 6.69% (Sb2S3@CNP-S) and 6.24% (Sb2S3@CNP-T), respectively, which are comparable to that using Pt CE measured under the same conditions (6.74%).

  18. Improved Antileishmanial Activity of Dppz through Complexation with Antimony(III and Bismuth(III: Investigation of the Role of the Metal

    Directory of Open Access Journals (Sweden)

    Cynthia Demicheli

    2012-10-01

    Full Text Available Two novel trivalent antimony(III and bismuth(III complexes with the nitrogen-donor heterocyclic ligand dipyrido[3,2-a:2',3'-c]phenazine (dppz were synthesized and characterized as [Sb(dppzCl3]∙H2O∙CH3OH and [Bi(dppzCl3]. The crystal structure of Sb(III complex was determined by X-ray crystallography. These complexes were evaluated for their activity against the promastigote form of Sb(III-sensitive and –resistant Leishmania infantum chagasi and Leishmania amazonensis strains. Both complexes were more effective than dppz alone in inhibiting the growth of Leishmania promastigotes and were at least 77 and 2,400 times more active than potassium antimonyl tartrate in Sb(III-sensitive and -resistant Leishmania, respectively. The cytotoxicity of dppz and its complexes against mouse peritoneal macrophages occurred at dppz concentrations at least 6-fold greater than those found to be active against Leishmania promastigotes.To investigate the role of the metal in the improved antileishmanial activity of dppz, the activity of the Sb(III complex was compared between the Sb-resistant mutants and their respective parental sensitive strains. The lack of cross-resistance to the Sb(III-dppz complex together with the much lower activity of antimonyl tartrate, SbCl3 and BiCl3 strongly support the model that the metal is not active by itself but improves the activity of dppz through complexation.

  19. Simultaneous trace analysis of organic arsenic and antimony compounds in an aquatic environment using HPLC/ICP-MS; Simultane Spurenanalytik arsen- und antimonorganischer Verbindungen in der aquatischen Umwelt mittels HPLC/ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, C.

    2000-07-01

    A method for simultaneous element species analysis of organometallic and inorganic compounds by direct coupling of HPLC and ICP-MS was used for the first time for analyses or arsenic and antimony compounds in an aquatic environment. [German] In der vorliegenden Arbeit wurde erstmalig eine Methode zur simultanen Elementspeziesanalytik metallorganischer und anorganischer Verbindungen mittels direkter Kopplung von HPLC und ICP-MS entwickelt und zur Untersuchung von Arsen und Antimonverbindungen in der aquatischen Umwelt eingesetzt. Ziel der Arbeiten war es, das Potential fluessigkeitschromatographischer Trennmethoden als Basis von Kopplungsmethoden zur simultanen Multielement-Speziesanalytik zu beschreiben und deren Leistungsfaehigkeit im Vergleich mit etablierten Methoden zu bewerten. (orig.)

  20. 从铅阳极泥中湿法提取铋、锑试验研究%Extraction of Bismuth and Antimony by Wet-process From Lead Anode Mud

    Institute of Scientific and Technical Information of China (English)

    贾辉; 王兴; 崔家友; 侯绍彬; 林浩

    2014-01-01

    Leaching of bismuth and antimony from lead anode mud oxidized at high temperature using hydrochloric acid as leaching agent ,ferric chloride as oxidant ,sodium chloride to provide more chloride ions was investigated .The effects of oxidizing temperature of lead anode mud ,hydrochloric acid concentration ,leaching temperature ,reaction time ,ratio between liquid volume and solid mass ,the amount of ferric chloride and sodium chloride on leaching of bismuth and antimony were examined . The experimental results show that the pretreatment for lead anode slime has a greater influence on the leaching of bismuth and antimony .Under the conditions of hydrochloric acid concentration of 5 mol/L ,ratio betw een liquid volume and solid mass of 5∶1 ,leaching temperature of 80 ℃ ,reaction time of 3 h ,ferric chloride concentration of 10 g/L ,sodium chloride concentration of 45 g/L ,the leaching of bismuth and antimony reach 99 .44% and 99 .69% respectively for the lead anode mud oxidized at 200 ℃ and through 200 mesh sieve .%介绍了以三氯化铁作氧化剂,氯化钠提供氯离子,用盐酸从高温氧化后的铅阳极泥中浸出铋、锑,考察了氧化温度、盐酸浓度、浸出温度、反应时间、液固体积质量比、三氯化铁和氯化钠用量对铋、锑浸出率的影响。试验结果表明:铅阳极泥预处理对铋、锑浸出率影响较大;铅阳极泥粉磨过200目筛,在氧化温度220℃、盐酸浓度5 mol/L、液固体积质量比5∶1、反应温度80℃、反应时间3 h、三氯化铁质量浓度10 g/L、氯化钠质量浓度45 g/L条件下,铋、锑浸出率分别为99.44%和99.69%,浸出效果较好。

  1. 氢化物发生原子荧光法测定稻田土中的锑形态%Determination of antimony species in rice paddy soils by hydride generation atomic fluorescence spetrometry

    Institute of Scientific and Technical Information of China (English)

    郎春燕; 周英; 赖晨焕

    2012-01-01

    Antimony species in rice paddy soils in east suburb of Chengdu were determined by hydride generation-atomic fluorescence spectrometry using aqua regia as a digestant and sequential extraction method. The detection limit of Sb was 0. 108 μg/L,and the recoveries of Sb were 96. 9% ~ 104. 8%. The results showed that the interferences from Cu2+ 、Co2+ 、Se4+ 、Sn2 +、Zn2+、Pb2+、As3+ 、As5+ 、Hg2+ which possibly existed in soils could be efficiently eliminated by using the mixture of thiourea and ascorbic acid. The concentrations of antimony were in the range from 0. 92 mg/kg to 2. 52 mg/kg in samples. The average concentration was 1. 76 mg/kg. The results were not much higher than the standard concentrations of Sb in soils in SiChuan( ≈1. 70 mg/kg, 1991). In the horizontal direction, the distribution of antimony species was different due to different soil conditions of rice paddy. The concentration of antimony species in the studied rice paddy soils generally followed the direction of residual phase > organic/sulphidic phase > Fe/Mn hydrous oxides > carbonate fraction > cation exchangeable. There was a very small proportion of cation exchangeable which could be easily absorbed by plants. In the vertical direction, the concentrations of antimony species had a decreasing tendency with the increased depth of soil.%采用王水消解及逐级浸提技术,以氢化物发生-原子荧光法对成都东郊稻田土中的Sb形态进行了分析,方法检出限为0.108 μg/L,回收率为96.9%~104.8%.加入硫脲-抗坏血酸溶液后,土壤样品中可能存在的金属离子Cu2+、Co2+、Se4、Sn2+、Zn2+、pb2+、As3+、As5+、Hg2+对Sb的干扰可以有效地消除;样品Sb含量在0.92 ~2.52 mg/kg之间波动,平均值为1.76 mg/kg,与四川省土壤Sb背景浓度(≈1.70 mg/kg,1991)相比相差不大.水平方向上,各形态Sb的浓度因所处稻田条件的不同而分布各异,大体呈以下规律:残渣态>有机/硫化物结合态>铁/锰

  2. Avaliação do efeito cumulativo do antimoniato de meglumina sobre a prole de camundongos swiss: ensaio biológico Evaluate the cumulative effect of meglumine antimoniate on the progeny of swiss mice: biologic assay

    Directory of Open Access Journals (Sweden)

    Michelle Rodrigues dos Santos

    2008-02-01

    Full Text Available OBJETIVOS: Avaliar o efeito do antimoniato de meglumina na transferência materno-fetal na geração F1 (prole de matrizes expostas ao composto, e conseqüências em progênies F2. MÉTODOS: Camundongos fêmeas Swiss foram tratados com antimoniato de meglumina, via subcutânea, com administração diária, do sétimo ao 12º dia de gestação (ddg, na dose equivalente a 100mgSb v/kg peso/dia. O grupo controle recebeu apenas o veículo (água destilada. Após o nascimento da prole (geração F1, 59 fêmeas foram examinadas diariamente para determinação do ciclo estral. Quando determinado o ciclo estro, acasalou-se 18 fêmeas com machos da mesma linhagem. No 18º ddg, as fêmeas foram eutanasiadas por câmara de CO2, o abdômen incisado e o útero exposto, quando avaliou-se os sítios de desenvolvimento embrionário e fetal quanto ao número de reabsorções, fetos vivos e mortos. Todos os fetos e placentas foram pesados para calcular o índice placentário. Três placentas de cada ninhada foram separadas para análise microscópica. RESULTADOS: A exposição ao antimoniato de meglumina não interferiu no ciclo estral dos animais tratados, pelo fato de não alterar o intervalo precoital e o índice de fertilidade. Não foram observadas alterações placentárias em progênies F2. CONCLUSÃO: O antimoniato de meglumina não altera a performance reprodutiva das mães expostas cronicamente. Estes dados sugerem que ocorre uma gradual eliminação do antimoniato de meglumina no organismo materno, sem acarretar danos a proles futuras.OBJECTIVES: Evaluate the effect of Meglumine Antimoniate on maternal-fetal transference in F1 generations (offspring of dams exposed to the drug, and embryotoxicity in F2 generations. METHODS: Female Swiss mice were treated with daily s.c. injection of Meglumine Antimoniate (100mgSb v/kg bw/day from day 7 until day 12 of pregnancy. The control group received only the vehicle (distilled water. After birth of offspring (F1

  3. Tailoring the Valence Band Offset of Al2O3 on Epitaxial GaAs(1-y)Sb(y) with Tunable Antimony Composition.

    Science.gov (United States)

    Liu, Jheng-Sin; Clavel, Michael; Hudait, Mantu K

    2015-12-30

    Mixed-anion, GaAs1-ySby metamorphic materials with tunable antimony (Sb) compositions extending from 0 to 100%, grown by solid source molecular beam epitaxy (MBE), were used to investigate the evolution of interfacial chemistry under different passivation conditions. X-ray photoelectron spectroscopy (XPS) was used to determine the change in chemical state progression as a function of surface preclean and passivation, as well as the valence band offsets, conduction band offsets, energy band parameters, and bandgap of atomic layer deposited Al2O3 on GaAs1-ySby for the first time, which is further corroborated by X-ray analysis and cross-sectional transmission electron microscopy. Detailed XPS analysis revealed that the near midpoint composition, GaAs0.45Sb0.55, passivation scheme exhibits a GaAs-like surface, and that precleaning by HCl and (NH4)2S passivation are mandatory to remove native oxides from the surface of GaAsSb. The valence band offsets, ΔEv, were determined from the difference in the core level to the valence band maximum binding energy of GaAs1-ySby. A valence band offset of >2 eV for all Sb compositions was found, indicating the potential of utilizing Al2O3 on GaAs1-ySby (0 ≤ y ≤ 1) for p-type metal-oxide-semiconductor (MOS) applications. Moreover, Al2O3 showed conduction band offset of ∼2 eV on GaAs1-ySby (0 ≤ y ≤ 1), suggesting Al2O3 dielectric can also be used for n-type MOS applications. The surface passivation of GaAs0.45Sb0.55 materials and the detailed band alignment analysis of Al2O3 high-κ dielectrics on tunable Sb composition, GaAs1-ySby materials, provides a pathway to utilize GaAsSb materials in future microelectronic and optoelectronic applications. PMID:26642121

  4. Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid–liquid–liquid microextraction

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Solid-state chemiluminescence based on CdSe QDs was developed. •QDs immobilization in a vial was achieved in a simple and fast way. •Antimony detection was achieved by inhibition of the CdSe QDs/H2O2 CL reaction. •LLLME allowed improving the selectivity and sensitivity of the CL assay. •The capping ligand played a critical role in the selectivity of the CL system. -- Abstract: On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H2O2 was observed for Sb, Se and Cu. Liquid–liquid–liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H2O2 chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H2O2 system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L−1 Sb and the repeatability expressed as relative standard deviation (N = 7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was performed with different types of water samples. Sb recoveries

  5. Biomonitoring of persons living in areas with high concentrations of mercury, arsenic and antimony in soil. Goals and methods; Biomonitoring-Untersuchung bei Personen in Wohngebieten mit erhoehten Bodenwerten an Quecksilber, Arsen und Antimon. Vorstellung und Studiendesign

    Energy Technology Data Exchange (ETDEWEB)

    Gebel, T. [Goettingen Univ. (Germany). Abt. Allgemeine Hygiene; Schaefer, J. [Mainz Univ. (Germany). Inst. fuer Medizinische Mikrobiologie und Hygiene; Beuermann, I. [Mainz Univ. (Germany). Inst. fuer Medizinische Mikrobiologie und Hygiene; Platen, H. von [Mainz Univ. (Germany). Inst. fuer Geowissenschaften; Dunkelberg, H. [Goettingen Univ. (Germany). Abt. Allgemeine Hygiene

    1995-07-01

    In the northern part of palatinate country in Germany (Nordpfaelzer Bergland; Rheinland-Pfalz) intense mercury activity had been situated beginning in the 15th century extending partly up into the 20th century. Nowadays in many cases former dump grounds of rubble caused by the mercury mining activities are used for agricultural and housing purposes. In soil material of these areas the natural background contents up to strongly elevated levels were found for mercury, arsenic and antimony. In the housing area soil concentrations (per dry matter) of less than 0,5 mg/kg up to 1364 mg/kg mercury, less than 2 mg/kg up to 605 mg/kg arsenic and less than 0,5 mg/kg up to 776 mg/kg antimony were detected. Mercury, arsenic and antimony are strongly bound to be ore in sulfidic forms of cinnabar or fahlore (gray copper) causing a bad availability. The concentration variance of the detected element levels is immense even relating to little spaces because of an inhomogenous distribution of the rubble; highly contaminated grounds can be found beneath not contaminated ground. A biomonitoring study is presented in which 219 exposed residents are involved. They are examined concerning a possible incorporation of the elements mentioned above. The proceeding of the study, the way of data collection, and the amnestical approach are discussed. This study ist compared to similar studies. (orig.) [Deutsch] Im Nordpfaelzer Bergland wurde vom 15. bis teilweise ins 20. Jahrhundert intensiv Quecksilberbergbau betrieben. Vielfach befinden sich landwirtschaftlich genutzte Flaechen und Wohngebiete auf oder neben Abraumhalden des ehemaligen Quecksilberbergbaus. In diesen Regionen fand man im Boden fuer das Schwermetall Quecksilber und die metalloide Arsen und Antimon von den natuerlichen Hintergrundkonzentrationen bis hin zu stark erhoehten Werten. In Wohngebieten waren dies bei Quecksilber weniger als 0,5 mg/kg Boden (Trockensubstanz) bis zu 1364 mg/kg, bei Arsen weniger als 2 mg/kg bis zu 605 mg

  6. Determination of trace amount of antimony (Ⅲ) by adsorption voltammetry on carbon paste electrode%碳糊电极吸附伏安法测定痕量锑

    Institute of Scientific and Technical Information of China (English)

    郭会时; 肖鹏峰; 聂立波; 李益恒; 何农跃

    2004-01-01

    根据锑与溴邻苯三酚红(BPR)生成的络合物在碳糊电极上的吸附特性, 建立了测定痕量锑的吸附伏安法. 整个分析过程分3个步骤: 吸附富集、还原和溶出. 用单因素变化法得出最佳试验条件为: 以含40 μmol/L BPR的0.10mol/L HCl为富集底液; 富集时间150 s; 还原和溶出介质为0.20mol/L HCl; 还原电位为-0.50V; 还原时间为60 s;扫描范围为-0.5~0.20V. 考察了共存离子的影响. 二次导数溶出峰电流与锑(Ⅲ)浓度在1. 0nmol/L~0. 50μmol/L范围内呈良好的线性关系, 检出限达0.5nmol/L. 该方法已成功应用于人发和水样中锑的测定.%A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration, reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode; a 0. 10mol/L HCl solution containing 40 μmol/L BPR as accumulation medium; a 0. 20mol/L HCl solution as reduction and stripping electrolyte; accumulation time, 150 s; reduction potential and time, -0. 50 V, 60 s; scan range from -0. 50 to 0. 20V. Interferences by other ions were studied as well. The detection limit was found to be 0. 5nmol/L for 150 s preconcentration. The linear range was from 1. 0nmol/L to 0. 50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.

