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Sample records for antimonates

  1. Ion-exchange selectivities on antimonic acids and metal antimonates

    International Nuclear Information System (INIS)

    Antimonic acids and metal antimonates as the inorganic ion-exchangers exhibit extremely high selectivity for a certain element or group of elements for comparison with sulfonated polystyrene ion-exchange resin. Various antimonic acid materials have been obtained with different compositions and ion-exchange properties, depending on the method of their preparations as well as on aging. The species can be divided into three groups - crystalline, amorphous and glassy. The affinity sequence for alkali metal ions shows LiNa>K>Rb>Cs. These selectivities are discussed in the terms of steric effect and entropy changes of the ion-exchange reactions. (author)

  2. Adsorption of Some Hazardous Radionuclides on Cerium(IV) Antimonate

    International Nuclear Information System (INIS)

    Cerium(IV) antimonate had been prepared by the dropwise addition of 0.6 M antimony pentachloride and 0.6 M cerium ammonium nitrate solutions by a molar radio of Ce/Sb 0.75. Exchange isotherms for H+/Co2+ , H+/Cs+, H+/Zn2+ , H+/Sr2+ and H+/Eu3+ have been determined at 25, 40 and 60 degree. Besides it was proved that europium is physically adsorbed while zinc, strontium, cobalt and cesium are chemically adsorbed. Moreover, the heat of adsorption of zinc, strontium, cobalt and cesium on cerium(IV) antimonate had been calculated and indicated that cerium(IV) antimonate is of endothermic behaviour towards these ions. Also the distribution coefficients of these ions were determined and it was found that the selectivity in the order: Eu3+ >Sr2+ > Cs+>Na+

  3. Sorption of radiocobalt and its EDTA complex on titanium antimonates

    International Nuclear Information System (INIS)

    The sorption properties of two synthesized titanium antimonate materials were tested in simulated nuclear power plant decontamination solutions. The aim was the removal of radiocobalt in the presence of complexing agents such as EDTA and oxalate. The first titanium antimonate material had a mixture of pyrochlore and rutile structures and it showed good tolerance for the complexing agents. 91% of cobalt was removed in the presence of EDTA, and oxalic acid had only a minor effect on the sorption. The other material, which had a mopungite structure, tolerated EDTA well (97% removal of cobalt) but its sorption properties for cobalt were restricted to a specific amount of oxalic acid. The sorption efficiency of cobalt increased for both materials when the cobalt concentration was less than 1 μM, indicating that the synthesized materials are efficient sorbents, especially for trace amounts of radiocobalt.

  4. Study of the polymerisation of some antimonates by the dry process and the aqueous process

    International Nuclear Information System (INIS)

    This work is an attempt to classify the different antimonic acid and alkaline antimonate species. A number of these were already known and their structures studied, but the temperature regions in which they could exist were generally unknown and certain characteristic properties needed to be defined. Other species, already described by some authors, were actually mixtures; it was possible to prepare them in the pure state by changing the conditions of preparation (as in the case of pyrochlore NaSbO3 and cubic KSbO3, 0.7 H2O). Finally, others had been prepared but their structure was still undefined (as with Sb2O5, 1/2 H2O) or they were not known to be crystallised (KSbO3, 2.2 H2O). New species such as amorphous sodium and silver antimonates and amorphous antimonic acid were also isolated. In addition, the study of the behavior of these antimonates in acid solution showed that whatever the nature of the antimonate, it is converted, partially of completely into a pyrochlore species of which the proportion can be predicted as a function of the acidity of the medium, and the composition as a function of the nature of the cation. (author)

  5. Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline antimonic acid

    OpenAIRE

    Beleze Fábio A.; Zarbin Aldo J. G.

    2001-01-01

    In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline antimonic acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic...

  6. Preparation and characterization of some antimonates as ion exchangers and their application sorption of molybdenum from nitric acid solutions

    International Nuclear Information System (INIS)

    Various antimonate compounds are well known as important inorganic ion exchangers, since they have radiation stabilities and also high selectivities towards different cations. Ceric, silicon and ferric antimonates were prepared in our laboratories. Characterization of these materials has been described using different techniques, including thermal analysis, surface area measurements, X-ray diffraction and Ir-spectroscopy. The selectivities of these exchangers towards molybdenum have measured under different conditions and a comparison between them had been conducted to enable the suitable exchanger that can be used in the separation of molybdenum from fission products

  7. 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

  8. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    OpenAIRE

    Bisacchi, Davide; Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita; Bordo, Domenico

    2006-01-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays.

  9. Synthesis and characterization of titanium vanadate and vanadium antimonate and their use in treatment of some toxic waste

    International Nuclear Information System (INIS)

    Ion exchangers are insoluble solid materials, which carry exchangeable cations or anions. When the ion exchanger is in contact with an electrolyte solution, these ions are exchanged with an equivalent amount of other ions of the same sign .Synthetic inorganic ion exchangers possess good ion-exchange capacity, high chemical and radiation stabilities, reproducibility and selectivity for heavy metals. These materials were characterized using X-ray (XRD and XRF), IR, TGA-DTA and total elemental analysis studies. On the basis of distribution studies, titanium vanadate was highly selective for Cs(I) while vanadium antimonate was selective for Cu2+ ions . Thermodynamic parameters (i.e. ΔGo, ΔSo and ΔHo) have also been calculated for the adsorption of Cs+, Cd2+, Cu2+ and Co2+ ions on titanium vanadate and vanadium antimonate showing that the overall adsorption process is spontaneous and endothermic. The mechanism of diffusion of Co2+, Cu2+, Cd2+ and Cs+ in the H -form of titanium vanadate and vanadium antimonate cation exchanger was studied as a function of particle size, concentration of the exchanging ions, reaction temperature, drying temperature. The exchange rate was controlled by particle diffusion mechanism as a limited batch technique and is confirmed from straight lines of B versus 1/r2 plots. The values of diffusion coefficients, activation energy and entropy of activation were calculated and their significance was discussed. The data obtained have been compared with that reported for other organic and inorganic exchangers. Exchange isotherms for H+/Co2+, H+/Cu2+, H+/Cd2+ and H+/Cs+ were determined at 25, 45 and 60±1 degree C. These isotherms showed that Co2+,Cu2+, Cd2+ and Cs+ are chemically adsorbed. Moreover, the values of thermodynamic parameters were determined and the overall adsorption processes were found spontaneous and endothermic. Finally, removal of the above mentioned cations on titanium vanadate and vanadium antimonate in column was performed.

  10. Conditioning of inorganic ion exchangers based on cerium (IV) antimonate in cement matrix. Vol. 3

    International Nuclear Information System (INIS)

    The use of inorganic adsorbents for treatment of aqueous radioactive waste has many advantages; namely; better resistance to chemical action, thermal stability, compatibility with immobilization matrices and resistance to radiation. Inorganic ion exchangers process many properties which make them more suitable for rad waste treatment than organic exchange resins. Inorganic ion exchange materials can be immobilized using cement matrix to obtain good solidified waste form. In this work, the removal of radioactive nuclides from radioactive waste is carried out by chemical in-situ precipitation. The addition of cerium (IV) antimonate (cesb) to cement mixture enhances the compressive strength more than plain cement. Waste package containing cesb increased the compressive strength relative to original ordinary portland cement (OPC) matrix for waste products immersed in tap water for one month. The compressive strength increases in the order; st Ce Sb> mix Ce Sb> Na Ce Sb> Co Ce Sb> Cs Ce Sb> OPC> Eu Ce Sb> Ce Sb; (mix refers to all the radionuclides used here). The cumulative leached fractions of 60 Co and 134 Cs decreased for solidified waste products containing Ce Sb in comparison to plain cement. 2 figs., 9 tabs

  11. A new strontium antimonateIII Sr5Sb22O38: Synthesis, crystal structure and characterizations

    International Nuclear Information System (INIS)

    A new strontium antimonateIII, Sr5Sb22O38, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. It crystallizes in the P21/n space group of the monoclinic system with a=11.739(9) Å, b=12.014(10) Å, c=16.412(13) Å, β=91.460(8)°, V=2314.0(3) Å3. The crystal structure is built of seven trigonal–pyramidal SbO3 and four sphenoid SbO4 polyhedra which are connected through sharing corner-oxygen atoms to form the complex three-dimensional ∞3[Sb22O38]10− anionic network with two different intersectant tunnels along the [111-bar ] and [11-bar 1-bar ] directions accommodating the electric charge balanced Sr2+ cations. First-principles electronic structure calculations based on the density functional theory (DFT) and the UV–vis diffuse reflectance spectroscopy measurements both indicate that the compound belongs to a direct band insulator with an optical gap value of 3.3 eV. - Graphical abstract: The 2D Sb–O slabs are stacked through sharing oxygen atoms to form the 3D network structure of the new strontium antimonateIII Sr5Sb22O38. - Highlights: • A new strontium antimonateIII, Sr5Sb22O38, has been hydrothermally synthesized. • The single crystal structure was determined by X-ray diffraction. • The powder XRD and UV–vis absorption spectroscopy were studied. • Theoretical studies interpret the relationships between optical absorption and crystal structure

  12. Autotrophic antimonate bio-reduction using hydrogen as the electron donor.

    Science.gov (United States)

    Lai, Chun-Yu; Wen, Li-Lian; Zhang, Yin; Luo, Shan-Shan; Wang, Qing-Ying; Luo, Yi-Hao; Chen, Ran; Yang, Xiaoe; Rittmann, Bruce E; Zhao, He-Ping

    2016-01-01

    Antimony (Sb), a toxic metalloid, is soluble as antimonate (Sb(V)). While bio-reduction of Sb(V) is an effective Sb-removal approach, its bio-reduction has been coupled to oxidation of only organic electron donors. In this study, we demonstrate, for the first time, the feasibility of autotrophic microbial Sb(V) reduction using hydrogen gas (H2) as the electron donor without extra organic carbon source. SEM and EDS analysis confirmed the production of the mineral precipitate Sb2O3. When H2 was utilized as the electron donor, the consortium was able to fully reduce 650 μM of Sb(V) to Sb(III) in 10 days, a rate comparable to the culture using lactate as the electron donor. The H2-fed culture directed a much larger fraction of it donor electrons to Sb(V) reduction than did the lactate-fed culture. While 98% of the electrons from H2 were used to reduce Sb(V) by the H2-fed culture, only 12% of the electrons from lactate was used to reduce Sb(V) by the lactate-fed culture. The rest of the electrons from lactate went to acetate and propionate through fermentation, to methane through methanogenesis, and to biomass synthesis. High-throughput sequencing confirmed that the microbial community for the lactate-fed culture was much more diverse than that for the H2-fed culture, which was dominated by a short rod-shaped phylotype of Rhizobium (α-Protobacteria) that may have been active in Sb(V) reduction. PMID:26519630

  13. Retention behavior of nickel, copper, cadmium and zinc ions from aqueous solutions on silico-titanate and silico-antimonate used as inorganic ion exchange materials

    International Nuclear Information System (INIS)

    Silico-titanate (SiTi) and silico-antimonate (SiSb) have been synthesized and characterized using X-ray diffraction patterns, infrared and thermal analysis techniques. Divalent cations such as Ni2+, Cd2+, Zn2+ and Cu2+ in the pH range 2 to 8 have been exchanged with the exchangeable active sites of the exchangers using a batch technique. From the results obtained, the equilibrium capacities and distribution coefficient values were calculated indicating high selectivity values for Ni2+, Cd2+, Zn2+ and Cu2+ ions on silico-titanate and silico-antimonate compared to other titanates and antimonates. Also SiTi and SiSb show high chemical stability in H2O, nitric and hydrochloric acids. All these results support the suitability of the prepared materials for the removal of the toxic metals concerned from waste waters. Based on the results obtained, practical separation experiments for the above mentioned cations on SiTi and SiSb columns from aqueous waste solutions were carried out. (author)

  14. Chromatography of 49 metal ions on stannic antimonate papers in dimethylsulfoxide: nitric acid systems and aqueous nitric acid systems

    International Nuclear Information System (INIS)

    Chromatographic separations of 49 metal ions on stannic antimonate papers have been performed using mixed solvent systems containing DMSO. Aqueous HNO3 systems have also been used. The utility of the papers has been demonstrated by achieving various difficult separations. Some of the important separations (R/sub f/ values given in parentheses) are: Cs+(0.20)-K+(0.30) and Sm3+(0.00)-Pr3+(0.72) in pure DMSO; Nb5+(0.14)-VO2+(0.95) in DMSO-6M HNO3 (1:1); Ti4+(0.00)-VO2(0.97) in DMSO-0.5M HNO3 (1:1); and Ba2+(0.06)-K+(0.52)-Sr2+(0.95), Ba2+(0.04)-Cs+(0.41)-Mg2+(0.93), and Ca2+(0.10)-Sr2+(0.94) in DMSO-0.1M HNO3 (1:1). The time of development in each case is two hours. A discussion is presented on the dependence of Ri, log R/sub f/, and R/sub M/ on pH of the solvent to understand the mechanism of the movement of metal ions on papers impregnated with inorganic materials. (U.S.)

