Reactions of atomic oxygen with the chlorate ion and the perchlorate ion

Science.gov (United States)

Anan'ev, Vladimir; Miklin, Mikhail; Kriger, Ludmila

2014-06-01

The reactions of the chlorate ion with atomic oxygen formed under photolysis of the nitrate ion introduced to potassium chlorate crystal by co-crystallization were studied by optical and infrared absorption spectroscopy. The perchlorate ion was found to form in solids as product of addition reaction of singlet atomic oxygen, formed under dissociation of the peroxynitrite ion - the product of isomerization of the excited nitrate ion. Triplet atomic oxygen does not react with the chlorate ion. The atomic oxygen formed under photolysis of the nitrate ion introduced to potassium perchlorate crystal by co-crystallization does not react with the perchlorate ion.

Why chlorate occurs in potable water and processed foods: a critical assessment and challenges faced by the food industry.

Science.gov (United States)

Kettlitz, Beate; Kemendi, Gabriella; Thorgrimsson, Nigel; Cattoor, Nele; Verzegnassi, Ludovica; Le Bail-Collet, Yves; Maphosa, Farai; Perrichet, Aurélie; Christall, Birgit; Stadler, Richard H

2016-06-01

Recently, reports have been published on the occurrence of chlorate mainly in fruits and vegetables. Chlorate is a by-product of chlorinating agents used to disinfect water, and can be expected to be found in varying concentrations in drinking water. Data on potable water taken at 39 sampling points across Europe showed chlorate to range from foods of 0.01 mg kg(-1). This default MRL has now led to significant problems in the EU, where routinely disinfected water, used in the preparation of food products such as vegetables or fruits, leaves chlorate residues in excess of the default MRL, and in strict legal terms renders the food unmarketable. Due to the paucity of data on the chlorate content of prepared foods in general, we collated chlorate data on more than 3400 samples of mainly prepared foods, including dairy products, meats, fruits, vegetables and different food ingredients/additives. In total, 50.5% of the food samples contained chlorate above 0.01 mg kg(-1), albeit not due to the use of chlorate as a pesticide but mainly due to the occurrence of chlorate as an unavoidable disinfectant by-product. A further entry point of chlorate into foods may be via additives/ingredients that may contain chlorate as a by-product of the manufacturing process (e.g. electrolysis). Of the positive samples in this study, 22.4% revealed chlorate above 0.1 mg kg(-1). In the absence of EU levels for chlorate in water, any future EU regulations must consider the already available WHO guideline value of 0.7 mg l(-1) in potable water, and the continued importance of the usage of oxyhalides for disinfection purposes.

Mechanisms of direct inhibition of the respiratory sulfate-reduction pathway by (per)chlorate and nitrate.

Science.gov (United States)

Carlson, Hans K; Kuehl, Jennifer V; Hazra, Amrita B; Justice, Nicholas B; Stoeva, Magdalena K; Sczesnak, Andrew; Mullan, Mark R; Iavarone, Anthony T; Engelbrektson, Anna; Price, Morgan N; Deutschbauer, Adam M; Arkin, Adam P; Coates, John D

2015-06-01

We investigated perchlorate (ClO(4)(-)) and chlorate (ClO(3)(-)) (collectively (per)chlorate) in comparison with nitrate as potential inhibitors of sulfide (H(2)S) production by mesophilic sulfate-reducing microorganisms (SRMs). We demonstrate the specificity and potency of (per)chlorate as direct SRM inhibitors in both pure cultures and undefined sulfidogenic communities. We demonstrate that (per)chlorate and nitrate are antagonistic inhibitors and resistance is cross-inducible implying that these compounds share at least one common mechanism of resistance. Using tagged-transposon pools we identified genes responsible for sensitivity and resistance in Desulfovibrio alaskensis G20. We found that mutants in Dde_2702 (Rex), a repressor of the central sulfate-reduction pathway were resistant to both (per)chlorate and nitrate. In general, Rex derepresses its regulon in response to increasing intracellular NADH:NAD(+) ratios. In cells in which respiratory sulfate reduction is inhibited, NADH:NAD(+) ratios should increase leading to derepression of the sulfate-reduction pathway. In support of this, in (per)chlorate or nitrate-stressed wild-type G20 we observed higher NADH:NAD(+) ratios, increased transcripts and increased peptide counts for genes in the core Rex regulon. We conclude that one mode of (per)chlorate and nitrate toxicity is as direct inhibitors of the central sulfate-reduction pathway. Our results demonstrate that (per)chlorate are more potent inhibitors than nitrate in both pure cultures and communities, implying that they represent an attractive alternative for controlling sulfidogenesis in industrial ecosystems. Of these, perchlorate offers better application logistics because of its inhibitory potency, solubility, relative chemical stability, low affinity for mineral cations and high mobility in environmental systems.

Stress Effects of Chlorate on Longan (Dimocarpus longan Lour. Trees: Changes in Nitrogen and Carbon Nutrition

Directory of Open Access Journals (Sweden)

Jiemei LU

2017-11-01

Full Text Available Three-year-old potted longan (Dimocarpus longan Lour. cv. Shixia trees were treated with potassium chlorate and effects on nitrogen and carbon nutrition were examined. The results showed that potassium chlorate at 10 and 20 g per pot failed to induce flower but suppressed shoot growth and caused leaf chlorosis and drop. The treatment significantly inhibited nitrate reductase but increased nitrogen concentration in the leaves and buds. Concentration of soluble amino acids in the leaves of treated trees increased within 14 days and then declined to the control level, while it increased constantly in buds. In both organs, the amino acid increase was an all-round one, with all the tested 21 amino acids increased. However, soluble proteins in the leaves were slightly increased by chlorate, indicating that de novo synthesis of amino acids was activated. Chlorate reduced photosynthetic rate and stomatal conductance but slightly increased CO2 concentration in the mesophyll, suggesting that chlorate treatment damaged photosynthetic apparatus. The damage was reflected by the destruction of thylakoids and grana in the chloroplasts. Chlorate also caused depletion of starch with significant accumulation of soluble sugars in the leaves. Accumulation of sugars and soluble amino acids indicates osmotic adjustment in response to the stress caused by chlorate treatment.

Stopped-flow injection spectrophotometric method for determination of chlorate in soil

OpenAIRE

Jaroon Jakmunee

2008-01-01

A stopped-flow injection (FI) spectrophotometric procedure based on iodometric reaction for the determination of chlorate has been developed. Standard/sample was injected into a stream of potassium iodide solution and then merged with a stream of hydrochloric acid solution to produce triiodide. By stopping the flow while the sample zone is being in a mixing coil, a slow reaction of chlorate with iodide in acidic medium was promoted to proceed with minimal dispersion of the triiodide product z...

Concurrent Haloalkanoate Degradation and Chlorate Reduction by Pseudomonas chloritidismutans AW-1T.

Science.gov (United States)

Peng, Peng; Zheng, Ying; Koehorst, Jasper J; Schaap, Peter J; Stams, Alfons J M; Smidt, Hauke; Atashgahi, Siavash

2017-06-15

Haloalkanoates are environmental pollutants that can be degraded aerobically by microorganisms producing hydrolytic dehalogenases. However, there is a lack of information about the anaerobic degradation of haloalkanoates. Genome analysis of Pseudomonas chloritidismutans AW-1 T , a facultative anaerobic chlorate-reducing bacterium, showed the presence of two putative haloacid dehalogenase genes, the l-DEX gene and dehI , encoding an l-2-haloacid dehalogenase (l-DEX) and a halocarboxylic acid dehydrogenase (DehI), respectively. Hence, we studied the concurrent degradation of haloalkanoates and chlorate as a yet-unexplored trait of strain AW-1 T The deduced amino acid sequences of l-DEX and DehI revealed 33 to 37% and 26 to 86% identities with biochemically/structurally characterized l-DEX and the d- and dl-2-haloacid dehalogenase enzymes, respectively. Physiological experiments confirmed that strain AW-1 T can grow on chloroacetate, bromoacetate, and both l- and d-α-halogenated propionates with chlorate as an electron acceptor. Interestingly, growth and haloalkanoate degradation were generally faster with chlorate as an electron acceptor than with oxygen as an electron acceptor. In line with this, analyses of l-DEX and DehI dehalogenase activities using cell-free extract (CFE) of strain AW-1 T grown on dl-2-chloropropionate under chlorate-reducing conditions showed up to 3.5-fold higher dehalogenase activity than the CFE obtained from AW-1 T cells grown on dl-2-chloropropionate under aerobic conditions. Reverse transcription-quantitative PCR showed that the l-DEX gene was expressed constitutively independently of the electron donor (haloalkanoates or acetate) or acceptor (chlorate or oxygen), whereas the expression of dehI was induced by haloalkanoates. Concurrent degradation of organic and inorganic halogenated compounds by strain AW-1 T represents a unique metabolic capacity in a single bacterium, providing a new piece of the puzzle of the microbial halogen cycle

Highly selective direct determination of chlorate ions by using a newly developed potentiometric electrode based on modified smectite.

Science.gov (United States)

Topcu, Cihan

2016-12-01

A novel polyvinyl chloride membrane chlorate (ClO 3 - ) selective electrode based on modified smectite was developed for the direct determination of chlorate ions and the potentiometric performance characteristics of its were examined. The best selectivity and sensitivity for chlorate ions were obtained for the electrode membrane containing ionophore/polyvinylchloride/o-nitrophenyloctylether in composition of 12/28/60 (w/w%). The proposed electrode showed a Nernstian response toward chlorate ions at pH=7 in the concentration range of 1×10 -7 -1×10 -1 M and the limit of detection was calculated as 9×10 -8 M from the constructed response plot. The linear slope of the electrode was -61±1mVdecade -1 for chlorate activity in the mentioned linear working range. The selectivity coefficients were calculated according to both the matched potential method and the separate solution method. The calculated selectivity coefficients showed that the electrode performed excellent selectivity for chlorate ions. The potentiometric response of electrode toward chlorate ions was found to be highly reproducible. The electrode potential was stable between pH=4-10 and it had a dynamic response time of <5s. The potentiometric behavior of the electrode in partial non-aqueous medium was also investigated and the obtained results (up to 5% (v/v) alcohol) were satisfactory. The proposed electrode was used during 15 weeks without any significant change in its potential response. Additionally, the electrode was very useful in water analysis studies such as dam water, river water, tap water, and swimming pool water where the direct determination of chlorate ions was required. Copyright © 2016 Elsevier B.V. All rights reserved.

A novel stopped flow injection-amperometric procedure for the determination of chlorate.

Science.gov (United States)

Tue-Ngeun, Orawan; Jakmunee, Jaroon; Grudpan, Kate

2005-12-15

A novel stopped flow injection-amperometric (sFI-Amp) procedure for determination of chlorate has been developed. The reaction of chlorate with excess potassium iodide and hydrochloric acid, forming iodine/triiodide that is further electrochemically reduced at a glassy carbon electrode at +200mV versus Ag/AgCl electrode is employed. In order to increase sensitivity without using of too high acid concentration, promoting of the reaction by increasing reaction time and temperature can be carried out. This can be done without increase of dispersion of the product zone by stopping the flow while the injected zone is being in a mixing coil which is immersed in a water bath of 55+/-0.5 degrees C. In a closed system of FIA, a side reaction of oxygen with iodide is also minimized. Under a set of conditions, linear calibration graphs were in the ranges of 1.2x10(-6)-6.0x10(-5)moll(-1)and 6.0x10(-5)-6.0x10(-4)moll(-1). A sample throughput of 25h(-1) was accomplished. Relative standard deviation was 2% (n=21, 1.2x10(-4)moll(-1) chlorate). The proposed sFI-Amp procedure was successfully applied to the determination of chlorate in soil samples from longan plantation area.

Studies on potassium chlorate as a primary oxidimetric reagent.

Science.gov (United States)

Murty, C R; Rao, G G

1972-01-01

Conditions have been established for the use of potassium chlorate as a primary oxidizing agent in the direct titration of vanadium(III), tin(II) and titanium(III) with visual or potentiometric end-points.

Energy loss in electrochemical diaphragm process of chlorine and alkali industry - A collateral effect of the undesirable generation of chlorate

Energy Technology Data Exchange (ETDEWEB)

Lima, Phabyanno Rodrigues; Mirapalheta, Almir; e Silva Zanta, Carmem Lucia de Paiva; Tonholo, Josealdo [Instituto de Quimica e Biotecnologia, Universidade Federal de Alagoas, 57072970 Maceio, AL (Brazil); Henrique dos Santos Andrade, Marcio [Instituto de Quimica e Biotecnologia, Universidade Federal de Alagoas, 57072970 Maceio, AL (Brazil); Braskem S/A, Maceio, AL (Brazil); Vilar, Eudesio Oliveira [Departamento de Engenharia Quimica, Universidade Federal de Campina, Grande, Campina Grande, PB (Brazil)

2010-05-15

Contamination of NaOH with chlorate constitutes a major problem for the chlorine-alkali industry, particularly when electrolytic cells based on the diaphragm process are employed. In this paper, pilot and laboratory cell experiments revealed that chlorate contamination in diaphragm cells also inhibits hydrogen evolution and gives rise to a significant increase in electrical energy consumption. Electrolysis carried out under conditions that simulated the industrial process (current density 240 mA cm{sup -2}; temperature 90 C; brine flux 23 L cm{sup -2} h{sup -1}) revealed that chlorate formation depends on brine flux and NaOH production. The inhibitory effect of chlorate on the main cathodic reaction was demonstrated in bench cell experiments, with cathodic displacement of the hydrogen evolution reaction by more than 100 mV in the presence of 0.4% chlorate compared with ideal conditions in which chlorate formation was absent. This hydrogen generation overpotential can charge the total electric energy balance in more than 5% of the total value, consisting of a critical loss for this process. (author)

Chiral hide-and-seek: retention of enantiomorphism in laser-induced nucleation of molten sodium chlorate.

Science.gov (United States)

Ward, Martin R; Copeland, Gary W; Alexander, Andrew J

2011-09-21

We report the observation of non-photochemical laser-induced nucleation (NPLIN) of sodium chlorate from its melt using nanosecond pulses of light at 1064 nm. The fraction of samples that nucleate is shown to depend linearly on the peak power density of the laser pulses. Remarkably, we observe that most samples are nucleated by the laser back into the enantiomorph (dextrorotatory or levorotatory) of the solid prior to melting. We do not observe a significant dependence on polarization of the light, and we put forward symmetry arguments that rule out an optical Kerr effect mechanism. Our observations of retention of chirality can be explained by decomposition of small amounts of the sodium chlorate to form sodium chloride, which provide cavities for retention of clusters of sodium chlorate even 18 °C above the melting point. These clusters remain sub-critical on cooling, but can be activated by NPLIN via an isotropic polarizability mechanism. We have developed a heterogeneous model of NPLIN in cavities, which reproduces the experimental data using simple physical data available for sodium chlorate.

Continuous, low-dose oral exposure to sodium chlorate reduces fecal Enterobacteriaceae coliforms in sheep feces without inducing subclinical chlorate toxicosis

Science.gov (United States)

Our objectives were to determine a minimal daily dose of sodium chlorate, to be included in the drinking water for 5 days, that is safe yet maintains efficacy in reducing fecal shedding of Escherichia coli in mature ewes. In a complete randomized experimental design, 25 Targhee ewes (age = 18- to 20...

Differential chlorate inhibition of Chaetomium globosum germination, hyphal growth, and perithecia synthesis.

Science.gov (United States)

Biles, Charles L; Wright, Desiree; Fuego, Marianni; Guinn, Angela; Cluck, Terry; Young, Jennifer; Martin, Markie; Biles, Josiah; Poudyal, Shubhra

2012-12-01

Chaetomium globosum Kunze:Fr is a dermatophytic, dematiaceous fungus that is ubiquitous in soils, grows readily on cellulolytic materials, and is commonly found on water-damaged building materials. Chlorate affects nitrogen metabolism in fungi and is used to study compatibility among anamorphic fungi by inducing nit mutants. The effect of chlorate toxicity on C. globosum was investigated by amending a modified malt extract agar (MEA), oat agar, and carboxymethyl cellulose agar (CMC) with various levels of potassium chlorate (KClO(3)). C. globosum perithecia production was almost completely inhibited (90-100 %) at low levels of KClO(3) (0.1 mM) in amended MEA. Inhibition of perithecia production was also observed on oat agar and CMC at 1 and 10 mM, respectively. However, hyphal growth in MEA was only inhibited 20 % by 0.1-100 mM KClO(3) concentrations. Hyphal growth was never completely inhibited at the highest levels tested (200 mM). Higher levels of KClO(3) were needed on gypsum board to inhibit perithecia synthesis. In additional experiments, KClO(3) did not inhibit C. globosum, Fusarium oxysporum, Aspergillus niger, Penicillum expansum, and airborne fungal spore germination. The various fungal spores were not inhibited by KClO(3) at 1-100 mM levels. These results suggest that C. globosum perithecia synthesis is more sensitive to chlorate toxicity than are hyphal growth and spore germination. This research provides basic information that furthers our understanding about perithecia formation and may help in developing control methods for fungal growth on building materials.

High-pressure X-ray diffraction studies of potassium chlorate

Energy Technology Data Exchange (ETDEWEB)

Pravica, Michael; Bai, Ligang; Bhattacharya, Neelanjan (UNLV)

2012-03-15

Two static high-pressure X-ray diffraction (XRD) studies of potassium chlorate have been performed at pressures of up to {approx}14.3 GPa in a diamond anvil cell at ambient temperature using the 16 ID-B undulator beamline at the Advanced Photon Source for the X-ray source. The first experiment was conducted to ascertain decomposition rates of potassium chlorate as a function of pressure. Below 2 GPa, the sample was observed to decompose rapidly in the presence of the X-ray beam and release oxygen. Above 2 GPa (near the phase I phase II transition), the decomposition rate dramatically slowed so that good quality XRD patterns could be acquired. This suggests a phase-dependent decomposition rate. In the second study, X-ray diffraction spectra were collected at pressures from 2 to 14.3 GPa by aligning virgin portions of the sample into the focused X-ray beam at each pressure. The results suggest the co-existence of mixed monoclinic (I) and rhombohedral (II) phases of potassium chlorate near 2 GPa. At pressures beyond 4 GPa, the XRD patterns show a very good fit to KClO{sub 3} in the rhombohedral phase with space group R3m, in agreement with earlier studies. No further phase transitions were observed with pressure. Decompression of the sample to ambient pressure indicated mixed phases I and II coupled with a small amount of synchrotron X-ray-induced decomposition product. The equation of state within this pressure regime has been determined.

Cranial MR imaging findings of potassium chlorate intoxication.

Science.gov (United States)

Mutlu, Hakan; Silit, Emir; Pekkafali, Zekai; Basekim, C Cinar; Kizilkaya, Esref; Ay, Hakan; Karsli, A Fevzi

2003-08-01

We present the case of a patient who attempted suicide by ingesting matchstick heads (55% potassium chlorate). The patient presented to the emergency room with loss of consciousness, and MR imaging revealed symmetric hyperintense signal within the deep gray matter and medial temporal lobes. The patient improved after undergoing conventional treatment and hyperbaric oxygen.

The vapour pressures over saturated aqueous solutions of sodium and potassium acetates, chlorates, and perchlorates

Energy Technology Data Exchange (ETDEWEB)

Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Manzurola, Emanuel [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)

2007-08-15

Vapour pressures of water over saturated solutions of sodium acetate, potassium acetate, sodium perchlorate, and potassium perchlorate were determined over the (278 to 318) K temperature range and compared with available in the literature data. The cases of saturated solutions of sodium chlorate and potassium chlorate are also considered. The determined vapour pressures were used to obtain the water activities, the osmotic coefficients, and the molar enthalpies of vaporization in considered systems.

RAPD cluster analysis and chlorate sensitivity of some Indian isolates of Macrophomina phaseolina from sorghum and their relationships with pathogenicity.

Science.gov (United States)

Das, I K; Fakrudin, B; Arora, D K

2008-01-01

Charcoal rot caused by Macrophomina phaseolina is an economically important disease in sorghum grown during the post rainy season in India. Variations in random amplified polymorphic DNA (RAPD) polymorphisms, chlorate sensitivity and pathogenicity were studied among sorghum isolates of M. phaseolina collected from different parts of India. RAPD data based on 14 random primers of Kit A and C (OPA and OPC) on 20 isolates showed a high degree of polymorphism (98.1%) in different isolates. UPGMA dendrogram on RAPD data produced 7 clusters at the level of 37% similarity. Isolates from the same locations showed a tendency to group closer, substantiating closer genetic relatedness. Sorghum infecting Macrophomina isolates showed a mixed response for sensitivity to potassium chlorate (120 mM). Chlorate-resistant isolates were predominant (>65% of the isolates) over sensitive isolates. Chlorate-sensitive isolates were found to be genetically closer among them than the resistant ones. For the first time it was shown that chlorate sensitivity in Macrophomina had some relations with charcoal rot severity in sorghum.

Foliar fertilization as an alternative to hand thinning fruit in chlorate treated Dimocarpus longan Lour. trees in Hawaii.

Science.gov (United States)

Longan, Dimocarpus longan Lour, is a member of the Sapindaceae, a family that also includes lychee, and rambutan. The discovery of potassium chlorate (KClO3) induced flowering solved the problem of alternate bearing and enabled the grower to produce off-season longan. Chlorate treatments commonly i...

Clorate Metabolism in Pure Cultures of E.Coli 0157:H7 Pretreated with Either Nitrate or Chlorate

Science.gov (United States)

Experiments were conducted to determine the effects of 5, 7.5, and 10 mM nitrate, and 5, 10, or 20 mM chlorate on total E. coli counts, chlorate metabolism, and volatile fatty acid (VFA) concentrations in anaerobic ruminal fluid cultures. Nitrate did not affect total E. coli counts (P = 0.05), chlor...

Influence of drinking water treatments on chlorine dioxide consumption and chlorite/chlorate formation.

Science.gov (United States)

Sorlini, Sabrina; Gialdini, Francesca; Biasibetti, Michela; Collivignarelli, Carlo

2014-05-01

Disinfection is the last treatment stage of a Drinking Water Treatment Plant (DWTP) and is carried out to maintain a residual concentration of disinfectant in the water distribution system. Chlorine dioxide (ClO2) is a widely used chemical employed for this purpose. The aim of this work was to evaluate the influence of several treatments on chlorine dioxide consumption and on chlorite and chlorate formation in the final oxidation/disinfection stage. A number of tests was performed at laboratory scale employing water samples collected from the DWTP of Cremona (Italy). The following processes were studied: oxidation with potassium permanganate, chlorine dioxide and sodium hypochlorite, coagulation/flocculation with ferric chloride and aluminum sulfate, filtration and adsorption onto activated carbon. The results showed that the chlorine dioxide demand is high if sodium hypochlorite or potassium permanganate are employed in pre-oxidation. On the other hand, chlorine dioxide leads to the highest production of chlorite and chlorate. The coagulation/flocculation process after pre-oxidation shows that chlorine dioxide demand decreases if potassium permanganate is employed as an oxidant, both with ferric chloride and aluminum sulfate. Therefore, the combination of these processes leads to a lower production of chlorite and chlorate. Aluminum sulfate is preferable in terms of the chlorine dioxide demand reduction and minimization of the chlorite and chlorate formation. Activated carbon is the most effective solution as it reduced the chlorine dioxide consumption by about 50% and the DBP formation by about 20-40%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isolation and characterization of Alicycliphilus denitrificans strain BC, which grows on benzene with chlorate as the electron acceptor

NARCIS (Netherlands)

Weelink, S.A.B.; Tan, N.C.G.; Broeke, H. ten; Kieboom, C. van den; Doesburg, W. van; Langenhoff, A.A.M.; Gerritse, J.; Junca, H.; Stams, A.J.M.

2008-01-01

A bacterium, strain BC, was isolated from a benzene-degrading chlorate-reducing enrichment culture. Strain BC degrades benzene in conjunction with chlorate reduction. Cells of strain BC are short rods that are 0.6 μm wide and 1 to 2 μm long, are motile, and stain gram negative. Strain BC grows on

Stress Effects of Chlorate on Longan (Dimocarpus longan Lour.) Trees: Changes in Nitrogen and Carbon Nutrition

OpenAIRE

Jiemei LU; Ruitao YANG; Huicong WANG; Xuming HUANG

2017-01-01

Three-year-old potted longan (Dimocarpus longan Lour. cv. Shixia) trees were treated with potassium chlorate and effects on nitrogen and carbon nutrition were examined. The results showed that potassium chlorate at 10 and 20 g per pot failed to induce flower but suppressed shoot growth and caused leaf chlorosis and drop. The treatment significantly inhibited nitrate reductase but increased nitrogen concentration in the leaves and buds. Concentration of soluble amino acids in the leaves of tre...

Infrared multiple photon dissociation spectroscopy of sodium and potassium chlorate anions

NARCIS (Netherlands)

Dain, R. P.; Leavitt, C. M.; Oomens, J.; Steill, J. D.; Groenewold, G. S.; van Stipdonk, M. J.

2010-01-01

The structures of gas-phase, metal chlorate anions with the formula [M(ClO3)(2)](-), M = Na and K, were determined using tandem mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. Structural assignments for both anions are based on comparisons of the experimental

Physiological and phylogenetic characterization of a stable benzene-degrading, chlorate-reducing microbial community

NARCIS (Netherlands)

Weelink, S.A.B.; Tan, N.C.G.; Broeke, H. ten; Doesburg, W. van; Langenhoff, A.A.M.; Gerritse, J.; Stams, A.J.M.

2007-01-01

A stable anoxic enrichment culture was obtained that degraded benzene with chlorate as an electron acceptor. The benzene degradation rate was 1.65 mM benzene per day, which is similar to reported aerobic benzene degradation rates but 20-1650 times higher than reported for anaerobic benzene

Kinetics of isothermal annealing of hypochlorite in γ-irradiated potassium chlorate

International Nuclear Information System (INIS)

Arnikar, H.J.; Patil, S.F.; Patil, B.T.

1977-01-01

The kinetics of isothermal annealing of hypochlorite formed in the gamma radiolysis of potassium chlorate crystals have been studied at different temperatures in the range of 100-160 deg C. The hypochlorite is found to anneal by a combination of first and second order processes, the former being fast, virtually reaching completion within a few hours. It is then followed by a slow second order process. (authors)

The Investigation of Chlorate and Perchlorate/Saponite Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater

Science.gov (United States)

Clark, J.; Sutter, B.; Min, D. W.; Mahaffy, P.

2016-01-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected O2 and HCl gas releases from all analyzed Gale Crater sediments, which are attributed to the presence of perchlorates and/or chlorates in martian sediment. Previous SAM analog laboratory analyses found that most pure perchlorates and chlorates release O2 and HCl at different temperatures than those observed in the SAM data. Subsequent studies examined the effects of perchlorate and chlorate mixtures with Gale Crater analog iron phases, which are known to catalyze oxychlorine decomposition. Several mixtures produced O2 releases at similar temperatures as Gale Crater materials, but most of these mixtures did not produce significant HCl releases comparable to those detected by the SAM instrument. In order to better explain the Gale Crater HCl releases, perchlorates and chlorates were mixed with Gale Crater analog saponite, which is found at abundances from 8 to 20 wt % in the John Klein and Cumberland drill samples. Mixtures of chlorates or perchlorates with calcium-saponite or ferrian-saponite were heated to 1000 deg C in a Labsys EVO differential scanning calorimeter/mass spectrometer configured to operate similarly to the SAM oven/quadrupole mass spectrometer system. Our results demonstrate that all chlorate and perchlorate mixtures produce significant HCl releases below 1000 deg C as well as depressed oxygen peak release temperatures when mixed with saponite. The type of saponite (calcium or ferrian saponite) did not affect the evolved gas results significantly. Saponite/Mg-perchlorate mixtures produced two HCl releases similar to the Cumberland drilled sample. Mg-chlorate mixed with saponite produced HCl releases similar to the Big Sky drilled sample in an eolian sandstone. A mixture of Ca-perchlorate and saponite produced HCl and oxygen releases similar to the Buckskin mudstone drilled sample and the Gobabeb 2 eolian dune material. Ca-chlorate mixed with saponite produced both

Stopped-flow injection spectrophotometric method for determination of chlorate in soil

Directory of Open Access Journals (Sweden)

Jaroon Jakmunee

2008-06-01

Full Text Available A stopped-flow injection (FI spectrophotometric procedure based on iodometric reaction for the determination of chlorate has been developed. Standard/sample was injected into a stream of potassium iodide solution and then merged with a stream of hydrochloric acid solution to produce triiodide. By stopping the flow while the sample zone is being in a mixing coil, a slow reaction of chlorate with iodide in acidic medium was promoted to proceed with minimal dispersion of the triiodide product zone. When the flow started again, a concentrated product zone was pushed into a flow cell and a signal profile due to light absorption of the product was recorded. Employing a lab-built semi-automatic stopped-FI analyser, the analysis can be performed with higher degree of automation and low chemical consumption. Linear calibration graph in the range of 5-50 mg ClO3- L-1 was obtained, with detection limit of 1.4 mg ClO3- L-1. Relative standard deviation of 2.2% (30 mg ClO3- L-1, n=10 and sample throughput of about 20 h-1 were achieved. The system was applied to soil samples and validated by batch spectrophotometric and standard titrimetric methods.

EFSA CONTAM Panel (EFSA Panel on Contaminants in the Food Chain), 2015. Scientific Opinion on risks for public health related to the presence of chlorate in food

DEFF Research Database (Denmark)

Petersen, Annette

Following a request from the European Commission, the risks to human health related to the presence of chlorate in food were assessed by the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel). The presence of chlorate in food can arise from the use of chlorinated water for food processing...... and the disinfection of food-processing equipment. Inhibition of iodine uptake in humans was identified as the critical effect for chronic exposure to chlorate. A tolerable daily intake (TDI) of 3 µg chlorate/kg body weight (b.w.) was set by read-across from a TDI of 0.3 µg/kg b.w. derived for this effect...... with mild or moderate iodine deficiency. Mean and 95th percentile acute exposures were below the ARfD for all age groups indicating no concern. Based on the current practices in food industry, application of a hypothetical maximum residue limit (MRL) of 0.7 mg/kg for all foodstuffs and drinking water would...

Fluorometric determination of vanadium (V) by utilizing its catalytic effect on the oxidation of o-aminophenol by chlorate

Energy Technology Data Exchange (ETDEWEB)

Hiraki, K; Shimizu, N; Nishikawa, Y [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology; Shigematsu, T

1981-12-01

The oxidation of o-aminophenol by chlorate ion takes place in acidic milieu and is catalyzed by a trace amount of vanadium (V). Vanadium (V) oxidizes o-aminophenol to 2-amino-3-phenoxazone, then the vanadium (IV) produced is reoxidized to vanadium (V) by the sodium chlorate. Further oxidation of o-aminophenol proceeds by repetition of these reactions. The oxidation product (2-amino-3-phenoxazone) gives an intense fluorescence; under optimum conditions, the fluorescence intensity is proportional to the concentration of vanadium. The most suitable concentration of o-aminophenol and sodium chlorate for the determination of vanadium (V) were found to be 0.02 M and 2 x 10/sup -4/ M, respectively. From 0.1 ppm to 5 ppm of vanadium (V) can be determined under the optimum conditions; reaction temperature 50/sup 0/C, reaction time 2 h, and at pH 2 +- 0.2. If the reaction time is increased to 3 h at 55/sup 0/C, the method may be extended from 2 ppb to 15 ppb of vanadium. Interferences of diverse ions were tested, among which Fe (III) and Mn (VII) caused positive errors, and Cr (VI), Mo (VI) negative errors if present in 40 fold w/w ratio to V (V).

(Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

KAUST Repository

Balk, Melike

2010-08-03

A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

(Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

KAUST Repository

Balk, Melike; Mehboob, Farrakh; van Gelder, Antonie H; Rijpstra, W Irene C; Damsté , Jaap S Sinninghe; Stams, Alfons J M

2010-01-01

A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

Suicidal intoxication with potassium chlorate successfully treated with renal replacement therapy and extracorporeal liver support.

Science.gov (United States)

Sein Anand, Jacek; Barwina, Małgorzata; Zajac, Maciej; Kaletha, Krystian

2012-01-01

We present a case of a 22-year-old male who, in a suicide attempt, ingested approximately 200 g of potassium chlorate. Upon admission to the hospital, he presented in full respiratory failure with cyanosis. Methylene blue antidote was given but found to be ineffective. The patient was intubated and mechanical ventilation was initiated. Because of renal failure with anuria, intermittent haemodialysis (iHD) followed by continuous venovenous hemodiafiltration (CVVHDF) was performed. His hospital stay was also complicated by hemolysis, disseminated intravascular coagulation, and atrial fibrillation. Transfusions of packed red blood cells, platelets, and fresh frozen plasma were necessary to correct the deficits. He also developed liver failure and required two sessions of molecular adsorbent recirculating system (MARS) therapy. On day 14 of his hospitalization, he regained consciousness, as well as full respiratory and circulatory function. There are no controlled studies addressing management of potassium chlorate poisoning. We suggest that early renal replacement therapy should be strongly considered.

Polarization characteristics of RTO anodes in the conditions of sodium chlorate preparation

International Nuclear Information System (INIS)

Ehberil', V.I.; Fedotova, N.S.; Novikov, E.A.

1997-01-01

By the method of polarization curves plotting in galvanostatic conditions in chloride-chlorate solutions of different compositions at different pH and temperatures it is shown that critical potential for oxide ruthenium-titanium anodes at current density less than 0.7 A/cm 2 is reached in solutions with NaCl concentration 50 g/l and low. The mechanism of potential transition to supercritical range is considered on the basis of ruthenium-water system analysis. (author)

Potential for chlorate interference in ion chromatographic determination of total nitrogen in natural waters following alkaline persulfate digestion.

Science.gov (United States)

Halstead, J A; Edwards, J; Soracco, R J; Armstrong, R W

1999-10-01

Determination of total nitrogen in aqueous samples after thermal potassium peroxydisulfate (persulfate) digestion is a commonly used alternative to the tedious Kjeldahl procedure. When ion chromatography is used to quantify the nitrate formed during digestion, there is a potential for interference from a chlorate peak if the digested sample initially contained chloride in concentrations close to or greater than the concentration of nitrogen. It was determined that this interference can be avoided either by using chromatographic conditions which cleanly resolve the nitrate and chlorate peaks (e.g., the Dionex AG9-HG column) or by using digestion reagent concentrations chosen to maintain a high pH throughout the digestion. The second alternative is not a viable option for investigators using a single digestion for both total nitrogen (TN) and total phosphorus (TP) analysis.

The discrimination of 72 nitrate, chlorate and perchlorate salts using IR and Raman spectroscopy

Science.gov (United States)

Zapata, Félix; García-Ruiz, Carmen

2018-01-01

Inorganic oxidizing energetic salts including nitrates, chlorates and perchlorates are widely used in the manufacture of not only licit pyrotechnic compositions, but also illicit homemade explosive mixtures. Their identification in forensic laboratories is usually accomplished by either capillary electrophoresis or ion chromatography, with the disadvantage of dissociating the salt into its ions. On the contrary, vibrational spectroscopy, including IR and Raman, enables the non-invasive identification of the salt, i.e. avoiding its dissociation. This study focuses on the discrimination of all nitrate, chlorate and perchlorate salts that are commercially available, using both Raman and IR spectroscopy, with the aim of testing whether every salt can be unequivocally identified. Besides the visual spectra comparison by assigning every band with the corresponding molecular vibrational mode, a statistical analysis based on Pearson correlation was performed to ensure an objective identification, either using Raman, IR or both. Positively, 25 salts (out of 72) were unequivocally identified using Raman, 30 salts when using IR and 44 when combining both techniques. Negatively, some salts were undistinguishable even using both techniques demonstrating there are some salts that provide very similar Raman and IR spectra.

Determination of trace aluminum by fluorescence quenching method based on catalysis of potassium chlorate oxidizing alizarin red

Science.gov (United States)

Shao-Qin, Lin; Xuan, Lin; Shi-Rong, Hu; Li-Qing, Zeng; Yan, Wang; Li, Chen; Jia-Ming, Liu; Long-Di, Li

2005-11-01

A new method for the determination of trace aluminum has been proposed. It is based on the fact that alizarin red can emit strong and stable fluorescence at 80 °C for 30 min and Al 3+ can effectively catalyze potassium chlorate oxidizing alizarin red to form non-fluorescence complex which cause the fluorescence quenching. The linear dynamic range of this method is 0.040-4.00 ng l -1 with a detection limit of 5.3 pg l -1. The regression equation can be expressed as Δ If = 8.731 + 21.73 c (ng l -1), with the correlation coefficient r = 0.9992 ( n = 6). This sensitive, rapid and accurate method has been applied to the determination of trace aluminum(III) in human hair and tea samples successfully. What is more, the mechanism of catalyzing potassium chlorate oxidizing alizarin red by the fluorescence quenching method is also discussed.

Influence of Temperature and Catalyst on the Decomposition of Potassium Chlorate in a Simple DTA-Apparatus.

Science.gov (United States)

Wiederholt, Erwin

1983-01-01

DTA is a technique in which the temperature difference between sample/reference is measured as a function of temperature, while both are subject to a controlled temperature program. Use of a simple DTA-apparatus in demonstrating catalytic effects of manganese dioxide and aluminum oxide on decomposition temperature of potassium chlorate is…

Balancing redox equations: reaction of Cr(III) and chlorate in basic solution.

OpenAIRE

Milla González, Miguel

2011-01-01

This file is an interactive exercise on balancing of redox reactions. The redox system consists of the Cr(III) oxidation by means of the action of chlorate anion in basic solution. In these circumstances, Cr(III) exists as the Cr(OH)3 green precipitate. After finding out the oxidation states of the species involved, the user must write the equations of the half-reactions for both processes. A counter of atoms and charges makes this task easy and four possible ways of balancing are possible...

Metabolic primers for detection of (Per)chlorate-reducing bacteria in the environment and phylogenetic analysis of cld gene sequences.

Science.gov (United States)

Bender, Kelly S; Rice, Melissa R; Fugate, William H; Coates, John D; Achenbach, Laurie A

2004-09-01

Natural attenuation of the environmental contaminant perchlorate is a cost-effective alternative to current removal methods. The success of natural perchlorate remediation is dependent on the presence and activity of dissimilatory (per)chlorate-reducing bacteria (DPRB) within a target site. To detect DPRB in the environment, two degenerate primer sets targeting the chlorite dismutase (cld) gene were developed and optimized. A nested PCR approach was used in conjunction with these primer sets to increase the sensitivity of the molecular detection method. Screening of environmental samples indicated that all products amplified by this method were cld gene sequences. These sequences were obtained from pristine sites as well as contaminated sites from which DPRB were isolated. More than one cld phylotype was also identified from some samples, indicating the presence of more than one DPRB strain at those sites. The use of these primer sets represents a direct and sensitive molecular method for the qualitative detection of (per)chlorate-reducing bacteria in the environment, thus offering another tool for monitoring natural attenuation. Sequences of cld genes isolated in the course of this project were also generated from various DPRB and provided the first opportunity for a phylogenetic treatment of this metabolic gene. Comparisons of the cld and 16S ribosomal DNA (rDNA) gene trees indicated that the cld gene does not track 16S rDNA phylogeny, further implicating the possible role of horizontal transfer in the evolution of (per)chlorate respiration.

Basal levels of pesticide organ chlorates in the plasma of dogs of Zaragoza, Spain

International Nuclear Information System (INIS)

Raldua Demetrio; Martinez Carmen

1997-01-01

During the month of January of 1992 they took samples of plasma in 83 dogs of the Center of Animal Protection of Zaragoza, Spain, specify their concentrations of pesticides organ chlorates. The biggest levels means were reached by the Endosulfan Sulfate and the Lindano, being also detected beta residuals and alpha - HCL, Endosulfan I and II, Dieldr and p,p - DDE. They have not been significant differences in the pesticides levels according to the sex, age or weight of it lauds animals

Modification of glassy carbon electrode with multi-walled carbon nanotubes and iron(III)-porphyrin film: Application to chlorate, bromate and iodate detection

International Nuclear Information System (INIS)

Salimi, Abdollah; MamKhezri, Hussein; Hallaj, Rahman; Zandi, Shiva

2007-01-01

In this study, multi-wall carbon nanotubes (MWCTs) is evaluated as a transducer, stabilizer and immobilization matrix for the construction of amperometric sensor based on iron-porphyrin. 5,10,15,20-Tetraphenyl-21H,23H-porphine iron(III) chloride (Fe(III)P) adsorbed on MWCNTs immobilized on the surface of glassy carbon electrode. Cyclic voltammograms of the Fe(III)P-incorporated-MWCNTs indicate a pair of well-defined and nearly reversible redox couple with surface confined characteristics at wide pH range (2-12). The surface coverage (Γ) and charge transfer rate constant (k s ) of Fe(III)P immobilized on MWCNTs were 7.68 x 10 -9 mol cm -2 and 1.8 s -1 , respectively, indicating high loading ability of MWCNTs for Fe(III)P and great facilitation of the electron transfer between Fe(III)P and carbon nanotubes immobilized on the electrode surface. Modified electrodes exhibit excellent electrocatalytic activity toward reduction of ClO 3 - , IO 3 - and BrO 3 - in acidic solutions. The catalytic rate constants for catalytic reduction of bromate, chlorate and iodate were 6.8 x 10 3 , 7.4 x 10 3 and 4.8 x 10 2 M -1 s -1 , respectively. The hydrodynamic amperometry of rotating-modified electrode at constant potential versus reference electrode was used for detection of bromate, chlorate and iodate. The detection limit, linear calibration range and sensitivity for chlorate, bromate and iodate detections were 0.5 μM, 2 μM to 1 mM, 8.4 nA/μM, 0.6 μM, 2 μM to 0.15 mM, 11 nA/μM, and 2.5 μM, 10 μM to 4 mM and 1.5 nA/μM, respectively. Excellent electrochemical reversibility of the redox couple, good reproducibility, high stability, low detection limit, long life time, fast amperometric response time, wide linear concentration range, technical simplicity and possibility of rapid preparation are great advantages of this sensor. The obtained results show promising practical application of the Fe(III)P-MWCNTs-modified electrode as an amperometric sensor for chlorate, iodate and

Modification of glassy carbon electrode with multi-walled carbon nanotubes and iron(III)-porphyrin film: Application to chlorate, bromate and iodate detection

Energy Technology Data Exchange (ETDEWEB)

Salimi, Abdollah [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Nanotechnology Research Center of University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); E-mail: absalimi@uok.ac.ir; MamKhezri, Hussein [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hallaj, Rahman [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Zandi, Shiva [Laboratory of Biochemistry, Kurdistan Medical University, Sanandaj (Iran, Islamic Republic of)

2007-06-10

In this study, multi-wall carbon nanotubes (MWCTs) is evaluated as a transducer, stabilizer and immobilization matrix for the construction of amperometric sensor based on iron-porphyrin. 5,10,15,20-Tetraphenyl-21H,23H-porphine iron(III) chloride (Fe(III)P) adsorbed on MWCNTs immobilized on the surface of glassy carbon electrode. Cyclic voltammograms of the Fe(III)P-incorporated-MWCNTs indicate a pair of well-defined and nearly reversible redox couple with surface confined characteristics at wide pH range (2-12). The surface coverage ({gamma}) and charge transfer rate constant (k {sub s}) of Fe(III)P immobilized on MWCNTs were 7.68 x 10{sup -9} mol cm{sup -2} and 1.8 s{sup -1}, respectively, indicating high loading ability of MWCNTs for Fe(III)P and great facilitation of the electron transfer between Fe(III)P and carbon nanotubes immobilized on the electrode surface. Modified electrodes exhibit excellent electrocatalytic activity toward reduction of ClO{sub 3} {sup -}, IO{sub 3} {sup -} and BrO{sub 3} {sup -} in acidic solutions. The catalytic rate constants for catalytic reduction of bromate, chlorate and iodate were 6.8 x 10{sup 3}, 7.4 x 10{sup 3} and 4.8 x 10{sup 2} M{sup -1} s{sup -1}, respectively. The hydrodynamic amperometry of rotating-modified electrode at constant potential versus reference electrode was used for detection of bromate, chlorate and iodate. The detection limit, linear calibration range and sensitivity for chlorate, bromate and iodate detections were 0.5 {mu}M, 2 {mu}M to 1 mM, 8.4 nA/{mu}M, 0.6 {mu}M, 2 {mu}M to 0.15 mM, 11 nA/{mu}M, and 2.5 {mu}M, 10 {mu}M to 4 mM and 1.5 nA/{mu}M, respectively. Excellent electrochemical reversibility of the redox couple, good reproducibility, high stability, low detection limit, long life time, fast amperometric response time, wide linear concentration range, technical simplicity and possibility of rapid preparation are great advantages of this sensor. The obtained results show promising practical

Challenges in using allylthiourea and chlorate as specific nitrification inhibitors

DEFF Research Database (Denmark)

Tatari, Karolina; Gülay, Arda; Thamdrup, B.

2017-01-01

Allylthiourea (ATU) and chlorate (ClO3-) are often used to selectively inhibit nitritation and nitratation. In this work we identified challenges with use of these compounds in inhibitory assays with filter material from a biological rapid sand filter for groundwater treatment. Inhibition...... was stronger at higher ATU levels and resulted in no NH4+ detection at 0.5 mM ATU. ClO3- at typical concentrations for inhibition assays (1-10 mM) inhibited nitratation by less than 6%, while nitritation was instead inhibited by 91% when NH4+ was supplied. On the other hand, nitratation was inhibited by 67......-71% at 10-20 mM ClO3- when NO2- was supplied, suggesting significant nitratation inhibition at higher NO2- concentrations. No chlorite (ClO2-) was detected in the effluent, and thus we could not confirm that nitritation inhibition was caused by ClO3- reduction to ClO2-. In conclusion, ATU and ClO3- should...

Efficient sodium chlorate/calcium/aluminum cathode for polymer light-emitting diodes

International Nuclear Information System (INIS)

Hu Yufeng; Shi Shengwei; Zhang Yanguang; Zhou Quanguo; Wang Lixiang; Ma Dongge; Li Xinglin

2005-01-01

A cathode system comprising an ultra thin sodium chlorate (NaCl) layer and an overlaid calcium (Ca) metal in polymer light-emitting diodes (PLEDs) based on poly[2-methoxy,5-(2-ethylhexoxy)-1,4-phenylene vinylene] is presented. It is demonstrated that introducing a thin NaCl layer further improves the brightness and electroluminescent efficiency of PLEDs. The maximum brightness and efficiency, respectively, reached 22 000 cd/m 2 and 3.5 lm/W for PLEDs with a 1 nm NaCl layer, which are much higher than 18 500 cd/m 2 and 2.0 lm/W for PLEDs with Ca cathode. The investigation of the electron injection in electron-only devices with and without a NaCl layer indicates that the introduction of the NaCl layer substantially enhances the electron injection current, which in case of PLEDs leads to the improvement of the brightness and efficiency

Widespread occurrence of (per)chlorate in the Solar System

Science.gov (United States)

Jackson, W. Andrew; Davila, Alfonso F; Sears, Derek W. G.; Coates, John D.; McKay, Christopher P.; Brundrett, Meaghan; Estrada, Nubia; Böhlke, John Karl

2015-01-01

Perchlorate (ClO− 4 ) and chlorate (ClO− 3 ) are ubiquitous on Earth and ClO− 4 has also been found on Mars. These species can play important roles in geochemical processes such as oxidation of organic matter and as biological electron acceptors, and are also indicators of important photochemical reactions involving oxyanions; on Mars they could be relevant for human habitability both in terms of in situ resource utilization and potential human health effects. For the first time, we extracted, detected and quantified ClO− 4 and ClO− 3 in extraterrestrial, non-planetary samples: regolith and rock samples from the Moon, and two chondrite meteorites (Murchison and Fayetteville). Lunar samples were collected by astronauts during the Apollo program, and meteorite samples were recovered immediately after their fall. This fact, together with the heterogeneous distribution of ClO− 4 and ClO− 3 within some of the samples, and their relative abundance with respect to other soluble species (e.g., NO− 3 ) are consistent with an extraterrestrial origin of the oxychlorine species. Our results, combined with the previously reported widespread occurrence on Earth and Mars, indicate that ClO− 4 and ClO− 3 could be present throughout the Solar System.

CATALYTIC WAVE OF CHLORATE IONS IN THE PREZENCE OF THE MOLYBDENUM (VI - 2,3-DIHYDROXYBENZALDEHYDE COMPLEX

Directory of Open Access Journals (Sweden)

Ludmila Kiriyak

2010-12-01

Full Text Available The polarographic catalytic current in acid solutions of Mo(VI, 2,3-dihydroxybenzaldehyde (2,3-DHBA and chlorate ions has been investigated. The scheme of reactions taking place in the solutions and on the electrode has been elaborated. The increase of the catalytic current is explained by the formation of the active intermediate complex [Mo(V×2,3-DHBA (ClO3-]. The rate constant of formation for the active intermediate complex K = 2.5 × 106 mol-1 × dm3 × s-1, the activation energy of reaction Ea=14.0 kcal×mol-1 and the activation entropy ∆Sa¹= -28.3 e.u. have also been determined.

Control of Sulfidogenesis Through Bio-oxidation of H₂S Coupled to (per)chlorate Reduction

Energy Technology Data Exchange (ETDEWEB)

Gregoire, Patrick [Univ. of California, Berkeley, CA (United States); Engelbrektson, Anna [Univ. of California, Berkeley, CA (United States); Hubbard, Christopher G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Metlagel, Zoltan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Csencsits, Roseann [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Auer, Manfred [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Conrad, Mark E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Thieme, Jurgen [Brookhaven National Lab. (BNL), Upton, NY (United States); Northrup, Paul [Brookhaven National Lab. (BNL), Upton, NY (United States); Coates, John D. [Univ. of California, Berkeley, CA (United States)

2014-04-04

Here, we investigate H₂S attenuation by dissimilatory perchlorate-reducing bacteria (DPRB). All DPRB tested oxidized H₂S coupled to (per)chlorate reduction without sustaining growth. H₂S was preferentially utilized over organic electron donors resulting in an enriched (34S)-elemental sulfur product. Electron microscopy revealed elemental sulfur production in the cytoplasm and on the cell surface of the DPRB Azospira suillum. We also propose a novel hybrid enzymatic-abiotic mechanism for H₂S oxidation similar to that recently proposed for nitrate-dependent Fe(II) oxidation. The results of this study have implications for the control of biosouring and biocorrosion in a range of industrial environments.