  7. Preparation and Structure Analysis of Antimony Trichloride and Bismuth Trichloride Comlexes with Valine%缬氨酸锑和缬氨酸铋配合物的制备与结构分析

    Institute of Scientific and Technical Information of China (English)

    杨宇翔; 郇伟伟; 纪国媛; 陈娅如

    2011-01-01

    Two compounds of antimony trichloride and bismuth trichloride with valine are synthesized by solid phase synthesis at room temperature.Their compositions,determined by element analysis, are Sb(C5H10O2N)3 · 2H2O and Bi(C5H10O2N)2Cl·0.5H2O.The crystal structure of antimony complex with valine belongs to triclinic system and its lattice parameters are: a = 0.959 9 nm, b = 1.506 8 nm,c=1.985 1 nm, α =92.27°,β= 95.05°,γ= 104.27°.The crystal structure of bismuth complex with valine belongs to monoclinic system and its lattice parameters are: a = 1.601 2 nm, b= 1.894 1 nm, c = 1.839 nm, β=99.73°.The farinfrared spectra and the infrared spectra show that the amino group and carboxyl of valine may be coordinated to antimony and bismuth, respectively, in two compounds.The TG-DSC results also reveal that the complexes are formed.%采用室温固相合成法合成了缬氨酸与三氯化锑、三氯化铋的两种生物配合物,其组成为Sb(C5H1002N)3·2H2O,Bi(C5 H1002N)2Cl·0.5H2O.缬氨酸锑配合物的晶体结构属于三斜晶系,晶胞参数为a=0.959 9 nm,b=1.506 8 nm,c=1.985 1 nm,α=92.27°,β=95.05°,γ=104.27°;缬氨酸铋配合物的晶体结构属于单斜晶系,晶胞参数为α=1.601 2nm,b=1.894 1 nm,c=1.839 nm,β=99.73°.远红外、红外光谱表明这两种新的配合物中锑、铋与缬氨酸的成键情况;并用差热-热重法对这两种配合物做了热分析,进一步验证了配合物的组成.

  8. Assessment of femoral head vascularity by technetium-99m antimony colloid bone marrow imaging within 24 hours of subcapital fracture: a prospective study of 30 patients followed for 2 years

    International Nuclear Information System (INIS)

    The rationale of preoperative imaging of bone marrow was based upon the demonstration of histochemical abnormalities secondary to ischaemia which first become apparent in marrow cells of the femoral head following interruption of the blood supply by subcapital fracture. These marrow abnormalities predate changes in bone cells by several days and may explain the absence of abnormality on conventional bone scans performed on avascular femoral heads within 24 hours of subcapital fracture. The use of an endoprosthesis for fresh femoral neck fractures in unselected patients results in high mortality, high infection rate, high incidence of thromboembolic disease and poor long term results. The successful prediction of avascular necrosis in 92% of 28 patients with active bone marrow in the femoral head in this study is sufficiently accurate to allow appropriate selection of patients for internal fixation or primary prosthetic replacement on the basis of preoperative Tc-99m antimony colloid imaging

  9. Oxygen 17 NMR in the evaluation of oxygen bounding with central ion using hydrolysis products of niobium, tantalum, arsenic, antimony pentafluorides as an example. Symbasis in the change of 17O and 19F chemical shifts

    International Nuclear Information System (INIS)

    Hydrolysis products of niobium, tantalum, antimony and arsenic pentafluorides in acetonitrile solution were studied by the methods of 17O and 19F NMR. In 17O NMR spectra of niobium and tantalum pentafluorides hydrolysis products resonance signals of oxo-, hydroxo- and aquafluorocomplexes were defined. Considerable shift of 17O NMR resonance signals towards weak field making up about 300 m.p., may indicate a higher covalency (Π-character) of Nb-O bond compared to Ta-O one. Symbasis in the change of chemical shifts in 17O NMR and 19F NMR of the relevant hexafluorides and hydrolysis products was detected implying similarity of chemical bond nature in oxygen and fluorine

  10. Supramolecular association via Sb...S and C-H...S interactions in dimeric tris(N,N-dimethyldithiocarbamato-S,S')antimony(III): an approach to overcome the concept of steric bulk on such interactions.

    Science.gov (United States)

    Chauhan, H P S; Carpenter, Jaswant

    2013-12-01

    Tris(N,N-dimethyldithiocarbamato-S,S')antimony(III) has been isolated as a dimer in acetonitrile. Single-crystal X-ray analysis shows that the molecule possesses both Sb···S and C-H···S interactions, which results in a supramolecular association in the absence of hydrogen-bonding functionality on the R group. The co-existence in the title compound of such interactions is a unique character of known dimeric antimony(III) alkyl and/or aryl dithiocarbamate complexes. The literature reveals that the species where the alkyl and/or aryl dithiocarbamates carry the following groups: R = methyl (chloroform solvated), ethyl, n-propyl, pyrrolidine, morpholine, piperidine, azepane, benzyl, methylphenyl, are not capable of forming significant hydrogen-bonding interactions. However, either Sb···S or C-H···S intermolecular interactions dominate between two centrosymmetrically related molecules leading to a supramolecular aggregation. In the species where the R group carries hydrogen-bonding functionality, i.e. 2-hydroxylethyl, the C-H···S interactions are subverted by O-H···O hydrogen bonding. In addition, the title compound does not have steric hindrance or any hydrogen-bonding group but is stabilized with the co-existence of Sb···S and C-H···S interactions. Analysis of the secondary interactions of a series of analogues previously reported reveals that steric bulk is unnecessary for the mitigation of Sb···S interactions and for the establishment of C-H···S secondary bonding. PMID:24253087

  11. Development and application of double membrane modified antimony pH electrode and its testing instrument%双层膜锑pH电极及其测试仪的研制与应用

    Institute of Scientific and Technical Information of China (English)

    盛庆元; 张西良; 李萍萍; 刘丽晨; 陈书田

    2013-01-01

    The value of pH is a key chemical parameter in the field of industrial and agricultural production, medicine, environmental protection and other fields. At present, commercial glass pH electrodes have been widely used in soil pH test in the laboratory due to its convenience and reliability. But with turbid and vibrate systems in the filed like on-the-go pH mapping, glass electrode cannot be used because of its brittleness of the glass membrane, sluggish response, which are difficult to miniaturize and planarize based on current manufacturing technologies. In this work, a simple, flexible, inexpensive and effective way to make bilayer membrane modified antimony pH electrode was presented and one pH tester was developed. The surface of the obtained antimony wire was oxidized in sodium dioxide melt to fabricate an antimony oxide film for pH sensing as first layer. The second layer was Nafion membrane with selective characteristics, which was coated after the first layer. The sensing response and open-circuit potential of the electrode had a good linear relationship (R2=0.997) with pH value in the test solution, which also exhibited small hysteresis, fast response than that of bare antimony pH electrode. The open-circuit potential of the electrode was almost drift-free, with an average variation as small as 0.1mV over an hour. Ion interference experiment showed that this electrode has good selectivity with common ions (Na+, K+, Ca2+, Cl-, Br-) in soil, redox ion([Fe(CN)6]3-, [Fe(CN)6]4-) and citrate ions ( C6H5O73-). The bilayer membrane modified antimony pH electrode and the Ag/AgCl reference electrode as sensor were employed to pH tester, which was designed based on 16 bit low power consumption microcontroller (Sunplus SPCE061A). Tester readings in soil turbid solution under controlled in the lab were compared with the data obtained by standard protocols of soil. The tests demonstrated a high degree of linearity between standard laboratory values and turbid soil

  12. Effect of Halogen-antimony Flame Retardant System on Thermoplastic Polyester Elastomer%卤-锑阻燃体系对热塑性聚酯弹性体性能的影响

    Institute of Scientific and Technical Information of China (English)

    奚溪; 张群朝; 赵辉; 蒋涛

    2013-01-01

      采用高分子型溴系阻燃剂溴化环氧树脂(EP-B)、溴化聚苯乙烯(PS-B)及小分子型溴系阻燃剂十溴二苯乙烷(DBDPE)协同Sb2O3作为卤–锑阻燃体系,研究卤–锑阻燃体系对热塑性聚酯弹性体(TPEE)性能的影响。研究表明,当溴系阻燃剂的质量分数为18%时,均能使TPEE达到UL94 V–0级别,极限氧指数达到27%以上,EP-B, PS-B分别与DBDPE复配使用时的阻燃效果优于EP-B,PS-B单独使用时的阻燃效果;EP-B和PS-B与TPEE具有较好的相容性,两者分别与DBDPE复配时可改善DBDPE与TPEE的相容性;当溴系阻燃剂的质量分数为18%时, EP-B和PS-B分别与DBDPE复配使用,可减少单独使用DBDPE阻燃TPEE力学性能的下降程度;添加阻燃剂改变了TPEE的热失重过程,与EP-B,PS-B阻燃TPEE的残炭率相比,两者分别与DBDPE复配后,阻燃TPEE的残炭率下降约20%。%  With two polymeric brominated flame retardants brominated epoxy resin(EP-B) and brominated polystyrene(PS-B) and a new type of low molecular weight brominated flame retardant decabromodiphenyl ethane(DBDPE) synchronized with antimony trioxide(Sb2O3) respectively as three halogen–antimony flame retardant systems,the effects of halogen–antimony flame retardant systems on thermoplastic polyester elastomer(TPEE) were discussed. The results show that when the mass fraction of brominated flame retardants is 18%,UL94 vertical burning of TPEE could reach V–0 level,the limit oxygen index could reach more than 27%,when EP-B and PS-B were compound with DBDPE respectively,the flame retardant efficiencies are better than that of the systems when they were used in TPEE alone. EP-B and PS-B had preferable compatibility with TPEE,when they were compound with DBDPE,the compatibility of DBDPE and TPEE could be improved. When the mass fraction of brominated flame retardants is 18%,EP-B and PS-B were compound with DBDPE respectively,the decline degree of

  13. 某锑金矿综合回收锑、金的试验研究%Comprehensive Recovery of Au and Sb from an Antimony-gold Concentrate

    Institute of Scientific and Technical Information of China (English)

    杨永斌; 刘波; 李骞; 姜涛

    2014-01-01

    采用酸法浸锑⁃浸锑渣焙烧脱硫⁃氰化浸金工艺从某锑金精矿中分离提取锑、金。酸法浸锑最佳工艺条件为:温度为95℃、[H+]=4 mol/L、液固比为4∶1、FeCl3过量系数为1.1、浸出时间为0.5 h,在此条件下,锑浸出率为99.05%,进入浸锑液的金仅为0.99%,实现了锑、金良好的选择性浸出。对浸锑渣直接氰化浸金,浸金率仅为71.93%。为了提高浸金率,在分析酸性浸锑渣的矿物组成的基础上,对浸锑渣进行氧化焙烧,结果表明:碚砂中硫品位仅为0.18%,硫脱除率达到了99.81%,渣中的单质硫及硫化物显著减少,主要以赤铁矿和脉石矿物为主。最终金浸出率达到95.92%,比浸锑渣直接氰化浸金提高了约24个百分点。%Comprehensive recovery of Sb and Au from an antimony⁃gold concentrate is studied by adopting a process of Sb leaching with acid solution⁃oxidizing roasting of the antimony residue⁃cyanide leaching of gold. Under the following optimum conditions, that is, leaching at 95℃ for 0.5 h with HCl concentration at 4.0 mol/L, liquid⁃solid rate at 4∶1, excess coefficient of FeCl3 being 1. 1, a favorable selective leaching effect can be realized for Sb and Au, with the leaching rate of Sb up to 99.05% and only 0.99% Au recovered into antimony leachate. However, the following direct cyanide leaching only resulted in the Au leaching rate of 71.93%. For the purpose of increasing the leaching rate of Au, the antimony leaching residue was subjected to oxidizing roasting process based on the analysis of its mineral compositions, leading to only 0.18%S in the calcined product, with removal rate of sulfur up to 99.81%. It is found that hematite and gangue minerals are the dominant minerals in the residue, with the content of sulfur and sulfide remarkably decreased. The ultimate leaching rate of Au reached 95. 92%, 24 percentage points higher than that by direct

  14. Synthesis and characterization of a novel mesoporous silica functionalized with [1,5 bis(di-2-pyridyl)methylene thiocarbohydrazide] and its application as enrichment sorbent for determination of antimony by FI-HG-ETAAS.

    Science.gov (United States)

    López Guerrero, M M; Siles Cordero, M T; Vereda Alonso, E; García de Torres, A; Cano Pavón, J M

    2014-11-01

    A simple, sensitive, low-cost and rapid flow injection (FI) on-line sorption preconcentration/hydride generation system has been synchronously coupled to an electrothermal atomic absorption spectrometer (ETAAS) for the determination of trace amounts of Sb in aqueous environmental samples (river and sea water samples). The system is based on retention of the analyte onto a micro-column filled with a novel mesoporous silica functionalised with [1,5 bis(di-2-pyridyl) methylene] thiocarbohydrazide placed in the injection valve of the FI manifold. The adsorption capacity of the resin for Sb was found to be 160.8 µmol g(-1). Chemicals and flow variables affecting the continuous preconcentration of antimony, the direct generation of antimony hydride and the final determination of this element by ETAAS were evaluated. The optimized operating conditions selected were: sample pH 5.0, sample flow rate 2.5 ml min(-1), eluent flow rate 5.4 ml min(-1), eluent 2.0% thiourea in 4.0% nitric acid. Under the optimum conditions, the calibration graph obtained was linear over the range 0.025-2.5 μg L(-1). At a sample frequency of 20 h(-1) and 120 s preconcentration time, the enrichment factor was 22. The detection limit of the method (3ơ) was 1 ng L(-1) for a 5.0 mL sample volume and the precision was 0.9% (RSD) for 11 replicate determinations at 1.0 μg L(-1) Sb. The preconcentration factor and detection limit can be improved by increasing the preconcentration time, which can be increased at least up to 5 min. The accuracy of the proposed method was demonstrated by analyzing two certified reference materials and by determining the analyte content in spiked environmental water samples. The results obtained using this method were in good agreement with the certified values of the standard reference materials and the recoveries for the spiked river and sea water samples were 91.3-109.9%. PMID:25127557

  15. Structure of PbSb/sub 2/O/sub 6/ and its relationship to the crystal chemistry of PbO/sub 2/ in antimonial lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R.J.

    1987-11-01

    The crystal structure of PbSb/sub 2/)/sub 6/, space group P anti 31m, a = 5.3006(1), c = 5.3792(1) A, V = 130.89(2) A, Z = 1, D/sub x/ = 6.936 g cm/sup -3/, has been refined at 295 K by Rietveld analysis of step-scan neutron powder diffraction data (lambda = 1.500 A, ..mu.. 0.179 cm/sup -1/): R/sub wp/ = 0.0614 for 2898 step intensities, R/sub B/ = 0.0141 for 150 reflections. The structure consists of gibbsitelike sheets of edge-sharing SbO/sub 6/ octahedra oriented perpendicular to the c-axis. These sheets alternate with layers of isolated PbO/sub 6/ octahedra positioned above and below the vacant sites in the adjacent (SbO/sub 6/)/sup 2 -/ layers. The SbO/sub 6/ octahedra have symmetry 32 and a bond length of 1.9904(4) A; the PbO/sub 6/ octahedra have symmetry anti 3m and a bond length of 2.5633(6) A. The properties of this structure and its relationship to the polymorphs of PbO/sub 2/ provide possible explanations for the well-known beneficial effect of antimony on the cycle life of lead-acid batteries.