  15. A new strontium antimonate{sup III} Sr{sub 5}Sb{sub 22}O{sub 38}: Synthesis, crystal structure and characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Lei, E-mail: lgeng.cn@gmail.com [Department of Physics and Electronic Information, Huaibei Normal University, Huaibei, Anhui 235000 (China); Meng, Chang-Yu [Department of Chemistry and Materials, Yulin Normal University, Yulin, Guangxi 537000 (China); Lin, Chen-Sheng [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Cheng, Wen-Dan, E-mail: cwd@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2013-07-15

    A new strontium antimonate{sup III}, Sr{sub 5}Sb{sub 22}O{sub 38}, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. It crystallizes in the P2{sub 1}/n space group of the monoclinic system with a=11.739(9) Å, b=12.014(10) Å, c=16.412(13) Å, β=91.460(8)°, V=2314.0(3) Å{sup 3}. The crystal structure is built of seven trigonal–pyramidal SbO{sub 3} and four sphenoid SbO{sub 4} polyhedra which are connected through sharing corner-oxygen atoms to form the complex three-dimensional {sub ∞}{sup 3}[Sb{sub 22}O{sub 38}]{sup 10−} anionic network with two different intersectant tunnels along the [111-bar ] and [11-bar 1-bar ] directions accommodating the electric charge balanced Sr{sup 2+} cations. First-principles electronic structure calculations based on the density functional theory (DFT) and the UV–vis diffuse reflectance spectroscopy measurements both indicate that the compound belongs to a direct band insulator with an optical gap value of 3.3 eV. - Graphical abstract: The 2D Sb–O slabs are stacked through sharing oxygen atoms to form the 3D network structure of the new strontium antimonate{sup III} Sr{sub 5}Sb{sub 22}O{sub 38}. - Highlights: • A new strontium antimonate{sup III}, Sr{sub 5}Sb{sub 22}O{sub 38}, has been hydrothermally synthesized. • The single crystal structure was determined by X-ray diffraction. • The powder XRD and UV–vis absorption spectroscopy were studied. • Theoretical studies interpret the relationships between optical absorption and crystal structure.

  16. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    Energy Technology Data Exchange (ETDEWEB)

    Bisacchi, Davide [Bioinformatics and Structural Proteomics, IST-National Cancer Research Institute, Genova (Italy); Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita [Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan (United States); Bordo, Domenico, E-mail: domenico.bordo@istge.it [Bioinformatics and Structural Proteomics, IST-National Cancer Research Institute, Genova (Italy)

    2006-10-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3{sub 1}21/P3{sub 2}21). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å.

  17. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    International Nuclear Information System (INIS)

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3121/P3221). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å

  18. Removal of some heavy metals from industrial waste water using polyacrylamide ferric antimonate as new ion exchange material

    International Nuclear Information System (INIS)

    Composite ion exchangers consist of one or more ion exchangers combined with another material, which can be inorganic or organic and may it be an ion exchanger. The reason for manufacturing a composite material is to produce a granular material, with sufficient strength for column use, from ion exchangers that do not form, or only form weak, granules themselves. Attempts in this study are focused to prepare composite ion exchangers for treatment of wastewater. Heavy metals when present in water in concentrations exceeding the permitted limits are injurious to the health. Hence, it is very important to treat such waters to remove the metal ions present before it is supplied for any useful purpose. Therefore, many investigations have studied to develop more effective process to treat such waste stream. Ion-exchange has been widely adopted in heavy metal containing wastewater and most of the ion-exchangers (i.e. ion-exchange media) currently being used are commercially mass-produced organic resins.Therefore, the main aim of this work is directed to find the optimum conditions for removal of some heavy metals from industrial waste water.1-Preparation of polyacrylamide ferric antimonate composite.2-Characterization of the prepared exchanger using IR spectra, X-ray diffraction pattern, DTA and TG analyses.3-Chemical stability, capacity and equilibrium measurements will be determined on the materials using at different conditions (ph heating temperature and reaction temperature).4-Kinetic studies of some heavy metals.5-Ion exchange isotherm.6-Breakthrough curves for removal of the investigated metal ions on the prepared exchanger under certain condition.

  19. Single step hydrothermal based synthesis of M(II)Sb2O6 (M = Cd and Zn) type antimonates and their photocatalytic properties

    Indian Academy of Sciences (India)

    Jyoti Singh; Neha Bhardwaj; S Uma

    2013-04-01

    Experiments involving single step hydrothermal reactions of the divalent metal (Zn2+, Cd2+, Pb2+, Cu2+, Ni2+ and Mn2+) salts with ilmenite NaSbO3 yielded pure divalent antimonates in the case of CdSb2O6 crystallizing in the PbSb2O6 type structure and ZnSb2O6 crystallizing in the trirutile structure type. In the case of Pb2+, Cu2+, Ni2+ and Mn2+ divalent cations, phase pure product could not be obtained. The obtained powders were characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and UVvisible diffuse reflectance spectroscopy. The oxide powders obtained possessed lower crystallite size as compared to their solid-state synthesized counterparts. This was evident from the broadening of the powder X-ray diffraction peaks. The antimonates were photocatalytically active for the decomposition of methylene blue (MB) dye under UV light irradiation.

  20. Thin-layer chromatography of 49 metal ions on stannic antimonate in aqueous and mixed solvent systems containing dimethylsulfoxide: quantitative separation of uranium from numerous metal ions

    International Nuclear Information System (INIS)

    Thin-layer chromatography of 40 metal ions in 31 aqueous and mixed solvent systems has been performed on stannic antimonate ion-exchange material. Dimethylsulfoxide has been utilized to resolve such binary mixtures as La3+ and Ce3+ from Pr3+, Nd3+, and Sm3+; VO2+ from Ti4+, Nb5+, and Ta5+; Ga3+ from In3+, Tl+, and Y3+; Fe3+ from VO2+; and Mg2+ from Al3+. Quantitative separation of 200 to 800 μg U from its binary mixtures and from the synthetic mixtures containing Mg2+, Bi3+, Fe3+, Th4+, Ce4+, Cr3+, Zr4+, Hf4+, Ti4+ Mn2+, Cu2+, Ce3+, In3+, Y3+, Ca2+, Co2+, Tl+, Nb5+, and Ag+ has been obtained

  1. Ateşli silah atış artıklarında voltametrik sıyırma yötemleri ile antimon, baryum ve kurşunun tayini

    OpenAIRE

    ERDEN, Sevcan

    2010-01-01

        Bu çalışmada, atış artıklarında antimon, baryum ve kurşunun tayini için diferansiyel puls adsorptif sıyırma (DPAdS) ve kare dalga adsorptif sıyırma (KDAdS) voltametri yöntemleri geliştirildi. Bu yöntemlerde kurşun(II) ve antimon(III)’ün rezorsinol ve katekol; baryumun diizooktilditiyofosfinik asit ile oluşturduğu kompleksin asılı cıva damla elektrot yüzeyinde adsorplanmasından yararlanıldı. Her bir metal iyonu için optimum deney koşulları (pH, biriktirm...

  2. 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

  3. Synthesis and characterization of arsenate antimonic acid AAAc(1 : 1)

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-wen; CHEN Qi-yuan; YIN Zhou-lan; ZHANG Ping-min; WANG Yu-wen

    2005-01-01

    The AAAc(1 : 1) was synthesized in water by As2O3 and Sb2O3 with molar ratio of 1 : 1: AAAc(1 : 1)was characterized by Raman, IR, TG/DTG, DSC, XPS and XRD. The results show that there are four peaks to vsof As-OH, As-O-Sb, Sb-OH and Sb-O-Sb in Raman spectra of AAAc(1 : 1) at 100 - 1 000 cm-1. The solution of AAAc(1 : 1) was also titrated with KOH solution. The titration results show that AAAc(1 : 1) is a hexabasic acid with dissociation constants of k1 = 3.62 × 10-2 , k2 = 3.05 × 10-3 , k3 = 6. 43 × 10-6 , k4 = 9. 78 × 10-8 ,k5 = 1.32 × 10-11 , k6 =3.87 × 10-12. AAAc(1 : 1) has a good solubility and stability in water, its solid obtained by free volatilizing water from its solution under air at ambient temperature is amorphous. Chemical and thermal analyture of AsO ( OH )2-OH-Sb ( OH )4-O-Sb ( OH )4-OH-AsO ( OH )2 or As ( OH )3-O-Sb(OH)4-O-Sb(OH)4-O-As(OH)3 (isomerism) through experimental determination and geometry optimization.

  4. Composition dependence of surface photoelectric and photodegradation activities of silver antimonates with pyrochlore-like structure

    International Nuclear Information System (INIS)

    Silver antimonite samples with different Ag/Sb ratios were prepared via ion exchange method through the mediator of silver proton-exchanged compounds. With the rise in the ratio of Ag to Sb in the samples, the optical band gap decreases due to the increasing contribution of Ag4d to the valence band; the surface photovoltage decreases and photocatalytic activity increases due to surface states related to the Sb3+ in the samples. The present results indicate that appropriate amount of Sb3+ is favorable for improving the photocatalytic activity under visible light irradiation.

  5. Kinetics properties of cations absorption by ion exchangers on the base of antimonic acid

    International Nuclear Information System (INIS)

    This article is devoted to study of kinetics of sorption one- and two-charge elements by antimony-silicon sorbent. Kinetic studies are conducted at ph=0-5 and temperature interval 10-50 deg C. Data on X-ray analysis of ion exchangers is considered.

  6. Niedervalente Bismut-Organyle, chirale Stibane und Antimon-Analoge des Betains und Cholins

    OpenAIRE

    Balazs Lucia

    2003-01-01

    The cyclobismuthanes (RBi):sub:n:/sub:, [R = 2-(Me:sub:2:/sub:NCH:sub:2:/sub:)C:sub:6:/sub:H:sub:4:/sub:, n = 3 (:b:1a:/b:), 4 (:b:1b:/b:)] were synthesized by reduction of RBiCl:sub:2:/sub: with Na in liquid ammonia or by reaction of R:sub:2:/sub:BiCl with LiAlH:sub:4:/sub: in ether. The reaction of :b:1a / b:/b: with W(CO):sub:5:/sub:THF (THF = tetrahydrofuran) gives the bismuthinidene complex RBi[W(CO):sub:5:/sub:]:sub:2:/sub: (:b:2:/b:). R:sub:2:/sub:BiCl reacts with Mg in THF to give R:s...

