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Sample records for thiourea-formaldehyde chelating resin

  1. Assessment of water-soluble thiourea-formaldehyde (WTF) resin for stabilization/solidification (S/S) of heavy metal contaminated soils.

    Science.gov (United States)

    Liu, She-Jiang; Jiang, Jia-Yu; Wang, Shen; Guo, Yu-Peng; Ding, Hui

    2018-03-15

    Stabilization/Solidification (S/S) can be regarded as necessary for remediation of heavy metal contaminated soil. There is, however, solid agent is not very convenient to use. Water-soluble thiourea-formaldehyde (WTF) is a novel chelating agent, which has more practical applications. The process of WTF resin for S/S process of heavy metal contaminated soils was studied. Laboratory-prepared slurries, made of field soils spiked with Cd 2+ and Cr 6+ were treated with WTF resin. The toxicity characteristic leaching procedure (TCLP) showed that with 2 wt% WTF, in the neutral condition of soil after treatment for 7 d, the leaching concentrations of Cd 2+ and Cr 6+ in contaminated soil were decreased by 80.3% and 92.6% respectively. Moreover, Tessier sequence extraction procedure showed WTF resin reduced the leaching concentration by transforming heavy metal from exchange form to organic form. The structure of WTF is obtained according to elemental analysis result and reaction mechanism. Through analysis of the infrared spectrogram of WTF and WTF heavy mental chelating precipitation, WTF can form stable chelate with heavy mental through coordination. The significant groups are hydroxyl, nitrogen and sulphur function groups in WTF mainly. Toxicology test revealed that the WTF resin is nontoxic to microorganism in the soils. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Kinetic study of ion exchange in phosphoric acid chelating resin

    International Nuclear Information System (INIS)

    Brikci-Nigassa, Mounir; Hamouche, Hafida

    1995-11-01

    Uranium may be recovered as a by product of wet phosphoric acid using a method based on specific ion exchange resins. These resins called chelates contain amino-phosphonic functional groups. The resin studied in this work is a purolite S-940; uranium may be loaded on this resin from 30% P2O5 phosphoric acid in its reduced state. The influence of different parameters on the successive steps of the process have been studied in batch experiments: uranium reduction, loading and oxydation. Uranium may be eluted with ammonium carbonate and the resin regeneration may be done with hydrochloric acid.Ferric ions reduce the effective resin capacity considerably and inert fixation conditions are proposed to enhance uranium loading

  3. Selective separation of indium by iminodiacetic acid chelating resin

    International Nuclear Information System (INIS)

    Fortes, M.C.B.; Benedetto, J.S.; Martins, A.H.

    2007-01-01

    - Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite R IRC748 (Rohm and Haas Co.-USA). High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite R IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5 mol/dm 3 sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite R IRC748. (author)

  4. Removal of cadmium from fish sauce using chelate resin.

    Science.gov (United States)

    Sasaki, Tetsuya; Araki, Ryohei; Michihata, Toshihide; Kozawa, Miyuki; Tokuda, Koji; Koyanagi, Takashi; Enomoto, Toshiki

    2015-04-15

    Fish sauce that is prepared from squid organs contains cadmium (Cd), which may be present at hazardous concentrations. Cd molecules are predominantly protein bound in freshly manufactured fish sauce, but are present in a liberated form in air-exposed fish sauce. In the present study, we developed a new method for removing both Cd forms from fish sauce using chelate resin and a previously reported tannin treatment. Sixteen-fold decreases in Cd concentrations were observed (0.78-0.05 mg/100 mL) following the removal of liberated Cd using chelate resin treatment, and the removal of protein-bound Cd using tannin treatment. Major nutritional components of fish sauce were maintained, including free amino acids and peptides, and angiotensin I-converting enzyme inhibitory and antioxidant activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Chelating ion exchange with macroreticular hydroxamic acid resins

    International Nuclear Information System (INIS)

    Phillips, R.J.

    1980-01-01

    The synthesis, reactions, and analytical applications of hydroxamic acids, including chelating resins with this functional group, are reviewed. A procedure for attaching N-phenyl hydroxamic acid groups to Amberlite XAD-4 is described. The extraction of 20 metal ions from 2 M hydrochloric acid by this resin is discussed. Conditions for the quantitative extraction and back-extraction of 9 ions are reported. Results are compared with work on solvent extraction with N-phenylbenzohydroxamic acid. Procedures for attaching N-methyl and N-unsubstituted hydroxamic acid groups to Amberlite XAD-4 are described. The N-phenyl, N-methyl, and N-unsubstituted hydroxamic acid resins are compared with respect to metal-ion complexation. The scope of applications for hydroxamic acid resins is investigated by studying the extraction of 19 metal ions as a function of pH. The resins are especially suitable for the extraction of zirconium(IV), titanium(IV), and uranium(IV) from strongly acidic solution. Aluminum(III) is separated from calcium and phosphate by extraction at pH 4. The use of the resins for the purification of reagents, concentration of trace constituents, and chromatographic separation is demonstrated

  6. Resinas quelantes amidoxímicas Amidoxime chelating resins

    Directory of Open Access Journals (Sweden)

    Fernanda M. B. Coutinho

    1999-12-01

    Full Text Available Resinas quelantes com grupos amidoxima foram sintetizadas por copolimerização em suspensão de acrilonitrila (AN e divinilbenzeno (DVB e subsequente modificação química dos grupos ciano por reação com hidroxilamina. Na copolimerização, a proporção de divinilbenzeno e o grau de diluição foram variados. Gelatina e carbonato de cálcio foram usados como estabilizadores de suspensão e sulfato de sódio foi adicionado para reduzir a solubilidade da acrilonitrila em água, por meio do efeito salting out. Os copolímeros de AN/DVB e as resinas amidoxímicas obtidos foram caracterizados por meio de densidade aparente, área específica, volume de poros e teor de nitrogênio. As resinas amidoxímicas foram também avaliadas em relação a capacidade de complexação de íons cobre.Chelating resins with amidoxime groups were synthesized by suspension copolymerization of acrylonitrile (AN and divinylbenzene (DVB and subsequent chemical modification of cyano groups by reaction with hydroxylamine. In the copolymerization, the proportion of divinylbenzene and the dilution degree were varied. Gelatin and calcium carbonate were used as suspension stabilizers and sodium sulphate was added in order to reduce acrylonitrile solubility in water, by salting out effect. The AN/DVB copolymers and amidoxime resins obtained were characterized by apparent density, surface area, pore volume and by the content of nitrogen. The amidoxime resins were also evaluated in relation to the complexation capacity of copper ion.

  7. Preparation of novel polyamine-type chelating resin with hyperbranched structures and its adsorption performance

    Science.gov (United States)

    Zhao, Wei; Wang, Huan; Li, Yuhong; Li, Chenxi

    2018-01-01

    This paper explored the method of combining atom transfer radical polymerization (ATRP) technology and hyperbranched polymer principle to prepare the high capacity chelating resin. First, surface-initiated atom transfer radical polymerization (SI-ATRP) method was used to graft glycidyl methacrylate (GMA) on chloromethylated cross-linked styrene-divinylbenzene resin, and then the novel polyamine chelating resin with a kind of hyperbranched structure was prepared through the amination reaction between amino group of (2-aminoethyl) triamine and epoxy group in GMA. This resin had a selective effect on As(V) and Cr(VI) at a relatively low pH and can be used for the disposal of waste water containing As(V) and Cr(VI). It had a relatively strong adsorption effect on Cu(II), Pb(II), Cd(II) and Cr(III) and can be used for the disposal of heavy metal ion waste water. The finding was that, the adsorption capacity of resin on the studied heavy metal ions was higher than that of the chelating resin synthesized by traditional technology and also higher than that of the resin modified by ATRP technology and bifunctional chelator, indicating that the combination of ATRP and hyperbranched polymer concept is an effective method to prepare chelating resin with high capacity. PMID:29515875

  8. Preparation of novel polyamine-type chelating resin with hyperbranched structures and its adsorption performance

    Science.gov (United States)

    Chen, Youning; Zhao, Wei; Wang, Huan; Li, Yuhong; Li, Chenxi

    2018-02-01

    This paper explored the method of combining atom transfer radical polymerization (ATRP) technology and hyperbranched polymer principle to prepare the high capacity chelating resin. First, surface-initiated atom transfer radical polymerization (SI-ATRP) method was used to graft glycidyl methacrylate (GMA) on chloromethylated cross-linked styrene-divinylbenzene resin, and then the novel polyamine chelating resin with a kind of hyperbranched structure was prepared through the amination reaction between amino group of (2-aminoethyl) triamine and epoxy group in GMA. This resin had a selective effect on As(V) and Cr(VI) at a relatively low pH and can be used for the disposal of waste water containing As(V) and Cr(VI). It had a relatively strong adsorption effect on Cu(II), Pb(II), Cd(II) and Cr(III) and can be used for the disposal of heavy metal ion waste water. The finding was that, the adsorption capacity of resin on the studied heavy metal ions was higher than that of the chelating resin synthesized by traditional technology and also higher than that of the resin modified by ATRP technology and bifunctional chelator, indicating that the combination of ATRP and hyperbranched polymer concept is an effective method to prepare chelating resin with high capacity.

  9. STUDY ON THE KINETICS OF POLYMERIZATION OF MMA BY COPPER(Ⅱ) CHELATING RESINS

    Institute of Scientific and Technical Information of China (English)

    WangHongzuo; JiangYuanzhang; 等

    1993-01-01

    The polymerization of MMA initiated by copper(Ⅱ) chelating resins/CCl4 system was studied.From the kinetic data,the kinetic equation of polymerization can be expressed as Rp=Ke-56400/RT[MMA]1.57[CCl4]m[RESIN-Cu]0.18 where m:3-4.5,when[CCl4] 0.1-6.93M.The free radical polymerization mechanism is proposed.The primary radicals are formed by the process of complexation-chlorine transformation among the copper(Ⅱ) chelating resin,CCl4 and methacrylate.

  10. Isotopic measurement of uranium using NP-type chelate resin beads

    International Nuclear Information System (INIS)

    Wu Lanbi; Chen Wenpo; Wang Shijun

    1994-08-01

    NP-type chelate resin beads is used as a carrier of samples in the isotopic measurements of uranium by mass spectrometry. The results show that its absorption efficiency for uranium can be greater than 50%. It is one order magnitude higher than that strong basic anion resin, however, the ionization efficiencies of both are almost the same. Therefore, the amount of uranium required for isotopic analysis can be reduced one order of magnitude. This method has been used for isotopic analysis of uranium in NP-type chelate resin beads contained 10 -9 ∼ 10 -7 g uranium. For standard sample UTB-500, the external precision of measurements are within +-0.2%, for natural uranium samples are within +- 0.5%. The application of NP-type chelate resin beads in the isotopic measurement of uranium is a new creative achievement. It has been used in the depletion test of uranium-atomic vapor laser isotope separation

  11. Functionalized dithiocarbamate chelating resin for the removal of Co2+ from simulated wastewater

    Science.gov (United States)

    Shi, Xuewei; Fu, Linwei; Wu, Yanyang; Zhao, Huiling; Zhao, Shuangliang; Xu, Shouhong

    2017-12-01

    Industrial wastewater that contains trace amounts of heavy metal ions is often seen in petrochemical industry. While this wastewater can not be directly discharged, it is difficult to treat due to the low concentration of metal ions. Introducing chelating reagents into this wastewater for selective ion adsorption, followed by a mechanical separation process, provides an appealing solution. Toward the success of this technology, the development of effective chelating resins is of key importance. In the present work, a chelating resin containing amino and dithiocarbamate groups was reported for the removal of Co(II) metal ions in trace concentrations from simulated wastewater. By investigating the adsorption performance of the chelating resin at different solution pH values, adsorbent dosages, contact time, initial ion concentrations, and adsorption temperatures, the maximum adsorption capacity of the resin for Co(II) was identified to be 24.89 mg g-1 for a 2 g L-1 adsorbent dosage and a pH value of 5. After four adsorption-desorption cycles, 97% of the adsorption capacity of the resin was maintained. The adsorption kinetics and thermodynamics were analyzed and discussed as well.

  12. Effect of the Alkyl Chain Length on the Adsorption Properties of Malonamide Chelating Resins

    International Nuclear Information System (INIS)

    Ismail, I.M.; Nogami, M.; Suzuki, K.

    2004-01-01

    In order to investigate the effect of the alkyl chain length of malonamide chelating resins on the rate of uptake of U(VI) ions and Ce(III) Ions, lV,N,N',N'-tetraethyl malonamide (TEMA), N,N,N',N'-tetra-n-propyl malonamide (TPrMA), lV,lV,N',N'-tetra-n-butyl malonamide (TBMA) and N,l V,N',N'-tetra-n-pentyl malonamide (Tamp) chelating resins were synthesized by chemically bonding these function groups to CMS-DVB co-polymer beads. N,lV,N',N'-tetraphenyl malonamide (TPhMA) chelating resin was also investigated and the results of these resins were compared with those of N,lY,N',N-tetra methylmalonamide (TMMA) previously reported. The batch technique was used to study the thermodynamic equilibrium, in terms of distribution coefficient, and the kinetics of the adsorption U(VI) and Ce(III) ions from 3 M HNO 3 , Acid, and 3 M NaNO 3 + 0.05 M HNO 3 , Salt, media. The introduction ratio of the function group into the polymer base and the uptake of U(VI) ions and C(III) ions were found to decrease with the increase in the alkyl chain length. The uptake was found to diminish in case of TPhMA resin due to the decrease of the function group ratio and the steric-hinder effect

  13. Chromatography of metal ions with a triazine chelating resin

    International Nuclear Information System (INIS)

    Wang, W.N.

    1979-05-01

    The synthesis, characterization, and some analytical applications of a new triazine resin are described. Separation of group IB, IIB, VIB, and VIIB metal ions from group VIII metal ions is achieved by this PDT-4 resin. Calcium(II) and magnesium(II) are taken up at pH = 6, 0.1 M acetate and are eluted at pH = 6, 0.1 M sodium nitrate. Copper(II) is retained at pH = 6, 0.1 M acetate and pH = 1 hydrochloric acid and is eluted subsequently by 5 M perchloric acid. Molybdenum(VI) is sorbed selectively from 0.1 N sulfuric acid or hydrochloric acid and is eluted in a tight band by 0.1 N sodium hydroxide. Numerous rapid column chromatographic separations are reported using this new resin, including analysis of NBS standard samples

  14. Arsenic Removal from Pinctada martensii Enzymatic Hydrolysate by Using Zr(Ⅳ)-Loaded Chelating Resin

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoman; DAI Wenjin; SUN Huili; PAN Jianyu

    2013-01-01

    The present study investigated the removal of inorganic arsenic from Pinctada martensii enzymatic hydrolysate through unmodified resin (D296) and Zr(Ⅳ)-loaded chelating resin (Zr-D401).By loading Zr to macroporous chelating resin D401,the as exchange adsorption active sites are generated.This transforms D401 from a material that does not have the arsenic adsorption capacity into a material that has excellent arsenic exchange adsorption capacity.The static adsorption experiments were conducted to investigate the optimal removal condition for D296 and Zr-D401.The experimental results show that:the optimum condition for D296 is that T=25℃,pH=5,resin additive amount=1 g(50mL)-1,and contact time=10h,the corresponding arsenic removal rate being 65.7%,and protein loss being 2.33%; the optimum condition for Zr-D401 is that T=25 ℃,pH=8,resin additive amount=1 g (50 mL)-1,and contact time=10 h,the corresponding arsenic removal rate being 70.3%,and protein loss being 4.65%.These results show that both of the two resins are effective in arsenic removal for preserving useful substance.Our research provides scientific evidence and advances in the processing technology for heavy metal removal in shellfish.

  15. Separation and recovery of uranium ore by chlorinating, chelate resin and molten salt treatment

    International Nuclear Information System (INIS)

    Taki, Tomohiro

    2000-12-01

    Three fundamental researches of separation and recovery of uranium from uranium ore are reported in this paper. Three methods used the chloride pyrometallurgy, sodium containing molten salts and chelate resin. When uranium ore is mixed with activated carbon and reacted for one hour under the mixed gas of chlorine and oxygen at 950 C, more than 90% uranium volatilized and vaporization of aluminum, silicone and phosphorus were controlled. The best activated carbon was brown coal because it was able to control the large range of oxygen concentration. By blowing oxygen into the molten sodium hydroxide, the elution rate of uranium attained to about 95% and a few percent of uranium was remained in the residue. On the uranium ore of unconformity-related uranium deposits, a separation method of uranium, molybdenum, nickel and phosphorus from the sulfuric acid elusion solution with U, Ni, As, Mo, Fe and Al was developed. Methylene phosphonic acid type chelate resin (RCSP) adsorbed Mo and U, and then 100 % Mo was eluted by sodium acetate solution and about 100% U by sodium carbonate solution. Ni and As in the passing solution were recovered by imino-diacetic acid type chelate resin and iron hydroxide, respectively. (S.Y.)

  16. Chelation Ion Exchange Properties of 2, 4-Dihydroxyacetophenone-Biuret-Formaldehyde Terpolymer Resin

    Directory of Open Access Journals (Sweden)

    Sanjiokumar S. Rahangdale

    2009-01-01

    Full Text Available The terpolymer resin 2, 4-HABF has been synthesized by the condensation of 2, 4-dihydroxyacetophenone (2, 4-HA and biuret (B with formaldehyde (F in 1:1:2 molar ratios in presence of 2 M hydrochloric acid as catalyst. UV-Visible, IR and proton NMR spectral studies have been carried out to elucidate the structure of the resin. A terpolymer (2, 4-HABF proved to be a selective chelating ion exchange polymer for certain metals. Chelating ion-exchange properties of this polymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The polymer showed highest selectivity for Fe3+, Cu2+ ions than for Ni2+, Co2+, Zn2+, Cd2+, and Pb2+ ions. Study of distribution ratio as a formation of pH indicates that the amount of metal ion taken by resin is increases with the increasing pH of the medium.

  17. Kinetics of ion exchange in the chelating resin Dowex A-1

    International Nuclear Information System (INIS)

    Matsuzuru, Hideo; Wadachi, Yoshiki

    1975-01-01

    The kinetics of ion exchanges of Ag + , Zn 2+ and Cr 3+ at extremely low concentrations on the chelating resin Dowex A-1 has been studied by means of finite volume method. The rate of exchanges for both Ag + and Zn 2+ is dependent on the ionic strength, particle size of the resin and reaction temperature. At higher ionic strength (0.1 - 0.05) the kinetics is controlled by particle diffusion, whereas at lower ionic one (0.01 - 0.001) film diffusion is predominant. The apparent activation energy obtained is 3.84 kcal/mol for Ag + and 3.91 kcal/mol for Zn 2+ . The exchange rate of Cr 3+ obeys a first-order rate equation independent of the ionic strength and particle size of the resin. The apparent activation energy is 15.5 kcal/mol. These results support the view that the rate-determining step of this reaction is chelate formation reaction. (auth.)

  18. Evaluation of extractants and chelating resins in polishing actinide-contaminated waste streams

    International Nuclear Information System (INIS)

    Schreiber, S.B.; Dunn, S.L.; Yarbro, S.L.

    1991-06-01

    At the Los Alamos National Laboratory Plutonium Facility, anion exchange is used for recovering plutonium from nitric acid solutions. Although this approach recovers >99%, the trace amounts of plutonium and other actinides remaining in the effluent require additional processing. We are doing research to develop a secondary unit operation that can directly polish the effluent so that actinide levels are reduced to below the maximum allowed for facility discharge. We selected solvent extraction, the only unit operation that can meet the stringent process requirements imposed; several carbonyl and phosphoryl extractants were evaluated and their performance characterized. We also investigated various engineering approaches for solvent extraction; the most promising was a chelating resin loaded with extractant. Our research now focuses on the synthesis of malonamides, and our goal is to bond these extractants to a resin matrix. 7 refs., 12 figs., 1 tab

  19. Adsorption equilibrium of uranium from seawater on chelating resin containing amide oxime group

    International Nuclear Information System (INIS)

    Hori, Takahiro; Saito, Kyoichi; Furusaki, Shintaro; Sugo, Takanobu; Okamoto, Jiro.

    1987-01-01

    Chelating resins containing amide oxime group were synthesized by radiation-induced graft polymerization. The amount of the amide oxime groups was controlled below about 0.1 mol per kg of base polymer. The adsorption equilibrium of uranium from seawater on this resin was investigated. It was suggested that two neighboring amide oxime groups on the grafted chain captured one uranyl ion, and that single amide oxime ligand had little capacity for the adsorption of uranium. The adsorption equilibrium was correlated by a Langmuir-type equation. The content of neighboring amide oxime groups was 0.406 x 10 -3 mol per kg of base polymer, which corresponded to 0.39 % of the total amount of amide oxime groups. The apparent stoichiometric stability constant for the complex of uranyl ion with the neighboring amide oxime groups in seawater was calculated to be 10 -21.7 . (author)

  20. Synthesis of a chelate resin with amido and phosphoric acid and its character in uranium extraction

    International Nuclear Information System (INIS)

    Qiu Yueshuang; Zhang Jianguo; Feng Yu; Zhao Chaoya

    2013-01-01

    A chelate resin (D814) with amido and phosphoric acid functional group was synthetized by means of the reactions of stytene-divinyl benzene chloromethylated sphere with ethylenedianmine and orth-phosphorous acid and formaldehyde. This resin can be used to adsorb uranium from leaching solution with high chloride ion in the rang of pH l.33-9.05, and the adsorption rate of uranium was above 95%. D814 resin had a good ability resistant to high chloride ion. The loading capacity for uranium was not apparently effected when chlorid ion concentration in solution was 60 g/L. The results of the adsorption experiment show that when the ratio of saturation volume to breakthrough volume was l.82, the uranium saturation capacity of D814 was 40.5 mg/g dry resin. NaCl + NaHCO 3 was used for eluting agent, and the eluting rate of uranium was 96.7%. Adsorption uranium mechanism by D814 was also discussed. (authors)

  1. Novel chelating resin with cyanoguanidine group: Useful recyclable materials for Hg(II) removal in aqueous environment

    International Nuclear Information System (INIS)

    Ma Xiaojie; Li Yanfeng; Ye Zhengfang; Yang Liuqing; Zhou Lincheng; Wang Liyuan

    2011-01-01

    A novel chelating resin containing cyanoguanidine moiety has been successfully prepared by the functionalizing reaction of a macroporous bead based on chloromethylated copolymer of styrene-divinylbenzene (CMPS) with dicyandiamide (DCDA) in the presence of phase transfer catalyst. The Fourier transform-infrared spectra (FT-IR) and scanning electron microscopy (SEM) were employed in the characterization of the resulting chelating resin, meanwhile, the adsorption properties of the resin for Hg(II) were investigated by batch and column methods. The results indicated that the resin displayed a marked advantage in Hg(II) binding capacity, and the saturated adsorption capacity estimated from the Langmuir model was dramatically up to 1077 mg g -1 at 45 deg. C. Furthermore, it was found that the resin was able to selectively separate Hg(II) from multicomponent solutions with Zn(II), Cu(II), Pb(II) and Mg(II). The desorption process of Hg(II) was tested with different eluents and the ratio of the highest recovery reached to 96% under eluting condition of 1 M HCl + 10% thiourea. Consequently, the resulting chelating resin would provide a potential application for treatment process of Hg(II) containing wastewater.

  2. Uranium(VI) adsorption properties of a chelating resin containing polyamine-substituted methylphosphonic acid moiety

    International Nuclear Information System (INIS)

    Matsuda, Masaaki; Akiyoshi, Yoshirou

    1991-01-01

    Uranium(VI) adsorption and desorption properties of a chelating resin containing polyamine-substituted methylphosphonic acid moiety of 2.29 mmol/g-resin (APA) were examined. Uranium(VI) adsorption properties of several ion exchange resins and extractant agents which were known as excellent adsorbents for uranium(VI), were examined together for a comparison with those of APA. Uranium(VI) adsorption capacity of APA at the concentration of 100 mg·dm -3 -uranium(VI) in 100 g·dm -3 -H 2 SO 4 aq. soln., 190 g·dm -3 -H 3 PO 4 aq. soln. and uranium enriched sea water, was 0.2, 0.05 and 0.05 mmol·g -1 respectively. The adsorption capacity of APA for uranium(VI) in these solutions was larger than that of another adsorbents, except the adsorption of uranium(VI) in enriched sea water on ion exchange resin containing phosphoric acid moiety (adsorption capacity ; 0.2 mmol·g -1 ). Uranium(VI) adsorption rate on APA was high and the relation between treatment time (t : min) and uranium(VI) concentration (y : mg·dm -3 ) in 100 g·dm -3 H 2 SO 4 aq. soln. after treatment, was shown as following equation, y=20 0.048t+1.90 (0≤t≤30). The adsorbed uranium(VI) on APA was able to be eluted with a mixed aq. soln. of hydrogen peroxide and sodium hydroxide and also was able to be eluted with an aq. alkaline soln. dissolved reduction agents such as sodium sulfite and hydrazine. From these results, it was thought that uranium(VI) adsorbed on APA was eluted due to the reduction to uranium(VI) by these eluents. (author)

  3. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    International Nuclear Information System (INIS)

    Wilkie, Emma M.; Roach, Anthony C.; Micevska, Tina; Kelaher, Brendan P.; Bishop, Melanie J.

    2010-01-01

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300 TM in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  4. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Wilkie, Emma M., E-mail: ewilkie@bio.mq.edu.a [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia); Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Roach, Anthony C. [Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Micevska, Tina [Centre for Environmental Contaminants Research, CSIRO Land and Water, Menai, NSW 2234 (Australia); Kelaher, Brendan P.; Bishop, Melanie J. [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia)

    2010-05-15

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300{sup TM} in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  5. Adsorption characteristics of 14C-labeled alanine, aspartic acid and adenosine triphosphate by metal-chelating resins

    International Nuclear Information System (INIS)

    Ishiyama, Toshio; Matsunami, Tadao; Shibata, Setsuko; Honda, Yoshihide.

    1987-01-01

    (1) Adsorption properties of 14 C-alanine, 14 C-ATP (adenosine triphosphate) and 14 C-aspartic acid on the metal-chelating resins were determined and found that the Cu(II)-Chelex 100 and Fe(III)-Unicellex UR10, Fe(III)-Chelex 100 chelating resins were highly effective for the adsorption of 14 C-alanine and 14 C-ATP, respectively. (2) Desorption rate of 14 C-ATP from the Fe(III)-Unicellex UR10 and Fe(III)-Chelex 100 resins was somewhat higher than the case of 14 C-alanine, probably because the coordination bonds of Cu-alanine might be stronger than those of Fe-ATP. Thus, 14 C-labeled organic compounds such as 14 C-alanine and 14 C-ATP of a low activity concentration (3.7 mBq/ml) (1 x 10 -7 μCi/ml) in aqueous solution may be measured with liquid scintillation counter after pre-concentration by use of the Fe(III)- and Cu(II)-chelating resin columns. (author)

  6. Determination of trace elements in seawater by air-flow injection/ICP-MS with chelating resin preconcentration

    International Nuclear Information System (INIS)

    Lee, Kyue-Hyung; Ohshima, Mitsuko; Motomizu, Shoji

    2002-01-01

    Multielement determination of major to trace metals in a deep seawater malt was accomplished by inductively coupled plasma-mass spectrometry (ICP-MS) together with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Major elements, such as Na, K, Mg, and Ca, were measured by ICP-AES and normal continuos nebulization ICP-MS after sample dilution by 10 3 -10 6 fold. Fifteen trace elements in the concentrated metal solutions pretreated with cation-exchange resin or chelating resin could be simultaneously determined by air-flow injection/ICP-mass spectrometry (AFI/ICP-MS). Since the injection volume for AFI/ICP-MS was 25 μl, final samples volumes less than 500 μl were enough for several replicate measurements. Three different preconcentration methods assisted with AFI/ICP-MS were examined and could be successfully applied to a deep seawater malt. The analytical results of rate earth elements (REEs) and Co, Ni, Cu, Zn, Cd, and Pb obtained by AFI/ICP-MS coupled with disk filtration method using iminodiacetate (IDA)-type chelating resin were favorably agreed with the data obtained by AFI/ICP-MS coupled with column preconcentration method using chitosan-based chelating resin. (author)

  7. Evaluation and improvement of gamma-ray stability of chelating resins containing oxy-acid groups of phosphorus

    International Nuclear Information System (INIS)

    Jyo, Akinori; Yamabe, Kazunori; Shuto, Taketomi

    1998-01-01

    Chelating resins containing oxy-acid groups of phosphorus, such as phosphonic and phosphoric acid groups have been studied from the point of view of solvent extraction processes for the separation of nuclear fuel elements as well as of fission product ones. The present work was planned to evaluate the effect of gamma-ray on properties of the resins and to obtain directional information for design of the resins having high stability to gamma-ray. It was clarified that gamma-ray stability of the resins is not high; tolerance limit is ca. 2.3x10 3 C/kg. The present work also clarified that polymers crosslinked with divinylbenzene have much higher gamma-ray stability than ones crosslinked with dimetacrylate esters of oligo (ethylene glycol)s. (J.P.N.)

  8. Surface Engineering of PAMAM-SDB Chelating Resin with Diglycolamic Acid (DGA) Functional Group for Efficient Sorption of U(VI) and Th(IV) from Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Ilaiyaraja, P.; Venkatraman, B., E-mail: chemila07@gmail.com [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Deb, A.K. Singha [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India); Ponraju, D. [Safety Engineering Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Ali, Sk. Musharaf [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    2017-04-15

    Highlights: • A new DGA-PAMAM-SDB chelating resin has been synthesized for actinide sorption. • Maximum sorption capacities of resin are 682 and 544.2 mg g{sup −1}for U(VI) and Th(IV). • DGA-PAMAM-SDB chelating resin could be regenerated and reused. • DFT calculation of actinides interaction with resin corroborates the experimental. • Resin is effective for sorption of actinides from both aqueous and HNO{sub 3} medium. - Abstract: A novel chelating resin obtained via growth of PAMAM dendron on surface of styrene divinyl benzene resin beads, followed by diglycolamic acid functionalization of the dendrimer terminal. Batch experiments were conducted to study the effects of pH, nitric acid concentration, amount of adsorbent, shaking time, initial metal ion concentration and temperature on U(VI) and Th(IV) adsorption efficiency. Diglycolamic acid terminated PAMAM dendrimer functionalized styrene divinylbenzene chelating resin (DGA-PAMAM-SDB) is found to be an efficient candidate for the removal of U(VI) and Th(IV) ions from aqueous (pH > 4) and nitric acid media (> 3 M). The sorption equilibrium could be reached within 60 min, and the experimental data fits with pseudo-second-order model. Langmuir sorption isotherm model correlates well with sorption equilibrium data. The maximum U(VI) and Th(IV) sorption capacity onto DGA-PAMAMG{sub 5}-SDB was estimated to be about 682 and 544.2 mg g{sup −1} respectively at 25 °C. The interaction of actinides and chelating resin is reversible and hence, the resin can be regenerated and reused. DFT calculation on the interaction of U(VI) and Th(IV) ions with chelating resin validates the experimental findings.

  9. Enhanced phosphate selectivity from wastewater using copper-loaded chelating resin functionalized with polyethylenimine.

    Science.gov (United States)

    An, Byungryul; Nam, Juhee; Choi, Jae-Woo; Hong, Seok-Won; Lee, Sang-Hyup

    2013-11-01

    In water and wastewater, phosphate is considered a critical contaminant due to cause algae blooms and eutrophication. To meet the stringent regulation of phosphate in water, a new commercial chelating resin functionalized with polyethylenimine was tested for phosphate removal by loading Cu(2+) and Fe(2+)/Fe(3+) to enhance selectivity for phosphate. Batch and column experiments showed that CR20-Cu exhibited high selectivity for phosphate over other strong anions such as sulfate. The average binary phosphate/nitrate and phosphate/sulfate factors for CR20-Cu were calculated to be 7.3 and 4.8, respectively, which were more than 0.97 and 0.22 for a commercial anion exchanger (AMP16). The optimal pH for the phosphate removal efficiency was determined to be 7. According to the fixed-bed column test, the breakthrough sequence for multiple ions was HPO4(2-)>SO4(2-)>NO3(-)>Cl(-). Saturated CR20-Cu can be regenerated using 4% NaCl at pH 7. More than 95% of the phosphate from CR20-Cu was recovered, and the phosphate uptake capacity for CR20-Cu was not reduced after 7 regeneration cycles. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Selective Removal of Toxic Metals like Copper and Arsenic from Drinking Water Using Phenol-Formaldehyde Type Chelating Resins

    Directory of Open Access Journals (Sweden)

    Debasis Mohanty

    2009-01-01

    Full Text Available The concentration of different toxic metals has increased beyond environmentally and ecologically permissible levels due to the increase in industrial activity. More than 100 million people of Bangladesh and West Bengal in India are affected by drinking ground water contaminated with arsenic and some parts of India is also affected by poisoning effect of copper, cadmium and fluoride. Different methods have been evolved to reduce the arsenic concentration in drinking water to a maximum permissible level of 10 μg/L where as various methods are also available to separate copper from drinking water. Of the proven methods available today, removal of arsenic by polymeric ion exchangers has been most effective. While chelating ion exchange resins having specific chelating groups attached to a polymer have found extensive use in sorption and pre concentration of Cu2+ ions. Both the methods are coupled here to separate and preconcentrate toxic metal cation Cu2+ and metal anion arsenate(AsO4– at the same time. We have prepared a series of low-cost polymeric resins, which are very efficient in removing copper ion from drinking water and after coordinating with copper ion they act as polymeric ligand exchanger, which are efficiently removing arsenate from drinking water. For this purpose Schiff bases were prepared by condensing o-phenylenediamine with o-, m-, and p-hydroxybenzaldehydes. Condensing these phenolic Schiff bases with formaldehyde afforded the chelating resins in high yields. These resins are loaded with Cu2+, Ni2+ 2+, and Fe3+ ions. The resins and the polychelates are highly insoluble in water. In powdered form the metal ion-loaded resins are found to very efficiently remove arsenate ion from water at neutral pH. Resins loaded with optimum amount of Cu2+ ion is more effective in removing arsenate ions compared to those with Fe3+ ion, apparently because Cu2+ is a stronger Lewis acid than Fe3+. Various parameters influencing the removal of the

  11. Characterization of hydroxybenzoic acid chelating resins: equilibrium, kinetics, and isotherm profiles for Cd(II and Pb(II uptake

    Directory of Open Access Journals (Sweden)

    BHAVNA A. SHAH

    2011-06-01

    Full Text Available Chelating ion-exchange resins were synthesized by polycondensation of ortho/para hydroxybenzoic acid with resorcinol/catechol employing formaldehyde as cross-linking agent at 80±5 °C in DMF. The resins were characterized by FTIR and XRD. The uptake behaviour of synthesized resins for Cd(II and Pb(II ions have been studied depending on contact time, pH, metal ion concentration and temperature. The sorption data obtained at optimized conditions were analyzed by the Langmuir and Freundlich isotherms. Experimental data of all metal–resin system were best represented by the Freundlich isotherm. The maximum obtained sorption capacity for cadmium was 69.53 mg g-1 and 169.32 mg g-1 for Lead. The adsorption process follows first order kinetics and the specific rate constant Kr was obtained by the application of the Lagergan equation. Thermodynamic parameters ∆Gads, ∆Sads and ∆Hads were calculated for the metal–resin systems. The external diffusion rate constant (KS and the intra-particle diffusion rate constant (Kid were calculated by the Spahn–Schlunder and Weber–Morris models, respectively. The sorption process was found to follow an intra-particle diffusion phenomenon.

  12. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs

  13. Separation of Mn(II) in presence of Al(III) in acid drainage from an Uranium mine with the use of chelating resins

    International Nuclear Information System (INIS)

    Soares, Eliane Pavesi B.; Gomes, Viviane T.; Vaitsman, Delmo S.

    2011-01-01

    The acid drainage of Osamu Utsumi mine is the main environmental impact from mining activities in Pocos de Caldas - MG - Brazil. The water produced in this process is characterized by high acidity and heavy metal concentration. To minimize this environmental impact, new technologies directed towards treatment of acid drainage of mine (ADM) have been studied. However, due to the presence of Al 3+ (which has a high charge) in the ADM, these resins get quickly saturated, preventing stripping of divalent cations like Mn 2+ . This study proposes the synthesis of chelating resins that provide preferential retention of Mn 2+ instead of Al 3+ . It was synthesized resins functionalized with amidoxime and dithiocarbamate. The capacity of retention of Mn 2+ e Al 3+ ions at different pH values was assessed for each resin. The stripping of Mn 2+ at 2, 3 and 4 (pH ADM range) by studied resins was not preferential for Mn 2+ in relation to Al 3+ , probably due to the strong electrostatic interaction between this last type of high charge density and the active sites from extractor agents and resins. However at pH 6 (stated by environmental norms for liquid effluents discharge) the synthesized resins had a good retention capacity for Mn 2+ . So it is proposed that the extraction technique using chelating resins could be employed to strip Mn 2+ from ADM at pH 6,0, since at this condition , Al 3+ is precipitated as Al(OH) 3 . (author)

  14. Synthesis, characterization and ion- exchange study of poly[(2,4-dihydroxy benzophenone)butylene] resin and its poly chelates with transition metals

    International Nuclear Information System (INIS)

    Joshi, J. D.; Patel, N.B.; Patel, S. D.

    2006-01-01

    The polymeric ligand poly[(2,4-dihydroxy benzophenone)butylene] H(DHBP-BD) forms 1 :2 metal-ligand complexes with Ni(ll), Co(ll), Cu(ll) and Zn(ll). The polymeric ligand and its poly chelates were characterized on the basis of elemental analyses, magnetic susceptibilities, IR-spectroscopy, UV-visible spectra, NMR, thermogravimetric analyses. The molecular weight of resin was determined using number average molecular weight (M n ) by vapour pressure osmometry method. The stereochemistry in case of the Cu(ll) poly chelate is square-planar, tetrahedral for Zn(ll) and octahedral for Ni(ll) and Co(ll). The stereochemistry in each chelate is proposed on the basis of magnetic susceptibilities and electronic spectra. The IR spectra show that the bidentate ligand coordinates through the oxygen atom of the carbonyl and phenolic group with replacement of hydrogen by metal ions, respectively. All the chelates are paramagnetic in nature except the Zn(ll) chelate which is diamagnetic. The ion-exchange study of the prepared resin was checked by batch equilibration method with selected metal ions [Cu(ll), Ni(ll), Fe(lll) and UO 2 2+( VI)] at varying electrolyte concentration, pH and time. It is found that, resin can be used as an ion-exchanger

  15. Study on Selective Removal of Impurity Iron from Leached Copper-Bearing Solution Using a Chelating Resin

    Directory of Open Access Journals (Sweden)

    Yubiao Li

    2016-10-01

    Full Text Available In order to selectively remove iron from copper laden solution after leaching but prior to electrowinning, equilibrium, kinetic, and thermodynamic studies have been conducted on an a chelating resin of Rexp-501 at pH 1.0 and at various temperatures. Both Langmuir and Freundlich models were investigated, with the Langmuir model proving to be more suitable for fitting iron removal performance, with little influence from copper concentration. Compared with the pseudo first order kinetic model, the pseudo second order kinetic model fitted the dynamic adsorption process better, indicating a chemisorption mechanism. Fourier transform infrared spectroscopy (FT-IR results indicated that C=O from carbonyl group played a key role in combining with iron and can be regenerated and reused. However, the C=O of the acylamino group combining with iron was not able to be released after oxalic acid was applied.

  16. Study and application of new chelating resin to recovery uranium from in-situ leach solution with high content saline chloride ion

    International Nuclear Information System (INIS)

    Zhang Jianguo; Qiu Yueshuang; Feng Yu; Deng Huidong; Zhao Chaoya

    2014-01-01

    Research on the adsorption and elution property of D814 chelating resin was carried out aiming at the difficult separation of uranium from high content saline chloride ion in situ leach liquor and the adsorption mechanism is also discussed. Influence factors such as contact time, pH value, Ca"2"+, Mg"2"+ and Cl"- concentration etc. to the resin adsorption were studied. Experimental results show that adsorption rate is lowly which need 6h to arrive at the adsorption equilibrium. The resin adsorption uranium pH in the solution is from l.33 to 9. When total salinity is over 20 g/L, calcium ion, and magnesium ion is about 3 g/L, there are no big influence on resin adsorption capacity. The resin has good chloride ion resistance. When chloride ion is over 60 g/L, it is no influence on resin adsorption uranium. Column experiment results indicate that ratio of saturation volume to break-through point volume is l.82, resin saturation uranium capacity is 40.5 mg. U/_g_(_∓_)_R. When elution volume bed number is 23, the eluted solution uranium concentration is below 80 mg/L. The elution rate of the uranium is 96.2%. (authors)

  17. Multielement determination of trace elements in seawater by inductively coupled plasma mass spectrometry after tandem preconcentration with cooperation of chelating resin adsorption and lanthanum coprecipitation

    International Nuclear Information System (INIS)

    Yabutani, Tomoki; Chiba, Koichi; Haraguchi, Hiroki

    2001-01-01

    A tandem preconcentration method, in which chelating resin adsorption and La coprecipitation were cooperatively employed for preconcentration, was developed as a pretreatment method for simultaneous multielement determination of trace elements in seawater by ICP-MS. First, the seawater sample (250 ml) was treated with a chelating resin for preconcentration of trace elements, and then trace elements with good recoveries were determined by ICP-MS. Trace elements with the chemical properties of oxoanion- and hydride-formation, which were poorly recovered in the chelating resin preconcentration, were further subjected to preconcentration by La coprecipitation. As a result, more than 30 elements could be determined in the concentration range from 9.6 μg L -1 for Mo to 0.00018 μg L -1 for Tm, when the present tandem method was applied to the analysis of open seawater standard reference material (NASS-4). Furthermore, the analytical results for open seawater reference materials were compared with those for coastal seawater reference material as well as for coastal seawater collected in the Ise Bay. It was found that the multielement data for trace elements in these seawater samples clearly showed different elemental distributions, reflecting the different marine environments. (author)

  18. Determination of rare earth elements in seawater by ICP-MS after preconcentration with a chelating resin-packed minicolumn

    International Nuclear Information System (INIS)

    Zhu Yanbei; Itoh, Akihide; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki

    2006-01-01

    Rare earth elements (REEs) in seawater were preconcentrated 20-fold (from 50 to 2.5 ml) by a chelating resin-packed minicolumn device and determined by inductively coupled plasma mass spectrometry (ICP-MS). The recoveries for REEs were in the range from 90% for Eu and Dy to 98% for Yb, and their standard deviations were less than 4%. The lower detection limits for REEs ranged from 0.06 ng l -1 for Lu to 0.5 ng l -1 for Sm. The analytical results for REEs in seawater reference materials (NASS-5, CASS-3, and CASS-4), the Take Island coastal seawater, and the Ise Bay coastal seawater were evaluated as the REE distribution patterns with shale-normalization and deep seawater-normalization. Slight relative enrichments of heavy REEs were observed in the Take Island coastal seawater and the Ise Bay coastal seawater, which might be attributed to the input from the river flows containing more dissolved heavy REEs. In addition, positive anomalies of Sm were found in the normalized REE distribution patterns for NASS-5, CASS-3, and CASS-4, which would be attributed to the contamination in the preparation process of reference materials by NRC

  19. Chelating resin immobilizing carboxymethylated polyethyleneimine for selective solid-phase extraction of trace elements: Effect of the molecular weight of polyethyleneimine and its carboxymethylation rate.

    Science.gov (United States)

    Kagaya, Shigehiro; Kajiwara, Takehiro; Gemmei-Ide, Makoto; Kamichatani, Waka; Inoue, Yoshinori

    2016-01-15

    The effect of the molecular weight of polyethyleneimine (PEI), defined as a compound having two or more ethyleneamine units, and of its carboxymethylation rate (CM/N), represented by the ratio of ion-exchange capacity to the amount of N on the resin, on the selective solid-phase extraction ability of the chelating resin immobilizing carboxymethylated (CM) PEI was investigated. The chelating resins (24 types) were prepared by immobilization of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, PEI300 (MW=ca. 300), and PEI600 (MW=ca. 600) on methacrylate resins, followed by carboxymethylation with various amounts of sodium monochloroacetate. When resins with approximately the same CM/N ratio (0.242-0.271) were used, the recovery of Cd, Co, Cu, Fe, Ni, Pb, Ti, Zn, and alkaline earth elements increased with increasing the molecular weight of PEIs under acidic and weakly acidic conditions; however, the extraction behavior of Mo and V was only slightly affected. This was probably due to the increase in N content of the resin, resulting in an increase in carboxylic acid groups; the difference in the molecular weight of PEIs immobilized on the resin exerts an insignificant influence on the selective extraction ability. The CM/N ratio considerably affected the extraction behavior for various elements. Under acidic and neutral conditions, the recovery of Cd, Co, Cu, Fe, Ni, Pb, Ti, and Zn increased with increasing CM/N values. However, under these conditions, the recovery of alkaline earth elements was considerably low when a resin with low CM/N ratio was used. This is presumably attributed to the different stability constants of the complexes of these elements with aminocarboxylic acids and amines, and to the electrostatic repulsion between the elements and the protonated amino groups in the CM-PEI. The recovery of Mo and V decreased or varied with increasing CM/N values, suggesting that the extraction of these elements occurred mainly

  20. An off-line automated preconcentration system with ethylenediaminetriacetate chelating resin for the determination of trace metals in seawater by high-resolution inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Minami, Tomoharu; Konagaya, Wataru; Zheng, Linjie; Takano, Shotaro; Sasaki, Masanobu; Murata, Rena; Nakaguchi, Yuzuru; Sohrin, Yoshiki

    2015-01-07

    A novel automated off-line preconcentration system for trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) in seawater was developed by improving a commercially available solid-phase extraction system SPE-100 (Hiranuma Sangyo). The utilized chelating resin was NOBIAS Chelate-PA1 (Hitachi High-Technologies) with ethylenediaminetriacetic acid and iminodiacetic acid functional groups. Parts of the 8-way valve made of alumina and zirconia in the original SPE-100 system were replaced with parts made of polychlorotrifluoroethylene in order to reduce contamination of trace metals. The eluent pass was altered for the back flush elution of trace metals. We optimized the cleaning procedures for the chelating resin column and flow lines of the preconcentration system, and developed a preconcentration procedure, which required less labor and led to a superior performance compared to manual preconcentration (Sohrin et al.). The nine trace metals were simultaneously and quantitatively preconcentrated from ∼120 g of seawater, eluted with ∼15 g of 1M HNO3, and determined by HR-ICP-MS using the calibration curve method. The single-step preconcentration removed more than 99.998% of Na, K, Mg, Ca, and Sr from seawater. The procedural blanks and detection limits were lower than the lowest concentrations in seawater for Mn, Ni, Cu, and Pb, while they were as low as the lowest concentrations in seawater for Al, Fe, Co, Zn, and Cd. The accuracy and precision of this method were confirmed by the analysis of reference seawater samples (CASS-5, NASS-5, GEOTRACES GS, and GD) and seawater samples for vertical distribution in the western North Pacific Ocean. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Phosphorus-modified poly(styrene-co-divinylbenzene)–PAMAM chelating resin for the adsorption of uranium(VI) in aqueous

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qiong [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Liu, Yaochi, E-mail: liuyaochi72@163.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Wang, Chunzhi [Baling Company, China Petroleum and Chemical Corporation (China); Cheng, Jiashun [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2013-12-15

    Highlights: • A series of phosphorus-modified poly(styrene-co-divinylbenzene)–PAMAM chelating resins were synthesized. • The materials were commercially available and economic. • The new resins were high effective and selective adsorbents. • U(VI) adsorption is fitted with pseudo-second-order equation and Langmuir model. • The new resins can be regenerated. -- Abstract: Polyamidoamine (PAMAM) modified poly(styrene-co-divinylbenzene) absorbents carrying phosphorus functional groups (PS-PAMAM-PPA) were prepared and used as adsorbents for the adsorption of uranium(VI) from aqueous solution. Different generations of PAMAM were used for obtaining different chelating resins, PS-PPA, PS-1.0G PAMAM-PPA, PS-2.0G PAMAM-PPA, PS-3.0G PAMAM-PPA and PS-4.0G PAMAM-PPA. The synthesized resins were characterized by FTIR and XPS. The effects of many physio-chemical properties on metal ion adsorption to adsorbent phase, such as solution pH, kinetic studies, initial uranium concentration, temperature, were investigated using batch method. The results showed that the maximum adsorption capacity (99.89 mg/g) was observed at the pH 5.0 and 25 °C with initial U(VI) concentration 100 mg/L and adsorbent dose 1 g/L. PS-1.0G PAMAM-PPA had the largest adsorption capacity for U(VI) compared with other prepared adsorbents. The adsorption kinetics of U(VI) onto PS-1.0G PAMAM-PPA followed the mechanism of the pseudo-second-order equation, indicating that the chemical adsorption was a rate-limiting step. The calculated thermodynamic parameters (ΔG, ΔH, ΔS) stated that the adsorption of U(VI) onto PS-1.0G PAMAM-PPA were spontaneous, endothermic and feasible. The adsorption isotherms obeyed the Langmuir isotherm models. The desorption studies showed that PS-1.0G PAMAM-PPA could be used repeatedly and adsorption and desorption percentage did not have any noticeable loss after 27 cycles in a fixed bed.

  2. Synthesis of a hollow fiber type porous chelating resin containing the amide oxime group by radiation induced graft polymerization for the uranium recovery

    International Nuclear Information System (INIS)

    Hori, Takahiro; Saito, Kyoichi; Furusaki, Shintaro; Sugo, Takanobu; Okamoto, Jiro.

    1986-01-01

    A hollow fiber type porous chelating resin containing amide oxime as a functional group was synthesized and used as an adsorbent for the recovery of uranium. Hollow fiber type porous polyethylene was used as a base polymer. Acrylonitrile was grafted onto it by the radiation-induced graft polymerization. By changing the reaction time, four kinds of graft polymer were obtained. The degree of grafting ranged from 79 % to 127 %. Each resin was soaked in hydroxylamine solution, and the cyano group was converted to amide oxime group. By elemental analysis, the amount of nitrogen introduced on the graft polymer resin in amidoximation was determined to range from 4.3 mmol to 8.5 mmol per 1 g of base polymer. Most of the nitrogen is considered to belong to the amide oxime group. The pore radius, which was initially distributed broadly from about 500 A to 10000 A for the base polymer, was changed to about 1000 A with narrow distribution by the grafting. The pore volume was 1.2 ∼ 1.4 cm 3 per 1 gram of the amide oxime resin, which was about half of that of the initial base polymer. But the pore volume per 1 g base polymer of the amide oxime resin increased with an increase in the grafting degree, e.g. 4.5 cm 3 /g base polymer at 127 % of grafting degree. Specific surface area, which was 30 m 2 /g in base polymer, decreased with an increase in the grafting degree, e.g. 15 m 2 /g at 127 % of grafting degree. Both the amounts of the adsorbed hydrochloric acid and the adsorbed copper were about 1.5 times of the amount of nitrogen introduced in the amidoximation. The reason is considered to be caused by the formation of hydroxamic acid and amide from the measurements of the IR spectra. The amount of uranium adsorbed on the resin was 64 % of the amount of nitrogen introduced in the amidoximation. (author)

  3. Adsorption performances and mechanisms of the newly synthesized N,N'-di (carboxymethyl) dithiocarbamate chelating resin toward divalent heavy metal ions from aqueous media

    International Nuclear Information System (INIS)

    Jing Xiaosheng; Liu Fuqiang; Yang Xin; Ling Panpan; Li Lanjuan; Long Chao; Li Aimin

    2009-01-01

    N,N'-di (carboxymethyl) dithiocarbamate chelating resin (PSDC) was synthesized by anchoring the chelating agent of N,N'-di (carboxymethyl) dithiocarbamate to the chloromethylated PS-DVB (Cl-PS-DVB) matrix, as a new adsorbent for removing divalent heavy metal ions from waste-stream. The physicochemical structures of Cl-PS-DVB and PSDC were elaborately characterized using Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), and were further morphologically characterized using BET and BJH methods. The adsorption performances of PSDC towards heavy metals such as Cu(II), Pb(II) and Ni(II) were systematically investigated, based upon which the adsorption mechanisms were deeply exploited. For the above target, the classic batch adsorption experiments were conducted to explore the kinetics and isotherms of the removal processes with pH-value, initial concentration, temperature, and contact time as the controlling parameters. The kinetic and isotherm data could be well elucidated with Lagergren-second-order equation and Langmuir model respectively. The strong affinity of PSDC toward these target soft acids could be well demonstrated with the electrostatic attraction and chelating interaction caused by IDA moiety and sulphur which were namely soft bases on the concept of hard and soft acids and bases (HASB). Thermodynamic parameters, involving ΔH o , ΔS o and ΔG o were also calculated from graphical interpretation of the experimental data. The standard heats of adsorption (ΔH o ) were found to be endothermic and the entropy change values (ΔS o ) were calculated to be positive for the adsorption of Cu(II), Pb(II) and Ni(II) ions onto the tested adsorbents. Negative values of ΔG o indicated that adsorption processes for all tested metal ions onto PSDC were spontaneous.