  16. 锑精炼除铅渣硝酸浸出回收铅的研究%Study on Lead Recovery from Lead Slag of Antimony Refining by Nitric Acid Leaching Process

    Institute of Scientific and Technical Information of China (English)

    韦岩松; 盘有旺

    2013-01-01

    采用硝酸浸出的方法从锑精炼除铅渣中回收金属铅,考察了液固比、浸出温度和时间、硝酸浓度等对铅浸出率的影响.结果表明,适宜的浸出工艺为:液固比4、浸出温度80℃、浸出时间50 min、硝酸浓度7.0 mol/L.在此条件下,铅浸出率可以达到94%.%Lead was recovered from lead slag of antimony refining by nitric acid leaching process.The effects of ratio of liquid to solid (L/S),leaching temperature and time,and nitric acid concentration on lead leaching rate were investigated.The results show that the lead leaching rate is above 94% under the optimum conditions including L/S of 4,leaching temperature of 80 ℃,leaching time of 50 min,and nitric acid concentration of 7.0 mol/L.

  17. Enhancement of the superconducting transition temperature and upper critical field of LaO{sub 0.8}F{sub 0.2}FeAs with antimony doping

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S J; Patnaik, S [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Prakash, J; Ganguli, A K [Department of Chemistry, Indian Institute of Technology, New Delhi 110016 (India)], E-mail: spatnaik@mail.jnu.ac.in, E-mail: ashok@chemistry.iitd.ernet.in

    2009-04-15

    We report the synthesis and characterization of the antimony-doped oxypnictide superconductor, LaO{sub 0.8}F{sub 0.2}FeAs{sub 1-x}Sb{sub x} (x = 0.05 and 0.10). The parent compound LaOFeAs with fluorine doping exhibits superconductivity at the maximum transition temperature {approx}28.5 K (at ambient pressure). Here we partially substitute As by Sb (LaO{sub 0.8}F{sub 0.2}FeAs{sub 1-x}Sb{sub x}) and observe enhancement of the transition temperature to 30.1 K. This is one rare case where T{sub c} increases with doping in the conducting layer (FeAs) and this leads to the highest transition temperature in any La-based oxypnictide. X-ray diffraction and energy-dispersive x-ray analysis measurements confirm the phase purity of the samples and the presence of Sb. The magneto-resistance measurements show that the value of the upper critical field H{sub c2}(0) is about 73 T, corresponding to a coherence length ({xi}{sub GL}) of 22 A. The Seebeck coefficient measurements indicate electron transport with a strong contribution from electron-electron correlation. These results provide interesting insight into the origin of superconductivity in this novel series of compounds.

  18. Enhanced separation efficiency of photoinduced charges for antimony-doped tin oxide (Sb-SnO{sub 2})/TiO{sub 2} heterojunction semiconductors with varied Sb doping concentration

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhen-Long [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Ma, Wen-Hai [School of Physical Education, Henan University, Kaifeng 475004 (China); Mao, Yan-Li, E-mail: ylmao1@163.com [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China)

    2014-09-07

    In this paper, antimony-doped tin oxide (Sb-SnO{sub 2}) nanoparticles were synthesized with varied Sb doping concentration, and the Sb-SnO{sub 2}/TiO{sub 2} heterojunction semiconductors were prepared with Sb-SnO{sub 2} and TiO{sub 2}. The separation efficiency of photoinduced charges was characterized with surface photovoltage (SPV) technique. Compared with Sb-SnO{sub 2} and TiO{sub 2}, Sb-SnO{sub 2}/TiO{sub 2} presents an enhanced separation efficiency of photoinduced charges, and the SPV enhancements were estimated to be 1.40, 1.43, and 1.99 for Sb-SnO{sub 2}/TiO{sub 2} composed of Sb-SnO{sub 2} with the Sb doping concentration of 5%, 10%, and 15%, respectively. To understand the enhancement, the band structure of Sb-SnO{sub 2} and TiO{sub 2} in the heterojunction semiconductor was determined, and the conduction band offsets (CBO) between Sb-SnO{sub 2} and TiO{sub 2} were estimated to be 0.56, 0.64, and 0.98 eV for Sb-SnO{sub 2}/TiO{sub 2} composed of Sb-SnO{sub 2} with the Sb doping concentration of 5%, 10%, and 15%, respectively. These results indicate that the separation efficiency enhancement is resulting from the energy level matching, and the increase of enhancement is due to the rising of CBO.

  19. 流动注射在线离子交换分离富集-氢化物发生原子荧光光谱法测定铜合金中痕量锑%Determination of trace antimony in copper alloys by flow injection on-line ion-exchange separation and enrichment-hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴良俊; 邱海鸥; 郝志红; 袁红战; 郑洪涛

    2009-01-01

    A method for the determination of trace antimony in copper by flow injection on-line ion-exchange separation and enrichment-hydride generation atomic fluorescence spectrometry is suggested. The manifolds and operating program for ftlow injection on-line ion-exchange were designed and chemical conditions were optimized. Antimony complex was absorbed on strongly basic anion exchange resin 717 with 1. 4 mol/L HC1 as absorbent medium and 2. 0 mol/L HNO_3 for elution. The interference of co-existent elements (i-ron, nickel, lead, etc) was eliminated while antimony was enriched and was determined by hydride generation-atomic fluorescence spectrometry. The method is easy to operate and fast, and has lesser pollution to environment. The linear range is 0. 2-120μg/L and the RSD is 3%~5% with detection limit of 0. 05 μg/L. The results for determination of antimony in standard samples of copper alloys are satisfactory.%提出了流动注射离子交换在线分离富集-氢化物发生原子荧光光谱法测定铜合金中痕量锑的分析方法.设计了流动注射在线离子交换的流路和操作程序,优化了各项化学条件.采用717强碱性阴离子交换树脂吸附锑,并能有效消除铁、镍、铅等元素的干扰,也使大量基体元素铜与待测元素分离,锑在1.4 mol/L的HCl介质中上柱,选用2.0 mol/L的HNO_3作为洗脱剂.实现了氢化物发生原子荧光光谱法对铜合金中痕量锑的在线测定.方法操作简便、快速,环境污染小,线性范围为0.15~120 μg/L,相对标准偏差在3%~5%之间,检出限为0.05μg/L.方法应用于铜合金标准样品,结果与推荐值吻合.

  20. Avaliação da tolerância e nefrotoxicidade do antimonial pentavalente administrado na dose de 40mg Sb v/kg/dia, de 12/12h, por 30 dias na forma cutaneo-mucosa de leishmaniose

    Directory of Open Access Journals (Sweden)

    Raimunda N.R. Sampaio

    1997-12-01

    Full Text Available Foi avaliada a função renal de 11 pacientes com leishmaniose cutâneo-mucosa tratados com antimonial pentavalente na dose de 40mg SbV/kg/dia aplicada de 12/12 horas, em esquema contínuo, durante trinta dias. No estudo, um paciente apresentou insuficiência renal reversível e dois desenvolveram alterações enzimáticas hepáticas e eletrocardiográficas sendo o esquema terapêutico interrompido. Nos demais pacientes observou-se efeitos nefrotóxicos tais como diminuição da taxa de filtração glomerular, diminuição da capacidade de concentração urinária, avaliada por um jejum hídrico de 16 horas e aumento na fração de excreção de sódio. No exame do sedimento urinário observou-se um aumento no número de leucócitos e cilindros. Os resultados encontrados neste estudo sugerem que o tratamento com antimonial pentavalente na dose de 40mg SbV/kg/dia foi menos tolerado em virtude de seus efeitos tóxicos, não parecendo apresentar índice de cura superior ao esquema atualmente preconizado de 20mg SbV/kg/dia.The renal function of eleven patients with mucocutaneous leishmaniasis was analyzed in a prospective study realized at the School Hospital of University of Brasília. The patients were treated with doses of 40mg/kg/day of pentavalent antimony (SbV, in a continuous scheme during thirty days. In this study three patients were excluded, one patient with reversible renal failure and two patients with hepatic and cardiac malfunctions. In the other eight patients, severe nephrotoxics effects were observed, like reduction of glomerular filtration rate, reduction of the urinary concentration capacity, evaluated by a sixteen hours hydric fasting and an increase of sodium fractional excretion. An increase in the number of leucocytes and cylinders were observed at the urinary sediment exam. Finally, the results shows that the treatment with pentavalent antimony in doses of 40mg Sb/kg/day was less tolerated on account of its renal toxics

  1. Research Progress on the Modification and Application of Antimony-Doped Tin Dioxide Electrodes%钛基锡锑氧化物电极掺杂改性及应用研究进展

    Institute of Scientific and Technical Information of China (English)

    梁吉艳; 耿聰; 李丹; 袁飞宇; 崔丽; 王新

    2016-01-01

    电催化氧化水处理技术是近年来发展起来的一种有效处理难降解有机废水的方法,钛基锡锑氧化物涂层阳极(Ti/SnO2-Sb)因其对有机污染物具有较高的电化学氧化活性而受到关注.综述了稀土金属、非稀土金属、碳纳米管(CNTs)等物质掺杂改性Ti/SnO2-Sb电极的研究进展.简述了掺杂剂影响Ti/SnO2-Sb电极电催化活性、电流效率和电极寿命的作用机理;介绍了Ti/SnO2-Sb及其改性电极降解有机污染物的应用研究情况;展望了今后Ti/SnO2-Sb电极涂层掺杂改性及应用研究值得关注的方向.%Electrocatalytic oxidation technology is an effective method for recalcitrant organic wastewater treatment developed in recent years.Antimony-doped tin oxide coating on Ti substrate as anodes (Ti/SnO2-Sb) attract more attention because of its higher electrochemical oxidation activity for organic contaminants.In this review,the progress of modified Ti/SnO2-Sb by doping with rare earth metals,non-rare earth metal and carbon nanotubes (CNTs) are summarized.The effect mechanism of the dopants on Ti/SnO2-Sb electrode electrocatalytic activity,current efficiency and electrode life is outlined,the research situations of Ti/SnO2-Sb and the modified Ti/SnO2-Sb electrode applied for removing organic pollutants is introduced,and the noteworthy direction of doping and application of Ti/SnO2-Sb electrode is prospected.

  2. 断续流动原子荧光法测定铅锡合金中的痕量锑%Determination of Trace Amount of Antimony in Lead-tin Alloy by Intermittent Flow Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    马毅红; 尹艺青; 陈玉珍

    2012-01-01

    目的:建立氢化物发生双道原子荧光法测定铅锡合金中锑含量的方法,为测定铅锡合金中锑提供依据。方法:选择了最佳的仪器条件,进行样品处理方法、KBH4浓度、检出限、回收率等研究。结果:本方法的标准曲线方程y=157.56x-2.3962,相关系数γ=0.9999,线性范围为0~40μg/L,精密度为1.3%,检出限为0.0304μg/L,回收率达115%。结论:本方法操作简单、快速、灵敏度高、干扰少,可获得满意的结果。%Purpose: A analytical method is recommended for determination of Trace Amount of Antimony in Lead-Tin Alloy by hydride generation double channel atomic fluorescence spectrometry,which provides basis for its measurement.Methods: Optimum condition for the instrument determination is applied to conduct researches relating to the method of sampling,concentration of KBH4,detection limits and recovery rate.Results: The standard curve of the linear equation was y=157.56x-2.3962 with correlation coefficient γ = 0.9999 and linear range of 0~40 μg/L.The precision and the detection limits were 1.3 % and 0.0304 μg/L respectively while the returns-ratio achieves 115 %.Conclusion: The method is easy,fast,highly sensitive and with no much interference during the operation,which can lead to satisfactory results.

  3. Estudo comparativo entre estibogluconato de sódio BP 88R e antimoniato de meglumina no tratamento da leishmaniose cutânea: I. Eficácia e segurança Comparative study between sodium stibogluconate BP 88R and meglumine antimoniate for cutaneous leishmaniasis treatment: I. Efficacy and safety

    Directory of Open Access Journals (Sweden)

    Ana Cristina R. Saldanha

    1999-08-01

    Full Text Available A eficácia e segurança do antimoniato de meglumina e do estibogluconato de sódio BP 88R foram comparadas no tratamento da leishmaniose cutânea em Corte de Pedra, Bahia, área endêmica de leishmaniose causada por Leishmania (Viannia braziliensis. Realizou-se um estudo quase-experimental que incluiu 127 pacientes cujo diagnóstico baseou-se na observação clínica e a intradermorreação de Montenegro. Cinqüenta e oito pacientes receberam antimoniato de meglumina e 69 estibogluconato de sódio. Utilizou-se a dose de 20 mg/Sb v/kg/dia por 20 dias, em ambos os grupos. Os pacientes foram acompanhados a cada dez dias durante o tratamento e mensalmente por três meses. Observou-se a cura em 62% dos pacientes tratados com antimoniato de meglumina e em 55% daqueles tratados com estibogluconato de sódio (p = 0,42. A cefaléia foi mais freqüente na primeira metade do tratamento no grupo tratado com estibogluconato de sódio (p = 0,026. Na segunda metade do tratamento, os pacientes tratados com estibogluconato de sódio apresentaram maior freqüencia de mialgia/artralgia (p = 0,004 e dor abdominal/anorexia (p = 0,004. Três pacientes tratados com o estibogluconato de sódio apresentaram efeitos colaterais graves.Efficacy and safety of meglumine antimoniate and sodium stibogluconate BP88R were compared in cutaneous leishmaniasis treatment in Corte de Pedra, Bahia, an endemic area of leishmaniasis due to Leishmania (Viannia braziliensis. An open trial was developed with one hundred twenty seven patients who were diagnosed based on clinical criteria and Montenegro´s skin test. Fifty eight patients were treated with meglumine antimoniate and 69 received sodium stibogluconate. Both groups received 20 mg/Sb v/kg/day for 20 days. Patients were followed every ten days during treatment and every month thereafter for three months. Sixty two percent patients cured with meglumine antimoniate and 55% cured with sodium stibogluconate (p = 0,42. Headache was

  4. Topological surface states scattering in antimony

    KAUST Repository

    Narayan, Awadhesh

    2012-11-05

    In this work we study the topologically protected states of the Sb(111) surface by using ab initio transport theory. In the presence of a strong surface perturbation we obtain standing-wave states resulting from the superposition of spin-polarized surface states. By Fourier analysis, we identify the underlying two dimensional scattering processes and the spin texture. We find evidence of resonant transmission across surface barriers at quantum well state energies and evaluate their lifetimes. Our results are in excellent agreement with experimental findings. We also show that despite the presence of a step edge along a different high-symmetry direction, the surface states exhibit unperturbed transmission around the Fermi energy for states with near to normal incidence. © 2012 American Physical Society.

  5. Antimony selenide thin-film solar cells

    Science.gov (United States)

    Zeng, Kai; Xue, Ding-Jiang; Tang, Jiang

    2016-06-01

    Due to their promising applications in low-cost, flexible and high-efficiency photovoltaics, there has been a booming exploration of thin-film solar cells using new absorber materials such as Sb2Se3, SnS, FeS2, CuSbS2 and CuSbSe2. Among them, Sb2Se3-based solar cells are a viable prospect because of their suitable band gap, high absorption coefficient, excellent electronic properties, non-toxicity, low cost, earth-abundant constituents, and intrinsically benign grain boundaries, if suitably oriented. This review surveys the recent development of Sb2Se3-based solar cells with special emphasis on the material and optoelectronic properties of Sb2Se3, the solution-based and vacuum-based fabrication process and the recent progress of Sb2Se3-sensitized and Sb2Se3 thin-film solar cells. A brief overview further addresses some of the future challenges to achieve low-cost, environmentally-friendly and high-efficiency Sb2Se3 solar cells.