The Investigation of Chlorates as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

Science.gov (United States)

Sutter, B.; Archer, D. P.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P; Stern, J. C.;

Electrodeposition and characterization of Fe–Mo alloys as cathodes for hydrogen evolution in the process of chlorate

Directory of Open Access Journals (Sweden)

B. N. GRGUR

2005-06-01

Full Text Available Fe–Mo alloys were electrodeposited from a pyrophosphate bath using a single diode rectified AC current. Their composition and morphology were investigated by SEM, optical microscopy and EDS, in order to determine the influence of the deposition conditions on the morphology and composition of these alloys. It was shown that the electrodeposition parameters, such as: chemical bath composition and current density, influenced both the composition of the Fe–Mo alloys and the current efficiency for their deposition, while the micro and macro-morphology did not change significantly with changing conditions of alloy electrodeposition. It was found that the electrodeposited Fe–Mo alloys possessed a 0.15 V to 0.30 V lower overvoltage than mild steel for hydrogen evolution in an electrolyte commonly used in commercial chlorate production, depending on the alloy composition, i.e., the conditions of alloy electrodeposition.

Ammonium carbonate and/or bicarbonate plus alkaline chlorate oxidant for recovery of uranium values

International Nuclear Information System (INIS)

Stapp, P.R.

1983-01-01

In accordance with the present invention, uranium values are extracted from materials containing uranium in valence states lower than its hexavalent state by contacting the materials containing uranium with an aqueous alkaline leach solution containing an alkaline chlorate in an amount sufficient to oxidize at least a portion of the uranium in valence states lower than its hexavalent state to its hexavalent state. In a further embodiment of the present invention, the alkaline leach solution is an aqueous solution of a carbonate selected from the group consisting of ammonium carbonate, ammonium bicarbonate and mixtures thereof. In yet another embodiment of the present invention, at least one catalytic compound of a metal selected from the group consisting of copper, cobalt, iron, nickel, chromium and mixtures thereof adapted to assure the presence of the ionic species Cu ++ , Co ++ , Fe +++ , Ni ++ , Cr +++ and mixtures thereof, respectively, during the contacting of the material containing uranium with the alkaline leach solution and in an amount sufficient to catalyze the oxidation of at least a portion of the uranium in its lower valence states to its hexavalent state, is present

Measurement of the energy dependence of X-ray-induced decomposition of potassium chlorate.

Science.gov (United States)

Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

2013-03-21

We report the first measurements of the X-ray induced decomposition of KClO3 as a function of energy in two experiments. KClO3 was pressurized to 3.5 GPa and irradiated with monochromatic synchrotron X-rays ranging in energy from 15 to 35 keV in 5 keV increments. A systematic increase in the decomposition rate as the energy was decreased was observed, which agrees with the 1/E(3) trend for the photoelectric process, except at the lowest energy studied. A second experiment was performed to access lower energies (10 and 12 keV) using a beryllium gasket; suggesting an apparent resonance near 15 keV or 0.83 Ǻ maximizing the chemical decomposition rate. A third experiment was performed using KIO3 to ascertain the anionic dependence of the decomposition rate, which was observed to be far slower than in KClO3, suggesting that the O-O distance is the critical factor in chemical reactions. These results will be important for more efficiently initiating chemical decomposition in materials using selected X-ray wavelengths that maximize decomposition to aid useful hard X-ray-induced chemistry and contribute understanding of the mechanism of X-ray-induced decomposition of the chlorates.

Basal levels of pesticide organ chlorates in the plasma of dogs of Zaragoza, Spain; Niveles basales de plaguicidas organoclorados en el plasma de perros de Zaragoza, Espana

Energy Technology Data Exchange (ETDEWEB)

Demetrio, Raldua; Carmen, Martinez

1997-07-01

During the month of January of 1992 they took samples of plasma in 83 dogs of the Center of Animal Protection of Zaragoza, Spain, specify their concentrations of pesticides organ chlorates. The biggest levels means were reached by the Endosulfan Sulfate and the Lindano, being also detected beta residuals and alpha - HCL, Endosulfan I and II, Dieldr and p,p - DDE. They have not been significant differences in the pesticides levels according to the sex, age or weight of it lauds animals.

Natural chlorate in the environment: application of a new IC-ESI/MS/MS method with a Cl¹⁸O₃-internal standard.

Science.gov (United States)

Balaji Rao, Balaji Rao; Hatzinger, Paul B; Böhlke, John Karl; Sturchio, Neil C; Andraski, Brian J; Eckardt, Frank D; Jackson, W Andrew

2010-11-15

A new ion chromatography electrospray tandem mass spectrometry (IC-ESI/MS/MS) method has been developed for quantification and confirmation of chlorate (ClO₃⁻) in environmental samples. The method involves the electrochemical generation of isotopically labeled chlorate internal standard (Cl¹⁸O₃⁻) using ¹⁸O water (H₂¹⁸O) he standard was added to all samples prior to analysis thereby minimizing the matrix effects that are associated with common ions without the need for expensive sample pretreatments. The method detection limit (MDL) for ClO₃⁻ was 2 ng L⁻¹ for a 1 mL volume sample injection. The proposed method was successfully applied to analyze ClO₃⁻ in difficult environmental samples including soil and plant leachates. The IC-ESI/MS/MS method described here was also compared to established EPA method 317.0 for ClO₃⁻ analysis. Samples collected from a variety of environments previously shown to contain natural perchlorate (ClO₄⁻) occurrence were analyzed using the proposed method and ClO₃⁻ was found to co-occur with ClO₄⁻ at concentrations ranging from 500 mg kg⁻¹ in caliche salt deposits from the Atacama Desert in Chile. Relatively low concentrations of ClO₃⁻ in some natural groundwater samples (0.1 µg L⁻¹) analyzed in this work may indicate lower stability when compared to ClO₄⁻ in the subsurface. The high concentrations ClO₃⁻ in caliches and soils (3-6 orders of magnitude greater) as compared to precipitation samples indicate that ClO₃⁻, like ClO₄⁻, may be atmospherically produced and deposited, then concentrated in dry soils, and is possibly a minor component in the biogeochemical cycle of chlorine.

Natural chlorate in the environment: Application of a new IC-ESI/MS/MS method with a Cl18O3- internal standard

Science.gov (United States)

Rao, Balaji; Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.; Andraski, Brian J.; Eckardt, Frank D.; Jackson, W. Andrew

2010-01-01

A new ion chromatography electrospray tandem mass spectrometry (IC-ESI/MS/MS) method has been developed for quantification and confirmation of chlorate (ClO3−) in environmental samples. The method involves the electro-chemical generation of isotopically labeled chlorate internal standard (Cl18O3−) using 18O water (H218O). The standard was added to all samples prior to analysis thereby minimizing the matrix effects that are associated with common ions without the need for expensive sample pretreatments. The method detection limit (MDL) for ClO3− was 2 ng L−1 for a 1 mL volume sample injection. The proposed method was successfully applied to analyze ClO3− in difficult environmental samples including soil and plant leachates. The IC-ESI/MS/MS method described here was also compared to established EPA method 317.0 for ClO3− analysis. Samples collected from a variety of environments previously shown to contain natural perchlorate (ClO4−) occurrence were analyzed using the proposed method and ClO3− was found to co-occur with ClO4− at concentrations ranging from 500 mg kg−1 in caliche salt deposits from the Atacama Desert in Chile. Relatively low concentrations of ClO3− in some natural groundwater samples (<0.1 μg L−1) analyzed in this work may indicate lower stability when compared to ClO4− in the subsurface. The high concentrations of ClO3− in caliches and soils (3−6 orders of magnitude greater) as compared to precipitation samples indicate that ClO3−, like ClO4−, may be atmospherically produced and deposited, then concentrated in dry soils, and is possibly a minor component in the biogeochemical cycle of chlorine.

THE INFLUENCE OF THIOSEMICARBAZONE 2,3-DIHYDROXYBENZALDEHYDE ON CATALYTIC CURRENTS IN THE SYSTEM MOLYBDENUM (VI – POTASSIUM CHLORATE IN ACID SULFATE SOLUTIONS

Directory of Open Access Journals (Sweden)

Ludmila Chiriac

2011-06-01

Full Text Available The polarographic catalytic current in acid solutions of Mo(VI, thiosemicarbazone 2,3-dihydroxybenzaldehyde (TSC 2,3-DHBA and chlorate ions has been investigated. The scheme of reactions, taking place in the solutions and on the electrode, has been proposed. The increase of the catalytic current is explained by the formation of an active intermediate complex [Mo(V×TSC 2,3-DHBA (ClO-3]. The rate constant of this complex formation K = 2.56 × 106 mol-1×dm3×s-1, the activation energy Ea = 15.9 kcal×mol-1 and the reaction activation entropy ∆Sa¹ = -23.5 e.u. have been calculated.

Study on the Electrochemical Behavior of Iodide at Platinum Electrode in Potassium Chlorate Solution

Energy Technology Data Exchange (ETDEWEB)

Jung, Sang Hyuk; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Radioactive iodine-131, is one of the most hazardous fission products which could be released from fuels of nuclear reactors during the severe accident of nuclear power plants. Due to its high radioactivity, high fission yield (2.8%) and hazardous biological effects, the behavior of iodine has been taken interests in many research groups. Iodine is known to be released from the fuels as a cesium iodide form, CsI. And, as nuclear fuels are mostly placed in the water pool, it is easily dissolved in the water after released from the fuels. In water, iodide anion could be oxidized into molecular iodine. As the molecular iodine is a volatile species and the oxidizing rate is affected by many environmental facts such as pH, radiolysis products and temperature, the oxidation reaction of the iodide ion has been considered as an important chemical reaction related to the severe accident of nuclear power plants In present work, the electrochemical behavior of iodide anion was observed by using cyclic voltammetric technique in potassium chlorate solutions. We observed two different oxidation waves in the oxidation potential region. From the comparison with the previous reported results, one is regarded as the oxidation of iodide into molecular iodine. The other is evaluated to be the formation of high-valent iodine-containing compounds

Enantioselective Crystallization of Sodium Chlorate in the Presence of Racemic Hydrophobic Amino Acids and Static Magnetic Fields

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María-Paz Zorzano

2014-06-01

Full Text Available We study the bias induced by a weak (200 mT external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl hydrophobic amino acids. By applying the Fisher test to pairs of experiments with opposing magnetic field orientation we conclude, with a confidence level of 99.7%, that at the water-air interface of this saline solution there is an enantioselective magnetic interaction that acts upon racemic mixtures of hydrophobic chiral amino acids. This interaction has been observed with the three tested racemic hydrophobic amino acids: dl-Phe, dl-Try and dl-Trp, at ambient conditions and in spite of the ubiquitous chiral organic contamination. This enantioselective magnetic dependence is not observed when there is only one handedness of added chiral amino-acid, if the added amino acid is not chiral or if there is no additive. This effect has been confirmed with a double blind test. This novel experimental observation may have implications for our view of plausible initial prebiotic scenarios and of the roles of the geomagnetic field in homochirality in the biosphere.

Long Term Performance of an Arsenite-Oxidizing-Chlorate-Reducing Microbial Consortium in an Upflow Anaerobic Sludge Bed (UASB) Bioreactor

Science.gov (United States)

Sun, Wenjie; Sierra-Alvarez, Reyes; Field, Jim A.

2011-01-01

A chlorate (ClO3−) reducing microbial consortium oxidized arsenite (As(III)) to arsenate (As(V)) in an upflow anaerobic sludge-bed bioreactor over 550 d operation. As(III) was converted with high conversion efficiencies (>98%) at volumetric loadings ranging from 0.45 to 1.92 mmol As/(Lreactor d). The oxidation of As(III) was linked to the complete reduction of ClO3− to Cl− and H2O, as demonstrated by a molar ratio of approximately 3.0 mol As(III) oxidized per mole of Cl− formed and by the greatly lowered ClO3−-reducing capacity without As(III) feeding. An autotrophic enrichment culture was established from the bioreactor biofilm. A 16S rRNA gene clone library indicated that the culture was dominated by Dechloromonas, and Stenotrophomonas as well as genera within the family Comamonadaceae. The results indicate that the oxidation of As(III) to less mobile As(V) utilizing ClO3− as a terminal electron acceptor provides a sustainable bioremediation strategy for arsenic contamination in anaerobic environments. PMID:21333531

Determination of trace selenium by solid substrate-room temperature phosphorescence enhancing method based on potassium chlorate oxidizing phenyl hydrazine-1,2-dihydroxynaphthalene-3,6-disulfonic acid system

Science.gov (United States)

Liu, Jia-Ming; Cui, Xiao-Jie; Li, Lai-Ming; Fu, Geng-Min; Lin, Shao-Xian; Yang, Min-Lan; Xu, Mei-Ying; Wu, Zhi-Qun

2007-04-01

A new method for the determination of trace selenium based on solid substrate-room temperature phosphorimetry (SS-RTP) has been established. This method was based on the fact that in HCl-KCl buffer solution, potassium chlorate could oxidize phenyl hydrazine to form chloridize diazo-ion after being heated at 100 °C for 20 min, and then the diazo-ion reacted with 1,2-dihydroxynaphthalene-3,6-disulfonic acid to form red azo-compound which could emit strong room temperature phosphorescence (RTP) signal on filter paper. Selenium could catalyze potassium chlorate oxidizing the reaction between phenyl hydrazine and 1,2-dihydroxynaphthalene-3,6-disulfonic acid, which caused the sharp enhancement of SS-RTP. Under the optimum condition, the relationship between the phosphorescence emission intensity (Δ Ip) and the content of selenium obeyed Beer's law when the concentration of selenium is within the range of 1.60-320 fg spot -1 (or 0.0040-0.80 ng ml -1 with a sample volume of 0.4 μl). The regression equation of working curve can be expressed as Δ Ip = 13.12 + 0.4839 CSe(IV) (fg spot -1) ( n = 6), with correlation coefficient r = 0.9991 and a detection limit of 0.28 fg spot -1 (corresponding to a concentration range of 7.0 × 10 -13 g ml -1 Se(IV), n = 11). After 11-fold measurement, R.S.D. were 2.8 and 3.5% for the samples containing 0.0040 and 0.80 ng ml -1 of Se(IV), respectively. This accurate and sensitive method with good repeatability has been successfully applied to the determination of trace selenium in Chinese wolfberry and egg yolk with satisfactory results. The mechanism of the enhancement of phosphorescence was also discussed.

Investigation of plant hormone level changes in shoot tips of longan (Dimocarpus longan Lour.) treated with potassium chlorate by liquid chromatography-electrospray ionization mass spectrometry.

Science.gov (United States)

Susawaengsup, Chanthana; Rayanakorn, Mongkon; Wongpornchai, Sugunya; Wangkarn, Sunanta

2011-08-15

The endogenous levels of indole-3-acetic acid (IAA), gibberellins (GAs), abscisic acid (ABA) and cytokinins (CKs) and their changes were investigated in shoot tips of ten longan (Dimocarpus longan Lour.) trees for off-season flowering until 60 days after potassium chlorate treatment in comparison with those of ten control (untreated) longan trees. These analytes were extracted and interfering matrices removed with a single mixed-mode solid phase extraction under optimum conditions. The recoveries at three levels of concentration were in the range of 72-112%. The endogenous plant hormones were separated and quantified by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). Detection limits based on the signal-to-noise ratio ranged from 10 ng mL(-1) for gibberellin A4 (GA4) to 200 ng mL(-1) for IAA. Within the first week after potassium chlorate treatment, dry weight (DW) amounts in the treated longan shoot tips of four gibberellins, namely: gibberellin A1(GA1), gibberellic acid (GA3), gibberellin A19 (GA19) and gibberellin A20 (GA20), were found to increase to approximately 25, 50, 20 and 60 ng g(-1) respectively, all of which were significantly higher than those of the controls. In contrast, gibberellin A8 (GA8) obtained from the treated longan was found to decrease to approximately 20 ng g(-1)DW while that of the control increased to around 80 ng g(-1)DW. Certain CKs which play a role in leaf bud induction, particularly isopentenyl adenine (iP), isopentenyl adenosine (iPR) and dihydrozeatin riboside (DHZR), were found to be present in amounts of approximately 20, 50 and 60 ng g(-1)DW in the shoot tips of the control longan. The analytical results obtained from the two-month off-season longan flowering period indicate that high GA1, GA3, GA19 and GA20 levels in the longan shoot tips contribute to flower bud induction while high levels of CKs, IAA and ABA in the control longan contribute more to the vegetative development. Copyright © 2011

Improved Medium for Selecting Nitrate-Nonutilizing (nit) Mutants of Verticillium dahliae.

Science.gov (United States)

Korolev, N; Katan, T

1997-10-01

ABSTRACT Nitrate-nonutilizing (nit) mutants are commonly used to determine vegetative compatibility between isolates of Verticillium dahliae by complementation (heterokaryon) testing. These mutants emerge spontaneously as chlorate-resistant sectors growing out of partially restricted, wild-type colonies on chlorate-amended media. The commonly used chlorate media are based on minimal medium (MMC) or cornmeal agar (CMC), amended with potassium chlorate. nit mutants recovered on these media constituted 10 to 36%(on MMC) and 25 to 45%(on CMC) of the apparently resistant sectors. An improved water agar chlorate medium (WAC) is described that is more effective for selecting chlorate-resistant nit mutants. WAC medium consists of agar (2%), glucose (0.02%), and potassium chlorate (2 to 5%). On WAC, growth of most V. dahliae isolates was strongly inhibited, and 66 to 100%(average >80%) of the chlorate-resistant sectors formed were nit mutants. Most mutants were characterized as nit1, and about 6% as NitM.

Current LWIR HSI Remote Sensing Activities at Defence R&D Canada - Valcartier

Science.gov (United States)

2009-10-01

concentration; # If spectral signature exists; ** for e.g., potassium chlorate (other chlorates /perchlorates will be similar) A b s o rb a n c e...Spill To be measured Chlorates ** Explosive Solid MAYBE* Spill YES Nitric acid Precursor Vapor/Liquid YES* Leak/Spill YES Hydrogen peroxide

Laser-Induced Breakdown Spectroscopy: A Review of Applied Explosive Detection

Science.gov (United States)

2013-09-01

ammonium nitrate (AN)), and explosive primers and propellants ( potassium chlorate and ammonium perchlorate...trinitrotoulene, DNT = 2,4-dinitrotoluene, PETN = pentaerythritol tetranitrate, TATP = triacetone triperoxide, AN = ammonium nitrate, KClO3 = potassium chlorate ...Sucrose C12H22O11 Precursor Material Chlorate KClO3, NH4ClO4 Primer, Propellant Note: EGDM = ethylene glycol dinitrate, TNT = 2,4,6

Radiative Transfer Model for Contaminated Rough Surfaces

Science.gov (United States)

2013-02-01

reflectance of potassium chlorate and ammonium nitrate contaminated surfaces in mid-wavelength and long-wavelength infrared for detection. Our framework...obtained excellent or good results for lab measurements of potassium chlorate on most aluminum surfaces; however, ammonium nitrate on painted aluminum...misidentify potassium chlorate as ammonium nitrate and vice versa). We also observed moderate success on field data. 15. SUBJECT TERMS radiative

Genetic Variability of Macrophomina phaseolina Isolates from Dry Beans in Turkey

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Serkan Yeşil

2016-04-01

Full Text Available Charcoal rot is a soil and seed borne, economically important fungal disease on dry bean in Turkey. Twenty bean isolates of M. phaseolina collected from different locations in Turkey during 2008 and 2012 years were studied for genetic variability using random amplified polymorphic DNA (RAPD assay, chlorate sensitivity on medium supplemented with 120mM of potassium, phenotype of colony, and pathogenicity. Isolates were identified as M. phaseolina based on morhological features and PCR assays using species-specific primers (MPKF1and MPKR1. Isolates of M. phaseolina were analysed for their aggressiveness on the susceptible bean cv. Akman 98, by soil inoculation method. Isolates exhibiting a dense chlorate phenotype were chlorate-resistant, while those possessing feathery and restricted chlorate phenotypes were chlorate-sensitive. More than half of the isolates (55% were resistant to chlorate and produced dense phenotype, while 35% isolates showed feathery and two isolates (10% showed restricted growth. DNA from 20 isolates was subjected to genetic diversity analysis by the RAPD method using 14 randomly chosen 10-base random primers, and low genetic diversity (33.3% was observed among the tested isolates.

Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for Detection System Design

Science.gov (United States)

2013-11-01

example for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. 15. SUBJECT TERMS Radiative transfer...detector m-out-of-n detector Potassium chlorate Probability theory System performance Probability of detection and false alarm iii...for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. Subject Terms Radiative transfer, contaminated

Standardized Sample Preparation Using a Drop-on-Demand Printing Platform

Science.gov (United States)

2013-05-07

and Materials Ammonium nitrate (AN), methanol (MeOH), distilled water (H2O), acetonitrile, sugar, urea, and potassium chlorate (KClO3) were...various pre-determined energetic and interferent compounds. The evaluated analytes were: AN, potassium chlorate , HMX, TNT, RDX, PETN, urea, and...KClO3 molecules dissolving and then breaking into potassium and chlorate ions in H2O. An additional concern was the interaction of adjacent

Host Specialization in the Charcoal Rot Fungus, Macrophomina phaseolina.

Science.gov (United States)

Su, G; Suh, S O; Schneider, R W; Russin, J S

2001-02-01

ABSTRACT To investigate host specialization in Macrophomina phaseolina, the fungus was isolated from soybean, corn, sorghum, and cotton root tissue and soil from fields cropped continuously to these species for 15 years in St. Joseph, LA. Chlorate phenotype of each isolate was determined after growing on a minimal medium containing 120 mM potassium chlorate. Consistent differences in chlorate sensitivity were detected among isolates from different hosts and from soil versus root. To further explore genetic differentiation among fungal isolates from each host, these isolates were examined by restriction fragment length polymorphism and random amplified polymorphic DNA (RAPD) analysis. No variations were observed among isolates in restriction patterns of DNA fragments amplified by polymerase chain reaction covering the internal transcribed spacer region, 5.8S rRNA and part of 25S rRNA, suggesting that M. phaseolina constitutes a single species. Ten random primers were used to amplify the total DNA of 45 isolates, and banding patterns resulting from RAPD analysis were compared with the neighbor-joining method. Isolates from a given host were genetically similar to each other but distinctly different from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. In greenhouse tests, soybean, sorghum, corn, and cotton were grown separately in soil infested with individual isolates of M. phaseolina that were chosen based on their host of origin and chlorate phenotype. Root colonization and plant weight were measured after harvesting. More colonization of corn roots occurred when corn was grown in soil containing corn isolates compared with isolates from other hosts. However, there was no host specialization in isolates from soybean, sorghum, or cotton. More root colonization in soybean occurred with chlorate-sensitive than with chlorate-resistant isolates.

RF Magnetic Field Uniformity of Rectangular Planar Coils for Resonance Imaging

Science.gov (United States)

2016-02-04

magnetic, potassium chlorate , nuclear quadrupole resonance, uniform field, coil, surface coil I. INTRODUCTION QR is a magnetic resonance phenomenon...material that will be used is this investigation is potassium chlorate (KCLO3). This paper utilizes the NQR signals detection from KCLO3 to determine the...frequency of potassium chlorate (KCLO3), and matched to a 50 ohm input impedance using L-network circuit of capacitors. Fig.1 shows a diagram of the

Prototype Scale Development of an Environmentally Benign Yellow Smoke Hand-Held Signal Formulation Based on Solvent Yellow 33

Science.gov (United States)

2013-04-15

safely implemented in several Navy signaling devices.21,22 ■ EXPERIMENTAL SECTION Materials. Potassium chlorate (MIL-P-150D, grade B, Class 7), sugar...the potassium chlorate overnight at 60 °C, formulations were prepared in 300 g batches by blending all ingredients according to their respective...damage. ■ ASSOCIATED CONTENT *S Supporting Information Particle size analyses for potassium chlorate (Table S1 and Figure S1), sugar (Table S2 and

Preparation of Chemical Samples On Relevant Surfaces Using Inkjet Technology

Science.gov (United States)

2013-04-01

printer. For the results in Section 3.1, 32 g/L of potassium chlorate was printed on a 2 × 2 in. pattern of aluminum substrate. All of the printed...maintained at 80 °C. Figures 6 and 7 are photographs of potassium chlorate crystals deposited with and without heating. Both photographs are at the...submicron size range. Figures B-1 and B-2 shows potassium chlorate crystals deposited with and without heating. Both photographs are at the same

Evaluation of Oxygen Concentrators and Chemical Oxygen Generators at Altitude and Temperature Extremes

Science.gov (United States)

2015-04-22

Current COGs typically contain one or more of the following solid compounds: sodium chlorate , sodium perchlorate, potassium superoxide, or...produces heat. The COGs evaluated in this study are the O2PAK, TraumAid, and BOB. 3.2.1 O2PAK. The main ingredient in the O2PAK is sodium chlorate ...In 1902, the Lancet reported on Kamm’s oxygen generator invention for medical use. The device used chlorate cakes and manganese oxide and, when

Coulometrische titration von hypochloriten und chloraten.

Science.gov (United States)

Gründler, P; Holzapfel, H

1970-03-01

Hypochlorite was determined by direct coulometric titration with iron(II) in an acetate buffered solution. Chlorate was titrated with titanium(III) in 2M hydrochloric acid. Amperometric indication with one and two electrodes, respectively, was used. Mixtures of hypochlorites and chlorates, e.g., in industrial electrolytes, may be analysed. On a déterminé l'hypochlorite par titrage coulométrique direct avec le fer(II) dans une solution tamponnée à l'acétate. On a titré le chlorate avec le titane(III) en acide chlorhydrique 2M. On a utilisé l'indication ampérométrique une et deux électrodes respectivement. On peut analyser des mélanges d'hypochlorites et de chlorates, par exemple dans des électrolytes industriels.

49 CFR 173.54 - Forbidden explosives.

Science.gov (United States)

2010-10-01

... dimension of which exceeds 23 mm (0.906 inch), or a toy torpedo containing a mixture of potassium chlorate... subpart. (b) An explosive mixture or device containing a chlorate and also containing: (1) An ammonium...

Counterterrorism: U.S. Agencies Face Challenges Countering the Use of Improvised Explosive Devices in the Afghanistan/Pakistan Region

Science.gov (United States)

2012-07-12

make IEDs. According to DOD, other products available in Pakistan—such as potassium chlorate , used in making matches, and urea, another commonly used...IED precursor chemicals. According to State officials, other substitutes for CAN, including potassium chlorate and urea, are exported by countries

Combating Terrorism: State Should Enhance Its Performance Measures for Assessing Efforts in Pakistan to Counter Improvised Explosive Devices

Science.gov (United States)

2012-05-01

readily switch to another precursor chemical to make IEDs. According to DOD, other products available in Pakistan such as potassium chlorate , used in...chemicals. According to State officials, other substitutes for CAN, including urea and potassium chlorate , are exported by countries other than Pakistan

Effect of Potassium Chlorate on the Treatment of Domestic Sewage by Achieving Shortcut Nitrification in a Constructed Rapid Infiltration System

Directory of Open Access Journals (Sweden)

Qinglin Fang

2018-04-01

Full Text Available A constructed rapid infiltration (CRI system is a new type of sewage biofilm treatment technology, but due to its anaerobic zone it lacks the carbon sources and the conditions for nitrate retention, and its nitrogen removal performance is very poor. However, a shortcut nitrification–denitrification process presents distinctive advantages, as it saves oxygen, requires less organic matter, and requires less time for denitrification compared to conventional nitrogen removal methods. Thus, if the shortcut nitrification–denitrification process could be applied to the CRI system properly, a simpler, more economic, and efficient nitrogen removal method will be obtained. However, as its reaction process shows that the first and the most important step of achieving shortcut nitrification–denitrification is to achieve shortcut nitrification, in this study we explored the feasibility to achieve shortcut nitrification, which produces nitrite as the dominant nitrogen species in effluent, by the addition of potassium chlorate (KClO3 to the influent. In an experimental CRI test system, the effects on nitrogen removal, nitrate inhibition, and nitrite accumulation were studied, and the advantages of achieving a shortcut nitrification–denitrification process were also analysed. The results showed that shortcut nitrification was successfully achieved and maintained in a CRI system by adding 5 mM KClO3 to the influent at a constant pH of 8.4. Under these conditions, the nitrite accumulation percentage was increased, while a lower concentration of 3 mM KClO3 had no obvious effect. The addition of 5mM KClO3 in influent presumably inhibited the activity of ammonia-oxidizing bacteria (AOB and nitrite-oxidizing bacteria (NOB, but inhibition of nitrite-oxidizing bacteria (NOB was so strong that it resulted in a maximum nitrite accumulation percentage of up to over 80%. As a result, nitrite became the dominant nitrogen product in the effluent. Moreover, if the

Effect of Potassium Chlorate on the Treatment of Domestic Sewage by Achieving Shortcut Nitrification in a Constructed Rapid Infiltration System.

Science.gov (United States)

Fang, Qinglin; Xu, Wenlai; Yan, Zhijiao; Qian, Lei

2018-04-04

A constructed rapid infiltration (CRI) system is a new type of sewage biofilm treatment technology, but due to its anaerobic zone it lacks the carbon sources and the conditions for nitrate retention, and its nitrogen removal performance is very poor. However, a shortcut nitrification–denitrification process presents distinctive advantages, as it saves oxygen, requires less organic matter, and requires less time for denitrification compared to conventional nitrogen removal methods. Thus, if the shortcut nitrification–denitrification process could be applied to the CRI system properly, a simpler, more economic, and efficient nitrogen removal method will be obtained. However, as its reaction process shows that the first and the most important step of achieving shortcut nitrification–denitrification is to achieve shortcut nitrification, in this study we explored the feasibility to achieve shortcut nitrification, which produces nitrite as the dominant nitrogen species in effluent, by the addition of potassium chlorate (KClO₃) to the influent. In an experimental CRI test system, the effects on nitrogen removal, nitrate inhibition, and nitrite accumulation were studied, and the advantages of achieving a shortcut nitrification–denitrification process were also analysed. The results showed that shortcut nitrification was successfully achieved and maintained in a CRI system by adding 5 mM KClO₃ to the influent at a constant pH of 8.4. Under these conditions, the nitrite accumulation percentage was increased, while a lower concentration of 3 mM KClO₃ had no obvious effect. The addition of 5mM KClO₃ in influent presumably inhibited the activity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), but inhibition of nitrite-oxidizing bacteria (NOB) was so strong that it resulted in a maximum nitrite accumulation percentage of up to over 80%. As a result, nitrite became the dominant nitrogen product in the effluent. Moreover, if the shortcut

Chloriet, chloraat en bromaat in drink- en oppervlaktewater: Voorkomen, herkomst en gezondheidsaspecten

NARCIS (Netherlands)

Versteegh JFM; Neele J; Cleven RFMJ

1992-01-01

Chlorate and chlorite exist in surface water especially in the rivers Meuse and Rhine. The average concentration of chlorite and chlorate in river water varies from 10 - 40 mug/l during the six months monitoring program in 1991/1992. The concentrations are lowered during dune infiltration and

Direct injection ion chromatography for the control of chlorinated drinking water: simultaneous estimation of nine haloacetic acids and quantitation of bromate, chlorite and chlorate along with the major inorganic anions.

Science.gov (United States)

Garcia-Villanova, Rafael J; Raposo Funcia, César; Oliveira Dantas Leite, M Vilani; Toruño Fonseca, Ivania M; Espinosa Nieto, Miguel; Espuelas India, Javier

2014-09-01

Most methods for the analysis of haloacetic acids published in recent years are based on ion chromatography with direct injection, employing a gradient elution with potassium hydroxide (KOH). This work reports the exploration of an alternative eluent, a buffer of sodium carbonate/sodium hydrogen carbonate, aimed at the simultaneous analysis of nine haloacetic acids along with bromate, chlorite and chlorate. The alternative of both a less alkaline eluent and a lower temperature of operation may prevent the partial decomposition of some of the haloacetic acids during the analytical process, especially the more vulnerable brominated ones. Gradient elution at temperature of 7 °C yielded the best results, with an acceptable separation of 17 analytes (which includes the major natural inorganic anions) and a good linearity. Precision ranges from 0.3 to 23.4 (% V.C.), and detection limits are within units of μg L⁻¹, except for tribromoacetic acid - somewhat high in comparison with those of the official methods. Nonetheless, with the basic instrumentation setup herein described, this method may be suitable for monitoring when the drinking water treatments are to be optimized. This is especially interesting for small communities or for developing/developed countries in which regulations on disinfection by-products others than trihalomethanes are being addressed.

Investigating a Drop-on-Demand Microdispenser for Standardized Sample Preparation

Science.gov (United States)

2012-09-01

potassium chlorate were obtained from Sigma-Aldrich. 1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7- tetranitro-tetrazocine (HMX), 2,4,6... potassium chlorate , HMX, TNT, RDX, PETN, urea, and sugar. The analyte of interest was dissolved in the appropriate solvent and then diluted to various

Chloroxyanion residue on seeds and sprouts after chlorine dioxide sanitation of alfalfa seed

Science.gov (United States)

The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and on the presence of chlorate and perchlorate residues in seed rinse, seed soak, and in alfalfa sprouts was determined. Chlorate residues in 20000 ppm cal...

Biodegradation of Perchlorate in Laboratory Reactors Under Different Environmental Conditions

Science.gov (United States)

2010-07-01

21 Figure 8. Initial and final mass of perchlorate, chloride, and chlorate ...is the soluble anion associated with the solid salts of ammonium, potassium , and sodium perchlorate. Large-scale production of ammonium perchlorate...ions. Most perchlorate-respiring microorganisms are capable of functioning under varying environmental conditions and use oxygen, nitrate, and chlorate

Copper and silver halates

CERN Document Server

Woolley, EM; Salomon, M

2013-01-01

Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

Stress-induced rearrangement of Fusarium retrotransposon sequences.

Science.gov (United States)

Anaya, N; Roncero, M I

1996-11-27

Rearrangement of fusarium oxysporum retrotransposon skippy was induced by growth in the presence of potassium chlorate. Three fungal strains, one sensitive to chlorate (Co60) and two resistant to chlorate and deficient for nitrate reductase (Co65 and Co94), were studied by Southern analysis of their genomic DNA. Polymorphism was detected in their hybridization banding pattern, relative to the wild type grown in the absence of chlorate, using various enzymes with or without restriction sites within the retrotransposon. Results were consistent with the assumption that three different events had occurred in strain Co60: genomic amplification of skippy yielding tandem arrays of the element, generation of new skippy sequences, and deletion of skippy sequences. Amplification of Co60 genomic DNA using the polymerase chain reaction and divergent primers derived from the retrotransposon generated a new band, corresponding to one long terminal repeat plus flanking sequences, that was not present in the wild-type strain. Molecular analysis of nitrate reductase-deficient mutants showed that generation and deletion of skippy sequences, but not genomic amplification in tandem repeats, had occurred in their genomes.

Technology Challenges in Solid Energetic Materials for Micro Propulsion Applications

Science.gov (United States)

2009-11-01

pressure and low temperature. NAB is used with/without lead rhodanide/ potassium chlorate /nitrocellulose (RK) to aid in the ignition. The impulse thrust...NAB boron/ potassium nitrate PETN Pentaerythritol tetranitrate RK lead rhodanide/ potassium chlorate /nitrocellulose Zr zirconium ZPP zirconium... potassium nitrate (NAB) propellant was selected over HTPB/AP and glycidyle azide polymer (GAP), because of its ignition capability at atmospheric

Background Perchlorate Source Identification Technical Guidance

Science.gov (United States)

2013-12-01

perchlorate was at one time used to treat thyroid dysfunction, particularly a hyperthyroidism condition known as Grave’s disease . Ecological impacts...chlorates are used for pulp and paper bleaching, non-selective contact herbicide application, and plant defoliation for cotton, sunflowers...safflower, rice, and chili peppers (OMRI, 2000). Effluents from pulp mills have been reported to contain chlorate (1 to 70 mg/L) (Warrington, 2002), but

Defeating Improvised Explosive Devices (IED): Asymmetric Threats and Capability Gaps

Science.gov (United States)

2011-03-23

City, Oklahoma bombings in 1995. In order to adapt and avoid detection, terrorists are exploring other options, such as using potassium chlorate ...white, odorless powder) or sodium chlorate (yellow, odorless powder) when making IEDs. High-profile, historic examples include the London attacks...and potassium nitrate. It is the main ingredient found in fireworks. In the past it was used as a propellant powder in ammunition, http

An Examination of Binder Systems and Their Influences on Burn Rates of High-Nitrogen Containing Formulations

Science.gov (United States)

2011-01-01

sought-after to advance existing HHS technology. Currently existing HHS candle formulations contain significant amounts of potassium perchlorate...Defense spends tens of billions of dollars annually on per- chlorate remediation efforts. Therefore, efforts to elimi- nate perchlorate from military...develop per- chlorate -free formulations of the M126A1 red star para- chute. To maximize the performance of these formula- tions, KClO4 was replaced

Demonstration of the Replacement of the Dyes and Sulfur in the M18 Red and Violet Smoke Grenades

Science.gov (United States)

2008-09-10

The liquid sucrose and decomposition products react with the solid potassium chlorate, thus liberating heat. At around 250oC, magnesium carbonate...begins to decompose endothermally into carbon dioxide and magnesium oxide . At approximately 350oC, the remaining potassium chlorate decomposes to...one port for particle sizing, and two ports for sampling hydrochloric acid (HCl). A dual-line filtered and heated sampling and manifold has been

High-Nitrogen-Based Pyrotechnics: Development of Perchlorate-Free Green-Light Illuminants for Military and Civilian Applications

Science.gov (United States)

2012-01-01

Table 1. Magnesium served as the main fuel in the formulation, barium nitrate and potassium per- chlorate served as the oxidizers, and dechlorane plus...course of the investigation needed to be changed. Although the initial investigation set out to remove potassium per- chlorate oxidizer from the M195 HHS...become a concern of the US Department of Defense is the “perchlorate issue.” Potassium perchlorate and ammonium perchlorate oxidizers, once believed to be

Promising Properties and System Demonstration of an Environmentally Benign Yellow Smoke Formulation for Hand-Held Signals

Science.gov (United States)

2014-04-18

Yellow 33 (colored smoke dye), sucrose (fuel), potassium chlorate (oxidizer), stearic acid ( lubr icant , process ing aid) , and hydromagnes i te (Mg5(CO3...flight test. ■ EXPERIMENTAL SECTION Materials. Potassium chlorate (MIL-P-150D, grade B, Class 7) and sugar (MIL-AA-20135D, Type 1, Style C) were...consisting of 33.0 wt % potassium nitrate, 24.5 wt % silicon, 20.8 wt % black iron oxide, 12.3 wt % aluminum, 3.8 wt % charcoal, and 5.6 wt % nitrocellulose

Explosion properties of aluminum/oxidizer mixtures in a closed vessel; Aluminium/sankazai kongobutsu no mippei yokinai deno bakuhatsu tokusei

Energy Technology Data Exchange (ETDEWEB)

Miyake, A.; Aochi, T.; Shiraki, K.; Ogawa, T. [Yokohama National University, Yokohama (Japan). Faculty of Engineering

1995-10-31

In order to understand explosion properties of aluminum/oxidized mixtures for firework a closed vessel test was carried out, and pressure profile and ignition delay time were measured. It was found that flake aluminum (Al(f))/oxidized mixtures were more reactive and showed higher pressure values than those of atomized aluminum (Al(a))/oxidized mixtures. At a positive oxygen balance region Al(f)/oxidized mixtures showed a good agreement with the theoretically predicted values of combustion pressure at a constant volume. The combustion parameters with equilibrium calculation of aluminum/potassium chlorate showed almost the same ones of aluminum/potassium perchlorate. Furthermore, to investigate the influence of particle diameter of potassium chlorate on the explosion properties of Al(f)/potassium chlorate mixtures, the same kind of closed vessel test was performed and it was found that the mixtures became less sensitive and reactive with the increase of particle diameter. 17 refs., 7 figs., 2 tabs.

Vibrational and Thermal Properties of Oxyanionic Crystals

Science.gov (United States)

Korabel'nikov, D. V.

2018-03-01

The vibrational and thermal properties of dolomite and alkali chlorates and perchlorates were studied in the gradient approximation of density functional theory using the method of a linear combination of atomic orbitals (LCAO). Long-wave vibration frequencies, IR and Raman spectra, and mode Gruneisen parameters were calculated. Equation-of-state parameters, thermodynamic potentials, entropy, heat capacity, and thermal expansion coefficient were also determined. The thermal expansion coefficient of dolomite was established to be much lower than for chlorates and perchlorates. The temperature dependence of the heat capacity at T > 200 K was shown to be generally governed by intramolecular vibrations.

Electrogeneration of disinfection byproducts at a boron-doped diamond anode with resorcinol as a model substance

International Nuclear Information System (INIS)

Li Hongna; Ni Jinren

2012-01-01

Highlights: ► DBPs formation was studied in BDD cell with several organics. ► Accumulated chloroform was wholly mineralized in the electrolysis. ► Chlorate produced was oxidized to perchlorate as electrolysis continued. ► Inorganic byproducts should be carefully watched in electrolysis with BDD. ► Resorcinol had the greatest reactivity for DBPs production in the studied precursors. - Abstract: Electrochemical disinfection in chloride electrolyte with a boron-doped diamond (BDD) electrode has unique advantages due to the high oxidizing ability of active chlorine and reactive oxygen species produced under certain conditions in the electrolysis. However, the electrogeneration of disinfection byproducts (DBPs) in the presence of organics in the system has rarely been reported. In this study, the discontinuous formation of DBPs (chloroform, chlorate and perchlorate) was investigated in model water containing chloride electrolyte (10 mM) with a BDD anode in the presence of resorcinol (0.5 mM) at a current density of 20 mA cm −2 . We found that the formation of chloroform and chlorate increased with the free available chlorine production at the beginning and reached peaks at 2 h (0.01 mM), 4 h (1.67 mM), respectively. When the free available chlorine started to decrease, chloroform was gradually mineralized and chlorate was oxidized to perchlorate due to the strong and non-selective oxidizing ability of the BDD. After electrolysis for 25 h, only perchlorate was left (3.84 mM). So inorganic DBPs should be carefully watched in the BDD system. The chloride concentration in the electrolyte affected the production of all three DBPs, due to its influence on the active chlorine production. Organic was not involved in the chlorate and perchlorate formation, and thus the resorcinol concentration had little impact on inorganic DBPs. DBPs formation at acidic pH was lower than that in the basic condition, mainly due to the different forms of resorcinol and chlorine

Evaluation of oxalate decarboxylase and oxalate oxidase for industrial applications.

Science.gov (United States)

Cassland, Pierre; Sjöde, Anders; Winestrand, Sandra; Jönsson, Leif J; Nilvebrant, Nils-Olof

2010-05-01

Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation. Oxalate decarboxylase degraded oxalic acid faster than oxalate oxidase in eight of the filtrates, while oxalate oxidase performed better in one filtrate. One of the filtrates inhibited both enzymes. The potential inhibitory effect of selected compounds on the enzymatic activity was tested. Oxalate decarboxylase was more sensitive than oxalate oxidase to hydrogen peroxide. Oxalate decarboxylase was not as sensitive to chlorate and chlorite as oxalate oxidase. Up to 4 mM chlorate ions, the highest concentration tested, had no inhibitory effect on oxalate decarboxylase. Analysis of the filtrates suggests that high concentrations of chlorate present in some of the filtrates were responsible for the higher sensitivity of oxalate oxidase in these filtrates. Oxalate decarboxylase was thus a better choice than oxalate oxidase for treatment of filtrates from chlorine dioxide bleaching.

Assessment of residual active chlorine in sodium hypochlorite solutions after dissolution of porcine incisor pulpal tissue.

Science.gov (United States)

Clarkson, R M; Smith, T K; Kidd, B A; Evans, G E; Moule, A J

2013-12-01

In previous studies, surfactant-containing Hypochlor brands of sodium hypochlorite showed better tissue solubilizing abilities than Milton; differences not explained by original active chlorine content or presence of surfactant. It was postulated that exhaustion of active chlorine content could explain differences. This study aimed to assess whether Milton's poorer performance was due to exhaustion of active chlorine. Parallel experiments assessed the influence of titration methods, and the presence of chlorates, on active chlorine measurements. Time required to dissolve one or groups of 10 samples of porcine incisor pulp samples in Milton was determined. Residual active chlorine was assessed by thermometric titration. Iodometric and thermometric titration was carried out on samples of Milton. Chlorate content was also measured. Dissolution of single and 10 pulp samples caused a mean loss of 1% and 3% respectively of active chlorine, not being proportional to tissue dissolved. Thermometric ammonium ion titration resulted in 10% lower values than iodometric titration. Chlorate accounted for much of this difference. Depletion of active chlorine is not the reason for differences in tissue dissolving capabilities of Milton. Thermometric ammonium ion titration gives more accurate measurement of active chlorine content than iodometric titration. © 2013 Australian Dental Association.

Electrochemical and Integrated Process Opportunities for On-Site/On-Demand Generation of Chlorine Dioxide - Final Report - 08/02/1996 - 08/01/1999; FINAL

International Nuclear Information System (INIS)

Tatarchuk, Bruce J.; Krishnagopalan, G.; Nickell, Ryan A.

2000-01-01

Due to continued evidence of environmental harm from elemental chlorine bleaching, the nation's paper industry continues to search for cost effective alternative bleaching. A practical and cost effective bleaching alternative is chlorine dioxide manufactured entirely from sodium chlorate. Sodium chlorate is produced by the electrolysis of brine in an undivided cell with steel plate cathodes and dimensionally stable anodes. Although the overpotential at the anode is only 50 mV, the cathodic overpotential is 940 mV. Thus, nearly one volt of electricity is wasted in driving hydrogen evolution at the cathode. Auburn University's Center for Microfibrous Materials Manufacturing has demonstrated that high performance, three dimensional, microfibrous electrodes can improve the performance of capacitors, batteries, hybrid power cells, and electrolysis electrodes in a variety of applications. The goal of this research was to apply this technology to a chlorate cell's cathode and reduce the overpotential between 200 and 400 mV. An economic analysis of the industry has shown that for every 100 mV reduction in overpotential,$100 per square meter of electrode can be saved annually. Due to their enhanced surface area over plates, corrosion of microfibrous electrodes is a major issue in this research. Samples based on chromium protection (i.e. stainless steel) have proved unfeasible for chlorate application. However, samples based on stainless steel and nickel show dramatic performance improvements over industry status quo in chlor-alkali application. Building microfibrous electrodes on a titanium base protected with a silver coating alleviates the corrosion problem and provides 100 mV or more of overpotential reduction. Further reduction is realized by impregnating silver-titanium microfibrous mesh with a PVDF binder and dispersed platinum on activated carbon. The resulting electrodes are mechanically sound, active towards hydrogen evolution, and hold promise for practical

Chlorine dioxine DBPs (disinfection by-products in drinking water

Directory of Open Access Journals (Sweden)

C. Lasagna

2013-01-01

Full Text Available Since the 1970s it has been well known that, though water for human consumption is generally disinfected before being distributed along the network, the use of chemicals results in the formation of many different Disinfection By-Products (DBPs. In the case of chlorine dioxide, the most important and represented DBPs are chlorite and chlorate: after an introduction concerning the current Italian regulation on this subject, in the experimental part the results of a 7-year minitoring campaign, concerning water of different origin collected from taps in various Italian regions, are shown. The analytical technique used for the determination of chlorite and chlorate was Ion Chromatography. The result obtained are finally discussed.

Thermal decomposition and isomerization of cis-permethrin and beta-cypermethrin in the solid phase.

Science.gov (United States)

González Audino, Paola; Licastro, Susana A; Zerba, Eduardo

2002-02-01

The stability to heart of cis-permethrin and beta-cypermethrin in the solid phase was studied and the decomposition products identified. Samples heated at 210 degrees C in an oven in the dark showed that, in the absence of potassium chlorate (the salt present in smoke-generating formulations of these pyrethroids), cis-permethrin was not isomerized, although in the presence of that salt, decomposition was greater and thermal isomerization occurred. Other salts of the type KXO3 or NaXO3, with X being halogen or nitrogen, also led to a considerable thermal isomerization. Heating the insecticides in solution in the presence of potassium chlorate did not produce isomerization in any of the solvents assayed. Salt-catalysed thermal cis-trans isomerization was also found for other pyrethroids derived from permethrinic or deltamethrinic acid but not for those derived from chrysanthemic acid. The main thermal degradation processes of cis-permethrin and beta-cypermethrin decomposition when potassium chlorate was present were cyclopropane isomerization, ester cleavage and subsequent oxidation of the resulting products. Permethrinic acid, 3-phenoxybenzyle chloride, alcohol, aldehyde and acid were identified in both cases, as well as 3-phenoxybenzyl cyanide from beta-cypermethrin. A similar decomposition pattern occurred after combustion of pyrethroid fumigant formulations.

Ex situ investigation of the step bunching on crystal surfaces by atomic force microscopy

Science.gov (United States)

Krasinski, Mariusz J.

1997-07-01

We are describing ex situ observation of step bunching on the surfaces of solution grown potassium dihydrogen phosphate (KDP) and sodium chlorate monocrystals. The measurements have been done with the use of atomic force microscope. The use of this equipment allowed us to see directly the structure of macrosteps. Observation confirmed the existence of step pinning which is one of the proposed mechanisms of step bunching. Despite the very high resolution of AFM it was not possible to determine the nature of pinning point. The monatomic steps on KDP and sodium chlorate crystal surfaces are mainly one unit cell high what seems to be the result of the steps pairing. The origin of observed step pattern is discussed in frames of existing theories.

A Reaction Involving Oxygen and Metal Sulfides.

Science.gov (United States)

Hill, William D. Jr.

1986-01-01

Describes a procedure for oxygen generation by thermal decomposition of potassium chlorate in presence of manganese dioxide, reacted with various sulfides. Provides a table of sample product yields for various sulfides. (JM)

Disinfection aboard cruise liners and naval units: formation of disinfection by-products using chlorine dioxide in different qualities of drinking water.

Science.gov (United States)

Ufermann, Petra; Petersen, Hauke; Exner, Martin

2011-12-01

The world-wide deployment of cruise liners and naval units has caused an increased need for the disinfection of drinking water. The main cause for this is the unknown quality of drinking water in foreign harbours--besides the formation of bio-films due to the climatically disadvantageous conditions in the operational area. Water conduits on board are currently disinfected with calcium hypochlorite in case of microbiological contamination. Chemical and physical analyses after disinfection with calcium hypochlorite have shown that organic by-products consisting of trihalomethanes develop in considerable amounts during disinfection. Furthermore, the method is susceptible to handling errors and thus often leads to insufficient disinfection results. Hitherto, the use of other disinfection methods allowed by government regulations, especially chlorine dioxide, is not widely spread. Unlike disinfection with calcium hypochlorite, chlorine dioxide does not lead to the formation of trihalomethanes. Typical disinfection by-products (DBP) are the anions chlorite and chlorate, which are formed in oxidative processes. The formation conditions of these anions have not yet been elucidated. For this reason, the probability of the generation of inorganic by-products after disinfection with chlorine dioxide has been determined, and their occurrence in drinking water on board has been examined with respect to a possible correlation between water quality and the formation of chlorate and chlorite. Therefore, a chromatographic method was developed and validated in order to determine the periodical development of chlorate and chlorite from chorine dioxide in purified water at different pH-values as well as in actual drinking water samples from water conduits on board. The formation of the by-products chlorite and chlorate after disinfection with chlorine dioxide is influenced neither by pH-value nor by chemical properties of the disinfected water. Considering the examined conditions

An Efficient Composition for Bengal Lights.