  4. Trace metals analysis in estuarine and seawater by ICP-MS using on line preconcentration and matrix elimination with chelating resin.

    Science.gov (United States)

    Nicolaı, M; Rosin, C; Tousset, N; Nicolai, Y

    1999-09-13

    The main difficulties of trace metals analysis in estuarine and seawater stem from their very low concentration (mug/l to sub-mug/l), and, by contrast, the high salt content (up to 38 g/l in the Mediterranean Sea). ICP-MS allows multi-elemental analysis and offers great sensitivity, but may be strongly affected by matrix effects induced by high salt contents (> 1 g/l). To perform trace metals analysis both in riverine, estuarine and seawater, we have developed a hyphenated method: ion chelation chromatography coupled on-line with ICP-MS. Iminodiacetate resin, Metpac CC-1 (Dionex), was used to concentrate most of the trace metals, and to separate them from alkaline and alkaline-earth metals. Behaviour of 17 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, In, Zn, V, Tl, Bi, Ag and Sn) towards the resin was qualitatively investigated. A method validation, partly derived from AFNOR standard XPT 90-210, was carried out on 12 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, Bi and In). Replicate measurements of multi-elemental standard solutions were used to check linearity, and to determine repeatability and detection limits. Method accuracy was then assessed by analysing two certified materials: a synthetic freshwater (SRM 1643d), and a natural filtered coastal seawater (NRCC CASS-3). An application assay of natural samples from the Rhône river (France) was eventually carried out, and the analytical results were found to be consistent with previous works.

  5. Determination of antimony by electrochemical hydride generation atomic absorption spectrometry in samples with high iron content using chelating resins as on-line removal system

    International Nuclear Information System (INIS)

    Bolea, E.; Arroyo, D.; Laborda, F.; Castillo, J.R.

    2006-01-01

    A method for the removal of the interference caused by iron on electrochemical generation of stibine is proposed. It consists of a chelating resin Chelex 100 column integrated into a flow injection system and coupled to the electrochemical hydride generator quartz tube atomic absorption spectrometer (EcHG-QT-AAS). Iron, as Fe(II), is retained in the column with high efficiency, close to 99.9% under optimal conditions. No significant retention was observed for Sb(III) under same conditions and a 97 ± 5% signal recovery was achieved. An electrochemical hydride generator with a concentric configuration and a reticulated vitreous carbon cathode was employed. The system is able to determine antimony concentrations in the range of ng ml -1 in presence of iron concentrations up to 400 mg l -1 . The procedure was validated by analyzing PACS-2 marine sediments reference material with a 4% (w/w) iron content and a [Fe]:[Sb] ratio of 4000:1, which caused total antimony signal suppression on the electrochemical hydride generation system. A compost sample with high iron content (0.7%, w/w), was also analyzed. A good agreement was found on both samples with the certified value and the antimony concentration determined by ICP-MS, respectively

  6. Recovery of uranium from seawater. 14. System arrangements for the recovery of uranium from seawater by spherical amidoxime chelating resins utilizing natural seawater motions

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Kabay, Nalan; Shuto, Taketomi; Jyo, Akinori

    1993-01-01

    In order to evaluate performances of lightly cross-linked highly porous amidoxime resins in uranium-adsorption systems utilizing natural seawater motions, uranium uptake by the resins from seawater was studied by different approaches, such as simulated sea current exposure tests, towing trials, and/or mooring trials. In general, the efficiency of uranium uptake became higher with a decrease in the thickness of packing layers, indicating important roles of fluidization of the resin particles. On the basis of these fundamental data, mooring tests in the natural sea current were designed and conducted. By mooring flat adsorption beds (base area 260 cm 2 , height 3.0 cm) packed with 780 ml of the resin for 40 h, promising uranium uptake as high as 44 mg/kg of resin (9.9 mg/l of resin) was achieved under sea conditions in which the velocity of sea currents and the vertical velocity of waves were 5.5-49.7 cm/s and 3.4-27 cm/s, respectively

  7. Development of a treatment process for the removal of heavy metals from raw water for drinking water supply using chelating ion exchange resins. Subproject 1. Final report; Entwicklung der Verfahrenstechnik zur Eliminierung von Schwermetallen aus Rohwaessern zur Trinkwassergewinnung mit chelatbildenden Kationenaustauscherharzen zur technischen Reife. Teilprojekt 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Overath, H.; Stetter, D.; Doerdelmann, O.

    2002-07-01

    Chelating cation exchange resins with iminodiacetic acid group (Lewatit TP 207 and Amberlite IRC 748) were tested for the removal of heavy metals in a drinking water treatment plant. The pilot scale filtration experiments were conducted by varying the operating conditions, such as flow rate and feed concentrations. Heavy metal concentrations (nickel, lead, cadmium, zinc) in the feed were adjusted between 20 and 200 {mu}g/L. Different methods for regeneration and conditioning of the resins were developed and investigated. Finally the ion exchange resins were tested according to German health regulations for ion exchangers in drinking water treatment. (orig.)

  8. Binding of Sr from milk by solid phase extraction with cryptand C222 sorbed on silica gel, cation exchange, chelating or adsorbent resins for simplified 90Sr analysis

    International Nuclear Information System (INIS)

    Tait, David; Wiechen, Arnold; Haase, Gerhard

    1995-01-01

    Several commercially available resins have been found to bind the bicyclic polyether cryptand C222 from aqueous acetonitrile solutions. The presence of C222 on some of these resins strongly improved their affinity for Sr, so that relatively small amounts of such resins sorbed Sr from milk. The resins investigated were silica gel, polyacrylic acid crosslinked with divinylbenzene (DVB), polystyrene crosslinked with divinylbenzene (PS-DVB) and PS-DVB containing sulphonate, aminomethylphosphonate, iminodiacetate and mercapto groups. The resins for which binding of C222 resulted in the largest improvement in Sr sorption from milk were PS-DVB containing mercapto groups (Chelite S) and silica gel (Si 60). Thus, 2 ml wet volume of either Chelite S containing 133 μmol of C222, or silica gel Si-60 containing 143 μmol of C222 sorbed 90 and 48%, respectively, of the Sr from 100-ml milk samples. As the sorption of Sr from milk by these systems is relatively slow, contact times of 24-36 h are required to attain these results. The Chelite S-C222 system separates Sr effectively from Cs and Ca. Under the conditions described here some 6% of the natural 40 K in milk sorbs with Sr to the resin. Ba behaves similarly to Sr. 90 Sr/ 90 Y sorbed on the silica gel Si-60-C222 system can be measured directly and efficiently by liquid scintillation counting. If adequate specificity can be attained this system might provide a very simple method of determining 90 Sr in milk

  9. The use of a chelating resin column for preconcentration of trace elements from sea-water in their determination by neutron-activation analysis

    International Nuclear Information System (INIS)

    Lee, C.; Kim, N.B.; Lee, I.C.; Chung, K.S.

    1977-01-01

    A Chelex-100 resin column has been employed for the preliminary concentration of trace elements in water samples before their determination by neutron-activation analysis. The column filled with a 1 : 1 mixture of the resin (50 to 100 mesh) and Pyrex glass powder of the same mesh size, is shown to maintain a constant flow-rate and give reproducible results. By a combination of preconcentration and neutron-activation analysis it is possible to determine Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, La, Mg, Mn, Sc, U, V and Zn in sea-water and/or fresh water simultaneously at the parts per milliard level. (author)

  10. MULTIELEMENT SOLID PHASE PRECONCENTRATION USING A CHELATING RESIN OF STYRENE DIVINYLBENZENE COPOLYMER AND APPLICATION TO ANALYSIS OF SEAWATER AND FISH OTOLITHS BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP�MS)

    Science.gov (United States)

    Zereen, Fahmida; Yilmaz, Vedat; Arslan, Zikri

    2013-01-01

    A new chelating resin has been synthesized by immobilizing 4–(2–thiazolylazo) resorcinol (TAR) onto styrene divinlybenzene copolymer and examined for on-line solid phase extraction/preconcentration of Cd, Co, Cu, Ni, Pb and Zn in seawater and fish otoliths for determination by inductively plasma mass spectrometry (ICP-MS). A volume of 5.0 mL sample solution was loaded onto the mini column of TAR immobilized resin at 2.0 mL min−1 via a sequential injection system. The optimum pH for multielement preconcentration was around pH 5.5. Recoveries were better than 96% in artificial seawater. Elution was achieved with 1.0 mL of 0.75 mol L−1 HNO3. The resin possesses large sorption capacity ranging from 82.0 µmol g−1 for Pb to 319 µmol g−1 for Cu. The detection limits (3s) varied between 0.0016 µg L−1 (Cd) and to 0.015 µg L−1 (Zn) for preconcentration of 5.0 mL blank solutions (pH 5.5). Relative standard deviation (RSD)for three replicate runs was between 0.3% (Cd) and 6% (Zn) at 1.0 µg L−1 level. The procedure was validated by analysis of Nearshore Seawater certified reference material (CASS–4), and then successfully applied to the determination of the trace elements in fish otoliths (CRM 22) and in coastal seawater and estuarine water samples. PMID:24976635

  11. Selective separation of uranium using alizarin red S (ARS)-modified anion-exchange resin or by flotation of U-ARS chelate

    International Nuclear Information System (INIS)

    Khalifa, M.E.

    1998-01-01

    An alizarin red S (ARS)-modified anion exchange resin was prepared by a simple reaction of ARS with the anion exchange Doulite A101 and used for the efficient sorption of uranium from aqueous media. The effect of various parameters on the sorption of U(VI) (pH effect, sorption kinetics, resin capacity and breakthrough curves) was investigated. The modified resin sorbs U(VI) over a wide range of pH (2.8--5) with a maximum sorption capacity of 0.68 mmol/g at pH 3.2 to 4.0. Iron(III), Zr(IV), Ti(IV), Cu(II), and Th(IV) ions are also sorbed to different extents, but Be(II), Bi(III), Ca(II), Mg(II), Pb(II), Hg(II), Zn(II), Cd(II), Al(III), Mn(II), Co(II) and Ni(II) are not sorbed; thus, conditions for separating U(VI) from these metal ions have been identified. For eluting U(VI) from the resin, 0.2 mol/L HCl was used and the recovery recorded was as high as 99.9%. The use of ARS is extended to float uranium quantitatively and selectively from aqueous media at pH ∼ 4 by using oleic acid as a surfactant. The different parameters affecting the flotation process have also been investigated. Uranium(VI) has been effectively separated from natural water samples and certified uranium ores using both procedures

  12. Coordination of two high-affinity hexamer peptides to copper(II) and palladium(II) models of the peptide-metal chelation site on IMAC resins.

    Science.gov (United States)

    Chen, Y; Pasquinelli, R; Ataai, M; Koepsel, R R; Kortes, R A; Shepherd, R E

    2000-03-20

    The coordination of peptides Ser-Pro-His-His-Gly-Gly (SPHHGG) and (His)6 (HHHHHH) to [PdII(mida)(D2O)] (mida2- = N-methyliminodiacetate) was studied by 1H NMR as model reactions for CuII(iminodiacetate)-immobilized metal affinity chromatography (IMAC) sites. This is the first direct physical description of peptide coordination for IMAC. A three-site coordination is observed which involves the first, third, and fourth residues along the peptide chain. The presence of proline in position 2 of SPHHGG achieves the best molecular mechanics and bonding angles in the coordinated peptide and enhances the interaction of the serine amino nitrogen. Histidine coordination of H1, H3, and H4 of (His)6 and H3 and H4 of SPHHGG was detected by 1H NMR contact shifts and H/D exchange of histidyl protons. The EPR spectra of SPHHGG and HHHHHH attached to the [CuII(mida)] unit were obtained for additional modeling of IMAC sites. EPR parameters of the parent [Cu(mida)(H2O)2] complex are representative: gzz = 2.31; gyy = 2.086; gxx = 2.053; A parallel = 161G; AN = 19G (three line, one N coupling). Increased rhombic distortion is detected relative to the starting aqua complex in the order of [Cu(mida)L] for distortion of HHHHHH > SPHHGG > (H2O)2. The lowering of symmetry is also seen in the decrease in the N-shf coupling, presumably to the imino nitrogen of mida2- in the order 19 G (H2O), 16 G (SPHHGG) and 11 G (HHHHHH). Visible spectra of the [Cu(mida)(SPHHGG)] and [Cu(mida)(HHHHHH)] as a function of pH indicate coordination of one histidyl donor at ca. 4.5, two in the range of pH 5-7, and two chelate ring attachments involving the terminal amino donor for SPHHGG or another histidyl donor of HHHHHH in the pH domain of 7-8 in agreement with the [PdII(mida)L] derivatives which form the two-chelate-ring attachment even at lower pH as shown by the 1H NMR methods.

  13. Multielement determination of trace metals in river water (certified reference material, JSAC 0301-1) by high efficiency nebulization ICP-MS after 100-fold preconcentration with a chelating resin-packed minicolumn

    International Nuclear Information System (INIS)

    Zhu, Yanbei; Hattori, Ryota; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki

    2005-01-01

    The determination of 34 trace metals in a river water certified reference material (CRM), i.e. JSAC 0301-1, which was issued by the Japan Society for Analytical Chemistry in January 2004, was performed by ICP-MS with a high efficiency nebulizer after preconcentration with a laboratory-made chelating resin-packed minicolumn, with which trace metals were concentrated 100-fold from 50 mL of a river water sample to 0.5 mL of the final analysis solution. Trace metals in JSAC 0301-1 were observed in the concentration range from 19 μg L -1 of Al to 0.000053 μg L -1 of Bi. It was found that most of the concentrations of trace metals, including rare earth elements (REEs), in JSAC 0301-1 were lower than those in JAC 0031, which was also a previously issued CRM prepared with water from the same river as that of JSAC 0301-1. The low concentrations of trace metals in JSAC 0301-1 might be attributed to the fact that there was heavy rain before collecting the original water sample to prepare the present CRM. Furthermore, the REE distribution patterns of JSAC 0301-1, JAC 0031 and the average values of river water samples in Japan were parallel to each other. These results indicate that the distributions of REEs in JSAC 0301-1 and JAC 0031 were the typical ones of river water samples in Japan. (author)

  14. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor; Villalobos Vazquez de la Parra, Luis Francisco; Hilke, Roland

    2015-01-01

    microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  15. Chelation in Metal Intoxication

    Directory of Open Access Journals (Sweden)

    Swaran J.S. Flora

    2010-06-01

    Full Text Available Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.

  16. Metal chelate process to remove pollutants from fluids

    Science.gov (United States)

    Chang, S.G.T.

    1994-12-06

    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO[sub x] and optionally SO[sub 2] from a fluid using a metal ion (Fe[sup 2+]) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution. 26 figures.

  17. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  18. Chelation in metal intoxication

    DEFF Research Database (Denmark)

    Aaseth, Jan; Skaug, Marit Aralt; Cao, yang

    2015-01-01

    The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the incon......The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due...... to the inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals. The hydrophilic dithiol chelators DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercapto-propanesulphonate) are less toxic and more efficient than BAL in the clinical treatment...... of heavy metal poisoning, and available as capsules for oral use. In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the new...

  19. Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

  20. Comments on chelation therapy

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1981-01-01

    The primary purpose of actinide chelation is to decrease the risk from radiation-induced cancer. While occupational exposures in the past have mainly involved low specific activity 239 Pu, future exposures will increasingly involve high specific activity plutonium, americium, and curium - all of which clear more rapidly from the lung. This will tend to shift the cancer risk from lung to bone and liver. Although therapy with Ca- or Zn-DTPA rapidly removes 241 Am from the canine, the sub-human primate, and the human liver, improved methods for removal from bone and lung are needed. DTPA can remove 241 Am more easily from the growing skeleton of a child than from the mature skeleton of an adult. Investigators at Karlsruhe are developing chelation agents for oral administration and are investigating the reduction in local dose to bone resulting from chelation therapy

  1. Chelation Therapy for Mercury Poisoning

    OpenAIRE

    Rong Guan; Han Dai

    2009-01-01

    Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role o...

  2. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  3. Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    Syamal, A.; Singh, M.M.

    1998-01-01

    A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH) 2 . DMF, PS L MoO 2 and PS-LUO 2 (where PS-LH 2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO 2 and PS-LUO 2 have octahedral structure, PS L Zn and PS-LCd are tetrahedral and PS-LZr(OH) 2 .DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

  4. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  5. Removal of heavy elements from Contaminated Matrices using amidoxime chelating starch

    International Nuclear Information System (INIS)

    Shama, S.A.; Wally, S.A.; Aly, H.F.

    2012-01-01

    The synthesis of a amidoxime chelating starch was carried out by grafting of acrylonitrile onto starch using the mutual irradiation techniques at dose rate 2.5 kGy. Conversion of nitrile groups of the grafted copolymer into the amidoxime was carried out by treatment with hydroxylamine under alkaline solution. The amidoxime chelating starch was characterized by FT-IR spectra, TG, Particle size, Surface area, SEM, and Elemental analyses. The chelating behavior of the prepared resin was carried out by using uranium. The binding capacity of uranium ion by the amidoxime resin was carried out by the batch technique. The sorption capacity was high for uranium, 86.9 mg/g at ph 6.5. The kinetic exchange rate was fast. It was observed that the uranium uptake ratio reaches 50% at 10 min (t 1/2 ). The treatment process using amidoxime sorbent is efficient to remove uranium from the waste solution of the FMPP plant.

  6. Process for hardening synthetic resins by ionizing radiation

    International Nuclear Information System (INIS)

    Hesse, W.; Ritz, J.

    1975-01-01

    Synthetic resins containing hydroxy groups and polymerizable carbon-carbon bonds are reacted with diketenes to yield aceto ester derivatives, which when reacted with metal compounds to form chelates, and mixed with copolymerizable monomers, are capable of being hardened by unusually low radiation doses to form coatings and articles with superior properties. (E.C.B.)

  7. Phenolic cation exchange resin material for recovery of cesium and strontium

    Science.gov (United States)

    Ebra, Martha A.; Wallace, Richard M.

    1983-01-01

    A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear waste solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs.sup.+ and Sr.sup.2+ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

  8. Phenolic cation-exchange resin material for recovery of cesium and strontium. [Patent application

    Science.gov (United States)

    Ebra, M.A.; Wallace, R.M.

    1982-05-05

    A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear wate solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs/sup +/ and Sr/sup 2 +/ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

  9. Article Commentary: Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

  10. Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride

    Directory of Open Access Journals (Sweden)

    M. Ghaemy

    2014-03-01

    Full Text Available Chelating resins are suitable materials for the removal of heavy metals in water treatments. A copolymer, Poly(MMA-co-MA, was synthesized by radical polymerization of maleic anhydride (MA and methyl methacrylate (MMA, characterized and transformed into multifunctional nanochelating resin beads (80–150 nm via hydrolysis, grafting and crosslink reactions. The resin beads were characterized by swelling studies, field emission scanning electron microscopy (FESEM and Fourier transform infrared spectroscopy (FTIR. The main purpose of this work was to determine the adsorption capacity of the prepared resins (swelling ratio ~55% towards metal ions such as Hg2+, Cd2+, Cu2+ from water at three different pH values (3, 6 and 9. Variations in pH and types of metal ions have not significantly affected the chelation capacity of these resins. The maximum chelation capacity of one of the prepared resin beads (Co-g-AP3 for Hg2+ was 63, 85.8 and 71.14 mg/g at pH 3, 6 and 9, respectively. Approximately 96% of the metal ions could be desorbed from the resin. Adsorption capacity of these resins towards three commercial synthetic azo dyes was also investigated. The maximum adsorption of dye AY42 was 91% for the resin Co-g-AP3 at room temperature. This insures the applicability of the synthesized resins for industrial applications.

  11. Overview of current chelation practices

    Directory of Open Access Journals (Sweden)

    Y. Aydinok

    2011-12-01

    Full Text Available Deferoxamine (DFO is reference standard therapy for transfusional iron overload since the 1980s. Although it is a highly effective iron chelator, the compliance problem to subcutaneous administration of DFO remains as the major problem. The oral chelator Deferiprone (DFP has no marketing licence in North America, however, it has been licensed in India since 1994 and the European Union (EU granted marketing approval for DFP in 1999, specifically for patients with thalassemia major when DFO is inadequate, intolerable or unacceptable. There are still limited data available on the use of DFP in children between 6 and 10 years of age, and no data on DFP use in children under 6 years of age. Subsequently the oral chelator Deferasirox (DFX was approved by FDA and EMA for the treatment of patients with transfusional iron overload -older than 2 years of age- as first line therapy, in 2005 and 2006 respectively. The primary objective of iron chelation is to maintain body iron at safe levels at all times but once iron is accumulated, the objective of iron chelation is to reduce tissue iron to safe levels which is a slow process. The chelation regimen, dose and frequency of administration, of the chelator(s are mainly determined based on body iron burden, presence of myocardial iron and the transfusional iron loading rate. A proper monitoring of chelation is of importance for measuring the response rate to a particular regimen and providing dose adjustments to enhance chelation efficacy and to avoid toxicity. Efficacy of a chelation regimen may exhibit individual variability resulting from factors such as absorbtion and metabolism of the chelator. Tolerability and compliance are also individual variables effecting the response to chelation. Understanding of advantages and limitations of chelators, accurately determining chelation needs of patients with iron overload and designing individualized chelation regimens with less toxicity but optimum efficacy

  12. Manganese(II) chelate contrast media

    International Nuclear Information System (INIS)

    Rocklage, S.M.; Quay, S.C.

    1994-01-01

    New chelate forming compounds for use as contrast media in NMR imaging are described. Especially mentioned are manganese(II) ion chelates of N,N' dipyridoxaldiamine, N,N' diacetic acid, and salts and esters thereof. 1 fig

  13. Immobilization of spent resin with epoxy resin

    International Nuclear Information System (INIS)

    Gultom, O.; Suryanto; Sayogo; Ramdan

    1997-01-01

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137 Cs from waste product was not detected in experiment (author)

  14. Method of heat decomposition for chemical decontaminating resin waste

    International Nuclear Information System (INIS)

    Kikuchi, Akira.

    1988-01-01

    Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

  15. A review of pitfalls and progress in chelation treatment of metal poisonings.

    Science.gov (United States)

    Andersen, Ole; Aaseth, Jan

    2016-12-01

    Most acute and chronic human metal poisonings are due to oral or inhalation exposure. Almost 80% of published animal experiments on chelation in metal poisoning used single or repeated intraperitoneal, intramuscular or intravenous administration of metal and chelator, impeding extrapolation to clinical settings. Intramuscular administration of dimercaptopropanol (BAL) has until now been used in acute arsenic, lead, and mercury poisonings, but repeated BAL administration increased the brain uptake of As, Pb and Hg in experimental animals. Also, diethyl dithiocarbamate (DDC) has been used as antidote in acute experimental animal parenteral Cd poisoning, and both DDC and tetraethylthiuram disulfide (TTD, disulfiram, Antabuse) have been used in nickel allergic patients. However, even one dose of DDC given immediately after oral Cd or Ni increased their brain uptake considerably. The calcium salt of ethylenediamminetetraacetic acid (CaEDTA) but not dimercaptosuccinic acid (DMSA) increased the brain uptake of Pb. In oral Cd or Hg poisoning, early oral administration of DMSA or dimercaptopropane sulfonate (DMPS) increased survival and reduced intestinal metal uptake. Oral administration of Prussian Blue or resins with fixed chelating groups that are not absorbed offer chelation approaches for decorporation after oral exposure to various metals. Diethylenetriaminepentaacetic acid (DTPA) nebulizers for pulmonary chelation after inhalation exposure need further development. Also, combined chelation with more than one compound may offer extensive advances. Solid knowledge on the chemistry of metal chelates together with relevant animal experiments should guide development of chelation procedures to alleviate and not aggravate the clinical status of poisoned patients. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Chelators for investigating zinc metalloneurochemistry

    OpenAIRE

    Radford, Robert John; Lippard, Stephen J.

    2013-01-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals o...

  17. Synthesis and characterization of an N-(2-hydroxyethyl)-ethylenediaminetriacetic acid resin

    International Nuclear Information System (INIS)

    Lai, Y.F.

    1977-10-01

    A chelating ion-exchange resin with N-(2-hydroxyethyl)ethylene-diaminetriacetic acid (HEDTA) used as the ligand chemically bonded to XAD-4 by an ester linkage, HEDTA-4, was synthesized. It is stable under normal experimental conditions with the liquid chromatograph. The structure of the resin was confirmed by an infrared spectrum, and by potentiometric titrations. The capacity of the resin was also obtained by potentiometric titration and by a nitrogen analysis. The resin was used to pack a column of 5 mm internal diameter and 5 cm long. The effect of pH on the retention of different metal ions on the resin was studied. It was found that the resin was most selective for chromium(III), copper(II), lead(II), mercury(II), uranium(VI), zirconium(IV) and zinc(II) at a pH of less than 3. Furthermore, the resin proves to be functioning with a chelating mechanism rather than ion-exchange, and it can concentrate trace metal ions in the presence of a large excess of calcium and magnesium. This makes the resin potentially useful for purifying and analyzing drinking water

  18. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

  19. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    International Nuclear Information System (INIS)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K.

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates

  20. Beliefs about chelation among thalassemia patients

    Directory of Open Access Journals (Sweden)

    Trachtenberg Felicia L

    2012-12-01

    Full Text Available Abstract Background Understanding patients’ views about medication is crucial to maximize adherence. Thalassemia is a congenital blood disorder requiring chronic blood transfusions and daily iron chelation therapy. Methods The Beliefs in Medicine Questionnaire (BMQ was used to assess beliefs in chelation in thalassemia patients from North America and London in the Thalassemia Longitudinal Cohort (TLC of the Thalassemia Clinical Research Network (TCRN. Chelation adherence was based on patient report of doses administered out of those prescribed in the last four weeks. Results Of 371 patients (ages 5-58y, mean 24y, 93% were transfused and 92% receiving chelation (26% deferoxamine (DFO; a slow subcutaneous infusion via portable pump, 63% oral, 11% combination. Patients expressed high “necessity” for transfusion (96%, DFO chelation (92% and oral chelation (89%, with lower “concern” about treatment (48%, 39%, 19% respectively. Concern about oral chelation was significantly lower than that of DFO (p Conclusions Despite their requirement for multimodal therapy, thalassemia patients have positive views about medicine, more so than in other disease populations. Patients may benefit from education about the tolerability of chelation and strategies to effectively cope with side effects, both of which might be beneficial in lowering body iron burden. Clinicaltrials.gov identifier NCT00661804

  1. Extrafibrillar collagen demineralization-based chelate-and-rinse technique bridges the gap between wet and dry dentin bonding.

    Science.gov (United States)

    Mai, Sui; Wei, Chin-Chuan; Gu, Li-Sha; Tian, Fu-Cong; Arola, Dwayne D; Chen, Ji-Hua; Jiao, Yang; Pashley, David H; Niu, Li-Na; Tay, Franklin R

    2017-07-15

    Limitations associated with wet-bonding led to the recent development of a selective demineralization strategy in which dentin was etched with a reduced concentration of phosphoric acid to create exclusive extrafibrillar demineralization of the collagen matrix. However, the use of acidic conditioners removes calcium via diffusion of very small hydronium ions into the intrafibrillar collagen water compartments. This defeats the purpose of limiting the conditioner to the extrafibrillar space to create a collagen matrix containing only intrafibrillar minerals to prevent collapse of the collagen matrix. The present work examined the use of polymeric chelators (the sodium salt of polyacrylic acid) of different molecular weights to selectively demineralize extrafibrillar dentin. These polymeric chelators exhibit different affinities for calcium ions (isothermal titration calorimetry), penetrated intrafibrillar dentin collagen to different extents based on their molecular sizes (modified size-exclusion chromatography), and preserve the dynamic mechanical properties of mineralized dentin more favorably compared with completely demineralized phosphoric acid-etched dentin (nanoscopical dynamic mechanical analysis). Scanning and transmission electron microscopy provided evidence for retention of intrafibrillar minerals in dentin surfaces conditioned with polymeric chelators. Microtensile bond strengths to wet-bonded and dry-bonded dentin conditioned with these polymeric chelators showed that the use of sodium salts of polyacrylic acid for chelating dentin prior to bonding did not result in significant decline in resin-dentin bond strength. Taken together, the findings led to the conclusion that a chelate-and-rinse conditioning technique based on extrafibrillar collagen demineralization bridges the gap between wet and dry dentin bonding. The chelate-and-rinse dental adhesive bonding concept differentiates from previous research in that it is based on the size

  2. Polyvinyl chloride resin

    International Nuclear Information System (INIS)

    Kim, Hong Jae

    1976-06-01

    This book contains polyvinyl chloride resin industry with present condition such as plastic industry and polyvinyl chloride in the world and Japan, manufacture of polyvinyl chloride resin ; suspension polymerization and solution polymerization, extruding, injection process, hollow molding vinyl record, vacuum forming, polymer powders process, vinyl chloride varnish, vinyl chloride latex, safety and construction on vinyl chloride. Each chapter has descriptions on of process and kinds of polyvinyl chloride resin.

  3. Isolation and characterization of iron chelators from turmeric (Curcuma longa): selective metal binding by curcuminoids.

    Science.gov (United States)

    Messner, Donald J; Surrago, Christine; Fiordalisi, Celia; Chung, Wing Yin; Kowdley, Kris V

    2017-10-01

    Iron overload disorders may be treated by chelation therapy. This study describes a novel method for isolating iron chelators from complex mixtures including plant extracts. We demonstrate the one-step isolation of curcuminoids from turmeric, the medicinal food spice derived from Curcuma longa. The method uses iron-nitrilotriacetic acid (NTA)-agarose, to which curcumin binds rapidly, specifically, and reversibly. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin each bound iron-NTA-agarose with comparable affinities and a stoichiometry near 1. Analyses of binding efficiencies and purity demonstrated that curcuminoids comprise the primary iron binding compounds recovered from a crude turmeric extract. Competition of curcuminoid binding to the iron resin was used to characterize the metal binding site on curcumin and to detect iron binding by added chelators. Curcumin-Iron-NTA-agarose binding was inhibited by other metals with relative potency: (>90% inhibition) Cu 2+  ~ Al 3+  > Zn 2+  ≥ Ca 2+  ~ Mg 2+  ~ Mn 2+ (80% by addition of iron to the media; uptake was completely restored by desferoxamine. Ranking of metals by relative potencies for blocking curcumin uptake agreed with their relative potencies in blocking curcumin binding to iron-NTA-agarose. We conclude that curcumin can selectively bind toxic metals including iron in a physiological setting, and propose inhibition of curcumin binding to iron-NTA-agarose for iron chelator screening.

  4. Chelating agents in pharmacology, toxicology and therapeutics

    International Nuclear Information System (INIS)

    1988-01-01

    The proceedings contain 71 abstracts of papers. Fourteen abstracts were inputted in INIS. The topics covered include: the effects of chelating agents on the retention of 63 Ni, 109 Cd, 203 Hg, 144 Ce, 95 Nb and the excretion of 210 Po, 63 Ni, 48 V, 239 Pu, 241 Am, 54 Mn; the applications of tracer techniques for studies of the efficacy of chelation therapy in patients with heart and brain disorders; and the treatment of metal poisoning with chelating agents. (J.P.)

  5. Chelation in root canal therapy reconsidered.

    Science.gov (United States)

    Zehnder, Matthias; Schmidlin, Patrick; Sener, Beatrice; Waltimo, Tuomas

    2005-11-01

    The aim of this study was to assess interactions of EDTA and citric acid (CA) with sodium hypochlorite (NaOCl), the indispensable endodontic irrigant. Other chelators were simultaneously evaluated as possible alternatives: sodium triphosphate (STP), amino tris methylenephosphonic acid (ATMA), and 1- hydroxyethylidene-1, 1-bisphosphonate (HEBP). Available chlorine was titrated in chelator-NaOCl solutions. All chelators other than HEBP and STP caused an almost complete, immediate loss of available chlorine in solution. Atomic absorbtion spectrometry and SEM evaluation of root canal walls of instrumented teeth indicated that NaOCl had no negative effect on calcium-complexing ability of chelators. STP was too weak a complexing agent to warrant further studies. Finally, CA-, EDTA-, and HEBP-NaOCl mixtures were evaluated for their antimicrobial capacity. Again, EDTA and CA negatively interfered with NaOCl, while HEBP did not.

  6. Chelates for Micronutrient Nutrition among Crops

    Indian Academy of Sciences (India)

    years, it has been recognised that compounds containing che- lated metals could .... when using small amounts and no build up of harmful levels. ... degradation of iron chelates. .... down by soil microorganisms into much smaller units for ab-.

  7. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    1976-01-01

    The preparation of the following chemicals is described: chelates of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The compounds described are suitable for intravenous injection, have an excellent in vivo stability and are good organ seekers. Tin(II) choride or other tin(II) compounds are used as chelating agents

  8. Fluid extraction using carbon dioxide and organophosphorus chelating agents

    Science.gov (United States)

    Smart, Neil G.; Wai, Chien M.; Lin, Yuehe; Kwang, Yak Hwa

    1998-01-01

    Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.

  9. Diphonix trademark Resin: A review of its properties and applications

    International Nuclear Information System (INIS)

    Chiarizia, R.; Horwitz, E.P.; Alexandratos, S.D.

    1995-01-01

    The recently developed Diphonix trademark resin is a new multifunctional chelating ion exchange resin containing seminally substituted diphosphonic acid ligands chemically bonded to a styrene-based polymeric matrix. Diphonix can be regarded as a dual mechanism polymer, with a sulfonic acid cation exchange group allowing for rapid access, mostly non-specific, of ions into the polymeric network, and the diphosphonic acid group responsible for specificity (recognition) for a number of metal cations. The Diphonix resin exhibits an extraordinarily strong affinity for actinides, especially in the tetra- and hexavalent oxidation states. It has potential applications in TRU and mixed waste treatment and characterization, and in the development of new procedures for rapid actinide preconcentration and separation from environmental samples. Metal uptake studies have been extended to alkaline earth cations, to transition and post transition metal species, and to metal sorption from neutral or near neutral solutions. Also the kinetic behavior of the resin has been investigated in detail. Influence of the most commonly occurring matrix constituents (Na, Ca, Al, Fe, hydrofluoric, sulfuric, oxalic and phosphoric acids) on the uptake of actinide ions has been measured. This review paper summarizes the most important results studies on the Diphonix resin and gives an overview of the applications already in existence or under development in the fields of mixed waste treatment, actinide separation procedures, treatment of radwaste from nuclear power plants, and removal of iron from copper electrowinning solutions

  10. Biological behaviour of some 67Ga and 64Cu chelates

    International Nuclear Information System (INIS)

    Leonovicova, T.; Angelis, B.; Cifka, J.; Cifkova, I.

    1984-01-01

    Chelates of 67 Ga and 64 Cu with iminodiacetic acid (IDA) and its two phenyl derivatives as well as with nitrilotriacetic acid (NTA) and benzylnitrilotriacetic acid (BNTA) were prepared. All the chelates were found to be negatively charged. A study of the biological distribution of these chelates in rats during time intervals of 3 to 180 min showed that the chelate of 67 Ga with IDA substituted at a phenyl by a hydrophobic substituent is excreted by the kidneys into the urine at a much higher rate than the IDA chelate of 67 Ga. The excretion of NTA and BNTA chelates of 67 Ga is the opposite. Blood clearance of 64 Cu chelates is more rapid than that of 67 Ga chelates. Chelates of 64 Cu accumulate in the liver and with the bile are slowly excreted into the intestines, urinary excretion is negligible. (author)

  11. Aminoalkylated Merrifield Resins Reticulated by Tris-(2-chloroethyl Phosphate for Cadmium, Copper, and Iron (II Extraction

    Directory of Open Access Journals (Sweden)

    Mokhtar Dardouri

    2015-01-01

    Full Text Available We aimed to synthesize novel substituted polymers bearing functional groups to chelate heavy metals during depollution applications. Three polyamine functionalized Merrifield resins were prepared via ethylenediamine (EDA, diethylenetriamine (DETA, and triethylenetetramine (TETA modifications named, respectively, MR-EDA, MR-DETA, and MR-TETA. The aminoalkylated polymers were subsequently reticulated by tris-(2-chloroethyl phosphate (TCEP to obtain new polymeric resins called, respectively, MR-EDA-TCEP, MR-DETA-TCEP, and MR-TETA-TCEP. The obtained resins were characterized via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, elemental analysis (EA, and thermogravimetric (TGA, thermodynamic (DTA, and differential thermogravimetric (DTG analysis. The synthesized resins were then assayed to evaluate their efficiency to extract metallic ions such as Cd2+, Cu2+, and Fe2+ from aqueous solutions.

  12. Decomposition rates of radiopharmaceutical indium chelates in serum

    International Nuclear Information System (INIS)

    Yeh, S.M.; Meares, C.F.; Goodwin, D.A.

    1979-01-01

    The rates at which six small aminopolycarboxylate chelates of trivalent 111 In and three protein-bound chelates of 111 In deliver indium to the serum protein transferrin have been studied in sterile human serum at pH 7.3, 37 deg C. Sterically hindered chelates containing a substituent on an ethylene carbon of EDTA decompose with rates in the range 0.03 to 0.11% per day - one to two orders of magnitude slower than other chelates. Only small differences are observed between rates of decomposition for low-molecular-weight chelates and for protein-bound chelates having analogous structures. (author)

  13. Review of actinide decorporation with chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Ansoborlo, E. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/CETAMA), 30 - Marcoule (France); Amekraz, B.; Moulin, Ch. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC/SECR), 91 - Gif sur Yvette (France); Moulin, V. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares (DEN/DDIN/MR), 91 - Gif Sur Yvette (France); Taran, F. [CEA Saclay (DSV/DBJC/SMMCB), 91 - Gif-sur-Yvette (France); Bailly, Th.; Burgada, R. [Centre National de la Recherche Scientifique (CNRS/LCSB/UMR 7033), 93 - Bobigny (France); Henge-Napoli, M.H. [CEA Valrho, Site de Marcoule (INSTN), 30 (France); Jeanson, A.; Den Auwer, Ch.; Bonin, L.; Moisy, Ph. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/SCPS), 30 - Marcoule (France)

    2007-10-15

    In case of accidental release of radionuclides in a nuclear facility or in the environment, internal contamination (inhalation, ingestion or wound) with actinides represents a severe health risk to human beings. It is therefore important to provide effective chelation therapy or decorporation to reduce acute radiation damage, chemical toxicity, and late radiation effects. Speciation governs bioavailability and toxicity of elements and it is a prerequisite tool for the design and success of new ligands or chelating agents. The purpose of this review is to present the state-of-the-art of actinide decorporation within biological media, to recall briefly actinide metabolism, to list the basic constraints of actinide-ligand for development, to describe main tools developed and used for decorporation studies, to review mainly the chelating agents tested for actinides, and finally to conclude on the future trends in this field. (authors)

  14. Separation of metal ions using an o-hydroxypropiophenoxime resin

    International Nuclear Information System (INIS)

    King, J.N.

    1977-12-01

    A chelating ion-exchange resin incorporating an o-hydroxypropiophenoxime functional group onto an XAD-4 polymer matrix has been synthesized. This resin has been used for the separation and quantitative determination of both copper and molybdenum by high-speed liquid chromatography. Iron, uranium, citrate, and fluoride were found to interfere in the determination of copper. Of the ions tested, none were found to interfere with the determination of molybdenum. Several NBS Standard samples were successfully analyzed for copper and molybdenum. The new method is both accurate and fast. Most samples can be analyzed in less than ten minutes. Bis(2-hydroxyethyl) dithiocarbamate was shown to be superior to PAR as a color-forming reagent for the continuous spectrophotometric detection of copper. Thiolactic acid was shown to be adaptable to the continuous spectrophotometric detection of molybdenum. Both dyes gave linear responses when peak height was plotted against micrograms of metal

  15. Labelling of bacteria with indium chelates

    International Nuclear Information System (INIS)

    Kleinert, P.; Pfister, W.; Endert, G.; Sproessig, M.

    1985-01-01

    The indium chelates were prepared by reaction of radioactive indiumchloride with 10 μg oxine, 15 μg tropolone and 3 mg acetylacetone, resp. The formed chelates have been incubated with 10 9 germs/ml for 5 minutes, with labelling outputs from 90 to 95%. Both gram-positive (Streptococcus, Staphylococcus) and gram-negative bacteria (Escherichia coli) can be labelled. The reproductive capacity of the bacteria was not impaired. The application of indium labelled bacteria allows to show the distribution of microorganisms within the living organism and to investigate problems of bacterial adherence. (author)

  16. Bone marrow and chelatable iron in patients with protein energy ...

    African Journals Online (AJOL)

    chelatable iron is present and is excreted in the urine of children with kwashiorkor ... venous blood sample was drawn for routine biochemical and haematological .... storage.l.1:m In response to chelation, the kwashiorkor children excrete large ...

  17. Ion Exchange Properties of a Terpolymer Resin Derived from 2, 4-Dihydroxybenzaldehyde, Oxamide and Formaldehyde

    Directory of Open Access Journals (Sweden)

    M. V. Tarase

    2009-01-01

    Full Text Available Terpolymer resins (2,4-DHBOF were synthesized by the condensation of 2,4-dihydroxybenzaldehyde and oxamide with formaldehyde in the presence of hydrochloric acid as catalyst, proved to be selective chelation ion exchange terpolymer resins for certain metals. Chelation ion exchange properties of these polymers were studied for Fe+3, Cu+2, Hg+2, Cd+2, Co+2, Zn+2, Ni+2 and Pb+2 ions. A batch equilibrium method was employed in the study of the selectivity of the distribution of a given metal ions between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in a media of various ionic strengths. The polymer showed a higher selectivity for Fe+3, Cd+2 and Co+2 ions than for Cu+2, Hg+2, Zn+2, Ni+2 and Pb+2 ions.

  18. Radiopharmaceutical chelates and method of external imaging

    International Nuclear Information System (INIS)

    Loberg, M.D.; Callery, P.S.; Cooper, M.

    1977-01-01

    A chelate of technetium-99m, cobalt-57, gallium-67, gallium-68, indium-111 or indium-113m and a substituted iminodiacetic acid or an 8-hydroxyquinoline useful as a radiopharmaceutical external imaging agent. The invention also includes preparative methods therefor

  19. Use of chelating agents as immovable phase in extraction chromatography

    International Nuclear Information System (INIS)

    Sebesta, F.

    1978-01-01

    Extraction chromatography using chelating agents is reviewed. The theory of element extraction by chelating agents and factors influencing this process (pH, extracting agent concentration in organic phase, masking agent concentration in aqueous phase) are briefly considered. The effect of kinetic factors on the extraction chromatography process is discussed. Ways of preparing columns are emphasized. Examples of using chelating reagents in various extraction chromatography systems are given. β-Diketones, oximes, hydroxamic acids, dithizon, diethyl dithiocarbamic acid are chosen as chelating agents

  20. Chelating agents as stationary phase in extraction chromatography, ch. 11

    International Nuclear Information System (INIS)

    Sebesta, F.

    1975-01-01

    Chelating agents have been used largely in extraction chromatography for separations related to activation analysis, for concentration of metals from dilute solutions, and for preparation of radiochemically pure or carrier-free radionuclides. This review deals with the theory of extraction by chelating agents, the experimental technique, and the chelating agents and systems used (β-diketones, oximes, hydroxamic acid, dithizone and diethyldithiocarbamic acid)

  1. Chelation therapy after the Trial to Assess Chelation Therapy: results of a unique trial

    Science.gov (United States)

    Avila, Maria D.; Escolar, Esteban; Lamas, Gervasio A.

    2014-01-01

    Purpose of review EDTA chelation therapy has been in off-label use for the treatment of atherosclerosis. We review the results of the first large-scale randomized trial of this treatment. Recent findings The trial to assess chelation therapy was a $30 million National Institutes of Health-funded study of the safety and efficacy of EDTA-based chelation infusions in 1708 post-myocardial infarction (MI) patients. The trial to assess chelation therapy demonstrated a significant (P = 0.035) 18% reduction in a combined primary endpoint of death, MI, stroke, coronary revascularization, or hospitalization for angina. In diabetic patients the benefit was more extreme, with a 41% relative reduction in risk (P = 0.0002) and a 43% reduction in total mortality (P = 0.011). Safety data were favorable. A reduction of oxidative stress by chelation of toxic metals has been proposed as a possible mechanism of action. Summary Recent research suggests that EDTA chelation may be a well-tolerated and effective treatment for post-MI patients. Future replication and mechanistic studies are important prior to implementation in all post-MI patients. PMID:25023079

  2. Biogenic glutamic acid-based resin: Its synthesis and application in the removal of cobalt(II)

    International Nuclear Information System (INIS)

    Jamiu, Zakariyah A.; Saleh, Tawfik A.; Ali, Shaikh A.

    2017-01-01

    Highlights: • A novel resin embedded with metal chelating glutamic acid was synthesized. • The biogenic amino acid residues imparted remarkable efficacy to remove Co(II). • The resin showed excellent ability to remove various metals from wastewater. - Abstract: Inexpensive biogenic glutamic acid has been utilized to synthesize a cross-linked dianionic polyelectrolyte (CDAP) containing metal chelating ligands. Cycloterpolymerization, using azoisobutyronitrile as an initiator, of N,N-diallylglutamic acid hydrochloride, sulfur dioxide and a cross-linker afforded a pH-responsive cross-linked polyzwitterionic acid (CPZA) which upon basification with NaOH was converted into CDAP. The new resin, characterized by a multitude of spectroscopic techniques as well as Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller (BET) analyses, was evaluated for the removal of Co(II) as a model case under different conditions. The adsorption capacity of 137 mg g"−"1 does indeed make the resin as one of the most effective sorbents in recent times. The resin leverages its cheap natural source and ease of regeneration in combination with its high and fast uptake capacities to offer a great promise for wastewater treatment. The resin has demonstrated remarkable efficiency in removing toxic metal ions including arsenic from a wastewater sample.

  3. Biogenic glutamic acid-based resin: Its synthesis and application in the removal of cobalt(II)

    Energy Technology Data Exchange (ETDEWEB)

    Jamiu, Zakariyah A.; Saleh, Tawfik A.; Ali, Shaikh A., E-mail: shaikh@kfupm.edu.sa

    2017-04-05

    Highlights: • A novel resin embedded with metal chelating glutamic acid was synthesized. • The biogenic amino acid residues imparted remarkable efficacy to remove Co(II). • The resin showed excellent ability to remove various metals from wastewater. - Abstract: Inexpensive biogenic glutamic acid has been utilized to synthesize a cross-linked dianionic polyelectrolyte (CDAP) containing metal chelating ligands. Cycloterpolymerization, using azoisobutyronitrile as an initiator, of N,N-diallylglutamic acid hydrochloride, sulfur dioxide and a cross-linker afforded a pH-responsive cross-linked polyzwitterionic acid (CPZA) which upon basification with NaOH was converted into CDAP. The new resin, characterized by a multitude of spectroscopic techniques as well as Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller (BET) analyses, was evaluated for the removal of Co(II) as a model case under different conditions. The adsorption capacity of 137 mg g{sup −1} does indeed make the resin as one of the most effective sorbents in recent times. The resin leverages its cheap natural source and ease of regeneration in combination with its high and fast uptake capacities to offer a great promise for wastewater treatment. The resin has demonstrated remarkable efficiency in removing toxic metal ions including arsenic from a wastewater sample.

  4. [Susceptibility of enterococci to natural and synthetic iron chelators].

    Science.gov (United States)

    Lisiecki, Paweł; Mikucki, Jerzy

    2002-01-01

    A total of 79 strains of enterococci belonging to 10 species were tested for susceptibility to natural and synthetic iron chelators. All strains produced siderophores. These enterococci were susceptible to three synthetic iron chelators only: 8-hydroxyquinoline, disodium versenate (EDTA) and o-phenanthroline. They were resistant to all other synthetic chelators: ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetate, 2,2'-bipiridyl, salicylic acid, 8-hydroxy-5-sulphonic acid and to all natural chelators: ovotransferrine, human apotransferrine, horse apoferritine, desferrioxamine B, ferrichrome and rhodotorulic acid. The relations between susceptibility/resistance, iron assimilation and structure and stability constants of iron chelators were discussed.

  5. Radiation curable epoxy resin

    International Nuclear Information System (INIS)

    Najvar, D.J.

    1978-01-01

    A carboxyl containing polymer is either prepared in the presence of a polyepoxide or reacted with a polyepoxide. The polymer has sufficient acid groups to react with only about 1 to 10 percent of the epoxide (oxirane) groups. The remaining epoxide groups are reacted with an unsaturated monocarboxylic acid such as acrylic or methacrylic acid to form a radiation curable resin

  6. Resin impregnation process for producing a resin-fiber composite

    Science.gov (United States)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  7. Obligatory reduction of ferric chelates in iron uptake by soybeans.

    Science.gov (United States)

    Chaney, R L; Brown, J C; Tiffin, L O

    1972-08-01

    The contrasting Fe(2+) and Fe(3+) chelating properties of the synthetic chelators ethylenediaminedi (o-hydroxyphenylacetate) (EDDHA) and 4,7-di(4-phenylsulfonate)-1, 10-phenanthroline (bathophenanthrolinedisulfonate) (BPDS) were used to determine the valence form of Fe absorbed by soybean roots supplied with Fe(3+)-chelates. EDDHA binds Fe(3+) strongly, but Fe(2+) weakly; BPDS binds Fe(2+) strongly but Fe(3+) weakly. Addition of an excess of BPDS to nutrient solutions containing Fe(3+)-chelates inhibited soybean Fe uptake-translocation by 99+%; [Fe(II) (BPDS)(3)](4-) accumulated in the nutrient solution. The addition of EDDHA caused little or no inhibition. These results were observed with topped and intact soybeans. Thus, separation and absorption of Fe from Fe(3+)-chelates appear to require reduction of Fe(3+)-chelate to Fe(2+)-chelate at the root, with Fe(2+) being the principal form of Fe absorbed by soybean.

  8. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-01-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity

  9. Decorporation of metal ions by chelating agents

    International Nuclear Information System (INIS)

    Koenig, T.