  6. Geochemistry, geochronology, mineralogy, and geology suggest sources of and controls on mineral systems in the southern Toquima Range, Nye County, Nevada; with geochemistry maps of gold, silver, mercury, arsenic, antimony, zinc, copper, lead, molybdenum, bismuth, iron, titanium, vanadium, cobalt, beryllium, boron, fluorine, and sulfur; and with a section on lead associations, mineralogy and paragenesis, and isotopes

    Science.gov (United States)

    Shawe, Daniel R.; Hoffman, James D.; Doe, Bruce R.; Foord, Eugene E.; Stein, Holly J.; Ayuso, Robert A.

    2003-01-01

    Geochemistry maps showing the distribution and abundance of 18 elements in about 1,400 rock samples, both mineralized and unmineralized, from the southern Toquima Range, Nev., indicate major structural and lithologic controls on mineralization, and suggest sources of the elements. Radiometric age data, lead mineralogy and paragenesis data, and lead-isotope data supplement the geochemical and geologic data, providing further insight into timing, sources, and controls on mineralization. Major zones of mineralization are centered on structural margins of calderas and principal northwest-striking fault zones, as at Round Mountain, Manhattan, and Jefferson mining districts, and on intersections of low-angle and steep structures, as at Belmont mining district. Paleozoic sedimentary rocks, mostly limestones (at Manhattan, Jefferson, and Belmont districts), and porous Oligocene ash-flow tuffs (at Round Mountain district) host the major deposits, although all rock types have been mineralized as evidenced by numerous prospects throughout the area. Principal mineral systems are gold-silver at Round Mountain where about 7 million ounces of gold and more than 4 million ounces of silver has been produced; gold at Gold Hill in the west part of the Manhattan district where about a half million ounces of gold has been produced; gold-mercury-arsenic-antimony in the east (White Caps) part of the Manhattan district where a few hundred thousand ounces of gold has been produced; and silver-lead-antimony at Belmont where more than 150,000 ounces of silver has been produced. Lesser amounts of gold and silver have been produced from the Jefferson district and from scattered mines elsewhere in the southern Toquima Range. A small amount of tungsten was produced from mines in the granite of the Round Mountain pluton exposed east of Round Mountain, and small amounts of arsenic, antimony, and mercury have been produced elsewhere in the southern Toquima Range. All elements show unique

  7. Estudo comparativo entre estibogluconato de sódio BP 88® e antimoniato de meglumina no tratamento da leishmaniose cutânea II. Toxicidade bioquímica e cardíaca Comparative study between sodium stibogluconate BP 88®and meglumine antimoniate in cutaneous leishmaniasis treatment. II. Biochemical and cardiac toxicity

    Directory of Open Access Journals (Sweden)

    Ana Cristina R. Saldanha

    2000-08-01

    Full Text Available Foi avaliada a toxicidade de dois antimoniais pentavalentes em 111 pacientes com leishmaniose cutânea. Quarenta e sete pacientes receberam antimoniato de meglumina (Grupo I e 64 pacientes, estibogluconato de sódio BP 88® (Grupo II, 20mg SbV/kg/dia por 20 dias. Realizou-se a avaliação de aminotransferases, fosfatase alcalina, amilase, creatinina, uréia, exame de urina e eletrocardiograma, antes do tratamento e no décimo e vigésimo dias. Observou-se maior freqüência de valores anormais de aminotransferases no décimo e vigésimo dias de tratamento no grupo II (p Toxicity of two antimonial pentavalents were evaluated in 111 patients with cutaneous leishmaniasis. Forty seven patients received meglumine antimoniate (Group I and 64 patients, sodium stibogluconate BP 88® (Group II, 20mg SbV/kg/day for 20 days. Evaluation of aminotransferases, alkaline phosphatase, amilase, creatinine, urea, urine analysis and electrocardiogram were performed at baseline, on the tenth and twentieth day of treatment. Greater frequency of aminotransferase abnormal levels were observed on the tenth and twentieth days in group II (p < 0,001 and a greater proportion of amilase abnormal levels at the tenth day in the same group (p < 0,001. There was a greater variation of aminotransferases, alkaline phosphatase and amilase in the first ten days of treatment in group II (p < 0,01. On the twentieth day there was a greater variation of aminotransferase levels in group II (p = 0,02 and p = 0,03, respectively. Forty three percent of group I and 54% of group II showed electrocardiographic abnormalities (p = 0,30.

  8. Analysis of the Characteristics of the Waterborne Arsenic Poisoning Caused by Arsenic-alkali Residue from Antimony Metallurgical Enterprise in Hunan and its Control Countermeasures%湖南锑冶炼业砷碱渣致水源性砷中毒特征分析与控制对策

    Institute of Scientific and Technical Information of China (English)

    王杰; 肖云龙; 王海鸿; 苏长征

    2013-01-01

    目的 探讨湖南锑冶炼砷废渣致水源性砷中毒的流行病学特征,为防治水源性砷中毒提供科学依据.方法 运用回顾性流行病学方法对水源性砷中毒进行调查分析.结果 水源性砷中毒,主要是砷碱渣污染水源所致,主要特征为急性和亚急性中毒,具有突发性、隐匿性、群体性,分布为饮同一水源,其年龄、性别无差异,可累及神经系统、消化系统、心血管系统以及血液、泌尿系统.根据患者的尿样及饮用水源的砷含量显著增高,可以确诊.结论 通过对湖南锑冶炼业砷污染水源致砷中毒调查发现,水源性砷中毒具有一定的特征性,据此可以早期诊断和及时处理.预防砷对水源的污染,砷中毒事故是可以控制的.%Objective To explore the epidemiological characteristics of acute and subacute arsenic poisoning due to drinking water source pollution by arsenic - alkali residue from antimony metallurgical enterprise in Hunan area,so as to provide scientific basis for the prevention and treatment of waterborne arsenic poisoning. Methods A waterborne arsenic poisoning was investigated and analyzed by retrospective epidemiology. Results The waterborne arsenic poisoning was mainly due to water source pollution by arsenic from arsenic - alkali residue released from the antimony metallurgical enterprise. It mainly manifested acute and subacute poisoning, which was sudden, latent and colonial. The sufferers shared the same drinking water source. The incidence was not different among different age and sexes. Their nervous, digestive, cardiovascular, blood and urinary system could be inflicted. The diagnosis could be confirmed by elevated arsenic levels in the urine and drinking water source. Conclusions The retrospective epidemiological investigation of the arsenic poisoning due to drinking water source pollution by arsenic -alkali residue from antimony metallurgical enterprise in Hunan area indicates that the arsenic

  9. 氢化物发生-原子荧光光谱法测定合金钢及合金中痕量元素铅、锡、砷、锑、铋的进展%Determination Progress of Trace Elements (Lead, Tin, Arsenic, Antimony, Bismuth)in Staliness Steel Alloys by HF-AFS

    Institute of Scientific and Technical Information of China (English)

    赵艳兵; 刘爱坤; 戴学谦; 王珺

    2011-01-01

    通过对近年来有关氢化物发生-原子荧光光谱法在复杂基体体系中痕量元素检测方面的资料总结,阐述了氢化物发生-原子荧光光谱法分析过程中的干扰类型、干扰机理及消除干扰的措施,对其在合金钢及合金中痕量元素铅、锡、砷、锑、铋测定中的应用进展作了评述,并对氢化物发生-原子荧光光谱法的发展前景提出了展望。%This paper presented a data summary of determination of trace elements in a complex matrix system by HG-AFS,covering the recent years. The interference type, interference mechanism and measures to eliminate interference of HG-AFS were also described. We reviewed the progress of the determination application of the Staliness Steel Alloys of trace elements, tin, lead, arsenic, antimony bismuth.We also discussed the HG-AFS development prospect.

  10. Interaction between uranium tetrafluoride oxide and antimony pentafluoride; fluorine-19 nuclear magnetic resonance investigations in solution; preparation and characterization of the adducts UF4O.nSbF5 (n=1-3) and crystal structure of UF4O.2SbF5

    International Nuclear Information System (INIS)

    The adducts UF4O.nSbF5 (n = 1 to 3) have been obtained as yellow-orange solids from the reaction of UF4O with SbF5 in SbF5 or HF solvents. A 19F n.m.r. study has helped explain the nature of the interaction taking place in solution. The solid adducts have been characterized by observation of reaction stoichiometries, chemical analysis, and vibrational spectra. An X-ray diffraction study has shown that crystals of UF4O.2SbF5 are monoclinic, space group P21/c. Unit-cell dimensions are reported. The structure has been refined by three-dimensional least-squares methods to R = 0.045 6 for 1 168 reflections. The structure is best regarded as a fluorine-bridged network of UF4O and SbF5 molecules in which the antimony is surrounded by a distorted octahedron of fluorine atoms and the uranium by a pentagonal-bipyramidal array of six fluorines and one oxygen. It is suggested that the structures of the 1:1 and 1:3 adducts will be related. (author)

  11. Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis

    Directory of Open Access Journals (Sweden)

    Leandro Ourives Neves

    2011-12-01

    Full Text Available FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respostas terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia guyanensis. MÉTODOS: 185 pacientes foram selecionados, conforme critérios de elegibilidade, e distribuídos, aleatoriamente, em 3 grupos - 2 com 74 enfermos e outro com 37 - que receberam, respectivamente, antimoniato de meglumina, isotionato de pentamidina e anfotericina B em doses, períodos e vias de administração padronizados. Os enfermos foram reexaminados um, dois e seis meses após o final dos tratamentos. RESULTADOS: Não houve diferença entre os grupos terapêuticos em relação ao sexo, idade, número ou local das lesões. A análise por intenção de tratar (ITT mostrou eficácias de 58,1% para a pentamidina e 55,5% para o antimoniato (p=0,857. O grupo da anfotericina B foi analisado separadamente, pois 28 (75,7% pacientes negaram-se a continuar no estudo após a randomização. Eventos adversos leves ou moderados foram relatados por 74 (40% pacientes, principalmente artralgia (20,3%, para o grupo do antimoniato, e dor (35,1% ou enduração (10,8% no local das injeções para a pentamidina. CONCLUSÕES: A pentamidina tem eficácia similar ao antimonial pentavalente para o tratamento da LTA ocasionada por L. guyanensis. Face aos baixos resultados de eficácia apresentados por ambas as drogas, necessita-se, com urgência, investigar novas opções terapêuticas para esta enfermidade.FUNDAMENTALS: American tegumentary leishmaniasis (ATL treatment remains a challenge, since most available drugs are injectable and only a small number of comparative, randomized clinical trials have been

  12. Comparative proteomic analysis in Miscanthus sinensis exposed to antimony stress

    International Nuclear Information System (INIS)

    To explore the molecular basis of Sb tolerance mechanism in plant, a comparative proteomic analysis of both roots and leaves in Miscanthus sinensis has been conducted in combination with physiological and biochemical analyses. M. sinensis seedlings were exposed to different doses of Sb, and both roots and leaves were collected after 3 days of treatment. Two-dimensional gel electrophoresis (2-DE) and image analyses found that 29 protein spots showed 1.5-fold change in abundance in leaves and 19 spots in roots, of which 31 were identified by MALDI-TOF-MS and MALDI-TOF-TOF-MS. Proteins involved in antioxidant defense and stress response generally increased their expression all over the Sb treatments. In addition, proteins relative to transcription, signal transduction, energy metabolism and cell division and cell structure showed a variable expression pattern over Sb concentrations. Overall these findings provide new insights into the probable survival mechanisms by which M. sinensis could be adapting to Sb phytotoxicity. - Highlights: • Proteomics in Miscanthus sinensis leaves and roots exposed to Sb stress were studied. • There were 31 spots that were identified by mass spectrometry. • Most of these proteins were involved in antioxidant defense and stress response. • Our findings provide new insights into the tolerant mechanisms to Sb stress. - Miscanthus sinensis proteomic analysis under Sb stress reveals probable molecular mechanisms on Sb detoxification

  13. Mercury and antimony in wastewater: fate and treatment

    OpenAIRE

    Hargreaves, Andrew J.; Vale, Peter; Whelan, Jonathan; Constantino, Carlos; Dotro, Gabriela; Cartmell, Elise

    2016-01-01

    It is important to understand the fate of Hg and Sb within the wastewater treatment process so as to examine potential treatment options and to ensure compliance with regulatory standards. The fate of Hg and Sb was investigated for an activated sludge process treatment works in the UK. Relatively high crude values (Hg 0.092 μg/L, Sb 1.73 μg/L) were observed at the works, whilst low removal rates within the primary (Hg 52.2 %, Sb 16.3 %) and secondary treatment stages (Hg 29.5 %, Sb −28.9 %) r...

  14. Urinary antimony speciation by HPLC-ICP-MS

    OpenAIRE

    Krachler, M; Emons, H

    2001-01-01

    This is the first study to report on the determination of Sb species in urine. To this end, HPLC was coupled online to an ICP-MS instrument using ultrasonic nebulization (USN) or hydride generation (HG) for sample introduction into the ICP-MS. The high chloride concentration in urine seriously hampered the chromatographic separation of Sb(v) and Sb(III) on the Dionex AS14 anion exchange column. Distinct signal suppression, shifting of retention times and severe peak broadening did not allow t...

  15. Copper Antimony Chalcogenide Thin Film PV Device Development

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Adam W.; Baranowski, Lauryn L.; de Souza Lucas, Francisco Willian; Toberer, Eric S.; Wolden, Colin A.; Zakutayev, Andriy

    2015-06-14

    Emerging ternary chalcogenide thin film solar cell technologies, such as CuSbS2 and CuSbSe2, have recently attracted attention as simpler alternatives to quaternary Cu2ZnSnS4 (CZTS). Despite suitable photovoltaic properties, the initial energy conversion efficiency of CuSbS2 is rather low (0.3%). Here, we report on our progress towards improving the efficiency of CuSbS2 solar cells using a high throughput approach. The combinatorial methodology quickly results in baseline solar cell prototypes with 0.6% efficiency, and then modification of the back contact architecture leads to 1% PV devices. We then translate the optimal CuSbS2 synthesis parameters to CuSbSe2 devices, which show 3% efficiencies.

  16. Recovery of antimony-125 from tin-124 irradiated by neutrons

    International Nuclear Information System (INIS)

    Separation of 125Sb from tin using highly basic, medium-basic, and weakly basic ion-exchangers was studied. The best results were obtained for AN-31 weakly basic anion exchanger. The yield of 125Sb was 95 -98 % of the initial activity, the yield of tin, 98 ± 0.5% of the initial amount. The separation coefficient is 106-107 for one cycle. A procedure based on ion exchange was developed. Extraction procedures of separation of 125Sb from tin were studied. Isoamyl alcohol, ethyl acetate, and di-n-butyl ether were used as extracting agents. The most efficient extracting agent is di-n-butyl ether. Carrier-free radiochemically pure sample of 125Sb was produced. More than 20 mCi of the target product was recovered. The extraction recovery procedure of 125Sb has been developed. (author)

  17. Recovery of antimony-125 from tin-124 irradiated by neutrons

    Science.gov (United States)

    Baluev, A. V.; Mityakhina, V. S.; Krasnikov, L. V.; Galkin, B. Ya.; Besnosyuk, V. I.