Science.gov (United States)

Comet, M.; Schreyeck, L.; Fuzellier, H.

2002-01-01

Reports the discovery of an efficient base composition for making bengal lights that is obtained with potassium chlorate and thiourea. Combining this mixture with appropriate flame coloring can produce several impressive bengal lights. (DDR)

Recoil effects of neutron-irradiated metal salts

International Nuclear Information System (INIS)

Lee, B.H.

1980-01-01

The distribution of sup(56)Mn and sup(38)Cl recoil species following radiative neutron capture permanganates, chlorates and perchlorates has been investigated by using ion-exchange chromatography method. The whole of the sup(56)Mn radioactivity in permanganates appeared in two valence states, the sup(38)Cl radioactivity in chlorates in two valence states and also the sup(38)Cl radioactivity in perchlorates in three valence states. Recoil energy was calculated. The internal conversion of sup(38m)Cl isomer transition affects the retention value. The greater the radii of the cation, the higher is the probability of the recoil atom breaking through the secondary cage. In ammonium salt, the ammonium ion behaves as a reducing agent. Crystal structures with their greater free space have shown by retention. (Author)

Making Sparklers: An Introductory Laboratory Experiment

Science.gov (United States)

Keeney, Allen; Walters, Christina; Cornelius, Richard D.

1995-07-01

A laboratory experiment consisting of the preparation of sparklers has been developed as part of a project which organizes the general chemistry sequence according to subjects with which students are familiar. This laboratory makes use of oxidation/reduction chemistry to produce a product familiar to students. The result is a mixture rather than a compound, but the composition must be carefully measured to produce a sparkler that will stay lit and produce sparks. The dramatic reaction may be the most impressive and memorable experience that students encounter in the laboratory. Sparklers are formulated from iron, magnesium, and aluminum powders, plus potassium chlorate and barium nitrate held on thick iron wire by a starch paste. At elevated temperatures metal nitrates and chlorates decompose to produces gases, providing the necessary force to eject bits of powdered, burning metal into the air.

Media for efficient generating nitrate- - nonutilizing (NIT) mutants of Verticillium dahliae, Colletotrichum gloeosporioides, Colletotrichum lindemuthianum and Fusarium oxysporum.

NARCIS (Netherlands)

Rataj-Guranowska, M.; Pieczul, K.; Nowak, E.; Hiemstra, J.A.; Drapikowska, M.

2001-01-01

The effect of several media amended wit potassium chlorate (1.5% and 6%) on generation of nit mutants, especially nit M mutants from Verticillium dahliae, Colletotrichum gloeosporioides, Colletotrichum lindemuthianum and Fusarium oxysporum were studied. For all species minimal medium with 6%

Chloroxyanion residues in cantaloupe and tomatoes after chlorine dioxide gas sanitation

Science.gov (United States)

Chlorine dioxide gas is effective at cleansing fruits and vegetables of bacterial pathogens and(or) rot organisms, but few data are available on chemical residues remaining subsequent to chlorine gas treatment. Therefore, studies were conducted to quantify chlorate and perchlorate residues after tom...

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Science.gov (United States)

2010-10-01

... Vent F Yes .55-1(e) NA NA G Potassium hydroxide solution, see Caustic potash solution iso-Propanolamine... chlorate solution (50% or less) Atmos. Amb. III 1 i 2 i Integral Gravity Open Open II G-1 NR Vent N No .50...

Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater.

Science.gov (United States)

Jasper, Justin T; Yang, Yang; Hoffmann, Michael R

2017-06-20

Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10-30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO 2 /IrO 2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO 2 /IrO 2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine).

The tropical fruit and nut collections and research activities at the USDA-ARS Pacific Basin Agricultural Research Center, Tropical Plant Genetic Resource and Disease Research unit

Science.gov (United States)

In Hawaii, consistency and reliability are important factors determining the success of a crop, for example, longan generated the highest income return for the farmers among the Sapindaceae (lychee, longan and rambutan) group in 2006 because of the use of potassium chlorate for off-season production...

Effect of Defects on Mechanisms of Initiation and Energy Release in Energetic Molecular Crystals

Science.gov (United States)

2011-02-10

also examined other energetic and reactive materials such as 1,3,5,7 cyclooctatetraene (COT) and potassium chlorate (KClO3) and ringed hydrocarbons...the space charge induced by the diffusive separation of potassium and fluoride ions in the shock wave affects polarization currents and depends on

The Detection of Evolved Oxygen from the Rocknest Eolian Bedform Material by the Sample Analysis at Mars(SAM) instrument at the Mars Curiosity Landing Site

Science.gov (United States)

Sutter, B.; Archer, D.; Ming, D.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A.; Mahaffy, P.; Stern, J.; Navarro-Gonzalex, R.;

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

Science.gov (United States)

Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

2017-03-01

Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtained graphite intercalation compounds have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), micro-Raman spectroscopy ( μ-RS), and thermal analysis (TGA). Delamination and pre-expansion phenomena were observed only for nitric acid, sodium chlorate, and hydrogen peroxide, while the presence of strong oxidizers (KMnO4, K2Cr2O7) led to stable graphite intercalation compounds. The largest content of intercalated bisulfate is achieved in the intercalated compounds obtained from NaIO4 and NaClO3.

Study of the sulfuric acid leaching and bacterial leaching of low grade uranium ore by orbital shaker experiment

International Nuclear Information System (INIS)

Li Guangyue; Liu Yulong; Wang Yongdong; Ding Dexin

2009-01-01

The sulphuric acid leaching and bacteria leaching by orbital shaker experiments were conducted for the low grade uranium ore from a uranium mine in Guangdong Province. The results show that, when the concentration of sulphuric acid and that of slurry were 30 g/L and 25%, respectively, the conditions were most favourable for sulphuric acid leaching and the rate of leaching reached 92.92%, that, when pH value was 1.5, inoculation amount, 10%, concentration of slurry, 10%, the conditions were most favourable for bacteria leaching and the rate of leaching reached 95.93%, that, compared with sulphuric acid leaching, bacteria leaching decreased sulphuric acid consumption by 17.2% and increased the rate of leaching by 3%, and that, under the most favourable conditions for suphuric acid leaching, if 1% natrium chlorate was added, the rate of leaching increased to 96.46%, but 10 kg of natrium chlorate was consumed for 1 ton of uranium ore. (authors)

Laser-Induced Breakdown Spectroscopy for Detection of Explosives Residues: A Review of Recent Advances, Challenges, and Future Prospects

Science.gov (United States)

2013-04-01

PETN), and nitrate and chlorate simulants mixed with sand (8%) at a distance of 50 m [104]. Early results for LIBS/Raman data originated in the art and...of black powder and its principle components (charcoal, sulfur, calcium sulfate, potassium nitrate, and ammonium nitrate) [22]. Although this ap

Clay mineralogy of selected borehole sediments from the Lawrence Livermore National Laboratory and Sandia National Laboratories, Livermore, California

International Nuclear Information System (INIS)

Smith, D.K.; Peifer, D.W.; Rood, C.K.

1992-04-01

Smectite, 90 to 100% interstratified illite-smectite, chlorate, and kaolinite are identified in boreholes drilled in fluvial and alluvial fan deposits of the Plio-Pleistocene Livermore Formation in the vicinity of Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), Livermore. X-ray diffraction, scanning electron microscopy, and electron microprobe studies indicate the clays persist through 150 ft of gravels, sands, silts, and mudstones of the vadose zone to total drilling depths of 200 ft in the saturated zone. Scanning electron microscopy indicates that true clays (layer silicate only) comprise between 2 and 15 modal percent of the Livermore Formation. Authigenic and detrital smectite, 90% interlayered illite-smectite, and chlorate persist throughout the stratigraphic section; kaolinite occurs only in the upper 100 ft of the section and is absent below. Smectite comprises between 60 to 90% of the true (layer silicate only) clay fraction. Illite and kaolinite±chlorite abundances fluctuate between 10 to 30% and 10 to 20% of this fraction, respectively. Authigenic smectite, illite, and chlorate crystallize together with detrital phases; the authigenic component increases with depth. The relative percentages of clay minerals define unique mineralogical intervals, which can be correlated between boreholes. Pervasive microfractures and interconnected porosity are inherent in the finer sediments; the microfractures typically are 1 mm or less in width and are variably spaced. Voids and microfractures are conspicuously lined by clays. Porosity for the argillaceous sediments ranges between 23 and 40%; Brunauer, Emmett, and Teller (BET) specific surface area decreases variably from 40 m 2 /g near the surface to 15 m 2 /g at the 115-ft depth. Within the pelitic matrix, iron, iron-titanium, chromium, and manganese oxides are pervasive

Ab-initio study of structural, vibrational and optical properties of solid oxidizers

Energy Technology Data Exchange (ETDEWEB)

Yedukondalu, N.; Vaitheeswaran, G., E-mail: gvsp@uohyd.ernet.in

2016-09-15

We report the structural, elastic and vibrational properties of five ionic-molecular solid oxidizers MNO{sub 3} (M = Li, Na, K) and MClO{sub 3} (M = Na, K). By treating long range electron-correlation effects, dispersion corrected method leads to more accurate predictions of structural properties and phase stability of KNO{sub 3} polymorphs. The obtained elastic moduli show soft nature of these materials and are consistent with Ultrasonic Pulse Echo measurements. We made a complete assignment of vibrational modes which are in good accord with available experimental results. From calculated IR and Raman spectra, it is found that the vibrational frequencies show a red-shift from Li → Na → K (Na → K) and N → Cl for nitrates (chlorates) due to increase in mass of metal and non-metal atoms, respectively. The calculated electronic structure using recently developed Tran-Blaha modified Becke-Johnson potential show that the materials are wide band gap insulators with predominant ionic bonding between M{sup +} (metal) and NO{sub 3}{sup −}/ClO{sub 3}{sup −} ions and covalent bonding (N−O and Cl−O) within nitrate and chlorate anionic group. From the calculated optical spectra, we observe that electric-dipole transitions are due to nitrate/chlorate group below 20 eV and cationic transitions occur above 20 eV. The calculated reflectivity spectra are consistent with the available experimental measurements. - Highlights: • Ground state properties with inclusion of dispersion correction method. • Elastic constants and mechanical properties. • Vibrational spectra and their complete assignment. • Raman and IR spectra. • Electronic structure and optical properties using TB-mBJ potential.

Damage and other changes that occur in some inorganic materials subjected to synchrotron radiation

International Nuclear Information System (INIS)

Bhat, H.L.; Sheen, D.B.; Sherwood, J.N.

1983-01-01

The subject is discussed under the headings: introduction (general description of white radiation topography experiments with the Daresbury SRS); experimental; results and discussion (ammonium perchlorate - orthorhombic lattice; sodium nitrate -rhombohedral lattice; sodium chlorate - modified cubic lattice; ammonium dihydrogen phosphate - tetragonal lattice; calcium carbonate - trigonal lattice). Mechanisms for the radiation effects observed are proposed. (U.K.)

Undersulfation of proteoglycans and proteins alter C6 glioma cells proliferation, adhesion and extracellular matrix organization.

Science.gov (United States)

Mendes de Aguiar, Claudia B N; Garcez, Ricardo Castilho; Alvarez-Silva, Marcio; Trentin, Andréa Gonçalves

2002-11-01

Proteoglycans are considered to be important molecule in cell-microenvironment interactions. They are overexpressed in neoplastic cells modifying their growth and migration in hosts. In this work we verified that undersulfation of proteoglycans and other sulfated molecules, induced by sodium chlorate treatment, inhibited C6 glioma cells proliferation in a dose-dependent way. This effect was restored by the addition of exogenous heparin. We could not detect significant cell mortality in our culture condition. The treatment also impaired in a dose-dependent manner, C6 cell adhesion to extracellular matrix (ECM) proteins (collagen IV, laminin and fibronectin). In addition, sodium chlorate treatment altered C6 glioma cell morphology, from the fibroblast-like to a more rounded one. This effect was accompanied by increased synthesis of fibronectin and alterations in its extracellular network organization. However, we could not observe modifications on laminin organization and synthesis. The results suggest an important connection between sulfation degree with important tumor functions, such as proliferation and adhesion. We suggest that proteoglycans may modulate the glioma microenvironment network during tumor cell progression and invasion.

Chlorine dioxide content of chlorine obtained by electrolysis of sodium chloride

NARCIS (Netherlands)

Westen, P.G.; Hoogland, J.G.

1967-01-01

Cl obtained by discharge of Cl- at a graphite anode contains a small amt. of ClO2 if chlorate is present in the electrolyte. Measurements of the rates of the reactions involved show that this ClO2 is not formed by a chem. reaction in the bulk of the electrolyte nor in the diffusion layer. Whether it

46 CFR Table 1 to Part 153 - Summary of Minimum Requirements

Science.gov (United States)

2010-10-01

... NR Open Open A, D .409, .440, .488, .908(a), (b) NA Potassium hydroxide solution, see Caustic potash solution Potassium oleate C P III NR Open Open A .409 NA Potassium thiosulfate (50% or less) C P III NR... NR Open Open NSR .236(a), (b), (c), (g), .440, .908(a), .933 NA Sodium chlorate solution (50% or less...

40 CFR Appendix V to Part 265 - Examples of Potentially Incompatible Waste

Science.gov (United States)

2010-07-01

... Calcium Lithium Magnesium Potassium Sodium Zinc powder Other reactive metals and metal hydrides Potential... concentrated waste in Groups 1-A or 1-B Water Calcium Lithium Metal hydrides Potassium SO2Cl2, SOCl2, PCl3...: Generation of toxic hydrogen cyanide or hydrogen sulfide gas. Group 6-A Group 6-B Chlorates Acetic acid and...

An Application of the Sugar-Potassium Chlorate Reaction

Science.gov (United States)

Ault, Addison

2001-08-01

Muir later said that "Although I was four years at the University, I did not take the regular course of studies, but instead picked out what I thought would be most useful to me, particularly chemistry, which opened a new world, and mathematics and physics, a little Greek and Latin, botany, and geology." Literature Cited Eliason, R.; Lee, E. J.; Wakefield, D.; Bergren, A. J. Chem. Educ. 2000, 77, 1581-1583. Muir, J. The Story of My Boyhood and Youth; Sierra Club Books: San Francisco, 1989; pp 154, 155.

Trinitromethyl Ethers and Other Derivatives as Superior Oxidizers

Science.gov (United States)

2011-08-26

metathetical reaction between anhy- drous silver perchlorate and potassium nitroformate in acetonitrile (separating the potassium per- chlorate precipitate...It was desired that the well known trimethylsilanolate anion, (CH3)3SiO– (commercially available as the sodium and potassium salts), could similarly...not reported. We tested the feasibility of similar reactions under very mild conditions, attempting a metathesis between potassium trimethylsilanolate

Dissolving method for nuclear fuel oxide

International Nuclear Information System (INIS)

Tomiyasu, Hiroshi; Kataoka, Makoto; Asano, Yuichiro; Hasegawa, Shin-ichi; Takashima, Yoichi; Ikeda, Yasuhisa.

1996-01-01

In a method of dissolving oxides of nuclear fuels in an aqueous acid solution, the oxides of the nuclear fuels are dissolved in a state where an oxidizing agent other than the acid is present together in the aqueous acid solution. If chlorate ions (ClO 3 - ) are present together in the aqueous acid solution, the chlorate ions act as a strong oxidizing agent and dissolve nuclear fuels such as UO 2 by oxidation. In addition, a Ce compound which generates Ce(IV) by oxidation is added to the aqueous acid solution, and an ozone (O 3 ) gas is blown thereto to dissolve the oxides of nuclear fuels. Further, the oxides of nuclear fuels are oxidized in a state where ClO 2 is present together in the aqueous acid solution to dissolve the oxides of nuclear fuels. Since oxides of the nuclear fuels are dissolved in a state where the oxidizing agent is present together as described above, the oxides of nuclear fuels can be dissolved even at a room temperature, thereby enabling to use a material such as polytetrafluoroethylene and to dissolve the oxides of nuclear fuels at a reduced cost for dissolution. (T.M.)

Metal Residue Deposition from Military Pyrotechnic Devices and Field Sampling Guidance

Science.gov (United States)

2012-05-01

contents of this report are not to be used for advertising , publication, or promotional purposes. Citation of trade names does not constitute an official...include boron, carbon, silicon, sulfur, or phosphorous. The oxidizers are salts of chlorates, chromates , dichromates, halocarbons, iodates, nitrates...assessment are barium, lead, and manganese. The highest concentration of any COPC is lead chromate , although the total mass is less than ½ gram per

Removal of chlorite by reaction with ferrous iron

OpenAIRE

Iatrou, Angela

1991-01-01

The use of chlorine dioxide as an oxidant and/or disinfectant for drinking water treatment has been an alternative considered when utilities seek to control trihalomethane concentrations. However, concern regarding residual concentrations of chlorite and chlorate have resulted in limitations on applied chlorine dioxide dosages. This study describes the use of ferrous iron as a possible reducing agent for the elimination of residual chlorite from drinking water.

2588-IJBCS-Article-Pascal Agbangnan

African Journals Online (AJOL)

hp

La présente étude vise à déterminer la qualité physico-chimique de l'eau de boisson des populations de deux ... Néanmoins, l'eau de consommation des populations de Dassa est plus alcaline et plus dure que celle de Cotonou : soit respectivement de 390 à 480 mg/l et de 25 à ..... chloration sur la désinfection des eaux de.

High-Nitrogen-Based Pyrotechnics: Longer- and Brighter-Burning, Perchlorate-Free, Red-Light Illuminants for Military and Civilian Applications

Science.gov (United States)

2011-01-01

combustion of these materials. To address the aforementioned perchlorate issues, an effort was initiated by ARDEC to remove potassium per- chlorate ...with acceptable burn times for pyrotechnic applications by using potassium nitrate– amorphous boron–crystalline boron/boron carbide–epoxy binder mixtures...3,4] Moreover, it was discovered by ARDEC that a potassium nitrate–boron carbide–epoxy binder mix- ture alone was able to generate suitable green

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

OpenAIRE

Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

2017-01-01

Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtain...

Saskatchewan resources. [including uranium

Energy Technology Data Exchange (ETDEWEB)

1979-09-01

The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

Jahn Teller effect of cations in water: The cupric ion in water

Energy Technology Data Exchange (ETDEWEB)

Halley, J.W. [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Wang, X.R. [Hong Kong Univ. of Science and Technology, Kowlon (Hong Kong). Dept. of Physics; Curtiss, L.A. [Argonne National Lab., IL (United States)

1993-02-01

We report a molecular dynamics model for the Jahn Teller effect in the solvation shell of a cation in solution in an aqueous liquid. We apply the model to the cupric ion and compare results with results of neutron scattering experiments on copper chlorate solutions. We conclude that the original interpretation of the experiments in terms of a Jan Teller effect may require modification.

Stability and kinetics of uranyl ion complexation by macrocycles in propylene carbonate

International Nuclear Information System (INIS)

Fux, P.

1984-06-01

A thermodynamic study of uranyl ion complexes formation with different macrocyclic ligands was realized in propylene carbonate as solvent using spectrophotometric and potentiometric techniques. Formation kinetics of two UO 2 complexes: a crown ether (18C6) and a coronand (22) was studied by spectrophotometry in propylene carbonate with addition of tetraethylammonium chlorate 0.1M at 25 0 C. Possible structures of complexes in solution are discussed [fr

Environmental biotechnology and microbiology of (per)chlorate reducing bacteria

NARCIS (Netherlands)

Mehboob, F.; Schraa, G.; Stams, A.J.M.

2011-01-01

Perchlorates are the salts derived from perchloric acid (HClO4). They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders and are used extensively within the pyrotechnics industry, and ammonium perchlorate is also

Infrared (1-12 μm) atomic and molecular emission signatures from energetic materials using laser-induced breakdown spectroscopy

Science.gov (United States)

Kumi Barimah, E.; Hömmerich, U.; Brown, E.; Yang, C. S.-C.; Trivedi, S. B.; Jin, F.; Wijewarnasuriya, P. S.; Samuels, A. C.; Snyder, A. P.

2013-05-01

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique to detect the elemental composition of solids, liquids, and gases in real time. For example, recent advances in UV-VIS LIBS have shown great promise for applications in chemical, biological, and explosive sensing. The extension of conventional UVVIS LIBS to the near-IR (NIR), mid-IR (MIR) and long wave infrared (LWIR) regions (~1-12 μm) offers the potential to provide additional information due to IR atomic and molecular signatures. In this work, a Q-switched Nd: YAG laser operating at 1064 nm was employed as the excitation source and focused onto several chlorate and nitrate compounds including KClO3, NaClO3, KNO3, and NaNO3 to produce intense plasma at the target surface. IR LIBS studies on background air, KCl , and NaCl were also included for comparison. All potassium and sodium containing samples revealed narrow-band, atomic-like emissions assigned to transitions of neutral alkali-metal atoms in accordance with the NIST atomic spectra database. In addition, first evidence of broad-band molecular LIBS signatures from chlorate and nitrate compounds were observed at ~10 μm and ~7.3 μm, respectively. The observed molecular emissions showed strong correlation with FTIR absorption spectra of the investigated materials.

Lack of genotoxicity of potassium iodate in the alkaline comet assay and in the cytokinesis-block micronucleus test. Comparison to potassium bromate.

Science.gov (United States)

Poul, J M; Huet, S; Godard, T; Sanders, P

2004-02-01

Iodine could be added to the diet of human population in the form of iodide or iodate but iodate had not been adequately tested for genotoxicity and carcinogenicity. In the present study, genotoxic effects of potassium iodate were evaluated in vitro using the alkaline comet assay and the cytokinesis-block micronucleus assay on CHO cells and compared to halogenate salt analogues potassium bromate and chlorate and also to their respective reduced forms (potassium iodide, bromide and chloride). The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM. This absence of primary DNA damage was confirmed in the cytokinesis-block micronucleus assay. In the same way, results showed that potassium chlorate as well as potassium iodide, bromide and chloride did not induced DNA damage in the alkaline comet assay for doses up to 10 mM. By contrast, potassium bromate exposure led to an increase in both DNA damage and frequency of micronucleated cells. The repair of bromate-induced DNA damage was incomplete 24 h after the end of treatment. These results seem to indicate that potassium bromate would induce DNA damage by several mechanisms besides oxidative stress.

Genetic Variability of Macrophomina phaseolina Isolates from Dry Beans in Turkey

OpenAIRE

Serkan Yeşil; Kubilay Kurtuluş Baştaş

2016-01-01

Charcoal rot is a soil and seed borne, economically important fungal disease on dry bean in Turkey. Twenty bean isolates of M. phaseolina collected from different locations in Turkey during 2008 and 2012 years were studied for genetic variability using random amplified polymorphic DNA (RAPD) assay, chlorate sensitivity on medium supplemented with 120mM of potassium, phenotype of colony, and pathogenicity. Isolates were identified as M. phaseolina based on morhological features and PCR assays ...

Enhanced chlorine dioxide decay in the presence of metal oxides: Relevance to drinking water distribution systems

KAUST Repository

Liu, Chao; von Gunten, Urs; Croue, Jean-Philippe

2013-01-01

Chlorine dioxide (ClO2) decay in the presence of typical metal oxides occurring in distribution systems was investigated. Metal oxides generally enhanced ClO2 decay in a second-order process via three pathways: (1) catalytic disproportionation with equimolar formation of chlorite and chlorate, (2) reaction to chlorite and oxygen, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly stronger abilities than goethite (α-FeOOH) to catalyze the ClO2 disproportionation (pathway 1), which predominated at higher initial ClO2 concentrations (56-81 μM). At lower initial ClO2 concentrations (13-31 μM), pathway 2 also contributed. The CuO-enhanced ClO2 decay is a base-assisted reaction with a third-order rate constant of 1.5 × 10 6 M-2 s-1 in the presence of 0.1 g L -1 CuO at 21 ± 1 C, which is 4-5 orders of magnitude higher than in the absence of CuO. The presence of natural organic matter (NOM) significantly enhanced the formation of chlorite and decreased the ClO 2 disproportionation in the CuO-ClO2 system, probably because of a higher reactivity of CuO-activated ClO2 with NOM. Furthermore, a kinetic model was developed to simulate CuO-enhanced ClO 2 decay at various pH values. Model simulations that agree well with the experimental data include a pre-equilibrium step with the rapid formation of a complex, namely, CuO-activated Cl2O4. The reaction of this complex with OH- is the rate-limiting and pH-dependent step for the overall reaction, producing chlorite and an intermediate that further forms chlorate and oxygen in parallel. These novel findings suggest that the possible ClO2 loss and the formation of chlorite/chlorate should be carefully considered in drinking water distribution systems containing copper pipes. © 2013 American Chemical Society.

Enhanced chlorine dioxide decay in the presence of metal oxides: Relevance to drinking water distribution systems

KAUST Repository

Liu, Chao

2013-07-19

Chlorine dioxide (ClO2) decay in the presence of typical metal oxides occurring in distribution systems was investigated. Metal oxides generally enhanced ClO2 decay in a second-order process via three pathways: (1) catalytic disproportionation with equimolar formation of chlorite and chlorate, (2) reaction to chlorite and oxygen, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly stronger abilities than goethite (α-FeOOH) to catalyze the ClO2 disproportionation (pathway 1), which predominated at higher initial ClO2 concentrations (56-81 μM). At lower initial ClO2 concentrations (13-31 μM), pathway 2 also contributed. The CuO-enhanced ClO2 decay is a base-assisted reaction with a third-order rate constant of 1.5 × 10 6 M-2 s-1 in the presence of 0.1 g L -1 CuO at 21 ± 1 C, which is 4-5 orders of magnitude higher than in the absence of CuO. The presence of natural organic matter (NOM) significantly enhanced the formation of chlorite and decreased the ClO 2 disproportionation in the CuO-ClO2 system, probably because of a higher reactivity of CuO-activated ClO2 with NOM. Furthermore, a kinetic model was developed to simulate CuO-enhanced ClO 2 decay at various pH values. Model simulations that agree well with the experimental data include a pre-equilibrium step with the rapid formation of a complex, namely, CuO-activated Cl2O4. The reaction of this complex with OH- is the rate-limiting and pH-dependent step for the overall reaction, producing chlorite and an intermediate that further forms chlorate and oxygen in parallel. These novel findings suggest that the possible ClO2 loss and the formation of chlorite/chlorate should be carefully considered in drinking water distribution systems containing copper pipes. © 2013 American Chemical Society.

Proceedings of the International Heat Flow Calorimetry Symposium for Energetic Materials (3rd) Held in French Lick, Indiana on April 8-11, 2002

Science.gov (United States)

2002-04-11

several smoke items deployed by the U.S. Army for both training and tactical missions. These formulations are essentially a mixture of potassium chlorate... polyacrylic rubber, and graphite were as listed in Table 1. Portions of the TA were substituted with PE, but the sum of the TA and PE was always 57...situation was true for other fuel I oxidizer combinations. Figures 8 through 11 show the results for the low temperature heating of sucrose I potassium

Pengaruh Tandem Booster TNT Terhadap Kecepatan Detonasi Campuran Bahan Peledak Tepung Kalium Klorat, Sulfur Dan Aluminium Sebagai Bahan Peldak High Explosive

OpenAIRE

Tarigan, Tarsim

2010-01-01

There are a research on velocity of detonation explosives from Improvised Bomb with potassium chlorate, sulfur and aluminum with a composition of 65:20:15% (weight / weight), 70 mesh, galvanized pipes and containers with some blasting mechanism, starts with an explosion that ignite by a improvise detonator, factory detonator without a booster, factory detonator with a tandem booster TNT, and TNT booster modifications by adding a layer of Pb plate and make a cavity between the main booster ch...

Burning Phosphorus under Water Safely

Science.gov (United States)

Taylor, Larry C.

1997-09-01

A safer method for demonstrating the burning of white phosphorous under water is described. This demonstration uses 3% hydrogen peroxide solution and manganese dioxide as the oxygen source, eliminating the use of potentially explosive potassium chlorate. The oxygen generation is manually controlled by means of a stopcock on the dropping funnel. The apparatus has been designed to provide a most spectacular display, especially in the dark, lasting an hour or longer if desired, and eliminates the noxious phosphorous odor.

New considerations on hydrogen peroxide and related substances as food additives in view of carcinogenicity.

Science.gov (United States)

Ito, R

1982-01-01

The use of hydrogen peroxide as a labile and safe food preservative in fish cake and boiled noodles has recently been restricted by the Japanese government, since hyperplasia has been found in the duodenum of mice after long-term peroral study. The action of compounds with resembling mode of action, potassium bromate as an improving agent in bread, and sodium chlorate as a weed killer are discussed in this paper in view of developmental and environmental pharmacology.

Determination of Nitrate Carry-Over on Bytac(registered) Strips Via Capillary Electrophoresis

Science.gov (United States)

2012-01-19

While nitrate is the primary anion of interest in many improvised explosives devices, simultaneous detection of sulfate, chlorate , chloride, ammonium...electrolyte (BGE) for the separation was 100 mM sodium tetraborate (pH 8.9). The sample matrix was 5 mM sodium tetraborate and included 50 µM potassium ...mM sodium tetraborate, 50 µM potassium bromide) was taken into a pipette. 3 This solution was pipetted back and forth over the surface of the

Determination of micro amounts of vanadium by oxidative coupling of α-naphthol and p-phenylenediamine

International Nuclear Information System (INIS)

Hainberger, S.J.; Damasceno, R.N.

1975-01-01

A sensitive determination of vanadium is described. In the presence of the necessary amount of potassium chlorate and small amounts of vanadium, α-naphthol and p-phenylenediamine react to yield a dyestuff, which exhibits an absorption maximum at 345 nm. The Lambert-Beer law is followed at 0.008-0.12 μg vanadium per ml. The molar extinction amounts to 54 x 10 4 .mol -1 The removal of the interfering cations is described. (author)

The use of ethephon and mixtures of ethephon luith inorganic defoliants to defoliate apple nursery trees

Directory of Open Access Journals (Sweden)

A. Basak

2015-06-01

Full Text Available Ethephon alone and in a mixture with inorganic defoliants was used to defoliate apple nursery trees of three cultivars: Yellow Transparent, McIntosh and Jonathan. The mixture of ethephon with copper sulphate or magnesium chlorate defoliated the trees better than ethophon or inorganic defoliants used seperately in twice as high concentrations as in a mixture. The tress defoliated with the mixtures of defoliants suffered less from frost injury than those treated with only the inorganic defoliants.

Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of chlorite dismutase: a detoxifying enzyme producing molecular oxygen

Energy Technology Data Exchange (ETDEWEB)

Geus, Daniël C. de, E-mail: d.de.geus@chem.leidenuniv.nl; Thomassen, Ellen A. J.; Feltz, Clarisse L. van der; Abrahams, Jan Pieter [Biophysical Structural Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden (Netherlands)

2008-08-01

Preliminary X-ray data collection and analysis for crystals of chlorite dismutase, a haem-based enzyme that very effectively reduces chlorite to chloride while producing molecular oxygen, is reported to 2.1 Å resolution. Chlorite dismutase, a homotetrameric haem-based protein, is one of the key enzymes of (per)chlorate-reducing bacteria. It is highly active (< 2 kU mg{sup −1}) in reducing the toxic compound chlorite to the innocuous chloride anion and molecular oxygen. Chlorite itself is produced as the intermediate product of (per)chlorate reduction. The chlorite dismutase gene in Azospira oryzae strain GR-1 employing degenerate primers has been identified and the active enzyme was subsequently overexpressed in Escherichia coli. Chlorite dismutase was purified, proven to be active and crystallized using sitting drops with PEG 2000 MME, KSCN and ammonium sulfate as precipitants. The crystals belonged to space group P2{sub 1}2{sub 1}2 and were most likely to contain six subunits in the asymmetric unit. The refined unit-cell parameters were a = 164.46, b = 169.34, c = 60.79 Å. The crystals diffracted X-rays to 2.1 Å resolution on a synchrotron-radiation source and a three-wavelength MAD data set has been collected. Determination of the chlorite dismutase structure will provide insights into the active site of the enzyme, for which no structures are currently available.

Ingestion of Fireworks: Rare Cause of Poisoning in Children.

Science.gov (United States)

Yuksekkaya, Hasan; Gumus, Meltem; Yucel, Aylin; Energin, Meltem; Demirci, Serafettin

2018-03-12

Mistaken ingestion of all manner of toxic matter is common in childhood, but poisoning with fireworks and matchsticks is rare. Fireworks usually contain 10% yellow phosphorus and 50% potassium chlorate. Potassium chlorate is an extremely reactive and toxic agent that is used in fireworks and matchstick heads. Eleven cases (7 females and 5 males; median age, 36 months [ranging from 24 to 48 months]) of poisoning after ingestion of fireworks and matchstick(s), between February 2008 and June 2014, were reviewed. The most common initial symptom was vomiting except for 2 cases in this group. Biochemical tests indicated that hyperphosphatemia was present in all patients, 8 patients (72.7%) had subclinical hepatic injury, 1 (9%) had acute hepatic failure, and 2 patients had no clinical or biochemical evidence of hepatic damage. Three patients had renal impairment, but none of them required dialysis. All of the patients recovered with supportive therapy except for 2 cases. One patient underwent cadaveric liver transplantation, whereas the other died because of circulatory dysfunction and respiratory failure due to pulmonary alveolar hemorrhage. Without prompt intervention, poisoning with fireworks carries high morbidity and mortality in children. It can cause pulmonary hemorrhage, in addition to other organ damage, including liver and kidney. Hyperphosphatemia is common, as it was seen in all of the study patients.

Culturing Security System of Chemical Laboratory in Indonesia

OpenAIRE

Pusfitasari, Eka Dian

2017-01-01

Indonesia has experiences on the lack of chemical security such as: a number of bombing terrors and hazardous chemicals found in food. Bomb used in terror is a homemade bomb made from chemicals which are widely spread in the research laboratories such as a mixture of pottasium chlorate, sulphur, and alumunium. Therefore, security of chemicals should be implemented to avoid the misused of the chemicals. Although it has experienced many cases of the misuse of chemicals, and many regulations and...

Evaluation of Perchlorate Sources in the Rialto-Colton and Chino California Subbasins using Chlorine and Oxygen Isotope Ratio Analysis

Science.gov (United States)

2015-03-01

matches, air bags , chlorine bleach, safety flares, perchloric acid, and chlorate herbicides (Trumpholt et al., 2005; Aziz et al., 2006, 2008). Based...L, assuming no losses to biodegradation or other removal processes. Additional information on Atacama NO3- fertilizers as a source of ClO4- can be...in each well), the IX columns were removed from the each well, sealed in Zip-Loc type bags , placed at 4oC (or on ice), and shipped to the UIC EIGL

Environmental Health Assessment for Pyrotechnic Perchlorate Elimination/Mitigation Program for M118/M119 Simulators

Science.gov (United States)

2009-09-11

17% Potassium Chlorate 3811-04-9 67% 80% Potassium Nitrate 7757-79-1 81% 13% 70% 70% Red Gum 9000-20-8 3% 3% Silicon 7440-21-3 6% Sulfur 7704-34-9 8... potassium perchlorate from the flash composition of the formulations for the Ml18 and Ml19 simulators. These simulators are used in training to produce...simulators that are more efficient, are life-cycle cost effective, and more conducive to human health and environmental quality. b. Potassium perchlorate

Method of production of granulates of ceramic nuclear fuels

International Nuclear Information System (INIS)

Wilkinson, W.L.

1975-01-01

To obtain a classified granulate of ceramic nuclear fuels with narrow grain size spectrum, the nuclear fuel powder is made into a slurry in a non-aqueous solvent with a water content as low as possible (e.g. chlorated hydrocarbon), a binder added to it, and spray-dried. The dry granulate desired is already obtained by this working stage. Polybutyl methacrylate in dibutylphthalate is proposed as binder. An example in which uranium dioxide powder is slurried in trichloro-ethylene is described in detail. (UWI/LH) [de

Sugar Dehydration without Sulfuric Acid: No More Choking Fumes in the Classroom!

Science.gov (United States)

Silverstein, Todd P.; Zhang, Yi

1998-06-01

Sugar is a common reagent often used in colorful classroom demonstrations. It produces a growing column of black ash when dehydrated by concentrated sulfuric acid, and it produces a brilliant purple flame when combusted with potassium chlorate. Unfortunately, both of these reactions also produce copious quantities of noxious fumes which make them problematic as lecture demonstrations. We have modified and combined these two reactions. Our demonstration uses no sulfuric acid, yields relatively little smoke, and produces an exciting and unpredictable growing column of black carbon.

Traitement du foisonnement filamenteux dû à Microthrix parvicella par ajout de sels métalliques

OpenAIRE

Durban, N.; Juzan, L.; Krier, J.; Héduit, A.; Gillot, S.

2012-01-01

National audience; Les dysfonctionnements biologiques dus au développement de bactéries filamenteuses posent de nombreux problèmes d’exploitation aux stations d'épuration du type boues activées. Le filament le plus souvent mis en cause dans ce type de dysfonctionnement en France est Microthrix parvicella. La solution curative la plus utilisée actuellement est la chloration, traitement efficace mais non spécifique, qui impacte également la biologie des boues activées. Une solution émergente co...

Anaerobic degradation of a mixture of MtBE, EtBE, TBA, and benzene under different redox conditions.

Science.gov (United States)

van der Waals, Marcelle J; Pijls, Charles; Sinke, Anja J C; Langenhoff, Alette A M; Smidt, Hauke; Gerritse, Jan

2018-04-01

The increasing use of biobased fuels and fuel additives can potentially change the typical fuel-related contamination in soil and groundwater. Anaerobic biotransformation of the biofuel additive ethyl tert-butyl ether (EtBE), as well as of methyl tert-butyl ether (MtBE), benzene, and tert-butyl alcohol (TBA, a possible oxygenate metabolite), was studied at an industrially contaminated site and in the laboratory. Analysis of groundwater samples indicated that in the field MtBE was degraded, yielding TBA as major product. In batch microcosms, MtBE was degraded under different conditions: unamended control, with medium without added electron acceptors, or with ferrihydrite or sulfate (with or without medium) as electron acceptor, respectively. Degradation of EtBE was not observed under any of these conditions tested. TBA was partially depleted in parallel with MtBE. Results of microcosm experiments with MtBE substrate analogues, i.e., syringate, vanillate, or ferulate, were in line with the hypothesis that the observed TBA degradation is a cometabolic process. Microcosms with ferulate, syringate, isopropanol, or diethyl ether showed EtBE depletion up to 86.5% of the initial concentration after 83 days. Benzene was degraded in the unamended controls, with medium without added electron acceptors and with ferrihydrite, sulfate, or chlorate as electron acceptor, respectively. In the presence of nitrate, benzene was only degraded after addition of an anaerobic benzene-degrading community. Nitrate and chlorate hindered MtBE, EtBE, and TBA degradation.

Zeeman perturbed nuclear quadrupole spin echo envelope modulations for spin 3/2 nuclei in polycrystalline specimens

Science.gov (United States)

Ramachandran, R.; Narasimhan, P. T.

The results of theoretical and experimental studies of Zeeman-perturbed nuclear quadrupole spin echo envelope modulations (ZSEEM) for spin 3/2 nuclei in polycrystalline specimens are presented. The response of the Zeeman-perturbed spin ensemble to resonant two pulse excitations has been calculated using the density matrix formalism. The theoretical calculation assumes a parallel orientation of the external r.f. and static Zeeman fields and an arbitrary orientation of these fields to the principal axes system of the electric field gradient. A numerical powder averaging procedure has been adopted to simulate the response of the polycrystalline specimens. Using a coherent pulsed nuclear quadrupole resonance spectrometer the ZSEEM patterns of the 35Cl nuclei have been recorded in polycrystalline specimens of potassium chlorate, barium chlorate, mercuric chloride (two sites) and antimony trichloride (two sites) using the π/2-τ-π/2 sequence. The theoretical and experimental ZSEEM patterns have been compared. In the case of mercuric chloride, the experimental 35Cl ZSEEM patterns are found to be nearly identical for the two sites and correspond to a near-zero value of the asymmetry parameter, η, of the electric field gradient tensor. The difference in the η values for the two 35Cl sites (η ˜0·06 and η˜0·16) in antimony trichloride is clearly reflected in the experimental and theoretical ZSEEM patterns. The present study indicates the feasibility of evaluating η for spin 3/2 nuclei in polycrystalline specimens from ZSEEM investigations.

Growth of sodium chlorate crystals in the presence of potassium sulphate

Science.gov (United States)

Kim, E. L.; Tsyganova, A. A.; Vorontsov, D. A.; Ovsetsina, T. I.; Katkova, M. R.; Lykov, V. A.; Portnov, V. N.

2015-09-01

In this work, we investigated the morphology and growth rates of NaClO3 crystals in solutions with K2SO4 additives. NaClO3 crystals were grown using the temperature gradient technique under concentration convection. We found that the crystal habitus changed from cubic to tetrahedral, and the growth of the cubic {100}, tetrahedral {111} and rhomb-dodecahedral {110} faces decelerated with an increase in the concentration of SO42- ions. The {110} face was the most and the {100} face was the least inhibited by sulphate ions. The mechanism of SO42- ions action is their adsorption on the crystal surface, which impedes attachment of the crystal's building units. We conclude that different atomic structure and charge state of various crystal faces determine their sensitivity to the action of the SO42- ions.

ENVIRONMENTAL AND POTASSIUM CHLORATE EFFECTS ON THE GROWTH OF CHAETOMIUM GLOBOSUM

Science.gov (United States)

Mold has been blamed for causing human health problems at work and at home. One fungus often found in indoor environments is Chaetomium globosum. This fungus produces sexual reproductive structures called perithecia (Fig. 2) that can be easily visualized on a media plate. Malt ex...

The indirect detection of bleach (sodium hypochlorite) in beverages as evidence of product tampering.

Science.gov (United States)

Jackson, David S; Crockett, David F; Wolnik, Karen A

2006-07-01

Bleach (sodium hypochlorite) has been identified as the adulterant in a relatively large number of product tamperings that have been investigated by the Forensic Chemistry Center (FCC) of the U.S. Food and Drug Administration. In this work, household bleach was added to 23 different beverages at each of three levels. The impact of sodium hypochlorite on these beverages over a 13-day study period was evaluated using the following techniques: diphenylamine spot test for oxidizing agents, potassium iodide-starch test paper for oxidizing agents, pH, iodometric titration for quantitating hypochlorite, ion chromatography for chloride and chlorate quantitation, automated headspace sampling with gas chromatography-flame ionization detection (GC-FID) for determination of chloroform, and visual and organoleptic observations. This study has shown that hypochlorite is fragile when added to most common beverages and typically breaks down either partially or completely over time. In cases where a beverage is suspected of being adulterated with bleach but tests for hypochlorite are negative, it is still possible to characterize the product to demonstrate that the results are consistent with the addition of bleach. An adulterated product will give a positive test for oxidizing agents using the diphenylamine spot test. It is likely that the pH of the adulterated product will be higher than a control of that product. Ion chromatographic analysis shows elevated chloride and chlorate as compared with a control. And, chloroform may also be detected by GC-FID especially if the beverage that was adulterated contains citric acid.

UV disinfection of water. 1. Effect on microorganisms/virus conditions which can limit the use of UV radiation as a means of disinfection

Energy Technology Data Exchange (ETDEWEB)

Skipperud, E; Johansen,; Myhrstad, J A [Statens Inst. for Folkehelse, Oslo (Norway)

1978-01-01

UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW).

Thermal properties of graphite oxide, thermally reduced graphene and chemically reduced graphene

Science.gov (United States)

Jankovský, Ondřej; Sedmidubský, David; Lojka, Michal; Sofer, Zdeněk

2017-07-01

We compared thermal behavior and other properties of graphite oxide, thermally reduced graphene and chemically reduced graphene. Graphite was oxidized according to the Hofmann method using potassium chlorate as oxidizing agent in strongly acidic environment. In the next step, the formed graphite oxide was chemically or thermally reduced yielding graphene. The mechanism of thermal reduction was studied using STA-MS. Graphite oxide and both thermally and chemically reduced graphenes were analysed by SEM, EDS, elemental combustion analysis, XPS, Raman spectroscopy, XRD and BET. These findings will help for the large scale production of graphene with appropriate chemical composition.

Influence of air pollution upon plants

Energy Technology Data Exchange (ETDEWEB)

Kangas, E

1963-01-01

This talk, which was given at a symposium concerned with pollution of the air, arranged by the Societas Biochemica Biophysica et Microbiologica of Finland, deals with the influence exerted by air pollution upon plants, and upon trees in particular. Mention is made of the gases which have in Finland caused pollution of the air and have damaged plants (SO/sub 2/, Cl, gases containing chlorates, and the smoke from coal and liquid fuel). The effect of these substances, and of their varying concentrations, is reported, together with the effect of forms of dirt, especially with respect to coniferous trees.

Note: A novel method for in situ loading of gases via x-ray induced chemistry

Energy Technology Data Exchange (ETDEWEB)

Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan (UNLV); (CIW)

2011-12-14

We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO{sub 3}) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

Connection between the growth rate distribution and the size dependent crystal growth

Science.gov (United States)

Mitrović, M. M.; Žekić, A. A.; IIić, Z. Z.

2002-07-01

The results of investigations of the connection between the growth rate dispersions and the size dependent crystal growth of potassium dihydrogen phosphate (KDP), Rochelle salt (RS) and sodium chlorate (SC) are presented. A possible way out of the existing confusion in the size dependent crystal growth investigations is suggested. It is shown that the size independent growth exists if the crystals belonging to one growth rate distribution maximum are considered separately. The investigations suggest possible reason for the observed distribution maxima widths, and the high data scattering on the growth rate versus the crystal size dependence.

Note: A novel method for in situ loading of gases via x-ray induced chemistry

Science.gov (United States)

Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan

2011-10-01

We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO3) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

UV disinfection of water

International Nuclear Information System (INIS)

Skipperud, E.; Johansen; Myhrstad, J.A.

1978-01-01

UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW)

Efficacy of chlorine dioxide on Escherichia coli inactivation during pilot-scale fresh-cut lettuce processing.

Science.gov (United States)

Banach, J L; van Overbeek, L S; Nierop Groot, M N; van der Zouwen, P S; van der Fels-Klerx, H J

2018-03-23

Controlling water quality is critical in preventing cross-contamination during fresh produce washing. Process wash water (PWW) quality can be controlled by implementing chemical disinfection strategies. The aim of this study was to evaluate the pilot-scale efficacy of chlorine dioxide (ClO 2 ) during processing on the reduction of Escherichia coli in the PWW and on processed fresh-cut 'Lollo Rossa' lettuce. The objective was to have a residual target concentration of either 5 or 3 mg/L ClO 2 in the washing tank (3.5 m 3 ) before and during 800 kg of lettuce processing (90 min). After 90 min., a nonpathogenic, non-Extended Spectrum Beta-Lactamase (ESBL) E. coli inoculum from an overnight culture broth (37 °C) was added to the tank resulting in an approximate final level of 10 6  CFU/mL. PWW and lettuce samples for microbiological and chemical analyses were taken before and after the input and supply halted. ClO 2 concentrations quickly decreased after ClO 2 input halted, yet a residual concentration of ≥2.5 mg/L and ≥2.1 mg/L ClO 2 , respectively for 5 and 3 mg/L pilots, was present 12 min after the supply halted. No detectable levels of E. coli (limit of detection 5 log) were determined in the water within 1 min after E. coli was added to the ClO 2 containing wash water. Results demonstrated that ClO 2 use at the semi-commercial pilot scale was able to reduce the E. coli peak contamination in the PWW. After storage (5 days, 4 °C), background microbial communities (i.e., fluorescent Pseudomonads and total heterotrophic bacteria) grew out on lettuce. Overall, ClO 2 decreased the potential for cross-contamination between batches compared to when no sanitizer was used. Chlorate levels of the lettuce sampled before entering the wash water ranged from 7.3-11.6 μg/kg. The chlorate levels of the lettuce sampled after being washed in the ClO 2 containing wash water, as well as after rinsing and centrifugation, ranged from 22.8-60.4�

Impact de la demande en chlore et de la chloration sur la ...

African Journals Online (AJOL)

SARAH

31 mars 2014 ... Les chloramines éliminent 100% des coliformes totaux et réduisent au maximum le nombre de ... Impact of the application for chlorine and chlorine disinfection of well ...... H. Shayeb, T. Riabi, M. Roustan et A. Hassan, 1998,.

Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean and sorghum.

Science.gov (United States)

Saleh, A A; Ahmed, H U; Todd, T C; Travers, S E; Zeller, K A; Leslie, J F; Garrett, K A

2010-01-01

Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58% among isolates in the tallgrass prairie, 71% in the maize fields, 75% in the sorghum fields and 80% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate 'hybrids' with novel genetic profiles and pathogenic capabilities.

Reduction of Campylobacter jejuni on chicken wings by chemical treatments.

Science.gov (United States)

Zhao, Tong; Doyle, Michael P

2006-04-01

Eight chemicals, including glycerol monolaurate, hydrogen peroxide, acetic acid, lactic acid, sodium benzoate, sodium chlorate, sodium carbonate, and sodium hydroxide, were tested individually or in combination for their ability to inactivate Campylobacter jejuni at 4 degrees C in suspension. Results showed that treatment for up to 20 min with 0.01% glycerol monolaurate, 0.1% sodium benzoate, 50 or 100 mM sodium chlorate, or 1% lactic acid did not substantially (5 log CFU/ml within 2 min. A combination of 0.5% acetic acid plus 0.05% potassium sorbate or 0.5% acetic acid plus 0.05% sodium benzoate reduced C. jejuni populations by >5 log CFU/ml within 1 min; however, substituting 0.5% lactic acid for 0.5% acetic acid was not effective, with a reduction of C. jejuni of 5 log CFU/ml within 1 min. All chemicals or chemical combinations for which there was a >5-log/ml reduction of C. jejuni in suspension were further evaluated for C. jejuni inactivation on chicken wings. Treatments at 4 degrees C of 2% acetic acid, 100 mM sodium carbonate, or 0.1 N sodium hydroxide for up to 45 s reduced C. jejuni populations by ca. 1.4, 1.6, or 3.5 log CFU/g, respectively. Treatment with ACS-LA at 4 degrees C for 15 s reduced C. jejuni by >5 log CFU/g to an undetectable level. The ACS-LA treatment was highly effective in chilled water at killing C. jejuni on chicken and, if recycled, may be a useful treatment in chill water tanks for poultry processors to reduce campylobacters on poultry skin after slaughter.