    1978-01-01

    Simple model designs to simulate the effect of therapeutical chelating agents on the behaviour of metals in mammal organisms with and without excretion have been derived and analytical solutions given for the corresponding differential equations. The possibilities of these models in the short-term description of plasma kinetics of various metals, the competition of the therapeutical ligands with proteins for the metal and of the metabolism of chelating agents were tested and the properties applying extreme conceivable parameters were analyzed. The simple models were successsively expanded in logical sequence, so that it was possible to qualitatively well describe over a long period of time, the metallic kinetics in plasma, organs and urine, the retention of the ligands and their effect on the metal excretion. Two suggestions were given to describe the so-called after-effect, an increased excretion of the metal at times when the ligand is almost completely excreted and their different behaviour after injecting the metal chelate is given. Calculations on the therapy with several ligand data as well as on dose fractionation are described resting on the ratios in the plutonium-239 chosen model parameters and the determining mechanisms analyzed. (orig./MG) [de

  10. IRON CHELATION THERAPY IN THALASSEMIA SYNDROMES

    Directory of Open Access Journals (Sweden)

    Paolo Cianciulli

    2009-06-01

    Full Text Available Transfusional hemosiderosis is a frequent complication in patients with transfusion dependent chronic diseases such as  thalassemias and severe type of sickle cell diseases. As there are no physiological mechanisms to excrete the iron contained in transfused red cells (1 unit of blood contains approximately 200 mg of iron the excess of iron is stored in various organs. Cardiomyopathy is the most severe complication covering more than 70% of the causes of death of thalassemic patients. Although the current reference standard iron chelator deferoxamine (DFO has been used clinically for over four decades, its effectiveness is limited by a demanding therapeutic regimen that leads to poor compliance. Despite poor compliance, because of the inconvenience of subcutaneous infusion, DFO improved considerably the survival and quality of life of patients with thalassemia. Deferiprone since 1998 and Deferasirox since 2005 were licensed for clinical use. The oral chelators have a better compliance because of oral use, a comparable efficacy to DFO in iron excretion and probably a better penetration to myocardial cells. Considerable increase in iron excretion was documented with combination therapy of DFO and Deferiprone. The proper use of the three chelators will improve the prevention and treatment of iron overload, it will reduce  complications, and improve survival and quality of life of transfused patients

  11. Embedding in thermosetting resins

    International Nuclear Information System (INIS)

    Buzonniere, A. de

    1985-01-01

    Medium activity waste coming either from nuclear power plants in operation such as evaporator concentrates, spent resins, filter cartridges or the dismantling of installations are embedded in order to obtain a product suitable for long term disposal. Embedding in thermosetting resins (polyester or epoxy) is one among currently used techniques; it is being developed by the CEA (Commissariat a l'Energie Atomique) and Technicatome (subsidiary of CEA and EDF). The process is easy to operate and yields excellent results particularly as far as volume reduction and radioelement containment (cesium particularly) are concerned. The process has already been in operation in four stationary plants for several years. Extension of the process to mobile units has been completed by Technicatome in collaboration with the CEA [fr

  12. Synthesis and Mechanism of Metal-Mediated Polymerization of Phenolic Resins

    Directory of Open Access Journals (Sweden)

    Zhao Yi

    2016-04-01

    Full Text Available Phenol-formaldehyde (PF resin is a high performance adhesive, but has not been widely developed due to its slow curing rate and high curing temperature. To accelerate the curing rate and to lower the curing temperature of PF resin, four types of metal-mediated catalysts were employed in the synthesis of PF resin; namely, barium hydroxide (Ba(OH2, sodium carbonate (Na2CO3, lithium hydroxide (LiOH, and zinc acetate ((CH3COO2Zn. The cure-acceleration effects of these catalysts on the properties of PF resins were measured, and the chemical structures of the PF resins accelerated with the catalysts were investigated by using Fourier transform infrared (FT-IR spectroscopy and quantitative liquid carbon-13 nuclear magnetic resonance (13C NMR. The results showed that the accelerated efficiency of these catalysts to PF resin could be ordered in the following sequence: Na2CO3 > (CH3COO2Zn > Ba(OH2 > LiOH. The catalysts (CH3COO2Zn and Na2CO3 increased the reaction activity of the phenol ortho position and the condensation reaction of ortho methylol. The accelerating mechanism of (CH3COO2Zn on PF resin is probably different from that of Na2CO3, which can be confirmed by the differences in the differential thermogravimetric (DTG curve and thermogravimetric (TG data. Compared to the Na2CO3-accelerated PF resin, the (CH3COO2Zn-accelerated PF resin showed different peaks in the DTG curve and higher weight residues. In the synthesis process, the catalyst (CH3COO2Zn may form chelating compounds (containing a metal-ligand bond, which can promote the linkage of formaldehyde to the phenolic hydroxyl ortho position.

  13. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  14. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  15. Mixed ligand chelates of rare earths in aqueous solution

    International Nuclear Information System (INIS)

    Lakhani, S.U.; Thakur, G.S.; Sangal, S.P.

    1981-01-01

    Mixed ligand chelates of the 1:1 trivalent lanthanoids-EDTA, HEDTA and NTA chelates-1, 2-Dihydroxybenzene (Pyrocatechol) have been investigated at 35degC and 0.2 M ionic strength maintained by NaC10 4 . The formation of mixed ligand chelates has been found in all cases. The formation of mixed ligand chelates with EDTA shows the coordination number of lanthanoids to be eight, while the mixed ligand chelates with HEDTA and NTA shows the coordination number to be seven and six respectively. The stability constants of mixed ligand chelates are smaller than the binary complexes. The order of stability constants with respect to primary ligands follows the order NTA>HEDTA>EDTA. With respect to metal ions the stability constants increases with the decrease in ionic radii such as Gd< Er< Yb. (author)

  16. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    Background. Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  17. Role of chelates in magnetic resonance imaging studies

    Directory of Open Access Journals (Sweden)

    Tripathi Laxmi

    2009-01-01

    Full Text Available Imaging studies are tests performed with a variety of techniques that produce pictures of the inside of a patient′s body. Magnetic resonance imaging (MRI is an imaging technique based on the principles of nuclear magnetic resonance. MRI uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of organs, soft tissues, bone, and virtually all other internal body structures. Chelates have a wide application in such imaging techniques. Chelates in imaging studies are used alone as radioactive agents or conjugated to monoclonal antibodies or to DNA as radioactive agents. Technetium chelates and gadolinium chelates are being widely used as magnetic resonance contrast media.

  18. Metal regeneration of iron chelates in nitric oxide scrubbing

    Science.gov (United States)

    Chang, S.G.; Littlejohn, D.; Shi, Y.

    1997-08-19

    The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.

  19. Relationship among chelator adherence, change in chelators, and quality of life in thalassemia.

    Science.gov (United States)

    Trachtenberg, Felicia L; Gerstenberger, Eric; Xu, Yan; Mednick, Lauren; Sobota, Amy; Ware, Hannah; Thompson, Alexis A; Neufeld, Ellis J; Yamashita, Robert

    2014-10-01

    Thalassemia, a chronic blood disease, necessitates life-long adherence to blood transfusions and chelation therapy to reduce iron overload. We examine stability of health-related quality of life (HRQOL) in thalassemia and adherence to chelation therapy over time, especially after changes in chelator choice. Thalassemia Longitudinal Cohort participants in the USA, UK, and Canada completed the SF-36v2 (ages 14+) and the PF-28 CHQ (parents of children health status) at baseline who made a single change in chelator, but declined among participants with multiple changes and/or high iron burden (worse health status). Mental health improved among participants with lower iron burden, but iron overload was negatively associated with social functioning. Adherence did not significantly change over follow-up except for an increase after a change from deferoxamine (DFO) infusion to oral deferasirox (p = 0.03). Predictors of lower adherence for adults/adolescents at follow-up included side effects, smoking, younger age, problems preparing DFO, increased number of days per week DFO prescribed, and lower physical quality of life . Strategies to balance medical needs with family, work, and personal life may assist in adherence.

  20. Resin regenerating device in condensate desalting system

    International Nuclear Information System (INIS)

    Sato, Yoshiaki; Igarashi, Hiroo; Oosumi, Katsumi; Nishimura, Yusaku; Ebara, Katsuya; Shindo, Norikazu.

    1984-01-01

    Purpose: To improve the accuracy in the separation of anionic and cationic exchange resins. Constitution: Resins transferred from a condensate desalting column are charged in a cationic exchange resin column. The temperature of water for separating and transferring the resins is measured by a temperature detector disposed in a purified water injection line, and water is adjusted to a suitable flow rate for the separation and transfer of the resins by an automatic flow rate control valve, and then is injected. The resins are separated into cationic exchange resins and anionic exchange resins, in which only the anionic exchange resins are transferred, through an anionic exchange transfer line, into an anionic exchange resin column. By controlling the flow rate depending on the temperature of the injected water, the developing rate of the resin layer is made constant to enable separation and transfer of the resins at high accuracy. (Seki, T.)

  1. Properties of the Carboxylate ion exchange resins

    International Nuclear Information System (INIS)

    Allard, Bert; Dario, Maarten; Boren, Hans; Torstenfelt, Boerje; Puigdomenech, Ignasi; Johansson, Claes

    2002-09-01

    Weakly acidic, carboxylic resin has been selected, together with strong base anion resins, for water purification at the Forsmark 1 and 2 reactors. For the strong (but not the weak) ion exchange resin the Nuclear Power Inspectorate has given permission to dispose the spent resins in the SFR 1 (the Final Repository for Radioactive Operational Waste). This report gives a review of the carboxylic resins and comes to the conclusion that the resins are very stable and that there should not exist any risks for increased leaching of radionuclides from SFR 1 if these resins are disposed (compared to the strong resins)

  2. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  3. Chemoviscosity modeling for thermosetting resins

    Science.gov (United States)

    Tiwari, S. N.; Hou, T. H.; Bai, J. M.

    1985-01-01

    A chemoviscosity model, which describes viscosity rise profiles accurately under various cure cycles, and correlates viscosity data to the changes of physical properties associated with structural transformations of the thermosetting resin system during cure, was established. Work completed on chemoviscosity modeling for thermosetting resins is reported.

  4. Cure shrinkage in casting resins

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J. Brock [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    A method is described whereby the shrinkage of a casting resin can be determined. Values for the shrinkage of several resin systems in frequent use by Sandia have been measured. A discussion of possible methods for determining the stresses generated by cure shrinkage and thermal contraction is also included.

  5. The effect of the conditions of amidoximation on the adsorptive characteristics of amide oxime resin for uranium recovery from seawater

    International Nuclear Information System (INIS)

    Hori, Takahiro; Furusaki, Shintaro; Sugo, Takanobu; Okamoto, Jiro.

    1987-01-01

    A hollow-fiber type chelating resin containing the amide oxime group for the recovery of uranium from seawater was synthesized by radiation-induced graft polymerization. The effect of the conditions of amidoximation on the amount and/or distribution of the functional groups and on the durability to the recycle adsorption was investigated. The amount of adsorbed copper on the resin increased with the reaction time of the amidoximation, but that of adsorbed hydrochloric acid gradually decreased after reaching the maximum. From the results of elemental analysis, infrared adsorption spectra, visible light and ultraviolet adsorption spectra and the observation of coloration of the resin by alkaline treatment, the amidoximation was found to be a consecutive reaction. The results also suggested that, after the introduction of the amide oxime group, the acidic amide, hydroxamic acid and/or cyclic functional groups were formed. From the measurement of the distribution of adsorbed copper by X-ray microanalyzer, it was confirmed that the amidoximation occured uniformly across the resin. An experiment was carried out on the recycle adsorption of the amide oxime resin using natural seawater, and the sufficient durability was recognized for the case that the resin was taken out from the hydroxylamine solution at the time when the amount of adsorbed hydrochloric acid reached the maximum. In this case the resin contained the largest amount of the amide oxime group and least amount of the by-products formed from the secondary reactions. (author)

  6. Chelate-assisted phytoextraction of lead from contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, E.M.; Sims, J.T.; Cunningham, S.D.; Huang, J.W.; Berti, W.R.

    1999-12-01

    Phytoextraction, a remediation strategy for lead (Pb)-contaminated soils that removes soil Pb through plant uptake and harvest, may be enhanced by use of synthetic chelates. The authors evaluated Pb desorption from four contaminated soils by seven chelates (CDTA, DTPA, EDDHA, EFTA, HEDTA, HEIDA, and NTA) at three rates. The three most effective chelates (CDTA, DTPA, and HEDTA) were used in greenhouse studies with an uncontaminated soil and a Pb-contaminated soil to determine the effect of chelate type and rate on growth, Pb uptake, and plant elemental composition. Lead desorption varied with chelate and soil and increased with chelate rate, averaging 948 mg Pb kg{sup {minus}1} at the 20 mmol kg{sup {minus}1} rate vs. 28 mg Pb kg{sup {minus}1} by the control. The general ranking of chelate effectiveness, based on total Pb desorbed, was HEDTA > CDTA > DTPA > EGTA > HEIDA > EDDHA {approximately} NTA. Plant uptake of Pb from the contaminated soil was enhanced by CDTA, DTPA, and HEDTA, but with even the most effective treatment (corn, high CDTA rate), the amount of Pb extracted by plants was rather low. Lead extractable by the Toxicity Characteristic Leaching Procedure (TCLP) was increased from 9 mg L{sup {minus}1} in the control to from 47 to 174 mg L{sup {minus}1} in soils treated with 20 mmol kg{sup {minus}1} CDTA or DTPA and chelates generally caused a shift in Pb from resistant to more soluble chemical fractions.

  7. Potentials and drawbacks of chelate-enhanced phytoremediation of soils

    NARCIS (Netherlands)

    Römkens, P.F.A.M.; Bouwman, L.A.; Japenga, J.; Draaisma, C.

    2002-01-01

    Chelate-enhanced phytoremediation has been proposed as an effective tool for the extraction of heavy metals from soils by plants. However, side-effects related to the addition of chelates, e.g. metal leaching and effects on soil micro-organisms, were usually neglected. Therefore, greenhouse and

  8. Chelation Treatment for Autism Spectrum Disorders: A Systematic Review

    Science.gov (United States)

    Davis, Tonya N.; O'Reilly, Mark; Kang, Soyeon; Lang, Russell; Rispoli, Mandy; Sigafoos, Jeff; Lancioni, Giulio; Copeland, Daelynn; Attai, Shanna; Mulloy, Austin

    2013-01-01

    Chelation treatment is used to eliminate specific metals from the body, such as mercury. It has been hypothesized that mercury poisoning may be a factor in autism and data suggest that perhaps 7% of individuals with autism spectrum disorder (ASD) have received chelation treatment. It would therefore seem timely to review studies investigating the…

  9. Development of iron chelators for Cooley's anemia. Final report

    International Nuclear Information System (INIS)

    Crosby, W.H.; Green, R.

    1982-01-01

    Iron chelators were screened in an iron-loaded rat model using selective radioiron probes. In all experiments, chelators D and F, in that order, induced significant loss of radioiron compared with controls. However, use of chelator D was associated with side effects, and resulted in the death of some animals. There was some evidence that chelator A also caused iron loss significantly greater than controls. Chelators B, C and E were without apparent enhancing effect on radioiron excretion. This was a blind study and the compounds used were A - 2,3-Dihydroxybenzoic acid; B - N,N1-Dimethyladipohydroxamic acid; C - DL-Phenylalanine hydroxamic acid; D - Ethylenediamine-N,N1-bis(2-hydroxphenylacetic acid); E - Propionohydroxamic acid; and F - Deferrioxamine B

  10. Treating Lead Toxicity: Possibilities beyond Synthetic Chelation

    Directory of Open Access Journals (Sweden)

    Shambhavi Tannir

    2013-01-01

    Full Text Available Lead, a ubiquitous metal, is one of the most abundant elements present on earth. Its easy availability and cost effectiveness made it an extremely popular component in the industrial revolution. However, its hazardous health effects were not considered at the time. Over the last few decades, with the adverse effects of lead coming to the forefront, nations across the world have started to recognize and treat lead toxicity. The most reliable and used method until now has been chelation therapy. Recent research has suggested the use of natural products and sources to treat lead poisoning with minimal or no side effects. This review has tried to summarize a few of the natural products/sources being investigated by various groups.

  11. Sorption Efficiency of a New Sorbent towards Cadmium(II: Methylphosphonic Acid Grafted Polystyrene Resin

    Directory of Open Access Journals (Sweden)

    Nacer Ferrah

    2013-01-01

    Full Text Available A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization by FTIR and elementary analysis, the new resin has been investigated in liquid-solid extraction of cadmium(II. The results indicated that phosphonic resin could adsorb Cd(II ion effectively from aqueous solution. The adsorption was strongly dependent on the pH of the medium and the optimum pH value level for better sorption was between 3.2 and 5.2. The influence of other analytical parameters including contact time, amount of resin, metal ion concentration, and the presence of some electrolytes was investigated. The maximum uptake capacity of Cd(II ions was 37,9 mg·g−1 grafted resin at ambient temperature, at an initial pH value of 5.0. The overall adsorption process was best described by pseudo second-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. Furthermore, more than 92% of Cd(II could be eluted by using 1.0 mol·L−1 HCl in one cycle.

  12. Chelating impact assessment of biological ad chemical chelates on metal extraction from contaminated soils

    International Nuclear Information System (INIS)

    Manwar, S.; Iram, S.

    2014-01-01

    Soil contamination is the result of uncontrolled waste dumping and poor practices by humans. Of all the pollutants heavy metals are of particular concern due to their atmospheric deposition, leaching capacity and non-biodegradability. Heavy metal containing effluent is discharged into the agricultural fields and water bodies. This results in the accumulation of heavy metals in soil and the crops grown on that soil. Studies have revealed detrimental impacts on soil fertility and the poor health of animals and humans. Phytoextraction is widely researched for remediation of heavy metal contaminated soil. To enhance the effect of phytoextraction heavy metals have to be available to the plants in soluble form. In this study the potential of different chelating agents was assessed in solubilizing the heavy metals making easy for plants to uptake them. For this purpose efficient chemical and biological chelating agent had to be identified. Along with that an optimum dose and application time for chemical chelating agent was determined. Ethylenediamine tetraacetic acid (EDTA), Diethylene triamine pentaacetic acid (DTPA), Nitriloacetic acid (NTA) were applied to the soil, containing Pb, Cr, Cu and Cd, at different concentrations and application time. Aspergillus niger and Aspergillus flavus were incubated in soil for different time periods. In correspondence with findings of the study, Pb and Cr were best solubilized by 5mM EDTA. For Cd and Cu 5mM DTPA carried out efficient chelation. NTA showed relatively inadequate solubilisation, although for Cr it performed equal to EDTA. A. niger and A. flavus instead of solubilizing adsorbed the metals in their biomass. Adsorption was mainly carried out by A. niger. (author)

  13. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  14. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  15. Effects of blood contamination on resin-resin bond strength.

    Science.gov (United States)

    Eiriksson, Sigurdur O; Pereira, Patricia N R; Swift, Edward J; Heymann, Harald O; Sigurdsson, Asgeir

    2004-02-01

    Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (microTBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin-resin bond strength. The top surfaces of 64, 4-mm composite blocks (Z-250, Renew, APX, Pertac II) were untreated as the control, or were treated as follows: blood applied and dried on the surface (Treatment 1), blood applied, rinsed, dried (Treatment 2), blood applied, rinsed, and an adhesive applied (Single Bond, One-Step, Clearfil SE, Prompt L-Pop) (Treatment 3). Fresh composite was applied and light-cured in 2-mm increments. After 24 h storage in water, the specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm(2), and loaded to failure at a crosshead speed of 1 mm/min using an Instron universal testing machine. Data were analyzed using two-way ANOVA and Fisher's PLSD test (pcontamination resulted in resin-resin bond strengths of only 1.0-13.1 MPa. Rinsing raised bond strengths to over 40 MPa for each material. Use of an adhesive further increased bond strengths except for Pertac II. Rinsing blood from contaminated surfaces increases the resin-resin bond strength significantly and the application of an appropriate adhesive increases the bond strength to control levels.

  16. Glyphosate, a chelating agent-relevant for ecological risk assessment?

    Science.gov (United States)

    Mertens, Martha; Höss, Sebastian; Neumann, Günter; Afzal, Joshua; Reichenbecher, Wolfram

    2018-02-01

    Glyphosate-based herbicides (GBHs), consisting of glyphosate and formulants, are the most frequently applied herbicides worldwide. The declared active ingredient glyphosate does not only inhibit the EPSPS but is also a chelating agent that binds macro- and micronutrients, essential for many plant processes and pathogen resistance. GBH treatment may thus impede uptake and availability of macro- and micronutrients in plants. The present study investigated whether this characteristic of glyphosate could contribute to adverse effects of GBH application in the environment and to human health. According to the results, it has not been fully elucidated whether the chelating activity of glyphosate contributes to the toxic effects on plants and potentially on plant-microorganism interactions, e.g., nitrogen fixation of leguminous plants. It is also still open whether the chelating property of glyphosate is involved in the toxic effects on organisms other than plants, described in many papers. By changing the availability of essential as well as toxic metals that are bound to soil particles, the herbicide might also impact soil life, although the occurrence of natural chelators with considerably higher chelating potentials makes an additional impact of glyphosate for most metals less likely. Further research should elucidate the role of glyphosate (and GBH) as a chelator, in particular, as this is a non-specific property potentially affecting many organisms and processes. In the process of reevaluation of glyphosate its chelating activity has hardly been discussed.

  17. Chelation: Harnessing and Enhancing Heavy Metal Detoxification—A Review

    Directory of Open Access Journals (Sweden)

    Margaret E. Sears

    2013-01-01

    Full Text Available Toxic metals such as arsenic, cadmium, lead, and mercury are ubiquitous, have no beneficial role in human homeostasis, and contribute to noncommunicable chronic diseases. While novel drug targets for chronic disease are eagerly sought, potentially helpful agents that aid in detoxification of toxic elements, chelators, have largely been restricted to overt acute poisoning. Chelation, that is multiple coordination bonds between organic molecules and metals, is very common in the body and at the heart of enzymes with a metal cofactor such as copper or zinc. Peptides glutathione and metallothionein chelate both essential and toxic elements as they are sequestered, transported, and excreted. Enhancing natural chelation detoxification pathways, as well as use of pharmaceutical chelators against heavy metals are reviewed. Historical adverse outcomes with chelators, lessons learned in the art of using them, and successes using chelation to ameliorate renal, cardiovascular, and neurological conditions highlight the need for renewed attention to simple, safe, inexpensive interventions that offer potential to stem the tide of debilitating, expensive chronic disease.

  18. Synthesis and characterization of a glycerol salicylate resin for bioactive root canal sealers.

    Science.gov (United States)

    Portella, F F; Santos, P D; Lima, G B; Leitune, V C B; Petzhold, C L; Collares, F M; Samuel, S M W

    2014-04-01

    To develop and characterize a salicylate resin with potential use in bioactive endodontic sealers. Methyl salicylate, glycerol and titanium isopropoxide were added in a closed system for the transesterification reaction. The resin obtained was characterized by proton nuclear magnetic resonance spectroscopy (1H NMR) and size exclusion chromatography (SEC). To verify the applicability of the resin to the development of endodontic sealers, experimental cements were prepared by mixing glycerol salicylate resin, calcium hydroxide and methyl salicylate in the ratios of 2 : 1 : 1, 1 : 2 : 1, 1 : 1 : 2, 1 : 1 : 1, 4 : 1 : 1, 1 : 4 : 1 and 1 : 1 : 4. Setting times were measured according to ISO 6876. Features of the hardening reaction were described by micro-RAMAN spectroscopy. The transesterification reaction had a 72% efficiency. The (1) H NMR analysis revealed the presence of the expected functional groups (hydroxyls and aromatic rings), and the SEC confirmed the molar mass of the resin produced. The setting times of experimental sealers ranged from 70 min (ratio 1 : 1 : 1) to 490 min (ratio 1 : 1 : 4). The conversion of the salicylic groups (1 613 cm(-1) ) to salicylate salt (1 543 cm(-1) ) and the reduction in calcium hydroxide peaks (1084 and 682 cm(-1) ) were confirmed by micro-RAMAN spectroscopy, which showed the calcium chelation by the resin. The new glycerol salicylate resin was successfully synthesized and revealed a potential application in the development of endodontic sealers. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. Removal of Pb2+ from Water by Synthesized Tannin Resins from Invasive South African Trees

    Directory of Open Access Journals (Sweden)

    Bamidele J. Okoli

    2018-05-01

    Full Text Available Contamination of water by Pb 2 + and the threat of invasive vegetation affects the quality and quantity of water accessible to all life forms and has become a primary concern to South Africa and the world at large. This paper synthesized, characterized, and evaluated the resins from tannin-rich invasive Acacia species as an environmentally benign Pb 2 + adsorbent. The analysis of the pore volume and surface area of the resins reveals a small pore dimension of 9 × 10−3 cc/g and large surface area (2.31–8.65 m2/g, presenting suitable physical parameters for adsorption of Pb 2 + . Langmuir model offers the best correlation data at pH 6 with maximum monolayer coverage capacity of 189.30, 105.70 and 98.82 mg/g for silver, black and green wattle tannin resins in aqueous solutions, respectively. The kinetic data suitably fits into a pseudo-second-order model, with the Dubinin–Radushkevich adsorption energy (E ≤ 7.07 KJ/mol and intra-particle diffusion model confirming an associated physisorption process within the bio-sorption system. The thermogravimetric analysis (TGA and Fourier-transform infrared (FT-IR data of the resins were informative of the high thermal stability and chelating functionality such as -OH and -NH2 responsible for the removal of Pb 2 + . All the resins showed good adsorption characteristics while silver wattle tannin resin has the best adsorption capacity compared to black and green wattle tannin resins. This study provides a prototype adsorbent from invasive plants for the removal of Pb 2 + in water.

  20. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  1. Mechanism for transporting used resin

    International Nuclear Information System (INIS)

    Sugimoto, Yoshikazu; Yusa, Hideo; Kamiya, Kunio.

    1975-01-01

    Object: In the operation of a light water reactor type atomic power plant, to permit transport and reuse of used ion exchange resin used for the filtering or cleaning of cooling water or the desalting of radioactive exhaust liquid through an ejector. Structure: Used ion exchange resin within a desalter having high radioactivity is withdrawn through the action of an ejector and led to a solid-liquid separator for separation into used resin and water. The separated resin is directly collected in a storage tank while the separated water is forced through a circulating pump to a gas-liquid separator for separation into gas having radioactivity and water. The separated gas is led to a radioactive gas treatment station while the water deprived of the gas is recirculated by a drive water pump for repeated use. (Kamimura, M.)

  2. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  3. Mechanism for transporting used resin

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Yusa, H; Kamiya, K

    1975-01-16

    In the operation of a light water reactor type atomic power plant the objectives is to permit transport and reuse of used ion exchange resin used for the filtering or cleaning of cooling water or the desalting of radioactive exhaust liquid through an ejector. Used ion exchange resin within a desalter having high radioactivity is withdrawn through the action of an ejector and led to a solid-liquid separator for separation into used resin and water. The separated resin is directly collected in a storage tank while the separated water is forced through a circulating pump to a gas-liquid separator for separation into gas having radioactivity and water. The separated gas is led to a radioactive gas treatment station while the water deprived of the gas is recirculated by a drive water pump for repeated use.

  4. Selectivity in extraction of copper and indium with chelate extractants

    International Nuclear Information System (INIS)

    Zivkovic, D.

    2003-01-01

    Simultaneous extraction of copper and indium with chelate extractants (LIX84 and D2E11PA) was described. Stechiometry of metal-organic complexes examined using the method of equimolar ratios resulted in CuR 2 and InR 3 forms of hydrophobic extracting species. A linear correlation was obtained between logarithm of distribution coefficients and chelate agents and pH, respectively. Selectivity is generally higher with higher concentrations of chelate agents in the organic phase, and is decreased with increase of concentration of hydrogen ions in feeding phase. (Original)

  5. Mixed and chelated waste test programs with bitumen solidification

    International Nuclear Information System (INIS)

    Simpson, S.I.; Morris, M.; Vidal, H.

    1988-01-01

    This paper presents the results of bitumen solidification tests on mixed wastes and chelated wastes. The French Atomic Energy Commission (CEA) performed demonstration tests on radioactive wastes contaminated with chelating agents for Associated Technologies, Inc. (ATI). The chelated wastes were produced and concentrated by Commonwealth Edison Co. as a result of reactor decontamination at Dresden Nuclear Station, Unit 1. Law Engineering in Charlotte, N. C. produced samples and performed tests on simulated heavy metal laden radioactive waste (mixed) to demonstrate the quality of the bituminous product. The simulation is intended to represent waste produced at Oak Ridge National Labs operated by Martin-Marietta

  6. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tetsurou (Nitto Denko Corp., Ibaraki, Osaka (Japan)); Sawa, Toshio; Shindoh, Toshikazu

    1989-09-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author).

  7. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    International Nuclear Information System (INIS)

    Adachi, Tetsurou; Sawa, Toshio; Shindoh, Toshikazu.

    1989-01-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author)

  8. 3-hydroxy-2(1H)-pyridinone chelating agents

    Science.gov (United States)

    Raymond, K.; Xu, J.

    1999-04-06

    Disclosed is a series of improved chelating agents and the chelates formed from these agents, which are highly effective upon both injection and oral administration. Several of the most effective are of low toxicity. These chelating agents incorporate within their structure 3-hydroxy-2-pyridinone (3,2-HOPO) moieties with a substituted carbamoyl group ortho to the hydroxy group of the hydroxypyridinone ring. The electron-withdrawing carbamoyl group increases the acidity, as well as the chemical stability towards oxidation and reduction, of the hydroxypyridinones. In the metal complexes of the chelating agents, the amide protons form very strong hydrogen bonds with the adjacent HOPO oxygen donor, making these complexes very stable at physiological conditions. The terminal N-substituents provide a certain degree of lipophilicity to the 3,2-HOPO, increasing oral activity. 2 figs.

  9. Chelation of di- and trivalent iron with some polyaminopolycarboxylic acids

    International Nuclear Information System (INIS)

    Hafez, M.B.; Sharabi, Nahid; Patti, Francois.

    1979-02-01

    The chelation of di- and trivalent iron with some polyaminopolycarboxylic acids was studied. The influence of pH on the formation of the complex was investigated, the molecular ratio and the stability constants were determined [fr

  10. Method of solidifying radioactive ion exchange resin

    International Nuclear Information System (INIS)

    Minami, Yuji; Tomita, Toshihide

    1989-01-01

    Spent anion exchange resin formed in nuclear power plants, etc. generally catch only a portion of anions in view of the ion exchange resins capacity and most of the anions are sent while possessing activities to radioactive waste processing systems. Then, the anion exchange resins increase the specific gravity by the capture of the anions. Accordingly, anions are caused to be captured on the anion exchange resin wastes such that the specific gravity of the anion exchange resin wastes is greater than that of the thermosetting resins to be mixed. This enables satisfactory mixing with the thermosetting resins and, in addition, enables to form integral solidification products in which anion exchange resins and cation exchange resins are not locallized separately and which are homogenous and free from cracks. (T.M.)

  11. Iron chelators ICL670 and 311 inhibit HIV-1 transcription

    International Nuclear Information System (INIS)

    Debebe, Zufan; Ammosova, Tatyana; Jerebtsova, Marina; Kurantsin-Mills, Joseph; Niu, Xiaomei; Charles, Sharroya; Richardson, Des R.; Ray, Patricio E.; Gordeuk, Victor R.; Nekhai, Sergei

    2007-01-01

    HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics

  12. Disposal of bead ion exchange resin wastes

    International Nuclear Information System (INIS)

    Gay, R.L.; Granthan, L.F.

    1985-01-01

    Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means

  13. The use of chelating ion exchanger in conjunction with radioisotope X-ray spectrometry for determination of trace amounts of metals in water

    International Nuclear Information System (INIS)

    Holynska, B.

    1974-01-01

    The chelating ion exchange resin Chelex-100 has been applied for collection of trace amounts of several metal ions from water solutions. The kinetics of the exchange reaction has been measured, as well as the influence of pH of the solution and Ca or Na ion concentrations on the metal collection. The radioisotope X-ray fluorescence method has been applied for determination of metal ions absorbed in the resin. The estimated limit of determination is 0.01 ppm for Fe 3+ , Zn 2+ , Cu 2+ , Hg 2+ , Pb 2+ and Cd 2+ . Total error (1 s) of the method varied from 3 to 15% depending on the metal concentration. (author)

  14. The magnesium chelation step in chlorophyll biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, J.

    1990-11-01

    In photosynthetic organisms, the biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins, and various lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX (Proto). Insertion of iron leads to the formation of hemes, while insertion of magnesium is the first step unique to chlorophyll formation. This project is directed toward identifying the enzyme(s) responsible for magnesium chelation and elucidating the mechanism which regulates the flux of precursors through the branch point enzymes in isolated chloroplasts. Using intact chloroplasts from greening cucumber cotyledons, we have confirmed the ATP requirement for Mg-Proto formation. Use of non-hydrolyzable ATP analogs, uncouplers and ionophores has led to the conclusions that ATP hydrolysis is necessary, but that this hydrolysis is not linked to the requirement for membrane intactness by transmembrane ion gradients or electrical potentials. The enzyme(s) are flexible with respect to the porphyrin substrate specificity, accepting porphyrins with -vinyl, -ethyl, or -H substituents at the 2 and 4 positions. The activity increases approximately four-fold during greening. Possible physiological feedback inhibitors such as heme, protochlorophyllide, and chlorophyllide had no specific effect on the activity. The activity has now been assayed in barely, corn and peas, with the system from peas almost ten-fold more active than the cucumber system. Work is continuing in pea chloroplasts with the development of a continuous assay and investigation of the feasibility of characterizing an active, organelle-free preparation. 6 figs.

  15. Action of ionizing radiation on epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, M. E.

    1970-12-01

    The resistance of classical and experimental epoxy resins to irradiation was studied. The resistance to irradiation of epoxy resins of diverse compositions as well as the development of resins having a radioresistance that approaches that of certain ceramics are discussed. Sources of irradiation and the techniques of dosimetry used are described. The structures of certain epoxy resins and of hardeners are given. The preparation of these resins and their physical properties is described. The effects of radiation on epoxy resins, as well as conditions of irradiation, and suggested mechanisms for degradation of the irradiated resins are discussed. The relationship between chemical structure of the resins and their physical properties is evaluated. (115 references) (JCB)

  16. Method for loading resin beds

    International Nuclear Information System (INIS)

    Notz, K.J.; Rainey, R.H.; Greene, C.W.; Shockley, W.E.

    1978-01-01

    An improved method of preparing nuclear reactor fuel by carbonizing a uranium loaded cation exchange resin provided by contacting a H+ loaded resin with a uranyl nitrate solution deficient in nitrate, comprises providing the nitrate deficient solution by a method comprising the steps of reacting in a reaction zone maintained between about 145 to 200 0 C, a first aqueous component comprising a uranyl nitrate solution having a boiling point of at least 145 0 C with a second aqueous component to provide a gaseous phase containing HNO 3 and a reaction product comprising an aqueous uranyl nitrate solution deficient in nitrate

  17. Matrix separation by chelation to prepare biological materials for isotopic zinc analysis by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Durrant, S.F.; Krushevska, A.; Amarasiriwardena, D.; Argentine, M.D.; Romon-Guesnier, S.; Barnes, R.M.

    1994-01-01

    Following an evaluation of three chelating resins [Chelex-100, poly(dithiocarbamate) (PDTC) and carboxymethylated poly(ethyleneimine)-poly(methylenepolyphenylene) isocyanate (CPPI)], a procedure was established with the last of these for the separation of Zn from biological matrix elements prior to 70 Zn: 68 Zn isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). The method was verified by establishing Zn recoveries and by determining its effectiveness in removing Cl and Na from buffered test solutions. Calcium, Na, and Zn concentration data were determined by inductively coupled plasma atomic emission spectrometry. Chlorine was measured by electrothermal vaporization ICP-MS. The efficacy of the technique was demonstrated by the determination of zinc isotope ratios in bovine milk and human urine. (Author)

  18. Resin for processing radioactive waste water

    International Nuclear Information System (INIS)

    Onozuka, Teruo; Shindo, Manabu; Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro.

    1995-01-01

    The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.)

  19. Resin for processing radioactive waste water

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan); Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro

    1995-11-07

    The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.).

  20. Preparation of thin {alpha}-particle sources using poly-pyrrole films functionalized by a chelating agent; Preparation de sources minces d'emetteurs alpha a l'aide de films de polypyrrole fonctionnalises par un ligand chelatant

    Energy Technology Data Exchange (ETDEWEB)

    Mariet, C. [CEA Saclay, INSTN, Institut National des Sciences et Techniques Nucleaires, 91 - Gif-sur-Yvette (France); Universite Pierre et Marie Curie, 75 - Paris (France)

    2000-07-01

    This work takes place in the scope of analysis of the {alpha}-particle emitting elements U, Pu and Am present in compound environmental matrix like sols and sediments. The samples diversity and above all the {alpha}-ray characteristics require the analyst to implement a sequence of chemical steps in which the more restricting is the actinides concentration in a uniform and thin layer en allowing an accurately measure of alpha activity. On this account, we studied a new technique for radioactive sources preparation based on tow steps: preparation of a thin film as source support; incorporation of radioactive elements by a chelating extraction mechanism. The thin films were obtained through electro-polymerization of pyrrole monomer functionalized by an chelating ligand able to extract actinides from concentrated acidic solutions. Polymerization conditions of this monomer were perfected, then obtained films were characterized from a physico-chemical point of view. We point out their extracting properties were comparable to (retention capacity, distribution coefficient) to those of usual ion-exchange resins. The underscore of uranyl and americium nitrate complexes formed in the thin layer allowed to calculate the extraction constants in case acid extraction is negligible. Thanks to this results, the values of the coefficients distribution D{sub U} and D{sub Am} could be provided for all nitric solutions in which acid extraction is negligible. Optimal actinides retention conditions in the polymer were defined and used to settle a protocol for plutonium analysis in environmental samples. (author)

  1. To chelate or not to chelate in MDS: That is the question!

    Science.gov (United States)

    Zeidan, Amer M; Griffiths, Elizabeth A

    2018-03-08

    Myelodysplastic syndromes (MDS) are a heterogeneous group of hemopathies that exhibit physical manifestations with clinical consequences of bone marrow failure and inherent risk of progression to acute myeloid leukemia. Iron overload (IO) is common in MDS due to chronic transfusion support and disease-related alterations in iron metabolism. IO has been conclusively associated with inferior outcomes among MDS patients. Despite lack of randomized trials showing a survival impact of iron chelation therapy (ICT), ICT is recommended by experts and guidelines for select MDS patients with IO and is often used. The availability of effective oral ICT agents has reignited the controversy regarding ICT use in patients with MDS and IO. Here we summarize the studies evaluating the value of ICT in MDS and suggest a practical approach for use of these therapies. We also highlight controversies regarding use of ICT in MDS and discuss some ongoing efforts to answer these questions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. 21 CFR 177.1680 - Polyurethane resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyurethane resins. 177.1680 Section 177.1680 Food... of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of the...

  3. Method of removing contaminants from plastic resins

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-11-18

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  4. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  5. In vitro and in vivo evaluation of potential aluminum chelators.

    Science.gov (United States)

    Graff, L; Muller, G; Burnel, D

    1995-10-01

    The potential for aluminium (Al) chelation by different compounds was determined using 2 in vitro techniques. The formation of stable complexes with Al in an aqueous solution was evaluated using pulse polarography. This technique allowed the influence of temperature and calcium (Ca) to be studied for each compound. Certain compounds (EDDHA, HAES, citric acid and HBED) showed great chelation in the absence of Ca2+ at a temperature of 37 +/- 1 C. An ultrafiltration technique combined with Al determination by atomic emission spectroscopy allowed the efficiency of different substances to complex Al that were previously bound to serum proteins to be estimated. The kinetics of chelation and minimum efficient concentration have been determined for all products studied. EDDHA had chelation potential similar to DFO. The real efficacies of the compounds were studied in vivo to compare the effectiveness of repeated administrations of the best chelating agents (EDDHA, DFO, HAES and tartaric acid) on the distribution and excretion of Al after repeated i.p. administrations to rats. Intraperitoneal EDDHA significantly increased urinary metal (Al, Ca, Cu, Fe and Zn) excretion. These excretions may be correlated to a renal toxic potential property.

  6. The adsorption of chelating reagents on oxide minerals

    International Nuclear Information System (INIS)

    Bryson, M.A.W.

    1984-06-01

    This work constitutes a fundamental study of the interaction between chelating reagents and oxide minerals. The adsorption mechanisms have been elucidated for most of the systems generated by the oxides of copper(II) or iron(III) and chelating reagents octyl hydroxamate, N-phenylbenzohydroxamate, salicylaldoxime, 5-nitro-salicylaldoxime or 8-hydroxyquinoline. In order to better understand the adsorption process associated with copper(II) oxide, the oxide was recrystallized to produce a coarser material with a more uniform surface. This allowed the oxide surface to be viewed under the scanning electron microscope. A detailed investigation of the effect of the system variables; pH, conditioning period, concentration, temperature, surface area and dispersing reagent on the rate of precipitation of the copper chelate species of general form, Cu(chel) 2 , was made. In addition the chemical nature of the adsorbed species and the structural form of the precipitates were determined with the aid of infra-red spectroscopy and the scanning electron microscope. On the basis of these results a model has been formulated for the adsorption processes. The precipitation process was examined in more detail by the study of the adsorption of chelate on copper metal. Contact angle measurements of air bubbles on copper metal conditioned with chelate were related to the adsorption results in an attempt to isolate the optimum conditions for flotation of oxide minerals

  7. Chelation therapy to prevent diabetes-associated cardiovascular events.

    Science.gov (United States)

    Diaz, Denisse; Fonseca, Vivian; Aude, Yamil W; Lamas, Gervasio A

    2018-05-24

    For over 60 years, chelation therapy with disodium ethylene diamine tetraacetic acid (EDTA, edetate) had been used for the treatment of cardiovascular disease (CVD) despite lack of scientific evidence for efficacy and safety. The Trial to Assess Chelation Therapy (TACT) was developed and received funding from the National Institutes of Health (NIH) to ascertain the safety and efficacy of chelation therapy in patients with CVD. This pivotal trial demonstrated an improvement in outcomes in postmyocardial infarction (MI) patients. Interestingly, it also showed a particularly large reduction in CVD events and all-cause mortality in the prespecified subgroup of patients with diabetes. The TACT results may support the concept of metal chelation to reduce metal-catalyzed oxidation reactions that promote the formation of advanced glycation end products, a precursor of diabetic atherosclerosis. In this review, we summarize the epidemiological and basic evidence linking toxic metal accumulation and diabetes-related CVD, supported by the salutary effects of chelation in TACT. If the ongoing NIH-funded TACT2, in diabetic post-MI patients, proves positive, this unique therapy will enter the armamentarium of endocrinologists and cardiologists seeking to reduce the atherosclerotic risk of their diabetic patients.

  8. Preparation of thin α-particle sources using poly-pyrrole films functionalized by a chelating agent

    International Nuclear Information System (INIS)

    Mariet, C.

    2000-01-01

    This work takes place in the scope of analysis of the α-particle emitting elements U, Pu and Am present in compound environmental matrix like sols and sediments. The samples diversity and above all the α-ray characteristics require the analyst to implement a sequence of chemical steps in which the more restricting is the actinides concentration in a uniform and thin layer en allowing an accurately measure of alpha activity. On this account, we studied a new technique for radioactive sources preparation based on tow steps: preparation of a thin film as source support; incorporation of radioactive elements by a chelating extraction mechanism. The thin films were obtained through electro-polymerization of pyrrole monomer functionalized by an chelating ligand able to extract actinides from concentrated acidic solutions. Polymerization conditions of this monomer were perfected, then obtained films were characterized from a physico-chemical point of view. We point out their extracting properties were comparable to (retention capacity, distribution coefficient) to those of usual ion-exchange resins. The underscore of uranyl and americium nitrate complexes formed in the thin layer allowed to calculate the extraction constants in case acid extraction is negligible. Thanks to this results, the values of the coefficients distribution D U and D Am could be provided for all nitric solutions in which acid extraction is negligible. Optimal actinides retention conditions in the polymer were defined and used to settle a protocol for plutonium analysis in environmental samples. (author)

  9. Resins production: batch plant automation

    International Nuclear Information System (INIS)

    Banti, M.; Mauri, G.

    1996-01-01

    Companies that look for automation in their plants without external resources, have at their disposal flexible, custom and easy to use DCS, open towards PLC. In this article it is explained why Hoechts has followed this way of new plants for resins production automation

  10. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  11. Bifunctional chelates of Rh-105 and Au-199 as potential radiotherapeutic agents

    International Nuclear Information System (INIS)

    Troutner, D.E.; Schlemper, E.O.

    1990-01-01

    Since last year we have: continued the synthesis of pentadentate bifunctional chelating agents based on diethylene triamine; studied the chelation Rh-105, Au-198 (as model for Au-199) and Tc-99m with these agents as well as chelation of Pd-109, Cu-67, In-111, and Co-57 with some of them; synthesized a new class of potential bifunctional chelating agents based on phenylene diamine; investigated the behavior of Au-198 as a model for Au-199; begun synthesis of bifunctional chelating agents based on terpyridly and similar ligands; and continued attempts to produce tetradentate bifunctional chelates based on diaminopropane. Each of these will be addressed in this report

  12. Albumin microspheres labeled with Ga-67 by chelation: concise communication

    International Nuclear Information System (INIS)

    Hnatowich, D.J.; Schlegel, P.

    1981-01-01

    Albumin microspheres have been synthesized with EDTA and DTPA chelating groups covalently bound to their surface. The microspheres may be labeled with Ga-67 at high yield (97 +- 2%) by transcomplexation from a 0.1 M Ga-67 acetate solution. With EDTA microspheres the resulting label dissociates only slightly after 24 hr in 50% plasma at 37 0 C, whereas with DTPA microspheres the label shows no detectable dissociation over this period. By contrast, microspheres without chelating groups lose their label virtually completely under these conditions. Following intravenous administration of sized Ga-67 DTPA microspheres in mice, about (84 +- 16)% of the activity localizes in the lungs at 5 min, with (60 +- 7)% remaining after 2 h. Since labeling is by chelation, the microspheres may also be tagged with other metallic radionuclides

  13. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89.

    Science.gov (United States)

    Bhatt, Nikunj B; Pandya, Darpan N; Xu, Jide; Tatum, David; Magda, Darren; Wadas, Thaddeus J

    2017-01-01

    The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. Differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimization is necessary to enhance 89Zr chelation.

  14. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89.

    Directory of Open Access Journals (Sweden)

    Nikunj B Bhatt

    Full Text Available The development of bifunctional chelators (BFCs for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2 as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. Differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimization is necessary to enhance 89Zr chelation.

  15. Inositol hexa-phosphate: a potential chelating agent for uranium

    International Nuclear Information System (INIS)

    Cebrian, D.; Tapia, A.; Real, A.; Morcillo, M.A.

    2007-01-01

    Chelation therapy is an optimal method to reduce the radionuclide-related risks. In the case of uranium incorporation, the treatment of choice is so far i.v infusion of a 1.4% sodium bicarbonate solution, but the efficacy has been proved to be not very high. In this study, we examine the efficacy of some substances: bicarbonate, citrate, diethylenetriamine pentaacetic acid (DTPA), ethidronate (EHBP) and inositol hexa-phosphate (phytic acid) to chelate uranium using a test developed by Braun et al. Different concentrations of phytic acid, an abundant component of plant seeds that is widely distributed in animal cells and tissues in substantial levels, were tested and compared to the same concentrations of sodium citrate, bicarbonate, EHBP and DTPA. The results showed a strong affinity of inositol hexa-phosphate for uranium, suggesting that it could be an effective chelating agent for uranium in vivo. (authors)

  16. Oxygen index tests of thermosetting resins

    Science.gov (United States)

    Gilwee, W. J., Jr.; Parker, J. A.; Kourtides, D. A.

    1980-01-01

    The flammability characteristics of nine thermosetting resins under evaluation for use in aircraft interiors are described. These resins were evaluated using the Oxygen Index (ASTM 2863) testing procedure. The test specimens consisted of both neat resin and glass reinforced resin. When testing glass-reinforced samples it was observed that Oxygen Index values varied inversely with resin content. Oxygen values were also obtained on specimens exposed to temperatures up to 300 C. All specimens experienced a decline in Oxygen Index when tested at an elevated temperature.

  17. Commercial Ion Exchange Resin Vitrification Studies

    International Nuclear Information System (INIS)

    Cicero-Herman, C.A

    2002-01-01

    In the nuclear industry, ion exchange resins are used for purification of aqueous streams. The major contaminants of the resins are usually the radioactive materials that are removed from the aqueous streams. The use of the ion exchange resins creates a waste stream that can be very high in both organic and radioactive constituents. Therefore, disposal of the spent resin often becomes an economic problem because of the large volumes of resin produced and the relatively few technologies that are capable of economically stabilizing this waste. Vitrification of this waste stream presents a reasonable disposal alternative because of its inherent destruction capabilities, the volume reductions obtainable, and the durable product that it produces

  18. Protracted chelate therapy after incorporation of plutonium 239 in rats

    International Nuclear Information System (INIS)

    Gemenetzis, E.

    1976-01-01

    The author has tested in how far 239 Pu can be mobilized by Ca and Zn, Desfenioxamin B(DFDA) and by combined doses of Ca-DTPA and DFDA. The pre-experiment covered the 239 Pu-metabolism in untreated male and female rats and the distribution in dependence of the way of application. If treatment is started immediately by multiple chelate doses, the first two injections play the main part in the decorporation of 239 Pu. The combination Ca-DTPA30 + DFDA30 μMol x kg -1 is proved to be the best means of decorporation for the whole body. The efficiency of another therapy depends essentially on the treatment used, a daily treatment showing the best effects. If treatment is started later with multiple chelate doses, the total decorporation efficiency is of less value, especially in the skeleton. Aequimolar doses of Ca-DTPA and Zn-DTPA have the same degree of efficiency. This indicates that during protracted chelate treatment starting later, Ca-DTPA could be substituted by the less toxic Zn-DTPA after incorporation of 239 Pu. These results show that intermittant administration of the week's dose is more efficient than a single chelate administration of the whole week's dose at once. Permanent chelate infusion does not seem necessary in any case since it has the same effect as 3 to 5 injections per week and is difficult to carry out in medical practice. Thus, it seems advisable to divide up the weekly dose into 3-5 injections. In case of a wound contamination, the efficiency of immediate intensive treatment depends on the 239 Pu compound used, on the chelate used, and on its dosage. (orig.) [de

  19. EDTA chelation therapy for cardiovascular disease: a systematic review

    Directory of Open Access Journals (Sweden)

    Wu Ping

    2005-11-01

    Full Text Available Abstract Background Numerous practitioners of both conventional and complementary and alternative medicine throughout North America and Europe claim that chelation therapy with EDTA is an effective means to both control and treat cardiovascular disease. These claims are controversial, and several randomized controlled trials have been completed dealing with this topic. To address this issue we conducted a systematic review to evaluate the best available evidence for the use of EDTA chelation therapy in the treatment of cardiovascular disease. Methods We conducted a systematic review of 7 databases from inception to May 2005. Hand searches were conducted in review articles and in any of the trials found. Experts in the field were contacted and registries of clinical trials were searched for unpublished data. To be included in the final systematic review, the studies had to be randomized controlled clinical trials. Results A total of seven articles were found assessing EDTA chelation for the treatment of cardiovascular disease. Two of these articles were subgroup analyses of one RCT that looked at different clinical outcomes. Of the remaining five studies, two smaller studies found a beneficial effect whereas the other three exhibited no benefit for cardiovascular disease from the use of EDTA chelation therapy. Adverse effects were rare but those of note included a few cases of hypocalcemia and a single case of increased creatinine in a patient on the EDTA intervention. Conclusion The best available evidence does not support the therapeutic use of EDTA chelation therapy in the treatment of cardiovascular disease. Although not considered to be a highly invasive or harmful therapy, it is possible that the use of EDTA chelation therapy in lieu of proven therapy may result in causing indirect harm to the patient.

  20. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    Science.gov (United States)

    Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

    2003-03-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

  1. Combinational chelation therapy abrogates lead-induced neurodegeneration in rats

    International Nuclear Information System (INIS)

    Pachauri, Vidhu; Saxena, Geetu; Mehta, Ashish; Mishra, Deepshikha; Flora, Swaran J.S.