    2003-01-01

    Separation of 125Sb from tin using highly basic, medium-basic, and weakly basic ion-exchangers was studied. The best results were obtained for AN-31 weakly basic anion exchanger. The yield of 125Sb was 95-98% of the initial activity, the yield of tin, 98±0.5% of the initial amount. The separation coefficient is 106-107 for one cycle. A procedure based on ion exchange was developed. Extraction procedures of separation of 125Sb from tin were studied. Isoamyl alcohol, ethyl acetate, and di- n-butyl ether were used as extracting agents. The most efficient extracting agent is di- n-butyl ether. Carrier-free radiochemically pure sample of 125Sb was produced. More than 20 mCi of the target product was recovered. The extraction recovery procedure of 125Sb has been developed.

  18. Antimony bonding in Ge-Sb-Te phase change materials

    Science.gov (United States)

    Bobela, David C.; Taylor, P. Craig; Kuhns, Phillip; Reyes, Arneil; Edwards, Arthur

    2011-01-01

    The amorphous phase in some technologically important Ge-Sb-Te systems is still not well understood despite many models that exist to explain it. Using nuclear magnetic resonance, we demonstrate that Sb bonding in these systems follows the 8-Nrule for chemical bonding in amorphous solids. We find that the Sb atoms preferentially bond to three atoms in a pyramidal configuration analogous to the sites occurring in Sb-S or Sb-Se systems. The data we present should be used as a guide for structural modeling of the amorphous phase.

  19. Structural and magnetic properties of nickel antimony ferrospinels

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, S.A. [Center of Materials Science, Karpov’ Institute of Physical Chemistry, Moscow, 105064 (Russian Federation); Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Tellgren, R. [Department of Chemistry, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Porcher, F.; André, G. [Laboratoire Leon Brillouin, Saclay (France); Ericsson, T. [Department of Chemistry, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Nordblad, P. [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Sadovskaya, N.; Kaleva, G.; Politova, E. [Center of Materials Science, Karpov’ Institute of Physical Chemistry, Moscow, 105064 (Russian Federation); Baldini, M. [HPSynC, Carnegie Institution of Washington, Argonne, IL 60439 (United States); Sun, C. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Arvanitis, D. [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden); Anil Kumar, P. [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Mathieu, R., E-mail: roland.mathieu@angstrom.uu.se [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden)

    2015-05-05

    Spinel-type compounds of Fe–Ni–Sb–O system were synthesized as polycrystalline powders. The crystal and magnetic properties were investigated using X-ray and neutron powder diffraction, Mössbauer and X-ray absorption spectroscopy and magnetization measurements. The samples crystallize in the cubic system, space group Fd – 3 m. The distribution of cations between octahedral and tetrahedral sites was refined from the diffraction data sets using constraints imposed by the magnetic, Mössbauer and EDS results and the ionic radii. The cation distribution and the temperature dependence of the lattice parameter (a) and the oxygen positional parameter (u) were obtained. A chemical formula close to Fe{sub 0.8}Ni{sub 1.8}Sb{sub 0.4}O{sub 4} was determined, with Sb{sup 5+} cations occupying octahedral sites, and Fe{sup 3+} and Ni{sup 2+} occupying both tetrahedral and octahedral sites. Fe{sup 3+} mainly (85/15 ratio) occupy tetrahedral sites, and conversely Ni{sup 2+} mainly reside on octahedral ones. The magnetic unit cell is the same as the crystallographic one, having identical symmetry relations. The results indicate that the compounds have a collinear ferrimagnetic structure with antiferromagnetic coupling between the tetrahedral (A) and octahedral (B) sites. Uniquely, the temperature dependence of the net magnetization of this rare earth free ferrimagnet exhibits a compensation point. - Highlights: • Polycrystalline spinel-type compounds of (Fe,Ni)[Fe,Ni,Sb]2O4 were synthesized. • Fe (3+) and Ni (2+) cations occupy mainly tetrahedral (resp. octahedral) sites. • The ferrimagnetic behavior observed below 650 K is investigated in detail. • Squid magnetometry and neutron powder diffraction data are compared.

  20. Neutron total scattering cross sections of elemental antimony

    International Nuclear Information System (INIS)

    Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V

  1. Vapor pressures of dimethylcadminum, trimethylbismuth, and tris(dimethylamino)antimony

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Fulem, Michal; Pangrác, Jiří; Hulicius, Eduard; Růžička, K.

    Jülich : Forschungszentrum Jülich GmbH, 2013 - (Hardtdegen, H.; Vescan, A.), s. 239-242 ISBN 978-3-89336-870-9. ISSN 1866-1777. [European Workshop on Metalorganic Vapour Phase Epitaxy /15./. Aachen (DE), 02.06.2013-05.06.2013] R&D Projects: GA ČR GA13-15286S Institutional support: RVO:68378271 Keywords : vapor pressure * static method * metalorganic precursors * MOVPE Subject RIV: CF - Physical ; Theoretical Chemistry

  2. A thermodynamic investigation of liquid gold-antimony alloys

    International Nuclear Information System (INIS)

    The enthalpies of mixing of liquid Au-Sb alloys were determined between 906 and 1028 K giving ΔmixHom = xSb xAu (-11.234-1.1078xSb + 5.713xSb2) kJ mol-1. The minimum was found at xSb = 0.45 with ΔmixHom = -2.62 ± 0.2 kJ mol-1 contrary to published measurements on liquid Au-Sb alloys. The limiting partial molar enthalpy of Au in Sb at 935 K was measured to Δmixhom(Au, liq, in ∞Sb, liq) = -6.05 ± 0.4 kJ mol-1. The enthalpy of formation of the solid compound AuSb2 determined at 298 K by solution calorimetry in liquid Sb, ΔfHom(AuSb2) = -5.40 ± 0.6 kJ mol-1, is found in fair agreement with literature data. DTA measurements were performed on the Au-rich part of the liquidus and a new liquidus curve is suggested between Au and the eutectic concentration. The eutectic point was found at 630.37 ± 0.25 K and xSb 0.350. (orig.)

  3. Reaction of isobutyl- and 2-chloroisobutyldichlorophosphines with antimony trifluoride

    International Nuclear Information System (INIS)

    We have shown that isobutyl- and 2-chloroisobutyldichlorophosphine react with SbF3 differently than has been described in the case of other alkyldichlorophosphines. Thus, when an equimolar ratio of reagents is used, dichlorophosphine forms with SbF3 a mixture consisting of isobutyltetrafluorophosphorane, isobutyldifluorophosphine, and isobutylfluorochlorophosphine. The 31NMR spectra were taken on the Bruker HX-90 instrument at 36.43 MHz. the chemical shifts were determined relative to 85% H3PO4

  4. Abiotic redox reactions of antimony and plutonium under anoxic conditions

    OpenAIRE

    Kirsch, Regina,

    2012-01-01

    Redox reactions of Sb(V) and Sb(III) with mackinawite (FeS) and of aqueous Pu(III) and Pu(V) with various Fe(II)-bearing minerals and Fe(III)-oxides have been investigated under anoxic conditions. X-ray absorption spectroscopy was used to analyze oxidation state and local coordination environment of Sb and Pu associated with the solid phase. After reaction with mackinawite, chukanovite and magnetite, PuO2, Pu(III) or mixtures of the two oxidation states were observed. On magnetite, a tridenta...

  5. Structural and magnetic properties of nickel antimony ferrospinels

    International Nuclear Information System (INIS)

    Spinel-type compounds of Fe–Ni–Sb–O system were synthesized as polycrystalline powders. The crystal and magnetic properties were investigated using X-ray and neutron powder diffraction, Mössbauer and X-ray absorption spectroscopy and magnetization measurements. The samples crystallize in the cubic system, space group Fd – 3 m. The distribution of cations between octahedral and tetrahedral sites was refined from the diffraction data sets using constraints imposed by the magnetic, Mössbauer and EDS results and the ionic radii. The cation distribution and the temperature dependence of the lattice parameter (a) and the oxygen positional parameter (u) were obtained. A chemical formula close to Fe0.8Ni1.8Sb0.4O4 was determined, with Sb5+ cations occupying octahedral sites, and Fe3+ and Ni2+ occupying both tetrahedral and octahedral sites. Fe3+ mainly (85/15 ratio) occupy tetrahedral sites, and conversely Ni2+ mainly reside on octahedral ones. The magnetic unit cell is the same as the crystallographic one, having identical symmetry relations. The results indicate that the compounds have a collinear ferrimagnetic structure with antiferromagnetic coupling between the tetrahedral (A) and octahedral (B) sites. Uniquely, the temperature dependence of the net magnetization of this rare earth free ferrimagnet exhibits a compensation point. - Highlights: • Polycrystalline spinel-type compounds of (Fe,Ni)[Fe,Ni,Sb]2O4 were synthesized. • Fe (3+) and Ni (2+) cations occupy mainly tetrahedral (resp. octahedral) sites. • The ferrimagnetic behavior observed below 650 K is investigated in detail. • Squid magnetometry and neutron powder diffraction data are compared

  6. Adsorption of ammonia on vanadium-antimony mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Hernan; German, Estefania [Departamento e Instituto de Fisica del Sur, Universidad Nacional del Sur-CONICET, Avda. Alem 1253, (8000) Bahia Blanca (Argentina); Juan, Alfredo, E-mail: cajuan@uns.edu.ar [Departamento e Instituto de Fisica del Sur, Universidad Nacional del Sur-CONICET, Avda. Alem 1253, (8000) Bahia Blanca (Argentina); Irigoyen, Beatriz [Departamento de Ingenieria Quimica, Facultad de Ingenieria, Universidad de Buenos Aires, Pabellon de Industrias, Ciudad Universitaria, (1428) Ciudad Autonoma de Buenos Aires (Argentina)

    2012-02-01

    We analyzed the adsorption of ammonia (NH{sub 3}) on the VSbO{sub 4}(1 1 0) catalyst surface using density functional theory (DFT) calculations. We followed the evolution of the chemical bonds between different atoms of the resulting NH{sub 3}/VSbO{sub 4} system and the changes in the electronic structure of the catalyst. NH{sub 3} preferential adsorption geometries were analyzed through the crystal orbital overlap population (COOP) concept and the density of states (DOS) curves. The VSbO{sub 4}(1 1 0) surface exhibits Lewis and Bronsted acid sites on which the ammonia molecule can interact. On the Lewis acid site, NH{sub 3} adsorption resulted in the interaction between the N and a surface V-isolated cation. On Bronsted acid site, N interacted with a surface H coming from the chemical dissociation of water. The COOP analysis indicate that NH{sub 3} interaction on the VSbO{sub 4}(1 1 0) surface is weak. In addition, the DOS curves show more developed electronic interactions for NH{sub 3} adsorption on Lewis acid site than over Bronsted acid site.

  7. Deposition of antimony telluride thin film by ECALE

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  8. Singular Diffusion as a Function of Nanoparticles Size in Antimony Film-Selenium Particles and Antimony Film-Tellurium Particles

    International Nuclear Information System (INIS)

    A recently developed chemical synthesis method using the nanoparticle size as a parameter has been applied to Sb film-Se particle and Sb film-Te particle systems. In the Sb-Se system, the diffusion of Se atoms to the Sb film can be clearly seen for Se particle sizes less than 50 nm. Diffusion of Sb atoms predominantly took place in the case of the Sb-Te system. The uniqueness of the reaction consists in the diffusion direction of nanoparticles. Comparison with previous work (Kaito et al., 1998b) is made on the basis of the particle stability and electronegativity

  9. Bioaccumulation of Antimony and Arsenic in Vegetables and Health Risk Assessment in the Superlarge Antimony-Mining Area, China

    OpenAIRE

    Defang Zeng; Saijun Zhou; Bozhi Ren; Tengshu Chen

    2015-01-01

    Heavy metal pollution in soils caused by mining and smelting has attracted worldwide attention for its potential health risks to residents. This paper studies the concentrations and accumulations of Sb and As in both soils and vegetables and the human health risks of Sb and As in vegetables from Xikuangshan (XKS) Sb mine, Hunan, China. Results showed that the soils were severely polluted by Sb and As; Sb and As have significant positive correlation. Sb and As concentrations in vegetables were...

  10. Antimony doped cadmium selenium nanobelts with enhanced electrical and optoelectrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lijie [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Nanomaterials and Chemistry Key Laboratory, Wenzhou University, Wenzhou 325027 (China); Yu, Hongfei; Cao, Wei; Dong, Youqing; Zou, Chao; Yang, Yun [Nanomaterials and Chemistry Key Laboratory, Wenzhou University, Wenzhou 325027 (China); Huang, Shaoming, E-mail: smhuang@wzu.edu.cn [Nanomaterials and Chemistry Key Laboratory, Wenzhou University, Wenzhou 325027 (China); Dai, Ning [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Zhu, Da-Ming, E-mail: ZhuD@umkc.edu [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); University of Missouri-Kansas City, Kansas City, MO 64110 (United States)

    2014-07-01

    Intrinsic and Sb-doped CdSe nanobelts (NBs) were synthesized via a thermal evaporation technique. The electrical transport properties of field effect transistors (FETs) fabricated using the NBs were investigated. The results indicate that the Sb-doped NBs behave as n-type semiconductors with improved electrical conductivity (10⁻¹ to 100 S/cm) compared with the intrinsic CdSe. Photodetectors made of single NB were also fabricated and investigated. The results show that Sb-doped NB photodetectors exhibit much higher responsivity (1.5 × 10⁴ A/W) and external quantum efficiency (1.2 × 10⁵) but lower on/off current ratio (~253) and longer response time (≤40 ms). Furthermore, both electrical transport and optoelectrical properties of the as-synthesized CdSe NBs can be tuned by changing the doping concentration. The results indicate that the as-synthesized NBs are excellent building blocks for constructing electronic and optoelectronic devices.

  11. Antimony doped cadmium selenium nanobelts with enhanced electrical and optoelectrical properties

    International Nuclear Information System (INIS)

    Intrinsic and Sb-doped CdSe nanobelts (NBs) were synthesized via a thermal evaporation technique. The electrical transport properties of field effect transistors (FETs) fabricated using the NBs were investigated. The results indicate that the Sb-doped NBs behave as n-type semiconductors with improved electrical conductivity (10−1 to 100 S/cm) compared with the intrinsic CdSe. Photodetectors made of single NB were also fabricated and investigated. The results show that Sb-doped NB photodetectors exhibit much higher responsivity (1.5 × 104 A/W) and external quantum efficiency (1.2 × 105) but lower on/off current ratio (∼253) and longer response time (≤40 ms). Furthermore, both electrical transport and optoelectrical properties of the as-synthesized CdSe NBs can be tuned by changing the doping concentration. The results indicate that the as-synthesized NBs are excellent building blocks for constructing electronic and optoelectronic devices.

  12. Low-Power Super-resolution Readout with Antimony Bismuth Alloy Film as Mask layer

    Institute of Scientific and Technical Information of China (English)

    JIANG Lai-Xin; WU Yi-Qun; WANG Yang; WEI Jing-Song; GAN Fu-Xi

    2009-01-01

    Sb-Bi alloy films are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb-Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the super-resolution pits with diameters of 38Onm are read out by a dynamic setup, the laser wavelength is 78Onto and the numerical aperture of pickup lens is 0.45. The effects of the Sb-Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb-Bi mask layer is about 0.5roW, and the corresponding carrier-to-noise ratio is about 20dB at the film thickness of 5Ohm. The super-resolution mechanism of the Sb-Bi alloy mask layer is discussed based on its temperature dependence of reflection.

  13. 78 FR 59679 - Antimony Trioxide TSCA Chemical Risk Assessment; Notice of Public Meetings and Opportunity To...

    Science.gov (United States)

    2013-09-27

    ... notice in the Federal Register (78 FR 1856) (FRL-9375-1) on the availability of five draft TSCA chemical... clearly as possible, avoiding the use of profanity or personal threats. viii. Make sure to submit...