Working out microsyntheses for different chlorinated biphenyls and preparation of 2,2'-dichlorobiphenyl-14C and 2,4'-dichlorobiphenyl-14C

International Nuclear Information System (INIS)

Geuenich, H.H.

1972-01-01

The microsyntheses for the preparation of chlorated biphenyls starting with benzene were worked out. 2,2'-dichlorobiphenyl- 14 C and 2,4'-dichlorobiphenyl- 14 C were prepared. 42 mCi benzene- 14 C were converted into nitrobenzene with nitrating acid, which was reduced to aniline by tin(II) chloride/hydrochloric acid. Following the acetylation of aniline with acetic anhydride, it was monochlorated in glacial acetic acid with chloride of lime, and the chlorination mixture was chromatographically separated in columns. 5.8 mCi o'-chloroanaline were diazotized and converted in ammoniacal copper(I) salt solution. 2 μCi 2,2'-dichlorobiphenyl were obtained. (orig./LH) [de

Aquatic macro algae of a region under Almirante Alvaro Alberto nuclear power plant influence. I. Spatial seasonal evaluation; Macroalgas marinhas da regiao sob influencia da Central Nuclear Almirante Alvaro Alberto (CNAAA), Saco de Piraquara de Fora, Angra dos Reis, RJ, Brasil. I. Avaliacao espaco-temporal

Energy Technology Data Exchange (ETDEWEB)

Pedrini, A.G. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)]|[Universidade Santa Ursula, Rio de Janeiro, RJ (Brazil). Centro de Ciencias Biologicas; Cassano, V.; Coelho, L.G.; Labronici, G.J. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia

1994-12-31

Marine macro algae from the area which is under in fluence of the heated and chlorate liquid effluent to the CNAAA were observed (1981-1983) at 3 collection points: Pingo Dagua, Velho Beach, discharge point. A total of 121 taxa were found: 29 Chlorophyta, 26 Phaeophyta and 66 Rhodophyta. The spring season was the richest in taxa (78) while autumn was the poorest (85). Overall, the data suggest that the point A (Pingo Dagua) macro algae community (which is similar to the discharge point (0,80) is adequate for the control of the CNAAA effluent impact ad Piraquara de Fora. (author). 11 refs, 5 figs, 1 tab.

Aquatic macro algae of a region under Almirante Alvaro Alberto nuclear power plant influence. I. Spatial seasonal evaluation

International Nuclear Information System (INIS)

Pedrini, A.G.; Universidade Santa Ursula, Rio de Janeiro, RJ; Cassano, V.; Coelho, L.G.; Labronici, G.J.

1994-01-01

Marine macro algae from the area which is under in fluence of the heated and chlorate liquid effluent to the CNAAA were observed (1981-1983) at 3 collection points: Pingo Dagua, Velho Beach, discharge point. A total of 121 taxa were found: 29 Chlorophyta, 26 Phaeophyta and 66 Rhodophyta. The spring season was the richest in taxa (78) while autumn was the poorest (85). Overall, the data suggest that the point A (Pingo Dagua) macro algae community (which is similar to the discharge point (0,80) is adequate for the control of the CNAAA effluent impact ad Piraquara de Fora. (author). 11 refs, 5 figs, 1 tab

Determination of binding-dioxygen in dioxygen complexes by headspace gas chromatography.

Science.gov (United States)

Wang, Wei; Feng, Shun; Li, Ya-ni; Wu, Meiying; Wang, Jide

2008-06-06

Dioxygen complexes play important roles in organisms' bodies, so the determination of binding-dioxygen has practical significance. A simple and robust method based on headspace gas chromatography was proposed to determine the binding-dioxygen in dioxygen complexes. By measuring the content change of nitrogen gas in a vial, the amount of oxygen released from dixoygen complexes can be determined. The method was validated using potassium chlorate as model sample, and the results exhibited good recoveries (90-99%) with the relative standard deviation less than 8%. It was also used to analyze dioxygen complex of cobalt bis(salicylaldehyde) ethylenediimine and polyamine cobalt complexes prepared by solid-phase reaction.

Ion exchange purification of scandium

Science.gov (United States)

Herchenroeder, Laurie A.; Burkholder, Harvey R.

1990-10-23

An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

Synthesis of semiconductor polymers by inductive plasma; Sintesis de polimeros semiconductores por plasmas inductivos

Energy Technology Data Exchange (ETDEWEB)

Fernandez, G.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Morales, J. [UAM-I, 09340 Mexico D.F. (Mexico)

2003-07-01

When carrying out the synthesis of semiconductor polymers by plasma it is important to consider the electric arrangement of the discharge since this it influences in the distribution of the energy of the particles in the reactor. The main electric arrangements in those that are developed the brightness discharges of radio frequency are resistive, capacitive and inductive. In the Laboratory of Materials processing by plasma of the ININ its have been worked different synthesis of polymers with resistive arrangements with good results. In this work the results of the synthesis and characterization of poly aniline and chlorate polyethylene by inductive plasma are presented. (Author)

Integrated Data Collection Analysis (IDCA) Program - AN and Bullseye Smokeless Powder

Energy Technology Data Exchange (ETDEWEB)

Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States); Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States); Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States); Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelley, Timothy J. [Bureau of Alcohol, Tobacco, and Firearms, Redstone Arsenal, AL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall Air Force Base, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-07-17

chlorate, sodium chlorate, sugar, dodecane, PETN, carbon, ammonium nitrate, Gunpowder, Bullseye® smokeless powder.

A potential role for chondroitin sulfate/dermatan sulfate in arm regeneration in Amphiura filiformis.

Science.gov (United States)

Ramachandra, Rashmi; Namburi, Ramesh B; Dupont, Sam T; Ortega-Martinez, Olga; van Kuppevelt, Toin H; Lindahl, Ulf; Spillmann, Dorothe

2017-05-01

Glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) and dermatan sulfate (DS) from various vertebrate and invertebrate sources are known to be involved in diverse cellular mechanisms during repair and regenerative processes. Recently, we have identified CS/DS as the major GAG in the brittlestar Amphiura filiformis, with high proportions of di- and tri-O-sulfated disaccharide units. As this echinoderm is known for its exceptional regeneration capacity, we aimed to explore the role of these GAG chains during A. filiformis arm regeneration. Analysis of CS/DS chains during the regeneration process revealed an increase in the proportion of the tri-O-sulfated disaccharides. Conversely, treatment of A. filiformis with sodium chlorate, a potent inhibitor of sulfation reactions in GAG biosynthesis, resulted in a significant reduction in arm growth rates with total inhibition at concentrations higher than 5 mM. Differentiation was less impacted by sodium chlorate exposure or even slightly increased at 1-2 mM. Based on the structural changes observed during arm regeneration we identified chondroitin synthase, chondroitin-4-O-sulfotransferase 2 and dermatan-4-O-sulfotransferase as candidate genes and sought to correlate their expression with the expression of the A. filiformis orthologue of bone morphogenetic factors, AfBMP2/4. Quantitative amplification by real-time PCR indicated increased expression of chondroitin synthase and chondroitin-4-O-sulfotransferase 2, with a corresponding increase in AfBMP2/4 during regeneration relative to nonregenerating controls. Our findings suggest that proper sulfation of GAGs is important for A. filiformis arm regeneration and that these molecules may participate in mechanisms controlling cell proliferation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Preliminary studies on the Marcoule site, using a wind-tunnel

International Nuclear Information System (INIS)

Chassany, J.Ph.; Salaun-Penquer, G.

1961-01-01

The tests were carried out in the 3.30 x 2.20 subsonic elliptical wind-tunnel of the Marseille Institute of fluid mechanics, on a 1/1000 scale model measuring 3 m x 3 m. The aerodynamic field developing above the site, made visible by ammonium, hydro-chlorate fumes, and the residues were observed and filmed by means of a synchronised cine-camera with stroboscopic lighting for 4 wind directions. The fall-out from the various waste products was obtained from a spraying of lead acetate solution on the model and hydrogen sulphide emissions. The zones of maximum pollution can be determined from a study of the film taken during the blackening of the spots. (author) [fr

Procedure for conditioning high-level solidified wastes

Energy Technology Data Exchange (ETDEWEB)

Hild, W; Krause, H; Scheffler, K

1974-05-30

The molds of glass, ceramic or basalt-similar mass in which highly radioactive wastes are incorporated are used for the conditioning of waste waters and/or of sewage or precipitating sludge or of natural water to obtain drinking water, prior to the end storage. By means of the gamma-radiation they emit, the viruses and bacteria and worm eggs are killed off as well as the poisonous, and organic substances such as, e.g., chlorated aromatics are destroyed. Furthermore, the filtration power is increased by coagulation, and the sludge is drained. Natural water is degermed. In particular, fission product mixtures of light water reactors can be incorporated in the molds. The molds are immersed in the media.

Performance assessment of refractory samples in the Los Alamos Controlled Air Incinerator

International Nuclear Information System (INIS)

Hutchins, D.A.; Borduin, L.C.; Koenig, R.A.; Vavruska, J.S.; Warner, C.L.

1986-01-01

A refractory evaluation project was initiated in 1979 to study the performance of six selected refractory materials within the Los Alamos Controlled Air Incinerator (CAI). Determining refractory resistance to thermal shock, chemical attack, and plutonium uptake was of particular interest. The experimental refractories were subjected to a variety of waste materials, including transuranic (TRU) contaminated wastes, highly chlorinated compounds and alkaline metal salts of perchlorate, chlorate, nitrate and oxylate, over the six year period of this study. Results of this study to date indicate that the use of high alumina, and possibly specialty plastic refractories, is advisable for the lining of incinerators used for the thermal destruction of diverse chemical compounds. 12 refs., 4 tabs

Exposure to Cobalt Causes Transcriptomic and Proteomic Changes in Two Rat Liver Derived Cell Lines

Science.gov (United States)

2013-12-30

15.75 12 Cobalt (II) nitrate 10141-05-6 10.75 5 15.75 13 Potassium permanganate 7722-64-7 10.75 5 15.75 14 Silver nitrate 7761-88-8 9.75 6 15.75 15... Potassium nitrate 7757-79-1 8.75 7 15.75 16 Sodium Nitrate 7631-99-4 8.5 7 15.5 17 Thallium 7440-28-0 14 1 15 18 Thallium sulfate 7446-18-6 13 2 15 19...Mercury 7439-97-6 10.5 4 14.5 24 Sodium chlorate 7775-09-9 8.5 6 14.5 25 Cadmium 7440-43-9 10 4 14 26 Bismuth 7440-69-9 10 4 14 27 Aluminum phosphide

An industrial customer's view of changes in electricity purchasing

International Nuclear Information System (INIS)

Muiznieks, R.

1995-01-01

The purchasing agent for Canadian Occidental Chemicals described his experiences in the purchase of electricity under the new circumstances of competition. Electrical power costs for Canadian Occidental's manufacturing operation were described as a key consideration in expanding their chlorate production. The ideal purchasing scheme was described from the purchaser's standpoint. A list of what purchasers wish to gain from increased supplier choices was provided. The behaviour of the electricity suppliers that provide power to CanadianOccidental was described since changes in British Columbia's electric power regulations were enacted. Electric utility marketing practices in Ontario, Manitoba and Alberta were noted in comparison. It was prophesized that deeregulation will ultimately benefit consumers and provincial economies, by transforming the power industry into a customer driven industry

Studies on uranium ore processing

International Nuclear Information System (INIS)

Kim, C.H.; Park, S.W.; Lim, J.K.; Chung, M.K.

1981-01-01

Chemical and chemical engineering techniques of the uranium ore processing established by France COGEMA (Compagnie Generale des Matieres Nucleaires) have been comprehensively reviewed in preparation for successful test operation of the pilot plant to be completed by the end of 1981. It was found that the amount of sulfuric acid (75 Kg/t, ore) and sodium chlorate (2.5 Kg/t, ore) recommended by COGEMA should be increased up to 100 Kg/t, ore and 10 Kg/t, ore respectively to obtain satisfactory leach of uranium for some ore samples produced at the different pits of Goesan uranium mine. Conditions of the other processes such as solvent extraction, stripping, and precipitation of yellow cake were generally agreed with the results of intensive studies done by this laboratory

The chemical defoliation of Ligitstrum vulgare L. and Spiraea x arguta Zab. shrubs in nursery

Directory of Open Access Journals (Sweden)

Szczepan Marczyński

2015-06-01

Full Text Available To defoliate Ligustrum vulgare and Spiraea x arguta – ethephon, KJ, Mg(ClO32•6H2O, CuSO4•5H2O and (NH42SO4 in various concentrations were used alone or in mixtures. Treating plants with potassium iodide gave the best results. KJ concentrations of 0.05-0,1% and 0.1-0.% were sufficient to defoliate Spiraea and Ligusturm respectively. Magnesium chlorate at concentration of 0.24 and 2% CuSO4 were also effective, the latter however, proved slight harmful to the plants. Spraying with defoliants on Sept. 26 gave better results than treating plants on Sept. 16. Chemical defoliation decreased negligibly the frost resistance of Ligusturm vulgare shrubs.

Pilot test of bacterial percolation leaching at Fuzhou uranium mine

International Nuclear Information System (INIS)

Fan Baotuan; Liu Jian; Jiang Yngqiong; Cai Chunhui; Jiang Lang; Zhou Renhua; Tong Changning; Zhang Hongli

2006-01-01

Total 18 t uranium ores of Fuzhou Uranium Mine packed in three or four columns in series were leached by bacterial percolation. The results show that without adding any other chemical oxidant such as sodium chlorate, the leaching rate measured by residue is 91.45%-94.48%, leaching time is 50-60 d, acid consumption is 6.17%-7.75%, and residue grade is 0.0149%-0.0208%. Compared with conventional percolation leaching process, the leaching rate is improved by 3%, leaching time is shorted by 26%, and acid consumption is saved by 34%. Accumulation pattern of ΣFe and F - in the process of leaching is discussed. Influence of F - on bacterial growth, regeneration of barren solution as well as correlative techniques are reviewed. (authors)

Safety and efficacy of low-dose, subacute exposure of mature ewes to sodium chlorate

Science.gov (United States)

The objective was to determine the safety and efficacy of low-dose, subacute exposure of mature ewes to NaClO3 in the drinking water. Twenty-five ewes (BW = 62.5 ± 7.3 kg) were placed indoors in individual pens with ad libitum access to water and feed. After 7 d of adaptation, ewes were assigned ran...

Direct electrochemical oxidation of ammonia on graphite as a treatment option for stored source-separated urine.

Science.gov (United States)

Zöllig, Hanspeter; Fritzsche, Cristina; Morgenroth, Eberhard; Udert, Kai M

2015-02-01

Electrolysis can be a viable technology for ammonia removal from source-separated urine. Compared to biological nitrogen removal, electrolysis is more robust and is highly amenable to automation, which makes it especially attractive for on-site reactors. In electrolytic wastewater treatment, ammonia is usually removed by indirect oxidation through active chlorine which is produced in-situ at elevated anode potentials. However, the evolution of chlorine can lead to the formation of chlorate, perchlorate, chlorinated organic by-products and chloramines that are toxic. This study focuses on using direct ammonia oxidation on graphite at low anode potentials in order to overcome the formation of toxic by-products. With the aid of cyclic voltammetry, we demonstrated that graphite is active for direct ammonia oxidation without concomitant chlorine formation if the anode potential is between 1.1 and 1.6 V vs. SHE (standard hydrogen electrode). A comparison of potentiostatic bulk electrolysis experiments in synthetic stored urine with and without chloride confirmed that ammonia was removed exclusively by continuous direct oxidation. Direct oxidation required high pH values (pH > 9) because free ammonia was the actual reactant. In real stored urine (pH = 9.0), an ammonia removal rate of 2.9 ± 0.3 gN·m(-2)·d(-1) was achieved and the specific energy demand was 42 Wh·gN(-1) at an anode potential of 1.31 V vs. SHE. The measurements of chlorate and perchlorate as well as selected chlorinated organic by-products confirmed that no chlorinated by-products were formed in real urine. Electrode corrosion through graphite exfoliation was prevented and the surface was not poisoned by intermediate oxidation products. We conclude that direct ammonia oxidation on graphite electrodes is a treatment option for source-separated urine with three major advantages: The formation of chlorinated by-products is prevented, less energy is consumed than in indirect ammonia oxidation and

Effect of evaporation and freezing on the salt paragenesis and habitability of brines at the Phoenix landing site

Science.gov (United States)

Elsenousy, Amira; Hanley, Jennifer; Chevrier, Vincent F.

2015-07-01

The WCL (Wet Chemistry Lab) instrument on board the Phoenix Lander identified the soluble ionic composition of the soil at the landing site. However, few studies have been conducted to understand the parent salts of these soluble ions. Here we studied the possible salt assemblages at the Phoenix landing site using two different thermodynamic models: FREZCHEM and Geochemist's Workbench (GWB). Two precipitation pathways were used: evaporation (T > 0 °C using both FREZCHEM and GWB) and freezing (T chlorate/perchlorate dominated), we calculated the resulting precipitated minerals. The results-through both freezing and evaporation-showed some common minerals that precipitated regardless of the ionic initial concentration. These ubiquitous minerals are magnesium chlorate hexahydrate Mg(ClO3)2ṡ6H2O, potassium perchlorate (KClO4) and gypsum (CaSO4ṡ2H2O). Other minerals evidence specific precipitation pathway. Precipitation of highly hydrated salts such as meridianiite (MgSO4ṡ11H2O) and MgCl2ṡ12H2O indicate freezing pathway, while precipitation of the low hydrated salts (anhydrite, kieserite and epsomite) indicate evaporation. The present hydration states of the precipitated hydrated minerals probably reflect the ongoing thermal processing and recent seasonally varying humidity conditions at the landing site, but these hydration states might not reflect the original depositional conditions. The simulations also showed the absence of Ca-perchlorate in all models, mainly because of the formation of two main salts: KClO4 and gypsum which are major sinks for ClO-4 and Ca2+ respectively. Finally, in consideration to the Martian life, it might survive at the very low temperatures and low water activities of the liquids formed. However, besides the big and widely recognized challenges to life posed by those extreme environmental parameters (especially low water activity), another main challenge for any form of life in such an environment is to maintain contact with the

Soil transport parameters of potassium under a tropical saline soil condition using STANMOD

Science.gov (United States)

Suzanye da Silva Santos, Rafaelly; Honorio de Miranda, Jarbas; Previatello da Silva, Livia

2015-04-01

Environmental responsibility and concerning about the final destination of solutes in soil, so more studies allow a better understanding about the solutes behaviour in soil. Potassium is a macronutrient that is required in high concentrations, been an extremely important nutrient for all agricultural crops. It plays essential roles in physiological processes vital for plant growth, from protein synthesis to maintenance of plant water balance, and is available to plants dissolved in soil water while exchangeable K is loosely held on the exchange sites on the surface of clay particles. K will tend to be adsorbed onto the surface of negatively charged soil particles. Potassium uptake is vital for plant growth but in saline soils sodium competes with potassium for uptake across the plasma membrane of plant cells. This can result in high Na+:K+ ratios that reduce plant growth and eventually become toxic. This study aimed to obtain soil transport parameters of potassium in saline soil, such as: pore water velocity in soil (v), retardation factor (R), dispersivity (λ) and dispersion coefficient (D), in a disturbed sandy soil with different concentrations of potassium chlorate solution (KCl), which is one of the most common form of potassium fertilizer. The experiment was carried out using soil samples collected in a depth of 0 to 20 cm, applying potassium chlorate solution containing 28.6, 100, 200 and 500 mg L-1 of K. To obtain transport parameters, the data were adjusted with the software STANMOD. At low concentrations, interaction between potassium and soil occur more efficiently. It was observed that only the breakthrough curve prepared with solution of 500 mg L-1 reached the applied concentration, and the solution of 28.6 mg L-1 overestimated the parameters values. The STANMOD proved to be efficient in obtaining potassium transport parameters; KCl solution to be applied should be greater than 500 mg L-1; solutions with low concentrations tend to overestimate

Corrosion-electrochemical behavior of metals in alkali solutions

International Nuclear Information System (INIS)

Levin, V.A.; Levina, E.Eh.

1995-01-01

Results of an investigation into corrosion-electrochemical behaviour of 12Kh18N10T, 10Kh17N13M2T, 08Kh21N6M2T and 15Kh25T steels, 06KhN28MDT and KhN78T alloys as well as NP-2 nickel in sodium, potassium and lithium hydroxide solutions at 95-180 deg C temperatures are considered. It is ascertained, that anode polarization curves of all metals irrespective of hydroxide nature, concentration, temperature, presence of chloride and chlorate additions, are of identic character. The movement of anode polarization curves in the direction of lower current of hydroxide type in NaOH-KOH-LiOH series, temperature and solution concentration reduction at other equal terms. 12 refs.; 6 figs

Enhancement of gamma-ray-induced mutation frequency in rice by post-treatment with chloral hydrate, methanol and their mixtures with ethanol

International Nuclear Information System (INIS)

Reddy, T.P.; Vaidyanath, K.

1979-01-01

An evaluation has been made of the mutagenic activity of ethanol, chlorate hydrate (CH) and methanol on rice seed. In independent treatments with ethanol, methanol, CH and four aqueous mixtures of these chemicals, chlorophyll-deficient mutants were not recovered in the M 2 generation. However, in sequential treatments with gamma rays + CH, gamma rays + methanol and gamma rays + aqueous mixtures of these chemicals, significant increases in the yields of chlorophyll mutations were observed as compared to that of a 30 kR gamma ray treatment. In contrast, post-irradiation treatment with ethanol failed to provoke any increase in the frequency of chlorophyll mutants in the M 2 generation. The results indicate that CH and methanol alone and mixed with ethanol can potentiate gamma ray-induced genetic lesions in rice seed. (author)

Disinfection of treated sewage. [Ultra-violet irradiation

Energy Technology Data Exchange (ETDEWEB)

From, J O

1976-09-02

The release of treated sewage in the vicinity of bathing places, drinking water sources or fish and shellfish culture plants is undesirable due to high bacterial content. Disinfection by chlorine would be relatively expensive and the toxicity would result in a local dead zone. The formation of small, but measurable, amounts of persistent chlorated hydrocarbons could also lead to long-term biological effects. Disinfection by ozone or gamma radiation would involve investments unacceptable in small plants. Ultraviolet radiation with wavelength 2500-2600 A has a powerful bacteriocidal effect and has been demonstrated to give bacterial mortality of 99.96 to 99.997 %. A standard plant produced in USA with a capacity of 11.3 m/sup 3//h is illustrated. UV radiation has no effect on the chemical composition of the water and the operating costs are low.

Laboratory studies on leaching of low grade uranium ores and treatment of low level liquid waste generated by leaching experiments

International Nuclear Information System (INIS)

Palabrica, O.T.; Antonino, E.J.; Caluag, L.A.; Villamater, D.

1980-07-01

Acid leaching experiments of preconcentrated uranium ore were carried out at a pulp density of 50% solids, using sulfuric acid with sodium chlorate as oxidant. The different leaching parameters considered in this work were temperature, oxidant level and leaching time. In the experimental procedure, the concentration of oxidant and the temperature were varied to determine how they affect the leaching process. Experimental results are illustrated in tabulated form for better interpretation. Uranium analyses were done by fluorimetric and delayed-neutron activation analysis. An anion exchange method using Dowex 1 x 8, 200-400 mesh (Cl - ) was used in treating the low-level liquid waste generated by leaching experiments. The purpose of this treatment was to minimize radioactive contamination in the waste materials and also to recover some of the uranium left in the liquid waste. (author)

The XPS study of physical and chemical forms of neptunium group on the surface of minerals

Directory of Open Access Journals (Sweden)

Teterin Anton Yu.

2010-01-01

Full Text Available The sorption behavior and the physical and chemical forms of neptunium on the surface of minerals of the two chlorate samples, biotite and kaolin, with different contents of Fe(II was studied. The liquid-liquid extraction and the X-ray photoelectron spectroscopy were employed to identify the valence forms of neptunium. On the basis of the obtained data the quantitative elemental composition of the surface of the studied minerals, as well as the ionic composition of the formed neptunium complexes was determined. It was shown that the Np(IV and Np(VI containing compounds did not form, while the complexes Np(VO+ -hydroxyl did form on the surface. The oxygen ions bonded with iron and oxygen belonging to water and/or of carboxyl were suggested to be present in the equatorial plane of the neptunyl group NpO+.

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

Science.gov (United States)

Viets, J.G.

1978-01-01

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

On eradication of woody plants with herbicides in fields and pastures

Directory of Open Access Journals (Sweden)

Jaakko Mukula

1950-01-01

Full Text Available On the initiative of the Department of Plant Husbandry of Agricultural Research Institute, experiments for destroying woody plants on fields and pastures were conducted in 1948—1949 with the following chemicals: Artificial hormones (sodium salt of 2,4-D, morpholine of 2,4-D, triethanolamine of 2,4-D, ethyl ester of 2,4-D, butyl ester of 2,4-D, and sodium salt of 2M-4K, potassium chlorate, and ammonium salt of dinitro-ortochresol. The substances Were applied in aqueous solutions, or as emulsions. Three different methods Were used: spray application to foliage, absorption through a cut branch, and application to soil. The following thicket-forming woody plants, common in Finland, were investigated: grey alder, Alnus incana (L. Willd., willow, Salix sp., birch, Betula sp., mountain ash, Sorbus aucuparia L., and aspen, Populus tremula L. Following conclusions have been drawn from the experiments; It is possible, and, probably with the exception of aspen, even advisable to destroy small sprouts, 0.5—1.5 m. in height, of these woody plants by spraying their foliage with artificial hormones early in summer, especially if mechanical clearing machines cannot be used. Of the experimented substances, esters of 2,4-D proved the most effective in spray applications, but satisfactory results were even secured with other artificial hormones. For different species of woody plants the necessary concentration of the solution varies from 0.1 to 0.4 % of the active substance (p. 6. For dense thickets, 0.5—1.5 m. in height, the amount of solution used Was 1250—2000 l. per ha., applied by means of knapsack type of pressure sprayers. All branches must be sprayed. It is difficult to make the treatment effective enough, if only one application is made. Therefore it is important to conduct a new control spraying after 2—3 weeks. Treatment is most effective, if given in Warm, sunny weather. The best results are secured with spraying towards the end of June or at

Chemical characterization of surface snow in Istanbul (NW Turkey) and their association with atmospheric circulations.

Science.gov (United States)

Baysal, Asli; Baltaci, Hakki; Ozbek, Nil; Destanoglu, Orhan; Ustabasi, Gul Sirin; Gumus, Gulcin

2017-06-01

The understanding of the impurities in natural snow is important in realizing its atmospheric quality, soil characteristics, and the pollution caused to the environment. Knowledge of the occurrence of major ions and trace metals in the snow in the megacity of Istanbul is very limited. This manuscript attempts to understand the origin of major soluble ions (fluoride, acetate, formate, chlorite, chloride, nitrite, chlorate, bromide, nitrate, sulfate, phosphate, and perchlorate) and some trace metals (Fe, Mn, Cd, Co, Ni, Pb, Zn, Cu) in winter surface snow, collected in Istanbul, Turkey. The sampling of the surface snow was conducted after each precipitation during the winter of 2015-2016 at three sites in the city. Besides the statistical evaluation of the major ions, and some trace metal concentrations, the chemical variations along with atmospheric circulations, which are important modification mechanisms that influence the concentrations, were investigated in the study. At examined locations and times, 12 major anions were investigated and in these anions fluoride, chlorite, chlorate, bromide, and perchlorate in the snow samples were below the detection limit; only SO 4 2- , NO 3 - , and CI - were found to be in the range of 1.11-17.90, 0.75-4.52, and 0.19-3.01 mg/L. Also, according to the trace element determination, the concentration was found to be 29.2-53.7, 2.0-16.1, 1.0-2.2, 50.1-71.1, 24.2-35.2, ND-7.9, 43.2-106.6, and 3.0-17.7 μg/L for Fe, Mn, Cd, Co, Ni, Pb, Zn, and Cu, respectively. The major anions and investigated trace elements here originated mainly from anthropogenic and atmospheric circulation and mainly influenced by northerly and southerly circulation patterns. While the main limitations in the present study may be the low number of samples that may not be entirely representative, accurately reflect identification, or support other previously observed local measurements, we believe that the type of data presented in this study has the potential

Structural and electrochemical properties of PEMA with the influence of MWCNT / TiO{sub 2} filler

Energy Technology Data Exchange (ETDEWEB)

Pradeepa, P.; Raj, S. Edwin; Kalaiselvimary, J.; Sowmya, G.; Selvakumar, K.; Prabhu, M. Ramesh, E-mail: Email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 003 (India)

2016-05-23

An attempt has been made to prepare a hybrid Nano composite polymer electrolytes (NCPES) based on Poly(ethyl methacrylate) (PEMA) doped with multiwalled carbon nanotubes (MWCNT) and Titanium oxide (TiO{sub 2}) as additives, Lithium per chlorate (LiClO{sub 4}) as ionic salt and Propylene Carbonate as plasticizer (PC) by using solvent casting technique. X-ray diffraction analysis (XRD) confirms the miscibility and amorphous nature of the prepared electrolytes. It has been found from the a.c impedance analysis that the inorganic filler reduces the bulk resistance of the electrolytes and thus ionic conductivity enhanced. A high dielectric loss value is observed for the case of doped MWCNT-PEMA in comparison with pure PEMA and doped TiO{sub 2} –PEMA membranes. Based on the study of relaxation spectra, it is found that the relaxation time decreases with increase in temperature.

Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

Energy Technology Data Exchange (ETDEWEB)

Nurhadini,, E-mail: nur-chem@yahoo.co.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institiut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

2015-09-30

This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

Enhanced specific capacitance of modified needle cokes by controlling oxidation treatment

International Nuclear Information System (INIS)

Yang, Sunhye; Kim, Ick-Jun; Choi, In-Sik; Soo Kim, Hyun; Tack Kim, Yu

2010-01-01

The electric double-layer performance of needle cokes can be affected by the morphology of structures. Hence, we introduce modified needle cokes by using simple oxidation treatment. The degree of graphitization with high specific capacitance is controlled by acid and heat treatment. The active sites of cokes are increased with increasing oxidation time. Dilute nitric acid (HNO 3 ) and sodium chlorate (NaClO 3 ) are used for the activation of cokes. In this case, the interlayer distance is dramatically increased from 3.5 to 8.9 A. The specific capacitances are 33 F g -1 and 30 F ml -1 , respectively, on a two-electrode system with a potential range of 0-2.5 V. The behaviors of double-layer capacitance are demonstrated by the charge-discharge process and the morphologies of modified needle cokes are analyzed by XRD, FE-SEM, BET and elemental analysis.

Delignification of softwood kraft pulp by chlorine dioxide in a laboratory bleaching liquor displacement reactor

International Nuclear Information System (INIS)

Hamzeh, Y.; Izadyar, S.

2008-01-01

The chlorine dioxide delignification efficiency of softwood kraft pulp in the laboratory liquor displacement reactor (fixed bed reactor) was investigated and compared with conventional batch reactor. The comparison of two reactors was made based on the effective efficiency and overall efficiency of chlorine dioxide. Effective efficiency corresponds to the oxidizing capacity of chlorine dioxide which consumed by organic materials. Comparison of two reactors based on the effective efficiency showed that the selectivity of delignification significantly enhanced in the displacement reactor in which the primary reaction products are eliminated from reaction zone by displacing flow. On the other hand, the formation of high amounts of chlorate in the reaction zone of displacement reactor reduces the overall efficiency of chlorine dioxide delignification stage. Thus, in spite of significant decrease in useless secondary reactions, this type of reactor would not be cost effective in the industrial scale

Capacitive behavior of highly-oxidized graphite

Science.gov (United States)

Ciszewski, Mateusz; Mianowski, Andrzej

2014-09-01

Capacitive behavior of a highly-oxidized graphite is presented in this paper. The graphite oxide was synthesized using an oxidizing mixture of potassium chlorate and concentrated fuming nitric acid. As-oxidized graphite was quantitatively and qualitatively analyzed with respect to the oxygen content and the species of oxygen-containing groups. Electrochemical measurements were performed in a two-electrode symmetric cell using KOH electrolyte. It was shown that prolonged oxidation causes an increase in the oxygen content while the interlayer distance remains constant. Specific capacitance increased with oxygen content in the electrode as a result of pseudo-capacitive effects, from 0.47 to 0.54 F/g for a scan rate of 20 mV/s and 0.67 to 1.15 F/g for a scan rate of 5 mV/s. Better cyclability was observed for the electrode with a higher oxygen amount.

Crossed-coil detection of two-photon excited nuclear quadrupole resonance

Science.gov (United States)

Eles, Philip T.; Michal, Carl A.

2005-08-01

Applying a recently developed theoretical framework for determining two-photon excitation Hamiltonians using average Hamiltonian theory, we calculate the excitation produced by half-resonant irradiation of the pure quadrupole resonance of a spin-3/2 system. This formalism provides expressions for the single-quantum and double-quantum nutation frequencies as well as the Bloch-Siegert shift. The dependence of the excitation strength on RF field orientation and the appearance of the free-induction signal along an axis perpendicular to the excitation field provide an unmistakable signature of two-photon excitation. We demonstrate single- and double-quantum excitation in an axially symmetric system using 35Cl in a single crystal of potassium chlorate ( ωQ = 28 MHz) with crossed-coil detection. A rotation plot verifies the orientation dependence of the two-photon excitation, and double-quantum coherences are observed directly with the application of a static external magnetic field.

Synthesis of Graphene Oxide by Oxidation of Graphite with Ferrate(VI) Compounds: Myth or Reality?

Science.gov (United States)

Sofer, Zdeněk; Luxa, Jan; Jankovský, Ondřej; Sedmidubský, David; Bystroň, Tomáš; Pumera, Martin

2016-09-19

It is well established that graphene oxide can be prepared by the oxidation of graphite using permanganate or chlorate in an acidic environment. Recently, however, the synthesis of graphene oxide using potassium ferrate(VI) ions has been reported. Herein, we critically replicate and evaluate this new ferrate(VI) oxidation method. In addition, we test the use of potassium ferrate(VI) for the synthesis of graphene oxide under various experimental routes. The synthesized materials are analyzed by a number of analytical methods in order to confirm or disprove the possibility of synthesizing graphene oxide by the ferrate(VI) oxidation route. Our results confirm the unsuitability of using ferrate(VI) for the oxidation of graphite on graphene oxide because of its high instability in an acidic environment and low oxidation power in neutral and alkaline environments. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The oxidation of alcohols and aldehydes by potassium chlorate in te presence of a ruthenium heteropolycomplex

International Nuclear Information System (INIS)

Kuznetsova, L.I.; Likholobov, V.A.; Detusheva, L.G.

1993-01-01

At interaction of K 2 RuOHCl 5 with Na 2 PW 11 O 39 catalyst for oxidation of primary alcohols and adlehydes up to proper carboxylic acid (yield ∼ 100%) was formed in aqueous solution, pH 2; 25-75 deg C. Acroleinwas demonstrated to be oxidized in acrylic acid with high selectivity

Meat Science and Muscle Biology Symposium: Ecological and dietary impactors of foodborne pathogens and methods to reduce fecal shedding in cattle.

Science.gov (United States)

Callaway, T R; Edrington, T S; Nisbet, D J

2014-04-01

Pathogenic bacteria can live asymptomatically within and on cattle and can enter the food chain but also can be transmitted to humans by fecal or direct animal contact. Reducing pathogenic bacterial incidence and populations within live cattle represents an important step in improving food safety. A broad range of preslaughter intervention strategies are being developed, which can be loosely classified as 1) directly antipathogen strategies, 2) competitive enhancement strategies (that use the microbiome's competitive nature against pathogens), and 3) animal management strategies. Included within these broad categories are such diverse methods as vaccination against foodborne pathogens, probiotics and prebiotics, bacterial viruses (i.e., bacteriophages), sodium chlorate feeding, and dietary and management changes that specifically alter the microbiome. The simultaneous application of 1 or more preharvest strategies has the potential to reduce human foodborne illnesses by erecting multiple hurdles preventing entry into humans. However, economic factors that govern producer profitability must be kept in mind while improving food safety.

GC-FTIR-MS analysis of volatile radiolytic products in the radiolysis of nitroaniline

International Nuclear Information System (INIS)

Kuruc, J.; Sahoo, M.K.; Kubinec, R.

1993-01-01

A good deal of products formed in the γ-radiolysis of isomeric nitroaniline solutions in carbon tetrachloride have been identified using GC-FTIR-MS technique. Tetrachloroethylene, chlorobenzene, hexachloroethane isomeric di-, tri- and tetrachlorobenzenes and chloroisocyanatobenzenes are among the important products formed in the radiolysis. Formation of dichlorobenzene is the result of ipso-substitution of both the nitro and aniline group by chlorine atom and the subsequent chloration of dichlorobenzene results in the formation of polychlorobenzenes. Chloroisocyanatobenzene is proposed to be the product arising from the interaction of dichlorocarbene and the nitro group of nitroaniline followed by chlorination of the resulting product, isocyanatobenzene. A 94% yield of undissolved 1,2-aminonitrobenzene chloride salt is obtained from the radiolysis of o-nitroaniline solution in carbon tetrachloride with a radiation yield of 1.83 molecules per 100 eV absorbed energy for an irradiation dose of 267 kGy. (author) 9 refs.; 3 figs.; 2 tabs

Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene

International Nuclear Information System (INIS)

Vasquez, M.; Cruz, G.; Timoshina, T.; Olayo, R.

2003-01-01

In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10 -2 Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

Some physiological aspects of nitrate reductase-deficient Nicotiana plumbaginifolia plants

International Nuclear Information System (INIS)

Saux, C.; Morot-Gaudry, J.F.; Lemoine, Y.; Caboche, M.

1986-01-01

Chlorate-resistant Nicotiana plumbaginifolia (cv. Viviani) mutants were found to be defective in the nitrate reductase apoprotein (NR - nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild type Nicotiana tabacum. The grafts of NR - plants were found to contain less malate but more amino acids, sugars and starch than the wild type. Moreover they were chlorotic, with a slight increase of the proportion of LH Chl a/b protein complexes and they exhibited a lowering of the efficiency of energy transfer between the light-harvesting complexes and the active centers. After 14 CO 2 pulse and chase experiments. The total 14 C incorporation of the mutant leaves was approximately 20% of that of the control. The NR - leaves mainly accumulated 14 C in the whole intermediates of the Calvin-cycle and in sucrose. In the most deficient NR leaves, chloroplasts were stuffed with large starch inclusions disorganizing the lamellar system

Some physiological aspects of nitrate reductase-deficient Nicotiana plumbaginifolia plants

Energy Technology Data Exchange (ETDEWEB)

Saux, C.; Morot-Gaudry, J.F.; Lemoine, Y.; Caboche, M.

1986-04-01

Chlorate-resistant Nicotiana plumbaginifolia (cv. Viviani) mutants were found to be defective in the nitrate reductase apoprotein (NR/sup -/ nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild type Nicotiana tabacum. The grafts of NR/sup -/ plants were found to contain less malate but more amino acids, sugars and starch than the wild type. Moreover they were chlorotic, with a slight increase of the proportion of LH Chl a/b protein complexes and they exhibited a lowering of the efficiency of energy transfer between the light-harvesting complexes and the active centers. After /sup 14/CO/sub 2/ pulse and chase experiments. The total /sup 14/C incorporation of the mutant leaves was approximately 20% of that of the control. The NR/sup -/ leaves mainly accumulated /sup 14/C in the whole intermediates of the Calvin-cycle and in sucrose. In the most deficient NR leaves, chloroplasts were stuffed with large starch inclusions disorganizing the lamellar system.

[Determination of inorganic ions in explosive residues by capillary zone electrophoresis].

Science.gov (United States)

Feng, Junhe; Guo, Baoyuan; Lin, Jin-Ming; Xu, Jianzhong; Zhou, Hong; Sun, Yuyou; Liu, Yao; Quan, Yangke; Lu, Xiaoming

2008-11-01

Five anions (chlorate, perchlorate, nitrate, nitrite, and sulfate) and two cations (ammonium and potassium) in explosive residues have been separated and determined by capillary zone electrophoresis (CZE) with indirect ultraviolet detection. The electrolyte buffer for the cation separation was 10 mmol/L pyridine (pH 4.5) -3 mmol/L 18-crown-6-ether. Ammonium and potassium ions were baseline separated in less than 2.6 min with the detection limits of 0.10 mg/L and 0.25 mg/L (S/N = 3), respectively. The electrolyte buffer for the anion separation consisted of 40 mmol/L boric acid-1.8 mmol/L potassium dichromate-2 mmol/L sodium tetraborate (pH 8.6), and tetramethyl ammonium hydroxide (TMAOH) was used as electroosmotic flow modifier. All five anions were well separated in less than 4.6 min with the detection limit range of 0.10 - 1.85 mg/L (S/N = 3). The method was successfully used in real sample investigations to confirm the type of explosives.

Simultaneous determination of inorganic anions and cations in explosive residues by ion chromatography.

Science.gov (United States)

Meng, Hong-Bo; Wang, Tian-Ran; Guo, Bao-Yuan; Hashi, Yuki; Guo, Can-Xiong; Lin, Jin-Ming

2008-07-15

A non-suppressed ion chromatographic method by connecting anion-exchange and cation-exchange columns directly was developed for the separation and determination of five inorganic anions (sulfate, nitrate, chloride, nitrite, and chlorate) and three cations (sodium, ammonium, and potassium) simultaneously in explosive residues. The mobile phase was composed of 3.5mM phthalic acid with 2% acetonitrile and water at flow rate of 0.2 mL/min. Under the optimal conditions, the eight inorganic ions were completely separated and detected simultaneously within 16 min. The limits of detection (S/N=3) of the anions and cations were in the range of 50-100 microg/L and 150-320 microg/L, respectively, the linear correlation coefficients were 0.9941-0.9996, and the R.S.D. of retention time and peak area were 0.10-0.29% and 5.65-8.12%, respectively. The method was applied successfully to the analysis of the explosive samples with satisfactory results.

MEMS-Based Solid Propellant Rocket Array Thruster

Science.gov (United States)

Tanaka, Shuji; Hosokawa, Ryuichiro; Tokudome, Shin-Ichiro; Hori, Keiichi; Saito, Hirobumi; Watanabe, Masashi; Esashi, Masayoshi

The prototype of a solid propellant rocket array thruster for simple attitude control of a 10 kg class micro-spacecraft was completed and tested. The prototype has 10×10 φ0.8 mm solid propellant micro-rockets arrayed at a pitch of 1.2 mm on a 20×22 mm substrate. To realize such a dense array of micro-rockets, each ignition heater is powered from the backside of the thruster through an electrical feedthrough which passes along a propellant cylinder wall. Boron/potassium nitrate propellant (NAB) is used with/without lead rhodanide/potassium chlorate/nitrocellulose ignition aid (RK). Impulse thrust was measured by a pendulum method in air. Ignition required electric power of at least 3 4 W with RK and 4 6 W without RK. Measured impulse thrusts were from 2×10-5 Ns to 3×10-4 Ns after the calculation of compensation for air dumping.

Maternal cautopyreiophagia as a rare cause of neonatal hemolysis: a case report.

Science.gov (United States)

Bernardo, Erika O; Matos, Renée I; Dawood, Taslim; Whiteway, Susan L

2015-03-01

Hyperbilirubinemia in the first 24 hours of life in a newborn is pathologic, necessitating additional evaluation. We report the first case of hemolysis and subsequent hyperbilirubinemia in an otherwise normal term neonate resulting from oxidative stress in the form of maternal cautopyreiophagia: the ingestion of burnt matchstick heads. During the third trimester of pregnancy, the infant's mother consumed more than 300 burnt matchstick heads weekly for 4 weeks. Matches contain potassium chlorate, a powerful oxidant that when ingested can ultimately lead to the destruction of erythrocytes, disseminated intravascular coagulation, kidney injury, or death. The infant's bilirubin rose as high as 17 mg/dL at 22 hours of life; however, the infant did well with a brief course of phototherapy. This case highlights the importance of prenatal questioning about maternal ingestion of potentially oxidative substances and assessing the possible risk for the infant. published in the public domain by the American Academy of Pediatrics.

Magnetic safety matches

Science.gov (United States)

Lindén, J.; Lindberg, M.; Greggas, A.; Jylhävuori, N.; Norrgrann, H.; Lill, J. O.

2017-07-01

In addition to the main ingredients; sulfur, potassium chlorate and carbon, ordinary safety matches contain various dyes, glues etc, giving the head of the match an even texture and appealing color. Among the common reddish-brown matches there are several types, which after ignition can be attracted by a strong magnet. Before ignition the match head is generally not attracted by the magnet. An elemental analysis based on proton-induced x-ray emission was performed to single out iron as the element responsible for the observed magnetism. 57Fe Mössbauer spectroscopy was used for identifying the various types of iron-compounds, present before and after ignition, responsible for the macroscopic magnetism: Fe2O3 before and Fe3O4 after. The reaction was verified by mixing the main chemicals in the match-head with Fe2O3 in glue and mounting the mixture on a match stick. The ash residue after igniting the mixture was magnetic.

Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene; Sintesis por plasma y caracterizacion de compuestos semiconductores derivados del poliacetileno

Energy Technology Data Exchange (ETDEWEB)

Vasquez, M.; Cruz, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [ESIQIE-IPN, 07738 Mexico D.F. (Mexico); Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

2003-07-01

In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

Survey of electrochemical production of inorganic compounds. Final report

Energy Technology Data Exchange (ETDEWEB)

1980-10-01

The electrochemical generation of inorganic compounds, excluding chlorine/caustic, has been critically reviewed. About 60 x 10/sup 12/ Btu/y fossil fuel equivalent will be used in the year 2000 for the electrosynthesis of inorganic compounds. Significant energy savings in chlorate production can result from the development of suitable electrocatalysts for lowering the cathodic overpotential. Perchlorates, electrolytic hypochlorite, electrolytic manganese dioxide, fluorine and other miscellaneous compounds use relatively small amounts of electrical energy. Implementation of caustic scrubber technology for stack gas cleanup would result in appreciable amounts of sodium sulfate which could be electrolyzed to regenerate caustic. Hydrogen peroxide, now produced by the alkyl anthraquinone process, could be made electrolytically by a new process coupling anodic oxidation of sulfate with cathodic reduction of oxygen in alkaline solution. Ozone is currently manufactured using energy-inefficient silent discharge equipment. A novel energy-efficient approach which uses an oxygen-enhanced anodic reaction is examined.

Integrative assessment of multiple pesticides as risk factors for non-Hodgkin's lymphoma among men.

Science.gov (United States)

De Roos, A J; Zahm, S H; Cantor, K P; Weisenburger, D D; Holmes, F F; Burmeister, L F; Blair, A

2003-09-01

An increased rate of non-Hodgkin's lymphoma (NHL) has been repeatedly observed among farmers, but identification of specific exposures that explain this observation has proven difficult. During the 1980s, the National Cancer Institute conducted three case-control studies of NHL in the midwestern United States. These pooled data were used to examine pesticide exposures in farming as risk factors for NHL in men. The large sample size (n = 3417) allowed analysis of 47 pesticides simultaneously, controlling for potential confounding by other pesticides in the model, and adjusting the estimates based on a prespecified variance to make them more stable. Reported use of several individual pesticides was associated with increased NHL incidence, including organophosphate insecticides coumaphos, diazinon, and fonofos, insecticides chlordane, dieldrin, and copper acetoarsenite, and herbicides atrazine, glyphosate, and sodium chlorate. A subanalysis of these "potentially carcinogenic" pesticides suggested a positive trend of risk with exposure to increasing numbers. Consideration of multiple exposures is important in accurately estimating specific effects and in evaluating realistic exposure scenarios.

Structure characterization, photoluminescence and dielectric properties of a new hybrid compound containing chlorate anions of zincate (II)

Science.gov (United States)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Ben Soltan, Wissem; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-04-01

A new hybrid compound, bis (2-aminophenylenamonium) tetrachlorozincate (II), was synthesized and formulated as (C6H9N2)2ZnCl4. Its crystal structure was solved by single crystal X-ray diffraction reveling that compound crystallizes in the monoclinic system, space group C2/c (N°: 15) with cell parameters a = 7.4957(4) Å, b = 25.6837(15) Å, c = 9.4041(5) Å, β = 94.35(0)°, V = 1805.23(45) Å3. Their atomic arrangement can be described as an alternation of inorganic and organic layers, [ZnCl4]2- tetrahedral anions and 2-aminophenylenamonium cations. The cohesion of the atomic arrangement is ensured by hydrogen bonds (strong Nsbnd H⋯N and weak Nsbnd H⋯Cl) and π-π stacking interactions between identical antiparallel organic moieties. In optical transmission and photoluminescence measurements, this material exhibit two absorption bands (253 and 316 nm) and a strong emission line (390 nm), while the thermal analysis disclosed a phase transition at 420-445 K previously to the sample decomposition at 476 K. Finally, electrical measurements were performed to discuss the phase-transition mechanism.

Evidence of martian perchlorate, chlorate, and nitrate in Mars meteorite EETA79001: Implications for oxidants and organics

Science.gov (United States)

Kounaves, Samuel P.; Carrier, Brandi L.; O'Neil, Glen D.; Stroble, Shannon T.; Claire, Mark W.