  7. Selective generation of substituted arsines-cryotrapping-atomic absorption spectrometry for arsenic speciation analysis in N-methylglucamine antimonate

    Czech Academy of Sciences Publication Activity Database

    Moraes, D. P.; Svoboda, Milan; Matoušek, Tomáš; Flores, E. M. D.; Dědina, Jiří

    2012-01-01

    Roč. 27, č. 10 (2012), s. 1734-1742. ISSN 0267-9477 R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : hydride generation * cryotrapping * arsenic speciation analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.155, year: 2012

  8. CO and C3H8 Sensitivity Behavior of Zinc Antimonate Prepared by a Microwave-Assisted Solution Method

    Directory of Open Access Journals (Sweden)

    Héctor Guillen-Bonilla

    2015-01-01

    Full Text Available ZnSb2O6 has been synthesized by a microwave-assisted solution method in order to test its possible application as a gas sensor. Zinc nitrate, antimony trichloride, and ethylenediamine were used as precursors and deionized water as solvent. Microwave radiation, with a power of ~350 W, was applied for solvent evaporation. The thermal decomposition of the precursors leads to the formation of ZnSb2O6 at 600°C. This oxide crystallized in a tetragonal structure with cell parameters a=4.66 Å, c=9.26 Å and space group P42/mnm. Microwires and microrods formed by nanocrystals were observed by means of scanning and transmission electron microscopies (SEM and TEM, resp.. Pellets of the oxide were tested as gas sensors in flowing atmospheres of carbon monoxide (CO and propane (C3H8. Sensitivity increased with the gas concentration (0–300 ppm and working temperatures (ambient, 150 and 250°C increase. The results indicate high sensitivity of ZnSb2O6 in both gases at different concentrations and operating temperatures.

  9. CO and C3H8 Sensitivity Behavior of Zinc Antimonate Prepared by a Microwave-Assisted Solution Method

    OpenAIRE

    Héctor Guillen-Bonilla; Verónica-M. Rodríguez-Betancourtt; José-Trinidad Guillén-Bonilla; Juan Reyes-Gómez; Lorenzo Gildo-Ortiz; Martín Flores-Martínez; Olvera-Amador, M. de la L.; Jaime Santoyo-Salazar

    2015-01-01

    ZnSb2O6 has been synthesized by a microwave-assisted solution method in order to test its possible application as a gas sensor. Zinc nitrate, antimony trichloride, and ethylenediamine were used as precursors and deionized water as solvent. Microwave radiation, with a power of ~350 W, was applied for solvent evaporation. The thermal decomposition of the precursors leads to the formation of ZnSb2O6 at 600°C. This oxide crystallized in a tetragonal structure with cell parameters a=4.66 Å, c=9.26...

  10. Speciation of eight arsenic compounds in human urine by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection using antimonate for internal chromatographic standardization

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pritzl, G.; Hansen, S. H.

    1993-01-01

    Four anionic and four cationic arsenic compounds in urine were separated by anion- and cation-exchange high-performance liquid chromatography and detected by inductively coupled plasma mass spectrometry (ICP-MS) at m/z 75. The species were the anions arsenite, arsenate, monomethylarsonate and...... arsenate in urine but was stable after at least 4-fold dilution of the urine with water. Arsenite was unstable in both urine samples and standard mixtures when diluted with the basic (pH 10.3) mobile phase used for anion chromatography. This could not be prevented by adding ascorbic acid as antioxidant...

  11. Synthesis and characterization of rare-earth barium antimonates, a new group of complex perovskites suitable as substrates for YBa2Cu3O7-δ films

    International Nuclear Information System (INIS)

    A new group of complex perovskites, REBa2SbO6 (where RE = Pr, Sm, and Gd), have been synthesized and sintered as single phase materials by the solid state reaction method. These materials are found to be isostructural and to have a complex cubic perovskite structure. X-ray diffraction and resistivity measurements have shown that there is no detectable chemical reaction between YBa2Cu3O7-δ and REBa2SbO6 even under severe heat treatment at 950 degrees C and that the addition of REBa2SbO6 up to 20 vol% in YBa2Cu3O7-δ shows no detrimental effect on the superconducting properties of YBa2Cu3O7-δ. The dielectric constant and loss factor values of the sintered REBa2SbO6 materials are in a range suitable for their use as substrates for microwave applications. Thick films of YBa2Cu3O7-δ fabricated on polycrystalline REBa2SbO6 substrates give superconducting zero resistivity transition temperature Tc(0) = 92 K, indicating the suitability of these materials as substrates for YBa2Cu3O7-δ films

  12. Untersuchungsergebnisse zur Mobilität und Remobilisierung von Kupfer und Antimon in wasserwirtschaftlich relevanten, porösen Lockergesteinen durch Säulenversuche und mit reaktiver Transportmodellierung

    OpenAIRE

    Fohrmann, Gina

    2003-01-01

    The aim of this study is to obtain a better understanding of the hydrological and geochemical contexts of the heavy metal transport in watersaturated porous aquifer sediments, where both copper (Cu) and antimony (Sb) are the main focus. The background of investigation is based on questions within the scope of the redevelopement of past industrial waste deposits areas and groundwater protection. The functional and experimental part of this study was initially comprised of planning, concept...

  13. 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 remaining 76% is probably to be found in the silicate matrix. Through multivariate calculations (PCA and MLR) and geochemical calculations (PHREEQC) aluminium and sulphate have been identified as being important for antimony leaching from the ashes. It is thus likely that ettringite governs antimony leachability at alkaline pH. When ettringite is solubilized the leachability of antimony will be dependent on the presence of effective sorbents. To decrease the leachability of antimony from the ashes addition of sulphate solution to the ashes is suggested, to increase the stability of ettringite at alkaline pH. Below the pH-range where ettringite is stable addition of manganese solution would give a new effective sorbent for antimony in solution. It was also noted that all fly ashes with addition of activated carbon did not exceed any guide lines for antimony leaching.

  14. 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); . the method was relatively simple; . the method could include an anaerobic step if needed; the method could include food; knowledge of the method existed in Sweden; and the method had been compared and evaluated in a scientific publication. In the experimental part of the study the bioaccessibility of antimony, arsenic, lead, cadmium, chromium, copper, nickel and zinc in seven different ashes at two different particle size fractions (<63 mum and <2 mm) was investigated. These fractions were chosen to represent voluntary (<2 mm) and involuntary (<63 mum) ingestion of ash. The investigated ashes were produced in different incineration plants and represented different categories, i.e. type of ash (fly ash or bottom ash), fuel and incinerator. In the experimental part the influence of total concentration of the elements on their bioaccessibility was also investigated, as well as the influence of particle size fraction on total content of the elements. The influence of type of ash on both bioaccessibility and total concentration of the specific elements was also investigated. The bioaccessible fraction of antimony, arsenic, cadmium, chromium, copper, lead, nickel and zinc in a selection of ashes showed a higher variation between the different elements than between the different ashes. With the exception of arsenic in two of the investigated ashes, the bioaccessible concentration was substantially less than the total concentration of all elements in all ashes. The bioaccessible fraction of arsenic was high both in fly ashes (>85%) and in bottom ashes (40-85%). The bioaccessible fraction of lead was also relatively high and varied between 14 and 60% in the different ashes. Cadmium also had a high bioaccessible fraction which varied between 50-75% in the investigated ashes. The bioaccessible fraction of chromium was much smaller compared to the bioaccessible fraction of the other elements, and was with two exceptions less than 12%. The bioaccessible fraction of copper was relatively high and varied between 20 and 70% in the different ashes. In this study, particle size fraction only had an effect on the bioaccessible fraction of arsenic, chromium, and copper. For these elements, bioaccessibility was higher in the smaller particle size fraction representing involuntary ingestion. Particle size fraction also had an effect on the total concentration of cadmium, nickel, antimony and zinc, with higher total concentrations in the smaller particle size fraction. Total concentration only had an effect on the bioaccessible fraction of arsenic, copper and lead, with higher bioaccessible fractions at lower total concentrations. The type of ash had an influence on the bioaccessible fraction of arsenic, cadmium, chromium and antimony, with a higher bioaccessible fraction of arsenic, chromium and antimony in fly ashes compared to in bottom ashes, and a higher bioaccessible fraction of cadmium in bottom ashes compared to in fly ashes.

  15. Selective propene oxidation on mixed metal oxide catalysts

    CERN Document Server

    James, D W

    2002-01-01

    Selective catalytic oxidation processes represent a large segment of the modern chemical industry and a major application of these is the selective partial oxidation of propene to produce acrolein. Mixed metal oxide catalysts are particularly effective in promoting this reaction, and the two primary candidates for the industrial process are based on iron antimonate and bismuth molybdate. Some debate exists in the literature regarding the operation of these materials and the roles of their catalytic components. In particular, iron antimonate catalysts containing excess antimony are known to be highly selective towards acrolein, and a variety of proposals for the enhanced selectivity of such materials have been given. The aim of this work was to provide a direct comparison between the behaviour of bismuth molybdate and iron antimonate catalysts, with additional emphasis being placed on the component single oxide phases of the latter. Studies were also extended to other antimonate-based catalysts, including coba...

  16. Selective propene oxidation on mixed metal oxide catalysts

    International Nuclear Information System (INIS)

    Selective catalytic oxidation processes represent a large segment of the modern chemical industry and a major application of these is the selective partial oxidation of propene to produce acrolein. Mixed metal oxide catalysts are particularly effective in promoting this reaction, and the two primary candidates for the industrial process are based on iron antimonate and bismuth molybdate. Some debate exists in the literature regarding the operation of these materials and the roles of their catalytic components. In particular, iron antimonate catalysts containing excess antimony are known to be highly selective towards acrolein, and a variety of proposals for the enhanced selectivity of such materials have been given. The aim of this work was to provide a direct comparison between the behaviour of bismuth molybdate and iron antimonate catalysts, with additional emphasis being placed on the component single oxide phases of the latter. Studies were also extended to other antimonate-based catalysts, including cobalt antimonate and vanadium antimonate. Reactivity measurements were made using a continuous flow microreactor, which was used in conjunction with a variety of characterisation techniques to determine relationships between the catalytic behaviour and the properties of the materials. The ratio of Fe/Sb in the iron antimonate catalyst affects the reactivity of the system under steady state conditions, with additional iron beyond the stoichiometric value being detrimental to the acrolein selectivity, while extra antimony provides a means of enhancing the selectivity by decreasing acrolein combustion. Studies on the single antimony oxides of iron antimonate have shown a similarity between the reactivity of 'Sb2O5' and FeSbO4, and a significant difference between these and the Sb2O3 and Sb2O4 phases, implying that the mixed oxide catalyst has a surface mainly comprised of Sb5+. The lack of reactivity of Sb2O4 implies a similarity of the surface with that of Sb2O3

  17. Ultrastructure of Gladiolus x hybridus root endodermis

    Directory of Open Access Journals (Sweden)

    Anna Rudzińska-Langwald

    2014-02-01

    Full Text Available Gladiolus.x hybridus Van Houtte roots had primary, secondary and tertiary endodermis depending on the distance from the root apex. Free calcium ions were localized with the method of Slocum and Roux (1982. Electron microscopic observations revealed that electron dense calcium antimonite deposits were localized in some endodermis cells. Endodermis cells situated above xylem elements were rich in calcium antimonate deposits in contrary to those situated above the phloem elements and passage cells. The cells rich in calcium ions were present both in endodermis 11 and III stage of development. Localization of calcium deposits was on plasma membrane and tonoplast. There were also numerous calcium antimonate deposits in vacuoles. Dictiosome's cisterns and Golgi derived vesicles show presence of calcium ions. Calcium rich endodermis cells had plastids with antimonate deposits present in their tylacoids lumen. Plasmode-smata looked the same in all endodermis cells, but those from calcium rich endodermis cells had calcium antimonate deposits in the lumen of plasmodesmata.

  18. Rediscovering ancient glass technologies through the examination of opacifier crystals

    Science.gov (United States)

    Lahlil, S.; Biron, I.; Galoisy, L.; Morin, G.

    2008-07-01

    The aim of the study is to understand how antimonate opacifying crystals were obtained throughout history. Two archaeological glass productions opacified with calcium and lead antimonates are studied in this paper, in order to rediscover ancient opaque glass technologies: Roman mosaic tesserae (1st cent. B.C. 4th cent. A.D.) and Nevers lampworking glass (18th cent. A.D.). The fine examination of crystalline phases and of the vitreous matrix is undertaken using various and complementary techniques. Results are compared with a modern reference production, for which the technological process is well known. We demonstrate that Ca-antimonate opacifiers in Roman mosaic tesserae, as well as in Nevers lampworking glass, were obtained by in situ crystallization. Nevertheless, Roman and Nevers glass would have undergone different firing processes. We propose that the addition of previously synthesized crystals or the use of “anime” could be the process used to obtain Pb-antimonate opacified glass, for both productions studied. We demonstrate that CaO, PbO and Sb2O3 concentrations in the bulk compositions and in the matrices, and their evolution with the crystallinity ratio, offer robust criteria for the distinction of the opacification process used. Also, the different crystalline structures help to provide information on the experimental conditions.