    2009-01-01

    Lead, a ubiquitous and potent neurotoxicant causes oxidative stress which leads to numerous neurobehavioral and physiological alterations. The ability of lead to bind sulfhydryl groups or compete with calcium could be one of the reasons for its debilitating effects. In the present study, we addressed: i) if chelation therapy could circumvent the altered oxidative stress and prevent neuronal apoptosis in chronic lead-intoxicated rats, ii) whether chelation therapy could reverse biochemical and behavioral changes, and iii) if mono or combinational therapy with captopril (an antioxidant) and thiol chelating agents (DMSA/MiADMSA) is more effective than individual thiol chelator in lead-exposed rats. Results indicated that lead caused a significant increase in reactive oxygen species, nitric oxide, and intracellular free calcium levels along with altered behavioral abnormalities in locomotor activity, exploratory behavior, learning, and memory that were supported by changes in neurotransmitter levels. A fall in membrane potential, release of cytochrome c, and DNA damage indicated mitochondrial-dependent apoptosis. Most of these alterations showed significant recovery following combined therapy with captopril with MiADMSA and to a smaller extend with captopril + DMSA over monotherapy with these chelators. It could be concluded from our present results that co-administration of a potent antioxidant (like captopril) might be a better treatment protocol than monotherapy to counter lead-induced oxidative stress. The major highlight of the work is an interesting experimental evidence of the efficacy of combinational therapy using an antioxidant with a thiol chelator in reversing neurological dystrophy caused due to chronic lead exposure in rats.

  2. Interaction of chelating agents with cadmium in mice and rats

    International Nuclear Information System (INIS)

    Eybl, V.; Sykora, J.; Koutensky, J.; Caisova, D.; Schwartz, A.; Mertl, F.

    1984-01-01

    The influence of several chelating agents (CaDTPA, ZnDTPA, CaEDTA, ZnEDTA, DMSA, D-penicillamine and DMPS, DMP and DDC) on the acute toxicity of CdCl 2 and on the whole body retention and tissue distribution of cadmium after the IV application of /sup 115mCdCl 2 was compared in mice. The chelating agents were applied immediately after the application of cadmium. CaDTPA, ZnDTPA and DMSA appeared to be the most effective antidotes. However, DMSA increased the amount of cadmium retained in kidneys. The treatement of cadmium-poisoned mice with the combination of DMSA (IP) and ZnDTPA (SC) (all the compounds were injected in equimolar dose) decreased the toxicity of cadmium more than treatment with one chelating agents (given in a 2:1 dose). However, by studying the effect of these chelating agents and their combination application of the antidotes showed little or no improvement over the results obtained with the most effective of the individual components. In the urine of rats injected with CdCl 2 and treated with the chelating agents (CaDTPA, ZnDTPA, DMSA), the presence of cadmium complexes was demonstrated. The formation of mixed ligand chelates in vivo was not proved. Experiments in mice given a single injection of /sup 115m/Cd-labeled Cd complexes of DMPS, DMSA and DTPA showed a high retention of cadmium in the organisms after the IV application of CdDMPS and CdDMSA complexes

  3. Interaction of chelating agents with cadmium in mice and rats.

    Science.gov (United States)

    Eybl, V; Sýkora, J; Koutenský, J; Caisová, D; Schwartz, A; Mertl, F

    1984-01-01

    The influence of several chelating agents (CaDTPA, ZnDTPA, CaEDTA, ZnEDTA, DMSA, D-penicillamine and DMPS, DMP and DDC) on the acute toxicity of CdCl2 and on the whole body retention and tissue distribution of cadmium after the IV application of 115mCdCl2 was compared in mice. The chelating agents were applied immediately after the application of cadmium. CaDTPA, ZnDTPA and DMSA appeared to be the most effective antidotes. However, DMSA increased the amount of cadmium retained in kidneys. The treatment of cadmium-poisoned mice with the combination of DMSA (IP) and ZnDTPA (SC) (all the compounds were injected in equimolar dose) decreased the toxicity of cadmium more than treatment with one chelating agents (given in a 2:1 dose). However, by studying the effect of these chelating agents and their combination of the retention and distribution of Cd in mice, it was demonstrated that the combined application of the antidotes showed little or no improvement over the results obtained with the most effective of the individual components. In the urine of rats injected with CdCl2 and treated with the chelating agents (CaDTPA, ZnDTPA, DMSA), the presence of cadmium complexes was demonstrated. The formation of mixed ligand chelates in vivo was not proved. Experiments in mice given a single injection of 115mCd-labeled Cd complexes of DMPS, DMSA and DTPA showed a high retention of cadmium in the organisms after the IV application of CdDMPS and CdDMSA complexes. PMID:6734561

  4. Chelation therapy in intoxications with mercury, lead and copper

    DEFF Research Database (Denmark)

    Cao, yang; Skaug, Marit Aralt; Andersen, Ole

    2015-01-01

    In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The relatively new chelators meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-propanesulphonate (DMPS) can effectively...... mobilize deposits of mercury as well as of lead into the urine. These drugs can be administered orally and have relatively low toxicity compared to the classical antidote dimercaptopropanol (BAL). d-Penicillamine has been widely used in copper overload, although 2,3-dimercaptosuccinic acid...

  5. Potentiometric study of Nd3+ chelates of substituted salicylhydroxamic acids

    International Nuclear Information System (INIS)

    Deshpande, R.G.; Jahagirdar, D.V.

    1976-01-01

    The interaction of Nd 3+ ion with salicylhydroxamic acid and 5-methyl, 5-chloro, 5-bromo, 5-nitro, 4-chloro, 4-bromo and 3-chloro salicylhydroxamic acids is investigated potentiometrically by Calvin-Bjerrum titration technique at 30 0 +- 0.1 0 and ionic strength μ=0.1 M(NaClO 4 ) in 50% v/v dioxane-water mixtures. Nd 3+ forms only 1:1 chelates with these ligands. The validity of the log K= apk + b relationship is examined for these chelates. (author)

  6. Spray drying of bead resins: feasibility tests

    International Nuclear Information System (INIS)

    Gay, R.L.; Grantham, L.F.; Jones, L.J.

    1984-01-01

    Rockwell International has developed a volume reduction system for low-level reactor wastes based on drying the wastes in a heated-air spray dryer. The drying of slurries of sodium sulfate, boric acid, and powdered ion exchange resins was demonstrated in previous tests. The drying of bead ion exchange resins can be especially difficult due to the relatively large size of bead resins (about 500 to 800 microns) and their natural affinity for water. This water becomes part of the pore structure of the resins and normally comprises 50 t 60 wt % of the resin weight. A 76-cm-diameter spray dryer was used for feasibility tests of spray drying of cation and anion bead resins. These resins were fed to the dryer in the as-received form (similar to dewatered resins) and as slurries. A dry, free-flowing product was produced in all the tests. The volume of the spray-dried product was one-half to one-third the volume of the as-received material. An economic analysis was made of the potential cost savings that can be achieved using the Rockwel spray dryer system. In-plant costs, transportation costs, and burial costs of spray-dried resins were compared to similar costs for disposal of dewatered resins. A typical utility producing 170 m 3 (6,000 ft 3 ) per year of dewatered resins can save $600,000 to $700,000 per year using this volume reduction system

  7. EDF specifications on nuclear grade resins

    International Nuclear Information System (INIS)

    Mascarenhas, Darren; Gressier, Frederic; Taunier, Stephane; Le-Calvar, Marc; Ranchoux, Gilles; Marteau, Herve; Labed, Veronique

    2012-09-01

    Ion exchange resins are widely used across EDF, especially within the nuclear division for the purification of water. Important applications include primary circuit, secondary circuit and effluent treatment, which require high quality nuclear grade resins to retain the dissolved species, some of which may be radioactive. There is a need for more and more efficient purification in order to decrease worker dose during maintenance but also to decrease volumes of radioactive resin waste. Resin performance is subject to several forms of degradation, including physical, chemical, thermal and radioactive, therefore appropriate resin properties have to be selected to reduce such effects. Work has been done with research institutes, manufacturers and on EDF sites to select these properties, create specifications and to continuously improve on these specifications. An interesting example of research regarding resin performance is the resin degradation under irradiation. Resins used in the CVCS circuit of EDF nuclear power plants are subject to irradiation over their lifetime. A study was carried out on the effects of total integrated doses of 0.1, 1 and 10 MGy on typically used EDF mixed bed resins in a 'mini-CVCS' apparatus to simultaneously test actual primary circuit fluid. The tests confirmed that the resins still perform efficiently after a typical CVCS radiation dose. Certain resins also need additional specifications in order to maintain the integrity of the particular circuits they are used in. Recently, EDF has updated its requirements on these high purity nuclear grade resins, produced generic doctrines for all products and materials used on site which include resins of all grades, and as a result have also updated a guide on recommended resin usage for the French fleet of reactors. An overview of the evolutions will be presented. (authors)

  8. Metal chelate conjugated monoclonal antibodies, wherein the metal is an α emitter

    International Nuclear Information System (INIS)

    Gansow, O.A.; Strand, M.

    1984-01-01

    Methods of manufacturing and purifying metal chelate conjugated monoclonal antibodies are described, wherein the chelated metal emits alpha radiation. The conjugates are suited for therapeutic uses being substantially free of nonchelated radiometal. (author)

  9. Foam, Foam-resin composite and method of making a foam-resin composite

    Science.gov (United States)

    Cranston, John A. (Inventor); MacArthur, Doug E. (Inventor)

    1995-01-01

    This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

  10. Chelating ligands: enhancers of quality and purity of biogas ...

    African Journals Online (AJOL)

    The quality of biogas depends largely on the percentage of methane and hydrogen sulphide gas present. High concentration of hydrogen sulphide results in low quality biogas. This work employed the use of chelating ligands in scrubbing hydrogen sulphide gas while improving the yield of methane gas. Experimental ...

  11. Studies on effect of Microbial Iron Chelators on Candida Albican

    International Nuclear Information System (INIS)

    Rehmani, Fouzia S.; Milicent, S.; Zaheer-Uddin

    2005-01-01

    Iron is an essential for the life of all microbe cells. It generally exists in the oxidized form Fe(III). Even under anaerobic reducing condition the metal appear to be taken up as Fe(III). Thus free-living microorganisms require specific and effective ferric ion transport system to cope with low availability of the metal. In iron deficient environment they produce a low molecular weight specific chelators called siderphores or microbial iron chelators. Siderphores compete for limited supplied of iron. These compounds came out of the cell but can not re-enter without iron due to high affinity of these siderphores often have more than one catechol/hydroxamate functions and are multidentate (usually hexadentate ligands). The aim of the present research is to check the effect of iron chelators, namely gallic acid and salisyl hydroxamate on the growth of Candida albican in vitro. C. albican is the opportunistic paltogen present as the normal flora inside human body. In vivo the growth of C. albican is distributed by the use of antibiotics and immuno suppressers. In cases of iron over-dosage in human being, the patients are treated with certain a-iron chelators. Hence an attempt is made to notice the effect that might be inhibition or enhancement of the organism in vitro. (author)

  12. Laccase Immobilization by Chelated Metal Ion Coordination Chemistry

    Directory of Open Access Journals (Sweden)

    Qingqing Wang

    2014-09-01

    Full Text Available In this work, amidoxime polyacrylonitrile (AOPAN nanofibrous membrane was prepared by a reaction between PAN nanofibers and hydroxylamine hydrochloride. The AOPAN nanofibrous membranes were used for four metal ions (Fe3+, Cu2+, Ni2+, Cd2+ chelation under different conditions. Further, the competition of different metal ions coordinating with AOPAN nanofibrous membrane was also studied. The AOPAN chelated with individual metal ion (Fe3+, Cu2+, Ni2+, Cd2+ and also the four mixed metal ions were further used for laccase (Lac immobilization. Compared with free laccase, the immobilized laccase showed better resistance to pH and temperature changes as well as improved storage stability. Among the four individual metal ion chelated membranes, the stability of the immobilized enzymes generally followed the order as Fe–AOPAN–Lac > Cu–AOPAN–Lac > Ni–AOPAN–Lac > Cd–AOPAN–Lac. In addition, the immobilized enzyme on the carrier of AOPAN chelated with four mixed metal ions showed the best properties.

  13. Chelation of thallium by combining deferasirox and desferrioxamine in rats.

    Science.gov (United States)

    Saljooghi, Amir Shokooh; Babaie, Maryam; Mendi, Fatemeh Delavar; Zahmati, Maliheh; Saljooghi, Zoheir Shokouh

    2016-01-01

    The hypothesis that two known chelators deferasirox (4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid) and desferrioxamine (DFO) might be more efficient as combined treatment than as monotherapies in removing thallium from the body was tested in a new acute rat model. 7-week-old male Wistar rats received chelators: deferasirox (orally), DFO (intraperitoneal; i.p.), or deferasirox + DFO as 75 or 150 mg/kg dose half an hour after a single i.p. administration of 8 mg thallium/kg body weight in the form of chloride. Serum thallium concentration, urinary thallium, and iron excretions were determined by graphite furnace atomic absorption spectrometry. Both chelators were effective only at the higher dose level, while DFO was more effective than deferasirox in enhancing urinary thallium excretion, deferasirox was more effective than DFO in enhancing urinary iron excretion. In the combined treatment group, deferasirox did not increase the DFO effect on thallium and DFO did not increase the effect of deferasirox on iron elimination. Our results support the usefulness of this animal model for preliminary in vivo testing of thallium chelators. Urinary values were more useful because of the high variability of serum results. © The Author(s) 2013.

  14. Mixed ligand chelate therapy for plutonium and cadmium poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J; Derr, S K [Hope Coll., Holland, MI (USA)

    1978-09-28

    Some experiments with mice are described in which complete removal of tissue deposits of /sup 239/Pu and prevention of mortality in animals given lethal doses of Cd were achieved using a mixed ligand chelate treatment (MLC). The mixed ligand consisted of diethylenetriaminepentaacetic acid and salicylic acid.

  15. Iron chelating activity, phenol and flavonoid content of some ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... require regular blood transfusions in order to improve both quality of ... fused red blood cells and the excess iron is deposited as ... potentiation of reactive oxygen species (ROS) and .... The percentage inhibition of ferrozine–Fe2+ complex formation was ... estimation of the chelating activity of the coexisting.

  16. Bone marrow and chelatable iron in patients with protein energy ...

    African Journals Online (AJOL)

    Objectives: To examine the iron status of malnourished children by comparing bone marrow iron deposits in children with protein energy malnutrition with those in well-nourished controls, and measuring chelatable urinary iron excretion in children with kwashiorkor. Design: Bone marrow iron was assessed histologicaHy in ...

  17. f-Element Ion Chelation in Highly Basic Media

    International Nuclear Information System (INIS)

    Paine, R.T.

    2000-01-01

    A large body of data has been collected over the last fifty years on the chemical behavior of f-element ions. The ions undergo rapid hydrolysis reactions in neutral or basic aqueous solutions that produce poorly understood oxide-hydroxide species; therefore, most of the fundamental f-element solution chemistry has allowed synthetic and separations chemists to rationally design advanced organic chelating ligands useful for highly selective partitioning and separation of f-element ions from complex acidic solution matrices. These ligands and new examples under development allow for the safe use and treatment of solutions containing highly radioactive species. This DOE/EMSP project was undertaken to address the following fundamental objectives: (1) study the chemical speciation of Sr and lanthanide (Ln) ions in basic aqueous media containing classical counter anions found in waste matrices; (2) prepare pyridine N-oxide phosphonates and phosphonic acids that might act as selective chelators for Ln ions in model basic pH waste streams; (3) study the binding of the new chelators toward Ln ions and (4) examine the utility of the chelators as decontamination and dissolution agents under basic solution conditions. The project has been successful in attacking selected aspects of the very difficult problems associated with basic pH solution f-element waste chemistry. In particular, the project has (1) shed additional light on the initial stages of Ln ion sol-gel-precipitate formulation under basic solution conditions; (2) generated new families of pyridine phosphonic acid chelators; (3) characterized the function of the chelators and (4) examined their utility as oxide-hydroxide dissolution agents. These findings have contributed significantly to an improved understanding of the behavior of Ln ions in basic media containing anions found in typical waste sludges as well as to the development of sludge dissolution agents. The new chelating reagents are easily made and could be

  18. Phenolic aminocarboxylic acids - new chelating agents for modifying gallium-67 biodistribution

    International Nuclear Information System (INIS)

    Hunt, F.C.; Maddalena, D.J.

    1982-01-01

    The chelating agents EDDHA and HBED were synthesised with carboxyl or sulphonyl groups in the phenolic ring to favour urinary excretion on complexing with gallium. Carboxyl EDDMA was administered to tumor-bearing rats, and its concentration in the tumours and other tissues determined by scintigraphic imaging. The chelating agents increase tumour to blood ratios by chelating gallium in vivo. (U.K.)

  19. Phenolic aminocarboxylic acids - new chelating agents for modifying gallium-67 biodistribution

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, F.C.; Maddalena, D.J. (Australian Atomic Energy Commission Research Establishment, Lucas Heights)

    The chelating agents EDDHA and HBED were synthesised with carboxyl or sulphonyl groups in the phenolic ring to favour urinary excretion on complexing with gallium. Carboxyl EDDMA was administered to tumor-bearing rats, and its concentration in the tumours and other tissues determined by scintigraphic imaging. The chelating agents increase tumour to blood ratios by chelating gallium in vivo.

  20. Chelator induced phytoextraction and in situ soil washing of Cu

    International Nuclear Information System (INIS)

    Kos, Bostjan; Lestan, Domen

    2004-01-01

    In a soil column experiment, we investigated the effect of 5 mmol kg -1 soil addition of citric acid, ethylenediamine tetraacetate (EDTA), diethylenetriamine-pentaacetate (DTPA) and [S,S]-stereoisomer of ethylenediamine-disuccinate (EDDS) on phytoextraction of Cu from a vineyard soil with 162.6 mg kg -1 Cu, into the test plant Brassica rapa var. pekinensis. We also examined the use of a horizontal permeable barrier, composed of layers of nutrient enriched sawdust and apatite, for reduction of chelator induced Cu leaching. The addition of all chelators, except citric acid, enhanced Cu mobility and caused leaching of 19.5-23% of initial total Cu from the soil column. However, Cu plant uptake did not increase accordingly; the most effective was the EDDS treatment, in which plant Cu concentration reached 37.8±1.3 mg kg -1 Cu and increased by 3.3-times over the control treatment. The addition of none of the chelators in the concentration range from 5 to 15 mmol kg -1 exerted any toxic effect on respiratory soil microorganisms. When EDDS was applied into the columns with horizontal permeable barriers, only 0.53±0.32% of the initial total Cu was leached. Cu (36.7%) was washed from the 18 cm soil layer above the barrier and accumulated in the barrier. Our results indicate that rather than for a reduction of Cu leaching during rather ineffective chelate induced Cu phytoextraction, horizontal permeable barriers could be more effective in a new remediation technique of controlled in situ soil washing of Cu with biodegradable chelates

  1. Copper chelators: chemical properties and bio-medical applications.

    Science.gov (United States)

    Tegoni, M; Valensin, D; Toso, L; Remelli, M

    2014-01-01

    Copper is present in different concentrations and chemical forms throughout the earth crust, surface and deep water and even, in trace amounts, in the atmosphere itself. Copper is one of the first metals used by humans, the first artifacts dating back 10,000 years ago. Currently, the world production of refined copper exceeds 16,000 tons/year. Copper is a micro-element essential to life, principally for its red-ox properties that make it a necessary cofactor for many enzymes, like cytochrome-c oxidase and superoxide dismutase. In some animal species (e.g. octopus, snails, spiders, oysters) copper-hemocyanins also act as carriers of oxygen instead of hemoglobin. However, these red-ox properties also make the pair Cu(+)/Cu(2+) a formidable catalyst for the formation of reactive oxygen species, when copper is present in excess in the body or in tissues. The treatment of choice in cases of copper overloading or intoxication is the chelation therapy. Different molecules are already in clinical use as chelators or under study or clinical trial. It is worth noting that chelation therapy has also been suggested to treat some neurodegenerative diseases or cardiovascular disorders. In this review, after a brief description of the homeostasis and some cases of dyshomeostasis of copper, the main (used or potential) chelators are described; their properties in solution, even in relation to the presence of metal or ligand competitors, under physiological conditions, are discussed. The legislation of the most important Western countries, regarding both the use of chelating agents and the limits of copper in foods, drugs and cosmetics, is also outlined.

  2. New resin gel for uranium determination by diffusive gradient in thin films technique

    International Nuclear Information System (INIS)

    Gregusova, Michaela; Docekal, Bohumil

    2011-01-01

    A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10 2 mg L -1 . The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

  3. New resin gel for uranium determination by diffusive gradient in thin films technique

    Energy Technology Data Exchange (ETDEWEB)

    Gregusova, Michaela, E-mail: gregusova@iach.cz [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic); Docekal, Bohumil [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic)

    2011-01-17

    A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10{sup 2} mg L{sup -1}. The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

  4. Highly hydrated poly(allylamine)/silica magnetic resin

    International Nuclear Information System (INIS)

    Johnson, Andrew K.; Kaczor, Jozef; Han, Hongmei; Kaur, Maninder; Tian, Guoxin; Rao, Linfeng; Qiang, You; Paszczynski, Andrzej J.

    2011-01-01

    The creation of multifunctional nanomaterials by combining organic and inorganic components is a growing trend in nanoscience. The unique size-dependent properties of magnetic nanoparticles (MNPs) make them amenable to numerous applications such as carriers of expensive biological catalysts, in magnetically assisted chemical separation of heavy metals and radionuclides from contaminated water sources. The separation of minor actinides from high-level radionuclide waste requires a sorbent stable in acidic pH, with ease of surface functionalization, and a high capacity for binding the molecules of interest. For the described experiments, the MNPs with 50 nm average size were used (size distribution from 20 to 100 nm and an iron content of 80–90 w/w%). The MNPs that have been double coated with an initial silica coating for protection against iron solubilization and oxidation in nitric acid solution (pH 1) and a second silica/polymer composite coating incorporating partially imbedded poly(allylamine) (PA). The final product is magnetic, highly swelling, containing >95% water, with >0.5 mmol amines g −1 available for functionalization. The amine groups of the magnetic resin were functionalized with the chelating molecules diethylenetriaminepentaacetic acid (DTPA) and N,N-dimethyl-3-oxa-glutaramic acid (DMOGA) for separation of minor actinides from used nuclear fuel.

  5. Solidifying power station resins and sludges

    International Nuclear Information System (INIS)

    Willis, A.S.D.; Haigh, C.P.

    1984-01-01

    Radioactive ion exchange resins and sludges arise at nuclear power stations from various operations associated with effluent treatment and liquid waste management. As the result of an intensive development programme, the Central Electricity Generating Board (CEGB) has designed a process to convert power station resins and sludges into a shielded, packaged solid monolithic form suitable for final disposal. Research and development, the generic CEGB sludge/resin conditioning plant and the CEGB Active Waste Project are described. (U.K.)

  6. Volumetric polymerization shrinkage of contemporary composite resins

    OpenAIRE

    Nagem Filho, Halim; Nagem, Haline Drumond; Francisconi, Paulo Afonso Silveira; Franco, Eduardo Batista; Mondelli, Rafael Francisco Lia; Coutinho, Kennedy Queiroz

    2007-01-01

    The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill ...

  7. Removal of radiocesium using cation exchange resin

    International Nuclear Information System (INIS)

    Morita-Murase, Yuko; Mizumura, Ryosuke; Tachibana, Yoshitaka; Kanazawa, Hideko

    2013-01-01

    Cation exchange resins (calcium polystyrene sulfonate, Ca-resin and sodium polystyrene sulfonate, Na-resin) have been used as agents to improve hyperkerlemia. For removing 137 Cs from the human body, the adsorption ability of the resin for 137 Cs was examined and evaluated. Resin (0.03 g) and 137 Cs (ca.1 kBq) were introduced into 3 mL of water, the Japanese Pharmacopoeia 1st fluid for a dissolution test (pH 1.2) and 2nd fluid (pH 6.8), respectively, and shaken. After 1-3 hours, the 137 Cs adsorption (%) of Na-resin was 99% in water, 60% in a pH 1.2 fluid and, 66% in a pH 6.8 fluid. By adding potassium, the 137 Cs adsorption (%) of Ca-resin was reduced. However, the 137 Cs adsorption (%) of Na-resin was almost unchanged. These results show that both resins have adsorption ability for 137 Cs in the stomach and the intestines. Therefore, the proposed method will be an effective means in the case of a radiological emergency due to 137 Cs. (author)

  8. The absorption of plutonium by anion resins

    Energy Technology Data Exchange (ETDEWEB)

    Durham, R. W.; Mills, R.

    1961-10-15

    Equilibrium experiments have shown Pu{sup +4} to be absorbed from nitric acid onto an anion resin as a complex anion Pu(NO{sub 3}){sub 6}{sup -2}. The amount of absorption is dependent on the plutonium and nitric acid concentrations in the equilibrium solution with a maximum at 7N to 8N HNO{sub 3}. A low cross-linked resin has a higher capacity and reaches equilibrium more rapidly than the normally supplied resin. Saturation capacity of one per cent cross-linked Nalcite SBR (Dowex 1), 50 -- 100 mesh, is 385 mg Pu/gram dry resin. (author)

  9. Improved paramagnetic chelate for molecular imaging with MRI

    International Nuclear Information System (INIS)

    Winter, Patrick; Athey, Phillip; Kiefer, Garry; Gulyas, Gyongyi; Frank, Keith; Fuhrhop, Ralph; Robertson, David; Wickline, Samuel; Lanza, Gregory

    2005-01-01

    The relaxivity and transmetallation of two lipophilic paramagnetic chelates incorporated onto perfluorocarbon nanoparticles, i.e., gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid phosphatidylethanolamine (Gd-MeO-DOTA-PE) and gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid triglycine phosphatidylethanolamine (Gd-MeO-DOTA-triglycine-PE (Gd-MeO-DOTA-triglycine-PE)), were compared to a prototypic gadolinium-diethylene-triamine-pentaacetic acid bis-oleate (Gd-DTPA-BOA) paramagnetic formulation. Nanoparticles with MeO-DOTA-based chelates demonstrated higher relaxivity (40% higher for Gd-MeO-DOTA-PE and 55% higher for Gd-MeO-DOTA-triglycine-PE) and less transmetallation than the original Gd-DTPA-BOA-based agent

  10. MULTIDENTATE TEREPHTHALAMIDATE AND HYDROXYPYRIDONATE LIGANDS: TOWARDS NEW ORALLY ACTIVE CHELATORS

    Energy Technology Data Exchange (ETDEWEB)

    Abergel, Rebecca J.; Raymond, Kenneth N.

    2011-07-13

    The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using {sup 59}Fe, {sup 238}Pu, and {sup 241}Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents [deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides] and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity.

  11. Treatment of some radioactive wastes by using new chelating membranes

    International Nuclear Information System (INIS)

    Hegazy, S.A.; El-Adham, K.; Abdel Geleel, M.; Soliman, S.A.

    2000-01-01

    The preparation of chelating membranes containing nitrile and carboxylic acid as functional groups was investigated. The modification of such membranes by chemical treatments to produce significant changes in their properties was studied. This modification results in a higher rate of exchange and higher capacity. The applicability of such modified membranes in the removal of Co-60 and Cs-137 from their wastes were tested. The dependence of these radioactive nuclides uptake on the time and degree of grafting for H CI-, NH 2 OH-and KOH-treated membranes was investigated. It was found that the adsorption rate and capacity were higher for KOH-treated membrane than those for the NH 2 OH and H CI treated ones. The prepared grafted membranes have a good affinity towards the adsorption or chelation with Co-60 and Cs-137. This result may make such prepared materials acceptable for practicable use in some radioactive waste treatments and recovery

  12. Chelation studies involving decontamination of light lanthanides by polyaminopolycarboxylic

    International Nuclear Information System (INIS)

    Hassan, N.E.H.

    1985-01-01

    The present thesis constitutes chelation studies involving decontamination of light lanthanides, cobalt , and uranium with 2,2-bis-acryloyliminomethylene- acid (BAETA) using the spectrophotometric method. the work carried out aimed to clear up the effectiveness of BAETA as a decontaminating agent for radioactive nuclides from human body . the thesis includes a general introduction , outlines the aim of work and contains three main chapters . the results of the work are discussed at the end of the thesis. the first chapter deals with a comprehensive survey of the relevant literature. this includes the metabolism and toxicity of cerium, uranium, cobalt and Ln +3 elements, general methodologies of internal decontamination, choice and effectiveness of chelating agents

  13. Iron overload and chelation therapy in myelodysplastic syndromes.

    Science.gov (United States)

    Temraz, Sally; Santini, Valeria; Musallam, Khaled; Taher, Ali

    2014-07-01

    Iron overload remains a concern in MDS patients especially those requiring recurrent blood transfusions. The consequence of iron overload may be more relevant in patients with low and intermediate-1 risk MDS who may survive long enough to experience such manifestations. It is a matter of debate whether this overload has time to yield organ damage, but it is quite evident that cellular damage and DNA genotoxic effect are induced. Iron overload may play a critical role in exacerbating pre-existing morbidity or even unmask silent ones. Under these circumstances, iron chelation therapy could play an integral role in the management of these patients. This review entails an in depth analysis of iron overload in MDS patients; its pathophysiology, effect on survival, associated risks and diagnostic options. It also discusses management options in relation to chelation therapy used in MDS patients and the impact it has on survival, hematologic response and organ function. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Encapsulation and retention of chelated-copper inside hydrophobic nanoparticles

    DEFF Research Database (Denmark)

    Hervella, Pablo; Ortiz, Elisa Parra; Needham, David

    2016-01-01

    ) Chelate copper into the octaethyl porphyrin; (3) Encapsulate OEP-Cu in nanoparticles: the encapsulation efficiency of copper into liquid nanoparticles (LNP), solid nanoparticles (SNP) and phospholipid liposomes (PL) was evaluated by UV-Vis and atomic absorption spectroscopy; (4) Retain the encapsulated...... OEP-Cu in the liquid or solid cores of the nanoparticles in the presence of a lipid sink. RESULTS: (1) The size of the nanoparticles was found to be strongly dependent on the Reynolds number and the initial concentration of components for the fast injection technique. At high Reynolds number (2181......), a minimum value for the particle diameter of ∼30nm was measured. (2) Copper was chelated by OEP in a 1:1mol ratio with an association constant of 2.57×10(5)M(-1). (3) The diameter of the nanoparticles was not significantly affected by the presence of OEP or OEP-Cu. The percentage of encapsulation of copper...

  15. Iron chelates: a challenge to chemists and Moessbauer spectroscopists

    Energy Technology Data Exchange (ETDEWEB)

    Homonnay, Z., E-mail: homonnay@chem.elte.hu; Szilagyi, P. A.; Vertes, A. [Eoetvoes Lorand University, Laboratory of Nuclear Chemistry, Institute of Chemistry (Hungary); Kuzmann, E. [Hungarian Academy of Sciences, Department of Nuclear Chemistry, Chemical Research Center (Hungary); Sharma, V. K. [Florida Institute of Technology (United States); Molnar, G.; Bousseksou, A. [CNRS UPR-8241, Laboratoire de Chimie de Coordination (France); Greneche, J.-M. [Universite du Maine, Laboratoire de Physique de l' Etat Condense, CNRS UMR 6087 (France); Brausam, A.; Meier, R.; Eldik, R. van [University of Erlangen-Nuernberg, Institute for Inorganic Chemistry (Germany)

    2008-02-15

    The speciation of iron in aqueous solutions containing Fe{sup 3+} and selected chelates such as EDTA, EDDA, CDTA and HEDTA has been studied using transmission {sup 57}Fe Moessbauer spectrometry in frozen solutions. The protonation of various complexes as well as binuclear complex formation could be detected as a function of pH. Autoreduction of Fe{sup 3+} to Fe{sup 2+} was observed in several cases. Reaction with hydrogen peroxide proved to be rather different for the four ligands, while the dihapto complex [XFe({eta}{sup 2}-O{sub 2})]{sup 3-} had surprisingly identical Moessbauer parameters for X = EDTA, CDTA or HEDTA. Paramagnetic spin relaxation observed in the Moessbauer spectra was found to be strongly influenced by the identity of the chelating ligand, despite the basically spin-spin origin of the phenomenon.

  16. Improved paramagnetic chelate for molecular imaging with MRI

    Science.gov (United States)

    Winter, Patrick; Athey, Phillip; Kiefer, Garry; Gulyas, Gyongyi; Frank, Keith; Fuhrhop, Ralph; Robertson, David; Wickline, Samuel; Lanza, Gregory

    2005-05-01

    The relaxivity and transmetallation of two lipophilic paramagnetic chelates incorporated onto perfluorocarbon nanoparticles, i.e., gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid phosphatidylethanolamine (Gd-MeO-DOTA-PE) and gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid triglycine phosphatidylethanolamine (Gd-MeO-DOTA-triglycine-PE (Gd-MeO-DOTA-triglycine-PE)), were compared to a prototypic gadolinium-diethylene-triamine-pentaacetic acid bis-oleate (Gd-DTPA-BOA) paramagnetic formulation. Nanoparticles with MeO-DOTA-based chelates demonstrated higher relaxivity (40% higher for Gd-MeO-DOTA-PE and 55% higher for Gd-MeO-DOTA-triglycine-PE) and less transmetallation than the original Gd-DTPA-BOA-based agent.

  17. Self-assembled polymeric chelate nanoparticles as potential theranostic agents

    Czech Academy of Sciences Publication Activity Database

    Škodová, Michaela; Černoch, Peter; Štěpánek, Petr; Chánová, Eliška; Kučka, Jan; Kálalová, Zuzana; Kaňková, Dana; Hrubý, Martin

    2012-01-01

    Roč. 13, č. 18 (2012), s. 4244-4250 ISSN 1439-4235 R&D Projects: GA ČR GPP207/10/P054; GA ČR GA202/09/2078; GA ČR GAP304/12/0950 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : chelate s * nanoparticles * polymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.349, year: 2012

  18. Decontamination of process equipment using recyclable chelating solvent

    Energy Technology Data Exchange (ETDEWEB)

    Jevec, J.; Lenore, C.; Ulbricht, S. [Babcock & Wilcox, Co., R& DD, Alliance, OH (United States)

    1995-10-01

    The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. This report describes the results of the performance testing of chelates and solvents for the dissolution of uranium.

  19. Polymeric metal chelates with piperazine(bis)dithiocarbamate

    International Nuclear Information System (INIS)

    Larionov, S.V.; Kosareva, L.A.; Ikorskij, V.N.; Uskov, E.M.

    1982-01-01

    Roentgenoamorphous polymer chelates of Fe 3 , Co 2 , Ni 2 , Cu 2 , Zn 2 , Cd 2 , Pb 2 with tetradentate bridge ligand piperazine-(bis) dithiocarbamate have been synthesized. IR spectra in the region 200-400 cm - 1 point to coordination of sulphur atoms of groups CS 2- with metals. It is found that among the polymers synthesized CuLxH 2 O possesses the lowest electric resistance

  20. Flue gas desulfurization/denitrification using metal-chelate additives

    Science.gov (United States)

    Harkness, J.B.L.; Doctor, R.D.; Wingender, R.J.

    1985-08-05

    A method of simultaneously removing SO/sub 2/ and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO/sub 2/ and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled. 3 figs.

  1. Reaction of gadolinium chelates with ozone and hydroxyl radicals.

    Science.gov (United States)

    Cyris, Maike; Knolle, Wolfgang; Richard, Jessica; Dopp, Elke; von Sonntag, Clemens; Schmidt, Torsten C

    2013-09-03

    Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

  2. Input to Resin Column Structural Analysis if Autocatalytic Resin Reaction Occurs in HB-Line Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Hallman, D.F.

    2001-07-10

    Solutions of plutonium in nitric acid are purified and concentrated using anion resin prior to precipitation. There have been instances of resin column explosions caused by autocatalytic reactions of anion resins in nitric acid within the DOE complex

  3. Mercury removal in utility wet scrubber using a chelating agent

    Science.gov (United States)

    Amrhein, Gerald T.

    2001-01-01

    A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S.sup.2- ions to convert Hg.sup.2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe.sup.2+ ions, which could otherwise induce the unwanted reduction of Hg.sup.2+ to the form, Hg.sup.0.

  4. Effectiveness of chelation therapy with time after acute uranium intoxication

    International Nuclear Information System (INIS)

    Domingo, J.L.; Ortega, A.; Llobet, J.M.; Corbella, J.

    1990-01-01

    The effect of increasing the time interval between acute uranium exposure and chelation therapy was studied in male Swiss mice. Gallic acid, 4,5-dihydroxy-1,3- benzenedisulfonic acid (Tiron), diethylenetriaminepentaacetic acid (DTPA), and 5-aminosalicylic acid (5-AS) were administered ip at 0, 0.25, 1, 4, and 24 hr after sc injection of 10 mg/kg of uranyl acetate dihydrate. Chelating agents were given at doses equal to one-fourth of their respective LD50 values. Daily elimination of uranium into urine and feces was determined for 4 days after which time the mice were killed, and the concentration of uranium was measured in kidney, spleen, and bone. The excretion of uranium was especially rapid in the first 24 hr. Treatment with Tiron or gallic acid at 0, 0.25, or 1 hr after uranium exposure significantly increased the total excretion of the metal. In kidney and bone, only administration of Tiron at 0, 0.25, or 1 hr after uranium injection, or gallic acid at 1 hr after uranium exposure significantly reduced tissue uranium concentrations. Treatment at later times (4 to 24 hr) did not increase the total excretion of the metal and did not decrease the tissue uranium concentrations 4 days after uranyl acetate administration. The results show that the length of time before initiating chelation therapy for acute uranium intoxication greatly influences the effectiveness of this therapy

  5. Hydroxyurea could be a good clinically relevant iron chelator.

    Science.gov (United States)

    Italia, Khushnooma; Colah, Roshan; Ghosh, Kanjaksha

    2013-01-01

    Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl's Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.

  6. Chelate forms of biometalls. Theoretical aspects of obtaining and characteristics

    Directory of Open Access Journals (Sweden)

    A. Kapustyan

    2017-04-01

    Full Text Available The problem of microelements bioavailability is highlighted and the correct ways of its solution are substantiated as a result of generalization of theoretical aspects of obtaining of the biometals chelate forms. The characteristics of the main biogenic elements, their physiological significance, electrochemical properties are presented. The main examples of the participation of biometals in various biological processes are given. The properties and the structure peculiarities of biometals coordination complexes are considered in detail. It is shown that in obtaining of biometals chelate forms, there is the mutual selectivity and the affinity of biometals and ligands. The main factors of obtaining a hard metal complex are given. Potential bioligands for obtaining bioavailable forms of microelements are detailed. Among them there are amino acids, peptides, proteins, nucleic acids, carbohydrates. The possible character of complexation depending on the nature of the bioligand is indicated. Practical examples of preparation of biometals mixed ligand complexes are given. The expediency of using metabolic products and processing of lactic acid bacteria as promising components of mixed ligand chelate complexes is substantiated. These substances contain in their composition a mass of potential donor atoms that are capable to form covalent and coordination bonds with biomethalles, and also possess high biological and immunotropic activities. The use of this system in the biocoordination compounds of the "metals of life" can provide a synergistic effect of the components, significantly to expand the range of their physiological activity and to increase the degree of assimilation by the body.

  7. High precision isotopic ratio analysis of volatile metal chelates

    International Nuclear Information System (INIS)

    Hachey, D.L.; Blais, J.C.; Klein, P.D.

    1980-01-01

    High precision isotope ratio measurements have been made for a series of volatile alkaline earth and transition metal chelates using conventional GC/MS instrumentation. Electron ionization was used for alkaline earth chelates, whereas isobutane chemical ionization was used for transition metal studies. Natural isotopic abundances were determined for a series of Mg, Ca, Cr, Fe, Ni, Cu, Cd, and Zn chelates. Absolute accuracy ranged between 0.01 and 1.19 at. %. Absolute precision ranged between +-0.01-0.27 at. % (RSD +- 0.07-10.26%) for elements that contained as many as eight natural isotopes. Calibration curves were prepared using natural abundance metals and their enriched 50 Cr, 60 Ni, and 65 Cu isotopes covering the range 0.1-1010.7 at. % excess. A separate multiple isotope calibration curve was similarly prepared using enriched 60 Ni (0.02-2.15 at. % excess) and 62 Ni (0.23-18.5 at. % excess). The samples were analyzed by GC/CI/MS. Human plasma, containing enriched 26 Mg and 44 Ca, was analyzed by EI/MS. 1 figure, 5 tables

  8. Hydroxyurea could be a good clinically relevant iron chelator.

    Directory of Open Access Journals (Sweden)

    Khushnooma Italia

    Full Text Available Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl's Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.

  9. Antibacterial and antibiofilm effects of iron chelators against Prevotella intermedia.

    Science.gov (United States)

    Moon, Ji-Hoi; Kim, Cheul; Lee, Hee-Su; Kim, Sung-Woon; Lee, Jin-Yong

    2013-09-01

    Prevotella intermedia, a major periodontopathogen, has been shown to be resistant to many antibiotics. In the present study, we examined the effect of the FDA-approved iron chelators deferoxamine (DFO) and deferasirox (DFRA) against planktonic and biofilm cells of P. intermedia in order to evaluate the possibility of using these iron chelators as alternative control agents against P. intermedia. DFRA showed strong antimicrobial activity (MIC and MBC values of 0.16 mg ml(-1)) against planktonic P. intermedia. At subMICs, DFRA partially inhibited the bacterial growth and considerably prolonged the bacterial doubling time. DFO was unable to completely inhibit the bacterial growth in the concentration range tested and was not bactericidal. Crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that DFRA significantly decreased the biofilm-forming activity as well as the biofilm formation, while DFO was less effective. DFRA was chosen for further study. In the ATP-bioluminescent assay, which reflects viable cell counts, subMICs of DFRA significantly decreased the bioactivity of biofilms in a concentration-dependent manner. Under the scanning electron microscope, P. intermedia cells in DFRA-treated biofilm were significantly elongated compared to those in untreated biofilm. Further experiments are necessary to show that iron chelators may be used as a therapeutic agent for periodontal disease.

  10. Copper and Zinc Chelation as a Treatment of Alzheimer's Disease

    Science.gov (United States)

    Hodak, Miroslav; Bernholc, Jerry

    2014-03-01

    Alzheimer's disease (AD) is a neurodegenerative disorder affecting millions of people in the U.S. The cause of the disease remains unknown, but amyloid- β (A β), a short peptide, is considered causal its pathogenesis. At cellular level, AD is characterized by deposits mainly composed of A β that also contain elevated levels of transition metals ions. Targeting metals is a promising new strategy for AD treatment, which uses moderately strong metal chelators to sequester them from A β or the environment. PBT2 is a chelating compound that has been the most promising in clinical trials. In our work, we use computer simulations to investigate complexes of a close analog of PBT2 with Cu2+ and Zn2+ ions. The calculations employ KS/FD DFT method, which combines Kohn-Sham DFT with the frozen-density DFT to achieve efficient description of explicit solvent beyond the first solvation shell. Our work is based on recent experiments and examines both 1:1 and 2:1 chelator-metal stochiometries detected experimentally. The results show that copper attaches more strongly than zinc, find that 1:1 complexes involve water in the first coordination shell and determine which one of several possible 2:1 geometries is the most preferable.

  11. f-Element Ion Chelation in Highly Basic Media

    International Nuclear Information System (INIS)

    Paine, Robert T.

    1999-01-01

    High-level radioactive waste (HLW) generated in the DOE complex is stored in tanks at several sites, but predominantly it is found at the Hanford reservation. Much of the material has been exposed to high pHs, consequently the waste exists in a complex, poorly understood mixture of solids, gels and solutions. The final waste remediation plan may involve chemical separation of fractions and a suitable, well developed molecular chemistry basis for performing these separations is not available. Indeed, the fundamental chemical behavior of most radioactive nuclides in basic media is not known. The goal of this project is to undertake fundamental studies of the coordination chemistry of f-element species in basic aqueous solutions containing common waste treatment ions (e.g., NO3 -, CO3 2-, organic carboxylates, and EDTA), as well as new waste scrubbing chelators produced in this study. The experimental agenda includes: 1. Studies of the speciation of Sr and Ln ions in basic solutions wit h and without common counterions; 2. Preparations of new multifunctional ligands that may act as strong, ion-specific chelators for Sr and/or Ln ions in basic media; and 3. Studies of the coordination and dissolution behavior of oxide-hydroxide species, as well as in insoluble sols, gels, and precipitates in combination with new chelating ligands. It is anticipated that this coordination chemistry will facilitate the design of advanced separation schemes required for handling the complex waste matrices found at the Hanford HLW facility

  12. Properties of the Carboxylate ion exchange resins; Karboxylatjonbytarmassans egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Allard, Bert; Dario, Maarten [Oerebro Univ. (Sweden); Boren, Hans [Linkoepings Univ. (Sweden); Torstenfelt, Boerje [Swedpower, Stockholm (Sweden); Puigdomenech, Ignasi; Johansson, Claes [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2002-09-01

    Weakly acidic, carboxylic resin has been selected, together with strong base anion resins, for water purification at the Forsmark 1 and 2 reactors. For the strong (but not the weak) ion exchange resin the Nuclear Power Inspectorate has given permission to dispose the spent resins in the SFR 1 (the Final Repository for Radioactive Operational Waste). This report gives a review of the carboxylic resins and comes to the conclusion that the resins are very stable and that there should not exist any risks for increased leaching of radionuclides from SFR 1 if these resins are disposed (compared to the strong resins)

  13. Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

    Science.gov (United States)

    Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

    2018-06-01

    Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

  14. Overview on resins available in microlithography

    International Nuclear Information System (INIS)

    Serre, B.; Schue, F.; Montginoul, C.; Giral, L.

    1985-01-01

    Lithographic equipments using electrons and X radiation are developed. Velocity and resolution requirements fix the nature of the material to irradiate. Circuit making principles are recalled here; resists (organic polymers) are employed for it. The different types of resins and then needed characteristics are reviewed here. In the scope of electron sensitive resins methyl polymethacrylate and derivative and its copolymers (and copolymers of methacrylonitrile) and reticulated copolymers are studied. Polysulfones are also presented (poly(buten-1 sulfone), poly(styrene sulfone), poly(methyl-1 cyclopentene-1 sulfone). The interest in photosensitive resins (such as AZ) as electron sensitive resins is recalled. In the field of negative resins, the polyepoxyds, polystyrene and halogenated derivates from polystyrene (CMS and PCMS), the poly(vinyl-2 naphtalene) and its derivatives (PSTTF) are presented. The X radiation sensitive resins are also reviewed: the methyl polymethacrylate and its halogenated derivates, the acrylic homopolymers and copolymers (example of poly(acrylate of chlorinated alcoyls). The resins developable by plasma are mentioned. At last, for photosensitive resins, the diazide polydiene systems are presented together with systems diazo-2 2H-naphtalenone-1. The systems with salt photolysis are just recalled [fr

  15. Epoxidation of linseed oil-Alkyd resins

    International Nuclear Information System (INIS)

    Motawie, A.M.; Ismail, E.A.; Mazroua, A.M.; Abd EI Aziem, M.S.; Ramadan, A.M.

    2004-01-01

    Three types of different linseed oil-alkyd resin ( Alk (I), Alk (II), and Alk (III) ) were prepared with the calculated amounts of mono glycerides and adipic acid (1:1, 1:2, and 2:1 Eq.Wt) respectively via monoglyceride method. The obtained alkyd resins were epoxidized via reaction with the calculated quantities of peracetic acid, which was prepared by the reaction of acetic anhydride with H 2 O 2 . Epoxidation occurred with the ratio (1: 1, 1 :3, and 1:6 Eq. Wt) of alkyd to peracetic acid. The effect of reaction time on the epoxy group content was measured during the epoxidation process. The prepared alkyd resins were analyzed by IR and H 1 NMR. The metal coated film properties of epoxidized alkyd resins were compared with those of unmodified alkyd resins. It was observed that the coating films of epoxidized alkyd resins have better in drying properties, hardness, adhesion, impact and flexibility than those of un epoxidized alkyd resins. The flammability properties of the paper coated films for the prepared brominated epoxidized alkyd resins were found to be fire retardant

  16. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... disodium salt of 4,4′-isopropylidenediphenol is made to react with 4,4′-dichlorodiphenyl sulfone in such a... Limitations Dimethyl sulfoxide Not to exceed 50 parts per million as residual solvent in finished basic resin... residual solvent in finished basic resin in paragraph (a)(1) of this section. N-methyl-2-pyrrolidone Not to...

  17. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ...′-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of 4,4... chloride Monochlorobenzene Not to exceed 500 p.p.m. as residual solvent in finished resin. Pentaerythritol...-88-3) Not to exceed 800 parts per million as residual solvent in finished resin. Triethylamine (c...

  18. 21 CFR 177.1595 - Polyetherimide resin.

    Science.gov (United States)

    2010-04-01

    ... polyetherimide resin identified in this section may be safely used as an article or component of an article... substances required in the production of basic resins or finished food-contact articles. The optional... and Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park...

  19. 21 CFR 177.2440 - Polyethersulfone resins.

    Science.gov (United States)

    2010-04-01

    ... Components of Articles Intended for Repeated Use § 177.2440 Polyethersulfone resins. Polyethersulfone resins identified in paragraph (a) of this section may be safely used as articles or components of articles intended... Petition Control (HFS-215), Center for Food Safety and Applied Nutrition, 1110 Vermont Ave. NW., suite 1200...

  20. Modified resins for solid-phase extraction

    Science.gov (United States)

    Fritz, James S.; Sun, Jeffrey J.

    1991-12-10

    A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

  1. Measurement of opalescence of resin composites.

    Science.gov (United States)

    Lee, Yong-Keun; Lu, Huan; Powers, John M

    2005-11-01

    Opalescence is an optical property, where there is light scattering of the shorter wavelengths of the visible spectrum, giving the material a bluish appearance under reflected light and an orange/brown appearance under transmitted light. The objective of this study was to determine the opalescence of resin composites with a color measuring spectrophotometer. Colors of A2 and enamel or translucent shades of four resin composites and of an unfilled resin measured in the reflectance and transmittance modes were compared, and the opalescence parameter (OP) was calculated as the difference in blue-yellow coordinate (Deltab*) and red-green parameter (Deltaa*) between the reflected and transmitted colors of 1-mm thick specimens. The masking effect was calculated as the color difference between the color of a black background and the color of specimen over the black background. The range of OP in resin composites was 5.7-23.7, which was higher than that of the unfilled resin. However, there were significant differences among the brands and shades of the resin composites. Opalescence varied by brand and shade of the resin composites, and contributed to the masking of background color along with translucency parameter. Some of the resin composites actually displayed opalescence.

  2. Bioprotective properties of Dragon's blood resin: In vitro evaluation of antioxidant activity and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Gupta Rajinder K

    2011-02-01

    Full Text Available Abstract Background Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. Methods In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Results Phytochemical analysis of extracts revealed high phenolic content in CH2Cl2 extract of resin. Free radical scavenging of CH2Cl2 extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH2Cl2 extract. Conclusions Our result provide evidence that CH2Cl2 extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH2Cl2 extract of Dragon's blood resin could be considered as possible source of food preservative.

  3. Embedding of reactor wastes in plastic resins

    International Nuclear Information System (INIS)

    1979-01-01

    STEAG Kernenergie GmbH is so far the only firm commercially to condition radioactive bead ion exchange resins by embedding in polystyrene resins. The objective of the work reported here was to study and develop methods for immobilization of other reactor wastes in plastic resins. Comparison studies on high quality cement however showed favourable results for cement with respect to process safety and economy. For this reason STEAG interrupted its work in the field of resin embedding after about one year. The work carried out during this period is surveyed in this report, which includes a comprehensive literature study on reactor wastes and their solidification in plastic resins as well as on regulations with regard to radioactive waste disposal in the member states of the European Communities

  4. Chemoviscosity modeling for thermosetting resins, 2

    Science.gov (United States)

    Hou, T. H.

    1985-01-01

    A new analytical model for simulating chemoviscosity of thermosetting resin was formulated. The model is developed by modifying the Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By assuming a linear relationship between the glass transition temperature and the degree of cure of the resin system under cure, the WLF theory can be modified to account for the factor of reaction time. Temperature dependent functions of the modified WLF theory constants were determined from the isothermal cure data of Lee, Loos, and Springer for the Hercules 3501-6 resin system. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data reported by Carpenter. A chemoviscosity model which is capable of not only describing viscosity profiles accurately under various cure cycles, but also correlating viscosity data to the changes of physical properties associated with the structural transformations of the thermosetting resin systems during cure was established.