2014-02-01

The results from the Viking mission in the mid 1970s provided evidence that the martian surface contained oxidants responsible for destroying organic compounds. In 2008 the Phoenix Wet Chemistry Lab (WCL) found perchlorate (ClO4-) in three soil samples at concentrations from 0.5 to 0.7 wt%. The detection of chloromethane (CH3Cl) and dichloromethane (CH2Cl2) by the Viking pyrolysis gas chromatograph-mass spectrometer (GC-MS) may have been a result of ClO4- at that site oxidizing either terrestrial organic contaminates or, if present, indigenous organics. Recently, the Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) Curiosity directly measured the presence of CH3Cl, CH2Cl2 and, along with measurements of HCl and oxygen, indirectly indicate the presence of ClO4-. However, except for Phoenix, no other direct measurement of the ClO4- anion in martian soil or rock has been made. We report here ion chromatographic (IC) and isotopic analyses of a unique sawdust portion of the martian meteorite EETA79001 that show the presence by mass of 0.6 ± 0.1 ppm ClO4-, 1.4 ± 0.1 ppm ClO3-, and 16 ± 0.2 ppm NO3- at a quantity and location within the meteorite that is difficult to reconcile with terrestrial contamination. The sawdust sample consists of basaltic material with a minor salt-rich inclusion in a mass ratio of ∼300:1, thus the salts may be 300 times more concentrated within the inclusion than the whole sample. The molar ratios of NO3-:ClO4- and Cl:ClO4-, are very different for EETA79001 at ∼40:1 and 15:1, respectively, than the Antarctic soils and ice near where the meteorite was recovered at ∼10,000:1 and 5000:1, respectively. In addition, the isotope ratios for EETA79001 with δ15N = -10.48 ± 0.32‰ and δ18O = +51.61 ± 0.74‰ are significantly different from that of the nearby Miller Range blue ice with δ15N = +102.80 ± 0.14‰ and δ18O = +43.11 ± 0.64‰. This difference is notable, because if the meteorite had been contaminated with nitrate from the blue ice, the δ15N values should be the same. More importantly, the δ15N is similar to the uncontaminated Tissint Mars meteorite with δ15N = -4.5‰. These findings suggest a martian origin of the ClO4-, ClO3- and NO3- in EETA79001, and in conjunction with previous discoveries, support the hypothesis that they are present and ubiquitous on Mars. The presence of ClO3- in EETA79001 suggests the accompanying presence of other highly oxidizing oxychlorines such as ClO2- or ClO-, produced both by UV oxidation of Cl- and γ- and X-ray radiolysis of ClO4-. Since such intermediary species may contribute to oxidization of organic compounds, only highly refractory and/or well-protected organics are likely to survive. The global presence of ClO4-, ClO3-, and NO3-, has broad implications for the planet-wide water cycle, formation of brines, human habitability, organics, and life.

Dissection of the mechanism of manganese porphyrin-catalyzed chlorine dioxide generation.

Science.gov (United States)

Umile, Thomas P; Wang, Dong; Groves, John T

2011-10-17

Chlorine dioxide, an industrially important biocide and bleach, is produced rapidly and efficiently from chlorite ion in the presence of water-soluble, manganese porphyrins and porphyrazines at neutral pH under mild conditions. The electron-deficient manganese(III) tetra-(N,N-dimethyl)imidazolium porphyrin (MnTDMImP), tetra-(N,N-dimethyl)benzimidazolium (MnTDMBImP) porphyrin, and manganese(III) tetra-N-methyl-2,3-pyridinoporphyrazine (MnTM23PyPz) were found to be the most efficient catalysts for this process. The more typical manganese tetra-4-N-methylpyridiumporphyrin (Mn-4-TMPyP) was much less effective. Rates for the best catalysts were in the range of 0.24-32 TO/s with MnTM23PyPz being the fastest. The kinetics of reactions of the various ClO(x) species (e.g., chlorite ion, hypochlorous acid, and chlorine dioxide) with authentic oxomanganese(IV) and dioxomanganese(V)MnTDMImP intermediates were studied by stopped-flow spectroscopy. Rate-limiting oxidation of the manganese(III) catalyst by chlorite ion via oxygen atom transfer is proposed to afford a trans-dioxomanganese(V) intermediate. Both trans-dioxomanganese(V)TDMImP and oxoaqua-manganese(IV)TDMImP oxidize chlorite ion by 1-electron, generating the product chlorine dioxide with bimolecular rate constants of 6.30 × 10(3) M(-1) s(-1) and 3.13 × 10(3) M(-1) s(-1), respectively, at pH 6.8. Chlorine dioxide was able to oxidize manganese(III)TDMImP to oxomanganese(IV) at a similar rate, establishing a redox steady-state equilibrium under turnover conditions. Hypochlorous acid (HOCl) produced during turnover was found to rapidly and reversibly react with manganese(III)TDMImP to give dioxoMn(V)TDMImP and chloride ion. The measured equilibrium constant for this reaction (K(eq) = 2.2 at pH 5.1) afforded a value for the oxoMn(V)/Mn(III) redox couple under catalytic conditions (E' = 1.35 V vs NHE). In subsequent processes, chlorine dioxide reacts with both oxomanganese(V) and oxomanganese(IV)TDMImP to afford chlorate

Identification of inorganic improvised explosive devices by analysis of postblast residues using portable capillary electrophoresis instrumentation and indirect photometric detection with a light-emitting diode.

Science.gov (United States)

Hutchinson, Joseph P; Evenhuis, Christopher J; Johns, Cameron; Kazarian, Artaches A; Breadmore, Michael C; Macka, Miroslav; Hilder, Emily F; Guijt, Rosanne M; Dicinoski, Greg W; Haddad, Paul R

2007-09-15

A commercial portable capillary electrophoresis (CE) instrument has been used to separate inorganic anions and cations found in postblast residues from improvised explosive devices (IEDs) of the type used frequently in terrorism attacks. The purpose of this analysis was to identify the type of explosive used. The CE instrument was modified for use with an in-house miniaturized light-emitting diode (LED) detector to enable sensitive indirect photometric detection to be employed for the detection of 15 anions (acetate, benzoate, carbonate, chlorate, chloride, chlorite, cyanate, fluoride, nitrate, nitrite, perchlorate, phosphate, sulfate, thiocyanate, thiosulfate) and 12 cations (ammonium, monomethylammonium, ethylammonium, potassium, sodium, barium, strontium, magnesium, manganese, calcium, zinc, lead) as the target analytes. These ions are known to be present in postblast residues from inorganic IEDs constructed from ammonium nitrate/fuel oil mixtures, black powder, and chlorate/perchlorate/sugar mixtures. For the analysis of cations, a blue LED (470 nm) was used in conjunction with the highly absorbing cationic dye, chrysoidine (absorption maximum at 453 nm). A nonaqueous background electrolyte comprising 10 mM chrysoidine in methanol was found to give greatly improved baseline stability in comparison to aqueous electrolytes due to the increased solubility of chrysoidine and its decreased adsorption onto the capillary wall. Glacial acetic acid (0.7% v/v) was added to ensure chrysoidine was protonated and to enhance separation selectivity by means of complexation with transition metal ions. The 12 target cations were separated in less than 9.5 min with detection limits of 0.11-2.30 mg/L (calculated at a signal-to-noise ratio of 3). The anions separation system utilized a UV LED (370 nm) in conjunction with an aqueous chromate electrolyte (absorption maximum at 371 nm) consisting of 10 mM chromium(VI) oxide and 10 mM sodium chromate, buffered with 40 mM tris

Sodium chlorate reduces presence of Escherichia coli in feces of lambs and ewes managed in shed-lambing systems

Science.gov (United States)

Our objective was to establish doses of orally-administered NaClO3 that reduced presence of generic Escherichia coli in intestines of ewes and neonatal lambs managed in a shed-lambing system. Neonatal lambs (n = 32; age = 7.1 ± 1.2 d; BW = 6.8 ± 1.0 kg) and yearling ewes (n = 44; BW = 74.8 ± 5.6 kg)...

μ-Peroxido-bis­[acetonitrile­bis­(ethyl­enediamine)­cobalt(III)] tetrakis(per­chlorate)

Science.gov (United States)

Regeta, Khrystyna O.; Odarich, Iryna; Pavlova, Svetlana V.; Kalibabchuk, Valentina A.; Haukka, Matti

2010-01-01

The title compound, [Co2(O2)(CH3CN)2(C2H8N2)4](ClO4)4, consists of centrosymmetric binuclear cations and perchlorate anions. Two CoIII atoms, which have a slightly distorted octa­hedral coordination, are connected through a peroxido bridge; the O—O distance is 1.476 (3) Å. Both acetonitrile ligands are situated in a trans position with respect to the O—O bridge. In the crystal, the complex cations are connected by N—H⋯O hydrogen bonds between ethyl­endiamine NH groups and O atoms from the perchlorate anions and peroxide O atoms. PMID:21589305

Gene replacement in Penicillium roqueforti.

Science.gov (United States)

Goarin, Anne; Silar, Philippe; Malagnac, Fabienne

2015-05-01

Most cheese-making filamentous fungi lack suitable molecular tools to improve their biotechnology potential. Penicillium roqueforti, a species of high industrial importance, would benefit from functional data yielded by molecular genetic approaches. This work provides the first example of gene replacement by homologous recombination in P. roqueforti, demonstrating that knockout experiments can be performed in this fungus. To do so, we improved the existing transformation method to integrate transgenes into P. roqueforti genome. In the meantime, we cloned the PrNiaD gene, which encodes a NADPH-dependent nitrate reductase that reduces nitrate to nitrite. Then, we performed a deletion of the PrNiaD gene from P. roqueforti strain AGO. The ΔPrNiaD mutant strain is more resistant to chlorate-containing medium than the wild-type strain, but did not grow on nitrate-containing medium. Because genomic data are now available, we believe that generating selective deletions of candidate genes will be a key step to open the way for a comprehensive exploration of gene function in P. roqueforti.

Genetic relatedness of Brazilian Colletotrichum truncatum isolates assessed by vegetative compatibility groups and RAPD analysis.

Science.gov (United States)

Sant'Anna, Juliane R; Miyamoto, Cláudia T; Rosada, Lúcia J; Franco, Claudinéia C S; Kaneshima, Edilson N; Castro-Prado, Marialba A A

2010-01-01

The genetic variation among nine soybean-originating isolates of Colletotrichum truncatum from different Brazilian states was studied. Nitrate non-utilizing (nit) mutants were obtained with potassium chlorate and used to characterize vegetative compatibility reactions, heterokaryosis and RAPD profile. Based on pairings of nit mutants from the different isolates, five vegetative complementation groups (VCG) were identified, and barriers to the formation of heterokaryons were observed among isolates derived from the same geographic area. No complementation was observed among any of the nit mutants recovered from the isolate A, which was designed heterokaryon-self-incompatible. Based on RAPD analysis, a polymorphism was detected among the wild isolate C and their nit1 and NitM mutants. RAPD amplification, with five different primers, also showed polymorphic profiles among Brazilian C. truncatum isolates. Dendrogram analysis resulted in a similarity degree ranging between 0.331 and 0.882 among isolates and identified three RAPD groups. Despite the lack of a correlation between the RAPD analysis and the vegetative compatibility grouping, results demonstrated the potential of VCG analysis to differentiate C. truncatum isolates genotypically similar when compared by RAPD.

Use of Cu+1 dopant and it's doping effects on polyaniline conducting system in water and tetrahydrofuran

Science.gov (United States)

Ali, Vazid; Kaur, Raminder; Kamal, Neel; Singh, Sukhmehar; Jain, S. C.; Kang, H. P. S.; Zulfequar, M.; Husain, M.

2006-04-01

The structural modification and properties of polymeric materials are of utmost importance in deciding their applications. In the present study, the synthesis of polyaniline (PANI) has been carried out via chemical oxidation in acidic medium by potassium-dichromate and the yield of synthesized polyaniline was found to be 75 80%. The copper per chlorate tetrabenzonitrile salt (CuClO4·4BN) used for chemical doping in synthesized polyaniline is stable in organic solvent like acetonitrile (AN) and benzonitrile (BN). The effect of Cu+1 oxidation state (dopant) in polyaniline has been characterized by FTIR. Electrical and dielectric measurements show the decrease in the intensity of the Cu+1 salt signal and the appearance of a radical signal due to the formation of oxidative coupled in polymeric species. Electrical and dielectric properties of doped polyaniline samples show significant changes due to the effect of dopant (CuClO4·4BN). It is observed that the conductivity is contributing both by formation of ionic complex and particularly dominated by electronic due to the mobility of charge carriers along the polyaniline chain.

Physiological Response of Wheat to Chemical Desiccants Used to Simulate Post-Anthesis Drought Stress

Directory of Open Access Journals (Sweden)

Nasrein Mohamed Kamal

2018-04-01

Full Text Available Post-anthesis drought stress is one of the main constraints on the production of wheat (Triticum aestivum L.. Because field screening for post-anthesis drought tolerance is difficult, effective and validated methods to simulate drought in order to identify sources of tolerance can facilitate screening of breeding materials. Chemical desiccants are widely used to simulate post-anthesis drought stress. We aimed to identify physiological traits that respond to desiccants as they do to drought. We examined the responses of ‘Norin 61’ to six treatments in a greenhouse: irrigated control, drought after anthesis, and 2% or 4% potassium chlorate (KClO3 at anthesis (A or grain filling (GF. We measured δ13C in leaves, aboveground fresh biomass, stomatal conductance, chlorophyll content, harvest index, and grain yield. Both 2% and 4% KClO3 at both A and GF simulated the effect of drought stress. Selection of drought-tolerant genotypes can be aided by chlorophyll content and δ13C measurement of leaves when 2% or 4% KClO3 is used to simulate drought.

Orange-Pigmented Sputum as a Manifestation of Smoke Grenade Inhalation Injury.

Science.gov (United States)

Chatzivasiloglou, Fotini; Katsenos, Stamatis; Psara, Anthoula; Tsintiris, Konstantinos

2016-01-01

A 34-year-old man presented with scanty hemoptysis, orange-colored expectoration, and mild dyspnea. He was in an enclosed building taking part in a military training exercise inhaling an orange-colored smoke from a smoke grenade ignition. His symptoms developed immediately after the initial exposure but he sought medical assistance 20 hours later because of their persistence. Fiberoptic bronchoscopy was performed revealing diffuse inflammatory tracheobronchial tree with streaky orange-pigmented secretions in the trachea and both main-stem bronchi. Acute tracheobronchitis was diagnosed and the patient was treated with nebulized bronchodilators and intravenous corticosteroids showing complete recovery. To our knowledge, this is the first well-documented report of inhalation injury induced by a smoke bomb explosion including potassium chlorate oxidizer and Sudan I and presenting with orange-pigmented sputum production. Smoke inhalation injury is associated with significant morbidity and mortality. The heterogeneity of the smoke and the large variety of the resulting symptoms may be the reason why a definition, specific diagnostic criteria, and therapeutic guidelines are still lacking.

Oxychlorine Detections on Mars: Implications for Cl Cycling

Science.gov (United States)

Sutter, B.; Jackson, W. A.; Ming, D. W.; Archer, P. D.; Stern, J. C.; Mahaffy, P. R.; Gellert, R.

2016-01-01

The Sample Analysis at Mars (SAM) instrument has detected evolved O2 and HCl indicating the presence of perchlorate and/or chlorate (oxychlorine) in all 11 sediments analyzed to date. The hyperarid martian climate is believed to have allowed accumulation of oxychlorine and assumed chloride contents similar to those in hyperarid terrestrial settings. The linear correlation of oxychlorine and chloride of Gale Crater sediments is low (r (sup 2) equals 0.64). Correlations present in hyperarid Antarctica and the Atacama Desert are attributed to unaltered atmospheric source coupled with minimal redox cycling by biological activity. Terrestrial semi-arid to arid settings have low correlations similar to Gale Crater and are attributed to additional inputs of Cl minus from sea salt, dust, and/or proximal playa settings, and possible reduction of oxychlorine phases during wetter periods. While microbiological processes could contribute to low oxychlorine/chloride correlations on Mars, several abiotic mechanisms are more likely, such as changing oxychlorine production rates with time and/or post-depositional geochemical redox processes that altered the Gale Crater oxychlorine and chloride contents.

Synthesis of the arginine labelled by {sup 15}N on the amidine group; Synthese de l'arginine marquee par {sup 15}N dans le groupe amidine

Energy Technology Data Exchange (ETDEWEB)

Pichat, L; Clement, J [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1955-07-01

For some biologic studies, it was necessarily to have (+) arginine marked by nitrogen 15 in the amidine group. This report describes the synthesis of the labelled arginine. The first step is the synthesis of the methyl-isourated hydro-chlorate, the intermediate reactive, from the ClNH{sub 4} isotope. The arginine is obtained from the ornithine which we previously blocked the amino group as cupric complex. The mean yield in arginine reaches 30%, based on the ammonium chloride uses. (M.B.) [French] Pour certaines etudes biologiques, il etait indispensable de disposer de (+) arginine marquee par l'azote 15 dans le groupement amidine. Ce rapport decrit la synthese de l'ariginine marquee. La premiere etape est la synthese du chlorhydrate de methylisouree, intermediaire reactif, a partir du ClNH{sub 4} isotopique. L'obtention de l'arginine est obtenue a partir de l'ornithine dont on a prealablement bloque le groupe amino sous forme de complexe cuivrique. Le rendement global moyen en arginine atteint 30 %, base sur le chlorure d'ammonium utilise. (M.B.)

A mathematical model for hydrogen evolution in an electrochemical cell and experimental validation

International Nuclear Information System (INIS)

Mahmut D Mat; Yuksel Kaplan; Beycan Ibrahimoglu; Nejat Veziroglu; Rafig Alibeyli; Sadiq Kuliyev

2006-01-01

Electrochemical reaction is largely employed in various industrial areas such as hydrogen production, chlorate process, electroplating, metal purification etc. Most of these processes often take place with gas evaluation on the electrodes. Presence of gas phase in the liquid phase makes the problem two-phase flow which is much knowledge available from heat transfer and fluid mechanics studies. The motivation of this study is to investigate hydrogen release in an electrolysis processes from two-phase flow point of view and investigate effect of gas release on the electrolysis process. Hydrogen evolution, flow field and current density distribution in an electrochemical cell are investigated with a two-phase flow model. The mathematical model involves solutions of transport equations for the variables of each phase with allowance for inter phase transfer of mass and momentum. An experimental set-up is established to collect data to validate and improve the mathematical model. Void fraction is determined from measurement of resistivity changes in the system due to the presence of bubbles. A good agreement is obtained between numerical results and experimental data. (authors)

Thermal Decomposition of Calcium Perchlorate/Iron-Mineral Mixtures: Implications of the Evolved Oxygen from the Rocknest Eolian Deposit in Gale Crater, Mars

Science.gov (United States)

Bruck, A. M.; Sutter, B.; Ming, D. W.; Mahaffy, P.

2014-01-01

A major oxygen release between 300 and 500 C was detected by the Mars Curiosity Rover Sample Analysis at Mars (SAM) instrument at the Rocknest eolian deposit. Thermal decomposition of perchlorate (ClO4-) salts in the Rocknest samples are a possible explanation for this evolved oxygen release. Releative to Na-, K-, Mg-, and Fe-perchlorate, the thermal decomposition of Ca-perchlorate in laboratory experiments released O2 in the temperature range (400-500degC) closest to the O2 release temperatures observed for the Rocknest material. Furthermore, calcium perchlorate could have been the source of Cl in the chlorinated-hydrocarbons species that were detected by SAM. Different components in the Martian soil could affect the decomposition temperature of calcium per-chlorate or another oxychlorine species. This interaction of the two components in the soil could result in O2 release temperatures consistent with those detected by SAM in the Rocknest materials. The decomposition temperatures of various alkali metal perchlorates are known to decrease in the presence of a catalyst. The objective of this work is to investigate catalytic interactions on calcium perchlorate from various iron-bearing minerals known to be present in the Rocknest material

Phase diagrams of NaOCl-Na3PO4-H2O ternary system. Jiaensosan natrium-rinsan natrium-mizu sanseibun soheiko jotaizu

Energy Technology Data Exchange (ETDEWEB)

Hamano, A. (Sasebo College of Tehcnology, Nagasaki (Japan)); Kito, K. (Nippon Steel Chemical Co. Ltd., Tokyo (Japan))

1993-10-30

Sodium chlorate (NaOCl) aqueous solution is used widely as a bleach. Attempts have been made to extract crystals from this aqueous solution, but only with difficulty because of instability of the generated crystals. Generating Na3PO4 and solid solution has been attempted as a method to stabilize the crystals. The present study has prepared a phase equilibrium diagram for three components of NaOCl-Na3PO4-H2O at 5[degree]C and 10[degree]C for theoretical elucidation thereof. In the prepared diagram, the conjugate lines linking the saturated solution with the solution containing solid phase have not crossed at one point, but scattered on the solid phase line. This has made clear that no double salt has been generated, but solid solution has been produced. The mol ratio of NaOCl in the generated solid solution was 0.071 to 0.447 at 15[degree]C and 0.026 to 0.6 at 5[degree]C indicating that solid solution with composition of wider range than in literatures reported conventionally has been produced. 8 refs., 2 figs., 2 tabs.

Recycling of battery brownstone. Recycling von Batteriebraunstein

Energy Technology Data Exchange (ETDEWEB)

Pfeiffer, T

1987-02-05

The author analyzed three processes for treating brownstone from spent, Mg-O-containing batteries. Wet chemical processing in H/sub 2/SO/sub 4/ resulted in a gamma-MnO/sub 2/ with an oxidation rate > 1.95 at a discharge capacity of 280 mAh/g. The Hg concentration of the product brownstone was reduced to < 0.05% by adding chlorate to the acid. Drawbacks are the low bulk weight of MnO/sub 2/ and the acid product solution which contains Fe, Hg, Zn, and K which requires further processing. In the second process, the battery mass was separated into manganese/graphite and zinc in a fluidized bed with SO/sub 2//air/gas mixtures. Mercury is expelled at reaction temperature. In the third process, slurries of battery material and water were converted in a wet chemical process by blowing SO/sub 2//O/sub 2/ (air) gas mixtures into the slurry. The products were coarse-grained and similar to the fluidized-bed products except for the lower MgO/sub 2/ oxidation rate. Here, too, an acid solution containing metal ions was obtained . (orig./MM)

Removal of NO from flue gas by aqueous chlorine-dioxide scrubbing solution in a lab-scale bubbling reactor.

Science.gov (United States)

Deshwal, Bal Raj; Jin, Dong Seop; Lee, Si Hyun; Moon, Seung Hyun; Jung, Jong Hyeon; Lee, Hyung Keun

2008-02-11

The present study attempts to clean up nitric oxide from the simulated flue gas using aqueous chlorine-dioxide solution in the bubbling reactor. Chlorine-dioxide is generated by chloride-chlorate process. Experiments are carried out to examine the effect of various operating variables like input NO concentration, presence of SO(2), pH of the solution and NaCl feeding rate on the NO(x) removal efficiency at 45 degrees C. Complete oxidation of nitric oxide into nitrogen dioxide occurred on passing sufficient ClO(2) gas into the scrubbing solution. NO is finally converted into nitrate and ClO(2) is reduced into chloride ions. A plausible reaction mechanism concerning NO(x) removal by ClO(2) is suggested. DeNO(x) efficiency increased slightly with the increasing input NO concentration. The presence of SO(2) improved the NO(2) absorption but pH of solution showed marginal effect on NO(2) absorption. NO(x) removal mechanism changed when medium of solution changed from acidic to alkaline. A constant NO(x) removal efficiency of about 60% has been achieved in the wide pH range of 3-11 under optimized conditions.

Genetic relatedness of Brazilian Colletotrichum truncatum isolates assessed by vegetative compatibility groups and RAPD analysis

Directory of Open Access Journals (Sweden)

JULIANE R SANT’ANNA

2010-01-01

Full Text Available The genetic variation among nine soybean-originating isolates of Colletotrichum truncatum from different Brazilian states was studied. Nitrate non-utilizing (nit mutants were obtained with potassium chlorate and used to characterize vegetative compatibility reactions, heterokaryosis and RAPD profile. Based on pairings of nit mutants from the different isolates, five vegetative complementation groups (VCG were identified, and barriers to the formation of heterokaryons were observed among isolates derived from the same geographic area. No complementation was observed among any of the nit mutants recovered from the isolate A, which was designed heterokaryon-self-incompatible. Based on RAPD analysis, a polymorphism was detected among the wild isolate C and their nit1 and NitM mutants. RAPD amplification, with five different primers, also showed polymorphic profiles among Brazilian C. truncatum isolates. Dendrogram analysis resulted in a similarity degree ranging between 0.331 and 0.882 among isolates and identified three RAPD groups. Despite the lack of a correlation between the RAPD analysis and the vegetative compatibility grouping, results demonstrated the potential of VCG analysis to differentiate C. truncatum isolates genotypically similar when compared by RAPD.

Evaluation of isolation methods for pathogenic Yersinia enterocolitica from pig intestinal content.

Science.gov (United States)

Laukkanen, R; Hakkinen, M; Lundén, J; Fredriksson-Ahomaa, M; Johansson, T; Korkeala, H

2010-03-01

The aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic Yersinia enterocolitica from pig intestinal content. The four methods comprised of 15 isolation steps using selective enrichments (irgasan-ticarcillin-potassium chlorate and modified Rappaport broth) and mildly selective enrichments at 4 or 25 degrees C. Salmonella-Shigella-desoxycholate-calcium chloride agar, cefsulodin-irgasan-novobiocin agar were used as plating media. The most sensitive method detected 78% (53/68) of the positive samples. Individual isolation steps using cold enrichment as the only enrichment or as a pre-enrichment step with further selective enrichment showed the highest sensitivities (55-66%). All isolation methods resulted in high numbers of suspected colonies not confirmed as pathogenic Y. enterocolitica. Cold enrichment should be used in the detection of pathogenic Y. enterocolitica from pig intestinal contents. In addition, more than one parallel isolation step is needed. The study shows that depending on the isolation method used for Y. enterocolitica, the detected prevalence of Y. enterocolitica in pig intestinal contents varies greatly. More selective and sensitive isolation methods need to be developed for pathogenic Y. enterocolitica.

Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by /sup 14/C putrescine method

Energy Technology Data Exchange (ETDEWEB)

Fogel, W A [Polish Academy of Sciences, Cracow (Poland). Inst. of Pharmacology; Bieganski, T; Wozniak, J; Maslinski, C

1978-01-01

The ..delta../sup 1/ pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi /sup 14/C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation ..delta../sup 1/ pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced ..delta../sup 1/ pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on ..delta../sup 1/ pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme.

Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by 14C putrescine method

International Nuclear Information System (INIS)

Fogel, W.A.; Bieganski, T.; Wozniak, J.; Maslinski, C.

1978-01-01

The Δ 1 pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi 14 C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation Δ 1 pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced Δ 1 pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on Δ 1 pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme. (author)

"Let's take back our roots through Science". The Sicilian Sulfur: a mineralogical treasure to rediscover.

Science.gov (United States)

Parisi, Bianca

2015-04-01

The name of sulfur is synonymous of Sicily! Sicilian Sulfur minerals and evaporitic deposits are well-known because they are connected with an important evolution stage of the old mediterranean area. In this Island, in the southern part of Italy, a geological formation of Messinian age, called "gessoso solfifera", outcrops. These rocks are widespread in the south and south-west Sicily, and, there, salt mines and "zolfare", sulfur mines, were located. The formation is characterized by large amounts of gypsum, potassium salts, sodium chlorates and other deposits. Most of the main mineralogical museum collections all over the world have at least a sample of one of these minerals that are usually characterized by a high aesthetic quality. When I proposed a lesson on the origin of sulfur in evaporitic rocks, I realized that an important part of the hystory of our region was in danger to be forgotten by younger generation. The exploitation of this mineral resource in the past is strictly linked to the troubled social and cultural transformation of Sicily during the last century. Thus, this is a particularly suitable topic for a multidisciplinary approach. In cooperation with the Mineralogical Museum (SteBiCeF Department, University of Palermo), a learning project was proposed to a group of 4th year high school students. It has been carrying on in order to develop the knowledge of the geological and chemical features of evaporitic deposits and to promote scientific abilities together with a better understanding of social-environmental issues. Project aims and activities include: ➢ Solubility and saturation experiments to reconstruct a simplified model of minerals deposition ➢ Working in groups: collection of data about old geological outcrops and current evaporating basins where rocks are forming in the world as well as information on sicilian mines from literature and historical documents (video, interviews, pictures, newspapers and others) ➢ a guided tour of the

The viability and performance characterization of nano scale energetic materials on a semiconductor bridge (SCB)

Science.gov (United States)

Strohm, Gianna Sophia

The move from conventional energetic composites to nano scale energetic mixtures (nano energetics) has shown dramatic improvement in energy release rate and sensitivity to ignition. A possible application of nano energetics is on a semiconductor bridge (SCB). An SCB typically requires a tenth of the energy input as compared to a bridge wire design with the same no-fire and is capable of igniting in tens of microseconds. For very low energy applications, SCBs can be manufactured to extremely small sizes and it is necessary to find materials with particle sizes that are even smaller to function. Reactive particles of comparable size to the bridge can lead to problems with ignition reliability for small bridges. Nano-energetic composites and the use of SCBs have been significantly studied individually, however, the process of combining nano energetics with an SCB has not been investigated extensively and is the focus of this work. Goals of this study are to determine if nano energetics can be used with SCBs to further reduce the minimum energy required and improve reliability. The performance of nano-scale aluminum (nAl) and bismuth oxide (Bi2O3) with nitrocellulose (NC), Fluorel(TM) FC 2175 (chemically equivalent to VitonRTM) and Glycidyl Azide Polymer (GAP) as binders where quantified initially using the SenTest(TM) algorithm at three weight fractions (5, 7, and 9%) of binder. The threshold energy was calculated and compared to previous data using conventional materials such as zirconium potassium chlorate (ZPC), mercuric 5-Nitrotetrazol (DXN-1) and titanium sub-hydride potassium per-chlorate (TSPP). It was found that even though there where only slight differences in performance between the binders with nAl/Bi2O 3 at any of the three binder weight fractions, the results show that these nano energetic materials require about half of the threshold energy compared to conventional materials using an SCB with an 84x42 mum bridge. Binder limit testing was conducted to

Corrigendum to “Widespread occurrence of (per)chlorate in the Solar System” [Earth Planet. Sci. Lett. 430 (2015) 470–476

Science.gov (United States)

Jackson, W. Andrew; Davila, Alfonso F.; Sears, Derek W. G.; Coates, John D.; McKay, Christopher P.; Brundrett, Maeghan; Estrada, Nubia; Böhlke, John Karl

2016-01-01

The authors regret that two sets of data (Atacama (Rao et al., 2010) and Mars Meteorite Range (Kounaves et al., 2014)) in Fig. 2 of our article were plotted in the wrong units. The correction does not change the relationship between ClO3−">ClO3− and ClO4−">ClO4−; it only shifts the magnitude of the concentrations. The conclusions of the article are not affected. The corrected Fig. 2 appears below.

Effect of gamma irradiation on sulfur-cured chlorobutyl rubber

International Nuclear Information System (INIS)

Scagliusi, Sandra R.; Cardoso, Elisabeth E.L.; Ono, Lilian S.; Lugao, Ademar B.

2011-01-01

Chlorobutyl rubber (CIIR) is similarly manufactured to butyl rubber (IIR). The insertion of chlorine atom in isoprene group represents an improvement in its properties, such as: high vulcanizing speed, low permanent stress and compatibility with other types of rubber. The presence of reactive chlorine in butyl chlorate allows a variety of vulcanizing techniques, being the cure via sulfur, the most conventional. In these compounds carbon-halogen bonds are weaker than carbon-carbon and carbon-hydrogen bonds, and the main effect of radiation is to break the carbon-halogen bond to give an organic free radical. Irradiations of certain alkyl chlorides can bring about isomerism in which the location of the halogen atom is changed, the carbon skeleton of molecule remaining unaltered. Irradiation of n-butyl chlorides gives high yields of tertiary carbon. The major effect of high energy photon, such as gamma rays, in organic polymers is the generation of free radicals, along changes in mechanical properties. This work aims to the study of irradiation effect on mechanical properties of a sulfur cured chlorobutyl rubber compound, gamma irradiated within 25, 50, 100, 150 e 200 kGy doses range. The techniques used in their characterization were: strength - stress analysis and elasticity modulus. Results obtained were investigated, demonstrated and discussed. (author)

Proton and deuterium NMR experiments in zero field

International Nuclear Information System (INIS)

Millar, J.M.

1986-02-01

High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution 2 H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs

Ammonia-oxidizing activity and microbial community structure in acid tea (Camellia sinensis) orchard soil

International Nuclear Information System (INIS)

Okamura, K; Yamada, T; Hiraishi, A; Takanashi, A

2012-01-01

The purpose of this study was to determine the ammonia-oxidizing activity and the phylogentic composition of microorganisms involved in acid tea (Camellia sinensis) orchard soil. All soil samples were collected from three sites located in Tahara and Toyohashi, Aichi Prefecture, Japan. The potential nitrification rate (PNR) was measured by the chlorate inhibition method. The soil pH of tea orchards studied ranged from 2.78 to 4.84, differing significantly from sample to sample, whereas that of meadow and unplanted fields ranged from 5.78 to 6.35. The PNR ranged from 0.050 to 0.193 μg NO 2 - -Ng -1 h -1 and were positively correlated with the soil pH (r 2 0.382, p 2 - -Ng -1 h -1 ) and subjected to PCR-aided clone library analyses targeting archaeal and bacterial amoA genes. The detected archaeal clones separated from the cluster of the 'Soil clones' and tightly clustered with the clones originating from other acidic soil environments including the Chinese tea orchard soil. These results suggest that the specific archaeal populations dominate as the ammonia oxidizers in acid tea-orchard soils and possibly other acid soils, independent of geographic locations, which results from the adaptation to specific ecological niches.

Mirror Symmetry Breaking in Helical Polysilanes: Preference between Left and Right of Chemical and Physical Origin

Directory of Open Access Journals (Sweden)

Michiya Fujiki

2010-08-01

Full Text Available From elemental particles to human beings, matter is dissymmetric with respect to mirror symmetry. In 1860, Pasteur conjectured that biomolecular handedness— homochirality—may originate from certain inherent dissymmetric forces existing in the universe. Kipping, a pioneer of organosilicon chemistry, was interested in the handedness of sodium chlorate during his early research life. Since Kipping first synthesized several Si-Si bonded oligomers bearing phenyl groups, Si-Si bonded high polymers carrying various organic groups—polysilanes—can be prepared by sodium-mediated condensation of the corresponding organodichlorosilanes. Among these polysilanes, optically active helical polysilanes with enantiomeric pairs of organic side groups may be used for testing the mirror symmetry-breaking hypothesis by weak neutral current (WNC origin in the realm of chemistry and material science. Several theoretical studies have predicted that WNC-existing chiral molecules with stereogenic centers and/or stereogenic bonds allow for distinguishing between image and mirror image molecules. Based on several amplification mechanisms, theorists claimed that minute differences, though still very subtle, may be detectable by precise spectroscopic and physicochemical measurements if proper chiral molecular pairs were employed. The present paper reports comprehensively an inequality between six pairs of helical polysilane high polymers, presumably, detectable by (chiroptical and achiral 29Si-/13C- NMR spectra, and viscometric measurements.

Removal of chromium (VI from aqueous medium using chemically modified banana peels as efficient low-cost adsorbent

Directory of Open Access Journals (Sweden)

Ashraf Ali

2016-09-01

Full Text Available The adsorptive removal of hexavalent chromium Cr(VI from aqueous solutions was investigated by acrylonitrile grafted banana peels (GBPs. Banana peels were treated with 10% HCl, followed by alkaline hydrolysis with 10% NaOH, and washed thoroughly. The bleaching of alkali hydrolyzed peels was carried out with sodium chlorate (NaClO3 in the presence of hydrogen peroxide and glacial acetic acid. The grafting co-polymerization of acrylonitrile onto the bleached pulp was initiated by Fenton’s reagent (Fe+2/H2O2. The optimum conditions for adsorption of Cr(VI were found to be the following: pH 3, adsorbent dose 4 g/L, concentration 400 mg/L and contact time of 120 min. The surface morphology of adsorbent was characterized by scanning electron microscopy (SEM before and after the adsorption. The adsorption of Cr(VI onto grafted banana peels (GBPs was recorded to be 96%. The adsorption data were fully fitted with the Freundlich and Langmuir isotherm model and followed a pseudo-second order kinetic model. Thermodynamic study showed that the adsorption is exothermic and spontaneous. Owing to high efficiency and low cost, grafted banana peels (GBPs can be used as effective adsorbent for Cr(VI removal from wastewater.

Effect of gamma irradiation on sulfur-cured chlorobutyl rubber

Energy Technology Data Exchange (ETDEWEB)

Scagliusi, Sandra R.; Cardoso, Elisabeth E.L.; Ono, Lilian S.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

Chlorobutyl rubber (CIIR) is similarly manufactured to butyl rubber (IIR). The insertion of chlorine atom in isoprene group represents an improvement in its properties, such as: high vulcanizing speed, low permanent stress and compatibility with other types of rubber. The presence of reactive chlorine in butyl chlorate allows a variety of vulcanizing techniques, being the cure via sulfur, the most conventional. In these compounds carbon-halogen bonds are weaker than carbon-carbon and carbon-hydrogen bonds, and the main effect of radiation is to break the carbon-halogen bond to give an organic free radical. Irradiations of certain alkyl chlorides can bring about isomerism in which the location of the halogen atom is changed, the carbon skeleton of molecule remaining unaltered. Irradiation of n-butyl chlorides gives high yields of tertiary carbon. The major effect of high energy photon, such as gamma rays, in organic polymers is the generation of free radicals, along changes in mechanical properties. This work aims to the study of irradiation effect on mechanical properties of a sulfur cured chlorobutyl rubber compound, gamma irradiated within 25, 50, 100, 150 e 200 kGy doses range. The techniques used in their characterization were: strength - stress analysis and elasticity modulus. Results obtained were investigated, demonstrated and discussed. (author)

Waste hydrogen utilization project receives $12 M in federal support

Energy Technology Data Exchange (ETDEWEB)

Anon.

2005-10-01

This article announced that $12.2 million dollars in federal funding support, over a 3 year period, will be made available to Sacre-Davey Innovations to support the development and demonstration of the Integrated Waste Hydrogen Utilization Project (IWHUP). The IWHUP is a clean energy project that will develop and demonstrate the feasibility of using hydrogen generated as a byproduct of a sodium chlorate manufacturing plant in North Vancouver. Greenhouse gas emissions and fossil fuels will be reduced by using purified hydrogen to fuel vehicles. The full hydrogen value chain will also be demonstrated by the IWHUP. This includes the supply, storage, distribution and use of hydrogen. Eight light-duty trucks running on hydrogen will be included in the demonstration, along with 4 public transit buses converted to run on a combination of compressed natural gas and hydrogen, and a fuel cell system operating on hydrogen while providing electrical power to a car wash. The newsletter article discussed the funding leveraged from various sources as well as the names of project participants. The article also mentioned that the IWHUP fuel station in North Vancouver will play a key role in sustainable transportation demonstrations during the 2010 Olympic and Paralympic Winter Games in Vancouver.

Microbial redox processes in deep subsurface environments and the potential application of (perchlorate in oil reservoirs

Directory of Open Access Journals (Sweden)

Martin G Liebensteiner

2014-09-01

Full Text Available The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese- and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (perchlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (perchlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (perchlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (metagenome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (perchlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (perchlorate for bioremediation, souring control and microbial enhanced oil recovery are addressed.

Proton and deuterium NMR experiments in zero field. [Perdeuterated p-demethoxybenzene, perdeuterated malonic acid, diethyl terephthalate-d4, nonadecane-2,2'-D2, sodium propionate-D2

Energy Technology Data Exchange (ETDEWEB)

Millar, J.M.

1986-02-01

High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution /sup 2/H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs.

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Science.gov (United States)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-12-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300-2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%-1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Direct nucleation of silver nanoparticles on graphene sheet.

Science.gov (United States)

Singh, Manoj K; Titus, E; Krishna, R; Hawaldar, R R; Goncalves, G; Marques, P A A P; Gracio, J

2012-08-01

Silver (Ag) nanoparticles were synthesized on the surface of graphene sheet by the simultaneous reduction of Ag+ and graphene oxide (GO) in the presence of simple reducing agent, hydrazine hydrate (N2H4 x H2O). Both the Ag+ and GO were reduced and Ag+ was nucleated onto graphene. GO flakes were prepared by conventional chemical exfoliation method and in the presence of strong acidic medium of potassium chlorate. Silver nanoparticles were prepared using 0.01 M AgNO3 solution. The reduced GO sheet decorated with Ag is referred as G-Ag sample. G-Ag was characterized by FTIR (Fourier transform infrared) spectroscopy using GO as standard. An explicit alkene peak appeared around 1625 cm(-1) was observed in G-Ag sample. Besides, the characteristic carbonyl and hydroxyl peaks shows well reduction of GO. The FTIR therefore confirms the direct interaction of Ag into Graphene. SEM (scanning electron microscopy) and TEM (transmission electron microscopy) analysis were performed for morphological probing. The average size of Ag nanoparticles was confirmed by around 5-10 nm by the high-resolution TEM (HRTEM). The Ag quantum dots incorporated nanocomposite material could become prominent candidate for diverse applications including photovoltaic, catalysis, and biosensors etc.

Capillary isotachophoresis for the analysis of ionic liquid entities.

Science.gov (United States)

Markowska, Aleksandra; Stepnowski, Piotr

2010-07-01

Simple, selective and sensitive isotachophoretic methods for the analysis of ionic liquid (IL) compartments were developed in this study. A leading electrolyte containing 10 mM L-histidine + 10 mM histidine hydrochloride and a terminating electrolyte containing 5 mM glutamic acid + 5 mM L-histidine were selected to separate nitrate(V), chlorate(V), hexafluorophosphate, dicyanimide, trifluoromethanesulfonate, phosphate(V) and bis(trifluoromethanesulfonyl)imide in anionic mode. In contrast, seven short-chain alkylimidazolium, alkylpyrrolidinium, alkylpyridinium and non-chromophoric tetraalkylammonium and tetraalkylphosphonium IL cations were separated with 10 mM potassium hydroxide + 10 mM acetic acid as leading electrolyte, and 10 mM beta-alanine + 10 mM acetate as terminating electrolyte. Both methods were optimized and validated with good analytical performance parameters. LOD was about 3-5 microM, and the repeatability lay in the range of 1.06-5.59%. These methods were evaluated for their applicability to the analysis of soil samples and freshwater contaminated with ILs. In light of hitherto the absence of reports on the determination of non-chromophoric IL cations, this study delivers for the first time a universal method enabling analysis of these species. Moreover, as there is still significant lack of methodologies of IL anion analysis, the obtained results offer an interesting alternative in that matter.

Studies in useful hard x-ray induced chemistry

Science.gov (United States)

Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

2013-06-01

The observed rapid decomposition of potassium chlorate (via 2KClO3 + h ν --> 2KCl +3O2) via synchrotron hard x-ray irradiation (>10 keV) has enabled experiments that are developing novel and useful hard x-ray chemistry. We have observed a number of radiation-induced in situ decomposition reactions in various substances which release O2, H2, N2, NH3, and H2O in a diamond anvil cell (DAC) at ambient and high pressures. These novel acatalytic and isothermal reactions represent a highly controllable, penetrating, and focused method to initiate chemistry (including x-ray induced combustion) in sealed and/or isolated chambers which maintain matter under extreme conditions. During our studies, we have typically observed a slowing of decomposition with pressure including phase dependent decomposition of KClO3. Energy dependent studies have observed an apparent resonance near 15 keV at which the decomposition rate is maximized. This may enable use of much lower flux and portable x-ray sources (e.g. x-ray tubes) in larger scale experiments. These developments support novel means to load DACs and control chemical reactions providing novel routes of synthesis of novel materials under extreme conditions.

Detection of Nonvolatile Inorganic Oxidizer-Based Explosives from Wipe Collections by Infrared Thermal Desorption-Direct Analysis in Real Time Mass Spectrometry.

Science.gov (United States)

Forbes, Thomas P; Sisco, Edward; Staymates, Matthew

2018-05-07

Infrared thermal desorption (IRTD) was coupled with direct analysis in real time mass spectrometry (DART-MS) for the detection of both inorganic and organic explosives from wipe collected samples. This platform generated discrete and rapid heating rates that allowed volatile and semivolatile organic explosives to thermally desorb at relatively lower temperatures, while still achieving elevated temperatures required to desorb nonvolatile inorganic oxidizer-based explosives. IRTD-DART-MS demonstrated the thermal desorption and detection of refractory potassium chlorate and potassium perchlorate oxidizers, compounds difficult to desorb with traditional moderate-temperature resistance-based thermal desorbers. Nanogram to sub-nanogram sensitivities were established for analysis of a range of organic and inorganic oxidizer-based explosive compounds, with further enhancement limited by the thermal properties of the most common commercial wipe materials. Detailed investigations and high-speed visualization revealed conduction from the heated glass-mica base plate as the dominant process for heating of the wipe and analyte materials, resulting in thermal desorption through boiling, aerosolization, and vaporization of samples. The thermal desorption and ionization characteristics of the IRTD-DART technique resulted in optimal sensitivity for the formation of nitrate adducts with both organic and inorganic species. The IRTD-DART-MS coupling and IRTD in general offer promising explosive detection capabilities to the defense, security, and law enforcement arenas.

Pressure induced structural phase transition in solid oxidizer KClO3: A first-principles study

Science.gov (United States)

Yedukondalu, N.; Ghule, Vikas D.; Vaitheeswaran, G.

2013-05-01

High pressure behavior of potassium chlorate (KClO3) has been investigated from 0 to 10 GPa by means of first principles density functional theory calculations. The calculated ground state parameters, transition pressure, and phonon frequencies using semiempirical dispersion correction scheme are in excellent agreement with experiment. It is found that KClO3 undergoes a pressure induced first order phase transition with an associated volume collapse of 6.4% from monoclinic (P21/m) → rhombohedral (R3m) structure at 2.26 GPa, which is in good accord with experimental observation. However, the transition pressure was found to underestimate (0.11 GPa) and overestimate (3.57 GPa) using local density approximation and generalized gradient approximation functionals, respectively. Mechanical stability of both the phases is explained from the calculated single crystal elastic constants. In addition, the zone center phonon frequencies have been calculated using density functional perturbation theory at ambient as well as at high pressure and the lattice modes are found to soften under pressure between 0.6 and 1.2 GPa. The present study reveals that the observed structural phase transition leads to changes in the decomposition mechanism of KClO3 which corroborates with the experimental results.

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

International Nuclear Information System (INIS)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-01-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Energy Technology Data Exchange (ETDEWEB)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Pantoya, M. L. [Mechanical Engineering Department, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-12-21

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Comparative enzymology of the adenosine triphosphate sulfurylases from leaf tissue of selenium-accumulator and non-accumulator plants

Energy Technology Data Exchange (ETDEWEB)

Shaw, W H; Anderson, J W

1974-01-01

ATP sulfurylases were partially purified (20-40-fold) from leaf tissue of Astragalus bisulcatus, Astragalus racemosus (selenium-accumulator species) and Astragalus hamosus and Astragalus sinicus (non-accumulator species). Activity was measured by sulfate-dependent PP/sub 1/-ATP exchange. The enzymes were separated from pyrophosphatase and adenosine triphosphatase activities. The properties of the Astragalus ATP sulfurylases were similar to the spinach enzyme. The ATP sulfurylases from both selenium-accumulator and non-accumulator species catalyzed selenate-dependent PP/sub 1/-ATP exchange; selenate competed with sulfate. The ratio of V(selenate)/V(sulfate) and K/sub m/ (selenate)/K/sub m/(sulfate) was approximately the same for the enzyme from each species. Sulfate-dependent PP/sub 1/-ATP exchange was inhibited by ADP, chlorate and nitrate. The kinetics of the inhibition for each enzyme were consistent with an ordered reaction mechanisms, in which ATP is the first substrate to react with the enzyme and PP/sub 1/ is the first product released. Synthesis of adenosine 5'-(/sup 35/S)sulfatophosphate from (/sup 35/S)sulfate was demonstrated by coupling the Astrgalus ATP sulfurylases with Mg/sup 2 +/-dependent pyrophosphatase; the reaction was inhibited by selenate. An analogous reaction using (/sup 75/Se)selenate as substrate could not be demonstrated.

PLA-b-PEG/magnetite hyperthermic agent prepared by Ugi four component condensation

Directory of Open Access Journals (Sweden)

L. P. Icart

2016-03-01

Full Text Available Ugi four component condensation (UFCC, is an important tool for the synthesis of different types of bioconjugate species. In this study, a PLA-PEG/magnetite magnetic composite was prepared by a synthetic-route approach based on UFCC. In particular, poly(lactic acid (PLA was synthesized by autocatalytic polycondensation. Also, poly(ethyleneglycol bis-amine (bis-amine PEG was synthesized by two different methods: via carbonyldiimidazol (CDI/ethylenediamine (ED (75% yield and via chlorate monochlorated acetyl (CCA/ED (95% yield. All products were characterized by gel permeation chromatography (GPC, hydrogen-1 nuclear magnetic resonance (NMR 1H, Fourier transform infrared (FTIR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. In addition, magnetite was prepared and modified to generate aldehyde groups which are also necessary for UFCC. This product was characterized by DSC, TGA, X-ray diffraction (XRD and magnetic force (MF techniques. Also, the magnetic composite PLA-PEG/magnetite was synthesized by UFCC. The calculated yield was equal to 80%. Furthermore, magnetic microspheres were prepared by the procedure of emulsion solvent-evaporation and characterized by scanning electron microscopy (SEM and magnetic induction hyperthermia (MIH. The main contribution of these results is to propose a new application for UFCC in the preparation of biomasked magnetic drug delivery systems able to improve the cancer treatment and even the welfare of the patients.

Highly dispersive ion exchangers in the analytical chemistry of uranium, particularly regarding separation methods

International Nuclear Information System (INIS)

Schoening, R.

1975-01-01

The reaction of water-insoluble polyvinyl pyrrolidon with uranium VI was investigated and a determination method for uranium was worked out in which the polyvinyl pyrrolidon was used as specific exchanger. Good separations of uranium from numerous transition metal ions were achieved here. The application of this exchanger for a fast and simple elution and determination method was of particular importance. A possible sorption mechanism was suggested based on the capacity curve of uranium with polyvinyl pyrrolidon and nitrogen and chloride content at maximum load. The sorption occurs by coordination of the carbonyl oxygen of single pyrrolidon rings with the protons of the complex acides and uranium. This assumption is supported by IR investigations. The sorbability of other inorganic acids was also investigated and possible structures were formulated for the sorption mechanism. In addition to this, ion exchangers were prepared based on cellulose by converting cellulose powder with aziridine and tris-1-aziridinyl-phosphine oxide. A polyethylene imine cellulose of high capacity was obtained in the conversion of cellulose powder with aziridine. This exchanger absorbs cobalt III very strongly. The exchanger loaded with cobalt III was used to separate the uranium as cyanato complex. The exchanger obtained in converting chlorated cellulose with tris-1-aziridinyl phosphine oxide also absorbs uranium VI very strongly. Thus a separation method of high specifity and selectivity was developed. (orig.) [de

Ammonia-oxidizing activity and microbial community structure in acid tea (Camellia sinensis) orchard soil

Science.gov (United States)

Okamura, K.; Takanashi, A.; Yamada, T.; Hiraishi, A.