  19. Differentiation of stem cells into insulin-producing cells under the influence of nanostructural polyoxometalates.

    Science.gov (United States)

    Bâlici, Ştefana; Şuşman, Sergiu; Rusu, Dan; Nicula, Gheorghe Zsolt; Soriţău, Olga; Rusu, Mariana; Biris, Alexandru S; Matei, Horea

    2016-03-01

    Two polyoxometalates (POMs) with W were synthesized by a two-step, self-assembling method. They were used for stimulation of mesenchymal stem cell differentiation into insulin-producing cells. The nanocompounds (tris(vanadyl)-substituted tungsto-antimonate(III) anions [POM1] and tris-butyltin-21-tungsto-9-antimonate(III) anions [POM2]) were characterized by analytical techniques, including ultraviolet-visible, Fourier transform infrared, nuclear magnetic resonance spectroscopy, and transmission electron microscopy. We found that these polyoxotungstates, with 2-4 nm diameters, did not present toxic effects at the tested concentrations. In vitro, POM1 stimulated differentiation of a greater number of dithizone-positive cells (also organized in clusters) than the second nanocompound (POM2). Based on our in vitro studies, we have concluded that both the POMs tested had significant biological activity acting as active stimuli for differentiation of stem cells into insulin-producing cells. PMID:26397720

  20. Berberine derivatives as antileishmanial drugs.

    OpenAIRE

    Vennerstrom, J L; Lovelace, J K; Waits, V B; Hanson, W L; Klayman, D L

    1990-01-01

    Berberine, a quaternary alkaloid, and several of its derivatives were tested for efficacy against Leishmania donovani and Leishmania braziliensis panamensis in golden hamsters. Tetrahydroberberine was less toxic and more potent than berberine against L. donovani but was not as potent as meglumine antimonate (Glucantime), a standard drug for the treatment of leishmaniasis. Only berberine and 8-cyanodihydroberberine showed significant activity (greater than 50% suppression of lesion size) again...

  1. Drug: D02491 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D02491 Drug Meglumine antimonate; Glucantime (TN) C7H17NO5. SbO3. H 365.0071 365.9797 D02491.gif ... REPELLENTS P01 ANTIPROTOZOALS P01C AGENTS AGAINST LEISHMANIASIS ... AND TRYPANOSOMIASIS P01CB Antimony compounds P01CB ... ectives [BR:br08307] Antiparasitics Agents against Leishmaniasis ... and Trypanosomiasis Antimony compounds Meglumine a ...

  2. Süße Gifte

    OpenAIRE

    Betz, Richard

    2009-01-01

    Die vorliegende Arbeit beschreibt die Synthese und Charakterisierung ein- und mehrkerniger Diol-, Polyol- und Kohlenhydrat-Verbindungen von Elementen der vierten, fünften und sechsten Hauptgruppe des Periodensystems. Im Zentrum der Untersuchungen standen dabei Spiro-Derivate des fünfwertigen Phosphors, Arsens und Antimons, des vierwertigen Selens und Tellurs sowie spirocyclische Ester der Orthokohlensäure. Ferner wurden alpha-Hydroxycarbonsäuren, Aminosäuren, Aminole und Hydroxythiole au...

  3. Cortical alveoli of Paramecium: a vast submembranous calcium storage compartment

    OpenAIRE

    1991-01-01

    The plasma membrane of Paramecium is underlain by a continuous layer of membrane vesicles known as cortical alveoli, whose function was unknown but whose organization had suggested some resemblance with muscle sarcoplasmic reticulum. The occurrence of antimonate precipitates within the alveoli first indicated to us that they may indeed correspond to a vast calcium storage site. To analyze the possible involvement of this compartment in calcium sequestration more directly, we have developed a ...

  4. Test procedure for cation exchange chromatography

    International Nuclear Information System (INIS)

    The purpose of this test plan is to demonstrate the synthesis of inorganic antimonate ion exchangers and compare their performance against the standard organic cation exchangers. Of particular interest is the degradation rate of both inorganic and organic cation exchangers. This degradation rate will be tracked by determining the ion exchange capacity and thermal stability as a function of time, radiation dose, and chemical reaction

  5. Experimental treatment of cutaneous leishmaniasis with argentilactone isolated from Annona haematantha

    OpenAIRE

    Waechter, A.I.; M. E. Ferreira; Fournet, Alain; Rojas de Arias, A.; Nakayama, H.; Torres, S.; Hocquemiller, R; Cavé, A.

    1997-01-01

    From the hexanic extract of roots of #Annona haematantha$ an alpha,bêta-unsaturated delta-lactone was isolated and identified as argentilactone. This compound exhibited in vitro activity against various strains of #Leishmania$ ssp. at 10 microg/ml. BALB/c mice infected with #Leishmania amazonensis$ were treated four weeks after infection with argentilactone by oral or subcutaneous routes for 14 days at 25 mg/kg daily. The reference drug, N-methylglucamine antimonate, was administratered by su...

  6. Use of inorganic ion exchange materials for the treatment of liquid waste

    International Nuclear Information System (INIS)

    To examine the ion exchange behaviour of the double salts of polybasic acid with tetravalent metals type such as cerium(IV) and tin(IV) antimonates, different samples were prepared, heated at different temperatures and exposed to γ-irradiation. These samples were subject to X-ray, infra-red and thermal analysis. The exchange properties of the studied materials improved on increasing the Sb, Ce or Sn molar ratios and the drying temperature. The rate of the isotopic exchange was controlled by particle diffusion for the metal ions studied and was faster as the heating temperature was increased but slower for materials with a higher exchange capacity. The physical thermodynamic parameters have been evaluated which give some information regarding the mechanism of ion exchange on the surface of inorganic materials. The removal of radioactive isotopes of Na+, Cs+, Sr2+, Co2+ and Eu3+ was carried out by in-situ precipitation or by using preformed precipitate of tin(IV) and cerium(IV) antimonates. The products of in-situ precipitations act as ion exchange materials with high chemical and radioactive stabilities. The new materials have relatively high capacity compared with CeSb and SnSb. The irradiated cerium(IV) antimonate has been successfully used for the quantitative separation of cesium which suggests its use in the treatment of active liquid waste. (author). 24 refs, 7 figs, 17 tabs

  7. 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

  8. Cytochemical localization of calcium in soybean root cap cells in microgravity

    Science.gov (United States)

    Klymchuk, D. O.; Brown, C. S.; Chapman, D. K.; Vorobyova, T. V.; Martyn, G. M.

    The antimonate precipitation technique was used to evaluate the effects of microgravity and ethylene on the cellular and subcellular distribution of free calcium ions in soybean root apices. Soybean (Glycine max L. [Merr.]) dry seeds were launched, activated by hydration, and germinated in the presence of KMnO4 (to remove ethylene) and in its absence onboard the space shuttle Columbia during the STS-87 mission. Primary root apices of 6-day old seedlings were fixed for electron microscopy after landing. Ultrastructural studies indicated that antimonate precipitation appeared as individual electron-dense particles which were more or less round in shape and varied in diameter from 10 nm (minimum size beginning from which the particles were well identified) to 90 nm. It was revealed that analyzed root cap cells varied in both the precipitate particle sizes and the amount particles per unit of the cellular area. In both flight and ground control treatments, antimonate precipitation level increases from apical meristem cells to peripheral (secretory) cells of root apices. In root cap statocytes, subcellular localization of precipitate particles was revealed in the cytoplasm, nucleus and small vacuoles. The quantitative analysis showed a reduction of precipitate density in the cytoplasm and the nucleus, and an increase in precipitate density in the vacuoles from statocytes of both spaceflight treatments in comparison with ground controls.

  9. 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.

  10. 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

  11. 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)

  12. 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)

  13. Ion Exchange Kinetics of CO2+ Ions In the Particles of Some Organic and Inorganic Sorbents

    International Nuclear Information System (INIS)

    The rate of exchange and diffusion mechanism of Co2+ and Zn2+ on the hydrogen form of cerium (IV) antimonate Ce/Sb and polyacrylamide acrylic acid resin impregnated with zirconium phosphate p(A M-A A) Zr-P was determined at different reaction temperatures 25,45 and 60 degree. The exchange rate was controlled by a particle diffusion mechanism and a limited batch technique. The effective diffusion coefficients of exchange reactions, values of activation energies, entropy of activation have been calculated and were confirmed by the B t versus t plots

  14. Hematološke promjene kao posljedice otrovanja

    OpenAIRE

    Duraković, Zijad; Labar, Boris

    2003-01-01

    Hematološke promjene u organizmu mogu se dogoditi tijekom otrovanja nekim metalima (olovo, kobalt, antimon, arsen), ugljikovodicima (benzin, benzen), ili djelovanjem ionizirajućeg zračenja. Mogu nastati zbog anemija, napose kao posljedice hemolize, zbog smanjenja sposobnosti prijenosa kisika s posljedičnom hipoksijom organa, kao i zbog promjena koagulacije krvi. Pri ocjeni hematoloških promjena tijekom profesionalne izloženosti treba voditi računa o kompleksnosti zbivanja, mogućim nuspojavama...

  15. Temporal and spatial changes in Ca2+ distribution during the programmed cell death of tracheary elements

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The changes in Ca2+ distribution in the tracheary elements (TEs) of the pepper leaves were studied using the cytochemical method of potassium antimonate. At the early stage of TEs formation, the vacuole and the nucleus held large volume, and antimonate Ca2+ deposits were observed mainly in the intercellular space and the cell wall. As the thickening of secondary wall occurred, the vacuole, nucleus and other organelles began to rupture, concomitant with the increase of calcium deposits in the cytosol, showing the influx of Ca2+ into the cell. With the further rupture of cytoplasm and other organelles, the number of calcium deposits at the non-thickening cell wall increased, but declined at the thickening bands of the secondary wall. When the cytoplasmic contents disappeared completely, the level of Ca2+ decreased at the non-thickening wall, but by contrast,increased at the thickening bands of the secondary wall.These observations indicated that the dynamic changes in Ca2+ distribution spatially and temporarily might have a close correlation with its distinct roles played during the formation of the secondary walls.

  16. Cation-selective extraction column study for the conception of nuclear medical radionuclide generators; Untersuchung kationenselektiver Extraktionssaeulen zur Konzeption nuklearmedizinischer Radionuklidgeneratoren

    Energy Technology Data Exchange (ETDEWEB)

    Streng, Roman

    2012-07-09

    The topic of the present work is the conception of a Yttrium-90 radionuclide generator for nuclear medicine applications. Due to its physical properties Yttrium-90 is considered as one of the most useful nuclides for radiotherapeutic cancer treatment. The parent nuclide Strontium-90 is gained during reprocessing of fission products. Thus, the sustained availability of large quantities of Yttrium-90 is limited to a number of research facilities. A radionuclide generator provides an independent Yttrium-90 source and enhances the capacities for radiopharmaceutical research and biomedical applications. The present work focussed on the identification of appropriate column materials for the separation of Strontium and Yttrium. The results for two materials are reported: AnaLig {sup registered} Sr-01 and crystalline antimonic acid. Based on the mode of operation of the Technetium-99m generator the aim was to enable the construction of a compact, enclosed apparatus. The projected device comprises a reservoir for the eluant, the ion-exchange column, pipings and radiation shielding. Elution of Yttrium-90 could then be easily performed by connecting evacuated vials to the outlet tube. The prospected concept involves physical and chemical confinements that exclude most of the known processes for Strontium-Yttrium separation. For example no ligands, no oxidizing reactants (e.g. nitric acid) and no organic solvents are to be used, but small volumes of isotonic or buffer solutions and dilute acids respectively. AnaLig {sup registered} Sr-01 is a commercially available resin used in extraction chromatography. Its high selectivity for Strontium cations results from the strictly defined cavity of the imbedded cryptand. Determination of weight distribution coefficients, elution studies and pre-generator experiments were carried out. Quantitative separation of Yttrium from Strontium and Zirconium is possible using small volumes of 0,05 M hydrochloric acid as eluant. Furthermore, high

  17. Cutaneous Leishmaniasis with Unusual Clinical and Histological Presentation: Report of Four Cases

    Directory of Open Access Journals (Sweden)

    Hamideh Moravvej

    2013-04-01

    Full Text Available Old world cutaneous leishmaniasis (OWCL usually causes a single, self-healing and uncomplicated lesion mainly on the exposed area of body. This report presents four cases of OWCL from Iran that misdiagnosed with sarcoidosis, lymphoma, and acne agminata. Two out of four patients showed a history of purplish red plaques for at least 5 years who misdiagnosed as sarcoidosis because of histological and clinical characteristics. The other one presented with flesh-colored nodules disseminated all over his skin that was misdiagnosed as lymphoma for ten years. The last patient was misdiagnosed as acne agminata due to tuberculoid reactions in examination of the lesion biopsy. All the patients responded to the treatment with meglumine antimonate.