  5. Electrodialytic decontamination of spent ion exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.

    1982-01-01

    Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

  6. Solidification of ion exchange resin wastes

    International Nuclear Information System (INIS)

    1982-08-01

    Solidification media investigated included portland type I, portland type III and high alumina cements, a proprietary gypsum-based polymer modified cement, and a vinyl ester-styrene thermosetting plastic. Samples formulated with hydraulic cement were analyzed to investigate the effects of resin type, resin loading, waste-to-cement ratio, and water-to-cement ratio. The solidification of cation resin wastes with portland cement was characterized by excessive swelling and cracking of waste forms, both after curing and during immersion testing. Mixed bed resin waste formulations were limited by their cation component. Additives to improve the mechanical properties of portland cement-ion exchange resin waste forms were evaluated. High alumina cement formulations dislayed a resistance to deterioration of mechanical integrity during immersion testing, thus providing a significant advantage over portland cements for the solidification of resin wastes. Properties of cement-ion exchange resin waste forms were examined. An experiment was conducted to study the leachability of 137 Cs, 85 Sr, and 60 Co from resins modified in portland type III and high alumina cements. The cumulative 137 Cs fraction release was at least an order of magnitude greater than that of either 85 Sr or 60 Co. Release rates of 137 Cs in high alumina cement were greater than those in portland III cement by a factor of two.Compressive strength and leach testing were conducted for resin wastes solidified with polymer-modified gypsum based cement. 137 Cs, 85 Sr, and 60 Co fraction releases were about one, two and three orders of magnitude higher, respectively, than in equivalent portland type III cement formulations. As much as 28.6 wt % dry ion exchange resin was successfully solidified using vinyl ester-styrene compared with a maximum of 25 wt % in both portland and gypsum-based cement

  7. Chelated mineral supplements for Nelore: quality and early embryonic development

    Directory of Open Access Journals (Sweden)

    Camila Pasa

    2014-01-01

    Full Text Available ABSTRACT. Pasa C., Hatamoto-Zervoudakis L.K., Zervoudakis J.T. & Soares L. [Chelated mineral supplements for Nelore: quality and early embryonic development.] Suplementos minerais quelatados para vacas Nelore: qualidade e desenvolvimento embrionário inicial. Revista Brasileira de Medicina Veterinária, 36(1:29-34, 2014. Programa de Pós-Graduação em Ciência Animal, Faculdade de Agronomia e Medicina Veterinária, Universidade Federal do Mato Grosso, Av. Fernando Corrêa da Costa, 2367, Bairro Boa Esperança, Cuiabá, MT 78060-900, Brasil. E-mail: pasa_camila@hotmail.com The objective of this study was to evaluate the quality and early development of embryos produced with oocytes of cows supplemented with copper, zinc and selenium in a non-chelated and chelated. The experiment was conducted in Cuiabá-MT during the months April to July 2009. We used 24 adult Nellore multiparous, aged, average weights of the initial 36 months, 395 kg and mean body condition score 4.8, respectively randomly divided into 2 groups: control group (CG, supplemented with conventional mineral and Supplemented Group (GS, animals supplemented with zinc, copper and selenium chelated. Each group was kept in a paddock of Brachiaria brizantha cv Marandu received 1 kg of animal per day. chelated mineral supplementation (GS and conventional mineral (GC delivered via the protein supplement was given during a period of 99 days with daily average 1kg/cabeça. During the experimental period were two follicular aspirations, one to 59 days and another at 99 days of supplementation. Every two weeks the animals were weighed and ECC evaluated. oocytes viable (grades I, II and III were used for in vitro production of embryos. The experiment was completely randomized and data were analyzed by ANOVA and a significance level of 10%. There was no effect (p> 0.10 of supplementation with chelated minerals on the percentage of cleaved oocytes, total embryos produced, percentage of produced

  8. Synthesis of novel chitosan resin derivatized with serine moiety for the column collection/concentration of uranium and the determination of uranium by ICP-MS

    International Nuclear Information System (INIS)

    Oshita, Koji; Oshima, Mitsuko; Gao Yunhua; Lee, Kyue-Hyung; Motomizu, Shoji

    2003-01-01

    A chitosan resin derivatized with serine moiety (serine-type chitosan) was newly developed by using the cross-linked chitosan as a base material. The adsorption behavior of trace amounts of metal ions on the serine-type chitosan resin was systematically examined by packing it in a mini-column, passing a metal solution through it and measuring metal ions in the effluent by ICP-MS. The resin could adsorb a number of metal cations at pH from neutral to alkaline region, and several oxoanionic metals at acidic pH region by an anion exchange mechanism. Uranium and Cu could be adsorbed selectively at pH from acidic to alkaline region by a chelating mechanism; U could be adsorbed quantitatively even at pH 3-4. Uranium adsorbed on the resin was easily eluted with 1 M nitric acid: the preconcentration (5-, 10-, 50- and 100-fold) of U was possible. The column treatment method was used prior to the ICP-MS measurement of U in natural river, sea and tap waters; R.S.D. were 2.63, 1.13 and 1.37%, respectively. Uranium in tap water could be determined by 10-fold preconcentration: analytical result was 1.46±0.02 ppt. The resin also was applied to the recovery of U in sea water: the recovery tests for artificial and natural sea water were 97.1 and 93.0%, respectively

  9. EPICOR-II resin degradation results from first resin samples of PF-8 and PF-20

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Sanders, R.D. Sr.

    1985-12-01

    The 28 March 1979 accident at Three Mile Island Unit 2 released approximately 560,000 gallons of contaminated water to the Auxiliary and Fuel Handling Buildings. The water was decontaminated using a demineralization system called EPICOR-II developed by Epicor, Inc. The Low-Level Waste Data Base Development - EPICOR-II Resin/Liner Investigation Project is studying the chemical and physical conditions of the synthetic ion exchange resins found in several EPICOR-II prefilters. This report summarizes results and analyses of the first sampling of ion exchange resins from EPICOR-II prefilters PE-8 and -20. Results are compared with baseline data from tests performed on unirradiated Epicor, Inc. resins to determine if degradation has occurred due to the high internal radiation dose received by the EPICOR-II resins. Results also are compared with recent findings on resin degradation by Battelle Columbus Laboratories and Brookhaven National Laboratory. Analyses comparing test results of resins from EPICOR-II prefilters PF-8 and -20 with unirradiated resins obtained from Epicor, Inc. show resin degradation has occurred in some of the EPICOR-II resins examined. The mechanism of degradation is compared with work of other researchers and is consistent with their findings. The strong acid cation resins (divinylbenzene, styrene base structure) are losing effective cross-linking along with scission of functional groups and are experiencing first an increase and eventually a decrease in total exchange capacity as the absorbed radiation dose increases. The phenolic cation resins (phenol-formaldehyde base structure) show a loss of effective cross-linking and oxidation of the polymer chain. Analyses of resins removed from EPICOR-II prefilters PF-8 and -20 over the next several years should show a further increase in degradation

  10. Rates of cuticular penetration of chelated Fe(III): role of humidity, concentration, adjuvants, temperature, and type of chelate.

    Science.gov (United States)

    Schönherr, Jörg; Fernández, Victoria; Schreiber, Lukas

    2005-06-01

    Time courses of cuticular penetration of FeCl3 and Fe(III) complexes of citric acid, EDTA, EDDHA (Sequestrene 138Fe), imidodisuccinic acid (IDHA), and ligninsulfonic acid (Natrel) were studied using astomatous cuticular membranes (CMs) isolated from Populus x canescens leaves. At 100% relative humidity, the Fe(III) chelates disappeared exponentially with time from the surface of the CMs; that is, penetration was a first-order process that can be described using rate constants or half-times of penetration (t(1/2)). Half-times ranged from 20 to 30 h. At 90% humidity, penetration rates were insignificant with the exception of Natrel, for which t(1/2) amounted to 58 h. Rate constants were independent of temperature (15, 25, and 35 degrees C). Permeability decreased with increasing Fe chelate concentration (IDHA and EDTA). At 100% humidity, half-times measured with FeIDHA were 11 h (2 mmol L(-1)), 17 h (10 mmol L(-1)) and 36 h (20 mmol L(-1)), respectively. In the presence of FeEDTA, penetration of CaCl2 was slowed greatly. Half-times for penetration of CaCl2, which were 1.9 h in the absence of FeEDTA, rose to 3.12 h in the presence of an equimolar concentration of EDTA and 13.3 h when the FeEDTA concentration was doubled. Hence, Fe chelates reduced permeability of CMs to CaCl2 and to the Fe chelates themselves. It is suggested that Fe chelates reduced the size of aqueous pores. This view is supported by the fact that rate constants for calcium salts were about 5 times higher than for Fe chelates with the same molecular weights. Adding Tween 20 (5 g L(-1)) as a humectant did not increase permeability to FeIDHA at 90% humidity and below, while addition of glycine betaine did. Penetration of FeCl3 applied at 5 g L(-1) (pH 1.5) was not a first order process as rate constants decreased rapidly with time. Only 2% of the dose penetrated during the first 2 h and less than that in the subsequent 8 h. Recovery was only 70%. This was attributed to the formation of insoluble Fe

  11. Decomposing method for ion exchange resin

    International Nuclear Information System (INIS)

    Sako, Takeshi; Sato, Shinshi; Akai, Yoshie; Moniwa, Shinobu; Yamada, Kazuo

    1998-01-01

    The present invention concerns a method of decomposing ion exchange resins generated in a nuclear power plant to carbon dioxide reliably in a short period of time. (1) The ion exchange resins are mixed with water, and then they are kept for a predetermined period of time in the presence of an inert gas at high temperature and high pressure exceeding the critical point of water to decompose the ion exchange resins. (2) The ion exchange resins is mixed with water, an oxidant is added and they are kept for a predetermined time in the presence of an inert gas at a high temperature and a high pressure exceeding a critical point of water of an inert gas at a high temperature to decompose the ion exchange resins. (3) An alkali or acid is added to ion exchange resins and water to control the hydrogen ion concentration in the solution and the ion exchange resins are decomposed in above-mentioned (1) or (2). Sodium hydroxide is used as the alkali and hydrochloric acid is used as the acid. In addition, oxygen, hydrogen peroxide or ozone is used as an oxidant. (I.S.)

  12. Study of cyclization of chelating compounds using electrospray ionization mass spectrometry

    International Nuclear Information System (INIS)

    Shi Ying; Campbell, J.A.

    2000-01-01

    Electrospray ionization mass spectrometry (ESI-MS) was used for the study of cyclization of organic chelating compounds (chelators). Four chelating compounds were studied: Symmetrical ethylenediaminediacetic acid (s-EDDA), Unsymmetrical ethylenediaminediacetic acid (u-EDDA), N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), and N-(2-hydroxyethyl)iminodiacetic acid (HEIDA). The chelators were cyclized with treatments of acids and heating. The open and cyclized form of the chelators were semi-quantified by both positive and negative ion modes ESI-MS. The kinetics of chelator cyclization was studied as a function of reaction temperature and the pH of the matrix. The cyclization of s-EDDA was found to be a pseudo-first order reaction in s-EDDA and overall second order. The cyclizations of HEIDA and HEDTA are reversible reactions. Higher temperature and lower pH favors cyclization. (author)

  13. Safety evaluation of cation-exchange resins

    International Nuclear Information System (INIS)

    Kalkwarf, D.R.

    1977-08-01

    Results are presented of a study to evaluate whether sufficient information is available to establish conservative limits for the safe use of cation-exchange resins in separating radionuclides and, if not, to recommend what new data should be acquired. The study was also an attempt to identify in-line analytical techniques for the evaluation of resin degradation during radionuclide processing. The report is based upon a review of the published literature and upon discussions with many people engaged in the use of these resins. It was concluded that the chief hazard in the use of cation-exchange resins for separating radionuclides is a thermal explosion if nitric acid or other strong oxidants are present in the process solution. Thermal explosions can be avoided by limiting process parameters so that the rates of heat and gas generation in the system do not exceed the rates for their transfer to the surroundings. Such parameters include temperature, oxidant concentration, the amounts of possible catalysts, the radiation dose absorbed by the resin and the diameter of the resin column. Current information is not sufficient to define safe upper limits for these parameters. They can be evaluated, however, from equations derived from the Frank-Kamenetskii theory of thermal explosions provided the heat capacities, thermal conductivities and rates of heat evolution in the relevant resin-oxidant mixtures are known. It is recommended that such measurements be made and the appropriate limits be evaluated. A list of additional safety precautions are also presented to aid in the application of these limits and to provide additional margins of safety. In-line evaluation of resin degradation to assess its safety hazard is considered impractical. Rather, it is recommended that the resin be removed from use before it has received the limiting radiation dose, evaluated as described above

  14. Posterior bulk-filled resin composite restorations.

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...... Class II, 4 SDR-CeramX mono+ and 6 CeramXmono+-only restorations. The main reasons for failurewere tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled-1.1% and for the resin composite-only restorations 1...

  15. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  16. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement, 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the products' properties. (author)

  17. Thermosetting resins for nuclear track detection

    International Nuclear Information System (INIS)

    Fujii, M.

    1985-01-01

    Several new thermosetting resins with a three dimensional network structure like CR-39 were polymerized to study their characteristics for use as nuclear track detectors. During the course of this study, thermosetting resins with good etching properties and various sensitivities have been obtained. The comparison of the molecular structures of these resins gives up an important clue for the development of highly sensitive polymeric track detectors. They will also be useful for observations of ultra-heavy cosmic rays and heavily ionizing particles at low energies. (orig.)

  18. Thermosetting resins for nuclear track detection

    International Nuclear Information System (INIS)

    Fujii, Masami; Yokota, Rikio

    1985-01-01

    Several new thermosetting resins with a three dimensional network structure like CR-39 were polymerized to study their characteristics for use as nuclear track detectors. During the course of this study, thermosetting resins with good etching properties and various sensitivities have been obtained. The comparison of the molecular structures of these resins gives us an important clue for the development of highly sensitive polymeric track detectors. They will also be useful for observations of ultra-heavy cosmic rays and heavily ionizing particles at low energies. (author)

  19. Incineration of ion-exchange resins

    International Nuclear Information System (INIS)

    Valkiainen, M.; Nykyri, M.

    1985-01-01

    Incineration of ion-exchange resins in a fluidized bed was studied on a pilot plant scale at the Technical Research Centre of Finland. Both granular and powdered resins were incinerated in dry and slurry form. Different bed materials were used in order to trap as much cesium and cobalt (inactive tracers) as possible in the bed. Also the sintering of the bed materials was studied in the presence of sodium. When immobilized with cement the volume of ash-concrete is 4 to 22% of the concrete of equal compressive strength acquired by direct solidification. Two examples of multi-purpose equipment capable of incinerating ion-exchange resins are presented. (orig.)

  20. SEM and elemental analysis of composite resins

    International Nuclear Information System (INIS)

    Hosoda, H.; Yamada, T.; Inokoshi, S.

    1990-01-01

    Twenty-four chemically cured, 21 light-cured anterior, three light-cured anterior/posterior, and 18 light-cured posterior composite resins were examined using scanning electron microscopy, and the elemental composition of their filler particles was analyzed with an energy dispersive electron probe microanalyzer. According to the results obtained, the composite resins were divided into five groups (traditional, microfilled type, submicrofilled type, hybrid type, and semihybrid), with two additional hypothetical categories (microfilled and hybrid). Characteristics of each type were described with clinical indications for selective guidance of respective composite resins for clinical use

  1. Effect of other metals on iron bioavailability in presence of a selective chelator

    International Nuclear Information System (INIS)

    Rehman, F.S.

    1995-01-01

    Iron (III) is generally very easily chelated by a number of chelators in the biological environment, either supplied by food or already present there. One of the these chelator is gallic acid. The stability constants of the complexes formed between gallic acid and other trace metals have been determined by a potentiometric method. The data obtained was computed with the help of computer program B est . The resulted Beta values were compared with already known values of iron gallic acid complexes. (author)

  2. Thermosetting behavior of pitch-resin from heavy residue

    Energy Technology Data Exchange (ETDEWEB)

    Qingfang, Z.; Yansheng, G.; Baohua, H.; Yuzhen, Z. [China Univ. of Petroleum, Dongying, Shandong (China). State Key LAboratory of Heavy Oil Processing, Heavy Oil Research Inst.

    2006-07-01

    Thermosetting resins are widely employed as a basic matrix for c/c composites in carbon materials production. A new type of synthesized thermosetting resin is called pitch resin. Pitch resin is a cheaper resin and possesses a potential opportunity for future use. However, the thermosetting behavior of pitch resin is not very clear. The hardening process and conditions for thermosetting are very important for future use of pitch resin. B-stage pitch resin is a soluble and meltable inter-media condensed polymer, which is not fully reacted and is of a low molecular weight. The insoluble and unmelted pitch resin can only be obtained from synthesized B-stage resin after a hardening stage. This paper presented an experiment that synthesized B-stage pitch resin with a link agent (PXG) under catalyst action from fluid catalytic cracking (FCC) of the slurry's aromatic enriched component (FCCDF). The paper discussed the experiment, including the synthesis of pitch resin and thermosetting of pitch resin. Two kinds of thermosetting procedures were used in the study called one-step thermosetting and two-step thermosetting. It was concluded that the B-stage pitch resin could be hardened after a thermosetting procedure by heat treatment. The thermosetting pitch resin from 2-step thermosetting possesses was found to have better thermal resistant properties than that of the 1-step thermosetting pitch resin. 13 refs., 2 tabs., 6 figs.

  3. Condensate-polisher resin-leakage quantification and resin-transport studies

    International Nuclear Information System (INIS)

    Stauffer, C.C.; Doss, P.L.

    1983-04-01

    The objectives of this program were to: (1) determine the extent of resin leakage from current generation condensate polisher systems, both deep bed and powdered resin design, during cut-in, steady-state and flow transient operation, (2) analyze moisture separator drains and other secondary system samples for resin fragments and (3) document the level of organics in the secondary system. Resin leakage samples were obtained from nine-power stations that have either recirculating steam generators or once through steam generators. Secondary system samples were obtained from steam generator feedwater, recirculating steam generator blowdown and moisture separator drains. Analysis included ultraviolet light examination, SEM/EDX, resin quantification and infrared analysis. Data obtained from the various plants were compared and factors affecting resin leakage were summarized

  4. The mechanism of uranium adsorption on Resin 508 and isoelectric point of the resin

    International Nuclear Information System (INIS)

    Han Qingping; Lu Weichang; Su Huijuan; Hu Jinbo; Zhang Liqin; Chen Banglin

    1990-01-01

    The adsorption process of uranium by Resin 508 at the solid-liquid interface was investigated and the mechanism of uranium adsorption including adsorption dynamics, adsorption thermodynamics and isoelectric point of resin was studied. The results are as follows: The maximum of uranium adsorption is attained at pH5-7; Uranium adsorption isotherm by Resin 508 in experimental conditions agrees with Langmuir's adsorption isotherm, the maximum of uranium adsorbed (Vm) is 716 mg U/g-dried resin; The adsorption of uranium by Resin 508 is an endothermic reaction and ΔH = 16.87 kJ/mol; The exchange-adsorption rate is mainly controlled by liquid film diffusion; The isoelectric points of Resin 508 before and after uranium adsorption are found to be pH7.5 and pH5.7 respectively. It is a specific adsorption for uranium

  5. Photocatalyzed removal of lead ion from lead-chelator solution

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hyun; Na, Jung Won; Sung, Ki Woung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-07-01

    The present study was undertaken to examine the influence of such chelating agents on the ease and speed of photocatalyzed metal removal and deposition. With excess EDTA, the free EDTA competes with Pb for oxidation, and at a ten fold excess, no lead oxidation (hence removal) occurs. With insufficient EDTA, the corresponding initial concentration of Pb-EDTA is decreased; after its destruction, the remaining Pb{sup 2+} is removed more slowly, at rates found with lead nitrate solution. The net result is that the maximum rate of lead deposition occurs at the stoichiometric ratio of 1:1 EDTA : Pb{sup 2+}.

  6. Optimized conditions for chelation of yttrium-90-DOTA immunoconjugates.

    Science.gov (United States)

    Kukis, D L; DeNardo, S J; DeNardo, G L; O'Donnell, R T; Meares, C F

    1998-12-01

    Radioimmunotherapy (RIT) with 90Y-labeled immunoconjugates has shown promise in clinical trials. The macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) binds 90Y with extraordinary stability, minimizing the toxicity of 90Y-DOTA immunoconjugates arising from loss of 90Y to bone. However, reported 90Y-DOTA immunoconjugate product yields have been typically only BAD) was conjugated to the monoclonal antibody Lym-1 via 2-iminothiolane (2IT). The immunoconjugate product, 2IT-BAD-Lym-1, was labeled in excess yttrium in various buffers over a range of concentrations and pH. Kinetic studies were performed in selected buffers to estimate radiolabeling reaction times under prospective radiopharmacy labeling conditions. The effect of temperature on reaction kinetics was examined. Optimal radiolabeling conditions were identified and used in eight radiolabeling experiments with 2IT-BAD-Lym-1 and a second immunoconjugate, DOTA-peptide-chimeric L6, with 248-492 MBq (6.7-13.3 mCi) of 90Y. Ammonium acetate buffer (0.5 M) was associated with the highest uptake of yttrium. On the basis of kinetic data, the time required to chelate 94% of 90Y (four half-times) under prospective radiopharmacy labeling conditions in 0.5 M ammonium acetate was 17-148 min at pH 6.5, but it was only 1-10 min at pH 7.5. Raising the reaction temperature from 25 degrees C to 37 degrees C markedly increased the chelation rate. Optimal radiolabeling conditions were identified as: 30-min reaction time, 0.5 M ammonium acetate buffer, pH 7-7.5 and 37 degrees C. In eight labeling experiments under optimal conditions, a mean product yield (+/- s.d.) of 91%+/-8% was achieved, comparable to iodination yields. The specific activity of final products was 74-130 MBq (2.0-3.5 mCi) of 90Y per mg of monoclonal antibody. The immunoreactivity of 90Y-labeled immunoconjugates was 100%+/-11%. The optimization of 90Y-DOTA chelation conditions represents an important advance in 90Y RIT

  7. Acidizing reservoirs while chelating iron with sulfosalicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, W A; Berkshire, D C

    1980-09-30

    A well treating process is described in which an aqueous solution of a strong acid capable of dissolving solids in a manner increasing the permeability of a subterranean earth formation is injected into a subterranean reservoir that contains an asphaltenic oil. At least the first injected portion of the aqueous acid and a solution or homogeneous dispersion of at least enough 5-sulfosalicylic acid to chelate with and prevent the formation of iron-asphaltene solids are included with substantially all of the ferric ions that become dissolved within the strong acid solution that enters the earth formation. 10 claims.

  8. Characterization and thermogravimetric analysis of lanthanide hexafluoroacetylacetone chelates.

    Science.gov (United States)

    Shahbazi, Shayan; Stratz, S Adam; Auxier, John D; Hanson, Daniel E; Marsh, Matthew L; Hall, Howard L

    2017-01-01

    This work reports the thermodynamic characterizations of organometallic species as a vehicle for the rapid separation of volatile nuclear fission products via gas chromatography due to differences in adsorption enthalpy. Because adsorption and sublimation thermodynamics are linearly correlated, there is considerable motivation to determine sublimation enthalpies. A method of isothermal thermogravimetric analysis, TGA-MS and melting point analysis are employed on thirteen lanthanide 1,1,1,5,5,5-hexafluoroacetylacetone complexes to determine sublimation enthalpies. An empirical correlation is used to estimate adsorption enthalpies of lanthanide complexes on a quartz column from the sublimation data. Additionally, four chelates are characterized by SC-XRD, elemental analysis, FTIR and NMR.

  9. Uranium and neodymium biosorption using novel chelating polysaccharide.

    Science.gov (United States)

    Elsalamouny, Ahmed R; Desouky, Osman A; Mohamed, Saad A; Galhoum, Ahmed A; Guibal, Eric

    2017-11-01

    A direct reaction is described to prepare hydrophobic α-aminomethylphosphonic acid as a novel chitosan-based material. It exhibits chelating properties for polyvalent metal ions such as U(VI) and Nd(III) ions. The new sorbent was fully characterized using Elemental analysis, scanning electron microscope (SEM) and FTIR spectra. Different parameters were examined in order to evaluate the optimum conditions for U(VI) and Nd(III) ions biosorption. Sorption mechanisms of metal ions were investigated using kinetic and isotherm models. In addition, the sorbent selectivity was tested for both metal ions together in a binary solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The influence of functional groups on the permeation and distribution of antimycobacterial rhodamine chelators.

    Science.gov (United States)

    Moniz, T; Leite, A; Silva, T; Gameiro, P; Gomes, M S; de Castro, B; Rangel, M

    2017-10-01

    We formerly hypothesized a mechanism whereby the antimycobacterial efficiency of a set of rhodamine labelled iron chelators is improved via the rhodamine fluorophore which enhances the chelators' permeation properties through membranes. To validate our hypothesis in a cellular context and to understand the influence of the structure of the fluorophore on the chelator's uptake and distribution within macrophages we now report comparative confocal microscopy studies performed with a set of rhodamine labelled chelators. We identify the functional groups of the chelator's framework that favor uptake by macrophages and conclude that the antimycobacterial effect is strongly related with the capacity of the chelator to distribute within the host cell and its compartments, a property that is closely related with the chelators' ability to interact with membranes. The quantification of the chelators' interaction with membranes was assessed through measurement of the corresponding partition constants in liposomes. The overall results support that the compounds which are preferentially taken up are the most efficient antimycobacterial chelators and for that reason we infer that the biological activity is modulated by the structural features of the fluorophore. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    OpenAIRE

    Liren Fan; Jiqing Song; Wenbo Bai; Shengping Wang; Ming Zeng; Xiaoming Li; Yang Zhou; Haifeng Li; Haiwei Lu

    2016-01-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shel...

  12. Spectroscopy, modeling and computation of metal chelate solubility in supercritical CO2. 1998 annual progress report

    International Nuclear Information System (INIS)

    Brennecke, J.F.; Chateauneuf, J.E.; Stadtherr, M.A.

    1998-01-01

    'This report summarizes work after 1 year and 8 months (9/15/96-5/14/98) of a 3 year project. Thus far, progress has been made in: (1) the measurement of the solubility of metal chelates in SC CO 2 with and without added cosolvents, (2) the spectroscopic determination of preferential solvation of metal chelates by cosolvents in SC CO 2 solutions, and (3) the development of a totally reliable computational technique for phase equilibrium computations. An important factor in the removal of metals from solid matrices with CO 2 /chelate mixtures is the equilibrium solubility of the metal chelate complex in the CO 2 .'

  13. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  14. Nanosilica Modification of Elastomer-Modified VARTM Epoxy Resins for Improved Resin and Composite Toughness

    National Research Council Canada - National Science Library

    Robinette, Jason; Bujanda, Andres; DeSchepper, Daniel; Dibelka, Jessica; Costanzo, Philip; Jensen, Robert; McKnight, Steven

    2007-01-01

    Recent publications have reported a synergy between rubber and silica in modified epoxy resins that results in significantly improved fracture toughness without reductions in other material properties...

  15. Method for regenerating magnetic polyamine-epichlorohydrin resin

    Science.gov (United States)

    Kochen, Robert L.; Navratil, James D.

    1997-07-29

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

  16. A method for producing a hydrocarbon resin

    Energy Technology Data Exchange (ETDEWEB)

    Tsachev, A B; Andonov, K S; Igliyev, S P

    1980-11-25

    Rock coal resin (KS), for instance, with a relative density of 1,150 to 1,190 kilograms per cubic meter, which contains 8 to 10 percent naphthaline, 1.5 to 2.8 percent phenol and 6 to 15 percent substances insoluble in toluene, or its mixture with rock coal or oil fractions of resin are subjected to distillation (Ds) in a pipe furnace with two evaporators (Is) and a distillation tower with a temperature mode in the second stage of 320 to 360 degrees and 290 to 340 degrees in the pitch compartment. A hydrocarbon resin is produced with a high carbon content, especially for the production of resin and dolomite refractory materials, as well as fuel mixtures for blast furnace and open hearth industry.

  17. Synthesis of improved phenolic and polyester resins

    Science.gov (United States)

    Delano, C. B.

    1980-01-01

    Thirty-seven cured phenolic resin compositions were prepared and tested for their ability to provide improved char residues and moisture resistance over state of the art epoxy resin composite matrices. Cyanate, epoxy novolac and vinyl ester resins were investigated. Char promoter additives were found to increase the anaerobic char yield at 800 C of epoxy novolacs and vinyl esters. Moisture resistant cyanate and vinyl ester compositions were investigated as composite matrices with Thornel 300 graphite fiber. A cyanate composite matrix provided state of the art composite mechanical properties before and after humidity exposure and an anaerobic char yield of 46 percent at 800 C. The outstanding moisture resistance of the matrix was not completely realized in the composite. Vinyl ester resins showed promise as candidates for improved composite matrix systems.

  18. Integrating Porous Resins In Enzymatic Processes

    DEFF Research Database (Denmark)

    Al-Haque, Naweed

    . Screening resins for moderately hydrophobic multi-component systems is challenging. Often it is found that the capacity of the resin is inversely related with product selectivity. Therefore a tradeoff has to be made between these parameters which can be crucial from an economic point of view. A low resin...... procedure. The screening therefore becomes a multi-objective task that has to be solved simultaneously. Such an approach has been applied in the method formulated in this framework. To overcome these challenges, different process strategies are required to obtain high yields. A number of different...... inhibition, has gained considerable recognition. The resins act as a reservoir for the inhibitory substrate and a sink for the inhibitory product and simultaneously attain the required high substrate loading to make the process economically feasible. In this way the potential benefit of the enzyme can...

  19. Amine chemistry. Update on impact on resin

    International Nuclear Information System (INIS)

    Bachman, Gregory; Kellogg, Douglas; Wilkes, Marty

    2012-01-01

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  20. Amine chemistry. Update on impact on resin

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gregory; Kellogg, Douglas [Siemens Industry, Inc., Rockford, IL (United States). Technology and Lab Services; Wilkes, Marty [Siemens Industry, Inc., Rockford, IL (United States). Water Technologies Div.

    2012-03-15

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  1. Feasibility of vitrifying EPICOR II organic resins

    International Nuclear Information System (INIS)

    Buelt, J.L.

    1981-11-01

    Two laboratory-scale runs have recently been completed to test the feasibility of a single-step incineration/vitrification process for Three Mile Island EPICOR II resins. The process utilizes vitrification equipment, specifically a 15-cm-dia in-can melter, and a specially designed feed technique. Two process tests, each conducted with 1.2 kg of EPICOR II resins loaded with nonradioactive cesium and strontium, showed excellent operational characteristics. Less than 0.8 wt% of the resins were entrained with the gaseous effluents in the second test. Cesium and strontium losses were controlled to 0.71 wt% and less. In addition, all the carbonaceous resins were converted completely to CO 2 with no detectable CO. Future activities are being directed to longer-term tests in laboratory-scale equipment to determine attainable volume reduction, process rates, and material conformance to processing conditions

  2. Photopolymerizable silicone monomers, oligomers, and resins

    International Nuclear Information System (INIS)

    Jacobine, A.F.; Nakos, S.T.

    1992-01-01

    The purpose of this chapter is to acquaint the general photopolymer researcher with the historical development of the chemistry and technology of photopolymerizable silicone monomers, fluids, and resins. The current status of research in these areas is assessed. The focus of this chapter is not only on the polymer chemistry and application of this technology, but also on important aspects of the synthetic chemistry involved in the preparation of UV-curable silicone monomers, oligomers, and resins. 236 refs., 6 tabs

  3. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    Verschueren, K.; Balwant Kaur

    1999-01-01

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  4. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  5. Synthesis of LaNiO3 perovskite type by chelating precursor method using EDTA: optimization of chelating content

    International Nuclear Information System (INIS)

    Santos, Jose Carlos dos; Pedrosa, Anne Michelle Garrido; Mesquita, Maria Eliane; Souza, Marcelo Jose Barros de

    2011-01-01

    The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO 3 perovskite type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis. The synthesized materials were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TG) and Infrared Spectroscopy (FTIR). In the optimization of the EDTA content the lowest ratio of metal / EDTA used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite. (author)

  6. Detoxication and removal of uranium by phenolic chelating agents

    International Nuclear Information System (INIS)

    Luo Meichu; Chen Guibao; Li Landi

    1992-01-01

    The use of phenolic chelating agents for detoxication and removal of uranyl nitrate in mice and rats is reported. Antidotal test: 8102, 7601 and 811 were given 2 mM/kg subcutaneously to mice and 1 mM/kg intramuscularly to rats when the animals were injected i.p. with different doses (100-500 mg/kg) of uranyl nitrate. The results showed that the antidotal effects of 8102 and 7601 were better than 811 in augmenting survival, survival time (day) and renal factor (kidney weight/body weight x100). 8102 was superior to 7601 against higher dose of uranyl nitrate intoxication. Removal test: five phenolic chelating agents (8102, 7601, 811, 7603 and 8307) were studied in rats. The results obtained demonstrated that 8102 and 7601 were better than 811, 7603 and 8307 in increasing U excretion in the urine after acute uranyl nitrate intoxication. The effects of different doses (300-1000 μM/kg) of 8102 was superior to 7601 in increasing U excretion in the urine and decreasing U deposition in the tissues. The toxicity and dose of 8102 in treating uranium intoxication are discussed

  7. Cleanup of TMI-2 demineralizer resins

    International Nuclear Information System (INIS)

    Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

    1985-01-01

    Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH 2 BO 3 -H 3 BO 3 solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB

  8. New Anion-Exchange Resins for Improved Separations of Nuclear Materials

    International Nuclear Information System (INIS)

    Bartsch, Richard A.; Barr, Mary E.

    2001-01-01

    Improved separations of nuclear materials will have a significant impact upon a broad range of DOE activities. DOE-EM Focus Areas and Crosscutting Programs have identified improved methods for the extraction and recovery of radioactive metal ions from process, waste, and environmental waters as critical needs for the coming years. We propose to develop multifunctional anion-exchange resins that facilitate anion uptake by carefully controlling the structure of the anion receptor site. Our new ion-exchange resins interface the field of ion-specific chelating ligands with robust, commercial ion-exchange technology to provide materials which exhibit superior selectivity and kinetics of sorption and desorption. The following Focus Areas and Crosscutting Programs have described needs that would be favorably impacted by the new material: Efficient Separations and Processing - radionuclide removal from aqueous phases; Plutonium - Pu, Am or total alpha removal to meet regulatory requirement s before discharge to the environment; Plumes - U and Tc in groundwater, U, Pu, Am, and Tc in soils; Mixed Waste - radionuclide partitioning; High-Level Tank Waste - actinide and Tc removal from supernatants and/or sludges. The basic scientific issues which need to be addressed are actinide complex speciation along with modeling of metal complex/functional site interactions in order to determine optimal binding-site characteristics. Synthesis of multifunctionalized extractants and ion-exchange materials that implement key features of the optimized binding site, and testing of these materials, will provide feedback to the modeling and design activities. Resin materials which actively facilitate the uptake of actinide complexes from solution should display both improved selectivity and kinetic properties. The long-range implications of this research, however, go far beyond the nuclear complex. This new methodology of ''facilitated uptake'' could revolutionize ion-exchange technology

  9. New anion-exchange resins for improved separations of nuclear materials

    International Nuclear Information System (INIS)

    Barr, M.E.; Bartsch, R.A.

    1998-01-01

    'The overall objective of this research is to develop a predictive capability which allows the facile design and implementation of multi-functionalized anion-exchange materials which selectively sorb metal complexes of interest from targeted process, waste, and environmental streams. The basic scientific issues addressed are actinide complex speciation along with modeling of the metal complex/functional-site interactions in order to determine optimal binding-site characteristics. The new ion-exchange resins interface the rapidly developing field of ion-specific chelating ligands with robust, commercial ion-exchange technology. Various Focus Areas and Crosscutting Programs have described needs that would be favorably impacted by the new materials: Efficient Separations and Processing; Plutonium; Plumes; Mixed Waste; High-Level Tank Waste. Sites within the DOE complex which would benefit from the improved anion-exchange technology include Hanford, INEL, Los Alamos, Oak Ridge, and Savannah River. As of April 1998, this report summarizes work after 1.6 years of a 3-year project. The authors technical approach combines empirical testing with theoretical modeling (applied in an iterative mode) in order to determine optimal binding-site characteristics. They determine actinide-complex speciation in specific media, then develop models for the metal complex/functional-site interactions Synthesis and evaluation of multi-functionalized extractants and ion-exchange materials that implement key features of the optimized binding site provide feedback to the modeling and design activities. Resin materials which actively facilitate the uptake of actinide complexes from solution should display both improved selectivity and kinetic properties. The implementation of the bifunctionality concept involves N-derivatization of pyridinium units from a base poly(4-vinylpyridine) resin with a second cationic site such that the two anion-exchange sites are linked by spacer arms of varying

  10. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Ronald [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 μl injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few μl of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  11. KINETICS OF THE OXIDATION OF FERROUS CHELATES OF EDTA AND HEDTA IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    WUBS, HJ; BEENACKERS, AACM

    1993-01-01

    The kinetics of the reaction of oxygen with ferrous chelates of EDTA and HEDTA was studied in a stirred cell reactor under industrial conditions. The temperature was varied from 20 to 60-degrees-C and the concentration of the ferrous chelate ranged from 0 to 100 mol/m3. The initial pH was 7.5. Under

  12. Antioxidant, Iron-chelating and Anti-glucosidase Activities of Typha ...

    African Journals Online (AJOL)

    Iron chelating activity was assessed using a ferrozine-based assay. Anti- glucosidase activity was determined using 4-nitrophenyl ... flavonoid (TF) content was determined based an aluminum chloride colorimetric assay [6]. TF content was ..... Dietary iron restriction or iron chelation protects from diabetes and loss of β-cell.

  13. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Directory of Open Access Journals (Sweden)

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  14. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel

    2007-01-01

    of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  15. Fluoride ion recognition by chelating and cationic boranes.

    Science.gov (United States)

    Hudnall, Todd W; Chiu, Ching-Wen; Gabbaï, François P

    2009-02-17

    Because of the ubiquity of fluoride ions and their potential toxicity at high doses, researchers would like to design receptors that selectively detect this anion. Fluoride is found in drinking water, toothpaste, and osteoporosis drugs. In addition, fluoride ions also can be detected as an indicator of uranium enrichment (via hydrolysis of UF(6)) or of the chemical warfare agent sarin, which releases the ion upon hydrolysis. However, because of its high hydration enthalpy, the fluoride anion is one of the most challenging targets for anion recognition. Among the various recognition strategies that are available, researchers have focused a great deal of attention on Lewis acidic boron compounds. These molecules typically interact with fluoride anions to form the corresponding fluoroborate species. In the case of simple triarylboranes, the fluoroborates are formed in organic solvents but not in water. To overcome this limitation, this Account examines various methods we have pursued to increase the fluoride-binding properties of boron-based receptors. We first considered the use of bifunctional boranes, which chelate the fluoride anion, such as 1,8-diborylnaphthalenes or heteronuclear 1-boryl-8-mercurio-naphthalenes. In these molecules, the neighboring Lewis acidic atoms can cooperatively interact with the anionic guest. Although the fluoride binding constants of the bifunctional compounds exceed those of neutral monofunctional boranes by several orders of magnitude, the incompatibility of these systems with aqueous media limits their utility. More recently, we have examined simple triarylboranes whose ligands are decorated by cationic ammonium or phosphonium groups. These cationic groups increase the electrophilic character of these boranes, and unlike their neutral analogs, they are able to complex fluoride in aqueous media. We have also considered cationic boranes, which form chelate complexes with fluoride anions. Our work demonstrates that Coulombic and chelate

  16. Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

    Energy Technology Data Exchange (ETDEWEB)

    Fatimah, Soja Siti, E-mail: soja-sf@upi.edu [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia); Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Bahti, Husein H.; Hastiawan, Iwan [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Permanasari, Anna [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia)

    2016-02-08

    The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, ({sup 1}H, and {sup 13}C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

  17. Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

    Science.gov (United States)

    Fatimah, Soja Siti; Bahti, Husein H.; Hastiawan, Iwan; Permanasari, Anna

    2016-02-01

    The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, (1H, and 13C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

  18. Preparation, characterization, magnetic and thermal studies of some chelate polymers of first series transition metal ions

    International Nuclear Information System (INIS)

    Ukey, Vaishali V.; Juneja, H.D.; Borkar, S.D.; Ghubde, R.S.; Naz, S.

    2006-01-01

    Azelaoyl-bis-hydroxamic acid used as bis ligand for the preparation of chelate polymers of Mn(II), Co(II), Ni(II) and Zn(II). These chelate polymers have been synthesized by refluxing the metal acetate and bis ligand as 1:1 stoichiometry. In the present work, structural determination of these newly synthesized chelate polymers has been studied on the basis of elemental analyses, infrared and reflectance spectral, magnetic and thermal studies. The decomposition temperature and the order of reaction have been determined by TGA analysis. On the basis of these studies, the Zn(II) chelate polymer has tetrahedral geometry, whereas Mn(II), Co(II) and Ni(II) chelate polymers have octahedral geometry and have the thermal stability in the order Ni(II) > Mn(II) > Zn(II) > Co(II)

  19. Studies of the competition for thorium ion between chelating agents and bovine serum albumin

    International Nuclear Information System (INIS)

    Luo Meichu; Zhang Meizhen; Sun Meizhen; Chen Shijie

    1995-01-01

    Fourteen chelation agents (polyaminopolcarboxylate type--TTHA, DTPA, EDTA; phenolicpolycarboxylate type--811, 8102, 7601, 7602, 7603, 7616, 7711, 7724, 7803, 7804, 8307) were studied their competitive ability to mobilize the thorium with bovine serum albumin (BSA). The experimental results showed that the competitive ability of TTHA, 8102, 811 to chelate Thorium with BSA were the strongest, and EDTA was the worst in all chelating agents. The measured order of the competitive ability of chelators is basically consistent with animal experimental results in vivo. The parameter F is defined as the competitive ability of chelators. F is taken as a screening criterion for de-corporate thorium which is simple, quick and effective method in vitro

  20. Red Blood Cell Transfusion Independence Following the Initiation of Iron Chelation Therapy in Myelodysplastic Syndrome

    Directory of Open Access Journals (Sweden)

    Maha A. Badawi

    2010-01-01

    Full Text Available Iron chelation therapy is often used to treat iron overload in patients requiring transfusion of red blood cells (RBC. A 76-year-old man with MDS type refractory cytopenia with multilineage dysplasia, intermediate-1 IPSS risk, was referred when he became transfusion dependent. He declined infusional chelation but subsequently accepted oral therapy. Following the initiation of chelation, RBC transfusion requirement ceased and he remained transfusion independent over 40 months later. Over the same time course, ferritin levels decreased but did not normalize. There have been eighteen other MDS patients reported showing improvement in hemoglobin level with iron chelation; nine became transfusion independent, nine had decreased transfusion requirements, and some showed improved trilineage myelopoiesis. The clinical features of these patients are summarized and possible mechanisms for such an effect of iron chelation on cytopenias are discussed.

  1. Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

    2014-10-01

    Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Preparation, Spectroscopic Investigation and Biological Activity of New Mixed Ligand Chelates

    International Nuclear Information System (INIS)

    Alassbaly, F.S.; Ajaily, M.M.E.

    2014-01-01

    Preparation and investigation of new Co(II), Ni(II), Zn(II) and Cr(III) chelates with mixed ligands including Schiff base (L1) formed from the condensation of 4-dimethylaminobenzaldehyde with 2-aminophenol and anthranilic acid (L2) were studied. The obtained Schiff base and mixed ligand chelates were subjected to several physiochemical techniques, in terms of CHN elemental analyses, molar conductivity, magnetic moment measurements, infrared, proton nuclear magnetic resonance, electronic and mass spectra. The analytical data showed the formation of the Schiff base compound and the ratio of metal to ligands of the chelates are 1:1:1(M:L1:L2). The infrared spectral data exhibited that the used ligands behaving as bidentate ligands towards the metal ions. The proton nuclear magnetic resonance spectral data showed the signals of the active groups in the ligands which entered in chelation with Zn(II) metal ion. The electronic spectral results showed the existence of pie (phenyl ring) and n = pie (C=N) of the ligands and suggested the geometrical structures of the chelates. Meanwhile, the mass spectral data revealed the fragmentations of the Schiff base, anthranilic acid and their Ni(II) mixed ligand chelate has been preformed the only chelate conducted for justification. All the prepared mixed chelates were non-electrolyte in nature. The antibacterial activity of the Schiff base, anthranilic acid, metal salts and mixed ligand chelates were studied and found to be that mixed ligand chelates have the most biological activity in comparison to the free ligands and salts. (author)

  3. Hot dewatering and resin encapsulation of intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Rickman, J.; Birch, D.

    1985-01-01

    The chemistry of the processes involved in the hot dewatering and encapsulation of alumino-ferric hydroxide floc in epoxide resin have been studied. Pretreatment of the floc to reduce resin attack and hydrolysis and to increase the dimensional stability of the solidified wasteform has been evaluated. It has been demonstrated that removal of ammonium nitrate from the floc and control of the residual water in the resin are important factors in ensuring dimensional stability of the solidified resin. Resin systems have been identified which, together with the appropriate waste pretreatment have successfully encapsulated a simulated magnox sludge producing a stable wasteform having mechanical and physical properties comparable with the basic resin. (author)

  4. Modeling systemic and renal gadolinium chelate transport with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Votaw, John R.; Martin, Diego [Emory University Hospital, Department of Radiology, Atlanta, GA (United States)

    2008-01-15

    The advent of modern MRI scanners and computer equipment permits the rapid sequential collection of images of gadolinium chelate (Gd) transit through the kidney. The excellent spatial and temporal (0.9 s) resolution permits analyzing the shape of the recovered curves with a sophisticated model that includes both space and time. The purpose of this manuscript is to present such a mathematical model. By building into the model significant physical processes that contribute to the shape of the measured curve, quantitative values can be assigned to important parameters. In this work, quantitative values are determined for blood dispersion through the cardio-pulmonary system, systemic clearance rate of Gd, blood flow into each kidney, blood transit time in each kidney, the extraction rate of Gd across the capillary membrane, interstitial distribution volume, and the GFR for each kidney. (orig.)

  5. 3,4,5-trihydroxybenzoic acid as chelating agent

    International Nuclear Information System (INIS)

    Agrawal, M.D.; Bhandari, C.S.; Dixit, M.K.; Sogani, N.C.

    1976-01-01

    Stability constants of praseodymium chelates of 3,4,5-trihydroxy sodium benzoate are determined by using Bjerrum-Calvin pH titration techniques at constant ionic strength 0.1M-sodium perchlorate and at 28+-0.1 0 C. Values calculated by different methods are in good agreement. The study reveals that during complexation only one proton of the ligand molecule is replaced by the metal and oxygen of adjacent phenolic group acts as a coordinating atom. IR and NMR spectral studies of the ligand reveal that one of the OH groups (in meta position to carboxylic group) remains free while two other phenolic groups are involved in intramolecular hydrogen bonding. One water molecule is found attached in crystalline gallic acid. (author)

  6. Mesoporous organosilica nanotubes containing a chelating ligand in their walls

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiao; Goto, Yasutomo; Maegawa, Yoshifumi; Inagaki, Shinji, E-mail: inagaki@mosk.tytlabs.co.jp [Toyota Central R and D Laboratories, Inc., Nagakute, Aichi 480-1192 (Japan); Japan Science and Technology Agency (JST)/ACT-C, Nagakute, Aichi, 480-1192 (Japan); Ohsuna, Tetsu [Toyota Central R and D Laboratories, Inc., Nagakute, Aichi 480-1192 (Japan)

    2014-11-01

    We report the synthesis of organosilica nanotubes containing 2,2′-bipyridine chelating ligands within their walls, employing a single-micelle-templating method. These nanotubes have an average pore diameter of 7.8 nm and lengths of several hundred nanometers. UV-vis absorption spectra and scanning transmission electron microscopy observations of immobilized nanotubes with an iridium complex on the bipyridine ligands showed that the 2,2′-bipyridine groups were homogeneously distributed in the benzene-silica walls. The iridium complex, thus, immobilized on the nanotubes exhibited efficient catalytic activity for water oxidation using Ce{sup 4+}, due to the ready access of reactants to the active sites in the nanotubes.

  7. Thermometric studies on the Fe(III)-EDTA chelate.

    Science.gov (United States)

    Dot, K

    1978-02-01

    A DeltaH of -11.5 +/- 0.5 kJ/mole has been determined for the formation of the Fe(III)-EDTA chelate at 25.0 degrees and mu = 0.1(= [HClO(4)] + [NaClO(4)]) by a direct thermometric titration procedure. The entropy change, DeltaS, has been calculated to be 440 J.mole(-1) .deg(-1) by combining the result of the heat measurements with the free energy change obtained from the stability constant previously determined. A relationship between the DeltaS values and the standard partial molal entropies of the tervalent metal ions is discussed. In addition, conditions for the thermometric titration of Fe(III) with NA(4)EDTA at room temperature have been investigated. Iron(III) can be determined in the presence of fairly large amounts of phosphate, Cr(III), Mn(II) and Al(III).

  8. Mesoporous organosilica nanotubes containing a chelating ligand in their walls

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    2014-11-01

    Full Text Available We report the synthesis of organosilica nanotubes containing 2,2′-bipyridine chelating ligands within their walls, employing a single-micelle-templating method. These nanotubes have an average pore diameter of 7.8 nm and lengths of several hundred nanometers. UV-vis absorption spectra and scanning transmission electron microscopy observations of immobilized nanotubes with an iridium complex on the bipyridine ligands showed that the 2,2′-bipyridine groups were homogeneously distributed in the benzene-silica walls. The iridium complex, thus, immobilized on the nanotubes exhibited efficient catalytic activity for water oxidation using Ce4+, due to the ready access of reactants to the active sites in the nanotubes.

  9. Chelation and stabilization of berkelium in oxidation state +IV

    Science.gov (United States)

    Deblonde, Gauthier J.-P.; Sturzbecher-Hoehne, Manuel; Rupert, Peter B.; An, Dahlia D.; Illy, Marie-Claire; Ralston, Corie Y.; Brabec, Jiri; de Jong, Wibe A.; Strong, Roland K.; Abergel, Rebecca J.

    2017-09-01

    Berkelium (Bk) has been predicted to be the only transplutonium element able to exhibit both +III and +IV oxidation states in solution, but evidence of a stable oxidized Bk chelate has so far remained elusive. Here we describe the stabilization of the heaviest 4+ ion of the periodic table, under mild aqueous conditions, using a siderophore derivative. The resulting Bk(IV) complex exhibits luminescence via sensitization through an intramolecular antenna effect. This neutral Bk(IV) coordination compound is not sequestered by the protein siderocalin—a mammalian metal transporter—in contrast to the negatively charged species obtained with neighbouring trivalent actinides americium, curium and californium (Cf). The corresponding Cf(III)-ligand-protein ternary adduct was characterized by X-ray diffraction analysis. Combined with theoretical predictions, these data add significant insight to the field of transplutonium chemistry, and may lead to innovative Bk separation and purification processes.

  10. Characterization of Polyimide Matrix Resins and Prepregs

    Science.gov (United States)

    Maximovich, M. G.; Galeos, R. M.

    1985-01-01

    Graphite/polyimide composite materials are attractive candidates for a wide range of aerospace applications. They have many of the virtues of graphite/epoxies, i.e., high specific strengths and stiffness, and also outstanding thermal/oxidative stability. Yet they are not widely used in the aerospace industry due to problems of procesability. By their nature, modern addition polyimide (PI) resins and prepregs are more complex than epoxies; the key to processing lies in characterizing and understanding the materials. Chemical and rheological characterizations are carried out on several addition polyimide resins and graphite reinforced prepregs, including those based on PMR-15, LARC 160 (AP 22), LARC 160 (Curithane 103) and V378A. The use of a high range torque transducer with a Rheometrics mechanical spectrometer allows rheological data to be generated on prepreg materials as well as neat resins. The use of prepreg samples instead of neat resins eliminates the need for preimidization of the samples and the data correlates well with processing behavior found in the shop. Rheological characterization of the resins and prepregs finds significant differences not readily detected by conventional chemical characterization techniques.