2012-03-01

The purpose of this study was to determine the ammonia-oxidizing activity and the phylogentic composition of microorganisms involved in acid tea (Camellia sinensis) orchard soil. All soil samples were collected from three sites located in Tahara and Toyohashi, Aichi Prefecture, Japan. The potential nitrification rate (PNR) was measured by the chlorate inhibition method. The soil pH of tea orchards studied ranged from 2.78 to 4.84, differing significantly from sample to sample, whereas that of meadow and unplanted fields ranged from 5.78 to 6.35. The PNR ranged from 0.050 to 0.193 μg NO2--Ng-1 h-1 and were positively correlated with the soil pH (r2 = 0.382, p<0.001). Bulk DNA was extracted from a tea orchard soil (pH 4.8; PNR, 0.078 μg NO2--Ng-1 h-1) and subjected to PCR-aided clone library analyses targeting archaeal and bacterial amoA genes. The detected archaeal clones separated from the cluster of the 'Soil clones' and tightly clustered with the clones originating from other acidic soil environments including the Chinese tea orchard soil. These results suggest that the specific archaeal populations dominate as the ammonia oxidizers in acid tea-orchard soils and possibly other acid soils, independent of geographic locations, which results from the adaptation to specific ecological niches.

Consequence of absence of nitrate reductase activity on photosynthesis in Nicotiana plumbaginifolia plants

International Nuclear Information System (INIS)

Saux, C.; Lemoine, Y.; Marion-Poll, A.; Valadier, M.H.; Deng, M.; Morot-Gaudry, J.F.

1987-01-01

Chlorate-resistant Nicotiana plumbaginifolia (cv Viviani) mutants were found to be deficient in the nitrate reductase apoprotein (NR - nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild-type Nicotiana tabacum plants. The grafts of mutant plants were chlorotic compared to the grafts of wild type. Mutant leaves did not accumulate nitrogen but contained less malate and more glutamine than wild leaves. They exhibited a slight increase of the proportion of the light-harvesting chlorophyll a/b protein complexes and a lowering of the efficiency of energy transfer between these complexes and the active centers. After a 3 second 14 CO 2 pulse, the total 14 C incorporation of the mutant leaves was approximately 20 5 of that of the control. The 14 C was essentially recovered in ribulose bisphosphate in these plants. It was consistent with a decline of ribulose bisphosphate carboxylase activity observed in the mutant. After a 3 second 14 CO 2 pulse followed by a 60 second chase with normal CO 2 , 14 C was mainly accumulated in starch which was labeled more in the mutant than in the wild type. These results confirm the observation that in the nitrate reductase deficient leaves, chloroplasts were loaded with large starch inclusions preceding disorganization of the photosynthetic apparatus

Retrotransposons of the Tnt1B family are mobile in Nicotiana plumbaginifolia and can induce alternative splicing of the host gene upon insertion.

Science.gov (United States)

Leprinc, A S; Grandbastien, M A; Christian, M

2001-11-01

Active retrotransposons have been identified in Nicotiana plumbaginifolia by their ability to disrupt the nitrate reductase gene in chlorate-resistant mutants selected from protoplast-derived cultures. In mutants E23 and F97, two independent insertions of Tnp2, a new retrotransposon closely related to the tobacco Tnt1 elements, were detected in the nitrate reductase gene. These two Tnp2 elements are members of the Tnt1B subfamily which shows that Tnt1B elements can be active and mutagenic in the N. plumbaginifolia genome. Furthermore, these results suggest that Tnt1B is the most active family of Tntl elements in N. plumbaginifolia, whereas in tobacco only members of the Tnt1A subfamily were found inserted in the nitrate reductase gene. The transcriptional regulations of Tnp2 and Tnt1A elements are most probably different due to non-conserved U3 regions. Our results thus support the hypothesis that different Nicotiana species contain different active Tntl subfamilies and that only one active Tntl subfamily might be maintained in each of these species. The Tnp2 insertion found in the F97 mutant was found to be spliced out of the nitrate reductase mRNA by activation of cryptic donor and acceptor sites in the nitrate reductase and the Tnp2 sequences respectively.

Consequence of absence of nitrate reductase activity on photosynthesis in Nicotiana plumbaginifolia plants

Energy Technology Data Exchange (ETDEWEB)

Saux, C.; Lemoine, Y.; Marion-Poll, A.; Valadier, M.H.; Deng, M.; Morot-Gaudry, J.F.

1987-05-01

Chlorate-resistant Nicotiana plumbaginifolia (cv Viviani) mutants were found to be deficient in the nitrate reductase apoprotein (NR/sup -/ nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild-type Nicotiana tabacum plants. The grafts of mutant plants were chlorotic compared to the grafts of wild type. Mutant leaves did not accumulate nitrogen but contained less malate and more glutamine than wild leaves. They exhibited a slight increase of the proportion of the light-harvesting chlorophyll a/b protein complexes and a lowering of the efficiency of energy transfer between these complexes and the active centers. After a 3 second /sup 14/CO/sub 2/ pulse, the total /sup 14/C incorporation of the mutant leaves was approximately 20/sup 5/ of that of the control. The /sup 14/C was essentially recovered in ribulose bisphosphate in these plants. It was consistent with a decline of ribulose bisphosphate carboxylase activity observed in the mutant. After a 3 second /sup 14/CO/sub 2/ pulse followed by a 60 second chase with normal CO/sub 2/, /sup 14/C was mainly accumulated in starch which was labeled more in the mutant than in the wild type. These results confirm the observation that in the nitrate reductase deficient leaves, chloroplasts were loaded with large starch inclusions preceding disorganization of the photosynthetic apparatus.

Effect of sampling and short isolation methodologies on the recovery of human pathogenic Yersinia enterocolitica from pig tonsils.

Science.gov (United States)

Van Damme, Inge; Berkvens, Dirk; De Zutter, Lieven

2012-07-01

The objective of this study was to determine the effect of sampling (swab samples compared to destructive samples) on isolation rates of human pathogenic Yersinia enterocolitica from pig tonsils. Moreover, the relative efficiency of different rapid, routinely applicable isolation methods was evaluated. Therefore, swab and destructive samples from tonsils of 120 pigs at slaughter were analyzed in parallel using direct plating and different enrichment methods. Salmonella-Shigella-desoxycholate-calcium chloride (SSDC) agar, cefsulodin-irgasan-novobiocin (CIN) agar, and Yersinia enterocolitica chromogenic medium (YeCM) were used as selective agar media. For enrichment, irgasan-ticarcillin-potassium chlorate (ITC) broth and peptone-sorbitol-bile (PSB) broth were incubated at 25°C for 48 h. Overall, 55 tonsils (45.8%) were positive for Y. enterocolitica bioserotype 4/O:3. Recovery was significantly higher using the destructive method compared to the swabbing method. Direct plating resulted in 47 and 28 Y. enterocolitica-positive destructive and swab samples, respectively. Alkali treatment of PSB and ITC enrichment broths significantly increased recovery of pathogenic Y. enterocolitica from destructive tonsil samples. The performance of YeCM for qualitative and quantitative isolation of pathogenic Y. enterocolitica from pig tonsils was equal to SSDC and CIN. In conclusion, direct plating and ISO 10273: 2003 with minor modifications are suitable and rapid methods for isolation of pathogenic Y. enterocolitica from destructive tonsil samples.

Canadian Occidental Petroleum Ltd. 1998 annual report

International Nuclear Information System (INIS)

1999-01-01

Financial information from Canadian Occidental Petroleum Ltd. and a review of their 1998 operations was made available for the benefit of shareholders. The company's core oil and gas business activities include exploration, development, production and marketing of crude oil and natural gas. The company produces oil and gas in Canada, Yemen, the Gulf of Mexico and Nigeria. Canadian Occidental also owns a 7.23 per cent share in the Syncrude joint venture. The company is developing new production in Hay, British Columbia, offshore west Africa and offshore northwest Australia. They are also one of North America's top three manufacturers of sodium chlorate. The report presents a summary of operations, a thorough management discussion and analysis of results and provides the customary consolidated financial statements and notes. Overall, 1998 was described as a difficult year financially, due to falling commodity prices. On the operations side, the company experienced its best results to date, producing more oil and gas than ever before. The company also invested over $ 950 million in new projects and opportunities. Some of the Company's most promising projects are located offshore Nigeria, offshore northwest Australia, in the Gulf of Mexico and in western Canada. These projects are expected to add 40,000 BOE of production by early 2000, with promise of attractive returns even at current low oil prices. tabs., figs

Nitrogen-doped graphene: effect of graphite oxide precursors and nitrogen content on the electrochemical sensing properties.

Science.gov (United States)

Megawati, Monica; Chua, Chun Kiang; Sofer, Zdenek; Klímová, Kateřina; Pumera, Martin

2017-06-21

Graphene, produced via chemical methods, has been widely applied for electrochemical sensing due to its structural and electrochemical properties as well as its ease of production in large quantity. While nitrogen-doped graphenes are widely studied materials, the literature showing an effect of graphene oxide preparation methods on nitrogen quantity and chemical states as well as on defects and, in turn, on electrochemical sensing is non-existent. In this study, the properties of nitrogen-doped graphene materials, prepared via hydrothermal synthesis using graphite oxide produced by various classical methods using permanganate or chlorate oxidants Staudenmaier, Hummers, Hofmann and Brodie oxidation methods, were studied; the resulting nitrogen-doped graphene oxides were labeled as ST-GO, HU-GO, HO-GO and BR-GO, respectively. The electrochemical oxidation of biomolecules, such as ascorbic acid, uric acid, dopamine, nicotinamide adenine nucleotide and DNA free bases, was carried out using cyclic voltammetry and differential pulse voltammetry techniques. The nitrogen content in doped graphene oxides increased in the order ST-GO graphene followed this trend, as shown in the cyclic voltammograms. This is a very important finding that provides insight into the electrocatalytic effect of N-doped graphene. The nitrogen-doped graphene materials exhibited improved sensitivity over bare glassy carbon for ascorbic acid, uric acid and dopamine detection. These studies will enhance our understanding of the effects of graphite oxide precursors on the electrochemical sensing properties of nitrogen-doped graphene materials.

VLT/SINFONI OBSERVATIONS OF EUROPA: NEW INSIGHTS INTO THE SURFACE COMPOSITION

Energy Technology Data Exchange (ETDEWEB)

Ligier, N.; Poulet, F.; Carter, J.; Brunetto, R. [Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, F-91405 Orsay cedex (France); Gourgeot, F., E-mail: nicolas.ligier@ias.u-psud.fr [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago de Chile (Chile)

2016-06-01

We present new insights into Europa’s surface composition on the global scale from linear spectral modeling of a high spectral resolution data set acquired during a ground-based observation campaign using SINFONI{sup 4}, an adaptive optics near-infrared instrument on the Very Large Telescope (ESO). The spectral modeling confirms the typical “bullseye” distribution of sulfuric acid hydrate on the trailing hemisphere, which is consistent with Iogenic sulfur ion implantation. However, the traditional hypothesis of the presence of sulfate salts on the surface of the satellite is challenged as Mg-bearing chlorinated species (chloride, chlorate, and perchlorate) are found to provide improved spectral fits. The derived global distribution of Mg-chlorinated salts (and particularly chloride) is correlated with large-scale geomorphologic units such as chaos and darker areas, thus suggesting an endogenous origin. Based on the 1.65 μ m water-ice absorption band shape and position, the surface temperature is estimated to be in the range 110–130 K, and water ice is found to be predominantly in its crystalline state rather than amorphous. While amorphous water ice exhibits a strong correlation with the expected intensity of the Ionian plasma torus bombardment, crystalline water ice is instead more associated with distinct geomorphological units. Endogenous processes such as jets and ice heating due to active geology may explain this relationship. Otherwise, no evidence of a correlation between grain size for the water ice and the sputtering rate has been detected so far.

In-source collision induced dissociation of inorganic explosives for mass spectrometric signature detection and chemical imaging

Energy Technology Data Exchange (ETDEWEB)

Forbes, Thomas P., E-mail: thomas.forbes@nist.gov; Sisco, Edward

2015-09-10

The trace detection, bulk quantification, and chemical imaging of inorganic explosives and components was demonstrated utilizing in-source collision induced dissociation (CID) coupled with laser desorption/ionization mass spectrometry (LDI-MS). The incorporation of in-source CID provided direct control over the extent of adduct and cluster fragmentation as well as organic noise reduction for the enhanced detection of both the elemental and molecular ion signatures of fuel-oxidizer mixtures and other inorganic components of explosive devices. Investigation of oxidizer molecular anions, specifically, nitrates, chlorates, and perchlorates, identified that the optimal in-source CID existed at the transition between fragmentation of the ionic salt bonds and molecular anion bonds. The chemical imaging of oxidizer particles from latent fingerprints was demonstrated, including both cation and anion components in positive and negative mode mass spectrometry, respectively. This investigation demonstrated LDI-MS with in-source CID as a versatile tool for security fields, as well as environmental monitoring and nuclear safeguards, facilitating the detection of elemental and molecular inorganic compounds at nanogram levels. - Highlights: • In-source CID enhanced detection of elemental inorganics up to 1000-fold. • In-source CID optimization of polyatomic oxidizers enhanced detection up to 100-fold. • Optimal CID identified at transition from breaking ionic salt to molecular anion bonds. • Trace detection of inorganic explosives at nanogram levels was demonstrated. • Oxidizer particles were chemically imaged directly from latent fingerprints.

Perchlorate-Coupled Carbon Monoxide (CO Oxidation: Evidence for a Plausible Microbe-Mediated Reaction in Martian Brines

Directory of Open Access Journals (Sweden)

Marisa R. Myers

2017-12-01

Full Text Available The presence of hydrated salts on Mars indicates that some regions of its surface might be habitable if suitable metabolizable substrates are available. However, several lines of evidence have shown that Mars’ regolith contains only trace levels of the organic matter needed to support heterotrophic microbes. Due to the scarcity of organic carbon, carbon monoxide (CO at a concentration of about 700 parts per million (about 0.4 Pa might be the single most abundant readily available substrate that could support near-surface bacterial activity. Although a variety of electron acceptors can be coupled to CO oxidation, perchlorate is likely the most abundant potential oxidant in Mars’ brines. Whether perchlorate, a potent chaotrope, can support microbial CO oxidation has not been previously documented. We report here the first evidence for perchlorate-coupled CO oxidation based on assays with two distinct euryarchaeal extreme halophiles. CO oxidation occurred readily in 3.8 M NaCl brines with perchlorate concentrations from 0.01 to 1 M. Both isolates were able to couple CO with perchlorate or chlorate under anaerobic conditions with or without nitrate as an inducer for nitrate reductase, which serves as a perchlorate reductase in extreme halophiles. In the presence of perchlorate, CO concentrations were reduced to levels well below those found in Mars’ atmosphere. This indicates that CO could contribute to the survival of microbial populations in hydrated salt formations or brines if water activities are suitably permissive.

Ntdin, a tobacco senescence-associated gene, is involved in molybdenum cofactor biosynthesis.

Science.gov (United States)

Yang, Seung Hwan; Berberich, Thomas; Miyazaki, Atsushi; Sano, Hiroshi; Kusano, Tomonobu

2003-10-01

To date, dozens of genes have been reported to be up-regulated with senescence in higher plants. Radish din1 and its ortholog sen1 of Arabidopsis are known as such, but their function is not clear yet. Here we have isolated their counterpart cDNA from tobacco and designated it as NTDIN: Its product, Ntdin, a 185 amino acid polypeptide with 56.8% and 54.2% identity to Atsen1 and Rsdin1, respectively, is localized in chloroplasts. Transcripts of Ntdin are induced by sulfate or nitrate but not by phosphate, suggesting its involvement in sulfur and nitrogen metabolism. A database search revealed that Ntdin shows similarity with the C-terminal region of Nicotiana plumbaginifolia Cnx5, which functions in molybdenum cofactor (Moco) biosynthesis. Transgenic tobacco plants with suppressed Ntdin are more tolerant to chlorate, a substrate analog of nitrate reductase, than controls, implying low nitrate reductase activity in the transgenic plants due to a deficiency of Moco. Indeed, enzymatic activities of two molybdoenzymes, nitrate reductase and xanthine dehydrogenase, in transgenic plants are found to be significantly lower than in control plants. Direct measurement of Moco contents reveals that those transgenic plants contain about 5% Moco of those of the control plants. Abscisic acid and indole-3-acidic acid, whose biosynthetic pathways require Moco, up-regulated Ntdin expression. Taken together, it is concluded that Ntdin functions in a certain step in Moco biosynthesis.

Derivation of the critical effect size/benchmark response for the dose-response analysis of the uptake of radioactive iodine in the human thyroid.

Science.gov (United States)

Weterings, Peter J J M; Loftus, Christine; Lewandowski, Thomas A

2016-08-22

Potential adverse effects of chemical substances on thyroid function are usually examined by measuring serum levels of thyroid-related hormones. Instead, recent risk assessments for thyroid-active chemicals have focussed on iodine uptake inhibition, an upstream event that by itself is not necessarily adverse. Establishing the extent of uptake inhibition that can be considered de minimis, the chosen benchmark response (BMR), is therefore critical. The BMR values selected by two international advisory bodies were 5% and 50%, a difference that had correspondingly large impacts on the estimated risks and health-based guidance values that were established. Potential treatment-related inhibition of thyroidal iodine uptake is usually determined by comparing thyroidal uptake of radioactive iodine (RAIU) during treatment with a single pre-treatment RAIU value. In the present study it is demonstrated that the physiological intra-individual variation in iodine uptake is much larger than 5%. Consequently, in-treatment RAIU values, expressed as a percentage of the pre-treatment value, have an inherent variation, that needs to be considered when conducting dose-response analyses. Based on statistical and biological considerations, a BMR of 20% is proposed for benchmark dose analysis of human thyroidal iodine uptake data, to take the inherent variation in relative RAIU data into account. Implications for the tolerated daily intakes for perchlorate and chlorate, recently established by the European Food Safety Authority (EFSA), are discussed. Copyright © 2016 The Author(s). Published by Elsevier Ireland Ltd.. All rights reserved.

Mutation of the Arabidopsis NRT1.5 nitrate transporter causes defective root-to-shoot nitrate transport.

Science.gov (United States)

Lin, Shan-Hua; Kuo, Hui-Fen; Canivenc, Geneviève; Lin, Choun-Sea; Lepetit, Marc; Hsu, Po-Kai; Tillard, Pascal; Lin, Huey-Ling; Wang, Ya-Yun; Tsai, Chyn-Bey; Gojon, Alain; Tsay, Yi-Fang

2008-09-01

Little is known about the molecular and regulatory mechanisms of long-distance nitrate transport in higher plants. NRT1.5 is one of the 53 Arabidopsis thaliana nitrate transporter NRT1 (Peptide Transporter PTR) genes, of which two members, NRT1.1 (CHL1 for Chlorate resistant 1) and NRT1.2, have been shown to be involved in nitrate uptake. Functional analysis of cRNA-injected Xenopus laevis oocytes showed that NRT1.5 is a low-affinity, pH-dependent bidirectional nitrate transporter. Subcellular localization in plant protoplasts and in planta promoter-beta-glucuronidase analysis, as well as in situ hybridization, showed that NRT1.5 is located in the plasma membrane and is expressed in root pericycle cells close to the xylem. Knockdown or knockout mutations of NRT1.5 reduced the amount of nitrate transported from the root to the shoot, suggesting that NRT1.5 participates in root xylem loading of nitrate. However, root-to-shoot nitrate transport was not completely eliminated in the NRT1.5 knockout mutant, and reduction of NRT1.5 in the nrt1.1 background did not affect root-to-shoot nitrate transport. These data suggest that, in addition to that involving NRT1.5, another mechanism is responsible for xylem loading of nitrate. Further analyses of the nrt1.5 mutants revealed a regulatory loop between nitrate and potassium at the xylem transport step.

Gummi-Bears On Fire! Bringing Students and Scientists Together at the Alaska Summer Research Academy (ASRA)

Science.gov (United States)

Drake, J.; Schamel, D.; Fisher, P.; Terschak, J. A.; Stelling, P.; Almberg, L.; Phillips, E.; Forner, M.; Gregory, D.

2002-12-01

When a gummi-bear is introduced into hot potassium chlorate there is a powerful reaction. This is analogous to the response we have seen to the Alaska Summer Research Academy (ASRA). ASRA is a residential science research camp supported by the College of Science, Engineering and Mathematics at the University of Alaska Fairbanks. The hallmark of ASRA is the opportunity for small groups of 4 or fewer students, ages 10-17, to conduct scientific research and participate in engineering design projects with university faculty and researchers as mentors. Participating scientists, engineers, faculty, graduate students, and K-12 teachers from a variety of disciplines design individual research units and guide the students through designing and constructing a project, collecting data, and synthesizing results. The week-long camp culminates with the students from each project making a formal presentation to the camp and public. In its second year ASRA is already a huge success, quadrupling in size from 21 students in 2001 to 89 students in 2002. Due to a high percentage of returning students, we anticipate there will be a waiting list next year. This presentation contains perspectives from administrators, instructors, staff, and students. Based on our experience we feel there is a large potential demand for education and public outreach (EPO) in university settings. We believe the quality and depth of the ASRA experience directly contributes to the success of a worthwhile EPO program. ASRA will be portrayed as a useful model for EPO at other institutions.

Design and validation of inert homemade explosive simulants for X-ray-based inspection systems

Science.gov (United States)

Faust, Anthony A.; Nacson, Sabatino; Koffler, Bruce; Bourbeau, Éric; Gagne, Louis; Laing, Robin; Anderson, C. J.

2014-05-01

Transport Canada (TC), the Canadian Armed Forces, and other public security agencies have an interest in the assessment of the potential utility of advanced explosives detection technologies to aid in the detection and interdiction of commercial grade, military grade, and homemade or improvised explosives (HME or IE). The availability of suitable, non-hazardous, non-toxic, explosive simulants is of concern when assessing the potential utility of such detection systems. Lack of simulants limits the training opportunities, and ultimately the detection probability, of security personnel using these systems. While simulants for commercial and military grade explosives are available for a wide variety of detection technologies, the design and production of materials to simulate improvised explosives has not kept pace with this emerging threat. Funded by TC and the Canadian Safety and Security Program, Defence Research and Development Canada (DRDC), Visiontec Systems, and Optosecurity engaged in an effort to develop inert, non-toxic Xray interrogation simulants for IE materials such as ammonium nitrate, potassium chlorate, and triacetone triperoxide. These simulants were designed to mimic key X-ray interrogation-relevant material properties of real improvised explosives, principally their bulk density and effective atomic number. Different forms of the simulants were produced and tested, simulating the different explosive threat formulations that could be encountered by front line security workers. These simulants comply with safety and stability requirements, and as best as possible match form and homogeneity. This paper outlines the research program, simulant design, and validation.

Polysulfonate suramin inhibits Zika virus infection.

Science.gov (United States)

Tan, Chee Wah; Sam, I-Ching; Chong, Wei Lim; Lee, Vannajan Sanghiran; Chan, Yoke Fun

2017-07-01

Zika virus (ZIKV) is an arthropod-borne flavivirus that causes newborn microcephaly and Guillian-Barré syndrome in adults. No therapeutics are available to treat ZIKV infection or other flaviviruses. In this study, we explored the inhibitory effect of glycosaminoglycans and analogues against ZIKV infection. Highly sulfated heparin, dextran sulfate and suramin significantly inhibited ZIKV infection in Vero cells. De-sulfated heparin analogues lose inhibitory effect, implying that sulfonate groups are critical for viral inhibition. Suramin, an FDA-approved anti-parasitic drug, inhibits ZIKV infection with 3-5 log 10  PFU viral reduction with IC 50 value of ∼2.5-5 μg/ml (1.93 μM-3.85 μM). A time-of-drug-addition study revealed that suramin remains potent even when administrated at 1-24 hpi. Suramin inhibits ZIKV infection by preventing viral adsorption, entry and replication. Molecular dynamics simulation revealed stronger interaction of suramin with ZIKV NS3 helicase than with the envelope protein. Suramin warrants further investigation as a potential antiviral candidate for ZIKV infection. Heparan sulfate (HS) is a cellular attachment receptor for multiple flaviviruses. However, no direct ZIKV-heparin interaction was observed in heparin-binding analysis, and downregulate or removal of cellular HS with sodium chlorate or heparinase I/III did not inhibit ZIKV infection. This indicates that cell surface HS is not utilized by ZIKV as an attachment receptor. Copyright © 2017 Elsevier B.V. All rights reserved.

The global nitrogen regulator, FNR1, regulates fungal nutrition-genes and fitness during Fusarium oxysporum pathogenesis.

Science.gov (United States)

Divon, Hege Hvattum; Ziv, Carmit; Davydov, Olga; Yarden, Oded; Fluhr, Robert

2006-11-01

SUMMARY Fusarium oxysporum is a soil-borne pathogen that infects plants through the roots and uses the vascular system for host ingress. Specialized for this route of infection, F. oxysporum is able to adapt to the scarce nutrient environment in the xylem vessels. Here we report the cloning of the F. oxysporum global nitrogen regulator, Fnr1, and show that it is one of the determinants for fungal fitness during in planta growth. The Fnr1 gene has a single conserved GATA-type zinc finger domain and is 96% and 48% identical to AREA-GF from Gibberella fujikuroi, and NIT2 from Neurospora crassa, respectively. Fnr1 cDNA, expressed under a constitutive promoter, was able to complement functionally an N. crassa nit-2(RIP) mutant, restoring the ability of the mutant to utilize nitrate. Fnr1 disruption mutants showed high tolerance to chlorate and reduced ability to utilize several secondary nitrogen sources such as amino acids, hypoxanthine and uric acid, whereas growth on favourable nitrogen sources was not affected. Fnr1 disruption also abolished in vitro expression of nutrition genes, normally induced during the early phase of infection. In an infection assay on tomato seedlings, infection rate of disruption mutants was significantly delayed in comparison with the parental strain. Our results indicate that FNR1 mediates adaptation to nitrogen-poor conditions in planta through the regulation of secondary nitrogen acquisition, and as such acts as a determinant for fungal fitness during infection.

Sulfate radical-based water treatment in presence of chloride: formation of chlorate, inter-conversion of sulfate radicals into hydroxyl radicals and influence of bicarbonate.

Science.gov (United States)

Lutze, Holger V; Kerlin, Nils; Schmidt, Torsten C

2015-04-01

Sulfate radical (SO4(-)) based oxidation is discussed as a potential water treatment option and is already used in ground water remediation. However, the complex SO4(-) chemistry in various matrices is poorly understood. In that regard, the fast reaction of SO4(-) with Cl(-) is of high importance since Cl(-) belongs to the main constituents in aqueous environments. This reaction yields chlorine atoms (Cl) as primary products. Cl initiate a cascade of subsequent reactions with a pH dependent product pattern. At low pH ( 5 Cl mainly react with water yielding hydroxyl radicals. Thus, at moderate Cl(-) concentrations (mM range) the SO4(-)-based process may be converted into a conventional (hydroxyl radical -based) advanced oxidation process. The conversion of SO4(-) into OH, however, is interrupted in presence of bicarbonate by scavenging of Cl. Copyright © 2014. Published by Elsevier Ltd.

Water-Quality Constituents, Dissolved-Organic-Carbon Fractions, and Disinfection By-Product Formation in Water from Community Water-Supply Wells in New Jersey, 1998-99

Science.gov (United States)

Hopple, Jessica A.; Barringer, Julia L.; Koleis, Janece

2007-01-01

to a pH of 7, dosed with sodium hypochlorite, and incubated for 168 hours (seven days) at 25 ?C to form disinfection by-products (DBPs). Concentrations of the DBPs-trihalomethanes, haloacetic acids, haloacetonitriles, and chlorate-were measured. Concentrations of these compounds, with few exceptions, were higher in water from Coastal Plain wells than from wells in glacial and bedrock aquifers. The organic-carbon fractions were dosed with sodium hypochlorite, incubated for 168 hours at 25 ?C, and analyzed for trihalomethanes, haloacetic acids, haloacetonitriles, and chlorate. Concentrations of trihalomethanes and haloacetic acids were higher in most of the hydrophobic organic-acid fractions than in the hydrophilic fractions, with the highest concentrations in samples from Coastal Plain aquifers. Traces of haloacetonitriles were measured, mostly in the hydrophilic fraction. The aromaticity of the precursor DOC, as estimated by measurements of the absorbance of ultraviolet light at 254 nanometers, apparently is a factor in the DBP formation potentials determined, as aromaticity was greater in the samples that developed high concentrations of DBPs. VOCs may have contributed to the organic carbon present in some of the samples, but much of the DOC present in water from the 20 wells appeared to be natural in origin. The sediments of the Coastal Plain aquifers, in particular, contain substantial amounts of organic matter, which contribute ammonia, organic nitrogen, and aromatic DOC compounds to the ground water. Thus, the geologic characteristics of the aquifers appear to be a major factor in the potential for ground water to form DBPs when chlorinated.

Cultivation and characterization of thermophilic Nitrospira species from geothermal springs in the US Great Basin, China, and Armenia.

Science.gov (United States)

Edwards, Tara A; Calica, Nicole A; Huang, Dolores A; Manoharan, Namritha; Hou, Weiguo; Huang, Liuqin; Panosyan, Hovik; Dong, Hailiang; Hedlund, Brian P

2013-08-01

Despite its importance in the nitrogen cycle, little is known about nitrite oxidation at high temperatures. To bridge this gap, enrichment cultures were inoculated with sediment slurries from a variety of geothermal springs. While nitrite-oxidizing bacteria (NOB) were successfully enriched from seven hot springs located in US Great Basin, south-western China, and Armenia at ≤ 57.9 °C, all attempts to enrich NOB from > 10 hot springs at ≥ 61 °C failed. The stoichiometric conversion of nitrite to nitrate, chlorate sensitivity, and sensitivity to autoclaving all confirmed biological nitrite oxidation. Regardless of origin, all successful enrichments contained organisms with high 16S rRNA gene sequence identity (≥ 97%) with Nitrospira calida. In addition, Armenian enrichments also contained close relatives of Nitrospira moscoviensis. Physiological properties of all enrichments were similar, with a temperature optimum of 45-50 °C, yielding nitrite oxidation rates of 7.53 ± 1.20 to 23.0 ± 2.73 fmoles cell(-1) h(-1), and an upper temperature limit between 60 and 65 °C. The highest rates of NOB activity occurred with initial NO2 - concentrations of 0.5-0.75 mM; however, lower initial nitrite concentrations resulted in shorter lag times. The results presented here suggest a possible upper temperature limit of 60-65 °C for Nitrospira and demonstrate the wide geographic range of Nitrospira species in geothermal environments. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Precipitation and purification of uranium from rock phosphate

International Nuclear Information System (INIS)

AbowSlama, E.H.Y.; Sam, A.K.; Etemad Ebraheem

2014-01-01

This study was carried-out to leach uranium from rock phosphate using sulphuric acid in the presence of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia, magnesia and sodium hydroxide as precipitants, as well as purification of the products with TBP and matching its impurity levels with specifications of the commercial products. Alpha-particle spectrometry was used for determination of activity concentration of uranium isotopes in rock phosphate, resulting phosphoric acid, and in different forms of the yellow cake. Likewise, atomic absorption spectroscopy was used for determination of impurities. On the average, the equivalent mass concentration of uranium was 119.38 ± 79.66 ppm (rock phosphate) and 57.85 ± 20.46 ppm (phosphoric acid) with corresponding low percent of dissolution (48 %) which is considered low. The isotopic ratio ( 234 U: 238 U) in all stages of hydrometallurgical process was not much different from unity indicating lack of fractionation. Upon comparing the levels of impurities in different form of crude yellow cakes, it was found that the lowest levels were measured in hydrated trioxide (UO 3 ·xH 2 O). This implies that saturated magnesia is least aggressive relative to other precipitants and gives relatively pure crude cake. Therefore, it was used as an index to judge the relative purity of other forms of yellow cakes by taking the respective elemental ratios. The levels of impurities (Fe, Zn, Mn, Cu, Ni, Cd and Pb) in the purified yellow cake were found comparable with those specified for commercial products. (author)

The use of ion chromatography in environmental and process control in the nuclear industry. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

Mohamed, M M [Ultra Tech Inc, 28 Teiba St. Dokki-Cairo, (Egypt)

1996-03-01

Ion chromatography has become the method choice for determining sub ppb for inorganic anions and cations, such as chloride, sulfide, fluoride, sodium, potassium, and ammonium, in aqueous matrices. Steam generators in pressurized water reactors nuclear power plants occasionally experience tubing degradation by a variety of corrosion related mechanisms which depends on water chemistry. Ion chromatography is also used in other environmental applications such as air pollution, industrial hygiene, drinking water quality, and industrial waste treatment. In this paper, several methods of separation and detection are present and also a number of examples of samples for various types of water are shown. The examples will include sub ppb amounts of chloride, sulfate, sodium, potassium, and ammonium in high purity turbine steam. Testing of chlorinated drinking water for inorganic anions including chlorite, chloride chlorate nitrite, nitrate as other organic anions using chemically suppressed conductivity. The role of chemical suppression is discussed. The analysis of ppb levels of transition moles in high purity water using ion chromatography with post column derivatization and UV detection are reviewed. Testing of disinfected drinking water with ozone for bromate, the detection of cyanide in waste after acid digestion, and the detection of highly toxic hexavalent in the presence of trivalent chromium is discussed. A fast method for the analysis of rain water for anions and cations is described. The presentation will also show new method (chelation ion chromatography) which enables ppb levels of heavy metals to be determined as pollutants in difficult environmental matrices such seawater, and oyster tissue. 4 figs.

Ideonella azotifigens sp. nov., an aerobic diazotroph of the Betaproteobacteria isolated from grass rhizosphere soil, and emended description of the genus Ideonella.

Science.gov (United States)

Noar, Jesse D; Buckley, Daniel H

2009-08-01

Strain 1a22T, a nitrogen-fixing bacterium, was isolated from soil associated with the rhizosphere of a perennial grass growing in a fallow agricultural field in Ithaca, New York, USA. Analysis of the 16S rRNA gene sequence placed the strain in the Rubrivivax-Roseateles-Leptothrix-Azohydromonas-Aquincola-Ideonella branch of the Betaproteobacteria and the closest characterized relative was the type strain of Ideonella dechloratans (97.7% 16S rRNA sequence similarity). Cells of strain 1a22T were Gram-negative, motile, straight rods, which formed polyhydroxybutyrate-like granules and were positive for oxidase and weakly positive for catalase. Cells were chemo-organotrophic, unable to grow by reduction of chlorate or nitrate and grew exclusively through aerobic respiration. Growth with mannitol on N-free solid media caused the strain to produce copious amounts of slime. The G+C content of the genomic DNA was 67.4 mol%. The major cellular fatty acids were C16:1 cis-9 and C16:0 and cells contained significant amounts of the hydroxy fatty acids C10:0 3-OH, C12:0 2-OH and C12:0 3-OH. Based on DNA-DNA hybridization studies, 16S rRNA gene sequence analysis, fatty acid analysis, and morphological and physiological characteristics, strain 1a22T represents a novel species in the genus Ideonella, for which the name Ideonella azotifigens sp. nov. is proposed. The type strain of Ideonella azotifigens is 1a22T (=JCM 15503T=DSM 21438T).

Consumers’ perception and knowledge of food safety: results of questionnaires accessible on IZSalimenTO website

Directory of Open Access Journals (Sweden)

Amaranta Traversa

2015-04-01

Full Text Available The present survey was undertaken to investigate consumers’ knowledge of the main foodborne agents and dietary regimen during pregnancy. Data were collected using monthly questionnaires available on IZSalimenTO website between March 2013 and January 2014. Hepatitis A virus questionnaire: 20 respondents (77% recognized berries as foodstuff linked to the outbreak of hepatitis A. The majority correctly indicated as precautionary advice to boil berries before consumption. Botulism questionnaire: 29 respondents (62% indicated pesto as food involved in botulism alert in July 2013. The risk of infant botulism in infant less than 1 year old due to honey consumption is known by 24 respondents (51%. Main foodborne disease questionnaire: the risk of infection by Salmonella after the consumption of foods made with raw eggs is known by the majority (94%; N=17 as well as the treatments to be applied in order to make fresh fish safe from parasites (76%. Pregnancy questionnaire: 20 respondents (74% believed that washing vegetables and fruits with sodium bicarbonate or chlorate solution is able to inactivate Toxoplasma; only 4 (15% reported both raw meat and vegetables washed with sodium bicarbonate as food at risk. Results indicate that all consumers should be trained on behaviour and dietary regimen to be adopted in pregnancy and in infant <1 year old. The website may be considered as a useful tool to assess consumers’ knowledge: both the news section and the contents published may be a source of information and education for consumers on food safety.

The use of ion chromatography in environmental and process control in the nuclear industry. Vol. 4

International Nuclear Information System (INIS)

Mohamed, M.M.

1996-01-01

Ion chromatography has become the method choice for determining sub ppb for inorganic anions and cations, such as chloride, sulfide, fluoride, sodium, potassium, and ammonium, in aqueous matrices. Steam generators in pressurized water reactors nuclear power plants occasionally experience tubing degradation by a variety of corrosion related mechanisms which depends on water chemistry. Ion chromatography is also used in other environmental applications such as air pollution, industrial hygiene, drinking water quality, and industrial waste treatment. In this paper, several methods of separation and detection are present and also a number of examples of samples for various types of water are shown. The examples will include sub ppb amounts of chloride, sulfate, sodium, potassium, and ammonium in high purity turbine steam. Testing of chlorinated drinking water for inorganic anions including chlorite, chloride chlorate nitrite, nitrate as other organic anions using chemically suppressed conductivity. The role of chemical suppression is discussed. The analysis of ppb levels of transition moles in high purity water using ion chromatography with post column derivatization and UV detection are reviewed. Testing of disinfected drinking water with ozone for bromate, the detection of cyanide in waste after acid digestion, and the detection of highly toxic hexavalent in the presence of trivalent chromium is discussed. A fast method for the analysis of rain water for anions and cations is described. The presentation will also show new method (chelation ion chromatography) which enables ppb levels of heavy metals to be determined as pollutants in difficult environmental matrices such seawater, and oyster tissue. 4 figs

Yersinia enterocolitica in slaughter pig tonsils: enumeration and detection by enrichment versus direct plating culture.

Science.gov (United States)

Van Damme, Inge; Habib, Ihab; De Zutter, Lieven

2010-02-01

Tonsil samples from 139 slaughter pigs were examined for the presence of pathogenic Yersinia enterocolitica by enrichment procedures based on the standard method ISO 10273:2003. In addition, samples were tested by direct plating method to evaluate its efficiency compared to the enrichment culture methods and to quantify the level of contamination in porcine tonsils. In total, 52 samples (37.4%) were positive for pathogenic Y. enterocolitica, all belonging to bioserotype 4/O:3. Fifty out of the 52 positive samples (96.2%) were detected by direct plating. Enumeration showed an average concentration of 4.5 log(10) CFU g(-1) and 4.4 log(10) CFU g(-1) tonsil on Salmonella-Shigella-desoxycholate-calcium chloride (SSDC) and cefsulodin-irgasan-novobiocin (CIN) agar plates, respectively. The enrichment procedures recommended by the ISO 10273:2003 method were not optimal for the isolation of pathogenic Y. enterocolitica from pig tonsils: two days enrichment in irgasan-ticarcillin-potassium chlorate (ITC) broth resulted in an isolation rate of 84.6%, while 5 days enrichment in peptone-sorbitol-bile (PSB) broth recovered only 59.6% of positive samples. Reducing the enrichment time in PSB from 5 to 2 days resulted in a significantly higher recovery rate (94.2%) and might serve as an appropriate enrichment protocol for the isolation of pathogenic Y. enterocolitica from pig tonsils. Compared to enrichment culture methods, results based on direct plating can be obtained in a shorter time course and provide quantitative data that might be needed for further risk assessment studies.

Study of consumer fireworks post-blast residues by ATR-FTIR.

Science.gov (United States)

Martín-Alberca, Carlos; Zapata, Félix; Carrascosa, Héctor; Ortega-Ojeda, Fernando E; García-Ruiz, Carmen

2016-03-01

Specific analytical procedures are requested for the forensic analysis of pre- and post-blast consumer firework samples, which present significant challenges. Up to date, vibrational spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) have not been tested for the analysis of post-blast residues in spite of their interesting strengths for the forensic field. Therefore, this work proposes a simple and fast procedure for the sampling and analysis of consumer firework post-blast residues by a portable FTIR instrument with an Attenuated Total Reflection (ATR) accessory. In addition, the post-blast residues spectra of several consumer fireworks were studied in order to achieve the identification of their original chemical compositions. Hence, this work analysed 22 standard reagents usually employed to make consumer fireworks, or because they are related to their combustion products. Then, 5 different consumer fireworks were exploded, and their residues were sampled with dry cotton swabs and directly analysed by ATR-FTIR. In addition, their pre-blast fuses and charges were also analysed in order to stablish a proper comparison. As a result, the identification of the original chemical compositions of the post-blast samples was obtained. Some of the compounds found were potassium chlorate, barium nitrate, potassium nitrate, potassium perchlorate or charcoal. An additional study involving chemometric tools found that the results might greatly depend on the swab head type used for the sampling, and its sampling efficiency. The proposed procedure could be used as a complementary technique for the analysis of consumer fireworks post-blast residues. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of a hybrid-smectite nanomaterial formed by immobilizing of N-pyridin-2-ylmethylsuccinamic acid onto (3-aminopropyl)triethoxysilane modified smectite and its potentiometric sensor application

Science.gov (United States)

Topcu, Cihan; Caglar, Sema; Caglar, Bulent; Coldur, Fatih; Cubuk, Osman; Sarp, Gokhan; Gedik, Kubra; Bozkurt Cirak, Burcu; Tabak, Ahmet

2016-09-01

A novel N-pyridin-2-ylmethylsuccinamic acid-functionalized smectite nanomaterial was synthesized by immobilizing of N-pyridin-2-ylmethylsuccinamic acid through chemical bonding onto (3-aminopropyl)triethoxysilane modified smectite. The structural, thermal, morphological and surface properties of raw, silane-grafted and the N-pyridin-2-ylmethylsuccinamic acid-functionalized smectites were investigated by various characterization techniques. The thermal analysis data showed the presence of peaks in the temperature range from 200 °C to 600 °C due to the presence of physically adsorbed silanes, intercalated silanes, surface grafted silanes and chemically grafted silane molecules between the smectite layers. The powder x-ray diffraction patterns clearly indicated that the aminopropyl molecules also intercalated into the smectite interlayers as bilayer arrangement whereas N-pyridin-2-ylmethylsuccinamic acid molecules were only attached to 3-aminopropyltriethoxysilane molecules on the external surface and edges of clay and they did not intercalate. Fourier transform infrared spectroscopy confirms N-pyridin-2-ylmethylsuccinamic acid molecules bonding through the amide bond between the amine group of aminopropyltriethoxysilane molecules and a carboxylic acid functional group of N-pyridin-2-ylmethylsuccinamic acid molecules. The guest molecules functionalized onto the smectite caused significant alterations in the textural and morphological parameters of the raw smectite. The anchoring of N-pyridin-2-ylmethylsuccinamic acid molecules led to positive electrophoretic mobility values when compared to starting materials. N-pyridin-2-ylmethylsuccinamic acid-functionalized smectite was employed as an electroactive ingredient in the structure of potentiometric PVC-membrane sensor. The sensor exhibited more selective potentiometric response towards chlorate ions compared to the other common anionic species.

Fe-based soft magnetic composites coated with NiZn ferrite prepared by a co-precipitation method

Energy Technology Data Exchange (ETDEWEB)

Peng, Yuandong; Yi, Yi; Li, Liya; Ai, Hengyu; Wang, Xiaoxu [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Chen, Lulu [Jiangsu Eagle-globe Group Co., Ltd., Nantong 226600 (China)

2017-04-15

Fe powder was coated with NiZn ferrite by a co-precipitation method using chlorate as the raw material. Soft magnetic composites were manufactured via compaction and heat treatment of the coated powder. The coated powder and heat treated powder were analysed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. Their magnetic properties were determined using a Quantum Design-Vibrating Sample Magnetometer (QD-VSM). The composites were analysed with SEM and EDS. The permeability and magnetic loss of the composites were measured with a B-H curve analyzer. The results show that, using the co-precipitation method, the raw precipitate was successfully prepared and coated the pure Fe powder and turned into spinel NiZn ferrite treated at 600 ℃ for 1 h. After heat treatment at 500 ℃ under air, the insulation coating layer of soft magnetic composite (SMC) was not destroyed and containing Fe, Ni, Zn and oxygen. The permeabilities of the SMC are stable at edge of the 2–200 kHz frequency range and the total loss was lower. - Graphical abstract: Scanning electron microscopy (SEM) images of Fe/(NiZn)Fe{sub 2}O{sub 4} composite powder heated at 600 ℃ for 1 h. - Highlights: • Fe particles were coated with (NiZn)Fe{sub 2}O{sub 4} via a co-precipitation and calcined method. • Coating layers were uniform and dense. • The permeabilities of the SMC are stable at edge of the 2–200 kHz frequency range.

Heparan Sulfate and Chondroitin Sulfate Glycosaminoglycans Are Targeted by Bleomycin in Cancer Cells.

Science.gov (United States)

Li, Xiulian; Lan, Ying; He, Yanli; Liu, Yong; Luo, Heng; Yu, Haibo; Song, Ni; Ren, Sumei; Liu, Tianwei; Hao, Cui; Guo, Yunliang; Zhang, Lijuan

2017-01-01

Bleomycin is a clinically used anti-cancer drug that produces DNA breaks once inside of cells. However, bleomycin is a positively charged molecule and cannot get inside of cells by free diffusion. We previously reported that the cell surface negatively charged glycosaminoglycans (GAGs) may be involved in the cellular uptake of bleomycin. We also observed that a class of positively charged small molecules has Golgi localization once inside of the cells. We therefore hypothesized that bleomycin might perturb Golgi-operated GAG biosynthesis. We used stable isotope labeling coupled with LC/MS analysis of GAG disaccharides simultaneously from bleomycin-treated and non-treated cancer cells. To further understand the cytotoxicity of bleomycin and its relationship to GAGs, we used sodium chlorate to inhibit GAG sulfation and commercially available GAGs to compete for cell surface GAG/bleomycin interactions in seven cell lines including CHO745 defective in both heparan sulfate and chondroitin sulfate biosynthesis. we discovered that heparan sulfate GAG was significantly undersulfated and the quantity and disaccharide compositions of GAGs were changed in bleomycin-treated cells in a concentration- and time-dependent manner. We revealed that bleomycin-induced cytotoxicity was directly related to cell surface GAGs. GAGs were targeted by bleomycin both at cell surface and at Golgi. Thus, GAGs might be the biological relevant molecules that might be related to the bleomycin-induced fibrosis in certain cancer patients, a severe side effect with largely unknown molecular mechanism. © 2017 The Author(s). Published by S. Karger AG, Basel.

Effect of the Presence of Chlorates and Perchlorates on the Pyrolysis of Organic Compounds: Implications for Measurements Done with the SAM Experiment Onboard the Curiosity Rover

Science.gov (United States)

Millan, M.; Szopa, C.; Buch, A.; Belmahdi, I.; Coll, P.; Glavin, D. P.; Freissinet, C.; Archer, P. D., Jr.; Sutter, B.; Summons, R. E.;

The characterisation of Manganese (IV) compounds and the study of the thermal decomposition of Potassium Chlorate alone and with Mn(IV) and other oxides and salts

OpenAIRE

Goldblatt, Nicholas Zalmon

1998-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Manganese dioxide compounds are preferred curing agents for Polysulphide resins used as sealants in industry. These are required to have consistent setting characteristics and the investigation was initiated to characterise a number of proffered compounds of this type an to establish criteria by which an informed choice could be made of an optimum curing ages for a specific set of conditio...

Culturing Security System of Chemical Laboratory in Indonesia

Directory of Open Access Journals (Sweden)

Eka Dian Pusfitasari

2017-04-01

Full Text Available Indonesia has experiences on the lack of chemical security such as: a number of bombing terrors and hazardous chemicals found in food. Bomb used in terror is a homemade bomb made from chemicals which are widely spread in the research laboratories such as a mixture of pottasium chlorate, sulphur, and alumunium. Therefore, security of chemicals should be implemented to avoid the misused of the chemicals. Although it has experienced many cases of the misuse of chemicals, and many regulations and seminars related to chemical security have been held, but the implementation of chemical security is still a new thing for Indonesian citizens. The evident is coming from the interviews conducted in this study. Questions asked in this interview/survey included: the implementation of chemical safety and chemical security in laboratory; chemical inventory system and its regulation; and training needed for chemical security implementation. Respondents were basically a researcher from Government Research Institutes, University laboratories, senior high school laboratories, and service laboratories were still ambiguous in distinguishing chemical safety and chemical security. Because of this condition, most Indonesia chemical laboratories did not totally apply chemical security system. Education is very important step to raise people awareness and address this problem. Law and regulations should be sustained by all laboratory personnel activities to avoid chemical diversion to be used for harming people and environment. The Indonesia Government could also develop practical guidelines and standards to be applied to all chemical laboratories in Indonesia. These acts can help Government’s efforts to promote chemical security best practices which usually conducted by doing seminars and workshop.

Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

Energy Technology Data Exchange (ETDEWEB)

Garcia-Segura, Sergi, E-mail: sergigarcia@ub.edu [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Keller, Jürg [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Brillas, Enric [Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Radjenovic, Jelena, E-mail: j.radjenovic@awmc.uq.edu.au [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia)

2015-02-11

Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl{sup −} ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl{sub 2}/HClO/ClO{sup −}), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO{sup −} species led to the production of ClO{sub 3}{sup −} and ClO{sub 4}{sup −} ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment.

Novel nanostructured materials to develop oxygen-sensitive films for optical sensors

International Nuclear Information System (INIS)

Fernandez-Sanchez, Jorge F.; Cannas, Rita; Spichiger, Stefan; Steiger, Rolf; Spichiger-Keller, Ursula E.

2006-01-01

Novel nanostructured materials, such as aluminum oxide (AlOOH), silicon oxide (SiO 2 ) or zirconium oxide (ZrO 2 ) embedded into PVA, were investigated as potential matrices to incorporate organometallic compounds (OMCs) for the development of optical oxygen-sensitive sensors which make use of the principle of luminescence quenching. In order to assess the benefits and drawbacks of the nanoporous material, the luminescence quantum yield and the Stern-Volmer constants were investigated and compared with the values shown for the same OMCs solubilized in polymer films (polystyrene). Referred to polymer films, the incorporation of the dyes into nanoporous membranes increased the Stern-Volmer constant by more than a factor of 100. Their response time was less than 1 s and the optode membranes were stable at room temperature for at least 9 months. Sterilization by autoclavation and gamma irradiation resulted in a marginal loss in activity. The photostability and sterilizability of the oxygen-sensitive membranes and the performance of the optodes with respect to of different types of metal oxides are discussed in the paper, as well as the influence of the total pore volume (TPV), the pore diameter (PD), the transparency of the film and the geometry of the pores. The OMCs used in this work were: ETH T -3003 (tris(4,7-bis(4-octylphenyl)-1,10-phenanthroline) ruthenium(II)), N-926 (bis(2-phenylpyridinyl)-N 4 ,N 4 ,N 4 ',N 4 '-tetramethyl-(4,4'-diamine-2,2'-bipyridine) iridium(III) chlorate), N-833 (tetrabutylammonium bis(isothiocyanate) bis(2-phenylpyridinyl)-iridium(III)) and N-837 (tetrabutylammonium bis(cyanate) bis(2-phenylpyridinyl)-iridium(III))

The role of glutathione in DNA damage by potassium bromate in vitro.