  18. Cutaneous leishmaniasis with unusual clinical and histological presentation: report of four cases.

    Science.gov (United States)

    Moravvej, Hamideh; Barzegar, Mohammadreza; Nasiri, Soheila; Abolhasani, Ehsan; Mohebali, Mehdi

    2013-01-01

    Old world cutaneous leishmaniasis (OWCL) usually causes a single, self-healing and uncomplicated lesion mainly on the exposed area of body. This report presents four cases of OWCL from Iran that misdiagnosed with sarcoidosis, lymphoma, and acne agminata. Two out of four patients showed a history of purplish red plaques for at least 5 years who misdiagnosed as sarcoidosis because of histological and clinical characteristics. The other one presented with flesh-colored nodules disseminated all over his skin that was misdiagnosed as lymphoma for ten years. The last patient was misdiagnosed as acne agminata due to tuberculoid reactions in examination of the lesion biopsy. All the patients responded to the treatment with meglumine antimonate. PMID:23690110

  19. Separation of carrier-free 90Y from 90Sr by ion exchange chromatography

    International Nuclear Information System (INIS)

    Separation of carrier free 90Y from fission product 90Sr by column chromatography was investigated using composite inorganic ion exchanger poly antimonic acid (PAA), which was developed in house. The optimum conditions of separation were obtained by studying the distribution coefficients for 90Y from different acid solutions (HNO3, HCl and H2SO4) in concentration range of 0.001 - 3 M on the sorbent. The results indicated that after loading 90S/90Y equilibrium solution, pure carrier free 90Y was obtained from the column using 1 M HNO3 solutions as eluent. The radiochemical purity of the separated 90Y was confirmed by studying its decay curve. (author)

  20. Heat capacity and thermodynamical functions of RbSbO3 within range 289.15-673 K

    International Nuclear Information System (INIS)

    Purpose of the work is study of rubidium meta-antimonate heat capacity within temperature range 298.15-673 K. Synthesis of RuSbO3 have been carried out by three-phase interaction of stoichiometric quantities of rubidium carbonates with antimony oxide. X-ray analysis of the solid mixture have been conducted on DRON-2,0 unit under Cu K-radiation. Isobar heat capacity was measured on IT-C-400 calorimeter. Results of calorimetric measurements and average deviation values are presented in tabular form. On base of experimental data a temperature dependence equation was received. Temperature dependences of thermodynamical functions received on base of experimental values of both heat capacity and entropy

  1. Study of the behaviour of some heavy elements in solvents containing hydrogen fluoride

    International Nuclear Information System (INIS)

    The anhydrous liquid mixtures: dinitrogen tetroxide-hydrogen fluoride and antimony pentafluoride-hydrogen fluoride were studied as solvents for heavy elements interesting nuclear energy: uranium, thorium, zirconium and for some of their compounds. For N2O4-HF mixtures, electric conductivity measurements and liquid phase infrared spectra were also obtained. Uranium and zirconium tetrafluoride are much more soluble in N2O4-HF mixtures than in pure hydrogen fluoride. Uranium dissolved in these mixtures is pentavalent. In SbF5-HF mixtures, uranium dissolves with hydrogen evolution and becomes trivalent. The solid compound resulting from the dissolution is a fluoro-antimonate: U(SbF6)3. (author)

  2. Investigation into thermal decomposition of rare earth metaantimonates

    International Nuclear Information System (INIS)

    Thermal decomposition of rare earth metaantimonates of Ln(SbO3)3 has been studied by the chemical, X-ray fluorescent, and X-ray phase analyses within the temperature range of 900-1400 deg C. The formation of intermediate compounds has been established, namely, rare earth antimonates Lnsub(2)Sbsub(3)Osub(10.5)(1) and LnSbO4(2), and of the final LnSbO7(3), where Ln=La, lanthanides in the series of Pr-Lu. The crystal structure of these compounds has been determined by the analytical method: 1 compound has a hexagonal lattice, 2 rhombic lattice, and 3 compound crystallizes in the structure of the fluoride type

  3. 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.”

  4. Ligand Influences on Properties of Uranium Coordination Complexes - Structure, Reactivity, and Spectroscopy

    OpenAIRE

    Kosog, Boris

    2012-01-01

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [((RArO)3tacn)UV(O)] and [((RArO)3tacn)UV(NSiMe3)] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [((RArO)3tacn)UVI(O)]SbF6 and [((RArO)3tacn)UVI(NSiMe3)]SbF6. While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influe...

  5. 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)

  6. 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

  7. Clinical features, epidemiology, and efficacy and safety of intralesional antimony treatment of cutaneous leishmaniasis: recent experience in Turkey.

    Science.gov (United States)

    Uzun, Soner; Durdu, Murat; Culha, Gulnaz; Allahverdiyev, Adil M; Memisoglu, Hamdi R

    2004-08-01

    A total of 1,030 patients, 40.2% men and 59.8% women, identified during the period of October 1998 to November 2002 as having cutaneous leishmaniasis (CL), were studied; 1,431 lesions were identified in the 1,030 patients. One lesion was present in 80.7% of the patients. The size of the lesions (longest axis) was 13.6 mm (standard, 12.1 mm; range 3-150 mm). Most of the lesions were of the papular type (51.2%), although several atypical clinical presentations of CL were observed. The duration of the disease ranged between 1 and 72 mo (mean duration, 10.8 mo). The clinical suspicion of CL was confirmed by the observation of amastigotes on lesion tissue samples stained by Giemsa. The test was positive in 851 of 1,030 patients (82.6%). Intralesional meglumine antimonate solution (85 mg Sb/ml, 0.2-1 ml, depending on the size of the lesion) weekly until complete cure or up to 20 wk was used for first-line therapy of 890 patients (86.4%). We found that this regimen of intralesional Sb has an efficacy of 97.2% with a low relapse rate of 3.9% and no serious adverse side effects. PMID:15357081

  8. Investigation of structure-properties relationship in a novel family of halogenoantimonates(III) and halogenobismuthates(III) with morpholinium cation: [NH2(C2H4)2O]MX4. Crystal structure, phase transitions and dynamics of molecules.

    Science.gov (United States)

    Owczarek, Magdalena; Jakubas, Ryszard; Pietraszko, Adam; Medycki, Wojciech; Baran, Jan

    2013-11-14

    Three new organic-inorganic hybrids based on halogenoantimonates(III) and halogenobismuthates(III) with the morpholinium cation, [NH2(C2H4)2O]SbCl4, [NH2(C2H4)2O]SbBr4 and [NH2(C2H4)2O]BiBr4, have been prepared and characterized with DSC, TGA, DTA and single-crystal X-ray diffraction. The common feature of the crystal structures of the studied compounds is the presence of polyanionic ([MX4]∞(-)) and morpholinium (head-to-tail configuration) chains, which expand themselves parallel to each other. The antimonate derivatives are isomorphous, crystallizing in a centrosymmetric orthorhombic Pbca space group and show no phase transitions (PTs) between 110 and 370 K. On the other hand, [NH2(C2H4)2O]BiBr4 undergoes two first-order structural PTs: I ↔ II at 321/343 K (cooling/heating) and II ↔ III at 285/289 K (cooling/heating). The mechanism of the PTs is discussed on the basis of crystallographic data and (1)H NMR and infrared spectroscopy. The PT at 343 K is accompanied by a spectacular switching of the spin-lattice T1 relaxation pathway. Structural parameters analysis has been performed to discuss a structure-properties relationship. PMID:23999763

  9. 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.

  10. A synthetic, spectroscopic and magnetic susceptibility study of selected main group and transition metal fluoro compounds

    Energy Technology Data Exchange (ETDEWEB)

    Cader, M.S.R.

    1992-01-01

    This study was initiated in order to synthesize and to investigate the magnetic properties of selected main group and transition metal cationic complexes, all stabilized by weakly basic fluoro anions derived either from the Broensted superacids HSO[sub 3]F and HSO[sub 3]CF[sub 3], or the Lewis acids SbF[sub 5] and AsF[sub 5]. The solvolysis of metal(II) fluorosulfates in excess SbF[sub 5] is found to be a useful synthetic route to the corresponding divalent hexafluoro antimonates. The Sn(SbF[sub 6])[sub 2] product from the above synthesis, and its precursor Sn(SO[sub 3]F)[sub 2], react with excess 1,3,5-trimethylbenzene(mes) to give the [pi]-arene adducts Sn(SbF[sub 6])[sub 2][center dot]2mes and Sn(SO[sub 3]F)[sub 2][center dot]mes in high yield. The adducts are characterized by elemental analysis and infrared spectra. The adduct formation is followed by [sup 119]Sn Moessbauer spectroscopy. The divalent fluorosulfates Ni(SO[sub 3]F)[sub 2], Pd(SO[sub 3]F)[sub 2], Pd(SO[sub 3]F)[sub 2] and Ag(SO[sub 3]F)[sub 2], precursors to the M(SbF[sub 6])[sub 2] compounds, and the mixed valency Pd(II) [Pd(IV)(SO[sub 3]F)[sub 6

  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. 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.

  13. Evaluating a Cumaean Sibyl: Domenichino or later? A multi analytical approach

    International Nuclear Information System (INIS)

    The purpose of this study is to clarify important details about a Cumaean Sibyl painting that is preserved in a private collection. This work, bearing neither signature nor date, has never undergone conservation. It was executed after Domenichino's Cumaean Sibyl, a work known to have been used as a model by many 18th century painters. Investigation of the anonymous artist's painting technique and identification of its constituent materials were facilitated by employing optical microscopy (OM), scanning electron microscopy (SEM/EDS), FTIR and microRaman spectroscopies and high performance liquid chromatography with diode array detection (HPLC-DAD). The painter's palette comprised lead white, yellow ochre, lead-antimonate yellow (Naples yellow), cinnabar, cochineal lake, madder lake, haematite, Prussian blue and carbon black. The detection of Prussian blue (synthesized in 1704 and widely used as artist's pigment after 1750) was decisive in establishing the work's authenticity for, as such, it cannot be attributed either to Domenico Zampieri (1581-1641) or to his apprentices. In addition, the identification of Naples yellow, which prevailed in the period from 1750 to 1850, supports this statement. Nevertheless, its elaborate painting technique strongly suggests an artist greatly influenced by the Renaissance masters. A comparison of its stylistic features with those of the Cumaean Sibyl of Angelica Kauffmann (1741-1807), a prolific 18th century artist known to have studied and to have copied Domenichino's Sibyl, reveals significant similarities between the two in composition and palette. The unsigned Sibyl, therefore, could well be by Kauffmann

  14. Synthesis, dehydration studies, and cation-exchange behavior of a new phase of niobium(V) phosphate

    International Nuclear Information System (INIS)

    Twenty-three samples of niobium(V) phosphate have been synthesized under different conditions using niobium sulfate and phosphoric acid solutions. The amorphous sample having the ion-exchange capacity of 1.06 mEq g-1 and niobium to phosphorus mole ratio of 0.670 was studied in detail for its cation-exchange behavior. Molar distribution coefficients for 25 cations have been studied on this gel at pH 1,2,3, and 5.5. Four quantitative separations of Mg2+-Ca2+, Mg2+-Ba2+, Zn2+-Cd2+, and Bi3+-Zn2+ have successfully been achieved on it. The properties of this sample have been compared with those of niobium arsenate, niobium antimonate, and niobium molybdate. A tentative structural formula is proposed for this sample of niobium phosphate on the basis of chemical composition, cation-exchange capacity, pH-titration, IR spectra, T.G.A., water absorption, and heat treatment data. (author)

  15. Visceral leishmaniasis in a renal transplant recipient treated with allopurinol

    Directory of Open Access Journals (Sweden)

    Harzallah Kais

    2010-01-01

    Full Text Available Leishmaniasis is an infection caused by a protozoan parasite belonging to the genus Leishmania and transmitted by the Phlebotomus sandfly. We report a case of visceral leishmaniasis in a 49-year-old male renal transplant recipient, a resident of the western part of Tunisia, which is an endemic zone for the disease. Just before and after the transplantation, the patient resided in Tunis, which is non-endemic for leishmaniasis. Visceral leishmaniasis occurred eight years after renal transplantation, and the clinical picture was characterized by fever and pancytopenia. Leish-maniae were detected by bone marrow aspiration. Pentavalent antimonal was used for 28 days and was substituted by allopurinol (20 mg/kg per day. One year after the infection, the patient remains totally asymptomatic. Our report suggests that visceral leishmaniasis may complicate the clinical course of organ transplantation and can be fatal, particularly when untreated. Relapses may occur after completion of the apparently effective treatment. Allopurinol could be a solution to avoid these relapses.