  11. Ion chromatography for the analysis of salt splitting capacities of cation and anion resin in premixed resin sample

    International Nuclear Information System (INIS)

    Ghosh, Satinath; Kumar, Rakesh; Tripathy, M.K.; Dhole, K.; Sharma, R.S.; Varde, P.V.

    2017-01-01

    Mixed bed ion exchange resin is commonly used in various plants including nuclear reactors for the purpose of fine polishing. The analysis of ion exchange capacities of cation and anion resin in resin mixture is therefore an agenda in the context of purchasing of premixed resin from the manufacturer. An ion chromatographic method for assaying ion exchange capacities of pure as well as mixed resin has been optimized. The proposed method in contrast to the conventional ASTM method has been found to be quite encouraging to consider it as an alternate method for the analysis of premixed resin. (author)

  12. Ponderosa pine resin defenses and growth: metrics matter.

    Science.gov (United States)

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  13. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-02-01

    Over the last seven years, Low Oxidation State Metal Ion reagents (LOMI) have been used to decontaminate the 100 MW(e) Steam Generating Heavy Water Ractor (SGHWR) at Winfrith. The use of these reagents has resulted in a dilute ionic solution containing activation products which are produced by corrosion of metallic components in the reactor. It has been demonstrated that the amount of activity in the solution can be reduced using organic ion exchanger resins. These resins consist of a cross linked polystyrene with sulphonic acid or quaternary ammonium function groups and can be successfully immobilised in blended cement systems. The formulation which has been developed is produced from a 9 to 1 blend of ground granulated blast furnace slag (BFS) and ordinary Portland cement (OPC) containing 28% ion exchange resin in the water saturated form. If 6% Microsilica is added to the blended cement the waste loading can be increased to 36 w/o. (author)

  14. Thermosetting resins for nuclear track detection

    International Nuclear Information System (INIS)

    Fujii, M.; Yokota, R.

    1986-01-01

    Several new thermosetting resins with a three dimensional network structure similar to that of CR-39 were polymerized to study their characteristics as nuclear track detectors. The comparison of the molecular structures of these resins gives us an important clue to develop highly sensitive polymeric track detectors. For example, butanediol bis allylcarbonate (BuAC) shows the sensitivity about ten times higher than diallyl and adipate (DAA). This suggests the carbonate groups in the BuAC molecule provide a much higher sensitivity than the ester groups in the DAA. During the course of this study, thermosetting resins with good etching properties and various sensitivities have been developed. Though the sensitivity of DAA is low, it will be useful for observations of ultra heavy cosmic rays and heavily ionizing particles at low energies. (author)

  15. Aging in CTBN modified epoxy resin stocks

    International Nuclear Information System (INIS)

    Creed, K.E. Jr.

    1979-01-01

    The cause of degradation in the glass transition temperature (T/sub G/) of a partially crystallized polymer was investigated. Sample epoxy resin filled capacitors were cured at 90 0 C for 24 hours, then stored at room atmospheric conditions. These showed typical degradation in T/sub G/ after storage for one month. One set of epoxy resin castings was stored at room atmosphere and another set was stored in a dry box at 0% relative humidity and 27 0 C. The samples at room atmospheric conditions showed typical degradation in T/sub G/, while the T/sub G/ for those stored in the dry box increased. Further tests were then made on epoxy resin castings at various curing temperatures and times at both room atmosphere and 0% humidity. Resulting data indicated that absorption of moisture during storage was the predominant cause of T/sub G/ degradation, with stress relaxation another, though smaller, contributing factor

  16. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2018-01-01

    For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth...... present an aesthetic problem due to exposure of un-aesthetic crown-margins. The invasive permanent crown restorations are therefore often not suc-cessful on a long-term scale. On the other hand, a conservative direct restoration of an extensively fractured incisor crown with resin composite may......-structure and with minimal risk of pulpal complication. In addition, it offers an aesthetic solution to the patient immediately after an injury, which may bring a little comfort in a sad situation. The resin composite build-up is often changed or repaired a couple of times, before the tooth is restored with a porcelain...

  17. Incineration of spent ion exchange resin

    International Nuclear Information System (INIS)

    Hasegawa, Chiaki

    1990-01-01

    It is a pressing need to reduce radioactive waste which is generated from the maintenance and operation of a nuclear power plant. Incineration of low level combustible solid waste such as polyethylene seats, paper and others have been successfully performed since 1984 at the Shimane Nuclear Power Station. Furthermore, for extending incineration treatment to spent ion exchange resin, the incineration test was carried out in 1989. However, as the cation exchange resin contains sulfur and then incineration generates SOx gases, so the components of this facility will be in a corrosive environment. We surveyed incineration conditions to improve the corrosive environment at the exhaust gas treatment system. This paper includes these test results and improved method to incinerate spent ion exchange resin. (author)

  18. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  19. Microshear bond strength of composite resins to enamel and porcelain substrates utilizing unfilled versus filled resins.

    Science.gov (United States)

    Najafi-Abrandabadi, Ahmad; Najafi-Abrandabadi, Siamak; Ghasemi, Amir; Kotick, Philip G

    2014-11-01

    Failures such as marginal discoloration and composite chipping are still the problems of tooth-colored restorations on the substrate of enamel and porcelain, which some of these problems are consequently as a result of failures in the bonding layer. Using filled resin has been recently introduced to increase the bond strength of this layer. The aim of this study was to compare the microshear bond strength (μ-SBS) of composite resins to enamel incubated in periods of 24 h and 9 months and porcelain with unfilled resin and flowable composites (filled resin). In this in vitro study, two groups of 75 enamel samples with different storage times (24 h and 9 months) and a group of 75 porcelain samples were used. They were divided into 5 experimental groups of 15 samples in each. Composite cylinders in tygon tubes were bonded on the surface of acid-etched enamel and pretreated porcelain. Wave, Wave MV, Wave HV, Grandioflow and Margin Bond were used as bonding agents. The μ-SBS was measured at the speed of 1.0 mm/min. The bond strengths were analyzed with one-way analysis of variance (ANOVA) test followed by Tukey test. P composites (filled resins) can be used instead of unfilled resins in bonding composite resins to enamel and porcelain substrates.

  20. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  1. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Science.gov (United States)

    2011-02-15

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-386 (Third Review)] Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International Trade Commission. ACTION: Termination of five... revocation of the antidumping duty order on granular polytetrafluoroethylene resin from Japan would be likely...

  2. Development of amino resin for paint formulation: Copolymerization ...

    African Journals Online (AJOL)

    SERVER

    2007-06-18

    Jun 18, 2007 ... IR spectroscopy and macro phase separation techniques. At a given TEA ... form aldehyde emission from urea formaldehyde resin through one step ..... of resin molecules (Barminas and Osemeahon, 2007;. Sekaran et al.

  3. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  4. Characterization of commercial iron chelates and their behavior in an alkaline and calcareous soil.

    Science.gov (United States)

    Cantera, Rodrigo G; Zamarreño, Angel M; García-Mina, José M

    2002-12-18

    Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time.

  5. MRI marrow observations in thalassemia: the effects of the primary disease, transfusional therapy, and chelation

    International Nuclear Information System (INIS)

    Levin, T.L.; Sheth, S.S.; Ruzal-Shapiro, C.; Abramson, S.; Piomelli, S.; Berdon, W.E.

    1995-01-01

    The magnetic resonance bone marrow patterns in thalassemia were evaluated to determine changes produced by transfusion and chelation therapy. Thirteen patients had T1- and T2-weighted images of the spine, pelvis and femurs. Three received no therapy (age range 2.5-3 years). Three were ''hypertransfused'' (transfused to maintain a hemoglobin greater than 10 g/dl) and not chelated because of age (age range 6 months-8 years). Seven were ''hypertransfused'' and chelated (age range 12-35 years). Signal characteristics of marrow were compared with those of surrounding muscle and fat. Fatty marrow (isointense with subcutaneous fat) was compared with red marrow (hypointense to fat and slightly hyperintense to muscle). Marrow hypointense to muscle was identified as iron deposition within red marrow. The untreated group demonstrated signal consistent with red marrow throughout the central and peripheral skeleton. Hypertransfused but not chelated patients demonstrated marked iron deposition in the central and peripheral skeleton. Hypertransfused and chelated patients demonstrated iron deposition in the central skeleton and a mixed appearance of marrow in the peripheral skeleton. The MR appearance of marrow in thalassemia is a reflection of the patient's transfusion and chelation therapy. Iron deposition occurs despite chelation therapy in sites of active red marrow. As red marrow retreats centrally with age, so does the pattern of iron deposition. The long-term biological effects of this iron deposition are unknown. (orig.). With 8 figs., 1 tab

  6. Synthesis of novel bifunctional chelators and their use in preparing monoclonal antibody conjugates for tumor targeting

    International Nuclear Information System (INIS)

    Westerberg, D.A.; Carney, P.L.; Rogers, P.E.; Kline, S.J.; Johnson, D.K.

    1989-01-01

    Bifunctional derivatives of the chelating agents ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid, in which a p-isothiocyanatobenzyl moiety is attached at the methylene carbon atom of one carboxymethyl arm, was synthesized by reductive alkylation of the relevant polyamine with (p-nitrophenyl)pyruvic acid followed by carboxymethylation, reduction of the nitro group, and reaction with thiophosgene. The resulting isothiocyanate derivatives reacted with monoclonal antibody B72.3 to give antibody-chelator conjugates containing 3 mol of chelator per mole of immunoglobulin, without significant loss of immunological activity. Such conjugates, labeled with the radioisotopic metal indium-111, selectively bound a human colorectal carcinoma implanted in nude mice when given intravenously. Uptake into normal tissues was comparable to or lower than that reported for analogous conjugates with known bifunctional chelators. It is concluded that substitution with a protein reactive group at this position in polyaminopolycarboxylate chelators does not alter the chelating properties of these molecules to a sufficient extent to adversely affect biodistribution and thus provides a general method for the synthesis of such chelators

  7. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    Science.gov (United States)

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-02-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed.

  8. Rapid viscosity measurements of powdered thermosetting resins

    Science.gov (United States)

    Price, H. L.; Burks, H. D.; Dalal, S. K.

    1978-01-01

    A rapid and inexpensive method of obtaining processing-related data on powdered thermosetting resins has been investigated. The method involved viscosity measurements obtained with a small specimen (less than 100 mg) parallel plate plastometer. A data acquisition and reduction system was developed which provided a value of viscosity and strain rate about 12-13 second intervals during a test. The effects of specimen compaction pressure and reduction of adhesion between specimen and parallel plates were examined. The plastometer was used to measure some processing-related viscosity changes of an addition polyimide resin, including changes caused by pre-test heat treatment, test temperature, and strain rate.

  9. Thermal behavior of halogenated imidebismaleimide resins

    International Nuclear Information System (INIS)

    Mohammad, A.; Al-Halim, N.Z.

    1995-01-01

    Several new poly-halogenated malecimides, bismaleimides and therir copoly resins were synthessised thermally from their corresponding amic acids. The synthesis was accomplished by two way method (amic acid-polimide) instead of the well-known three way method (amic acid-imide-polyimide). Thermal characterization of monomers and their cured resins was achieved using differential thermal analysis (DTA), dynamic thermogravimetric analysis (TGA) and isothermal gravimetric analysis (IGA). The effect of halogen substituent, especially in the ortho postion, is clear in the imidization proces, while polymerization proceeds almost equally in all systems. Thermal properties of homo and copolymers were correlated with their chemical structures. (author). 15 refs., 4

  10. Understanding of the color in composite resin

    Directory of Open Access Journals (Sweden)

    Jeong-Won Park

    2011-07-01

    Full Text Available In clinic, esthetic restoration of a defective natural tooth with composite resin is challenging procedure and needs complete understanding of the color of tooth itself and materials used. The optical characteristics of the composites are different because the chemical compositions and microstructures are not same. This review provided basic knowledge of the color and the color measurement devices, and analyze the color of the natural tooth. Further, the accuracy of the shade tab, color of the composite resins before and after curing, effect of the water, food and bleaching agent, and translucency, opalescence, and fluorescence effects were evaluated.

  11. Different photoluminescent properties of binary and ternary europium chelates doped in PMMA

    International Nuclear Information System (INIS)

    Liu Hongguo; Park, Seongtae; Jang, Kiwan; Zhang Wansong; Seo, Hyo-Jin; Lee, Yong-Ill

    2003-01-01

    Two kinds of europium-β-diketone chelates, binary Eu(DBM) 3 and ternary Eu(DBM) 3 phen were doped in poly(methyl methacrylate) (PMMA). These chelates show very different photoluminescent (PL) behaviors: the hypersensitive 5 D 0 → 7 F 2 emission bands of Eu(DBM) 3 phen change slightly with the molar ratios, while those of Eu(DBM) 3 change obviously and regularly with the molar ratios. The results of the luminescent lifetimes of 5 D 0 levels show that the binary chelate exists as two kinds of species in the doped systems, and the lifetimes and contents of each species change with the molar ratios, while the ternary chelate exists as one kind of species in the doped systems. X-ray diffraction (XRD) patterns of the binary chelate doped systems give some diffraction peaks that are different from those of pure chelate and change with the molar ratios, indicating new kinds of crystal structures formed, and consequently, the first coordination sphere of Eu 3+ ion changes; while those of the ternary chelate doped systems just show amorphous diffraction halos of the host, indicating that the ternary chelate exist in an amorphous state and disperse well in the host. The FTIR spectra of PMMA also change gradually with increasing the molar ratios of the doped two kinds of chelates, and the XRD patterns show that the amorphous halos of PMMA in the doped systems are different from those of pure PMMA and change with the molar ratios, too, suggesting the interaction between the guest and the host

  12. Study of Anti-Fatigue Effect in Rats of Ferrous Chelates Including Hairtail Protein Hydrolysates

    Directory of Open Access Journals (Sweden)

    Saibo Huang

    2015-12-01

    Full Text Available The ability of ferrous chelates including hairtail protein hydrolysates to prevent and reduce fatigue was studied in rats. After hydrolysis of hairtail surimi with papain, the hairtail protein hydrolysates (HPH were separated into three groups by range of relative molecular weight using ultrafiltration membrane separation. Hairtail proteins were then chelated with ferrous ions, and the antioxidant activity, the amino acid composition and chelation rate of the three kinds of ferrous chelates including hairtail protein hydrolysates (Fe-HPH were determined. Among the three groups, the Fe-HPH chelate showing the best conditions was selected for the anti-fatigue animal experiment. For it, experimental rats were randomly divided into seven groups. Group A was designated as the negative control group given distilled water. Group B, the positive control group, was given glutathione. Groups C, D and E were designated as the Fe-HPH chelate treatment groups and given low, medium, and high doses, respectively. Group F was designated as HPH hydrolysate treatment group, and Group G was designated as FeCl2 treatment group. The different diets were orally administered to rats for 20 days. After that time, rats were subjected to forced swimming training after 1 h of gavage. Rats given Fe-FPH chelate had higher haemoglobin regeneration efficiency (HRE, longer exhaustive swimming time and higher SOD activity. Additionally, Fe-FPH chelate was found to significantly decrease the malondialdehyde content, visibly enhance the GSH-Px activity in liver and reduce blood lactic acid of rats. Fe-HPH chelate revealed an anti-fatigue effect, similar to or better than the positive control substance and superior to HPH or Fe when provided alone.

  13. Study on the Novel Dicyanate Ester Resin Containing Naphthalene Unit

    Institute of Scientific and Technical Information of China (English)

    Hong Qiang YAN; Hong Yun PENG; Li JI; Guo Rong QI

    2004-01-01

    The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 (C /min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.

  14. Modification of Aliphatic Petroleum Resin by Peracetic Acid

    OpenAIRE

    Bondaletov, Vladimir Grigoryevich; Bondaletova, Lyudmila Ivanovna; Hamlenko, A.; Bondaletov, Oleg Vladimirovich; Starovoit, M.

    2014-01-01

    This work demonstrates the possibility of obtaining modified aliphatic resin (PRC5) by means of petroleum resin oxidation by peracetic acid. We have experimentally determined oxidation conditions that lead to producing resin with maximum epoxy and acid numbers. Ratio of "oxidative system: PRC5" is 0.5:1, process duration is 2 hours. The modified resin structure is determined by IR and NMR spectroscopy.

  15. Performances and improvement of copper-hydrazine complexation deoxidising resin

    International Nuclear Information System (INIS)

    Liu Fenfen; Zhang Hao; Sun Haijun; Liu Xiaojie

    2012-01-01

    Copper-hydrazine complexation deoxidising resin is tested to examine its performances including effluent water quality and capacity of deoxidisation. By the means of changing the resin type and regeneration, the deoxidising capacity of the resin can be improved to 13 times more than before. At the same time, physical performances of the resin are also greatly improved while maintaining its velocity of deoxidisation and effluent quality. (authors)

  16. Recovery of tretrachloroaurate through ion exchange with Dowex 11 resin

    International Nuclear Information System (INIS)

    Alguacil, F.J.

    1998-01-01

    The recovery of the tretrachloroaurate complex by the anionic ion exchange resin Dowex 11 has been studied. The kinetics of gold adsorption were dependent of both gold and resin concentrations and temperature. The adsorption isotherm can be described by the expression Q=kC''n. The loaded resin could be eluted by an acidic thiourea solution at 20 degree centigree. After several adsorption-elution cycles there is not any apparent loss in the adsorption properties of the resin. (Author) 6 refs

  17. Management of white spots: resin infiltration technique and microabrasion

    Directory of Open Access Journals (Sweden)

    Jeong-Hye Son

    2011-01-01

    Full Text Available This case report compared the effectiveness of resin infiltration technique (Icon, DMG with microabrasion (Opalustre, Ultradent Products, Inc. in management of white spot lesions. It demonstrates that although neither microabrasion nor resin infiltration technique can remove white spot lesions completely, resin infiltration technique seems to be more effective than microabrasion. Therefore resin infiltration technique can be chosen preferentially for management of white spot lesions and caution should be taken for case selection.

  18. Evaluation of an Experimental Adhesive Resin for Orthodontic Bonding

    Science.gov (United States)

    Durgesh, B. H.; Alkheraif, A. A.; Pavithra, D.; Hashem, M. I.; Alkhudhairy, F.; Elsharawy, M.; Divakar, D. D.; Vallittu, P. K.; Matinlinna, J. P.

    2017-07-01

    The aim of this study was to evaluate in vitro the effect of an experimental adhesive resin for orthodontic bonding by measuring some the chemical and mechanical properties. The resin demonstrated increased values of nanohardness and elastic modulus, but the differences were not significant compared with those for the Transbond XT adhesives. The experimental adhesive resin could be a feasible choice or a substitute for the traditional bis-GMA-based resins used in bonding orthodontic attachments.

  19. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... thermosetting resins subcategory. 414.50 Section 414.50 Protection of Environment ENVIRONMENTAL PROTECTION... Thermosetting Resins § 414.50 Applicability; description of the thermosetting resins subcategory. The provisions... the products classified under SIC 28214 thermosetting resins including those resins and resin groups...

  20. The influence of resin flexural modulus on the magnitude of ceramic strengthening.

    LENUS (Irish Health Repository)

    Fleming, Garry J P

    2012-07-01

    The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a \\'zero\\' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical \\'zero\\' resin-coating thickness.

  1. Chelating extractants of improved selectivity. Progress report, September 1, 1976--October 31, 1977

    International Nuclear Information System (INIS)

    Freiser, H.

    1977-07-01

    New means of characterizing metal chelating reagent selectivity have been developed and incorporated into a theoretical factor analysis of the chelate stability constants of 24 metal ions with 14 ligands of the EDTA family. The factor analysis will be extended to extracting ligand families. A computer-controlled automated metal chelate stability constant apparatus has been assembled and successfully tested. A high performance liquid chromatograph has been set up and preliminary examination of comparison of reversed phase chromatographic separation of metal ions with their solvent extraction behavior begun

  2. [Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents

    International Nuclear Information System (INIS)

    1991-01-01

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III)

  3. [Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

  4. (Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents)

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

  5. AAZTA: an ideal chelating agent for the development of {sup 44}Sc PET imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Gabor; Szikra, Dezso; Trencsenyi, Gyoergy [Scanomed Ltd., Debrecen (Hungary); University of Debrecen, Medical Imaging Clinic (Hungary); Fekete, Aniko [University of Debrecen, Medical Imaging Clinic (Hungary); Garai, Ildiko [Scanomed Ltd., Debrecen (Hungary); Giani, Arianna M.; Negri, Roberto [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); Masciocchi, Norberto [Dipartimento di Scienza e Alta Tecnologia e To.Sca.Lab, Universita degli Studi dell' Insubria, Como (Italy); Maiocchi, Alessandro; Uggeri, Fulvio [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Toth, Imre [Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary); Aime, Silvio [Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Universita degli Studi di Torino (Italy); Giovenzana, Giovanni B. [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); CAGE Chemicals srl, Novara (Italy); Baranyai, Zsolt [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary)

    2017-02-13

    Unprecedented fast and efficient complexation of Sc{sup III} was demonstrated with the chelating agent AAZTA (AAZTA=1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)] amino-6-methylperhydro-1,4-d iazepine) under mild experimental conditions. The robustness of the {sup 44}Sc(AAZTA){sup -} chelate and conjugated biomolecules thereof is further shown by in vivo PET imaging in healthy and tumor mice models. The new results pave the way towards development of efficient Sc-based radiopharmaceuticals using the AAZTA chelator. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Design, synthesis, and evaluation of polyhydroxamate chelators for selective complexation of actinides

    International Nuclear Information System (INIS)

    Gopalan, A.; Jacobs, H.; Koshti, N.; Stark, P.; Huber, V.; Dasaradhi, L.; Caswell, W.; Smith, P.; Jarvinen, G.

    1995-01-01

    Specific chelating polymers targeted for actinides have much relevance to problems involving remediation of nuclear waste. Goal is to develop polymer supported, ion specific extraction systems for removing actinides and other hazardous metal ions from wastewaters. This is part of an effort to develop chelators for removing actinide ions such as Pu from soils and waste streams. Selected ligands are being attached to polymeric backbones to create novel chelating polymers. These polymers and other water soluble and insoluble polymers have been synthesized and are being evaluated for ability to selectively remove target metal ions from process waste streams

  7. Assessment of the body burden of chelatable lead: a model and its application to lead workers

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Ushio, K.

    1982-05-01

    A hypothetical model was introduced to estimate the body burden of chelatable lead from the mobilisation yield of lead by calcium disodium ethylenediamine tetra-acetate. It was estimated that, on average, 14 and 19% of the body burden was mobilized into the urine during the 24 hours after an injection of 53.4 mumol and 107 mumol CaEDTA per kg bodyweight, respectively. The body burden of chelatable lead ranged from 4 mumol to 120 mumol in lead workers with blood lead concentrations of 0.3-2.9 mumol/kg. There were linear relationships between blood lead concentrations and body burden of chelatable lead on a log scale.

  8. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    Directory of Open Access Journals (Sweden)

    H. Kimura

    2011-12-01

    Full Text Available Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR. As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring co-reacted with cyanate ester group. The properties of the cured thermosetting resin were estimated by mechanical properties, electrical resistivity, water resistance and heat resistance. The cured thermosetting resin from benzoxazine and cyanate ester resin showed good heat resistance, high electrical resistivity and high water resistance, compared with the cured thermosetting resin from benzoxazine and epoxy resin.

  9. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such as...

  10. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a water...

  11. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the...

  12. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Science.gov (United States)

    2010-11-01

    ... Polytetrafluoroethylene Resin From Italy and Japan AGENCY: United States International Trade Commission. ACTION... resin from Italy and Japan. SUMMARY: The Commission hereby gives notice that it has instituted reviews... revocation of the antidumping duty orders on granular polytetrafluoroethylene resin from Italy and Japan...

  13. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670 Section...

  14. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for the...

  15. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of molded...

  16. Evaluation of some anionic exchange resins as potential tablet ...

    African Journals Online (AJOL)

    The effect of resin concentration and compression force on the properties of tablets using the selected resin was investigated. In addition, the disintegrant efficacy of the selected resin in the tablet formulations containing either a basic drug, e.g., dextromethorphan hydrobromide (DMP), or an acidic drug, e.g., diclofenac ...

  17. Development of radiation-curable resin based on natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Dahlan; Harun, Abdul Ghani [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

    1994-12-31

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive.

  18. 21 CFR 177.2430 - Polyether resins, chlorinated.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyether resins, chlorinated. 177.2430 Section 177... Components of Articles Intended for Repeated Use § 177.2430 Polyether resins, chlorinated. Chlorinated polyether resins may be safely used as articles or components of articles intended for repeated use in...

  19. Development of radiation-curable resin based on natural rubber

    International Nuclear Information System (INIS)

    Dahlan Mohd; Abdul Ghani Harun

    1993-01-01

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive

  20. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  1. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

  2. Resin Flow in Fiber Preformed by Vacuum Assisted Resin Transfer Molding with Flexible Tools

    Directory of Open Access Journals (Sweden)

    M.M. Shokrieh

    2008-12-01

    Full Text Available Vacuum assisted resin transfer molding, as a sub-branch of RTM is a method of manufacturing composite specimens. Considering the industrial development of this method, different modified techniques are designed to improve its performance. Among these techniques, using a half flexible mold is regarded as an important method. In this work, dominant equations of resin flow through the mold in polar coordinates are solved analytically. Based on this approach, closed-form solutions have been presented for different parameters such as thickness variation of preformed fiber, resin pressure, resin velocity and fiber volume fraction as functions of two variables, namely, time and the distance from injection port. After verification of the approach employed in this work, the results are presented. Important parameters influencing the quality and the rate production are studied in detail.

  3. 21 CFR 177.1555 - Polyarylate resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... in contact with all foods except beverages containing more than 8 volume percent ethanol under...

  4. Microbial treatment of ion exchange resins

    International Nuclear Information System (INIS)

    Kouznetsov, A.; Kniazev, O.

    2001-01-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  5. [Resin-bonded fixed partial dentures

    NARCIS (Netherlands)

    Kreulen, C.M.; Creugers, N.H.J.

    2013-01-01

    A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed

  6. Studies on chemoviscosity modeling for thermosetting resins

    Science.gov (United States)

    Bai, J. M.; Hou, T. H.; Tiwari, S. N.

    1987-01-01

    A new analytical model for simulating chemoviscosity of thermosetting resins has been formulated. The model is developed by modifying the well-established Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By introducing a relationship between the glass transition temperature Tg(t) and the degree of cure alpha(t) of the resin system under cure, the WLF theory can be modified to account for the factor of reaction time. Temperature dependent functions of the modified WLF theory constants C sub 1 (t) and C sub 2 (t) were determined from the isothermal cure data. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data. This work represents progress toward establishing a chemoviscosity model which is capable of not only describing viscosity profiles accurately under various cure cycles, but also correlating viscosity data to the changes of physical properties associated with the structural transformation of the thermosetting resin systems during cure.

  7. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    .... Polyestercarbonate resins may be safely used as articles or components of articles intended for use in producing.... Copies are available from the Office of Premarket Approval, Center for Food Safety and Applied Nutrition... examined at the Center for Food Safety and Applied Nutrition's Library, Food and Drug Administration, 5100...

  8. Effect of Resin Extract from Commiphora swynnertonii

    African Journals Online (AJOL)

    Dr Olaleye

    of Commiphora swynnertonii resin on biochemical parameters in rats was investigated. Sixty rats were ... significantly elevated protein and albumin levels but had no significant effect on bilirubin and all the liver enzymes in the rats. These findings are ... hypoglycemic and hypolipidemic effects against high fat diet- induced ...

  9. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  10. Specific chelating reagent to extract uranium from the sea water

    International Nuclear Information System (INIS)

    Tabushi, Iwao; Kobuke, Yoshiaki

    1982-01-01

    The behavior of uranyl ions as seen from the chemistry of complex as the object of molecule recognition was examined on the basis of the research of structure and equilibrium in solution, in an attempt for the search of specific ligands and the molecular design of adsorbents. What is the most essential for the extraction of uranyl ions from sea water is the development of an excellent adsorbent with rapid adsorption, large equilibrium adsorption and high physical-chemical stability. Based on this appreciation, attempt has been made to find out the molecular design of an excellent adsorbent, starting with the chemistry of complex of uranyl ions. For the purpose, the following matters are reviewed: uranium in nature, the chemistry of complex of uranyl ions, specific ligands for the uranyl ions in sea water, the adsorbent resins for sea-water uranium, the proposals for an adsorbent system. (Mori, K.)

  11. ANALYSIS OF VENTING OF A RESIN SLURRY

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  12. Synthesis of a novel bicyclic bifunctional chelating agent

    International Nuclear Information System (INIS)

    Sweet, M.P.; Mease, R.C.; Joshi, V.; Srivastava, S.C.

    1994-01-01

    Semi-rigid ligands such as cyclohexyl EDTA (CDTA) and 4-isothiocyanato-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (4-ICE) form chelates that are more stable in vivo compared to those of EDTA or DTPA. The authors have synthesized a new class of ligands in which the metal-binding polyaminocarboxylate groups are incorporated onto the rigid bicyclo[2.2.2]octane ring system. These ligands are expected to contribute to even higher in vivo stability of radiometal complexes. The synthesis of the first in this series of ligands (2.3-diaminobicyclo[2.2.2]octane-N,N,N',N'-tetraacetic acid, BODTA) began with a Diels-Alder reaction of 1,3-diacetylimidazolin-2-one and 1,3-cyclohexadiene. Base hydrolysis afforded the diamine. Following alkylation of the diamine with ethyl iodoacetate and hydrogenation of the double bond, hydrolysis of the esters gave BODTA. For initial conjugation with proteins, an average of one carboxylic acid of BODTA was converted into an NHS ester. In vivo testing of radioimmunoconjugates, prepared using this method, is in progress

  13. Assessment of toxicity on chelating agent DTPA (diethylenetriaminepentaacetic acid)

    International Nuclear Information System (INIS)

    Fukuda, Satoshi

    1989-01-01

    DTPA (diethylenetriaminepentaacetic acid) is a very important chelating agent to decorporate the radionuclides such as plutonium and americium from human body. However, before DTPA will be administered to humans, the toxicity should be clarified. This report described the summary on data of DTPA toxicities obtained from animal experiments and assessment on the safety for humans, based on the results that compared their data among animal species. In short, Ca-DTPA is less toxic than Zn-DTPA when it is injected intravenously, while Zn-DTPA is less toxic than Ca-DTPA when it is administered orally. Both DTPAs acted on the serum calcium metabolism and induced the functional damages of cardiovascular system. Particularly, it is stressed that Zn-DTPA by intravenous injection occurred the heart failure, increases of blood pressure and pulse with hypocalcemia in even normal rats and beagle dogs. Other side effects by both DTPAs were also observed in the intestine, liver, kidney and bone. It is estimated that there are almost no species differences on DTPA toxicity between animals and humans. As a result, it is concluded that DTPA should be used very carefully for humans, with reference to the results obtained from animal experiments. (author) 61 refs

  14. Assessment of toxicity on chelating agent DTPA (diethylenetriaminepentaacetic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Satoshi (National Inst. of Radiological Sciences, Chiba (Japan))

    1989-09-01

    DTPA (diethylenetriaminepentaacetic acid) is a very important chelating agent to decorporate the radionuclides such as plutonium and americium from human body. However, before DTPA will be administered to humans, the toxicity should be clarified. This report described the summary on data of DTPA toxicities obtained from animal experiments and assessment on the safety for humans, based on the results that compared their data among animal species. In short, Ca-DTPA is less toxic than Zn-DTPA when it is injected intravenously, while Zn-DTPA is less toxic than Ca-DTPA when it is administered orally. Both DTPAs acted on the serum calcium metabolism and induced the functional damages of cardiovascular system. Particularly, it is stressed that Zn-DTPA by intravenous injection occurred the heart failure, increases of blood pressure and pulse with hypocalcemia in even normal rats and beagle dogs. Other side effects by both DTPAs were also observed in the intestine, liver, kidney and bone. It is estimated that there are almost no species differences on DTPA toxicity between animals and humans. As a result, it is concluded that DTPA should be used very carefully for humans, with reference to the results obtained from animal experiments. (author) 61 refs.

  15. Chelating water-soluble polymers for waste minimization

    International Nuclear Information System (INIS)

    Smith, B.; Cournoyer, M.; Duran, B.; Ford, D.; Gibson, R.; Lin, M.; Meck, A.; Robinson, P.; Robison, T.

    1996-01-01

    Within the DOE complex and in industry there is a tremendous need for advanced metal ion recovery and waste minimization techniques. This project sought to employ capabilities for ligand-design and separations chemistry in which one can develop and evaluate water- soluble chelating polymers for recovering actinides and toxic metals from various process streams. Focus of this work was (1) to develop and select a set of water-soluble polymers suitable for a selected waste stream and (2) demonstrate this technology in 2 areas: removal of (a) actinides and toxic RCRA metals from waste water and (b) recovery of Cu and other precious metals from industrial process streams including from solid catalysts and aqueous waste streams. The R ampersand D was done in 4 phases for each of the 2 target areas: polymer synthesis for scaleup, equipment assembly, process demonstration at a DOE or industrial site, and advanced ligand/polymer synthesis. The TA- 50 site at Los Alamos was thought to be appropriate due to logistics and to its being representative of similar problems throughout the DOE complex

  16. Mechanisms of oxide dissolution by acid chelating agents

    International Nuclear Information System (INIS)

    Blesa, M.A.; Maroto, A.J.G.

    1982-01-01

    In this paper, the different possible rate controlling processes in the dissolution of metallic oxides are examined. In particular, the following situations are assessed: mass-transfer control; coupling of mass-transfer and reactions at the interface; interface equilibration with the solution; various interface disruption and reconstruction phenomena. For each of the above mentioned cases, the influence of variables such as reagent concentration, temperature, pH, fluid hydrodynamics and general and specific catalysts is discussed. Depending upon the particular situation it is found that a more rational basis for the development of reagent is given by these considerations. The influence of chelating agents on both the thermodynamics and kinetics of the process is discussed, and the results of experimental studies in batch on magnetite and various ferrites are presented and discussed. For this purpose, several reagents were studied, including some very effective ones like thioglycolic acid, and others commonly used in actual decontamination, like ethylenediaminetetraacetic acid and oxalic acid. The relation to other (reductive) chemical decontamination procedures is discussed. The relevance of these studies to decontamination of metallic surfaces is discussed

  17. Chelatable trace zinc causes low, irreproducible KDAC8 activity.

    Science.gov (United States)

    Toro, Tasha B; Edenfield, Samantha A; Hylton, Brandon J; Watt, Terry J

    2018-01-01

    Acetylation is an important regulatory mechanism in cells, and emphasis is being placed on identifying substrates and small molecule modulators of this post-translational modification. However, the reported in vitro activity of the lysine deacetylase KDAC8 is inconsistent across experimental setups, even with the same substrate, complicating progress in the field. We detected trace levels of zinc, a known inhibitor of KDAC8 when present in excess, even in high-quality buffer reagents, at concentrations that are sufficient to significantly inhibit the enzyme under common reaction conditions. We hypothesized that trace zinc in solution could account for the observed variability in KDAC8 activity. We demonstrate that addition of chelators, including BSA, EDTA, and citrate, and/or the use of a phosphate-based buffer instead of the more common tris-based buffer, eliminates the inhibition from low levels of zinc as well as the dependence of specific activity on enzyme concentration. This results in high KDAC8 activity that is consistent across buffer systems, even using low concentrations of enzyme. We report conditions that are suitable for several assays to increase both enzyme activity and reproducibility. Our results have significant implications for approaches used to identify substrates and small molecule modulators of KDAC8 and interpretation of existing data. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. ATMP-stabilized iron nanoparticles: chelator-controlled nanoparticle synthesis

    Science.gov (United States)

    Greenlee, Lauren F.; Rentz, Nikki S.

    2014-11-01

    In this study, we characterize iron nanoparticles synthesized in water in the presence of a phosphonate chelator, amino tris(methylene phosphonic acid) (ATMP) for a range of molar ratios of ATMP to iron. An increase in the molar ratio from 0.05 to 0.8 decreases nanoparticle size from approximately 150 nm to less than 10 nm. Zeta potential measurements were used to evaluate colloidal stability. Zeta potential values varied as a function of pH, and zeta potential values decreased with increasing pH. At lower molar ratios of ATMP to iron, the zeta potential varied between 15 and -40 mV, passing through an isoelectric point at pH 7.5. At higher ratios, the zeta potential was negative across the measured pH range of 2-12 and varied from -2 to -55 mV. Diffraction analysis indicates that ATMP-stabilized iron nanoparticles may have a nano-crystalline structure, potentially with regions of amorphous iron. Characterization results of ATMP-stabilized iron nanoparticles are compared to results obtained for carboxymethyl cellulose (CMC)-stabilized iron nanoparticles. CMC stabilization caused similar peak broadening in diffraction spectra as for ATMP, suggesting similar nano-crystalline/amorphous structure; however, an increase in the molar ratio of CMC to iron did not cause the same reduction in nanoparticle size as was observed for ATMP-stabilized iron nanoparticles.

  19. Metal chelators and neurotoxicity: lead, mercury, and arsenic.

    Science.gov (United States)

    Bjørklund, Geir; Mutter, Joachim; Aaseth, Jan

    2017-12-01

    This article reviews the clinical use of the metal chelators sodium 2,3-dimercapto-1-propanesulfonate (DMPS), meso-2,3-dimercaptosuccinic acid (DMSA), and calcium disodium edetate (CaEDTA, calcium EDTA) in overexposure and poisonings with salts of lead (Pb), mercury (Hg), and arsenic (As). DMSA has considerably lower toxicity than the classic heavy metal antagonist BAL (2,3-dimercaptopropanol) and is also less toxic than DMPS. Because of its adverse effects, CaEDTA should be replaced by DMSA as the antidote of choice in treating moderate Pb poisoning. Combination therapy with BAL and CaEDTA was previously recommended in cases of severe acute Pb poisoning with encephalopathy. We suggest that BAL in such cases acted as a shuttling Pb transporter from the intra- to the extracellular space. The present paper discusses if a combination of the extracellularly distributed DMSA with the ionophore, Monensin may provide a less toxic combination for Pb mobilization by increasing both the efflux of intracellularly deposited Pb and the urinary Pb excretion. Anyhow, oral therapy with DMSA should be continued with several intermittent courses. DMPS and DMSA are also promising antidotes in Hg poisoning, whereas DMPS seems to be a more efficient agent against As poisoning. However, new insight indicates that a combination of low-dosed BAL plus DMPS could be a preferred antidotal therapy to obtain mobilization of the intracerebral deposits into the circulation for subsequent rapid urinary excretion.

  20. The performance of 2-nitroso-1-naphthol chelating pigment in paint ...

    African Journals Online (AJOL)

    The performance of 2-nitroso-1-naphthol chelating pigment in paint formulation with gum Arabic and polyvinyl acetate as binders, Paper I: UV- visible spectroscopy, viscosity and breaking stress of the paints.

  1. Study of chelating agent as a surface modifier for retarding corrosion attack on ferrous metal

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Muhamad Daud; Siti Radiah Mohd Kamarudin; Zaifol Samsu; Azali Muhamad; Rusni Rejab; Mohd Saari Ripin; Mohd Shariff Sattar

    2010-01-01

    A different concentration of chelating agents in electrolyte of 3.5 % NaCl was applied to bare ferrous metal and tested for their effectiveness as a corrosion retardant. The performance of the samples was measured using corrosion measurement system. The results indicated that the contribution of chelating agent was expediting the reduction of the passive film. The anodic behavior was clearly found to be influenced by the concentration of the chelating agent. It was also found that some of the corrosion was apparently converted to protective layer over a period of time. Excessive moisture caused breakdown of film by removing the unreacted chelating agent and causing regrowth of the existing rust. (author)

  2. Bifunctional chelating agent for the design and development of site specific radiopharmaceuticals and biomolecule conjugation strategy

    Science.gov (United States)

    Katti, Kattesh V.; Prabhu, Kandikere R.; Gali, Hariprasad; Pillarsetty, Nagavara Kishore; Volkert, Wynn A.

    2003-10-21

    There is provided a method of labeling a biomolecule with a transition metal or radiometal in a site specific manner to produce a diagnostic or therapeutic pharmaceutical compound by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radio metal or a transition metal, and covalently linking the resulting metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. Also provided is a method of synthesizing the --PR.sub.2 containing biomolecules by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radiometal or a transition metal, and covalently linking the resulting radio metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. There is provided a therapeutic or diagnostic agent comprising a --PR.sub.2 containing biomolecule.

  3. Effect of calcium chelators on physical changes in casein micelles in concentrated micellar casein solutions

    NARCIS (Netherlands)

    Kort, de E.J.P.; Minor, M.; Snoeren, T.H.M.; Hooijdonk, van A.C.M.; Linden, van der E.

    2011-01-01

    The effect of calcium chelators on physical changes of casein micelles in concentrated micellar casein solutions was investigated by measuring calcium-ion activity, viscosity and turbidity, and performing ultracentrifugation. The highest viscosities were measured on addition of sodium

  4. Click-to-Chelate: Development of Technetium and Rhenium-Tricarbonyl Labeled Radiopharmaceuticals

    Directory of Open Access Journals (Sweden)

    Thomas L. Mindt

    2013-03-01

    Full Text Available The Click-to-Chelate approach is a highly efficient strategy for the radiolabeling of molecules of medicinal interest with technetium and rhenium-tricarbonyl cores. Reaction of azide-functionalized molecules with alkyne prochelators by the Cu(I-catalyzed azide-alkyne cycloaddition (CuAAC; click reaction enables the simultaneous synthesis and conjugation of tridentate chelating systems for the stable complexation of the radiometals. In many cases, the functionalization of (biomolecules with the ligand system and radiolabeling can be achieved by convenient one-pot procedures. Since its first report in 2006, Click-to-Chelate has been applied to the development of numerous novel radiotracers with promising potential for translation into the clinic. This review summarizes the use of the Click-to-Chelate approach in radiopharmaceutical sciences and provides a perspective for future applications.

  5. A Zinc Chelator TPEN Attenuates Airway Hyperresponsiveness Airway Inflammation in Mice In Vivo

    Directory of Open Access Journals (Sweden)

    Satoru Fukuyama

    2011-01-01

    Conclusions: In pulmonary allergic inflammation induced in mice immunized with antigen without alum, zinc chelator inhibits airway inflammation and hyperresponsiveness. These findings suggest that zinc may be a therapeutic target of allergic asthma.

  6. Hydrolysis of Some C,N-Chelated Organotin(IV) Species Used in Catalysis

    OpenAIRE

    Švec, P.

    2012-01-01

    This work deals with the reactivity of the selected C, N-chelated organotin (IV) species towards cyclohexene oxide, ethylene carbonate, and CO2. Structure of organotin(IV) hydrolytic products isolated from respective reaction mixtures was described.

  7. Diagnostic compositions containing a chelate of radioactive indium and 8-hydroxyquinoline

    International Nuclear Information System (INIS)

    Goedemans, W.T.

    1981-01-01

    There are disclosed aqueous, radioassaying solutions of a chelate of radioactive indium and an 8-hydroxyquinoline, having an essential absence of an organic solvent, e.g., alcohol or chloroform. The solutions are useful in radioassaying warmblooded animals. (author)

  8. Incineration of ion exchange resins using concentric burners

    International Nuclear Information System (INIS)

    Fukasawa, T.; Chino, K.; Kawamura, F.; Kuriyama, O.; Yusa, H.

    1985-01-01

    A new incineration method, using concentric burners, is studied to reduce the volume of spent ion exchange resins generated from nuclear power plants. Resins are ejected into the center of a propane-oxygen flame and burned within it. The flame length is theoretically evaluated by the diffusion-dominant model. By reforming the burner shape, flame length can be reduced by one-half. The decomposition ratio decreases with larger resin diameters due to the loss of unburned resin from the flame. A flame guide tube is adapted to increase resin holding time in the flame, which improves the decomposition ratio to over 98 wt%

  9. Method for curing alkyd resin compositions by applying ionizing radiation

    International Nuclear Information System (INIS)

    Watanabe, T.; Murata, K.; Maruyama, T.

    1975-01-01

    An alkyd resin composition is prepared by dissolving a polymerizable alkyd resin having from 10 to 50 percent of oil length into a vinyl monomer. The polymerizable alkyd resin is obtained by a half-esterification reaction of an acid anhydride having a polymerizable unsaturated group and an alkyd resin modified with conjugated unsaturated oil having at least one reactive hydroxyl group per one molecule. The alkyd resin composition thus obtained is coated on an article, and ionizing radiation is applied on the article to cure the coated film thereon. (U.S.)

  10. Method for detecting resin leakage in LWR coolant

    International Nuclear Information System (INIS)

    Girard, J.E.

    1988-05-01

    Resin leakage from condensate polishing units can result in steam generator corrosion. This report describes the development of a resin leakage detection method based in analyzing the organic breakdown products released from resin on heating. The breakdown products are analyzed using high performance liquid chromatography (HPLC) with fluorescence detection. Some of the organic products formed have been identified. A design for a resin monitoring unit, suitable for incorporation into the IONTRAC system, is presented. Theoretically, detection of ppB levels of resin by processing about one liter of water, is possible

  11. Theoretical analysis of the influence of chelate-ring size and vicinal effects on electronic circular dichroism spectra of cobalt(III) EDDA-type complexes.

    Science.gov (United States)

    Wang, Ai; Wang, Yuekui; Jia, Jie; Feng, Lixia; Zhang, Chunxia; Liu, Linlin

    2013-06-20

    To assess the contributions of configurational and vicinal effects as well as chelate-ring size to rotational strengths, the geometries of a series of cobalt(III) complexes [Co(EDDA-type)(L)](±) with the tetradentate EDDA-type ligands, EDDA (ethylenediamine-N,N'-diacetate), DMEDDA (N,N'-dimethylethylenediamine-N,N'-diacetate), DEEDDA (N,N'-diethylethylenediamine-N,N'-diacetate), and a bidentate ancillary ligand L (L = ethylenediamine, oxalate, carbonate, (S)-alanine, and malonate) in aqueous solution have been optimized at the DFT/B3LYP/6-311++G(2d,p) level of theory. Based on the optimized geometries, the excitation energies and oscillator and rotational strengths have been calculated using the time-dependent density functional theory (TDDFT) method with the same functional and basis set. The calculated circular dichroism (CD) curves are in excellent agreement with the observed ones except for some small red or blue shifts in peak wavelengths. For the influence of chelate-ring size of the bidentate ligands on the CD intensities, a qualitative analysis together with the quantitative TDDFT calculation reveal that it depends on the symmetry of the cobalt-EDDA backbone. For the s-cis-isomers, the influence is negligible due to the perturbation is symmetric. For the uns-cis-isomers, the perturbation is unsymmetric. Since a small ring size means a large perturbation, this leads to the integral CD intensities decreasing with increasing the chelate ring size. The vicinal effects of asymmetric nitrogens incorporate both the substitutent effects and conformational relaxation effects, with the former being dominant. By analyzing the contributions of chiral arrays to rotational strengths, we found that the part of contributions dominated by the S-type chiral nitrogens could be considered as a good measure for the vicinal effects of chiral nitrogens. In addition, we found that the twist form (δ/λ) of the backbone ethylenediamine ring (E-ring) of the coordinated EDDA

  12. Iron overload of organism and current options of chelation treatment in onco haematology

    International Nuclear Information System (INIS)

    Guman, T.; Rothova, E.; Kafkova, A.; Fricova, M.; Dulova, I.; Stecova, N.; Hlebaskova, M.; Surova, M.; Takac, V.

    2011-01-01

    The article summarizes the biological importance of iron in the organism, primary and secondary causes of iron overload, complications in function of liver, heart and endocrine organs due to overload of iron, the pathophysiology of iron overload, transfusion risks associated with the iron overload, assessment of risk groups of patients suitable for chelation treatment fulfilling the indication criteria, treatment modalities of chelation therapy and its significance regarding the prevention and treatment effectiveness. (author)

  13. Synthesis, Characterization and Chelating Properties of 4-Butyrylsemicarbazone-1-phenyl-3-methyl-2-pyrazolin-5-one

    Directory of Open Access Journals (Sweden)

    J. D. Patel

    2010-01-01

    Full Text Available 4-Butyrylsemicarbazone-1-phenyl-3-methyl-2-pyrazolin-5-one (BUMP-SC was prepared and its metal chelates of Cu2+, Ni2+, Co2+, Mn2+, Fe2+, Fe3+, Cr3+, UO2 and OV were prepared. The ligands and its chelates were characterized by elemental analysis, metal:ligand (M:L stoichiometry, IR-electronic spectral studies and magnetic properties. The compounds also were screened for their antimicrobial activity.

  14. Chelation therapy and cardiovascular disease: connecting scientific silos to benefit cardiac patients.

    Science.gov (United States)

    Peguero, Julio G; Arenas, Ivan; Lamas, Gervasio A

    2014-08-01

    Medical practitioners have treated atherosclerotic disease with chelation therapy for over 50 years. Lack of strong of evidence led conventional practitioners to abandon its use in the 1960s and 1970s. This relegated chelation therapy to complementary and alternative medicine practitioners, who reported good anecdotal results. Concurrently, the epidemiologic evidence linking xenobiotic metals with cardiovascular disease and mortality gradually accumulated, suggesting a plausible role for chelation therapy. On the basis of the continued use of chelation therapy without an evidence base, the National Institutes of Health released a Request for Applications for a definitive trial of chelation therapy. The Trial to Assess Chelation Therapy (TACT) was formulated as a 2 × 2 factorial randomized controlled trial of intravenous EDTA-based chelation vs. placebo and high-dose oral multivitamins and multiminerals vs. oral placebo. The composite primary endpoint was death, reinfarction, stroke, coronary revascularization, or hospitalization for angina. A total of 1708 post-MI patients who were 50 years or older with a creatinine of 2.0 or less were enrolled and received 55,222 infusions of disodium EDTA or placebo with a median follow-up of 55 months. Patients were on evidence-based post-MI medications including statins. EDTA proved to be safe. EDTA chelation therapy reduced cardiovascular events by 18%, with a 5-year number needed to treat (NNT) of 18. Prespecified subgroup analysis revealed a robust benefit in patients with diabetes mellitus with a 41% reduction in the primary endpoint (5-year NNT = 6.5), and a 43% 5-year relative risk reduction in all-cause mortality (5-year NNT = 12). The magnitude of benefit is such that it suggests urgency in replication and implementation, which could, due to the excellent safety record, occur simultaneously. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Method of burning ion-exchange resin contaminated with radioactivity

    International Nuclear Information System (INIS)

    Suzuki, Shigenori.

    1986-01-01

    Purpose: To process spent ion exchange resins to reduce their volume, without increasing the load on a off-gas system and in a stable state and at the same time not leaving any uncombusted portions. Method: The water slurries of the ion exchange resins contaminated with radioactive materials is dehydrated or dry combusted to reduce the water content. A binder is then added to solidify the ion exchange resin. The solidified ion exchange resins are then combusted in a furnace. This prevents the ion exchange resin from being dispersed by air and combustion gases. Furthermore, the solidified ion exchange resins in the form of small pellets burn from the surface inwards. Moreover the binder is carbonized by the combustion heat and promotes combustion to convert the ion exchange resins into a solid mass, making sure that no uncombusted portion is left. (Takahashi, M.)

  16. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    International Nuclear Information System (INIS)

    Cicero-Herman, C.A.; Workman, P.; Poole, K.; Erich, D.; Harden, J.