  14. Kinetic modeling of antimony(III) oxidation and sorption in soils.

    Science.gov (United States)

    Cai, Yongbing; Mi, Yuting; Zhang, Hua

    2016-10-01

    Kinetic batch and saturated column experiments were performed to study the oxidation, adsorption and transport of Sb(III) in two soils with contrasting properties. Kinetic and column experiment results clearly demonstrated the extensive oxidation of Sb(III) in soils, and this can in return influence the adsorption and transport of Sb. Both sorption capacity and kinetic oxidation rate were much higher in calcareous Huanjiang soil than in acid red Yingtan soil. The results indicate that soil serve as a catalyst in promoting oxidation of Sb(III) even under anaerobic conditions. A PHREEQC model with kinetic formulations was developed to simulate the oxidation, sorption and transport of Sb(III) in soils. The model successfully described Sb(III) oxidation and sorption data in kinetic batch experiment. It was less successful in simulating the reactive transport of Sb(III) in soil columns. Additional processes such as colloid facilitated transport need to be quantified and considered in the model. PMID:27214003

  15. Thermal decomposition of complex halides of arsenic(3), antimony(3) and bismuth(3) with alkali metals

    Energy Technology Data Exchange (ETDEWEB)

    Cyganski, A.; Ptaszynski, B.; Zalewicz, M. (Politechnika Lodzka (Poland))

    1980-01-01

    Thermal analyses of complexes M/sub 3/(As/sub 2/X/sub 9/) (M = Rb, Cs; X = Cl, Br), M/sub 3/(Sb/sub 2/X/sub 9/) (M = Rb, Cs; X = Cl, Br, I), Rb/sub 3/(BiX/sub 6/) (X = Cl, Br) and Cs/sub 3/(Bi/sub 2/X/sub 9/) (X = Cl, Br, I) were performed. From chemical and X-ray analyses of their solid decomposition products the mechanism of thermal decomposition reactions was established. From thermogravimetric curves apparent activation energies were calculated using Coats-Redfern's and Zsako's methods. Thermal stability of complexes increases distinctly in the following order: As

  16. The determination of arsenic, selenium, antimony, and tin in complex environmental samples by hydride generation AAS

    International Nuclear Information System (INIS)

    Hydride generation techniques are used routinely for the determination of As, Se, Sb and Sn in water samples. Advantages include high sensitivity, simplicity, and relative freedom from interferences. Continuous-flow designs greatly reduce analysis time as well as improve precision and allow for automation. However the accurate analysis of more complex environmental samples such as industrial sludges, soil samples, river sediments, and fly ash remains difficult. Numerous contributing factors influence the accuracy of the hydride technique. Sample digestion methods and sample preparation procedures are of critical importance. The digestion must adequately solubilize the elements of interest without loss by volatilization. Sample preparation procedures that guarantee the proper analyte oxidation state and eliminate the nitric acid and inter-element interferences are needed. In this study, difficult environmental samples were analyzed for As, Se, Sb, and Sn by continuous flow hydride generation. Sample preparation methods were optimized to eliminate interferences. The results of spike recovery studies will be presented. Data from the analysis of the same samples by graphite furnace AAS will be presented for comparison of accuracy, precision, and analysis time

  17. Separation of trace antimony and arsenic prior to hydride generation atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    A separation method utilizing a synthetic zeolite (mordenite) was developed in order to eliminate the gas phase interference of Sb(III) on As(III) during quartz furnace hydride generation atomic absorption spectrometric (HGAAS) determination. The efficiency of the proposed separation method in the reduction of suppression effects of transition metal ions on As(III) signal was also investigated. Among the volatile hydride-forming elements and their different oxidation states tested (Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), and Te(VI)), only Sb(III) was found to have a signal depression effect even at low (μg l-1) concentrations under the experimental conditions employed. It has been shown that mordenite adsorbs Sb(III) quantitatively, even at a concentration of 1000 μg l-1, at pHs greater than two, and also, it reduces the initial concentrations of the transition metal ions to lower levels which can be tolerated in many studies. The adsorption of Sb(III) on mordenite follows the Freundlich isotherm and is endothermic in nature

  18. Effect of antimony(III) on carbon steel corrosion inhibition by molybdate in citric acid solution

    International Nuclear Information System (INIS)

    Molybdate is known as a good corrosion inhibitor of carbon steel (CS). But it cannot inhibit CS corrosion in citric acid solution at 85 °C. It has been observed that the presence of small concentration of Sb(III) along with MoO42- inhibits CS corrosion efficiently. The corrosion inhibition by MoO42- have been studied extensively by varying the concentration of Sb(III) and MoO42-. A critical concentration of MoO42- is required to passivate CS in acid medium in the presence of Sb(III). The study shows that molybdate forms a thin protective layer on CS surface in presence of Sb(III) which provides the corrosion inhibition. Inhibition property and the layer composition on CS surface have been studied by electrochemical and surface analytical techniques. The protective layer is found to be composed of both Mo and Sb and appears to be formed due to cathodic reduction of Mo6+ to Mo5+ and Mo4+ and anodic oxidation of Fe and Sb. (author)

  19. Thermodynamic Properties of Liquid Silver-Antimony-Tin Alloys Determined from Electrochemical and Calorimetric Measurements

    Science.gov (United States)

    Łapsa, Joanna; Onderka, Bogusław

    2016-05-01

    The thermodynamic properties of liquid Ag-Sb-Sn alloys were obtained through use of the drop solution calorimetric method and electromotive force (emf) measurements of galvanic cells with a yttria stabilized zirconia (YSZ) solid electrolyte. The experiments were carried out along Ag0.25Sb0.75, Ag0.5Sb0.5 and Ag0.75Sb0.25 sections of the ternary system in the temperature range from 973 K to 1223 K. From the measured emf, the tin activity in liquid solutions of Ag-Sb-Sn was determined for the first time. The partial and integral enthalpy of mixing were determined from calorimetric measurements at two temperatures. These measurements were performed along two cross-sections: Sb0.5Sn0.5 at 912 K and 1075 K, and Ag0.75Sb0.25 at 1075 K. Both experimental data sets were used to find ternary interaction parameters by applying the Redlich-Kister-Muggianu model of the substitutional solution. Consequently, the set of parameters describing the thermodynamic properties of the liquid phase was derived.

  20. Ab initio study of the adsorption of antimony and arsenic on the Si(110) surface

    Energy Technology Data Exchange (ETDEWEB)

    Huitzil-Tepanecatl, Arely [Postgrado en Fisica Aplicada, Facultad de Ciencias Fisico-Matematicas, BUAP, Apartado Postal 52, Puebla 72000 (Mexico); Cocoletzi, Gregorio H., E-mail: cocoletz@sirio.ifuap.buap.m [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Km. 107 Carretera Tijuana-Ensenada, Codigo Postal 22860, Apartado Postal 2732 Ensenada, Baja California (Mexico); Centro de Nanociencia y Nanotecnologia, Universidad Nacional Autonoma de Mexico, Apartado Postal 2681, Ensenada, Baja California, 22800 (Mexico); Instituto de Fisica, Universidad Autonoma de Puebla, Apartado Postal J-48, Puebla 72570 (Mexico); Takeuchi, Noboru [Centro de Nanociencia y Nanotecnologia, Universidad Nacional Autonoma de Mexico, Apartado Postal 2681, Ensenada, Baja California, 22800 (Mexico)

    2010-10-29

    We have performed first principles total energy calculations to investigate the adsorption of Sb and As adatoms on the Si(110) surface using a (2 x 3) supercell. The energetics and atomic structures have been investigated in four atomic configurations. One structure is obtained by placing 1/3 of a monolayer (ML) of Sb (As) atoms on the Si(110) surface. The other three geometries are obtained by depositing 1 ML of Sb (As) atoms on the surface. In the first case the structure is formed by four trimers, in the second case the geometry is formed by zigzag atomic chains and in the third case the structure contains 'microfacets'. The energetics results of the Sb adsorption show that for low coverage the tetrahedrons formed by the adsorption of 1/3 ML is the most stable configuration, while in the monolayer region the zigzag atomic chain is the most stable structure. However, the total energies of the trimer and microfacet structures are slightly higher, indicating that under some conditions, they may be formed. In an experimental report it has been suggested that the adsorption of 1/3 and 1 ML of Sb corresponds to the low and high coverage in the experiments of Zotov et al. [A. V. Zotov, V. G. Lifshifts, and A. N. Demidchik, Surf. Sci. 274, L583 (1992)]. On the other hand, our results of the As adsorption show that for low coverage, the tetrahedrons in the adsorption of 1/3 ML also give the most stable configuration. However, at the 1 ML coverage, a structure formed by microfacets is the most stable structure, in agreement with previous results.

  1. Arsenic, antimony and selenium in urban soils: potential risks for human health in urban gardening

    OpenAIRE

    Izquierdo, Miguel; Miguel García, Eduardo de; Gómez San Martín, Amaia; Mingot Marcilla, Juan

    2015-01-01

    The benefits of urban agriculture are many and well documented, ranging from health improvement to community betterment, more sustainable urban development and environment protection. On the negative side, urban soils are commonly enriched in toxic trace elements that have accumulated over time through the deposition of atmospheric particles (generated by automotive traffic, heating systems, historical industrial activities and resuspended street dust), and the uncontrolled disposal of domest...

  2. Structural and optical studies on antimony and zinc doped CuInS2 thin films

    Science.gov (United States)

    Ben Rabeh, M.; Chaglabou, N.; Kanzari, M.; Rezig, B.

    2009-11-01

    The influence of Zn and Sb impurities on the structural, optical and electrical properties of CuInS2 thin films on corning 7059 glass substrates was studied. Undoped and Zn or Sb doped CuInS2 thin films were deposited by thermal evaporation method and annealed in vacuum at temperature of 450 ∘C Undoped thin films were grown from CuInS2 powder using resistively heated tungsten boats. Zn species was evaporated from a thermal evaporator all together to the CuInS2 powder and Sb species was mixed in the starting powders. The amount of the Zn or Sb source was determined to be in the range 0-4 wt% molecular weight compared with the CuInS2 alloy source. The films were studied by means of X-ray diffraction (XRD), Optical reflection and transmission and resistance measurements. The films thicknesses were in the range 450-750 nm. All the Zn: CuInS2 and Sb: CuInS2 thin films have relatively high absorption coefficient between 104 cm-1 and 105 cm-1 in the visible and the near-IR spectral range. The bandgap energies are in the range of 1.472-1.589 eV for Zn: CuInS2 samples and 1.396-1.510 eV for the Sb: CuInS2 ones. The type of conductivity of these films was determined by the hot probe method. Furthermore, we found that Zn and Sb-doped CuInS2 thin films exhibit P type conductivity and we predict these species can be considered as suitable candidates for use as acceptor dopants to fabricate CuInS2-based solar cells.

  3. Calculation of small arsenic and antimony chalcogenide clusters with an application to vitreous chalcogenide structure

    OpenAIRE

    Gurin, V.; Shpotyuk, O.; Boyko, V

    2015-01-01

    Small clusters of the As/Sb-S/Se system that is of importance for simulation of elementary structure units of chalcogenide glasses are calculated using DFT technique. Different structures of As2Xn- and Sb2Xn- (X=S,Se) with proper hydrogen termination are compared by the total electronic energy values. The most stable As-X structures are of corner-sharing (CS) type (i.e. the elementary AsX3-pyramids linked via one X atom, and in the case of Sb-X family a new asymmetrical Sb2Se3 cluster appears...

  4. 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

    -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...

  5. Functionalized Thallium Antimony Films as Excellent Candidates for Large-Gap Quantum Spin Hall Insulator.

    Science.gov (United States)

    Zhang, Run-wu; Zhang, Chang-wen; Ji, Wei-xiao; Li, Sheng-shi; Yan, Shi-shen; Li, Ping; Wang, Pei-ji

    2016-01-01

    Group III-V films are of great importance for their potential application in spintronics and quantum computing. Search for two-dimensional III-V films with a nontrivial large-gap are quite crucial for the realization of dissipationless transport edge channels using quantum spin Hall (QSH) effects. Here we use first-principles calculations to predict a class of large-gap QSH insulators in functionalized TlSb monolayers (TlSbX2; (X = H, F, Cl, Br, I)), with sizable bulk gaps as large as 0.22~0.40 eV. The QSH state is identified by Z2 topological invariant together with helical edge states induced by spin-orbit coupling (SOC). Noticeably, the inverted band gap in the nontrivial states can be effectively tuned by the electric field and strain. Additionally, these films on BN substrate also maintain a nontrivial QSH state, which harbors a Dirac cone lying within the band gap. These findings may shed new light in future design and fabrication of QSH insulators based on two-dimensional honeycomb lattices in spintronics. PMID:26882865

  6. Simultaneous determination of arsenic, selenium and antimony species using HPLC/ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, T.; Prange, A.; Neidhart, B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physikalische und Chemische Analytik; Dannecker, W. [Univ. of Hamburg (Germany). Inst. for Inorganic and Applied Chemistry

    1999-07-01

    A new method for the simultaneous separation and determination of four arsenic species [As(III), As(V), monomethylarsonic acid and dimethylarsinic acid], three selenium species [Se(IV), Se(VI) and selenomethionine] as well as Sb(III) and Sb(V) is presented. The speciation was achieved by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic parameters such as the composition and pH of the mobile phase were optimised. Limits of detection are below 4.5 {mu}g L{sup -1} (as element) for Sb(III) and the selenium species and below 0.5 {mu}g L{sup -1} for the other species. Precisions of retention times were better than 2% RSD and of peak areas better than 8% RSD for all the species investigated. (orig.) With 5 figs., 3 tabs., 41 refs.

  7. Migration of antimony from polyethylene terephthalate used in mineral water bottles.

    Science.gov (United States)

    Carneado, S; Hernández-Nataren, E; López-Sánchez, J F; Sahuquillo, A

    2015-01-01

    The influence of storage time and temperature on Sb migration from PET bottles into mineral water was studied in short-term tests lasting up to 15 days and long-term studies lasting up to 220 days. Samples purchased were stored in three different coloured bottles: clear (CL), light blue (LB) and dark blue (DB). Sb migration was assayed by HG-AFS for total determination and HPLC-ICP-MS for speciation analysis. Migration studies showed that waters stored at 4 and 20 °C were not subject to Sb migration. At 40 °C there was a significant increase in Sb concentration, although the maximum limit established by the European Union (5.0 μgL(-)(1)) was not exceeded, whereas at 60 °C samples were subject to considerable Sb migration after 30 days of storage. In this case, the maximum limit established by the European Union was exceeded and both Sb (V) and Sb (III) were detected. PMID:25053092

  8. Migration of antimony from polyethylene terephthalate used in mineral water bottles.

    OpenAIRE

    Carneado, S.; Hernández-Nataren, E.; López Sánchez, José Fermín; Sahuquillo Estrugo, Àngels

    2014-01-01

    The influence of storage time and temperature on Sb migration from PET bottles into mineral water was studied in short-term tests lasting up to 15 days and long-term studies lasting up to 220 days. Samples purchased were stored in three different coloured bottles: clear (CL), light blue (LB) and dark blue (DB). Sb migration was assayed by HG-AFS for total determination and HPLC-ICP-MS for speciation analysis. Migration studies showed that waters stored at 4 and 20 oC were not subject to Sb mi...

  9. Water-dispersible small monodisperse electrically conducting antimony doped tin oxide nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Peters, K.; Zeller, P.; Štefanić, G.; Skoromets, Volodymyr; Němec, Hynek; Kužel, Petr; Fattakhova-Rohlfing, D.

    2015-01-01

    Roč. 27, č. 3 (2015), 1090-1099. ISSN 0897-4756 R&D Projects: GA ČR GA13-12386S Grant ostatní: AVČR(CZ) M100101218 Institutional support: RVO:68378271 Keywords : conducting nanoparticles * electrical conductivity * charge transport Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 8.354, year: 2014

  10. Antimony doped tin oxide nanoparticles and their assembly in mesostructured film

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rasp, M.; Stefanic, G.; Günther, S.; Rathouský, Jiří; Niederberger, M.; Fattakhova-Rohlfing, D.