  16. PXRF, μ-XRF, vacuum μ-XRF, and EPMA analysis of Email Champlevé objects present in Belgian museums.

    Science.gov (United States)

    Van der Linden, Veerle; Meesdom, Eva; Devos, Annemie; Van Dooren, Rita; Nieuwdorp, Hans; Janssen, Elsje; Balace, Sophie; Vekemans, Bart; Vincze, Laszlo; Janssens, Koen

    2011-10-01

    The enamel of 20 Email Champlevé objects dating between the 12th and 19th centuries was investigated by means of microscopic and portable X-ray fluorescence analysis (μ-XRF and PXRF). Seven of these objects were microsampled and the fragments were analyzed with electron probe microanalysis (EPMA) and vacuum μ-XRF to obtain quantitative data about the composition of the glass used to produce these enameled objects. As a result of the evolution of the raw materials employed to produce the base glass, three different compositional groups could be discriminated. The first group consisted of soda-lime-silica glass with a sodium source of mineral origin (with low K content) that was opacified by addition of calcium antimonate crystals. This type of glass was only used in objects made in the 12th century. Email Champlevé objects from the beginning of the 13th century onward were enameled with soda-lime-silica glass with a sodium source of vegetal origin. This type of glass, which has a higher potassium content, was opacified with SnO2 crystals. The glass used for 19th century Email Champlevé artifacts was produced with synthetic and purified components resulting in a different chemical composition compared to the other groups. Although the four analytical techniques employed in this study have their own specific characteristics, they were all found to be suitable for classifying the objects into the different chronological categories. PMID:21939587

  17. Protons conductive membranes from sulfonated styrenic copolymers; Membranas conductoras de protons a partir de copolimeros estirenicos sulfonados

    Energy Technology Data Exchange (ETDEWEB)

    Brum, F.J.B.; Silva, M.A.G.; Amico, S.C.; Malfatti, C.F.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul (EE/UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia], e-mail: mmcforte@ufrgs.br; Vargas, J.V.C. [Universidade Federal do Parana (DEM/UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica

    2008-07-01

    Fuel cells working with polymeric electrolyte known as Proton Exchange Membrane Fuel Cell (PEMFC) have become a promising source for energy generation since they can produce high density electric current in an effective way. In this work, a polymeric precursor based on sulfonated styrenic copolymer (RHS) was used with the aim of producing ion-exchange membranes thermally stable at 80 deg C and over. Films of RHS and poly(vinylalcohol) (PVA) mixtures with different polyelectrolyte content were prepared, using glutaraldehyde as a crosslinking agent and antimonic acid. The films or membranes were analyzed by infrared and electrochemical impedance spectroscopy, differential scanning calorimetry, thermogravimetry and water absorption content. The impedance studies showed that the ionic conductivity of the RHS/PVA membranes was highly dependent on the electrolyte polymer in a way that the higher the content, the higher the membrane ionic conductivity. The RHS66{sub G}1 showed ionic conductivity similar to the Nafion membrane analyzed at the same conditions. (author)

  18. A fruitful demonstration in sensors based on upconversion luminescence of Yb3+/Er3+codoped Sb2O3-WO3-Li2O (SWL) glass-ceramic

    Science.gov (United States)

    Prasad Sukul, Prasenjit; Kumar, Kaushal

    2016-07-01

    In this article, erbium and ytterbium doped lithium tungsten antimonate (Yb3+/Er3+:Sb2O3-WO3-Li2O) glass-ceramics (GC) is synthesized and its novel applications in temperature sensing and detection of latent fingerprints is studied. It is also estimated that this material could be useful as a solar cell concentrator. The upconversion emission studies on Yb3+/Er3+:SWL glass-ceramics have shown intense green emission at 525 nm (2H11/2 → 4I15/2) & 545 nm (4s3/2 → 4I15/2). The variation of UC intensities with external temperature have shown a well-fashioned pattern, which suggests that the 2H11/2 and 4S3/2 levels of Er3+ ion are thermally coupled and can act as a temperature sensor in the 300–500 K temperature range. Dry powder of Yb3+/Er3+:SWL glass-ceramic is used to develop latent fingerprint with high contrast in green color on glass slide.

  19. Dating ancient mosaic glasses by luminescence: The case study of San Pietro in Vaticano

    Science.gov (United States)

    Galli, A.; Martini, M.; Sibilia, E.; Vandini, M.; Villa, I.

    2011-12-01

    The preliminary results of a study on the dosimetric properties of a set of glass tesserae from the mosaics of the vaults of St. Peter's Basilica in Rome (late XVI century) are reported. The main goal of the research was to assess the possibility of dating them by means of luminescence techniques. The samples had already been extensively studied and investigated from a historical, artistic and compositional point of view. The period of the making of the mosaic was rather well known, and could be the basis to test the experimental procedures we used for dosimetry. The experiments also aimed at demonstrating the validity of the hypothesis we put forward, i.e. the positive link between the presence of micro-crystals and the luminescence sensitivity in mosaic glass: to this aim, the samples richer in crystalline inclusions were selected. The role of calcium antimonate and cassiterite was definitely demonstrated. For what concerns their thermoluminescence (TL) characteristics, a preliminary investigation suggested that the available configuration of the detection systems did not properly fit the wavelength of the emitted TL. Much more promising results have been achieved by the use of Optically Stimulated Luminescence (OSL), even if the measured absorbed doses were rather scattered. For one sample with high OSL sensitivity, it was possible to establish its recent age, relative to one of the documented restorations that took place during the last century.

  20. In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii

    Directory of Open Access Journals (Sweden)

    Dayane Priscilla de Souza Queiroz

    2016-01-01

    Full Text Available The polar hydroethanolic extract from Selaginella sellowii(SSPHE has been previously proven active on intracellular amastigotes (in vitro test and now was tested on hamsters infected with Leishmania (Leishmania amazonensis (in vivo test. SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb (28 mg/Kg/day × 5. When orally administered, SSPHE (50 mg/kg/day × 20 suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis.

  1. Cytochemical localization of calcium in cap cells of primary roots of Zea mays L

    Science.gov (United States)

    Moore, R.

    1986-01-01

    The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.

  2. Calcium pretreatment increases thermotolerance of Laminaria japonica sporophytes

    Institute of Scientific and Technical Information of China (English)

    You Wang; Qingyun Yu; Xuexi Tang; Lili Wang

    2009-01-01

    Calcium is a secondary messenger in plant signaling,and its concentration changes spatially and temporally during the course of heat stress.In the present study,potassium antimonate was used to visualize calcium localization in blades of a marine macroalga,the juvenile Laminariajaponica sporophytes under heat stress (25 ℃).Result showed that loosely bound calcium was mainly distributed on the cell wall under normal conditions (10 ℃),and flowed into the cytoplasm when exposed to heat.The simutaneous assay on the antioxidant system changes was performed.Oxidative damage,as measured by generation of reactive oxygen species (ROS) malondialdehyde (MDA) content,increased significantly during heat stress,and calcium pretreatment alleviated oxidative damage.The assay on the activities of six antioxidant enzymes demonstrated that their enzymatic activities were inhibited when exposed to heat stress,but Ca2+ pretreatment effectively attenuated the inhibition.Results in the present study inferred that calcium homeostasis plays an essential role in L.japonica sporophyte when exposed to heat,and calcium pretreatment could improve its thermo-tolerance.

  3. Effects of Exterior Abscisic Acid on Calcium Distribution of Mesophyll Cells and Calcium Concentration of Guard Cells in Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    GUO Xiu-lin; MA Yuan-yuan; LIU Zi-hui; LIU Bin-hui

    2008-01-01

    In this study, the direct effects of exterior abscisic acid (ABA) on both calcium distribution of mesophyll cells and cytosolic calcium concentration of guard cells were examined. The distribution of Ca2+ localization were observed with calcium antimonate precipitate-electromicroscopic-cyto-chemical methods after treated with ABA and pretreated with ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA), verapamil (Vp), and trifluoperazine (TFP). The laser scanning confocal microscopy was used to measure the cytosolic calcium concentrations of guard cells under different treatments. The results showed that the cytosolic Ca2+ concentration of mesophyll cells was induced to increase by ABA, but to decrease in both outside cell and the vacuoles within 10 min after treatments. The cytosolic calcium concentration of guard cells was increased gradually with the lag in treatment time. However, both EGTA and TFP could inverse those effects, indicating that the increase of cytosolic calcium induced by exterior ABA was mainly caused by calcium influx. The results also showed that calmodulin could influence both the calcium distribution of mesophyll cells and calcium concentration of guard cells. It shows that calmodulin participates in the process of ABA signal transduction, but the mechanism is not known as yet. The changes both calcium distribution of mesophyll cells and calcium concentration of guard cells further proved that the variations of cytosolic Ca2+ concentration induced by ABA were involved in the stomatal movements of maize seedlings.

  4. Synthesis, characterization, sintering and dielectric properties of nanostructured perovskite-type oxide, Ba2GdSbO6

    Indian Academy of Sciences (India)

    C Vijayakumar; H Padma Kumar; Sam Solomon; J K Thomas; P R S Warriar; J Koshy

    2008-10-01

    Nanoparticles of barium gadolinium antimonate (Ba2GdSbO6), a complex perovskite-type oxide, has been synthesized using an auto ignition combustion process for the first time. The nanoparticles thus obtained have been characterized by powder X-ray diffraction, thermogravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The XRD studies have shown that the as-prepared powder is phase pure Ba2GdSbO6 and has a complex cubic perovskite (A2BB′O6) crystalline structure with lattice constant, = 8.449 Å. The TEM image reveals that the particle size of the as-prepared nano powder was in the range 30–60 nm. The nanocrystals of Ba2GdSbO6 synthesized by the combustion technique could be sintered to 96% of the theoretical density by heating at a temperature of 1560°C for a short duration of 3 h. The surface morphology of the sintered pellet has been studied by scanning electron microscope (SEM). The dielectric constant ($\\varepsilon_{r}$) was 20 and the loss factor (tan) was 0.03 at 3 MHz. By the present combustion technique a phase pure nanopowder of Ba2GdSbO6 could be obtained by a single step process without the need of any calcination step.

  5. Three-Dimensional Reduced Graphene Oxide Coupled with Mn3O4 for Highly Efficient Removal of Sb(III) and Sb(V) from Water.