Science.gov (United States)

Parsons, J L; Chipman, J K

2000-07-01

We have investigated the role of reduced glutathione (GSH) in the genetic toxicity of the rodent renal carcinogen potassium bromate (KBrO(3)). A statistically significant increase in the concentration of 8-oxodeoxyguanosine (8-oxodG) relative to deoxyguanosine was measured following incubation of calf thymus DNA with KBrO(3) and GSH or N-acetylcysteine (NACys). This was dependent on these thiols and was associated with the loss of GSH and production of oxidized glutathione. A short-lived (potassium chlorate (KClO(3)) or potassium iodate (KIO(3)) were used instead of KBrO(3), though GSH depletion also occurred with KIO(3), but not with KClO(3). Other reductants and thiols in combination with KBrO(3) did not cause a significant increase in DNA oxidation. DNA strand breakage was also induced by KBrO(3) in human white blood cells (5 mM) and rat kidney epithelial cells (NRK-52E, 1.5 mM). This was associated with an apparent small depletion of thiols in NRK-52E cells at 15 min and with an elevation of 8-oxodG at a delayed time of 24 h. Depletion of intra-cellular GSH by diethylmaleate in human lymphocytes decreased the amount of strand breakage induced by KBrO(3). Extracellular GSH, however, protected against DNA strand breakage by KBrO(3), possibly due to the inability of the reactive product to enter the cell. In contrast, membrane-permeant NACys enhanced KBrO(3)-induced DNA strand breakage in these cells. DNA damage by KBrO(3) is therefore largely dependent on access to intracellular GSH.

Nutrição mineral da soja perene (Glycine wightii Verdc.: I - Ensaio de adubação em solo de cerrado Mineral fertilization of soybeans (Glycine wightii Verdc.: I - Fertilizer trial in "cerrado" soil

Directory of Open Access Journals (Sweden)

Luiz A. C. Lovadini

1971-05-01

Full Text Available São relatados os resultados de uma experiência de adubação com delineamento fatorial 3³, instalada em solo de cerrado (Latossolo Vermelho Escuro fase arenosa, na Estação Experimental de Jupiá (CESP, para o estudo dos efeitos da aplicação de calcário, fósforo e potássio, em três níveis, na produção de forragem de soja perene. Os resultados experimentais revelam que o calcário e o fósforo produziram efeitos altamente significativos sôbre a produção; o potássio não provocou efeitos significativos, e tampouco foram significativas as interações entre os elementos estudados. Embora não significativa, ocorreu interação negativa entre calcário e fósforo: o efeito de cada um dêles foi diminuído sempre que a dose do outro foi aumentada.In this paper are discussed the results of a factorial experiment 3³ designed to study the effect of Ca (dolomite lime, P (superphosphate and K (potassium chlorate, on the production of perennial soybean on Dark Red Latosol. Both Ca and P alone had a highly significant effect on the production whereas K did not show any effect. There was no interaction among the three elements, but it was noticed that as Ca levels were increased it decreased the effect of P and as P levels were increased it decreased the Ca effect. In other words there was a negative relationship which was not significant.

Deregulation experiences in Alberta and Ontario

International Nuclear Information System (INIS)

Axford, D.

2003-01-01

A brief introduction of Nexen Chemicals, one of the largest producers of sodium chlorate in the world, was offered, and a map displaying its locations throughout the world was displayed. Nexen is one of Canada's largest independent oil and gas producers, while Nexen Marketing is involved in the marketing of natural gas in North America. In January 2001, the deregulated market opened in Alberta. High natural gas prices, generation shortages, high prices in California and an upcoming provincial election all combined to complicate the situation. A high degree of volatility characterized the market. A chart displaying weekly average Alberta power and gas prices from Jan 2002 to 13 Oct 2002 was shown. In Ontario, the market opened in May 2002, and the demand growth rate was in the 1 to 2 per cent range. The author indicated that approximately 20 per cent of homeowners in Ontario have signed deals with retailers, contrary to Alberta where very few have done so. A similar chart displaying weekly average Ontario power prices was presented. The issues in Ontario are: consistency in policy, increase market transparency, transmission / distribution price flexibility, overall transmission / distribution to industrial consumers high, and increasing costs of the system operator. In Alberta, the issues are: government intent, congestion management issues, and billing settlement errors that continue. The opportunities offered by a deregulated market include process responsiveness which is rewarded, the ability to look in forward prices when prices fit margin requirement, and gives companies the opportunity to participate in the development of the market. Various charts were also displayed to further illustrate the market in both Alberta and Ontario. figs

Bioaccumulation and locomotor effects of manganese phosphate/sulfate mixture in Sprague-Dawley rats following subchronic (90 days) inhalation exposure

International Nuclear Information System (INIS)

Salehi, Fariba; Krewski, Daniel; Mergler, Donna; Normandin, Louise; Kennedy, Greg; Philippe, Suzanne; Zayed, Joseph

2003-01-01

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound added to unleaded gasoline in Canada. The primary combustion products of MMT are Mn phosphate, Mn sulfate, and a Mn phosphate/Mn sulfate mixture. Concerns have been raised that the combustion products of MMT containing Mn could be neurotoxic, even at low levels of exposure. The objective of this study is to investigate exposure-response relationships for bioaccumulation and locomotor effects following subchronic inhalation exposure to a mixture of manganese phosphates/sulfate mixture. A control group and three groups of 30 male Sprague-Dawley rats were exposed in inhalation chambers for a period of 13 weeks, 5 days per week, 6 h a day. Exposure concentrations were 3000, 300, and 30 μg/m 3 . At the end of the exposure period, locomotor activity and resting time tests were conducted for 36 h using a computerized autotrack system. Rats were then euthanized by exsanguination and Mn concentrations in different tissues (liver, lung, testis, and kidney) and blood and brain (caudate putamen, globus pallidus, olfactory bulb, frontal cortex, and cerebellum) were determined by neutron activation analysis. Increased manganese concentrations were observed in blood, kidney, lung, testis, and in all brain sections in the highest exposure group. Mn in the lung and in the olfactory bulb were dose dependent. Our data indicate that the olfactory bulb accumulated more Mn than other brain regions following inhalation exposure. Locomotor activity was increased at 3000 μg/m 3 , but no difference was observed in resting time among the exposed groups. At the end of the experiment, rats exposed to 300 and 3000 μg/m 3 exhibited significantly decreased body weight in comparison with the control group. Biochemical profiles also revealed some significant differences in certain parameters, specifically alkaline phospatase, urea, and chlorate

Chlorine and Sulfur Volatiles from in Situ Measurements of Martian Surface Materials

Science.gov (United States)

Clark, B. C.

2014-12-01

A sentinel discovery by the first in situ measurements on Mars was the high sulfur and chlorine content of global-wide soils. A variety of circumstantial evidence led to the conclusion that soil S is in the form of sulfate, and the Cl is probably chloride. An early hypothesis states that these volatiles are emitted as gases from magmas, and quickly react with dust, soil, and exposed rocks. Subsequent determination that SNC meteorites are also samples of the martian crust revealed a significantly higher S content, as sulfide, than terrestrial igneous rocks but substantially less than in soils. The ensuing wet chemical analyses by the high-latitude Phoenix mission discovered not only chloride but also perchlorate and possibly chlorate. MSL data now also implicate perchlorate at low latitudes. Gaseous interactions may have produced amorphous material on grain surfaces without forming stoichiometric salts. Yet, when exposed to liquid water, Phoenix samples released electrolytes, indicating that the soils have not been leached by rain or fresh groundwater. Sulfate occurrences at many locations on Mars, as well as some chloride enrichments, have now been discovered by remote sensing, Landed missions have discovered Cl-enrichments and ferric, Mg, Ca and more complex sulfates as duricrust, subsurface soil horizons, sandstone evaporites, and rock coatings - most of which cannot be detected from orbit. Salt-forming volatiles affect habitability wherever they are in physical contact: physicochemical parameters (ionic strength, freezing point, water activity); S is an essential element for terrestrial organisms; perchlorate is an oxidant which can degrade some organics but also can be utilized as an energy source; the entire valence range of S-compounds has been exploited by diverse microbiota on Earth. Whether such salt-induced conditions are "extremes" of habitability depends on the relative abundance of liquid H2O.

Detection of Evolved Carbon Dioxide in the Rocknest Eolian Bedform by the Sample Analysis at Mars(SAM) Instrument at the Mars Curiosity Landing Site

Science.gov (United States)

Sutter, B.; Archer, D.; McAdam, A.; Franz, H.; Ming, D. W.; Eigenbrode, J. L.; Glavin, D. P.; Mahaffy, P.; Stern, J.; Navarro-Gonzalez, R.

2013-01-01

The Sample Analysis at Mars (SAM) instrument detected four releases of carbon dioxide (CO2) that ranged from 100 to 700 C from the Rocknest eolian bedform material (Fig. 1). Candidate sources of CO2 include adsorbed CO2, carbonate(s), combusted organics that are either derived from terrestrial contamination and/or of martian origin, occluded or trapped CO2, and other sources that have yet to be determined. The Phoenix Lander s Thermal Evolved Gas Analyzer (TEGA) detected two CO2 releases (400-600, 700-840 C) [1,2]. The low temperature release was attributed to Fe- and/or Mg carbonates [1,2], per-chlorate interactions with carbonates [3], nanophase carbonates [4] and/or combusted organics [1]. The high temperature CO2 release was attributed to a calcium bearing carbonate [1,2]. No evidence of a high temperature CO2 release similar to the Phoenix material was detected in the Rocknest materials by SAM. The objectives of this work are to evaluate the temperature and total contribution of each Rocknest CO2 release and their possible sources. Four CO2 releases from the Rocknest material were detected by SAM. Potential sources of CO2 are adsorbed CO2, (peak 1) and Fe/Mg carbonates (peak 4). Only a fraction of peaks 2 and 3 (0.01 C wt.%) may be partially attributed to combustion of organic contamination. Meteoritic organics mixed in the Rocknest bedform could be present, but the peak 2 and 3 C concentration (approx.0.21 C wt. %) is likely too high to be attributed solely to meteoritic organic C. Other inorganic sources of C such as interactions of perchlorates and carbonates and sources yet to be identified will be evaluated to account for CO2 released from the thermal decomposition of Rocknest material.

Influence of Oxychlorine Phases During the Pyrolysis of Organic Molecules: Implications for the Quest of Organics on Mars with the SAM Experiment Onboard the Curiosity Rover

Science.gov (United States)

Millan, M.; Szopa, C.; Buch, A.; Belmahdi, I.; Glavin, D. P.; Freissinet, C.; Eigenbrode, J. L.; Archer, P. D., Jr,; Sutter, B.; Mahaffy, P.

2017-01-01

One among the main objectives of the Sample Analysis at Mars (SAM) experiment is the in situ molecular analysis of gases evolving from solid samples heated up to approximately 850 degrees Centigrade, and collected by Curiosity on Mars surface/sub-surface in Gale crater. With this aim, SAM uses a gas-chromatograph coupled to a quadrupole mass spectrometer (GC-QMS) devoted to separate, detect and identify both volatile inorganic and organic compounds. SAM detected chlorinated organic molecules produced in evolved gas analysis (EGA) experiments. Several of these were also detected by the Viking experiments in 1976. SAM also detected oxychlorine compounds that were present at the Phoenix landing site. The oxychlorines may be prevelant over much of the martian surface. The C1 to C3 aliphatic chlorohydrocarbons (chloromethane and di- and trichloromethane) detected by SAM were attributed to reaction products occurring between the oxychlorines phases and the organic compounds coming from SAM instrument background. But SAM also showed the presence of a large excess of chlorobenzene and C2 to C4 dichloroalkanes among the volatile species released by the Cumberland sample of the Sheepbed mudstone. For the first time in the history of the Mars exploration, this proved the presence of Mars indigenous organic material at the Mars' surface. However, the identification of the precursor organic compounds of these chlorohydrocarbons is difficult due to the complexity of the reactions occurring during the sample pyrolysis. Laboratory pyrolysis experiments have demonstrated that oxychlorines phases such as perchlorates and chlorates, decomposed into dioxygen and volatile chlorine bearing molecules (HCl and/or Cl2) during the pyrolysis. These chemical species can then react with the organic molecules present in the martian solid samples through oxidation, chlorination and oxychlorination processes.

Bioaccumulation and locomotor effects of manganese phosphate/sulfate mixture in Sprague-Dawley rats following subchronic (90 days) inhalation exposure.

Science.gov (United States)

Salehi, Fariba; Krewski, Daniel; Mergler, Donna; Normandin, Louise; Kennedy, Greg; Philippe, Suzanne; Zayed, Joseph

2003-09-15

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound added to unleaded gasoline in Canada. The primary combustion products of MMT are Mn phosphate, Mn sulfate, and a Mn phosphate/Mn sulfate mixture. Concerns have been raised that the combustion products of MMT containing Mn could be neurotoxic, even at low levels of exposure. The objective of this study is to investigate exposure-response relationships for bioaccumulation and locomotor effects following subchronic inhalation exposure to a mixture of manganese phosphates/sulfate mixture. A control group and three groups of 30 male Sprague-Dawley rats were exposed in inhalation chambers for a period of 13 weeks, 5 days per week, 6 h a day. Exposure concentrations were 3000, 300, and 30 microg/m(3). At the end of the exposure period, locomotor activity and resting time tests were conducted for 36 h using a computerized autotrack system. Rats were then euthanized by exsanguination and Mn concentrations in different tissues (liver, lung, testis, and kidney) and blood and brain (caudate putamen, globus pallidus, olfactory bulb, frontal cortex, and cerebellum) were determined by neutron activation analysis. Increased manganese concentrations were observed in blood, kidney, lung, testis, and in all brain sections in the highest exposure group. Mn in the lung and in the olfactory bulb were dose dependent. Our data indicate that the olfactory bulb accumulated more Mn than other brain regions following inhalation exposure. Locomotor activity was increased at 3000 microg/m(3), but no difference was observed in resting time among the exposed groups. At the end of the experiment, rats exposed to 300 and 3000 microg/m(3) exhibited significantly decreased body weight in comparison with the control group. Biochemical profiles also revealed some significant differences in certain parameters, specifically alkaline phospatase, urea, and chlorate.

Ductile flow by water-assisted cataclasis

Science.gov (United States)

den Brok, Bas

2003-04-01

In the presence of water otherwise brittle materials may deform macroscopically ductile by water-assisted cataclastic creep. This is possible as long as (i) solubility is high enough, so that stress-corrosion can occur, and (ii) local stress is low enough, to that fracturing remains subcritical. Water-assisted cataclastic creep (WACC) may play an important role in the middle and lower continental crust where mineral solubilities are high and stresses low. WACC is a poorly understood deformation process. Experiments were performed on very soluble brittle salts (Na-chlorate; K-alum) to study microstructure development by WACC. The experiments were carried out at room temperature and atmospheric pressure in a small see-through vessel. In this way the cataclastic deformation process could be studied "in-situ" under the microscope. Crystals were loaded in the presence of saturated salt solution. It appeared that originally straight mineral surfaces were instable when kept under stress. Grooves (or channels) slowly developed in the surface by local dissolution. These grooves behave like so-called Grinfeld instabilities. They develop because the energy of a grooved surface under stress is lower than the energy of a straight surface under stress. The grooves may deepen and turn into subcritical cracks when local stress further increases. These cracks propagate slowly. They propagate parallel to sigma1 but also at an angle and even perpendicular to sigma1, often following crystallographically controlled directions. The fractures mostly change direction while propagating, locally making turns of more than 180 degrees. Irregular fracture fragments thus develop. The fractures may migrate sideways (as with grain bounday migration) probably by solution-redeposition driven by differences in stress between both sides of the fracture. Thus the shape of the fragments changes. The size of the fracture fragments seems to be controlled by the distance of the grooves, which decreases

Role of phosphate and other proton-donating anions in respiration-coupled transport of Ca2+ by mitochondria.

Science.gov (United States)

Lehninger, A L

1974-04-01

Measurements of extra oxygen consumption, (45)Ca(2+) uptake, and the osmotic expansion of the matrix compartment show that not all permeant anions are capable of supporting and accompanying the energy-dependent transport of Ca(2+) from the medium into the matrix in respiring rat-liver mitochondria. Phosphate, arsenate, acetate, butyrate, beta-hydroxybutyrate, lactate, and bicarbonate + CO(2) supported Ca(2+) uptake, whereas the permeant anions, nitrate, thiocyanate, chlorate, and perchlorate, did not. The active anions share a common denominator, the potential ability to donate a proton to the mitochondrial matrix; the inactive anions lack this capacity. Phosphate and the other active permeant anions move into the matrix in response to the alkaline-inside electrochemical gradient of protons generated across the mitochondrial membrane by electron transport, thus forming a negative-inside anion gradient. It is postulated that the latter gradient is the immediate "pulling" force for the influx of Ca(2+) on the electrogenic Ca(2+) carrier in respiring mitochondria under intracellular conditions. Since mitochondria in the cell are normally exposed to an excess of phosphate (and the bicarbonate-CO(2) system), particularly in state 4, inward transport of these proton-yielding anions probably precedes and is necessary for inward transport of Ca(2+) and other cations under biological conditions. These observations indicate that a negative-inside gradient of phosphate generated by electron transport is a common step and provides the immediate motive power not only for (a) the inward transport of dicarboxylates and tricarboxylates and (b) the energy-dependent exchange of external ADP(3-) for internal ATP(4-) during oxidative phosphorylation, as has already been established, but also for (c) the inward transport of Ca(2+), K(+), and other cations.

A Cabin Air Separator for EVA Oxygen

Science.gov (United States)

Graf, John C.

2011-01-01

Presently, the Extra-Vehicular Activities (EVAs) conducted from the Quest Joint Airlock on the International Space Station use high pressure, high purity oxygen that is delivered to the Space Station by the Space Shuttle. When the Space Shuttle retires, a new method of delivering high pressure, high purity oxygen to the High Pressure Gas Tanks (HPGTs) is needed. One method is to use a cabin air separator to sweep oxygen from the cabin air, generate a low pressure/high purity oxygen stream, and compress the oxygen with a multistage mechanical compressor. A main advantage to this type of system is that the existing low pressure oxygen supply infrastructure can be used as the source of cabin oxygen. ISS has two water electrolysis systems that deliver low pressure oxygen to the cabin, as well as chlorate candles and compressed gas tanks on cargo vehicles. Each of these systems can feed low pressure oxygen into the cabin, and any low pressure oxygen source can be used as an on-board source of oxygen. Three different oxygen separator systems were evaluated, and a two stage Pressure Swing Adsorption system was selected for reasons of technical maturity. Two different compressor designs were subjected to long term testing, and the compressor with better life performance and more favorable oxygen safety characteristics was selected. These technologies have been used as the basis of a design for a flight system located in Equipment Lock, and taken to Preliminary Design Review level of maturity. This paper describes the Cabin Air Separator for EVA Oxygen (CASEO) concept, describes the separator and compressor technology trades, highlights key technology risks, and describes the flight hardware concept as presented at Preliminary Design Review (PDR)

Rotation driven translational diffusion of polyatomic ions in water: A novel mechanism for breakdown of Stokes-Einstein relation

Science.gov (United States)

Banerjee, Puja; Yashonath, Subramanian; Bagchi, Biman

2017-04-01

While most of the existing theoretical and simulation studies have focused on simple, spherical, halide and alkali ions, many chemically, biologically, and industrially relevant electrolytes involve complex non-spherical polyatomic ions like nitrate, chlorate, and sulfate to name only a few. Interestingly, some polyatomic ions in spite of being larger in size show anomalously high diffusivity and therefore cause a breakdown of the venerable Stokes-Einstein (S-E) relation between the size and diffusivity. Here we report a detailed analysis of the dynamics of anions in aqueous potassium nitrate (KNO3) and aqueous potassium acetate (CH3COOK) solutions. The two ions, nitrate (-NO3) and acetate (CH3-CO2 ), with their similar size show a large difference in diffusivity values. We present evidence that the translational motion of these polyatomic ions is coupled to the rotational motion of the ion. We show that unlike the acetate ion, nitrate ion with a symmetric charge distribution among all periphery oxygen atoms shows a faster rotational motion with large amplitude rotational jumps which enhances its translational motion due to translational-rotational coupling. By creating a family of modified-charge model systems, we have analysed the rotational motion of asymmetric polyatomic ions and the contribution of it to the translational motion. These model systems help clarifying and establishing the relative contribution of rotational motion in enhancing the diffusivity of the nitrate ion over the value predicted by the S-E relation and also over the other polyatomic ions having asymmetric charge distribution like the acetate ion. In the latter case, reduced rotational motion results in lower diffusivity values than those with symmetric charge distribution. We propose translational-rotational coupling as a general mechanism of the breakdown of the S-E relation in the case of polyatomic ions.

Determining the prevalence of inv-positive and ail-positive Yersinia enterocolitica in pig tonsils using PCR and culture methods.

Science.gov (United States)

Stachelska, Milena Alicja

2017-01-01

Yersiniosis is believed to be the third most common intestinal zoonosis in the European Union, after campylobacteriosis and salmonellosis. Yersinia enterocolitica is the most common species responsible for human infections. Pigs are regarded as the biggest reservoir of pathogenic Y. enterocolitica strains, which are mainly isolated from pig tonsils. The aim of this paper is to examine the prevalence of inv-positive and ail-positive Y. enterocolitica in pigs which were slaughtered in a Polish abattoir. Real-time PCR and culture methods were used to assess the prevalence of patho- genic Y. enterocolitica strains in pig tonsils. Real-time PCR was applied to detect inv-positive and ail-positive Y. enterocolitica. Y. enterocolitica was also isolated by applying direct plating, unselective (tryptic soy broth) and selective (irgasan-ticarcillin-potassium chlorate bouillon) enrichment. A total of 180 pigs were studied, of which 85% and 32% respectively were found to be infected with inv-positive and ail-positive Y. enterocolitica. The 92 inv-positive and ail-positive isolates, from 57 culture- positive tonsils, underwent bio- and serotyping. The most common was bioserotype 4/O:3, which was found in 53 (93%) out of 57 culture-positive tonsils. Strains of bioserotypes 2/O:5, 2/O:9 and 2/O:5.27 occurred in significantly lower numbers. The prevalence of inv-positive and ail-positive Y. enterocolitica was found to be high in the ton- sils of slaughtered pigs, using real-time PCR. The real-time PCR method for the detection and identification of pathogenic Y. enterocolitica is sensitive and specific, which has been verified by specificity and sensitivity tests using the pure cultures. Serotypes were distinguished from each other using PCR serotyping. The PCR method was essential in forming our conclusions.

Identification of homemade inorganic explosives by ion chromatographic analysis of post-blast residues.

Science.gov (United States)

Johns, Cameron; Shellie, Robert A; Potter, Oscar G; O'Reilly, John W; Hutchinson, Joseph P; Guijt, Rosanne M; Breadmore, Michael C; Hilder, Emily F; Dicinoski, Greg W; Haddad, Paul R

2008-02-29

Anions and cations of interest for the post-blast identification of homemade inorganic explosives were separated and detected by ion chromatographic (IC) methods. The ionic analytes used for identification of explosives in this study comprised 18 anions (acetate, benzoate, bromate, carbonate, chlorate, chloride, chlorite, chromate, cyanate, fluoride, formate, nitrate, nitrite, perchlorate, phosphate, sulfate, thiocyanate and thiosulfate) and 12 cations (ammonium, barium(II), calcium(II), chromium(III), ethylammonium, magnesium(II), manganese(II), methylammonium, potassium(I), sodium(I), strontium(II), and zinc(II)). Two IC separations are presented, using suppressed IC on a Dionex AS20 column with potassium hydroxide as eluent for anions, and non-suppressed IC for cations using a Dionex SCS 1 column with oxalic acid/acetonitrile as eluent. Conductivity detection was used in both cases. Detection limits for anions were in the range 2-27.4ppb, and for cations were in the range 13-115ppb. These methods allowed the explosive residue ions to be identified and separated from background ions likely to be present in the environment. Linearity (over a calibration range of 0.05-50ppm) was evaluated for both methods, with r(2) values ranging from 0.9889 to 1.000. Reproducibility over 10 consecutive injections of a 5ppm standard ranged from 0.01 to 0.22% relative standard deviation (RSD) for retention time and 0.29 to 2.16%RSD for peak area. The anion and cation separations were performed simultaneously by using two Dionex ICS-2000 chromatographs served by a single autoinjector. The efficacy of the developed methods was demonstrated by analysis of residue samples taken from witness plates and soils collected following the controlled detonation of a series of different inorganic homemade explosives. The results obtained were also confirmed by parallel analysis of the same samples by capillary electrophoresis (CE) with excellent agreement being obtained.

The relationship between anammox and denitrification in the sediment of an inland river

Energy Technology Data Exchange (ETDEWEB)

Zhou, Sheng, E-mail: zhous@outlook.com [Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences, No. 1000 Jinqi Road, Shanghai 201403 (China); Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Borjigin, Sodbilig; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki [Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)

2014-08-15

This study measured the microbial processes of anaerobic ammonium oxidation (anammox) and denitrification in sediment sampled from two sites in the estuary of an inland river (Koisegawa River, Ibaragi prefecture, Japan) using a nitrogen isotope pairing technique (IPT). The responses of anammox and denitrification activities to temperature and nitrate concentration were also evaluated. Further, to elucidate the correlation between anammox and denitrification processes, an inhibition experiment was conducted, using chlorate to inhibit the first step of denitrification. Denitrification activity was much higher than anammox activity, and it reached a maximum at the surface layer in February 2012. Denitrification activity decreased as sediment depth increased, and a similar phenomenon was observed for anammox activity in the sediment of site A, where aquatic plants were absent from the surroundings. The activities of both denitrification and anammox were temperature-dependent, but they responded differently to changes in incubation temperature. Compared to a linear increase in denitrification as temperature rose to 35 °C, the optimal temperature for anammox was 25 °C, after which the activity decreased sharply. At the same time, both anammox and denitrification activities increased with NO{sub 3}{sup −} concentration. The Michaelis–Menten kinetic constants (V{sub max} and K{sub m}) of denitrification were significantly higher than those of the anammox process. Furthermore, anammox activity decreased accordingly when the first step of denitrification was inhibited, which probably reduced the amount of the intermediate NO{sub 2}{sup −}. Our study provides the first direct exploration of the denitrification-dependent correlation of anammox activity in the sediment of inland river. - Highlights: • The activity of denitrification in river sediment was much higher than anammox. • Denitrification and anammox respond differently to changes in temperature. �

Production and consumption of nitric oxide by three methanotrophic bacteria.

Science.gov (United States)

Ren, T; Roy, R; Knowles, R

2000-09-01

We studied nitrogen oxide production and consumption by methanotrophs Methylobacter luteus (group I), Methylosinus trichosporium OB3b (group II), and an isolate from a hardwood swamp soil, here identified by 16S ribosomal DNA sequencing as Methylobacter sp. strain T20 (group I). All could consume nitric oxide (nitrogen monoxide, NO), and produce small amounts of nitrous oxide (N(2)O). Only Methylobacter strain T20 produced large amounts of NO (>250 parts per million by volume [ppmv] in the headspace) at specific activities of up to 2.0 x 10(-17) mol of NO cell(-1) day(-1), mostly after a culture became O(2) limited. Production of NO by strain T20 occurred mostly in nitrate-containing medium under anaerobic or nearly anaerobic conditions, was inhibited by chlorate, tungstate, and O(2), and required CH(4). Denitrification (methanol-supported N(2)O production from nitrate in the presence of acetylene) could not be detected and thus did not appear to be involved in the production of NO. Furthermore, cd(1) and Cu nitrite reductases, NO reductase, and N(2)O reductase could not be detected by PCR amplification of the nirS, nirK, norB, and nosZ genes, respectively. M. luteus and M. trichosporium produced some NO in ammonium-containing medium under aerobic conditions, likely as a result of methanotrophic nitrification and chemical decomposition of nitrite. For Methylobacter strain T20, arginine did not stimulate NO production under aerobiosis, suggesting that NO synthase was not involved. We conclude that strain T20 causes assimilatory reduction of nitrate to nitrite, which then decomposes chemically to NO. The production of NO by methanotrophs such as Methylobacter strain T20 could be of ecological significance in habitats near aerobic-anaerobic interfaces where fluctuating O(2) and nitrate availability occur.

Acute exposure to the biopesticide azadirachtin affects parameters in the gills of common carp (Cyprinus carpio).

Science.gov (United States)

Murussi, Camila R; Costa, Maiara D; Leitemperger, Jossiele W; Flores-Lopes, Fábio; Menezes, Charlene C; Loebens, Luisa; de Avila, Luis Antonio; Rizzetti, Tiele M; Adaime, Martha B; Zanella, Renato; Loro, Vania L

2016-02-01

The biopesticide, azadirachtin (Aza) is less hazardous to the environment, but may cause several toxic effects in aquatic organisms. The Cyprinus carpio (n=12, for all concentrations) after 10days of acclimation under controlled conditions, were exposed at 20, 40, and 60μL/L of Aza during 96h. After this period, fish were anesthetized and euthanized then mucus layer and gills collected. In this study, the effects of exposure to different Aza concentrations were analysed through a set of biomarkers: Na(+)/K(+-)ATPase, lipid peroxidation (TBARS), protein carbonyl (PC), superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase (CAT), glutathione peroxidase (GPx), non-protein thiols (NPSH), ascorbic acid (AsA) and histological parameters and, yet, protein and glucose concentration in the surface area of mucous layer. Na(+)K(+-)ATPase was inhibited at 40 and 60μL/L compared to control. TBARS decreased at 40μL/L compared to control. PC, SOD and GST increased at 60μL/L in comparison to control. CAT increased at 20 and 60μL/L, and GPx increased in all Aza concentrations compared to control. NPSH decreased and AsA increased in all concentrations in comparison to control. Histological analyses demonstrated an increase in the intensity of the damage with increasing Aza concentration. Alterations in histological examination were elevation and hypertrophy of the epithelial cells of the secondary filament, hypertrophy and hyperplasia of the mucous and chlorate cells and lamellar aneurism. Glucose and protein concentrations in mucus layer increased at 60μL/L compared to control. In general, we suggest that 60μL/L Aza concentration affected several parameters causing disruptions carp metabolism. Copyright © 2015 Elsevier Inc. All rights reserved.

Investigation, Analysis, and Testing of Self-contained Oxygen Generators

Science.gov (United States)

Keddy, Christopher P.; Haas, Jon P.; Starritt, Larry

2008-01-01

Self Contained Oxygen Generators (SCOGs) have widespread use in providing emergency breathing oxygen in a variety of environments including mines, submarines, spacecraft, and aircraft. These devices have definite advantages over storing of gaseous or liquid oxygen. The oxygen is not generated until a chemical briquette containing a chlorate or perchlorate oxidizer and a solid metallic fuel such as iron is ignited starting a thermal decomposition process allowing gaseous oxygen to be produced. These devices are typically very safe to store, easy to operate, and have primarily only a thermal hazard to the operator that can be controlled by barriers or furnaces. Tens of thousands of these devices are operated worldwide every year without major incident. This report examines the rare case of a SCOG whose behavior was both abnormal and lethal. This particular type of SCOG reviewed is nearly identical to a flight qualified version of SCOG slated for use on manned space vehicles. This Investigative Report is a compilation of a NASA effort in conjunction with other interested parties including military and aerospace to understand the causes of the particular SCOG accident and what preventative measures can be taken to ensure this incident is not repeated. This report details the incident and examines the root causes of the observed SCOG behavior from forensic evidence. A summary of chemical and numerical analysis is provided as a background to physical testing of identical SCOG devices. The results and findings of both small scale and full scale testing are documented on a test-by-test basis along with observations and summaries. Finally, conclusions are presented on the findings of this investigation, analysis, and testing along with suggestions on preventative measures for any entity interested in the safe use of these devices.

Properties of the periplasmic ModA molybdate-binding protein of Escherichia coli.

Science.gov (United States)

Rech, S; Wolin, C; Gunsalus, R P

1996-02-02

The modABCD operon, located at 17 min on the Escherichia coli chromosome, encodes the protein components of a high affinity molybdate uptake system. Sequence analysis of the modA gene (GenBank L34009) predicts that it encodes a periplasmic binding protein based on the presence of a leader-like sequence at its N terminus. To examine the properties of the ModA protein, the modA structural gene was overexpressed, and its product was purified. The ModA protein was localized to the periplasmic space of the cell, and it was released following a gentle osmotic shock. The N-terminal sequence of ModA confirmed that a leader region of 24 amino acids was removed upon export from the cell. The apparent size of ModA is 31.6 kDa as determined by gel sieve chromatography, whereas it is 22.5 kDa when examined by SDS-polyacrylamide gel electrophoresis. A ligand-dependent protein mobility shift assay was devised using a native polyacrylamide gel electrophoresis protocol to examine binding of molybdate and other anions to the ModA periplasmic protein. Whereas molybdate and tungstate were bound with high affinity (approximately 5 microM), sulfate, chromate, selenate, phosphate, and chlorate did not bind even when tested at 2 mM. A UV spectral assay revealed apparent Kd values of binding for molybdate and tungstate of 3 and 7 microM, respectively. Strains defective in the modA gene were unable to transport molybdate unless high levels of the anion were supplied in the medium. Therefore the modA gene product is essential for high affinity molybdate uptake by the cell. Tungstate interference of molybdate acquisition by the cell is apparently due in part to the high affinity of the ModA protein for this anion.

Chlorine by-products in sea water at the Penly nuclear power plant. Measurement survey in May 1993; Residus de chloration en mer a Penly. Campagne de mesures de Mai 1993

Energy Technology Data Exchange (ETDEWEB)

Khalanski, M.; Delesmont, R.

1994-09-01

The objective of the measurement survey conducted at the Penly nuclear power plant on May 27 and 28, 1993, was to determine the distribution of residual oxidants and volatile organo-halogenated compounds (THM) concentrations in the discharge plume when both units of the plants are carrying out chlorination. The data collected provide a mapping of the chemical types analyzed and will serve in calibration of a numerical model to simulate the evolution of these compounds in the discharge plume. During the two days of measurements, quantitative analyses were performed on samples taken by helicopter, once at high tide and twice at low tide with mean tidal coefficients. The chlorine injection level ranged from 0.84 to 0.92 mg/l (ppm) in unit 1 and from 0.64 to 0.70 mg/l in unit 2. Residual oxidants were measured as Total Chlorine equivalents using the colorimetric DPD method. Bromoform accounted for 97.8 % of the THM generated by chlorination. Three minutes after injection of hypochlorite, in the discharge basin, bromoform reached 60 % of its maximum concentration (29.23 {mu}g/l). The maximum reaction yield of bromoform formation is 2,9 %. Three zones were defined according to their proximity to releases. In each zone, given the lake of precision in measurements, the concentration of residual oxidants found did not reach significant levels ({<=}0.03 mg/l). The bromoform concentration, on the contrary, reached measurable levels in each of the samples. Its distribution differs significantly from one zone to another: -release zone : 1.66{+-}0.40{mu}g/l -nearby zone: 0.44{+-}0.13{mu}g/l - distant zone : 0.26{+-}0.10{mu}g/l. Our analysis, which indicates a background level of the order of 0.1 {mu}g/l for the entire studied area, raises the question of possible other sources of bromoform, independent of discharge from Penly. (authors). 15 refs., 11 figs., 5 tabs., 4 annexes.

Microbial degradation of chloroethenes in groundwater systems

Science.gov (United States)

Bradley, Paul M.

éthane (DCE) et le chlorure de vinyl (VC). Bien que des études de laboratoire réalisées avec des micro-organismes adaptés aux composés halogénés montrent que la réduction complète en éthane est possible, dans la plupart des nappes la réaction de déchloration par réduction s'arrête apparemment au DCE et au VC. Cependant, des recherches récentes menées sur des sédiments d'un aquifère et d'alluvions ont démontré que l'oxydation microbienne de ces descendants réduits peut se produire de manière significative dans des conditions de redox anérobies. La déchloration par réduction de PCE et de TCE dans des conditions anérobies suivie par une oxydation microbienne anérobie des DCE et VC fournit une piste microbienne possible pour obtenir une dégradation complète des chloroéthanes polluants dans les aquifères. Resumen Los cloroetanos (tetracloroetano PCE y tricloroetano TCE) son contaminantes muy habituales en los acuíferos. Hasta 1980 se consideraba que los cloroetanos no eran biodegradables y, por tanto, los métodos de rehabilitación en acuíferos contaminados con cloroetanos se limitaban al pump-and-treat, generalmente con poco éxito. Posteriormente se vio que, en condiciones reductoras, algunos microorganismos pueden reducir PCE y TCE a unos subproductos menos clorados, como el dicloroetano (DCE) y el cloruro de vinilo (VC). Aunque estudios de laboratorio recientes sugieren que la reducción completa a etano es posible, en la mayoría de los sistemas acuíferos la decloración suele detenerse en los DCE o VC. Sin embargo, investigaciones más recientes en acuíferos y sedimentos fluviales demuestran que la oxidación microbiana de estos subproductos puede ser importante bajo condiciones redox anaerobias. La combinación de la reducción de PCE y TCE en condiciones anaerobias seguida de la oxidación microbiana anaerobia de DCE y VC proporciona un método potencial para la degradación total de los cloroetanos en los sistemas acuíferos.

Tyrosine sulfation of the amino terminus of PSGL-1 is critical for enterovirus 71 infection.

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Yorihiro Nishimura

Full Text Available Enterovirus 71 (EV71 is one of the major causative agents of hand, foot, and mouth disease, a common febrile disease in children; however, EV71 has been also associated with various neurological diseases including fatal cases in large EV71 outbreaks particularly in the Asia Pacific region. Recently we identified human P-selectin glycoprotein ligand-1 (PSGL-1 as a cellular receptor for entry and replication of EV71 in leukocytes. PSGL-1 is a sialomucin expressed on the surface of leukocytes, serves as a high affinity counterreceptor for selectins, and mediates leukocyte rolling on the endothelium. The PSGL-1-P-selectin interaction requires sulfation of at least one of three clustered tyrosines and an adjacent O-glycan expressing sialyl Lewis x in an N-terminal region of PSGL-1. To elucidate the molecular basis of the PSGL-1-EV71 interaction, we generated a series of PSGL-1 mutants and identified the post-translational modifications that are critical for binding of PSGL-1 to EV71. We expressed the PSGL-1 mutants in 293T cells and the transfected cells were assayed for their abilities to bind to EV71 by flow cytometry. We found that O-glycosylation on T57, which is critical for PSGL-1-selectin interaction, is not necessary for PSGL-1 binding to EV71. On the other hand, site-directed mutagenesis at one or more potential tyrosine sulfation sites in the N-terminal region of PSGL-1 significantly impaired PSGL-1 binding to EV71. Furthermore, an inhibitor of sulfation, sodium chlorate, blocked the PSGL-1-EV71 interaction and inhibited PSGL-1-mediated viral replication of EV71 in Jurkat T cells in a dose-dependent manner. Thus, the results presented in this study reveal that tyrosine sulfation, but not O-glycosylation, in the N-terminal region of PSGL-1 may facilitate virus entry and replication of EV71 in leukocytes.

Temperature effect in potassium and nitrate ions in soil transport Efeito da temperatura no transporte dos íons potássio e nitrato no solo

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Adriano D. M. A. Gonçalves

2008-09-01

Full Text Available When doing researches on solute dynamics in porous medium, the knowledge of medium characteristics and percolating liquids, as well as of external factors is very important. An important external factor is temperature and, in this sense, our purpose was determining potassium and nitrate transport parameters for different values of temperature, in miscible displacement experiments. Evaluated parameters were retardation factor (R, diffusion/dispersion coefficient (D and dispersivity, at ambient temperature (25 up to 28 ºC, 40 ºC and 50 ºC. Salts used were potassium nitrate and potassium chlorate, prepared in a solution made up of 5 ppm nitrate and 2.000 ppm potassium, with Red-Yellow Latosol porous medium. Temperature exhibited a positive influence upon porous medium solution and upon dispersion coefficient.No estudo da dinâmica de solutos num meio poroso, é de suma importância o conhecimento das propriedades do meio e dos líquidos percolantes, bem como de fatores externos. Um fator externo relevante é a temperatura e, nesse sentido, teve-se como objetivo determinar os parâmetros de transporte dos íons potássio e nitrato para diferentes valores de temperatura em experimentos de deslocamento miscível. Os parâmetros avaliados foram o fator de retardamento (R, o coeficiente de difusão/dispersão (D e a dispersividade (λ , e as temperaturas utilizadas foram a ambiente (25 a 28 ºC, 40 ºC e 50 ºC. Os sais utilizados foram nitrato de potássio e cloreto de potássio, preparados em solução composta de 50 ppm de nitrato e 2.000 ppm de potássio, sendo o meio poroso um Latossolo Vermelho-Amarelo, textura média. A temperatura apresentou influência positiva na velocidade da solução no meio poroso e no coeficiente de dispersão.

Fibrose quística: Revisão

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C. Damas

2008-01-01

Full Text Available Resumo: A fibrose quística (FQ é a doença autossómica recessiva mais frequente na raça caucasiana. Caracteriza-se por mutações na CFTR, uma proteína transmembranar responsável pelo transporte de cloretos. Esta proteína tem uma ampla distribuição epitelial, o que dá um carácter sistémico a esta doença e consequentemente múltiplas manifestações clínicas de gravidade variável. A melhoria dos cuidados de saúde, associada ao desenvolvimento do arsenal terapêutico, permitiu um aumento da sobrevida destes doentes, de tal forma que a FQ já não pode ser abordada como doença da idade pediátrica. Também a evolução técnica na transplantação abriu novas perspectivas quanto ao tratamento desta afecção.Assim, cada vez mais esta patologia implica um envolvimento multidisciplinar no qual a pneumologia tem uma parte preponderante. Abstract: Cystic Fibrosis (CF is the recessive autossomic disease more frequent in the caucasian race. The main characteristic is a mutation in CFTR, a trans-membranar protein, responsible for chlorates transportation. This protein has a diffuse epithelial distribution, which gives a multissistemic involvement to this disease, with clinical manifestations with variable degrees of severity. The development of better health care associated with new therapeutic options became responsible for an increase of survival, so CF is no longer a paediatric disease. Lung transplantation also has an important role, bringing new treatment perspectives.So, this pathology has an increased multi-disciplinary involvement in which the pulmonologist have a preponderant role. Palavras-chave: Fibrose quística, revisão, Key-words: Cystic fibrosis, review

The Effect of Gamma Radiation on Mars Mineral Matrices: Implications for Perchlorate Formation on Mars

Science.gov (United States)

Fox, A. C.; Eigenbrode, J. L.; Pavlov, A.; Lewis, J.

2017-12-01

Observations by the Phoenix Wet Chemistry Lab of the Martian surface indicate the presence of perchlorate in high concentrations. Additional observations by the Sample Analysis at Mars and the Viking Landers indirectly support the presence of perchlorate at other localities on Mars. The evidence for perchlorate at several localities on Mars coupled with its detection in Martian meteorite EETA79001 suggests that perchlorate is present globally on Mars. The presence of perchlorate on Mars further complicates the search for organic molecules indicative of past life. While perchlorate is kinetically limited in Martian conditions, the intermediate species associated with its formation or decomposition, such as chlorate or chlorite, could oxidize Martian organic species. As a result, it is vital to understand the mechanism of perchlorate formation on Mars in order to determine its role in the degradation of organics. Here, we explore an alternate mechanism of formation of perchlorate by bombarding Cl-salts and Mars-relevant mineral mixtures with gamma radiation both with and without the presence of liquid water, under vacuum. Previous work has shown that OClO can form from both UV radiation and energetic electrons bombardment of Cl-ices or Cl-salts, which then reacts with either OH- or O-radicals to produce perchlorate. Past research has suggested that liquid water or ice is the source of these hydroxyl and oxygen radicals, which limits the location of perchlorate formation on Mars. We demonstrate that trace amounts of perchlorate are potentially formed in samples containing silica dioxide or iron oxide and Cl-salts both with and without liquid water. Perchlorate was also detected in a portion of samples that were not irradiated, suggesting possible contamination. We did not detect perchlorate in samples that contained sulfate minerals. If perchlorate was formed without liquid water, it is possible that oxide minerals could be a potential source of oxygen radicals

Distinguishing Active Site Characteristics of Chlorite Dismutases with Their Cyanide Complexes.

Science.gov (United States)

Geeraerts, Zachary; Celis, Arianna I; Mayfield, Jeffery A; Lorenz, Megan; Rodgers, Kenton R; DuBois, Jennifer L; Lukat-Rodgers, Gudrun S

2018-03-06

O 2 -evolving chlorite dismutases (Clds) efficiently convert chlorite (ClO 2 - ) to O 2 and Cl - . Dechloromonas aromatica Cld ( DaCld) is a highly active chlorite-decomposing homopentameric enzyme, typical of Clds found in perchlorate- and chlorate-respiring bacteria. The Gram-negative, human pathogen Klebsiella pneumoniae contains a homodimeric Cld ( KpCld) that also decomposes ClO 2 - , albeit with an activity 10-fold lower and a turnover number lower than those of DaCld. The interactions between the distal pocket and heme ligand of the DaCld and KpCld active sites have been probed via kinetic, thermodynamic, and spectroscopic behaviors of their cyanide complexes for insight into active site characteristics that are deterministic for chlorite decomposition. At 4.7 × 10 -9 M, the K D for the KpCld-CN - complex is 2 orders of magnitude smaller than that of DaCld-CN - and indicates an affinity for CN - that is greater than that of most heme proteins. The difference in CN - affinity between Kp- and DaClds is predominantly due to differences in k off . The kinetics of binding of cyanide to DaCld, DaCld(R183Q), and KpCld between pH 4 and 8.5 corroborate the importance of distal Arg183 and a p K a of ∼7 in stabilizing complexes of anionic ligands, including the substrate. The Fe-C stretching and FeCN bending modes of the DaCld-CN - (ν Fe-C , 441 cm -1 ; δ FeCN , 396 cm -1 ) and KpCld-CN - (ν Fe-C , 441 cm -1 ; δ FeCN , 356 cm -1 ) complexes reveal differences in their FeCN angle, which suggest different distal pocket interactions with their bound cyanide. Conformational differences in their catalytic sites are also reported by the single ferrous KpCld carbonyl complex, which is in contrast to the two conformers observed for DaCld-CO.

Role of Heparan Sulfate in Cellular Infection of Integrin-Binding Coxsackievirus A9 and Human Parechovirus 1 Isolates.

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Pirjo Merilahti

Full Text Available Heparan sulfate/heparin class of proteoglycans (HSPG have been shown to function in cellular attachment and infection of numerous viruses including picornaviruses. Coxsackievirus A9 (CV-A9 and human parechovirus 1 (HPeV-1 are integrin-binding members in the family Picornaviridae. CV-A9 Griggs and HPeV-1 Harris (prototype strains have been reported not to bind to heparin, but it was recently shown that some CV-A9 isolates interact with heparin in vitro via VP1 protein with a specific T132R/K mutation. We found that the infectivity of both CV-A9 Griggs and HPeV-1 Harris was reduced by sodium chlorate and heparinase suggestive of HSPG interactions. We analyzed the T132 site in fifty-four (54 CV-A9 clinical isolates and found that only one of them possessed T132/R mutation while the other nine (9 had T132K. We then treated CV-A9 Griggs and HPeV-1 Harris and eight CV-A9 and six HPeV-1 clinical isolates with heparin and protamine. Although infectivity of Griggs strain was slightly reduced (by 25%, heparin treatment did not affect the infectivity of the CV-A9 isolates that do not possess the T132R/K mutation, which is in line with the previous findings. Some of the HPeV-1 isolates were also affected by heparin treatment, which suggested that there may be a specific heparin binding site in HPeV-1. In contrast, protamine (a specific inhibitor of heparin completely inhibited the infection of both prototypes and clinical CV-A9 and HPeV-1 isolates. We conclude that T132R/K mutation has a role in heparin binding of CV-A9, but we also show data, which suggest that there are other HSPG binding sites in CV-A9. In all, we suggest that HSPGs play a general role in both CV-A9 and HPeV-1 infections.

The Investigation of Perchlorate/Iron Phase Mixtures as A Possible Source of Oxygen Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

Science.gov (United States)

Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.;

Integrated waste hydrogen utilization project

International Nuclear Information System (INIS)

Armstrong, C.

2004-01-01

'Full text:' The BC Hydrogen Highway's, Integrated Waste Hydrogen Utilization Project (IWHUP) is a multi-faceted, synergistic collaboration that will capture waste hydrogen and promote its use through the demonstration of 'Hydrogen Economy' enabling technologies developed by Canadian companies. IWHUP involves capturing and purifying a small portion of the 600 kg/hr of by-product hydrogen vented to the atmosphere at the ERCO's electrochemical sodium chlorate plant in North Vancouver, BC. The captured hydrogen will then be compressed so it is suitable for transportation on roadways and can be used as a fuel in transportation and stationary fuel cell demonstrations. In summary, IWHUP invests in the following; Facilities to produce up to 20kg/hr of 99.999% pure 6250psig hydrogen using QuestAir's leading edge Pressure Swing Absorption technology; Ultra high-pressure transportable hydrogen storage systems developed by Dynetek Industries, Powertech Labs and Sacre-Davey Engineering; A Mobile Hydrogen Fuelling Station to create Instant Hydrogen Infrastructure for light-duty vehicles; Natural gas and hydrogen (H-CNG) blending and compression facilities by Clean Energy for fueling heavy-duty vehicles; Ten hydrogen, internal combustion engine (H-ICE), powered light duty pick-up vehicles and a specialized vehicle training, maintenance, and emissions monitoring program with BC Hydro, GVRD and the District of North Vancouver; The demonstration of Westport's H-CNG technology for heavy-duty vehicles in conjunction with local transit properties and a specialized vehicle training, maintenance, and emissions monitoring program; The demonstration of stationary fuel cell systems that will provide clean power for reducing peak-load power demands (peak shaving), grid independence and water heating; A comprehensive communications and outreach program designed to educate stakeholders, the public, regulatory bodies and emergency response teams in the local community, Supported by industry

Kinetics and mechanism of styrene epoxidation by chlorite: role of chlorine dioxide.