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper

  17. Comparison of Mechanical Properties of Resin Composites with Resin Modified Glass Ionomers

    Directory of Open Access Journals (Sweden)

    Taha NA

    2015-06-01

    Full Text Available Statement of Problem: There are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. Some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. Evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionomers is not widely studied. Objectives: To measure and compare the flexural strength and Vickers hardness of three resin composites and two resins modified glass ionomer cements before and after ageing. Materials and Methods: Three resin composites, i.e. Filtek Supreme XTE (3M ESPE, Ice (SDI, Gradia (GC, and two resins modified glass ionomers, i.e. Fuji II LC (GC and Riva Light Cure (SDI, were selected. Ten barshaped specimens were prepared for each material and cured using LED curing light. After 24 hours storage in distilled water at 37oC, the specimens were randomly divided into two equal groups (n=5. The first group was tested as a baseline and the second group was restored at 37oC for another 29 days. Flexural strength was performed by four-point bending test using universal testing machine at crosshead speed of 0.5mm/min, and the maximum load at failure was recorded. The specimen’s halves were used for evaluating Vickers hardness, using a Digital Hardness Tester (300 g/15 sec and the Vickers hardness number (VHN was recorded. Data were analyzed using one-way analysis of variance (ANOVA, Tukey’s and student’s t-test. Results: After 24 hours of immersion, the highest hardness number was found for Filtek Supreme and Ice and the highest flexural strength was obtained for Gradia. After 30 days of storage, hardness of Fuji II LC and Gradia showed a significant decrease; flexural strength of Ice and Fuji II LC revealed a significant increase while Gradia and Filtek Supreme showed a significant decrease. Conclusions: Resin modified glass ionomers showed

  18. Mathematical modeling of the effects of aerobic and anaerobic chelate biodegradation on actinide speciation

    International Nuclear Information System (INIS)

    Banaszak, J.E.; VanBriesen, J.; Rittmann, B.E.; Reed, D.T.

    1998-01-01

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and, hence, the mobility of actinides in subsurface environments. We combined mathematical modeling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bio-utilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modeling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems

  19. Chelate chase of radiopharmaceuticals reversibly bound to monoclonal antibodies improves dosimetry

    International Nuclear Information System (INIS)

    Goodwin, D.A.; Smith, S.I.; Meares, C.F.; David, G.S.; McTigue, M.; Finston, R.A.

    1986-01-01

    One hundred micrograms of monoclonal antibody (MoAb) CHA 255 with a binding constant Kb of 4 x 10 9 was complexed with indium-111 labeled BLEDTA II, GLEDTA IV, benzyl EDTA, and an EDTA conjugate of Fab. The 24-hour tumor and organ distribution in BALB/c mice bearing KHJJ tumors was studied for each compound alone, the antibody complex, and 3 hours following a chelate chase of the antibody complex. Whole-body biological half-life was measured for 7 days with and without a chelate chase for each antibody complex. The 24-hour whole-body counts dropped 20-60% within 3 hours of administering the chelate chase. Blood concentration fell over 89% within 3 hours of administering the chase and there was a decrease in concentration in all organs, except the kidneys, of 10 to 85%. Theoretical equivalent human doses were calculated from the 24-hour organ concentrations, effective half-life, and MIRD 11 S values (absorbed dose per cumulated activity). Liver and spleen were the target organs, with the dose ranging from 0.50 to 3.91 rads per millicurie. The reduction in organ radiation dose varied up to 95% following the chelate chase. Rapid selective renal clearance of chelate labeled radiopharmaceuticals by competitive inhibition (chelate chase) of their reversible binding to monoclonal antibodies, greatly improves the radiation dosimetry of tumor imaging agents. 28 references, 5 figures, 5 tables

  20. Chelating effect of silver nitrate by chitosan on its toxicity and growth performance in broiler chickens

    Directory of Open Access Journals (Sweden)

    Yemdjie Mane Divine Doriane

    2017-06-01

    Full Text Available Objective: This study was conducted to investigate the chelating effect of silver nitrate (AgNO3 by chitosan on growth performances, hematological and biochemical parameters, and the histopathological structure of the liver and the kidney in broiler chicken. Materials and methods: A total of 192 day-old Cobb 500 strain chicks were randomly assigned to 3 treatments of 64 chicks each. Control group was fed on basal diet without supplement (R0 and the two others groups were fed on rations supplemented with 10 mg of unchelated (RAg or chelated (RCs-Ag AgNO3 per Kg of feed, respectively. Parameters that have been studied consisted of feed intake, weight gain, blood and serum biochemical, and histopathological analyses of liver and kidney. Results: Results revealed that chelation of AgNO3 by chitosan did not have any effect on growth performances and hematological parameters in chicken. However, chelated and unchelated AgNO3 increased the serum content in triglyceride, and cholesterol and decreased the serum content in creatinin, albumin and alanine aminotransferase (ALAT. Chelating AgNO3 with chitosan prevented and corrected the toxicity induced on the histological structure of liver and kidney. Conclusion: Chitosan can be used as a chelating agent to alleviate the harmful effects of AgNO3 as silver ion for poultry. [J Adv Vet Anim Res 2017; 4(2.000: 187-193

  1. Mathematical modelling of the effects of aerobic and anaerobic chelate biodegradation on actinide speciation

    International Nuclear Information System (INIS)

    Banaszak, J.E.; VanBriesen, J.M.; Rittmann, B.E.; Reed, D.T.

    1998-01-01

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and hence, the mobility of actinides in subsurface environments. We combined mathematical modelling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bioutilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modelling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems. (orig.)

  2. ELECTED PROBLEMS RELATED TO ENVIRONMENTAL HEAVY METALS EXPOSURE AND CHELATION THERAPY

    Directory of Open Access Journals (Sweden)

    Anna Skoczyńska

    2010-09-01

    Full Text Available Background: Exposure to heavy metals leads to functional and metabolic disturbances and many of them are included in pathogenesis of common diseases (arterial hypertension, atherosclerosis, neurodegenerative processes. In this context new therapeutic and prophylactic strategies are necessary. Patients diagnosed with chronic heavy metals intoxication usually require chelation to increase mobilisation of metals from tissues and elimination of them via urine. Acute poisoning with toxic metal may be difficult to diagnosis, especially in case of accidental intoxication or suicidal intention. Patients also require chelation after causative factor is identified. Objectives: To describe some problems connected with toxicity of metals poisoning and to review pharmacologic therapies that could have a role in poisoning with metals. Methods: A review of the literature was carried out and expert opinion expressed. Results/conclusion: Chelation is a common therapy in case of poisoning with toxic metals but it is satisfied only partially. A combined therapy with structurally different chelators or long-term acting chelators could become viable alternatives in the future. A combined therapy with an antioxidant plus chelator may be a good choice in patients chronically poisoned with metals. Exposure to lead should be taken into account during estimation of global cardiovascular risk.

  3. Chelation therapy to treat atherosclerosis, particularly in diabetes: is it time to reconsider?

    Science.gov (United States)

    Lamas, Gervasio A; Ergui, Ian

    2016-08-01

    Case reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes. The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. We discuss results and future research. Expert commentary: Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years, with a 41% relative reduction in risk of a cardiac event (p = 0.0002). These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. We are seeking participating sites for TACT2.

  4. Deaths associated with hypocalcemia from chelation therapy--Texas, Pennsylvania, and Oregon, 2003-2005.

    Science.gov (United States)

    2006-03-03

    Chelating agents bind lead in soft tissues and are used in the treatment of lead poisoning to enhance urinary and biliary excretion of lead, thus decreasing total lead levels in the body. During the past 30 years, environmental and dietary exposures to lead have decreased substantially, resulting in a considerable decrease in population blood lead levels (BLLs) and a corresponding decrease in the number of patients requiring chelation therapy. Chelating agents also increase excretion of other heavy metals and minerals, such as zinc and, in certain cases, calcium. This report describes three deaths associated with chelation-therapy--related hypocalcemia that resulted in cardiac arrest. Several drugs are used in the treatment of lead poisoning, including edetate disodium calcium (CaEDTA), dimercaperol (British anti-Lewisite), D-penicillamine, and meso-2,3-dimercaptosuccinic acid (succimer). Health-care providers who are unfamiliar with chelating agents and are considering this treatment for lead poisoning should consult an expert in the chemotherapy of lead poisoning. Hospital pharmacies should evaluate whether continued stocking of Na2EDTA is necessary, given the established risk for hypocalcemia, the availability of less toxic alternatives, and an ongoing safety review by the Food and Drug Administration (FDA). Health-care providers and pharmacists should ensure that Na2EDTA is not administered to children during chelation therapy.

  5. [Physical properties of resins for veneer crown. (Part 1) Bending strength of thermosetting methacrylic resins (author's transl)].

    Science.gov (United States)

    Kashiwada, T

    1979-01-01

    The physical properties of thermosetting methacrylic resins contain a kind or more than two kinds of cross linking agents were investigated. Knoop hardness and bending strength after drying, water sorption and thermal cycling were listed in table 4 and 5. Hydrophilic resins absorbed water about 3 times as much as hydrophobic resins. The materials contain a small amount of hydrophobic cross linking agents in MMA indicate comparatively excellent properties after drying, water sorption and thermal cycling. Knoop hardness of resins generally reduced by water sorption, especially in the case of the resin contains a large amount of triethylene glycol dimethacrylate.

  6. Development and application of high performance resins for crud removal

    International Nuclear Information System (INIS)

    Deguchi, Tatsuya; Izumi, Takeshi; Hagiwara, Masahiro

    1998-01-01

    The development of crud removal technology has started with the finding of the resin aging effect that an old ion exchange resin, aged by long year of use in the condensate demineralizer, had an enhanced crud removal capability. It was confirmed that some physical properties such as specific surface area and water retention capacity were increased due to degradation caused by long year of contact with active oxygens in the condensate water. So, it was speculated that those degradation in the resin matrix enhanced the adsorption of crud particulate onto the resin surface, hence the crud removal capability. Based on this, crud removal resin with greater surface area was first developed. This resin has shown an excellent crud removal efficiency in an actual power plant, and the crud iron concentration in the condensate effluent was drastically reduced by this application. However, the cross-linkage of the cation resin had to be lowered in a delicate manner for that specific purpose, and this has caused higher organic leachables from the resin, and the sulfate level in the reactor was raised accordingly. Our major goals, therefore, has been to develop a crud resin of as little organic leachables as possible with keeping the original crud removal efficiency. It was revealed through the evaluation of the first generation crud resin and its improved version installed in the actual condensate demineralizers that there was a good correlation between crud removal efficiency and organic leaching rate. The bast one among a number of developmental resins has shown the organic leaching rate of 1/10 of that of the original crud resin (ETR-C), and the crud removal efficiency of 90%. So far as we understand, the resin was considered to have the best overall balance between crud removal and leaching characteristics. The result of six month evaluation of this developmental resin, ETR-C3, in one vessel of condensate demineralizer of a power plant will be presented. (J.P.N.)

  7. Evaluation of single amino acid chelate derivatives and regioselective radiolabelling of a cyclic peptide for the urokinase plasminogen activator receptor

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Andrea F.; Lemon, Jennifer A. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Czorny, Shannon K. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Singh, Gurmit [Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Valliant, John F. [Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, L8S 4M1 (Canada)], E-mail: valliant@mcmaster.ca

    2009-11-15

    Introduction: The aim of this work was to investigate the relative radiolabelling kinetics and affinity of a series of ligands for the [{sup 99m}Tc(CO){sub 3}]{sup +} core, both in the absence and in the presence of competing donors. This information was used to select a suitable ligand for radiolabelling complex peptide-based targeting vectors in high yield under mild conditions. Methods: A series of {alpha}-N-Fmoc-protected lysine derivatives bearing two heterocyclic donor groups at the {epsilon}-amine (, 2-pyridyl; , quinolyl; , 6-methoxy-2-pyridyl; 1d, 2-thiazolyl; 1e, N-methylimidazolyl; , 3-pyridyl) were synthesized and labelled with {sup 99m}Tc. A resin-capture purification strategy for the separation of residual ligand from the radiolabelled product was also developed. The binding affinities of targeted peptides 4, 5a and 5b for uPAR were determined using flow cytometry. Results: Variable temperature radiolabelling reactions using - and [{sup 99m}Tc(CO){sub 3}]{sup +} revealed optimal kinetics and good selectivity for compounds and 1d; in the case of , 1d, and 1e, the labelling can be conducted at ambient temperature. The utility of this class of ligands was further demonstrated by the radiolabelling of a cyclic peptide that is known to target the serine protease receptor uPAR; essentially quantitative incorporation of {sup 99m}Tc occurred exclusively at the SAAC site, despite the presence of a His residue, and without disruption of the disulfide bond. Conclusion: A series of single amino acid chelate (SAAC) ligands have been evaluated for their ability to incorporate {sup 99m}Tc into peptides. The lead agent to emerge from this work is the thiazole SAAC derivative 1d which has demonstrated the ability to regioselectively label the widest range of peptides.

  8. Characteristics of floc formation of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    International Nuclear Information System (INIS)

    Adachi, Tetsurou; Sawa, Toshio; Shindoh, Toshikazu.

    1989-01-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of floc formation. The physical, chemical and electrochemical properties of powdered ion exchange resin were measured and the factors related to floc formation of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index. It was found that these factors were mixing ratio, nature of resins and particle size of resins. In addition, it was assumed on the bases of these results that the amount of resin floc was related to sum of the surface electric charges of both resins. The filling ratio of resin floc was related to their product by multiplication and an experimental expression was obtained. The specific settle volume of resin floc could then be simulated by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author)

  9. Characteristics of floc formation of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tetsurou (Nitto Denko Corp., Ibaraki, Osaka (Japan)); Sawa, Toshio; Shindoh, Toshikazu

    1989-09-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of floc formation. The physical, chemical and electrochemical properties of powdered ion exchange resin were measured and the factors related to floc formation of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index. It was found that these factors were mixing ratio, nature of resins and particle size of resins. In addition, it was assumed on the bases of these results that the amount of resin floc was related to sum of the surface electric charges of both resins. The filling ratio of resin floc was related to their product by multiplication and an experimental expression was obtained. The specific settle volume of resin floc could then be simulated by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author).

  10. Nanomechanical properties of dental resin-composites.

    Science.gov (United States)

    El-Safty, S; Akhtar, R; Silikas, N; Watts, D C

    2012-12-01

    To determine by nanoindentation the hardness and elastic modulus of resin-composites, including a series with systematically varied filler loading, plus other representative materials that fall into the categories of flowable, bulk-fill and conventional nano-hybrid types. Ten dental resin-composites: three flowable, three bulk-fill and four conventional were investigated using nanoindentation. Disc specimens (15mm×2mm) were prepared from each material using a metallic mold. Specimens were irradiated in the mold at top and bottom surfaces in multiple overlapping points (40s each) with light curing unit at 650mW/cm(2). Specimens were then mounted in 3cm diameter phenolic ring forms and embedded in a self-curing polystyrene resin. After grinding and polishing, specimens were stored in distilled water at 37°C for 7 days. Specimens were investigated using an Agilent Technologies XP nanoindenter equipped with a Berkovich diamond tip (100nm radius). Each specimen was loaded at one loading rate and three different unloading rates (at room temperature) with thirty indentations, per unloading rate. The maximum load applied by the nanoindenter to examine the specimens was 10mN. Dependent on the type of the resin-composite material, the mean values ranged from 0.73GPa to 1.60GPa for nanohardness and from 14.44GPa to 24.07GPa for elastic modulus. There was a significant positive non-linear correlation between elastic modulus and nanohardness (r(2)=0.88). Nonlinear regression revealed a significant positive correlation (r(2)=0.62) between elastic moduli and filler loading and a non-significant correlation (r(2)=0.50) between nanohardness and filler loading of the studied materials. Varying the unloading rates showed no consistent effect on the elastic modulus and nanohardness of the studied materials. For a specific resin matrix, both elastic moduli and nanohardness correlated positively with filler loading. For the resin-composites investigated, the group-average elastic

  11. Study on the pyrolysis of phenol-formaldehyde (PF) resin and modified PF resin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jigang, E-mail: wangjigang@seu.edu.cn [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Jiang, Haiyun [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); School of Materials Science and Engineering, Southeast University, Nanjing Institute of Technology, Nanjing 210013 (China); Jiang, Nan [Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China)

    2009-12-10

    The pyrolysis of pure phenol-formaldehyde (PF) resin and boron carbide (B{sub 4}C) modified PF resin was investigated by using thermogravimetry (TG) and pyrolysis gas-chromatography-mass-spectrometry (PY-GC/MS). Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectroscopy were also employed to investigate the micro-structural evolution. It was shown from the TG analysis that the char residues of pure PF resin were 62.9 and 60.5% after being pyrolyzed at 700 and 1000 {sup o}C, respectively. The degradation and failure of the resin matrix were mainly resulted from the release of volatiles. The phenol and its methyl derivates took a large proportion in the amount of volatiles. In comparison with the pure PF resin, the char residues of B{sub 4}C modified PF resin were obviously higher, with the values of 71.9 and 68.4% at 700 and 1000 {sup o}C, respectively. Due to the oxidation-reduction reactions between B{sub 4}C additive and oxygen-containing volatiles including CO and H{sub 2}O, partial carbon and oxygen elements in the volatiles remained in the resin matrix in the forms of amorphous carbon and B{sub 2}O{sub 3}, respectively. The results of SEM and FT-IR characterization demonstrated the occurrence of the modification, and the amorphous carbon existed in the form of reticular substance. In addition, the amount of the released phenol and its methyl derivates was also decreased drastically due to the formation of borate.

  12. Effect of Resin Coating and Chlorhexidine on Microleakage of Two Resin Cements after Storage

    Directory of Open Access Journals (Sweden)

    F. Shafie

    2010-03-01

    Full Text Available Objective: Evaluating the effect of resin coating and chlorhexidine on microleakage of two resin cements after water storage.Materials and Methods: Standardized class V cavities were prepared on facial and lingual surfaces of one hundred twenty intact human molars with gingival margins placed 1mm below the cemento-enamel junction. Indirect composite inlays were fabricated and thespecimens were randomly assigned into 6 groups. In Groups 1 to 4, inlays were cemented with Panavia F2.0 cement. G1: according to the manufacturer’s instruction. G2: with light cured resin on the ED primer. G3: chlorhexidine application before priming. G4: withchlorhexidine application before priming and light cured resin on primer. G5: inlays were cemented with Nexus 2 resin cement. G6: chlorhexidine application after etching. Each group was divided into two subgroups based on the 24-hour and 6-month water storagetime. After preparation for microleakage test, the teeth were sectioned and evaluated at both margins under a 20×stereomicroscope. Dye penetration was scored using 0-3 criteria.The data was analyzed using Kruskal-Wallis and complementary Dunn tests.Results: There was significantly less leakage in G2 and G4 than the Panavia F2.0 control group at gingival margins after 6 months (P<0.05. There was no significant differences in leakage between G1 and G3 at both margins after 24 hours and 6 months storage. After 6months, G6 revealed significantly less leakage than G5 at gingival margins (P=0.033. In general, gingival margins showed more leakage than occlusal margins.Conclusion: Additionally, resin coating in self-etch (Panavia F2.0 and chlorhexidine application in etch-rinse (Nexus resin cement reduced microleakage at gingival margins after storage.

  13. Cadmium decontamination using in-house resin

    International Nuclear Information System (INIS)

    Pal, Sangita; Thalor, K.L; Prabhakar, S.; Srivastava, V.K.; Goswami, J.L.; Tewari, P.K.; Dhanpal, Pranav; Goswami, J.L.

    2010-01-01

    A selective and strong in-house chelator has been studied w.r.t. basic parameters like concentration, time, and elution. De-contamination of cadmium, mercury, chromium, lead etc by using high uptake values fro cadmium ions proves its selectivity with high elution ratio ensures further decontamination of run-off water during natural calamities. In three step cascade use the concentration of original cadmium solution (500 ppm) decocted to safe disposable attribute. This polymeric ligand exchanger displayed outlet effluent concentration to 1 ppm and less than 200 ppb when treated for inlet feed concentration of 50 ppm and 500 ppm respectively. (author)

  14. Post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin

    International Nuclear Information System (INIS)

    Yap, A.U.J.

    1997-01-01

    This study examined the post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin using a digital microhardness tester. Change in hardness of these materials over a period of 6 months was compared to that of conventional glass ionomer cements and a composite resin. With the exception of the composite resin, all materials showed a significant increase in hardness over 24 h after their initial set. Dual-cure resin-modified glass ionomer cements showed decreased hardness with increased storage time in saline at 37 o C. Results suggest that the addition of resins to glass ionomer cements does not improve initial hardness and does not negate the acid-base reaction of conventional cements. Resin addition may, however, lead to increased water sorption and decreased hardness. (author)

  15. Development of chelate tagging method of protein at low temperature

    International Nuclear Information System (INIS)

    Oida, Shigeru; Sekiya, Keizo

    1999-01-01

    This study aimed at development of a protein labelling method at a low temperature, available for functional proteins, such as antibodies and enzymes mostly unstable at high temperatures. A solution of anti-mouse IgG antibody added with EDTA was incubated with 51 CrCl 3 at 4degC for 24 hours. After stopping the reaction with 100-fold amount of EDTA-2Na, the solution was fractionated into antibody fraction and metal fraction by HPLC. After incubation, non-specific Cr adsorption on the antibody in no relation to the chelate reagent was chased with 10-fold amount of CrCl 3 . To remove free Cr, the sample solution was incubated with 10 to 50-fold ICB-EDTA solution containing N,N-dimethyl-formamide. Then, the amount of Cr-labelling on the antibody was determined. In Western-blotting, chick actin was applied onto SDS-polyacrylamide gel electrophoresis. One part of the lane was stained with brilliant-blue and the other was transferred on nitrocellulose membrane by semi-dry method and stained with panceau-S. Anti-actin monoclonal antibody and anti-mouse IgG antibody were used as the first antibody and the second one, respectively. When incubated with ICB-EDTA for 3 days, labelling reached the maximum level. Although labelling of the second antibody was performed with maleimido-C 3 -benzyl EDTA and 45 Ca as a substitute for 51 Cr, the rate of labelling was lower than the rate for a combination of ICB-EDTA and 51 Cr. Autoradiography of the anti-mouse IgG preparation after SDS-acrylamide gel electrophoresis revealed that radioactivity was detected on the site of H-chain but not L-chain. This indicates that 51 Cr labelling of protein is stable even under the conditions of SDS denaturation. (M.N.)

  16. Chelation of intracellular calcium blocks insulin action in the adipocyte

    International Nuclear Information System (INIS)

    Pershadsingh, H.A.; Shade, D.L.; Delfert, D.M.; McDonald, J.M.

    1987-01-01

    The hypothesis that intracellular Ca 2+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca 2+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl 2 and the Ca 2+ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl 2 from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 μM quin-2 or quin-2 AM had no effect on intracellular ATP concentration or the specific binding of 125 I=labeled insulin to adipocytes. These findings suggest that intracellular Ca 2+ is an essential component in the coupling of the insulin-activated receptor complex to cellular physiological/metabolic machinery. Furthermore, differing quin-2 AM dose-response profiles suggest the presence of dual Ca 2+ -dependent pathways in the adipocyte. One involves insulin stimulation of glucose transport and oxidation, whereas the other involves the antilipolytic action of insulin

  17. Decontamination of process equipment using recyclable chelating solvent

    International Nuclear Information System (INIS)

    Jevec, J.; Lenore, C.; Ulbricht, S.

    1995-01-01

    The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. With sufficient decontamination, some of the material from DOE facilities could be released as scrap into the commercial sector for recycle, thereby reducing the volume of radioactive waste requiring disposal. Although recycling may initially prove to be more costly than current disposal practices, rapidly increasing disposal costs are expected to make recycling more and more cost effective. Additionally, recycling is now perceived as the ethical choice in a world where the consequences of replacing resources and throwing away reusable materials are impacting the well-being of the environment. Current approaches to the decontamination of metals most often involve one of four basic process types: (1) chemical, (2) manual and mechanical, (3) electrochemical, and (4) ultrasonic. open-quotes Hardclose quotes chemical decontamination solutions, capable of achieving decontamination factors (Df's) of 50 to 100, generally involve reagent concentrations in excess of 5%, tend to physically degrade the surface treated, and generate relatively large volumes of secondary waste. open-quotes Softclose quotes chemical decontamination solutions, capable of achieving Df's of 5 to 10, normally consist of reagents at concentrations of 0.1 to 1%, generally leave treated surfaces in a usable condition, and generate relatively low secondary waste volumes. Under contract to the Department of Energy, the Babcock ampersand Wilcox Company is developing a chemical decontamination process using chelating agents to remove uranium compounds and other actinide species from process equipment

  18. Treatment of spent ion-exchange resins

    International Nuclear Information System (INIS)

    Ghattas, N.K.; Ikladious, N.E.; Eskander, S.B.

    1981-01-01

    PMMA was studied with the aim to evaluate its usefulness as an incorporation medium for the final containment of spent ion-exchange resins. The study of the effect of water content (ranging from 25 to 100%) of the incorporated resin into PMMA on the compression strength of the final solid products shows that with the increasing water content the compression strength of the final products decreases sharply. Hardness of the final products follows nearly the same trend of compression strength. Increasing gamma irradiation doses, up to 7.77x10 7 rad, PMMA shows increase in compression strength and hardness for small doses and then decreases with increasing irradiation dose due to the increase in polymerization process and the degradation of the incorporation medium

  19. Epoxy resins used to seal brachytherapy seed

    International Nuclear Information System (INIS)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos

    2013-01-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  20. Lysine purification with cation exchange resin

    International Nuclear Information System (INIS)

    Khayati, GH.; Mottaghi Talab, M.; Hamooni Hagheeghat, M.; Fatemi, M.

    2003-01-01

    L-lysine is an essential amino acid for the growth most of animal species and the number one limiting amino acid for poultry. After production and biomass removal by filtration and centrifugation, the essential next step is the lysine purification and recovery. There are different methods for lysine purification. The ion exchange process is one of the most commonly used purification methods. Lysine recovery was done from broth by ion exchange resin in three different ways: repeated passing, resin soaking and the usual method. Impurities were isolated from the column by repeated wash with distilled water. Recovery and purification was done with NH 4 OH and different alcohol volumes respectively. The results showed that repeated passing is the best method for lysine absorption (maximum range 86.21 %). Washing with alkali solution revealed that most of lysine is obtained in the first step of washing. The highest degree of lysine purification was achieved with the use of 4 volumes of alcohol

  1. CARDIAC FUNCTION AND IRON CHELATION IN THALASSEMIA MAJOR AND INTERMEDIA: A REVIEW OF THE UNDERLYING PATHOPHYSIOLOGY AND APPROACH TO CHELATION MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Athanasios Aessopos

    2009-07-01

    Full Text Available Heart disease is the leading cause of mortality and one of the main causes of morbidity in beta-thalassemia. Patients with homozygous thalassemia may have either a severe phenotype which is usually transfusion dependent or a milder form that is thalassemia intermedia.  The two main factors that determine cardiac disease in homozygous β thalassemia are the high output state that results from chronic tissue hypoxia, hypoxia-induced compensatory reactions and iron overload.  The high output state playing a major role in thalassaemia intermedia and the iron load being more significant in the major form. Arrhythmias, vascular involvement that leads to an increased pulmonary vascular resistance and an increased systemic vascular stiffness and valvular abnormalities also contribute to the cardiac dysfunction in varying degrees according to the severity of the phenotype.  Endocrine abnormalities, infections, renal function and medications can also play a role in the overall cardiac function.  For thalassaemia major, regular and adequate blood transfusions and iron chelation therapy are the mainstays of management. The approach to thalassaemia intermedia, today, is aimed at monitoring for complications and initiating, timely, regular transfusions and/or iron chelation therapy.  Once the patients are on transfusions, then they should be managed in the same way as the thalassaemia major patients.  If cardiac manifestations of dysfunction are present in either form of thalassaemia, high pre transfusion Hb levels need to be maintained in order to reduce cardiac output and appropriate intensive chelation therapy needs to be instituted.  In general recommendations on chelation, today, are usually made according to the Cardiac Magnetic Resonance findings, if available.  With the advances in the latter technology and the ability to tailor chelation therapy according to the MRI findings as well as the availability of three iron chelators, together with

  2. Handling sticky resin by stingless bees (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Markus Gastauer

    2011-06-01

    Full Text Available For their nest defense, stingless bees (Meliponini collect plant resins which they stick on intruders like ants or cleptobiotic robber bees causing their immobilization. The aim of this article is to identify all parts of stingless bee workers contacting these sticky resins. Of special interest are those body parts with anti-adhesive properties to resin, where it can be removed without residues. For that, extensive behavioral observations during foraging flight, handling and application of the resin have been carried out. When handling the resin, all tarsi touch the resin while walking above it. For transportation from plants to the nest during foraging flight, the resin is packed to the corbicula via tarsi and basitarsi of front and middle legs. Once stuck to the resin or after the corbicula had been unloaded, the bee's legs have to be cleaned thoroughly. Only the tips of the mandibles, that form, cut and apply the sticky resin, seem to have at least temporarily resin-rejecting properties.

  3. Evaluation of the resin oxidation process using Fenton's reagent

    International Nuclear Information System (INIS)

    Araujo, Leandro G.; Goes, Marcos M.; Marumo, Julio T.

    2013-01-01

    The ion exchange resin is considered radioactive waste after its final useful life in nuclear reactors. Usually, this type of waste is treated with the immobilization in cement Portland, in order to form a solid monolithic matrix, reducing the possibility of radionuclides release in to environment. Because of the characteristic of expansion and contraction of the resins in presence of water, its incorporation in the common Portland cement is limited in 10% in direct immobilization, causing high costs in the final product. A pre-treatment would be able to reduce the volume, degrading the resins and increasing the load capacity of this material. This paper is about a method of degradation of ion spent resins from the nuclear research reactor of Nuclear and Energy Research Institute (IPEN/CNEN-SP), Brazil, using the Fenton's reagent. The resin evaluated was a mixture of cationic and anionic resins. The reactions were conducted by varying the concentration of the catalyst (25 to 80 mM), with and without external heat. The time of reaction was two hours. The concentration of 50 mM of catalyst was the most effective in degrading approximately 99%. The resin degradation was confirmed by the presence of CaCO 3 as a white precipitate resulting from the reaction between the Ca(OH) 2 and the CO 2 from the resin degradation. It was possible to degrade the resins without external heating. The calcium carbonates showed no correlation with the residual resin mass. (author)

  4. 4-META opaque resin--a new resin strongly adhesive to nickel-chromium alloy.

    Science.gov (United States)

    Tanaka, T; Nagata, K; Takeyama, M; Atsuta, M; Nakabayashi, N; Masuhara, E

    1981-09-01

    1) A new adhesive opaque resin containing a reactive monomer, 4-methacryloxy-ethyl trimellitate anhydride (4-META), was prepared, and its application to thermosetting acrylic resin veneer crowns was studied. 2) The 4-META opaque resin was applied to a variety of nickel-chromium dental alloy specimens which had undergone different treatment, and endurance tests were conducted to evaluate the durability of adhesion. 3) Stable adhesion against water penetration was achieved with metal surfaces first etched with HCl and then oxidized with HNO3. A bond strength of 250 kg/cm2 was maintained even after immersion in water at 37 degrees C for 30 wk or at 80 degrees C for ten wk. Furthermore, this value did not decrease even after the specimens were subjected to 500 thermal cycles. 4) The 4-META opaque resin studied can eliminate the necessity for retention devices on metal castings. 5) The smooth 4-META opaque resin should have no adverse effects on gingivae.

  5. Chemoviscosity modeling for thermosetting resin systems, 4

    Science.gov (United States)

    Hou, T. H.; Huang, Joan Y. Z.

    1989-01-01

    An experimental study on the changes of chemorheological properties has been conducted and analyzed on commercial Hercules 3501-6 resin system cured under several isothermal conditions between 375 and 435 K. For the cure temperatures equal to or greater than 385 K, the storage modulus curing curves, G prime (t), exhibited abrupt changes in slope which occurred at various times depending on the curing temperatures and were attributed to the onset of gelation reactions. The crossover points between G prime (t) and G double prime (t) curves were observed for curing temperatures equal to or greater than 400 K. The gelation and the crossover points obtained from the chemorheological measurements, therefore, defined two characteristic resin states during cure. Approximately the same value for the degree of cure was reached by the advancement of the reaction at each of these states. The temperature dependency of the viscosities for the characteristic resin states and the rate constants of increase in moduli at different stages of curing were analyzed. Various G prime (t) and G double prime (t) isothermal curing curves were also shown to be capable of being superimposed on one another by the principle of time-temperature superposition. The resultant shift factors a sub t(t) and a Eta(T) were shown to follow the Arrhenius type relationship. Values of the activation energy suggested that the reaction kinetics, instead of the diffusion mechanism, was the limiting step in the overall resin advancement for the cure at temperatures equal to or greater than 385 K.

  6. Processable polyimide adhesive and matrix composite resin

    Science.gov (United States)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Progar, Donald J. (Inventor)

    1990-01-01

    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

  7. Potential contribution of exposed resin to ecosystem emissions of monoterpenes

    Science.gov (United States)

    Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

    2013-10-01

    Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

  8. Sequestration Resins for Accelerating Removal of Radioactive Contaminants

    International Nuclear Information System (INIS)

    Frattini, Paul-L.; Wells, Daniel-M.; Garcia, Susan-E.; Richard, Kohlmann; Asay, Roger; Yengoyan, Leon

    2012-09-01

    The Electric Power Research Institute (EPRI) is developing sequestration resins that can be used in the treatment of nuclear plant water streams for the enhanced removal of ionic cobalt. EPRI is focusing on three key areas of success: 1. Plant safety. The resins that are synthesized must be fully tested to determine that no leachable species or decomposition products (in the event of a resin bed failure) would be introduced to the plant. 2. Acceptable system performance. The resins are currently being synthesized in a powdered form for use in the reactor water clean-up and fuel pool clean-up systems that utilize pre-coatable filter elements. The resins must have effective flocking behavior; uniform application over the underlay resin and efficient removal from the septa elements after use. Bead type resins are also under development. 3. Enhanced cobalt removal. The resins are expected to out-perform the currently used ion exchange resins in the removal of ionic cobalt. During nuclear plant maintenance or refueling outages, current ion exchange resins may require several days to reduce concentrations of cobalt (for example, radio-cobalt 60 Co and 58 Co) and other activated corrosion products to safe levels in reactor coolant streams. This performance limitation often delays key maintenance activities. EPRI's resins are expected to provide at least a three-fold increase in removal capacity in light water reactor coolants. These resins also offer the potential for higher overall removal efficiencies reducing occupational exposures and waste management costs. This paper addresses issues from the range of novel resin development for radio-cobalt removal from synthesis at the bench-top level through scale-up to demonstration of use in an actual operating nuclear power plant. (authors)

  9. Curing kinetics of alkyd/melamine resin mixtures

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

  10. Anion-exchange resin-based desulfurization process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A C; Dharmapurikar, R; Strevel, S D

    1994-01-01

    The following investigations were performed: (1) batch mode screening of eleven(11) commercially available resins and selection of three candidate resins for further evaluation in a fixed-bed setup. (2) Process variables study using three candidate resins in the fixed-bed setup and selection of the ``best`` resin for process economics development. (3) Exhaustion efficiency and solution concentration were found to be inversely related necessitating a trade-off between the resin cost versus the cost of evaporation/concentration of ensuing effluents. (4) Higher concentration of the HCO{sub 3}{sup {minus}} form of active sites over less active CO{sub 3}{sup 2{minus}} form of sites in the resin was believed to be the main reason for the observed increase in the equilibrium capacity of the resin at an elevated static CO{sub 2}-pressure. This Increase in capacity was found to level off around 80--120 psig range. The increase in CO{sub 2}-pressure, however, did not appear to affect the overall ion-exchange kinetics. (5) In the fixed-bed mode, the solution concentration was found to affect the equilibrium capacity of candidate resins. Their relationship was well satisfied by the Langmuir type non-linear equilibrium isotherm. Alternatively, the effect of solution concentration on overall ion-exchange kinetics varied from resin to resin. (6) Product inhibition effect on the resin was observed as an initial increase followed by a significant decrease in the resin`s equilibrium capacity for SO{sub 4}{sup 2{minus}} as the HCO{sub 3}{sup {minus}}/SO{sub 4}{sup 2{minus}} molar ratio in the solution was increased from 0 to 1.0. This ratio, however, did not affect the overall ion-exchange kinetics.

  11. Chemoviscosity modeling for thermosetting resins - I

    Science.gov (United States)

    Hou, T. H.

    1984-01-01

    A new analytical model for chemoviscosity variation during cure of thermosetting resins was developed. This model is derived by modifying the widely used WLF (Williams-Landel-Ferry) Theory in polymer rheology. Major assumptions involved are that the rate of reaction is diffusion controlled and is linearly inversely proportional to the viscosity of the medium over the entire cure cycle. The resultant first order nonlinear differential equation is solved numerically, and the model predictions compare favorably with experimental data of EPON 828/Agent U obtained on a Rheometrics System 4 Rheometer. The model describes chemoviscosity up to a range of six orders of magnitude under isothermal curing conditions. The extremely non-linear chemoviscosity profile for a dynamic heating cure cycle is predicted as well. The model is also shown to predict changes of glass transition temperature for the thermosetting resin during cure. The physical significance of this prediction is unclear at the present time, however, and further research is required. From the chemoviscosity simulation point of view, the technique of establishing an analytical model as described here is easily applied to any thermosetting resin. The model thus obtained is used in real-time process controls for fabricating composite materials.

  12. Method of processing spent ion exchange resins

    International Nuclear Information System (INIS)

    Mori, Kazuhide; Tamada, Shin; Kikuchi, Makoto; Matsuda, Masami; Aoyama, Yoshiyuki.

    1985-01-01

    Purpose: To decrease the amount of radioactive spent ion exchange resins generated from nuclear power plants, etc and process them into stable inorganic compounds through heat decomposition. Method: Spent ion exchange resins are heat-decomposed in an inert atmosphere to selectively decompose only ion exchange groups in the preceeding step while high molecular skeltons are completely heat-decomposed in an oxidizing atmosphere in the succeeding step. In this way, gaseous sulfur oxides and nitrogen oxides are generated in the preceeding step, while gaseous carbon dioxide and hydrogen requiring no discharge gas procession are generated in the succeeding step. Accordingly, the amount of discharged gases requiring procession can significantly be reduced, as well as the residues can be converted into stable inorganic compounds. Further, if transition metals are ionically adsorbed as the catalyst to the ion exchange resins, the ion exchange groups are decomposed at 130 - 300 0 C, while the high molecular skeltons are thermally decomposed at 240 - 300 0 C. Thus, the temperature for the heat decomposition can be lowered to prevent the degradation of the reactor materials. (Kawakami, Y.)

  13. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  14. Metal-chelating active packaging film enhances lysozyme inhibition of Listeria monocytogenes.

    Science.gov (United States)

    Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2014-07-01

    Several studies have demonstrated that metal chelators enhance the antimicrobial activity of lysozyme. This study examined the effect of metal-chelating active packaging film on the antimicrobial activity of lysozyme against Listeria monocytogenes. Polypropylene films were surface modified by photoinitiated graft polymerization of acrylic acid (PP-g-PAA) from the food contact surface of the films to impart chelating activity based on electrostatic interactions. PP-g-PAA exhibited a carboxylic acid density of 113 ± 5.4 nmol cm(-2) and an iron chelating activity of 53.7 ± 9.8 nmol cm(-2). The antimicrobial interaction of lysozyme and PP-g-PAA depended on growth media composition. PP-g-PAA hindered lysozyme activity at low ionic strength (2.48-log increase at 64.4 mM total ionic strength) and enhanced lysozyme activity at moderate ionic strength (5.22-log reduction at 120 mM total ionic strength). These data support the hypothesis that at neutral pH, synergy between carboxylate metal-chelating films (pKa(bulk) 6.45) and lysozyme (pI 11.35) is optimal in solutions of moderate to high ionic strength to minimize undesirable charge interactions, such as lysozyme absorption onto film. These findings suggest that active packaging, which chelates metal ions based on ligand-specific interactions, in contrast to electrostatic interactions, may improve antimicrobial synergy. This work demonstrates the potential application of metal-chelating active packaging films to enhance the antimicrobial activity of membrane-disrupting antimicrobials, such as lysozyme.

  15. Synergy and antagonism between iron chelators and antifungal drugs in Cryptococcus.

    Science.gov (United States)

    Lai, Yu-Wen; Campbell, Leona T; Wilkins, Marc R; Pang, Chi Nam Ignatius; Chen, Sharon; Carter, Dee A

    2016-10-01

    Fungal infections remain very difficult to treat, and developing new antifungal drugs is difficult and expensive. Recent approaches therefore seek to augment existing antifungals with synergistic agents that can lower the therapeutic dose, increase efficacy and prevent resistance from developing. Iron limitation can inhibit microbial growth, and iron chelators have been employed to treat fungal infections. In this study, chequerboard testing was used to explore combinations of iron chelators with antifungal agents against pathogenic Cryptococcus spp. with the aim of determining how disruption to iron homeostasis affects antifungal susceptibility. The iron chelators ethylenediaminetetraacetic acid (EDTA), deferoxamine (DFO), deferiprone (DFP), deferasirox (DSX), ciclopirox olamine and lactoferrin (LF) were paired with the antifungal agents amphotericin B (AmB), fluconazole, itraconazole, voriconazole and caspofungin. All chelators except for DFO increased the efficacy of AmB, and significant synergy was seen between AmB and LF for all Cryptococcus strains. Addition of exogenous iron rescued cells from the antifungal effect of LF alone but could not prevent inhibition by AmB + LF, indicating that synergy was not due primarily to iron chelation but to other properties of LF that were potentiated in the presence of AmB. Significant synergy was not seen consistently for other antifungal-chelator combinations, and EDTA, DSX and DFP antagonised the activity of azole drugs in strains of Cryptococcus neoformans var. grubii. This study highlights the range of interactions that can be induced by chelators and indicates that most antifungal drugs are not enhanced by iron limitation in Cryptococcus. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  16. Enhanced in vitro activity of tigecycline in the presence of chelating agents.

    Science.gov (United States)

    Deitchman, Amelia N; Singh, Ravi Shankar Prasad; Rand, Kenneth H; Derendorf, Hartmut

    2018-05-01

    The lack of availability of novel antibiotic agents and the rise of resistance to existing therapies has led clinicians to utilise combination therapy to adequately treat bacterial infections. Here we examined how chelators may impact the in vitro activity of tigecycline (TIG) against Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Minimum inhibitory concentrations (MICs) were determined by broth dilution with and without various combinations of chelators (EDTA and other tetracyclines) and metal ions (i.e. calcium, magnesium). Trimethoprim (TMP) was used as a non-chelating control. Addition of metal ions led to increases in MICs, whilst addition of EDTA led to decreases in MICs. The chelating effects of EDTA were reversed by addition of magnesium and most profoundly calcium. Similar effects of EDTA and calcium were observed for tetracycline (TET) and TMP. When other tetracyclines (TET, oxytetracycline (OXY) and chlortetracycline (CHL)) were used as chelators at concentrations below their MICs, TIG MICs decreased for P. aeruginosa but not for E. coli. Some decreases in TIG MICs were observed for K. pneumoniae when TET and CHL were added. A dose-dependent decrease in TIG MIC was observed for TET and was reversed by the addition of calcium. The presence of effects of EDTA and calcium on TMP MICs indicates that mechanisms outside of TIG chelation likely play a role in enhanced activity. Full characterisation of an unexpected interaction such as TIG-TET with different microorganisms could provide valuable insights into the underlying mechanisms and design of physiologically viable chelators as candidates for future combinations regimens. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  17. Olivine-type cathode for rechargeable batteries: Role of chelating agents

    International Nuclear Information System (INIS)

    Kandhasamy, Sathiyaraj; Singh, Pritam; Thurgate, Stephen; Ionescu, Mihail; Appadoo, Dominique; Minakshi, Manickam

    2012-01-01

    Highlights: ► Olivine powder was synthesized by sol–gel method using a range of chelating agents. ► Role of chelating agents in olivine cathode was investigated for battery application. ► Battery was fabricated with olivine cathode, Zn anode and aqueous electrolyte. ► Synergetic effect of additives (CA + TEA + PVP) led to improved storage capacity. - Abstract: Olivine (LiCo 1/3 Mn 1/3 Ni 1/3 PO 4 ) powders were synthesized at 550–600 °C for 6 h in air by a sol–gel method using multiple chelating agents and used as a cathode material for rechargeable batteries. Range of chelating agents like a weak organic acid (citric acid – CA), emulsifier (triethanolamine – TEA) and non-ionic surfactant (polyvinylpyrrolidone – PVP) in sol–gel wet chemical synthesis were used. The dependence of the physicochemical properties of the olivine powders such as particle size, morphology, structural bonding and crystallinity on the chelating agent was extensively investigated. Among the chelating agents used, unique cycling behavior (75 mAh/g after 25 cycles) is observed for the PVP assisted olivine. This is due to volumetric change in trapped organic layer for first few cycles. The trapped organic species in the electrode–electrolyte interface enhances the rate of lithium ion diffusion with better capacity retention. In contrast, CA and TEA showed a gradual capacity fade of 30 and 38 mAh/g respectively after multiple cycles. The combination of all the three mixed chelating agents showed an excellent electrochemical behavior of 100 mAh/g after multiple cycles and the synergistic effect of these agents are discussed.

  18. Organically complexed copper, zinc, and chelating agents in the rivers of Western Puerto Rico

    International Nuclear Information System (INIS)

    Montgomery, J.R.; Echevarria, J.E.

    1975-01-01

    The method for determining soluble chelators gives their concentration in copper-equivalent chelating capacity units in fresh or slightly brackish (less than 3 percent salinity) water. The mean concentration of chelators in the Rio Guanajibo for December 1973 and January 1974 was 0.4 mg of copper per liter of water (N = 21, SD = 0.2) and for February 1974, 0.9 mg/liter (N = 8, SD = 0.4). The combined mean for the Rio Anasco and Culebrinas was 0.5 mg/liter (N = 7, SD = 0.4) in January and February 1974. The mean concentration of ionic copper was 0.5 μg/liter (N = 7, SD = 0.6) and of ionic zinc, 0.2 μg/liter (N = 8, SD = 0.1) in the Rio Guanajibo from November 1972 to February 1973. The concentration of organically bound copper was 0.3 μ/liter (N = 7, SD = 0.2) and that of organically bound zinc was 0.6 μg/liter (N = 8, SD = 0.6); this indicates that there was more than a sufficient quantity of chelator available in the river to complex all the soluble copper. The presence of a high ratio of Ca 2+ to Cu 2+ probably prevents the formation of larger concentrations of organically complexed copper. The mean concentration of chelating agents in the Guanajibo River seems to be directly related to the increased organic input from municipalities and a sugar mill. The concentration of chelators in tropical rivers appears to be higher than that found in Canadian lakes. The mean concentration for particulate organic carbon (POC) was 3653 μg atoms/liter (SD = 3653, N = 29). The dissolved reactive phosphate (DRP) ranged from a mean of 1.1 μg atom/liter. No significant correlation could be found between POC, DRP, and the concentration of chelators

  19. Correlations of norbornenyl crosslinked polyimide resin structures with resin thermo-oxidative stability, resin glass transition temperature and composite initial mechanical properties

    Science.gov (United States)

    Alston, William B.

    1988-01-01

    PMR (polymerization of monomeric reactants) methodology was used to prepare 70 different polyimide oligomeric resins and 30 different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glass transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (1) decreasing aliphatic content, or (2) increasing benzylic/aliphatic content stoichiometry ratio over a wide range of resin compositions was observed. An almost linear correlation of Tg versus molecular distance between the crosslinks was also observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288, and 316 C. Perhaps more importantly, what did become apparent during the correlation study was (1) the PMR methodology could be used to prepare composites from resins containing a wide variety of monomer modifications, (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins formulated exhibited satisfactory processing flow, and (3) that PMR resins exhibited predictable rates of 316 C weight loss/surface area based on their benzylic/aliphatic stoichiometery ratio.

  20. Resin Poliester Tak Jenuh Untuk Imobilisasi Resin Bekas Pengolahan Simulasi Limbah Radioaktif Cair

    Directory of Open Access Journals (Sweden)

    Herlan Martono

    2017-03-01

    Full Text Available Telah dilakukan penelitian tentang imobilisasi resin bekas pengolah limbah trans-uranium denganresin poliester tak jenuh untuk mengetahui kualitas blok polimer-limbah sebagai fungsi kandunganlimbah. Polimerisasi dilakukan dengan mencampurkan resin poliester tak jenuh dengan katalisdengan perbandingan katalis 1% dari jumlah resin poliester tak jenuh yang digunakan, kemudianditambahkan limbah cair transuranium simulasi. blok polimer-limbah yang terjadi diukur densitas,kuat tekan dengan alat Paul Weber, dan laju pelindihan dengan alat soxhlet pada 100 0C dan 1 atmselama 6 jam. Blok polimer dibuat dengan kandungan limbah 10, 20, 30, 40, dan 50 % berat. Hasilpenelitian menunjukkan bahwa semakin besar kandungan limbah maka kuat tekan blok polimerlimbahsemakin kecil, sedangkan laju pelindihannya semakin besar. Berdasarkan kuat tekan dan lajupelindihan, maka hasil terbaik diperoleh untuk blok-polimer dengan kandungan limbah 20 % dan 30%.

  1. A study on the adsorption and subsurface transport of radioactive solutes in the presence of chelating agents

    International Nuclear Information System (INIS)

    Baik, Min Hoon

    1994-02-01

    In this study, adsorption and transport models were developed to analyze the effect of chelating agents on the adsorption and subsurface transport of radioactive solutes. The effect of chelating agents on the adsorption of radioactive solutes was analyzed by developing an adsorption model based upon the extended concept of distribution coefficient reflecting the presence of chelating agents. Also, a batch adsorption experiment was conducted in order to validate the developed adsorption model and to investigate the effect of chelating agent on the adsorption of radioactive metal solutes. In this experiment, a Cobalt(II)/EDTA/Bentonite system was considered as a representative chelation/adsorption system. It was found from the results that the presence of chelating agents significantly reduced the adsorbing capacity of geologic media such as clay minerals and soils. Thus it was concluded that the presence of chelating agents even in a small amount could contribute to the mobilization of radioactive solutes from radioactive waste burial sites by reducing the adsorbing capacity of geologic media. The effect of chelating agents on the transport of radioactive solutes in subsurface porous media was analyzed by formulating an advective-dispersive transport model which incorporated chelate formation, adsorption, decay, and degradations and by introducing the concept of a tenad. Particularly the governing equation for the tenad of radioactive solutes, M, was presented as a linear partial differential form by introducing the extended distribution coefficient, K D . The calculated results from the model showed that the transport rate of the chelated radionuclides was much greater than that of the free ionic radionuclides. This much faster transport of the chelated radionuclides was found to be due to the lower retardation factor of the chelated radionuclides than the free ionic radionuclides. The effect of parameters on the transport of radioactive solutes was also analyzed

  2. Effects of layering technique on the shade of resin overlays and the microhardness of dual cure resin cement

    Directory of Open Access Journals (Sweden)

    Hoon-Sang Chang

    2014-06-01

    Full Text Available The purpose of this study was to assess the color of layered resin overlays and to test the early microhardness of dual cure resin cement (DCRC light cured through the layered resin overlays. Resin overlays of 1.5 mm thickness were fabricated with the A3 shade of Z350 (Group 1L, the A3B and A3E shades of Supreme XT (Group 2L, and the A3, E3, and T1 shades of Sinfony (Group 3L using one, two, and three layers, respectively (n = 7. Each layer of the resin overlays was set in equal thickness. The color of the resin overlays was measured with a colorimeter and compared with an A3 shade resin denture tooth. DCRC was light cured through the resin overlays, and the early microhardness of the DCRC was measured. The ΔE value between the denture tooth and the resin overlays and the Vickers hardness number (VHN of the DCRC were analyzed with one-way ANOVA and Tukey’s HSD test. The color differences were 8.9 ± 0.5, 5.3 ± 1.0, and 7.3 ± 0.5 and the VHNs were 19.4 ± 1.1, 21.1 ± 0.9, and 29.3 ± 0.6 for Groups 1L, 2L, and 3L, respectively. Therefore, to match the designated tooth color of resin inlays and to increase the early microhardness of DCRC, layered resin inlays are more appropriate than single-dentin-layer resin inlays. However, the translucent layer should be used cautiously because the color difference of resin inlays with a translucent layer was affected more than those without a translucent layer.