    Science.gov (United States)

    Zou, Jian-Ping; Liu, Hui-Long; Luo, Jinming; Xing, Qiu-Ju; Du, Hong-Mei; Jiang, Xun-Heng; Luo, Xu-Biao; Luo, Sheng-Lian; Suib, Steven L

    2016-07-20

    Highly porous, three-dimensional (3D) nanostructured composite adsorbents of reduced graphene oxides/Mn3O4 (RGO/Mn3O4) were fabricated by a facile method of a combination of reflux condensation and solvothermal reactions and systemically characterized. The as-prepared RGO/Mn3O4 possesses a mesoporous 3D structure, in which Mn3O4 nanoparticles are uniformly deposited on the surface of the reduced graphene oxide. The adsorption properties of RGO/Mn3O4 to antimonite (Sb(III)) and antimonate (Sb(V)) were investigated using batch experiments of adsorption isotherms and kinetics. Experimental results show that the RGO/Mn3O4 composite has fast liquid transport and superior adsorption capacity toward antimony (Sb) species in comparison to six recent adsorbents reported in the literature and summarized in a table in this paper. Theoretical maximum adsorption capacities of RGO/Mn3O4 toward Sb(III) and Sb(V) are 151.84 and 105.50 mg/g, respectively, modeled by Langmuir isotherms. The application of RGO/Mn3O4 was demonstrated by using drinking water spiked with Sb (320 μg/L). Fixed-bed column adsorption experiments indicate that the effective breakthrough volumes were 859 and 633 mL bed volumes (BVs) for the Sb(III) and Sb(V), respectively, until the maximum contaminant level of 5 ppb was reached, which is below the maximum limits allowed in drinking water according to the most stringent regulations. The advantages of being nontoxic, highly stable, and resistant to acid and alkali and having high adsorption capacity toward Sb(III) and Sb(V) confirm the great potential application of RGO/Mn3O4 in Sb-spiked water treatment. PMID:27355752

  6. 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.

  7. Oxalic acid has an additional, detoxifying function in Sclerotinia sclerotiorum pathogenesis.

    Directory of Open Access Journals (Sweden)

    Annerose Heller

    Full Text Available The mechanism of the diseases caused by the necrotroph plant pathogen Sclerotinia sclerotiorum is not well understood. To investigate the role of oxalic acid during infection high resolution, light-, scanning-, transmission electron microscopy and various histochemical staining methods were used. Our inoculation method allowed us to follow degradation of host plant tissue around single hyphae and to observe the reaction of host cells in direct contact with single invading hyphae. After penetration the outer epidermal cell wall matrix appeared degraded around subcuticular hyphae (12-24 hpi. Calcium oxalate crystals were detected in advanced (36-48 hpi and late (72 hpi infection stages, but not in early stages. In early infection stages, surprisingly, no toxic effect of oxalic acid eventually secreted by S. sclerotiorum was observed. As oxalic acid is a common metabolite in plants, we propose that attacked host cells are able to metabolize oxalic acid in the early infection stage and translocate it to their vacuoles where it is stored as calcium oxalate. The effects, observed on healthy tissue upon external application of oxalic acid to non-infected, living tissue and cell wall degradation of dead host cells starting at the inner side of the walls support this idea. The results indicate that oxalic acid concentrations in the early stage of infection stay below the toxic level. In plant and fungi oxalic acid/calcium oxalate plays an important role in calcium regulation. Oxalic acid likely could quench calcium ions released during cell wall breakdown to protect growing hyphae from toxic calcium concentrations in the infection area. As calcium antimonate-precipitates were found in vesicles of young hyphae, we propose that calcium is translocated to the older parts of hyphae and detoxified by building non-toxic, stable oxalate crystals. We propose an infection model where oxalic acid plays a detoxifying role in late infection stages.

  8. Obtaining membranes for alternative treatment hydrogels of cutaneous leishmaniasis; Obtencao de membranas de hidrogeis para tratamento alternativo da leishmaniose tegumentar

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Maria Jose Alves de

    2013-07-01

    Polymeric Hydrogels formed by crosslinked polymeric chains were obtained by ionizing radiation process according to Rosiak technique. In the last 40 years the use of hydrogels has been investigated for various applications as curatives. In this work hydrogel membranes were synthesized with poly (N-2-pyrrolidone) (PVP), poly (vinyl alcohol) (PVA), chitosan and laponita clay for use as a vehicle for controlled glucantime release on the surface of skin tissues injured by leishmaniasis. Leishmaniasis is a disease caused by a protozoan parasite of the genus Leishmania transmitted by the bite of phlebotomies sandfly. The traditional treatment of patients infected by these parasites is done with pentavalent antimony in injectable form. However, these antimonates are highly toxic and cause side effects in these patients. In addition, patients with heart and kidney disease can not use this treatment. In treatment with drug delivery hydrogel membrane applied on the surface of leishmaniasis injured tissues the drug is released directly to the wound in a controlled manner, reducing the side effects. Membranes prepared in this study were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG), swelling, gel fraction, infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The characterizations of cytotoxicity and drug release were made 'in vitro' and 'in vivo' with functional test according to ethical protocol of the Division of Infectious and Parasitic Diseases at the Hospital of Clinics, Sao Paulo University-School of Medicine, University. The 'in vivo' test of these membranes proved to be effective in controlled release of drugs directly into leishmaniasis damaged tissues. Results of 'in vivo' tests using PVP/PVAl / clay 1,5% and glucantime membrane showed remarkable contribution to wound reduction and cure in clinical therapy. (author)

  9. Phosphorus removal from aqueous solution using iron coated natural and engineered sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Boujelben, N. [Laboratoire Eau Energie et Environnement, departement de genie geologique, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia)], E-mail: nesrine.boujelben@tunet.tn; Bouzid, J.; Elouear, Z. [Laboratoire Eau Energie et Environnement, departement de genie geologique, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia); Feki, M. [Unite de chimie industrielle I, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia); Jamoussi, F. [Laboratoire de Georessources CERTE BP 95, 2050 Hamam-Lif (Tunisia); Montiel, A. [Societe Anonyme de Gestion des Eaux de Paris, 9 rue Schoelcher, 75675 Paris Cedex 14 (France)

    2008-02-28

    New filtration materials covered with metallic oxides are good adsorbents for both cation and anion forms of pollutants. Sfax is one of the most important industrial towns in Tunisia. Its phosphate manufacture in particular is causing considerable amounts of water pollution. Therefore, there is a need to find out a new way of getting rid of this excessive phosphate from water. This work is aimed to examining the potential of three sorbent materials (synthetic iron oxide coated sand (SCS), naturally iron oxide coated sand (NCS) and iron oxide coated crushed brick (CB)) for removing phosphate ions from aqueous solutions. According to our literature survey CB was not used as adsorbent previously. Phosphate ions are used here as species model for the elimination of other similar pollutants (arsenates, antimonates). Optical microscope and scanning electron microscope (SEM) analyses were used to investigate the surface properties and morphology of the coated sorbents. Infra-red spectroscopy and X-ray diffraction techniques were also used to characterize the sorbent structures. Results showed that iron coated crushed brick possess more micro pores and a higher surface area owing to its clay nature. The comparative sorption of PO{sub 4}{sup 3-} from aqueous solutions by SCS, CB and NCS was investigated by batch experiments. The estimated optimum pH of phosphate ion retention for the considered sorbents was 5. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The sorption capacities of PO{sub 4}{sup 3-} at pH 5 were 1.5 mg/g for SCS, 1.8 mg/g for CB and 0.88 mg/g for NCS. The effect of temperature on sorption phenomenon was also investigated. The results indicated that adsorption is an endothermic process for phosphate ions removal. This study demonstrates that all the considered sorbents can be used as an alternative emerging technology for water treatment without any side effect or treatment process alteration.

  10. Evaluating a Cumaean Sibyl: Domenichino or later? A multi analytical approach

    Energy Technology Data Exchange (ETDEWEB)

    Daniilia, Sister [Ormylia Foundation - Art Diagnosis Centre, Sacred Convent of the Annunciation, 63071 Ormylia, Chalkidiki (Greece)], E-mail: ormylia@artdiagnosis.gr; Minopoulou, Elpida [Ormylia Foundation - Art Diagnosis Centre, Sacred Convent of the Annunciation, 63071 Ormylia, Chalkidiki (Greece); Andrikopoulos, Konstantinos S. [Physics Division, School of Technology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Karapanagiotis, Ioannis [Ormylia Foundation - Art Diagnosis Centre, Sacred Convent of the Annunciation, 63071 Ormylia, Chalkidiki (Greece); Kourouklis, Gerasimos A. [Physics Division, School of Technology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2008-03-24

    The purpose of this study is to clarify important details about a Cumaean Sibyl painting that is preserved in a private collection. This work, bearing neither signature nor date, has never undergone conservation. It was executed after Domenichino's Cumaean Sibyl, a work known to have been used as a model by many 18th century painters. Investigation of the anonymous artist's painting technique and identification of its constituent materials were facilitated by employing optical microscopy (OM), scanning electron microscopy (SEM/EDS), FTIR and microRaman spectroscopies and high performance liquid chromatography with diode array detection (HPLC-DAD). The painter's palette comprised lead white, yellow ochre, lead-antimonate yellow (Naples yellow), cinnabar, cochineal lake, madder lake, haematite, Prussian blue and carbon black. The detection of Prussian blue (synthesized in 1704 and widely used as artist's pigment after 1750) was decisive in establishing the work's authenticity for, as such, it cannot be attributed either to Domenico Zampieri (1581-1641) or to his apprentices. In addition, the identification of Naples yellow, which prevailed in the period from 1750 to 1850, supports this statement. Nevertheless, its elaborate painting technique strongly suggests an artist greatly influenced by the Renaissance masters. A comparison of its stylistic features with those of the Cumaean Sibyl of Angelica Kauffmann (1741-1807), a prolific 18th century artist known to have studied and to have copied Domenichino's Sibyl, reveals significant similarities between the two in composition and palette. The unsigned Sibyl, therefore, could well be by Kauffmann.

  11. Obtaining membranes for alternative treatment hydrogels of cutaneous leishmaniasis

    International Nuclear Information System (INIS)

    Polymeric Hydrogels formed by crosslinked polymeric chains were obtained by ionizing radiation process according to Rosiak technique. In the last 40 years the use of hydrogels has been investigated for various applications as curatives. In this work hydrogel membranes were synthesized with poly (N-2-pyrrolidone) (PVP), poly (vinyl alcohol) (PVA), chitosan and laponita clay for use as a vehicle for controlled glucantime release on the surface of skin tissues injured by leishmaniasis. Leishmaniasis is a disease caused by a protozoan parasite of the genus Leishmania transmitted by the bite of phlebotomies sandfly. The traditional treatment of patients infected by these parasites is done with pentavalent antimony in injectable form. However, these antimonates are highly toxic and cause side effects in these patients. In addition, patients with heart and kidney disease can not use this treatment. In treatment with drug delivery hydrogel membrane applied on the surface of leishmaniasis injured tissues the drug is released directly to the wound in a controlled manner, reducing the side effects. Membranes prepared in this study were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG), swelling, gel fraction, infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The characterizations of cytotoxicity and drug release were made 'in vitro' and 'in vivo' with functional test according to ethical protocol of the Division of Infectious and Parasitic Diseases at the Hospital of Clinics, Sao Paulo University-School of Medicine, University. The 'in vivo' test of these membranes proved to be effective in controlled release of drugs directly into leishmaniasis damaged tissues. Results of 'in vivo' tests using PVP/PVAl / clay 1,5% and glucantime membrane showed remarkable contribution to wound reduction and cure in clinical therapy. (author)

  12. Preparation and application of aqueous organosilicon-modified polyester resin%水性有机硅改性聚酯树脂的合成与应用

    Institute of Scientific and Technical Information of China (English)

    张丽丽; 曾敬荣; 江俊鸿; 杨雁; 俞金柱

    2013-01-01

    In this paper, hydroxy polyester resins were synthesized through melting. In this process, anti-monous oxide was used as catalyst and 10%, 30% and 50% of organosilicon intermediate was used to chemical modification respectively. The modified organosilicon polyester resin with trimellitic anhydride was processed with water base-side processing,then salted with dimethylethanolamine. This kind of water-soluble organosilicon modified polyester resin treated with this way was used to cure and film with amino resin, which performs excellent high temperature resistant, high solidity and excellent flexibility. The experiment results showed that the compositive property and the price performance is the best when the content of organosilicon is 30%.%本文以Sb2O3为催化剂,采用熔融法合成端羟基聚酯树脂,分别以10%、30%、50%的有机硅中间体进行化学改性,以偏苯三甲酸酐对有机硅改性后的聚酯进行了水性化封端,并采用二甲基乙醇胺成盐,制备的水性有机硅改性聚酯树脂配以氨基树脂固化成膜后,表现出具有优良耐高温性、高硬度、良好柔韧性等性能,实验表明,当有机硅含量为30%时,改性聚酯树脂树脂的综合性能和性价比最好.