    2011-01-01

    Roč. 8, č. 6 (2011), s. 1759-1763. ISSN 1862-6351 R&D Projects: GA ČR GA104/08/0435 Institutional research plan: CEZ:AV0Z40400503 Keywords : transparent conducting oxides * mesoporous films * nanoparticles Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Electrodeposition and characterization of nano-crystalline antimony telluride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lensch-Falk, J.L.; Banga, D. [Sandia National Laboratories, Livermore, CA 94550 (United States); Hopkins, P.E. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Robinson, D.B.; Stavila, V. [Sandia National Laboratories, Livermore, CA 94550 (United States); Sharma, P.A. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Medlin, D.L., E-mail: dlmedli@sandia.gov [Sandia National Laboratories, Livermore, CA 94550 (United States)

    2012-07-31

    Electrodeposition is a promising low-cost method to fabricate nanostructured thermoelectric thin films such as Sb{sub 2}Te{sub 3}. However, electrodeposition of crystalline Sb{sub 2}Te{sub 3} without the need for additional processing and with good compositional control has presented a challenge. Here we report on the electrodeposition of crystalline Sb{sub 2}Te{sub 3} thin films at room temperature from a tartaric-nitric acid electrolyte using a pulsed, potentiostatic process. The effects of synthesis conditions on the resulting microstructure and compositional homogeneity are investigated using x-ray diffraction, electron diffraction, electron microscopy, and energy dispersive x-ray spectroscopy. The composition of the Sb-Te films was found to be dependent on the interval between pulses, a result that is likely due to the slow kinetics associated with Sb{sub 2}Te{sub 3} formation at the surface. We also observed a change in texture and microstructure with varied applied pulse duration: for short pulse durations a lamellar microstructure with a {l_brace}000 Script-Small-L {r_brace} texture forms, whereas for longer pulse durations a more equiaxed and randomly oriented microstructure forms. The thermal conductivities of the pulsed electrodeposited films are surprisingly low at less than 2 W/K{center_dot}m and are found to systematically decrease with reduced pulse time. - Highlights: Black-Right-Pointing-Pointer We investigate the growth, microstructure, and thermal conductivity of Sb{sub 2}Te{sub 3} films. Black-Right-Pointing-Pointer Pulsed electrodeposition is used to grow crystalline Sb{sub 2}Te{sub 3} films. Black-Right-Pointing-Pointer Film composition and microstructure depend on the growth conditions. Black-Right-Pointing-Pointer Kinetics and thermodynamics are used to explain these observations. Black-Right-Pointing-Pointer The low thermal conductivities observed are correlated to microstructure and texture.

  12. Preparation, characterization and catalytic activity of uranium-antimony oxide for selective oxidation of propene

    International Nuclear Information System (INIS)

    The selective oxidation of propene to acrolein over USb3O10 was studied in a continuous flow reactor. The experimental results show that the preparation of a well-defined catalyst of uniform composition depends on the temperature and time of calcination. The kinetic data indicate that acrolein is formed via a redox mechanism in which the surface of the catalyst is partially reduced. Moessbauer spectroscopy reveals the presence of Sb5+ and Sb3+ in the used catalyst. I.r. spectroscopy shows a structural modification. On the basis of these results it is concluded that each steady-state condition is characterized by a vacancy concentration leading to the observed modifications of the catalyst. (author)

  13. Novel superstructure of the rocksalt type and element distribution in germanium tin antimony tellurides

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Tobias [Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany); Welzmiller, Simon [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Neudert, Lukas [Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany); Urban, Philipp [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Fitch, Andy [European Synchrotron Radiation Facility, CS40220, 38043 Grenoble Cedex 9 (France); Oeckler, Oliver, E-mail: oliver.oeckler@gmx.de [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany)

    2014-11-15

    A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge{sub 3.25(7)}Sn{sub 1.10(3)}Sb{sub 1.10(3)}Te{sub 6} was elucidated by X-ray diffraction using fourfold twinned crystals (space group P3{sup ¯}m1, a=4.280(1) Å, c=20.966(3) Å). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the 〈1 1 1〉 directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 µm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7} (R3{sup ¯}m, a=4.24990(4) Å, c=73.4677(9) Å). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks. - Graphical abstract: High-resolution transmission electron micrograph, SAED pattern and reciprocal lattice section of X-ray single crystal data of Ge{sub 3.25}Sn{sub 1.1}Sb{sub 1.1}Te{sub 6} with an 11P-type superstructure of the rocksalt type. - Highlights: • A novel superstructure of the rocksalt-type in the system Ge–Sn–Sb–Te is elucidated. • It combines the cubic stacking of the HT phase with building blocks of the RT phase. • It indicates the ordering mechanism during the phase transition of GST materials. • A hierarchical structure motif is promising with respect to the reduction of κ{sub L}. • Resonant diffraction reveals the element distribution in 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7}.

  14. Thermodynamic Properties of Liquid Silver-Antimony-Tin Alloys Determined from Electrochemical and Calorimetric Measurements

    Science.gov (United States)

    Łapsa, Joanna; Onderka, Bogusław

    2016-08-01

    The thermodynamic properties of liquid Ag-Sb-Sn alloys were obtained through use of the drop solution calorimetric method and electromotive force (emf) measurements of galvanic cells with a yttria stabilized zirconia (YSZ) solid electrolyte. The experiments were carried out along Ag0.25Sb0.75, Ag0.5Sb0.5 and Ag0.75Sb0.25 sections of the ternary system in the temperature range from 973 K to 1223 K. From the measured emf, the tin activity in liquid solutions of Ag-Sb-Sn was determined for the first time. The partial and integral enthalpy of mixing were determined from calorimetric measurements at two temperatures. These measurements were performed along two cross-sections: Sb0.5Sn0.5 at 912 K and 1075 K, and Ag0.75Sb0.25 at 1075 K. Both experimental data sets were used to find ternary interaction parameters by applying the Redlich-Kister-Muggianu model of the substitutional solution. Consequently, the set of parameters describing the thermodynamic properties of the liquid phase was derived.

  15. Antimony Doping in Solution-processed Cu2 ZnSn(S,Se)4 Solar Cells.

    Science.gov (United States)

    Tai, Kong Fai; Fu, Dongchuan; Chiam, Sing Yang; Huan, Cheng Hon Alfred; Batabyal, Sudip Kumar; Wong, Lydia Helena

    2015-10-26

    Kesterite Cu2 ZnSn(S,Se)4 (CZTSSe) is obtained using a facile precursor-solution method followed by selenization. Power-conversion efficiency of 6.0 % is achieved and further improved to 8.2 % after doping the absorber with 0.5 mol % Sb. XRD and Raman spectroscopy show similar characteristics for the undoped and doped CZTSSe. Increasing the Sb concentration increases the grain size and lowers the series resistance. However, further Sb doping beyond 0.5 mol % degrades device performance due to lower open-circuit voltage (and therefore lower fill factor). The effect of Sb doping and the doping concentration are investigated by power-dependent and temperature-dependent photoluminescence studies, revealing that trap density is significant reduced with 0.5 mol % Sb doping. Additional doping beyond 0.5 mol % creates more defects that quench the photoexcited carriers and decrease the open-circuit voltage. PMID:26376602

  16. Interface Promoted Reversible Mg Insertion in Nanostructured Tin-Antimony Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yingwen; Shao, Yuyan; Parent, Lucas R.; Sushko, Maria L.; Li, Guosheng; Sushko, Petr; Browning, Nigel D.; Wang, Chong M.; Liu, Jun

    2015-11-11

    This paper demonstrates intermetallic compounds SnSb are highly active materials for reversibly hosting Mg ions. Compared with monometallic Sn and Sb, SnSb alloy exhibited exceptionally high reversible capacity (420 mAh/g), excellent rate capability and good cyclic stability. Mg insertion into pristine SnSb involves an activation process to complete, which induces particle breakdown and results in phase segregation to Sn-rich and Sb-rich phases. Both experimental analysis and DFT simulation suggest that the Sn-rich phase is particularly active and provides most of the capacity whereas the Sb-rich phase is not as active, and the interface between these two phases play a key role in promoting the formation and stabilization of the cubic Sn phase that is more favorable for fast and reversible Mg insertion. We further show that activated SnSb alloy has good compatibility with simple Mg electrolytes. Overall, this work could provide new approaches for designing materials capable of reversible Mg ion insertion and new opportunities for understanding Mg electrochemistry.

  17. Solvent extraction of indium, tin, arsenic, and antimony by non-phosphorous compounds

    International Nuclear Information System (INIS)

    The extraction methods of In, Ti, Sn, As and Sb using non-phosphorous compounds are reviewed. This report is the continuation of the BIB-212 (pt.1) report concerned by Zn, Cd, Pb and Ag. So, the main elements of Zn ores are studied in these two reports

  18. Antimony leaching from MSWI bottom ash: modelling of the effect of pH and carbonation.

    Science.gov (United States)

    Cornelis, Geert; Van Gerven, Tom; Vandecasteele, Carlo

    2012-02-01

    Development of treatment methods to reduce Sb leaching from municipal solid waste incinerator (MSWI) bottom ash, such as accelerated carbonation, is being complicated by insufficient understanding of Sb geochemistry. The leaching of antimonate (Sb(V)) and antimonite (Sb(III)) in MSWI bottom was studied as a function of pH and degree of carbonation. While total (Sb(V)+Sb(III)) leaching was lowest (1.2 mg kg(-1)) at the natural pH (i.e. 10.6) of uncarbonated bottom ash, HPLC-ICP-MS analysis showed that acidification and carbonation increased Sb(V) leaching, but decreased Sb(III) leaching, probably because Sb(III)(OH)(4)(-) became less stable. PHREEQC geochemical modelling suggested that Sb(V) concentrations approached equilibrium with the romeites, i.e. calcium antimonates, Ca(1.13)Sb(2)(OH)(0.26)·0.74H(2)O at pH=10.6 and Ca[Sb(OH)(6)](2) at pH=8. It is hypothesised that not interaction with ettringite but dissolution of romeite controls antimonate leaching in the pH range 8-11 in MSWI bottom ash, because while Ca is preferentially leached from romeite, the mineral structures containing more Ca at higher pH are less soluble. A model was proposed where acidification and carbonation both lead to lower Ca(2+) and/or hydroxyl concentration, which removes Ca(2+) and hydroxyls from the romeite structure and leads to comparably higher Sb(V) concentration in equilibrium with romeite. Sb solubility depends on pH and Ca(2+) availability in this model, which has implications for bottom ash valorisation and risk assessment. PMID:22035902

  19. High Performance Liquid Metal Battery with Environmentally Friendly Antimony-Tin Positive Electrode.

    Science.gov (United States)

    Li, Haomiao; Wang, Kangli; Cheng, Shijie; Jiang, Kai

    2016-05-25

    For the first time, Sb-Sn alloys are reported as environmentally friendly positive electrodes for high performance liquid metal batteries (LMBs). Meanwhile, the dominant role of Sb in setting the potential and the inert "solvent" role of Sn in lowering the melting point and decreasing the cell cost are clarified on the basis of electrochemical titration and ex situ analysis. The Li||Sb-Sn LMB exhibits superior rate performance (only 13% capacity loss from 100 mA cm(-2) to 1 A cm(-2) of current densities), low materials cost (73 $ kW h(-1)), and high energy density (200.4 W h kg(-1)) at reduced operating temperature. Most notably, after 3500 h of operation (more than 430 full charge-discharge cycles), a discharge capacity of 20.6 Ah is maintained with a capacity retention of 96.7%, corresponding to a fade rate of 0.0078% per cycle, which potentially meets the metrics of large-scale energy storage without environmental concerns. PMID:27149506

  20. Surface functionalization of mesoporous antimony doped tin oxide by metalorganic reaction

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Haase, F.; Rathouský, Jiří; Fattakhova-Rohlfing, D.

    2012-01-01

    Roč. 137, č. 1 (2012), s. 207-212. ISSN 0254-0584 Institutional support: RVO:61388955 Keywords : oxides * organometallic compounds * chemical synthesis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.072, year: 2012

  1. Photocatalytic Properties of Tin Oxide and Antimony-Doped Tin Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    J. C. M. Brokken-Zijp

    2011-01-01

    Full Text Available For the first time it is shown that N-doped SnO2 nanoparticles photocatalyze directly the polymerization of the C=C bonds of (methacrylates under visible light illumination. These radical polymerizations also occur when these particles are doped with Sb and when the surfaces of these particles are grafted with methacrylate (MPS groups. During irradiation with visible or UV light the position and/or intensity of the plasmon band absorption of these nanoparticles are always changed, suggesting that the polymerization starts by the transfer of an electron from the conduction band of the particle to the (methacrylate C=C bond. By using illumination wavelengths with a very narrow band width we determined the influence of the incident wavelength of light, the Sb- and N-doping, and the methacrylate (MPS surface grafting on the quantum efficiencies for the initiating radical formation (Φ and on the polymer and particle network formation. The results are explained by describing the effects of Sb-doping, N-doping, and/or methacrylate surface grafting on the band gaps, energy level distributions, and surface group reactivities of these nanoparticles. N-doped (MPS grafted SnO2 (Sb ≥ 0% nanoparticles are new attractive photocatalysts under visible as well as UV illumination.

  2. Photoelectrocatalytic activity of two antimony doped SnO2 films for oxidation of phenol pollutants

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; FAN Cai-mei; HUA Bo; LIANG Zhen-hai; SUN Yan-pin

    2009-01-01

    Two types of Sb-doped SnO2 films on titanium substrate were prepared by the combination of electro-deposition and dip-coating (Ti/SnO2-Sb2O4/SnO2-Sb2O4) and single dip-coating (Ti/SnO2-Sb2O4), respectively. The surface morphology and crystalline structure of both film electrodes were characterized using X-ray diffractometry(XRD) and scanning electron microscopy(SEM). XRD spectra indicate that the rutile SnO2 forms in two films and a TiO2 crystallite exists only in Ti/SnO2-Sb2O4 electrode. SEM images show that the surface morphology of two films is typically cracked-mud structure. The photooxidation experiment was proceeded to further confirm the two electrode activity. The results show that the photoelectrocatalytic degradation efficiency of Ti/SnO2-Sb2O4 electrode with sub-layer is higher than that of simple Ti/SnO2-Sb2O4 electrode using phenol as a model organic pollutant. The Ti/SnO2-Sb2O4/SnO2-Sb2O4 photoanode has a better photoelectrochemical performance than Ti/SnO2-Sb2O4 photoanode for the removal of organic pollutants from water.