  3. Uptake of actinides by sulphonated phosphinic acid resin from acid medium

    International Nuclear Information System (INIS)

    Jaya Mohandas; Srinivasa Rao, V.; Vijayakumar, N.; Kumar, T.; Velmurugan, S.; Narasimhan, S.V.

    2014-01-01

    The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. (author)

  4. Solidification of ion exchange resin wastes in hydraulic cement

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.; Kalb, P.; Fuhrmann, M.; Colombo, P.

    1982-01-01

    Work has been conducted to investigate the solidification of ion exchange resin wastes with portland cements. These efforts have been directed toward the development of acceptable formulations for the solidification of ion exchange resin wastes and the characterization of the resultant waste forms. This paper describes formulation development work and defines acceptable formulations in terms of ternary phase compositional diagrams. The effects of cement type, resin type, resin loading, waste/cement ratio and water/cement ratio are described. The leachability of unsolidified and solidified resin waste forms and its relationship to full-scale waste form behavior is discussed. Gamma irradiation was found to improve waste form integrity, apparently as a result of increased resin crosslinking. Modifications to improve waste form integrity are described. 3 tables

  5. Design of systems for handling radioactive ion exchange resin beads

    International Nuclear Information System (INIS)

    Shapiro, S.A.; Story, G.L.

    1979-01-01

    The flow of slurries in pipes is a complex phenomenon. There are little slurry data available on which to base the design of systems for radioactive ion exchange resin beads and, as a result, the designs vary markedly in operating plants. With several plants on-line, the opportunity now exists to evaluate the designs of systems handling high activity spent resin beads. Results of testing at Robbins and Meyers Pump Division to quantify the behavior of resin bead slurries are presented. These tests evaluated the following slurry parameters; resin slurry velocity, pressure drop, bead degradation, and slurry concentration effects. A discussion of the general characteristics of resin bead slurries is presented along with a correlation to enable the designer to establish the proper flowrate for a given slurry composition and flow regime as a function of line size. Guidelines to follow in designing a resin handling system are presented

  6. Comparison of bifunctional chelates for {sup 64}Cu antibody imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Cara L.; Crisp, Sarah; Bensimon, Corinne [MDS Nordion, Vancouver, BC (Canada); Yapp, Donald T.T.; Ng, Sylvia S.W. [British Columbia Cancer Agency Research Centre, Vancouver, BC (Canada); University of British Columba, The Faculty of Pharmaceutical Sciences, Vancouver, BC (Canada); Sutherland, Brent W. [British Columbia Cancer Agency Research Centre, Vancouver, BC (Canada); Gleave, Martin [Prostate Centre at Vancouver General Hospital, Vancouver, BC (Canada); Jurek, Paul; Kiefer, Garry E. [Macrocyclics Inc., Dallas, TX (United States)

    2010-11-15

    Improved bifunctional chelates (BFCs) are needed to facilitate efficient {sup 64}Cu radiolabeling of monoclonal antibodies (mAbs) under mild conditions and to yield stable, target-specific agents. The utility of two novel BFCs, 1-Oxa-4,7,10-triazacyclododecane-5-S-(4-isothiocyanatobenzyl)-4,7,10-triacetic acid (p-SCN-Bn-Oxo-DO3A) and 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-4-S-(4-isothiocyanatobenzyl)-3,6,9-triacetic acid (p-SCN-Bn-PCTA), for mAb imaging with {sup 64}Cu were compared to the commonly used S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (p-SCN-Bn-DOTA). The BFCs were conjugated to trastuzumab, which targets the HER2/neu receptor. {sup 64}Cu radiolabeling of the conjugates was optimized. Receptor binding was analyzed using flow cytometry and radioassays. Finally, PET imaging and biodistribution studies were done in mice bearing either HER2/neu-positive or HER2/neu-negative tumors. {sup 64}Cu-Oxo-DO3A- and PCTA-trastuzumab were prepared at room temperature in >95% radiochemical yield (RCY) in <30 min, compared to only 88% RCY after 2 h for the preparation of {sup 64}Cu-DOTA-trastuzumab under the same conditions. Cell studies confirmed that the immunoreactivity of the mAb was retained for each of the bioconjugates. In vivo studies showed that {sup 64}Cu-Oxo-DO3A- and PCTA-trastuzumab had higher uptake than the {sup 64}Cu-DOTA-trastuzumab at 24 h in HER2/neu-positive tumors, resulting in higher tumor to background ratios and better tumor images. By 40 h all three of the {sup 64}Cu-BFC-trastuzumab conjugates allowed for clear visualization of the HER2/neu-positive tumors but not the negative control tumor. The antibody conjugates of PCTA and Oxo-DO3A were shown to have superior {sup 64}Cu radiolabeling efficiency and stability compared to the analogous DOTA conjugate. In addition, {sup 64}Cu-PCTA and Oxo-DO3A antibody conjugates may facilitate earlier imaging with greater target to background ratios than

  7. N-acetylcysteine protects rats with chronic renal failure from gadolinium-chelate nephrotoxicity.

    Directory of Open Access Journals (Sweden)

    Leonardo Victor Barbosa Pereira

    Full Text Available The aim of this study was to evaluate the effect of Gd-chelate on renal function, iron parameters and oxidative stress in rats with CRF and a possible protective effect of the antioxidant N-Acetylcysteine (NAC. Male Wistar rats were submitted to 5/6 nephrectomy (Nx to induced CRF. An ionic-cyclic Gd (Gadoterate Meglumine was administrated (1.5 mM/KgBW, intravenously 21 days after Nx. Clearance studies were performed in 4 groups of anesthetized animals 48 hours following Gd- chelate administration: 1--Nx (n = 7; 2--Nx+NAC (n = 6; 3--Nx+Gd (n = 7; 4--Nx+NAC+Gd (4.8 g/L in drinking water, initiated 2 days before Gd-chelate administration and maintained during 4 days (n = 6. This group was compared with a control. We measured glomerular filtration rate, GFR (inulin clearance, ml/min/kg BW, proteinuria (mg/24 hs, serum iron (µg/dL; serum ferritin (ng/mL; transferrin saturation (%, TIBC (µg/dL and TBARS (nmles/ml. Normal rats treated with the same dose of Gd-chelate presented similar GFR and proteinuria when compared with normal controls, indicating that at this dose Gd-chelate is not nephrotoxic to normal rats. Gd-chelate administration to Nx-rats results in a decrease of GFR and increased proteinuria associated with a decrease in TIBC, elevation of ferritin serum levels, transferrin oversaturation and plasmatic TBARS compared with Nx-rats. The prophylactic treatment with NAC reversed the decrease in GFR and the increase in proteinuria and all alterations in iron parameters and TBARS induced by Gd-chelate. NAC administration to Nx rat did not modify the inulin clearance and iron kinetics, indicating that the ameliorating effect of NAC was specific to Gd-chelate. These results suggest that NAC can prevent Gd-chelate nephrotoxicity in patients with chronic renal failure.

  8. Targeted Catalytic Inactivation of Angiotensin Converting Enzyme by Lisinopril-Coupled Transition Metal Chelates

    Science.gov (United States)

    Joyner, Jeff C.; Hocharoen, Lalintip; Cowan, J. A.

    2012-01-01

    A series of compounds that target reactive transition metal chelates to somatic Angiotensin Converting Enzyme (sACE-1) have been synthesized. Half maximal inhibitory concentrations (IC50) and rate constants for both inactivation and cleavage of full length sACE-1 have been determined and evaluated in terms of metal-chelate size, charge, reduction potential, coordination unsaturation, and coreactant selectivity. Ethylenediamine-tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), 1,4,7,10-tetraazacyclo-dodecane-1,4,7,10-tetraacetic acid (DOTA), and tripeptide GGH were linked to the lysine sidechain of lisinopril by EDC/NHS coupling. The resulting amide-linked chelate-lisinopril (EDTA-lisinopril, NTA-lisinopril, DOTA-lisinopril, and GGH-lisinopril) conjugates were used to form coordination complexes with iron, cobalt, nickel and copper, such that lisinopril could mediate localization of the reactive metal chelates to sACE-1. ACE activity was assayed by monitoring cleavage of the fluorogenic substrate Mca-RPPGFSAFK(Dnp)-OH, a derivative of bradykinin, following pre-incubation with metal-chelate-lisinopril compounds. Concentration-dependent inhibition of sACE-1 by metal-chelate-lisinopril complexes revealed IC50 values ranging from 44 nM to 4,500 nM for Ni-NTA-lisinopril and Ni-DOTA-lisinopril, respectively, versus 1.9 nM for lisinopril. Stronger inhibition was correlated with smaller size and lower negative charge of the attached metal chelates. Time-dependent inactivation of sACE-1 by metal-chelate-lisinopril complexes revealed a remarkable range of catalytic activities, with second order rate constants as high as 150,000 M−1min−1 (Cu-GGH-lisinopril), while catalyst-mediated cleavage of sACE-1 typically occurred at much lower rates, indicating that inactivation arose primary from sidechain modification. Optimal inactivation of sACE-1 was observed when the reduction potential for the metal center was poised near 1000 mV, reflecting the difficulty of protein

  9. Targeted catalytic inactivation of angiotensin converting enzyme by lisinopril-coupled transition-metal chelates.

    Science.gov (United States)

    Joyner, Jeff C; Hocharoen, Lalintip; Cowan, J A

    2012-02-22

    A series of compounds that target reactive transition-metal chelates to somatic angiotensin converting enzyme (sACE-1) have been synthesized. Half-maximal inhibitory concentrations (IC(50)) and rate constants for both inactivation and cleavage of full-length sACE-1 have been determined and evaluated in terms of metal chelate size, charge, reduction potential, coordination unsaturation, and coreactant selectivity. Ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), and tripeptide GGH were linked to the lysine side chain of lisinopril by 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride/N-hydroxysuccinimide coupling. The resulting amide-linked chelate-lisinopril (EDTA-lisinopril, NTA-lisinopril, DOTA-lisinopril, and GGH-lisinopril) conjugates were used to form coordination complexes with iron, cobalt, nickel, and copper, such that lisinopril could mediate localization of the reactive metal chelates to sACE-1. ACE activity was assayed by monitoring cleavage of the fluorogenic substrate Mca-RPPGFSAFK(Dnp)-OH, a derivative of bradykinin, following preincubation with metal chelate-lisinopril compounds. Concentration-dependent inhibition of sACE-1 by metal chelate-lisinopril complexes revealed IC(50) values ranging from 44 to 4500 nM for Ni-NTA-lisinopril and Ni-DOTA-lisinopril, respectively, versus 1.9 nM for lisinopril. Stronger inhibition was correlated with smaller size and lower negative charge of the attached metal chelates. Time-dependent inactivation of sACE-1 by metal chelate-lisinopril complexes revealed a remarkable range of catalytic activities, with second-order rate constants as high as 150,000 M(-1) min(-1) (Cu-GGH-lisinopril), while catalyst-mediated cleavage of sACE-1 typically occurred at much lower rates, indicating that inactivation arose primarily from side chain modification. Optimal inactivation of sACE-1 was observed when the reduction potential for the

  10. Mechanism and efficiency of cell death of type II photosensitizers: effect of zinc chelation.

    Science.gov (United States)

    Pavani, Christiane; Iamamoto, Yassuko; Baptista, Maurício S

    2012-01-01

    A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  11. Self-diffusion coefficient of iron as affected by chelating agents using tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Massoud, M.A.; Abd-El-Sabour, M.F. (Agriculture Dept. for Soil and Water Research, Nuclear Research Centre, A.E.A., Cairo (Egypt)); Omar, M.A. (Ain Shams Univ., Cairo (Egypt). Faculty of Agriculture)

    1983-01-01

    The effect of Fe/sub 2/(So/sub 4/)/sub 3/, Fe-DTPA, and Fe-EDDHA on the self-diffusion coefficient of Fe in some soils of Egypt was studied. The effect of chelating compounds on the ratio between solid phase fraction of the labile Fe and its concentration in the soil solution (capacity factor) was also studied. The data reveals the following items of more interesting: 1) The use of chelating agents, i.e., DTPA and EDDHA increased the amount of Fe in soil solution, hence the capacity factor was decreased using these compounds. It seems that as the addition of Fe was in the chelated form in soil solution, the slight loss of 59Fe from solution when 59Fe - chelate was used could be attributed to the isotopic exchange with soil Fe. 2) It was found that the addition of either Fe-DTPA or Fe-EDDHA significantly increased the self-diffusion of Fe in soil as compared with Fe/sub 2/(So/sub 4/)/sub 3/. It was also noticed that the self-diffusion for Fe in the alluvial soil was greater than in the calcareous one due to the instance competition between Ca and Fe for the chelating ligands in the calcareous soil. It was also seen that soil texture affects Fe self-diffusion.

  12. Immobilization of Fe chelators on sepharose gel and its effect on their chemical properties.

    Science.gov (United States)

    Yehuda, Zehava; Hadar, Yitzhak; Chen, Yona

    2003-09-24

    Iron chelates are usually costly and easily leached beyond the root zone. This creates a need to frequently replenish the rhizosphere with chelated Fe and might contaminate groundwater with organic compounds and metals. The development of a slow-release Fe fertilizer that will efficiently supply Fe to plants while exhibiting high resistance toward leaching and/or degradation in the rhizosphere has been the focus of this study. Desferrioxamine B (DFOB) and ethylenediaminebis(o-hydroxyphenylacetic acid) (EDDHA) were immobilized on Sepharose. (13)C NMR and FTIR measurements confirmed that coupling of DFOB to the gel did not appear to influence its ability to chelate Fe(3+) or its binding nature. Isotherms for the immobilized ligands were determined in the presence of 1 mM HEDTA, at 25 degrees C and at an ionic strength of 0.1 M. The isotherms showed a high affinity of Fe(3+) to the ligands and binding up to saturation level throughout the pH range examined (4.0-9.0). The K(app) values for the immobilized Fe chelates were determined using a modified Scatchard model and found to be lower than the soluble ones. This decrease in K(app) might facilitate Fe uptake from these chelates by plants.

  13. Metal-chelating compounds produced by ectomycorrhizal fungi collected from pine plantations.

    Science.gov (United States)

    Machuca, A; Pereira, G; Aguiar, A; Milagres, A M F

    2007-01-01

    To investigate the in vitro production of metal-chelating compounds by ectomycorrhizal fungi collected from pine plantations in southern Chile. Scleroderma verrucosum, Suillus luteus and two isolates of Rhizopogon luteolus were grown in solid and liquid modified Melin-Norkans (MMN) media with and without iron addition and the production of iron-chelating compounds was determined by Chrome Azurol S (CAS) assay. The presence of hydroxamate and catecholate-type compounds and organic acids was also investigated in liquid medium. All isolates produced iron-chelating compounds as detected by CAS assay, and catecholates, hydroxamates as well as oxalic, citric and succinic acids were also detected in all fungal cultures. Scleroderma verrucosum produced the greatest amounts of catecholates and hydroxamates whereas the highest amounts of organic acids were detected in S. luteus. Nevertheless, the highest catecholate, hydroxamate and organic acid concentrations did not correlate with the highest CAS reaction which was observed in R. luteolus (Yum isolate). Ectomycorrhizal fungi produced a variety of metal-chelating compounds when grown in liquid MMN medium. However, the addition of iron to all fungi cultures reduced the CAS reaction, hydroxamate and organic acid concentrations. Catecholate production was affected differently by iron, depending on the fungal isolate. The ectomycorrhizal fungi described in this study have never been reported to produce metal-chelating compound production. Moreover, apart from some wood-rotting fungi, this is the first evidence of the presence of catecholates in R. luteolus, S. luteus and S. verrucosum cultures.

  14. Which psychosocial factors are related to chelation adherence in thalassemia? A systematic review.

    Science.gov (United States)

    Evangeli, Michael; Mughal, Kulsoom; Porter, John B

    2010-06-01

    Good adherence to iron chelation therapy in thalassemia is crucial. Although there is evidence that adherence is related to regimen factors, there has been less emphasis on the relationship between psychosocial (psychological, demographic and social) factors and adherence. We present a systematic review of psychosocial correlates of chelation adherence in thalassemia. Nine studies met the inclusion criteria. Information was extracted regarding the study characteristics and the relationship between psychosocial factors and chelation adherence. Methodological quality was rated. The studies took place in a range of countries, were mostly cross sectional in design, and examined adherence to deferoxamine (DFO) only. Sample sizes ranged from 15 to 1573. A variety of psychosocial variables were examined. Definitions of adherence varied between studies and non adherence rates were also variable (9 to 66%). Older age was consistently associated with lower levels of chelation adherence. There were few other consistent findings. The methodological quality of studies was variable. There is a need for more methodologically sophisticated and theoretically informed studies on psychosocial correlates of chelation adherence. We offer specific suggestions.

  15. Effect of different chelated zinc sources on the growth and yield of maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    M. Tahir

    2009-05-01

    Full Text Available A field study was conducted at Agronomic Research Area, University of Agriculture, Faisalabad during spring, 2007 to evaluate the effect of different chelated zinc sources on growth and yield of maize (Zea mays L.. Crop was sown on well prepared soil in 1st week of March, 2007. The experiment was laid out according to randomized complete block design. The treatments comprised of different chelated zinc sources: ZnSO4-DTPA, ZnSO4-Fulvate, ZnSO4-Lignosulphonate, ZnSO4-EDTA and ZnSO4-H2O along with control (no zinc, repeated three times. Results showed that number of cobs plant-1, grain rows cob-1 and oil contents did not differ significantly. However, differences among treatments for plant height at harvest (cm, leaf area plant-1 (cm2, stem diameter (cm, cob length (cm, cob diameter (cm, 100-grains weight (g, number of grains cob-1, grains weight cob-1(g, biological yield (tons ha-1, grain yield (tons ha-1 and protein contents (% were significantly higher. Moreover, results also revealed that ZnSO4-DPTA was found the most effective Zn chelated source among all the treatments. Rest of the chelating agents were not too impressive as they showed varied response for different variables. The result of this experiment suggest further experimentation to explore behaviour of Zn-DTPA with other macro and micro nutrients and to calculate cost benefit ratio for use ofZn chelated compounds.

  16. Increased Uptake of Chelated Copper Ions by Lolium perenne Attributed to Amplified Membrane and Endodermal Damage

    Directory of Open Access Journals (Sweden)

    Anthea Johnson

    2015-10-01

    Full Text Available The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transport pathways for free and chelated metals, identifying mechanisms involved in chelate-enhanced phytoextraction. Hypothesized transport mechanisms and parameters specific to amendment treatments are estimated, with simulated results compared to experimental data. Parameter values for each amendment treatment are estimated based on literature and experimental values, and used for model calibration and simulation of amendment influences on solute transport pathways and mechanisms. Modeling indicates that chelation alters the pathways for Cu transport. For free ions, Cu transport to leaf tissue can be described using purely apoplastic or transcellular pathways. For strong chelators (ethylenediaminetetraacetic acid (EDTA and diethylenetriaminepentaacetic acid (DTPA, transport by the purely apoplastic pathway is insufficient to represent measured Cu transport to leaf tissue. Consistent with experimental observations, increased membrane permeability is required for simulating translocation in EDTA and DTPA treatments. Increasing the membrane permeability is key to enhancing phytoextraction efficiency.

  17. Self-diffusion coefficient of iron as affected by chelating agents using tracer technique

    International Nuclear Information System (INIS)

    Massoud, M.A.; Abd-El-Sabour, M.F.; Omar, M.A.

    1983-01-01

    The effect of Fe 2 (So 4 ) 3 , Fe-DTPA, and Fe-EDDHA on the self-diffusion coefficient of Fe in some soils of Egypt was studied. The effect of chelating compounds on the ratio between solid phase fraction of the labile Fe and its concentration in the soil solution (capacity factor) was also studied. The data reveals the following items of more interesting: 1) The use of chelating agents, i.e., DTPA and EDDHA increased the amount of Fe in soil solution, hence the capacity factor was decreased using these compounds. It seems that as the addition of Fe was in the chelated form in soil solution, the slight loss of 59Fe from solution when 59Fe - chelate was used could be attributed to the isotopic exchange with soil Fe. 2) It was found that the addition of either Fe-DTPA or Fe-EDDHA significantly increased the self-diffusion of Fe in soil as compared with Fe 2 (So 4 ) 3 . It was also noticed that the self-diffusion for Fe in the alluvial soil was greater than in the calcareous one due to the instance competition between Ca and Fe for the chelating ligands in the calcareous soil. It was also seen that soil texture affects Fe self-diffusion

  18. Reversible adsorption of catalase onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogels.

    Science.gov (United States)

    Aktaş Uygun, Deniz; Uygun, Murat; Akgöl, Sinan; Denizli, Adil

    2015-05-01

    In this presented study, poly(acrylamide-glycidyl methacrylate) [poly(AAm-GMA)] cryogels were synthesized by cryopolymerization technique at sub-zero temperature. Prepared cryogels were then functionalized with iminodiacetic acid (IDA) and chelated with Fe(3+) ions in order produce the metal chelate affinity matrix. Synthesized cryogels were characterized with FTIR, ESEM and EDX analysis, and it was found that the cryogel had sponge like structure with interconnected pores and their pore diameter was about 200 μm. Fe(3+) chelated poly(AAm-GMA)-IDA cryogels were used for the adsorption of catalase and optimum adsorption conditions were determined by varying the medium pH, initial catalase concentration, temperature and ionic strength. Maximum catalase adsorption onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was found to be 12.99 mg/g cryogel at 25 °C, by using pH 5.0 acetate buffer. Adsorbed catalase was removed from the cryogel by using 1.0M of NaCl solution and desorption yield was found to be 96%. Additionally, reusability profile of the Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was also investigated and it was found that, adsorption capacity of the cryogels didn't decrease significantly at the end of the 40 reuses. Catalase activity studies were also tested and it was demonstrated that desorbed catalase retained 70% of its initial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effect of the chelation of metal cation on the antioxidant activity of chondroitin sulfates.

    Science.gov (United States)

    Ajisaka, Katsumi; Oyanagi, Yutaka; Miyazaki, Tatsuo; Suzuki, Yasuhiro

    2016-06-01

    The antioxidant potencies of chondroitin sulfates (CSs) from shark cartilage, salmon cartilage, bovine trachea, and porcine intestinal mucosa were compared by three representative methods for the measurement of the antioxidant activity; DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity. CSs from salmon cartilage and bovine trachea showed higher potency in comparison with CSs from shark cartilage and porcine intestinal mucosa. Next, CS from salmon cartilage chelating with Ca(2+), Mg(2+), Mn(2+), or Zn(2+) were prepared, and their antioxidant potencies were compared. CS chelating with Ca(2+) or Mg(2+) ions showed rather decreased DPPH radical scavenging activity in comparison with CS of H(+) form. In contrast, CS chelating with Ca(2+) or Mg(2+) ion showed remarkably enhanced superoxide radical scavenging activity than CS of H(+) or Na(+) form. Moreover, CS chelating with divalent metal ions, Ca(2+), Mg(2+), Mn(2+), or Zn(2+), showed noticeably higher hydroxyl radical scavenging activity than CS of H(+) or Na(+) form. The present results revealed that the scavenging activities of, at least, superoxide radical and hydroxyl radical were enhanced by the chelation with divalent metal ions.

  20. Analytical applications of resins containing amide and polyamine functional groups

    International Nuclear Information System (INIS)

    Orf, G.M.

    1977-12-01

    A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from sea water

  1. Analytical applications of resins containing amide and polyamine functional groups

    Energy Technology Data Exchange (ETDEWEB)

    Orf, Gene Michael [Iowa State Univ., Ames, IA (United States)

    1977-12-01

    A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from sea water.

  2. Analytical applications of resins containing amide and polyamine functional groups

    International Nuclear Information System (INIS)

    Orf, G.M.

    1977-01-01

    Resins are prepared by chemically bonding N,N-dialkylamides and polyamine functional groups to Amberlite XAD-4. These resins are applied to the concentration of metal ions from dilute aqueous solution and the rapid separation of metal ions by high-speed liquid chromatography with continuous on-line detection of the eluent stream. A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from seawater. A triethylenetetramine resin is used for the separation of copper(II) from equal molar amounts and large excesses of nickel(II), cobalt(II), zinc(II), cadmium(II), iron(III) and aluminum(III). Copper(II), nickel(II), zinc(II), cobalt(II) and cadmium(II) are determined in the presence of large excesses of calcium(II) and magnesium(II). The resin was found to be selective for silver(I) and mercury(II) at low pH values and a rapid separation of equal molar amounts of copper(II) and silver(I) was performed. The resin was also found to have an affinity for anionic metal complexes such as iron(III)-tartrate when the resin is in the hydrogen form. A study of the retention of the anions chromium(III)-tartrate and dichromate at various pH values was performed to better understand the anion exchange properties of the resin. Triethylenetetramine resins were also prepared from polystyrene gel to make a resin with higher capacities for copper

  3. Versatile composite resins simplifying the practice of restorative dentistry.

    Science.gov (United States)

    Margeas, Robert

    2014-01-01

    After decades of technical development and refinement, composite resins continue to simplify the practice of restorative dentistry, offering clinicians versatility, predictability, and enhanced physical properties. With a wide range of products available today, composite resins are a reliable, conservative, multi-functional restorative material option. As manufacturers strive to improve such properties as compression strength, flexural strength, elastic modulus, coefficient of thermal expansion, water sorption, and wear resistance, several classification systems of composite resins have been developed.

  4. PEG-related polymer resins as synthetic supports

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Combinatorial chemistry has become a significant part of the discovery and optimization process for novel drugs,affinity ligands,and catalysts.The polymeric supports play a key role in combinatory chemistry.Therefore,various kinds of functional polymer resins have been exploited as supports,reagents,and catalysts in organic synthesis.In comparison to the conventional Merrifield resins,the poly(ethylene glycol)(PEG)-related polymer resins have advantages including good compatibilities with polar solvents,good solvent absorbency and swelling properties.This review focuses primarily on the more recent work in the field of developing PEG-related polymer resins as supports for organic synthesis.

  5. Maleimido substituted cyclotriphosphazene resins for fire and heat resistant composites

    Science.gov (United States)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A new class of fire- and heat-resistant matrix resins have been synthesized by the thermal polymerization of maleimido substituted phenoxycyclotriphosphazenes. The resins have exhibited a char yield of 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates based on a resin of this class have shown a limiting oxygen index of 100 percent even at 300 C. Details of the fabrication of the resins and the composites and testing procedures are discussed.

  6. Low activity resin processing and disposal options review

    International Nuclear Information System (INIS)

    Gardner, F.

    1996-01-01

    New processing options for low activity resin processing and disposal are available. This presentation reviews the economics and technical requirements associated with the following low activity resin processing options. (1) Bulk release resin. (2) Direct disposal. (3) Decontamination and bulk release of cleaned resin. New processing and disposal options have been developed during 1995. Commercial experience with each of these options will be reviewed and the economics associated with the processing method described in detail. Technical requirements for each option will be identified specifying the activity limits and operational requirements for implementation

  7. Spherical powder for retaining thermosetting acrylic resin veneers.

    Science.gov (United States)

    Tanaka, T; Atsuta, M; Uchiyama, Y; Nakabayashi, N; Masuhara, E

    1978-03-01

    1. Nine different sizes of spherical powder were prepared, and their effectiveness as retentive devices was evaluated against those available commercially. 2. Smaller-diameter spherical powder (No. 5) gave the best results of all retaining devices tested. 3. The physical properties of the resins play an important role in the retentive strength with No. 5 retention beads. The retentive strength was reduced when brittle resin was used. 4. The retentive strength of the resin veneer was greatly affected by the angle of stress at the incisal resin. The retentive strength increased as the angle between the longitudinal axis of the specimen and the direction of stress decreased.

  8. Retrofitting Trojan Nuclear Plant's spent resin transfer system

    International Nuclear Information System (INIS)

    Pierce, R.E.

    1979-01-01

    The spent resin slurry transport system at the Trojan Nuclear Plant operated by Portland General Electric Company is one of the most advanced systems of its type in the nuclear industry today. The new system affords the plant's operators safe remote sonic indication for spent resin and cover water levels, manual remote dewatering and watering capability to establish desirable resin-to-water volumetric ratios, reliable non-mechanical resin agitation utilizing fixed spargers, and controllable process flow utilizing a variable speed recessed impeller pump

  9. Resins characterization strategy at Kozloduy Nuclear Power Plant

    International Nuclear Information System (INIS)

    Fenoy, A.; González, R.; Molleda, P.; Sánchez, L.; Herrera, J.

    2013-01-01

    The Consortium ENSA- Gas Natural Fenosa Engineering has a contract with Kozloduy Nuclear Power Plant (KNPP) for the retrieval and conditioning of the resins. Before that, the project deals with resins characterization to verify the fulfillment the Bulgarian authorities’ requirements. The project includes all the resins generated during the operation of the BACKGROUND Resins characterization strategy at Kozloduy Nuclear Power Plant units 1, 2, 3 and 4, which were stored into six big dimensions tanks: four low tanks and two intermediate tanks. They only have a manhole above for tanks access. The methodology and the progress of the work are presented

  10. Treatment method for stabilization of radioactive exchange resin

    International Nuclear Information System (INIS)

    Hideo, Oni; Takashi, Miyake; Hitoshi, Miyamoto; Toshio, Funakoshi; Yuzo, Inagaki.

    1988-01-01

    This is a method for eluting radioactive nuclides from a radioactive ion exchange resin in which it has been absorbed. First, the Cs in this resin is extracted using a neutral salt solution which contains Na + . The Cs that has been transferred to the neutral salt solution is absorbed and expelled by inorganic ion exchangers. Then the Co, Fe, Mn and Sr in said resin are eluted using an acidic solution; the Co, Fe, Mn and Sr that have been transferred to the acidic solution are separated from that solution by means of a diffusion dialysis vat. This process is a unique characteristic of this ion exchange resin treatment method. 1 fig

  11. Development of heat resistant ion exchange resin. First Report

    International Nuclear Information System (INIS)

    Onozuka, Teruo; Shindo, Manabu

    1995-01-01

    In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.)

  12. Development of heat resistant ion exchange resin. First Report

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan)

    1995-01-01

    In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.).

  13. Electro regeneration of iodide loaded resin. Contributed Paper RD-18

    International Nuclear Information System (INIS)

    Kumar, Ratnesh; Kumar, T.; Sree Kumar, B.; Seshadri, K.S.; Paul, Biplob

    2014-01-01

    Spent resins generated in the nuclear reactor contain essentially cationic activities due to Cesium, Strontium, Cobalt, and anionic activities due to Iodide, Iodate etc with activity loading to the extent of 0.1 Cim -3 and a surface dose of the order of 5 R. It is necessary to convert the spent resin into innocuous, reusable forms. An attempt has been made to regenerate Iodide containing spent resin into OH - electrolytically by using the OH - produced at the cathode compartment of an electrolytic cell. Results show that the regeneration of the spent resin containing Iodide could be completely accomplished electrolytically more efficiently than by addition of alkali. (author)

  14. Zinc and resin bonded NdFeB magnets

    International Nuclear Information System (INIS)

    Leonowicz, M.; Kaszuwara, W.

    2002-01-01

    Zinc and resin bonded NdFeB magnets were processed. Basic magnetic parameters as well as compressive strength were evaluated versus annealing temperature and volume fraction of the bonding agent. For the zinc bonded magnets phase composition was investigated. The additional NdZn 5 phase was found in the Zn bonded magnets after annealing. Comparison of the Zn and resin bonded magnets reveals higher remanence for the former and higher coercivity for the latter. For the Zn and resin bonded magnets, 15 wt.% Zn / 370 o C and 7-10 wt.% resin were chosen as the optimal processing parameters. (author)

  15. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2018-03-01

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE 00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  16. Modified ion exchange resins - synthesis and properties. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Doescher, F.; Klein, J.; Pohl, F.; Widdecke, H.

    1982-01-22

    Sulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene-co-divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer-bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly(1-(4-hydroxysulfomethylphenyl)ethylene) (3) is obtained by reaction of poly(1-(4-hydroxyphenyl)ethylene) (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are investigated.

  17. Emission and Mechanical Evaluations of Vinyl-Ester Resin Systems

    National Research Council Canada - National Science Library

    Sands, James

    2003-01-01

    Vinyl-ester resins (VE) are frequently used in liquid molding of composite materials for several applications including naval and army structures, commercial boat manufacturing, and building construction...

  18. Development of amino resins for emulsion paint formulation: effect of ...

    African Journals Online (AJOL)

    SERVER

    2007-11-19

    Mirmohseni and Hassanzadeh, 2000). The resins were ... of absorption, slight changes occurred. ..... Urethane-Modified Alumina – Filled Polyesteramide Anticorrosive ... of Polyurethanes Using Ammonium Polyphosphate. J. Appl.

  19. Effect of repair resin type and surface treatment on the repair strength of polyamide denture base resin.

    Science.gov (United States)

    Gundogdu, Mustafa; Yanikoglu, Nuran; Bayindir, Funda; Ciftci, Hilal

    2015-01-01

    The purpose of the present study was to evaluate the effects of different repair resins and surface treatments on the repair strength of a polyamide denture base material. Polyamide resin specimens were prepared and divided into nine groups according to the surface treatments and repair materials. The flexural strengths were measured with a 3-point bending test. Data were analyzed with a 2-way analysis of variance, and the post-hoc Tukey test (α=0.05). The effects of the surface treatments on the surface of the polyamide resin were examined using scanning electron microscopy. The repair resins and surface treatments significantly affected the repair strength of the polyamide denture base material (p0.05). The flexural strength of the specimens repaired with the polyamide resin was significantly higher than that of those repaired with the heat-polymerized and autopolymerizing acrylic resins.

  20. Facile deferration of commercial fertilizers containing iron chelates for their NMR analysis.

    Science.gov (United States)

    Laghi, Luca; Alcañiz, Sara; Cerdán, Mar; Gomez-Gallego, Mar; Sierra, Miguel Angel; Placucci, Giuseppe; Cremonini, Mauro Andrea

    2009-06-24

    Ethylenediamine-N,N'-bis(o-hydroxyphenylacetic) acid (o,o-EDDHA) is widely used in commercial formulations as a Fe(3+) chelating agent to remedy iron shortage in calcareous and alkaline soils. Commercially available o,o-EDDHA-Fe(3+) formulations contain a mixture of EDDHA regioisomers (o,p-EDDHA and p,p-EDDHA), together with other, still uncharacterized, products. NMR spectroscopy can be applied to their study as long as iron is accurately removed prior to the observation. This paper shows that it is possible to obtain a deferrated solution of the organic ligands present in commercial fertilizers containing the EDDHA-Fe(3+) chelate by treating the chelate with ferrocyanide, thus forming Prussian Blue that can be easily removed by centrifugation. This iron removal process does not cause significant losses of the o,o-EDDHA ligand or its minor structural isomers.

  1. Antioxidant and mercury chelating activity of Psidium guajava var. pomifera L. leaves hydroalcoholic extract.

    Science.gov (United States)

    Pinho, Antonio Ivanildo; Oliveira, Cláudia Sirlene; Lovato, Fabricio Luís; Waczuk, Emily Pansera; Piccoli, Bruna Candia; Boligon, Aline Augusti; Leite, Nadghia Figueredo; Coutinho, Henrique Douglas Melo; Posser, Thais; Da Rocha, João Batista Teixeira; Franco, Jeferson Luis

    2017-01-01

    Mercury (Hg) is widely distributed in the environment and is known to produce several adverse effects in organisms. The aim of the present study was to examine the in vitro antioxidant activity and Hg chelating ability of the hydroalcoholic extract of Psidium guajava leaves (HEPG). In addition, the potential protective effects of HEPG against Hg(II) were evaluated using a yeast model (Saccharomyces cerevisiae). HEPG was found to exert significant antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenger and inhibition of lipid peroxidation induced by Fe(II) assays in a concentration-dependent manner. The extract also exhibited significant Hg(II) chelating activity. In yeast, Hg(II) induced a significant decrease in cell viability. In contrast, HEPG partially prevented the fall in cell viability induced by Hg(II). In conclusion, HEPG exhibited protective effects against Hg(II)-mediated toxicity, which may be related to both antioxidant and Hg(II)-chelating activities.

  2. REVIEW ARTICLE:Future of Lead Chelation – Distribution and Treatment

    Directory of Open Access Journals (Sweden)

    Venkatesh Thuppil

    2012-01-01

    Full Text Available Lead is the major environmental toxin resulting in the ill health and deleterious effect on almost all organs in the human body in a slow and effective manner. The best treatment for lead poisoning is chelation therapy which is next only to prevention. The authors describe the disruption of homeostasis of the human body by lead in various tissues like blood, bones, liver, kidneys and brain; and the ability of lead to enter the cell using calcium channels and calcium receptors like Ca++ dependant K+ ion channels, transient receptor potential channels, T-tubules, calmodulin receptors, inositol trisphosphate receptors and ryanodine receptors. We report a few novel chelating agents like ionophores, decadentate ligands, picolinate ligands, octadentate ligand, allicin, thiamine, that show good potential for being used in chelation therapy. Future of leadpoisoning is a challenge to all and it needs to be meticulously studies to have an economic and health approach.

  3. Preparation and Properties of the Chitosan/PVA Blend for Heavy Metals Chelation

    Directory of Open Access Journals (Sweden)

    Zuhair Jabbar Abdul Ameer

    2016-09-01

    Full Text Available Current research based on the use of extracted chitosan mixed with Polyvinyl alcohol to manufacture blend that can been used in water purification from heavy metals such as copper, this due to chitosan properties and its ability to chelation these metals because of the presence of the functional groups in their structure. The blend has been treated with borax to increase the viscosity, and then high density polyethylene granulated coated with polymer solution to increase the surface area for chelation. The ultraviolet test showed the efficiency of blend to chelation of copper ions through lower the copper ions absorbance peak after each stage where the solution of copper ions pass on the polymer blend containing chitosan.

  4. Microbial screening of thorium(IV) and dioxouranium(VI) chelates with oxine and phenols

    International Nuclear Information System (INIS)

    Kapadia, M.A.; Patel, M.M.; Patel, G.P.; Joshi, J.D.

    2007-01-01

    In the present investigation synthesis, characterization of mixed ligand chelates of the type MA 2 L 2 , where, M = Th 4+ and UO 2 2+ , A 8-hydroxyquinoline (oxine) and L = phenols, H2L I = catechol, H 2 L 2 pyrogallol, H 2 L 3 = 2,3-dihydroxy naphthalene, H 2 L 4 = 1,5-dihydroxy naphthalene and H 2 L 5 = 1,7-dihydroxy naphthalene have been reported. Their geometry have been elucidated on the basis of elemental analyses, thermogravimetric, magnetic moments, NMR, IR and electronic spectra. A study of thermal properties has also been carried out. The antimicrobial activity of 8-hydroxyquinoline and MA 2 L 2 chelates have been determined and described. All the chelates showed an effective antimicrobial activity than the free ligand. (author)

  5. Chronic Toxic Metal Exposure and Cardiovascular Disease: Mechanisms of Risk and Emerging Role of Chelation Therapy.

    Science.gov (United States)

    Aneni, Ehimen C; Escolar, Esteban; Lamas, Gervasio A

    2016-12-01

    Over the last few decades, there has been a growing body of epidemiologic evidence linking chronic toxic metal exposure to cardiovascular disease-related morbidity and mortality. The recent and unexpectedly positive findings from a randomized, double-blind, multicenter trial of metal chelation for the secondary prevention of atherosclerotic cardiovascular disease (Trial to Assess Chelation Therapy (TACT)) have focused the discussion on the role of chronic exposure to toxic metals in the development and propagation of cardiovascular disease and the role of toxic metal chelation therapy in the secondary prevention of cardiovascular disease. This review summarizes the most recent evidence linking chronic toxic metal exposure to cardiovascular disease and examines the findings of TACT.

  6. Modeling for Colloid and Chelator Facilitated Nuclide Transport in Radioactive Waste Disposal System

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Jeong, Jong Tae

    2010-08-01

    A modeling study and development of a total system performance assessment (TSPA) program template, by which assessment of safety and performance for a radioactive waste repository with normal and/or abnormal nuclide release cases can be made has been developed. Colloid and chelator facilitated transport that is believed to result for faster nuclide transport in various mediabothinthegeosphereandbiospherehas been evaluated deterministically and probabilistically to demonstrate the capability of the template developed through this study. To this end colloid and chelator facilitated nuclide transport has been modeled rather strainghtforwardly with assumed data through this study by utilizing some powerful function offered by GoldSim. An evaluation in view of apparent influence of colloid and chelator on the nuclide transport in the various media in and around a repository system with data assumed are illustrated

  7. Chiral DOTA chelators as an improved platform for biomedical imaging and therapy applications.

    Science.gov (United States)

    Dai, Lixiong; Jones, Chloe M; Chan, Wesley Ting Kwok; Pham, Tiffany A; Ling, Xiaoxi; Gale, Eric M; Rotile, Nicholas J; Tai, William Chi-Shing; Anderson, Carolyn J; Caravan, Peter; Law, Ga-Lai

    2018-02-27

    Despite established clinical utilisation, there is an increasing need for safer, more inert gadolinium-based contrast agents, and for chelators that react rapidly with radiometals. Here we report the syntheses of a series of chiral DOTA chelators and their corresponding metal complexes and reveal properties that transcend the parent DOTA compound. We incorporated symmetrical chiral substituents around the tetraaza ring, imparting enhanced rigidity to the DOTA cavity, enabling control over the range of stereoisomers of the lanthanide complexes. The Gd chiral DOTA complexes are shown to be orders of magnitude more inert to Gd release than [GdDOTA] - . These compounds also exhibit very-fast water exchange rates in an optimal range for high field imaging. Radiolabeling studies with (Cu-64/Lu-177) also demonstrate faster labelling properties. These chiral DOTA chelators are alternative general platforms for the development of stable, high relaxivity contrast agents, and for radiometal complexes used for imaging and/or therapy.

  8. Assessment of the body burden of chelatable lead: a model and its application to lead workers.

    Science.gov (United States)

    Araki, S; Ushio, K

    1982-01-01

    A hypothetical model was introduced to estimate the body burden of chelatable lead from the mobilisation yield of lead by calcium disodium ethylenediamine tetra-acetate (CaEDTA). It was estimated that, on average, 14 and 19% of the body burden was mobilised into the urine during the 24 hours after an injection of 53.4 mumol (20 mg) and 107 mumol (40 mg) CaEDTA per kg bodyweight, respectively. The body burden of chelatable lead ranged from 4 mumol (0.8 mg) to 120 mumol (24.9 mg) (mean 37 mumol (7.7 mg) in lead workers with blood lead concentrations of 0.3-2.9 mumol/kg (6-60 microgram/100 g) (mean 1.4 mumol/kg (29 microgram/100 g)). There were linear relationships between blood lead concentrations and body burden of chelatable lead on a log scale. PMID:6802167

  9. Enhancement of 67Ga tumor-to-blood ratios by chelating agent

    International Nuclear Information System (INIS)

    Saji, Hideo; Yokoyama, Akira; Hata, Naotaka; Misaki, Atsushi; Tanaka, Hisashi.

    1980-01-01

    Chelating agent, such as, CaEDTA, CaDTPA, D-penicillamine, DMSA, desferoxamine, NTA, cysteine ethyl ester, BAL, α-MPG, phthalein complexone, were tested as a possible contrast enhancing agent for tumor imaging with 67 Ga-citrate. The intravenous administration of a chelating agent to Ehrlich's tumor bearing mice, one hour after the injection of 67 Ga-citrate, accelerated the blood clearance with only a very slight change of activity in the target, increasing the tumor-to-blood ratio, and consequently achieving a better visualization. Among the tested chelating agents, D-penicillamine showed the highest target-to-nontarget ratio at a shorter time: a good tumor-to-blood ratio, performed after 24 hr with non-treated animals, was achieved in only 1-3 hr with post-treated animals. Thus, D-penicillamine hold a considerable promise as a contrast enhancing agent for future clinical use. (author)

  10. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

  11. Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

    NARCIS (Netherlands)

    Bhowmik, S.; Poulis, J.A.; Benedictus, R.

    2008-01-01

    The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a

  12. Evaluating resin-enamel bonds by microshear and microtensile bond strength tests: effects of composite resin

    Directory of Open Access Journals (Sweden)

    Andrea Mello de Andrade

    2010-12-01

    Full Text Available OBJECTIVES: The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350 and adhesive system [(Solobond Plus, Futurabond NR (VOCO and Adper Single Bond (3M ESPE] on the microtensile (μTBS and microshear bond strength (μSBS tests on enamel, and to correlate the bond strength means between them. MATERIAL AND METHODS: Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for μTBS and the other one for μSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37(0C/24 h specimens were stressed (0.5 mm/min. Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05. RESULTS: The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05. For both tests only the main factor resin composite was statistically significant (p<0.05. The correlation test detected a positive (r=0.91 and significant (p=0.01 correlation between the tests. CONCLUSIONS: The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions.

  13. HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

    International Nuclear Information System (INIS)

    Duignan, M; Charles Nash, C; Timothy Punch, T

    2007-01-01

    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit

  14. Polymerization shrinkage stress of composite resins and resin cements – What do we need to know?

    Directory of Open Access Journals (Sweden)

    Carlos José SOARES

    2017-08-01

    Full Text Available Abstract Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.

  15. Polymerization shrinkage stress of composite resins and resin cements - What do we need to know?

    Science.gov (United States)

    Soares, Carlos José; Faria-E-Silva, André Luis; Rodrigues, Monise de Paula; Vilela, Andomar Bruno Fernandes; Pfeifer, Carmem Silvia; Tantbirojn, Daranee; Versluis, Antheunis

    2017-08-28

    Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.

  16. Microwave Assisted Regioselective Bromomethoxylation of Alkenes Using Polymer Supported Bromine Resins

    OpenAIRE

    Gopalakrishnan, Geetha; Kasinath, Viswanathan; Singh, N. D. Pradeep; Krishnan, V. P. Santhana; Solomon, K. Anand; Rajan, S. S.

    2002-01-01

    A facile regio- and chemoselective bromomethoxylation of alkenes under microwave irradiation conditions employing a new polymer supported brominechloride resin is reported. The resin is prepared from the commercially available chloride resin by a simple one step procedure.

  17. Microwave Assisted Regioselective Bromomethoxylation of Alkenes Using Polymer Supported Bromine Resins

    Directory of Open Access Journals (Sweden)

    S. S. Rajan

    2002-05-01

    Full Text Available A facile regio- and chemoselective bromomethoxylation of alkenes under microwave irradiation conditions employing a new polymer supported brominechloride resin is reported. The resin is prepared from the commercially available chloride resin by a simple one step procedure.

  18. Molecular engineering of lanthanide ion chelating phospholipids generating assemblies with a switched magnetic susceptibility.

    Science.gov (United States)

    Isabettini, Stéphane; Massabni, Sarah; Hodzic, Arnel; Durovic, Dzana; Kohlbrecher, Joachim; Ishikawa, Takashi; Fischer, Peter; Windhab, Erich J; Walde, Peter; Kuster, Simon

    2017-08-09

    Lanthanide ion (Ln 3+ ) chelating amphiphiles are powerful molecules for tailoring the magnetic response of polymolecular assemblies. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA) complexed to Ln 3+ deliver highly magnetically responsive bicelles. Their magnetic properties are readily tuned by changing the bicellar size or the magnetic susceptibility Δχ of the bilayer lipids. The former technique is intrinsically bound to the region of the phase diagram guarantying the formation of bicelles. Methods aiming towards manipulating the Δχ of the bilayer are comparatively more robust, flexible and lacking. Herein, we synthesized a new Ln 3+ chelating phospholipid using glutamic acid as a backbone: DMPE-Glu-DTPA. The chelate polyhedron was specifically engineered to alter the Δχ, whilst remaining geometrically similar to DMPE-DTPA. Planar asymmetric assemblies hundreds of nanometers in size were achieved presenting unprecedented magnetic alignments. The DMPE-Glu-DTPA/Ln 3+ complex switched the Δχ, achieving perpendicular alignment of assemblies containing Dy 3+ and parallel alignment of those containing Tm 3+ . Moreover, samples with chelated Yb 3+ were more alignable than the Tm 3+ chelating counterparts. Such a possibility has never been demonstrated for planar Ln 3+ chelating polymolecular assemblies. The physico-chemical properties of these novel assemblies were further studied by monitoring the alignment behavior at different temperatures and by including 16 mol% of cholesterol (Chol-OH) in the phospholipid bilayer. The DMPE-Glu-DTPA/Ln 3+ complex and the resulting assemblies are promising candidates for applications in numerous fields including pharmaceutical technologies, structural characterization of membrane biomolecules by NMR spectroscopy, as contrasting agents for magnetic resonance imaging, and for the development of smart optical gels.

  19. On-load chelating agent treatments for conventional and nuclear power stations

    International Nuclear Information System (INIS)

    Turner, D.J.

    1978-01-01

    The paper is concerned with the application of on-load chelating agent treatments to those types of water circuit for which they are not currently available: high pressure drum boilers, sub-critical once-through boilers and water reactors. An attempt was made to see whether the most thermally stable types of chelating agent are likely to be sufficiently strong chelating agents either to dissolve established Fe 3 O 4 deposits or to prevent their precipitation from solution. It seems likely that they are strong enough to prevent Fe 3 O 4 depositing in a once-through boiler, through some may require that mildly reducing conditions are maintained. They would not be effective in a high pressure drum boiler (at 350 0 C) unless much more strongly reducing conditions could be maintained. For such boilers it would probably be better to seek multidentate ligands of less than maximum thermal stability. There are some indications that chelating agents based on carbon chains are more stable than NTA or EDTA so that citric acid or some of the unidentified chelating agents recently found to be produced radiolytically may have potential in the treatment of high pressure drum boilers. The prospects for periodic full-load cleaning seem less good for both types of boiler. There may also be a role for radiolytically produced chelating agents in alleviating some of the problems caused by the deposition of radioactive corrosion products in water reactor circuits. The chances for successful development fall from quite good to very low down the series SGHWR moderator circuit, PWR primary circuit, ammonia dosed BWR, neutral chemistry BWR (including SGHWR). (author)

  20. The preparation and characterization of novel human-like collagen metal chelates

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chenhui; Sun, Yan [Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering Northwest University, Xi' an 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Xi' an 710069 (China); Wang, Yaoyu [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Xi' an 710069 (China); Luo, Yane, E-mail: luoyane@nwu.edu.cn [Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering Northwest University, Xi' an 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Xi' an 710069 (China); Fan, Daidi, E-mail: fandaidi@nwu.edu.cn [Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering Northwest University, Xi' an 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Xi' an 710069 (China)

    2013-07-01

    In order to develop the nutritional trace elements which could be absorbed and utilized effectively, protein chelates were adopted. Calcium, copper and manganese were considered based on their physiological functions, and the new chelates of HLC-Ca, HLC-Cu and HLC-Mn were formed in MOPS or MES buffer and purified by gel chromatography, and then freeze-dried. And they were detected and analyzed by atomic absorption spectrophotometry, ultraviolet–visible absorption (UV–vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, fluorescence quenching method, circular dichroism (CD) and differential scanning calorimetry (DSC). The results showed that some chemical reactions happened between HLC and the three metal ions to form new chemical compounds. The thermodynamic parameters, ∆H, ∆G and ∆S, showed that the chelation process between HLC and metal ions was performed spontaneously. Fluorescence quenching spectra of HLC indicated that the quenching mechanism was static in nature. According to the data of DSC, the new chelates were more stable than the free HLC. And HLC-metal complex was non-toxic to the BHK21 cell through MTT assay. - Highlights: ► HLC-Ca, HLC-Cu and HLC-Mn were new chemical compounds and different to free HLC. ► Possible sites for Ca{sup 2+}, Cu{sup 2+} and Mn{sup 2+} to bind with HLC were presented. ► The chelation process between HLC and metal ions was performed spontaneously. ► The thermodynamic stability of the new chelates was higher than that of free HLC.