Science.gov (United States)

Leigh, Jessica K; Rajput, Jonathan; Richardson, David E

2014-07-07

An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to account for the observed kinetics and product distributions. The model provides an unusually detailed quantitative mechanism for the complex reactions that occur in mixtures of chlorine species and organic substrates, particularly when the strong oxidant chlorite is employed. Kinetic control of the reaction is achieved by the addition of chlorine dioxide to the reaction mixture, thereby eliminating a substantial induction period observed when chlorite is used alone. The epoxidation agent is identified as chlorine dioxide, which is continually formed by the reaction of chlorite with hypochlorous acid that results from ClO produced by the epoxidation reaction. The overall stoichiometry is the result of two competing chain reactions in which the reactive intermediate ClO reacts with either chlorine dioxide or chlorite ion to produce hypochlorous acid and chlorate or chloride, respectively. At high chlorite ion concentrations, HOCl is rapidly eliminated by reaction with chlorite, minimizing side reactions between HOCl and Cl2 with the starting material. Epoxide selectivity (>90% under optimal conditions) is accurately predicted by the kinetic model. The model rate constant for direct reaction of styrene with ClO2(aq) to produce epoxide is (1.16 ± 0.07) × 10(-2) M(-1) s(-1) for 60:40 water/acetonitrile with 0.20 M acetate buffer. Rate constants for para substituted styrenes (R = -SO3(-), -OMe, -Me, -Cl, -H, and -NO2) with ClO2 were determined. The results support the radical addition/elimination mechanism originally proposed by Kolar and Lindgren to account for the formation of styrene oxide in the reaction of styrene with chlorine dioxide.

Studies of the antitumor mechanism of action of dermaseptin B2, a multifunctional cationic antimicrobial peptide, reveal a partial implication of cell surface glycosaminoglycans.

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Célia Dos Santos

Full Text Available Dermaseptin-B2 (DRS-B2 is a multifunctional cationic antimicrobial peptide (CAP isolated from frog skin secretion. We previously reported that DRS-B2 possesses anticancer and antiangiogenic activities in vitro and in vivo. In the present study, we evaluated the antiproliferative activity of DRS-B2 on numerous tumor cell lines, its cell internalization and studies of its molecular partners as well as their influences on its structure. Confocal microscopy using ([Alexa594]-(Cys0-DRS-B2 shows that in sensitive human tumor cells (PC3, DRS-B2 seems to accumulate rapidly at the cytoplasmic membranes and enters the cytoplasm and the nucleus, while in less sensitive tumor cells (U87MG, DRS-B2 is found packed in vesicles at the cell membrane. Furthermore FACS analysis shows that PC3 cells viability decreases after DRS-B2 treatment while U87 MG seems to be unaffected. However, "pull down" experiments performed with total protein pools from PC3 or U87MG cells and the comparison between the antiproliferative effect of DRS-B2 and its synthetic analog containing all D-amino acids suggest the absence of a stereo-selective protein receptor. Pretreatment of PC3 cells with sodium chlorate, decreases the antiproliferative activity of DRS-B2. This activity is partially restored after addition of exogenous chondroitin sulfate C (CS-C. Moreover, we demonstrate that at nanomolar concentrations CS-C potentiates the antiproliferative effect of DRS-B2. These results highlight the partial implication of glycosaminoglycans in the mechanism of antiproliferative action of DRS-B2. Structural analysis of DRS-B2 by circular dichroism in the presence of increasing concentration of CS-C shows that DRS-B2 adopts an α-helical structure. Finally, structure-activity-relationship studies suggest a key role of the W residue in position 3 of the DRS-B2 sequence for its antiproliferative activity.

Children at health risks.

Science.gov (United States)

Sekar, H R

1992-01-01

In India, 69% of the children of the working class die, most of whom are child laborers. Economic pressure forces parents to make their children work. Employers want child workers because they can manipulate them and pay them low wages, thereby ensuring their viability. The caste system induces social inequality, inheritance invokes cultural inequality, and patriarchal socialization is responsible for gender inequality, all of which perpetuates exploitation of children by employers. In Sivakasi, an estimated 125,000 children make up the child labor force, comprising 30% of the entire labor force. 75% are from the lowest castes. 90% of child workers are girls because they are more obedient and accept even lower wages than boys, and girls need to save for their dowry. Girls often suffer verbal and physical abuse. Like their parents who were also child workers, child workers are illiterate and work long hours. A small rich elite in Sivakasi controls most of the trading and industrial capital, educational institutions, and voluntary organizations. Employers' agents give parents a loan and use their children's labor as security. Each day, they bring child workers to Sivakasi in factory buses from villages to work at least 12 hour days. They work under hazardous conditions, e.g., working with toxic chemicals. Coughing, sore throat, dizziness, methemoglobinemia, and anemia are common effects of ingestion or inhalation of chlorate dust. Inhalation of sulphur dust causes respiratory infections, eye infections, and chronic lung diseases (e.g., asthma). Fires and explosions are common risks for working children. Factory management seldom undertake fire prevention measures. An extensive survey of the problem of child labor is needed in Sivakasi before systematic planning to protect children could be done. Overall development, especially agricultural development, is needed. Parents, employers, enforcement authorities, trade unions, and social groups need to be sensitized to the

Perchlorate and Volatiles in the Brine of Lake Vida (antarctica): Implication for the Analysis of Mars Sediments

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Kenig, F. P. H.; Chou, L.; McKay, C.; Jackson, W. A.; Doran, P. T.; Murray, A. E.; Fritsen, C. H.

2015-12-01

A cold (-13.4 °C), saline (188 psu) evaporative brine is encapsulated in the thick (> 27 m) ice of Lake Vida (McMurdo Dry Valleys, Antarctica). The Lake Vida brine (LVBr), which contains abundant dissolved organic carbon (48.2 mmol/L), support an active but slow microbial community. LVBr contains oxychlorines with 50 μg/L of perchlorate and 11 μg/L of chlorate. The McMurdo Dry Valleys have often been considered as a good Mars analog. The oxychlorine-rich brine of Lake Vida constitutes a potential equivalent to perchlorate-rich preserved saline liquid water on Mars. We report here on the artifacts created by oxychlorines upon analysis of volatiles and volatile organic compounds (VOCs) of LVBr by direct immersion (DI) and head space (HS) solid phase micro extraction (SPME) gas chromatography-mass spectrometry (GCMS). We compare analytical blanks to a standard containing 40 μg/L of perchlorate and to actual LVBr sample runs. All blanks, perchlorate blanks and samples were analyzed using two types of SPME fibers, CarboxenTM/polydimethylsiloxane (PDMS) and divinylbenzene (DVB)/ PDMS. The similarities and differences between our results and those obtained by the Sample Analysis at Mars instruments of the rover Curiosity are discussed. The volatiles evolved from LVBr upon analysis with DI- and HS-SPME GCMS are dominated by CO2, dichloromethane, HCl, and volatile organic sulfur compounds (VOSCs, such as DMS, DMDS). The volatiles also include oxygenated compounds such as acids and ketones, aromatic compounds, hydrocarbons, chlorinated compounds (dominated by dichloromethane). Apart from the VOSCs, short chain hydrocarbons and some functionalized compounds derived from the brine itself, all compounds observed are artifacts formed upon oxychlorine breakdown in the injector of the GCMS. The distribution of aromatic compounds seems to be directly dependant on the type of SPME fiber used. The perchlorate blanks show a clear pattern of carbon limitation, likely affecting the

Effects of oxidizing adulterants on detection of 11-nor-delta9-THC-9-carboxylic acid in urine.

Science.gov (United States)

Paul, Buddha D; Jacobs, Aaron

2002-10-01

Bleach, nitrite, chromate, and hydrogen peroxide-peroxidase are effective urine adulterants used by the illicit drug users to conceal marijuana-positive results. Methods for detecting nitrite and chromate are available. Effects of other oxidizing agents that could possibly be used as adulterants and are difficult to detect or measure are presented in this report. Urine samples containing 40 ng/mL of 11-nor-delta9-THC-9-carboxylic acid (THC-acid) were treated with 10 mmol/L of commonly available oxidizing agents. Effects of horseradish peroxidase of activity 10 unit/mL and extracts from 2.5 g of red radish (Raphanus sativus, Radicula group), horseradish (Armoracia rusticana), Japanese radish (Raphanus sativus, Daikon group), and black mustard seeds (Brassica nigra), all with 10 mmol/L of hydrogen peroxide, were also examined. After 5 min, 16 h and 48 h of exposure at room temperature (23 degrees C) the specimens were tested by a gas chromatographic-mass spectrometric method for THC-acid. A control group treated with sodium hydrosulfite to reduce the oxidants, was also tested to investigate the effect of oxidizing agents on THC-acid in the extraction method. THC-acid was lost completely in the extraction method when treated with chromate, nitrite, oxone, and hydrogen peroxide/ferrous ammonium sulfate (Fenton's reagent). Some losses were also observed with persulfate and periodate (up to 25%). These oxidants, and other oxidizing agents like permanganate, periodate, peroxidase, and extracts from red radish, horseradish, Japanese radish and black mustard seeds destroyed most of the THC-acid (> 94%) within 48 h of exposure. Chlorate, perchlorate, iodate, and oxychloride under these conditions showed little or no effect. Complete loss was observed when THC-acid was exposed to 50 mmol/L of oxychloride for 48 h. Several oxidizing adulterants that are difficult to test by the present urine adulterant testing methods showed considerable effects on the destruction of THC

Review on the assessment of safety and risks

Energy Technology Data Exchange (ETDEWEB)

Leiber, C.O. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany); Doherty, R.M. [Naval Surface Warfare Center, Indian Head, MD (United States)

2001-12-01

Historically explosion accidents are linked with energetic materials. There is the further belief, that the proneness to accidents-and their severity-is linked with the sensitivity of these explosives. Consequently there exist seemingly very insensitive materials for which it is believed that their accidental explosion can be ignored, so that safety distances can be reduced to those that apply to materials for which the hazard is assumed to be mass fire rather than mass detonation. Evidence is presented here that shows these assumptions to be invalid. Reports of explosion accidents are gathered here for substances that are not generally considered to be explosives (non UN-class 1 substances, like ammonium nitrate (AN), neat alkali metal chlorates, and even hypochlorites and nitromethane). In most of these cases the proneness of accidents had not been foreseen by testing. The basic explosion mechanisms are of a more general nature than simply those that apply to high explosives. Explosion is not solely a matter of energy, but of any physical power conversion. In order to prove this, a survey of explosion events is given: Natural events, like the impacts of celestial bodies and volcanic erptions. Fuel/liquid interactions in nature are industrial risks too, which occur at very different occasions and sites: Cellulose processing, the oil industry, foundries, power stations, explosions of hot cinders, chemical processing, fire extinguishing, and (most common) in the kitchen, and (most catastrophic) in nuclear reactors. Explosions of similar type are Hydraulic Transients, Bubble resonance explosions with the possibility of associated chemical room explosions (BLEVE), Rollovers. Second order effects are sorption/desorption resonance explosions, which most powerful also occur in nature (Nios Lake (CO{sub 2}-release), Kivu Lake, Monoun Lake, 1984, Tanganjika Lake, all in Africa, and the Ocracoke in the Gulf of Mexico (CH{sub 4}-release))-and at the lowest end shaken

Characterization of dissolved organic material in the interstitial brine of Lake Vida, Antarctica

Science.gov (United States)

Cawley, Kaelin M.; Murray, Alison E.; Doran, Peter T.; Kenig, Fabien; Stubbins, Aron; Chen, Hongmei; Hatcher, Patrick G.; McKnight, Diane M.

2016-06-01

Lake Vida (LV) is located in the McMurdo Dry Valleys (Victoria Valley, East Antarctica) and has no inflows, outflows, or connectivity to the atmosphere due to a thick (16 m), turbid ice surface and cold (organic carbon concentration (DOC; 580 mg-C L-1 or greater); the study of which provides a unique opportunity to better understand biological and/or abiotic processes taking place in an isolated saline ecosystem with no external inputs. We isolated two sub-fractions of LV dissolved organic matter (DOM) by chemical separation using XAD-8 and XAD-4 resins in series. This separation was followed by physical separation using ultrafiltration to isolate a higher molecular weight (HMW) fraction that was retained by the membrane and a salty, dilute low molecular weight fraction. This analytical path resulted in three, low salt sub-fractions and allowed comparison to other Antarctic lake DOM samples isolated using similar procedures. Compared to other Antarctic lakes, a lower portion of the DOC was retained by XAD-8 (∼10% vs. 16-24%) resin, while the portions retained by XAD-4 (∼8%) resin and the 1 kDa ultrafiltration membrane (∼50%) were similar. The 14C radiocarbon ages of the XAD-8 (mean 3940 ybp), XAD-4 (mean 4048 ybp) and HMW (mean 3270 ybp) fractions are all older than the apparent age of ice-cover formation (2800 ybp). Ultrahigh resolution mass spectrometry showed that compounds with two and three nitrogen atoms in the molecular formulas were common in both the LV-XAD8 and LV-XAD4 fractions, consistent with microbial production and processing. The long-term oxidation of LVBr DOM by abiotic oxidants including perchlorate and chlorate may explain the low portion in the XAD8 fraction and the lack of aromatic carbon, as measured by 13C NMR spectroscopy, found for all but the most hydrophobic fraction, LV-XAD8. Overall, the chemical characteristics of Lake Vida brine DOM suggest that legacy DOM sealed and concentrated within the brine has been altered due to a

Effect of counterion binding efficiency on structure and dynamics of wormlike micelles.

Science.gov (United States)

Oelschlaeger, C; Suwita, P; Willenbacher, N

2010-05-18

We have studied the effect of counterion binding efficiency on the linear viscoelastic properties of wormlike micelles formed from hexadecyltrimethylammonium bromide (CTAB) in the presence of different nonpenetrating inorganic salts: potassium bromide (KBr), sodium nitrate (NaNO(3)), and sodium chlorate (NaClO(3)). We have varied the salt/surfactant ratio R at fixed surfactant concentration of 350 mM. Results are compared to data for the system cetylpyridinium chloride (CPyCl) and the penetrating counterion sodium salicylate (NaSal) (Oelschlaeger, C.; Schopferer, M.; Scheffold, F.; Willenbacher, N. Langmuir 2009, 25, 716-723). Mechanical high-frequency rheology and diffusing wave spectroscopy (DWS) based tracer microrheology are used to determine the shear moduli G' and G'' in the frequency range from 0.1 Hz up to 1 MHz (Willenbacher, N.; Oelschlaeger, C.; Schopferer, M.; Fischer, P.; Cardinaux, F.; Scheffold, F. Phys. Rev. Lett. 2007, 99, 068302, 1-4). This enables us to determine the plateau modulus G(0), which is related to the cross-link density or mesh size of the entanglement network, the bending stiffness kappa (also expressed as persistence length l(p) = kappa/k(B)T) corresponding to the semiflexible nature of the micelles, and the scission energy E(sciss), which is related to their contour length. The viscosity maximum shifts to higher R values, and the variation of viscosity with R is less pronounced as the binding strength decreases. The plateau modulus increases with R at low ionic strength and is constant around the viscosity maximum; the increase in G(0) at high R, which is presumably due to branching, is weak compared to the system with penetrating counterion. The scission energy E(sciss) approximately = 20 k(B)T is independent of counterion binding efficiency irrespective of R and is slightly higher compared to the system CPyCl/NaSal, indicating that branching may be significant already at the viscosity maximum in this latter case. The micellar

Possible Detection of Perchlorates by the Sample Analysis at Mars (SAM) Instrument: Comparison with Previous Missions

Science.gov (United States)

Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher;

Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide ((38)ArO4) from ((38)ClO4(-)) and the evolution of chemical bonding over the nuclear transmutation reaction path.

Science.gov (United States)

Timm, Matthew J; Matta, Chérif F

2014-12-01

Argon tetroxide (ArO4) is the last member of the N=50 e(-) isoelectronic and isosteric series of ions: SiO4(4-), PO4(3-), SO4(2-), and ClO4(-). A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ~298kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295-8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52-53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4(-)) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope (38)Cl to the stable rare argon isotope (38)Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar-O bond. As a result, a primary retention yield of ~1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar-O bond dissociation product ArO3+O((3)P) from which the predicted barrier to dissociation is ca. 22kcal/mol and the exothermic reaction energy is ca. 28kcal/mol [(U)MP2/6-311+G(d)]. Copyright © 2014

Enhanced bromate formation during chlorination of bromide-containing waters in the presence of CuO: Catalytic disproportionation of hypobromous acid

KAUST Repository

Liu, Chao

2012-10-16

Bromate (BrO3 -) in drinking water is traditionally seen as an ozonation byproduct from the oxidation of bromide (Br-), and its formation during chlorination is usually not significant. This study shows enhanced bromate formation during chlorination of bromide-containing waters in the presence of cupric oxide (CuO). CuO was effective to catalyze hypochlorous acid (HOCl) or hypobromous acid (HOBr) decay (e.g., at least 104 times enhancement for HOBr at pH 8.6 by 0.2 g L-1 CuO). Significant halate concentrations were formed from a CuO-catalyzed hypohalite disproportionation pathway. For example, the chlorate concentration was 2.7 ± 0.2 μM (225.5 ± 16.7 μg L-1) after 90 min for HOCl (Co = 37 μM, 2.6 mg L-1 Cl2) in the presence of 0.2 g L-1 CuO at pH 7.6, and the bromate concentration was 6.6 ± 0.5 μM (844.8 ± 64 μg L -1) after 180 min for HOBr (Co = 35 μM) in the presence of 0.2 g L-1 CuO at pH 8.6. The maximum halate formation was at pHs 7.6 and 8.6 for HOCl or HOBr, respectively, which are close to their corresponding pKa values. In a HOCl-Br--CuO system, BrO3 - formation increases with increasing CuO doses and initial HOCl and Br- concentrations. A molar conversion (Br - to BrO3 -) of up to (90 ± 1)% could be achieved in the HOCl-Br--CuO system because of recycling of Br - to HOBr by HOCl, whereas the maximum BrO3 - yield in HOBr-CuO is only 26%. Bromate formation is initiated by the formation of a complex between CuO and HOBr/OBr-, which then reacts with HOBr to generate bromite. Bromite is further oxidized to BrO3 - by a second CuO-catalyzed process. These novel findings may have implications for bromate formation during chlorination of bromide-containing drinking waters in copper pipes. © 2012 American Chemical Society.

The Effects of Perchlorate and its Precursors on Organic Molecules under Simulated Mars Conditions

Science.gov (United States)

Carrier, B. L.; Beegle, L. W.; Bhartia, R.; Abbey, W. J.

2016-12-01

Perchlorate (ClO4-) was first detected on Mars by the Phoenix Lander in 2008 [1] and has subsequently been detected by Curiosity in Gale Crater [2], in Mars meteorite EETA79001 [3], and has been proposed as a possible explanation for results obtained by Viking [4]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [5]. The discovery of perchlorate on Mars has raised important questions about its effects on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [2, 4], few studies have been conducted on the potential effects of perchlorate and its precursors on organic molecules prior to analysis. Perchlorate is typically inert under Mars temperatures and pressures, but it has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-), hypochlorite (ClO-) and chlorine dioxide (ClO2) when exposed to Mars conditions including ionizing radiation [6]. The oxidation of chloride to perchlorate also results in the formation of reactive oxychlorine species such as chlorate (ClO3-) [5]. Here we investigate the effects of perchlorate and its oxychlorine precursors on organic molecules. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of Mojave Mars Simulant (MMS) [7] and each organic, as well as varying concentrations of perchlorate and/or chloride salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination

Surface composition of Europa based on VLT observations

Science.gov (United States)

Ligier, N.; Poulet, F.; Carter, J.

2016-12-01

, chlorate, and perchlorate) is supported by linear spectral modeling of the data, while the presence of sulfate salts is challenged. The distribution of some of these species is inconsistent with exogenic processes mainly impacting the trailing orbital hemisphere. These species may be traces of endogenous processes occurring on Europa.

Microbial activities in boreal soils: Biodegradation of organic contaminants at low temperature and ammonia oxidation

Energy Technology Data Exchange (ETDEWEB)

Kurola, J. (University of Helsinki, Faculty of Biosciences, Department of Ecological and Environmental Sciences, Lahti (FI))

2006-07-01

This thesis deals with the response of biodegradation of selected anthropogenic organic contaminants and natural autochthonous organic matter to low temperature in boreal surface soils. Furthermore, the thesis describes activity, diversity and population size of autotrophic ammonia-oxidizing bacteria (AOB) in a boreal soil used for landfarming of oil-refinery wastes, and presents a new approach, in which the particular AOB were enriched and cultivated in situ from the landfarming soil onto cation exchange membranes. This thesis demonstrates that rhizosphere fraction of natural forest humus soil and agricultural clay loam soil from Helsinki Metropolitan area were capable of degrading of low to moderate concentrations (0.2 - 50 mug cm-3) of PCP, phenanthrene and 2,4,5-TCP at temperatures realistic to boreal climate (-2.5 to +15 deg C). At the low temperatures, the biodegradation of PCP, phenanthrene and 2,4,5-TCP was more effective (Q10-values from 1.6 to 7.6) in the rhizosphere fraction of the forest soil than in the agricultural soil. Q10-values of endogenous soil respiration (carbon dioxide evolution) and selected hydrolytic enzyme activities (acetate-esterase, butyrate-esterase and beta-glucosidase) in acid coniferous forest soil were 1.6 to 2.8 at temperatures from -3 to +30 deg C. The results indicated that the temperature dependence of decomposition of natural autochthonous soil organic matter in the studied coniferous forest was only moderate. The numbers of AOB in the landfarming (sandy clay loam) soil were determined with quantitative polymerase chain reaction (real-time PCR) and with Most Probable Number (MPN) methods, and potential ammonium oxidation activity was measured with the chlorate inhibition technique. The results indicated presence of large and active AOB populations in the heavily oil-contaminated and urea-fertilised landfarming soil. Assessment of the populations of AOB with denaturing gradient gel electrophoresis (DGGE) profiling and sequence

Nitrate assimilation pathway (NAP): role of structural (nit) and transporter (ntr1) genes in Fusarium oxysporum f.sp. lycopersici growth and pathogenicity.

Science.gov (United States)

Gomez-Gil, Lucia; Camara Almiron, Jesus; Rodriguez Carrillo, Patricia Lizett; Olivares Medina, Cindy Nayely; Bravo Ruiz, Gustavo; Romo Rodriguez, Pamela; Corrales Escobosa, Alma Rosa; Gutierrez Corona, Felix; Roncero, M Isabel

2018-04-01

The tomato pathogen Fusarium oxysporum f.sp. lycopersici possesses the capability to use nitrate as the only nitrogen source under aerobic and anaerobic conditions and to activate virulence-related functions when cultivated in the presence of nitrate, but not in ammonium. The genome of F. oxysporum f.sp. lycopersici encodes three paralogs nitrate reductase (NR) genes (nit1, nit2 and nit3) and one predicted ortholog of the Aspergillus nidulans high-affinity nitrate/nitrite transporters NtrA and NtrB, named ntr1. We set out to clarify the role of nit1, nit2, nit3 and ntr1 genes in nitrate assimilation and in the virulence of F. oxysporum f.sp. lycopersici. Quantitative RT-PCR analysis revealed that only nit1, nit2 and ntr1 are expressed at significant levels during growth in nitrate as the only nitrogen source. Targeted deletion of nit1 and ntr1, but not of nit2 or nit3, severely impaired growth of F. oxysporum on nitrate as nitrogen source, indicating that Nit1 and Ntr1 proteins are involved in nitrate assimilation by the fungus; biochemical analysis of nit mutants indicated that Nit1 and Nit2 enzymes contribute to about 50 and 30% of the total NR activity, respectively. In addition, a spontaneous chlorate-resistant mutant derived from F. oxysporum 4287, denoted NitFG, was characterized, showing inability to grow in nitrate under aerobic and anaerobic conditions and low levels of NR activity, in spite of its increased transcription levels of nit1 and nit2 genes. Tomato plant infection assays showed that NitFG and ∆ntr1 mutants induced an earlier death in tomato plants, whereas the single mutants ∆nit1, ∆nit2 and ∆nit1∆nit2 double mutant showed a mortality rate similar to the wild-type strain. Taken together, these results indicate that the Nit1 and Ntr1 proteins are important for nitrate assimilation of F. oxysporum f.sp. lycopersici incubated under aerobic and anaerobic conditions and that this metabolic process is not essential for the virulence of

An investigation of sodium–CO{sub 2} interaction byproduct cleaning agent for SFR coupled with S-CO{sub 2} Brayton cycle

Energy Technology Data Exchange (ETDEWEB)

Jung, Hwa-Young, E-mail: jhy0523@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Division of SFR NSSS System Design, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Wi, Myung-Hwan, E-mail: mhwi@kaeri.re.kr [Division of SFR NSSS System Design, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ahn, Hong Joo, E-mail: ahjoo@kaeri.re.kr [Division of Nuclear Chemistry Research, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2016-02-15

Highlights: • Study on cleaning agent was conducted to remove Na–CO{sub 2} interaction byproducts. • Screening criteria to select candidate substances as cleaning agents were suggested. • The mixtures of Na{sub 2}CO{sub 3} with NaBrO{sub 3}, NaClO{sub 3}, or NaBF{sub 4} were thermally analyzed with the TG/DTA studies. • Three candidate substances decomposed before 600 °C and did not react with Na{sub 2}CO{sub 3}. - Abstract: One of the promising future nuclear energy systems, the Sodium-cooled Fast Reactor (SFR) has been actively developed internationally. Recently, to improve safety and economics of a SFR further, coupling supercritical CO{sub 2} power cycle was suggested. However, there can be a chemical reaction between sodium and CO{sub 2} at high temperature (more than 400 °C) when the pressure boundary fails in a sodium–CO{sub 2} heat exchanger. To ensure the performance of such a system, it is important to employ a cleaning agent to recover the system back to normal condition after the reaction. When sodium and CO{sub 2} react, solid and gaseous reaction products such as sodium carbonate (Na{sub 2}CO{sub 3}) and carbon monoxide (CO) appear. Since most of solid reaction products are hard and can deteriorate system performance, quick removal of solid reaction products becomes very important for economic performance of the system. Thus, the authors propose the conceptual method to remove the byproducts with a chemical reaction at high temperature. The chemical reaction will take place between the reaction byproducts and a cleaning agent while the cleaning agent is inert with sodium. Thus, various sodium-based compounds were first investigated and three candidate substances satisfying several criteria were selected; sodium bromate (NaBrO{sub 3}), sodium chlorate (NaClO{sub 3}), and sodium tetrafluoroborate (NaBF{sub 4}). The selected substances were thermally analyzed with the TG/DTA studies. Unfortunately, it was revealed that all candidate

COMPARATIVE STUDY OF CHLORATED AND PHOSPHORATED INSECTICIDES IN BAIT ATTRACTIVENESS BY “BANANA BORER” (Cosmopolites sordidus GERMAR, 1824 ESTUDO COMPARATIVO DE INSETICIDAS CLORADOS E FOSFORADOS NA ATRATIVIDADE DE ISCAS PELO “MOLEQUE DA BANANEIRA” (Cosmopolites sordidus Germar, 1824

Directory of Open Access Journals (Sweden)

Ronaldo Veloso Naves

2007-09-01

Full Text Available

The efficiency of several insecticides for the control of the banana borer were tested in two kinds of traps. The cloride insecticides are most widely used but they are probably repellent to the weevil. DDT, Aldrin, Diazinon and Parathion were compared in two kinds of traps: slices of rhizome and pieces of pseudostem. The best results were obtained with Parathion in rhizome slices.

A broca-da-bananeira ou “moleque” (Cosmopolites sordidus Germar é urna das pragas mais importantes da bananeira. A revisão de literatura mostra que os produtos clorados são os mais utilizados e recomendados no combate a essa praga, principalmente, Aldrin. O presente trabalho visou a testar inseticidas fosforados e também verificar o tipo de isca mais atrativa. A análise estatística dos dados obtidos demonstrou haver diferença significativa entre os tratamentos, entre os dois tipos de iscas, e na interação iscas x tratamento. Com base nos resultados e observações feitas durante a fase experimental, podemos tirar as seguintes conclusões: a As iscas do tipo sanduíche, feitas com pedaços de rizoma são mais atrativas do que as do tipo telha, feita de pedaços de pseudo-caule, cortados longitudinalmente; b O inseticida que apresentou melhores resultados foi o RHODIATOX (Parathion.

The effectiveness of selected feed and water additives for reducing Salmonella spp. of public health importance in broiler chickens: a systematic review, meta-analysis, and meta-regression approach.

Science.gov (United States)

Totton, Sarah C; Farrar, Ashley M; Wilkins, Wendy; Bucher, Oliver; Waddell, Lisa A; Wilhelm, Barbara J; McEwen, Scott A; Rajić, Andrijana

2012-10-01

Eating inappropriately prepared poultry meat is a major cause of foodborne salmonellosis. Our objectives were to determine the efficacy of feed and water additives (other than competitive exclusion and antimicrobials) on reducing Salmonella prevalence or concentration in broiler chickens using systematic review-meta-analysis and to explore sources of heterogeneity found in the meta-analysis through meta-regression. Six electronic databases were searched (Current Contents (1999-2009), Agricola (1924-2009), MEDLINE (1860-2009), Scopus (1960-2009), Centre for Agricultural Bioscience (CAB) (1913-2009), and CAB Global Health (1971-2009)), five topic experts were contacted, and the bibliographies of review articles and a topic-relevant textbook were manually searched to identify all relevant research. Study inclusion criteria comprised: English-language primary research investigating the effects of feed and water additives on the Salmonella prevalence or concentration in broiler chickens. Data extraction and study methodological assessment were conducted by two reviewers independently using pretested forms. Seventy challenge studies (n=910 unique treatment-control comparisons), seven controlled studies (n=154), and one quasi-experiment (n=1) met the inclusion criteria. Compared to an assumed control group prevalence of 44 of 1000 broilers, random-effects meta-analysis indicated that the Salmonella cecal colonization in groups with prebiotics (fructooligosaccharide, lactose, whey, dried milk, lactulose, lactosucrose, sucrose, maltose, mannanoligosaccharide) added to feed or water was 15 out of 1000 broilers; with lactose added to feed or water it was 10 out of 1000 broilers; with experimental chlorate product (ECP) added to feed or water it was 21 out of 1000. For ECP the concentration of Salmonella in the ceca was decreased by 0.61 log(10)cfu/g in the treated group compared to the control group. Significant heterogeneity (Cochran's Q-statistic p≤0.10) was observed

Oxidation of spin-traps by chlorine dioxide (ClO2) radical in aqueous solutions: first ESR evidence of formation of new nitroxide radicals.

Science.gov (United States)

Ozawa, T; Miura, Y; Ueda, J

1996-01-01

The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy. The ClO2 radical was generated from the redox reaction of Ti3+ with potassium chlorate (KClO3) in aqueous solutions. When one of the spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), was included in the Ti3+-KClO3 reaction system, ESR spectrum due to the ClO2 radical completely disappeared and a new ESR spectrum [aN(1) = 0.72 mT, aH(2) = 0.41 mT], which is different from that of DMPO-ClO2 adduct, was observed. The ESR parameters of this new ESR signal was identical to those of 5,5-dimethylpyrrolidone-(2)-oxyl-(1) (DMPOX), suggesting the radical species giving the new ESR spectrum is assignable to DMPOX. The similar ESR spectrum consisting of a triplet [aN(1) = 0.69 mT] was observed when the derivative of DMPO, 3,3,5,5-tetramethyl-1-pyrroline N-oxide (M4PO) was included in the Ti3+-KClO3 reaction system. This radical species is attributed to the oxidation product of M4PO, 3,3,5,5-tetramethylpyrrolidone-(2)-oxyl-(1) (M4POX). When another nitrone spin-trap, alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN) was used as a spin-trap, the ESR signal intensity due to the ClO2 radical decreased and a new ESR signal consisting of a triplet [aN(1) = 0.76 mT] was observed. The similar ESR spectrum was observed when N-t-butyl-alpha- nitrone (PBN) was used as a spin-trap. This ESR parameter [a(N)(1) = 0.85 mT] was identical to the oxidation product of PBN, PBNX. Thus, the new ESR signal observed from POBN may be assigned to the oxidation product of POBN, POBNX. These results suggest that the ClO2, radical does not form the stable spin adducts with nitrone spin-traps, but oxidizes these spin-traps to give the corresponding nitroxyl radicals. On the other hand, nitroso spin-traps, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS), and 2-methyl-2-nitrosopropane (MNP) did not trap

High-Temperature, Perhaps Silicic, Volcanism on Mars Evidenced by Tridymite Detection in High-SiO2 Sedimentary Rock at Gale Crater, Mars

Science.gov (United States)

Morris, R. V.; Vaniman, D. T.; Blake, D. F.; Gellert, R.; Chipera, S. J.; Rampe, E. B.; Ming, D. W.; Morrison, S. M.; Downs, R. T.; Treiman, A. H.;

Efeito do cloreto de cálcio na qualidade de melancias minimamente processadas Effect of calcium chloride on the quality of minimally processed watermelon

Directory of Open Access Journals (Sweden)

Ana Carolina Almeida Miguel

2007-09-01

Full Text Available Foi avaliada a qualidade de melancias minimamente processadas, tratadas com cloreto de cálcio, durante o armazenamento sob refrigeração. Utilizaram-se melancias 'Crimson Sweet', maduras, adquiridas no comércio de Piracicaba, SP, oriundas do Rio Grande do Sul. Os frutos foram lavados e desinfetados com água clorada (200 mg L-1. A polpa foi cortada em cubos (2,5 cm de aresta, os quais foram imersos, por 3 min nas soluções que corresponderam aos tratamentos, imersão em água pura (controle, solução de cloreto de cálcio a 1%. Em seguida foram escorridos por 3 min, acondicionados em copos de tereftalato de polietileno (PET transparente de 450 mL de capacidade, com tampa, e armazenados sob refrigeração a 10,0 ± 3,2°C e 79% UR. A cada dois dias, os pedaços foram avaliados sensorialmente e quanto à perda de massa fresca, aparência, coloração interna, textura, teores de sólidos solúveis (SS e de acidez titulável (AT, pH, relação SS/AT e conteúdos de ácido ascórbico e de pectinas, solúvel e total. O uso da solução de cloreto de cálcio promoveu maior firmeza na textura de melancias minimamente processadas, porém não se mostrou efetivo no prolongamento da vida útil, que foi de 2 dias do ponto de vista sensorial.This study evaluated the refrigerated storage and quality of minimally processed watermelon treated with calcium chloride. Ripe Crimson Sweet watermelons produced in Rio Grande do Sul State, Brazil, and acquired at a local market in Piracicaba, SP, were washed and the surface sanitized with chlorated water (200 mg L-1. Samples were then cut into pulp cubes (2.5 cm across. Cubes were subjected to two treatments: immersion for 3 min in pure water (control and 1% calcium chloride. Subsequently, the cubes were drained for 3 min and packaged in transparent polyethylene terephthalate cups and stored at 10.0 ? 3.2?C and 79% RH. Every two days cubes from each treatment were sensorially evaluated as well as the loss of fresh

Comparative study on precipitation methods of yellow-cake from acid leachate of rock phosphate and Its purification

International Nuclear Information System (INIS)

Abow Slama, E. H. Y.

2009-05-01

This study was carried-out to leach uranium from rock phosphate using sulphuric acid in presences of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia ((NH 4 ) 2 U 2 O 7 ), magnesia (UO 3 .xH 2 O) and sodium hydroxide (Na 2 U 2 O 7 ) as precipitants, as well as purification of the products with TBP extraction and matching its impurity levels with specification of the commercial products. Alpha-particle spectrometry was for used for determination of activity concentration of uranium isotopes (''2''3''4U and ''2''3''8U) in rock phosphate, resulting green phosphoric acid solution, and in different forms of the yellow cake from which the equivalent mass concentration of uranium was deduced. Likewise, AAS was used for determination of impurities (Pb, Ni, Cd, Fe, Zn, Mn, and Cu). On the average, the activity concentration of uranium in the rock phosphate was 1468±979 Bq/Kg (119.38±79.66 ppm), and 711±252 Bq/L (57.85±20.46 ppm) in the resulting green solution with corresponding percent of dissolution amounting to 48% which is considered low indicating that the experimental conditions (i.e. dissolution container, temperature, PH, retention time) were not optimal. However, the isotopic ratio (''2''3''4U, ''2''3''8U) in all stages of hydrometallurgical process was not much different from unity indicating lack of fractionation. Crude yellow cakes (hydrate uranium trioxide, ammonium diuranate and sodium diuranate) were precipitated from the green solutions prior to separation of iron and once after iron separation. Although, iron was tested using bipyridine and SCN, it was found in all types of crude samples analyzed this might be attributed to either the quality of the reagent used or inhibition of Fe present in the solution by stronger complexing agent. Uranium mass concentration in crude yellow cakes precipitated before iron separation was found following the order: UO 3 .xH 2 O

SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

Energy Technology Data Exchange (ETDEWEB)

Robert C. Brown; Maohong Fan; Adrienne Cooper

2004-11-01

Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. Characterizations of dry PFS synthesized from SO{sub 2} show the PFS possesses amorphous structure, which is desired for it to be a good coagulant in water and wastewater treatment. A series of lab-scale experiments were conducted to evaluate the performance of PFS synthesized from waste sulfur dioxide, ferrous sulfate and sodium chlorate. The performance assessments were based on the comparison of PFS and other conventional and new coagulants for the removal of turbidity and arsenic under different laboratory coagulant conditions. Pilot plant studies were conducted at Des Moines Water Works in Iowa and at the City of Savannah Industrial and Domestic (I&D) Water Treatment Plant in Port Wentworth, Georgia. PFS performances were compared with those of conventional coagulants. The tests in both water treatment plants have shown that PFS is, in general, comparable or better than other coagulants in removal of turbidity and organic substances. The corrosion behavior of polymeric ferric sulfate (PFS) prepared from SO{sub 2} and ferric chloride (FC) were compared. Results

Exposure assessment of a burning ground for chemical ammunition on the Great War battlefields of Verdun.

Science.gov (United States)

Bausinger, Tobias; Bonnaire, Eric; Preuss, Johannes

2007-09-01

severe arsenic contamination and the transfer of this carcinogen by leachate, surface runoff and probably by wind. Nevertheless, some studies on the effects of the contaminant inventory on the local vegetation revealed that ammonium nitrate elutable zinc is responsible for the spatial distribution of some tolerant plant species and not arsenic. Previously undetected buried munitions from the former delaboration facility can be an other source of environmental contaminants. This is supported by elevated concentrations of chlorate (cmax.=71 mg/l) and perchlorate (cmax.=0.8 mg/l) detected in the leachate samples. This is the second report about environmental contamination related to post-war ammunition destruction activities along the 1914/18 Western Front.

Oxidation of formic acid by oxyanions of chlorine and its implications to the Viking Labeled Release experiment

Science.gov (United States)

Martinez, P.; Navarro-gonzalez, R.

2013-05-01

The Viking Landers that arrived on Mars in 1976 carried out three biological experiments designed to investigate if there was microbial life. These were the Gas-Exchange, Pyrolitic Release and Labeled Release experiments. The three experiments yielded positive responses but the Labeled Release experiment had a kinetic response indicative of microbial activity. The experiment consisted of adding a broth of nutrients (formic acid, glycolic acid, glycine, D- and L-alanine and D- and L-lactic acid uniformly marked with 14C) to martian soil samples. The results were surprising; the nutrients were consumed releasing radioactive gases in a manner that is compatible by terrestrial microorganisms. The existence of Martian life was contradicted by soil chemical analysis that indicated the absence of organic compounds above the detection limits of parts per billion (ppb). Instead the positive response of the Labeled Release Experiment was attributed to the existence of peroxides and/or superoxides in the Martian soils that destroyed the nutrients upon contact. Recently, the Phoenix mission that landed in the Martian Arctic in 2008 revealed the presence of a highly oxidized form of the element chlorine in the soil: perchlorate. Perchlorate is thought to have formed in the Martian atmosphere by the oxidation of chloride from volcanic sources with ozone. Therefore perchlorate is formed by the stepwise oxidation of hypochlorite, chlorite and chlorate. These oxyanions of chlorine are powerful oxidizers that may exist in the Martian soil and may have reacted with the nutrients of the Labeled Release Experiment. This paper aims to better understand these results by designing experiments to determine the kinetics of decomposition of formic acid to carbon dioxide with different oxidized forms of chlorine by headspace technique in gas chromatography coupled to mass spectrometry (GC / MS). Previous studies done in the laboratory showed that only hypochlorite quantitatively reacted with

Laser-induced Fluorescence Spectroscopy for applications in chemical sensing and optical refrigeration

Science.gov (United States)

Kumi Barimah, Eric

Laser-induced breakdown spectroscopy (LIBS) is an innovative technique that has been used as a method for fast elemental analysis in real time. Conventional ultraviolet-visible (UV-VIS) LIBS has been applied to detect the elemental composition of different materials, including explosives, pharmaceutical drugs, and biological samples. The extension of conventional LIBS to the infrared region (˜1-12 mum) promises to provide additional information on molecular emission signatures due to rotational-vibrational transitions. In this research, a pulsed Nd: YAG laser operating at 1064 nm was focused onto several sodium compounds (NaCl, NaClO3, Na2CO3 and NaClO4) and potassium compounds (KCl, KClO3, K2CO3 and KClO4) to produce an intense plasma at the target surface. Several distinct infrared (IR) atomic emission signatures were observed from all sodium and potassium containing compounds. The atomic emission lines observed from the investigated samples matched assigned transitions of neutral sodium and potassium atoms published in the National Institute of Standards and Technology (NIST) atomic database. In addition to the intense atomic lines, the rst evidence of molecular LIBS emission structures were observed at ˜10.0 m in KClO3 and NaClO3 for the chlorate anion (ClO3 --1), at ˜6.7 to 8.0 mum in KNO3 and NaNO 3 for the nitrate anion (NO3--1 ), ˜8.0 to 10.0 mum in KClO4 and NaClO4 for perchlorate anion (ClO4--1 ), and ˜6.88 mum and 11.53 mum in Na2CO3 for the carbonate anion (CO3--1 ). The observed molecular emission showed strong correlation with the conventional Fourier Transform Infrared Spectrometry (FTIR) absorption spectra of the investigated samples. IR LIBS was also applied to determine the limit of detection (LOD) for the perchlorate anion in KClO4 using the 8.0 -11.0 mum IR-LIBS emission band. The calibration curve of ClO4 in KClO4 was constructed using peak and integrated emission intensities for known concentrations of mixed KClO4/NH4NO3 samples. The

Design, installation, and performance of a multi-layered permeable reactive barrier, Los Alamos National Laboratory

International Nuclear Information System (INIS)

Kaszuba, John P.; Longmire, Patrick A.; Strietelmeier, Elizabeth A.; Taylor, Tammy P.; Den-Baars, Peter S.

2004-01-01

engineered structure. Groundwater sampling upgradient, within, and downgradient of the PRB took place from May through August 2003. Concentrations of strontium-90 have diminished by 80% and 40% within the central portion of the phosphate rock (apatite) and bio-barrier cells, respectively. Higher concentrations of this radionuclide occur in groundwater near the north and south perimeters of the two cells. The non-uniform distribution of strontium-90 may result from varying residence time and saturated thickness of pore water. Initial concentrations of nitrate (8-12 parts per million or ppm as nitrate) and perchlorate (0.035 ppm) have been reduced in the phosphate rock and bio-barrier cells to concentrations that are less than method detection limits (0.01 and 0.002 ppm, respectively). Initial microbial analyses suggest the presence of both dissimilatory perchlorate- and nitrate-reducing bacterial populations, along with production of acetate and propionate, and decreasing dissolved oxygen and pH. The dominant group of perchlorate reducers consists of members of the previously described Dechloromonas genus, in the beta subclass of the Proteobacteria, which together with the Dechlorosoma genus are considered to be the dominant genera in circum-neutral mesophilic environments. Groundwater flow through the multiple PRB is taking place at a very slow rate based on similar concentrations of nitrate, perchlorate, chlorate, and chlorite in the upgradient well MCO-4B and downgradient well MCO-5. Concentrations of these constituents also increase within the limestone cell. Decreased precipitation due to extreme drought is probably responsible for decreasing saturated thickness within both the alluvium and PRB, resulting in stagnant conditions. Varying distributions of ammonium, nitrate, sulfate, iron, and manganese within the phosphate rock, bio-barrier, and limestone cells also support this hypothesis.

Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue.

Science.gov (United States)

Bradberry, Sally M

2003-01-01

Methaemoglobin is formed by oxidation of ferrous (FeII) haem to the ferric (FeIII) state and the mechanisms by which this occurs are complex. Most cases are due to one of three processes. Firstly, direct oxidation of ferrohaemoglobin, which involves the transfer of electrons from ferrous haem to the oxidising compound. This mechanism proceeds most readily in the absence of oxygen. Secondly, indirect oxidation, a process of co-oxidation which requires haemoglobin-bound oxygen and is involved, for example, in nitrite-induced methaemoglobinaemia. Thirdly, biotransformation of a chemical to an active intermediate that initiates methaemoglobin formation by a variety of mechanisms. This is the means by which most aromatic compounds, such as amino- and nitro-derivatives of benzene, produce methaemoglobin. Methaemoglobinaemia is an uncommon occupational occurrence. Aromatic compounds are responsible for most cases, their lipophilic nature and volatility facilitating absorption during dermal and inhalational exposure, the principal routes implicated in the workplace. Methaemoglobinaemia presents clinically with symptoms and signs of tissue hypoxia. Concentrations around 80% are life-threatening. Features of toxicity may develop over hours or even days when exposure, whether by inhalation or repeated skin contact, is to relatively low concentrations of inducing chemical(s). Not all features observed in patients with methaemoglobinaemia are due to methaemoglobin formation. For example, the intravascular haemolysis caused by oxidising chemicals such as chlorates poses more risk to life than the methaemoglobinaemia that such chemicals induce. If an occupational history is taken, the diagnosis of methaemoglobinaemia should be relatively straightforward. In addition, two clinical observations may help: firstly, the victim is often less unwell than one would expect from the severity of 'cyanosis' and, secondly, the 'cyanosis' is unresponsive to oxygen therapy. Pulse oximetry is

Development of sustainable Palladium-based catalysts for removal of persistent contaminants from drinking water

Science.gov (United States)

Shuai, Danmeng

Pd-based catalytic reduction has emerged as an advanced treatment technology for drinking water decontamination, and a suite of persistent contaminants including oxyanions, N-nitrosoamines, and halogenated compounds are amenable to catalytic reduction. The primary goal of this study is to develop novel Pd-based catalysts with enhanced performance (i.e., activity, selectivity, and sustainability) to remove contaminants from drinking water. The effects of water quality (i.e., co-contaminants in water matrix), catalyst support, and catalyst metal were explored, and they provide insights for preparing catalysts with faster kinetics, higher selectivity, and extended lifetime. Azo dyes are wide-spread contaminants, and they are potentially co-exisiting with target contaminants amenable for catalytic removal. The probe azo dye methyl orange (MO) enhanced catalytic reduction kinetics of a suite of oxyanions (i.e., nitrate, nitrite, bromate, chlorate, and perchlorate) and diatrizoate significantly but not N-nitrosodimethylamine (NDMA) with a variety of Pd-based catalysts. Nitrate was selected as a probe contaminant, and several different azo dyes (i.e., (methyl orange, methyl red, fast yellow AB, metanil yellow, acid orange 7, congo red, eriochrome black T, acid red 27, acid yellow 11, and acid yellow 17) were evaluated for their ability to enhance reduction. A hydrogen atom shuttling mechanism was proposed and a kinetic model was proposed based on Bronsted-Evans-Polanyi (BEP) theory, and they suggest sorbed azo dyes and reduced hydrazo dyes shuttle hydrogen atoms to oxyanions or diatrizoate to enhance their reduction kinetics. Next, vapor-grown carbon nanofiber (CNF) supports were used to explore the effects of Pd nanoparticle size and interior versus exterior loading on nitrite reduction activity and selectivity (i.e., dinitrogen over ammonia production). In order to evaluate the amount of interior versus exterior loading of Pd nanoparticles, a fast and accurate geometric

On line pre-concentration for simultaneous determination of low molecular weight organic acids and inorganic anions in Amazonian river water samples employing ion chromatography with conductivity detection Pré-concentração em linha para a determinação simultânea de ácidos carboxílicos de baixo peso molecular e ânions inorgânicos em amostras de rios da Amazônia empregando cromatografia de íons com detecção por condutividade elétrica

Directory of Open Access Journals (Sweden)

Cristiane Azevedo Tumang

2009-01-01

Full Text Available An ion chromatography procedure, employing an IonPac AC15 concentrator column was used to investigate on line preconcentration for the simultaneous determination of inorganic anions and organic acids in river water. Twelve organic acids and nine inorganic anions were separated without any interference from other compounds and carry-over problems between samples. The injection loop was replaced by a Dionex AC15 concentrator column. The proposed procedure employed an auto-sampler that injected 1.5 ml of sample into a KOH mobile phase, generated by an Eluent Generator, at 1.5 mL min-1, which carried the sample to the chromatographic columns (one guard column, model AG-15, and one analytical column, model AS15, with 250 x 4mm i.d.. The gradient elution concentrations consisted of a 10.0 mmol l-1 KOH solution from 0 to 6.5 min, gradually increased to 45.0 mmol l-1 KOH at 21 min., and immediatelly returned and maintained at the initial concentrations until 24 min. of total run. The compounds were eluted and transported to an electro-conductivity detection cell that was attached to an electrochemical detector. The advantage of using concentrator column was the capability of performing routine simultaneous determinations for ions from 0.01 to 1.0 mg l-1 organic acids (acetate, propionic acid, formic acid, butyric acid, glycolic acid, pyruvate, tartaric acid, phthalic acid, methanesulfonic acid, valeric acid, maleic acid, oxalic acid, chlorate and citric acid and 0.01 to 5.0 mg l-1 inorganic anions (fluoride, chloride, nitrite, nitrate, bromide, sulfate and phosphate, without extensive sample pretreatment and with an analysis time of only 24 minutes.A metodologia analítica foi desenvolvida empregando coluna pré-concentradora AC15 em linha na cromatografia iônica na determinação simultânea de ânions orgânicos e inorgânicos, com uso de coluna de guarda AG15 e analítica AS15, 250 x 4 mm i.d. (Dionex Corp.. O gradiente de concentração do eluente