  13. Novel highly selective selective inorganic ion exchangers for the treatment of problematic liquid radwaste

    International Nuclear Information System (INIS)

    Novel highly selective inorganic ion exchange materials have been studied for the removal of radionuclides from diverse liquids such as alpha-bearing scintillation cocktails and acidic decontamination solutions. In addition, the removal of oxo-anionic radionuclides 99Tc (pertechnetate) and 125Sb (antimonate) has been investigated. Large number of ion exchange materials were screened for the removal 241Am by batch experiments (determination of 241Am distribution coefficient) from Wallac HISafe 3 liquid scintillation cocktails. The aquatic phase in the cocktails was either 0.2-0.4 M NaNO3 or HNO3. The liquid scintillation cocktail was studied as such or mixed with methanol, ethanol or propanol diluents. The tentative test comprised the measurement of the distribution coefficient Kd of the tracer batchwise in the various liquids for the different ion exchange materials. In general, the americium uptakes were low (Kd d > 10,000,000 ml/g) for SrTreat material. Further work was carried out with best materials (SrTreat-titanate, antimonysilicate, manganese oxide) to optimise the amount of diluents and to conduct column experiments. It was found that 241Am uptake in the materials increased with increasing dilution until the dilution ratio reached about 1:2. Columns (10 mL) packed with MnO2 and SbSiO2 removed 241Am efficiently from diluted HiSafe liquid with a maximum DF of 60-250. There was no sigh of column exhaustion when 2.5 L (250 BV) of liquid had been processed. A total of 8 L of scintillation liquids were purified in the column tests. In addition, americium-bearing nitric waste liquids (pH = 1.1) were decontaminated successfully using SbSiO2-columns and acid solution was disposed of in the sewer after neutralisation. Also, removal of Co-57 has been studied from acids commonly used for decontamination (oxalic acid, citric acid, formic acid, sulphuric acid and nitric acid) using novel manganese antimonate material. Uptake of Co-57 was more dependent on solution p

  14. Platinum mineralization in the Kapalagulu Intrusion, western Tanzania

    Science.gov (United States)

    Wilhelmij, Harry R.; Cabri, Louis J.

    2016-03-01

    . Impersistent, stratiform PGE mineralized horizons occur within the MCSS harzburgite from which drill core samples were taken for platinum-group mineral (PGM) characterization from two drill holes. Where the PGE reefs reach the surface there is residual PGE mineralization within the laterite regolith from which drill core samples were taken from various laterite lithological units for PGM characterization. As the harzburgite PGE reefs contain significant concentrations of both sulfide and chromite (including chromitite seams) they resemble the PGE-rich chromitite seams of the Bushveld Complex rather than the PGE-bearing Main Sulfide Zone of the Great Dyke and Main Sulfide Layer of the Munni Munni Complex. The dominant Pd PGM in three PGE reef samples varies, ranging ( n = 164, relative wt%) from bismuthides (63 %), bismuthtellurides (19 %), and tellurides (6 %), to tellurides (39 %), bismuthtellurides (24 %), stannides (14 %), and alloys (13 %), and to antimon-arsenides (33 %), stannides (21 %), bismuthides (17 %), tellurides (13 %), and alloys (10 %). From 13.5 % to 21.0 % of the total Pd occurs as a solid solution in pentlandite. The three samples have similar Pt PGM modal distributions ( n = 172, relative wt%); the dominant Pt mineral is sperrylite (79, 58, and 47 %) followed by tellurides (15, 17, 21 %), alloys (2, 1, 1 %), and sulfides (2, 1, 0 %). Comparison of Pd/Pt ratios from assays to those calculated from minerals show that the data for the Pt and Pd PGM are very robust, confirming the concentration methodology and characterization. Study of samples from a shallow drill hole penetrating the laterite regolith shows that the primary Pd mineralization has not survived oxidation, is mainly dispersed, but some was reconstituted to form secondary minerals: cabriite, unnamed tellurides, a selenide, a Pd-Te-Hg mineral, alloys and Pd-bearing secondary sulfides (millerite and heazlewoodite). The primary Pt minerals are more resistant to oxidation and dissolution, especially

  15. Ligand influences on properties of uranium coordination complexes. Structure, reactivity, and spectroscopy

    International Nuclear Information System (INIS)

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [((RArO)3tacn)UV(O)] and [((RArO)3tacn)UV(NSiMe3)] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [((RArO)3tacn)UVI(O)]SbF6 and [((RArO)3tacn)UVI(NSiMe3)]SbF6. While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influence, normal axial coordination is observed for the Ad-derivative and both imido complexes. The inverse trans-influence was thus proven to be a key factor for the coordination mode of a terminal ligand on high valent uranium complexes. LIII XANES was shown to be a great tool for the determination of oxidation states of uranium complexes. Therefore, a series of uranium complexes in all stable oxidation states for uranium, +III to +VI was prepared, and their spectra analyzed. All compounds bear only O-donor ligands in addition to the chlating trisaryloxide-tacn-ligand. A separation of 1.5 to 3 eV in the white line energy is observed between the different oxidation states. This series can be used as reference for compounds, where oxidation state assignment is not obvious, such as a ketyl radical complex [((t-BuAr)O3tacn)U(O-C(t-BuPh)2.-)]. For this complex, the oxidation state of +IV could be assigned. Moreover, a series of isostructural uranium(IV) complexes was prepared. The influence of different ligands according to the spectrochemical series on the electronic and magnetic properties could be shown using UV/vis/NIR spectroscopy and variable temperature SQUID measurements. Calculations of uranium LIII XANES spectra show a variation in the shape of the spectra and thus high resolution PFY-XANES would be a great tool to determine the electronic influence of these different axial ligands. Using the single N-anchored ligand system, the first example of a uranium(IV)

  16. Immobilization of antimony in waste-to-energy bottom ash by addition of calcium and iron containing additives.

    Science.gov (United States)

    Van Caneghem, Jo; Verbinnen, Bram; Cornelis, Geert; de Wijs, Joost; Mulder, Rob; Billen, Pieter; Vandecasteele, Carlo

    2016-08-01

    The leaching of Sb from waste-to-energy (WtE) bottom ash (BA) often exceeds the Dutch limit value of 0.32mgkg(-1) for recycling of BA in open construction applications. From the immobilization mechanisms described in the literature, it could be concluded that both Ca and Fe play an important role in the immobilization of Sb in WtE BA. Therefore, Ca and Fe containing compounds were added to the samples of the sand fraction of WtE BA, which in contrast to the granulate fraction is not recyclable to date, and the effect on the Sb leaching was studied by means of batch leaching tests. Results showed that addition of 0.5 and 2.5% CaO, 5% CaCl2, 2.5% Fe2(SO4)3 and 1% FeCl3 decreased the Sb leaching from 0.62±0.02mgkgDM(-1) to 0.20±0.02, 0.083±0.044, 0.25±0.01, 0.27±0.002 and 0.29±0.02mgkgDM(-1), respectively. Due to the increase in pH from 11.41 to 12.53 when 2.5% CaO was added, Pb and Zn leaching increased and exceeded the respective leaching limits. Addition of 5% CaCO3 had almost no effect on the Sb leaching, as evidenced by the resulting 0.53mgkgDM(-1) leaching concentration. This paper shows a complementary enhancement of the effect of Ca and Fe, by comparing the aforementioned Sb leaching results with those of WtE BA with combined addition of 2.5% CaO or 5% CaCl2 with 2.5% Fe2(SO4)3 or 1% FeCl3. These lab scale results suggest that formation of romeites with a high Ca content and formation of iron antimonate (tripuhyite) with a very low solubility are the main immobilization mechanisms of Sb in WtE BA. Besides the pure compounds and their mixtures, also addition of 10% of two Ca and Fe containing residues of the steel industry, hereafter referred to as R1 and R2, was effective in decreasing the Sb leaching from WtE BA below the Dutch limit value for reuse in open construction applications. To evaluate the long term effect of the additives, pilot plots of WtE BA with 10% of R1 and 5% and 10% of R2 were built and samples were submitted to leaching tests at

  17. Ligand influences on properties of uranium coordination complexes. Structure, reactivity, and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kosog, Boris

    2012-11-02

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [(({sup R}ArO){sub 3}tacn)U{sup V}(O)] and [(({sup R}ArO){sub 3}tacn)U{sup V}(NSiMe{sub 3})] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [(({sup R}ArO){sub 3}tacn)U{sup VI}(O)]SbF{sub 6} and [(({sup R}ArO){sub 3}tacn)U{sup VI}(NSiMe{sub 3})]SbF{sub 6}. While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influence, normal axial coordination is observed for the Ad-derivative and both imido complexes. The inverse trans-influence was thus proven to be a key factor for the coordination mode of a terminal ligand on high valent uranium complexes. L{sub III} XANES was shown to be a great tool for the determination of oxidation states of uranium complexes. Therefore, a series of uranium complexes in all stable oxidation states for uranium, +III to +VI was prepared, and their spectra analyzed. All compounds bear only O-donor ligands in addition to the chlating trisaryloxide-tacn-ligand. A separation of 1.5 to 3 eV in the white line energy is observed between the different oxidation states. This series can be used as reference for compounds, where oxidation state assignment is not obvious, such as a ketyl radical complex [(({sup t-Bu}Ar)O{sub 3}tacn)U(O-C({sup t-Bu}Ph){sub 2}{sup .-})]. For this complex, the oxidation state of +IV could be assigned. Moreover, a series of isostructural uranium(IV) complexes was prepared. The influence of different ligands according to the spectrochemical series on the electronic and magnetic properties could be shown using UV/vis/NIR spectroscopy and variable temperature SQUID measurements. Calculations of uranium L{sub III} XANES spectra show a variation in the shape of the spectra and thus high resolution PFY-XANES would be a great tool to determine the electronic

  18. 高铅铜阳极泥的工艺矿物学

    Institute of Scientific and Technical Information of China (English)

    杨洪英; 李雪娇; 佟琳琳; 陈国宝

    2014-01-01

    In order to improve the technology of the process of noble metal extracted from high lead copper anode slime, the process mineralogy was investigated by XRD, SEM and microscope. The particle size of high lead anode slime is small, and the composition is complex. The main noble metals are Au 0.33%, Ag 9.94%and Pd 0.1%(mass fraction), and the main base metals are Cu 16.35%and Pb 13.74%. The chief phases include Au and gold­lead alloy, eukairite, sulfate, arsenate, antimonate and oxygen. The results show that there are two main phases of gold as elemental gold and gold­lead alloy with the mass ratio of approximately 3:1. The particle size is uneven, the biggest particle size is about 15μm and the smallest one is about 0.1μm. The elemental Au is often wrapped in copper sulfate, so, Cu should be removal before extracting Au. Ag exists in silver selenide and eukairite. Three elements are miscible and form a solid solution. Cu and Pb are major base metal. Cu exists in Cu, copper sulphate, eukairite and chalcopyrite. Pb exists in lead sulfate, lead antimonite, lead arsenate and lead sulphide. Arsenic antimony bismuth compounds mainly include lead antimonite, bismuth arsenate and antimony arsenate. The characteristics of the structure indicates that bought­out anode slime structured on copper sulphate, nickel oxide constantly wrapped copper, antimony arsenate constantly wrapped chalcopyrite, barium sulfate and lead sulfate constantly growed interactively.%为了高效回收高铅铜阳极泥中贵金属,改进阳极泥的现行生产工艺,采用XRD、SEM和显微镜等对阳极泥进行工艺矿物学研究。结果表明:阳极泥的颗粒较细,成分复杂,贵金属主要为Au 0.33%、Ag 9.94%、Pd 0.1%(质量分数);贱金属主要为Cu 16.35%、Pb 13.74%。主要物相包括金以及金铅合金、铜银硒化合物、硫酸盐、砷酸盐、锑酸盐以及氧化物。分析得知,金主要有单质金以及金铅合金两种