  3. Optical properties of multicomponent antimony-silver nanoclusters formed in silica by sequential ion implantation

    International Nuclear Information System (INIS)

    The linear and nonlinear optical properties of nanometer dimension metal colloids embedded in a dielectric depend explicitly on the electronic structure of the metal nanoclusters. The ability to control the electronic structure of the nanoclusters may make it possible to tailor the optical properties for enhanced performance. By sequential implantation of different metal ion species multi-component nanoclusters can be formed with significantly different optical properties than single element metal nanoclusters. The authors report the formation of multi-component Sb/Ag nanoclusters in silica by sequential implantation of Sb and Ag. Samples were implanted with relative ratios of Sb to Ag of 1:1 and 3:1. A second set of samples was made by single element implantations of Ag and Sb at the same energies and doses used to make the sequentially implanted samples. All samples were characterized using RBS and both linear and nonlinear optical measurements. The presence of both ions significantly modifies the optical properties of the composites compared to the single element nanocluster glass composites. In the sequentially implanted samples the optical density is lower, and the strong surface plasmon resonance absorption observed in the Ag implanted samples is not present. At the same time the nonlinear response of the these samples is larger than for the samples implanted with Sb alone, suggesting that the addition of Ag can increase the nonlinear response of the Sb particles formed. The results are consistent with the formation of multi-component Sb/Ag colloids

  4. FABRICATION, MORPHOLOGICAL AND OPTOELECTRONIC PROPERTIES OF ANTIMONY ON POROUS SILICON AS MSM PHOTODETECTOR

    Directory of Open Access Journals (Sweden)

    H. A. Hadi

    2015-07-01

    Full Text Available We report on the fabrication and characterization of MSM photodetector. We investigated the surface morphological and the structural properties of the porous silicon by optical microscopy, atomic force microscope (AFM and X-ray diffraction. The metal–semiconductor–metal photodetector were fabricated by using Sb as Schottky contact metal.The junction exhibits good rectification ratio of 105 at bias of 2V. A large photocurrent to dark-current contrast ratio higher than 55 orders of magnitude and low dark currents below 0.89 nA .High   responsivity of 0.225A/W at 400 nm and 0.15 A/W at 400 and 700nm were observed at an operating bias of less than -2 V, corresponding quantum efficiency of 70% and 26% respectively. The lifetimes are evaluated using OCVD method and the carrier life time is 100 μs. The results show that Sb on porous silicon (PS structures will act as good candidates for making highly efficient photodiodes.

  5. FABRICATION, MORPHOLOGICAL AND OPTOELECTRONIC PROPERTIES OF ANTIMONY ON POROUS SILICON AS MSM PHOTODETECTOR

    Directory of Open Access Journals (Sweden)

    H. A. Hadi

    2014-12-01

    Full Text Available We report on the fabrication and characterization of MSM photodetector. We investigated the surface morphological and the structural properties of the porous silicon by optical microscopy, atomic force microscope (AFM and X-ray diffraction. The metal–semiconductor–metal photodetector were fabricated by using Sb as Schottky contact metal.The junction exhibits good rectification ratio of 105 at bias of 2V. A large photocurrent to dark-current contrast ratio higher than 55 orders of magnitude and low dark currents below 0.89 nA .High responsivity of 0.225A/W at 400 nm and 0.15 A/W at 400 and 700nm were observed at an operating bias of less than -2 V, corresponding quantum efficiency of 70% and 26% respectively. The lifetimes are evaluated using OCVD method and the carrier life time is 100 μs. The results show that Sb on porous silicon (PS structures will act as good candidates for making highly efficient photodiodes.

  6. Pulsed laser deposition and investigation of antimony-doped ZnO films

    Science.gov (United States)

    Puzikov, A. S.; Lyanguzov, N. V.; Kaidashev, E. M.

    2014-10-01

    We have investigated the influence of oxygen partial pressure, temperature of synthesis and annealing conditions on nanocsrystallineSb-doped thin films, grown by pulsed laser deposition. It is shown that the minimum resistivity (~8·10-3Ω·cm) and the maximum carriers density (~ 2·1019 cm-3) corresponds to the pressure range 5·10-3-7·10-3 mbar, to the temperature 550 ° C and in situ annealing at 700 °C.Also we show the features of the crystal lattice's dynamics, which are found in the Raman research.

  7. Influence of antimony ions in negative electrolyte on the electrochemical performance of vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Sb3+ ions are introduced into the negative electrolyte of vanadium redox flow batteries (VRFB), and their influence on the electrochemical performance of VRFB are investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the electrochemical activity and sluggish kinetics of V(II)/V(III) redox couple can be improved by the addition of Sb3+ ions, and the optimal concentration of Sb3+ ions is found to be 5 mM. Meanwhile, Sb3+ ions can lead to an increase of the diffusion coefficient of V(III) species and a decrease of charge transfer resistance. Moreover, the VRFB cell using negative electrolyte with Sb3+ ions exhibits excellent cycling stability and high average energy efficiency, especially under high power operation. The energy efficiency (67.1%) of the VRFB employing electrolyte with 5 mM Sb3+ ions is increased by 9.6% at a current density of 120 mA · cm−2, compared to the pristine one (57.5%). The improved electrochemical performance should be ascribed to the prominent catalytic effect of Sb particles, which are simultaneously electrodeposited onto the surface of graphite felts during operation of the flow cell and facilitate charge transfer process

  8. Antimony Tin Oxide: From Computational Research to MEA Manufacturing Challenges in the Value Chain

    OpenAIRE

    Colmenares, Luis; Dahl, Paul; Oyarce, Alejandro; Fu, Qiang; Vegge, Tejs; Brault, Pascal

    2015-01-01

    Communication par Affiche. Lauréat Prix Poster de la conférence International audience One of the main objectives in SMARTCat is to synthetize conductive tin oxide (SnO2) as a support material forthe electrocatalyst. The task is to systematically improve specific properties such as electronic conductivity (σ),surface area (SA) and stability of SnO2-based support materials. Through such improvements, the goal is toprovide a PEM fuel cell cathode catalyst with enhance durability and stabi...

  9. Radiochemical separation of antimony and tellurium in isotope production and in radionuclide generators

    International Nuclear Information System (INIS)

    A potentially useful radionuclide generator for PET studies is based on 118Te/118Sb. A novel single-step approach using anion-exchange chromatography was developed to separate the 118Te parent activity from proton-irradiated targets. The average yield of radiotellurium using this method was 88%, with no detectable radioantimony contamination. A generator system employing activated carbon as a column chromatography adsorbent was studied. An 118Sb elution yield of 87%, with a radiotellurium breakthrough of less than 0.1%/ml, was achieved. Oxidation state studies indicate that approximately 39% of the 118Sb formed in the decay of 118Te is in the form of Sb(V). Details of these separations are presented. (author)

  10. Synthesis and characterization of nanometer sized thermoelectric lead-antimony-silver-tellurium compounds and related materials

    International Nuclear Information System (INIS)

    The present dissertation deals with different variants of synthesis and processing of nanocrystalline composites of various thermoelectric compounds based on lead telluride including LAST-m (AgPbmSbTem+2), LASTT-m-x (AgPbm-xSnxSbTem+2), LABST-m-x (AgPbmSb1-xBixTem+2), doped LAST-m and (PbTe)m(M152Te3) and the characterization thereof. A new route of manufacturing nanocrystalline composites was developed. The so called co-ball milling-route includes the synthesis of bi- or multinary compounds by conventional solid state melting methods followed by combined milling of appropriate amounts in a planetary ball mill; a process related to the widely used mechanical alloying of elemental powders. The as produced powders were shortly annealed for one hour and a.erwards compacted either at room temperature followed by pressureless sintering or combined application of high pressure and elevated temperatures via spark-plasma-sintering or short-term-sintering. The ball milling yielded micron-sized agglomerates consisting of crystallites with diameters ranging from 10 to 50 nm. These crystallites exhibited complicated internal nanostructures severe crystal defects as a consequence of the high energy processing. During short-term annealing some grain coarsening occured and the crystal defects partly healed, which was confirmed by TEM and HRTEM investigations as well as profile analysis of XRD powder pattern. Local EDX-analysis showed different compositions at every point as a consequence of synthesis and decomposition of the compounds. Measurements of thermopower, electrical and thermal conductivity were carried out and the values of the figure of merit ZT and the powerfactor were calculated. In general the compounds exhibited larger thermopower than corresponding bulk materials, which might be attributed to energy filtering of charge carriers at partly oxidized grain boundaries. Due to enhanced phonon scattering at grain boundarys, nanoscopic precipitates and crystal defects the thermal conductivity was generally low. Similar to other reports the powder processing caused a deleterious effect on the electrical conductivity. The comparison between short term annealed and long term sintered polycrystalline bulk samples revealed that the annealing temperature caused partly connected particles for the LAST-derivates but well sintered compacts for the non-LAST-compounds. For both classes, long-term sintering caused a simultanious increase of both thermopower and electrical conductivity which shows that co-ball milling leads to a decoupling of those two properties. This could prove usefull in further investigations and the development of new thermoelectric materials and the processing thereof.

  11. 19F NMR of antimony and arsenic pentafluoride-graphite derivatives

    International Nuclear Information System (INIS)

    19F NMR results are reported on first stage SbF5-graphite intercalation compounds and second stage AsF5-graphite intercalation compounds as a function of temperature. Above a cutting temperature the authors postulate the existence of two fluorine populations at least, which they have tried to identify on their spectra according to a pentafluoride oxidation reaction. The results are correlated with a charge transfer coefficient evolving with temperature, and are discussed in comparison with other experimental results. (Auth.)

  12. Study of solid-phase interaction of antimony and bismuth trifluorides with alkali metal fluorides

    International Nuclear Information System (INIS)

    Methods of X-ray phase, differential thermal and chemical analyses have been used to study and plot phase diagrams of RbF-SbF3, CSF-SbF3, RbF-BjF,L3, CSF-BjF3 systems. X-ray diffraction study on the phases formed in the systems is conducted temperatures of phase transitions are determined, General regularities displayed in M'F-MF3 systems (M'=Li, Na, K, Rb, Cs, M=Sb, Bi) are discussed

  13. Complexing of antimony(3) fluoride with rare alkali metal fluorides in formic acid

    International Nuclear Information System (INIS)

    Using the method of isothermal solubility with the establishment of solid phase compositions according to ''residue method'' the systems HCOOH-SbF3-RbF3 and HCOOH-SbF3-CsF are studied at 15 deg C. The existence of complex compounds of different compositions is established. The individual character of the compounds prepared is confirmed by the data of chemical and X-ray phase analysis

  14. Spectral determination admixture of tin, antimony, lead, germanium by the method of fluoride sublimation

    International Nuclear Information System (INIS)

    In article introduced spectrographic investigation of selective treatment of Sn, Pb, Sb, Ge in form of their volatile fluoride, which are the product of decomposition of synthesized fluorine complex with iron

  15. NMR study of the reactions of tin(2) difluoride and antimony(3) trifluoride with niobium pentachloride

    International Nuclear Information System (INIS)

    Interaction of SnF2 and SbF3 with NbCl5 in solutions of acetonitrile and dimethylsulfoxide was studied by the method of 19F, 93Nb, 119Sn NMR. It is shown that anionic octahedral chlorofluoride complexes of niobium are formed in acetonitrile, while neutral ones- in dimethylsulfoxide. SnF2 and SnF3 are effective sources of fluorine ions when preparing fluorochloride and fluoride compounds of niobium

  16. Determination and modeling of the thermodynamic properties of liquid calcium–antimony alloys

    International Nuclear Information System (INIS)

    The thermodynamic properties of Ca–Sb alloys were determined by emf measurements in a cell configured as Ca(s)|CaF2|Ca–Sb over the temperature range 550–830 °C. Activity coefficients of Ca and Sb, enthalpy, Gibbs free energy, and entropy of mixing of Ca–Sb alloys were calculated for xCa 2 associate, and the molecular interaction volume model (MIVM). For the first time, the MIVM was used successfully to model the activity coefficients of a system with high-melting intermetallics, reducing the number of fitting parameters necessary from 5 (regular associated model) to 2 (MIVM). From the interaction parameters optimized by fitting at 800 °C, the activity coefficient of Ca was predicted at 650 °C, with an average error of less than 0.6% in the emf value.

  17. Electron spin resonance spectra of certain fluorohydride radicals of phosphorus, arsenic, and antimony

    International Nuclear Information System (INIS)

    Isotropic ESR spectra of a series of phosphorus fluorohydride radicals PH/sub n/F/sub 4 - n/, where n = 0--4, have been observed in γ-irradiated solid solutions of PF3, PF2H, and PH3 in neopentane or SF6. The spectra of AsH3F and SbH3F are also reported. The hyperfine interactions of these radicals are consistent with a totally symmetric semioccupied orbital in a framework possessing either C/sub 2v/ or C/sub s/ symmetry. The relative merits of Huckel and INDO molecular orbital calculations in predicting the various observed trends are discussed. (auth)

  18. Antimony(III) Sulfide Thin Films as a Photoanode Material in Photocatalytic Water Splitting.

    Science.gov (United States)

    DeAngelis, Alexander Daniel; Kemp, Kingsley Christian; Gaillard, Nicolas; Kim, Kwang S

    2016-04-01

    For the first time, we present exploratory investigations on the performance of thermally evaporated Sb2S3 thin film photoanodes for solar-assisted water-splitting applications. With a band gap of 1.72 eV, a 250 nm thick Sb2S3 photoanode showed a saturation photocurrent density of ∼600 μA cm(-2) measured at 1.0 V reversible hydrogen electrode (RHE) in 0.1 M Na2SO4 under 1-sun illumination, with an onset potential of ∼0.25 V RHE. However, subsequent photodegradation studies revealed that the material dissolves relatively quickly with the application of both illumination and bias. Nonetheless, Sb2S3 does have the advantage of having a relatively low optimal fabrication temperature of 300 °C and thus may have utility as a top cell absorber of a tandem device where the bottom cell is temperature sensitive, if protected from corrosion. Therefore, we characterized relevant aspects of the material in an attempt to explain the large difference between the theoretical maximum and measured current density. From our characterization it is believed that the photocatalytic efficiency of this material can be improved by modifying the surface to reduce optical reflection and addressing inherent issues such as high electrical resistivity and surface defects. PMID:27003726

  19. Proton induced nuclear reactions on natural antimony up to 17 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Elbinawi, Alaa; Al-abyad, Mogahed; Hassan, Khaled F. [Atomic Energy Authority, Cairo (Egypt). Cyclotron Facility; Abd-Elmageed, Karima E. [Benha Univ. (Egypt). Dept. of Physics; Ditroi, Ferenc [Hungarian Academy of Sciences, Debrecen (Hungary). Inst. for Nuclear Research (ATOMKI)

    2016-08-01

    The activation cross sections of proton induced reactions on {sup nat}Sb target leading to the formation of the radioisotopes {sup 121m,g,123m}Te were measured. The experimental excitation functions were compared with the theoretical model calculations using the codes EMPIRE-3.1 and TALYS-1.4. The integral yields of the three radionuclides were calculated and the possibility of their production is discussed.

  20. Bioaccumulation trends of arsenic and antimony in a freshwater ecosystem affected by mine drainage

    Science.gov (United States)

    Dovick, Meghan A.; Kulp, Thomas R.; Arkle, Robert .; Pilliod, David

    2016-01-01

    We compared As and Sb bioaccumulation and biomagnification when these metalloids co-occurred at varying environmental concentrations in a stream and wetlands near a contaminated mine site in Idaho (USA). We measured As and Sb concentrations in water and substrate samples, and in tissues of organisms representing several trophic levels. Bioaccumulation of both As and Sb was observed in stream organisms with the following trend of bio-diminution with increasing trophic level: primary producers>tadpoles>macroinvertebrates>trout. We also note reductions in metalloid concentrations in one of two stream remediation reaches engineered within the past 17 years to ameliorate metalloid contamination in the stream. Several wetlands contained thick microbial mats and were highly populated with boreal toad tadpoles that fed on them. The mats were extremely contaminated (up to 76 564 mg kg-1 As and 675 mg kg-1 Sb) with amorphous As- and Sb-bearing minerals that we interpret as biogenic precipitates from geomicrobiological As- and Sb-cycling. Ingested mat material provided a direct source of metalloids to tadpoles, and concentrations of 3867 mg kg-1 (As) and 375 mg kg-1 (Sb) reported here represent the highest whole body As and Sb levels ever reported in living tadpoles. The bulk of tadpole metalloid burden remained in the gut despite attempts to purge the tadpoles prior to analysis. This study adds to a number of recent investigations reporting bioaccumulation, but not biomagnification, of As and Sb in food webs. Moreover, our results suggest that tadpoles, in particular, may be more resistant to metalloid contamination than previously assumed.